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Sample records for brachial artery bifurcation

  1. Unilateral high bifurcation of brachial artery: a case report | Auwal ...

    African Journals Online (AJOL)

    The Profunda Brachii, Superior Ulnar Collateral and Inferior Ulnar Collateral arteries arose from the relatively short brachial arterial trunk. Although the documented incidence of this anatomical variation is low in Nigeria, its concomitant widespread documentation in other parts of the world makes it a sufficiently important ...

  2. Vascular patterns of upper limb: an anatomical study with accent on superficial brachial artery

    Directory of Open Access Journals (Sweden)

    David Kachlik

    2011-02-01

    Full Text Available The aim of the study was to evaluate the terminal segmentation of the axillary artery and to present four cases of anomalous branching of the axillary artery, the superficial brachial artery (arteria brachialis superficialis, which is defined as the brachial artery that runs superficially to the median nerve. Totally, 130 cadaveric upper arms embalmed by classical formaldehyde technique from collections of the Department of Anatomy, Third Faculty of Medicine, Charles University in Prague, were macroscopically dissected with special focus on the branching arrangement of the axillary artery. The most distal part of the axillary artery (infrapectoral part terminated in four cases as a bifurcation into two terminal branches: the superficial brachial artery and profunda brachii artery, denominated according to their relation to the median nerve. The profunda brachii artery primarily gave rise to the main branches of the infrapectoral part of the axillary artery. The superficial brachial artery descended to the cubital fossa where it assumed the usual course of the brachial artery in two cases and in the other two cases its branches (the radial and ulnar arteries passed superficially to the flexors. The incidence of the superficial brachial artery in our study was 5% of cases. The reported incidence is a bit contradictory, from 0.12% to 25% of cases. The anatomical knowledge of the axillary region is of crucial importance for neurosurgeons and specialists using the radiodiagnostic techniques, particularly in cases involving traumatic injuries. The improved knowledge would allow more accurate diagnostic interpretations and surgical treatment.

  3. Brachial artery approach for outpatient arteriography

    International Nuclear Information System (INIS)

    You, Jai Kyung; Park, Sung Il; Lee, Do Yun; Won, Jae Hwan

    1999-01-01

    To evaluate the diagnostic usefulness of brachial approach arteriography for outpatients, with particular regard to safety and image quality. The angiographic findings and follow-up medical records of 131 brachial approach arteriographies in 121 outpatients were retrospectively analysed. 5 F pigtail catheters were used in 125 cases and 5-F OCU-A catheters were used in three cases of renal arteriography, and three of upper extremity arteriography without catheter. Except for three cases of brachial artery puncture failure, all procedures were performed successfully. One hundred and fifteen of 119 lower extremity arteriographies were visualized down to the level of the tibioperoneal artery. The non-visualized cases were three in which there was multiple obstruction at the distal common iliac artery and one with insufficient contrast amount due to renal failure In four cases there were complications : two involved arterial thrombosis, one was an intramuscular hematoma, and one an A-V fistula. For outpatients, brachial approach arteriography can replace the femoral approach. Its image quality is excellent, there are time-cost benefits, and the rate of complications is relatively low

  4. An anatomical study of variations in termination of brachial artery, with its embryological basis and clinical significance

    Directory of Open Access Journals (Sweden)

    Deepa T. K

    2016-03-01

    Full Text Available The brachial artery is the main artery of the arm. It begins as the continuation of 3rd part of axillary artery, at the level of inferior border of teres major muscle. It ends at the level of the neck of radius by dividing into radial and ulnar arteries. In the present study we found higher division of brachial artery at mid arm level into its terminal branches with superficial course of radial artery. The present study was done on 51 cadavers from our dept. of Anatomy. The upper limbs of the cadaver were dissected and observed for any variations in the branching pattern of brachial artery. In the present study, a total number of 51 cadaver’s, 102 upper limbs were studied. In one male cadaver we found bilateral higher division of brachial artery, trifurcation on left side and bifurcation on right side brachial artery, with superficial course of radial artery. The knowledge of variation in origin and course of brachial artery is useful for orthopaedicians, physicians, radiologist, vascular and plastic surgeons.

  5. Brachial artery aneurysm and thrombosis secondary to fibromuscular dysplasia

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    Julia Louise Jones, MBBS

    2016-09-01

    Full Text Available Fibromuscular dysplasia is a pathologic process causing stenosis and dilation of medium-caliber arteries of unknown etiology. It most commonly affects the renal and carotid arteries; however, it has been described in virtually all anatomic areas, including, rarely, the brachial artery. We describe a case of brachial artery aneurysm and thrombosis in a 29-year-old man secondary to fibromuscular dysplasia, treated surgically with excision, embolectomy, interposed vein graft, and anticoagulation.

  6. Sex differences in intracranial arterial bifurcations

    DEFF Research Database (Denmark)

    Lindekleiv, Haakon M; Valen-Sendstad, Kristian; Morgan, Michael K

    2010-01-01

    Subarachnoid hemorrhage (SAH) is a serious condition, occurring more frequently in females than in males. SAH is mainly caused by rupture of an intracranial aneurysm, which is formed by localized dilation of the intracranial arterial vessel wall, usually at the apex of the arterial bifurcation. T....... The female preponderance is usually explained by systemic factors (hormonal influences and intrinsic wall weakness); however, the uneven sex distribution of intracranial aneurysms suggests a possible physiologic factor-a local sex difference in the intracranial arteries....

  7. Asymmetric Bilateral Variations in the Musculocutaneous and Median Nerves with High Branching of Brachial Artery

    Directory of Open Access Journals (Sweden)

    Vandana Tomar

    2012-01-01

    Full Text Available Brachial Plexus is formed by the union of the anterior rami of cervical 5, 6, 7, 8 and thoracic 1 nerves. These nerves unite and divide to form the key nerves innervating the upper limb. Variations in the course of these nerves are clinically important to anesthetists, neurologists and orthopedicians. We report bilateral variations in the arterial and neural structures in the upper limb of a 65 year old cadaver. The muscles of the arm on one side were innervated by the median nerve with absence of musculocutaneous. While on the other side the musculocutaneous nerve contributed to the formation of the median nerve. There was a presence of high bifurcation of brachial artery on both sides. Knowledge of such variations in the innervations of muscles and the arterial supply of the limbs are important to remember before performing any reconstructive procedures or interventions on the limb.

  8. Arterial function of carotid and brachial arteries in postmenopausal vegetarians

    Directory of Open Access Journals (Sweden)

    Su T

    2011-08-01

    Full Text Available Ta-Chen Su1, Pao-Ling Torng2, Jiann-Shing Jeng3, Ming-Fong Chen1, Chiau-Suong Liau1,41Division of Cardiology, Department of Internal Medicine, 2Department of Obstetrics and Gynecology, 3Department of Neurology, National Taiwan University Hospital, National Taiwan University College of Medicine, 4Cardiovascular Center, Taipei Buddist Tzu-Chi Hospital, Hsin-Dian, Taipei, TaiwanBackground: Vegetarianism is associated with a lower risk of cardiovascular disease. However, studies of arterial function in vegetarians are limited.Methods: This study investigated arterial function in vegetarianism by comparing 49 healthy postmenopausal vegetarians with 41 age-matched omnivores. The arterial function of the common carotid artery was assessed by carotid duplex, while the pulse dynamics method was used to measure brachial artery distensibility (BAD, compliance (BAC, and resistance (BAR. Fasting blood levels of glucose, lipids, lipoprotein (a, high-sensitivity C-reactive protein, homocysteine, and vitamin B12 were also measured.Results: Vegetarians had significantly lower serum cholesterol, high-density and low-density lipoprotein, and glucose compared with omnivores. They also had lower vitamin B12 but higher homocysteine levels. Serum levels of lipoprotein (a and high-sensitivity C-reactive protein were no different between the two groups. There were no significant differences in carotid beta stiffness index, BAC, and BAD between the two groups even after adjustment for associated covariates. However, BAR was significantly lower in vegetarians than in omnivores. Multiple linear regression analysis revealed that age and pulse pressure were two important determinants of carotid beta stiffness index and BAD. Vegetarianism is not associated with better arterial elasticity.Conclusion: Apparently healthy postmenopausal vegetarians are not significantly better in terms of carotid beta stiffness index, BAC, and BAD, but have significantly decreased BAR than

  9. Case report: Iatrogenic brachial artery dissection with complete anterograde occlusion during elective arterial line placement

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    Laurence Weinberg

    2018-01-01

    Conclusion: We review our diagnostic pathway and treatment of this rare complication. Recommendations to minimise the risks of complications from brachial arterial line insertion are also overviewed. We recommend the routine utilization of ultrasound-guided technique and regular post-insertion neurovascular monitoring for the prevention and early recognition of complications from brachial artery catheter insertion.

  10. Screening for Peripheral Artery Disease and Cardiovascular Disease Risk Assessment with Ankle Brachial Index in Adults

    Science.gov (United States)

    ... Force Recommendations Screening for Peripheral Artery Disease and Cardiovascular Disease Risk Assessment with Ankle Brachial Index in Adults ... on Screening for Peripheral Artery Disease (PAD) and Cardiovascular Disease (CVD) Risk Assessment with Ankle Brachial Index (ABI) ...

  11. Delayed presentation of a traumatic brachial artery pseudoaneurysm.

    LENUS (Irish Health Repository)

    Forde, James C

    2009-09-01

    Delayed presentation of a brachial artery pseudoaneurysm following penetrating trauma is infrequently reported. We report the case of a 23-year-old male who presented three months following a penetrating trauma to his antecubital fossa with a sudden exacerbation of swelling and tenderness of his elbow. Doppler ultrasound and computed tomography arteriography confirmed the presence of a large pseudoaneurysm. Surgical reconstruction was performed using the long saphenous vein as an interposition vein graft, restoring normal arterial circulation.

  12. Anatomical Variations of Brachial Artery - Its Morphology, Embryogenesis and Clinical Implications

    Science.gov (United States)

    KS, Siddaraju; Venumadhav, Nelluri; Sharma, Ashish; Kumar, Neeraj

    2014-01-01

    Background: Accurate knowledge of variation pattern of the major arteries of upper limb is of considerable practical importance in the conduct of reparative surgery in the arm, forearm and hand however brachial artery and its terminal branches variations are less common. Aim: Accordingly the present study was designed to evaluate the anatomical variations of the brachial artery and its morphology, embryogenesis and clinical implications. Materials and Methods: In an anatomical study 140 upper limb specimens of 70 cadavers (35 males and 35 females) were used and anatomical variations of the brachial artery have been documented. Results: Accessory brachial artery was noted in eight female cadavers (11.43%). Out of eight cadavers in three cadavers (4.29%) an unusual bilateral accessory brachial artery arising from the axillary artery and it is continuing in the forearm as superficial accessory ulnar artery was noted. Rare unusual variant unilateral accessory brachial artery and its reunion with the main brachial artery in the cubital fossa and its variable course in relation to the musculocutaneous nerve and median nerve were also noted in five cadavers (7.14%). Conclusion: As per our knowledge such anatomical variations of brachial artery and its terminal branches with their relation to the surrounding structures are not reported in the modern medical literature. An awareness of such a presence is valuable for the surgeons and radiologists in evaluation of angiographic images, vascular and re-constructive surgery or appropriate treatment for compressive neuropathies. PMID:25653931

  13. Recent perspective on coronary artery bifurcation interventions.

    Science.gov (United States)

    Dash, Debabrata

    2014-01-01

    Coronary bifurcation lesions are frequent in routine practice, accounting for 15-20% of all lesions undergoing percutaneous coronary intervention (PCI). PCI of this subset of lesions is technically challenging and historically has been associated with lower procedural success rates and worse clinical outcomes compared with non-bifurcation lesions. The introduction of drug-eluting stents has dramatically improved the outcomes. The provisional technique of implanting one stent in the main branch remains the default approach in most bifurcation lesions. Selection of the most effective technique for an individual bifurcation is important. The use of two-stent techniques as an intention to treat is an acceptable approach in some bifurcation lesions. However, a large amount of metal is generally left unapposed in the lumen with complex two-stent techniques, which is particularly concerning for the risk of stent thrombosis. New technology and dedicated bifurcation stents may overcome some of the limitations of two-stent techniques and revolutionise the management of bifurcation PCI in the future.

  14. Hand-arm vibration syndrome with distal brachial artery occlusion

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    Vladyslava Bazylevska

    2017-01-01

    Full Text Available Abstract             Hand-arm vibration syndrome (HAVS is a complex disorder of the peripheral extremities that is associated with occupational or recreational exposure to hand-transmitted vibration. Digital artery occlusion in HAVS is a common finding; however, proximal involvement is less likely.  We present a case of HAVS with the initial presentation of acute limb ischemia and with thrombus burden extending from the distal brachial artery and into the ulnar and radial arteries. To our knowledge, no case of HAVS syndrome of similar severity has been previously described. This case emphasizes the potential dangers of HAVS and the necessity for proper prophylactic interventions at the workplace.

  15. Sex differences in intracranial arterial bifurcations

    DEFF Research Database (Denmark)

    Lindekleiv, Haakon M; Valen-Sendstad, Kristian; Morgan, Michael K

    2010-01-01

    . The female preponderance is usually explained by systemic factors (hormonal influences and intrinsic wall weakness); however, the uneven sex distribution of intracranial aneurysms suggests a possible physiologic factor-a local sex difference in the intracranial arteries....

  16. Estimation of brachial artery volume flow by duplex ultrasound imaging predicts dialysis access maturation.

    Science.gov (United States)

    Ko, Sae Hee; Bandyk, Dennis F; Hodgkiss-Harlow, Kelley D; Barleben, Andrew; Lane, John

    2015-06-01

    This study validated duplex ultrasound measurement of brachial artery volume flow (VF) as predictor of dialysis access flow maturation and successful hemodialysis. Duplex ultrasound was used to image upper extremity dialysis access anatomy and estimate access VF within 1 to 2 weeks of the procedure. Correlation of brachial artery VF with dialysis access conduit VF was performed using a standardized duplex testing protocol in 75 patients. The hemodynamic data were used to develop brachial artery flow velocity criteria (peak systolic velocity and end-diastolic velocity) predictive of three VF categories: low (800 mL/min). Brachial artery VF was then measured in 148 patients after a primary (n = 86) or revised (n = 62) upper extremity dialysis access procedure, and the VF category correlated with access maturation or need for revision before hemodialysis usage. Access maturation was conferred when brachial artery VF was >600 mL/min and conduit imaging indicated successful cannulation based on anatomic criteria of conduit diameter >5 mm and skin depth 800 mL/min was predicted when the brachial artery lumen diameter was >4.5 mm, peak systolic velocity was >150 cm/s, and the diastolic-to-systolic velocity ratio was >0.4. Brachial artery velocity spectra indicating VF 800 mL/min. Duplex testing to estimate brachial artery VF and assess the conduit for ease of cannulation can be performed in 5 minutes during the initial postoperative vascular clinic evaluation. Estimation of brachial artery VF using the duplex ultrasound, termed the "Fast, 5-min Dialysis Duplex Scan," facilitates patient evaluation after new or revised upper extremity dialysis access procedures. Brachial artery VF correlates with access VF measurements and has the advantage of being easier to perform and applicable for forearm and also arm dialysis access. When brachial artery velocity spectra criteria confirm a VF >800 mL/min, flow maturation and successful hemodialysis are predicted if anatomic criteria

  17. Use of a Collagen-Based Device for Closure of Low Brachial Artery Punctures

    International Nuclear Information System (INIS)

    Belenky, A.; Aranovich, D.; Greif, F.; Bachar, G.; Bartal, G.; Atar, E.

    2007-01-01

    Purpose. To report our experience with the Angioseal vascular closure device for hemostasis of distal brachial artery puncture. Methods. Between September 2003 and August 2005, 64 Angioseal vascular closure devices were inserted in 64 patients (40 men, 24 women; mean age 65 years) immediately after diagnostic or therapeutic arterial angiographies performed through a 5 Fr to 7 Fr sheath via the distal brachial artery. Ultrasound examination of the brachial artery preceded the angiography in all cases and only arteries wider than 4 mm were closed by the Angioseal. In cases of a sonographically evident thin subcutaneous space of the cubital fossa, tissue tumescence, using 1% Lidocaine, was performed prior to the arterial closure. Results. The deployment success rate was 100%. No major complications were encountered; only 2 patients developed puncture site hematoma, and these were followed conservatively. Conclusions. Closure of low brachial artery punctures with the Angioseal is simple and safe. No additional manual compression is required. We recommend its use after brachial artery access interventions, through appropriately wide arteries, to improve early patient ambulation and potentially reduce possible puncture site complications

  18. Brachial Artery Aneurysm as a Limb Threatening Condition: a Case Report

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    Farhad Heydari

    2015-05-01

    Full Text Available Brachial artery aneurysms are rare but potentially limb threatening condition. The presented case here is a 52-year old male referred to the emergency department complaining a sudden onset and progressive pain with coldness of his right upper extremity during brushing. The right upper extremity was pulseless and three-dimensional computed tomography showed an aneurysm of the proximal right brachial artery associated with arterial occlusion in its distal branch. Embolectomy was done, the aneurysm resected, and the artery successfully re-vascularised by interposing a saphenous vein graft. 

  19. Coronary interventionism for dissection of the artery brachial right

    International Nuclear Information System (INIS)

    Conde Cerdeira, Hector; Obregon Santos, Angel Gaspar; Aroche Aportela, Ronald; Dominguez Perez, Reyber Jesus

    2007-01-01

    A prospective, no controlled study was conducted from march 1 to December 31 of 2004. 23 patients were enrolled who made outpatients coronariography and were implanted coronary stents (25 lesions) by angioplasty with optimal results. Found 73,9% of male, stable angina 52,2%, mean age 55.1 + 8.9 years. Hypertension associates to smoke habits were most frequent risk factors. 80% receive 300 mg of clopidogrel during or immediately after procedure. Left anterior descending artery was most frequently treated (44%) and B2 type lessons (64%). The mid time procedure was 48 minutes. Reference diameter 2,87 + 0.42 mm, stenosis diameter 71,6 + 15.1 mm; minimal lumen diameter 0,97 + 0.64 mm; length lesson 14,72 + 5.6 mm; stent diameter 2,9 + 0.42 mm; stent length 16,8 + 5.44 mm; insufflation's time 36,4 + 7.3 seconds; atmospheres 13,56 + 1.7; acute gain 1,96 + 0.61 mm. Two patients had minor bleeding at dissection site (8.7%) and one a little haematoma (4,3%). The radial pulse from the arm's dissection was present in all patients event 24 hours after. We conclude brachial dissection ambulatory angioplasty stent in selected patients with optimal angiography results is feasible and safe

  20. Brachial artery protected by wrapped latissimus dorsi muscle flap in high voltage electrical injury

    Science.gov (United States)

    Gencel, E.; Eser, C.; Kokacya, O.; Kesiktas, E.; Yavuz, M.

    2016-01-01

    Summary High voltage electrical injury can disrupt the vascular system and lead to extremity amputations. It is important to protect main vessels from progressive burn necrosis in order to salvage a limb. The brachial artery should be totally isolated from the burned area by a muscle flap to prevent vessel disruption. In this study, we report the use of a wrap-around latissimus dorsi muscle flap to protect a skeletonized brachial artery in a high voltage electrical injury in order to salvage the upper extremity and restore function. The flap wrapped around the exposed brachial artery segment and luminal status of the artery was assessed using magnetic resonance angiography. No vascular intervention was required. The flap survived completely with good elbow function. Extremity amputation was not encountered. This method using a latissimus dorsi flap allows the surgeon to protect the main upper extremity artery and reconstruct arm defects, which contributes to restoring arm function in high voltage electrical injury. PMID:28149236

  1. Stents in Renal Artery Bifurcation Stenosis: A Case Report

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    Polytimi Leonardou

    2011-01-01

    Full Text Available A 39-year-old patient presented with poorly controlled hypertension, and she was referred to renal angiogram and potential renal angioplasty. Renal angiogram showed a bifurcation lesion of the right renal artery. A guide wire was used to cross the upper branch, while the lower branch was protected by another same-type guide wire through the same introducer. Two thin monorail balloons were used to dilate the two branches; however, despite balloon dilatation, the stenosis of the vessels persisted. The “kissing balloon” technique was then attempted by simultaneously inflating both branches using the same balloons, but more than a 70% residual stenosis persisted in each branch. Two stents were finally placed in a “kissing” way through the main renal artery. The imaging and clinical results were good, without any procedure-related complications. Three years clinical followup was also good, without any reason for further interventional approach.

  2. Stents in Renal Artery Bifurcation Stenosis: A Case Report

    Science.gov (United States)

    Leonardou, Polytimi; Pappas, Paris

    2011-01-01

    A 39-year-old patient presented with poorly controlled hypertension, and she was referred to renal angiogram and potential renal angioplasty. Renal angiogram showed a bifurcation lesion of the right renal artery. A guide wire was used to cross the upper branch, while the lower branch was protected by another same-type guide wire through the same introducer. Two thin monorail balloons were used to dilate the two branches; however, despite balloon dilatation, the stenosis of the vessels persisted. The “kissing balloon” technique was then attempted by simultaneously inflating both branches using the same balloons, but more than a 70% residual stenosis persisted in each branch. Two stents were finally placed in a “kissing” way through the main renal artery. The imaging and clinical results were good, without any procedure-related complications. Three years clinical followup was also good, without any reason for further interventional approach. PMID:21789043

  3. Right retrograde brachial cerebral angiography with simultaneous compression of the left carotid artery

    International Nuclear Information System (INIS)

    Ericson, K.; Mosskin, M.

    1981-01-01

    Right retrograde brachial angiography with simultaneous compression of the left common carotid artery was performed in 12 patients, invariably resulting in filling of the right vertebral and the basilar artery. In all but one patient, the right carotid artery and its branches were also filled. Retrograde filling of the left internal carotid artery occurred in 8 patients. Furthermore, retrograde filling of the intracranial part of the left vertebral artery was obtained in 5 of 12 patients. A complete four-vessel cranial angiography was thus obtained in one third of the patients. The method may be considered as a safe and valuable adjunct to other angiographic techniques. (Auth.)

  4. Ultrasound-guided compression repair of pseudoaneurysms of brachial and femoral arteries - 2 cases-

    International Nuclear Information System (INIS)

    Kim, Hak Soo; Choi, Yeon Hyeon; Kim, Ji Eun; Lee, Sang Hoon; Kim, Myung A; Kim, Tae Kyoung; Cho, Jae Min

    1994-01-01

    Ultrasound-guided compression repair of postcatherization pseudoaneurysm has been reported recently. We successfuly treated two cases of cardiac catherization-related pseudoaneurysms of brachial and femoral arteries with compression repair technique under color Doppler US-guidance. We regard US-guided compression repair as a saft and effective first-line treatment for catherization-related pseudoaneurysm

  5. Peripheral artery questionnaire improves ankle brachial index screening in symptomatic patients with peripheral artery disease.

    Science.gov (United States)

    Kim, B-H; Cho, K-I; Spertus, J; Park, Y-H; Je, H-G; Shin, M-S; Lee, J-H; Jang, J-S

    2014-12-01

    The peripheral artery questionnaire (PAQ) is a disease-specific health status measure of patients with peripheral artery disease (PAD). Whether the PAQ scores are associated with a PAD diagnosis among patients with symptoms suspicious for PAD is unknown and could help increase the pretest probability of ankle brachial index (ABI) screening among patients with suspicious symptoms. The PAQ was completed by 567 patients evaluated for potential intermittent claudication at six tertiary centres. Demographics, medical history, physical examination findings and the PAQ domain scores were compared with ABI. A diagnostic threshold PAQ scores. The correlation between the PAQ Summary Score and ABI was also calculated. The PAQ Summary Score was significantly lower in patients with low ABI as compared with those having a normal ABI (37.6 ± 19.0 vs. 70.1 ± 22.7, p PAQ Summary Score and ABI were highly correlated (r = 0.56, p PAQ Summary Score for predicting low ABI was 50.3 (AUC = 0.86, sensitivity 80.3%, specificity 78.3%). The PAQ Summary Score was associated with an increased likelihood of PAD in patients with suspected PAD symptoms, and a low summary score (≤ 50.3) was an optimal threshold for predicting PAD among patients referred for ABI. © 2014 John Wiley & Sons Ltd.

  6. Cardiac tamponade and coronary artery pseudoaneurysm after brachial arterial embolectomy, possible role for an aberrant origin of the right coronary artery

    Directory of Open Access Journals (Sweden)

    Irit Stessman-Lande, MD

    2018-03-01

    Full Text Available A patient developed hemopericardium shortly after left brachial arterial embolectomy using an embolectomy catheter. Evaluation disclosed evolving pseudoaneurysm of the right coronary artery that was successfully managed by stenting. Misplacement of the embolectomy catheter within the coronary vessel was facilitated by an anomalous origin of the right coronary artery. This complication highlights the importance of correct insertion of the embolectomy catheter using the markers to avoid maladvancement and damage to central vessels.

  7. Aortic-Brachial Pulse Wave Velocity Ratio: A Measure of Arterial Stiffness Gradient Not Affected by Mean Arterial Pressure.

    Science.gov (United States)

    Fortier, Catherine; Desjardins, Marie-Pier; Agharazii, Mohsen

    2018-03-01

    Aortic stiffness, measured by carotid-femoral pulse wave velocity (cf-PWV), is used for the prediction of cardiovascular risk. This mini-review describes the nonlinear relationship between cf-PWV and operational blood pressure, presents the proposed methods to adjust for this relationship, and discusses a potential place for aortic-brachial PWV ratio (a measure of arterial stiffness gradient) as a blood pressure-independent measure of vascular aging. PWV is inherently dependent on the operational blood pressure. In cross-sectional studies, PWV adjustment for mean arterial pressure (MAP) is preferred, but still remains a nonoptimal approach, as the relationship between PWV and blood pressure is nonlinear and varies considerably among individuals due to heterogeneity in genetic background, vascular tone, and vascular remodeling. Extrapolations from the blood pressure-independent stiffness parameter β (β 0 ) have led to the creation of stiffness index β, which can be used for local stiffness. A similar approach has been used for cardio-ankle PWV to generate a blood pressure-independent cardio-ankle vascular index (CAVI). It was recently demonstrated that stiffness index β and CAVI remain slightly blood pressure-dependent, and a more appropriate formula has been proposed to make the proper adjustments. On the other hand, the negative impact of aortic stiffness on clinical outcomes is thought to be mediated through attenuation or reversal of the arterial stiffness gradient, which can also be influenced by a reduction in peripheral medium-sized muscular arteries in conditions that predispose to accelerate vascular aging. Arterial stiffness gradient, assessed by aortic-brachial PWV ratio, is emerging to be at least as good as cf-PWV for risk prediction, but has the advantage of not being affected by operating MAP. The negative impacts of aortic stiffness on clinical outcomes are proposed to be mediated through attenuation or reversal of arterial stiffness gradient

  8. Hyperspectral imaging and ankle: brachial indices in peripheral arterial disease.

    Science.gov (United States)

    Jafari-Saraf, Lida; Gordon, Ian L

    2010-08-01

    To evaluate the correlation between ankle:brachial indices (ABI) and visible light reflectance spectroscopy hyperspectral imaging (HSI) determinations of oxygenated and deoxygenated hemoglobin (oxyHgb and deoxyHgb) levels in the skin of the distal lower extremity. This is a prospective, open, comparator trial which took place at the Vascular laboratory of a Veterans Administration Hospital in Long Beach, USA. Fifty-eight patients (85 limbs) were referred for routine vascular laboratory studies including ABI had concomitant HSI. Limbs with noncompressible pedal signals were excluded from the analysis. ABI was determined with continuous wave Doppler ultrasound and leg blood pressure cuffs. A commercial HSI system (Oxu-Vu(R), Hypermed, Inc.) was used to measure oxyHgb, deoxyHgb, and percent oxygenated hemoglobin (%oxyHgb) in the dorsum of the foot and ankle. HSI measurements of volar forearm skin were also obtained to normalize the lower extremity HSI measurements in a manner comparable with ABI. For purposes of comparison, data sets were divided into 3 groups: ABI > 0.9 (n = 53), 0.45 failed to show a clinically useful correlation between HSI measurements of oxyHgb levels, further evaluation of this novel technology is warranted. Published by Elsevier Inc.

  9. Brachial artery injury due to closed posterior elbow dislocation: case report☆

    Directory of Open Access Journals (Sweden)

    Alberto Naoki Miyazaki

    2016-04-01

    Full Text Available An association between closed posterior elbow dislocation and traumatic brachial artery injury is rare. Absence of radial pulse on palpation is an important warning sign and arteriography is the gold-standard diagnostic test. Early diagnosis is essential for appropriate treatment to be provided. This consists of joint reduction and immobilization, along with urgent surgical restoration of arterial flow. Here, a case (novel to the Brazilian literature of an association between these injuries (and the treatment implemented in a 27-year-old male patient is reported. These injuries were sustained through physical assault.

  10. Ankle Brachial Index: simple non-invasive estimation of peripheral artery disease

    Science.gov (United States)

    Pieniak, Marcin; Cieślicki, Krzysztof; Żyliński, Marek; Górski, Piotr; Murgrabia, Agnieszka; Cybulski, Gerard

    2014-11-01

    According to international guidelines, patients with Peripheral Artery Disease (PAD) are burdened with high cardiovascular risk. One of the simplest, non-invasive methods for PAD detection is the ankle-brachial index (ABI) measurement. The ABI is calculated as the ratio of systolic blood pressure at the ankle (pressure in the posterior tibial artery or the dorsal artery) to the systolic pressure in the arm (in the brachial artery) when the body is in a horizontal position. The physiological value of the ABI is assumed to be between 1 and 1.3; however, these limits vary from study to study. A value less than 0.9 indicates PAD. Some authors propose also measuring the ABI on both sides of the body to highlight possible differences in blood pressure between the opposite arterial segments. The aim of this study was to perform a meta-analysis of the ABI diagnostic criteria used in different publications. Additionally, ABI measurements were performed on 19 healthy patients in age ranged from 20 to 63 years. The results showed a slight dependence between age and the differences between the values obtained from left and right sides of the body.

  11. Brachial artery vasomotion and transducer pressure effect on measurements by active contour segmentation on ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Cary, Theodore W.; Sultan, Laith R.; Sehgal, Chandra M., E-mail: sehgalc@uphs.upenn.edu [Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Reamer, Courtney B.; Mohler, Emile R. [Department of Medicine, Division of Cardiovascular Medicine, Section of Vascular Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

    2014-02-15

    Purpose: To use feed-forward active contours (snakes) to track and measure brachial artery vasomotion on ultrasound images recorded in both transverse and longitudinal views; and to compare the algorithm's performance in each view. Methods: Longitudinal and transverse view ultrasound image sequences of 45 brachial arteries were segmented by feed-forward active contour (FFAC). The segmented regions were used to measure vasomotion artery diameter, cross-sectional area, and distention both as peak-to-peak diameter and as area. ECG waveforms were also simultaneously extracted frame-by-frame by thresholding a running finite-difference image between consecutive images. The arterial and ECG waveforms were compared as they traced each phase of the cardiac cycle. Results: FFAC successfully segmented arteries in longitudinal and transverse views in all 45 cases. The automated analysis took significantly less time than manual tracing, but produced superior, well-behaved arterial waveforms. Automated arterial measurements also had lower interobserver variability as measured by correlation, difference in mean values, and coefficient of variation. Although FFAC successfully segmented both the longitudinal and transverse images, transverse measurements were less variable. The cross-sectional area computed from the longitudinal images was 27% lower than the area measured from transverse images, possibly due to the compression of the artery along the image depth by transducer pressure. Conclusions: FFAC is a robust and sensitive vasomotion segmentation algorithm in both transverse and longitudinal views. Transverse imaging may offer advantages over longitudinal imaging: transverse measurements are more consistent, possibly because the method is less sensitive to variations in transducer pressure during imaging.

  12. Percutaneous brachial artery catheterization for coronary angiography and percutaneous coronary interventions (pci): an encouraging experience of 100 cases

    International Nuclear Information System (INIS)

    Islam, Z.U.; Maken, G.R.; Saif, M.; Khattak, Z.A.

    2013-01-01

    Objective: To evaluate the practicability and safety of the percutaneous transbrachial approach (TBA) for diagnostic coronary angiography and therapeutic percutaneous coronary interventions. Study Design: Quasi experimental study. Place and Duration of Study: The study was carried out in Armed Forces Institute of Cardiology- National Institute of Heart Diseases (AFIC-NIHD) from March 2009 to May 2011. Patients and Methods: We collected data of 100 consecutive patients who underwent coronary catheterization by the percutaneous transbrachial approach. Transbrachial catheterization was performed only if the radial access failed or radial pulse was feeble. Study endpoints included successful brachial artery catheterization, vascular and neurological complications at access site and procedure success rate. Results: Mean age of the patients was 54 years (range 33-79 yrs) and 65(65%) were males and 35 (35%) were females. The right brachial artery was used in all of the cases. Procedural success was achieved in 100% of the patients. Coronary angiography was performed in 70 patients and percutaneous coronary interventions were done in 30 cases. Out of these 30 cases, PCI to left coronary arteries (LAD and LCX) were performed in 19 patients while 11 patients had PCI to right coronary artery (RCA). No case of vascular complications such as major access site bleeding, vascular perforation, brachial artery occlusion causing forearm ischemia, compartment syndrome, vascular spasm or failure to catheterize coronary arteries requiring alternate vascular access were observed. Conclusion: Brachial artery is a safe and easily accessible approach for coronary angiography and percutaneous coronary interventions. (author)

  13. Changes of brachial arterial doppler waveform during immersion of the hand of young men in ice-cold water

    International Nuclear Information System (INIS)

    Kim, Young Goo

    1994-01-01

    To evaluate the changes of brachial arterial Doppler waveform during immersion of the hand of young men in ice-cold water. Doppler waveforms of brachial arteries in 11 young male patients were recorded before and during immersion of ipsilateral hand in ice-cold water(4-5 .deg. C). The procedure was repeated on separate days. Patterns of waveform during immersion were compared with the changes of pulsatility index. Four men showed high impedance waveforms, and 5 men showed low impedance waveforms during immersion both at the first and at the second study. Two men, however, showed high impedance waveforms at the first study and tow impedance waveforms at the second study. The pulsatility index rose and fell in high and low impedance waveforms, respectively. The changes of brachial arterial Doppler waveforms could be classified into high and low impedance patterns, probably reflecting the acute changes in downstream impedance during immersion of hand in ice-cold water

  14. Ankle Brachial Index <0.9 Underestimates the Prevalence of Peripheral Artery Occlusive Disease Assessed with Whole-Body Magnetic Resonance Angiography in the Elderly

    International Nuclear Information System (INIS)

    Wikstroem, J.; Hansen, T.; Johansson, L.; Lind, L.; Ahlstroem, H.

    2008-01-01

    Background: Whole-body magnetic resonance angiography (WBMRA) permits noninvasive vascular assessment, which can be utilized in epidemiological studies. Purpose: To assess the relation between a low ankle brachial index (ABI) and high-grade stenoses in the pelvic and leg arteries in the elderly. Material and Methods: WBMRA was performed in a population sample of 306 subjects aged 70 years. The arteries below the aortic bifurcation were graded after the most severe stenosis according to one of three grades: 0-49% stenosis, 50-99% stenosis, or occlusion. ABI was calculated for each side. Results: There were assessable WBMRA and ABI examinations in 268 (right side), 265 (left side), and 258 cases (both sides). At least one ≥50% stenosis was found in 19% (right side), 23% (left side), and 28% (on at least one side) of the cases. The corresponding prevalences for ABI <0.9 were 4.5%, 4.2%, and 6.6%. An ABI cut-off value of 0.9 resulted in a sensitivity, specificity, and positive and negative predictive value of 20%, 99%, 83%, and 84% on the right side, and 15%, 99%, 82%, and 80% on the left side, respectively, for the presence of a ≥ 50% stenosis in the pelvic or leg arteries. Conclusion: An ABI <0.9 underestimates the prevalence of peripheral arterial occlusive disease in the general elderly population

  15. Classification of coronary artery bifurcation lesions and treatments: Time for a consensus!

    DEFF Research Database (Denmark)

    Louvard, Yves; Thomas, Martyn; Dzavik, Vladimir

    2007-01-01

    by intention to treat, it is necessary to clearly define which vessel is the distal main branch and which is (are) the side branche(s) and give each branch a distinct name. Each segment of the bifurcation has been named following the same pattern as the Medina classification. The classification......, heterogeneity, and inadequate description of techniques implemented. Methods: The aim is to propose a consensus established by the European Bifurcation Club (EBC), on the definition and classification of bifurcation lesions and treatments implemented with the purpose of allowing comparisons between techniques...... in various anatomical and clinical settings. Results: A bifurcation lesion is a coronary artery narrowing occurring adjacent to, and/or involving, the origin of a significant side branch. The simple lesion classification proposed by Medina has been adopted. To analyze the outcomes of different techniques...

  16. A pilot study of the relationship between Doppler-estimated carotid and brachial artery flow and cardiac index.

    Science.gov (United States)

    Weber, U; Glassford, N J; Eastwood, G M; Bellomo, R; Hilton, A K

    2015-10-01

    We measured carotid and brachial artery blood flow by Doppler ultrasound in 11 human volunteers, and related these to cardiac index and to each other. The median (IQR [range]) carotid arterial blood flow was 0.334 (0.223-0.381 [0.052-0.563]) l.min(-1) on the right and 0.315 (0.223-0.369 [0.061-0.690]) l.min(-1) on the left. The brachial arterial blood flow was 0.049 (0.033-0.062 [0.015-0.204]) l.min(-1) on the right and 0.039 (0.027-0.054 [0.011-0.116]) on the left. Cardiac index was 3.2 (2.8-3.5 [1.9-5.4]) l.min(-1) .m(-2) . There was a moderate to good correlation between right-and left-sided flows (brachial: ρ = 0.45; carotid: ρ = 0.567). Brachial and carotid flow had no or a negative correlation with cardiac index (right brachial: ρ = -0.145, left brachial: ρ = -0.349; right carotid: ρ = -0.376, left carotid: ρ = -0.285). In contrast to some previous studies, we found that Doppler-estimated peripheral arterial blood flows only show a weak correlation with cardiac index and cannot be used to provide non-invasive estimates of cardiac index in man. © 2015 The Association of Anaesthetists of Great Britain and Ireland.

  17. Brachial artery repair using the basilic vein as a reliable conduit in a 3-year-old child

    Directory of Open Access Journals (Sweden)

    Hyunyoung G. Kim

    2017-04-01

    Full Text Available A supracondylar fracture of the humerus is the most common upper extremity fracture in children with concurrent neurovascular complications. However, bypass grafting in the management of a pediatric open elbow dislocation with an arterial injury has rarely been reported in the literature. Hence, an adequate conduit for a vessel graft interposition remains questionable when a primary anastomosis is limited in an arterial reconstruction. The purpose of this study is to present a brachial artery reconstruction in a 3-year-old patient with an open supracondylar fracture of the humerus. In the clinical and surgical examination of the patient, an open wound in the left antecubital fossa presented with accompanying brachial artery injury. To repair the artery, a reverse end-to-end anastomosis was conducted using basilic vein graft from the ipsilateral arm under general anesthesia. The patient had palpable radial pulses in the postoperative clinical examination and was discharged without complications. The great saphenous vein (GSV has proven to be the most common and the best conduit for arterial reconstruction of the upper extremity in the adult patients. However, the GSV graft is known to have the propensity for becoming aneurysmal in pediatric patients. Some studies have demonstrated the basilic vein as a suitable conduit in pediatric patients, in that it has durable patency, fewer branches, size compatibility for anastomosis, and proximity to the brachial artery. Our case confirms the safety of using this autogenous vein from within the zone of injury for arterial reconstruction, after a supracondylar humeral fracture. The management of pediatric elbow fractures accompanying vascular injuries can be technically demanding due to relatively small, delicate structures and concurrent neurovascular network. Nonetheless, a vascular injury should be treated with high level of suspicion and immediate intervention to avoid any limb ischemia or loss. In

  18. Effects of iodinated contrast media on common carotid and brachial artery blood flow and wall shear stress

    International Nuclear Information System (INIS)

    Irace, C.; Tamburini, S.; Bertucci, B.; Franceschi, M.S. de; Gnasso, A.

    2006-01-01

    The aim of our study was to evaluate the effect of the intravenous contrast media iomeprol on wall shear stress, blood flow and vascular parameters in the common carotid and brachial artery. Thirty outpatients undergoing thoracic or abdominal spiral CT scans were studied. The internal diameter and flow velocity of the common carotid and brachial artery were evaluated by ultrasound, and blood viscosity was measured before and after low osmolality iomeprol (Iomeron 350) injection. The wall shear stress, blood flow and pulsatility index were calculated. To test the differences between groups, the Wilcoxon rank test and Mann Whitney U test were applied. Blood viscosity decreased slightly, but significantly after contrast media (4.6±0.7 vs. 4.5±0.7 mPa.s, P=0.02). Contrarily, blood flow and wall shear stress did not change in the common carotid artery, but significantly decreased in the brachial artery (0.9±0.4 vs. 0.6±0.3 ml/s, P<0.0001, and 41.5±13.9 vs. 35.3±11.0 dynes/cm2, P<0.002, respectively), whereas the pulsatility index significantly increased in the brachial artery (5.0±3.3 vs. 7.5±5.3, P<0.001). Iomeprol injection causes blood flow and wall shear stress reduction of the brachial artery; the rise in the pulsatility index suggests an increase in peripheral vascular resistance. Further investigation is needed to evaluate whether these modifications can be clinically relevant. (orig.)

  19. Thrombosed persistent median artery causing carpal tunnel syndrome associated with bifurcated median nerve: A case report

    International Nuclear Information System (INIS)

    Salter, M.; Sinha, N. R.; Szmigielski, W.

    2011-01-01

    Background: Carpal tunnel syndrome is a sporadically occurring abnormality due to compression of median nerve. It is exceedingly rare for it to be caused by thrombosis of persistent median artery. Case Report: A forty two year old female was referred for ultrasound examination due to ongoing wrist pain, not relived by pain killers and mild paraesthesia on the radial side of the hand. High resolution ultrasound and Doppler revealed a thrombosed persistent median artery and associated bifurcated median nerve. The thrombus resolved on treatment with anticoagulants. Conclusions: Ultrasound examination of the wrist when done for patients with carpal tunnel syndrome should preferably include looking for persistent median artery and its patency. (authors)

  20. Luminal flow amplifies stent-based drug deposition in arterial bifurcations.

    Directory of Open Access Journals (Sweden)

    Vijaya B Kolachalama

    2009-12-01

    Full Text Available Treatment of arterial bifurcation lesions using drug-eluting stents (DES is now common clinical practice and yet the mechanisms governing drug distribution in these complex morphologies are incompletely understood. It is still not evident how to efficiently determine the efficacy of local drug delivery and quantify zones of excessive drug that are harbingers of vascular toxicity and thrombosis, and areas of depletion that are associated with tissue overgrowth and luminal re-narrowing.We constructed two-phase computational models of stent-deployed arterial bifurcations simulating blood flow and drug transport to investigate the factors modulating drug distribution when the main-branch (MB was treated using a DES. Simulations predicted extensive flow-mediated drug delivery in bifurcated vascular beds where the drug distribution patterns are heterogeneous and sensitive to relative stent position and luminal flow. A single DES in the MB coupled with large retrograde luminal flow on the lateral wall of the side-branch (SB can provide drug deposition on the SB lumen-wall interface, except when the MB stent is downstream of the SB flow divider. In an even more dramatic fashion, the presence of the SB affects drug distribution in the stented MB. Here fluid mechanic effects play an even greater role than in the SB especially when the DES is across and downstream to the flow divider and in a manner dependent upon the Reynolds number.The flow effects on drug deposition and subsequent uptake from endovascular DES are amplified in bifurcation lesions. When only one branch is stented, a complex interplay occurs - drug deposition in the stented MB is altered by the flow divider imposed by the SB and in the SB by the presence of a DES in the MB. The use of DES in arterial bifurcations requires a complex calculus that balances vascular and stent geometry as well as luminal flow.

  1. Arterial and venous revascularization with bifurcation of a single central artery: a reliable strategy for Tamai Zone I replantation.

    Science.gov (United States)

    Hsu, Chung-Chen; Lin, Yu-Te; Moran, Steven L; Lin, Cheng-Hung; Wei, Fu-Chan; Lin, Chih-Hung

    2010-12-01

    Replantation of the distal phalanx and pulp can be performed to improve finger function and finger aesthetics; however, establishing adequate venous drainage is a challenge. Slattery et al. reported microsurgical reattachment of a partial distal phalanx with the use of a bifurcated terminal digital artery. The bifurcation was divided into two pedicles, one of which was used for venous drainage. In this article, the authors report their experience with a similar technique and propose a new algorithm for distal finger replantation. From January of 2008 to February of 2009, five replantations were performed using a single central artery. The replanted levels were pulp, avulsed fingertip of the thumb, and distal phalanges. There was no volar vein, dorsal vein, or second artery available in the amputated part for standard venous drainage. Venous drainage in all cases was established by creating an anastomosis from a branch of the solitary terminal artery to a recipient vein. All digits were replanted successfully without evidence of arterial insufficiency or venous congestion. Partial necrosis was not identified postoperatively in any of the five fingers. There were no cases of wound infection. A branch of the central solitary artery may be used successfully to reestablish venous outflow in cases of distal finger tip replantation. This technique allowed for the salvage of all fingers in this study without the use of leeches or other techniques used in cases of venous insufficiency.

  2. Measurement system for an in-vitro characterization of the biomechanics and hemodynamics of arterial bifurcations

    International Nuclear Information System (INIS)

    Suárez-Bagnasco, D; Balay, G; Negreira, C A; Cymberknop, L; Armentano, R L

    2013-01-01

    Arterial behaviour in-vivo is influenced, amongst other factors, by the interaction between blood flow and the arterial wall endothelium, and the biomechanical properties of the arterial wall. This interaction plays an important role in pathogenic mechanisms of cardiovascular diseases such as atherosclerosis and arteriosclerosis. To quantify these interactions both from biomechanical and hemodynamical standpoints, a complete characterization and modelling of the arterial wall, blood flow, shear wall and circumferential wall stresses are needed. The development of a new multi-parameter measurement system (distances, pressures, flows, velocity profiles, temperature, viscosity) for an in-vitro characterization of the biomechanics and hemodynamics in arterial bifurcations (specially in carotid bifurcations) is described. This set-up represents an improvement relative to previous set-ups developed by the group FCIEN-FMED and is presently under development. Main subsystems interactions and environment-system interactions were identified and compensated to improve system's performance. Several interesting problems related with signal acquisition using a variety of sensors and some experimental results are shown and briefly discussed. Experimental data allow construction of meshes and parameter estimation of the biomechanical properties of the arterial wall, as well as boundary conditions, all suitable to be employed in CFD and FSI numerical simulation.

  3. Effect of force-induced mechanical stress at the coronary artery bifurcation stenting: Relation to in-stent restenosis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Cheng-Hung [Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou, Chang Gung University College of Medicine, Tao-Yuan, Taiwan (China); Department of Mechanical Engineering, Chang Gung University, Tao-Yuan, Taiwan (China); Jhong, Guan-Heng [Graduate Institute of Medical Mechatronics, Chang Gung University, Tao-Yuan, Taiwan (China); Hsu, Ming-Yi; Wang, Chao-Jan [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Tao-Yuan, Taiwan (China); Liu, Shih-Jung, E-mail: shihjung@mail.cgu.edu.tw [Department of Mechanical Engineering, Chang Gung University, Tao-Yuan, Taiwan (China); Hung, Kuo-Chun [Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou, Chang Gung University College of Medicine, Tao-Yuan, Taiwan (China)

    2014-05-28

    The deployment of metallic stents during percutaneous coronary intervention has become common in the treatment of coronary bifurcation lesions. However, restenosis occurs mostly at the bifurcation area even in present era of drug-eluting stents. To achieve adequate deployment, physicians may unintentionally apply force to the strut of the stents through balloon, guiding catheters, or other devices. This force may deform the struts and impose excessive mechanical stresses on the arterial vessels, resulting in detrimental outcomes. This study investigated the relationship between the distribution of stress in a stent and bifurcation angle using finite element analysis. The unintentionally applied force following stent implantation was measured using a force sensor that was made in the laboratory. Geometrical information on the coronary arteries of 11 subjects was extracted from contrast-enhanced computed tomography scan data. The numerical results reveal that the application of force by physicians generated significantly higher mechanical stresses in the arterial bifurcation than in the proximal and distal parts of the stent (post hoc P < 0.01). The maximal stress on the vessels was significantly higher at bifurcation angle <70° than at angle ≧70° (P < 0.05). The maximal stress on the vessels was negatively correlated with bifurcation angle (P < 0.01). Stresses at the bifurcation ostium may cause arterial wall injury and restenosis, especially at small bifurcation angles. These finding highlight the effect of force-induced mechanical stress at coronary artery bifurcation stenting, and potential mechanisms of in-stent restenosis, along with their relationship with bifurcation angle.

  4. Effect of force-induced mechanical stress at the coronary artery bifurcation stenting: Relation to in-stent restenosis

    International Nuclear Information System (INIS)

    Lee, Cheng-Hung; Jhong, Guan-Heng; Hsu, Ming-Yi; Wang, Chao-Jan; Liu, Shih-Jung; Hung, Kuo-Chun

    2014-01-01

    The deployment of metallic stents during percutaneous coronary intervention has become common in the treatment of coronary bifurcation lesions. However, restenosis occurs mostly at the bifurcation area even in present era of drug-eluting stents. To achieve adequate deployment, physicians may unintentionally apply force to the strut of the stents through balloon, guiding catheters, or other devices. This force may deform the struts and impose excessive mechanical stresses on the arterial vessels, resulting in detrimental outcomes. This study investigated the relationship between the distribution of stress in a stent and bifurcation angle using finite element analysis. The unintentionally applied force following stent implantation was measured using a force sensor that was made in the laboratory. Geometrical information on the coronary arteries of 11 subjects was extracted from contrast-enhanced computed tomography scan data. The numerical results reveal that the application of force by physicians generated significantly higher mechanical stresses in the arterial bifurcation than in the proximal and distal parts of the stent (post hoc P < 0.01). The maximal stress on the vessels was significantly higher at bifurcation angle <70° than at angle ≧70° (P < 0.05). The maximal stress on the vessels was negatively correlated with bifurcation angle (P < 0.01). Stresses at the bifurcation ostium may cause arterial wall injury and restenosis, especially at small bifurcation angles. These finding highlight the effect of force-induced mechanical stress at coronary artery bifurcation stenting, and potential mechanisms of in-stent restenosis, along with their relationship with bifurcation angle.

  5. Stent implantation for the treatment of wide-necked aneurysms located at internal carotid artery bifurcation

    International Nuclear Information System (INIS)

    Xing Ming; Yang Pengfei; Huang Qinghai; Zhao Wenyuan; Hong Bo; Xu Yi; Liu Jianmin

    2012-01-01

    Objective: To preliminarily evaluate the feasibility, safety and efficacy of stent placement for the treatment of wide-necked aneurysms located at internal carotid artery bifurcation. Methods: Eleven patients with wide-necked aneurysms located at internal carotid artery bifurcation, who were encountered during the period from Jan. 2004 to Dec. 2010 in hospital, were collected. A total of 16 intracranial aneurysms were detected, of which 11 were wide-necked and were located at internal carotid artery bifurcation. The diameters of the aneurysms ranged from 2.5 mm to 18 mm. Individual stent type and stenting technique was employed for each patient. Follow-up at 1, 3, 6 and 12 months after the procedure was conducted. Results: A total of 11 different stents were successfully deployed in the eleven patients. The stents included balloon expandable stent (n=1) and self-expanding stent (n=10). According to Raymond grading for the immediate occlusion of the aneurysm, grade Ⅰ (complete obliteration) was obtained in 4, grade Ⅱ (residual neck) in 2 and grade Ⅲ (residual aneurysm) in 5 cases. No procedure-related complications occurred. At the time of discharge, the modified Rankin score was 0-1 in the eleven patients. During the follow-up period lasting for 1-108 months, all the patients were in stable condition and no newly-developed neurological dysfunction or bleeding observed. Follow-up examination with angiography (1-48 months) showed that the aneurysms were cured (no visualization) in 4 cases, improved in 2 cases and in stable condition in one case. Conclusion: For the treatment of wide-necked aneurysms located at internal carotid artery bifurcation, stent implantation is clinically feasible, safe and effective. Further studies are required to evaluate its long-term efficacy. (authors)

  6. Experimental study on representation of flow on the bifurcated carotid arterial phantoms using magnetic resonance angiography

    International Nuclear Information System (INIS)

    Chung, Tae Sub; Rhim, Yoon Chul; Kim, Kyung Oh; Suh, Sang Ho; Jin, En Hao

    1995-01-01

    A common finding of carotid artery on magnetic resonance angiograms(MRAs) is a signal dropout along the posterior wall of carotid bulb due to reverse flow. The purpose of this study is to evaluate variable flow patterns on bifurcated carotid arterial phantoms using steady-state flow. We designed phantoms of a bifurcated carotid artery with acrylic materials. Flow patterns were evaluated with axial and coronal imaging of MRA(2D-TOF, 3D-TOF), color Doppler imaging, and computational fluid dynamics (CFD) within the phantoms constructed of an automated closed-type circulatory system filled with 4% sugar solution. These findings were compared with findings obtained from normal volunteers. Axial 3D-TOF MRA images exhibited closer resemblance to the contour of the inner wall of phantoms when compared to coronal 2D-TOF MRA imaging. However, 2D-TOF MRA showed good contrast difference of signal intensities between forward flow area and reverse flow area. Dark zones with reduced signal intensities due to reversed flow were separated from the outer wall of the internal and external carotid arteries by a thin layer of forward flow along the wall on the source slice image of MRA. The general hemodynamics of the phantoms on MRA were identical to hemodynamics on color Doppler imaging and CFD. The results obtained with the phantoms matched the findings on normal volunteers. Although representations of bifurcated carotid arterial phantoms on axial 3D-TOF MRA were excellent if ideally designed, the zone of reversed flow could be a significant factor in creating distorted image when the zone of reversed flow contacted directly with curved or deformed arterial wall

  7. Analysis of the flow in stenosed carotid artery bifurcation models--hydrogen-bubble visualisation.

    Science.gov (United States)

    Palmen, D E; van de Vosse, F N; Janssen, J D; van Dongen, M E

    1994-05-01

    This paper deals with the effect of geometric changes of mild stenoses on large-scale flow disturbances in the carotid artery bifurcation. Hydrogen-bubble visualisation experiments have been performed in Plexiglas models of a non-stenosed and a 25% stenosed carotid artery bifurcation. The flow conditions approximate physiological flow. The experiments show that shortly after the onset of the diastolic phase vortex formation occurs in the plane of symmetry. This vortex formation is found in a shear layer, which is formed in the carotid sinus. The shear layer is located between a region with low shear rates at the non-divider wall and a region with high shear rates at the divider wall. In order to gain insight into the parameters that are important with respect to the stability of the shear layer, experiments have been performed in which the influence of the shape of the flow pulse, the Reynolds number (Re), the Womersley parameter (alpha) and the flow division ratio (gamma) on the flow phenomena is studied. From these experiments it appears that the flow phenomena in the carotid artery bifurcation are significantly influenced by Re, alpha the systolic acceleration (sa) and deceleration (sd) and the duration of the peak-systolic flow (Tmax). With these results a simplified flow pulse is chosen, with which the experiments in the non-stenosed and the 25% stenosed bifurcation are performed. Comparison of the hydrogen-bubble profiles in the 0 and 25% stenosed models with similar flow conditions shows that the geometric change of the 25% stenosis only slightly influences the flow phenomena. The most striking influences are found in the stability of the shear layer. Quantitative experiments by means of laser Doppler anemometry measurements and numerical computations are needed to analyse the influence of the stenosis of the flow field more accurately.

  8. Non-invasive assessment of peripheral arterial disease: Automated ankle brachial index measurement and pulse volume analysis compared to duplex scan.

    Science.gov (United States)

    Lewis, Jane Ea; Williams, Paul; Davies, Jane H

    2016-01-01

    This cross-sectional study aimed to individually and cumulatively compare sensitivity and specificity of the (1) ankle brachial index and (2) pulse volume waveform analysis recorded by the same automated device, with the presence or absence of peripheral arterial disease being verified by ultrasound duplex scan. Patients (n=205) referred for lower limb arterial assessment underwent ankle brachial index measurement and pulse volume waveform recording using volume plethysmography, followed by ultrasound duplex scan. The presence of peripheral arterial disease was recorded if ankle brachial index 50% was evident with ultrasound duplex scan. Outcome measure was agreement between the measured ankle brachial index and interpretation of pulse volume waveform for peripheral arterial disease diagnosis, using ultrasound duplex scan as the reference standard. Sensitivity of ankle brachial index was 79%, specificity 91% and overall accuracy 88%. Pulse volume waveform sensitivity was 97%, specificity 81% and overall accuracy 85%. The combined sensitivity of ankle brachial index and pulse volume waveform was 100%, specificity 76% and overall accuracy 85%. Combining these two diagnostic modalities within one device provided a highly accurate method of ruling out peripheral arterial disease, which could be utilised in primary care to safely reduce unnecessary secondary care referrals.

  9. [Brachial artery pseudoaneurysm: a rare but serious complication in hemodialysis patients with arteriovenous fistula].

    Science.gov (United States)

    Mancini, Andrea; Castriotta, Giuseppe; Angelini, Pernina; Bozzi, Michele; Giancaspro, Vincenzo; La Raia, Elvira; Nisi, Maria Teresa; Proscia, Anna Rita; Tarantino, Giuseppe; Vitale, Ottavia; Cuzzola, Cristoforo

    2017-06-01

    A pseudoaneurysm or false aneurysm of the brachial artery is an uncommon occurrence in patients receiving hemodialysis with arteriovenous fistula (AVF). We describe the case of a 76-year-old woman presenting with a large, tender, pulsatile mass in the right antecubital region 10 cm from the AVF. B-mode ultrasound examination revealed a saccular hematoma. Color doppler showed a recirculation movement of blood, creating a two colors image called "Korean flag". The patient was transferred to the surgical unit where she first underwent ultrasound-guided compression and then surgical repair of the pseudoaneurysm. Two weeks after surgery the AVF was used again as an access for hemodialysis. Differentiating between a false and a true aneurysm based on ultrasound is not always straightforward. Doppler ultrasound findings can be decisive for the early diagnosis of a pseudoaneurysm to ensure proper treatment planning given the dangerous complications of ruptures. Treatment options include: compression, percutaneous thrombin injection, endovascular exclusion with covered stents, aneurysmectomy and surgical repair. Copyright by Società Italiana di Nefrologia SIN, Rome, Italy.

  10. Brachial artery responses to ambient pollution, temperature, and humidity in people with type 2 diabetes: a repeated-measures study.

    Science.gov (United States)

    Zanobetti, Antonella; Luttmann-Gibson, Heike; Horton, Edward S; Cohen, Allison; Coull, Brent A; Hoffmann, Barbara; Schwartz, Joel D; Mittleman, Murray A; Li, Yongsheng; Stone, Peter H; de Souza, Celine; Lamparello, Brooke; Koutrakis, Petros; Gold, Diane R

    2014-03-01

    Extreme weather and air pollution are associated with increased cardiovascular risk in people with diabetes. In a population with diabetes, we conducted a novel assessment of vascular brachial artery responses both to ambient pollution and to weather (temperature and water vapor pressure, a measure of humidity). Sixty-four 49- to 85-year-old Boston residents with type 2 diabetes completed up to five study visits (279 repeated measures). Brachial artery diameter (BAD) was measured by ultrasound before and after brachial artery occlusion [i.e., flow-mediated dilation (FMD)] and before and after nitroglycerin-mediated dilation (NMD). Ambient concentrations of fine particulate mass (PM2.5), black carbon (BC), organic carbon (OC), elemental carbon, particle number, and sulfate were measured at our monitoring site; ambient concentrations of carbon monoxide, nitrogen dioxide, and ozone were obtained from state monitors. Particle exposure in the home and during each trip to the clinic (home/trip exposure) was measured continuously and as a 5-day integrated sample. We used linear models with fixed effects for participants, adjusting for date, season, temperature, and water vapor pressure on the day of each visit, to estimate associations between our outcomes and interquartile range increases in exposure. Baseline BAD was negatively associated with particle pollution, including home/trip-integrated BC (-0.02 mm; 95% CI: -0.04, -0.003, for a 0.28 μg/m3 increase in BC), OC (-0.08 mm; 95% CI: -0.14, -0.03, for a 1.61 μg/m3 increase) as well as PM2.5, 5-day average ambient PM2.5, and BC. BAD was positively associated with ambient temperature and water vapor pressure. However, exposures were not consistently associated with FMD or NMD. Brachial artery diameter, a predictor of cardiovascular risk, decreased in association with particle pollution and increased in association with ambient temperature in our study population of adults with type 2 diabetes. Zanobetti A, Luttmann

  11. Dynamics of motion of a clot through an arterial bifurcation: a finite element analysis

    Energy Technology Data Exchange (ETDEWEB)

    Abolfazli, Ehsan; Fatouraee, Nasser [Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Vahidi, Bahman, E-mail: e.abolfazli@aut.ac.ir, E-mail: nasser@aut.ac.ir, E-mail: bahman_vahidi@ut.ac.ir [Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran (Iran, Islamic Republic of)

    2014-10-01

    Although arterial embolism is important as a major cause of brain infarction, little information is available about the hemodynamic factors which govern the path emboli tend to follow. A method which predicts the trajectory of emboli in carotid arteries would be of a great value in understanding ischemic attack mechanisms and eventually devising hemodynamically optimal techniques for prevention of strokes. In this paper, computational models are presented to investigate the motion of a blood clot in a human carotid artery bifurcation. The governing equations for blood flow are the Navier–Stokes formulations. To achieve large structural movements, the arbitrary Lagrangian–Eulerian formulation (ALE) with an adaptive mesh method was employed for the fluid domain. The problem was solved by simultaneous solution of the fluid and the structure equations. In this paper, the phenomenon was simulated under laminar and Newtonian flow conditions. The measured stress–strain curve obtained from ultrasound elasticity imaging of the thrombus was set to a Sussman–Bathe material model representing embolus material properties. Shear stress magnitudes in the inner wall of the internal carotid artery (ICA) were measured. High magnitudes of wall shear stress (WSS) occurred in the areas in which the embolus and arterial are in contact with each other. Stress distribution in the embolus was also calculated and areas prone to rapture were identified. Effects of embolus size and embolus density on its motion velocity were investigated and it was observed that an increase in either embolus size or density led to a reduction in movement velocity of the embolus. Embolus trajectory and shear stress from a simulation of embolus movement in a three-dimensional model with patient-specific carotid artery bifurcation geometry are also presented.

  12. Effect of mechanical behaviour of the brachial artery on blood pressure measurement during both cuff inflation and cuff deflation.

    Science.gov (United States)

    Zheng, Dingchang; Pan, Fan; Murray, Alan

    2013-10-01

    The aim of this study was to investigate the effect of different mechanical behaviour of the brachial artery on blood pressure (BP) measurements during cuff inflation and deflation. BP measurements were taken from each of 40 participants, with three repeat sessions under three randomized cuff deflation/inflation conditions. Cuff pressure was linearly deflated and inflated at a standard rate of 2-3 mmHg/s and also linearly inflated at a fast rate of 5-6 mmHg/s. Manual auscultatory systolic and diastolic BPs, and pulse pressure (SBP, DBP, PP) were measured. Automated BPs were determined from digitally recorded cuff pressures by fitting a polynomial model to the oscillometric pulse amplitudes. The BPs from cuff deflation and inflation were then compared. Repeatable measurements between sessions and between the sequential order of inflation/deflation conditions (all P > 0.1) indicated stability of arterial mechanical behaviour with repeat measurements. Comparing BPs obtained by standard inflation with those from standard deflation, manual SBP was 2.6 mmHg lower (P deflation suggest different arterial mechanical behaviour between arterial opening and closing during BP measurement. We have shown that the mechanical behaviour of the brachial artery during BP measurement differs between cuff deflation and cuff inflation.

  13. Carotid bifurcation calcium and correlation with percent stenosis of the internal carotid artery on CT angiography

    International Nuclear Information System (INIS)

    McKinney, Alexander M.; Casey, Sean O.; Teksam, Mehmet; Truwit, Charles L.; Kieffer, Stephen; Lucato, Leandro T.; Smith, Maurice

    2005-01-01

    The aim of this paper was to determine the correlation between calcium burden (expressed as a volume) and extent of stenosis of the origin of the internal carotid artery (ICA) by CT angiography (CTA). Previous studies have shown that calcification in the coronary arteries correlates with significant vessel stenosis, and severe calcification (measured by CT) in the carotid siphon correlates with significant (greater than 50% stenosis) as determined angiographically. Sixty-one patients (age range 50-85 years) underwent CT of the neck with intravenous administration of iodinated contrast for a variety of conditions. Images were obtained with a helical multidetector array CT scanner and reviewed on a three-dimensional workstation. A single observer manipulated window and level to segment calcified plaque from vascular enhancement in order to quantify vascular calcium volume (cc) in the region of the bifurcation of the common carotid artery/ICA origin, and to measure the extent of ICA stenosis near the origin. A total of 117 common carotid artery bifurcations were reviewed. A ''significant'' stenosis was defined arbitrarily as >40% (to detect lesions before they become hemodynamically significant) of luminal diameter on CTA using NASCET-like criteria. All ''significant'' stenoses (21 out of 117 carotid bifurcations) had measurable calcium. We found a relatively strong correlation between percent stenosis and the calcium volume (Pearson's r= 0.65, P<0.0001). We also found that there was an even stronger correlation between the square root of the calcium volume and the percent stenosis as measured by CTA (r= 0.77, P<0.0001). Calcium volumes of 0.01, 0.03, 0.06, 0.09 and 0.12 cc were used as thresholds to evaluate for a ''significant'' stenosis. A receiver operating characteristic (ROC) curve demonstrated that thresholds of 0.06 cc (sensitivity 88%, specificity 87%) and 0.03 cc (sensitivity 94%, specificity 76%) generated the best combinations of sensitivity and

  14. Brachial Artery Flow-mediated Dilation Following Exercise with Augmented Oscillatory and Retrograde Shear Rate

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    Johnson Blair D

    2012-08-01

    Full Text Available Abstract Background Acute doses of elevated retrograde shear rate (SR appear to be detrimental to endothelial function in resting humans. However, retrograde shear increases during moderate intensity exercise which also enhances post-exercise endothelial function. Since SR patterns differ with the modality of exercise, it is important to determine if augmented retrograde SR during exercise influences post-exercise endothelial function. This study tested the hypothesis that (1 increased doses of retrograde SR in the brachial artery during lower body supine cycle ergometer exercise would attenuate post-exercise flow-mediated dilation (FMD in a dose-dependent manner, and (2 antioxidant vitamin C supplementation would prevent the attenuated post-exercise FMD response. Methods Twelve men participated in four randomized exercise sessions (90 W for 20 minutes on separate days. During three of the sessions, one arm was subjected to increased oscillatory and retrograde SR using three different forearm cuff pressures (20, 40, 60 mmHg (contralateral arm served as the control and subjects ingested placebo capsules prior to exercise. A fourth session with 60 mmHg cuff pressure was performed with 1 g of vitamin C ingested prior to the session. Results Post-exercise FMD following the placebo conditions were lower in the cuffed arm versus the control arm (arm main effect: P P > 0.05. Following vitamin C treatment, post-exercise FMD in the cuffed and control arm increased from baseline (P P > 0.05. Conclusions These results indicate that augmented oscillatory and retrograde SR in non-working limbs during lower body exercise attenuates post-exercise FMD without an evident dose–response in the range of cuff pressures evaluated. Vitamin C supplementation prevented the attenuation of FMD following exercise with augmented oscillatory and retrograde SR suggesting that oxidative stress contributes to the adverse effects of oscillatory and

  15. Ankle-brachial index as indicator of chronic arterial insufficiency of the lower extremities and renal artery stenosis CT/DS angiography

    International Nuclear Information System (INIS)

    Georgiev, A.; Chervenkov, L.; Karadon, S.

    2015-01-01

    Full text: The aim is to validate the measurements of ankle -brachial index (ABI), as part of routine examination algorithm in conducting CTA/DSA of the extremities in patients suffering from PAD. Correlations between ABI values and renal artery stenosis. The present study includes 200 patients (138 men and 62 women, aged between 60 and 75 years). 130 of them were examined by a computer- tomography angiography - 95 men and 32 women. 70 patients were examined by digital subtraction angiography - 50 men and 20 women. Measurements of ankle-brachial index (ABI) were performed on all patients by measuring the systolic blood pressure on both brachial arteries and determine the peak pressure in both aa. dorsalis pedis. Statistical data processing. There are no patients in the study with ABI values above 0.7 that have established renal artery stenosis. All patients with severe atherosclerotic changes have values of the ABI below 0.7, and those with the most severe changes below 0.5. This fully corresponds to global data showing that values below 0.9 ABI show mild engagement, below 0.7 average, and below 0.5 severe involvement. According to the results of this survey sensitivity of ABI for renal arteries below 0.7 equals 100% and its specificity = 67.5%. For values of ABI below 0.5: Sensitivity =100%; Specificity = 83.85%. By determining ABI values both symptomatic and asymptomatic form of a PAD can be diagnosed. the method is fast, non-invasive, inexpensive and applicable everywhere. No special preparation of the patient is needed. The method can be used not only to assess the degree of commitment of the vessels of the lower limbs, but also as an indicator for the state of renal arteries in those patients

  16. Association of particulate air pollution and secondhand smoke on endothelium-dependent brachial artery dilation in healthy children

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    Mohammad Hashemi

    2012-01-01

    Full Text Available Background: This study aimed to determine the association of particulate matters with endothelial function, measured by flow mediated dilation (FMD of brachial artery, in children with or without exposure to secondhand smoke. Methods: This cross-sectional study was conducted from January to March 2011 in Isfahan, which is the second large and air-polluted city in Iran. The areas of the city with lowest and highest air pollution were determined, and in each area, 25 prepubescent boys with or without exposure to daily tobacco smoke in home were selected, i.e. 100 children were studied in total. Results: FMD was significantly smaller in those living in high-polluted area and those exposed to secondhand smoke. Multiple linear regression analysis, adjusted for age and body mass index, showed that both passive smoking status and living area in terms of particulate air pollution were effective determinants of the brachial artery diameter. The standardized coefficient of passive smoking status was –0.36 (SD = 0.09, P < 0.0001 showing negative association with percent increase in FMD. Likewise, the percent increase in brachial artery diameter was lower in passive smoker children. Similar relationship was documented for PM 10 concentration with a regression coefficient of –0.32 (SD = 0.04, P < 0.0001. Without considering passive smoking variable, PM 10 concentration has significant independent effect on FMD level. Conclusion: Our findings provide evidence on the association of environmental factors on endothelial dysfunction from early life. Studying such associations among healthy children may help identify the underlying mechanisms. The clinical implications of environmental factors on early stages of atherosclerosis should be confirmed in longitudinal studies.

  17. Enterprise stent for waffle-cone stent-assisted coil embolization of large wide-necked arterial bifurcation aneurysms.

    Science.gov (United States)

    Padalino, David J; Singla, Amit; Jacobsen, Walter; Deshaies, Eric M

    2013-01-01

    Large wide-necked arterial bifurcation aneurysms present a unique challenge for endovascular coil embolization treatment. One technique described in the literature deploys a Neuroform stent into the neck of the aneurysm in the shape of a waffle-cone, thereby acting as a scaffold for the coil mass. This case series presents four patients with large wide-necked bifurcation aneurysms treated with the closed-cell Enterprise stent using the waffle-cone technique. Four patients (59 ± 18 years of age) with large wide-necked arterial bifurcation aneurysms (three basilar apex and one MCA bifurcation) were treated with the waffle-cone technique using the Enterprise stent as a supporting device for stent-assisted coil embolization. Three of the patients presented with aneurysmal subarachnoid hemorrhage (Hunt-Hess 2-3; Fisher Grade 3-4). There was no procedural morbidity or mortality associated with treatment itself. One aneurysm was completely obliterated, and three had small residual necks. One patient developed an area of PCA infarct and visual field cut one month after the procedure and required recoiling of the residual neck. The flared ends of the Enterprise stent remodeled the aneurysm neck by conforming to the shape of the neck without any technical difficulty, resulting in a stable scaffold holding the coils into the aneurysm. The closed cell construction, flexibility, and flared ends of the Enterprise stent allow it to conform to the waffle-cone configuration and provide a stable scaffold for coil embolization of large wide-necked arterial bifurcation aneurysms. We have had excellent initial results using the Enterprise stent with the waffle-cone technique. However, this technique is higher risk than standard treatment methods and therefore should be reserved for large wide-necked bifurcation aneurysms where Y stenting is needed, but not possible, and surgical clip ligation is not an option.

  18. Experimental investigation of the flow of a blood analogue fluid in a replica of a bifurcated small artery.

    Science.gov (United States)

    Anastasiou, A D; Spyrogianni, A S; Koskinas, K C; Giannoglou, G D; Paras, S V

    2012-03-01

    The scope of this work is to study the pulsatile flow of a blood mimicking fluid in a micro channel that simulates a bifurcated small artery, in which the Fahraeus-Lindqvist effect is insignificant. An aqueous glycerol solution with small amounts of xanthan gum was used for simulating viscoelastic properties of blood and in vivo flow conditions were reproduced. Local flow velocities were measured using micro Particle Image Velocimetry (μ-PIV). From the measured velocity distributions, the wall shear stress (WSS) and its variation during a pulse were estimated. The Reynolds numbers employed are relatively low, i.e. similar to those prevailing during blood flow in small arteries. Experiments both with a Newtonian and a non-Newtonian fluid (having asymptotic viscosity equal to the viscosity of the Newtonian one) proved that the common assumption that blood behaves as a Newtonian fluid is not valid for blood flow in small arteries. It was also shown that the outer wall of the bifurcation, which is exposed to a lower WSS, is more predisposed to atherosclerotic plaque formation. Moreover, this region in small vessels is shorter than the one in large arteries, as the developed secondary flow decays faster. Finally, the WSS values in small arteries were found to be lower than those in large ones. Copyright © 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

  19. Tomographic particle image velocimetry investigation of the flow in a modeled human carotid artery bifurcation

    Science.gov (United States)

    Buchmann, N. A.; Atkinson, C.; Jeremy, M. C.; Soria, J.

    2011-04-01

    Hemodynamic forces within the human carotid artery are well known to play a key role in the initiation and progression of vascular diseases such as atherosclerosis. The degree and extent of the disease largely depends on the prevailing three-dimensional flow structure and wall shear stress (WSS) distribution. This work presents tomographic PIV (Tomo-PIV) measurements of the flow structure and WSS in a physiologically accurate model of the human carotid artery bifurcation. The vascular geometry is reconstructed from patient-specific data and reproduced in a transparent flow phantom to demonstrate the feasibility of Tomo-PIV in a complex three-dimensional geometry. Tomographic reconstruction is performed with the multiplicative line-of-sight (MLOS) estimation and simultaneous multiplicative algebraic reconstruction (SMART) technique. The implemented methodology is validated by comparing the results with Stereo-PIV measurements in the same facility. Using a steady flow assumption, the measurement error and RMS uncertainty are directly inferred from the measured velocity field. It is shown that the measurement uncertainty increases for increasing light sheet thickness and increasing velocity gradients, which are largest near the vessel walls. For a typical volume depth of 6 mm (or 256 pixel), the analysis indicates that the velocity derived from 3D cross-correlation can be measured within ±2% of the maximum velocity (or ±0.2 pixel) near the center of the vessel and within ±5% (±0.6 pixel) near the vessel wall. The technique is then applied to acquire 3D-3C velocity field data at multiple axial locations within the carotid artery model, which are combined to yield the flow field and WSS in a volume of approximately 26 mm × 27 mm × 60 mm. Shear stress is computed from the velocity gradient tensor and a method for inferring the WSS distribution on the vessel wall is presented. The results indicate the presence of a complex and three-dimensional flow structure, with

  20. The relation between ankle-brachial index (ABI and coronary artery disease severity and risk factors: an angiographic study

    Directory of Open Access Journals (Sweden)

    Masoumeh Sadeghi

    2011-07-01

    Full Text Available BACKGROUND: The current study aims to determine the relation between ankle–brachialindex (ABI and angiographic findings and major cardiovascular risk factors in patients withsuspected coronary artery diseases (CAD in Isfahan.METHODS: In this cross-sectional descriptive-analytic research, patients with suspected CADwere studied. Characteristics of studied subjects including demographics, familial history, pastmedical history and atherosclerotic risk factors such as diabetes mellitus, hypertension,hyperlipidemia and smoking were obtained using a standard questionnaire. ABI was measuredin all studied patients. ABI ≤ 0.9 (ABI+ was considered as peripheral vessel disease and ABI >0.9 (ABI- was considered as normal. Then, all studied patients underwent coronary arteryangiography. The results of the questionnaire and angiographic findings were compared in ABI+and ABI- groups. Data were analyzed by SPSS 15 using ANOVA, t-test, Spearman's rankcorrelation coefficient, and discriminant analysis.RESULTS: In this study, 125 patients were investigated. ABI ≤ 0.9 was seen in 25 patients (20%.The prevalence of ABI+ among men and women was 25.9% and 7.5%, respectively (P = 0.01. Theprevalence of atherosclerotic risk factors was significantly higher in ABI+ patients than in ABIones(P < 0.05. ABI+ patients had more significant stenosis than ABI- ones. The mean ofocclusion was significantly higher in ABI+ patients with left main artery (LMA, right coronaryartery (RCA, left anterior descending artery (LAD, diagonal artery 1 (D1 and left circumflexartery (LCX involvements (P < 0.05.CONCLUSION: The findings of this research indicated that ABI could be a useful method inassessing both the atherosclerotic risk factors and the degree of coronary involvements insuspected patients. However, in order to make more accurate decisions for using this method indiagnosing and preventing CAD, we should plan further studies in large sample sizes of generalpopulation

  1. Angle change of the parent arteries after stent-assisted coil embolization of wide-necked intracranial bifurcation aneurysms

    International Nuclear Information System (INIS)

    Cho, W.-S.; Kang, H.-S.; Kim, J.E.; Kwon, O.-K.; Oh, C.W.; Cho, Y.D.; Han, M.H.

    2014-01-01

    Aim: To investigate the angle changes of the parent arteries after stent-assisted coil embolization of wide-necked intracranial bifurcation aneurysms. Materials and methods: The adjacent parent arterial angles before and after stent-assisted coil embolization were measured in 38 patients with aneurysms of the anterior communicating artery (ACoAA) and 41 patients with bifurcation aneurysms of the middle cerebral artery (MCABA). Variables were analysed in relation to the angle changes. Results: Vascular angles of the parent arteries significantly increased by 27.8° (±18.5°) immediately after stent-assisted coil embolization in 79 cases (p < 0.001), with 25.7° (±14.8°) in ACoAA and 29.7° (±21.4°) in MCABA, respectively. In 51 (64.6%) cases with follow-up angiography (mean interval 13.5 ± 4.1 months), vascular angles increased by 27.2° (±17.1°) immediately after treatment and further increased by 20.7° (±14.3°) at the last follow-up (all p < 0.001). More acute pre-stent angles of the parent arteries correlated with greater post-stent angle changes (p = 0.006). Younger age tended to be inversely related to post-stent angle changes (p = 0.091). Conclusion: Stent placement during coil embolization induced significant changes in the aneurysm–parent artery relationship. Further study is needed to elicit the association between angle change of the parent arteries and aneurysmal stability after coil embolization

  2. Correlation between Patient-Reported Symptoms and Ankle-Brachial Index after Revascularization for Peripheral Arterial Disease

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    Hyung Gon Je

    2015-05-01

    Full Text Available Improvement in quality of life (QoL is a primary treatment goal for patients with peripheral arterial disease (PAD. The current study aimed to quantify improvement in the health status of PAD patients following peripheral revascularization using the peripheral artery questionnaire (PAQ and ankle-brachial index (ABI, and to evaluate possible correlation between the two methods. The PAQ and ABI were assessed in 149 symptomatic PAD patients before, and three months after peripheral revascularization. Mean PAQ summary scores improved significantly three months after revascularization (+49.3 ± 15 points, p < 0.001. PAQ scores relating to patient symptoms showed the largest improvement following revascularization. The smallest increases were seen in reported treatment satisfaction (all p’s < 0.001. As expected the ABI of treated limbs showed significant improvement post-revascularization (p < 0.001. ABI after revascularization correlated with patient-reported changes in the physical function and QoL domains of the PAQ. Twenty-two percent of PAD patients were identified as having a poor response to revascularization (increase in ABI < 0.15. Interestingly, poor responders reported improvement in symptoms on the PAQ, although this was less marked than in patients with an increase in ABI > 0.15 following revascularization. In conclusion, data from the current study suggest a significant correlation between improvement in patient-reported outcomes assessed by PAQ and ABI in symptomatic PAD patients undergoing peripheral revascularization.

  3. Correlation between Patient-Reported Symptoms and Ankle-Brachial Index after Revascularization for Peripheral Arterial Disease.

    Science.gov (United States)

    Je, Hyung Gon; Kim, Bo Hyun; Cho, Kyoung Im; Jang, Jae Sik; Park, Yong Hyun; Spertus, John

    2015-05-18

    Improvement in quality of life (QoL) is a primary treatment goal for patients with peripheral arterial disease (PAD). The current study aimed to quantify improvement in the health status of PAD patients following peripheral revascularization using the peripheral artery questionnaire (PAQ) and ankle-brachial index (ABI), and to evaluate possible correlation between the two methods. The PAQ and ABI were assessed in 149 symptomatic PAD patients before, and three months after peripheral revascularization. Mean PAQ summary scores improved significantly three months after revascularization (+49.3 ± 15 points, p PAQ scores relating to patient symptoms showed the largest improvement following revascularization. The smallest increases were seen in reported treatment satisfaction (all p's PAQ. Twenty-two percent of PAD patients were identified as having a poor response to revascularization (increase in ABI PAQ, although this was less marked than in patients with an increase in ABI > 0.15 following revascularization. In conclusion, data from the current study suggest a significant correlation between improvement in patient-reported outcomes assessed by PAQ and ABI in symptomatic PAD patients undergoing peripheral revascularization.

  4. Evaluation of Asymptomatic Peripheral Arterial Disease by Ankle-brachial Index in Patients with Concomitant Coronary Arterial Disease

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    Hosein Vakili

    2012-12-01

    Full Text Available Background: Peripheral arterial disease is associated with adverse cardiovascular outcomes. As such, it is found that screening for peripheral arterial disease (PAD improves risk assessment. Thus, intensive risk factor modification and medical treatment in these patients are necessary. Objectives: The purpose of this study was to determine the prevalence of asymptomatic peripheral arterial disease in patients with concomitant coronary arterial disease. Methods: Asymptomatic peripheral arterial disease was investigated in 400 patients (60% males, 40% females, aged 59.7± 11.3 with a documented coronary arterial disease. Results: Among patients with documented CAD, 12% had asymptomatic PAD with the ABI ratio of less than 0.9. Conclusions: It is advisable to screen for PAD not only as a disease but also as a risk assessment method for atherosclerosis.

  5. Unruptured internal carotid artery bifurcation aneurysms: general features and overall results after modern treatment.

    Science.gov (United States)

    La Pira, Biagia; Brinjikji, Waleed; Burrows, Anthony M; Cloft, Harry J; Vine, Roanna L; Lanzino, Giuseppe

    2016-11-01

    Internal carotid artery bifurcation aneurysms (ICAbifAs) present unique challenges to endovascular and surgical operators, and little is known about their natural history. We reviewed our institution's experience with ICAbifAs studying outcomes of surgical and endovascular management and natural history. Consecutive patients with unruptured ICAbifAs evaluated and/or treated over an 8-year interval were studied. Baseline demographics, neurovascular risk factors, aneurysm location and size, clinical presentation, treatment recommendations, and outcomes were prospectively collected and retrospectively analyzed. Continuous variables were compared with Student's t test and categorical variables with Chi-square tests. Fifty-nine patients with 61 unruptured ICAbifAs were included. Seven aneurysms were treated surgically (11.5 %), 22 underwent endovascular treatment (36 %), and 32 were managed conservatively (52.5 %). In the surgical group, short- and long-term complete aneurysm occlusion rates were 100 % with no cases of perioperative or long-term permanent morbidity or treatment-related mortality. In the endovascular group, two patients (11.7 %) with giant aneurysms had perioperative thromboembolic events with transient morbidity. There was one case of aneurysm rupture at follow-up in a giant aneurysm treated with partial coil embolization. Complete/near-complete occlusion rates were 63 %. There was one case of aneurysm rupture after 114 aneurysm-years of follow-up in the conservative management group (0.89 %/year), but no ruptures were observed in small aneurysms selected for conservative management. Unruptured small ICAbifAs have a benign natural history. In patients selected for treatment, excellent results can be achieved in the vast majority of patients with judicious use of endovascular and surgical therapy.

  6. Evaluation of the impact of carotid artery bifurcation angle on hemodynamics by use of computational fluid dynamics: a simulation and volunteer study.

    Science.gov (United States)

    Saho, Tatsunori; Onishi, Hideo

    2016-07-01

    In this study, we evaluated the hemodynamics of carotid artery bifurcation with various geometries using simulated and volunteer models based on magnetic resonance imaging (MRI). Computational fluid dynamics (CFD) was analyzed by use of OpenFOAM. The velocity distribution, streamline, and wall shear stress (WSS) were evaluated in a simulated model with known bifurcation angles (30°, 40°, 50°, 60°, derived from patients' data) and in three-dimensional (3D) healthy volunteer models. Separated flow was observed at the outer side of the bifurcation, and large bifurcation models represented upstream transfer of the point. Local WSS values at the outer bifurcation [both simulated (100 Pa). The bifurcation angle had a significant negative correlation with the WSS value (p<0.05). The results of this study show that the carotid artery bifurcation angle is related to the WSS value. This suggests that hemodynamic stress can be estimated based on the carotid artery geometry. The construction of a clinical database for estimation of developing atherosclerosis is warranted.

  7. Relation of Long-term Exposure to Air Pollution to Brachial Artery Flow-Mediated Dilation and Reactive Hyperemia

    Science.gov (United States)

    Wilker, Elissa H.; Ljungman, Petter L.; Rice, Mary B.; Kloog, Itai; Schwartz, Joel; Gold, Diane R.; Koutrakis, Petros; Vita, Joseph A.; Mitchell, Gary F.; Vasan, Ramachandran S.; Benjamin, Emelia J.; Hamburg, Naomi M.; Mittleman, Murray A.

    2014-01-01

    Long-term exposure to ambient air pollution has been associated with cardiovascular morbidity and mortality. Impaired vascular responses may in part explain these findings, but the association of such long-term exposure with measures of both conduit artery and microvascular function have not been widely reported. We evaluated the association between residential proximity to a major roadway (primary or secondary highway) and spatially resolved average fine particulate matter (PM2.5) and baseline brachial artery diameter and mean flow velocity, flow mediated dilation % and hyperemic flow velocity, in the Framingham Offspring and Third Generation Cohorts. We examined 5,112 participants (2,731 (53%) women, mean age 49±14 years). Spatially resolved average PM2.5 was associated with lower flow mediated dilation% and hyperemic flow velocity. An interquartile range difference in PM2.5 (1.99 μg/m3) was associated with −0.16% (95%CI: −0.27%, −0.05%) lower FMD% and −0.72 (95%CI: −1.38, −0.06) cm/s lower hyperemic flow velocity %. Residential proximity to a major roadway was negatively associated with flow mediated dilation %. Compared to living ≥400 m away, living <50 m from a major roadway was associated with 0.32% lower flow mediated dilation (95% confidence interval (CI): −0.58%, −0.06%), but results for hyperemic flow velocity had wide confidence intervals −0.68 cm/s (95%CI: −2.29, 0.93). In conclusion, residential proximity to a major roadway and higher levels of spatially resolved estimates of PM2.5 at participant residences are associated with impaired conduit artery and microvascular function in this large community-based cohort of middle-aged and elderly adults. PMID:24793676

  8. 3-D flow characterization and shear stress in a stenosed carotid artery bifurcation model using stereoscopic PIV technique.

    Science.gov (United States)

    Kefayati, Sarah; Poepping, Tamie L

    2010-01-01

    The carotid artery bifurcation is a common site of atherosclerosis which is a major leading cause of ischemic stroke. The impact of stenosis in the atherosclerotic carotid artery is to disturb the flow pattern and produce regions with high shear rate, turbulence, and recirculation, which are key hemodynamic factors associated with plaque rupture, clot formation, and embolism. In order to characterize the disturbed flow in the stenosed carotid artery, stereoscopic PIV measurements were performed in a transparent model with 50% stenosis under pulsatile flow conditions. Simulated ECG gating of the flowrate waveform provides external triggering required for volumetric reconstruction of the complex flow patterns. Based on the three-component velocity data in the lumen region, volumetric shear-stress patterns were derived.

  9. Stent impact on the geometry of the carotid bifurcation and the course of the internal carotid artery

    International Nuclear Information System (INIS)

    Berkefeld, J.; Zanella, F.E.; Rosendahl, H.; Theron, J.G.; Guimaraens, L.; Treggiari-Venzi, M.M.

    2002-01-01

    A measurement system is proposed to evaluate reconstructive effects of carotid stents on the geometry of the carotid bifurcation and the course of the internal carotid artery. To describe deviations of the stenotic internal carotid artery (ICA) from the extended axis of the common carotid artery (CCA) the CCA-ICA angle is measured between the CCA midaxis and the midaxis of the stenotic ICA segment. Maximal extensions of ICA tortuosities perpendicular to the course of the CCA axis are defined as ICA offset. The measurements were applied to DSA images of 224 carotid stenoses to evaluate variation and correlation between the two parameters. Comparative pre- and post-stent evaluation was performed in two series of 55 and 31 carotid stenoses treated with Wallstents and in a historic control group of 35 stenoses treated with Strecker stents. Straight course of the ICA was associated with low angle and low offset values, whereas tortuous course of the ICA showed larger angle and offset. A moderate linear correlation between the two parameters was found. Corresponding to a straightening of the stented segment, Wallstents reduced mean angle and offset values significantly. In five cases of the second series of Wallstents, transferrals of curves above the distal stent end associated with kinks were observed, and offset remained constant or increased. Strecker stent implantation caused no significant changes of bifurcational geometry. The proposed parameters corresponded to visual aspects of ICA tortuosity and detected reconstructive effects of self-expanding Wallstents on the ICA course. The measurement system may provide a basis for geometric evaluation of different stent types or implantation concepts with the aim: to optimize anatomic recanalization results in tortuous high angle-high offset bifurcations. (orig.)

  10. Number of distal limb and brachial pressure measurements required when diagnosing peripheral arterial disease by laser Doppler flowmetry

    International Nuclear Information System (INIS)

    Høyer, C; Biurrun Manresa, J A; Petersen, L J

    2013-01-01

    We examine the reliability of single and repeated blood pressure measurements at ankle, toe, and arm levels for the diagnosis of peripheral arterial disease (PAD) by laser Doppler flowmetry. Segmental pressures were measured in 200 patients with known or suspected PAD. Segmental indices were calculated using (1) one measurement [M-1], two measurements [M-2], or by a predefined reproducibility criterion (RC) as well as (2) by using one brachial blood-pressure (BBP-one) or correspondent to each segmental pressure (BBP-all) as reference. The agreement in diagnosis of PAD by Cohen's Kappa was κ = 0.930 when comparing RC to M-1, and κ = 0.977 when comparing RC to M-2. The same comparison showed excellent relative reliability for segmental indices (all intra-class correlation coefficients (ICC) ≥ 0.980). Diagnostic classification agreement for BBP-all versus BBP-one were κ = 0.831 for RC, κ = 0.804 for M-1, and κ = 0.847 for M-2. The relative reliability analysis showed excellent correlation in segmental indices (all ICC ≥ 0.957). The study shows minimal difference in segmental indices and diagnostic classification when comparing calculations based on the listed strategies. However, the study indicated that it is important to measure BBPs correspondent to each segmental pressure. (paper)

  11. Gender differences in the relationships among obesity, adiponectin and brachial artery distensibility in adolescents and young adults.

    Science.gov (United States)

    Urbina, E M; Khoury, P; Martin, L J; D'Alessio, D; Dolan, L M

    2009-10-01

    Obesity-related cardiovascular diseases (CVDs) are a major cause of cardiovascular (CV) mortality. Obesity-related reduction in vascular protective adipose-derived proteins, such as adiponectin (APN), has an important role. We compared brachial artery distensibility (BrachD) with APN, the level of adiposity and other CV risk factors (CVRFs) in 431 post-pubertal subjects (mean 17.9 years). Gender differences in average values were examined by t-tests. Correlations among BrachD, obesity and other CVRFs were examined. Regression analysis was performed to determine whether APN provided an independent contribution to BrachD, while controlling for obesity and other CVRFs. Male subjects had lower BrachD (5.72+/-1.37 vs 6.45+/-1.60% change per mm Hg, Pgender, APN*gender and BMI z-score predicted BrachD (r(2)=0.305). On the basis of gender difference, only BMI z-score was significant for male subjects (r(2)=0.080), whereas APN and BMI z-score contributed for female subjects (r(2)=0.242, all Pobesity in both male and female subjects. In female subjects, APN exerts an additional independent effect even after adjusting for blood pressure (BP), lipid levels and insulin. Differences in the effect of the APN-adiposity relationship on obesity-related vascular disease may be one reason for gender differences in the development and progression of atherosclerosis.

  12. Effect of black tea consumption on brachial artery flow-mediated dilation and ischaemia-reperfusion in humans.

    Science.gov (United States)

    Schreuder, Tim H A; Eijsvogels, Thijs M H; Greyling, Arno; Draijer, Richard; Hopman, Maria T E; Thijssen, Dick H J

    2014-02-01

    Tea consumption is associated with reduced cardiovascular risk. Previous studies found that tea flavonoids work through direct effects on the vasculature, leading to dose-dependent improvements in endothelial function. Cardioprotective effects of regular tea consumption may relate to the prevention of endothelial ischaemia-reperfusion (IR) injury. Therefore, we examined the effect of black tea consumption on endothelial function and the ability of tea to prevent IR injury. In a randomized, crossover study, 20 healthy subjects underwent 7 days of tea consumption (3 cups per day) or abstinence from tea. We examined brachial artery (BA) endothelial function via flow-mediated dilation (FMD), using high resolution echo-Doppler, before and 90 min after tea or hot water consumption. Subsequently, we followed a 20-min ischaemia and 20-min reperfusion protocol of the BA after which we measured FMD to examine the potential of tea consumption to protect against IR injury. Tea consumption resulted in an immediate increase in FMD% (pre-consumption: 5.8 ± 2.5; post-consumption: 7.2 ± 3.2; p FMD (p FMD. However, the impact of the IR protocol on FMD was not influenced by tea consumption. Therefore, the cardioprotective association of tea ingestion relates to a direct effect of tea on the endothelium in humans in vivo.

  13. A control systems approach to quantify wall shear stress normalization by flow-mediated dilation in the brachial artery.

    Directory of Open Access Journals (Sweden)

    Frank C G van Bussel

    Full Text Available Flow-mediated dilation is aimed at normalization of local wall shear stress under varying blood flow conditions. Blood flow velocity and vessel diameter are continuous and opposing influences that modulate wall shear stress. We derived an index FMDv to quantify wall shear stress normalization performance by flow-mediated dilation in the brachial artery. In 22 fasting presumed healthy men, we first assessed intra- and inter-session reproducibilities of two indices pFMDv and mFMDv, which consider the relative peak and relative mean hyperemic change in flow velocity, respectively. Second, utilizing oral glucose loading, we evaluated the tracking performance of both FMDv indices, in comparison with existing indices [i.e., the relative peak diameter increase (%FMD, the peak to baseline diameter ratio (Dpeak/Dbase, and the relative peak diameter increase normalized to the full area under the curve of blood flow velocity with hyperemia (FMD/shearAUC or with area integrated to peak hyperemia (FMD/shearAUC_peak]. Inter-session and intra-session reproducibilities for pFMDv, mFMDv and %FMD were comparable (intra-class correlation coefficients within 0.521-0.677 range. Both pFMDv and mFMDv showed more clearly a reduction after glucose loading (reduction of ~45%, p≤0.001 than the other indices (% given are relative reductions: %FMD (~11%, p≥0.074; Dpeak/Dbase (~11%, p≥0.074; FMD/shearAUC_peak (~20%, p≥0.016 and FMD/shearAUC (~38%, p≤0.038. Further analysis indicated that wall shear stress normalization under normal (fasting conditions is already far from ideal (FMDv << 1, which (therefore does not materially change with glucose loading. Our approach might be useful in intervention studies to detect intrinsic changes in shear stress normalization performance in conduit arteries.

  14. Relation between respiratory function and arterial stiffness assessed using brachial-ankle pulse wave velocity in healthy workers.

    Science.gov (United States)

    Inomoto, Atsushi; Fukuda, Rika; Deguchi, Junko; Toyonaga, Toshihiro

    2017-09-01

    [Purpose] Current studies report that patients with chronic obstructive pulmonary disease (COPD) may also have arteriosclerosis. This study aimed to investigate the relationship between respiratory function and arterial stiffness in healthy workers using the brachial-ankle pulse wave velocity (baPWV). [Subjects and Methods] This study included 104 male Japanese workers without COPD. We collected participant information and measured hemodynamics, body composition, and respiratory function. [Results] In the correlation analysis, baPWV showed a significant positive correlation with age, smoking index, systolic blood pressure, diastolic blood pressure, and heart rate, and a significant negative correlation with height, fat free mass, lower limb muscle mass, forced vital capacity (FVC), and forced expiratory volume in one second (FEV1). In multiple regression analysis using factors other than baPWV and respiratory function as adjustment variables, both FVC and FEV1 showed a significant negative relationship with baPWV (p=0.009 and p=0.027, respectively). FEV1/FVC was not significantly related to baPWV (p=0.704). [Conclusion] The results of this study indicated that FEV1/FVC and the proportion of FEV1 predicted, which are indicators of airflow limitation, are not predictors of baPWV in workers without airflow limitation. However, since baPWV showed a significant negative relationship with FVC and FEV 1, the reduction in respiratory function that does not cause airflow limitation, such as FVC or FEV1 decline, may be related to an increase in the risk of arterial stiffness.

  15. Efficacy of different types of self-expandable stents in carotid artery stenting for carotid bifurcation stenosis.

    Science.gov (United States)

    Liu, Ya-min; Qin, Hao; Zhang, Bo; Wang, Yu-jing; Feng, Jun; Wu, Xiang

    2016-02-01

    Both open and closed loop self-expandable stents were used in carotid artery stenting (CAS) for carotid bifurcation stenosis. We sought to compare the efficacy of two types of stents in CAS. The data of 212 patients treated with CAS (42 and 170 cases implanted with closed and open loop stents, respectively) for carotid bifurcation stenosis and distal filtration protection devices were retrospectively analyzed. Between closed and open loop stents, there were no significant differences in hospitalization duration, NIHSS score before and after the treatment, stenosis at 12th month, and cumulative incidence of primary endpoint events within 30 days or from the 31st day to the 12th month; while there were significant differences in hemodynamic changes and rate of difficulty in recycling distal filtration protection devices. Use of open vs. closed loop stents for carotid bifurcation stenosis seems to be associated with similar incidence of complications, except for greater rate of hemodynamic changes and lower rate of difficulty in recycling the distal filtration protection devices.

  16. Perigraft Plug Embolization of the Internal Iliac Artery and Implantation of a Bifurcated Stentgraft: One Treatment Option for Insufficient Tubular Stentgraft Repair of a Common Iliac Artery Aneurysm

    Energy Technology Data Exchange (ETDEWEB)

    Goltz, Jan Peter, E-mail: janpeter.goltz@uksh.de; Loesaus, Julia; Frydrychowicz, Alex; Barkhausen, Jörg [University Hospital of Schleswig-Holstein, Department for Radiology and Nuclear Medicine (Germany); Wiedner, Marcus [University Hospital of Schleswig-Holstein, Clinic for Surgery (Germany)

    2016-02-15

    We report an endovascular technique for the treatment of type Ia endoleak after a plain tubular stentgraft had been implanted for a large common iliac artery aneurysm with an insufficient proximal landing zone and without occlusion of the hypogastric in another hospital. CT follow-up showed an endoleak with continuous sac expansion over 12 months. This was classified as type Ia by means of dynamic contrast-enhanced MRI. Before a bifurcated stentgraft was implanted to relocate the landing zone more proximally, the still perfused ipsilateral hypogastric artery was embolized to prevent a type II endoleak. A guidewire was manipulated alongside the indwelling stentgraft. The internal iliac artery could then be selectively intubated followed by successful plug embolization of the vessel’s orifice despite the stentgraft being in place.

  17. Reliability of palpation of the radial artery compared with auscultation of the brachial artery in measuring SBP

    NARCIS (Netherlands)

    van der Hoeven, Niels V.; van den Born, Bert-Jan H.; van Montfrans, Gert A.

    2011-01-01

    Background Systolic blood pressure contributes more to cardiovascular disease than DBP, especially in elderly persons. Palpation of the radial artery to assess SBP - Riva-Rocci's technique-may be an attractive alternative for auscultatory SBP in these patients. Therefore, we investigated the

  18. Measurement of brachial artery endothelial function using a standard blood pressure cuff

    International Nuclear Information System (INIS)

    Maltz, Jonathan S; Budinger, Thomas F; Tison, Geoffrey H; Olgin, Jeffrey; Alley, Hugh F; Owens, Christopher D

    2015-01-01

    The integrity of endothelial function in major arteries (EFMA) is a powerful independent predictor of heart attack and stroke. Existing ultrasound-based non-invasive assessment methods are technically challenging and suitable only for laboratory settings. EFMA, like blood pressure (BP), is both acutely and chronically affected by factors such as lifestyle and medication. Consequently, laboratory-based measurements cannot fully gauge the effects of medical interventions on EFMA. EFMA and BP have, arguably, comparable (but complementary) value in the assessment of cardiovascular health. Widespread deployment of EFMA assessment is thus a desirable clinical goal. To this end, we propose a device based on modifying the measurement protocol of a standard electronic sphygmomanometer. The protocol involves inflating the cuff to sub-diastolic levels to enable recording of the pulse waveform before and after vasodilatory stimulus. The mechanical unloading of the arterial wall provided by the cuff amplifies the distension that occurs with each pulse, which is measured as a pressure variation in the cuff. We show that the height of the rising edge of each pulse is proportional to the change in lumen area between diastole and systole. This allows the effect of vasodilatory stimuli on the artery to be measured with high sensitivity. We compare the proposed cuff flow-mediated dilation (cFMD) method to ultrasound flow-mediated dilation (uFMD). We find significant correlation (r  =  0.55, p  =0.003, N  =  27) between cFMD- and uFMD-based metrics obtained when the release of a 5 min cuff occlusion is employed to induce endothelial stimulus via reactive hyperemia. cFMD is approximately proportional to the square of uFMD, representing a typical increase in sensitivity to vasodilation of 300–600%. This study illustrates the potential for an individual to conveniently measure his/her EFMA by using a low-cost reprogrammed home sphygmomanometer. (paper)

  19. A COMPUTATIONAL FRAMEWORK INVOLVING CFD AND DATA MINING TOOLS FOR ANALYZING DISEASE IN CAROTID ARTERY BIFURCATION

    OpenAIRE

    Tabib, Mandar; Rasheed, Adil; Fonn, Eivind

    2017-01-01

    Cardiovascular diseases, like Carotid Artery Disease and Coronary Artery Disease (CAD) are associated with the narrowing of artery due to build-up of fatty substances and cholesterol deposits (called plaque). Carotid Artery Disease increases the chances of brain stroke. Hence, the main objective of this work is to apply computational tools to help differentiate between the healthy and unhealthy artery (with 25% stenosis) using a combination of Computational Fluid Dynamics (CFD) and data minin...

  20. Flow studies in canine artery bifurcations using a numerical simulation method.

    Science.gov (United States)

    Xu, X Y; Collins, M W; Jones, C J

    1992-11-01

    Three-dimensional flows through canine femoral bifurcation models were predicted under physiological flow conditions by solving numerically the time-dependent three-dimensional Navier-stokes equations. In the calculations, two models were assumed for the blood, those of (a) a Newtonian fluid, and (b) a non-Newtonian fluid obeying the power law. The blood vessel wall was assumed to be rigid this being the only approximation to the prediction model. The numerical procedure utilized a finite volume approach on a finite element mesh to discretize the equations, and the code used (ASTEC) incorporated the SIMPLE velocity-pressure algorithm in performing the calculations. The predicted velocity profiles were in good qualitative agreement with the in vivo measurements recently obtained by Jones et al. The non-Newtonian effects on the bifurcation flow field were also investigated, and no great differences in velocity profiles were observed. This indicated that the non-Newtonian characteristics of the blood might not be an important factor in determining the general flow patterns for these bifurcations, but could have local significance. Current work involves modeling wall distensibility in an empirically valid manner. Predictions accommodating these will permit a true quantitative comparison with experiment.

  1. Long-Term Results After Simple Versus Complex Stenting of Coronary Artery Bifurcation Lesions Nordic Bifurcation Study 5-Year Follow-Up Results

    DEFF Research Database (Denmark)

    Maeng, M.; Holm, N. R.; Erglis, A.

    2013-01-01

    Objectives This study sought to report the 5-year follow-up results of the Nordic Bifurcation Study. Background Randomized clinical trials with short-term follow-up have indicated that coronary bifurcation lesions may be optimally treated using the optional side branch stenting strategy. Methods...... complex strategy of planned stenting of both the main vessel and the side branch. (C) 2013 by the American College of Cardiology Foundation...

  2. Differential identification of atypical pneumonia pathogens in aorta and internal mammary artery related to ankle brachial index and walking distance.

    Science.gov (United States)

    Iriz, Erkan; Cirak, Meltem Yalinay; Zor, Mustafa Hakan; Engin, Doruk; Oktar, Levent; Unal, Yusuf

    2013-08-01

    We studied the existence of agents in aorta biopsies, such as Chlamydia pneumoniae, cytomegalovirus, and Mycoplasma pneumoniae, that are thought to have a role in atherosclerosis etiopathogenesis role, and their association with peripheral artery disease. We examined aorta wall and internal mammarian artery (IMA) biopsies taken from two different places in 63 patients in whom coronary artery bypass was performed. In these biopsies, we evaluated the deoxyribonuclease (DNA) of these microorganisms using polymerase chain reaction. From the same patients, we recorded the ankle brachial index, road walking distance information, lipid profile, C-reactive proteins, blood parameters such as fibrinogen, and the patient's operation data. In the nine aorta biopsies taken from 63 patients, we isolated C pneumoniae DNA. In IMA biopsies taken from the same patients, we detected no microorganism DNA (P artery disease. In the development of atherosclerosis with C pneumoniae, there may be a determinant pathogen in both the aorta and the peripheral arteries. The nonexistence of C pneumoniae DNA in the IMA biopsies may indicate infectious agents because of the predominant endothelial functions in this artery, and thus its resistance to atherosclerosis. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. The impact of menstrual phase on brachial artery flow-mediated dilatation during handgrip exercise in healthy premenopausal women.

    Science.gov (United States)

    D'Urzo, Katrina A; King, Trevor J; Williams, Jennifer S; Silvester, Morgan D; Pyke, Kyra E

    2018-02-01

    What is the central question of this study? The aim of this study was to determine the influence of menstrual phase on flow-mediated dilatation in response to sustained, exercise-induced increases in shear stress. What is the main finding and its importance? We showed, for the first time, that in healthy, premenopausal women the flow-mediated dilatation stimulated by exercise-induced increases in shear stress did not fluctuate across two phases of the menstrual cycle, despite significant fluctuations in oestrogen. This suggests that endothelial function is not consistently augmented in the high-oestrogen phase. Flow-mediated dilatation (FMD) in response to a sustained shear-stress stimulus (e.g. via handgrip exercise; HGEX) is emerging as a useful tool for assessing endothelial function; however, the impact of menstrual phase on HGEX-FMD is unknown. The purpose of this study was to determine whether HGEX-FMD fluctuates with cyclical changes in oestrogen concentrations over two discrete phases (low and high oestrogen) of the menstrual cycle. Brachial artery (BA) diameter and blood velocity were assessed with two-dimesional and Doppler ultrasound, respectively. Shear stress was estimated using shear rate (SR = BA blood velocity/BA diameter). Participants (12 healthy, regularly cycling women, 21 ± 2 years of age) completed two experimental visits: (i) low oestrogen (early follicular, EF); and (ii) high oestrogen (late follicular, LF). Reactive hyperaemia-stimulated FMD (RH-FMD) and HGEX-FMD (6 min of handgrip exercise) were assessed during each visit. Results are mean values ± SD. Oestrogen increased from the EF to LF phase (EF, 33 ± 9 pg ml -1 ; LF, 161 ± 113 pg ml -1 , P = 0.003). However, neither the SR stimuli (HGEX, P = 0.501; RH, P = 0.173) nor the FMD responses differed between phases (EF versus LF: HGEX-FMD, 4.8 ± 2.8 versus 4.6 ± 2.2%, P = 0.601; RH-FMD, 7.9 ± 4.3 versus 6.4 ± 3.1%, P = 0.071). These results extend

  4. Association between the severity of coronary artery stenosis and the combination of the difference in blood pressure between arms and brachial-ankle pulse wave velocity.

    Science.gov (United States)

    Miyase, Yuiko; Miura, Shin-Ichiro; Shiga, Yuhei; Yano, Masaya; Suematsu, Yasunori; Adachi, Sen; Norimatsu, Kenji; Nakamura, Ayumi; Saku, Keijiro

    2016-01-01

    A difference in systolic blood pressure (SBP) ≥10 mmHg between the arms is associated with an increased risk of coronary artery disease (CAD) and mortality in high-risk patients. Four hundred and fourteen patients were divided into three groups according to the percent most severe luminal narrowing of a coronary artery as diagnosed by coronary computed tomography angiography: no or mild coronary stenosis (0-49%), moderate stenosis (50-69%) and severe stenosis (≥70%) groups. The relative difference in SBP between arms in the severe group was significantly lower than those in the no or mild and moderate groups. The brachial-ankle pulse wave velocity (baPWV) significantly increased as the severity of coronary stenosis increased. We confirmed that severe coronary stenosis was independently associated with both the relative difference in SBP between arms and baPWV, in addition to age, gender, hypertension, dyslipidemia, diabetes mellitus and ankle-brachial index by a logistic regression analysis. The group with a relative difference in SBP between arms of difference in SBP between arms and baPWV may be a more effective approach for the non-invasive assessment of the severity of CAD.

  5. Association between temporal mean arterial pressure and brachial noninvasive blood pressure during shoulder surgery in the beach chair position during general anesthesia.

    Science.gov (United States)

    Triplet, Jacob J; Lonetta, Christopher M; Everding, Nathan G; Moor, Molly A; Levy, Jonathan C

    2015-01-01

    Estimation of cerebral perfusion pressure during elective shoulder surgery in the beach chair position is regularly performed by noninvasive brachial blood pressure (NIBP) measurements. The relationship between brachial mean arterial pressure and estimated temporal mean arterial pressure (eTMAP) is not well established and may vary with patient positioning. Establishing a ratio between eTMAP and NIBP at varying positions may provide a more accurate estimation of cerebral perfusion using noninvasive measurements. This prospective study included 57 patients undergoing elective shoulder surgery in the beach chair position. All patients received an interscalene block and general anesthesia. After the induction of general anesthesia, values for eTMAP and NIBP were recorded at 0°, 30°, and 70° of incline. A statistically significant, strong, and direct correlation between NIBP and eTMAP was found at 0° (r = 0.909, P ≤ .001), 30° (r = 0.874, P Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  6. Aneurisma infectado de artéria braquial após endocardite infecciosa de valva mitral Infected aneurysm of brachial artery after mitral valve infective endocarditis

    Directory of Open Access Journals (Sweden)

    Heraldo Guedis Lobo Filho

    2011-03-01

    Full Text Available Apresentamos um caso de aneurisma infectado de artéria braquial em paciente com endocardite infecciosa por Streptococcus bovis. Homem de 49 anos de idade se apresentou com febre, dispnéia e sopro regurgitativo em foco mitral com irradiação para axila. O ecocardiograma demonstrou vegetação em valva mitral nativa. Após troca valvar mitral com implante de prótese biológica, observou-se massa pulsátil de cinco centímetros de diâmetro em fossa antecubital direita. Foi feito o diagnóstico de aneurisma infectado de artéria braquial, e o tratamento cirúrgico foi realizado com sucesso. O objetivo desse relato de caso é apresentar uma complicação pouco comum após endocardite infecciosa.We present a case of brachial artery infected aneurysm in a patient with infective endocarditis caused by Streptococcus bovis. A 49-year-old man presented with fever dyspnea and a pansystolic murmur with irradiation to axilla. The echocardiogram revealed vegetation in native mitral valve. After mitral valve replacement with bioprosthesis, it was observed pulsatile mass of five centimeters in diameter at antecubital fossa of right upper limb. It was made the diagnosis of infected aneurysm of the brachial artery, and the surgery was performed successfully. The aim of this case report is to show a rare complication after infective endocarditis.

  7. Treatment of an Unusual Occurrence of a Complex Left Subclavian Artery/Left Internal Mammary Artery Bifurcation Stenosis in the Setting of Coronary Subclavian Steal Syndrome and Ischemic Left Ventricular Systolic Dysfunction

    Directory of Open Access Journals (Sweden)

    Michael J. Martinelli

    2018-01-01

    Full Text Available This case will illustrate the clinical and unique technical challenges, not previously reported, in a patient with a history of progressive left ventricular (LV systolic dysfunction, congestive heart failure (CHF, myocardial infarction (MI, and a complex bifurcation lesion of the left subclavian artery (SA involving the left internal mammary artery (LIMA in the setting of coronary subclavian steal syndrome (CSSS. The approach to this lesion is complicated by significant LIMA involvement requiring intervention directed toward both the SA and the LIMA in the presence of severe LV systolic dysfunction. This clinical scenario necessitates a careful technique, utilizing bifurcation methods similar to those used in coronary intervention.

  8. Occluded Brescia-Cimino Hemodialysis Fistulas: Endovascular Treatment with Both Brachial Arterial and Venous Access Using the Pull-Through Technique

    International Nuclear Information System (INIS)

    Miyayama, Shiro; Matsui, Osamu; Taki, Keiichi; Minami, Tetsuya; Shinmura, Rieko; Ito, Chiharu; Takamatsu, Shigeyuki; Kobayashi, Miki; Ushiogi, Yashuyuki

    2005-01-01

    We retrospectively evaluated the usefulness of both arterial and venous access with the pull-through technique in endovascular treatment of totally occluded Brescia-Cimino fistulas. We treated 26 patients (17 men, 9 women; age range 43-82 years, mean age 66 years) with occluded Brescia-Cimino fistulas. First, the occluded segment was traversed from the antegrade brachial arterial access using a microcatheter-guidewire system. Second, the vein was retrogradely punctured after confirmation of all diseased segments, and a 0.014- or 0.016-inch guidewire was pulled through the venous access when the occluded segment was long. All interventions including thrombolysis, thromboaspiration, angioplasty, and stent placement were performed via the venous access. The occlusion was successfully crossed via the brachial arterial access in 23 patients (88%). In 2 patients it was done from the venous approach. In the remaining patient it was not possible to traverse the occluded segment. The pull-through technique was successful in all 19 attempts. Clinical success was achieved in 96%, the primary patency rates at 6, 12, and 18 months were 83%, 78%, and 69%, the primary assisted patency rates were 92%, 92%, and 72%, and the secondary patency rates were 92%, 92%, and 92%, respectively. Minor complications in 5 patients included venous perforation in 2 (8%), venous rupture in 1 (4%), and regional hematoma in 2 (8%). Our study suggests that endovascular treatments with both arterial and venous access using the pull-through technique are highly effective in restoring function in totally occluded Brescia-Cimino fistulas

  9. Intramural location and size of arterial calcification are associated with stenosis at carotid bifurcation

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Shigeki, E-mail: shigekiyamada3@gmail.com [Department of Neurosurgery and Stroke Center, Rakuwakai Otowa Hospital, Otowachinji-cho 2, Yamashina-ku, Kyoto 607-8602 (Japan); Department of Neurosurgery, Hamamatsu Rosai Hospital, 25 Shogen-cho, Higashi-ku, Hamamatsu city, Shizuoka 430-8525 (Japan); Interfaculty Initiative in Information Studies/Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Oshima, Marie, E-mail: marie@iis.u-tokyo.ac.jp [Interfaculty Initiative in Information Studies/Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Watanabe, Yoshihiko, E-mail: ynabe@magic.odn.ne.jp [Department of Neurosurgery, Hamamatsu Rosai Hospital, 25 Shogen-cho, Higashi-ku, Hamamatsu city, Shizuoka 430-8525 (Japan); Ogata, Hideki, E-mail: hidogata@gmail.com [Department of Neurosurgery, Hamamatsu Rosai Hospital, 25 Shogen-cho, Higashi-ku, Hamamatsu city, Shizuoka 430-8525 (Japan); Hashimoto, Kenji, E-mail: hashiken8022@yahoo.co.jp [Department of Neurosurgery, Kishiwada Municipal Hospital, 1001 Gakuhara-cho, Kishiwada city, Osaka 596-8501 (Japan); Miyake, Hidenori, E-mail: hi-miyake@hamamatsuh.rofuku.go.jp [Department of Neurosurgery, Hamamatsu Rosai Hospital, 25 Shogen-cho, Higashi-ku, Hamamatsu city, Shizuoka 430-8525 (Japan)

    2014-06-15

    Purpose: The purpose of this study was to investigate the association between internal carotid artery (ICA) stenosis and intramural location and size of calcification at the ICA origins and the origins of the cervical arteries proximal to the ICA. Method: A total of 1139 ICAs were evaluated stenosis and calcification on the multi-detector row CT angiography. The intramural location was categorized into none, outside and inside location. The calcification size was evaluated on the 4-point grading scale. The multivariate analyses were adjusted for age, serum creatinine level, hypertension, hyperlipidemia, diabetes mellitus, smoking and alcohol habits. Results: Outside calcification at the ICA origins showed the highest multivariate odds ratio (OR) for the presence of ICA stenosis (30.0) and severe calcification (a semicircle or more of calcification at the arterial cross-sectional surfaces) did the second (14.3). In the subgroups of >70% ICA stenosis, the multivariate OR of outside location increased to 44.8 and that of severe calcification also increased to 32.7. Four of 5 calcified carotid plaque specimens extracted by carotid endarterectomy were histologically confirmed to be calcified burdens located outside the internal elastic lamia which were defined as arterial medial calcification. Conclusions: ICA stenosis was strongly associated with severe calcification located mainly outside the carotid plaque. Outside calcification at the ICA origins should be evaluated separately from inside calcification, as a marker for the ICA stenosis. Additionally, we found that calcification at the origins of the cervical arteries proximal to the ICA was significantly associated with the ICA stenosis.

  10. Clinical significance of inter-arm pressure difference and ankle-brachial pressure index in patients with suspected coronary artery disease

    International Nuclear Information System (INIS)

    Igarashi, Yuko; Chikamori, Taishiro; Tomiyama, Hirofumi; Usui, Yasuhiro; Hida, Satoshi; Tanaka, Hirokazu; Nagao, Tadashi; Yamashina, Akira

    2007-01-01

    Although measuring blood pressure at the bilateral brachia is common in medical practice, its clinical significance in patients with suspected coronary artery disease (CAD) has not been fully clarified. The method of this study was to define the significance of inter-arm systolic blood pressure difference in patients with suspected CAD, and to assess the relationship between inter-arm pressure difference and CAD, simultaneous brachial and ankle blood pressure measurements and stress myocardial single-photon emission computed tomography (SPECT) were performed in 386 consecutive patients with suspected CAD, excluding those with previous myocardial infarction or coronary revascularization. Subclavian artery stenosis, defined as ≥15 mmHg inter-arm systolic blood pressure difference, was found in 27 patients (7%). Age (65±12 vs 65±11 years), male sex (21/27 vs 244/359), prevalence of hypertension (63% vs 56%), hypercholesterolemia (63% vs 62%), diabetes mellitus (33% vs 38%), cigarette smoking (44% vs 41%) and family history of CAD (15% vs 12%) were similar between patients with subclavian artery stenosis and those without. The incidence of decreased ankle-brachial pressure index (ABI) was higher (37% vs 12%, p=0.001), and percentage ischemic myocardium as assessed by SPECT was greater (9.0±8.5% vs 5.6±6.6%, p=0.05) in patients with subclavian artery stenosis than in those without. Furthermore, significant correlations were observed between inter-arm pressure difference and percentage ischemic myocardium (r=0.13; p=0.01), and ABI (r=-0.26, p<0.0001). Among 386 patients, 283 underwent coronary angiography, and 63% of those who had inter-arm blood pressure difference had CAD. Furthermore, 83% of those CAD patients had multi-vessel CAD, which is regarded as a high-risk subset for subsequent cardiac events. Inter-arm pressure difference is often found in patients with suspected CAD, and is associated with significant CAD and peripheral artery disease. Thus, inter

  11. Percutaneous reconstruction of the innominate bifurcation using the retrograde 'kissing stents' technique

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Shun-ichi; Kazekawa, Kiyoshi; Matsubara, Shuko [Fukuoka University Chikushi Hospital, Department of Neurosurgery, Chikushino, Fukuoka (Japan); Sugata, Sei [Bironoki Neurosurgical Hospital, Shibushi, Kagoshima (Japan)

    2006-08-15

    Obstructions of the supraaortic vessels are an important cause of morbidity associated with a variety of symptoms. Percutaneous transluminal angioplasty has evolved as an effective and safe treatment modality for occlusive lesions of the supraaortic vessels. However, the endovascular management of an innominate bifurcation has not previously been reported. A 53-year-old female with a history of systematic hypertension, diabetes mellitus and hypercholesterolemia presented with left hemiparesis and dysarthria. Angiography of the innominate artery showed a stenosis of the innominate bifurcation. The lesion was successfully treated using the retrograde kissing stent technique via a brachial approach and an exposed direct carotid approach. The retrograde kissing stent technique for the treatment of a stenosis of the innominate bifurcation was found to be a safe and effective alternative to conventional surgery. (orig.)

  12. Percutaneous reconstruction of the innominate bifurcation using the retrograde 'kissing stents' technique

    International Nuclear Information System (INIS)

    Nagata, Shun-ichi; Kazekawa, Kiyoshi; Matsubara, Shuko; Sugata, Sei

    2006-01-01

    Obstructions of the supraaortic vessels are an important cause of morbidity associated with a variety of symptoms. Percutaneous transluminal angioplasty has evolved as an effective and safe treatment modality for occlusive lesions of the supraaortic vessels. However, the endovascular management of an innominate bifurcation has not previously been reported. A 53-year-old female with a history of systematic hypertension, diabetes mellitus and hypercholesterolemia presented with left hemiparesis and dysarthria. Angiography of the innominate artery showed a stenosis of the innominate bifurcation. The lesion was successfully treated using the retrograde kissing stent technique via a brachial approach and an exposed direct carotid approach. The retrograde kissing stent technique for the treatment of a stenosis of the innominate bifurcation was found to be a safe and effective alternative to conventional surgery. (orig.)

  13. Hybrid treatment of bullet embolism at the abdominal aortic bifurcation, complicated with thoracoabdominal aorta pseudoaneurysm and common iliac artery occlusion: case report

    Directory of Open Access Journals (Sweden)

    Patrick Bastos Metzger

    2014-03-01

    Full Text Available Embolization due to a firearm projectile entering the bloodstream is a rare event that is unlikely to be suspected during initial treatment of trauma patients. We describe and discuss a case of bullet embolism of the abdominal aortic bifurcation, complicated by a pseudoaneurysm of the thoracoabdominal aorta and occlusion of the right common iliac artery, but successfully treated using a combination of endovascular methods and conventional surgery.

  14. Elbow dislocation with ipsilateral fracture of the distal radius associated with a brachial artery injury: A new pathological condition of traumatic origin.

    Science.gov (United States)

    Trigo Lahoz, L; Lamas Gomez, C; Sarasquete Reiriz, J; de Caso Rodriguez, J; Proubasta Renart, I

    Elbow dislocation associated with ipsilateral fracture of the distal radius and a brachial artery injury is an uncommon traumatic entity. The two references of this injury combination appeared in 2015, although both authors did not realise that they were the first two cases published in the medical literature. Although mentioned in the text of the articles, no mention was made of the fracture of the distal radius in the titles. The purpose of this paper is to present three cases with this new traumatic pathological entity, explaining its pathogenetic mechanism, the treatment used, and the results obtained. Copyright © 2016 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. The effect of α1 -adrenergic blockade on post-exercise brachial artery flow-mediated dilatation at sea level and high altitude.

    Science.gov (United States)

    Tymko, Michael M; Tremblay, Joshua C; Hansen, Alex B; Howe, Connor A; Willie, Chris K; Stembridge, Mike; Green, Daniel J; Hoiland, Ryan L; Subedi, Prajan; Anholm, James D; Ainslie, Philip N

    2017-03-01

    Our objective was to quantify endothelial function (via brachial artery flow-mediated dilatation) at sea level (344 m) and high altitude (3800 m) at rest and following both maximal exercise and 30 min of moderate-intensity cycling exercise with and without administration of an α 1 -adrenergic blockade. Brachial endothelial function did not differ between sea level and high altitude at rest, nor following maximal exercise. At sea level, endothelial function decreased following 30 min of moderate-intensity exercise, and this decrease was abolished with α 1 -adrenergic blockade. At high altitude, endothelial function did not decrease immediately after 30 min of moderate-intensity exercise, and administration of α 1 -adrenergic blockade resulted in an increase in flow-mediated dilatation. Our data indicate that post-exercise endothelial function is modified at high altitude (i.e. prolonged hypoxaemia). The current study helps to elucidate the physiological mechanisms associated with high-altitude acclimatization, and provides insight into the relationship between sympathetic nervous activity and vascular endothelial function. We examined the hypotheses that (1) at rest, endothelial function would be impaired at high altitude compared to sea level, (2) endothelial function would be reduced to a greater extent at sea level compared to high altitude after maximal exercise, and (3) reductions in endothelial function following moderate-intensity exercise at both sea level and high altitude are mediated via an α 1 -adrenergic pathway. In a double-blinded, counterbalanced, randomized and placebo-controlled design, nine healthy participants performed a maximal-exercise test, and two 30 min sessions of semi-recumbent cycling exercise at 50% peak output following either placebo or α 1 -adrenergic blockade (prazosin; 0.05 mg kg  -1 ). These experiments were completed at both sea-level (344 m) and high altitude (3800 m). Blood pressure (finger photoplethysmography

  16. The effect of α1‐adrenergic blockade on post‐exercise brachial artery flow‐mediated dilatation at sea level and high altitude

    Science.gov (United States)

    Tremblay, Joshua C.; Hansen, Alex B.; Howe, Connor A.; Willie, Chris K.; Stembridge, Mike; Green, Daniel J.; Hoiland, Ryan L.; Subedi, Prajan; Anholm, James D.; Ainslie, Philip N.

    2016-01-01

    Key points Our objective was to quantify endothelial function (via brachial artery flow‐mediated dilatation) at sea level (344 m) and high altitude (3800 m) at rest and following both maximal exercise and 30 min of moderate‐intensity cycling exercise with and without administration of an α1‐adrenergic blockade.Brachial endothelial function did not differ between sea level and high altitude at rest, nor following maximal exercise.At sea level, endothelial function decreased following 30 min of moderate‐intensity exercise, and this decrease was abolished with α1‐adrenergic blockade. At high altitude, endothelial function did not decrease immediately after 30 min of moderate‐intensity exercise, and administration of α1‐adrenergic blockade resulted in an increase in flow‐mediated dilatation.Our data indicate that post‐exercise endothelial function is modified at high altitude (i.e. prolonged hypoxaemia). The current study helps to elucidate the physiological mechanisms associated with high‐altitude acclimatization, and provides insight into the relationship between sympathetic nervous activity and vascular endothelial function. Abstract We examined the hypotheses that (1) at rest, endothelial function would be impaired at high altitude compared to sea level, (2) endothelial function would be reduced to a greater extent at sea level compared to high altitude after maximal exercise, and (3) reductions in endothelial function following moderate‐intensity exercise at both sea level and high altitude are mediated via an α1‐adrenergic pathway. In a double‐blinded, counterbalanced, randomized and placebo‐controlled design, nine healthy participants performed a maximal‐exercise test, and two 30 min sessions of semi‐recumbent cycling exercise at 50% peak output following either placebo or α1‐adrenergic blockade (prazosin; 0.05 mg kg −1). These experiments were completed at both sea‐level (344 m) and high altitude (3800

  17. Relationship between resistant hypertension and arterial stiffness assessed by brachial-ankle pulse wave velocity in the older patient

    Directory of Open Access Journals (Sweden)

    Chung CM

    2014-09-01

    Full Text Available Chang-Min Chung,1,2 Hui-Wen Cheng,2 Jung-Jung Chang,2 Yu-Sheng Lin,2 Ju-Feng Hsiao,2 Shih-Tai Chang,1 Jen-Te Hsu2,31School of Traditional Chinese Medicine, College of Medicine, Chang Gung University, 2Division of Cardiology, Chang Gung Memorial Hospital, Chiayi, 3Department of Medicine, College of Medicine, Chang Gung University, Taoyuan County, TaiwanBackground: Resistant hypertension (RH is a common clinical condition associated with increased cardiovascular mortality and morbidity in older patients. Several factors and conditions interfering with blood pressure (BP control, such as excess sodium intake, obesity, diabetes, older age, kidney disease, and certain identifiable causes of hypertension are common in patients resistant to antihypertensive treatment. Arterial stiffness, measured by brachial-ankle pulse wave velocity (baPWV, is increasingly recognized as an important prognostic index and potential therapeutic target in hypertensive patients. The aim of this study was to determine whether there is an association between RH and arterial stiffness. Methods: This study included 1,620 patients aged ≥65 years who were referred or self-referred to the outpatient hypertension unit located at a single cardiovascular center. They were separated into normotensive, controlled BP, and resistant hypertension groups. Home BP, blood laboratory parameters, echocardiographic studies and baPWV all were measured. Results: The likelihood of diabetes mellitus was significantly greater in the RH group than in the group with controlled BP (odds ratio 2.114, 95% confidence interval [CI] 1.194–3.744, P=0.010. Systolic BP was correlated in the RH group significantly more than in the group with controlled BP (odds ratio 1.032, 95% CI 1.012–1.053, P=0.001. baPWV (odds ratio 1.084, 95% CI 1.016–1.156, P=0.015 was significantly correlated with the presence of RH. The other factors were negatively correlated with the existence of RH.Conclusion: In

  18. [Ultrasonographic evaluation of selected parameters of the endothelial function in brachial arteries and IMT measurements in carotid arteries in children with diabetes type 1 using personal insulin pumps--preliminary report].

    Science.gov (United States)

    Tołwińska, Joanna; Głowińska-Olszewska, Barbara; Urban, Mirosława; Florys, Bozena; Peczyńska, Jadwiga

    2006-01-01

    Type 1 diabetes is a known risk factor for arterial atherosclerosis. The first symptoms can be found even in childhood. The ultrasonographic measurements of intimal plus medial thickness in carotid arteries (IMT) and flow mediated dilatation (FMD) evaluated in brachial arteries, play a known role in the detection in these cases. The diabetes treatment intensification is an important factor in delaying early atherosclerotic changes. Currently, intensive treatment of children's diabetes with use of continuous subcutaneous insulin infusion with personal insulin pumps is gaining more and more popularity. THE AIM OF THIS STUDY was the evaluation of IMT and FMD indexes in children suffering from type 1 diabetes in the context of treatment intensification (multidose insulin injections v. personal insulin pumps). We examined 64 children (29 boys and 35 girls) in the mean age 15.5 years treated with the multidose insulin injections method and 10 children using personal insulin pumps (4 girls and 6 boys) in the mean age 14.5 years. Using high resolution ultrasonography we evaluated IMT values in carotid arteries and FMD parameters in brachial arteries. In our analysis we estimated the blood concentration of lipid parameters, values of systolic and diastolic blood pressure, the age of diabetes onset, duration time of the illness and the values of HbA1c as a marker of metabolic control. We noticed significantly higher FMD values in patients treated with personal insulin pumps (13.7 vs. 5.5%, p=0.001). IMT values were similar in both groups (0.52 vs. 0.5 mm, p=0. 41). The level of HDL cholesterol was higher and triglycerides lower in the group with treatment intensification. The metabolic control was the same in both groups. In patients treated by the multidose insulin injections IMT correlated with systolic blood pressure values. We didn't notice any correlation between IMT and FMD in any group. 1. Treatment intensification (personal insulin pumps) influences better vascular

  19. Severe upper extremity polyneuropathy due to inferior brachial plexus compression as a result of left subclavian artery pseudoaneurism

    Directory of Open Access Journals (Sweden)

    George Kosmadakis

    2012-01-01

    Full Text Available In the present report, we describe the case of a 76-year-old hemodialysis patient who was admitted with clinical features of neurological thoracic exit syndrome due to subclavian artery pseudoaneurism following the insertion of a dual lumen vascular internal jugular catheter (vascath with excellent outcome after endo-arterial stent placement.

  20. Computational fluid dynamics comparisons of wall shear stress in patient-specific coronary artery bifurcation using coronary angiography and optical coherence tomography

    Science.gov (United States)

    Poon, Eric; Thondapu, Vikas; Chin, Cheng; Scheerlinck, Cedric; Zahtila, Tony; Mamon, Chris; Nguyen, Wilson; Ooi, Andrew; Barlis, Peter

    2016-11-01

    Blood flow dynamics directly influence biology of the arterial wall, and are closely linked with the development of coronary artery disease. Computational fluid dynamics (CFD) solvers may be employed to analyze the hemodynamic environment in patient-specific reconstructions of coronary arteries. Although coronary X-ray angiography (CA) is the most common medical imaging modality for 3D arterial reconstruction, models reconstructed from CA assume a circular or elliptical cross-sectional area. This limitation can be overcome with a reconstruction technique fusing CA with intravascular optical coherence tomography (OCT). OCT scans the interior of an artery using near-infrared light, achieving a 10-micron resolution and providing unprecedented detail of vessel geometry. We compared 3D coronary artery bifurcation models generated using CA alone versus OCT-angiography fusion. The model reconstructed from CA alone is unable to identify the detailed geometrical variations of diseased arteries, and also under-estimates the cross-sectional vessel area compared to OCT-angiography fusion. CFD was performed in both models under pulsatile flow in order to identify and compare regions of low wall shear stress, a hemodynamic parameter directly linked with progression of atherosclerosis. Supported by ARC LP150100233 and VLSCI VR0210.

  1. Derivation and validation of REASON: a risk score identifying candidates to screen for peripheral arterial disease using ankle brachial index.

    Science.gov (United States)

    Ramos, Rafel; Baena-Díez, Jose Miguel; Quesada, Miquel; Solanas, Pascual; Subirana, Isaac; Sala, Joan; Alzamora, Maite; Forès, Rosa; Masiá, Rafel; Elosua, Roberto; Grau, María; Cordón, Ferran; Pera, Guillem; Rigo, Fernando; Martí, Ruth; Ponjoan, Anna; Cerezo, Carlos; Brugada, Ramon; Marrugat, Jaume

    2011-02-01

    The recommendation of screening with ankle brachial index (ABI) in asymptomatic individuals is controversial. The aims of the present study were to develop and validate a pre-screening test to select candidates for ABI measurement in the Spanish population 50-79 years old, and to compare its predictive capacity to current Inter-Society Consensus (ISC) screening criteria. Two population-based cross-sectional studies were used to develop (n = 4046) and validate (n = 3285) a regression model to predict ABI guidelines, and similar sensitivity. This resulted in fewer patients screened per diagnosis of ABI < 0.9 (10.6 vs. 8.75) and a lower proportion of the population aged 50-79 years candidate to ABI screening (63.3% vs. 55.0%). This model provides accurate ABI < 0.9 risk estimates for ages 50-79, with a better predictive capacity than that of ISC criteria. Its use could reduce possible harms and unnecessary work-ups of ABI screening as a risk stratification strategy in primary prevention of peripheral vascular disease. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  2. Improved brachial artery shear patterns and increased flow-mediated dilation after low-volume high-intensity interval training in type 2 diabetes.

    Science.gov (United States)

    Ghardashi Afousi, Alireza; Izadi, Mohammad Reza; Rakhshan, Kamran; Mafi, Farnoosh; Biglari, Soheil; Gandomkar Bagheri, Habibalah

    2018-06-22

    What is the central question of this study? Endothelial function is impaired because of increased oscillatory and retrograde shear in patients with type 2 diabetes. It is unclear whether low-volume high-intensity interval training and continuous moderate intensity exercise can modulate oscillatory and retrograde shear, blood flow and flow-mediated arterial dilation in these patients. What is the main finding and its importance? We found that low-volume high-intensity interval training, by increasing anterograde shear and decreasing retrograde shear and oscillatory index, can increase nitric oxide production and consequently result in increased flow-mediated dilation and outward arterial remodelling in patients with type 2 diabetes. Atherosclerosis in patients with type 2 diabetes is characterized by endothelial dysfunction associated with impaired flow-mediated dilation (FMD) and increases retrograde and oscillatory shear. The present study investigated endothelium-dependent vasodilation and shear rate in patients with type 2 diabetes at baseline and follow-up after 12 weeks of low-volume high-intensity interval training (LV-HIIT) or continuous moderate intensity training (CMIT). Seventy five sedentary patients with type 2 diabetes and untreated pre- or stage I hypertension were randomly divided into LV-HIIT, CMIT and control groups. The LV-HIIT group intervention was 12 intervals of 1.5 min at 85%-90% HR max and 2 min at 55%-60% HR max . The CMIT group intervention was 42 min of exercise at 70% HR max for 3 sessions per week during 12 weeks. High-resolution Doppler ultrasound was used to measure FMD, arterial diameter, anterograde and retrograde blood flow and shear rate patterns. Brachial artery FMD increased significantly in the LV-HIIT group (3.83 ± 1.13 baseline, 7.39 ± 3.6% follow-up), whereas there were no significant increase in the CMIT group (3.45 ± 0.97 baseline, 4.81 ± 2.36% follow-up) compared to the control group (3.16 ± 0

  3. Effect of cocoa/chocolate ingestion on brachial artery flow-mediated dilation and its relevance to cardiovascular health and disease in humans.

    Science.gov (United States)

    Monahan, Kevin D

    2012-11-15

    Prospective studies indicate that high intake of dietary flavanols, such as those contained in cocoa/chocolate, are associated with reduced rates of cardiovascular-related morbidity and mortality in humans. Numerous mechanisms may underlie these associations such as favorable effects of flavanols on blood pressure, platelet aggregation, thrombosis, inflammation, and the vascular endothelium. The brachial artery flow-mediated dilation (FMD) technique has emerged as a robust method to quantify endothelial function in humans. Collectively, the preponderance of evidence indicates that FMD is a powerful surrogate measure for firm cardiovascular endpoints, such as cardiovascular-related mortality, in humans. Thus, literally thousands of studies have utilized this technique to document group differences in FMD, as well as to assess the effects of various interventions on FMD. In regards to the latter, numerous studies indicate that both acute and chronic ingestion of cocoa/chocolate increases FMD in humans. Increases in FMD after cocoa/chocolate ingestion appear to be dose-dependent such that greater increases in FMD are observed after ingestion of larger quantities. The mechanisms underlying these responses are likely diverse, however most data suggest an effect of increased nitric oxide bioavailability. Thus, positive vascular effects of cocoa/chocolate on the endothelium may underlie (i.e., be linked mechanistically to) reductions in cardiovascular risk in humans. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Femoral Artery Atherosclerosis Is Associated With Physical Function Across the Spectrum of the Ankle-Brachial Index: The San Diego Population Study.

    Science.gov (United States)

    Wassel, Christina L; Ellis, Alicia M; Suder, Natalie C; Barinas-Mitchell, Emma; Rifkin, Dena E; Forbang, Nketi I; Denenberg, Julie O; Marasco, Antoinette M; McQuaide, Belinda J; Jenny, Nancy S; Allison, Matthew A; Ix, Joachim H; Criqui, Michael H

    2017-07-20

    The ankle-brachial index (ABI) is inadequate to detect early-stage atherosclerotic disease, when interventions to prevent functional decline may be the most effective. We determined associations of femoral artery atherosclerosis with physical functioning, across the spectrum of the ABI, and within the normal ABI range. In 2007-2011, 1103 multiethnic men and women participated in the San Diego Population Study, and completed all components of the summary performance score. Using Doppler ultrasound, superficial and common femoral intima media thickness and plaques were ascertained. Logistic regression was used to assess associations of femoral atherosclerosis with the summary performance score and its individual components. Models were adjusted for demographics, lifestyle factors, comorbidities, lipids, and kidney function. In adjusted models, among participants with a normal-range ABI (1.00-1.30), the highest tertile of superficial intima media thickness was associated with lower odds of a perfect summary performance score of 12 (odds ratio=0.56 [0.36, 0.87], P =0.009), and lower odds of a 4-m walk score of 4 (0.34 [0.16, 0.73], P =0.006) and chair rise score of 4 (0.56 [0.34, 0.94], P =0.03). Plaque presence (0.53 [0.29, 0.99], P =0.04) and greater total plaque burden (0.61 [0.43, 0.87], P =0.006) were associated with worse 4-m walk performance in the normal-range ABI group. Higher superficial intima media thickness was associated with lower summary performance score in all individuals ( P =0.02). Findings suggest that use of femoral artery atherosclerosis measures may be effective in individuals with a normal-range ABI, especially, for example, those with diabetes mellitus or a family history of peripheral artery disease, when detection can lead to earlier intervention to prevent functional declines and improve quality of life. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  5. Association of Far-Infrared Radiation Therapy and Ankle-Brachial Index of Patients on Hemodialysis with Peripheral Artery Occlusive Disease.

    Science.gov (United States)

    Chen, Szu-Chia; Lee, Mei-Yueh; Huang, Jiun-Chi; Kuo, I-Ching; Mai, Hsiu-Chin; Kuo, Po-Lin; Chang, Jer-Ming; Hwang, Shang-Jyh; Chen, Hung-Chun

    2016-01-01

    Background and Aim: The ankle-brachial index (ABI) is recognized to be a good marker for atherosclerosis, and is useful in the diagnosis of peripheral artery occlusive disease (PAOD) which is prevalent among patients on hemodialysis (HD). Methods: This randomized trial aimed to evaluate the effect of far-infrared radiation (FIR) therapy on ABI in HD patients with PAOD. PAOD was defined as patients with ABI < 0.95. One hundred and eight HD patients were enrolled, including 50 in the control group and 58 in the FIR group. A WS TY101 FIR emitter was applied for 40 minutes during each HD session, three times per week for six months. The ABI was measured before and after the FIR therapy. Results: Regardless of FIR therapy, the bilateral ABI decreased (in the FIR group, left: 0.88±0.22 to 0.85±0.24, p = 0.188; right: 0.92±0.20 to 0.90±0.23, p = 0.372; in control group, left: 0.91±0.23 to 0.88±0.21, p = 0144; right: 0.93±0.17 to 0.89±0.21, p = 0.082). Multivariate logistic analysis of the FIR group revealed that high uric acid (odds ratio [OR]: 2.335; 95% confidence interval [CI]: 1.117-4.882; p =0.024) and aspirin use (OR: 16.463; 95% CI: 1.787-151.638; p =0.013) were independently associated with increased bilateral ABI after FIR therapy. Conclusions: This study demonstrates that ABI is not increased after FIR therapy in HD patients with PAOD. However, in the FIR group, patients with higher uric acid level or those who used aspirin have increased bilateral ABI after FIR therapy.

  6. High Central Aortic Rather than Brachial Blood Pressure is Associated with Carotid Wall Remodeling and Increased Arterial Stiffness in Childhood.

    Science.gov (United States)

    Peluso, Gonzalo; García-Espinosa, Victoria; Curcio, Santiago; Marota, Marco; Castro, Juan; Chiesa, Pedro; Giachetto, Gustavo; Bia, Daniel; Zócalo, Yanina

    2017-03-01

    In adults, central blood pressure (cBP) is reported to associate target organ damages (TODs) rather than peripheral blood pressure (pBP). However, data regarding the association of pre-clinical TODs with cBP and pBP in pediatric populations are scarce. To evaluate in children and adolescents the importance of cBP and pBP levels, in terms of their association with hemodynamic and vascular changes. 315 subjects [age (mean/range) 12/8-18 years] were included. pBP (oscillometry, Omron-HEM433INT and Mobil-O-Graph), cBP levels and waveforms (oscillometry, Mobil-O-Graph; applanation tonometry, SphygmoCor), aortic wave reflection-related parameters, carotid intima-media thickness (CIMT) and carotid (elastic modulus, stiffness-index) and aortic stiffness (carotid-femoral pulse wave velocity, PWV). Four groups were defined considering pBP and cBP percentiles (th): cBP ≥90th, cBP th, pBP ≥90th, pBP th. In each group, haemodynamic and vascular parameters were compared for subgroups defined considering the level of the remaining blood pressure (cBP or pBP). Subgroups were matched for anthropometric and cardiovascular risk factors (propensity matching-score). Subjects with high cBP showed a worse cardiovascular risk profile in addition to worse peripheral hemodynamic conditions. The CIMT, carotid and aortic stiffness levels were also higher in those subjects. CIMT and carotid stiffness remained statistically higher when subjects were matched for pBP and other cardiovascular risk factors. There were no differences in arterial properties when subjects were analyzed (compared) considering similar pBP levels, during normal and high cBP conditions. Compared with pBP, the cBP levels show a greater association with vascular alterations (high CIMT and arterial stiffness), in children and adolescents.

  7. Brachial Plexus Injuries

    Science.gov (United States)

    ... Brachial Plexus Injuries Show More Show Less Search Disorders SEARCH SEARCH Definition Treatment Prognosis Clinical Trials Organizations Publications Definition The brachial plexus is a network of nerves that conducts signals from the spine to the shoulder, arm, ...

  8. Cuff-Based Oscillometric Central and Brachial Blood Pressures Obtained Through ABPM are Similarly Associated with Renal Organ Damage in Arterial Hypertension

    Directory of Open Access Journals (Sweden)

    Patricia Fernández-Llama

    2017-12-01

    Full Text Available Background/Aims: Central blood pressure (BP has been suggested to be a better estimator of hypertension-associated risks. We aimed to evaluate the association of 24-hour central BP, in comparison with 24-hour peripheral BP, with the presence of renal organ damage in hypertensive patients. Methods: Brachial and central (calculated by an oscillometric system through brachial pulse wave analysis office BP and ambulatory BP monitoring (ABPM data and aortic pulse wave velocity (PWV were measured in 208 hypertensive patients. Renal organ damage was evaluated by means of the albumin to creatinine ratio and the estimated glomerular filtration rate. Results: Fifty-four patients (25.9% were affected by renal organ damage, displaying either microalbuminuria (urinary albumin excretion ≥30 mg/g creatinine or an estimated glomerular filtration rate (eGFR <60 ml/min/1.73 m2. Compared to those without renal abnormalities, hypertensive patients with kidney damage had higher values of office brachial systolic BP (SBP and pulse pressure (PP, and 24-h, daytime, and nighttime central and brachial SBP and PP. They also had a blunted nocturnal decrease in both central and brachial BP, and higher values of aortic PWV. After adjustment for age, gender, and antihypertensive treatment, only ABPM-derived BP estimates (both central and brachial showed significant associations with the presence of renal damage. Odds ratios for central BP estimates were not significantly higher than those obtained for brachial BP. Conclusion: Compared with peripheral ABPM, cuff-based oscillometric central ABPM does not show a closer association with presence of renal organ damage in hypertensive patients. More studies, however, need to be done to better identify the role of central BP in clinical practice.

  9. Cuff-Based Oscillometric Central and Brachial Blood Pressures Obtained Through ABPM are Similarly Associated with Renal Organ Damage in Arterial Hypertension.

    Science.gov (United States)

    Fernández-Llama, Patricia; Pareja, Júlia; Yun, Sergi; Vázquez, Susana; Oliveras, Anna; Armario, Pedro; Blanch, Pedro; Calero, Francesca; Sierra, Cristina; de la Sierra, Alejandro

    2017-01-01

    Central blood pressure (BP) has been suggested to be a better estimator of hypertension-associated risks. We aimed to evaluate the association of 24-hour central BP, in comparison with 24-hour peripheral BP, with the presence of renal organ damage in hypertensive patients. Brachial and central (calculated by an oscillometric system through brachial pulse wave analysis) office BP and ambulatory BP monitoring (ABPM) data and aortic pulse wave velocity (PWV) were measured in 208 hypertensive patients. Renal organ damage was evaluated by means of the albumin to creatinine ratio and the estimated glomerular filtration rate. Fifty-four patients (25.9%) were affected by renal organ damage, displaying either microalbuminuria (urinary albumin excretion ≥30 mg/g creatinine) or an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m2. Compared to those without renal abnormalities, hypertensive patients with kidney damage had higher values of office brachial systolic BP (SBP) and pulse pressure (PP), and 24-h, daytime, and nighttime central and brachial SBP and PP. They also had a blunted nocturnal decrease in both central and brachial BP, and higher values of aortic PWV. After adjustment for age, gender, and antihypertensive treatment, only ABPM-derived BP estimates (both central and brachial) showed significant associations with the presence of renal damage. Odds ratios for central BP estimates were not significantly higher than those obtained for brachial BP. Compared with peripheral ABPM, cuff-based oscillometric central ABPM does not show a closer association with presence of renal organ damage in hypertensive patients. More studies, however, need to be done to better identify the role of central BP in clinical practice. © 2017 The Author(s). Published by S. Karger AG, Basel.

  10. Models of brachial to finger pulse wave distortion and pressure decrement

    NARCIS (Netherlands)

    Gizdulich, P.; Prentza, A.; Wesseling, K.H.

    1997-01-01

    Objective: To model the pulse wave distortion and pressure decrement occurring between brachial and finger arteries. Distortion reversion and decrement correction were also our aims. Methods: Brachial artery pressure was recorded intra-arterially and finger pressure was recorded non-invasively by

  11. Right brachial angiography with compression

    International Nuclear Information System (INIS)

    Ruggiero, G.; Dalbuono, S.; Tampieri, D.

    1982-01-01

    A technique for performing right brachial anigography by compressing the right anterior-inferior part of the neck is proposed, as a result of studying the left carotid circulation without puncturing the left carotid artery. A success was obtained in about 75% of cases. The success of the technique depends mainly on the anatomical nature of the innominate artery. When the technique is successful both left carotid arteries in the neck and their intracranial branches can be satisfactorily visualized. In some cases visualization of the left vertebral artery was also otbained. Attention is drawn also on the increased diagnostic possibilities of studying the vessels in the neck with a greater dilution of the contrast medium. (orig.)

  12. Dynamic Bifurcations

    CERN Document Server

    1991-01-01

    Dynamical Bifurcation Theory is concerned with the phenomena that occur in one parameter families of dynamical systems (usually ordinary differential equations), when the parameter is a slowly varying function of time. During the last decade these phenomena were observed and studied by many mathematicians, both pure and applied, from eastern and western countries, using classical and nonstandard analysis. It is the purpose of this book to give an account of these developments. The first paper, by C. Lobry, is an introduction: the reader will find here an explanation of the problems and some easy examples; this paper also explains the role of each of the other paper within the volume and their relationship to one another. CONTENTS: C. Lobry: Dynamic Bifurcations.- T. Erneux, E.L. Reiss, L.J. Holden, M. Georgiou: Slow Passage through Bifurcation and Limit Points. Asymptotic Theory and Applications.- M. Canalis-Durand: Formal Expansion of van der Pol Equation Canard Solutions are Gevrey.- V. Gautheron, E. Isambe...

  13. Angiographic follow-up after carotid artery stenting of bifurcation stenosis; Angiographische Verlaufskontrolle nach Stentimplantation zur Behandlung der Karotisbifurkationsstenose

    Energy Technology Data Exchange (ETDEWEB)

    Hauth, E.A.; Forsting, M. [Inst. fuer Diagnostische und Interventionelle Radiologie und Neuroradiologie, Universitaetsklinik Essen (Germany); Jansen, C.; Drescher, R.; Mathias, K. [Radiologische Klinik, Klinikum Dortmund (Germany); Schwarz, M. [Neurologische Klinik, Klinikum Dortmund (Germany); Christmann, A. [Fachbereich Statistik, Univ. Dortmund (Germany); Jaeger, H. [Radiologische Klinik, Klinikum Dortmund (Germany); Marien-Hospital Wesel, Praxis fuer Radiologie, Neuroradiologie and Nuklearmedizin (Germany)

    2006-08-15

    Purpose: the purpose of this prospective study was to determine the restenosis grade, the intima hyperplasia and the stent expansion via angiographic follow-up six months after carotid artery stenting. Materials and methods: in 100 patients, angiographic follow-up was performed 5.9 months (range: 2.9 - 11.4 months) after carotid artery stenting. The restenosis grade, the intima hyperplasia and the stent expansion were measured by selective angiography of the treated carotid artery. Results: the mean restenosis grade was 16% (range: 0 - 78%). In 6 of 100 patients (6%), a restenosis grade of > 50% was measured. In 4 patients the restenosis grade was 50 - 70%. In 2 patients the restenosis grade was > 70%. In 91 of 100 patients (91%), the restenosis was localized in the former area of stenosis of the carotid artery, and in 9 of 100 patients (9%), the restenosis was localized in the cranial stent end. The mean grade of intima hyperplasia was 31% (range: 2 - 70%). The mean increase in stent expansion at the time of follow-up was 10% (range: 0 - 59%). No correlation was able to be determined between the grade of stenosis and the grade of restenosis (rho = 0,017, range: -0.180 - 0.213), between the grade of residual stenosis and the grade of restenosis (rho = 0,257, range: 0.064 - 0.431) and between intima hyperplasia and the grade of restenosis (rho = 0,476, range: 0.309 - 0.615). Conclusions: carotid artery stenting is associated with a low incidence of high-grade restenosis 6 months after an intervention. The intima hyperplasia, which can be observed in each Wallstent, is partly compensated by the expansion of the self-expandable stent. Without a correlation between the grade of residual stenosis and the grade of restenosis, low-grade residual stenosis can be accepted. Therefore, we recommend undersized postdilation of the Wallstent. (orig.)

  14. Hybrid treatment of tandem, common carotid/innominate artery and ipsilateral carotid bifurcation stenoses by simultaneous, retrograde proximal stenting and eversion carotid endarterectomy: Preliminary results of a case series.

    Science.gov (United States)

    Illuminati, Giulio; Pizzardi, Giulia; Pasqua, Rocco; Frezzotti, Francesca; Palumbo, Piergaspare; Macrina, Francesco; Calio', Francesco

    2018-04-01

    Tandem stenoses of the internal carotid artery (ICA) and proximal, ipsilateral common carotid artery (CCA) or innominate artery can be treated with a hybrid approach, combining conventional carotid endarterectomy (CEA) and retrograde stenting of the proximal stenosis, through surgical exposure of the carotid bifurcation. The purpose of this study was to evaluate the results of combining eversion CEA with retrograde CCA/innominate artery stenting. From January 2015 to July 2017, 7 patients, 6 men of a mean age of 72 years (range 59-83 years) underwent simultaneous, retrograde stenting of the proximal CCA/innominate artery and an eversion CEA of the ipsilateral ICA, through surgical exposure of the carotid bifurcation, for severe tandem stenoses. The proximal stenosis involved the left proximal CCA in 4 patients, the proximal innominate artery in 2 patients and the right CCA in one patient. The procedure was performed under general anesthesia in a conventional operating room equipped with a mobile C-arm. A covered, balloon expandable stent was deployed over the proximal stenosis via a 6-F sheath directly introduced into the proximal CCA through the obliquely transected carotid bulb. After removing the sheath, debris were flushed through the carotid bulb and eversion CEA completed the procedure. Study endpoints were: postoperative stroke/mortality rate, cardiac mortality and morbidity, peripheral nerve injury, cervical hematoma, overall late survival, freedom from ipsilateral stroke and patency of arterial reconstruction. No postoperative mortality or neurologic morbidity was observed in any patient. Cervical hematomas and peripheral nerve injuries were likewise absent. At a mean follow-up of 18 months, all the patients were alive, free from neurologic events of new onset and free from restenosis. Combined proximal stenting and eversion CEA for tandem lesions seems a valid treatment, with the advantages of eversion CEA over other techniques of carotid bifurcation

  15. Assessing the perceived quality of brachial artery Flow Mediated Dilation studies for inclusion in meta-analyses and systematic reviews: Description of data employed in the development of a scoring ;tool based on currently accepted guidelines

    Directory of Open Access Journals (Sweden)

    Arno Greyling

    2016-09-01

    Full Text Available Brachial artery Flow Mediated Dilation (FMD is widely used as a non-invasive measure of endothelial function. Adherence to expert consensus guidelines on FMD measurement has been found to be of vital importance to obtain reproducible data. This article lists the literature data which was considered in the development of a tool to aid in the objective judgement of the extent to which published studies adhered to expert guidelines for FMD measurement. Application of this tool in a systematic review of FMD studies (http://dx.doi.org/10.1016/j.atherosclerosis.2016.03.011 (Greyling et al., 2016 [1] indicated that adherence to expert consensus guidelines is strongly correlated to the reproducibility of FMD data. Keywords: Cardiovascular disease, Atherosclerosis, Endothelial function, Reproducibility, Methodology

  16. HIGH ORIGIN OF SUPERFICIAL ULNAR ARTERY- A CASE REPORT

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    Anjana Jayakumaran Nair

    2017-03-01

    Full Text Available BACKGROUND High origin and superficially placed ulnar artery is a rare anatomical variant that usually arises either in the axilla or arm and runs a superficial course in the forearm, enters the hand and participates in the formation of superficial palmar arch. During routine dissection of cadavers in our department, we observed a unilateral case of high origin and superficial ulnar artery in a human male cadaver. It originated from the brachial artery in the lower third of arm 4 cm above its bifurcation. From its origin, it passed downwards along the medial aspect of forearm, superficial to the flexors, entered hand superficial to the flexor retinaculum and formed superficial palmar arch. The knowledge of existence of a superficial ulnar artery is important during vascular and reconstructive surgery and also in evaluation of angiographic images. Superficial position makes it more vulnerable to trauma and more accessible to cannulation.

  17. Analysis of Surgical Freedom Variation Across the Basilar Artery Bifurcation: Towards a Deeper Insight Into Approach Selection for Basilar Apex Aneurysms.

    Science.gov (United States)

    Tayebi Meybodi, Ali; Benet, Arnau; Rodriguez Rubio, Roberto; Yousef, Sonia; Lawton, Michael T

    2018-03-03

    The orbitozygomatic approach is generally advocated over the pterional approach for basilar apex aneurysms. However, the impact of the extensions of the pterional approach on the obtained maneuverability over multiple vascular targets (relevant to basilar apex surgery) has not been studied before. To analyze the patterns of surgical freedom change across the basilar bifurcation between the pterional, orbitopterional, and orbitozygomatic approaches. Surgical freedom was assessed for 3 vascular targets important in basilar apex aneurysm surgery (ipsilateral and contralateral P1-P2 junctions, and basilar apex), and compared between the pterional, orbitopterional, and orbitozygomatic approaches in 10 cadaveric specimens. Transitioning from the pterional to orbitopterional approach, the surgical freedom increased significantly at all 3 targets (P < .05). However, the gain in surgical freedom declined progressively from the most superficial target (60% for ipsilateral P1-P2 junction) to the deepest target (35% for contralateral P1-P2 junction). Conversely, transitioning from the orbitopterional to the orbitozygomatic approach, the gain in surgical freedom was minimal for the ipsilateral P1-P2 and basilar apex (<4%), but increased dramatically to 19% at the contralateral P1-P2 junction. The orbitopterional approach provides a remarkable increase in surgical maneuverability compared to the pterional approach for the basilar apex target and the relevant adjacent arterial targets. However, compared to the orbitopterional, the orbitozygomatic approach adds little maneuverability except for the deepest target (ie, contralateral P1-P2 junction). Therefore, the orbitozygomatic approach may be most efficacious with larger basilar apex aneurysms limiting the control over of the contralateral P1 PCA.

  18. The effect of an apple polyphenol extract rich in epicatechin and flavan-3-ol oligomers on brachial artery flow-mediated vasodilatory function in volunteers with elevated blood pressure.

    Science.gov (United States)

    Saarenhovi, Maria; Salo, Pia; Scheinin, Mika; Lehto, Jussi; Lovró, Zsófia; Tiihonen, Kirsti; Lehtinen, Markus J; Junnila, Jouni; Hasselwander, Oliver; Tarpila, Anneli; Raitakari, Olli T

    2017-10-27

    The primary aim of this study was to test the hypothesis that an orally ingested apple polyphenol extract rich in epicatechin and flavan-3-ol oligomers improves endothelium-dependent brachial artery flow-mediated vasodilatation (FMD) in volunteers with borderline hypertension. The secondary aim of the study was to test whether the investigational product would improve endothelium-independent nitrate-mediated vasodilatation (NMD). This was a single centre, repeated-dose, double-blind, placebo-controlled, crossover study in 60 otherwise healthy subjects (26 men, 34 women; aged 40-65 years) with borderline hypertension (blood pressure 130-139/85-89 mmHg) or unmedicated mild hypertension (blood pressure 140-165/90-95 mmHg). The subjects were randomised to receive placebo or the apple polyphenol extract to provide a daily dose of 100 mg epicatechin for 4 weeks, followed by a four to five-week wash-out period, and then 4 weeks intake of the product that they did not receive during the first treatment period. FMD and NMD of the left brachial artery were investigated with ultrasonography at the start and end of both treatment periods, and the per cent increase of the arterial diameter (FMD% and NMD%) was calculated. With the apple extract treatment, a significant acute improvement was detected in the mean change of maximum FMD% at the first visit 1.16 (p = 0.04, 95% CI: 0.04; 2.28), last visit 1.37 (p = 0.02, 95% CI: 0.22; 2.52) and for both visits combined 1.29 (p effect of apple extract on FMD% was not different from placebo. No statistically significant differences between the apple extract and placebo treatments were observed for endothelium-independent NMD. A significant acute improvement in maximum FMD% with apple extract administration was found. However, superiority of apple extract over placebo was not statistically significant in our study subjects with borderline hypertension or mild hypertension. The study raised no safety concerns regarding the

  19. Anomalies of radial and ulnar arteries

    Directory of Open Access Journals (Sweden)

    Rajani Singh

    Full Text Available Abstract During dissection conducted in an anatomy department of the right upper limb of the cadaver of a 70-year-old male, both origin and course of the radial and ulnar arteries were found to be anomalous. After descending 5.5 cm from the lower border of the teres major, the brachial artery anomalously bifurcated into a radial artery medially and an ulnar artery laterally. In the arm, the ulnar artery lay lateral to the median nerve. It followed a normal course in the forearm. The radial artery was medial to the median nerve in the arm and then, at the level of the medial epicondyle, it crossed from the medial to the lateral side of the forearm, superficial to the flexor muscles. The course of the radial artery was superficial and tortuous throughout the arm and forearm. The variations of radial and ulnar arteries described above were associated with anomalous formation and course of the median nerve in the arm. Knowledge of neurovascular anomalies are important for vascular surgeons and radiologists.

  20. A Unique Branching Pattern of the Axillary Artery: A Case Report

    OpenAIRE

    Bagoji, Ishwar B.; Hadimani, Gavishiddappa A.; Bannur, Balappa M.; Patil, B.G.; Bharatha, Ambadasu

    2013-01-01

    During routine dissection classes for under graduate students, we found a unique and unusual case regarding the anomalous branching in the third part of the axillary artery was terminated into subscapular arterial trunk, superficial brachial artery and deep brachial artery. The subscapular arterial trunk was origin of several important arteries as the circumflex scapular, thoracodorsal, posterior circumflex humeral, thoraco-acromial and lateral thoracic arteries. The deep brachial artery in t...

  1. Accuracy of Physical Examination, Ankle-Brachial Index, and Ultrasonography in the Diagnosis of Arterial Injury in Patients With Penetrating Extremity Trauma: A Systematic Review and Meta-analysis.

    Science.gov (United States)

    deSouza, Ian S; Benabbas, Roshanak; McKee, Sean; Zangbar, Bardiya; Jain, Ashika; Paladino, Lorenzo; Boudourakis, Leon; Sinert, Richard

    2017-08-01

    Penetrating Extremity Trauma (PET) may result in arterial injury, a rare but limb- and life-threatening surgical emergency. Timely, accurate diagnosis is essential for potential intervention in order to prevent significant morbidity. Using a systematic review/meta-analytic approach, we determined the utility of physical examination, Ankle-Brachial Index (ABI), and Ultrasonography (US) in the diagnosis of arterial injury in emergency department (ED) patients who have sustained PET. We applied a test-treatment threshold model to determine which evaluations may obviate CT Angiography (CTA). We searched PubMed, Embase, and Scopus from inception to November 2016 for studies of ED patients with PET. We included studies on adult and pediatric subjects. We defined the reference standard to include CTA, catheter angiography, or surgical exploration. When low-risk patients did not undergo the reference standard, trials must have specified that patients were observed for at least 24 hours. We used the Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS-2) to evaluate bias and applicability of the included studies. We calculated positive and negative likelihood ratios (LR+ and LR-) of physical examination ("hard signs" of vascular injury), US, and ABI. Using established CTA test characteristics (sensitivity = 96.2%, specificity = 99.2%) and applying the Pauker-Kassirer method, we developed a test-treatment threshold model (testing threshold = 0.14%, treatment threshold = 72.9%). We included eight studies (n = 2,161, arterial injury prevalence = 15.5%). Studies had variable quality with most at high risk for partial and double verification bias. Some studies investigated multiple index tests: physical examination (hard signs) in three studies (n = 1,170), ABI in five studies (n = 1,040), and US in four studies (n = 173). Due to high heterogeneity (I 2  > 75%) of the results, we could not calculate LR+ or LR- for hard signs or LR+ for ABI. The weighted

  2. Central aortic systolic blood pressure can predict prolonged QTc duration better than brachial artery systolic blood pressure in rural community residents.

    Science.gov (United States)

    Huang, Yuqing; Tang, Songtao; Chen, Ji-Yan; Huang, Cheng; Li, Jie; Cai, An-Ping; Feng, Yingqing

    2018-01-01

    Previous studies have suggested that prolonged electrocardiogram QTc duration was independent risk factor for both increased cardiovascular and all-cause mortality, but there was no dating about the relationship between central aortic systolic blood pressure (CASP) and QTc duration. The aim of this study was to analyze the relationship between CASP and QTc duration, and assess whether CASP can predict prolonged QTc duration more than BSBP. A total of 500 patients were enrolled in this study, central and brachial aortic blood pressure and electrocardiogram QTc duration were measured. Pearson correlation was assessed for determining the associations of QTc duration with clinical conditions. Multivariate logistic regression analyses were performed to determine the independent predictor of prolonged QTc duration. Receiver operating characteristic (ROC) curve was used to evaluate the utility of blood pressure for prolonged QTc duration. We found QTc durations were significantly positive with CASP (r = 0.308, p AUC: 0.771 vs. 0.646, p < 0.001) BSBP. Our results suggested that the non-invasive CASP is independently correlated with QTc duration, and CASP can predict prolonged QTc duration more than BSBP.

  3. Use of a Novel Abdominal Aortic and Junctional Tourniquet to Reduce or Eliminate Flow in the Brachial and Popliteal Arteries in Human Subjects.

    Science.gov (United States)

    Lyon, Matthew; Johnson, Daniel; Gordon, Richard

    2015-01-01

    Penetrating injuries of the proximal large arteries are a common cause of death on the battlefield due to rapid exsanguination. Applying an effective tourniquet to stop bleeding at the axillary and proximal femoral arteries (junctional sites) is difficult. Prior studies have shown that the Abdominal Aortic and Junctional Tourniquet (AAJT) effectively reduced blood flow in the common femoral artery with application of the device around the lower abdomen. Our objective was to determine the effectiveness of the AAJT to stop blood flow in the proximal femoral artery (PFA), and the axillary artery (AA). This was a prospective observational trial using human volunteers. The AAJT consists of a wedge-shaped bladder and integrated strap. The bladder has an integrated manometer, which is used to measure the pressure in the bladder. For the AA, the AAJT was placed over the axillary junction at the anterior axillary line with the strap placed across the contralateral shoulder. For the PFA, the AAJT bladder was placed over the right groin with the strap positioned across both femoral trochanters. Spectral Doppler measurements were taken of the PFA and AA at baseline and as the bladder was inflated. Collected data included pressure of the AAJT.

  4. Accidental Coverage of Both Renal Arteries during Infrarenal Aortic Stent-Graft Implantation: Cause and Treatment

    Directory of Open Access Journals (Sweden)

    Umberto Marcello Bracale

    2014-01-01

    Full Text Available The purpose of this paper is to report a salvage maneuver for accidental coverage of both renal arteries during endovascular aneurysm repair (EVAR of an infrarenal abdominal aortic aneurysm (AAA. A 72-year-old female with a 6 cm infrarenal abdominal aortic aneurysm was treated by endovascular means with a standard bifurcated graft. Upon completing an angiogram, both renal arteries were found to be accidentally occluded. Through a left percutaneous brachial approach, the right renal artery was catheterized and a chimney stent was deployed; however this was not possible for the left renal artery. A retroperitoneal surgical approach was therefore carried out with a retrograde chimney stent implanted to restore blood flow. After three months, both renal arteries were patent and renal function was not different from the baseline. Both endovascular with percutaneous access via the brachial artery and open retroperitoneal approaches with retrograde catheterization are feasible rescue techniques to recanalize the accidentally occluded renal arteries during EVAR.

  5. Growth hormone (GH) and atherosclerosis: changes in morphology and function of major arteries during GH treatment.

    Science.gov (United States)

    Pfeifer, M; Verhovec, R; Zizek, B

    1999-04-01

    Patients with hypopituitarism have increased carotid artery intima-media thickness and reduced arterial distensibility. The effect of 2 years of growth hormone (GH) replacement therapy on these parameters was studied in 11 GH-deficient men (age range, 24-49 years) with hypopituitarism and compared with 12 healthy, age-matched men with no evidence of pituitary or vascular disease. Before treatment the intima-media of the common carotid arteries and the carotid bifurcations were significantly thicker in patients (P < 0.001) than in the control group. Treatment with GH normalized the intima-media thickness of the common carotid artery within 6 months and of the carotid bifurcation within 3 months. The changes in intima-media thickness of the carotid artery were negatively correlated with changes in serum levels of insulin-like growth factor I during treatment. There was a significant improvement in flow-mediated, endothelium-dependent dilation of the brachial artery at 3 months, which was sustained at 6, 18 and 24 months of GH treatment (P < 0.05). Thus, GH replacement therapy in GH-deficient men reverses early morphological and functional atherosclerotic changes in major arteries, and may reduce rates of vascular morbidity and mortality.

  6. Brachial Plexus Blocker Prototype

    OpenAIRE

    Stéphanie Coelho Monteiro

    2017-01-01

    Although the area of surgical simulation has been the subject of study in recent years, it is still necessary to develop artificial experimental models with a perspective to dismiss the use of biological models. Since this makes the simulators more real, transferring the environment of the health professional to a physical or virtual reality, an anesthetic prototype has been developed, where the motor response is replicated when the brachial plexus is subjected to a proximal nervous stimulus....

  7. Peripheral artery disease assessed by ankle-brachial index in patients with established cardiovascular disease or at least one risk factor for atherothrombosis - CAREFUL Study: A national, multi-center, cross-sectional observational study

    Directory of Open Access Journals (Sweden)

    Tabak Omur

    2011-01-01

    Full Text Available Abstract Background To investigate the presence of peripheral artery disease (PAD via the ankle brachial index (ABI in patients with known cardiovascular and/or cerebrovascular diseases or with at least one risk factor for atherothrombosis. Methods Patients with a history of atherothrombotic events, or aged 50-69 years with at least one cardiovascular risk factor, or > = 70 years of age were included in this multicenter, cross-sectional, non-interventional study (DIREGL04074. Demographics, medical history, physical examination findings, and physician awareness of PAD were analyzed. The number of patients with low ABI ( Results A total of 530 patients (mean age, 63.4 ± 8.7 years; 50.2% female were enrolled. Hypertension and dyslipidemia were present in 88.7% and 65.5% of patients, respectively. PAD-related symptoms were evident in about one-third of the patients, and at least one of the pedal pulses was negative in 6.5% of patients. The frequency of low ABI was 20.0% in the whole study population and 30% for patients older than 70 years. Older age, greater number of total risk factors, and presence of PAD-related physical findings were associated with increased likelihood of low ABI (p Conclusion Our results indicate that advanced age, greater number of total risk factors and presence of PAD-related physical findings were associated with increased likelihood of low ABI. These findings are similar to those reported in similar studies of different populations, and document a fairly high prevalence of PAD in a Mediterranean country.

  8. Pitfalls in the ankle-brachial index and brachial-ankle pulse wave velocity

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    Ato D

    2018-04-01

    Full Text Available Dai Ato Gakujutsu Shien Co., Ltd., Tokyo, Japan Background: The ankle-brachial index (ABI and pulse wave velocity (PWV are indices of atherosclerosis and arterial stiffness. The Japan-made measuring devices of those indices have spread widely because of their convenience and the significance of the parameters. However, studies that comprehensively discuss the various pitfalls in using these indices are not available.Methods: This study presents several representative pitfalls in using the ABI and brachial-ankle PWV (baPWV by showing the result sheets of the device, “the Vascular Profiler”. Furthermore, some considerations when utilizing these indices in the future are also discussed.Results: Several diseases such as arteriosclerosis obliterans (ASO, arterial calcification in the lower limb, arterial stenosis in the right upper-limb, aortic valve diseases, arterial stenosis in the upper-limb of the contralateral side of the hemodialysis access, are the representative pitfalls when evaluating ABI and baPWV. Moreover, a measurement error is found to actually exist. Furthermore, same phenomena are considered most likely to occur when using other similar indices and devices.Conclusion: The ABI and baPWV are the useful and significant biomarkers. Nevertheless, caution is sometimes necessary when interpreting them. Moreover, rigorous patient exclusion criteria should be considered when using those indices in the severely conditioned patient population. And the results of this study can be applied to enhance the literacy using other indices, such as the cardio-ankle vascular index and other similar devices. Keywords: ankle-brachial index, pulse wave velocity, peripheral arterial disease, aortic valve disease, hemodialysis

  9. Adult traumatic brachial plexus injury

    International Nuclear Information System (INIS)

    Rankine, J.J.

    2004-01-01

    Injury to the brachial plexus in the adult is usually a closed injury and the result of considerable traction to the shoulder. Brachial plexus injury in the adult is an increasingly common clinical problem. Recent advances in neurosurgical techniques have improved the outlook for patients with brachial plexus injuries. The choice of surgical procedure depends on the level of the injury and the radiologist has an important role in guiding the surgeon to the site of injury. This article will describe the anatomy and pathophysiology of traction brachial plexus injury in the adult. The neurosurgical options available will be described with emphasis on the information that the surgeon wants from imaging studies of the brachial plexus. The relative merits of MRI and CT myelography are discussed

  10. Brachial index does not reflect upper extremity functionality following surgery for vascular trauma

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    Erdal Simsek

    2014-04-01

    Full Text Available OBJECTIVES: Vascular injuries to the upper extremities requiring surgical repair are common after accidents. However, neither postoperative functionality nor hemodynamic status of the extremity are routinely described. We evaluated the postoperative functional and hemodynamic status of patients with vascular traumas in the upper extremities. METHODS: 26 patients who suffered penetrating vascular traumas in the upper extremities from November 2008 to December 2011 were retrospectively evaluated. Data on first approach, surgical technique employed and early postoperative outcomes were recorded. Further data on the post-discharge period, including clinical functional status of the arm, Doppler ultrasonography and brachial-brachial index were also evaluated. RESULTS: Average follow up was 33.5±10.8 months. Right (1.05±0.09 and left (1.04±0.08 brachial indexes were measured during follow up,. Doppler ultrasonography showed arterial occlusion in 4 patients (15%. Near-normal brachial-brachial indexes was observed in all four of these patients with occlusion of one of the upper extremity arteries, even though they exhibited limited arm function for daily work. CONCLUSIONS: Evaluation of the postoperative outcomes of this small series of patients with penetrating vascular traumas in the upper extremity revealed that 15% of them suffered occlusion of one artery of the upper extremity. Artery occlusion did not correlate with brachial-brachial Doppler index, probably due to rich collateral circulation, but occlusion was associated with an extremity that was dysfunctional for the purposes of daily work. The result of the brachial-brachial index does not therefore correlate with functionality.

  11. Relação anatômica entre o nervo hipoglosso e a bifurcação carotídea Anatomical relation between the hypoglossal nerve and the carotid artery bifurcation

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    Felipe S. G. Fortes

    to establish the anatomical relation between the carotid artery bifurcation and hypoglossal nerve. Study design: experimental. Material and method: Carotid artery and hypoglossal nerve dissections were carried out in 38 fresh corpses. All the individuals were placed in standard position and the dissections were performed with surgical technique. The measurements were done in centimeters and millimeters from the dissected carotid bifurcation to the XII nerve in the cervical area. Results: Twenty-six individuals were male and 12 female. The majority were whites, 30, and 8 were non-whites. The distance between hypoglossal nerve and carotid artery bifurcation ranged from 0.5 cm to 4.3 cm, with mean of 2.1 cm, median 2.0 cm and standard deviation of 0.63 cm. Neck length, age, gender and race were related with the measurements and failed to show significant statistic correlation (a > 0.05. Conclusion: In this sample there is a great anatomic variation of the distance between hypoglossal nerve and carotid artery bifurcation and there was no statistical difference concerning age, gender, race and neck length. A better understanding of the anatomic course of this nerve and its variation in relation to carotid artery bifurcation, are relevant to prevent hypoglossal nerve lesions in the carotid artery surgery.

  12. Unfolding the Riddling Bifurcation

    DEFF Research Database (Denmark)

    Maistrenko, Yu.; Popovych, O.; Mosekilde, Erik

    1999-01-01

    We present analytical conditions for the riddling bifurcation in a system of two symmetrically coupled, identical, smooth one-dimensional maps to be soft or hard and describe a generic scenario for the transformations of the basin of attraction following a soft riddling bifurcation.......We present analytical conditions for the riddling bifurcation in a system of two symmetrically coupled, identical, smooth one-dimensional maps to be soft or hard and describe a generic scenario for the transformations of the basin of attraction following a soft riddling bifurcation....

  13. Brachial Plexus Blocker Prototype

    Directory of Open Access Journals (Sweden)

    Stéphanie Coelho Monteiro

    2017-08-01

    Full Text Available Although the area of surgical simulation has been the subject of study in recent years, it is still necessary to develop artificial experimental models with a perspective to dismiss the use of biological models. Since this makes the simulators more real, transferring the environment of the health professional to a physical or virtual reality, an anesthetic prototype has been developed, where the motor response is replicated when the brachial plexus is subjected to a proximal nervous stimulus. Using action-research techniques, with this simulator it was possible to validate that the human nerve response can be replicated, which will aid the training of health professionals, reducing possible risks in a surgical environment.

  14. Double profunda brachii artery

    OpenAIRE

    Gavishiddappa A Hadimani; Jyoti V Hadimani; Ishwar B Bagoji; Shardha Bai Rathod; Balappa M Bannur

    2016-01-01

    Brachial artery (BA) is a continuation of the axillary artery at the lower border of teres major. In the cubital fossa, BA divides into radial artery and ulnar artery as terminal branches. Large branch given from the BA in the upper part is profunda brachii artery. In the present case, we noticed double profunda brachii that arises from the BA. They are profunda brachii artery 1 and profunda brachii artery 2. Profunda brachii artery 1 arises in the proximal part of the BA and profunda brachii...

  15. MR imaging of brachial plexus

    International Nuclear Information System (INIS)

    Carriero, A.; Ciccotosto, C.; Dragani, M.; Manes, L.; Bonomo, L.

    1991-01-01

    The brachial plexus is a difficult region to evaluate with radiological techniques. MR imaging has great potentials for the depiction of the various anatomical structures of the branchial plexus - i.e., spinal ganglion, ventral nerve rami root exit of the neural foramina, trunks an cordes. Moreover, MR imaging, thanks to its direct multiplanarity, to its excellent soft-tissue contrast, and to its lack of motion artifacts, allows good evaluation of pathologic conditions in the branchial plexus, especially traumas and cancers. On the contrary CT, in spite of its high spatial resolution and good contrast, cannot demonstrate the anatomical structures of the brachial plexus. US detects superficials structures, and conventional radiographs depict only indirect changes in the adjacent lung apex and skeletal structures. From November 1989 to May 1990, 20 normal volunteers (15 males and 5 females; average age: 35 years) were studied with MR imaging. Multisection technique was employed with a dedicated coil and a primary coil. The anatomical structures of the brachial plexus were clearly demonstrated by T1-weighted sequences on the sagittal and axial planes. T2-weighted pulse sequences on the coronal plane were useful for the anatomical definition of the brachial plexus and for eventual tissue characterization. The correct representation of the anatomical structures of the brachial plexus allowed by MR imaging with author's standard technique makes MR imaging the most appropriate exam for the diagnosis of pathologic conditions in the brachial plexus, although its use must be suggested by specific clinical questions

  16. Valve-Like and Protruding Calcified Intimal Flap Complicating Common Iliac Arteries Kissing Stenting

    Directory of Open Access Journals (Sweden)

    George S. Georgiadis

    2015-01-01

    Full Text Available Endovascular therapy for iliac artery chronic total occlusions is nowadays associated with low rates of procedure-related complications and improved clinical outcomes, and it is predominantly used as first-line therapy prior to aortobifemoral bypass grafting. Herein, we describe the case of a patient presenting with an ischemic left foot digit ulcer and suffering complex aortoiliac lesions, who received common iliac arteries kissing stents, illustrating at final antegrade and retrograde angiograms the early recognition of a blood flow obstructing valve-like calcified intimal flap protruding through the stent struts, which was obstructing antegrade but not retrograde unilateral iliac arterial axis blood flow. The problem was resolved by reconstructing the aortic bifurcation at a more proximal level. Completion angiogram verified normal patency of aorta and iliac vessels. Additionally, a severe left femoral bifurcation stenosis was also corrected by endarterectomy-arterioplasty with a bovine patch. Postintervention ankle brachial pressure indices were significantly improved. At the 6-month and 2-year follow-up, normal peripheral pulses were still reported without intermittent claudication suggesting the durability of the procedure. Through stent-protruding calcified intimal flap, is a very rare, but existing source of antegrade blood flow obstruction after common iliac arteries kissing stents.

  17. Relative Lyapunov Center Bifurcations

    DEFF Research Database (Denmark)

    Wulff, Claudia; Schilder, Frank

    2014-01-01

    Relative equilibria (REs) and relative periodic orbits (RPOs) are ubiquitous in symmetric Hamiltonian systems and occur, for example, in celestial mechanics, molecular dynamics, and rigid body motion. REs are equilibria, and RPOs are periodic orbits of the symmetry reduced system. Relative Lyapunov...... center bifurcations are bifurcations of RPOs from REs corresponding to Lyapunov center bifurcations of the symmetry reduced dynamics. In this paper we first prove a relative Lyapunov center theorem by combining recent results on the persistence of RPOs in Hamiltonian systems with a symmetric Lyapunov...... center theorem of Montaldi, Roberts, and Stewart. We then develop numerical methods for the detection of relative Lyapunov center bifurcations along branches of RPOs and for their computation. We apply our methods to Lagrangian REs of the N-body problem....

  18. Visualization and analysis of flow patterns of human carotid bifurcation by computational fluid dynamics

    International Nuclear Information System (INIS)

    Xue Yunjing; Gao Peiyi; Lin Yan

    2007-01-01

    Objective: To investigate flow patterns at carotid bifurcation in vivo by combining computational fluid dynamics (CFD)and MR angiography imaging. Methods: Seven subjects underwent contrast-enhanced MR angiography of carotid artery in Siemens 3.0 T MR. Flow patterns of the carotid artery bifurcation were calculated and visualized by combining MR vascular imaging post-processing and CFD. Results: The flow patterns of the carotid bifurcations in 7 subjects were varied with different phases of a cardiac cycle. The turbulent flow and back flow occurred at bifurcation and proximal of internal carotid artery (ICA) and external carotid artery (ECA), their occurrence and conformation were varied with different phase of a cardiac cycle. The turbulent flow and back flow faded out quickly when the blood flow to the distal of ICA and ECA. Conclusion: CFD combined with MR angiography can be utilized to visualize the cyclical change of flow patterns of carotid bifurcation with different phases of a cardiac cycle. (authors)

  19. Double profunda brachii artery

    Directory of Open Access Journals (Sweden)

    Gavishiddappa A Hadimani

    2016-01-01

    Full Text Available Brachial artery (BA is a continuation of the axillary artery at the lower border of teres major. In the cubital fossa, BA divides into radial artery and ulnar artery as terminal branches. Large branch given from the BA in the upper part is profunda brachii artery. In the present case, we noticed double profunda brachii that arises from the BA. They are profunda brachii artery 1 and profunda brachii artery 2. Profunda brachii artery 1 arises in the proximal part of the BA and profunda brachii artery 2 arises distal to the profunda brachii artery 1. Both the arteries run inferolaterally in the spiral groove along with radial nerve. Variations of profunda brachii artery are important during harvesting of the lateral arm flaps and may lead to inadvertent injury during percutaneous arterial catheterization or injection of drugs.

  20. Bifurcations of transition states: Morse bifurcations

    International Nuclear Information System (INIS)

    MacKay, R S; Strub, D C

    2014-01-01

    A transition state for a Hamiltonian system is a closed, invariant, oriented, codimension-2 submanifold of an energy level that can be spanned by two compact codimension-1 surfaces of unidirectional flux whose union, called a dividing surface, locally separates the energy level into two components and has no local recrossings. For this to happen robustly to all smooth perturbations, the transition state must be normally hyperbolic. The dividing surface then has locally minimal geometric flux through it, giving an upper bound on the rate of transport in either direction. Transition states diffeomorphic to S 2m−3 are known to exist for energies just above any index-1 critical point of a Hamiltonian of m degrees of freedom, with dividing surfaces S 2m−2 . The question addressed here is what qualitative changes in the transition state, and consequently the dividing surface, may occur as the energy or other parameters are varied? We find that there is a class of systems for which the transition state becomes singular and then regains normal hyperbolicity with a change in diffeomorphism class. These are Morse bifurcations. Various examples are considered. Firstly, some simple examples in which transition states connect or disconnect, and the dividing surface may become a torus or other. Then, we show how sequences of Morse bifurcations producing various interesting forms of transition state and dividing surface are present in reacting systems, by considering a hypothetical class of bimolecular reactions in gas phase. (paper)

  1. Renal denervation beyond the bifurcation: The effect of distal ablation placement on safety and blood pressure.

    Science.gov (United States)

    Beeftink, Martine M A; Spiering, Wilko; De Jong, Mark R; Doevendans, Pieter A; Blankestijn, Peter J; Elvan, Arif; Heeg, Jan-Evert; Bots, Michiel L; Voskuil, Michiel

    2017-04-01

    Renal denervation may be more effective if performed distal in the renal artery because of smaller distances between the lumen and perivascular nerves. The authors reviewed the angiographic results of 97 patients and compared blood pressure reduction in relation to the location of the denervation. No significant differences in blood pressure reduction or complications were found between patient groups divided according to their spatial distribution of the ablations (proximal to the bifurcation in both arteries, distal to the bifurcation in one artery and distal in the other artery, or distal to the bifurcation in both arteries), but systolic ambulatory blood pressure reduction was significantly related to the number of distal ablations. No differences in adverse events were observed. In conclusion, we found no reason to believe that renal denervation distal to the bifurcation poses additional risks over the currently advised approach of proximal denervation, but improved efficacy remains to be conclusively established. ©2017 Wiley Periodicals, Inc.

  2. Bifurcation with memory

    International Nuclear Information System (INIS)

    Olmstead, W.E.; Davis, S.H.; Rosenblat, S.; Kath, W.L.

    1986-01-01

    A model equation containing a memory integral is posed. The extent of the memory, the relaxation time lambda, controls the bifurcation behavior as the control parameter R is increased. Small (large) lambda gives steady (periodic) bifurcation. There is a double eigenvalue at lambda = lambda 1 , separating purely steady (lambda 1 ) from combined steady/T-periodic (lambda > lambda 1 ) states with T → infinity as lambda → lambda + 1 . Analysis leads to the co-existence of stable steady/periodic states and as R is increased, the periodic states give way to the steady states. Numerical solutions show that this behavior persists away from lambda = lambda 1

  3. Long-Term Results after Placement of Aortic Bifurcation Self-Expanding Stents: 10 Year Mortality, Stent Restenosis, and Distal Disease Progression

    International Nuclear Information System (INIS)

    Houston, J. Graeme; Bhat, Raj; Ross, Rose; Stonebridge, Peter A.

    2007-01-01

    Purpose. To retrospectively evaluate the 10 year follow-up results in patients who had 'kissing' self-expanding stent aortic bifurcation reconstruction. Methods. Forty-three patients were treated with 'kissing' self-expanding stents for aortoiliac occlusive disease. Early follow-up with clinical and ankle brachial pressure indices (ABPI) was performed at 3, 6, 12, and 24 months and with intra-arterial digital subtraction angiography at 12-24 months; clinical and angiographic follow-up was performed for symptom recurrence up to 10 years after treatment. Retrospective record review was performed to assess mortality, clinical patency, angiographic patency, and secondary assisted patency of both stents and downstream peripheral vessels at 5 and 10 years follow-up. Results. The 2 year primary angiographic and secondary assisted stent patencies were 89% and 93%, respectively. At 10 years follow-up in 40 patients the mortality was 38% (due to myocardial infarction, stroke, chronic renal failure, malignancy, and liver failure). At 5 and 10 years follow-up the primary clinical stent patency was 82% and 68%, and the secondary assisted stent patency 93% and 86%, respectively. At 5 and 10 years, the distal vessel patency was 86% and 72%, and the secondary assisted distal vessel patency treated by surgical or endovascular techniques was 94% and 88%, respectively. At 10 years there was no limb loss. Conclusion. The long-term (10 year) results of aortic bifurcation arterial self-expanding stent placement in patients with arterial occlusive disease show a 10 year primary stent patency rate of 68% but a secondary assisted patency rate of 86%. In addition there is a high overall mortality due to other cardiovascular causes and the rate of distal disease progression and loss of patency is similar to the loss of stent patency rate

  4. Stenting-plasty with brachial puncture in the treatment of subclavian steal syndrome

    International Nuclear Information System (INIS)

    Chen Quan; Jing Zaiping; Zhao Zhiqing; Feng Xiang; Lu Qingsheng; Mei Zhijun

    2007-01-01

    Objective: To study the clinical effect of stenting-plasty with retrograde brachial puncture for subclavian steal syndrome patients. Methods: To analyze the clinical results of stenting-plasty with retrograde brachial puncture in 15 patients with subclavian steal syndrome. Results: MRA or DSA showed the subclavian arteries with different degrees of stenosis (80%-100%) in all patients. Stenting-plasty with retrograde brachia] puncture was used in all patients. After placement of wall or polmaz stent, the pulse recovered and the syndrome disappeared. Postoperative angiography showed patency of the artery and stent. The patients were followed up for 3-30 months without recurrence of symptoms. Conclusions: Stenting-plasty with retrograde brachial puncture is a rather proper method to treat subclavian steal syndrome with more coincidence to the vascular anatomy, decrease the maneuver trouble and increase the successful rate. (authors)

  5. Energetics and monsoon bifurcations

    Science.gov (United States)

    Seshadri, Ashwin K.

    2017-01-01

    Monsoons involve increases in dry static energy (DSE), with primary contributions from increased shortwave radiation and condensation of water vapor, compensated by DSE export via horizontal fluxes in monsoonal circulations. We introduce a simple box-model characterizing evolution of the DSE budget to study nonlinear dynamics of steady-state monsoons. Horizontal fluxes of DSE are stabilizing during monsoons, exporting DSE and hence weakening the monsoonal circulation. By contrast latent heat addition (LHA) due to condensation of water vapor destabilizes, by increasing the DSE budget. These two factors, horizontal DSE fluxes and LHA, are most strongly dependent on the contrast in tropospheric mean temperature between land and ocean. For the steady-state DSE in the box-model to be stable, the DSE flux should depend more strongly on the temperature contrast than LHA; stronger circulation then reduces DSE and thereby restores equilibrium. We present conditions for this to occur. The main focus of the paper is describing conditions for bifurcation behavior of simple models. Previous authors presented a minimal model of abrupt monsoon transitions and argued that such behavior can be related to a positive feedback called the `moisture advection feedback'. However, by accounting for the effect of vertical lapse rate of temperature on the DSE flux, we show that bifurcations are not a generic property of such models despite these fluxes being nonlinear in the temperature contrast. We explain the origin of this behavior and describe conditions for a bifurcation to occur. This is illustrated for the case of the July-mean monsoon over India. The default model with mean parameter estimates does not contain a bifurcation, but the model admits bifurcation as parameters are varied.

  6. Impact of Age and Aerobic Exercise Training on Conduit Artery Wall Thickness: Role of the Shear Pattern.

    Science.gov (United States)

    Tanahashi, Koichiro; Kosaki, Keisei; Sawano, Yuriko; Yoshikawa, Toru; Tagawa, Kaname; Kumagai, Hiroshi; Akazawa, Nobuhiko; Maeda, Seiji

    2017-01-01

    Hemodynamic shear stress is the frictional force of blood on the arterial wall. The shear pattern in the conduit artery affects the endothelium and may participate in the development and progression of atherosclerosis. We investigated the role of the shear pattern in age- and aerobic exercise-induced changes in conduit artery wall thickness via cross-sectional and interventional studies. In a cross-sectional study, we found that brachial shear rate patterns and brachial artery intima-media thickness (IMT) correlated with age. Additionally, brachial artery shear rate patterns were associated with brachial artery IMT in 102 middle-aged and older individuals. In an interventional study, 39 middle-aged and older subjects were divided into 2 groups: control and exercise. The exercise group completed 12 weeks of aerobic exercise training. Aerobic exercise training significantly increased the antegrade shear rate and decreased the retrograde shear rate and brachial artery IMT. Moreover, changes in the brachial artery antegrade shear rate and the retrograde shear rate correlated with the change in brachial artery IMT. The results of the present study indicate that changes in brachial artery shear rate patterns may contribute to age- and aerobic exercise training-induced changes in brachial artery wall thickness. © 2017 S. Karger AG, Basel.

  7. Models of brachial to finger pulse wave distortion and pressure decrement.

    Science.gov (United States)

    Gizdulich, P; Prentza, A; Wesseling, K H

    1997-03-01

    To model the pulse wave distortion and pressure decrement occurring between brachial and finger arteries. Distortion reversion and decrement correction were also our aims. Brachial artery pressure was recorded intra-arterially and finger pressure was recorded non-invasively by the Finapres technique in 53 adult human subjects. Mean pressure was subtracted from each pressure waveform and Fourier analysis applied to the pulsations. A distortion model was estimated for each subject and averaged over the group. The average inverse model was applied to the full finger pressure waveform. The pressure decrement was modelled by multiple regression on finger systolic and diastolic levels. Waveform distortion could be described by a general, frequency dependent model having a resonance at 7.3 Hz. The general inverse model has an anti-resonance at this frequency. It converts finger to brachial pulsations thereby reducing average waveform distortion from 9.7 (s.d. 3.2) mmHg per sample for the finger pulse to 3.7 (1.7) mmHg for the converted pulse. Systolic and diastolic level differences between finger and brachial arterial pressures changed from -4 (15) and -8 (11) to +8 (14) and +8 (12) mmHg, respectively, after inverse modelling, with pulse pressures correct on average. The pressure decrement model reduced both the mean and the standard deviation of systolic and diastolic level differences to 0 (13) and 0 (8) mmHg. Diastolic differences were thus reduced most. Brachial to finger pulse wave distortion due to wave reflection in arteries is almost identical in all subjects and can be modelled by a single resonance. The pressure decrement due to flow in arteries is greatest for high pulse pressures superimposed on low means.

  8. The pharmacokinetics of ropivacaine after four different techniques of brachial plexus blockade.

    NARCIS (Netherlands)

    Rettig, H.C.; Lerou, J.G.C.; Gielen, M.J.M.; Boersma, E.; Burm, A.G.L.

    2007-01-01

    Arterial plasma concentrations of ropivacaine were measured after brachial plexus blockade using four different approaches: lateral interscalene (Winnie), posterior interscalene (Pippa), axillary and vertical infraclavicular. Four groups of 10 patients were given a single 3.75 mg.kg(-1) injection of

  9. Dedicated bifurcation stents

    Directory of Open Access Journals (Sweden)

    Ajith Ananthakrishna Pillai

    2012-03-01

    Full Text Available Bifurcation percutaneous coronary intervention (PCI is still a difficult call for the interventionist despite advancements in the instrumentation, technical skill and the imaging modalities. With major cardiac events relate to the side-branch (SB compromise, the concept and practice of dedicated bifurcation stents seems exciting. Several designs of such dedicated stents are currently undergoing trials. This novel concept and pristine technology offers new hope notwithstanding the fact that we need to go a long way in widespread acceptance and practice of these gadgets. Some of these designs even though looks enterprising, the mere complex delivering technique and the demanding knowledge of the exact coronary anatomy makes their routine use challenging.

  10. Bifurcation and Nonlinear Oscillations.

    Science.gov (United States)

    1980-09-28

    Structural stability and bifurcation theory. pp. 549-560 in Dinamical Systems (Ed. MI. Peixoto), Academic Press, 1973. [211 J. Sotomayor, Generic one...Dynamical Systems Brown University ELECTP" 71, Providence, R. I. 02912 1EC 2 4 1980j //C -*)’ Septabe-4., 1980 / -A + This research was supported in...problems are discussed. The first one deals with the characterization of the flow for a periodic planar system which is the perturbation of an autonomous

  11. Numerical analysis of bifurcations

    International Nuclear Information System (INIS)

    Guckenheimer, J.

    1996-01-01

    This paper is a brief survey of numerical methods for computing bifurcations of generic families of dynamical systems. Emphasis is placed upon algorithms that reflect the structure of the underlying mathematical theory while retaining numerical efficiency. Significant improvements in the computational analysis of dynamical systems are to be expected from more reliance of geometric insight coming from dynamical systems theory. copyright 1996 American Institute of Physics

  12. Brachial Plexopathy After Cervical Spine Surgery

    OpenAIRE

    Than, Khoi D.; Mummaneni, Praveen V.; Smith, Zachary A.; Hsu, Wellington K.; Arnold, Paul M.; Fehlings, Michael G.; Mroz, Thomas E.; Riew, K. Daniel

    2017-01-01

    Study Design: Retrospective, multicenter case-series study and literature review. Objectives: To determine the prevalence of brachial plexopathy after cervical spine surgery and to review the literature to better understand the etiology and risk factors of brachial plexopathy after cervical spine surgery. Methods: A retrospective case-series study of 12?903 patients at 21 different sites was performed to analyze the prevalence of several different complications, including brachial plexopathy....

  13. Ankle-brachial index and inter-artery blood pressure differences as predictors of cognitive function in overweight and obese older adults with diabetes: results from the Action for Health in Diabetes movement and memory study.

    Science.gov (United States)

    Espeland, Mark A; Beavers, Kristen M; Gibbs, Bethany Barone; Johnson, Karen C; Hughes, Timothy M; Baker, Laura D; Jakicic, John; Korytkowski, Mary; Miller, Marsha; Bray, George A

    2015-10-01

    Ankle-brachial index (ABI) and interartery systolic blood pressure differences, as markers of vascular disease, are plausible risk factors for deficits in cognitive function among overweight and obese adults with type 2 diabetes. The ABI and maximum interartery differences (MIAD) in systolic blood pressures were assessed annually for five years among 479 participants assigned to the control condition in a randomized clinical trial of a behavioral weight loss intervention. A battery of standardized cognitive function tests was administered 4 to 5 years later. Analyses of covariance were used to assess relationships that ABI, MIAD, and progression of ABI and MIAD had with cognitive function. There was a curvilinear relationship between ABI and a composite index of cognitive function (p = 0.03), with lower ABI being associated with poorer function. In graded fashions, both greater MIAD and increases in MIAD over time also had modest relationships with poorer verbal memory (both p ≤ 0.05), processing speed (both p ≤ 0.05), and composite cognitive function (both p cognitive function 4-5 years later. Copyright © 2014 John Wiley & Sons, Ltd.

  14. The artery blood supply variant of the upper limb

    Science.gov (United States)

    MASLARSKI, IVAN

    2015-01-01

    Variations of arterial patterns in the upper limb have represented the most common subject of vascular anatomy. Different types of artery branching pattern of the upper limb are very important for orthopedists in angiographic and microvascular surgical practice. The brachial artery (BA) is the most important vessel in the normal vascular anatomy of the upper limb. The classical pattern of the palmar hand region distribution shows the superficial palmar arch. Normally this arch is formed by the superficial branch of the ulnar artery and completed on the lateral side by one of these arteries: the superficial palmar branch of the radial artery, the princeps pollicis artery, the superficial palmar branch of the radial artery or the median artery. After the routine dissection of the right upper limb of an adult male cadaver, we found a very rare variant of the superficial arch artery – a division in a higher level brachial artery. We found this division at 10.4 cm from the beginning of the brachial artery. This superficial brachial artery became a radial artery and was not involved in the formation of the palm arch. In the forearm region, the artery variant was present with the median artery and the ulnar artery, which form the superficial palm arch. PMID:26733754

  15. Spiral blood flow in aorta-renal bifurcation models.

    Science.gov (United States)

    Javadzadegan, Ashkan; Simmons, Anne; Barber, Tracie

    2016-01-01

    The presence of a spiral arterial blood flow pattern in humans has been widely accepted. It is believed that this spiral component of the blood flow alters arterial haemodynamics in both positive and negative ways. The purpose of this study was to determine the effect of spiral flow on haemodynamic changes in aorta-renal bifurcations. In this regard, a computational fluid dynamics analysis of pulsatile blood flow was performed in two idealised models of aorta-renal bifurcations with and without flow diverter. The results show that the spirality effect causes a substantial variation in blood velocity distribution, while causing only slight changes in fluid shear stress patterns. The dominant observed effect of spiral flow is on turbulent kinetic energy and flow recirculation zones. As spiral flow intensity increases, the rate of turbulent kinetic energy production decreases, reducing the region of potential damage to red blood cells and endothelial cells. Furthermore, the recirculation zones which form on the cranial sides of the aorta and renal artery shrink in size in the presence of spirality effect; this may lower the rate of atherosclerosis development and progression in the aorta-renal bifurcation. These results indicate that the spiral nature of blood flow has atheroprotective effects in renal arteries and should be taken into consideration in analyses of the aorta and renal arteries.

  16. Bubble transport in bifurcations

    Science.gov (United States)

    Bull, Joseph; Qamar, Adnan

    2017-11-01

    Motivated by a developmental gas embolotherapy technique for cancer treatment, we examine the transport of bubbles entrained in liquid. In gas embolotherapy, infarction of tumors is induced by selectively formed vascular gas bubbles that originate from acoustic vaporization of vascular droplets. In the case of non-functionalized droplets with the objective of vessel occlusion, the bubbles are transported by flow through vessel bifurcations, where they may split prior to eventually reach vessels small enough that they become lodged. This splitting behavior affects the distribution of bubbles and the efficacy of flow occlusion and the treatment. In these studies, we investigated bubble transport in bifurcations using computational and theoretical modeling. The model reproduces the variety of experimentally observed splitting behaviors. Splitting homogeneity and maximum shear stress along the vessel walls is predicted over a variety of physical parameters. Maximum shear stresses were found to decrease with increasing Reynolds number. The initial bubble length was found to affect the splitting behavior in the presence of gravitational asymmetry. This work was supported by NIH Grant R01EB006476.

  17. Avaliação da função endotelial em pacientes com esclerose sistêmica limitada por meio do eco Doppler da artéria braquial Evaluation of endothelial function in patients with limited systemic sclerosis by use of brachial artery Doppler ultrasound

    Directory of Open Access Journals (Sweden)

    Tatiana Melo Fernandes

    2012-08-01

    Full Text Available OBJETIVO: O objetivo deste estudo foi comparar a resposta dilatadora dependente e independente do endotélio em pacientes portadores de esclerose sistêmica limitada (ESL com aquela de indivíduos sadios de mesmo gênero, idade e cor. MÉTODOS: Vinte mulheres adultas, não obesas, não tabagistas, não diabéticas, não dislipidêmicas, não hipertensas, que preencheram os critérios para esclerose sistêmica (ES segundo o American College of Rheumatology, foram submetidas ao exame de Doppler de artéria braquial do membro superior direito. Foi analisada a resposta dilatadora, dependente do endotélio, após isquemia induzida com esfigmomanômetro por cinco minutos no braço direito, e a resposta dilatadora, independente do endotélio, após administração de 300 mcg de nitroglicerina (NTG sublingual. Esses resultados foram comparados com a resposta obtida em indivíduos sadios. RESULTADOS: O diâmetro longitudinal da artéria braquial (DAB foi significativamente menor na fase basal 1 nos pacientes com ESL (3,57 ± 0,52 mm e 3,93 ± 0,39 mm, respectivamente no grupo paciente (P e grupo-controle (C, P = 0,005. Não foi encontrada diferença estatisticamente significativa entre a velocidade das hemácias (VH após isquemia/hiperemia reativa (HR e após NTG (110,2 ± 43,86 cm/s vs. 102,0 ± 25,89 cm/s e 63,80 ± 17,69 cm/s vs. 65,4 ± 12,90 cm/s nos grupos P e C, após HR e NTG, respectivamente. Também não foi encontrada diferença significativa entre o DAB após HR e após NTG (3,77 ± 0,59 mm vs. 4,14 ± 0,49 mm e 4,44 ± 0,64 mm vs. 4,70 ± 0,58 mm nos grupos P e C, após HR e NTG, respectivamente. CONCLUSÃO: Embora o grupo de pacientes com ESL tenha apresentado menor DAB basal, a resposta dilatadora dependente e independente do endotélio se manteve preservada em ambos os grupos.OBJECTIVES: The aim of this study was to compare the brachial artery endothelium-dependent and endothelium-independent dilating responses in patients with limited

  18. Hepatic artery aneurysms (HAAs)

    International Nuclear Information System (INIS)

    Nosratini, H.

    2004-01-01

    The hepatic artery aneurysms are rare, especially in interahepatic branches, The frequency consists of 75-80% extrahepatic and 20-25% intrahepatic. Catheterization is achieved usually from common femoral artery, other methods implemented in the case of unsuccessful catheterization from femoral artery, are translumbar and brachial catheterization. The study consist of 565 patients that were referred to the angiography ward, During seven years of assessment, five cases of hepatic artery aneurysm were found; this is a rare condition reported in the English literature. In the literature as well as in this case report the hepatic artery aneurysms are rare. In reported series the extrahepatic artery aneurysms are found more often than in the intrahepatic artery aneurysm but in this case report intrahepatic artery aneurysms are more than extrahepatic one. (author)

  19. OCT/PS-OCT imaging of brachial plexus neurovascular structures

    Science.gov (United States)

    Raphael, David T.; Zhang, Jun; Zhang, Yaoping; Chen, Zhongping; Miller, Carol; Zhou, Li

    2004-07-01

    Introduction: Optical coherence tomography (OCT) allows high-resolution imaging (less than 10 microns) of tissue structures. A pilot study with OCT and polarization-sensitive OCT (PS-OCT) was undertaken to image ex-vivo neurovascular structures (vessels, nerves) of the canine brachial plexus. Methods: OCT is an interferometry-based optical analog of B-mode ultrasound, which can image through non-transparent biological tissues. With approval of the USC Animal Care and Use Committee, segments of the supra- and infraclavicular brachial plexus were excised from euthanized adult dogs, and the ex-vivo specimens were placed in cold pH-buffered physiologic solution. An OCT beam, in micrometer translational steps, scanned the fixed-position bisected specimens in transverse and longitudinal views. Two-dimensional images were obtained from identified arteries and nerves, with specific sections of interest stained with hematoxylin-eosin for later imaging through a surgical microscope. Results: with the beam scan direction transverse to arteries, the resulting OCT images showed an identifiable arterial lumen and arterial wall tissue layers. By comparison, transverse beam OCT images of nerves revealed a multitude of smaller nerve bundles contained within larger circular-shaped fascicles. PS-OCT imaging was helpful in showing the characteristic birefringence exhibited by arrayed neural structures. Discussion: High-resolution OCT imaging may be useful in the optical identification of neurovascular structures during attempted regional nerve blockade. If incorporated into a needle-shaped catheter endoscope, such a technology could prevent intraneural and intravascular injections immediately prior to local anesthetic injection. The major limitation of OCT is that it can form a coherent image of tissue structures only to a depth of 1.5 - 2 mm.

  20. Brachial Plexopathy After Cervical Spine Surgery.

    Science.gov (United States)

    Than, Khoi D; Mummaneni, Praveen V; Smith, Zachary A; Hsu, Wellington K; Arnold, Paul M; Fehlings, Michael G; Mroz, Thomas E; Riew, K Daniel

    2017-04-01

    Retrospective, multicenter case-series study and literature review. To determine the prevalence of brachial plexopathy after cervical spine surgery and to review the literature to better understand the etiology and risk factors of brachial plexopathy after cervical spine surgery. A retrospective case-series study of 12 903 patients at 21 different sites was performed to analyze the prevalence of several different complications, including brachial plexopathy. A literature review of the US National Library of Medicine and the National Institutes of Health (PubMed) database was conducted to identify articles pertaining to brachial plexopathy following cervical spine surgery. In our total population of 12 903 patients, only 1 suffered from postoperative brachial plexopathy. The overall prevalence rate was thus 0.01%, but the prevalence rate at the site where this complication occurred was 0.07%. Previously reported risk factors for postoperative brachial plexopathy include age, anterior surgical procedures, and a diagnosis of ossification of the posterior longitudinal ligament. The condition can also be due to patient positioning during surgery, which can generally be detected via the use of intraoperative neuromonitoring. Brachial plexopathy following cervical spine surgery is rare and merits further study.

  1. Ayres' bifurcated solar model

    International Nuclear Information System (INIS)

    Kalkofen, W.

    1985-01-01

    The assumptions of Ayres' model of the upper solar atmosphere are examined. It is found that the bistable character of his model is postulated - through the assumptions concerning the opacity sources and the effect of mechanical waves, which are allowed to destroy the CO molecules but not to heat the gas. The neglect of cooling by metal lines is based on their reduced local cooling rate, but it ignores the increased depth over which this cooling occurs. Thus, the bifurcated model of the upper solar atmosphere consists of two models, one cold at the temperature minimum, with a kinetic temperature of 2900 K, and the other hot, with a temperature of 4900 K. 8 references

  2. Bifurcations sights, sounds, and mathematics

    CERN Document Server

    Matsumoto, Takashi; Kokubu, Hiroshi; Tokunaga, Ryuji

    1993-01-01

    Bifurcation originally meant "splitting into two parts. " Namely, a system under­ goes a bifurcation when there is a qualitative change in the behavior of the sys­ tem. Bifurcation in the context of dynamical systems, where the time evolution of systems are involved, has been the subject of research for many scientists and engineers for the past hundred years simply because bifurcations are interesting. A very good way of understanding bifurcations would be to see them first and study theories second. Another way would be to first comprehend the basic concepts and theories and then see what they look like. In any event, it is best to both observe experiments and understand the theories of bifurcations. This book attempts to provide a general audience with both avenues toward understanding bifurcations. Specifically, (1) A variety of concrete experimental results obtained from electronic circuits are given in Chapter 1. All the circuits are very simple, which is crucial in any experiment. The circuits, howev...

  3. Use of multidetector computed tomography angiography of upper limb circulation in patients undergoing coronary artery bypass grafting surgery

    Directory of Open Access Journals (Sweden)

    Hasan B Altinsoy

    2017-01-01

    Full Text Available Objective: This study aimed to evaluate the bilateral forehand circulation using a 64-channel multidetector computed tomography (MDCT as a noninvasive method to define criteria for an upper extremity arterial anatomy and pathology prior to the use of arterial conduits. Materials and Methods: Fifty-five patients with coronary artery disease who underwent total arterial coronary artery bypass grafting (CABG were randomly selected for this prospective study. MDCT angiography was performed for 110 examinations of forearm and hand arterial anatomy. Prior to MDCT, Allen tests were performed in all patients with a normal result, except four. Thirteen patients had diabetes mellitus (DM, 8 had peripheral artery occlusive disease, and 19 had a history of smoking. Results: All arteries, including axillary, ulnar artery (UA and radial artery (RA, were clearly visualized in all patients. Upper extremity anatomical and pathological results were examined in 16 patients (29.1%. Severely calcified RA and/or UA were found in 6 patients who had a moderate renal failure. Nearly total occlusion of the RA was detected in another two patients. Focal intimal RA calcification was recorded in 1 female and 3 male patients. Ten patients who had severe calcification or intimal sclerosis of the upper extremity arteries had DM. The remaining patients had normal forehand arterial circulation. A persistent median artery with the absence of radial and ulnar arteries and a high bifurcation of RA from the brachial artery was detected as an anatomic variation in seven patients (12.7%. Conclusions: The major advantages of MDCT angiography are its non-invasiveness and the ability to detect calcific subadventitial plaques, which are difficult to diagnose using conventional angiography. MDCT may be used as a safe and non-invasive method to assess RA and UA prior to harvesting the upper limb artery. Preoperative imaging of forehand arteries is a means to avoid unnecessary forearm

  4. Riddling bifurcation and interstellar journeys

    International Nuclear Information System (INIS)

    Kapitaniak, Tomasz

    2005-01-01

    We show that riddling bifurcation which is characteristic for low-dimensional attractors embedded in higher-dimensional phase space can give physical mechanism explaining interstellar journeys described in science-fiction literature

  5. Small-bubble transport and splitting dynamics in a symmetric bifurcation

    KAUST Repository

    Qamar, Adnan; Warnez, Matthew; Valassis, Doug T.; Guetzko, Megan E.; Bull, Joseph L.

    2017-01-01

    Simulations of small bubbles traveling through symmetric bifurcations are conducted to garner information pertinent to gas embolotherapy, a potential cancer treatment. Gas embolotherapy procedures use intra-arterial bubbles to occlude tumor blood supply. As bubbles pass through bifurcations in the blood stream nonhomogeneous splitting and undesirable bioeffects may occur. To aid development of gas embolotherapy techniques, a volume of fluid method is used to model the splitting process of gas bubbles passing through artery and arteriole bifurcations. The model reproduces the variety of splitting behaviors observed experimentally, including the bubble reversal phenomenon. Splitting homogeneity and maximum shear stress along the vessel walls is predicted over a variety of physical parameters. Small bubbles, having initial length less than twice the vessel diameter, were found unlikely to split in the presence of gravitational asymmetry. Maximum shear stresses were found to decrease exponentially with increasing Reynolds number. Vortex-induced shearing near the bifurcation is identified as a possible mechanism for endothelial cell damage.

  6. Small-bubble transport and splitting dynamics in a symmetric bifurcation

    KAUST Repository

    Qamar, Adnan

    2017-06-28

    Simulations of small bubbles traveling through symmetric bifurcations are conducted to garner information pertinent to gas embolotherapy, a potential cancer treatment. Gas embolotherapy procedures use intra-arterial bubbles to occlude tumor blood supply. As bubbles pass through bifurcations in the blood stream nonhomogeneous splitting and undesirable bioeffects may occur. To aid development of gas embolotherapy techniques, a volume of fluid method is used to model the splitting process of gas bubbles passing through artery and arteriole bifurcations. The model reproduces the variety of splitting behaviors observed experimentally, including the bubble reversal phenomenon. Splitting homogeneity and maximum shear stress along the vessel walls is predicted over a variety of physical parameters. Small bubbles, having initial length less than twice the vessel diameter, were found unlikely to split in the presence of gravitational asymmetry. Maximum shear stresses were found to decrease exponentially with increasing Reynolds number. Vortex-induced shearing near the bifurcation is identified as a possible mechanism for endothelial cell damage.

  7. Small-bubble transport and splitting dynamics in a symmetric bifurcation.

    Science.gov (United States)

    Qamar, Adnan; Warnez, Matthew; Valassis, Doug T; Guetzko, Megan E; Bull, Joseph L

    2017-08-01

    Simulations of small bubbles traveling through symmetric bifurcations are conducted to garner information pertinent to gas embolotherapy, a potential cancer treatment. Gas embolotherapy procedures use intra-arterial bubbles to occlude tumor blood supply. As bubbles pass through bifurcations in the blood stream nonhomogeneous splitting and undesirable bioeffects may occur. To aid development of gas embolotherapy techniques, a volume of fluid method is used to model the splitting process of gas bubbles passing through artery and arteriole bifurcations. The model reproduces the variety of splitting behaviors observed experimentally, including the bubble reversal phenomenon. Splitting homogeneity and maximum shear stress along the vessel walls is predicted over a variety of physical parameters. Small bubbles, having initial length less than twice the vessel diameter, were found unlikely to split in the presence of gravitational asymmetry. Maximum shear stresses were found to decrease exponentially with increasing Reynolds number. Vortex-induced shearing near the bifurcation is identified as a possible mechanism for endothelial cell damage.

  8. Dynamic bifurcations on financial markets

    International Nuclear Information System (INIS)

    Kozłowska, M.; Denys, M.; Wiliński, M.; Link, G.; Gubiec, T.; Werner, T.R.; Kutner, R.; Struzik, Z.R.

    2016-01-01

    We provide evidence that catastrophic bifurcation breakdowns or transitions, preceded by early warning signs such as flickering phenomena, are present on notoriously unpredictable financial markets. For this we construct robust indicators of catastrophic dynamical slowing down and apply these to identify hallmarks of dynamical catastrophic bifurcation transitions. This is done using daily closing index records for the representative examples of financial markets of small and mid to large capitalisations experiencing a speculative bubble induced by the worldwide financial crisis of 2007-08.

  9. Asociación entre enfermedad periodontal y disfunción endotelial valorada por vasodilatación mediada por flujo en la arteria braquial: Estudio piloto Association between periodontal disease and endothelial dysfunction assessed by flow-mediated dilation in the brachial artery: Pilot study

    Directory of Open Access Journals (Sweden)

    Álvaro J Ruiz

    2013-02-01

    Full Text Available Objetivo: evaluar la disfunción endotelial a través de la vasodilatación mediada por flujo (VMF en la arteria braquial en pacientes fumadores con periodontitis crónica avanzada y compararla con pacientes fumadores sin enfermedad periodontal, para determinar si hay diferencias en cuando a disfunción endotelial entre quienes presentan o no periodontitis crónica avanzada. Métodos: se incluyeron 30 pacientes con hábito de tabaquismo, 15 con periodontitis crónica avanzada y 15 sin periodontitis. Se realizó historia clínica completa, exámenes de laboratorio y prueba de vasodilatación mediada por flujo de la arteria braquial. Resultados: el estudio mostró que había diferencias significativas en los diámetros finales, resultantes de vasodilatación mediada por flujo (p=0,0328, con menores valores finales para quienes tenían enfermedad periodontal. Las diferencias en las respuestas porcentuales y en el número de personas con disfunción determinada dicotómicamente, no alcanzaron significación estadística. Conclusión: se observó que el grupo de pacientes con periodontitis crónica avanzada tuvo diámetros resultantes luego de la prueba que fueron significativamente menores que los del grupo de controles. Aunque al evaluar las diferencias en porcentajes no se alcanzó significación estadística, el estudio mostró una respuesta claramente menor en vasodilatación en el grupo con enfermedad periodontal.Objective: To evaluate endothelial dysfunction through flow-mediated vasodilation (FMD in the brachial artery in smokers with advanced chronic periodontitis and compare it with smokers without periodontal disease, to determine whether there are differences in endothelial dysfunction among those with or without advanced chronic periodontitis. Methods: We included 30 patients with smoking habit, 15 with advanced chronic periodontitis and 15 without periodontal disease. We performed a complete medical history, laboratory tests and flow

  10. Clip reconstruction of a large right MCA bifurcation aneurysm. Case report

    Directory of Open Access Journals (Sweden)

    Giovani A.

    2014-06-01

    Full Text Available We report a case of complex large middle cerebral artery (MCA bifurcation aneurysm that ruptured during dissection from the very adherent MCA branches but was successfully clipped and the MCA bifurcation reconstructed using 4 Yasargill clips. Through a right pterional craniotomy the sylvian fissure was largely opened as to allow enough workspace for clipping the aneurysm and placing a temporary clip on M1. The pacient recovered very well after surgery and was discharged after 1 week with no neurological deficit. Complex MCA bifurcation aneurysms can be safely reconstructed using regular clips, without the need of using fenestrated clips or complex by-pass procedures.

  11. Dermatoglyphs and brachial plexus palsy.

    Science.gov (United States)

    Polovina, Svetislav; Cvjeticanin, Miljenko; Milicić, Jasna; Proloscić, Tajana Polovina

    2006-09-01

    Perinatal brachial plexus palsy (PBPP) is a handicap quite commonly encountered in daily routine. Although birth trauma is considered to be the major cause of the defect, it has been observed that PBPP occurs only in some infants born under identical or nearly identical conditions. The aim of this study was to test the hypothesis of genetic predisposition for PBPP. It is well known that digito-palmar dermatoglyphs can be used to determine hereditary roots of some diseases. Thus, we found it meaningful to do a study analysis of digito-palmar dermatoglyphs in this disease as well, conducting it on 140 subjects (70 males and 70 females) diagnosed with PBPP. The control group was composed of fingerprints obtained from 400 adult and phenotypically healthy subjects (200 males and 200 females) from the Zagreb area. The results of multivariate and univariate analysis of variance have shown statistically significant differences between the groups observed. In spite of lower percentage of accurately classified female subjects by discriminant analysis, the results of quantitative analysis of digito-palmar dermatoglyphs appeared to suggest a genetic predisposition for the occurrence of PBPP.

  12. Central hemodynamics in risk assessment strategies: additive value over and above brachial blood pressure.

    Science.gov (United States)

    Yannoutsos, Alexandra; Rinaldi, Elisa R; Zhang, Yi; Protogerou, Athanassios D; Safar, Michel E; Blacher, Jacques

    2015-01-01

    Although the clinical relevance of brachial blood pressure (BP) measurement for cardiovascular (CV) risk stratification is nowadays widely accepted, this approach can nevertheless present several limitations. Pulse pressure (PP) amplification accounts for the notable increase in PP from central to peripheral arterial sites. Target organs are more greatly exposed to central hemodynamic changes than peripheral organs. The pathophysiological significance of local BP pulsatility, which has a role in the pathogenesis of target organ damage in both the macro- and the microcirculation, may therefore not be accurately captured by brachial BP as traditionally evaluated with cuff measurements. The predictive value of central systolic BP and PP over brachial BP for major clinical outcomes has been demonstrated in the general population, in elderly adults and in patients at high CV risk, irrespective of the invasive or non-invasive methods used to assess central BP. Aortic stiffness, timing and intensity of wave reflections, and cardiac performance appear as major factors influencing central PP. Great emphasis has been placed on the role of aortic stiffness, disturbed arterial wave reflections and their intercorrelation in the pathophysiological mechanisms of CV diseases as well as on their capacity to predict target organ damage and clinical events. Comorbidities and age-related changes, together with gender-related specificities of arterial and cardiac parameters, are known to affect the predictive ability of central hemodynamics on individual CV risk.

  13. Anomalous external carotid artery-internal carotid artery anastomosis in two patients with proximal internal carotid arterial remnants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chang Hun [Dept. of Neurology, Stroke Center, Myongji Hospital, Goyang (Korea, Republic of); Cho, Young Dae; Kang, Hyun Seung; Kim, Jeong Eun; Han, Moon Hee [Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of); Jung, Seung Chai [Dept. of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Ahn, Jun Hyong [Dept. of Neurosurgery, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang (Korea, Republic of)

    2015-08-15

    Two angiographic instances of anomalous external carotid artery (ECA) and internal carotid artery (ICA) anastomosis are described, each occurring at the C2-3 level and bearing remnants of proximal ICA. The ICA remnant of one patient (identifiable immediately upon bifurcation of the common carotid artery) was hypoplastic, and that of the other patient was an occluded arterial stump. These features are not typical of non-bifurcating ICA. The occipital artery originated from an anomalous connection in one instance and from the main trunk of the ECA (just past the ECA-ICA connection) in the other.

  14. Combined use of intraarterial digital subtraction angiography with conventional retrograde brachial vertebral angiography

    International Nuclear Information System (INIS)

    Yamaguchi, Tatsuo; Ogawa, Toshihide; Inugami, Atsushi; Kawata, Yasushi; Shishido, Fumio; Uemura, Kazuo

    1985-01-01

    For 102 patients who had the examination of conventional bilaterally retrograde brachial vertebral angiography (retrograde VAG), intraarterial digital subtraction angiography (DSA) was successively performed to investigate steno-occlusive lesions of proximal vertebral and subclavian arteries. All the patients had no complication due to the DSA procedure. In 50% of 72 ischemic stroke cases, positive findings were found either in the origin of the vertebral artery or in the subclavian artery. Stenosis of more than 50% of the lumen of the vertebral artery were found in 14% of the cases at the origin of the right one and also in 14% in the left one. Occlusion of the vertebral artery was found in 4% in the left side only. In 30 cases with non-ischemic brain diseases, positive findings were noted in 10%. Intraarterial DSA combined with retrograde VAG was thought to be useful, especially in the examination for ischemic stroke. (author)

  15. Role of dexamethasone in brachial plexus block

    International Nuclear Information System (INIS)

    Dawood, M.

    2015-01-01

    To evaluate the effect of dexamethasone added to (lignocaine) on the onset and duration of axillary brachial plexus block. Study Design: Randomized controlled trial. Place and Duration of Study: Combined Military Hospital Rawalpindi, from September 2009 to March 2010. Patients and Methods: A total of 100 patients, who were scheduled for elective hand and forearm surgery under axillary brachial plexus block, were randomly allocated to group A in which patients received 40 ml 1.5% lidocaine with 2 ml of isotonic saline (0.9%) and group B in which patients received 40 ml 1.5% lidocaine with 2 ml of dexamethasone (8 mg). Nerve stimulator with insulated needle for multiple stimulations technique was used to locate the brachial plexus nerves. After the injection onset of action and duration of sensory blockade of brachial plexus were recorded at 5 minutes and 15 minutes interval. Results: Group A showed the onset of action of 21.64 ± 2.30 min and in group B it was 15.42 ± 1.44 min (p< 0.001). Duration of nerve block was 115.08 ± 10.92 min in group A and 265.42 ± 16.56 min in group B (p < 0.001). Conclusion: The addition of dexamethasone to 1.5% lignocaine solution in axillary brachial plexus block prolongs the duration of sensory blockade significantly. (author)

  16. Quantitative angiography methods for bifurcation lesions

    DEFF Research Database (Denmark)

    Collet, Carlos; Onuma, Yoshinobu; Cavalcante, Rafael

    2017-01-01

    Bifurcation lesions represent one of the most challenging lesion subsets in interventional cardiology. The European Bifurcation Club (EBC) is an academic consortium whose goal has been to assess and recommend the appropriate strategies to manage bifurcation lesions. The quantitative coronary...... angiography (QCA) methods for the evaluation of bifurcation lesions have been subject to extensive research. Single-vessel QCA has been shown to be inaccurate for the assessment of bifurcation lesion dimensions. For this reason, dedicated bifurcation software has been developed and validated. These software...

  17. Does the principle of minimum work apply at the carotid bifurcation: a retrospective cohort study

    International Nuclear Information System (INIS)

    Beare, Richard J; Das, Gita; Ren, Mandy; Chong, Winston; Sinnott, Matthew D; Hilton, James E; Srikanth, Velandai; Phan, Thanh G

    2011-01-01

    There is recent interest in the role of carotid bifurcation anatomy, geometry and hemodynamic factors in the pathogenesis of carotid artery atherosclerosis. Certain anatomical and geometric configurations at the carotid bifurcation have been linked to disturbed flow. It has been proposed that vascular dimensions are selected to minimize energy required to maintain blood flow, and that this occurs when an exponent of 3 relates the radii of parent and daughter arteries. We evaluate whether the dimensions of bifurcation of the extracranial carotid artery follow this principle of minimum work. This study involved subjects who had computed tomographic angiography (CTA) at our institution between 2006 and 2007. Radii of the common, internal and external carotid arteries were determined. The exponent was determined for individual bifurcations using numerical methods and for the sample using nonlinear regression. Mean age for 45 participants was 56.9 ± 16.5 years with 26 males. Prevalence of vascular risk factors was: hypertension-48%, smoking-23%, diabetes-16.7%, hyperlipidemia-51%, ischemic heart disease-18.7%. The value of the exponent ranged from 1.3 to 1.6, depending on estimation methodology. The principle of minimum work (defined by an exponent of 3) may not apply at the carotid bifurcation. Additional factors may play a role in the relationship between the radii of the parent and daughter vessels

  18. Pierce instability and bifurcating equilibria

    International Nuclear Information System (INIS)

    Godfrey, B.B.

    1981-01-01

    The report investigates the connection between equilibrium bifurcations and occurrence of the Pierce instability. Electrons flowing from one ground plane to a second through an ion background possess a countable infinity of static equilibria, of which only one is uniform and force-free. Degeneracy of the uniform and simplest non-uniform equilibria at a certain ground plan separation marks the onset of the Pierce instability, based on a newly derived dispersion relation appropriate to all the equilibria. For large ground plane separations the uniform equilibrium is unstable and the non-uniform equilibrium is stable, the reverse of their stability properties at small separations. Onset of the Pierce instability at the first bifurcation of equilibria persists in more complicated geometries, providing a general criterion for marginal stability. It seems probable that bifurcation analysis can be a useful tool in the overall study of stable beam generation in diodes and transport in finite cavities

  19. Severe brachial plexus injuries in rugby.

    Science.gov (United States)

    Altaf, F; Mannan, K; Bharania, P; Sewell, M D; Di Mascio, L; Sinisi, M

    2012-03-01

    We describe the mechanisms, pattern of injuries, management and outcomes of severe injuries to the brachial plexus sustained during the play of rugby. Thirteen cases of severe injury to the brachial plexus caused by tackles in rugby had detailed clinical assessment, and operative exploration of the brachial plexus. Seventeen spinal nerves were avulsed, two were ruptured and there were traction lesions in continuity of 24 spinal nerves. The pattern of nerve lesion was related to the posture of the neck and the forequarter at the moment of impact. Early repair by nerve transfer enabled some functional recovery, and decompression of lesions in continuity was followed by recovery of nerve function and relief of pain. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Prediction of fibre architecture and adaptation in diseased carotid bifurcations.

    LENUS (Irish Health Repository)

    Creane, Arthur

    2011-12-01

    Many studies have used patient-specific finite element models to estimate the stress environment in atherosclerotic plaques, attempting to correlate the magnitude of stress to plaque vulnerability. In complex geometries, few studies have incorporated the anisotropic material response of arterial tissue. This paper presents a fibre remodelling algorithm to predict the fibre architecture, and thus anisotropic material response in four patient-specific models of the carotid bifurcation. The change in fibre architecture during disease progression and its affect on the stress environment in the plaque were predicted. The mean fibre directions were assumed to lie at an angle between the two positive principal strain directions. The angle and the degree of dispersion were assumed to depend on the ratio of principal strain values. Results were compared with experimental observations and other numerical studies. In non-branching regions of each model, the typical double helix arterial fibre pattern was predicted while at the bifurcation and in regions of plaque burden, more complex fibre architectures were found. The predicted change in fibre architecture in the arterial tissue during plaque progression was found to alter the stress environment in the plaque. This suggests that the specimen-specific anisotropic response of the tissue should be taken into account to accurately predict stresses in the plaque. Since determination of the fibre architecture in vivo is a difficult task, the system presented here provides a useful method of estimating the fibre architecture in complex arterial geometries.

  1. Rare high origin of the radial artery: a bilateral, symmetrical case ...

    African Journals Online (AJOL)

    Arterial variations in the upper limb can occur at the level of the axillary, brachial, radial and ulnar arteries as well as the palmar arches. This is a report of bilateral, symmetrical high origin of the radial artery from the axillary artery. Knowledge of such variations is important in vascular and reconstructive surgery. (Nig J Surg ...

  2. Homoclinic bifurcation in Chua's circuit

    Indian Academy of Sciences (India)

    spiking and bursting behaviors of neurons. Recent experiments ... a limit cycle increases in a wiggle with alternate sequences of stable and unstable orbits via ... further changes in parameter, the system shows period-adding bifurcation when .... [21–23] transition from limit cycle to single scroll chaos via PD and then to alter-.

  3. Bifurcation scenarios for bubbling transition.

    Science.gov (United States)

    Zimin, Aleksey V; Hunt, Brian R; Ott, Edward

    2003-01-01

    Dynamical systems with chaos on an invariant submanifold can exhibit a type of behavior called bubbling, whereby a small random or fixed perturbation to the system induces intermittent bursting. The bifurcation to bubbling occurs when a periodic orbit embedded in the chaotic attractor in the invariant manifold becomes unstable to perturbations transverse to the invariant manifold. Generically the periodic orbit can become transversely unstable through a pitchfork, transcritical, period-doubling, or Hopf bifurcation. In this paper a unified treatment of the four types of bubbling bifurcation is presented. Conditions are obtained determining whether the transition to bubbling is soft or hard; that is, whether the maximum burst amplitude varies continuously or discontinuously with variation of the parameter through its critical value. For soft bubbling transitions, the scaling of the maximum burst amplitude with the parameter is derived. For both hard and soft transitions the scaling of the average interburst time with the bifurcation parameter is deduced. Both random (noise) and fixed (mismatch) perturbations are considered. Results of numerical experiments testing our theoretical predictions are presented.

  4. Bifurcation of steady tearing states

    International Nuclear Information System (INIS)

    Saramito, B.; Maschke, E.K.

    1985-10-01

    We apply the bifurcation theory for compact operators to the problem of the nonlinear solutions of the 3-dimensional incompressible visco-resistive MHD equations. For the plane plasma slab model we compute branches of nonlinear tearing modes, which are stationary for the range of parameters investigated up to now

  5. MR evaluation of brachial plexus injuries

    International Nuclear Information System (INIS)

    Gupta, R.K.; Jain, R.K.; Mehta, V.S.; Banerji, A.K.

    1989-01-01

    Ten cases of brachial plexus injury were subjected to magnetic resonance (MR) to demonstrate the roots, trunks, divisions or cord abnormalities. Both normal and abnormal brachial plexuses were imaged in sagittal, axial, coronal and axial oblique planes. Myelography, using water soluble contrast agents, was performed in seven cases. MR demonstrated one traumatic meningocele, one extradural cerebrospinal fluid (CSF) collection, trunk and/or root neuromas in four, focal root fibrosis in two and diffuse fibrosis in the remaining two cases. Results of MR were confirmed at surgery in four cases with neuromas, while myelography was normal in two and was not carried out in the remaining two. In two cases, where MR demonstrated diffuse fibrosis of the brachial plexus, myelography showed C7 and T1 traumatic meningocele in one and was normal in the other. Both these patients showed excellent clinical and electrophysiological correlation with MR findings and in one of them surgical confirmation was also obtained. In the other two cases with focal nerve root fibrosis, myelography was normal in one and showed a traumatic meningocele in another. Operative findings in these cases confirmed focal root fibrosis but no root avulsion was observed although seen on one myelogram. Focal fibrosis, however, was noted at operation in more roots than was observed with MR. Initial experience suggests that MR may be the diagnostic procedure of choice for complete evaluation of brachial plexus injuries. (orig.)

  6. Bifurcation in a buoyant horizontal laminar jet

    Science.gov (United States)

    Arakeri, Jaywant H.; Das, Debopam; Srinivasan, J.

    2000-06-01

    The trajectory of a laminar buoyant jet discharged horizontally has been studied. The experimental observations were based on the injection of pure water into a brine solution. Under certain conditions the jet has been found to undergo bifurcation. The bifurcation of the jet occurs in a limited domain of Grashof number and Reynolds number. The regions in which the bifurcation occurs has been mapped in the Reynolds number Grashof number plane. There are three regions where bifurcation does not occur. The various mechanisms that prevent bifurcation have been proposed.

  7. Variação do diâmetro da artéria braquial em crianças obesas: presente e futuro Variación del diámetro de la arteria braquial en niños obesos: presente y futuro Variation of the brachial artery diameter in obese children: present and future

    Directory of Open Access Journals (Sweden)

    Karla Cristina M. Costa

    2012-09-01

    como predictor de riesgo para enfermedades cardiovasculares, tales como aterosclerosis y enfermedad cardíaca coronariana, puesto que la lesión endotelial es un importante evento en la fisiopatología de tales enfermedades. CONCLUSIONES: La dilatación de la arteria braquial mediada por flujo se muestra importante como herramienta diagnóstica y pronóstica en la evaluación de la función endotelial de niños y adolescentes con exceso de peso, por ser un método no invasivo, con buena aplicabilidad respecto al costo, a la inclusión y al beneficio.OBJECTIVE: Literature review on the use of the variation measure of the brachial artery diameter by high-resolution ultrasound (flow-mediated dilation as a predictor of cardiovascular disease risk in children and adolescents. DATA SOURCE: Survey of studies indexed in Medline/Pubmed, which were published between 2002 and 2011 using the following keywords in various combinations:"endothelium," "child", "ultrasonography" and "obesity", as well as classic texts on the subject. We found 54 publications and 32 were included in this review. SYNTHESIS OF DATA: The study of endothelial dysfunction has been used as a predictor of risk for cardiovascular diseases such as atherosclerosis and coronary heart disease, since endothelial injury is an important event in the physiopathology of these diseases. CONCLUSIONS: The flow-mediated dilation of the brachial artery seems to be important as a diagnostic and prognostic tool to assess endothelial function in children and adolescents who are overweight, because it is a noninvasive method with good profile regarding cost, safety, and benefits.

  8. Accessory brachialis muscle associated with high division of brachial artery

    OpenAIRE

    Krishnamurthy A; David S; Bagoji IB; Nayak SR; Pai MM; Murlimanju BV; Kumar GC

    2010-01-01

    During routine dissection for the undergraduate students in the Department of Anatomy, Kasturba Medical College, Mangalore, of a male cadaver aged 73 years, we encountered an additional slip of brachialis muscle taking origin in the flexor compartment of left arm and inserting into the forearm. The origin of the additional muscle belly was from the anteromedial surface of shaft and medial supracondylar ridge of lower end of humerus. The additional muscle slip merged with the tendon of pronato...

  9. Bifurcation routes and economic stability

    Czech Academy of Sciences Publication Activity Database

    Vošvrda, Miloslav

    2001-01-01

    Roč. 8, č. 14 (2001), s. 43-59 ISSN 1212-074X R&D Projects: GA ČR GA402/00/0439; GA ČR GA402/01/0034; GA ČR GA402/01/0539 Institutional research plan: AV0Z1075907 Keywords : macroeconomic stability * foreign investment phenomenon * the Hopf bifurcation Subject RIV: AH - Economics

  10. Bifurcations of Fibonacci generating functions

    Energy Technology Data Exchange (ETDEWEB)

    Ozer, Mehmet [Istanbul Kultur University, E5 Karayolu Uzeri Sirinevler, 34191 Istanbul (Turkey) and Semiconductor Physics Institute, LT-01108 and Vilnius Gediminas Technical University, Sauletekio 11, LT-10223 (Lithuania)]. E-mail: m.ozer@iku.edu.tr; Cenys, Antanas [Semiconductor Physics Institute, LT-01108 and Vilnius Gediminas Technical University, Sauletekio 11, LT-10223 (Lithuania); Polatoglu, Yasar [Istanbul Kultur University, E5 Karayolu Uzeri Sirinevler, 34191 Istanbul (Turkey); Hacibekiroglu, Guersel [Istanbul Kultur University, E5 Karayolu Uzeri Sirinevler, 34191 Istanbul (Turkey); Akat, Ercument [Yeditepe University, 26 Agustos Campus Kayisdagi Street, Kayisdagi 81120, Istanbul (Turkey); Valaristos, A. [Aristotle University of Thessaloniki, GR-54124, Thessaloniki (Greece); Anagnostopoulos, A.N. [Aristotle University of Thessaloniki, GR-54124, Thessaloniki (Greece)

    2007-08-15

    In this work the dynamic behaviour of the one-dimensional family of maps F{sub p,q}(x) = 1/(1 - px - qx {sup 2}) is examined, for specific values of the control parameters p and q. Lyapunov exponents and bifurcation diagrams are numerically calculated. Consequently, a transition from periodic to chaotic regions is observed at values of p and q, where the related maps correspond to Fibonacci generating functions associated with the golden-, the silver- and the bronze mean.

  11. Bifurcations of Fibonacci generating functions

    International Nuclear Information System (INIS)

    Ozer, Mehmet; Cenys, Antanas; Polatoglu, Yasar; Hacibekiroglu, Guersel; Akat, Ercument; Valaristos, A.; Anagnostopoulos, A.N.

    2007-01-01

    In this work the dynamic behaviour of the one-dimensional family of maps F p,q (x) = 1/(1 - px - qx 2 ) is examined, for specific values of the control parameters p and q. Lyapunov exponents and bifurcation diagrams are numerically calculated. Consequently, a transition from periodic to chaotic regions is observed at values of p and q, where the related maps correspond to Fibonacci generating functions associated with the golden-, the silver- and the bronze mean

  12. Flow patterns on spectral-domain optical coherence tomography reveal flow directions at retinal vessel bifurcations

    DEFF Research Database (Denmark)

    Willerslev, Anne; Li, Xiao Q; Munch, Inger C

    2014-01-01

    PURPOSE: To study intravascular characteristics of flowing blood in retinal vessels using spectral-domain optical coherence tomography (SD-OCT). METHODS: Examination of selected arterial bifurcations and venous sites of confluence in 25 healthy 11-year-old children recruited as an ad hoc subsample...

  13. Symptomatic peripheral arterial disease: the value of a validated questionnaire and a clinical decision rule

    NARCIS (Netherlands)

    Bendermacher, Bianca L. W.; Teijink, Joep A. W.; Willigendael, Edith M.; Bartelink, Marie-Louise; Büller, Harry R.; Peters, Ron J. G.; Boiten, Jelis; Langenberg, Machteld; Prins, Martin H.

    2006-01-01

    BACKGROUND: If a validated questionnaire, when applied to patients reporting with symptoms of intermittent claudication, could adequately discriminate between those with and without peripheral arterial disease, GPs could avoid the diagnostic measurement of the ankle brachial index. AIM: To

  14. Association Between Chromosome 9p21 Variants and the Ankle-Brachial Index Identified by a Meta-Analysis of 21 Genome-Wide Association Studies

    NARCIS (Netherlands)

    Murabito, Joanne M.; White, Charles C.; Kavousi, Maryam; Sun, Yan V.; Feitosa, Mary F.; Nambi, Vijay; Lamina, Claudia; Schillert, Arne; Coassin, Stefan; Bis, Joshua C.; Broer, Linda; Crawford, Dana C.; Franceschini, Nora; Frikke-Schmidt, Ruth; Haun, Margot; Holewijn, Suzanne; Huffman, Jennifer E.; Hwang, Shih-Jen; Kiechl, Stefan; Kollerits, Barbara; Montasser, May E.; Nolte, Ilja M.; Rudock, Megan E.; Senft, Andrea; Teumer, Alexander; van der Harst, Pim; Vitart, Veronique; Waite, Lindsay L.; Wood, Andrew R.; Wassel, Christina L.; Absher, Devin M.; Allison, Matthew A.; Amin, Najaf; Arnold, Alice; Asselbergs, Folkert W.; Aulchenko, Yurii; Bandinelli, Stefania; Barbalic, Maja; Boban, Mladen; Brown-Gentry, Kristin; Couper, David J.; Criqui, Michael H.; Dehghan, Abbas; den Heijer, Martin; Dieplinger, Benjamin; Ding, Jingzhong; Doerr, Marcus; Espinola-Klein, Christine; Felix, Stephan B.; Ferrucci, Luigi; Folsom, Aaron R.; Fraedrich, Gustav; Gibson, Quince; Goodloe, Robert; Gunjaca, Grgo; Haltmayer, Meinhard; Heiss, Gerardo; Hofman, Albert; Kieback, Arne; Kiemeney, Lambertus A.; Kolcic, Ivana; Kullo, Iftikhar J.; Kritchevsky, Stephen B.; Lackner, Karl J.; Li, Xiaohui; Lieb, Wolfgang; Lohman, Kurt; Meisinger, Christa; Melzer, David; Mohler, Emile R.; Mudnic, Ivana; Mueller, Thomas; Navis, Gerjan; Oberhollenzer, Friedrich; Olin, Jeffrey W.; O'Connell, Jeff; O'Donnell, Christopher J.; Palmas, Walter; Penninx, Brenda W.; Petersmann, Astrid; Polasek, Ozren; Psaty, Bruce M.; Rantner, Barbara; Rice, Ken; Rivadeneira, Fernando; Rotter, Jerome I.; Seldenrijk, Adrie; Stadler, Marietta; Summerer, Monika; Tanaka, Toshiko; Tybjaerg-Hansen, Anne; Uitterlinden, Andre G.; van Gilst, Wiek H.; Vermeulen, Sita H.; Wild, Sarah H.; Wild, Philipp S.; Willeit, Johann; Zeller, Tanja; Zemunik, Tatijana; Zgaga, Lina; Assimes, Themistocles L.; Blankenberg, Stefan; Campbell, Harry; Boerwinkle, Eric; Cooke, John P.; de Graaf, Jacqueline; Herrington, David; Kardia, Sharon L. R.; Mitchell, Braxton D.; Murray, Anna; Muenzel, Thomas; Newman, Anne B.; Oostra, Ben A.; Rudan, Igor; Shuldiner, Alan R.; Snieder, Harold; van Duijn, Cornelia M.; Voelker, Uwe; Wright, Alan F.; Wichmann, H. -Erich; Wilson, James F.; Witteman, Jacqueline C. M.; Liu, Yongmei; Hayward, Caroline; Borecki, Ingrid B.; Ziegler, Andreas; North, Kari E.; Cupples, L. Adrienne; Kronenberg, Florian; Dorr, M.; Munzel, T.; Volker, U.

    Background-Genetic determinants of peripheral arterial disease (PAD) remain largely unknown. To identify genetic variants associated with the ankle-brachial index (ABI), a noninvasive measure of PAD, we conducted a meta-analysis of genome-wide association study data from 21 population-based cohorts.

  15. Association Between Chromosome 9p21 Variants and the Ankle-Brachial Index Identified by a Meta-Analysis of 21 Genome-Wide Association Studies

    DEFF Research Database (Denmark)

    Murabito, Joanne M; White, Charles C; Kavousi, Maryam

    2012-01-01

    BACKGROUND: -Genetic determinants of peripheral arterial disease (PAD) remain largely unknown. To identify genetic variants associated with the ankle-brachial index (ABI), a noninvasive measure of PAD, we conducted a meta-analysis of genome-wide association study data from 21 population-based coh...

  16. Ankle brachial index values, leg symptoms, and functional performance among community-dwelling older men and women in the lifestyle interventions and independence for elders study

    Science.gov (United States)

    The prevalence and significance of low normal and abnormal ankle brachial index (ABI) values in a community dwelling population of sedentary, older individuals is unknown. We describe the prevalence of categories of definite peripheral artery disease (PAD), borderline ABI, low-normal ABI and no PAD...

  17. Brachial Plexus Neuropraxia: A Case Report

    Directory of Open Access Journals (Sweden)

    Bayram Kelle

    2012-08-01

    Full Text Available Neuropraxia develops as a result of localized nerve compression. The anatomical structure of the nerve is protected. Motor loss and paresthesias may occur, pain sensation is rarely affected. The distal portion of the extremities are affected more often. Clinical symptoms respond well to treatments. In this case was presented brachial plexus neuropraxia which is a very rare situation und the literature was reviewed. [Cukurova Med J 2012; 37(4.000: 247-250

  18. Analysis of Arterial Mechanics During Head-Down-Tilt Bed Rest

    Science.gov (United States)

    Elliott, Morgan B.; Martin, David S.; Westby, Christian M.; Stenger, Michael B.; Platts, Steven H.

    2014-01-01

    Carotid, brachial, and tibial arteries reacted differently to HDTBR. Previous studies have not analyzed the mechanical properties of the human brachial or anterior tibial arteries. After slight variations during bed-rest, arterial mechanical properties and IMT returned to pre-bed rest values, with the exception of tibial stiffness and PSE, which continued to be reduced post-bed rest while the DC remained elevated. The tibial artery remodeling was probably due to decreased pressure and volume. Resulting implications for longer duration spaceflight are unclear. Arterial health may be affected by microgravity, as shown by increased thoracic aorta stiffness in other ground based simulations (Aubert).

  19. The natural history and management of brachial plexus birth palsy

    OpenAIRE

    Buterbaugh, Kristin L.; Shah, Apurva S.

    2016-01-01

    Brachial plexus birth palsy (BPBP) is an upper extremity paralysis that occurs due to traction injury of the brachial plexus during childbirth. Approximately 20 % of children with brachial plexus birth palsy will have residual neurologic deficits. These permanent and significant impacts on upper limb function continue to spur interest in optimizing the management of a problem with a highly variable natural history. BPBP is generally diagnosed on clinical examination and does not typically req...

  20. Blood urea level and diabetes duration are independently associated with ankle-brachial index in type 2 diabetic patients.

    NARCIS (Netherlands)

    Bosevski, M.; Soedamah-Muthu, S.S.

    2012-01-01

    Aim

    The purpose of the study was to determine factors of ankle-brachial index (ABI) in a population of patients with type 2 diabetes and coronary artery disease.

    Material and methods

    370 patients (mean age 60.3 ± 8.3 years and diabetes duration 8.6 ± 6.2 years) with type 2

  1. Anatomy and function relation in the coronary tree: from bifurcations to myocardial flow and mass.

    Science.gov (United States)

    Kassab, Ghassan S; Finet, Gerard

    2015-01-01

    The study of the structure-function relation of coronary bifurcations is necessary not only to understand the design of the vasculature but also to use this understanding to restore structure and hence function. The objective of this review is to provide quantitative relations between bifurcation anatomy or geometry, flow distribution in the bifurcation and degree of perfused myocardial mass in order to establish practical rules to guide optimal treatment of bifurcations including side branches (SB). We use the scaling law between flow and diameter, conservation of mass and the scaling law between myocardial mass and diameter to provide geometric relations between the segment diameters of a bifurcation, flow fraction distribution in the SB, and the percentage of myocardial mass perfused by the SB. We demonstrate that the assessment of the functional significance of an SB for intervention should not only be based on the diameter of the SB but also on the diameter of the mother vessel as well as the diameter of the proximal main artery, as these dictate the flow fraction distribution and perfused myocardial mass, respectively. The geometric and flow rules for a bifurcation are extended to a trifurcation to ensure optimal therapy scaling rules for any branching pattern.

  2. Resonant Homoclinic Flips Bifurcation in Principal Eigendirections

    Directory of Open Access Journals (Sweden)

    Tiansi Zhang

    2013-01-01

    Full Text Available A codimension-4 homoclinic bifurcation with one orbit flip and one inclination flip at principal eigenvalue direction resonance is considered. By introducing a local active coordinate system in some small neighborhood of homoclinic orbit, we get the Poincaré return map and the bifurcation equation. A detailed investigation produces the number and the existence of 1-homoclinic orbit, 1-periodic orbit, and double 1-periodic orbits. We also locate their bifurcation surfaces in certain regions.

  3. Brachial blood flow under relative levels of blood flow restriction is decreased in a nonlinear fashion.

    Science.gov (United States)

    Mouser, J Grant; Ade, Carl J; Black, Christopher D; Bemben, Debra A; Bemben, Michael G

    2018-05-01

    Blood flow restriction (BFR), the application of external pressure to occlude venous return and restrict arterial inflow, has been shown to increase muscular size and strength when combined with low-load resistance exercise. BFR in the research setting uses a wide range of pressures, applying a pressure based upon an individual's systolic pressure or a percentage of occlusion pressure; not a directly determined reduction in blood flow. The relationship between relative pressure and blood flow has not been established. To measure blood flow in the arm under relative levels of BFR. Forty-five people (18-40 years old) participated. Arterial occlusion pressure in the right arm was measured using a 5-cm pneumatic cuff. Blood flow in the brachial artery was measured at rest and at pressures between 10% and 90% of occlusion using ultrasound. Blood flow decreased in a nonlinear, stepped fashion. Blood flow decreased at 10% of occlusion and remained constant until decreasing again at 40%, where it remained until 90% of occlusion. The decrease in brachial blood flow is not proportional to the applied relative pressure. The prescription of blood flow restriction should take into account the stimulus provided at each relative level of blood flow. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  4. Brachial edema after treatment of mammary carcinoma. Significance of phlebography

    Energy Technology Data Exchange (ETDEWEB)

    Botsch, H; Soerensen, R [Freie Univ. Berlin (Germany, F.R.). Klinik fuer Radiologie, Nuklearmedizin und Physikalische Therapie

    1977-01-01

    The frequency of thromboses or of obstacles to the venous flow in brachial or axillary regions has been examined by a phlebographic survey of 102 patients who were treated surgically and radiotherapeutically because of cancers of the breast. Thromboses or venous obstruction were found in the 86 patients with brachial edema. Ten of the patients with brachial edema had thromboses. Further 15 suffered from an obstruction to the venous flow. The results are discussed in detail, and compared with the rather contradictory data in literature. As a consequence of this study an indication for brachial phlebography would be justified on a larger scale with patients having been treated surgically because of mammary carcinoma.

  5. Percutaneous coronary intervention for the left main stem and other bifurcation lesions: 12th consensus document from the European Bifurcation Club.

    Science.gov (United States)

    Lassen, Jens Flensted; Burzotta, Francesco; Banning, Adrian P; Lefèvre, Thierry; Darremont, Olivier; Hildick-Smith, David; Chieffo, Alaide; Pan, Manuel; Holm, Niels Ramsing; Louvard, Yves; Stankovic, Goran

    2018-01-20

    The European Bifurcation Club (EBC) was initiated in 2004 to support a continuous overview of the field of coronary artery bifurcation interventions and aims to facilitate a scientific discussion and an exchange of ideas on the management of bifurcation disease. The EBC hosts an annual, two-day compact meeting, dedicated to bifurcations, which brings together physicians, pathologists, engineers, biologists, physicists, mathematicians, epidemiologists and statisticians for detailed discussions. Every meeting is finalised with a consensus statement that reflects the unique opportunity of combining the opinion of interventional cardiologists with the opinion of a large variety of other scientists on bifurcation management. A series of consensus sessions dedicated to specific topics, to strengthen the consensus debates and focus the discussions, was introduced at this year's meeting. The sessions comprise an intensive overview of the present literature, a pro and con debate and a voting system, to guide the consensus-building process. The present document represents the summary of the up-to-date EBC consensus and recommendations from the 12th annual EBC meeting in 2016 in Rotterdam.

  6. Ultrasound-guided approach for axillary brachial plexus, femoral nerve, and sciatic nerve blocks in dogs.

    Science.gov (United States)

    Campoy, Luis; Bezuidenhout, Abraham J; Gleed, Robin D; Martin-Flores, Manuel; Raw, Robert M; Santare, Carrie L; Jay, Ariane R; Wang, Annie L

    2010-03-01

    To describe an ultrasound-guided technique and the anatomical basis for three clinically useful nerve blocks in dogs. Prospective experimental trial. Four hound-cross dogs aged 2 +/- 0 years (mean +/- SD) weighing 30 +/- 5 kg and four Beagles aged 2 +/- 0 years and weighing 8.5 +/- 0.5 kg. Axillary brachial plexus, femoral, and sciatic combined ultrasound/electrolocation-guided nerve blocks were performed sequentially and bilaterally using a lidocaine solution mixed with methylene blue. Sciatic nerve blocks were not performed in the hounds. After the blocks, the dogs were euthanatized and each relevant site dissected. Axillary brachial plexus block Landmark blood vessels and the roots of the brachial plexus were identified by ultrasound in all eight dogs. Anatomical examination confirmed the relationship between the four ventral nerve roots (C6, C7, C8, and T1) and the axillary vessels. Three roots (C7, C8, and T1) were adequately stained bilaterally in all dogs. Femoral nerve block Landmark blood vessels (femoral artery and femoral vein), the femoral and saphenous nerves and the medial portion of the rectus femoris muscle were identified by ultrasound in all dogs. Anatomical examination confirmed the relationship between the femoral vessels, femoral nerve, and the rectus femoris muscle. The femoral nerves were adequately stained bilaterally in all dogs. Sciatic nerve block. Ultrasound landmarks (semimembranosus muscle, the fascia of the biceps femoris muscle and the sciatic nerve) could be identified in all of the dogs. In the four Beagles, anatomical examination confirmed the relationship between the biceps femoris muscle, the semimembranosus muscle, and the sciatic nerve. In the Beagles, all but one of the sciatic nerves were stained adequately. Ultrasound-guided needle insertion is an accurate method for depositing local anesthetic for axillary brachial plexus, femoral, and sciatic nerve blocks.

  7. A unique branching pattern of the axillary artery: a case report.

    Science.gov (United States)

    Bagoji, Ishwar B; Hadimani, Gavishiddappa A; Bannur, Balappa M; Patil, B G; Bharatha, Ambadasu

    2013-12-01

    During routine dissection classes for under graduate students, we found a unique and unusual case regarding the anomalous branching in the third part of the axillary artery was terminated into subscapular arterial trunk, superficial brachial artery and deep brachial artery. The subscapular arterial trunk was origin of several important arteries as the circumflex scapular, thoracodorsal, posterior circumflex humeral, thoraco-acromial and lateral thoracic arteries. The deep brachial artery in the arm gave anterior circumflex humeral artery at the surgical neck of humerus, which terminated in the cubital fossa by dividing into radial and ulnar arteries. The superficial brachial artery gave two profunda brachii arteries, both of which passed through spiral groove, along with radial nerve and three muscular branches, to brachialis muscle. This variation is very rare. As per our knowledge, we did not find any literature which explained variations which were similar to this. The normal and abnormal anatomy of the axillary region has practical importance among vascular radiologists and surgeons and it should be known for making an accurate diagnostic interpretation.

  8. [The ankle brachial index in type 2 diabetes].

    Science.gov (United States)

    Nussbaumerová, B; Rosolová, H; Ferda, J; Sifalda, P; Sípová, I; Sefrna, F

    2011-03-01

    The ankle brachial index (ABI), i.e. the ratio of systolic blood pressure (SBP) on the ankle and on the arm, is diagnostic for peripheral occlusive artery disease and a marker of cardiovascular (CV) risk. The association between the low ABI 101) or according to the global CV Risk Score > or = 5% (SCORE). Wilcoxon's unpaired test, chi2 test, multiple logistic regression. The ABI homocystein (17.2 +/- 7.1 micromol/L) (p or = 0.9 (age 66 +/- 9 years, CAC 234 +/- 458, total cholesterol 5.0 +/- 0.9, total homocystein 14.3 +/- 78). Many CV risk factors correlated positively with the low ABI homocystein and CAC (p < 0.05). Low ABI < 0.9 predicted ischemic stroke in subjects with T2DM and manifest CV diseases in the further 3 years. There was no correlation between the ABI and the ultrasensitive C-reactive protein. Low ABI < 0.9 was in a strong association with the CV risk. The ABI measurement is a simple, noninvasive, time-nonconsuming and inexpensive method for subclinical atherosclerosis detection; the ABI can supply standard methods for the CV risk prediction.

  9. Ankle-brachial index by automated method and renal function

    Directory of Open Access Journals (Sweden)

    Ricardo Pereira Silva

    2017-05-01

    Full Text Available Background The Ankle-brachial index (ABI is a non-invasive method used for the diagnosis of peripheral arterial occlusive disease (PAOD. Aims To determine the clinical features of patients submitted to ABI measurement by automatic method. To investigate association between ABI and renal function. Methods The present is a cross-sectional study. The study was performed in a private clinic in the city of Fortaleza (Ce- Brazil. For ABI analysis, we utilized automatic methodology using a Microlife device. Data collection took place from March 2012 to January 2016. During this period, ABI was measured in 375 patients aged >50 years, who had a diagnosis of hypertension, diabetes or vascular disease. Results Of the 375 patients, 18 were categorized as having abnormal ABI (4.8 per cent and 357 were normal ABI (95.2 per cent. Patients with abnormal ABI showed older mean age when compared to patients with normal ABI. Among patients with normal renal function, only 0.95 per cent showed abnormal ABI; among patients with abnormal renal function, 6 per cent showed abnormal ABI. Conclusion 1 No differences were observed when comparing the groups regarding gender or the prevalence of hypertension, diabetes, dyslipidaemia or CAD. 2 Group with abnormal ABI had renal function greater impairment.

  10. Bifurcations of optimal vector fields: an overview

    NARCIS (Netherlands)

    Kiseleva, T.; Wagener, F.; Rodellar, J.; Reithmeier, E.

    2009-01-01

    We develop a bifurcation theory for the solution structure of infinite horizon optimal control problems with one state variable. It turns out that qualitative changes of this structure are connected to local and global bifurcations in the state-costate system. We apply the theory to investigate an

  11. Anomalous patterns of formation and distribution of the brachial ...

    African Journals Online (AJOL)

    block Background: Structural variations in the patterns of formation and distribution of the brachial plexus have drawn attentions both in anatomy and anaesthesia. Method: An observational study. Results: The brachial plexus was carefully inspected in both the right and left arms in 90 Nigerian cadavers, comprising of 74 ...

  12. Muscle and joint sequelae in brachial plexus injury

    NARCIS (Netherlands)

    Duijnisveld, B.J.

    2016-01-01

    A brachial plexus injury is caused by traction on the brachial plexus during delivery or due to a high-energy road traffic accident in young adults. Muscle denervation and subsequent muscle degeneration results in functional limitations of the shoulder, elbow, wrist and hand including contractures

  13. Bifurcation of the spin-wave equations

    International Nuclear Information System (INIS)

    Cascon, A.; Koiller, J.; Rezende, S.M.

    1990-01-01

    We study the bifurcations of the spin-wave equations that describe the parametric pumping of collective modes in magnetic media. Mechanisms describing the following dynamical phenomena are proposed: (i) sequential excitation of modes via zero eigenvalue bifurcations; (ii) Hopf bifurcations followed (or not) by Feingenbaum cascades of period doubling; (iii) local and global homoclinic phenomena. Two new organizing center for routes to chaos are identified; in the classification given by Guckenheimer and Holmes [GH], one is a codimension-two local bifurcation, with one pair of imaginary eigenvalues and a zero eigenvalue, to which many dynamical consequences are known; secondly, global homoclinic bifurcations associated to splitting of separatrices, in the limit where the system can be considered a Hamiltonian subjected to weak dissipation and forcing. We outline what further numerical and algebraic work is necessary for the detailed study following this program. (author)

  14. Voltage stability, bifurcation parameters and continuation methods

    Energy Technology Data Exchange (ETDEWEB)

    Alvarado, F L [Wisconsin Univ., Madison, WI (United States)

    1994-12-31

    This paper considers the importance of the choice of bifurcation parameter in the determination of the voltage stability limit and the maximum power load ability of a system. When the bifurcation parameter is power demand, the two limits are equivalent. However, when other types of load models and bifurcation parameters are considered, the two concepts differ. The continuation method is considered as a method for determination of voltage stability margins. Three variants of the continuation method are described: the continuation parameter is the bifurcation parameter the continuation parameter is initially the bifurcation parameter, but is free to change, and the continuation parameter is a new `arc length` parameter. Implementations of voltage stability software using continuation methods are described. (author) 23 refs., 9 figs.

  15. Brachial plexopathy: recurrent cancer or radiation

    International Nuclear Information System (INIS)

    Lederman, R.J.; Wilbourn, A.J.

    1984-01-01

    We reviewed clinical and electrodiagnostic features of 16 patients with neoplastic brachial plexopathy (NBP) and 17 patients with radiation-induced plexopathy (RBP). The groups were similar in symptom-free interval after cancer diagnosis and location of the plexus lesions. NBP patients had pain and Horner's syndrome; RBP patients had paresthesias, but rarely Horner's. NBP patients presented earlier after symptom onset and had a shorter course. RBP patients more frequently had abnormal sensory and normal motor nerve conduction studies and characteristically had fasciculations or myokymia on EMG

  16. Bifurcation and chaos in neural excitable system

    International Nuclear Information System (INIS)

    Jing Zhujun; Yang Jianping; Feng Wei

    2006-01-01

    In this paper, we investigate the dynamical behaviors of neural excitable system without periodic external current (proposed by Chialvo [Generic excitable dynamics on a two-dimensional map. Chaos, Solitons and Fractals 1995;5(3-4):461-79] and with periodic external current as system's parameters vary. The existence and stability of three fixed points, bifurcation of fixed points, the conditions of existences of fold bifurcation, flip bifurcation and Hopf bifurcation are derived by using bifurcation theory and center manifold theorem. The chaotic existence in the sense of Marotto's definition of chaos is proved. We then give the numerical simulated results (using bifurcation diagrams, computations of Maximum Lyapunov exponent and phase portraits), which not only show the consistence with the analytic results but also display new and interesting dynamical behaviors, including the complete period-doubling and inverse period-doubling bifurcation, symmetry period-doubling bifurcations of period-3 orbit, simultaneous occurrence of two different routes (invariant cycle and period-doubling bifurcations) to chaos for a given bifurcation parameter, sudden disappearance of chaos at one critical point, a great abundance of period windows (period 2 to 10, 12, 19, 20 orbits, and so on) in transient chaotic regions with interior crises, strange chaotic attractors and strange non-chaotic attractor. In particular, the parameter k plays a important role in the system, which can leave the chaotic behavior or the quasi-periodic behavior to period-1 orbit as k varies, and it can be considered as an control strategy of chaos by adjusting the parameter k. Combining the existing results in [Generic excitable dynamics on a two-dimensional map. Chaos, Solitons and Fractals 1995;5(3-4):461-79] with the new results reported in this paper, a more complete description of the system is now obtained

  17. A comparison between brachial and echocardiographic systolic time intervals.

    Directory of Open Access Journals (Sweden)

    Ho-Ming Su

    Full Text Available Systolic time interval (STI is an established noninvasive technique for the assessment of cardiac function. Brachial STIs can be automatically determined by an ankle-brachial index (ABI-form device. The aims of this study are to evaluate whether the STIs measured from ABI-form device can represent those measured from echocardiography and to compare the diagnostic values of brachial and echocardiographic STIs in the prediction of left ventricular ejection fraction (LVEF <50%. A total of 849 patients were included in the study. Brachial pre-ejection period (bPEP and brachial ejection time (bET were measured using an ABI-form device and pre-ejection period (PEP and ejection time (ET were measured from echocardiography. Agreement was assessed by correlation coefficient and Bland-Altman plot. Brachial STIs had a significant correlation with echocardiographic STIs (r = 0.644, P<0.001 for bPEP and PEP; r  = 0.850, P<0.001 for bET and ET; r = 0.708, P<0.001 for bPEP/bET and PEP/ET. The disagreement between brachial and echocardiographic STIs (brachial STIs minus echocardiographic STIs was 28.55 ms for bPEP and PEP, -4.15 ms for bET and ET and -0.11 for bPEP/bET and PEP/ET. The areas under the curve for bPEP/bET and PEP/ET in the prediction of LVEF <50% were 0.771 and 0.765, respectively. Brachial STIs were good alternatives to STIs obtained from echocardiography and also helpful in prediction of LVEF <50%. Brachial STIs automatically obtained from an ABI-form device may be helpful for evaluation of left ventricular systolic dysfunction.

  18. Use of short-radius centrifugation to augment ankle-brachial indices.

    Science.gov (United States)

    Grenon, S Marlene; Mateus, Jaime; Hsiang, York; Sidhu, Ravi; Young, Laurence; Gagnon, Joel

    2009-06-01

    Peripheral arterial disease is mainly caused by atherosclerosis and is characterized by decreased circulation, lower blood pressure, and insufficient tissue perfusion in the lower extremities. The hemodynamics of standing and altered gravity environments have been well studied relative to arm blood pressures but are less well understood for ankle pressures. Because regional blood pressure depends, in part, on the gravitational pressure gradient, we hypothesized that artificial gravity exposure on a short-arm centrifuge with the center of rotation above the head would increase blood pressure in the lower extremities. Cardiovascular parameters for 12 healthy subjects were measured during exposure to supine short-arm centrifugation at 20, 25, and 30 revolutions per minute (rpm), corresponding to centripetal accelerations of 0.94, 1.47, and 2.11 Gz at the foot level, respectively. Systolic ankle blood pressure significantly increased at all levels of centrifugation. Ankle-brachial indices (the ratio of systolic ankle to arm blood pressures) increased significantly from 1.17 +/- 0.03 to 1.58 +/- 0.03 at 0.94 Gz (P blood pressure significantly increased at 2.11 Gz, but heart rate did not change significantly. All parameters returned to normal after cessation of centrifugation. We demonstrated that short-radius centrifugation leads to an increase in ankle-brachial indices. This could have potential implications for the treatment of peripheral arterial disease.

  19. Nonlinear stability control and λ-bifurcation

    International Nuclear Information System (INIS)

    Erneux, T.; Reiss, E.L.; Magnan, J.F.; Jayakumar, P.K.

    1987-01-01

    Passive techniques for nonlinear stability control are presented for a model of fluidelastic instability. They employ the phenomena of λ-bifurcation and a generalization of it. λ-bifurcation occurs when a branch of flutter solutions bifurcates supercritically from a basic solution and terminates with an infinite period orbit at a branch of divergence solutions which bifurcates subcritically from the basic solution. The shape of the bifurcation diagram then resembles the greek letter λ. When the system parameters are in the range where flutter occurs by λ-bifurcation, then as the flow velocity increase the flutter amplitude also increases, but the frequencies of the oscillations decrease to zero. This diminishes the damaging effects of structural fatigue by flutter, and permits the flow speed to exceed the critical flutter speed. If generalized λ-bifurcation occurs, then there is a jump transition from the flutter states to a divergence state with a substantially smaller amplitude, when the flow speed is sufficiently larger than the critical flutter speed

  20. Quantum entanglement and fixed-point bifurcations

    International Nuclear Information System (INIS)

    Hines, Andrew P.; McKenzie, Ross H.; Milburn, G.J.

    2005-01-01

    How does the classical phase-space structure for a composite system relate to the entanglement characteristics of the corresponding quantum system? We demonstrate how the entanglement in nonlinear bipartite systems can be associated with a fixed-point bifurcation in the classical dynamics. Using the example of coupled giant spins we show that when a fixed point undergoes a supercritical pitchfork bifurcation, the corresponding quantum state--the ground state--achieves its maximum amount of entanglement near the critical point. We conjecture that this will be a generic feature of systems whose classical limit exhibits such a bifurcation

  1. A case study in bifurcation theory

    Science.gov (United States)

    Khmou, Youssef

    This short paper is focused on the bifurcation theory found in map functions called evolution functions that are used in dynamical systems. The most well-known example of discrete iterative function is the logistic map that puts into evidence bifurcation and chaotic behavior of the topology of the logistic function. We propose a new iterative function based on Lorentizan function and its generalized versions, based on numerical study, it is found that the bifurcation of the Lorentzian function is of second-order where it is characterized by the absence of chaotic region.

  2. Bifurcations of non-smooth systems

    Science.gov (United States)

    Angulo, Fabiola; Olivar, Gerard; Osorio, Gustavo A.; Escobar, Carlos M.; Ferreira, Jocirei D.; Redondo, Johan M.

    2012-12-01

    Non-smooth systems (namely piecewise-smooth systems) have received much attention in the last decade. Many contributions in this area show that theory and applications (to electronic circuits, mechanical systems, …) are relevant to problems in science and engineering. Specially, new bifurcations have been reported in the literature, and this was the topic of this minisymposium. Thus both bifurcation theory and its applications were included. Several contributions from different fields show that non-smooth bifurcations are a hot topic in research. Thus in this paper the reader can find contributions from electronics, energy markets and population dynamics. Also, a carefully-written specific algebraic software tool is presented.

  3. Effect of dietary intervention and lipid-lowering treatment on brachial vasoreactivity in patients with ischemic heart disease and hypercholesterolemia

    DEFF Research Database (Denmark)

    Søndergaard, Eva; Møller, Jacob E; Egstrup, Kenneth

    2003-01-01

    BACKGROUND: The "Mediterranean" diet and statin treatment have both independently been shown to improve survival and reduce the risk of cardiovascular events in patients with ischemic heart disease (IHD), but no studies have evaluated the effect of this combination on endothelial function. We...... factors and vessel size (P =.02; beta = -2.66 [-4.91; -0.41]). CONCLUSION: Dietary intervention with the Mediterranean diet and statin treatment improve FMD in the brachial artery in patients with IHD and hypercholesterolemia to a greater degree than statin treatment alone....... therefore sought to evaluate the effect of the combination dietary intervention and lipid-lowering treatment on brachial vasoreactivity. METHODS: A total of 131 consecutive patients with documented IHD and a serum cholesterol level > or =5 mmol/L (193 mg/dL) were randomized to receive Mediterranean dietary...

  4. Bifurcation Control of Chaotic Dynamical Systems

    National Research Council Canada - National Science Library

    Wang, Hua O; Abed, Eyad H

    1992-01-01

    A nonlinear system which exhibits bifurcations, transient chaos, and fully developed chaos is considered, with the goal of illustrating the role of two ideas in the control of chaotic dynamical systems...

  5. Bifurcation and instability problems in vortex wakes

    DEFF Research Database (Denmark)

    Aref, Hassan; Brøns, Morten; Stremler, Mark A.

    2007-01-01

    A number of instability and bifurcation problems related to the dynamics of vortex wake flows are addressed using various analytical tools and approaches. We discuss the bifurcations of the streamline pattern behind a bluff body as a vortex wake is produced, a theory of the universal Strouhal......-Reynolds number relation for vortex wakes, the bifurcation diagram for "exotic" wake patterns behind an oscillating cylinder first determined experimentally by Williamson & Roshko, and the bifurcations in topology of the streamlines pattern in point vortex streets. The Hamiltonian dynamics of point vortices...... in a periodic strip is considered. The classical results of von Kármán concerning the structure of the vortex street follow from the two-vortices-in-a-strip problem, while the stability results follow largely from a four-vortices-in-a-strip analysis. The three-vortices-in-a-strip problem is argued...

  6. Bifurcation structure of successive torus doubling

    International Nuclear Information System (INIS)

    Sekikawa, Munehisa; Inaba, Naohiko; Yoshinaga, Tetsuya; Tsubouchi, Takashi

    2006-01-01

    The authors discuss the 'embryology' of successive torus doubling via the bifurcation theory, and assert that the coupled map of a logistic map and a circle map has a structure capable of generating infinite number of torus doublings

  7. Role of ultrasound-guided continuous brachial plexus block in the management of neonatal ischemia in upper limb

    Directory of Open Access Journals (Sweden)

    Vrushali C Ponde

    2012-01-01

    Full Text Available Neonatal upper limb ischemia due to accidental arterial damage remains a major concern, which can lead to devastating complications if untreated. The primary objective of this case report is to emphasize the role of continuous infraclavicular brachial plexus block, the issues related with block performance in an ischemic hand, and the importance of ultrasound guidance in this particular case scenario. A 1.1 kg infant suffered from distal forearm ischemia due to accidental arterial damage, which was treated with brachial plexus block. An ultrasound-guided single shot block with 0.5 mL/kg of 0.25% bupivacaine was followed by ultrasound-guided catheter placement in the target area. A continuous infusion of 0.03% of bupivacaine at the rate of 0.5 mL/kg/hr (approx. 0.15 mg/kg/h of bupivacaine was administered for 36 h. This treatment resulted in reversal of ischemia. Permanent ischemic damage was eventually confined to the tips of 4 fingers. We conclude that ultrasound-guided continuous infraclavicular block has a therapeutic role to play in the treatment of hand ischemia due to arterial damage and subsequent arterial spasm in neonates with added benefits.

  8. Neurotization of elements of the brachial plexus.

    Science.gov (United States)

    Friedman, A H

    1991-01-01

    Satisfactory therapy for an avulsion injury of the brachial plexus has yet to be described. Dorsal root entry zone lesions will usually mitigate the searing pain which is so disabling in some of these patients. Neurotization procedures are effective in restoring limited function to these patients. The most useful isolated movement of the upper extremity is elbow flexion, which is thus the primary target of neurotization procedures. Intercostal nerves and elements of the cervical plexus are the most commonly used donor nerves for neurotization procedures. From our experience and from a review of the literature, it appears that these procedures will be successful in approximately 50% of cases. It must be stressed that before performing a nerve transfer, the surgeon must be certain that the patient is not a candidate for a simple nerve graft.

  9. Arterial endothelial function measurement method and apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Maltz, Jonathan S; Budinger, Thomas F

    2014-03-04

    A "relaxoscope" (100) detects the degree of arterial endothelial function. Impairment of arterial endothelial function is an early event in atherosclerosis and correlates with the major risk factors for cardiovascular disease. An artery (115), such as the brachial artery (BA) is measured for diameter before and after several minutes of either vasoconstriction or vasorelaxation. The change in arterial diameter is a measure of flow-mediated vasomodification (FMVM). The relaxoscope induces an artificial pulse (128) at a superficial radial artery (115) via a linear actuator (120). An ultrasonic Doppler stethoscope (130) detects this pulse 10-20 cm proximal to the point of pulse induction (125). The delay between pulse application and detection provides the pulse transit time (PTT). By measuring PTT before (160) and after arterial diameter change (170), FMVM may be measured based on the changes in PTT caused by changes in vessel caliber, smooth muscle tone and wall thickness.

  10. Hopf bifurcation in an Internet congestion control model

    International Nuclear Information System (INIS)

    Li Chunguang; Chen Guanrong; Liao Xiaofeng; Yu Juebang

    2004-01-01

    We consider an Internet model with a single link accessed by a single source, which responds to congestion signals from the network, and study bifurcation of such a system. By choosing the gain parameter as a bifurcation parameter, we prove that Hopf bifurcation occurs. The stability of bifurcating periodic solutions and the direction of the Hopf bifurcation are determined by applying the normal form theory and the center manifold theorem. Finally, a numerical example is given to verify the theoretical analysis

  11. Discretization analysis of bifurcation based nonlinear amplifiers

    Science.gov (United States)

    Feldkord, Sven; Reit, Marco; Mathis, Wolfgang

    2017-09-01

    Recently, for modeling biological amplification processes, nonlinear amplifiers based on the supercritical Andronov-Hopf bifurcation have been widely analyzed analytically. For technical realizations, digital systems have become the most relevant systems in signal processing applications. The underlying continuous-time systems are transferred to the discrete-time domain using numerical integration methods. Within this contribution, effects on the qualitative behavior of the Andronov-Hopf bifurcation based systems concerning numerical integration methods are analyzed. It is shown exemplarily that explicit Runge-Kutta methods transform the truncated normalform equation of the Andronov-Hopf bifurcation into the normalform equation of the Neimark-Sacker bifurcation. Dependent on the order of the integration method, higher order terms are added during this transformation.A rescaled normalform equation of the Neimark-Sacker bifurcation is introduced that allows a parametric design of a discrete-time system which corresponds to the rescaled Andronov-Hopf system. This system approximates the characteristics of the rescaled Hopf-type amplifier for a large range of parameters. The natural frequency and the peak amplitude are preserved for every set of parameters. The Neimark-Sacker bifurcation based systems avoid large computational effort that would be caused by applying higher order integration methods to the continuous-time normalform equations.

  12. Description of the celiac artery in domestic pigeons (Columba livia

    Directory of Open Access Journals (Sweden)

    Cibele Geeverghese

    2012-06-01

    Full Text Available This paper aimed to define the origin and distribution of the celiac artery and its collateral branches in 15 fowls from the Columba livia species, which were obtained from the Zoonosis Control Center of Brasilia, Brazil. In order to mark the arterial system of the specimens, the left brachiocephalic trunk was canullated and a colored water-latex solution was injected there. Afterwards, fowls were fixed in a 10% v/v formaldehyde solution and dissected with appropriate equipment, presenting the results described in this paper. The celiac artery originated from the ventral face of the descendent aorta. The first collateral branch arose from the celiac artery itself, forming the esophageal artery. Then, the celiac artery has bifurcated into two branches, named left and right branches of the celiac artery. The left branch emitted the proventricular ventral artery, followed by the splenic arteries, proventricular dorsal artery, and the left hepatic artery. The left branch has bifurcated into two branches, known as ventral and left gastric arteries. The right branch emitted the right hepatic artery, followed by the ileal artery and the right gastric artery. Finally, the right branch turned into the pancreaticoduodenal artery. Our findings showed a great similarity with the avian lineages of the Gallus gallus species, except for the lack of ileocecal artery, cystic branches, and dorsal gastric artery.

  13. Brachiomedian artery (arteria brachiomediana revisited: a comprehensive review

    Directory of Open Access Journals (Sweden)

    David Kachlik

    2016-03-01

    Full Text Available This article reviews in detail the superficial brachiomedian artery (arteria brachiomediana superficialis, a very rare variant of the main arterial trunks of the upper limb. It branches either from the axillary artery or the brachial artery, descends superficially in the arm (similar to the course of the superficial brachial artery and continues across the cubital fossa, runs superficially in the forearm, approaches the median nerve and enters the carpal canal to reach the hand. It usually terminates in the superficial palmar arch. The first drawing was published, in 1830, and the first description was published, in 1844. Altogether, to our knowledge, only 31 cases of a true, superficial brachiomedian artery have been reported (Some cases are incorrectly reported as superficial brachioradiomedian artery or superficial brachioulnomedian artery. Based on a meta-analysis of known, available studies, the incidence is 0.23% in Caucasians and 1.48% in Mongolians. Knowing whether or not this arterial variant is present is important in clinical medicine and relevant for: The catheterization via the radial or ulnar artery; harvesting the vascular pedicle for a forearm flap based on the radial, ulnar or superficial brachiomedian arteries; the possible collateral circulation in cases of the arterial closure; and the surgical management of carpal tunnel syndrome. Its presence can elevate the danger of an injury to the superficially located variant artery or of an accidental injection.

  14. Brachial plexus endoscopic dissection and correlation with open dissection.

    Science.gov (United States)

    Lafosse, T; Masmejean, E; Bihel, T; Lafosse, L

    2015-12-01

    Shoulder endoscopy is evolving and becoming extra-articular. More and more procedures are taking place in the area of the brachial plexus (BP). We carried out an anatomical study to describe the endoscopic anatomy of the BP and the technique used to dissect and expose the BP endoscopically. Thirteen fresh cadavers were dissected. We first performed an endoscopic dissection of the BP, using classical extra-articular shoulder arthroscopy portals. Through each portal, we dissected as many structures as possible and identified them. We then did an open dissection to corroborate the endoscopic findings and to look for damage to the neighboring structures. In the supraclavicular area, we were able to expose the C5, C6 and C7 roots, and the superior and middle trunks in 11 of 13 specimens through two transtrapezial portals by following the suprascapular nerve. The entire infraclavicular portion of the BP (except the medial cord and its branches) was exposed in 11 of 13 specimens. The approach to the infraclavicular portion of the BP led directly to the lateral and posterior cords, but the axillary artery hid the medial cord. The musculocutaneous nerve was the first nerve encountered when dissecting medially from the anterior aspect of the coracoid process. The axillary nerve was the first nerve encountered when following the anterior border of the subscapularis medially from the posterior aspect of the coracoid process. Knowledge of the endoscopic anatomy of the BP is mandatory to expose and protect this structure while performing advanced arthroscopic shoulder procedures. Copyright © 2015 SFCM. Published by Elsevier Masson SAS. All rights reserved.

  15. Schwannoma of the left brachial plexus mimicking a ...

    African Journals Online (AJOL)

    Schwannoma of the left brachial plexus mimicking a cervicomediastinal ... Her voice was hoarse but there was no eye signs suggestive of thyrotoxicosis. ... A presumptive diagnosis of thyroid carcinoma with retrosternal extension was made.

  16. Nerve Transfers for Traumatic Brachial Plexus Injury: Advantages and Problems

    OpenAIRE

    Hems, Tim

    2011-01-01

    In recent years nerve transfers have been increasingly used to broaden reconstructive options for brachial plexus reconstruction. Nerve transfer is a procedure where an expendable nerve is connected to a more important nerve in order to reinnervate that nerve. This article outlines the experience of the Scottish National Brachial Plexus Injury Service as our use of nerve transfers has increased. Outcomes have improved for reconstruction of the paralysed shoulder using transfer of the accessor...

  17. Transcutaneous measurement of the arterial input function in positron emission tomography

    International Nuclear Information System (INIS)

    Litton, J.E.; Eriksson, L.

    1990-01-01

    Positron emission tomography (PET) provides a powerful tool in medical research. Biochemical function can be both precisely localized and quantitatively measured. To achieve reliable quantitation it is necessary to know the time course of activity concentration in the arterial blood during the measurement. In this study the arterial blood curve from the brachial artery is compared to the activity measured in the internal carotid artery with a new transcutaneous detector

  18. Technique and results of femoral bifurcation endarterectomy by eversion.

    Science.gov (United States)

    Dufranc, Julie; Palcau, Laura; Heyndrickx, Maxime; Gouicem, Djelloul; Coffin, Olivier; Felisaz, Aurélien; Berger, Ludovic

    2015-03-01

    , with a statistically higher rate for patients with malnutrition (P = .029), preoperative platelet count >450 ×10(9)/L (P = .0071), platelet aggregation inhibitor treatment other than clopidogrel (P = .022), preoperative deep femoral artery occlusion or stenosis >75% (P = .0064), and poor tibial runoff (P = .00042). Eversion femoral bifurcation endarterectomy is a safe, efficient, and reproducible technique for the treatment of atherosclerotic femoral lesions. Advantages are notable, especially the lack of need for prosthetic angioplasty, eliminating the risk of patch infection or pseudoaneurysms and permitting direct puncture if endovascular procedures are needed for assisted patency. Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  19. Geometrically Induced Interactions and Bifurcations

    Science.gov (United States)

    Binder, Bernd

    2010-01-01

    In order to evaluate the proper boundary conditions in spin dynamics eventually leading to the emergence of natural and artificial solitons providing for strong interactions and potentials with monopole charges, the paper outlines a new concept referring to a curvature-invariant formalism, where superintegrability is given by a special isometric condition. Instead of referring to the spin operators and Casimir/Euler invariants as the generator of rotations, a curvature-invariant description is introduced utilizing a double Gudermann mapping function (generator of sine Gordon solitons and Mercator projection) cross-relating two angular variables, where geometric phases and rotations arise between surfaces of different curvature. Applying this stereographic projection to a superintegrable Hamiltonian can directly map linear oscillators to Kepler/Coulomb potentials and/or monopoles with Pöschl-Teller potentials and vice versa. In this sense a large scale Kepler/Coulomb (gravitational, electro-magnetic) wave dynamics with a hyperbolic metric could be mapped as a geodesic vertex flow to a local oscillator singularity (Dirac monopole) with spherical metrics and vice versa. Attracting fixed points and dynamic constraints are given by special isometries with magic precession angles. The nonlinear angular encoding directly provides for a Shannon mutual information entropy measure of the geodesic phase space flow. The emerging monopole patterns show relations to spiral Fresnel holography and Berry/Aharonov-Bohm geometric phases subject to bifurcation instabilities and singularities from phase ambiguities due to a local (entropy) overload. Neutral solitons and virtual patterns emerging and mediating in the overlap region between charged or twisted holographic patterns are visualized and directly assigned to the Berry geometric phase revealing the role of photons, neutrons, and neutrinos binding repulsive charges in Coulomb, strong and weak interaction.

  20. Flow visualisation study of spiral flow in the aorta-renal bifurcation.

    Science.gov (United States)

    Fulker, David; Javadzadegan, Ashkan; Li, Zuming; Barber, Tracie

    2017-10-01

    The aim of this study was to analyse the flow dynamics in an idealised model of the aorta-renal bifurcation using flow visualisation, with a particular focus on the effect of aorta-to-renal flow ratio and flow spirality. The recirculation length was longest when there was low flow in the renal artery and smaller in the presence of spiral flow. The results also indicate that patients without spiral flow or who have low flow in the renal artery due to the presence of stenosis may be susceptible to heightened development of atherosclerotic lesions.

  1. Índice tornozelo-braço em pacientes hemodialíticos Ankle-brachial index in hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Mariane Torres Uchôa

    2012-12-01

    . The ankle-brachial index was calculated for each artery of the lower limb. It was considered normal ankle-brachial index from 0.9 to 1.3. RESULTS: We diagnosed peripheral arterial disease and poorly compressible arteries in 26.9 and 30.8% of hemodialysis patients and in 33 and 22.7% of the Control Group. In hemodialysis patients, we found abnormal ankle-brachial index in 75% of symptomatic patients (p=0.005, in 67.3% of men and 31% of women (p<0.005, in 78.6% of the elderly, 34.8% of young adults (p<0.01, and 76.9% of diabetics (p<0.005 versus nondiabetic. These patients had a higher prevalence of severe peripheral arterial disease than the Control Group. CONCLUSIONS: Abnormal ankle-brachial index was very prevalent in the groups studied; however, hemodialysis patients had more severe changes, when compared to the Control Group. Diabetes mellitus, male gender, and advanced age were important risk factors for abnormal ankle-brachial index in hemodialysis patients. The ankle-brachial index was a good method of screening for the studied changes; therefore, we suggest the routine use in the management of hemodialysis patients.

  2. Cutting Balloon Angioplasty in the Treatment of Short Infrapopliteal Bifurcation Disease.

    Science.gov (United States)

    Iezzi, Roberto; Posa, Alessandro; Santoro, Marco; Nestola, Massimiliano; Contegiacomo, Andrea; Tinelli, Giovanni; Paolini, Alessandra; Flex, Andrea; Pitocco, Dario; Snider, Francesco; Bonomo, Lorenzo

    2015-08-01

    To evaluate the safety, feasibility, and effectiveness of cutting balloon angioplasty in the management of infrapopliteal bifurcation disease. Between November 2010 and March 2013, 23 patients (mean age 69.6±9.01 years, range 56-89; 16 men) suffering from critical limb ischemia were treated using cutting balloon angioplasty (single cutting balloon, T-shaped double cutting balloon, or double kissing cutting balloon technique) for 47 infrapopliteal artery bifurcation lesions (16 popliteal bifurcation and 9 tibioperoneal bifurcation) in 25 limbs. Follow-up consisted of clinical examination and duplex ultrasonography at 1 month and every 3 months thereafter. All treatments were technically successful. No 30-day death or adverse events needing treatment were registered. No flow-limiting dissection was observed, so no stent implantation was necessary. The mean postprocedure minimum lumen diameter and acute gain were 0.28±0.04 and 0.20±0.06 cm, respectively, with a residual stenosis of 0.04±0.02 cm. Primary and secondary patency rates were estimated as 89.3% and 93.5% at 6 months and 77.7% and 88.8% at 12 months, respectively; 1-year primary and secondary patency rates of the treated bifurcation were 74.2% and 87.0%, respectively. The survival rate estimated by Kaplan-Meier analysis was 82.5% at 1 year. Cutting balloon angioplasty seems to be a safe and effective tool in the routine treatment of short/ostial infrapopliteal bifurcation lesions, avoiding procedure-related complications, overcoming the limitations of conventional angioplasty, and improving the outcome of catheter-based therapy. © The Author(s) 2015.

  3. Simple or Complex Stenting for Bifurcation Coronary Lesions: A Patient-Level Pooled-Analysis of the Nordic Bifurcation Study and the British Bifurcation Coronary Study

    DEFF Research Database (Denmark)

    Behan, Miles W; Holm, Niels Ramsing; Curzen, Nicholas P

    2011-01-01

    Background— Controversy persists regarding the correct strategy for bifurcation lesions. Therefore, we combined the patient-level data from 2 large trials with similar methodology: the NORDIC Bifurcation Study (NORDIC I) and the British Bifurcation Coronary Study (BBC ONE). Methods and Results— B...

  4. Exercise-mediated changes in conduit artery wall thickness in humans: role of shear stress

    NARCIS (Netherlands)

    Thijssen, D.H.J.; Dawson, E.A.; Munckhof, I.C. van den; Tinken, T.M.; Drijver, E. den; Hopkins, N.; Cable, N.T.; Green, D.J.

    2011-01-01

    Episodic increases in shear stress have been proposed as a mechanism that induces training-induced adaptation in arterial wall remodeling in humans. To address this hypothesis in humans, we examined bilateral brachial artery wall thickness using high-resolution ultrasound in healthy men across an

  5. Bifurcation analysis of a three dimensional system

    Directory of Open Access Journals (Sweden)

    Yongwen WANG

    2018-04-01

    Full Text Available In order to enrich the stability and bifurcation theory of the three dimensional chaotic systems, taking a quadratic truncate unfolding system with the triple singularity equilibrium as the research subject, the existence of the equilibrium, the stability and the bifurcation of the system near the equilibrium under different parametric conditions are studied. Using the method of mathematical analysis, the existence of the real roots of the corresponding characteristic equation under the different parametric conditions is analyzed, and the local manifolds of the equilibrium are gotten, then the possible bifurcations are guessed. The parametric conditions under which the equilibrium is saddle-focus are analyzed carefully by the Cardan formula. Moreover, the conditions of codimension-one Hopf bifucation and the prerequisites of the supercritical and subcritical Hopf bifurcation are found by computation. The results show that the system has abundant stability and bifurcation, and can also supply theorical support for the proof of the existence of the homoclinic or heteroclinic loop connecting saddle-focus and the Silnikov's chaos. This method can be extended to study the other higher nonlinear systems.

  6. Bifurcations of Tumor-Immune Competition Systems with Delay

    Directory of Open Access Journals (Sweden)

    Ping Bi

    2014-01-01

    Full Text Available A tumor-immune competition model with delay is considered, which consists of two-dimensional nonlinear differential equation. The conditions for the linear stability of the equilibria are obtained by analyzing the distribution of eigenvalues. General formulas for the direction, period, and stability of the bifurcated periodic solutions are given for codimension one and codimension two bifurcations, including Hopf bifurcation, steady-state bifurcation, and B-T bifurcation. Numerical examples and simulations are given to illustrate the bifurcations analysis and obtained results.

  7. Angioplasty in stenosis of the innominate artery

    International Nuclear Information System (INIS)

    Kobinia, G.S.; Bergmann, H. Jr.

    1983-01-01

    We describe a successful percutaneous transluminal dilatation (PTD) of an innominate artery stenosis in a 40-year-old patient with aortic arch syndrome. Five years earlier both a left central carotid artery occlusion and an innominate and left subclavian artery stenosis were treated by grafting from the aorta to the distal vessels. At recurrence of the neurological symptoms, reocclusion of the graft to the innominate artery and subtotal stenosis of the left carotid anastomosis were noted. The prevent the hazards of a reoperation, the innominate artery stenosis was dilated by means of PTD via the right brachial artery. Success of the procedure was demonstrated by Doppler sonography and angiography. It appears that PTD serves as an excellent method of treating stenoses of the aortic arch branches in aortic arch syndrome. (orig.)

  8. Risk Factors for Brachial Plexus Birth Injury

    Science.gov (United States)

    Louden, Emily; Marcotte, Michael; Mehlman, Charles; Lippert, William; Huang, Bin; Paulson, Andrea

    2018-01-01

    Over the course of decades, the incidence of brachial plexus birth injury (BPBI) has increased despite advances in healthcare which would seem to assist in decreasing the rate. The aim of this study is to identify previously unknown risk factors for BPBI and the risk factors with potential to guide preventative measures. A case control study of 52 mothers who had delivered a child with a BPBI injury and 132 mothers who had delivered without BPBI injury was conducted. Univariate, multivariable and logistic regressions identified risk factors and their combinations. The odds of BPBI were 2.5 times higher when oxytocin was used and 3.7 times higher when tachysystole occurred. The odds of BPBI injury are increased when tachysystole and oxytocin occur during the mother’s labor. Logistic regression identified a higher risk for BPBI when more than three of the following variables (>30 lbs gained during the pregnancy, stage 2 labor >61.5 min, mother’s age >26.4 years, tachysystole, or fetal malpresentation) were present in any combination. PMID:29596309

  9. Risk Factors for Brachial Plexus Birth Injury

    Directory of Open Access Journals (Sweden)

    Emily Louden

    2018-03-01

    Full Text Available Over the course of decades, the incidence of brachial plexus birth injury (BPBI has increased despite advances in healthcare which would seem to assist in decreasing the rate. The aim of this study is to identify previously unknown risk factors for BPBI and the risk factors with potential to guide preventative measures. A case control study of 52 mothers who had delivered a child with a BPBI injury and 132 mothers who had delivered without BPBI injury was conducted. Univariate, multivariable and logistic regressions identified risk factors and their combinations. The odds of BPBI were 2.5 times higher when oxytocin was used and 3.7 times higher when tachysystole occurred. The odds of BPBI injury are increased when tachysystole and oxytocin occur during the mother’s labor. Logistic regression identified a higher risk for BPBI when more than three of the following variables (>30 lbs gained during the pregnancy, stage 2 labor >61.5 min, mother’s age >26.4 years, tachysystole, or fetal malpresentation were present in any combination.

  10. Hemi-central retinal artery occlusion in young adults

    Directory of Open Access Journals (Sweden)

    Rishi Pukhraj

    2010-01-01

    Full Text Available Amongst the clinical presentations of retinal artery occlusion, hemi-central retinal artery occlusion (Hemi-CRAO is rarely described. This case series of four adults aged between 22 and 36 years attempts to describe the clinical profile, etiology and management of Hemi-CRAO. Case 1 had an artificial mitral valve implant. Polycythemia and malignant hypertension were noted in Case 2. The third patient had Leiden mutation while the fourth patient had Eisenmenger′s syndrome. Clinical examination and fundus fluorescein angiography revealed a bifurcated central retinal artery at emergence from the optic nerve head, in all cases. Color Doppler examination of the central retinal artery confirmed branching of the artery behind the lamina cribrosa. It is hypothesized that bifurcation of central retinal artery behind the lamina cribrosa may predispose these hemi-trunks to develop an acute occlusion if associated with underlying risk factors. The prognosis depends upon arterial recanalisation and etiology of the thromboembolic event.

  11. Attractors near grazing–sliding bifurcations

    International Nuclear Information System (INIS)

    Glendinning, P; Kowalczyk, P; Nordmark, A B

    2012-01-01

    In this paper we prove, for the first time, that multistability can occur in three-dimensional Fillipov type flows due to grazing–sliding bifurcations. We do this by reducing the study of the dynamics of Filippov type flows around a grazing–sliding bifurcation to the study of appropriately defined one-dimensional maps. In particular, we prove the presence of three qualitatively different types of multiple attractors born in grazing–sliding bifurcations. Namely, a period-two orbit with a sliding segment may coexist with a chaotic attractor, two stable, period-two and period-three orbits with a segment of sliding each may coexist, or a non-sliding and period-three orbit with two sliding segments may coexist

  12. Post-Treatment Hemodynamics of a Basilar Aneurysm and Bifurcation

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, J; Hartman, J; Rodriguez, J; Maitland, D

    2008-01-16

    Aneurysm re-growth and rupture can sometimes unexpectedly occur following treatment procedures that were initially considered to be successful at the time of treatment and post-operative angiography. In some cases, this can be attributed to surgical clip slippage or endovascular coil compaction. However, there are other cases in which the treatment devices function properly. In these instances, the subsequent complications are due to other factors, perhaps one of which is the post-treatment hemodynamic stress. To investigate whether or not a treatment procedure can subject the parent artery to harmful hemodynamic stresses, computational fluid dynamics simulations are performed on a patient-specific basilar aneurysm and bifurcation before and after a virtual endovascular treatment. The simulations demonstrate that the treatment procedure produces a substantial increase in the wall shear stress. Analysis of the post-treatment flow field indicates that the increase in wall shear stress is due to the impingement of the basilar artery flow upon the aneurysm filling material and to the close proximity of a vortex tube to the artery wall. Calculation of the time-averaged wall shear stress shows that there is a region of the artery exposed to a level of wall shear stress that can cause severe damage to endothelial cells. The results of this study demonstrate that it is possible for a treatment procedure, which successfully excludes the aneurysm from the vascular system and leaves no aneurysm neck remnant, to elevate the hemodynamic stresses to levels that are injurious to the immediately adjacent vessel wall.

  13. Bifurcation structure of parameter plane for a family of unimodal piecewise smooth maps: Border-collision bifurcation curves

    International Nuclear Information System (INIS)

    Sushko, Iryna; Agliari, Anna; Gardini, Laura

    2006-01-01

    We study the structure of the 2D bifurcation diagram for a two-parameter family of piecewise smooth unimodal maps f with one break point. Analysing the parameters of the normal form for the border-collision bifurcation of an attracting n-cycle of the map f, we describe the possible kinds of dynamics associated with such a bifurcation. Emergence and role of border-collision bifurcation curves in the 2D bifurcation plane are studied. Particular attention is paid also to the curves of homoclinic bifurcations giving rise to the band merging of pieces of cyclic chaotic intervals

  14. Measurement of carotid bifurcation pressure gradients using the Bernoulli principle.

    Science.gov (United States)

    Illig, K A; Ouriel, K; DeWeese, J A; Holen, J; Green, R M

    1996-04-01

    Current randomized prospective studies suggest that the degree of carotid stenosis is a critical element in deciding whether surgical or medical treatment is appropriate. Of potential interest is the actual pressure drop caused by the blockage, but no direct non-invasive means of quantifying the hemodynamic consequences of carotid artery stenoses currently exists. The present prospective study examined whether preoperative pulsed-Doppler duplex ultrasonographic velocity (v) measurements could be used to predict pressure gradients (delta P) caused by carotid artery stenoses, and whether such measurements could be used to predict angiographic percent diameter reduction. Preoperative Doppler velocity and intraoperative direct pressure measurements were obtained, and per cent diameter angiographic stenosis measured in 76 consecutive patients who underwent 77 elective carotid endarterectomies. Using the Bernoulli principle (delta P = 4v(2), pressure gradients across the stenoses were calculated. The predicted delta P, as well as absolute velocities and internal carotid artery/common carotid velocity ratios were compared with the actual delta P measured intraoperatively and with preoperative angiography and oculopneumoplethysmography (OPG) results. An end-diastolic velocity of > or = 1 m/s and an end-diastolic internal carotid artery/common carotid artery velocity ratio of > or = 10 predicted a 50% diameter angiographic stenosis with 100% specificity. Although statistical significance was reached, preoperative pressure gradients derived from the Bernoulli equation could not predict actual individual intraoperative pressure gradients with enough accuracy to allow decision making on an individual basis. Velocity measurements were as specific and more sensitive than OPG results. Delta P as predicted by the Bernoulli equation is not sufficiently accurate at the carotid bifurcation to be useful for clinical decision making on an individual basis. However, end

  15. Innominate artery war injury

    Directory of Open Access Journals (Sweden)

    Ilić Radoje

    2005-01-01

    Full Text Available Aim. A case is reported of successfully surgically treated explosive war injury to the innominate artery. Case report. A 26 - year-old soldier was injured in combat by a fragment of mortar shell. In the field hospital, the wound gauze packing was applied, followed by orotracheal intubation and thoracic drainage. The soldier was admitted to MMA six hours later. Physical examination, on admission, revealed huge swelling of the neck, the absence of pulse in the right arm and the right common carotid artery. Chest x-ray revealed hemopneumothorax of the right side and the foreign metal body in the projection of the right sternoclavicular joint. Due to the suspicion of large vessel injury, a median sternotomy was immediately performed. Surgery revealed disrupted bifurcation of the right innominate artery, so the ligation was performed. Aortography was performed postoperatively, followed by the reconstruction of innominate bifurcation with synthetic grafts. Control aortography showed good graft patency, and the patient was discharged from the hospital in good general condition with palpable pulses and mild anisocoria as a sole neurological sequela. Conclusion. A rare and life-threatening injury was successfully managed, mainly due to the rational treatment carried out in the field hospital that helped the injured to survive and arrive to the institution capable of performing the most sophisticated diagnostic and therapeutic procedures.

  16. Bifurcation of Jovian magnetotail current sheet

    Directory of Open Access Journals (Sweden)

    P. L. Israelevich

    2006-07-01

    Full Text Available Multiple crossings of the magnetotail current sheet by a single spacecraft give the possibility to distinguish between two types of electric current density distribution: single-peaked (Harris type current layer and double-peaked (bifurcated current sheet. Magnetic field measurements in the Jovian magnetic tail by Voyager-2 reveal bifurcation of the tail current sheet. The electric current density possesses a minimum at the point of the Bx-component reversal and two maxima at the distance where the magnetic field strength reaches 50% of its value in the tail lobe.

  17. Bifurcation of Jovian magnetotail current sheet

    Directory of Open Access Journals (Sweden)

    P. L. Israelevich

    2006-07-01

    Full Text Available Multiple crossings of the magnetotail current sheet by a single spacecraft give the possibility to distinguish between two types of electric current density distribution: single-peaked (Harris type current layer and double-peaked (bifurcated current sheet. Magnetic field measurements in the Jovian magnetic tail by Voyager-2 reveal bifurcation of the tail current sheet. The electric current density possesses a minimum at the point of the Bx-component reversal and two maxima at the distance where the magnetic field strength reaches 50% of its value in the tail lobe.

  18. Constriction of collateral arteries induced by "head-up tilt" in patients with occlusive arterial disease of the legs

    DEFF Research Database (Denmark)

    Agerskov, K; Henriksen, O; Tønnesen, K H

    1981-01-01

    The effect of head-up tilt on leg blood flow and segmental arterial blood pressures was studied in 21 patients with occlusion or severe stenosis of the common or superficial femoral artery. Arterial pressure was measured directly in the brachial artery, common femoral artery and popliteal artery....... Relative change in blood flow in the leg during tilt was estimated by changes in arterio-venous oxygen differences and by the indicator dilution technique in nine patients. Head-up tilt caused a decrease in leg blood flow of 36% corresponding to an increase in total vascular resistance of 57%. Tilt did...... not change the pressure gradient from femoral to popliteal artery in the patients with occlusion of the superficial femoral artery, indicating that the flow resistance offered by the collateral arteries had increased. In a bilateral sympathectomised patient the increase in collateral resistance was almost...

  19. Discretizing the transcritical and pitchfork bifurcations – conjugacy results

    KAUST Repository

    Ló czi, Lajos

    2015-01-01

    © 2015 Taylor & Francis. We present two case studies in one-dimensional dynamics concerning the discretization of transcritical (TC) and pitchfork (PF) bifurcations. In the vicinity of a TC or PF bifurcation point and under some natural assumptions

  20. Bifurcations of a class of singular biological economic models

    International Nuclear Information System (INIS)

    Zhang Xue; Zhang Qingling; Zhang Yue

    2009-01-01

    This paper studies systematically a prey-predator singular biological economic model with time delay. It shows that this model exhibits two bifurcation phenomena when the economic profit is zero. One is transcritical bifurcation which changes the stability of the system, and the other is singular induced bifurcation which indicates that zero economic profit brings impulse, i.e., rapid expansion of the population in biological explanation. On the other hand, if the economic profit is positive, at a critical value of bifurcation parameter, the system undergoes a Hopf bifurcation, i.e., the increase of delay destabilizes the system and bifurcates into small amplitude periodic solution. Finally, by using Matlab software, numerical simulations illustrate the effectiveness of the results obtained here. In addition, we study numerically that the system undergoes a saddle-node bifurcation when the bifurcation parameter goes through critical value of positive economic profit.

  1. Bifurcation structure of a model of bursting pancreatic cells

    DEFF Research Database (Denmark)

    Mosekilde, Erik; Lading, B.; Yanchuk, S.

    2001-01-01

    One- and two-dimensional bifurcation studies of a prototypic model of bursting oscillations in pancreatic P-cells reveal a squid-formed area of chaotic dynamics in the parameter plane, with period-doubling bifurcations on one side of the arms and saddle-node bifurcations on the other. The transit......One- and two-dimensional bifurcation studies of a prototypic model of bursting oscillations in pancreatic P-cells reveal a squid-formed area of chaotic dynamics in the parameter plane, with period-doubling bifurcations on one side of the arms and saddle-node bifurcations on the other....... The transition from this structure to the so-called period-adding structure is found to involve a subcritical period-doubling bifurcation and the emergence of type-III intermittency. The period-adding transition itself is not smooth but consists of a saddle-node bifurcation in which (n + 1)-spike bursting...

  2. Codimension-2 bifurcations of the Kaldor model of business cycle

    International Nuclear Information System (INIS)

    Wu, Xiaoqin P.

    2011-01-01

    Research highlights: → The conditions are given such that the characteristic equation may have purely imaginary roots and double zero roots. → Purely imaginary roots lead us to study Hopf and Bautin bifurcations and to calculate the first and second Lyapunov coefficients. → Double zero roots lead us to study Bogdanov-Takens (BT) bifurcation. → Bifurcation diagrams for Bautin and BT bifurcations are obtained by using the normal form theory. - Abstract: In this paper, complete analysis is presented to study codimension-2 bifurcations for the nonlinear Kaldor model of business cycle. Sufficient conditions are given for the model to demonstrate Bautin and Bogdanov-Takens (BT) bifurcations. By computing the first and second Lyapunov coefficients and performing nonlinear transformation, the normal forms are derived to obtain the bifurcation diagrams such as Hopf, homoclinic and double limit cycle bifurcations. Some examples are given to confirm the theoretical results.

  3. Congenital Arterial Thrombosis in Newborn: a Case Report

    OpenAIRE

    Özdemir, Özmert M. A.; Özdemir, Yavuz; Kılıç, İlknur; Güleç, Bülent; Sücüllü, İlker; Küçüktaşçı, Kazım; Filiz, Ali İlker; Gürses, Dolunay; Karaca, Abdullah; Oto, Murat; Çetin, Gökhan Ozan; Caner, Vildan

    2014-01-01

    Neonatal thrombosis is a serious event that can cause mortality or severe morbidity. Although catheters are the most common cause of neonatal thrombosis, spontaneous events can also occur. Arterial thrombosis is very rare and accounts for approximately half of all thrombotic events in neonates. Genetic prothrombotic risk factors may affect the occurence of neonatal thrombosis. In this report, a case of left brachial, radial, and ulnar arterial thrombosis associated with methylene-tetrahydrofo...

  4. Merging flows in an arterial confluence : The vertebro-basilar junction

    NARCIS (Netherlands)

    Ravensbergen, J; Krijger, JKB; Hillen, B; Hoogstraten, HW

    1995-01-01

    The basilar artery is one of the three vessels providing the blood supply to the human brain. It arises from the confluence of the two vertebral arteries. In fact, it is the only artery of this size in the human body arising from a confluence instead of a bifurcation. Earlier work, concerning flow

  5. Comments on the Bifurcation Structure of 1D Maps

    DEFF Research Database (Denmark)

    Belykh, V.N.; Mosekilde, Erik

    1997-01-01

    -within-a-box structure of the total bifurcation set. This presents a picture in which the homoclinic orbit bifurcations act as a skeleton for the bifurcational set. At the same time, experimental results on continued subharmonic generation for piezoelectrically amplified sound waves, predating the Feigenbaum theory......, are called into attention....

  6. NUMERICAL HOPF BIFURCATION OF DELAY-DIFFERENTIAL EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper we consider the numerical solution of some delay differential equations undergoing a Hopf bifurcation. We prove that if the delay differential equations have a Hopf bifurcation point atλ=λ*, then the numerical solution of the equation also has a Hopf bifurcation point atλh =λ* + O(h).

  7. Bifurcation of elastic solids with sliding interfaces

    Science.gov (United States)

    Bigoni, D.; Bordignon, N.; Piccolroaz, A.; Stupkiewicz, S.

    2018-01-01

    Lubricated sliding contact between soft solids is an interesting topic in biomechanics and for the design of small-scale engineering devices. As a model of this mechanical set-up, two elastic nonlinear solids are considered jointed through a frictionless and bilateral surface, so that continuity of the normal component of the Cauchy traction holds across the surface, but the tangential component is null. Moreover, the displacement can develop only in a way that the bodies in contact do neither detach, nor overlap. Surprisingly, this finite strain problem has not been correctly formulated until now, so this formulation is the objective of the present paper. The incremental equations are shown to be non-trivial and different from previously (and erroneously) employed conditions. In particular, an exclusion condition for bifurcation is derived to show that previous formulations based on frictionless contact or `spring-type' interfacial conditions are not able to predict bifurcations in tension, while experiments-one of which, ad hoc designed, is reported-show that these bifurcations are a reality and become possible when the correct sliding interface model is used. The presented results introduce a methodology for the determination of bifurcations and instabilities occurring during lubricated sliding between soft bodies in contact.

  8. Climate bifurcation during the last deglaciation?

    NARCIS (Netherlands)

    Lenton, T.M.; Livina, V.N.; Dakos, V.; Scheffer, M.

    2012-01-01

    There were two abrupt warming events during the last deglaciation, at the start of the Bolling-Allerod and at the end of the Younger Dryas, but their underlying dynamics are unclear. Some abrupt climate changes may involve gradual forcing past a bifurcation point, in which a prevailing climate state

  9. Bifurcation structure of an optical ring cavity

    DEFF Research Database (Denmark)

    Kubstrup, C.; Mosekilde, Erik

    1996-01-01

    One- and two-dimensional continuation techniques are applied to determine the basic bifurcation structure for an optical ring cavity with a nonlinear absorbing element (the Ikeda Map). By virtue of the periodic structure of the map, families of similar solutions develop in parameter space. Within...

  10. Resource competition: a bifurcation theory approach.

    NARCIS (Netherlands)

    Kooi, B.W.; Dutta, P.S.; Feudel, U.

    2013-01-01

    We develop a framework for analysing the outcome of resource competition based on bifurcation theory. We elaborate our methodology by readdressing the problem of competition of two species for two resources in a chemostat environment. In the case of perfect-essential resources it has been

  11. Digital subtraction angiography of carotid bifurcation

    International Nuclear Information System (INIS)

    Vries, A.R. de.

    1984-01-01

    This study demonstrates the reliability of digital subtraction angiography (DSA) by means of intra- and interobserver investigations as well as indicating the possibility of substituting catheterangiography by DSA in the diagnosis of carotid bifurcation. Whenever insufficient information is obtained from the combination of non-invasive investigation and DSA, a catheterangiogram will be necessary. (Auth.)

  12. Percutaneous coronary intervention for coronary bifurcation disease

    DEFF Research Database (Denmark)

    Lassen, Jens Flensted; Holm, Niels Ramsing; Banning, Adrian

    2016-01-01

    of combining the opinions of interventional cardiologists with the opinions of a large variety of other scientists on bifurcation management. The present 11th EBC consensus document represents the summary of the up-to-date EBC consensus and recommendations. It points to the fact that there is a multitude...

  13. Bifurcation of self-folded polygonal bilayers

    Science.gov (United States)

    Abdullah, Arif M.; Braun, Paul V.; Hsia, K. Jimmy

    2017-09-01

    Motivated by the self-assembly of natural systems, researchers have investigated the stimulus-responsive curving of thin-shell structures, which is also known as self-folding. Self-folding strategies not only offer possibilities to realize complicated shapes but also promise actuation at small length scales. Biaxial mismatch strain driven self-folding bilayers demonstrate bifurcation of equilibrium shapes (from quasi-axisymmetric doubly curved to approximately singly curved) during their stimulus-responsive morphing behavior. Being a structurally instable, bifurcation could be used to tune the self-folding behavior, and hence, a detailed understanding of this phenomenon is appealing from both fundamental and practical perspectives. In this work, we investigated the bifurcation behavior of self-folding bilayer polygons. For the mechanistic understanding, we developed finite element models of planar bilayers (consisting of a stimulus-responsive and a passive layer of material) that transform into 3D curved configurations. Our experiments with cross-linked Polydimethylsiloxane samples that change shapes in organic solvents confirmed our model predictions. Finally, we explored a design scheme to generate gripper-like architectures by avoiding the bifurcation of stimulus-responsive bilayers. Our research contributes to the broad field of self-assembly as the findings could motivate functional devices across multiple disciplines such as robotics, artificial muscles, therapeutic cargos, and reconfigurable biomedical devices.

  14. Modified jailed balloon technique for bifurcation lesions.

    Science.gov (United States)

    Saito, Shigeru; Shishido, Koki; Moriyama, Noriaki; Ochiai, Tomoki; Mizuno, Shingo; Yamanaka, Futoshi; Sugitatsu, Kazuya; Tobita, Kazuki; Matsumi, Junya; Tanaka, Yutaka; Murakami, Masato

    2017-12-04

    We propose a new systematic approach in bifurcation lesions, modified jailed balloon technique (M-JBT), and report the first clinical experience. Side branch occlusion brings with a serious complication and occurs in more than 7.0% of cases during bifurcation stenting. A jailed balloon (JB) is introduced into the side branch (SB), while a stent is placed in the main branch (MB) as crossing SB. The size of the JB is half of the MB stent size. While the proximal end of JB attaching to MB stent, both stent and JB are simultaneously inflated with same pressure. JB is removed and then guidewires are recrossed. Kissing balloon dilatation (KBD) and/or T and protrusion (TAP) stenting are applied as needed. Between February 2015 and February 2016, 233 patients (254 bifurcation lesions including 54 left main trunk disease) underwent percutaneous coronary intervention (PCI) using this technique. Procedure success was achieved in all cases. KBD was performed for 183 lesions and TAP stenting was employed for 31 lesions. Occlusion of SV was not observed in any of the patients. Bench test confirmed less deformity of MB stent in M-JBT compared with conventional-JBT. This is the first report for clinical experiences by using modified jailed balloon technique. This novel M-JBT is safe and effective in the preservation of SB patency during bifurcation stenting. © 2017 Wiley Periodicals, Inc.

  15. Prognostic value of thumb pain sensation in birth brachial plexopathy

    Directory of Open Access Journals (Sweden)

    Carlos O. Heise

    2012-08-01

    Full Text Available OBJECTIVE: To evaluate the prognostic value of absent thumb pain sensation in newborns and young infants with birth brachial plexopathy. METHODS: We evaluated 131 patients with birth brachial plexopathy with less than two months of age. Pain sensation was evoked by thumb nail bed compression to evaluate sensory fibers of the upper trunk (C6. The patients were followed-up monthly. Patients with less than antigravity elbow flexion at six months of age were considered to have a poor outcome. RESULTS: Thirty patients had absent thumb pain sensation, from which 26 showed a poor outcome. Sensitivity of the test was 65% and specificity was 96%. CONCLUSION: Evaluation of thumb pain sensation should be included in the clinical assessment of infants with birth brachial plexopathy.

  16. Reversible brachial plexopathy following primary radiation therapy for breast cancer

    International Nuclear Information System (INIS)

    Salner, A.L.; Botnick, L.E.; Herzog, A.G.; Goldstein, M.A.; Harris, J.R.; Levene, M.B.; Hellman, S.

    1981-01-01

    Reversible brachial plexopathy has occurred in very low incidence in patients with breast carcinoma treated definitively with radiation therapy. Of 565 patients treated between January 1968 and December 1979 with moderate doses of supervoltage radiation therapy (average axillary dose of 5000 rad in 5 weeks), eight patients (1.4%) developed the characteristic symptoms at a median time of 4.5 months after radiation therapy. This syndrome consists of paresthesias in all patients, with weakness and pain less commonly seen. The symptom complex differs from other previously described brachial plexus syndromes, including paralytic brachial neuritis, radiation-induced injury, and carcinoma. A possible relationship to adjuvant chemotherapy exists, though the etiology is not well-understood. The cases described demonstrate temporal clustering. Resolution is always seen

  17. Tolerance of the Brachial Plexus to High-Dose Reirradiation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Allen M., E-mail: achen5@kumc.edu; Yoshizaki, Taeko; Velez, Maria A.; Mikaeilian, Argin G.; Hsu, Sophia; Cao, Minsong

    2017-05-01

    Purpose: To study the tolerance of the brachial plexus to high doses of radiation exceeding historically accepted limits by analyzing human subjects treated with reirradiation for recurrent tumors of the head and neck. Methods and Materials: Data from 43 patients who were confirmed to have received overlapping dose to the brachial plexus after review of radiation treatment plans from the initial and reirradiation courses were used to model the tolerance of this normal tissue structure. A standardized instrument for symptoms of neuropathy believed to be related to brachial plexus injury was utilized to screen for toxicity. Cumulative dose was calculated by fusing the initial dose distributions onto the reirradiation plan, thereby creating a composite plan via deformable image registration. The median elapsed time from the initial course of radiation therapy to reirradiation was 24 months (range, 3-144 months). Results: The dominant complaints among patients with symptoms were ipsilateral pain (54%), numbness/tingling (31%), and motor weakness and/or difficulty with manual dexterity (15%). The cumulative maximum dose (Dmax) received by the brachial plexus ranged from 60.5 Gy to 150.1 Gy (median, 95.0 Gy). The cumulative mean (Dmean) dose ranged from 20.2 Gy to 111.5 Gy (median, 63.8 Gy). The 1-year freedom from brachial plexus–related neuropathy was 67% and 86% for subjects with a cumulative Dmax greater than and less than 95.0 Gy, respectively (P=.05). The 1-year complication-free rate was 66% and 87%, for those reirradiated within and after 2 years from the initial course, respectively (P=.06). Conclusion: The development of brachial plexus–related symptoms was less than expected owing to repair kinetics and to the relatively short survival of the subject population. Time-dose factors were demonstrated to be predictive of complications.

  18. Complete Brachial Plexus Injury - An Amputation Dilemma. A Case Report

    Directory of Open Access Journals (Sweden)

    Choong CYL

    2015-11-01

    Full Text Available Brachial plexus injuries with intact yet flail limb presents with problems of persistent neuropathic pain and recurrent shoulder dislocations, that render the flail limb a damn nuisance. As treating surgeons, we are faced with the dilemma of offering treatment options, bearing in mind the patient’s functional status and expectations. We present a case of a 55-year old housewife with complete brachial plexus injury begging for surgical amputation of her flail limb, 6 years post-injury. Here we discuss the outcome of transhumeral amputation and the possibility of offering early rather than delayed amputations in this group of patients.

  19. Surgical treatment of adult traumatic brachial plexus injuries: an overview

    Directory of Open Access Journals (Sweden)

    Mario G. Siqueira

    2011-06-01

    Full Text Available Traumatic injuries to the brachial plexus in adults are severely debilitating. They generally affect young individuals. A thorough understanding of the anatomy, clinical evaluation, imaging and electrodiagnostic assessments, treatment options and proper timing of surgical interventions will enable nerve surgeons to offer optimal care to patients. Advances in microsurgical technique have improved the outcome for many of these patients. The treatment options offer patients with brachial plexus injuries the possibility of achieving elbow flexion, shoulder stability with limited abduction and the hope of limited but potentially useful hand function.

  20. Long-term results of obstetric brachial plexus surgery

    OpenAIRE

    Kirjavainen , Mikko

    2010-01-01

    Background: Brachial plexus birth palsy (BPBP) most often occurs as a result of foetal-maternal disproportion. The C5 and C6 nerve roots of the brachial plexus are most frequently affected. In contrast, roots from the C7 to Th1 that result in total injury together with C5 and C6 injury, are affected in fewer than half of the patients. BPBP was first described by Smellie in 1764. Erb published his classical description of the injury in 1874 and his name became linked with the paralysis that is...

  1. Vessel bifurcation localization based on intraoperative three-dimensional ultrasound and catheter path for image-guided catheter intervention of oral cancers.

    Science.gov (United States)

    Luan, Kuan; Ohya, Takashi; Liao, Hongen; Kobayashi, Etsuko; Sakuma, Ichiro

    2013-03-01

    We present a method to localize intraoperative target vessel bifurcations under bones for ultrasound (US) image-guided catheter interventions. A catheter path is recorded to acquire skeletons for the target vessel bifurcations that cannot be imaged by intraoperative US. The catheter path is combined with the centerlines of the three-dimensional (3D) US image to construct a preliminary skeleton. Based on the preliminary skeleton, the orientations of target vessels are determined by registration with the preoperative image and the bifurcations were localized by computing the vessel length. An accurate intraoperative vessel skeleton is obtained for correcting the preoperative image to compensate for vessel deformation. A reality check of the proposed method was performed in a phantom experiment. Reasonable results were obtained. The in vivo experiment verified the clinical workflow of the proposed method in an in vivo environment. The accuracy of the centerline length of the vessel for localizing the target artery bifurcation was 2.4mm. These results suggest that the proposed method can allow the catheter tip to stop at the target artery bifurcations and enter into the target arteries. This method can be applied for virtual reality-enhanced image-guided catheter intervention of oral cancers. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. The Aortic Bifurcation Angle as a Factor in Application of the Outback for Femoropopliteal Lesions in Ipsilateral Versus Contralateral Approaches.

    Science.gov (United States)

    Raskin, Daniel; Khaitovich, Boris; Balan, Shmuel; Silverberg, Daniel; Halak, Moshe; Rimon, Uri

    2018-01-01

    To assess the technical success of the Outback reentry device in contralateral versus ipsilateral approaches for femoropopliteal arterial occlusion. A retrospective review of patients treated for critical limb ischemia (CLI) using the Outback between January 2013 and July 2016 was performed. Age, gender, length and site of the occlusion, approach site, aortic bifurcation angle, and reentry site were recorded. Calcification score was assigned at both aortic bifurcation and reentry site. Technical success was assessed. During the study period, a total of 1300 endovascular procedures were performed on 489 patients for CLI. The Outback was applied on 50 femoropopliteal chronic total occlusions. Thirty-nine contralateral and 11 ipsilateral antegrade femoral were accessed. The device was used successfully in 41 patients (82%). There were nine failures, all in the contralateral approach group. Six due to inability to deliver the device due to acute aortic bifurcation angle and three due to failure to achieve luminal reentry. Procedural success was significantly affected by the aortic bifurcation angle (p = 0.013). The Outback has high technical success rates in treatment of femoropopliteal occlusion, when applied from either an ipsi- or contralateral approach. When applied in contralateral access, acute aortic bifurcation angle predicts procedural failure.

  3. Morphometry of medial gaps of human brain artery branches.

    Science.gov (United States)

    Canham, Peter B; Finlay, Helen M

    2004-05-01

    The bifurcation regions of the major human cerebral arteries are vulnerable to the formation of saccular aneurysms. A consistent feature of these bifurcations is a discontinuity of the tunica media at the apex of the flow divider. The objective was to measure the 3-dimensional geometry of these medial gaps or "medial defects." Nineteen bifurcations and 2 junctions of human cerebral arteries branches (from 4 male and 2 female subjects) were formalin-fixed at physiological pressure and processed for longitudinal serial sectioning. The apex and adjacent regions were examined and measurements were made from high-magnification photomicrographs, or projection microscope images, of the gap dimensions at multiple levels through the bifurcation. Plots were made of the width of the media as a function of distance from the apex. The media at each edge of the medial gap widened over a short distance, reaching the full width of the media of the contiguous daughter vessel. Medial gap dimensions were compared with the planar angle of the bifurcation, and a strong negative correlation was found, ie, the acute angled branches have the more prominent medial gaps. A discontinuity of the media at the apex was seen in all the bifurcations examined and was also found in the junction regions of brain arteries. We determined that the gap width is continuous with well-defined dimensions throughout its length and average length-to-width ratio of 6.9. The gaps were generally centered on the prominence of the apical ridge.

  4. Combined aerobic and resistance exercise training decreases peripheral but not central artery wall thickness in subjects with type 2 diabetes.

    NARCIS (Netherlands)

    Schreuder, T.H.A.; Munckhof, I.C.L. van den; Poelkens, F.; Hopman, M.T.; Thijssen, D.H.

    2015-01-01

    OBJECTIVE: Little is known about the impact of exercise training on conduit artery wall thickness in type 2 diabetes. We examined the local and systemic impact of exercise training on superficial femoral (SFA), brachial (BA), and carotid artery (CA) wall thickness in type 2 diabetes patients and

  5. Stochastic bifurcation in a model of love with colored noise

    Science.gov (United States)

    Yue, Xiaokui; Dai, Honghua; Yuan, Jianping

    2015-07-01

    In this paper, we wish to examine the stochastic bifurcation induced by multiplicative Gaussian colored noise in a dynamical model of love where the random factor is used to describe the complexity and unpredictability of psychological systems. First, the dynamics in deterministic love-triangle model are considered briefly including equilibrium points and their stability, chaotic behaviors and chaotic attractors. Then, the influences of Gaussian colored noise with different parameters are explored such as the phase plots, top Lyapunov exponents, stationary probability density function (PDF) and stochastic bifurcation. The stochastic P-bifurcation through a qualitative change of the stationary PDF will be observed and bifurcation diagram on parameter plane of correlation time and noise intensity is presented to find the bifurcation behaviors in detail. Finally, the top Lyapunov exponent is computed to determine the D-bifurcation when the noise intensity achieves to a critical value. By comparison, we find there is no connection between two kinds of stochastic bifurcation.

  6. Bifurcation Behavior Analysis in a Predator-Prey Model

    Directory of Open Access Journals (Sweden)

    Nan Wang

    2016-01-01

    Full Text Available A predator-prey model is studied mathematically and numerically. The aim is to explore how some key factors influence dynamic evolutionary mechanism of steady conversion and bifurcation behavior in predator-prey model. The theoretical works have been pursuing the investigation of the existence and stability of the equilibria, as well as the occurrence of bifurcation behaviors (transcritical bifurcation, saddle-node bifurcation, and Hopf bifurcation, which can deduce a standard parameter controlled relationship and in turn provide a theoretical basis for the numerical simulation. Numerical analysis ensures reliability of the theoretical results and illustrates that three stable equilibria will arise simultaneously in the model. It testifies the existence of Bogdanov-Takens bifurcation, too. It should also be stressed that the dynamic evolutionary mechanism of steady conversion and bifurcation behavior mainly depend on a specific key parameter. In a word, all these results are expected to be of use in the study of the dynamic complexity of ecosystems.

  7. The natural history and management of brachial plexus birth palsy.

    Science.gov (United States)

    Buterbaugh, Kristin L; Shah, Apurva S

    2016-12-01

    Brachial plexus birth palsy (BPBP) is an upper extremity paralysis that occurs due to traction injury of the brachial plexus during childbirth. Approximately 20 % of children with brachial plexus birth palsy will have residual neurologic deficits. These permanent and significant impacts on upper limb function continue to spur interest in optimizing the management of a problem with a highly variable natural history. BPBP is generally diagnosed on clinical examination and does not typically require cross-sectional imaging. Physical examination is also the best modality to determine candidates for microsurgical reconstruction of the brachial plexus. The key finding on physical examination that determines need for microsurgery is recovery of antigravity elbow flexion by 3-6 months of age. When indicated, both microsurgery and secondary shoulder and elbow procedures are effective and can substantially improve functional outcomes. These procedures include nerve transfers and nerve grafting in infants and secondary procedures in children, such as botulinum toxin injection, shoulder tendon transfers, and humeral derotational osteotomy.

  8. Brachial versus central blood pressure and vascular stiffness

    DEFF Research Database (Denmark)

    Rasmussen, Susanne; Hansen, Tine; Frimodt-Møller, Marie

    2010-01-01

    Central blood pressure (BP) estimates the true load imposed on the left ventricle to a higher degree than does brachial BP. Increased aortic pulse wave velocity (aPWV) and central BP are risk markers for cardiovascular disease. Both can be measured by simple and noninvasive methods. Guidelines...

  9. Brachial versus central blood pressure and vascular stiffness

    DEFF Research Database (Denmark)

    Rasmussen, Susanne; Hansen, Tine; Frimodt-Møller, Marie

    2009-01-01

    Central blood pressure (BP) estimates the true load imposed on the left ventricle to a higher degree than does brachial BP. Increased aortic pulse wave velocity (aPWV) and central BP are risk markers for cardiovascular disease. Both can be measured by simple and noninvasive methods. Guidelines...

  10. Brachial plexus injury in anterior dislocation of shoulder -case report ...

    African Journals Online (AJOL)

    Brachial plexus injury in anterior dislocation of shoulder -case report and literature review. D Dhar. Abstract. No Abstract. Nigerian Journal of Orthopaedics and Trauma Vol. 6 () 2007: pp. 37-38. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  11. Lumbosacral Plexus Injury and Brachial Plexus Injury Following Prolonged Compression

    Directory of Open Access Journals (Sweden)

    Chung-Lan Kao

    2006-11-01

    Full Text Available We report the case of a 36-year-old woman who developed right upper and lower limb paralysis with sensory deficit after sedative drug overdose with prolonged immobilization. Due to the initial motor and sensory deficit pattern, brachial plexus injury or C8/T1 radiculopathy was suspected. Subsequent nerve conduction study/electromyography proved the lesion level to be brachial plexus. Painful swelling of the right buttock was suggestive of gluteal compartment syndrome. Elevation of serum creatine phosphokinase and urinary occult blood indicated rhabdomyolysis. The patient received medical treatment and rehabilitation; 2 years after the injury, her right upper and lower limb function had recovered nearly completely. As it is easy to develop complications such as muscle atrophy and joint contracture during the paralytic period of brachial plexopathy and lumbosacral plexopathy, early intervention with rehabilitation is necessary to ensure that the future limb function of the patient can be recovered. Our patient had suspected gluteal compartment syndrome that developed after prolonged compression, with the complication of concomitant lumbosacral plexus injury and brachial plexus injury, which is rarely reported in the literature. A satisfactory outcome was achieved with nonsurgical management.

  12. Posterior subscapular dissection: An improved approach to the brachial plexus for human anatomy students.

    Science.gov (United States)

    Hager, Shaun; Backus, Timothy Charles; Futterman, Bennett; Solounias, Nikos; Mihlbachler, Matthew C

    2014-05-01

    Students of human anatomy are required to understand the brachial plexus, from the proximal roots extending from spinal nerves C5 through T1, to the distal-most branches that innervate the shoulder and upper limb. However, in human cadaver dissection labs, students are often instructed to dissect the brachial plexus using an antero-axillary approach that incompletely exposes the brachial plexus. This approach readily exposes the distal segments of the brachial plexus but exposure of proximal and posterior segments require extensive dissection of neck and shoulder structures. Therefore, the proximal and posterior segments of the brachial plexus, including the roots, trunks, divisions, posterior cord and proximally branching peripheral nerves often remain unobserved during study of the cadaveric shoulder and brachial plexus. Here we introduce a subscapular approach that exposes the entire brachial plexus, with minimal amount of dissection or destruction of surrounding structures. Lateral retraction of the scapula reveals the entire length of the brachial plexus in the subscapular space, exposing the brachial plexus roots and other proximal segments. Combining the subscapular approach with the traditional antero-axillary approach allows students to observe the cadaveric brachial plexus in its entirety. Exposure of the brachial dissection in the subscapular space requires little time and is easily incorporated into a preexisting anatomy lab curriculum without scheduling additional time for dissection. Copyright © 2014 Elsevier GmbH. All rights reserved.

  13. Symmetry breaking bifurcations of a current sheet

    International Nuclear Information System (INIS)

    Parker, R.D.; Dewar, R.L.; Johnson, J.L.

    1990-01-01

    Using a time evolution code with periodic boundary conditions, the viscoresistive hydromagnetic equations describing an initially static, planar current sheet with large Lundquist number have been evolved for times long enough to reach a steady state. A cosh 2 x resistivity model was used. For long periodicity lengths L p , the resistivity gradient drives flows that cause forced reconnection at X point current sheets. Using L p as a bifurcation parameter, two new symmetry breaking bifurcations were found: a transition to an asymmetric island chain with nonzero, positive, or negative phase velocity, and a transition to a static state with alternating large and small islands. These states are reached after a complex transient behavior, which involves a competition between secondary current sheet instability and coalescence

  14. Symmetry breaking bifurcations of a current sheet

    International Nuclear Information System (INIS)

    Parker, R.D.; Dewar, R.L.; Johnson, J.L.

    1988-08-01

    Using a time evolution code with periodic boundary conditions, the viscoresistive hydromagnetic equations describing an initially static, planar current sheet with large Lundquist number have been evolved for times long enough to reach a steady state. A cosh 2 x resistivity model was used. For long periodicity lengths, L p , the resistivity gradient drives flows which cause forced reconnection at X point current sheets. Using L p as a bifurcation parameter, two new symmetry breaking bifurcations were found - a transition to an asymmetric island chain with nonzero, positive or negative phase velocity, and a transition to a static state with alternating large and small islands. These states are reached after a complex transient behavior which involves a competition between secondary current sheet instability and coalescence. 31 refs., 6 figs

  15. Experimental Study of Flow in a Bifurcation

    Science.gov (United States)

    Fresconi, Frank; Prasad, Ajay

    2003-11-01

    An instability known as the Dean vortex occurs in curved pipes with a longitudinal pressure gradient. A similar effect is manifest in the flow in a converging or diverging bifurcation, such as those found in the human respiratory airways. The goal of this study is to characterize secondary flows in a bifurcation. Particle image velocimetry (PIV) and laser-induced fluorescence (LIF) experiments were performed in a clear, plastic model. Results show the strength and migration of secondary vortices. Primary velocity features are also presented along with dispersion patterns from dye visualization. Unsteadiness, associated with a hairpin vortex, was also found at higher Re. This work can be used to assess the dispersion of particles in the lung. Medical delivery systems and pollution effect studies would profit from such an understanding.

  16. Bifurcations and chaos of DNA solitonic dynamics

    International Nuclear Information System (INIS)

    Gonzalez, J.A.; Martin-Landrove, M.; Carbo, J.R.; Chacon, M.

    1994-09-01

    We investigated the nonlinear DNA torsional equations proposed by Yakushevich in the presence of damping and external torques. Analytical expressions for some solutions are obtained in the case of the isolated chain. Special attention is paid to the stability of the solutions and the range of soliton interaction in the general case. The bifurcation analysis is performed and prediction of chaos is obtained for some set of parameters. Some biological implications are suggested. (author). 11 refs, 13 figs

  17. Torus bifurcations in multilevel converter systems

    DEFF Research Database (Denmark)

    Zhusubaliyev, Zhanybai T.; Mosekilde, Erik; Yanochkina, Olga O.

    2011-01-01

    embedded one into the other and with their basins of attraction delineated by intervening repelling tori. The paper illustrates the coexistence of three stable tori with different resonance behaviors and shows how reconstruction of these tori takes place across the borders of different dynamical regimes....... The paper also demonstrates how pairs of attracting and repelling tori emerge through border-collision torus-birth and border-collision torus-fold bifurcations. © 2011 World Scientific Publishing Company....

  18. Perturbed period-doubling bifurcation. I. Theory

    DEFF Research Database (Denmark)

    Svensmark, Henrik; Samuelsen, Mogens Rugholm

    1990-01-01

    -defined way that is a function of the amplitude and the frequency of the signal. New scaling laws between the amplitude of the signal and the detuning δ are found; these scaling laws apply to a variety of quantities, e.g., to the shift of the bifurcation point. It is also found that the stability...... of a microwave-driven Josephson junction confirm the theory. Results should be of interest in parametric-amplification studies....

  19. Drift bifurcation detection for dissipative solitons

    International Nuclear Information System (INIS)

    Liehr, A W; Boedeker, H U; Roettger, M C; Frank, T D; Friedrich, R; Purwins, H-G

    2003-01-01

    We report on the experimental detection of a drift bifurcation for dissipative solitons, which we observe in the form of current filaments in a planar semiconductor-gas-discharge system. By introducing a new stochastic data analysis technique we find that due to a change of system parameters the dissipative solitons undergo a transition from purely noise-driven objects with Brownian motion to particles with a dynamically stabilized finite velocity

  20. Assessment of shear stress related parameters in the carotid bifurcation using mouse-specific FSI simulations.

    Science.gov (United States)

    De Wilde, David; Trachet, Bram; Debusschere, Nic; Iannaccone, Francesco; Swillens, Abigail; Degroote, Joris; Vierendeels, Jan; De Meyer, Guido R Y; Segers, Patrick

    2016-07-26

    The ApoE(-)(/)(-) mouse is a common small animal model to study atherosclerosis, an inflammatory disease of the large and medium sized arteries such as the carotid artery. It is generally accepted that the wall shear stress, induced by the blood flow, plays a key role in the onset of this disease. Wall shear stress, however, is difficult to derive from direct in vivo measurements, particularly in mice. In this study, we integrated in vivo imaging (micro-Computed Tomography-µCT and ultrasound) and fluid-structure interaction (FSI) modeling for the mouse-specific assessment of carotid hemodynamics and wall shear stress. Results were provided for 8 carotid bifurcations of 4 ApoE(-)(/)(-) mice. We demonstrated that accounting for the carotid elasticity leads to more realistic flow waveforms over the complete domain of the model due to volume buffering capacity in systole. The 8 simulated cases showed fairly consistent spatial distribution maps of time-averaged wall shear stress (TAWSS) and relative residence time (RRT). Zones with reduced TAWSS and elevated RRT, potential indicators of atherosclerosis-prone regions, were located mainly at the outer sinus of the external carotid artery. In contrast to human carotid hemodynamics, no flow recirculation could be observed in the carotid bifurcation region. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Angiographic diagnosis of the carotid artery pseudoaneurysm

    International Nuclear Information System (INIS)

    Qi Yueyong; Zou Liguang; Dai Shuhua; Tan Yinghui; Li Zhongyu; Zhou Zheng

    2004-01-01

    Objective: To create a further understanding of the angiographic features of the carotid artery pseudoaneurysm (CAPA) and to explore the clinical diagnostic value of angiography. Methods: Sixteen cases of CAPA with clinical and angiographic data were analyzed retrospectively. The angiographic appearances in all of the patients were observed dynamically and precisely with a double blind method by two experienced radiologists together and formed a consensus interpretation. Results: Angiography provided a definite diagnosis for all cases. The parent arteries included the common carotid artery (1 case), common carotid artery bifurcation (9 cases), internal carotid artery (5 cases) and external carotid artery (1 case). The angiographic features of the CAPA were: All cases showed the contrast media retension in the aneurysms; turbulent flow within aneurysm in 9 cases; the 'jetting sign' at the leak of the parent artery in 7 cases; increase angulation of the bifurcation of internal and external carotid arteries in 12 cases. Conclusions: Angiography is the most valuable examination method in diagnosis of CAPA, and it can not only provide definite diagnosis, but also play an important role in selection of therapeutic plan. (authors)

  2. Ankle-brachial index and cardiovascular outcomes in the Bypass Angioplasty Revascularization Investigation 2 Diabetes trial.

    Science.gov (United States)

    Abbott, J Dawn; Lombardero, Manuel S; Barsness, Gregory W; Pena-Sing, Ivan; Buitrón, L Virginia; Singh, Premranjan; Woodhead, Gail; Tardif, Jean-Claude; Kelsey, Sheryl F

    2012-10-01

    Peripheral arterial disease increases cardiovascular risk in many patient populations. The risks associated with an abnormal ankle-brachial index (ABI) in patients with type 2 diabetes and stable coronary artery disease have not been well described with respect to thresholds and types of cardiovascular events. We examined 2,368 patients in the BARI 2D trial who underwent ABI assessment at baseline. Death and major cardiovascular events (death, myocardial infarction and stroke) during follow-up (average 4.3 years) were assessed across the ABI spectrum and by categorized ABI: low (≤0.90), normal (0.91-1.3), high (>1.3), or noncompressible. A total of 12,568 person-years were available for mortality analysis. During follow-up, 316 patients died, and 549 had major cardiovascular events. After adjustment for potential confounders, with normal ABI as the referent group, a low ABI conferred an increased risk of death (relative risk [RR] 1.6, CI 1.2-2.2, P = .0005) and major cardiovascular events (RR 1.4, CI 1.1-1.7, P = .004). Patients with a high ABI had similar outcomes as patients with a normal ABI, but risk again increased in patients with a noncompressible ABI with a risk of death (RR 1.9, CI 1.3-2.8, P = .001) and major cardiovascular event (RR 1.5, CI 1.1-2.1, P = .01). In patients with coronary artery disease and type 2 diabetes, ABI screening and identification of ABI abnormalities including a low ABI (<1.0) or noncompressible artery provide incremental prognostic information. Copyright © 2012 Mosby, Inc. All rights reserved.

  3. Arterial Stiffness in Children: Pediatric Measurement and Considerations

    Science.gov (United States)

    Savant, Jonathan D.; Furth, Susan L.; Meyers, Kevin E.C.

    2014-01-01

    Background Arterial stiffness is a natural consequence of aging, accelerated in certain chronic conditions, and predictive of cardiovascular events in adults. Emerging research suggests the importance of arterial stiffness in pediatric populations. Methods There are different indices of arterial stiffness. The present manuscript focuses on carotid-femoral pulse wave velocity and pulse wave analysis, although other methodologies are discussed. Also reviewed are specific measurement considerations for pediatric populations and the literature describing arterial stiffness in children with certain chronic conditions (primary hypertension, obesity, diabetes, chronic kidney disease, hypercholesterolemia, genetic syndromes involving vasculopathy, and solid organ transplant recipients). Conclusions The measurement of arterial stiffness in children is feasible and, under controlled conditions, can give accurate information about the underlying state of the arteries. This potentially adds valuable information about the functionality of the cardiovascular system in children with a variety of chronic diseases well beyond that of the brachial artery blood pressure. PMID:26587447

  4. Energized Oxygen : Speiser Current Sheet Bifurcation

    Science.gov (United States)

    George, D. E.; Jahn, J. M.

    2017-12-01

    A single population of energized Oxygen (O+) is shown to produce a cross-tail bifurcated current sheet in 2.5D PIC simulations of the magnetotail without the influence of magnetic reconnection. Treatment of oxygen in simulations of space plasmas, specifically a magnetotail current sheet, has been limited to thermal energies despite observations of and mechanisms which explain energized ions. We performed simulations of a homogeneous oxygen background, that has been energized in a physically appropriate manner, to study the behavior of current sheets and magnetic reconnection, specifically their bifurcation. This work uses a 2.5D explicit Particle-In-a-Cell (PIC) code to investigate the dynamics of energized heavy ions as they stream Dawn-to-Dusk in the magnetotail current sheet. We present a simulation study dealing with the response of a current sheet system to energized oxygen ions. We establish a, well known and studied, 2-species GEM Challenge Harris current sheet as a starting point. This system is known to eventually evolve and produce magnetic reconnection upon thinning of the current sheet. We added a uniform distribution of thermal O+ to the background. This 3-species system is also known to eventually evolve and produce magnetic reconnection. We add one additional variable to the system by providing an initial duskward velocity to energize the O+. We also traced individual particle motion within the PIC simulation. Three main results are shown. First, energized dawn- dusk streaming ions are clearly seen to exhibit sustained Speiser motion. Second, a single population of heavy ions clearly produces a stable bifurcated current sheet. Third, magnetic reconnection is not required to produce the bifurcated current sheet. Finally a bifurcated current sheet is compatible with the Harris current sheet model. This work is the first step in a series of investigations aimed at studying the effects of energized heavy ions on magnetic reconnection. This work differs

  5. Sixth International Symposium on Bifurcations and Instabilities in Fluid Dynamics (BIFD2015)

    DEFF Research Database (Denmark)

    Bar-Yoseph, P. Z.; Brøns, Morten; Gelfgat, A.

    2016-01-01

    dynamics and remain a challenge for experimental, theoretical and computational studies. Examples of prototypical hydrodynamic instabilities are the Rayleigh–Bénard, Taylor–Couette, Bénard–Marangoni, Rayleigh–Taylor, and Kelvin–Helmholtz instabilities. A fundamental understanding of bifurcation patterns...... diseases, such as atherosclerotic and vulnerable plaques, abdominal aortic aneurisms, carotid artery disease, and pulmonary embolisms and implications for vascular interventions such as grafting and stenting. The collection of papers in this issue is a selection of the presentations given at the Sixth...

  6. Outcome of patients with reduced ankle brachial index undergoing open heart surgery with cardiopulmonary bypass.

    Science.gov (United States)

    Meyborg, Matthias; Abdi-Tabari, Zila; Hoffmeier, Andreas; Engelbertz, Christiane; Lüders, Florian; Freisinger, Eva; Malyar, Nasser M; Martens, Sven; Reinecke, Holger

    2016-05-01

    In open heart surgery using cardiopulmonary bypass, perfusion of the lower extremities is markedly reduced which may induce critical ischaemia in patients with pre-existing peripheral artery disease. Whether these patients have an increased risk for amputation and should better undergo peripheral revascularization prior to surgery remains unclear. From 1 January 2009 to 31 December 2010, 785 consecutive patients undergoing open heart surgery were retrospectively included. In 443 of these patients, preoperative ankle brachial index (ABI) measurements were available. The cohort was divided into four groups: (i) ABI heart surgery showed more wound-healing disturbances, and higher long-term mortality compared with those with normal ABIs. However, no perioperative ischaemia requiring amputation occurred. Thus, reduced ABIs were not associated with increased peripheral risks in open heart surgery but ABI may be helpful in selecting the site for saphenectomy to potentially avoid delayed healing of related wounds in legs with severely impaired arterial perfusion. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  7. Global Bifurcation of a Novel Computer Virus Propagation Model

    Directory of Open Access Journals (Sweden)

    Jianguo Ren

    2014-01-01

    Full Text Available In a recent paper by J. Ren et al. (2012, a novel computer virus propagation model under the effect of the antivirus ability in a real network is established. The analysis there only partially uncovers the dynamics behaviors of virus spread over the network in the case where around bifurcation is local. In the present paper, by mathematical analysis, it is further shown that, under appropriate parameter values, the model may undergo a global B-T bifurcation, and the curves of saddle-node bifurcation, Hopf bifurcation, and homoclinic bifurcation are obtained to illustrate the qualitative behaviors of virus propagation. On this basis, a collection of policies is recommended to prohibit the virus prevalence. To our knowledge, this is the first time the global bifurcation has been explored for the computer virus propagation. Theoretical results and corresponding suggestions may help us suppress or eliminate virus propagation in the network.

  8. Bifurcation theory for finitely smooth planar autonomous differential systems

    Science.gov (United States)

    Han, Maoan; Sheng, Lijuan; Zhang, Xiang

    2018-03-01

    In this paper we establish bifurcation theory of limit cycles for planar Ck smooth autonomous differential systems, with k ∈ N. The key point is to study the smoothness of bifurcation functions which are basic and important tool on the study of Hopf bifurcation at a fine focus or a center, and of Poincaré bifurcation in a period annulus. We especially study the smoothness of the first order Melnikov function in degenerate Hopf bifurcation at an elementary center. As we know, the smoothness problem was solved for analytic and C∞ differential systems, but it was not tackled for finitely smooth differential systems. Here, we present their optimal regularity of these bifurcation functions and their asymptotic expressions in the finite smooth case.

  9. Bifurcation structure of a model of bursting pancreatic cells

    DEFF Research Database (Denmark)

    Mosekilde, Erik; Lading, B.; Yanchuk, S.

    2001-01-01

    . The transition from this structure to the so-called period-adding structure is found to involve a subcritical period-doubling bifurcation and the emergence of type-III intermittency. The period-adding transition itself is not smooth but consists of a saddle-node bifurcation in which (n + 1)-spike bursting...... behavior is born, slightly overlapping with a subcritical period-doubling bifurcation in which n-spike bursting behavior loses its stability.......One- and two-dimensional bifurcation studies of a prototypic model of bursting oscillations in pancreatic P-cells reveal a squid-formed area of chaotic dynamics in the parameter plane, with period-doubling bifurcations on one side of the arms and saddle-node bifurcations on the other...

  10. Clinical research of comprehensive rehabilitation in treating brachial plexus injury patients.

    Science.gov (United States)

    Zhou, Jun-Ming; Gu, Yu-Dong; Xu, Xiao-Jun; Zhang, Shen-Yu; Zhao, Xin

    2012-07-01

    Brachial plexus injury is one of the difficult medical problems in the world. The aim of this study was to observe the clinical therapeutic effect of comprehensive rehabilitation in treating dysfunction after brachial plexus injury. Forty-three cases of dysfunction after brachial plexus injury were divided into two groups randomly. The treatment group, which totaled 21 patients (including 14 cases of total brachial plexus injury and seven cases of branch brachial plexus injury), was treated with comprehensive rehabilitation including transcutaneous electrical nerve stimulation, mid-frequency electrotherapy, Tuina therapy, and occupational therapy. The control group, which totaled 22 patients (including 16 cases of total brachial plexus injury and six cases of branch brachial plexus injury), was treated with home-based electrical nerve stimulation and occupational therapy. Each course was of 30 days duration and the patients received four courses totally. After four courses, the rehabilitation effect was evaluated according to the brachial plexus function evaluation standard and electromyogram (EMG) assessment. In the treatment group, there was significant difference in the scores of brachial plexus function pre- and post-treatment (P injury. The scores of two "total injury" groups had statistical differences (P injury" groups had statistical differences (P brachial plexus injury than nonintegrated rehabilitation.

  11. Effect of aorto-iliac bifurcation and iliac stenosis on flow dynamics in an abdominal aortic aneurysm

    Science.gov (United States)

    Patel, Shivam; Usmani, Abdullah Y.; Muralidhar, K.

    2017-06-01

    Physiological flows in rigid diseased arterial flow phantoms emulating an abdominal aortic aneurysm (AAA) under rest conditions with aorto-iliac bifurcation and iliac stenosis are examined in vitro through 2D PIV measurements. Flow characteristics are first established in the model resembling a symmetric AAA with a straight outlet tube. The influence of aorto-iliac bifurcation and iliac stenosis on AAA flow dynamics is then explored through a comparison of the nature of flow patterns, vorticity evolution, vortex core trajectory and hemodynamic factors against the reference configuration. Specifically, wall shear stress and oscillatory shear index in the bulge portion of the models are of interest. The results of this investigation indicate overall phenomenological similarity in AAA flow patterns across the models. The pattern is characterized by a central jet and wall-bounded vortices whose strength increases during the deceleration phase as it moves forward. The central jet impacts the wall of AAA at its distal end. In the presence of an aorto-iliac bifurcation as well as iliac stenosis, the flow patterns show diminished strength, expanse and speed of propagation of the primary vortices. The positions of the instantaneous vortex cores, determined using the Q-function, correlate with flow separation in the bulge, flow resistance due to a bifurcation, and the break in symmetry introduced by a stenosis in one of the legs of the model. Time-averaged WSS in a healthy aorta is around 0.70 N m-2 and is lowered to the range ±0.2 N m-2 in the presence of the downstream bifurcation with a stenosed common iliac artery. The consequence of changes in the flow pattern within the aneurysm on disease progression is discussed.

  12. Effect of aorto-iliac bifurcation and iliac stenosis on flow dynamics in an abdominal aortic aneurysm

    International Nuclear Information System (INIS)

    Patel, Shivam; Usmani, Abdullah Y; Muralidhar, K

    2017-01-01

    Physiological flows in rigid diseased arterial flow phantoms emulating an abdominal aortic aneurysm (AAA) under rest conditions with aorto-iliac bifurcation and iliac stenosis are examined in vitro through 2D PIV measurements. Flow characteristics are first established in the model resembling a symmetric AAA with a straight outlet tube. The influence of aorto-iliac bifurcation and iliac stenosis on AAA flow dynamics is then explored through a comparison of the nature of flow patterns, vorticity evolution, vortex core trajectory and hemodynamic factors against the reference configuration. Specifically, wall shear stress and oscillatory shear index in the bulge portion of the models are of interest. The results of this investigation indicate overall phenomenological similarity in AAA flow patterns across the models. The pattern is characterized by a central jet and wall-bounded vortices whose strength increases during the deceleration phase as it moves forward. The central jet impacts the wall of AAA at its distal end. In the presence of an aorto-iliac bifurcation as well as iliac stenosis, the flow patterns show diminished strength, expanse and speed of propagation of the primary vortices. The positions of the instantaneous vortex cores, determined using the Q -function, correlate with flow separation in the bulge, flow resistance due to a bifurcation, and the break in symmetry introduced by a stenosis in one of the legs of the model. Time-averaged WSS in a healthy aorta is around 0.70 N m −2 and is lowered to the range ±0.2 N m −2 in the presence of the downstream bifurcation with a stenosed common iliac artery. The consequence of changes in the flow pattern within the aneurysm on disease progression is discussed. (paper)

  13. Effect of aorto-iliac bifurcation and iliac stenosis on flow dynamics in an abdominal aortic aneurysm

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Shivam; Usmani, Abdullah Y; Muralidhar, K, E-mail: kmurli@iitk.ac.in [Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India)

    2017-06-15

    Physiological flows in rigid diseased arterial flow phantoms emulating an abdominal aortic aneurysm (AAA) under rest conditions with aorto-iliac bifurcation and iliac stenosis are examined in vitro through 2D PIV measurements. Flow characteristics are first established in the model resembling a symmetric AAA with a straight outlet tube. The influence of aorto-iliac bifurcation and iliac stenosis on AAA flow dynamics is then explored through a comparison of the nature of flow patterns, vorticity evolution, vortex core trajectory and hemodynamic factors against the reference configuration. Specifically, wall shear stress and oscillatory shear index in the bulge portion of the models are of interest. The results of this investigation indicate overall phenomenological similarity in AAA flow patterns across the models. The pattern is characterized by a central jet and wall-bounded vortices whose strength increases during the deceleration phase as it moves forward. The central jet impacts the wall of AAA at its distal end. In the presence of an aorto-iliac bifurcation as well as iliac stenosis, the flow patterns show diminished strength, expanse and speed of propagation of the primary vortices. The positions of the instantaneous vortex cores, determined using the Q -function, correlate with flow separation in the bulge, flow resistance due to a bifurcation, and the break in symmetry introduced by a stenosis in one of the legs of the model. Time-averaged WSS in a healthy aorta is around 0.70 N m{sup −2} and is lowered to the range ±0.2 N m{sup −2} in the presence of the downstream bifurcation with a stenosed common iliac artery. The consequence of changes in the flow pattern within the aneurysm on disease progression is discussed. (paper)

  14. Nonlinear physical systems spectral analysis, stability and bifurcations

    CERN Document Server

    Kirillov, Oleg N

    2013-01-01

    Bringing together 18 chapters written by leading experts in dynamical systems, operator theory, partial differential equations, and solid and fluid mechanics, this book presents state-of-the-art approaches to a wide spectrum of new and challenging stability problems.Nonlinear Physical Systems: Spectral Analysis, Stability and Bifurcations focuses on problems of spectral analysis, stability and bifurcations arising in the nonlinear partial differential equations of modern physics. Bifurcations and stability of solitary waves, geometrical optics stability analysis in hydro- and magnetohydrodynam

  15. Stability and bifurcation analysis in a delayed SIR model

    International Nuclear Information System (INIS)

    Jiang Zhichao; Wei Junjie

    2008-01-01

    In this paper, a time-delayed SIR model with a nonlinear incidence rate is considered. The existence of Hopf bifurcations at the endemic equilibrium is established by analyzing the distribution of the characteristic values. A explicit algorithm for determining the direction of the Hopf bifurcation and the stability of the bifurcating periodic solutions are derived by using the normal form and the center manifold theory. Numerical simulations to support the analytical conclusions are carried out

  16. Bifurcation of rupture path by linear and cubic damping force

    Science.gov (United States)

    Dennis L. C., C.; Chew X., Y.; Lee Y., C.

    2014-06-01

    Bifurcation of rupture path is studied for the effect of linear and cubic damping. Momentum equation with Rayleigh factor was transformed into ordinary differential form. Bernoulli differential equation was obtained and solved by the separation of variables. Analytical or exact solutions yielded the bifurcation was visible at imaginary part when the wave was non dispersive. For the dispersive wave, bifurcation of rupture path was invisible.

  17. Obesity and overweight associated with increased carotid diameter and decreased arterial function in young otherwise healthy men.

    Science.gov (United States)

    Kappus, Rebecca M; Fahs, Christopher A; Smith, Denise; Horn, Gavin P; Agiovlasitis, Stomatis; Rossow, Lindy; Jae, Sae Y; Heffernan, Kevin S; Fernhall, Bo

    2014-04-01

    Obesity is linked to cardiovascular disease, stroke, increased mortality and vascular remodeling. Although increased arterial diameter is associated with multiple cardiovascular risk factors and obesity, it is unknown whether lumen enlargement is accompanied by unfavorable vascular changes in young and otherwise healthy obese individuals. The purpose of this study was to compare carotid and brachial artery diameter, blood pressure, arterial stiffness, and endothelial function in young, apparently healthy, normal-weight, overweight, and obese male subjects. One hundred sixty-five male subjects (27.39±0.59 years) were divided into 3 groups (normal weight, overweight, and obese) according to body mass index. Subjects underwent cardiovascular measurements to determine arterial diameter, function, and stiffness. After adjusting for age, the obese group had significantly greater brachial, carotid, and aortic pressures, brachial pulse wave velocity, carotid intima media thickness, and carotid arterial diameter compared with both the overweight and normal-weight groups. Obesity is associated with a much worse arterial profile, as an increased carotid lumen size was accompanied by higher blood pressure, greater arterial stiffness, and greater carotid intima media thickness in obese compared with overweight or normal-weight individuals. These data suggest that although obesity may be a factor in arterial remodeling, such remodeling is also accompanied by other hemodynamic and arterial changes consistent with reduced arterial function and increased cardiovascular risk.

  18. A codimension two bifurcation in a railway bogie system

    DEFF Research Database (Denmark)

    Zhang, Tingting; True, Hans; Dai, Huanyun

    2017-01-01

    In this paper, a comprehensive analysis is presented to investigate a codimension two bifurcation that exists in a nonlinear railway bogie dynamic system combining theoretical analysis with numerical investigation. By using the running velocity V and the primary longitudinal stiffness (Formula...... coexist in a range of the bifurcation parameters which can lead to jumps in the lateral oscillation amplitude of the railway bogie system. Furthermore, reduce the values of the bifurcation parameters gradually. Firstly, the supercritical Hopf bifurcation turns into a subcritical one with multiple limit...

  19. Hopf bifurcation for tumor-immune competition systems with delay

    Directory of Open Access Journals (Sweden)

    Ping Bi

    2014-01-01

    Full Text Available In this article, a immune response system with delay is considered, which consists of two-dimensional nonlinear differential equations. The main purpose of this paper is to explore the Hopf bifurcation of a immune response system with delay. The general formula of the direction, the estimation formula of period and stability of bifurcated periodic solution are also given. Especially, the conditions of the global existence of periodic solutions bifurcating from Hopf bifurcations are given. Numerical simulations are carried out to illustrate the the theoretical analysis and the obtained results.

  20. Predicting bifurcation angle effect on blood flow in the microvasculature.

    Science.gov (United States)

    Yang, Jiho; Pak, Y Eugene; Lee, Tae-Rin

    2016-11-01

    Since blood viscosity is a basic parameter for understanding hemodynamics in human physiology, great amount of research has been done in order to accurately predict this highly non-Newtonian flow property. However, previous works lacked in consideration of hemodynamic changes induced by heterogeneous vessel networks. In this paper, the effect of bifurcation on hemodynamics in a microvasculature is quantitatively predicted. The flow resistance in a single bifurcation microvessel was calculated by combining a new simple mathematical model with 3-dimensional flow simulation for varying bifurcation angles under physiological flow conditions. Interestingly, the results indicate that flow resistance induced by vessel bifurcation holds a constant value of approximately 0.44 over the whole single bifurcation model below diameter of 60μm regardless of geometric parameters including bifurcation angle. Flow solutions computed from this new model showed substantial decrement in flow velocity relative to other mathematical models, which do not include vessel bifurcation effects, while pressure remained the same. Furthermore, when applying the bifurcation angle effect to the entire microvascular network, the simulation results gave better agreements with recent in vivo experimental measurements. This finding suggests a new paradigm in microvascular blood flow properties, that vessel bifurcation itself, regardless of its angle, holds considerable influence on blood viscosity, and this phenomenon will help to develop new predictive tools in microvascular research. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Sympathetic reflex control of resistance in collateral arteries in the lower extremities in patients with diabetes mellitus

    DEFF Research Database (Denmark)

    Agerskov, K; Tønnesen, K H

    1982-01-01

    The vascular response in the lower extremities to 40 degrees head-up tilt was studied in 5 patients with occlusion of the superficial femoral artery and maturity onset diabetes mellitus with symptoms suggesting autonomic neuropathy. The pressure measurements were performed via catheters placed...... in the brachial artery, femoral artery and vein and popliteal artery and vein. Relative blood flow was calculated as the relative change in arterio-venous oxygen saturation. Absolute blood flow in the common femoral artery was measured by an indicator dilution technique. Resistance of the collateral arteries...

  2. Topography of the accessory left gastric artery (ALGA) analyzed by CT angiography from the left hepatic artery

    International Nuclear Information System (INIS)

    Shioyama, Yasukazu; Takasaka, Isao; Onaya, Hiroaki

    2003-01-01

    To avoid gastric complications when we perform transcatheter treatment via left hepatic artery, we analyzed the topography of ALGA (accessory left gastric artery) by left hepatic arteriography and CT angiography from left hepatic artery. Six hundred seventy eight cases of CT angiography were performed between 1995 and 2000. Among them, selective left hepatic arteriography was done in 85 cases. We analyzed the frequency and the course of ALGA on the hepatic angiogram and CT angiogram. ALGA were identified in eighteen (21.2 %) of the 85 cases. We classified them into eleven cases of the proximal type and six cases of the distal type. When ALGA bifurcated from the left hepatic artery very close to the bifurcation of A2 (dorsolateral branch) and A3 (ventrolateral branch), we classified them as the distal type on hepatic angiogram. On the other hand, when ALGA bifurcated from the left hepatic artery apart from the bifurcation of A2 and A3 they were classified as the proximal type. In one rare case ALGA originated from the dorsolateral branch of the left hepatic artery. ALGA were classified as the distal and proximal types. Distal type of ALGA often overlapped dorsolateral branch of the left hepatic artery, and it was sometimes difficult to notice the existence of them. We should check the existence of ALGA on the arterial phase of dynamic CT before we plan to make a transcatheter treatment from the left hepatic artery. Then we can avoid gastric complications caused by a transcatheter treatment from the left hepatic artery. (author)

  3. Double Hopf bifurcation in delay differential equations

    Directory of Open Access Journals (Sweden)

    Redouane Qesmi

    2014-07-01

    Full Text Available The paper addresses the computation of elements of double Hopf bifurcation for retarded functional differential equations (FDEs with parameters. We present an efficient method for computing, simultaneously, the coefficients of center manifolds and normal forms, in terms of the original FDEs, associated with the double Hopf singularity up to an arbitrary order. Finally, we apply our results to a nonlinear model with periodic delay. This shows the applicability of the methodology in the study of delay models arising in either natural or technological problems.

  4. Bifurcation theory for toroidal MHD instabilities

    International Nuclear Information System (INIS)

    Maschke, E.K.; Morros Tosas, J.; Urquijo, G.

    1992-01-01

    Using a general representation of magneto-hydrodynamics in terms of stream functions and potentials, proposed earlier, a set of reduced MHD equations for the case of toroidal geometry had been derived by an appropriate ordering with respect to the inverse aspect ratio. When all dissipative terms are neglected in this reduced system, it has the same linear stability limits as the full ideal MHD equations, to the order considered. When including resistivity, thermal conductivity and viscosity, we can apply bifurcation theory to investigate nonlinear stationary solution branches related to various instabilities. In particular, we show that a stationary solution of the internal kink type can be found

  5. Bifurcation of Mobility, Bifurcation of Law : Externalization of migration policy before the EU Court of Justice

    NARCIS (Netherlands)

    Spijkerboer, T.P.

    2017-01-01

    The externalization of European migration policy has resulted in a bifurcation of global human mobility, which is divided along a North/South axis. In two judgments, the EU Court of Justice was confronted with cases challenging the exclusion of Syrian refugees from Europe. These cases concern core

  6. Technical note: the humeral canal approach to the brachial plexus.

    LENUS (Irish Health Repository)

    Frizelle, H P

    2012-02-03

    Many variations to the axillary approach to the brachial plexus have been described. However, the success rate varies depending on the approach used and on the definition of success. Recent work describes a new approach to regional anaesthesia of the upper limb at the humeral\\/brachial canal using selective stimulation of the major nerves. This report outlines initial experience with this block, describing the technique and results in 50 patients undergoing hand and forearm surgery. All patients were assessed for completeness of motor and sensory block. The overall success rate was 90 percent. Motor block was present in 80 percent of patients. Completion of the block was necessary in 5 patients. Two patients required general anaesthesia. The preponderance of ulnar deficiencies agrees with previously published data on this technique. No complications were described. Initial experience confirms the high success rate described using the Dupre technique. This technically straightforward approach with minimal complications can be recommended for regional anaesthesia of the upper limb.

  7. Computer model analysis of the radial artery pressure waveform.

    Science.gov (United States)

    Schwid, H A; Taylor, L A; Smith, N T

    1987-10-01

    Simultaneous measurements of aortic and radial artery pressures are reviewed, and a model of the cardiovascular system is presented. The model is based on resonant networks for the aorta and axillo-brachial-radial arterial system. The model chosen is a simple one, in order to make interpretation of the observed relationships clear. Despite its simplicity, the model produces realistic aortic and radial artery pressure waveforms. It demonstrates that the resonant properties of the arterial wall significantly alter the pressure waveform as it is propagated from the aorta to the radial artery. Although the mean and end-diastolic radial pressures are usually accurate estimates of the corresponding aortic pressures, the systolic pressure at the radial artery is often much higher than that of the aorta due to overshoot caused by the resonant behavior of the radial artery. The radial artery dicrotic notch is predominantly dependent on the axillo-brachial-radial arterial wall properties, rather than on the aortic valve or peripheral resistance. Hence the use of the radial artery dicrotic notch as an estimate of end systole is unreliable. The rate of systolic upstroke, dP/dt, of the radial artery waveform is a function of many factors, making it difficult to interpret. The radial artery waveform usually provides accurate estimates for mean and diastolic aortic pressures; for all other measurements it is an inadequate substitute for the aortic pressure waveform. In the presence of low forearm peripheral resistance the mean radial artery pressure may significantly underestimate the mean aortic pressure, as explained by a voltage divider model.

  8. Delivery factors for brachial plexus palsy by newborns

    Directory of Open Access Journals (Sweden)

    D. Balić

    2007-02-01

    Full Text Available Brachial plexus injuries represent a low percentage of delivery complications. Most newborns fully recover from the injury, very few retain a permanent neurological deficit whereas some remain unnoticed. An objective of this study was to establish delivery factors for brachial plexus palsy at the Clinic for Gynecology and Obstetrics and relation between the deficits with length of delivery, the length of delivery periods, induction of delivery and surgical interventions at delivery. The analysed group involved 90 newborn babies with an injury of brachial plexus made at the delivery in the period between 01.01.1996 and 31.12.2005. The controlled group included 90 newborns randomly selected. The comparison was made using an χ2 test. The incidence of injuries of plexus brachialis was 1.72 per 1,000 newborns. Analysing the length of delivery there was no difference found between the analysed and controlled group (p > 0.05. In the group of newborns with the injury of brachial plexus it was found that the second delivery period was significantly shorter (p < 0.01. In the analysed group 89 (98.8% newborn babies were delivered vaginally and one (1.2% was delivered by the cesarean section. 13 newborns (14.4% from the analysed group were delivered with application of vacuum extractor and in the controlled group it was the case with one (1.2% newborn baby (p < 0.01. The delivery of 98.8% newborns from the analysed group started spontaneously and two deliveries (1.2% were induced. Risk factors for injuries of plexus brachialis in newborns at the Clinic for Gynaecology and Obstetrics of the University Clinical Centre Tuzla include shortened second delivery period and completion of deliveries applying the vacuum extractor.

  9. Delayed radiation-induced damage to the brachial plexus

    Energy Technology Data Exchange (ETDEWEB)

    Burns, R J

    1978-01-01

    Three patients are described who developed a brachial plexus neuropathy following radiation treatment for cancer of the breast. The clinical features consisted of a painless, slowly progressive sensory motor disturbance, affecting especially the hand. The latent period between the radiation therapy and the onset of the neuropathy was exceptionally long, being 8, 15 and 15 years respectively. Two patients were initially incorrectly diagnosed as having a carpal tunnel syndrome. The possible mechanisms of the insidious neuropathy are discussed.

  10. Rhabdomyolysis resulting in concurrent Horner's syndrome and brachial plexopathy: a case report.

    Science.gov (United States)

    Lee, Susan C; Geannette, Christian; Wolfe, Scott W; Feinberg, Joseph H; Sneag, Darryl B

    2017-08-01

    This case report describes a 29-year-old male who presented with immediate onset of Horner's syndrome and ipsilateral brachial plexopathy after sleeping with his arm dangling outside a car window for 8 h. Outside workup and imaging revealed rhabdomyolysis of the left neck musculature. Subsequent electrodiagnostic testing and high-resolution brachial plexus magnetic resonance imaging at the authors' institution attributed the Horner's syndrome and concurrent brachial plexopathy to rhabdomyolysis of the longus colli and scalene musculature, which had compressed-and consequently scar tethered-the cervical sympathetic trunk and brachial plexus. This case of co-existent Horner's syndrome and brachial plexopathy demonstrates the role of high-resolution brachial plexus MRI in diagnosing plexopathy and the importance of being familiar with plexus and paravertebral muscle anatomy.

  11. Rhabdomyolysis resulting in concurrent Horner's syndrome and brachial plexopathy: a case report

    International Nuclear Information System (INIS)

    Lee, Susan C.; Geannette, Christian; Sneag, Darryl B.; Wolfe, Scott W.; Feinberg, Joseph H.

    2017-01-01

    This case report describes a 29-year-old male who presented with immediate onset of Horner's syndrome and ipsilateral brachial plexopathy after sleeping with his arm dangling outside a car window for 8 h. Outside workup and imaging revealed rhabdomyolysis of the left neck musculature. Subsequent electrodiagnostic testing and high-resolution brachial plexus magnetic resonance imaging at the authors' institution attributed the Horner's syndrome and concurrent brachial plexopathy to rhabdomyolysis of the longus colli and scalene musculature, which had compressed - and consequently scar tethered - the cervical sympathetic trunk and brachial plexus. This case of co-existent Horner's syndrome and brachial plexopathy demonstrates the role of high-resolution brachial plexus MRI in diagnosing plexopathy and the importance of being familiar with plexus and paravertebral muscle anatomy. (orig.)

  12. Transplantation of human amniotic epithelial cells repairs brachial plexus injury:pathological and biomechanical analyses

    Institute of Scientific and Technical Information of China (English)

    Qi Yang; Min Luo; Peng Li; Hai Jin

    2014-01-01

    A brachial plexus injury model was established in rabbits by stretching the C6 nerve root. Imme-diately after the stretching, a suspension of human amniotic epithelial cells was injected into the injured brachial plexus. The results of tensile mechanical testing of the brachial plexus showed that the tensile elastic limit strain, elastic limit stress, maximum stress, and maximum strain of the injured brachial plexuses were signiifcantly increased at 24 weeks after the injection. The treat-ment clearly improved the pathological morphology of the injured brachial plexus nerve, as seen by hematoxylin eosin staining, and the functions of the rabbit forepaw were restored. These data indicate that the injection of human amniotic epithelial cells contributed to the repair of brachial plexus injury, and that this technique may transform into current clinical treatment strategies.

  13. Rhabdomyolysis resulting in concurrent Horner's syndrome and brachial plexopathy: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Susan C.; Geannette, Christian; Sneag, Darryl B. [Hospital for Special Surgery, Department of Radiology and Imaging, New York, NY (United States); Wolfe, Scott W. [Hospital for Special Surgery, Hand and Upper Extremity, Department of Orthopedics, New York, NY (United States); Feinberg, Joseph H. [Hospital for Special Surgery, Physical Medicine and Rehabilitation, New York, NY (United States)

    2017-08-15

    This case report describes a 29-year-old male who presented with immediate onset of Horner's syndrome and ipsilateral brachial plexopathy after sleeping with his arm dangling outside a car window for 8 h. Outside workup and imaging revealed rhabdomyolysis of the left neck musculature. Subsequent electrodiagnostic testing and high-resolution brachial plexus magnetic resonance imaging at the authors' institution attributed the Horner's syndrome and concurrent brachial plexopathy to rhabdomyolysis of the longus colli and scalene musculature, which had compressed - and consequently scar tethered - the cervical sympathetic trunk and brachial plexus. This case of co-existent Horner's syndrome and brachial plexopathy demonstrates the role of high-resolution brachial plexus MRI in diagnosing plexopathy and the importance of being familiar with plexus and paravertebral muscle anatomy. (orig.)

  14. EXERCISE-INDUCED ARTERIAL ADAPTATIONS IN ELITE JUDO ATHLETES

    Directory of Open Access Journals (Sweden)

    Panagiotis Karagounis

    2009-09-01

    Full Text Available The purpose of this study was to examine exercise-induced arterial adaptations in elite Judo male and female athletes. 27 male Judo athletes (age 24.06 ± 2 years, 11 female Judoka (age 24.27 ± 1 years, 27 sedentary healthy men (age 24.01 ± 2 years and 11 women (age 24.21 ± 1 years participated in the current study. The examined vessels included brachial, radial, ulnar, popliteal, anterior and posterior tibial arteries. The experimental parameters were recorded with the use of Duplex ultrasound at rest. Diastolic diameter and blood mean flow velocity of the examined arteries in Judo athletes were found to be both significantly increased (p < 0.05 compared to the findings of the control groups. In male Judo athletes the brachial (p < 0.001, radial (p < 0.001, and anterior tibial artery (p < 0.001 presented the highest difference on the diastolic diameter, compared with the control male group. In female Judo athletes, ulnar (p < 0.001, radial (p < 0.001, and brachial (p < 0.001 arteries illustrated the highest diastolic diameter. The highest blood mean flow velocity was recorded in ulnar (p < 0.001 and popliteal arteries (p < 0.001 of the Judo athletes groups. Recording differences between the two genders, male participants presented larger arteries than females. Conclusively, Judo has been found to be a highly demanding physical sport, involving upper and lower limbs leading to significant arterial adaptations. Obtaining vascular parameters provide a useful tool to the medical team, not only in the direction of enhancement of the efficacy of physical training, but in unknown so far parameters that may influence athletic performance of both male and female elite Judokas

  15. Neurolysis and myocutaneous flap for radiation induced brachial plexus neuropathy

    International Nuclear Information System (INIS)

    Hirachi, Kazuhiko; Minami, Akio; Kato, Hiroyuki; Nishio, Yasuhiko; Ohnishi, Nobuki

    1998-01-01

    Surgical treatment for radiation induced brachial plexus neuropathy is difficult. We followed 9 patients of radiation induced brachial plexus neuropathy who were surgically treated with neurolysis and myocutaneous flap coverage. Their ages ranged from 29 to 72 years old. Their diagnoses were breast cancer in 6 patients, lingual cancer in 1, thyroid cancer in 1 and malignant lymphoma in 1. Total dose of radiation ranged from 44 to 240 Gy. Interval from radiation therapy to our surgery ranged from 1 to 18 years (mean 6.7 years). Chief complaints were dysesthesia in 9 patients, motor weakness in 7 patients and dullach in scar formation of radiated skin in 7 patients. Preoperative neural functions were slight palsy in 1, moderate palsy in 5 and complete palsy in 3. In surgical treatment, neurolysis of the brachial plexus was done and it was covered by latissimus dorsi myocutaneous flap. We evaluated about dysesthesia and motor recovery after treatment for neuropathy. Follow up periods ranged from 1 to 11 years (average in 5 years). Dysesthesia improved in 6 patients and got worse in 3 patients. Motor weakness recovered in only 2 patients and got worse in 7 patients. From our results, intolerable dysesthesia which was first complaint of these patients improved. But motor function had not recovered. Our treatment was thought to be effective for extraneural factor like an compression neuropathy by scar formation and poor vascularity. But it was not effective for intraneural damage by radiation therapy. (author)

  16. Treatment of a radiation-induced brachial plexopathy

    International Nuclear Information System (INIS)

    Tanaka, Ichirou; Harashina, Takao; Inoue, Takeo; Ueda, Kouichi; Hatoko, Mituo; Shidara, Yukinobu; Ito, Yoshiyasu.

    1990-01-01

    A radiation-induced brachial plexopathy after a mastectomy causes severe pain and numbness, as well as motor and sensory disorders. Severe pain is often resistant to analgesic blocks, and in most instances, the effect of neurolysis is only temporary. We have treated two such patients with microsurgical neurolysis and then have covered the nerve by transferred muscles. In one case, the exposed brachial plexus was covered with a pedicled latissimus dorsi muscle flap, and in the other, with a free rectus abdominis muscle flap. Pain and numbness were markedly improved in these two patients soon after the surgery, and the improvement in the sensory function also was relatively satisfactory. In one case, the motor function also improved. These patients have had no recurrence of pain or numbness for 4 years and 2 months and 4 years and 7 months after surgery, respectively. Further, their sensory and motor disorders did not advance. Surgical indications for a radiation-induced brachial plexopathy remain controversial, since the operation does not always ensure a marked improvement in the sensory and motor functions. Further, the operation is ineffective for patients with advanced nerve degeneration. Taking these factors into consideration, the preoperative predication of beneficial effects from this surgery is difficult. Despite our limited experience, however, our surgical method has been thought to be effective because it achieves a marked improvement in the numbness and pain experienced in the arms, which are usually the patients' chief complaints. (author)

  17. Neonatal brachial plexus palsy--management and prognostic factors.

    Science.gov (United States)

    Yang, Lynda J-S

    2014-06-01

    Successful treatment of patients with neonatal brachial plexus palsy (NBPP) begins with a thorough understanding of the anatomy of the brachial plexus and of the pathophysiology of nerve injury via which the brachial plexus nerves stretched in the perinatal period manifest as a weak or paralyzed upper extremity in the newborn. NBPP can be classified by systems that can guide the prognosis and the management as these systems are based on the extent and severity of nerve injury, anatomy of nerve injury, and clinical presentation. Serial physical examinations, supplemented by a thorough maternal and perinatal history, are critical to the formulation of the treatment plan that relies upon occupational/physical therapy and rehabilitation management but may include nerve reconstruction and secondary musculoskeletal surgeries. Adjunctive imaging and electrodiagnostic studies provide additional information to guide prognosis and treatment. As research improves not only the technical aspects of NBPP treatment but also the ability to assess the activity and participation as well as body structure and function of NBPP patients, the functional outcomes for affected infants have an overall optimistic prognosis, with the majority recovering adequate functional use of the affected arm. Of importance are (i) early referral to interdisciplinary specialty clinics that can provide up-to-date advances in clinical care and (ii) increasing research/awareness of the psychosocial and patient-reported quality-of-life issues that surround the chronic disablement of NBPP. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. A novel technique for teaching the brachial plexus.

    Science.gov (United States)

    Lefroy, Henrietta; Burdon-Bailey, Victoria; Bhangu, Aneel; Abrahams, Peter

    2011-09-01

    The brachial plexus has posed problems for both students and teachers throughout generations of medical education. The anatomy is intricate, and traditional pictorial representations can be difficult to understand and learn. Few innovative teaching methods have been reported. The basic anatomy of the brachial plexus is core knowledge required by medical students to aid clinical examination and diagnosis. A more detailed understanding is necessary for a variety of specialists, including surgeons, anaesthetists and radiologists. Here, we present a novel, cheap and interactive method of teaching the brachial plexus. Using coloured pipe cleaners, teachers and students can construct three-dimensional models using different colours to denote the origin and outflow of each nerve. The three-dimensional nature of the model also allows for a better understanding of certain intricacies of the plexus. Students may use these models as adjuncts for self study, didactic lectures and tutorials. Compared with traditional textbooks and whiteboards, the pipe-cleaner model was preferred by medical students, and provided a higher level of student satisfaction. This was demonstrated and analysed using student feedback forms. Our model could be incorporated into current curricula to provide an effective and enjoyable way of rapidly teaching a difficult concept. Other such novel methods for teaching complex anatomical principles should be encouraged and explored. © Blackwell Publishing Ltd 2011.

  19. Balloon Occlusion of the Contralateral Iliac Artery to Assist Recanalization of the Ipsilateral Iliac Artery in Total Aortoiliac Occlusion: A Technical Note

    Directory of Open Access Journals (Sweden)

    Abdel Aziz A. Jaffan

    2013-01-01

    Full Text Available Endovascular recanalization of chronic total aortoiliac occlusion is technically challenging. Inability to reenter the true aortic lumen, following retrograde iliac recanalization, is one of the most common causes of failure. We describe a case of a total aortoiliac occlusion where balloon occlusion of the right common iliac artery, following its recanalization from a brachial approach, was used to facilitate antegrade recanalization of the occluded contralateral left common iliac artery.

  20. A STUDY ON THE RISK FACTORS FOR OBSTETRICAL BRACHIAL PLEXUS PALSY

    OpenAIRE

    Farah ASHRAFZADEH; Hasan BOSKABADI; Mohammad FARAJI RAD; Parisa SEYYED HOSSEINEE

    2011-01-01

    ObjectiveConsiderable medical and legal debates have surrounded the prognosis and outcome of obstetrical brachial plexus injuries and obstetricians are oftenconsidered responsible for the injury. In this study, we assessed the factors related to the outcome of brachial plexus palsy.Material & MethodsDuring 24 months, 21 neonates with obstetrical brachial plexus injuries were enrolled.Electrophysiology studies were done at the age of three weeks. They received physiotherapy and occupational th...

  1. Bifurcation into functional niches in adaptation.

    Science.gov (United States)

    White, Justin S; Adami, Christoph

    2004-01-01

    One of the central questions in evolutionary biology concerns the dynamics of adaptation and diversification. This issue can be addressed experimentally if replicate populations adapting to identical environments can be investigated in detail. We have studied 501 such replicas using digital organisms adapting to at least two fundamentally different functional niches (survival strategies) present in the same environment: one in which fast replication is the way to live, and another where exploitation of the environment's complexity leads to complex organisms with longer life spans and smaller replication rates. While these two modes of survival are closely analogous to those expected to emerge in so-called r and K selection scenarios respectively, the bifurcation of evolutionary histories according to these functional niches occurs in identical environments, under identical selective pressures. We find that the branching occurs early, and leads to drastic phenotypic differences (in fitness, sequence length, and gestation time) that are permanent and irreversible. This study confirms an earlier experimental effort using microorganisms, in that diversification can be understood at least in part in terms of bifurcations on saddle points leading to peak shifts, as in the picture drawn by Sewall Wright.

  2. Bifurcation theory of ac electric arcing

    International Nuclear Information System (INIS)

    Christen, Thomas; Peinke, Emanuel

    2012-01-01

    The performance of alternating current (ac) electric arcing devices is related to arc extinction or its re-ignition at zero crossings of the current (so-called ‘current zero’, CZ). Theoretical investigations thus usually focus on the transient behaviour of arcs near CZ, e.g. by solving the modelling differential equations in the vicinity of CZ. This paper proposes as an alternative approach to investigate global mathematical properties of the underlying periodically driven dynamic system describing the electric circuit containing the arcing device. For instance, the uniqueness of the trivial solution associated with the insulating state indicates the extinction of any arc. The existence of non-trivial attractors (typically a time-periodic state) points to a re-ignition of certain arcs. The performance regions of arcing devices, such as circuit breakers and arc torches, can thus be identified with the regions of absence and existence, respectively, of non-trivial attractors. Most important for applications, the boundary of a performance region in the model parameter space is then associated with the bifurcation of the non-trivial attractors. The concept is illustrated for simple black-box arc models, such as the Mayr and the Cassie model, by calculating for various cases the performance boundaries associated with the bifurcation of ac arcs. (paper)

  3. Post-operative brachial plexus neuropraxia: A less recognised complication of combined plastic and laparoscopic surgeries

    Directory of Open Access Journals (Sweden)

    Jimmy Thomas

    2014-01-01

    Full Text Available This presentation is to increase awareness of the potential for brachial plexus injury during prolonged combined plastic surgery procedures. A case of brachial plexus neuropraxia in a 26-year-old obese patient following a prolonged combined plastic surgery procedure was encountered. Nerve palsy due to faulty positioning on the operating table is commonly seen over the elbow and popliteal fossa. However, injury to the brachial plexus has been a recently reported phenomenon due to the increasing number of laparoscopic and robotic procedures. Brachial plexus injury needs to be recognised as a potential complication of prolonged combined plastic surgery. Preventive measures are discussed.

  4. Novel Axillary Approach for Brachial Plexus in Robotic Surgery: A Cadaveric Experiment

    Directory of Open Access Journals (Sweden)

    Cihangir Tetik

    2014-01-01

    Full Text Available Brachial plexus surgery using the da Vinci surgical robot is a new procedure. Although the supraclavicular approach is a well known described and used procedure for robotic surgery, axillary approach was unknown for brachial plexus surgery. A cadaveric study was planned to evaluate the robotic axillary approach for brachial plexus surgery. Our results showed that robotic surgery is a very useful method and should be used routinely for brachial plexus surgery and particularly for thoracic outlet syndrome. However, we emphasize that new instruments should be designed and further studies are needed to evaluate in vivo results.

  5. Child neurology: Brachial plexus birth injury: what every neurologist needs to know.

    Science.gov (United States)

    Pham, Christina B; Kratz, Johannes R; Jelin, Angie C; Gelfand, Amy A

    2011-08-16

    While most often transient, brachial plexus birth injury can cause permanent neurologic injury. The major risk factors for brachial plexus birth injury are fetal macrosomia and shoulder dystocia. The degree of injury to the brachial plexus should be determined in the neonatal nursery, as those infants with the most severe injury--root avulsion--should be referred early for surgical evaluation so that microsurgical repair of the plexus can occur by 3 months of life. Microsurgical repair options include nerve grafts and nerve transfers. All children with brachial plexus birth injury require ongoing physical and occupational therapy and close follow-up to monitor progress.

  6. Analysis of Vehicle Steering and Driving Bifurcation Characteristics

    Directory of Open Access Journals (Sweden)

    Xianbin Wang

    2015-01-01

    Full Text Available The typical method of vehicle steering bifurcation analysis is based on the nonlinear autonomous vehicle model deriving from the classic two degrees of freedom (2DOF linear vehicle model. This method usually neglects the driving effect on steering bifurcation characteristics. However, in the steering and driving combined conditions, the tyre under different driving conditions can provide different lateral force. The steering bifurcation mechanism without the driving effect is not able to fully reveal the vehicle steering and driving bifurcation characteristics. Aiming at the aforementioned problem, this paper analyzed the vehicle steering and driving bifurcation characteristics with the consideration of driving effect. Based on the 5DOF vehicle system dynamics model with the consideration of driving effect, the 7DOF autonomous system model was established. The vehicle steering and driving bifurcation dynamic characteristics were analyzed with different driving mode and driving torque. Taking the front-wheel-drive system as an example, the dynamic evolution process of steering and driving bifurcation was analyzed by phase space, system state variables, power spectral density, and Lyapunov index. The numerical recognition results of chaos were also provided. The research results show that the driving mode and driving torque have the obvious effect on steering and driving bifurcation characteristics.

  7. Sediment discharge division at two tidally influenced river bifurcations

    NARCIS (Netherlands)

    Sassi, M.G.; Hoitink, A.J.F.; Vermeulen, B.; Hidayat, H.

    2013-01-01

    [1] We characterize and quantify the sediment discharge division at two tidally influenced river bifurcations in response to mean flow and secondary circulation by employing a boat-mounted acoustic Doppler current profiler (ADCP), to survey transects at bifurcating branches during a semidiurnal

  8. Views on the Hopf bifurcation with respect to voltage instabilities

    Energy Technology Data Exchange (ETDEWEB)

    Roa-Sepulveda, C A [Universidad de Concepcion, Concepcion (Chile). Dept. de Ingenieria Electrica; Knight, U G [Imperial Coll. of Science and Technology, London (United Kingdom). Dept. of Electrical and Electronic Engineering

    1994-12-31

    This paper presents a sensitivity study of the Hopf bifurcation phenomenon which can in theory appear in power systems, with reference to the dynamics of the process and the impact of demand characteristics. Conclusions are drawn regarding power levels at which these bifurcations could appear and concern the concept of the imaginary axis as a `hard` limit eigenvalue analyses. (author) 20 refs., 31 figs.

  9. Bifurcations of heterodimensional cycles with two saddle points

    Energy Technology Data Exchange (ETDEWEB)

    Geng Fengjie [School of Information Technology, China University of Geosciences (Beijing), Beijing 100083 (China)], E-mail: gengfengjie_hbu@163.com; Zhu Deming [Department of Mathematics, East China Normal University, Shanghai 200062 (China)], E-mail: dmzhu@math.ecnu.edu.cn; Xu Yancong [Department of Mathematics, East China Normal University, Shanghai 200062 (China)], E-mail: yancongx@163.com

    2009-03-15

    The bifurcations of 2-point heterodimensional cycles are investigated in this paper. Under some generic conditions, we establish the existence of one homoclinic loop, one periodic orbit, two periodic orbits, one 2-fold periodic orbit, and the coexistence of one periodic orbit and heteroclinic loop. Some bifurcation patterns different to the case of non-heterodimensional heteroclinic cycles are revealed.

  10. Numerical bifurcation analysis of a class of nonlinear renewal equations

    NARCIS (Netherlands)

    Breda, Dimitri; Diekmann, Odo; Liessi, Davide; Scarabel, Francesca

    2016-01-01

    We show, by way of an example, that numerical bifurcation tools for ODE yield reliable bifurcation diagrams when applied to the pseudospectral approximation of a one-parameter family of nonlinear renewal equations. The example resembles logistic-and Ricker-type population equations and exhibits

  11. Travelling waves and their bifurcations in the Lorenz-96 model

    Science.gov (United States)

    van Kekem, Dirk L.; Sterk, Alef E.

    2018-03-01

    In this paper we study the dynamics of the monoscale Lorenz-96 model using both analytical and numerical means. The bifurcations for positive forcing parameter F are investigated. The main analytical result is the existence of Hopf or Hopf-Hopf bifurcations in any dimension n ≥ 4. Exploiting the circulant structure of the Jacobian matrix enables us to reduce the first Lyapunov coefficient to an explicit formula from which it can be determined when the Hopf bifurcation is sub- or supercritical. The first Hopf bifurcation for F > 0 is always supercritical and the periodic orbit born at this bifurcation has the physical interpretation of a travelling wave. Furthermore, by unfolding the codimension two Hopf-Hopf bifurcation it is shown to act as an organising centre, explaining dynamics such as quasi-periodic attractors and multistability, which are observed in the original Lorenz-96 model. Finally, the region of parameter values beyond the first Hopf bifurcation value is investigated numerically and routes to chaos are described using bifurcation diagrams and Lyapunov exponents. The observed routes to chaos are various but without clear pattern as n → ∞.

  12. Bifurcations of heterodimensional cycles with two saddle points

    International Nuclear Information System (INIS)

    Geng Fengjie; Zhu Deming; Xu Yancong

    2009-01-01

    The bifurcations of 2-point heterodimensional cycles are investigated in this paper. Under some generic conditions, we establish the existence of one homoclinic loop, one periodic orbit, two periodic orbits, one 2-fold periodic orbit, and the coexistence of one periodic orbit and heteroclinic loop. Some bifurcation patterns different to the case of non-heterodimensional heteroclinic cycles are revealed.

  13. Screen or not to screen for peripheral arterial disease: Guidance from a decision model

    NARCIS (Netherlands)

    A. Vaidya (Anil); M.A. Joore (Manuela); A.J. Ten Cate-Hoek (Arina J); H. ten Cate (Hugo); J.L. Severens (Hans)

    2014-01-01

    markdownabstract__Abstract__ Background: Asymptomatic Peripheral Arterial Disease (PAD) is associated with greater risk of acute cardiovascular events. This study aims to determine the cost-effectiveness of one time only PAD screening using Ankle Brachial Index (ABI) test and subsequent anti

  14. Impaired left ventricular systolic function and increased brachial-ankle pulse-wave velocity are independently associated with rapid renal function progression.

    Science.gov (United States)

    Chen, Szu-Chia; Lin, Tsung-Hsien; Hsu, Po-Chao; Chang, Jer-Ming; Lee, Chee-Siong; Tsai, Wei-Chung; Su, Ho-Ming; Voon, Wen-Chol; Chen, Hung-Chun

    2011-09-01

    Heart failure and increased arterial stiffness are associated with declining renal function. Few studies have evaluated the association between left ventricular ejection fraction (LVEF) and brachial-ankle pulse-wave velocity (baPWV) and renal function progression. The aim of this study was to assess whether LVEFfunction was estimated by eGFR slope. The renal end point was defined as ≥25% decline in eGFR. Clinical and echocardiographic parameters were compared and analyzed. After a multivariate analysis, serum hematocrit was positively associated with eGFR slope, and diabetes mellitus, baPWV (P=0.031) and LVEFfunction decline and progression to the renal end point.

  15. Surgical repair of a celiac artery aneurysm using a sutureless proximal anastomosis device

    Directory of Open Access Journals (Sweden)

    Tetsuro Uchida, MD, PhD

    2017-12-01

    Full Text Available Some celiac artery aneurysms are not suitable for endovascular therapy. We describe the case of a 63-year-old man with a celiac trunk aneurysm extending to the hepatosplenic bifurcation. The aneurysm was resected and oversewn at the origin from the abdominal aorta. A saphenous vein bypass from the supraceliac aorta to the celiac artery bifurcation was performed using a sutureless anastomotic device (PAS-Port system; Cardica, Redwood City, Calif to create the proximal anastomosis, eliminating the need for aortic clamping. This system is thought to make direct proximal aortic anastomosis safe and easy in patients requiring surgical reconstruction of celiac artery aneurysms.

  16. Bifurcation diagram of a cubic three-parameter autonomous system

    Directory of Open Access Journals (Sweden)

    Lenka Barakova

    2005-07-01

    Full Text Available In this paper, we study the cubic three-parameter autonomous planar system $$displaylines{ dot x_1 = k_1 + k_2x_1 - x_1^3 - x_2,cr dot x_2 = k_3 x_1 - x_2, }$$ where $k_2, k_3$ are greater than 0. Our goal is to obtain a bifurcation diagram; i.e., to divide the parameter space into regions within which the system has topologically equivalent phase portraits and to describe how these portraits are transformed at the bifurcation boundaries. Results may be applied to the macroeconomical model IS-LM with Kaldor's assumptions. In this model existence of a stable limit cycles has already been studied (Andronov-Hopf bifurcation. We present the whole bifurcation diagram and among others, we prove existence of more difficult bifurcations and existence of unstable cycles.

  17. Critical bifurcation surfaces of 3D discrete dynamics

    Directory of Open Access Journals (Sweden)

    Michael Sonis

    2000-01-01

    Full Text Available This paper deals with the analytical representation of bifurcations of each 3D discrete dynamics depending on the set of bifurcation parameters. The procedure of bifurcation analysis proposed in this paper represents the 3D elaboration and specification of the general algorithm of the n-dimensional linear bifurcation analysis proposed by the author earlier. It is proven that 3D domain of asymptotic stability (attraction of the fixed point for a given 3D discrete dynamics is bounded by three critical bifurcation surfaces: the divergence, flip and flutter surfaces. The analytical construction of these surfaces is achieved with the help of classical Routh–Hurvitz conditions of asymptotic stability. As an application the adjustment process proposed by T. Puu for the Cournot oligopoly model is considered in detail.

  18. Bifurcation of transition paths induced by coupled bistable systems.

    Science.gov (United States)

    Tian, Chengzhe; Mitarai, Namiko

    2016-06-07

    We discuss the transition paths in a coupled bistable system consisting of interacting multiple identical bistable motifs. We propose a simple model of coupled bistable gene circuits as an example and show that its transition paths are bifurcating. We then derive a criterion to predict the bifurcation of transition paths in a generalized coupled bistable system. We confirm the validity of the theory for the example system by numerical simulation. We also demonstrate in the example system that, if the steady states of individual gene circuits are not changed by the coupling, the bifurcation pattern is not dependent on the number of gene circuits. We further show that the transition rate exponentially decreases with the number of gene circuits when the transition path does not bifurcate, while a bifurcation facilitates the transition by lowering the quasi-potential energy barrier.

  19. Hopf Bifurcation of Compound Stochastic van der Pol System

    Directory of Open Access Journals (Sweden)

    Shaojuan Ma

    2016-01-01

    Full Text Available Hopf bifurcation analysis for compound stochastic van der Pol system with a bound random parameter and Gaussian white noise is investigated in this paper. By the Karhunen-Loeve (K-L expansion and the orthogonal polynomial approximation, the equivalent deterministic van der Pol system can be deduced. Based on the bifurcation theory of nonlinear deterministic system, the critical value of bifurcation parameter is obtained and the influence of random strength δ and noise intensity σ on stochastic Hopf bifurcation in compound stochastic system is discussed. At last we found that increased δ can relocate the critical value of bifurcation parameter forward while increased σ makes it backward and the influence of δ is more sensitive than σ. The results are verified by numerical simulations.

  20. Treatment of a symptomatic intrathoracic internal carotid artery

    Directory of Open Access Journals (Sweden)

    Christopher R. Brown

    2017-09-01

    Full Text Available Intrathoracic common carotid artery bifurcations are an anatomic anomaly with such rarity that only six cases have been reported to date. The true incidence of and preferred treatment options for a diseased intrathoracic common carotid artery bifurcation or internal carotid artery (ICA have not been clearly described. This case report describes a 72-year-old man who experienced a postoperative right hemispheric stoke after an aortic valve replacement, radiofrequency maze procedure, and left atrial appendage clip. Postoperative cerebrovascular evaluation revealed a severely diseased intrathoracic ICA that was treated by ligation of the diseased proximal ICA and transposition of the distal ICA to the disease-free external carotid artery. The patient provided written consent to present the history, data, and images in this manuscript.

  1. Bifurcation of solutions to Hamiltonian boundary value problems

    Science.gov (United States)

    McLachlan, R. I.; Offen, C.

    2018-06-01

    A bifurcation is a qualitative change in a family of solutions to an equation produced by varying parameters. In contrast to the local bifurcations of dynamical systems that are often related to a change in the number or stability of equilibria, bifurcations of boundary value problems are global in nature and may not be related to any obvious change in dynamical behaviour. Catastrophe theory is a well-developed framework which studies the bifurcations of critical points of functions. In this paper we study the bifurcations of solutions of boundary-value problems for symplectic maps, using the language of (finite-dimensional) singularity theory. We associate certain such problems with a geometric picture involving the intersection of Lagrangian submanifolds, and hence with the critical points of a suitable generating function. Within this framework, we then study the effect of three special cases: (i) some common boundary conditions, such as Dirichlet boundary conditions for second-order systems, restrict the possible types of bifurcations (for example, in generic planar systems only the A-series beginning with folds and cusps can occur); (ii) integrable systems, such as planar Hamiltonian systems, can exhibit a novel periodic pitchfork bifurcation; and (iii) systems with Hamiltonian symmetries or reversing symmetries can exhibit restricted bifurcations associated with the symmetry. This approach offers an alternative to the analysis of critical points in function spaces, typically used in the study of bifurcation of variational problems, and opens the way to the detection of more exotic bifurcations than the simple folds and cusps that are often found in examples.

  2. Impact of a systolic parameter, defined as the ratio of right brachial pre-ejection period to ejection time, on the relationship between brachial-ankle pulse wave velocity and left ventricular diastolic function.

    Science.gov (United States)

    Hsu, Po-Chao; Lin, Tsung-Hsien; Lee, Chee-Siong; Chu, Chun-Yuan; Su, Ho-Ming; Voon, Wen-Chol; Lai, Wen-Ter; Sheu, Sheng-Hsiung

    2011-04-01

    Arterial stiffness is correlated with left ventricular (LV) diastolic function as well as susceptibility to LV systolic function. Therefore, if LV systolic function is not known, the relationship between arterial stiffness and LV diastolic function is difficult to determine. A total of 260 patients were included in the study. The brachial-ankle pulse wave velocity (baPWV) and the ratio of right brachial pre-ejection period to ejection time (rbPEP/rbET) were measured using an ABI-form device. Patients were classified into four groups. Groups 1, 2, 3 and 4 were patients with rbPEP/rbET and baPWV below the median, rbPEP/rbET above but baPWV below the median, rbPET/rbET below but baPWV above the median, and rbPET/rbET and baPWV above the median, respectively. The LV ejection fractions in groups 1 and 3 were higher than those in groups 2 and 4 (Pwave velocity to Ea that were comparable to those in groups 3 and 4. In conclusion, rbPEP/rbET had an impact on the relationship between baPWV and LV diastolic function. In patients with high rbPEP/rbET but low baPWV, low baPWV may not indicate good LV diastolic function but implies that cardiac dysfunction may precede vascular dysfunction in such patients. When interpreting the relationship between baPWV and LV diastolic function, the rbPEP/rbET value obtained from the same examination should be considered.

  3. Climate bifurcation during the last deglaciation?

    Directory of Open Access Journals (Sweden)

    T. M. Lenton

    2012-07-01

    Full Text Available There were two abrupt warming events during the last deglaciation, at the start of the Bølling-Allerød and at the end of the Younger Dryas, but their underlying dynamics are unclear. Some abrupt climate changes may involve gradual forcing past a bifurcation point, in which a prevailing climate state loses its stability and the climate tips into an alternative state, providing an early warning signal in the form of slowing responses to perturbations, which may be accompanied by increasing variability. Alternatively, short-term stochastic variability in the climate system can trigger abrupt climate changes, without early warning. Previous work has found signals consistent with slowing down during the last deglaciation as a whole, and during the Younger Dryas, but with conflicting results in the run-up to the Bølling-Allerød. Based on this, we hypothesise that a bifurcation point was approached at the end of the Younger Dryas, in which the cold climate state, with weak Atlantic overturning circulation, lost its stability, and the climate tipped irreversibly into a warm interglacial state. To test the bifurcation hypothesis, we analysed two different climate proxies in three Greenland ice cores, from the Last Glacial Maximum to the end of the Younger Dryas. Prior to the Bølling warming, there was a robust increase in climate variability but no consistent slowing down signal, suggesting this abrupt change was probably triggered by a stochastic fluctuation. The transition to the warm Bølling-Allerød state was accompanied by a slowing down in climate dynamics and an increase in climate variability. We suggest that the Bølling warming excited an internal mode of variability in Atlantic meridional overturning circulation strength, causing multi-centennial climate fluctuations. However, the return to the Younger Dryas cold state increased climate stability. We find no consistent evidence for slowing down during the Younger Dryas, or in a longer

  4. Bifurcations and Patterns in Nonlinear Dissipative Systems

    Energy Technology Data Exchange (ETDEWEB)

    Guenter Ahlers

    2005-05-27

    This project consists of experimental investigations of heat transport, pattern formation, and bifurcation phenomena in non-linear non-equilibrium fluid-mechanical systems. These issues are studies in Rayleigh-B\\'enard convection, using both pure and multicomponent fluids. They are of fundamental scientific interest, but also play an important role in engineering, materials science, ecology, meteorology, geophysics, and astrophysics. For instance, various forms of convection are important in such diverse phenomena as crystal growth from a melt with or without impurities, energy production in solar ponds, flow in the earth's mantle and outer core, geo-thermal stratifications, and various oceanographic and atmospheric phenomena. Our work utilizes computer-enhanced shadowgraph imaging of flow patterns, sophisticated digital image analysis, and high-resolution heat transport measurements.

  5. The bifurcations of nearly flat origami

    Science.gov (United States)

    Santangelo, Christian

    Self-folding origami structures provide one means of fabricating complex, three-dimensional structures from a flat, two-dimensional sheet. Self-folding origami structures have been fabricated on scales ranging from macroscopic to microscopic and can have quite complicated structures with hundreds of folds arranged in complex patterns. I will describe our efforts to understand the mechanics and energetics of self-folding origami structures. Though the dimension of the configuration space of an origami structure scales with the size of the boundary and not with the number of vertices in the interior of the structure, a typical origami structure is also floppy in the sense that there are many possible ways to assign fold angles consistently. I will discuss our theoretical progress in understanding the geometry of the configuration space of origami. For random origami, the number of possible bifurcations grows surprisingly quickly even when the dimension of the configuration space is small. EFRI ODISSEI-1240441, DMR-0846582.

  6. Transport Bifurcation in a Rotating Tokamak Plasma

    International Nuclear Information System (INIS)

    Highcock, E. G.; Barnes, M.; Schekochihin, A. A.; Parra, F. I.; Roach, C. M.; Cowley, S. C.

    2010-01-01

    The effect of flow shear on turbulent transport in tokamaks is studied numerically in the experimentally relevant limit of zero magnetic shear. It is found that the plasma is linearly stable for all nonzero flow shear values, but that subcritical turbulence can be sustained nonlinearly at a wide range of temperature gradients. Flow shear increases the nonlinear temperature gradient threshold for turbulence but also increases the sensitivity of the heat flux to changes in the temperature gradient, except over a small range near the threshold where the sensitivity is decreased. A bifurcation in the equilibrium gradients is found: for a given input of heat, it is possible, by varying the applied torque, to trigger a transition to significantly higher temperature and flow gradients.

  7. Bifurcated SEN with Fluid Flow Conditioners

    Directory of Open Access Journals (Sweden)

    F. Rivera-Perez

    2014-01-01

    Full Text Available This work evaluates the performance of a novel design for a bifurcated submerged entry nozzle (SEN used for the continuous casting of steel slabs. The proposed design incorporates fluid flow conditioners attached on SEN external wall. The fluid flow conditioners impose a pseudosymmetric pattern in the upper zone of the mold by inhibiting the fluid exchange between the zones created by conditioners. The performance of the SEN with fluid flow conditioners is analyzed through numerical simulations using the CFD technique. Numerical results were validated by means of physical simulations conducted on a scaled cold water model. Numerical and physical simulations confirmed that the performance of the proposed SEN is superior to a traditional one. Fluid flow conditioners reduce the liquid free surface fluctuations and minimize the occurrence of vortexes at the free surface.

  8. Oscillatory bifurcation for semilinear ordinary differential equations

    Directory of Open Access Journals (Sweden)

    Tetsutaro Shibata

    2016-06-01

    \\] where $f(u = u + (1/2\\sin^k u$ ($k \\ge 2$ and $\\lambda > 0$ is a bifurcation parameter. It is known that $\\lambda$ is parameterized by the maximum norm $\\alpha = \\Vert u_\\lambda\\Vert_\\infty$ of the solution $u_\\lambda$ associated with $\\lambda$ and is written as $\\lambda = \\lambda(k,\\alpha$. When we focus on the asymptotic behavior of $\\lambda(k,\\alpha$ as $\\alpha \\to \\infty$, it is natural to expect that $\\lambda(k, \\alpha \\to \\pi^2/4$, and its convergence rate is common to $k$. Contrary to this expectation, we show that $\\lambda(2n_1+1,\\alpha$ tends to $\\pi^2/4$ faster than $\\lambda(2n_2,\\alpha$ as $\\alpha \\to \\infty$, where $n_1\\ge 1,\\ n_2 \\ge 1$ are arbitrary given integers.

  9. Equilibrium-torus bifurcation in nonsmooth systems

    DEFF Research Database (Denmark)

    Zhusubahyev, Z.T.; Mosekilde, Erik

    2008-01-01

    Considering a set of two coupled nonautonomous differential equations with discontinuous right-hand sides describing the behavior of a DC/DC power converter, we discuss a border-collision bifurcation that can lead to the birth of a two-dimensional invariant torus from a stable node equilibrium...... point. We obtain the chart of dynamic modes and show that there is a region of parameter space in which the system has a single stable node equilibrium point. Under variation of the parameters, this equilibrium may disappear as it collides with a discontinuity boundary between two smooth regions...... in the phase space. The disappearance of the equilibrium point is accompanied by the soft appearance of an unstable focus period-1 orbit surrounded by a resonant or ergodic torus. Detailed numerical calculations are supported by a theoretical investigation of the normal form map that represents the piecewise...

  10. Inverse parameter identification for a branching 1 D arterial network

    CSIR Research Space (South Africa)

    Bogaers, Alfred EJ

    2012-07-01

    Full Text Available In this paper we investigate the invertability of a branching 1 D arterial blood flow network. We limit our investigation to a single bifurcating vessel, where the material properties, unloaded areas and variables characterizing the input and output...

  11. Clausius entropy for arbitrary bifurcate null surfaces

    International Nuclear Information System (INIS)

    Baccetti, Valentina; Visser, Matt

    2014-01-01

    Jacobson’s thermodynamic derivation of the Einstein equations was originally applied only to local Rindler horizons. But at least some parts of that construction can usefully be extended to give meaningful results for arbitrary bifurcate null surfaces. As presaged in Jacobson’s original article, this more general construction sharply brings into focus the questions: is entropy objectively ‘real’? Or is entropy in some sense subjective and observer-dependent? These innocent questions open a Pandora’s box of often inconclusive debate. A consensus opinion, though certainly not universally held, seems to be that Clausius entropy (thermodynamic entropy, defined via a Clausius relation dS=đQ/T) should be objectively real, but that the ontological status of statistical entropy (Shannon or von Neumann entropy) is much more ambiguous, and much more likely to be observer-dependent. This question is particularly pressing when it comes to understanding Bekenstein entropy (black hole entropy). To perhaps further add to the confusion, we shall argue that even the Clausius entropy can often be observer-dependent. In the current article we shall conclusively demonstrate that one can meaningfully assign a notion of Clausius entropy to arbitrary bifurcate null surfaces—effectively defining a ‘virtual Clausius entropy’ for arbitrary ‘virtual (local) causal horizons’. As an application, we see that we can implement a version of the generalized second law (GSL) for this virtual Clausius entropy. This version of GSL can be related to certain (nonstandard) integral variants of the null energy condition. Because the concepts involved are rather subtle, we take some effort in being careful and explicit in developing our framework. In future work we will apply this construction to generalize Jacobson’s derivation of the Einstein equations. (paper)

  12. Training to Perform Ankle-Brachial Index: Systematic Review and Perspectives to Improve Teaching and Learning.

    Science.gov (United States)

    Chaudru, S; de Müllenheim, P-Y; Le Faucheur, A; Kaladji, A; Jaquinandi, V; Mahé, G

    2016-02-01

    To conduct a systematic review focusing on the impact of training programs on ankle-brachial index (ABI) performance by medical students, doctors and primary care providers. Lower extremity peripheral artery disease (PAD) is a highly prevalent disease affecting ∼202 million people worldwide. ABI is an essential component of medical education because of its ability to diagnose PAD, and as it is a powerful prognostic marker for overall and cardiovascular related mortality. A systematic search was conducted (up to May 2015) using Medline, Embase, and Web of Science databases. Five studies have addressed the impact of a training program on ABI performance by either medical students, doctors or primary care providers. All were assigned a low GRADE system quality. The components of the training vary greatly either in substance (what was taught) or in form (duration of the training, and type of support which was used). No consistency was found in the outcome measures. According to this systematic review, only few studies, with a low quality rating, have addressed which training program should be performed to provide the best way of teaching how to perform ABI. Future high quality researches are required to define objectively the best training program to facilitate ABI teaching and learning. Copyright © 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  13. Dynamic contrast-enhanced ultrasound and transient arterial occlusion for quantification of arterial perfusion reserve in peripheral arterial disease

    International Nuclear Information System (INIS)

    Amarteifio, E.; Wormsbecher, S.; Krix, M.; Demirel, S.; Braun, S.; Delorme, S.; Böckler, D.; Kauczor, H.-U.; Weber, M.-A.

    2012-01-01

    Objective: To quantify muscular micro-perfusion and arterial perfusion reserve in peripheral arterial disease (PAD) with dynamic contrast-enhanced ultrasound (CEUS) and transient arterial occlusion. Materials and methods: This study had local institutional review board approval and written informed consent was obtained from all subjects. We examined the dominant lower leg of 40 PAD Fontaine stage IIb patients (mean age, 65 years) and 40 healthy volunteers (mean age, 54 years) with CEUS (7 MHz; MI, 0.28) during continuous intravenous infusion of 4.8 mL microbubbles. Transient arterial occlusion at mid-thigh level simulated physical exercise. With time–CEUS–intensity curves obtained from regions of interest within calf muscles, we derived the maximum CEUS signal after occlusion (max) and its time (t max ), slope to maximum (m), vascular response after occlusion (AUC post ), and analysed accuracy, receiver operating characteristic (ROC) curves, and correlations with ankle-brachial index (ABI) and walking distance. Results: All parameters differed in PAD and volunteers (p max was delayed (31.2 ± 13.6 vs. 16.7 ± 8.5 s, p post as optimal parameter combination for diagnosing PAD and therefore impaired arterial perfusion reserve. Conclusions: Dynamic CEUS with transient arterial occlusion quantifies muscular micro-perfusion and arterial perfusion reserve. The technique is accurate to diagnose PAD.

  14. Uric Acid Level Has a J-Shaped Association with Arterial Stiffness in Korean Postmenopausal Women.

    Science.gov (United States)

    Lee, Hyungbin; Jung, Young-Hyo; Kwon, Yu-Jin; Park, Byoungjin

    2017-11-01

    Uric acid has been reported to function both as an oxidant or antioxidant depending on the context. A previous study in the Korean population reported a positive linear association between serum uric acid level and arterial stiffness in men, but little is known about how serum uric acid level is related to the risk of increased arterial stiffness in Korean postmenopausal women. We performed a cross-sectional study of 293 subjects who participated in a health examination program run by the health promotion center of Gangnam Severance Hospital between October 2007 and July 2010. High brachial-ankle pulse wave velocity was defined as a brachial-ankle pulse wave velocity of more than 1,450 cm/s. The odds ratios (ORs) for high brachial-ankle pulse wave velocity were calculated using multivariate logistic regression analysis across uric acid quartiles after adjusting for other indicators of cardiovascular risk. The 293 postmenopausal women were divided into quartiles according to uric acid level. The mean brachial-ankle pulse wave velocity values of each quartile were as follows: Q1, 1,474 cm/s; Q2, 1,375 cm/s; Q3, 1,422 cm/s; Q4, 1,528 cm/s. The second quartile was designated as the control group based on mean brachial-ankle pulse wave velocity value. Multivariate adjusted ORs (95% confidence intervals) for brachial-ankle pulse wave velocity across the uric acid quartiles were 2.642 (Q1, 1.095-6.3373), 1.00, 4.305 (Q3, 1.798-10.307), and 4.375 (Q4, 1.923-9.949), after adjusting for confounding variables. Serum uric acid level has a J-shaped association with arterial stiffness in Korean postmenopausal women.

  15. Genetically elevated levels of circulating triglycerides and brachial-ankle pulse wave velocity in a Chinese population.

    Science.gov (United States)

    Yao, W-M; Zhang, H-F; Zhu, Z-Y; Zhou, Y-L; Liang, N-X; Xu, D-J; Zhou, F; Sheng, Y-H; Yang, R; Gong, L; Yin, Z-J; Chen, F-K; Cao, K-J; Li, X-L

    2013-04-01

    Elevated levels of circulating triglycerides and increased arterial stiffness are associated with cardiovascular disease. Numerous studies have reported an association between levels of circulating triglycerides and arterial stiffness. We used Mendelian randomization to test whether this association is causal. We investigated the association between circulating triglyceride levels, the apolipoprotein A-V (ApoA5) -1131T>C single nucleotide polymorphism and brachial-ankle pulse wave velocity (baPWV) by examining data from 4421 subjects aged 18-74 years who were recruited from the Chinese population. baPWV was significantly associated with the levels of circulating triglycerides after adjusting for age, sex, body mass index (BMI), systolic blood pressure, heart rate, waist-to-hip ratio, antihypertensive treatment and diabetes mellitus status. The -1131C allele was associated with a 5% (95% confidence interval 3-8%) increase in circulating triglycerides (adjusted for age, sex, BMI, waist-to-hip ratio, diabetes mellitus and antihypertensive treatment). Instrumental variable analysis showed that genetically elevated levels of circulating triglycerides were not associated with increased baPWV. These results do not support the hypothesis that levels of circulating triglycerides have a causal role in the development of arterial stiffness.

  16. Feasibility Study of Ex Ovo Chick Chorioallantoic Artery Model for Investigating Pulsatile Variation of Arterial Geometry.

    Directory of Open Access Journals (Sweden)

    Kweon-Ho Nam

    Full Text Available Despite considerable research efforts on the relationship between arterial geometry and cardiovascular pathology, information is lacking on the pulsatile geometrical variation caused by arterial distensibility and cardiomotility because of the lack of suitable in vivo experimental models and the methodological difficulties in examining the arterial dynamics. We aimed to investigate the feasibility of using a chick embryo system as an experimental model for basic research on the pulsatile variation of arterial geometry. Optical microscope video images of various arterial shapes in chick chorioallantoic circulation were recorded from different locations and different embryo samples. The high optical transparency of the chorioallantoic membrane (CAM allowed clear observation of tiny vessels and their movements. Systolic and diastolic changes in arterial geometry were visualized by detecting the wall boundaries from binary images. Several to hundreds of microns of wall displacement variations were recognized during a pulsatile cycle. The spatial maps of the wall motion harmonics and magnitude ratio of harmonic components were obtained by analyzing the temporal brightness variation at each pixel in sequential grayscale images using spectral analysis techniques. The local variations in the spectral characteristics of the arterial wall motion were reflected well in the analysis results. In addition, mapping the phase angle of the fundamental frequency identified the regional variations in the wall motion directivity and phase shift. Regional variations in wall motion phase angle and fundamental-to-second harmonic ratio were remarkable near the bifurcation area. In summary, wall motion in various arterial geometry including straight, curved and bifurcated shapes was well observed in the CAM artery model, and their local and cyclic variations could be characterized by Fourier and wavelet transforms of the acquired video images. The CAM artery model with

  17. A Limb-Threatening Long Arterial Dissection Caused by Humerus Neck Fracture: A Case Report

    Directory of Open Access Journals (Sweden)

    Kurnaz R

    2018-03-01

    Full Text Available Proximal humerus fracture is a common arm trauma and rarely occurs with vascular injury which however is a serious complication. In this case report, we present a long segment dissection of the axillary and brachial arteries as a rare complication due to fragmented proximal humerus fracture and shoulder dislocation. An 80-year old female patient was seen at the emergency department. Radiograph examination has revealed a fragmented proximal humerus fracture besides dislocation of the head of humerus towards the axillary area. On vascular examination, acute arterial occlusion such as absence of radial and ulnar pulses were observed in her left hand. The patient was immediately taken to the operating room. The dissection included the entire segment approximately 20cm between the distal subclavian artery and the distal brachial artery. This injured segment was removed and a 6mm Polytetrafluroethylene (PTFE graft with rings was interpositoned between subclavian and brachial arteries. This case is a rarity because of such a significant complication after a small injury. Axillary artery injuries caused by humeral neck fractures are rare but should not be missed by the physician.

  18. Brachial plexus magnetic resonance imaging differentiates between inflammatory neuropathies and does not predict disease course

    NARCIS (Netherlands)

    Jongbloed, BA; Bos, Jeroen W; Rutgers, Dirk; van der Pol, WL; van den Berg, Leonard H

    OBJECTIVE: The main objective of this study was to evaluate the correlation between the distribution of brachial plexus magnetic resonance imaging (MRI) abnormalities and clinical weakness, and to evaluate the value of brachial plexus MRI in predicting disease course and response to treatment in

  19. Anatomical study of prefixed versus postfixed brachial plexuses in adult human cadaver.

    Science.gov (United States)

    Guday, Edengenet; Bekele, Asegedech; Muche, Abebe

    2017-05-01

    The brachial plexus is usually formed by the fusion of anterior primary rami of the fifth to eighth cervical and the first thoracic spinal nerves. Variations in the formation of the brachial plexus may occur. Variations in brachial plexus anatomy are important to radiologists, surgeons and anaesthesiologists performing surgical procedures in the neck, axilla and upper limb regions. These variations may lead to deviation from the expected dermatome distribution as well as differences in the motor innervation of muscles of the upper limb. This study is aimed to describe the anatomical variations of brachial plexus in its formation among 20 Ethiopian cadavers. Observational based study was conducted by using 20 cadavers obtained from the Department of Human Anatomy at University of Gondar, Bahir Dar, Addis Ababa, Hawasa, Hayat Medical College and St Paul Hospital Millennium Medical College. Data analysis was conducted using thematic approaches. A total of 20 cadavers examined bilaterally for the formation of brachial plexus. Of the 40 sides, 30 sides (75%) were found normal, seven sides (17.5%) prefixed, three sides (7.5%) postfixed and one side of the cadaver lacks cord formation. The brachial plexus formation in most subjects is found to be normal. Among the variants, the numbers of the prefixed brachial plexuses are greater than the postfixed brachial plexuses. © 2016 Royal Australasian College of Surgeons.

  20. Measurement of blood pressure, ankle blood pressure and calculation of ankle brachial index in general practice

    DEFF Research Database (Denmark)

    Nexøe, Jørgen; Damsbo, Bent; Lund, Jens Otto

    2012-01-01

    BACKGROUND: Low ankle brachial index (ABI) is a sensitive measure of 'burden' of atherosclerosis, indicating cardiovascular risk of the asymptomatic patient. Conventionally, ABI values......BACKGROUND: Low ankle brachial index (ABI) is a sensitive measure of 'burden' of atherosclerosis, indicating cardiovascular risk of the asymptomatic patient. Conventionally, ABI values...

  1. 3 T MR tomography of the brachial plexus: Structural and microstructural evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Mallouhi, Ammar, E-mail: Ammar.Mallouhi@meduniwien.ac.at [Department of Radiology, Division of Neuroradiology and Musculoskeletal Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Marik, Wolfgang, E-mail: Wolfgang.Marik@meduniwien.ac.at [Department of Radiology, Division of Neuroradiology and Musculoskeletal Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Prayer, Daniela, E-mail: Daniela.Prayer@meduniwien.ac.at [Department of Radiology, Division of Neuroradiology and Musculoskeletal Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Kainberger, Franz, E-mail: Franz.Kainberger@meduniwien.ac.at [Department of Radiology, Division of Neuroradiology and Musculoskeletal Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Bodner, Gerd, E-mail: Gerd.Bodner@meduniwien.ac.at [Department of Radiology, Division of Neuroradiology and Musculoskeletal Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Kasprian, Gregor, E-mail: Gregor.Kasprian@meduniwien.ac.at [Department of Radiology, Division of Neuroradiology and Musculoskeletal Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)

    2012-09-15

    Magnetic resonance (MR) neurography comprises an evolving group of techniques with the potential to allow optimal noninvasive evaluation of many abnormalities of the brachial plexus. MR neurography is clinically useful in the evaluation of suspected brachial plexus traumatic injuries, intrinsic and extrinsic tumors, and post-radiogenic inflammation, and can be particularly beneficial in pediatric patients with obstetric trauma to the brachial plexus. The most common MR neurographic techniques for displaying the brachial plexus can be divided into two categories: structural MR neurography; and microstructural MR neurography. Structural MR neurography uses mainly the STIR sequence to image the nerves of the brachial plexus, can be performed in 2D or 3D mode, and the 2D sequence can be repeated in different planes. Microstructural MR neurography depends on the diffusion tensor imaging that provides quantitative information about the degree and direction of water diffusion within the nerves of the brachial plexus, as well as on tractography to visualize the white matter tracts and to characterize their integrity. The successful evaluation of the brachial plexus requires the implementation of appropriate techniques and familiarity with the pathologies that might involve the brachial plexus.

  2. Correlation between ultrasound imaging, cross-sectional anatomy, and histology of the brachial plexus: a review.

    Science.gov (United States)

    van Geffen, Geert J; Moayeri, Nizar; Bruhn, Jörgen; Scheffer, Gert J; Chan, Vincent W; Groen, Gerbrand J

    2009-01-01

    The anatomy of the brachial plexus is complex. To facilitate the understanding of the ultrasound appearance of the brachial plexus, we present a review of important anatomic considerations. A detailed correlation of reconstructed, cross-sectional gross anatomy and histology with ultrasound sonoanatomy is provided.

  3. Unusual cause of brachial palsy with diaphragmatic palsy.

    Science.gov (United States)

    Gupta, Vishal; Pandita, Aakash; Panghal, Astha; Hassan, Neha

    2018-05-12

    We report a preterm neonate born with respiratory distress. The neonate was found to have diaphragmatic palsy and brachial palsy. The neonate was born by caesarean section and there was no history of birth trauma. On examination, there was bilateral congenital talipes equinovarus and a scar was present on the forearm. The mother had a history of chickenpox during the 16 weeks of pregnancy for which no treatment was sought. On investigation, PCR for varicella was found to be positive in the neonate. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  4. Postirradiation lesions of the brachial plexus. Results of surgical treatment

    International Nuclear Information System (INIS)

    LeQuang, C.

    1989-01-01

    In a series of 103 cases of postirradiation lesions of the brachial plexus operated on between 1978 and 1986--of which 60 patients have been reviewed with a follow up from 2 to 9 years--the surgical results are analyzed according to an anatomic classification, a clinical classification, and the surgical procedures. We conclude that the radiation plexitis should be treated surgically and at the earliest possible time after the onset of paresthesias. Also, the surgical procedure which gives the best results is neurolysis with pedicled omentoplasty

  5. Arterial stiffness and cognitive impairment.

    Science.gov (United States)

    Li, Xiaoxuan; Lyu, Peiyuan; Ren, Yanyan; An, Jin; Dong, Yanhong

    2017-09-15

    Arterial stiffness is one of the earliest indicators of changes in vascular wall structure and function and may be assessed using various indicators, such as pulse-wave velocity (PWV), the cardio-ankle vascular index (CAVI), the ankle-brachial index (ABI), pulse pressure (PP), the augmentation index (AI), flow-mediated dilation (FMD), carotid intima media thickness (IMT) and arterial stiffness index-β. Arterial stiffness is generally considered an independent predictor of cardiovascular and cerebrovascular diseases. To date, a significant number of studies have focused on the relationship between arterial stiffness and cognitive impairment. To investigate the relationships between specific arterial stiffness parameters and cognitive impairment, elucidate the pathophysiological mechanisms underlying the relationship between arterial stiffness and cognitive impairment and determine how to interfere with arterial stiffness to prevent cognitive impairment, we searched PUBMED for studies regarding the relationship between arterial stiffness and cognitive impairment that were published from 2000 to 2017. We used the following key words in our search: "arterial stiffness and cognitive impairment" and "arterial stiffness and cognitive impairment mechanism". Studies involving human subjects older than 30years were included in the review, while irrelevant studies (i.e., studies involving subjects with comorbid kidney disease, diabetes and cardiac disease) were excluded from the review. We determined that arterial stiffness severity was positively correlated with cognitive impairment. Of the markers used to assess arterial stiffness, a higher PWV, CAVI, AI, IMT and index-β and a lower ABI and FMD were related to cognitive impairment. However, the relationship between PP and cognitive impairment remained controversial. The potential mechanisms linking arterial stiffness and cognitive impairment may be associated with arterial pulsatility, as greater arterial pulsatility

  6. Evaluation of the carotid artery stenosis based on minimization of mechanical energy loss of the blood flow.

    Science.gov (United States)

    Sia, Sheau Fung; Zhao, Xihai; Li, Rui; Zhang, Yu; Chong, Winston; He, Le; Chen, Yu

    2016-11-01

    Internal carotid artery stenosis requires an accurate risk assessment for the prevention of stroke. Although the internal carotid artery area stenosis ratio at the common carotid artery bifurcation can be used as one of the diagnostic methods of internal carotid artery stenosis, the accuracy of results would still depend on the measurement techniques. The purpose of this study is to propose a novel method to estimate the effect of internal carotid artery stenosis on the blood flow based on the concept of minimization of energy loss. Eight internal carotid arteries from different medical centers were diagnosed as stenosed internal carotid arteries, as plaques were found at different locations on the vessel. A computational fluid dynamics solver was developed based on an open-source code (OpenFOAM) to test the flow ratio and energy loss of those stenosed internal carotid arteries. For comparison, a healthy internal carotid artery and an idealized internal carotid artery model have also been tested and compared with stenosed internal carotid artery in terms of flow ratio and energy loss. We found that at a given common carotid artery bifurcation, there must be a certain flow distribution in the internal carotid artery and external carotid artery, for which the total energy loss at the bifurcation is at a minimum; for a given common carotid artery flow rate, an irregular shaped plaque at the bifurcation constantly resulted in a large value of minimization of energy loss. Thus, minimization of energy loss can be used as an indicator for the estimation of internal carotid artery stenosis.

  7. Characterization of volumetric flow rate waveforms at the carotid bifurcations of older adults

    International Nuclear Information System (INIS)

    Hoi, Yiemeng; Xie, Yuanyuan J; Steinman, David A; Wasserman, Bruce A; Najjar, Samer S; Lakatta, Edward G; Ferruci, Luigi; Gerstenblith, Gary

    2010-01-01

    While it is widely appreciated that volumetric blood flow rate (VFR) dynamics change with age, there has been no detailed characterization of the typical shape of carotid bifurcation VFR waveforms of older adults. Toward this end, retrospectively gated phase contrast magnetic resonance imaging was used to measure time-resolved VFR waveforms proximal and distal to the carotid bifurcations of 94 older adults (age 68 ± 8 years) with little or no carotid artery disease, recruited from the BLSA cohort of the VALIDATE study of factors in vascular aging. Timings and amplitudes of well-defined feature points from these waveforms were extracted automatically and averaged to produce representative common, internal and external carotid artery (CCA, ICA and ECA) waveform shapes. Relative to young adults, waveforms from older adults were found to exhibit a significantly augmented secondary peak during late systole, resulting in significantly higher resistance index (RI) and flow augmentation index (FAI). Cycle-averaged VFR at the CCA, ICA and ECA were 389 ± 74, 245 ± 61 and 125 ± 49 mL min −1 , respectively, reflecting a significant cycle-averaged outflow deficit of 5%, which peaked at around 10% during systole. A small but significant mean delay of 13 ms between arrivals of ICA versus CCA/ECA peak VFR suggested differential compliance of these vessels. Sex and age differences in waveform shape were also noted. The characteristic waveforms presented here may serve as a convenient baseline for studies of VFR waveform dynamics or as suitable boundary conditions for models of blood flow in the carotid arteries of older adults

  8. Subintimal stent placement in patients with long segment occlusion of the iliac artery

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Ho Jung; Kim, Young Hwan; Kim, Si Hyung; Ko, Sung Min; Choi, Jin Soo; Lee, Hyun Jin; Kim, Hyung Tae; Jo, Won Hyun [Dongsan Medical Center, Keimyung University College of Medicine, Daegu (Korea, Republic of); Kim, Yong Joo [Andong General Hospital, Andong (Korea, Republic of)

    2008-01-15

    We evaluated the technical feasibility and clinical efficacy of subintimal stent placement for long segment occlusion of the iliac artery. From March 2003 to February 2007, subintimal stent placement for long segment occlusion of the iliac artery of 24 limbs in 22 patients was analyzed retrospectively. Endovascular access was performed via the ipsilateral femoral artery in 7 cases, via the contralateral femoral artery in 6 cases, via both femoral arteries in 10 cases and via the brachial artery in one case. The SAFARI (subintimal arterial flossing with antegrade-retrograde intervention) technique using a microcatheter was performed to recannalize iliac artery occlusion in three cases. Medical records were reviewed for the collection of follow-up data. The stent patency rate was analyzed by use of the Kaplan-Meier method. Subintimal stent placement was technically successful in 23 of 24 procedures (95.8%). The mean ankle-brachial index (ABI) increased form 0.26 to 0.82. The Fontaine classification was improved after stent placement in all patients. Major complications occurred in four procedures: three distal embolizations and one arterial rupture. All of the complications were successfully treated by endovascular intervention. The primary stent patency rates at 6-months, 1-, 2-and 3-years were 95%, 88%, 88% and 88%, respectively. Subintimal stent placement is a safe and effective treatment for long segment occlusion of the iliac artery.

  9. Paired anterior spinal arteries in a case of locked-in syndrome

    International Nuclear Information System (INIS)

    Kawamura, J.; Matsubayashi, K.; Fukuyama, H.; Kitanaka, H.

    1981-01-01

    Paired anterior spinal arteries have rarely been demonstrated angiographically, although several anatomical studies have shown that they are not uncommonly observed. This report describes the angiographic and autopsy findings of such a variation, which was observed in a 65-year-old man with a locked-in syndrome. The paired trunks of the anterior spinal artery were visualized in a retrograde fashion through the left inferior thyroid artery and a radical branch at the 5th cervical level by left retrograde brachial angiography. The uppermost segments of either vertebral artery and the lower portion of the basilar artery were opacified through these channels. The autopsy confirmed the paired trunks of the anterior spinal artery, occlusion of the vertebral arteries just caudal to the origin of the main branches of the anterior spinal artery, and an old infarct involving the pontine tegmentum and cerebellum. (orig.)

  10. Variations in the origins of the thyroid arteries on CT angiography.

    Science.gov (United States)

    Esen, Kaan; Ozgur, Anil; Balci, Yuksel; Tok, Sermin; Kara, Engin

    2018-02-01

    To investigate the anatomical variations in the origins of the thyroid arteries on CT angiography images. The presence and the origins of the superior thyroid artery, the inferior thyroid artery, and the thyroidea ima artery were retrospectively evaluated based on carotid CT angiography examinations. The bifurcation level of the common carotid artery with respect to the cervical vertebrae and disc spaces was also determined. A total of 640 patients were included in the study. The right and left superior thyroid arteries arose from the external carotid artery in 413 (64.5%) and 254 (39.7%) patients, from the bifurcation of the common carotid artery in 131 (20.5%) and 148 (23.1%) patients, and from the common carotid artery in 90 (14.1%) and 226 (35.3%) patients, respectively. We could not observe the right and the left superior thyroid arteries in 6 (0.9%) and 12 (1.9%) of the patients, respectively. However, the right and left inferior thyroid arteries were not identified in 14 (2.2%) and 45 (7%) of the patients, respectively. The thyroidea ima artery was detected in 2.3% of the patients. The visualization of thyroid arteries on CT angiography images enables the anatomy of the arterial supply system of the thyroid gland to be explored in a noninvasive manner prior to surgery.

  11. Kidney transplantation improves arterial function measured by pulse wave analysis and endothelium-independent dilatation in uraemic patients despite deterioration of glucose metabolism

    DEFF Research Database (Denmark)

    Hornum, Mads; Clausen, Peter; Idorn, Thomas

    2011-01-01

    for kidney transplantation (uraemic control group, age 47 ± 11 years). Arterial function was estimated by the pulse wave velocity (PWV) of the carotid-femoral pulse wave, aortic augmentation index (AIX), flow-mediated (FMD) and nitroglycerin-induced vasodilatation (NID) of the brachial artery performed......BACKGROUND: The aim of this study is to investigate the effect of kidney transplantation on arterial function in relation to changes in glucose metabolism. METHODS: Included were 40 kidney recipients (Tx group, age 38 ± 13 years) and 40 patients without known diabetes remaining on the waiting list...... before transplantation and after 12 months. PWV recorded sequentially at the carotid and femoral artery is an estimate of arterial stiffness; AIX is an integrated index of vascular and ventricular function. FMD and NID are the dilatory capacities of the brachial artery after increased flow (endothelium...

  12. Fractional noise destroys or induces a stochastic bifurcation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Qigui, E-mail: qgyang@scut.edu.cn [School of Sciences, South China University of Technology, Guangzhou 510640 (China); Zeng, Caibin, E-mail: zeng.cb@mail.scut.edu.cn [School of Sciences, South China University of Technology, Guangzhou 510640 (China); School of Automation Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Wang, Cong, E-mail: wangcong@scut.edu.cn [School of Automation Science and Engineering, South China University of Technology, Guangzhou 510640 (China)

    2013-12-15

    Little seems to be known about the stochastic bifurcation phenomena of non-Markovian systems. Our intention in this paper is to understand such complex dynamics by a simple system, namely, the Black-Scholes model driven by a mixed fractional Brownian motion. The most interesting finding is that the multiplicative fractional noise not only destroys but also induces a stochastic bifurcation under some suitable conditions. So it opens a possible way to explore the theory of stochastic bifurcation in the non-Markovian framework.

  13. Optimization Design and Application of Underground Reinforced Concrete Bifurcation Pipe

    Directory of Open Access Journals (Sweden)

    Chao Su

    2015-01-01

    Full Text Available Underground reinforced concrete bifurcation pipe is an important part of conveyance structure. During construction, the workload of excavation and concrete pouring can be significantly decreased according to optimized pipe structure, and the engineering quality can be improved. This paper presents an optimization mathematical model of underground reinforced concrete bifurcation pipe structure according to real working status of several common pipe structures from real cases. Then, an optimization design system was developed based on Particle Swarm Optimization algorithm. Furthermore, take the bifurcation pipe of one hydropower station as an example: optimization analysis was conducted, and accuracy and stability of the optimization design system were verified successfully.

  14. Arctic melt ponds and bifurcations in the climate system

    Science.gov (United States)

    Sudakov, I.; Vakulenko, S. A.; Golden, K. M.

    2015-05-01

    Understanding how sea ice melts is critical to climate projections. In the Arctic, melt ponds that develop on the surface of sea ice floes during the late spring and summer largely determine their albedo - a key parameter in climate modeling. Here we explore the possibility of a conceptual sea ice climate model passing through a bifurcation point - an irreversible critical threshold as the system warms, by incorporating geometric information about melt pond evolution. This study is based on a bifurcation analysis of the energy balance climate model with ice-albedo feedback as the key mechanism driving the system to bifurcation points.

  15. FFT Bifurcation Analysis of Routes to Chaos via Quasiperiodic Solutions

    Directory of Open Access Journals (Sweden)

    L. Borkowski

    2015-01-01

    Full Text Available The dynamics of a ring of seven unidirectionally coupled nonlinear Duffing oscillators is studied. We show that the FFT analysis presented in form of a bifurcation graph, that is, frequency distribution versus a control parameter, can provide a valuable and helpful complement to the corresponding typical bifurcation diagram and the course of Lyapunov exponents, especially in context of detailed identification of the observed attractors. As an example, bifurcation analysis of routes to chaos via 2-frequency and 3-frequency quasiperiodicity is demonstrated.

  16. Bifurcation of learning and structure formation in neuronal maps

    DEFF Research Database (Denmark)

    Marschler, Christian; Faust-Ellsässer, Carmen; Starke, Jens

    2014-01-01

    to map formation in the laminar nucleus of the barn owl's auditory system. Using equation-free methods, we perform a bifurcation analysis of spatio-temporal structure formation in the associated synaptic-weight matrix. This enables us to analyze learning as a bifurcation process and follow the unstable...... states as well. A simple time translation of the learning window function shifts the bifurcation point of structure formation and goes along with traveling waves in the map, without changing the animal's sound localization performance....

  17. High resolution neurography of the brachial plexus by 3 Tesla magnetic resonance imaging.

    Science.gov (United States)

    Cejas, C; Rollán, C; Michelin, G; Nogués, M

    2016-01-01

    The study of the structures that make up the brachial plexus has benefited particularly from the high resolution images provided by 3T magnetic resonance scanners. The brachial plexus can have mononeuropathies or polyneuropathies. The mononeuropathies include traumatic injuries and trapping, such as occurs in thoracic outlet syndrome due to cervical ribs, prominent transverse apophyses, or tumors. The polyneuropathies include inflammatory processes, in particular chronic inflammatory demyelinating polyneuropathy, Parsonage-Turner syndrome, granulomatous diseases, and radiation neuropathy. Vascular processes affecting the brachial plexus include diabetic polyneuropathy and the vasculitides. This article reviews the anatomy of the brachial plexus and describes the technique for magnetic resonance neurography and the most common pathologic conditions that can affect the brachial plexus. Copyright © 2016 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  18. Effects of early nerve repair on experimental brachial plexus injury in neonatal rats.

    Science.gov (United States)

    Bourke, Gráinne; McGrath, Aleksandra M; Wiberg, Mikael; Novikov, Lev N

    2018-03-01

    Obstetrical brachial plexus injury refers to injury observed at the time of delivery, which may lead to major functional impairment in the upper limb. In this study, the neuroprotective effect of early nerve repair following complete brachial plexus injury in neonatal rats was examined. Brachial plexus injury induced 90% loss of spinal motoneurons and 70% decrease in biceps muscle weight at 28 days after injury. Retrograde degeneration in spinal cord was associated with decreased density of dendritic branches and presynaptic boutons and increased density of astrocytes and macrophages/microglial cells. Early repair of the injured brachial plexus significantly delayed retrograde degeneration of spinal motoneurons and reduced the degree of macrophage/microglial reaction but had no effect on muscle atrophy. The results demonstrate that early nerve repair of neonatal brachial plexus injury could promote survival of injured motoneurons and attenuate neuroinflammation in spinal cord.

  19. Effect of Cervical Siphon of External and Internal Carotid Arteries.

    Science.gov (United States)

    Singh, Rajani; Tubbs, Richard Shane

    2017-10-01

    Variant courses, configuration, and branching pattern of the external and internal carotid arteries, especially when curved in S-shape, are important for hemodynamic changes and clinical implications. Therefore, the aim of the study is to report abnormal cervical siphons observed in external and internal carotid arteries to explore clinical significance by review of literature and hemodynamic changes theoretically.The right common carotid artery bifurcated into external and internal carotid arteries at the level of the upper border of thyroid cartilage in a 70-year-old female cadaver. After bifurcation, the external carotid artery underwent severe tortuosity coursing through 5 bends at points A, B, C, D, and E from its origin to termination and 2 bends at A' and B' in internal carotid artery in the cervical region. The angles between inflow and out flow of the blood at the bends were measured and the change in velocity at each bend was computed for both arteries. Hemodynamic changes were calculated, compared and relevant clinical complications were theoretically correlated.The angles of 20°, 30°, 51°, 52°, 60°, and 28°, 48° were formed by 5 bends of external and 2 bends of internal carotid arteries, respectively. The curved courses of these arteries caused reduction in velocity/stasis, turbulence, and low shear stress. Such kinks might cause stroke, ischemia and mistaken for tumors and abscess in imagery leading to or otherwise producing iatrogenic repercussions. This study will be useful for anatomists, clinicians, and radiologists.

  20. Oscillometric blood pressure measurement: a simple method in screening for peripheral arterial disease

    DEFF Research Database (Denmark)

    Mehlsen, Jesper; Wiinberg, Niels; Bruce, Christopher

    2008-01-01

    Blood pressure at the ankle level is a reliable indicator of peripheral arterial disease (PAD) and the ankle brachial index (ABI) is a useful non-invasive screening tool for the early detection of atherosclerosis. In the first part of the study, systolic blood pressures obtained by oscillometry...... of PAD was sufficiently high in subjects over the age of 60 years to warrant screening. The ankle brachial index based on measurements with an oscillometric device was shown reliable in the exclusion of PAD, thereby fulfilling an important criterion for the use in screening....

  1. A Rare Case of Atypical Renal Arteries Arrangement with Ectopic Kidneys in a Guinea Pig

    Directory of Open Access Journals (Sweden)

    Maženský D.

    2016-12-01

    Full Text Available We recorded a very rare case of atypical renal arteries arrangement in a guinea pig using the corrosion technique in the study of the arterial system. The right renal artery originated from the ventral wall of the abdominal aorta at the level of the caudal aspect of the 5th lumbar vertebra. The left renal artery originated from the left common iliac artery approximately 12 mm caudally to the aortic bifurcation. The right kidney was located ventral to the aortic bifurcation and the left kidney inside the pelvic cavity between the common iliac arteries. According to the vascular pattern, we determined that the ectopic kidneys in this guinea pig were unusual. This is the first case describing bilateral ectopic kidneys in a guinea pig.

  2. Association of Aortic Compliance and Brachial Endothelial Function with Cerebral Small Vessel Disease in Type 2 Diabetes Mellitus Patients: Assessment with High-Resolution MRI

    Directory of Open Access Journals (Sweden)

    Yan Shan

    2016-01-01

    Full Text Available Objective. To assess the possible association of aortic compliance and brachial endothelial function with cerebral small vessel disease in type 2 diabetes mellitus (DM2 patients by using 3.0 T high-resolution magnetic resonance imaging. Methods. Sixty-two clinically confirmed DM2 patients (25 women and 37 men; mean age: 56.8±7.5 years were prospectively enrolled for noninvasive MR examinations of the aorta, brachial artery, and brain. Aortic arch pulse wave velocity (PWV, flow-mediated dilation (FMD of brachial artery, lacunar brain infarcts, and periventricular and deep white matter hyperintensities (WMHs were assessed. Pearson and Spearman correlation analysis were performed to analyze the association between PWV and FMD with clinical data and biochemical test results. Univariable logistic regression analyses were used to analyze the association between PWV and FMD with cerebral small vessel disease. Multiple logistic regression analyses were used to find out the independent predictive factors of cerebral small vessel disease. Results. Mean PWV was 6.73±2.00 m/s and FMD was 16.67±9.11%. After adjustment for compounding factors, PWV was found significantly associated with lacunar brain infarcts (OR = 2.00; 95% CI: 1.14–3.2; P<0.05 and FMD was significantly associated with periventricular WMHs (OR = 0.82; 95% CI: 0.71–0.95; P<0.05. Conclusions. Quantitative evaluation of aortic compliance and endothelial function by using high-resolution MRI may be potentially useful to stratify DM2 patients with risk of cerebral small vessel disease.

  3. CISM Session on Bifurcation and Stability of Dissipative Systems

    CERN Document Server

    1993-01-01

    The first theme concerns the plastic buckling of structures in the spirit of Hill’s classical approach. Non-bifurcation and stability criteria are introduced and post-bifurcation analysis performed by asymptotic development method in relation with Hutchinson’s work. Some recent results on the generalized standard model are given and their connection to Hill’s general formulation is presented. Instability phenomena of inelastic flow processes such as strain localization and necking are discussed. The second theme concerns stability and bifurcation problems in internally damaged or cracked colids. In brittle fracture or brittle damage, the evolution law of crack lengths or damage parameters is time-independent like in plasticity and leads to a similar mathematical description of the quasi-static evolution. Stability and non-bifurcation criteria in the sense of Hill can be again obtained from the discussion of the rate response.

  4. Bifurcation dynamics of the tempered fractional Langevin equation

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Caibin, E-mail: macbzeng@scut.edu.cn; Yang, Qigui, E-mail: qgyang@scut.edu.cn [School of Mathematics, South China University of Technology, Guangzhou 510640 (China); Chen, YangQuan, E-mail: ychen53@ucmerced.edu [MESA LAB, School of Engineering, University of California, Merced, 5200 N. Lake Road, Merced, California 95343 (United States)

    2016-08-15

    Tempered fractional processes offer a useful extension for turbulence to include low frequencies. In this paper, we investigate the stochastic phenomenological bifurcation, or stochastic P-bifurcation, of the Langevin equation perturbed by tempered fractional Brownian motion. However, most standard tools from the well-studied framework of random dynamical systems cannot be applied to systems driven by non-Markovian noise, so it is desirable to construct possible approaches in a non-Markovian framework. We first derive the spectral density function of the considered system based on the generalized Parseval's formula and the Wiener-Khinchin theorem. Then we show that it enjoys interesting and diverse bifurcation phenomena exchanging between or among explosive-like, unimodal, and bimodal kurtosis. Therefore, our procedures in this paper are not merely comparable in scope to the existing theory of Markovian systems but also provide a possible approach to discern P-bifurcation dynamics in the non-Markovian settings.

  5. Deformable 4DCT lung registration with vessel bifurcations

    International Nuclear Information System (INIS)

    Hilsmann, A.; Vik, T.; Kaus, M.; Franks, K.; Bissonette, J.P.; Purdie, T.; Beziak, A.; Aach, T.

    2007-01-01

    In radiotherapy planning of lung cancer, breathing motion causes uncertainty in the determination of the target volume. Image registration makes it possible to get information about the deformation of the lung and the tumor movement in the respiratory cycle from a few images. A dedicated, automatic, landmark-based technique was developed that finds corresponding vessel bifurcations. Hereby, we developed criteria to characterize pronounced bifurcations for which correspondence finding was more stable and accurate. The bifurcations were extracted from automatically segmented vessel trees in maximum inhale and maximum exhale CT thorax data sets. To find corresponding bifurcations in both data sets we used the shape context approach of Belongie et al. Finally, a volumetric lung deformation was obtained using thin-plate spline interpolation and affine registration. The method is evaluated on 10 4D-CT data sets of patients with lung cancer. (orig.)

  6. Multiple bifurcations and periodic 'bubbling' in a delay population model

    International Nuclear Information System (INIS)

    Peng Mingshu

    2005-01-01

    In this paper, the flip bifurcation and periodic doubling bifurcations of a discrete population model without delay influence is firstly studied and the phenomenon of Feigenbaum's cascade of periodic doublings is also observed. Secondly, we explored the Neimark-Sacker bifurcation in the delay population model (two-dimension discrete dynamical systems) and the unique stable closed invariant curve which bifurcates from the nontrivial fixed point. Finally, a computer-assisted study for the delay population model is also delved into. Our computer simulation shows that the introduction of delay effect in a nonlinear difference equation derived from the logistic map leads to much richer dynamic behavior, such as stable node → stable focus → an lower-dimensional closed invariant curve (quasi-periodic solution, limit cycle) or/and stable periodic solutions → chaotic attractor by cascading bubbles (the combination of potential period doubling and reverse period-doubling) and the sudden change between two different attractors, etc

  7. Bifurcation theory for hexagonal agglomeration in economic geography

    CERN Document Server

    Ikeda, Kiyohiro

    2014-01-01

    This book contributes to an understanding of how bifurcation theory adapts to the analysis of economic geography. It is easily accessible not only to mathematicians and economists, but also to upper-level undergraduate and graduate students who are interested in nonlinear mathematics. The self-organization of hexagonal agglomeration patterns of industrial regions was first predicted by the central place theory in economic geography based on investigations of southern Germany. The emergence of hexagonal agglomeration in economic geography models was envisaged by Krugman. In this book, after a brief introduction of central place theory and new economic geography, the missing link between them is discovered by elucidating the mechanism of the evolution of bifurcating hexagonal patterns. Pattern formation by such bifurcation is a well-studied topic in nonlinear mathematics, and group-theoretic bifurcation analysis is a well-developed theoretical tool. A finite hexagonal lattice is used to express uniformly distri...

  8. Periodic solutions and bifurcations of delay-differential equations

    International Nuclear Information System (INIS)

    He Jihuan

    2005-01-01

    In this Letter a simple but effective iteration method is proposed to search for limit cycles or bifurcation curves of delay-differential equations. An example is given to illustrate its convenience and effectiveness

  9. [Coronary angioplasty simultaneous with the "kissing" technique in a bifurcation lesion: use of a guidewire, and 2 monorail systems of rapid interchange].

    Science.gov (United States)

    Escudero, X

    1996-01-01

    Coronary branch occlusion complicating percutaneous coronary angioplasty has been recognized in certain bifurcation lesions. The utilization of double angioplasty systems simultaneously has been called "kissing" because the image of contact between balloons, and has been utilized as an alternative to protect the jeopardized branch or prevent snowplow lesion of the principal artery. The technological advance with the use of wide lumen catheters and low profile dilation balloons make the application of this technique possible in those type of lesions using a single guiding catheter. The present paper describes one case treated with this technique using conventional angioplasty systems in a complex bifurcating lesion of the circumflex artery. Some technical considerations about the procedure are made.

  10. Defining Electron Bifurcation in the Electron-Transferring Flavoprotein Family.

    Science.gov (United States)

    Garcia Costas, Amaya M; Poudel, Saroj; Miller, Anne-Frances; Schut, Gerrit J; Ledbetter, Rhesa N; Fixen, Kathryn R; Seefeldt, Lance C; Adams, Michael W W; Harwood, Caroline S; Boyd, Eric S; Peters, John W

    2017-11-01

    Electron bifurcation is the coupling of exergonic and endergonic redox reactions to simultaneously generate (or utilize) low- and high-potential electrons. It is the third recognized form of energy conservation in biology and was recently described for select electron-transferring flavoproteins (Etfs). Etfs are flavin-containing heterodimers best known for donating electrons derived from fatty acid and amino acid oxidation to an electron transfer respiratory chain via Etf-quinone oxidoreductase. Canonical examples contain a flavin adenine dinucleotide (FAD) that is involved in electron transfer, as well as a non-redox-active AMP. However, Etfs demonstrated to bifurcate electrons contain a second FAD in place of the AMP. To expand our understanding of the functional variety and metabolic significance of Etfs and to identify amino acid sequence motifs that potentially enable electron bifurcation, we compiled 1,314 Etf protein sequences from genome sequence databases and subjected them to informatic and structural analyses. Etfs were identified in diverse archaea and bacteria, and they clustered into five distinct well-supported groups, based on their amino acid sequences. Gene neighborhood analyses indicated that these Etf group designations largely correspond to putative differences in functionality. Etfs with the demonstrated ability to bifurcate were found to form one group, suggesting that distinct conserved amino acid sequence motifs enable this capability. Indeed, structural modeling and sequence alignments revealed that identifying residues occur in the NADH- and FAD-binding regions of bifurcating Etfs. Collectively, a new classification scheme for Etf proteins that delineates putative bifurcating versus nonbifurcating members is presented and suggests that Etf-mediated bifurcation is associated with surprisingly diverse enzymes. IMPORTANCE Electron bifurcation has recently been recognized as an electron transfer mechanism used by microorganisms to maximize

  11. Ergodicity-breaking bifurcations and tunneling in hyperbolic transport models

    Science.gov (United States)

    Giona, M.; Brasiello, A.; Crescitelli, S.

    2015-11-01

    One of the main differences between parabolic transport, associated with Langevin equations driven by Wiener processes, and hyperbolic models related to generalized Kac equations driven by Poisson processes, is the occurrence in the latter of multiple stable invariant densities (Frobenius multiplicity) in certain regions of the parameter space. This phenomenon is associated with the occurrence in linear hyperbolic balance equations of a typical bifurcation, referred to as the ergodicity-breaking bifurcation, the properties of which are thoroughly analyzed.

  12. Bunch lengthening with bifurcation in electron storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun-San; Hirata, Kohji [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

    1996-08-01

    The mapping which shows equilibrium particle distribution in synchrotron phase space for electron storage rings is discussed with respect to some localized constant wake function based on the Gaussian approximation. This mapping shows multi-periodic states as well as double bifurcation in dynamical states of the equilibrium bunch length. When moving around parameter space, the system shows a transition/bifurcation which is not always reversible. These results derived by mapping are confirmed by multiparticle tracking. (author)

  13. Hopf bifurcation of the stochastic model on business cycle

    International Nuclear Information System (INIS)

    Xu, J; Wang, H; Ge, G

    2008-01-01

    A stochastic model on business cycle was presented in thas paper. Simplifying the model through the quasi Hamiltonian theory, the Ito diffusion process was obtained. According to Oseledec multiplicative ergodic theory and singular boundary theory, the conditions of local and global stability were acquired. Solving the stationary FPK equation and analyzing the stationary probability density, the stochastic Hopf bifurcation was explained. The result indicated that the change of parameter awas the key factor to the appearance of the stochastic Hopf bifurcation

  14. Iterative Controller Tuning for Process with Fold Bifurcations

    DEFF Research Database (Denmark)

    Huusom, Jakob Kjøbsted; Poulsen, Niels Kjølstad; Jørgensen, Sten Bay

    2007-01-01

    Processes involving fold bifurcation are notoriously difficult to control in the vicinity of the fold where most often optimal productivity is achieved . In cases with limited process insight a model based control synthesis is not possible. This paper uses a data driven approach with an improved...... version of iterative feedback tuning to optimizing a closed loop performance criterion, as a systematic tool for tuning process with fold bifurcations....

  15. Bifurcated states of the error-field-induced magnetic islands

    International Nuclear Information System (INIS)

    Zheng, L.-J.; Li, B.; Hazeltine, R.D.

    2008-01-01

    We find that the formation of the magnetic islands due to error fields shows bifurcation when neoclassical effects are included. The bifurcation, which follows from including bootstrap current terms in a description of island growth in the presence of error fields, provides a path to avoid the island-width pole in the classical description. The theory offers possible theoretical explanations for the recent DIII-D and JT-60 experimental observations concerning confinement deterioration with increasing error field

  16. Increased Vessel Depiction of the Carotid Bifurcation with a Specialized 16-Channel Phased Array Coil at 3T

    Science.gov (United States)

    Tate, Quinn; Kim, Seong-Eun; Treiman, Gerald; Parker, Dennis L.; Hadley, J. Rock

    2012-01-01

    The purpose of this work was to design and construct a multi-channel receive-only RF coil for 3 Tesla magnetic resonance imaging of the human carotid artery and bifurcation with optimized signal to noise ratio in the carotid vessels along the full extent of the neck. A neck phantom designed to match the anatomy of a subject with a neck representing the body habitus often seen in subjects with carotid arterial disease, was constructed. Sixteen circular coil elements were arranged on a semi-rigid fiberglass former that closely fit the shape of the phantom, resulting in a 16-channel bilateral phased array coil. Comparisons were made between this coil and a typical 4-channel carotid coil in a study of 10 carotid vessels in 5 healthy volunteers. The 16-channel carotid coil showed a 73% average improvement in signal to noise ratio (SNR) at the carotid bifurcation. This coil also maintained an SNR greater than the peak SNR of the 4-channel coil over a vessel length of 10 cm. The resulting increase in SNR improved vessel depiction of the carotid arteries over an extended field of view, and demonstrated better image quality for higher parallel imaging reduction factors compared to the 4-channel coil. PMID:22777692

  17. Attractors, bifurcations, & chaos nonlinear phenomena in economics

    CERN Document Server

    Puu, Tönu

    2003-01-01

    The present book relies on various editions of my earlier book "Nonlinear Economic Dynamics", first published in 1989 in the Springer series "Lecture Notes in Economics and Mathematical Systems", and republished in three more, successively revised and expanded editions, as a Springer monograph, in 1991, 1993, and 1997, and in a Russian translation as "Nelineynaia Economicheskaia Dinamica". The first three editions were focused on applications. The last was differ­ ent, as it also included some chapters with mathematical background mate­ rial -ordinary differential equations and iterated maps -so as to make the book self-contained and suitable as a textbook for economics students of dynamical systems. To the same pedagogical purpose, the number of illus­ trations were expanded. The book published in 2000, with the title "A ttractors, Bifurcations, and Chaos -Nonlinear Phenomena in Economics", was so much changed, that the author felt it reasonable to give it a new title. There were two new math­ ematics ch...

  18. Bifurcated equilibria in centrifugally confined plasma

    International Nuclear Information System (INIS)

    Shamim, I.; Teodorescu, C.; Guzdar, P. N.; Hassam, A. B.; Clary, R.; Ellis, R.; Lunsford, R.

    2008-01-01

    A bifurcation theory and associated computational model are developed to account for abrupt transitions observed recently on the Maryland Centrifugal eXperiment (MCX) [R. F. Ellis et al. Phys. Plasmas 8, 2057 (2001)], a supersonically rotating magnetized plasma that relies on centrifugal forces to prevent thermal expansion of plasma along the magnetic field. The observed transitions are from a well-confined, high-rotation state (HR-mode) to a lower-rotation, lesser-confined state (O-mode). A two-dimensional time-dependent magnetohydrodynamics code is used to simulate the dynamical equilibrium states of the MCX configuration. In addition to the expected viscous drag on the core plasma rotation, a momentum loss term is added that models the friction of plasma on the enhanced level of neutrals expected in the vicinity of the insulators at the throats of the magnetic mirror geometry. At small values of the external rotation drive, the plasma is not well-centrifugally confined and hence experiences the drag from near the insulators. Beyond a critical value of the external drive, the system makes an abrupt transition to a well-centrifugally confined state in which the plasma has pulled away from the end insulator plates; more effective centrifugal confinement lowers the plasma mass near the insulators allowing runaway increases in the rotation speed. The well-confined steady state is reached when the external drive is balanced by only the viscosity of the core plasma. A clear hysteresis phenomenon is shown.

  19. Bursting oscillations, bifurcation and synchronization in neuronal systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang Haixia [School of Science, Nanjing University of Science and Technology, Nanjing 210094 (China); Wang Qingyun, E-mail: drwangqy@gmail.com [Department of Dynamics and Control, Beihang University, Beijing 100191 (China); Lu Qishao [Department of Dynamics and Control, Beihang University, Beijing 100191 (China)

    2011-08-15

    Highlights: > We investigate bursting oscillations and related bifurcation in the modified Morris-Lecar neuron. > Two types of fast-slow bursters are analyzed in detail. > We show the properties of some crucial bifurcation points. > Synchronization transition and the neural excitability are explored in the coupled bursters. - Abstract: This paper investigates bursting oscillations and related bifurcation in the modified Morris-Lecar neuron. It is shown that for some appropriate parameters, the modified Morris-Lecar neuron can exhibit two types of fast-slow bursters, that is 'circle/fold cycle' bursting and 'subHopf/homoclinic' bursting with class 1 and class 2 neural excitability, which have different neuro-computational properties. By means of the analysis of fast-slow dynamics and phase plane, we explore bifurcation mechanisms associated with the two types of bursters. Furthermore, the properties of some crucial bifurcation points, which can determine the type of the burster, are studied by the stability and bifurcation theory. In addition, we investigate the influence of the coupling strength on synchronization transition and the neural excitability in two electrically coupled bursters with the same bursting type. More interestingly, the multi-time-scale synchronization transition phenomenon is found as the coupling strength varies.

  20. Bifurcation magnetic resonance in films magnetized along hard magnetization axis

    Energy Technology Data Exchange (ETDEWEB)

    Vasilevskaya, Tatiana M., E-mail: t_vasilevs@mail.ru [Ulyanovsk State University, Leo Tolstoy 42, 432017 Ulyanovsk (Russian Federation); Sementsov, Dmitriy I.; Shutyi, Anatoliy M. [Ulyanovsk State University, Leo Tolstoy 42, 432017 Ulyanovsk (Russian Federation)

    2012-09-15

    We study low-frequency ferromagnetic resonance in a thin film magnetized along the hard magnetization axis performing an analysis of magnetization precession dynamics equations and numerical simulation. Two types of films are considered: polycrystalline uniaxial films and single-crystal films with cubic magnetic anisotropy. An additional (bifurcation) resonance initiated by the bistability, i.e. appearance of two closely spaced equilibrium magnetization states is registered. The modification of dynamic modes provoked by variation of the frequency, amplitude, and magnetic bias value of the ac field is studied. Both steady and chaotic magnetization precession modes are registered in the bifurcation resonance range. - Highlights: Black-Right-Pointing-Pointer An additional bifurcation resonance arises in a case of a thin film magnetized along HMA. Black-Right-Pointing-Pointer Bifurcation resonance occurs due to the presence of two closely spaced equilibrium magnetization states. Black-Right-Pointing-Pointer Both regular and chaotic precession modes are realized within bifurcation resonance range. Black-Right-Pointing-Pointer Appearance of dynamic bistability is typical for bifurcation resonance.

  1. Bifurcation magnetic resonance in films magnetized along hard magnetization axis

    International Nuclear Information System (INIS)

    Vasilevskaya, Tatiana M.; Sementsov, Dmitriy I.; Shutyi, Anatoliy M.

    2012-01-01

    We study low-frequency ferromagnetic resonance in a thin film magnetized along the hard magnetization axis performing an analysis of magnetization precession dynamics equations and numerical simulation. Two types of films are considered: polycrystalline uniaxial films and single-crystal films with cubic magnetic anisotropy. An additional (bifurcation) resonance initiated by the bistability, i.e. appearance of two closely spaced equilibrium magnetization states is registered. The modification of dynamic modes provoked by variation of the frequency, amplitude, and magnetic bias value of the ac field is studied. Both steady and chaotic magnetization precession modes are registered in the bifurcation resonance range. - Highlights: ► An additional bifurcation resonance arises in a case of a thin film magnetized along HMA. ► Bifurcation resonance occurs due to the presence of two closely spaced equilibrium magnetization states. ► Both regular and chaotic precession modes are realized within bifurcation resonance range. ► Appearance of dynamic bistability is typical for bifurcation resonance.

  2. Endothelial dysfunction, carotid artery plaque burden, and conventional exercise-induced myocardial ischemia as predictors of coronary artery disease prognosis

    Directory of Open Access Journals (Sweden)

    Ishihara Masayuki

    2008-12-01

    Full Text Available Abstract Background While both flow-mediated vasodilation (FMD in the brachial artery (BA, which measures endothelium-dependent vasodilatation, and intima-media thickness (IMT in the carotid artery are correlated with the prognosis of coronary artery disease (CAD, it is not clear which modality is a better predictor of CAD. Furthermore, it has not been fully determined whether either of these modalities is superior to conventional ST-segment depression on exercise stress electrocardiogram (ECG as a predictor. Thus, the goal of the present study was to compare the predictive value of FMD, IMT, and stress ECG for CAD prognosis. Methods and Results A total of 103 consecutive patients (62 ± 9 years old, 79 men with clinically suspected CAD had FMD and nitroglycerin-induced dilation (NTG-D in the BA, carotid artery IMT measurement using high-resolution ultrasound, and exercise treadmill testing. The 73 CAD patients and 30 normal coronary patients were followed for 50 ± 15 months. Fifteen patients had coronary events during this period (1 cardiac death, 2 non-fatal myocardial infarctions, 3 acute heart failures, and 9 unstable anginas. On Kaplan-Meier analysis, only FMD and stress ECG were significant predictors for cardiac events. Conclusion Brachial endothelial function as reflected by FMD and conventional exercise stress testing has comparable prognostic value, whereas carotid artery plaque burden appears to be less powerful for predicting future cardiac events.

  3. Rivaroxaban with or without aspirin in patients with stable peripheral or carotid artery disease

    DEFF Research Database (Denmark)

    Anand, Sonia S; Bosch, Jackie; Eikelboom, John W

    2018-01-01

    BACKGROUND: Patients with peripheral artery disease have an increased risk of cardiovascular morbidity and mortality. Antiplatelet agents are widely used to reduce these complications. METHODS: This was a multicentre, double-blind, randomised placebo-controlled trial for which patients were...... recruited at 602 hospitals, clinics, or community practices from 33 countries across six continents. Eligible patients had a history of peripheral artery disease of the lower extremities (previous peripheral bypass surgery or angioplasty, limb or foot amputation, intermittent claudication with objective...... evidence of peripheral artery disease), of the carotid arteries (previous carotid artery revascularisation or asymptomatic carotid artery stenosis of at least 50%), or coronary artery disease with an ankle-brachial index of less than 0·90. After a 30-day run-in period, patients were randomly assigned (1...

  4. Anatomical variations of hepatic arterial system, coeliac trunk and renal arteries: an analysis with multidetector CT angiography.

    Science.gov (United States)

    Ugurel, M S; Battal, B; Bozlar, U; Nural, M S; Tasar, M; Ors, F; Saglam, M; Karademir, I

    2010-08-01

    The purpose of our investigation was to determine the anatomical variations in the coeliac trunk-hepatic arterial system and the renal arteries in patients who underwent multidetector CT (MDCT) angiography of the abdominal aorta for various reasons. A total of 100 patients were analysed retrospectively. The coeliac trunk, hepatic arterial system and renal arteries were analysed individually and anatomical variations were recorded. Statistical analysis of the relationship between hepatocoeliac variations and renal artery variations was performed using a chi(2) test. There was a coeliac trunk trifurcation in 89% and bifurcation in 8% of the cases. Coeliac trunk was absent in 1%, a hepatosplenomesenteric trunk was seen in 1% and a splenomesenteric trunk was present in 1%. Hepatic artery variation was present in 48% of patients. Coeliac trunk and/or hepatic arterial variation was present in 23 (39.7%) of the 58 patients with normal renal arteries, and in 27 (64.3%) of the 42 patients with accessory renal arteries. There was a statistically significant correlation between renal artery variations and coeliac trunk-hepatic arterial system variations (p = 0.015). MDCT angiography permits a correct and detailed evaluation of hepatic and renal vascular anatomy. The prevalence of variations in the coeliac trunk and/or hepatic arteries is increased in people with accessory renal arteries. For that reason, when undertaking angiographic examinations directed towards any single organ, the possibility of variations in the vascular structure of other organs should be kept in mind.

  5. Stabilization of a percutaneously implanted port catheter system for hepatic artery chemotherapy infusion

    International Nuclear Information System (INIS)

    Shindoh, Noboru; Ozaki, Yutaka; Kyogoku, Shinsuke; Yamana, Daigo; Sumi, Yukiharu; Katayama, Hitoshi

    1999-01-01

    A port catheter system for hepatic artery infusion chemotherapy was implanted percutaneously via the left subclavian artery in 41 patients for treatment of unresectable liver metastases. The catheter tip was inserted into the gastroduodenal artery (GDA), the end hole was occluded with a guidewire fragment, and a side-hole for infusion was positioned at the bifurcation of the proper hepatic artery and the GDA. The GDA was embolized with steel coils around the infusion catheter tip via a transfemoral catheter. This procedure is designed to reduce the incidence of hepatic artery occlusion and infusion catheter dislocation.

  6. Dose Constraints to Prevent Radiation-Induced Brachial Plexopathy in Patients Treated for Lung Cancer

    International Nuclear Information System (INIS)

    Amini, Arya; Yang Jinzhong; Williamson, Ryan; McBurney, Michelle L.; Erasmus, Jeremy; Allen, Pamela K.; Karhade, Mandar; Komaki, Ritsuko; Liao, Zhongxing; Gomez, Daniel; Cox, James; Dong, Lei; Welsh, James

    2012-01-01

    Purpose: As the recommended radiation dose for non-small-cell lung cancer (NSCLC) increases, meeting dose constraints for critical structures like the brachial plexus becomes increasingly challenging, particularly for tumors in the superior sulcus. In this retrospective analysis, we compared dose-volume histogram information with the incidence of plexopathy to establish the maximum dose tolerated by the brachial plexus. Methods and Materials: We identified 90 patients with NSCLC treated with definitive chemoradiation from March 2007 through September 2010, who had received >55 Gy to the brachial plexus. We used a multiatlas segmentation method combined with deformable image registration to delineate the brachial plexus on the original planning CT scans and scored plexopathy according to Common Terminology Criteria for Adverse Events version 4.03. Results: Median radiation dose to the brachial plexus was 70 Gy (range, 56–87.5 Gy; 1.5–2.5 Gy/fraction). At a median follow-up time of 14.0 months, 14 patients (16%) had brachial plexopathy (8 patients [9%] had Grade 1, and 6 patients [7%] had Grade ≥2); median time to symptom onset was 6.5 months (range, 1.4–37.4 months). On multivariate analysis, receipt of a median brachial plexus dose of >69 Gy (odds ratio [OR] 10.091; 95% confidence interval [CI], 1.512–67.331; p = 0.005), a maximum dose of >75 Gy to 2 cm 3 of the brachial plexus (OR, 4.909; 95% CI, 0.966–24.952; p = 0.038), and the presence of plexopathy before irradiation (OR, 4.722; 95% CI, 1.267–17.606; p = 0.021) were independent predictors of brachial plexopathy. Conclusions: For lung cancers near the apical region, brachial plexopathy is a major concern for high-dose radiation therapy. We developed a computer-assisted image segmentation method that allows us to rapidly and consistently contour the brachial plexus and establish the dose limits to minimize the risk of brachial plexopathy. Our results could be used as a guideline in future

  7. A numerical investigation of the functionality of coronary bifurcation lesions with respect to lesion configuration and stenosis severity.

    Science.gov (United States)

    Pagiatakis, Catherine; Tardif, Jean-Claude; L'Allier, Philippe L; Mongrain, Rosaire

    2015-09-18

    The intervention of coronary bifurcation lesions is associated with higher rates of peri- and post-procedural clinical events compared to the treatment of isolated lesions. Overall, the factors that influence the dynamics of these types of configurations are still not well understood. A geometric multiscale model, consisting of a 3D representation of the left main coronary artery bifurcation and a 0D representation of the rest of the cardiovascular system, was developed. Computational fluid dynamics simulations of the 3D domain were executed by implementing the multiscale algorithm, in order to characterize the functionality of different multilesional configurations as a function of stenosis severity. The investigation found that coronary branch steal has a significant impact on the functionality of the disease and can render a two-lesion configuration more severe compared to a three-lesion configuration. As a result of the complexity of this phenomenon, it was also suggested that certain lesion configurations could result in false negatives in diagnosis when employing a pullback pressure recording across the tandem lesions. In conclusion, this study showed that coronary bifurcation lesions are subject to intricate haemodynamic interactions which render the characterization of their functionality complex and could have significant clinical implications with regards to their diagnosis and prognosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Lack of evidence of the effectiveness of primary brachial plexus surgery for infants (under the age of two years) diagnosed with obstetric brachial plexus palsy.

    Science.gov (United States)

    Bialocerkowski, Andrea; Gelding, Bronwyn

    2006-12-01

    Background  Obstetric brachial plexus palsy, which occurs in 1-3 per 1000 live births, results from traction and/or compression of the brachial plexus in utero, during descent through the birth canal or during delivery. This results in a spectrum of injuries that range in extent of damage and severity and can lead to a lifelong impairment and functional difficulties associated with the use of the affected upper limb. Most infants diagnosed with obstetric brachial plexus palsy receive treatment, such as surgery to the brachial plexus, physiotherapy or occupational therapy, within the first months of life. However, there is controversy regarding the most effective form of management. This review follows on from our previous systematic review which investigated the effectiveness of primary conservative management in infants with obstetric brachial plexus palsy. This systematic review focuses on the effects of primary surgery. Objectives  The objective of this review was to systematically assess and collate all available evidence on effectiveness of primary brachial plexus surgery for infants with obstetric brachial plexus palsy. Search strategy  A systematic literature search was performed using 13 databases: TRIP, MEDLINE, CINAHL, Web of Science, Proquest 5000, Evidence Based Medicine Reviews, Expanded Academic ASAP, Meditext, Science Direct, the Physiotherapy Evidence Database, Proquest Digital Dissertations, Open Archives Initiative Search Engine, the Australian Digital Thesis program. Those studies that were reported in English and published between July 1992 to June 2004 were included in this review. Selection criteria  Quantitative studies that investigated the effectiveness of primary brachial plexus surgery for infants with obstetric brachial plexus palsy were eligible for inclusion into this review. This excluded studies where infants were solely managed conservatively or with pharmacological agents, or underwent surgery for the management of

  9. Brachial plexus injury in adults: Diagnosis and surgical treatment strategies

    Directory of Open Access Journals (Sweden)

    Mukund R Thatte

    2013-01-01

    Full Text Available Adult post traumatic Brachial plexus injury is unfortunately a rather common injury in young adults. In India the most common scenario is of a young man injured in a motorcycle accident. Exact incidence figures are not available but of the injuries presenting to us about 90% invole the above combination This article reviews peer-reviewed publications including clinical papers, review articles and Meta analysis of the subject. In addition, the authors′ experience of several hundred cases over the last 15 years has been added and has influenced the ultimate text. Results have been discussed and analysed to get an idea of factors influencing final recovery. It appears that time from injury and number of roots involved are most crucial.

  10. Brachial plexus variations in its formation and main branches

    Directory of Open Access Journals (Sweden)

    Valéria Paula Sassoli Fazan

    2003-01-01

    Full Text Available PURPOSE: The brachial plexus has a complex anatomical structure since its origin in the neck throughout its course in the axillary region. It also has close relationship to important anatomic structures what makes it an easy target of a sort of variations and provides its clinical and surgical importance. The aims of the present study were to describe the brachial plexus anatomical variations in origin and respective branches, and to correlate these variations with sex, color of the subjects and side of the body. METHODS: Twenty-seven adult cadavers separated into sex and color had their brachial plexuses evaluated on the right and left sides. RESULTS: Our results are extensive and describe a large number of variations, including some that have not been reported in the literature. Our results showed that the phrenic nerve had a complete origin from the plexus in 20% of the cases. In this way, a lesion of the brachial plexus roots could result in diaphragm palsy. It is not usual that the long thoracic nerve pierces the scalenus medius muscle but it occurred in 63% of our cases. Another observation was that the posterior cord was formed by the posterior divisions of the superior and middle trunks in 9%. In these cases, the axillary and the radial nerves may not receive fibers from C7 and C8, as usually described. CONCLUSION: Finally, the plexuses studied did not show that sex, color or side of the body had much if any influence upon the presence of variations.OBJETIVOS: O plexo braquial apresenta uma estrutura anatômica complexa, desde sua origem, no pescoço, até sua ramificação terminal, na região axilar. Ele também apresenta relações importantes com outras estruturas anatômicas locais, o que o torna vulnerável ao aparecimento de uma série de variações anatômicas, marcando sua importância clínica e cirúrgica. Os objetivos desse estudo foram de descrever as variações anatômicas do plexo braquial, desde sua origem até seus

  11. A Review of Brachial Plexus Birth Palsy: Injury and Rehabilitation.

    Science.gov (United States)

    Raducha, Jeremy E; Cohen, Brian; Blood, Travis; Katarincic, Julia

    2017-11-01

    Brachial plexus injuries during the birthing process can leave infants with upper extremity deficits corresponding to the location of the lesion within the complex plexus anatomy. Manifestations can range from mild injuries with complete resolution to severe and permanent disability. Overall, patients have a high rate of spontaneous recovery (66-92%).1,2 Initially, all lesions are managed with passive range motion and observation. Prevention and/or correction of contractures with occupational therapy and serial splinting/casting along with encouraging normal development are the main goals of non-operative treatment. Surgical intervention may be war- ranted, depending on functional recovery. [Full article available at http://rimed.org/rimedicaljournal-2017-11.asp].

  12. Outcome following nonoperative treatment of brachial plexus birth injuries.

    Science.gov (United States)

    DiTaranto, Patricia; Campagna, Liliana; Price, Andrew E; Grossman, John A I

    2004-02-01

    Ninety-one infants who sustained a brachial plexus birth injury were treated with only physical and occupational therapy. The children were evaluated at 3-month intervals and followed for a minimum of 2 years. Sixty-three children with an upper or upper-middle plexus injury recovered good to excellent shoulder and hand function. In all of these children, critical marker muscles recovered M4 by 6 months of age. Twelve infants sustained a global palsy, with critical marker muscles remaining at M0-M1 at 6 months, resulting in a useless extremity. Sixteen infants with upper and upper-middle plexus injuries failed to recover greater than M1-M2 deltoid and biceps by 6 months, resulting in a very poor final outcome. These data provide useful guidelines for selection of infants for surgical reconstruction to improve ultimate outcome.

  13. Ultrasound assessment of the posterior circumflex humeral artery in elite volleyball players: Aneurysm prevalence, anatomy, branching pattern and vessel characteristics

    OpenAIRE

    van de Pol, Daan; Maas, Mario; Terpstra, Aart; Pannekoek-Hekman, Marja; Alaeikhanehshir, Sena; Kuijer, P. Paul F. M.; Planken, R. Nils

    2016-01-01

    Objectives To determine the prevalence of posterior circumflex humeral artery (PCHA) aneurysms and vessel characteristics of the PCHA and deep brachial artery (DBA) in elite volleyball players. Methods Two-hundred and eighty players underwent standardized ultrasound assessment of the dominant arm by a vascular technologist. Assessment included determination of PCHA aneurysms (defined as segmental vessel dilatation ?150 %), PCHA and DBA anatomy, branching pattern, vessel course and diameter. R...

  14. Morphometric Atlas Selection for Automatic Brachial Plexus Segmentation

    International Nuclear Information System (INIS)

    Van de Velde, Joris; Wouters, Johan; Vercauteren, Tom; De Gersem, Werner; Duprez, Fréderic; De Neve, Wilfried; Van Hoof, Tom

    2015-01-01

    Purpose: The purpose of this study was to determine the effects of atlas selection based on different morphometric parameters, on the accuracy of automatic brachial plexus (BP) segmentation for radiation therapy planning. The segmentation accuracy was measured by comparing all of the generated automatic segmentations with anatomically validated gold standard atlases developed using cadavers. Methods and Materials: Twelve cadaver computed tomography (CT) atlases (3 males, 9 females; mean age: 73 years) were included in the study. One atlas was selected to serve as a patient, and the other 11 atlases were registered separately onto this “patient” using deformable image registration. This procedure was repeated for every atlas as a patient. Next, the Dice and Jaccard similarity indices and inclusion index were calculated for every registered BP with the original gold standard BP. In parallel, differences in several morphometric parameters that may influence the BP segmentation accuracy were measured for the different atlases. Specific brachial plexus-related CT-visible bony points were used to define the morphometric parameters. Subsequently, correlations between the similarity indices and morphometric parameters were calculated. Results: A clear negative correlation between difference in protraction-retraction distance and the similarity indices was observed (mean Pearson correlation coefficient = −0.546). All of the other investigated Pearson correlation coefficients were weak. Conclusions: Differences in the shoulder protraction-retraction position between the atlas and the patient during planning CT influence the BP autosegmentation accuracy. A greater difference in the protraction-retraction distance between the atlas and the patient reduces the accuracy of the BP automatic segmentation result

  15. Radiation-induced brachial plexus neuropathy in breast cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, N.K.; Pfeiffer, P.; Mondrup, K.; Rose, C. (Odense Univ. Hospital (Denmark). Dept. of Neurology Odense Univ. Hospital (Denmark). Dept. of Clinical Neurophysiology Odense Univ. Hospital (Denmark). Dept. of Oncology R)

    1990-01-01

    The incidence and latency period of radiation-induced brachial plexopathy (RBP) were assessed in 79 breast cancer patients by a neurological follow-up examination at least 60 months (range 67-130 months) after the primary treatment. All patients were treated primarily with simple mastectomy, axillary nodal sampling and radiotherapy (RT). Postoperatively, pre- and postmenopausal patients were randomly allocated chemotherapy for antiestrogen treatment. All patients were recurrence-free at time of examination. Clinically, 35% (25-47%) of the patients had RBP; 19% (11-29%) had definite RBP, i.e. were physically disabled, and 16% (9-26%) had probable RBP. Fifty percent (31-69%) had affection of the entire plexus, 18% (7-35%) of the upper trunk only, and 4% (1-18%) of the lower trunk. In 28% (14-48%) of cases assessment of a definite level was not possible. RBP was more common after radiotherapy and chemotherapy (42%) than after radiotherapy alone (26%) but the difference was not statistically significant (p = 0.10). The incidence of definite RBP was significantly higher in the younger age group (p = 0.02). This could be due to more extensive axillary surgery but also to the fact that chemotherapy was given to most premenopausal patients. In most patients with RBP the symptoms began during or immediately after radiotherapy, and were thus without significant latency. Chemotherapy might enhance the radiation-induced effect on nerve tissue, thus diminishing the latency period. Lymphedema was present in 22% (14-32%), especially in the older patients, and not associated with the development of RBP. In conclusion, the damaging effect of RT on peripheral nerve tissue was documented. Since no successful treatment is available, restricted use of RT to the brachial plexus is warranted, especially when administered concomitantly with cytotoxic therapy. (orig.).

  16. Psychometric Evaluation of the Brachial Assessment Tool Part 1: Reproducibility.

    Science.gov (United States)

    Hill, Bridget; Williams, Gavin; Olver, John; Ferris, Scott; Bialocerkowski, Andrea

    2018-04-01

    To evaluate reproducibility (reliability and agreement) of the Brachial Assessment Tool (BrAT), a new patient-reported outcome measure for adults with traumatic brachial plexus injury (BPI). Prospective repeated-measure design. Outpatient clinics. Adults with confirmed traumatic BPI (N=43; age range, 19-82y). People with BPI completed the 31-item 4-response BrAT twice, 2 weeks apart. Results for the 3 subscales and summed score were compared at time 1 and time 2 to determine reliability, including systematic differences using paired t tests, test retest using intraclass correlation coefficient model 1,1 (ICC 1,1 ), and internal consistency using Cronbach α. Agreement parameters included standard error of measurement, minimal detectable change, and limits of agreement. BrAT. Test-retest reliability was excellent (ICC 1,1 =.90-.97). Internal consistency was high (Cronbach α=.90-.98). Measurement error was relatively low (standard error of measurement range, 3.1-8.8). A change of >4 for subscale 1, >6 for subscale 2, >4 for subscale 3, and >10 for the summed score is indicative of change over and above measurement error. Limits of agreement ranged from ±4.4 (subscale 3) to 11.61 (summed score). These findings support the use of the BrAT as a reproducible patient-reported outcome measure for adults with traumatic BPI with evidence of appropriate reliability and agreement for both individual and group comparisons. Further psychometric testing is required to establish the construct validity and responsiveness of the BrAT. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  17. Bifurcation analysis and stability design for aircraft longitudinal motion with high angle of attack

    Directory of Open Access Journals (Sweden)

    Xin Qi

    2015-02-01

    Full Text Available Bifurcation analysis and stability design for aircraft longitudinal motion are investigated when the nonlinearity in flight dynamics takes place severely at high angle of attack regime. To predict the special nonlinear flight phenomena, bifurcation theory and continuation method are employed to systematically analyze the nonlinear motions. With the refinement of the flight dynamics for F-8 Crusader longitudinal motion, a framework is derived to identify the stationary bifurcation and dynamic bifurcation for high-dimensional system. Case study shows that the F-8 longitudinal motion undergoes saddle node bifurcation, Hopf bifurcation, Zero-Hopf bifurcation and branch point bifurcation under certain conditions. Moreover, the Hopf bifurcation renders series of multiple frequency pitch oscillation phenomena, which deteriorate the flight control stability severely. To relieve the adverse effects of these phenomena, a stabilization control based on gain scheduling and polynomial fitting for F-8 longitudinal motion is presented to enlarge the flight envelope. Simulation results validate the effectiveness of the proposed scheme.

  18. Bifurcations of a periodically forced microbial continuous culture model with restrained growth rate

    Science.gov (United States)

    Ren, Jingli; Yuan, Qigang

    2017-08-01

    A three dimensional microbial continuous culture model with a restrained microbial growth rate is studied in this paper. Two types of dilution rates are considered to investigate the dynamic behaviors of the model. For the unforced system, fold bifurcation and Hopf bifurcation are detected, and numerical simulations reveal that the system undergoes degenerate Hopf bifurcation. When the system is periodically forced, bifurcation diagrams for periodic solutions of period-one and period-two are given by researching the Poincaré map, corresponding to different bifurcation cases in the unforced system. Stable and unstable quasiperiodic solutions are obtained by Neimark-Sacker bifurcation with different parameter values. Periodic solutions of various periods can occur or disappear and even change their stability, when the Poincaré map of the forced system undergoes Neimark-Sacker bifurcation, flip bifurcation, and fold bifurcation. Chaotic attractors generated by a cascade of period doublings and some phase portraits are given at last.

  19. Epithelioid hemangioma of brachial artery: report of a case and review of the literature

    Directory of Open Access Journals (Sweden)

    Ragazzi Moira

    2015-01-01

    Full Text Available Epithelioid hemangioma (EH is an uncommon benign vascular lesion, also known as angioblastic lymphoid (or angiolymphoid hyperplasia with eosinophilia, characterized by an unclear etiopathogenesis.

  20. Short- and long-term influence of diet and simvastatin on brachial artery endothelial function

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Thayssen, Per; Petersen, Knud Erik

    2006-01-01

    BACKGROUND: Endothelium-dependent dilation (EDD) has often been studied in patients with hypercholesterolemia without overt coronary atherosclerosis where an improvement after statin treatment has been documented within few weeks. The aim of the study was to assess the short-term effect of diet...

  1. Anatomical surgical arterial segments of the kidneys of Santa Inês ovines

    Directory of Open Access Journals (Sweden)

    Antônio Chaves de Assis Neto

    2007-03-01

    Full Text Available The main goal of the study was describe the distribution of the renal arteries of the renal parenchyma and the proportional area of the arterial vascular system. The renal arterial vascularization in Santa Ines ovines was analyzed in fifteen pairs of organs of male adult animal, after attainment of vascular models through the techniques of corrosion and arteriography. The renal artery always appeared single, and before reaching the renal hilus, it bifurcated into sectorial dorsal and ventral arteries, giving rise to the segmentary arteries which varied from 6 to 10 in number in the right kidney and 7 to 11 in the left kidney. These vessels vascularized independent areas in each renal sector, the renal arterial segments, separated by non-vascularized planes. Bilateral symmetry of the arterial segmentation was found in 13.33% of cases. In accordance with the arterial characterization, the realization of setoriectomy and segmentectomy on the kidneys of Santa Ines ovines is therefore deemed possible.

  2. ANNUAL FORECAST IN PATIENTS WITH ACUTE ISCHEMIC STROKE: ROLE OF PATHOLOGICAL ANKLE-BRACHIAL INDEX

    Directory of Open Access Journals (Sweden)

    A. N. Sumin

    2016-01-01

    Full Text Available Aim. To study the factors associated with a poor annual prognosis in patients with acute stroke and prognostic role of pathological ankle-brachial index (ABI.Material and methods. The study included 345 patients (age 63.6±7.8 years, 181 males and 164 females with ischemic stroke that were observed for 1 year. All patients were divided into 2 groups: Group 1 included patients with favorable annual outcome of stroke; Group 2 included patients that during a year had any clinical events including death. All patients underwent a standard neurological and instrumental examination including assessment of peripheral arteries status by sphygmomanometry.Results. Both groups did not differ by age and sex. The frequency of unfavorable outcomes (death, re-stroke, cardiovascular events 1 year after ischemic stroke was 29.5%. Chronic heart failure, atrial fibrillation, previous cardiovascular events, presence of peripheral atherosclerosis, overweight were identified most commonly in Group 2. Patients of Group 2 initially had a rough neurological deficit. The pathological ABI was detected in 70.7% of patients in Group 2 vs 33.8% of patients in Group 1 (p=0.000001. A strong relationship of pathological ABI with a poor outcome of stroke was found by regression analysis.Conclusions. Detection of pathological ABI in patients with ischemic stroke makes it possible to reveal peripheral atherosclerosis and to carry out the targeted preventive measures in these patients. Risk stratification can contribute to more individual and effective secondary prevention in patients with cerebrovascular disease. 

  3. Can we measure the ankle-brachial index using only a stethoscope? A pilot study.

    Science.gov (United States)

    Carmo, G A L; Mandil, A; Nascimento, B R; Arantes, B D; Bittencourt, J C; Falqueto, E B; Ribeiro, A L

    2009-02-01

    Ankle-brachial index (ABI) is an excellent method for the diagnosis of peripheral arterial disease (PAD) when it is performed with Doppler. However, this device is not always available for primary care physicians. The ABI measured with stethoscope is an easy alternative approach, but have not been proved to be useful. To assess the accuracy of the ABI measured using a stethoscope comparatively to that of the current eligible method for the diagnosis of PAD, the Doppler ABI, and describe the characteristics of this new approach. We conducted a diagnostic study of ABI measured with a stethoscope and a Doppler probe and compared the results. Eighty-eight patients were accessed by both methods. Mean stethoscope ABI, 1.01 +/- 0.15, and mean Doppler ABI, 1.03 +/- 0.20, (P = 0.047) displayed a good correlation. Measurements of stethoscope ABI diagnostic accuracy in recognizing a Doppler ABI are described. The comparison of this data with the current gold standard method results gave a sensitivity of 71.4% [95% confidence interval (CI), 41.9-91.6] and specificity of 91.0% (95% CI, 81.5-96.6), with predictive positive value of 62.5% (95% CI, 38.6-81.5) and negative predictive value of 93.8% (95% CI, 85.2-97.6). The study accuracy was 87.7%. The area under the ROC curve was 0.895 (95% CI, 0.804-0.986, P stethoscope ABI is a useful method to detect PAD and it may be suitable for its screening in the primary care setting.

  4. Prognostic value of low and high ankle-brachial index in hospitalized medical patients.

    Science.gov (United States)

    Pasqualini, Leonella; Schillaci, Giuseppe; Pirro, Matteo; Vaudo, Gaetano; Leli, Christian; Colella, Renato; Innocente, Salvatore; Ciuffetti, Giovanni; Mannarino, Elmo

    2012-04-01

    Peripheral arterial disease (PAD) is frequently underdiagnosed in the clinical practice, leading to a lack of opportunity to detect subjects at a high risk for cardiovascular (CV) death. The ankle-brachial pressure index (ABI) represents a noninvasive, objective tool to diagnose PAD and to predict adverse outcome. ABI was determined by means of Doppler velocimetry, in 707 patients, aged 50 years or older, consecutively hospitalized in an internal medicine ward, who were followed-up for at least 12 months in order to assess all-cause and CV mortality. Symptomatic PAD affected 8% of the population while the prevalence of PAD, defined as ABI 1.40) was found in 8% of the patients. After a mean follow-up period of 1.6 years, both low and high ABI were independently associated with CV mortality with a hazard ratio of 1.99 (p=0.016) for low and 2.13 (p=0.04) for high ABI, compared with normal ABI (0.90-1.40). High ABI also independently predicted all-cause mortality with a hazard ratio of 1.77 (p=0.04). ABI measurement reveals a large number of individuals with asymptomatic PAD among those hospitalized in an internal medicine department. An increased mortality was observed in patients with both low and high ABI. Hospital admission for any reason may serve as an opportunity to detect PAD and start appropriate preventive actions. Copyright © 2011 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  5. Bifurcation and Fractal of the Coupled Logistic Map

    Science.gov (United States)

    Wang, Xingyuan; Luo, Chao

    The nature of the fixed points of the coupled Logistic map is researched, and the boundary equation of the first bifurcation of the coupled Logistic map in the parameter space is given out. Using the quantitative criterion and rule of system chaos, i.e., phase graph, bifurcation graph, power spectra, the computation of the fractal dimension, and the Lyapunov exponent, the paper reveals the general characteristics of the coupled Logistic map transforming from regularity to chaos, the following conclusions are shown: (1) chaotic patterns of the coupled Logistic map may emerge out of double-periodic bifurcation and Hopf bifurcation, respectively; (2) during the process of double-period bifurcation, the system exhibits self-similarity and scale transform invariability in both the parameter space and the phase space. From the research of the attraction basin and Mandelbrot-Julia set of the coupled Logistic map, the following conclusions are indicated: (1) the boundary between periodic and quasiperiodic regions is fractal, and that indicates the impossibility to predict the moving result of the points in the phase plane; (2) the structures of the Mandelbrot-Julia sets are determined by the control parameters, and their boundaries have the fractal characteristic.

  6. Secondary Channel Bifurcation Geometry: A Multi-dimensional Problem

    Science.gov (United States)

    Gaeuman, D.; Stewart, R. L.

    2017-12-01

    The construction of secondary channels (or side channels) is a popular strategy for increasing aquatic habitat complexity in managed rivers. Such channels, however, frequently experience aggradation that prevents surface water from entering the side channels near their bifurcation points during periods of relatively low discharge. This failure to maintain an uninterrupted surface water connection with the main channel can reduce the habitat value of side channels for fish species that prefer lotic conditions. Various factors have been proposed as potential controls on the fate of side channels, including water surface slope differences between the main and secondary channels, the presence of main channel secondary circulation, transverse bed slopes, and bifurcation angle. A quantitative assessment of more than 50 natural and constructed secondary channels in the Trinity River of northern California indicates that bifurcations can assume a variety of configurations that are formed by different processes and whose longevity is governed by different sets of factors. Moreover, factors such as bifurcation angle and water surface slope vary with discharge level and are continuously distributed in space, such that they must be viewed as a multi-dimensional field rather than a single-valued attribute that can be assigned to a particular bifurcation.

  7. Magneto-elastic dynamics and bifurcation of rotating annular plate*

    International Nuclear Information System (INIS)

    Hu Yu-Da; Piao Jiang-Min; Li Wen-Qiang

    2017-01-01

    In this paper, magneto-elastic dynamic behavior, bifurcation, and chaos of a rotating annular thin plate with various boundary conditions are investigated. Based on the thin plate theory and the Maxwell equations, the magneto-elastic dynamic equations of rotating annular plate are derived by means of Hamilton’s principle. Bessel function as a mode shape function and the Galerkin method are used to achieve the transverse vibration differential equation of the rotating annular plate with different boundary conditions. By numerical analysis, the bifurcation diagrams with magnetic induction, amplitude and frequency of transverse excitation force as the control parameters are respectively plotted under different boundary conditions such as clamped supported sides, simply supported sides, and clamped-one-side combined with simply-anotherside. Poincaré maps, time history charts, power spectrum charts, and phase diagrams are obtained under certain conditions, and the influence of the bifurcation parameters on the bifurcation and chaos of the system is discussed. The results show that the motion of the system is a complicated and repeated process from multi-periodic motion to quasi-period motion to chaotic motion, which is accompanied by intermittent chaos, when the bifurcation parameters change. If the amplitude of transverse excitation force is bigger or magnetic induction intensity is smaller or boundary constraints level is lower, the system can be more prone to chaos. (paper)

  8. Shells, orbit bifurcations, and symmetry restorations in Fermi systems

    Energy Technology Data Exchange (ETDEWEB)

    Magner, A. G., E-mail: magner@kinr.kiev.ua; Koliesnik, M. V. [NASU, Institute for Nuclear Research (Ukraine); Arita, K. [Nagoya Institute of Technology, Department of Physics (Japan)

    2016-11-15

    The periodic-orbit theory based on the improved stationary-phase method within the phase-space path integral approach is presented for the semiclassical description of the nuclear shell structure, concerning themain topics of the fruitful activity ofV.G. Soloviev. We apply this theory to study bifurcations and symmetry breaking phenomena in a radial power-law potential which is close to the realistic Woods–Saxon one up to about the Fermi energy. Using the realistic parametrization of nuclear shapes we explain the origin of the double-humped fission barrier and the asymmetry in the fission isomer shapes by the bifurcations of periodic orbits. The semiclassical origin of the oblate–prolate shape asymmetry and tetrahedral shapes is also suggested within the improved periodic-orbit approach. The enhancement of shell structures at some surface diffuseness and deformation parameters of such shapes are explained by existence of the simple local bifurcations and new non-local bridge-orbit bifurcations in integrable and partially integrable Fermi-systems. We obtained good agreement between the semiclassical and quantum shell-structure components of the level density and energy for several surface diffuseness and deformation parameters of the potentials, including their symmetry breaking and bifurcation values.

  9. Inverse bifurcation analysis: application to simple gene systems

    Directory of Open Access Journals (Sweden)

    Schuster Peter

    2006-07-01

    Full Text Available Abstract Background Bifurcation analysis has proven to be a powerful method for understanding the qualitative behavior of gene regulatory networks. In addition to the more traditional forward problem of determining the mapping from parameter space to the space of model behavior, the inverse problem of determining model parameters to result in certain desired properties of the bifurcation diagram provides an attractive methodology for addressing important biological problems. These include understanding how the robustness of qualitative behavior arises from system design as well as providing a way to engineer biological networks with qualitative properties. Results We demonstrate that certain inverse bifurcation problems of biological interest may be cast as optimization problems involving minimal distances of reference parameter sets to bifurcation manifolds. This formulation allows for an iterative solution procedure based on performing a sequence of eigen-system computations and one-parameter continuations of solutions, the latter being a standard capability in existing numerical bifurcation software. As applications of the proposed method, we show that the problem of maximizing regions of a given qualitative behavior as well as the reverse engineering of bistable gene switches can be modelled and efficiently solved.

  10. Stochastic Bifurcation Analysis of an Elastically Mounted Flapping Airfoil

    Directory of Open Access Journals (Sweden)

    Bose Chandan

    2018-01-01

    Full Text Available The present paper investigates the effects of noisy flow fluctuations on the fluid-structure interaction (FSI behaviour of a span-wise flexible wing modelled as a two degree-of-freedom elastically mounted flapping airfoil. In the sterile flow conditions, the system undergoes a Hopf bifurcation as the free-stream velocity exceeds a critical limit resulting in a stable limit-cycle oscillation (LCO from a fixed point response. On the other hand, the qualitative dynamics changes from a stochastic fixed point to a random LCO through an intermittent state in the presence of irregular flow fluctuations. The probability density function depicts the most probable system state in the phase space. A phenomenological bifurcation (P-bifurcation analysis based on the transition in the topology associated with the structure of the joint probability density function (pdf of the response variables has been carried out. The joint pdf corresponding to the stochastic fixed point possesses a Dirac delta function like structure with a sharp single peak around zero. As the mean flow speed crosses the critical value, the joint pdf bifurcates to a crater-like structure indicating the occurrence of a P-bifurcation. The intermittent state is characterized by the co-existence of the unimodal as well as the crater like structure.

  11. Brachial Plexus Injury from CT-Guided RF Ablation Under General Anesthesia

    International Nuclear Information System (INIS)

    Shankar, Sridhar; Sonnenberg, Eric van; Silverman, Stuart G.; Tuncali, Kemal; Flanagan, Hugh L.; Whang, Edward E.

    2005-01-01

    Brachial plexus injury in a patient under general anesthesia (GA) is not uncommon, despite careful positioning and, particularly, awareness of the possibility. The mechanism of injury is stretching and compression of the brachial plexus over a prolonged period. Positioning the patient within the computed tomography (CT) gantry for abdominal or chest procedures can simulate a surgical procedure, particularly when GA is used. The potential for brachial plexus injury is increased if the case is prolonged and the patient's arms are raised above the head to avoid CT image degradation from streak artifacts. We report a case of profound brachial plexus palsy following a CT-guided radiofrequency ablation procedure under GA. Fortunately, the patient recovered completely. We emphasize the mechanism of injury and detail measures to combat this problem, such that radiologists are aware of this potentially serious complication

  12. COMPLICATIONS DURING A SUPRACLAVICULAR ANESTHESIA OF THE BRACHIAL PLEXUS WITH INTERSCALENE APPROACH

    Directory of Open Access Journals (Sweden)

    Minko Minkov

    2012-11-01

    Full Text Available A hemidiaphragmatic paresis is one of the most frequently observed complications following the supraclavicular anesthesia of the brachial plexus with interscalene approach. In patients, crucially dependant on adequate diaphragmatic function, hemidiaphragmatic paresis may provoke acute respiratory disturbances. The aim of this study was to analyze the anatomical features the brachial plexus with regard of the anesthesia of specific areas of the shoulder and the upper limb.A dissection of the cervical and the brachial plexuses was done in human cadavers. We established that in some cases the phrenic nerve and the accessory phrenic nerve arise from the superior trunk of the brachial plexus. This type of anatomical arrangement significantly increases the risk of hemidiaphragmatic paresis during supraclavicular anesthesia with interscalene approach because the anesthetic tends to invade the supraclavicular space.

  13. Neonatal brachial plexus injury: comparison of incidence and antecedents between 2 decades.

    LENUS (Irish Health Repository)

    Walsh, Jennifer M

    2011-04-01

    We sought to compare the incidence and antecedents of neonatal brachial plexus injury (BPI) in 2 different 5-year epochs a decade apart following the introduction of specific staff training in the management of shoulder dystocia.

  14. Profile of children with new-born brachial plexus palsy managed in a ...

    African Journals Online (AJOL)

    olayemitoyin

    Summary: New-born Brachial Plexus Palsy (NBPP) is birth injury resulting from ... NBPP located from the database of the Physiotherapy department were retrieved in order to assess .... child and maternal characteristics and this were noted.

  15. Salvage of bilateral renal artery occlusion after endovascular aneurysm repair with open splenorenal bypass

    Directory of Open Access Journals (Sweden)

    Samuel Jessula, MDCM

    2017-09-01

    Full Text Available We report renal salvage maneuvers after accidental bilateral renal artery coverage during endovascular aneurysm repair of an infrarenal abdominal aortic aneurysm. A 79-year-old man with an infrarenal abdominal aortic aneurysm was treated with endovascular aneurysm repair. Completion angiography demonstrated coverage of the renal arteries. Several revascularization techniques were attempted, including endograft repositioning and endovascular stenting through the femoral and brachial approach. The patient eventually underwent open splenorenal bypass with a Y Gore-Tex graft (W. L. Gore & Associates, Flagstaff, Ariz. After 3 months, computed tomography showed no evidence of endoleak and patent renal arteries. Renal function was well maintained, and the patient did not require dialysis.

  16. Correlation between peripheral arterial disease and coronary artery disease using ankle brachial index-a study in Indian population

    Directory of Open Access Journals (Sweden)

    Sharmistha Sarangi

    2012-01-01

    Conclusion: There is a definite and strong correlation between PAD and CAD. Correct diagnosis and supervision of patients with PAD is important for preventing the local progression of the disease and effective secondary prevention of future coronary and cerebrovascular events.

  17. Sediment sorting at a side channel bifurcation

    Science.gov (United States)

    van Denderen, Pepijn; Schielen, Ralph; Hulscher, Suzanne

    2017-04-01

    Side channels have been constructed to reduce the flood risk and to increase the ecological value of the river. In various Dutch side channels large aggradation in these channels occurred after construction. Measurements show that the grain size of the deposited sediment in the side channel is smaller than the grain size found on the bed of the main channel. This suggest that sorting occurs at the bifurcation of the side channel. The objective is to reproduce with a 2D morphological model the fining of the bed in the side channel and to study the effect of the sediment sorting on morphodynamic development of the side channel. We use a 2D Delft3D model with two sediment fractions. The first fraction corresponds with the grain size that can be found on the bed of the main channel and the second fraction corresponds with the grain size found in the side channel. With the numerical model we compute several side channel configurations in which we vary the length and the width of the side channel, and the curvature of the upstream channel. From these computations we can derive the equilibrium state and the time scale of the morphodynamic development of the side channel. Preliminary results show that even when a simple sediment transport relation is used, like Engelund & Hansen, more fine sediment enters the side channel than coarse sediment. This is as expected, and is probably related to the bed slope effects which are a function of the Shields parameter. It is expected that by adding a sill at the entrance of the side channel the slope effect increases. This might reduce the amount of coarse sediment which enters the side channel even more. It is unclear whether the model used is able to reproduce the effect of such a sill correctly as modelling a sill and reproducing the correct hydrodynamic and morphodynamic behaviour is not straightforward in a 2D model. Acknowledgements: This research is funded by STW, part of the Dutch Organization for Scientific Research under

  18. COMPLICATIONS DURING A SUPRACLAVICULAR ANESTHESIA OF THE BRACHIAL PLEXUS WITH INTERSCALENE APPROACH

    OpenAIRE

    Minko Minkov; Maria Vankova; Radoslav Minkov; Stefaniya Terzieva; Toni Dimitrov; Iskren Velikov

    2012-01-01

    A hemidiaphragmatic paresis is one of the most frequently observed complications following the supraclavicular anesthesia of the brachial plexus with interscalene approach. In patients, crucially dependant on adequate diaphragmatic function, hemidiaphragmatic paresis may provoke acute respiratory disturbances. The aim of this study was to analyze the anatomical features the brachial plexus with regard of the anesthesia of specific areas of the shoulder and the upper limb.A dissection of the c...

  19. Assessment tools used by occupational therapists in children with obstetric brachial plexus palsy

    OpenAIRE

    Thaianny Taís Dantas de Brito; Carolinne Linhares Pinheiro

    2016-01-01

    Introduction: The Obstetric Brachial Plexus Palsy (OBPP) is a result of brachial plexus injury at birth and may cause dysfunction of the affected upper limb, reflecting significantly in the child’s life. When evaluating a child with OBPP the occupational therapist can use evaluation tools, and has to have knowledge to choose and apply the most appropriate instrument. Objective: This review aimed to analyze the literature on the use of evaluation tools by occupational therapists in...

  20. Irradiation-induced changes in the subclavian and axillary arteries after radiotherapy for carcinoma of the breast

    International Nuclear Information System (INIS)

    Kretschmer, G.; Niederle, B.; Polterauer, P.; Waneck, R.

    1986-01-01

    Three case reports are reviewed to illustrate the possibility of treating irradiation-induced lesions of the subclavian-brachial vascular segment (aneurysm and segmental occlusions) 14, 20, and 26 years after radical mastectomy and subsequent radiotherapy. All patients had an extraanatomic vein bypass graft from the carotid to the brachial artery crossing the shoulder near the acromioclavicular joint, with the advantage that the tissue changed by radiotherapy or infected by ulceration could be circumvented. There were no postoperative complications, with adequate function of the grafts (follow-up, 17, 24, and 20 months, respectively)

  1. The reliability of the ankle-brachial index in the Atherosclerosis Risk in Communities (ARIC study and the NHLBI Family Heart Study (FHS

    Directory of Open Access Journals (Sweden)

    Catellier Diane J

    2006-02-01

    Full Text Available Abstract Background A low ankle-brachial index (ABI is associated with increased risk of coronary heart disease, stroke, and death. Regression model parameter estimates may be biased due to measurement error when the ABI is included as a predictor in regression models, but may be corrected if the reliability coefficient, R, is known. The R for the ABI computed from DINAMAP™ readings of the ankle and brachial SBP is not known. Methods A total of 119 participants in both the Atherosclerosis Risk in Communities (ARIC study and the NHLBI Family Heart Study (FHS had repeat ABIs taken within 1 year, using a common protocol, automated oscillometric blood pressure measurement devices, and technician pool. Results The estimated reliability coefficient for the ankle systolic blood pressure (SBP was 0.68 (95% CI: 0.57, 0.77 and for the brachial SBP was 0.74 (95% CI: 0.62, 0.83. The reliability for the ABI based on single ankle and arm SBPs was 0.61 (95% CI: 0.50, 0.70 and the reliability of the ABI computed as the ratio of the average of two ankle SBPs to two arm SBPs was estimated from simulated data as 0.70. Conclusion These reliability estimates may be used to obtain unbiased parameter estimates if the ABI is included in regression models. Our results suggest the need for repeated measures of the ABI in clinical practice, preferably within visits and also over time, before diagnosing peripheral artery disease and before making therapeutic decisions.

  2. Prevalencia de calcificación arterial y factores de riesgo cardiovascular asociados: Estudio multicéntrico poblacional ARTPER Prevalence of arterial calcification and related risk factors: The multicenter population-based ARTPER study

    Directory of Open Access Journals (Sweden)

    María Teresa Alzamora

    2012-02-01

    Full Text Available Objetivos: Estudiar la prevalencia de calcificación arterial (índice tobillo-brazo >1,4 y de factores de riesgo cardiovascular asociados en población general >49 años de edad. Métodos: Estudio transversal, 3786 sujetos seleccionados aleatoriamente en 28 centros. Para el cálculo de la prevalencia se usó toda la muestra, excluyendo los sujetos con arteriopatía periférica (índice tobillo-brazo Objective: To determine the prevalence of arterial calcification (ankle-brachial index >1.4 and its related factors among the general population aged >49 years. Methods: We performed a cross-sectional study of 3,786 people randomly selected from 28 centers. To assess the factors associated with arterial calcification using a multivariate logistic model, the whole sample was used to compute prevalence, excluding persons with peripheral arterial disease (ankle-brachial index <0.9. Results: Arterial calcification was found in 235 persons (prevalen 6.2%; 95% CI: 5.6-7.0, and was twice as frequent in men as in women. Patients with arterial calcification were older, had more previous cardiovascular events, diabetes and obesity, and were less able to perform physical activity than persons with a healthy ankle-brachial index. Conclusions: We recommend measurement of the ankle-brachial index in primary care centers to detect arterial calcification among men, persons with diabetes, overweight, obesity or difficulty in performing physical activity, and in those with left ventricular hypertrophy.

  3. Primary benign brachial plexus tumors: an experience of 115 operated cases.

    Science.gov (United States)

    Desai, Ketan I

    2012-01-01

    Primary benign brachial plexus tumors are rare. They pose a great challenge to the neurosurgeon, because the majority of patients present with minimal or no neurological deficits. Radical to complete excision of the tumor with preservation of neurological function of the involved nerve is an ideal surgical treatment option with benign primary brachial plexus tumor surgery. We present a review article of our 10-year experience with primary benign brachial plexus tumors surgically treated at King Edward Memorial Hospital and P.D. Hinduja National Hospital from 2000 to 2009. The clinical presentations, radiological features, surgical strategies, and the eventual outcome following surgery are analyzed, discussed, and compared with available series in the world literature. Various difficulties and problems faced in the management of primary benign brachial plexus tumors are analyzed. Irrespective of the tumor size, the indications for surgical intervention are also discussed. The goal of our study was to optimize the treatment of patients with benign brachial plexus tumors with minimal neurological deficits. It is of paramount importance that brachial plexus tumors be managed by a peripheral nerve surgeon with expertise and experience in this field to minimize the neurological insult following surgery.

  4. Concepts of nerve regeneration and repair applied to brachial plexus reconstruction.

    Science.gov (United States)

    Bertelli, Jayme Augusto; Ghizoni, Marcos Flávio

    2006-01-01

    Brachial plexus injury is a serious condition that usually affects young adults. Progress in brachial plexus repair is intimately related to peripheral nerve surgery, and depends on clinical and experimental studies. We review the rat brachial plexus as an experimental model, together with its behavioral evaluation. Techniques to repair nerves, such as neurolysis, nerve coaptation, nerve grafting, nerve transfer, fascicular transfer, direct muscle neurotization, and end-to-side neurorraphy, are discussed in light of the authors' experimental studies. Intradural repair of the brachial plexus by graft implants into the spinal cord and motor rootlet transfer offer new possibilities in brachial plexus reconstruction. The clinical experience of intradural repair is presented. Surgical planning in root rupture or avulsion is proposed. In total avulsion, the authors are in favor of the reconstruction of thoraco-brachial and abdomino-antebrachial grasping, and on the transfer of the brachialis muscle to the wrist extensors if it is reinnervated. Surgical treatment of painful conditions and new drugs are also discussed.

  5. EXPERIMENTAL STUDY ON SEDIMENT DISTRIBUTION AT CHANNEL BIFURCATION

    Institute of Scientific and Technical Information of China (English)

    G.M. Tarekul ISLAM; M.R. KABIR; Ainun NISHAT

    2002-01-01

    This paper presents the experimental results on the distribution of sediments at channel bifurcation.The experiments have been conducted in a physical model of channel bifurcation. It consists of a straight main channel which bifurcates into two branch channels of different widths. The test rig is a mobile bed with fixed bank. Four different noses have been used to study the phenomenon. For each nose, three upstream discharges viz. 20 l/s, 30 l/s and 40 l/s have been employed. From the measured data, discharges and sediment transport ratios per unit width are calculated in the downstream branches.These data have been set to the general nodal point relation and a set of equations has been developed to describe the distribution of sediments to the downstream branches for different nose angles.

  6. Adaptive Control of Electromagnetic Suspension System by HOPF Bifurcation

    Directory of Open Access Journals (Sweden)

    Aming Hao

    2013-01-01

    Full Text Available EMS-type maglev system is essentially nonlinear and unstable. It is complicated to design a stable controller for maglev system which is under large-scale disturbance and parameter variance. Theory analysis expresses that this phenomenon corresponds to a HOPF bifurcation in mathematical model. An adaptive control law which adjusts the PID control parameters is given in this paper according to HOPF bifurcation theory. Through identification of the levitated mass, the controller adjusts the feedback coefficient to make the system far from the HOPF bifurcation point and maintain the stability of the maglev system. Simulation result indicates that adjusting proportion gain parameter using this method can extend the state stability range of maglev system and avoid the self-excited vibration efficiently.

  7. Hopf bifurcation and chaos in macroeconomic models with policy lag

    International Nuclear Information System (INIS)

    Liao Xiaofeng; Li Chuandong; Zhou Shangbo

    2005-01-01

    In this paper, we consider the macroeconomic models with policy lag, and study how lags in policy response affect the macroeconomic stability. The local stability of the nonzero equilibrium of this equation is investigated by analyzing the corresponding transcendental characteristic equation of its linearized equation. Some general stability criteria involving the policy lag and the system parameter are derived. By choosing the policy lag as a bifurcation parameter, the model is found to undergo a sequence of Hopf bifurcation. The direction and stability of the bifurcating periodic solutions are determined by using the normal form theory and the center manifold theorem. Moreover, we show that the government can stabilize the intrinsically unstable economy if the policy lag is sufficiently short, but the system become locally unstable when the policy lag is too long. We also find the chaotic behavior in some range of the policy lag

  8. Bifurcated equilibria in two-dimensional MHD with diamagnetic effects

    International Nuclear Information System (INIS)

    Ottaviani, M.; Tebaldi, C.

    1998-12-01

    In this work we analyzed the sequence of bifurcated equilibria in two-dimensional reduced magnetohydrodynamics. Diamagnetic effects are studied under the assumption of a constant equilibrium pressure gradient, not altered by the formation of the magnetic island. The formation of an island when the symmetric equilibrium becomes unstable is studied as a function of the tearing mode stability parameter Δ' and of the diamagnetic frequency, by employing fixed-points numerical techniques and an initial value code. At larger values of Δ' a tangent bifurcation takes place, above which no small island solutions exist. This bifurcation persists up to fairly large values of the diamagnetic frequency (of the order of one tenth of the Alfven frequency). The implications of this phenomenology for the intermittent MHD dynamics observed in tokamaks is discussed. (authors)

  9. Bifurcations of propellant burning rate at oscillatory pressure

    Energy Technology Data Exchange (ETDEWEB)

    Novozhilov, Boris V. [N. N. Semenov Institute of Chemical Physics, Russian Academy of Science, 4 Kosygina St., Moscow 119991 (Russian Federation)

    2006-06-15

    A new phenomenon, the disparity between pressure and propellant burning rate frequencies, has revealed in numerical studies of propellant burning rate response to oscillatory pressure. As is clear from the linear approximation, under small pressure amplitudes, h, pressure and propellant burning rate oscillations occur with equal period T (T-solution). In the paper, however, it is shown that at a certain critical value of the parameter h the system in hand undergoes a bifurcation so that the T-solution converts to oscillations with period 2T (2T-solution). When the bifurcation parameter h increases, the subsequent behavior of the system becomes complicated. It is obtained a sequence of period doubling to 4T-solution and 8T-solution. Beyond a certain value of the bifurcation parameter h an apparently fully chaotic solution is found. These effects undoubtedly should be taken into account in studies of oscillatory processes in combustion chambers. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  10. Stochastic stability and bifurcation in a macroeconomic model

    International Nuclear Information System (INIS)

    Li Wei; Xu Wei; Zhao Junfeng; Jin Yanfei

    2007-01-01

    On the basis of the work of Goodwin and Puu, a new business cycle model subject to a stochastically parametric excitation is derived in this paper. At first, we reduce the model to a one-dimensional diffusion process by applying the stochastic averaging method of quasi-nonintegrable Hamiltonian system. Secondly, we utilize the methods of Lyapunov exponent and boundary classification associated with diffusion process respectively to analyze the stochastic stability of the trivial solution of system. The numerical results obtained illustrate that the trivial solution of system must be globally stable if it is locally stable in the state space. Thirdly, we explore the stochastic Hopf bifurcation of the business cycle model according to the qualitative changes in stationary probability density of system response. It is concluded that the stochastic Hopf bifurcation occurs at two critical parametric values. Finally, some explanations are given in a simply way on the potential applications of stochastic stability and bifurcation analysis

  11. Dynamical systems V bifurcation theory and catastrophe theory

    CERN Document Server

    1994-01-01

    Bifurcation theory and catastrophe theory are two of the best known areas within the field of dynamical systems. Both are studies of smooth systems, focusing on properties that seem to be manifestly non-smooth. Bifurcation theory is concerned with the sudden changes that occur in a system when one or more parameters are varied. Examples of such are familiar to students of differential equations, from phase portraits. Moreover, understanding the bifurcations of the differential equations that describe real physical systems provides important information about the behavior of the systems. Catastrophe theory became quite famous during the 1970's, mostly because of the sensation caused by the usually less than rigorous applications of its principal ideas to "hot topics", such as the characterization of personalities and the difference between a "genius" and a "maniac". Catastrophe theory is accurately described as singularity theory and its (genuine) applications. The authors of this book, the first printing of w...

  12. Bifurcation analysis of a delayed mathematical model for tumor growth

    International Nuclear Information System (INIS)

    Khajanchi, Subhas

    2015-01-01

    In this study, we present a modified mathematical model of tumor growth by introducing discrete time delay in interaction terms. The model describes the interaction between tumor cells, healthy tissue cells (host cells) and immune effector cells. The goal of this study is to obtain a better compatibility with reality for which we introduced the discrete time delay in the interaction between tumor cells and host cells. We investigate the local stability of the non-negative equilibria and the existence of Hopf-bifurcation by considering the discrete time delay as a bifurcation parameter. We estimate the length of delay to preserve the stability of bifurcating periodic solutions, which gives an idea about the mode of action for controlling oscillations in the tumor growth. Numerical simulations of the model confirm the analytical findings

  13. Bifurcations in the optimal elastic foundation for a buckling column

    International Nuclear Information System (INIS)

    Rayneau-Kirkhope, Daniel; Farr, Robert; Ding, K.; Mao, Yong

    2010-01-01

    We investigate the buckling under compression of a slender beam with a distributed lateral elastic support, for which there is an associated cost. For a given cost, we study the optimal choice of support to protect against Euler buckling. We show that with only weak lateral support, the optimum distribution is a delta-function at the centre of the beam. When more support is allowed, we find numerically that the optimal distribution undergoes a series of bifurcations. We obtain analytical expressions for the buckling load around the first bifurcation point and corresponding expansions for the optimal position of support. Our theoretical predictions, including the critical exponent of the bifurcation, are confirmed by computer simulations.

  14. Bifurcations in the optimal elastic foundation for a buckling column

    Energy Technology Data Exchange (ETDEWEB)

    Rayneau-Kirkhope, Daniel, E-mail: ppxdr@nottingham.ac.u [School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD (United Kingdom); Farr, Robert [Unilever R and D, Olivier van Noortlaan 120, AT3133, Vlaardingen (Netherlands); London Institute for Mathematical Sciences, 22 South Audley Street, Mayfair, London (United Kingdom); Ding, K. [Department of Physics, Fudan University, Shanghai, 200433 (China); Mao, Yong [School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD (United Kingdom)

    2010-12-01

    We investigate the buckling under compression of a slender beam with a distributed lateral elastic support, for which there is an associated cost. For a given cost, we study the optimal choice of support to protect against Euler buckling. We show that with only weak lateral support, the optimum distribution is a delta-function at the centre of the beam. When more support is allowed, we find numerically that the optimal distribution undergoes a series of bifurcations. We obtain analytical expressions for the buckling load around the first bifurcation point and corresponding expansions for the optimal position of support. Our theoretical predictions, including the critical exponent of the bifurcation, are confirmed by computer simulations.

  15. Bifurcation-free design method of pulse energy converter controllers

    International Nuclear Information System (INIS)

    Kolokolov, Yury; Ustinov, Pavel; Essounbouli, Najib; Hamzaoui, Abdelaziz

    2009-01-01

    In this paper, a design method of pulse energy converter (PEC) controllers is proposed. This method develops a classical frequency domain design, based on the small signal modeling, by means of an addition of a nonlinear dynamics analysis stage. The main idea of the proposed method consists in fact that the PEC controller, designed with an application of the small signal modeling, is tuned after with taking into the consideration an essentially nonlinear nature of the PEC that makes it possible to avoid bifurcation phenomena in the PEC dynamics at the design stage (bifurcation-free design). Also application of the proposed method allows an improvement of the designed controller performance. The application of this bifurcation-free design method is demonstrated on an example of the controller design of direct current-direct current (DC-DC) buck converter with an input electromagnetic interference filter.

  16. Brachial cuff measurements of blood pressure during passive leg raising for fluid responsiveness prediction.

    Science.gov (United States)

    Lakhal, K; Ehrmann, S; Benzekri-Lefèvre, D; Runge, I; Legras, A; Dequin, P-F; Mercier, E; Wolff, M; Régnier, B; Boulain, T

    2012-05-01

    The passive leg raising maneuver (PLR) for fluid responsiveness testing relies on cardiac output (CO) measurements or invasive measurements of arterial pressure (AP) whereas the initial hemodynamic management during shock is often based solely on brachial cuff measurements. We assessed PLR-induced changes in noninvasive oscillometric readings to predict fluid responsiveness. Multicentre interventional study. In ICU sedated patients with circulatory failure, AP (invasive and noninvasive readings) and CO measurements were performed before, during PLR (trunk supine, not modified) and after 500-mL volume expansion. Areas under the ROC curves (AUC) were determined for fluid responsiveness (>10% volume expansion-induced increase in CO) prediction. In 112 patients (19% with arrhythmia), changes in noninvasive systolic AP during PLR (noninvasiveΔ(PLR)SAP) only predicted fluid responsiveness (cutoff 17%, n=21, positive likelihood ratio [LR] of 26 [18-38]), not unresponsiveness. If PLR-induced change in central venous pressure (CVP) was at least of 2 mm Hg (n=60), suggesting that PLR succeeded in altering cardiac preload, noninvasiveΔ(PLR)SAP performance was good: AUC of 0.94 [0.85-0.98], positive and negative LRs of 5.7 [4.6-6.8] and 0.07 [0.009-0.5], respectively, for a cutoff of 9%. Of note, invasive AP-derived indices did not outperform noninvasiveΔ(PLR)SAP. Regardless of CVP (i.e., during "blind PLR"), noninvasiveΔ(PLR)SAP more than 17% reliably identified fluid responders. During "CVP-guided PLR", in case of sufficient change in CVP, noninvasiveΔ(PLR)SAP performed better (cutoff of 9%). These findings, in sedated patients who had already undergone volume expansion and/or catecholamines, have to be verified during the early phase of circulatory failure (before an arterial line and/or a CO measuring device is placed). Copyright © 2012 Société française d’anesthésie et de réanimation (Sfar). Published by Elsevier SAS. All rights reserved.

  17. An Approach to Robust Control of the Hopf Bifurcation

    Directory of Open Access Journals (Sweden)

    Giacomo Innocenti

    2011-01-01

    Full Text Available The paper illustrates a novel approach to modify the Hopf bifurcation nature via a nonlinear state feedback control, which leaves the equilibrium properties unchanged. This result is achieved by recurring to linear and nonlinear transformations, which lead the system to locally assume the ordinary differential equation representation. Third-order models are considered, since they can be seen as proper representatives of a larger class of systems. The explicit relationship between the control input and the Hopf bifurcation nature is obtained via a frequency approach, that does not need the computation of the center manifold.

  18. Three dimensional nilpotent singularity and Sil'nikov bifurcation

    International Nuclear Information System (INIS)

    Li Xindan; Liu Haifei

    2007-01-01

    In this paper, by using the normal form, blow-up theory and the technique of global bifurcations, we study the singularity at the origin with threefold zero eigenvalue for nonsymmetric vector fields with nilpotent linear part and 4-jet C ∼ -equivalent toy-bar -bar x+z-bar -bar y+ax 3 y-bar -bar z,with a 0, and analytically prove the existence of Sil'nikov bifurcation, and then of the strange attractor for certain subfamilies of the nonsymmetric versal unfoldings of this singularity under some conditions

  19. Global bifurcations in a piecewise-smooth Cournot duopoly game

    International Nuclear Information System (INIS)

    Tramontana, Fabio; Gardini, Laura; Puu, Toenu

    2010-01-01

    The object of the work is to perform the global analysis of the Cournot duopoly model with isoelastic demand function and unit costs, presented in Puu . The bifurcation of the unique Cournot fixed point is established, which is a resonant case of the Neimark-Sacker bifurcation. New properties associated with the introduction of horizontal branches are evidenced. These properties differ significantly when the constant value is zero or positive and small. The good behavior of the case with positive constant is proved, leading always to positive trajectories. Also when the Cournot fixed point is unstable, stable cycles of any period may exist.

  20. Communication: Mode bifurcation of droplet motion under stationary laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Takabatake, Fumi [Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan); Department of Bioengineering and Robotics, Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8579 (Japan); Yoshikawa, Kenichi [Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto 610-0394 (Japan); Ichikawa, Masatoshi, E-mail: ichi@scphys.kyoto-u.ac.jp [Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan)

    2014-08-07

    The self-propelled motion of a mm-sized oil droplet floating on water, induced by a local temperature gradient generated by CW laser irradiation is reported. The circular droplet exhibits two types of regular periodic motion, reciprocal and circular, around the laser spot under suitable laser power. With an increase in laser power, a mode bifurcation from rectilinear reciprocal motion to circular motion is caused. The essential aspects of this mode bifurcation are discussed in terms of spontaneous symmetry-breaking under temperature-induced interfacial instability, and are theoretically reproduced with simple coupled differential equations.

  1. Transportation and concentration inequalities for bifurcating Markov chains

    DEFF Research Database (Denmark)

    Penda, S. Valère Bitseki; Escobar-Bach, Mikael; Guillin, Arnaud

    2017-01-01

    We investigate the transportation inequality for bifurcating Markov chains which are a class of processes indexed by a regular binary tree. Fitting well models like cell growth when each individual gives birth to exactly two offsprings, we use transportation inequalities to provide useful...... concentration inequalities.We also study deviation inequalities for the empirical means under relaxed assumptions on the Wasserstein contraction for the Markov kernels. Applications to bifurcating nonlinear autoregressive processes are considered for point-wise estimates of the non-linear autoregressive...

  2. Bifurcated transition of radial transport in the HIEI tandem mirror

    International Nuclear Information System (INIS)

    Sakai, O.; Yasaka, Y.

    1995-01-01

    Transition to a high radial confinement mode in a mirror plasma is triggered by limiter biasing. Sheared plasma rotation is induced in the high confinement phase which is characterized by reduction of edge turbulence and a confinement enhancement factor of 2-4. Edge plasma parameters related to radial confinement show a hysteresis phenomenon as a function of bias voltage or bias current, leading to the fact that transition from low to high confinement mode occurs between the bifurcated states. A transition model based on azimuthal momentum balance is employed to clarify physics of the observed bifurcation. copyright 1995 American Institute of Physics

  3. Flow Topology Transition via Global Bifurcation in Thermally Driven Turbulence

    Science.gov (United States)

    Xie, Yi-Chao; Ding, Guang-Yu; Xia, Ke-Qing

    2018-05-01

    We report an experimental observation of a flow topology transition via global bifurcation in a turbulent Rayleigh-Bénard convection. This transition corresponds to a spontaneous symmetry breaking with the flow becomes more turbulent. Simultaneous measurements of the large-scale flow (LSF) structure and the heat transport show that the LSF bifurcates from a high heat transport efficiency quadrupole state to a less symmetric dipole state with a lower heat transport efficiency. In the transition zone, the system switches spontaneously and stochastically between the two long-lived metastable states.

  4. Bifurcation analysis of nephron pressure and flow regulation

    DEFF Research Database (Denmark)

    Barfred, Mikael; Mosekilde, Erik; Holstein-Rathlou, N.-H.

    1996-01-01

    One- and two-dimensional continuation techniques are applied to study the bifurcation structure of a model of renal flow and pressure control. Integrating the main physiological mechanisms by which the individual nephron regulates the incoming blood flow, the model describes the interaction between...... the tubuloglomerular feedback and the response of the afferent arteriole. It is shown how a Hopf bifurcation leads the system to perform self-sustained oscillations if the feedback gain becomes sufficiently strong, and how a further increase of this parameter produces a folded structure of overlapping period...

  5. Discretizing the transcritical and pitchfork bifurcations – conjugacy results

    KAUST Repository

    Lóczi, Lajos

    2015-01-07

    © 2015 Taylor & Francis. We present two case studies in one-dimensional dynamics concerning the discretization of transcritical (TC) and pitchfork (PF) bifurcations. In the vicinity of a TC or PF bifurcation point and under some natural assumptions on the one-step discretization method of order (Formula presented.) , we show that the time- (Formula presented.) exact and the step-size- (Formula presented.) discretized dynamics are topologically equivalent by constructing a two-parameter family of conjugacies in each case. As a main result, we prove that the constructed conjugacy maps are (Formula presented.) -close to the identity and these estimates are optimal.

  6. Double Kissing Crush Versus Provisional Stenting for Left Main Distal Bifurcation Lesions: DKCRUSH-V Randomized Trial.

    Science.gov (United States)

    Chen, Shao-Liang; Zhang, Jue-Jie; Han, Yaling; Kan, Jing; Chen, Lianglong; Qiu, Chunguang; Jiang, Tiemin; Tao, Ling; Zeng, Hesong; Li, Li; Xia, Yong; Gao, Chuanyu; Santoso, Teguh; Paiboon, Chootopol; Wang, Yan; Kwan, Tak W; Ye, Fei; Tian, Nailiang; Liu, Zhizhong; Lin, Song; Lu, Chengzhi; Wen, Shangyu; Hong, Lang; Zhang, Qi; Sheiban, Imad; Xu, Yawei; Wang, Lefeng; Rab, Tanveer S; Li, Zhanquan; Cheng, Guanchang; Cui, Lianqun; Leon, Martin B; Stone, Gregg W

    2017-11-28

    Provisional stenting (PS) is the most common technique used to treat distal left main (LM) bifurcation lesions in patients with unprotected LM coronary artery disease undergoing percutaneous coronary intervention. The double kissing (DK) crush planned 2-stent technique has been shown to improve clinical outcomes in non-LM bifurcations compared with PS, and in LM bifurcations compared with culotte stenting, but has never been compared with PS in LM bifurcation lesions. The authors sought to determine whether a planned DK crush 2-stent technique is superior to PS for patients with true distal LM bifurcation lesions. The authors randomized 482 patients from 26 centers in 5 countries with true distal LM bifurcation lesions (Medina 1,1,1 or 0,1,1) to PS (n = 242) or DK crush stenting (n = 240). The primary endpoint was the 1-year composite rate of target lesion failure (TLF): cardiac death, target vessel myocardial infarction, or clinically driven target lesion revascularization. Routine 13-month angiographic follow-up was scheduled after ascertainment of the primary endpoint. TLF within 1 year occurred in 26 patients (10.7%) assigned to PS, and in 12 patients (5.0%) assigned to DK crush (hazard ratio: 0.42; 95% confidence interval: 0.21 to 0.85; p = 0.02). Compared with PS, DK crush also resulted in lower rates of target vessel myocardial infarction I (2.9% vs. 0.4%; p = 0.03) and definite or probable stent thrombosis (3.3% vs. 0.4%; p = 0.02). Clinically driven target lesion revascularization (7.9% vs. 3.8%; p = 0.06) and angiographic restenosis within the LM complex (14.6% vs. 7.1%; p = 0.10) also tended to be less frequent with DK crush compared with PS. There was no significant difference in cardiac death between the groups. In the present multicenter randomized trial, percutaneous coronary intervention of true distal LM bifurcation lesions using a planned DK crush 2-stent strategy resulted in a lower rate of TLF at 1 year than a PS

  7. Systematization and description of the internal carotid arteries and their main ramifications at the brain base in turtles (Trachemys scripta elegans).

    Science.gov (United States)

    Voll, Juliana; Campos, Rui

    2016-08-01

    Thirty turtle brains (Trachemys scripta elegans) were injected with latex to systematize and describe the internal carotid arteries and their main ramifications at the brain base. The internal carotid arteries had one intercarotid anastomosis. At the level of the tuber cinereum, the internal carotid artery bifurcated into its terminal branches, the rostral and the caudal branches. The rostral branch emitted the rostral choroid artery, the orbital artery, and a series of middle cerebral arteries. After giving off the last middle cerebral artery, the rostral branch continued as the rostral cerebral artery in the cerebral longitudinal fissure, and had one anastomosis with its contralateral homologous artery, the rostral communicating artery, making the first rostral closure of the cerebral arterial circle. Next, the rostral cerebral arteries anastomosed forming a rostral interhemispheric artery, making the second rostral closure of the cerebral arterial circle. The internal carotid artery, after emitting its rostral branch, continued caudally as the caudal branch. The caudal branch ran caudally along the ventral surface of the mesencephalic tegmentum, emitted the caudal cerebral artery and the mesencephalic artery, and continued caudomedially while progressively narrowing, and anastomosed with its contralateral homologous artery, forming the basilar artery. The narrower portion also emitted the trigeminal artery. The anastomosis of the caudal branches closed the cerebral arterial circle caudally. The internal carotid arteries exclusively supplied the cerebral arterial circle of the turtle. Anat Rec, 299:1090-1098, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  8. INSTRUMENTAL AND DIAGNOSTIC CRITERIA OF HEMODYNAMIC DISORDERS AND ENDOTHELIAL DYSFUNCTION CORRECTION IN PREGNANTS WITH ARTERIAL HYPERTENSION

    Directory of Open Access Journals (Sweden)

    S. M. Heryak

    2014-12-01

    Conclusions. It was found that the brachial artery ultrasound measuring and occlusive plethysmography procedure by Dietz is an early and safe method of endothelial dysfunction diagnostic in pregnants with hypertension. Doppler ultrasound of blood flow in uterine, umbilical arteries, and middle cerebral arteries of the fetus allows timely diagnosis of the side effect of antihypertensive drugs on the fetus. The therapy of choice for pregnants with Stage II Arterial Hypertension should be based on methyldopa and calcium channel antagonists or selective beta-blockers combination. Highly selective beta-blockers with vasodilative effect (nebivolol hydrochloride and L-arginine (Tivortin allow to prevent perinatal adverse effects of antihypertensive therapy, to correct hemodynamic disorders and endothelial dysfunction in pregnants with arterial hypertension. KEY WORDS: arterial hypertension, uterine-placental hemodynamics, endothelial dysfunction

  9. Surgical outcomes following nerve transfers in upper brachial plexus injuries

    Directory of Open Access Journals (Sweden)

    Bhandari P

    2009-01-01

    Full Text Available Background: Brachial plexus injuries represent devastating injuries with a poor prognosis. Neurolysis, nerve repair, nerve grafts, nerve transfer, functioning free-muscle transfer and pedicle muscle transfer are the main surgical procedures for treating these injuries. Among these, nerve transfer or neurotization is mainly indicated in root avulsion injury. Materials and Methods: We analysed the results of various neurotization techniques in 20 patients (age group 20-41 years, mean 25.7 years in terms of denervation time, recovery time and functional results. The inclusion criteria for the study included irreparable injuries to the upper roots of brachial plexus (C5, C6 and C7 roots in various combinations, surgery within 10 months of injury and a minimum follow-up period of 18 months. The average denervation period was 4.2 months. Shoulder functions were restored by transfer of spinal accessory nerve to suprascapular nerve (19 patients, and phrenic nerve to suprascapular nerve (1 patient. In 11 patients, axillary nerve was also neurotized using different donors - radial nerve branch to the long head triceps (7 patients, intercostal nerves (2 patients, and phrenic nerve with nerve graft (2 patients. Elbow flexion was restored by transfer of ulnar nerve motor fascicle to the motor branch of biceps (4 patients, both ulnar and median nerve motor fascicles to the biceps and brachialis motor nerves (10 patients, spinal accessory nerve to musculocutaneous nerve with an intervening sural nerve graft (1 patient, intercostal nerves (3rd, 4th and 5th to musculocutaneous nerve (4 patients and phrenic nerve to musculocutaneous nerve with an intervening graft (1 patient. Results: Motor and sensory recovery was assessed according to Medical Research Council (MRC Scoring system. In shoulder abduction, five patients scored M4 and three patients M3+. Fair results were obtained in remaining 12 patients. The achieved abduction averaged 95 degrees (range, 50 - 170

  10. Brachial and Cerebrovascular Functions Are Enhanced in Postmenopausal Women after Ingestion of Chocolate with a High Concentration of Cocoa.

    Science.gov (United States)

    Marsh, Channa E; Carter, Howard H; Guelfi, Kym J; Smith, Kurt J; Pike, Kerryn E; Naylor, Louise H; Green, Daniel J

    2017-09-01

    Background: Cocoa contains polyphenols that are thought to be beneficial for vascular health. Objective: We assessed the impact of chocolate containing distinct concentrations of cocoa on cerebrovascular function and cognition. Methods: Using a counterbalanced within-subject design, we compared the acute impact of consumption of energy-matched chocolate containing 80%, 35%, and 0% single-origin cacao on vascular endothelial function, cognition, and cerebrovascular function in 12 healthy postmenopausal women (mean ± SD age: 57.3 ± 5.3 y). Participants attended a familiarization session, followed by 3 experimental trials, each separated by 1 wk. Outcome measures included cerebral blood flow velocity (CBF v ) responses, recorded before and during completion of a computerized cognitive assessment battery (CogState); brachial artery flow-mediated dilation (FMD); and hemodynamic responses (heart rate and blood pressure). Results: When CBF v data before and after chocolate intake were compared between conditions through the use of 2-factor ANOVA, an interaction effect ( P = 0.003) and main effects for chocolate ( P = 0.043) and time ( P = 0.001) were evident. Post hoc analysis revealed that both milk chocolate (MC; 35% cocoa; P = 0.02) and dark chocolate (DC; 80% cocoa; P = 0.003) induced significantly lower cerebral blood flow responses during the cognitive tasks, after normalizing for changes in arterial pressure. DC consumption also increased brachial FMD compared with the baseline value before chocolate consumption ( P = 0.002), whereas MC and white chocolate (0% cocoa) caused no change ( P- interaction between conditions = 0.034). Conclusions: Consumption of chocolate containing high concentrations of cocoa enhanced vascular endothelial function, which was reflected by improvements in FMD. Cognitive function outcomes did not differ between conditions; however, cerebral blood flow responses during these cognitive tasks were lower in those consuming MC and DC. These

  11. Hopf bifurcation analysis of Chen circuit with direct time delay feedback

    International Nuclear Information System (INIS)

    Hai-Peng, Ren; Wen-Chao, Li; Ding, Liu

    2010-01-01

    Direct time delay feedback can make non-chaotic Chen circuit chaotic. The chaotic Chen circuit with direct time delay feedback possesses rich and complex dynamical behaviours. To reach a deep and clear understanding of the dynamics of such circuits described by delay differential equations, Hopf bifurcation in the circuit is analysed using the Hopf bifurcation theory and the central manifold theorem in this paper. Bifurcation points and bifurcation directions are derived in detail, which prove to be consistent with the previous bifurcation diagram. Numerical simulations and experimental results are given to verify the theoretical analysis. Hopf bifurcation analysis can explain and predict the periodical orbit (oscillation) in Chen circuit with direct time delay feedback. Bifurcation boundaries are derived using the Hopf bifurcation analysis, which will be helpful for determining the parameters in the stabilisation of the originally chaotic circuit

  12. Bifurcation structure of positive stationary solutions for a Lotka-Volterra competition model with diffusion I

    Science.gov (United States)

    Kan-On, Yukio

    2007-04-01

    This paper is concerned with the bifurcation structure of positive stationary solutions for a generalized Lotka-Volterra competition model with diffusion. To establish the structure, the bifurcation theory and the interval arithmetic are employed.

  13. Hypertrophic remodeling and increased arterial stiffness in patients with intracranial aneurysms.

    Science.gov (United States)

    Maltete, David; Bellien, Jeremy; Cabrejo, Lucie; Iacob, Michele; Proust, François; Mihout, Bruno; Thuillez, Christian; Guegan-Massardier, Evelyne; Joannides, Robinson

    2010-08-01

    Because an underlying arteriopathy might contribute to the development of intracranial aneurysms (IAs), we assessed the elastic properties of proximal conduit arteries in patients with IA. In 27 patients with previous ruptured IA and 27 control subjects matched for age, gender and BMI, we determined arterial pressure, internal diameter, intima-media thickness (IMT), circumferential wall stress (CWS) and elastic modulus (wall stiffness) in common carotid arteries using applanation tonometry and echotracking. Moreover, carotid augmentation index (AIx, arterial wave reflections) and carotid-to-femoral pulse wave velocity (PWV, aortic stiffness) were assessed. Compared with controls, patients with IA exhibited higher brachial and carotid systolic and diastolic blood pressures, with similar brachial but higher carotid artery pulse pressure (35 + or - 6mm Hg vs. 41 + or - 8mm Hg, P=0.014). Moreover, patients have higher PWV (7.8 + or - 1.2ms(-1) vs. 8.3 + or - 1.1ms(-1), P=0.048) and AIx (15.8 + or - 10.8% vs. 21.1 + or - 8.5%, PIA display a particular carotid artery phenotype with an exaggerated hypertrophic remodeling and altered elastic properties. Thus, a systemic arteriopathy might contribute, together with the arterial wall fatiguing effect of the increased pulsatile stress, to the pathogenesis of IA. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  14. Calculation of arterial wall temperature in atherosclerotic arteries: effect of pulsatile flow, arterial geometry, and plaque structure

    Directory of Open Access Journals (Sweden)

    Kim Taehong

    2007-03-01

    Full Text Available Abstract Background This paper presents calculations of the temperature distribution in an atherosclerotic plaque experiencing an inflammatory process; it analyzes the presence of hot spots in the plaque region and their relationship to blood flow, arterial geometry, and inflammatory cell distribution. Determination of the plaque temperature has become an important topic because plaques showing a temperature inhomogeneity have a higher likelihood of rupture. As a result, monitoring plaque temperature and knowing the factors affecting it can help in the prevention of sudden rupture. Methods The transient temperature profile in inflamed atherosclerotic plaques is calculated by solving an energy equation and the Navier-Stokes equations in 2D idealized arterial models of a bending artery and an arterial bifurcation. For obtaining the numerical solution, the commercial package COMSOL 3.2 was used. The calculations correspond to a parametric study where arterial type and size, as well as plaque geometry and composition, are varied. These calculations are used to analyze the contribution of different factors affecting arterial wall temperature measurements. The main factors considered are the metabolic heat production of inflammatory cells, atherosclerotic plaque length lp, inflammatory cell layer length lmp, and inflammatory cell layer thickness dmp. Results The calculations indicate that the best location to perform the temperature measurement is at the back region of the plaque (0.5 ≤ l/lp ≤ 0.7. The location of the maximum temperature, or hot spot, at the plaque surface can move during the cardiac cycle depending on the arterial geometry and is a direct result of the blood flow pattern. For the bending artery, the hot spot moves 0.6 millimeters along the longitudinal direction; for the arterial bifurcation, the hot spot is concentrated at a single location due to the flow recirculation observed at both ends of the plaque. Focusing on the

  15. Traumatic aneurysms of the pericallosal arteries

    International Nuclear Information System (INIS)

    Nakstad, P.; Nornes, H.; Hauge, H.N.

    1986-01-01

    Of a total of 912 operated intracranial aneurysms only three were classified as traumatic (0.3%). They were found in children after severe head trauma and were all located on the pericallosal artery or its branches and not a bifurcations. Shearing forces between the falx, the arteries and the brain at the time of injury are held responsible for the development of these aneurysms. Unlike these traumatic aneurysms, 29 ''spontaneous'' pericallosal aneurysms (3.2%) in adults were located at the bifurcations of the artery. As significantly fewer reports of traumatic aneurysms have been published during the last decade than before 1976, it is suggested that some might have been overlooked as a consequence of CT replacing cerebral angiography in the neuroradiological evaluation of severe head injury. This possibility should be kept in mind, especially when dealing with children after head injury and when CT scans indicate brain damage around the falx. The possibility of overlooking traumatic pericallosal aneurysms is described by other authors and discussed further in this paper. (orig.)

  16. Inflammation and neuropathic attacks in hereditary brachial plexus neuropathy

    Science.gov (United States)

    Klein, C; Dyck, P; Friedenberg, S; Burns, T; Windebank, A; Dyck, P

    2002-01-01

    Objective: To study the role of mechanical, infectious, and inflammatory factors inducing neuropathic attacks in hereditary brachial plexus neuropathy (HBPN), an autosomal dominant disorder characterised by attacks of pain and weakness, atrophy, and sensory alterations of the shoulder girdle and upper limb muscles. Methods: Four patients from separate kindreds with HBPN were evaluated. Upper extremity nerve biopsies were obtained during attacks from a person of each kindred. In situ hybridisation for common viruses in nerve tissue and genetic testing for a hereditary tendency to pressure palsies (HNPP; tomaculous neuropathy) were undertaken. Two patients treated with intravenous methyl prednisolone had serial clinical and electrophysiological examinations. One patient was followed prospectively through pregnancy and during the development of a stereotypic attack after elective caesarean delivery. Results: Upper extremity nerve biopsies in two patients showed prominent perivascular inflammatory infiltrates with vessel wall disruption. Nerve in situ hybridisation for viruses was negative. There were no tomaculous nerve changes. In two patients intravenous methyl prednisolone ameliorated symptoms (largely pain), but with tapering of steroid dose, signs and symptoms worsened. Elective caesarean delivery did not prevent a typical postpartum attack. Conclusions: Inflammation, probably immune, appears pathogenic for some if not all attacks of HBPN. Immune modulation may be useful in preventing or reducing the neuropathic attacks, although controlled trials are needed to establish efficacy, as correction of the mutant gene is still not possible. The genes involved in immune regulation may be candidates for causing HBPN disorders. PMID:12082044

  17. A giant plexiform schwannoma of the brachial plexus: case report

    Directory of Open Access Journals (Sweden)

    Kohyama Sho

    2011-11-01

    Full Text Available Abstract We report the case of a patient who noticed muscle weakness in his left arm 5 years earlier. On examination, a biloculate mass was observed in the left supraclavicular area, and Tinel's sign caused paresthesia in his left arm. Magnetic resonance imaging showed a continuous, multinodular, plexiform tumor from the left C5 to C7 nerve root along the course of the brachial plexus to the left brachia. Tumor excision was attempted. The median and musculocutaneous nerves were extremely enlarged by the tumor, which was approximately 40 cm in length, and showed no response to electric stimulation. We resected a part of the musculocutaneous nerve for biopsy and performed latissimus dorsi muscle transposition in order to repair elbow flexion. Morphologically, the tumor consisted of typical Antoni A areas, and immunohistochemistry revealed a Schwann cell origin of the tumor cells moreover, there was no sign of axon differentiation in the tumor. Therefore, the final diagnosis of plexiform Schwannoma was confirmed.

  18. Necessary and sufficient conditions for Hopf bifurcation in tri-neuron equation with a delay

    International Nuclear Information System (INIS)

    Liu Xiaoming; Liao Xiaofeng

    2009-01-01

    In this paper, we consider the delayed differential equations modeling three-neuron equations with only a time delay. Using the time delay as a bifurcation parameter, necessary and sufficient conditions for Hopf bifurcation to occur are derived. Numerical results indicate that for this model, Hopf bifurcation is likely to occur at suitable delay parameter values.

  19. Local bifurcation analysis in nuclear reactor dynamics by Sotomayor’s theorem

    International Nuclear Information System (INIS)

    Pirayesh, Behnam; Pazirandeh, Ali; Akbari, Monireh

    2016-01-01

    Highlights: • When the feedback reactivity is considered as a nonlinear function some complex behaviors may emerge in the system such as local bifurcation phenomenon. • The qualitative behaviors of a typical nuclear reactor near its equilibrium points have been studied analytically. • Comprehensive analytical bifurcation analyses presented in this paper are transcritical bifurcation, saddle- node bifurcation and pitchfork bifurcation. - Abstract: In this paper, a qualitative approach has been used to explore nuclear reactor behaviors with nonlinear feedback. First, a system of four dimensional ordinary differential equations governing the dynamics of a typical nuclear reactor is introduced. These four state variables are the relative power of the reactor, the relative concentration of delayed neutron precursors, the fuel temperature and the coolant temperature. Then, the qualitative behaviors of the dynamical system near its equilibria have been studied analytically by using local bifurcation theory and Sotomayor’s theorem. The results indicated that despite the uncertainty of the reactivity, we can analyze the qualitative behavior changes of the reactor from the bifurcation point of view. Notably, local bifurcations that were considered in this paper include transcritical bifurcation, saddle-node bifurcation and pitchfork bifurcation. The theoretical analysis showed that these three types of local bifurcations may occur in the four dimensional dynamical system. In addition, to confirm the analytical results the numerical simulations are given.

  20. Bifurcation of limit cycles for cubic reversible systems

    Directory of Open Access Journals (Sweden)

    Yi Shao

    2014-04-01

    Full Text Available This article is concerned with the bifurcation of limit cycles of a class of cubic reversible system having a center at the origin. We prove that this system has at least four limit cycles produced by the period annulus around the center under cubic perturbations