Use of corrosion casting techniques to evaluate coronary collateral vessels and anastomoses in hearts of canine cadavers.

Science.gov (United States)

Noestelthaller, Arne; Probst, Alexander; Koenig, Horst E

2005-10-01

To study and investigate branching patterns of the canine coronary arteries and collateral circulation by use of corrosion casting techniques. 31 hearts obtained from cadavers of clinically normal dogs of various ages and breeds and of either sex. 3-dimensional reproduction of coronary arteries was achieved by postmortem injection and perfusion with casting materials into the aortic sinus via the ascending aorta. Perfused hearts were macerated and carefully irrigated; the air-dried specimens were examined macroscopically and with a magnifying headset. Collateral arteries and inter- and intra-arterial anastomoses were successfully detected in 8 corrosion cast specimens. In total, 9 coronary collateral arteries and 3 interarterial anastomoses were found. Our finding of coronary collateral arteries in canine hearts is in agreement with recent findings in coronary flow study. On the basis of our results, vasodilation treatment to improve collateral vessel remodeling in dogs with myocardial dysfunction may be warranted.

Diabetes mellitus and female gender are the strongest predictors of poor collateral vessel development in patients with severe coronary artery stenosis.

Science.gov (United States)

Yetkin, Ertan; Topal, Ergun; Erguzel, Nuri; Senen, Kubilay; Heper, Gulumser; Waltenberger, Johannes

2015-04-01

Coronary collateral vessel development (CVD), i.e., arteriogenesis, is regarded as one of the most important mechanisms—along with angiogenesis—to result in protection of the myocardium. Coronary CVD is associated with a reduction in infarct size, future cardiovascular events and improved survival in patients with occlusive coronary artery disease by enhancing regional perfusion in the chronically ischemic myocardium. In the present study, we aimed to investigate the relation of cardiovascular risk factors and hematological parameters with collateral development in patients with severely stenotic (≥95%) and totally occluded coronary artery disease including at least one major coronary artery. The study population was selected from the patients who underwent coronary angiography between January 2008 and March 2009. Five hundred and two patients who had at least one coronary artery stenosis ≥95% (368 men; mean age 59 ± 10 years) comprised the study population. Of the 502 patients, 228 had total occlusion in at least one major epicardial coronary artery. Collateral artery grading was performed by using Cohen-Rentrop method to the vessel with coronary artery stenosis of ≥95% and patients with chronic total occlusions (CTO). Patients with grade 0-1 collateral development were regarded as the poor collateral group, and patients with grade 2-3 collateral development were regarded as the good collateral group. Two hundred and fifty-eight (51%) of 502 patients had poor collateral development, and 244 (49%) had good collateral development. Logistic regression analysis revealed that DM was independently associated with poor CVD in patients with ≥95% stenosis (p risk factor for poor CVD in addition to DM in patients with CTO.

Angiographic findings of collateral vessels in cervicofacial vascular lesions with previously ligated carotid artery

International Nuclear Information System (INIS)

Na, Dong Gyu; Han, Moon Hee; Chang, Kee Hyun; Han, Gi Seok; Yeon, Kung Mo

1995-01-01

The purpose of this study is to describe the angiographic findings of collateral vessels in cervicofacial vascular lesions with previously ligated carotid arteries and to evaluate the extent of angiographic assessment needed before embolization. We retrospectively reviewed 10 cervicofacial vascular lesions with previously ligated carotid artery, which were 6 cases of arteriovenous malformation, 2 cases of carotid cavernous fistula, 1 case of hemangioma and 1 case of arteriovenous malformation with carotid cavernous fistula. The previously ligated arteries are proximal external carotid artery (n = 5), branches of external carotid artery (n = 2) and common carotid artery (n = 3). Common carotid artery or internal carotid artery (n = 9), vertebral artery (n = 5), ipsilateral external carotid artery (n = 4), contralateral external carotid artery (n = 5), costocervical trunk (n = 2), thyrocervical trunk (n = 2) were assessed by conventional angiography. Angiography of both carotid and vertebral arteries was performed in 5 cases. The collateral vascular channels were inferolateral trunk of internal carotid artery (n = 8), vertebral artery (n = 5), contralateral external carotid artery (n = 5), ipsilateral external carotid artery (n = 4), deep cervical artery (n = 2) and ascending cervical artery (n = 1). Embolization were performed in 9 cases with operative cannulation (n = 4), embolization via collateral branches of ipsilateral external carotid artery (n = 1), embolization via collateral branches of contralateral external carotid artery (n = 3) and balloon occlusion via direct puncture (n = 1). The collateral channels in cervicofacial vascular lesions with previously ligated carotid artery were inferolateral trunk of internal carotid artery, contralateral or ipsilateral external carotid artery, vertebral artery, deep cervical artery and ascending cervical artery on angiography. Complete angiographic assessment of possible collateral channels is mandatory for the

The collateral circulation of the heart

Science.gov (United States)

2013-01-01

The coronary arteries have been regarded as end arteries for decades. However, there are functionally relevant anastomotic vessels, known as collateral arteries, which interconnect epicardial coronary arteries. These vessels provide an alternative source of blood supply to the myocardium in cases of occlusive coronary artery disease. The relevance of these collateral arteries is a matter of ongoing debate, but increasing evidence indicates a relevant protective role in patients with coronary artery disease. The collateral circulation can be assessed by different methods; the gold standard involves intracoronary pressure measurements. While the first clinical trials to therapeutically induce growth of collateral arteries have been unavailing, recent pilot studies using external counterpulsation or growth factors such as granulocyte colony stimulating factor (G-CSF) have shown promising results. PMID:23735225

The relationship between mean platelet volume and coronary collateral vessels in patients with acute coronary syndromes

Directory of Open Access Journals (Sweden)

Gaurav Singhal

2016-01-01

Full Text Available Background: Elevated mean platelet volume (MPV has been proposed as a risk factor for coronary artery disease (CAD and is associated with poor clinical outcome in acute coronary syndrome (ACS. However, some studies have contradictory findings. Hence, we aimed to evaluate the association of MPV with the presence of coronary collateral vessel (CCV in patients with ACS. Objective: To find MPV value in ACS patients and to find the predictive value of MPV in the spectrum of CAD and to examine whether levels of MPV predict the presence of CCVs. Methods: A total of 180 patients with first ACS were included in the study. MPV was measured. All patients underwent coronary angiography to know disease severity and CCVs. The CCVs are graded according to the Rentrop scoring system and according to coronary angiography results; patients were divided into two groups as Group 1 (poor CCV and Group 2 (good CCV. Results: The MPV was 10.74 ± 2 fl in poor collateral group patients and 11.01 ± 1.7 fl in good collateral group (P = 0.421. The presence of CCV was not significantly associated with high levels of MPV. MPV value did not show any prediction of the spectrum of CAD. Conclusion: MPV on admission was not associated with the development of CCV positively in patients with ACS. Furthermore, it is not associated with a number of vessel involvements.

Comparative analysis of the development of collateral vessels in macular edema due to branch retinal vein occlusion following grid laser or ranibizumab treatment

Directory of Open Access Journals (Sweden)

Kokolaki AE

2015-09-01

Full Text Available Afroditi Eleni Kokolaki, Ilias Georgalas, Chryssanthi Koutsandrea, Athanasios Kotsolis, Maria Niskopoulou, Ioannis LadasDepartment of Ophthalmology, University of Athens, Athens, Greece Purpose: To evaluate the differences in the development of collateral vessels in patients with macular edema due to branch retinal vein occlusion (BRVO after treatment with either grid laser or ranibizumab (RNB.Methods: Comparative study including patients with macular edema due to acute BRVO and best-corrected visual acuity (BCVA between 20/40 and 20/200. The sample was divided into two groups according to the treatment applied: laser group, including eyes treated with Argon laser when retinal hemorrhages were sufficiently absorbed to perform the treatment, and RNB group,  including patients treated initially with one monthly intravitreal injection for a period of 3 months of RNB and more injections according to need thereafter.. Before treatment patients in both groups, received a complete ophthalmic examination, including BCVA, fundus examination, optical coherence tomography, fundus color photography, and fundus fluorescein angiography (FA. This same protocol of examination was repeated in every visit after treatment, except FA that was only repeated every 3 months. The detection of the collateral vessels was done by two experienced examiners based on the analysis of the early phase of the FA. If there was a discrepancy in their judgment, the criterion of a third examiner evaluating the FA was considered.Results: Mean baseline BCVA was 0.86±0.26 and 0.82±0.25 (logMAR [logarithm of the minimum angle of resolution] in the RNB and laser groups, respectively (P=0.83. At the end of the follow-up, mean BCVA was 0.38±0.18 and 0.64±0.33 (logMAR in the RNB and laser groups, respectively. The difference in the final BCVA between both groups was statistically significant (P=0.002. Collaterals developed in both groups; 66.67% of patients (14 out of 21�

Cardiovascular risk factors and collateral artery formation.

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de Groot, D; Pasterkamp, G; Hoefer, I E

2009-12-01

Arterial lumen narrowing and vascular occlusion is the actual cause of morbidity and mortality in atherosclerotic disease. Collateral artery formation (arteriogenesis) refers to an active remodelling of non-functional vascular anastomoses to functional collateral arteries, capable to bypass the site of obstruction and preserve the tissue that is jeopardized by ischaemia. Hemodynamic forces such as shear stress and wall stress play a pivotal role in collateral artery formation, accompanied by the expression of various cytokines and invasion of circulating leucocytes. Arteriogenesis hence represents an important compensatory mechanism for atherosclerotic vessel occlusion. As arteriogenesis mostly occurs when lumen narrowing by atherosclerotic plaques takes place, presence of cardiovascular risk factors (e.g. hypertension, hypercholesterolaemia and diabetes) is highly likely. Risk factors for atherosclerotic disease affect collateral artery growth directly and indirectly by altering hemodynamic forces or influencing cellular function and proliferation. Adequate collateralization varies significantly among atherosclerotic patients, some profit from the presence of extensive collateral networks, whereas others do not. Cardiovascular risk factors could increase the risk of adverse cardiovascular events in certain patients because of the reduced protection through an alternative vascular network. Likewise, drugs primarily thought to control cardiovascular risk factors might contribute or counteract collateral artery growth. This review summarizes current knowledge on the influence of cardiovascular risk factors and the effects of cardiovascular medication on the development of collateral vessels in experimental and clinical studies.

Stroke etiology and collaterals: atheroembolic strokes have greater collateral recruitment than cardioembolic strokes.

Science.gov (United States)

Rebello, L C; Bouslama, M; Haussen, D C; Grossberg, J A; Dehkharghani, S; Anderson, A; Belagaje, S R; Bianchi, N A; Grigoryan, M; Frankel, M R; Nogueira, R G

2017-06-01

Chronic hypoperfusion from athero-stenotic lesions is thought to lead to better collateral recruitment compared to cardioembolic strokes. It was sought to compare collateral flow in stroke patients with atrial fibrillation (AF) versus stroke patients with cervical atherosclerotic steno-occlusive disease (CASOD). This was a retrospective review of a prospectively collected endovascular database. Patients with (i) anterior circulation large vessel occlusion stroke, (ii) pre-treatment computed tomography angiography (CTA) and (iii) intracranial embolism from AF or CASOD were included. CTA collateral patterns were evaluated and categorized into two groups: absent/poor collaterals (CTA collateral score 0-1) versus moderate/good collaterals (CTA collateral score 2-4). CT perfusion was also utilized for baseline core volume and evaluation of infarct growth. A total of 122 patients fitted the inclusion criteria, of whom 88 (72%) had AF and 34 (27%) CASOD. Patients with AF were older (P Collateral scores were lower in the AF group (P = 0.01) with patients having poor collaterals in 28% of cases versus 9% in the CASOD group (P = 0.03). Mortality rates (20% vs. 0%; P = 0.02) were higher in the AF patients whilst rates of any parenchymal hemorrhage (6% vs. 26%; P collaterals (odds ratio 4.70; 95% confidence interval 1.17-18.79; P = 0.03). Atheroembolic strokes seem to be associated with better collateral flow compared to cardioembolic strokes. This may in part explain the worse outcomes of AF-related stroke. © 2017 EAN.

Coronary Collateral Growth—Back to the Future

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Chilian, William M.; Penn, Marc S.; Pung, Yuh Fen; Dong, Feng; Mayorga, Maritza; Ohanyan, Vahagn; Logan, Suzanna; Yin, Liya

2012-01-01

The coronary collateral circulation is critically important as an adaptation of the heart to prevent the damage from ischemic insults. In their native state, collaterals in the heart would be classified as part of the microcirculation, existing as arterial-arterial anastomotic connections in the range of 30 to 100 μM in diameter. However, these vessels also show a propensity to remodel into components of the macrocirculation and can become arteries larger than a 1000 μM in diameter. This process of outward remodelling is critically important in the adaptation of the heart to ischemia because the resistance to blood flow is inversely related to the fourth power of the diameter of the vessel. Thus, an expansion of a vessel from 100 to 1000 μM would reduce resistance (in this part of the circuit) to a negligible amount and enable delivery of flow to the region at risk. Our goal in this review is to highlight the voids in understanding this adaptation to ischemia—the growth of the coronary collateral circulation. In doing so we discuss the controversies and unknown aspects of the causal factors that stimulate growth of the collateral circulation, the role of genetics, and the role of endogenous stem and progenitor cells in the context of the normal, physiological situation and under more pathological conditions of ischemic heart disease or with some of the underlying risk factors, e.g., diabetes. The major conclusion of this review is that there are many gaps in our knowledge of coronary collateral growth and this knowledge is critical before the potential of stimulating collateralization in the hearts of patients can be realized. PMID:22210280

High rebleeding risk associated with choroidal collateral vessels in hemorrhagic moyamoya disease: analysis of a nonsurgical cohort in the Japan Adult Moyamoya Trial.

Science.gov (United States)

Funaki, Takeshi; Takahashi, Jun C; Houkin, Kiyohiro; Kuroda, Satoshi; Takeuchi, Shigekazu; Fujimura, Miki; Tomata, Yasutake; Miyamoto, Susumu

2018-03-02

OBJECTIVE Choroidal collateral vessels typical of moyamoya disease have received attention as a potential bleeding source. The authors' previous angiographic cross-sectional analysis suggested a possible association between choroidal collaterals and posterior hemorrhage, indicating a high risk for rebleeding. The present longitudinal analysis is intended to determine whether choroidal collaterals are a predictor of rebleeding in hemorrhagic moyamoya disease. METHODS The Japan Adult Moyamoya Trial group designed an ancillary cohort study using 5-year follow-up data on 37 patients included in the nonsurgical arm of the original randomized controlled trial and compared the rebleeding rate of those with and those without choroidal collaterals, represented by the connection between the anterior or posterior choroidal arteries and the medullary arteries. An expert panel determined whether a choroidal collateral was present in each patient through the measurement of baseline angiography studies. The rebleeding rate comparison was adjusted for age, diagnosis of hypertension, and involvement of the posterior cerebral artery. RESULTS Choroidal collaterals were present in 21 patients (56.8%). The rebleeding rate was 13.1% per year in the collateral-positive group as compared with 1.3% in the negative group (p = 0.008, log-rank test). The adjusted hazard ratio for rebleeding in the collateral-positive group relative to the negative group remained statistically significant (HR 11.10, 95% CI 1.37-89.91). Radiographic assessment of the collateral-positive group revealed good correspondence between the distribution of collaterals and rebleeding sites. CONCLUSIONS Results of this study suggest that choroidal collaterals are a bleeding source with a high risk for hemorrhagic recurrence and a predictor of rebleeding in hemorrhagic moyamoya disease.

Ketanserin effect on limb perfusion and arterial collaterals

International Nuclear Information System (INIS)

Grassi, C.J.; Janicek, M.; Hollenberg, N.K.; Meyerovitz, M.F.; Harrington, D.P.

1987-01-01

Arterial collateral flow and major vessel patency are important in patients with intermittent claudication. Activity of serotonin released from platelets has been demonstrated experimentally, and serotonin antagonists have been investigated in treadmill testing. Ketanserin, a serotonin (5-HT/sup 2/) antagonist, was investigated in 20 patients with intermittent claudication to assess its effect on collaterals. Blood-pressure ratio (thigh/arm), mercury-strain gauge plethysmography, Doppler pressures, and repeat arteriography were performed. Ketanserin (3-30 μg/kg IA) increased collateral vessel size on angiography in 12 patients (60%) and increased blood-flow ratio and plethysmogrpahy pressures on average. These observations, confirming clinical studies that some patients show a dramatic response and others do not, might prove useful in identifying patients who will respond to ketanserin for occlusive vascular disease

The dynamics of the coronary collateral circulation.

Science.gov (United States)

Zimarino, Marco; D'Andreamatteo, Mariangela; Waksman, Ron; Epstein, Stephen E; De Caterina, Raffaele

2014-04-01

Coronary collaterals are present at birth, with wide interindividual variation in their functional capacity. These vessels protect jeopardized myocardium, and the number of collaterals and the extent of their coverage are associated with improved survival in patients with coronary heart disease. The collateral circulation is not a permanent set of structures, but undergoes dynamic changes with important consequences for cardioprotection. If a severe atherosclerotic lesion develops in an artery supplying tissue downstream of a total occlusion through collateral blood flow, pressure gradients across the collateral bed change. The result is that some of the collateral flow previously supplying the perfusion territory of the totally occluded artery is redirected to the perfusion territory of the donor artery, thus producing a 'collateral steal'. The collateral circulation can regress once antegrade flow in the main dependent artery is re-established, as occurs following the recanalization of a chronic total occlusion. The clinical benefits of coronary revascularization must be cautiously weighed against the risk of reducing the protective support derived from coronary collaterals. Consequently, pharmacological, gene-based, and cell-based therapeutic attempts have been made to enhance collateral function. Although such approaches have so far yielded no, or modest, beneficial results, the rapidly accruing data on coronary collateral circulation will hopefully lead to new effective therapeutic strategies.

The association between circulating endothelial progenitor cells and coronary collateral formation.

Science.gov (United States)

Tokgözoğlu, Lale; Yorgun, Hikmet; Gürses, Kadri Murat; Canpolat, Uğur; Ateş, Ahmet Hakan; Tülümen, Erol; Kaya, Ergün Barış; Aytemir, Kudret; Kabakçı, Giray; Tuncer, Murat; Oto, Ali

2011-12-01

We investigated the relationship between coronary collateral formation and circulating endothelial progenitor cells (EPC) in patients undergoing coronary angiography. Circulating CD133(+)/34(+) and CD34(+)/KDR(+) EPCs were determined in 68 patients (normal coronary vessels in 24 patients and coronary artery disease (CAD) in 44 patients) (age: 58.7 ± 10.1, 64.7% male). Circulating EPCs were higher among patients with normal coronary vessels compared to patients with CAD for CD133(+)/34(+) (p collateral formation (p collateral formation after adjustment for other cardiovascular risk factors and extent of CAD (p = 0.037). In patients with severe coronary stenosis, those with increased circulating EPCs had better collateral formation compared to those with lower EPC counts. Our findings implicate that in addition to presence of critical stenosis, intact response of bone marrow is necessary for collateral formation in CAD. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Persistence of recruitable coronary collaterals in the absence of coronary vasospasm in a patient with variant angina

International Nuclear Information System (INIS)

Yamashita, Kazuhito; Takeuchi, Masaaki; Nakashima, Yasuhide

1998-01-01

Recruitable coronary collaterals may appear when spasm suddenly occludes the coronary artery. We report a patient with variant angina who had visible collateral vessels on a control coronary angiogram, despite the presence of normally appearing coronary arteries. These collaterals disappeared after intracoronary administration of nitroglycerin. These findings suggest that recruitable collateral vessels can remain patent long after spontaneous attacks of angina have resolved, and become visible when there is a pressure difference between two small coronary arteries.

Persistence of Recruitable Coronary Collaterals in the Absence of Coronary Vasospasm in a Patient with Variant Angina

International Nuclear Information System (INIS)

Yamashita, Kazuhito; Takeuchi, Masaaki; Nakashima, Yasuhide

1998-01-01

Recruitable coronary collaterals may appear when spasm suddenly occludes the coronary artery. We report a patient with variant angina who had visible collateral vessels on a control coronary angiogram, despite the presence of normally appearing coronary arteries. These collaterals disappeared after intracoronary administration of nitroglycerin. These findings suggest that recruitable collateral vessels can remain patent long after spontaneous attacks of angina have resolved, and become visible when there is a pressure difference between two small coronary arteries

Effective collateral circulation may indicate improved perfusion territory restoration after carotid endarterectomy.

Science.gov (United States)

Lin, Tianye; Lai, Zhichao; Lv, Yuelei; Qu, Jianxun; Zuo, Zhentao; You, Hui; Wu, Bing; Hou, Bo; Liu, Changwei; Feng, Feng

2018-02-01

To investigate the relationship between the level of collateral circulation and perfusion territory normalisation after carotid endarterectomy (CEA). This study enrolled 22 patients with severe carotid stenosis that underwent CEA and 54 volunteers without significant carotid stenosis. All patients were scanned with ASL and t-ASL within 1 month before and 1 week after CEA. Collateral circulation was assessed on preoperative ASL images based on the presence of ATA. The postoperative flow territories were considered as back to normal if they conformed to the perfusion territory map in a healthy population. Neuropsychological tests were performed on patients before and within 7 days after surgery. ATA-based collateral score assessed on preoperative ASL was significantly higher in the flow territory normalisation group (n=11, 50 %) after CEA (P mean differences+2SD among control (MMSE=1.35, MOCA=1.02)]. This study demonstrated that effective collateral flow in carotid stenosis patients was associated with normalisation of t-ASL perfusion territory after CEA. The perfusion territory normalisation group tends to have more cognitive improvement after CEA. • Evaluation of collaterals before CEA is helpful for avoiding ischaemia during clamping. • There was good agreement on ATA-based ASL collateral grading. • Perfusion territories in carotid stenosis patients are altered. • Patients have better collateral circulation with perfusion territory back to normal. • MMSE and MOCA test scores improved more in the territory normalisation group.

CT imaging of collaterals in stenoses of large mediastinal veins

International Nuclear Information System (INIS)

Goerich, J.; Flentje, M.; Gueckel, F.; Beyer-Enke, S.A.; Kaick, G. van; Heidelberg Univ.

1988-01-01

Scans of angio-computed tomography (CT) of 53 patients suffering from mediastinal space-occupying growths were reviewed: 16 patients showed stenosis of mediastinal veins with demonstration of subcutaneous venous channels, 17 showed an obstruction without collateral pathways and 20 patients had normal mediastinal vessels. Two thirds of the cases with external vein compression were caused by bronchogenic carcinoma. The degree of obstruction in patients showing collateral circulation was between 70 and 100 percent and significantly greater than in patients without collaterals (40%). The most important collaterals bypassing the upper mediastinal veins are discussed. (orig.) [de

Collateral blood flow in different cerebrovascular hierarchy provides endogenous protection in cerebral ischemia.

Science.gov (United States)

Luo, Chuanming; Liang, Fengyin; Ren, Huixia; Yao, Xiaoli; Liu, Qiang; Li, Mingyue; Qin, Dajiang; Yuan, Ti-Fei; Pei, Zhong; Su, Huanxing

2017-11-01

Collateral blood flow as vascular adaptions to focal cerebral ischemia is well recognized. However, few studies directly investigate the dynamics of collateral vessel recruitment in vivo and little is known about the effect of collateral blood flow in different cerebrovascular hierarchy on the neuropathology after focal ischemic stroke. Here, we report that collateral blood flow is critically involved in blood vessel compensations following regional ischemia. We occluded a pial arteriole using femtosecond laser ablating under the intact thinned skull and documented the changes of collateral flow around the surface communication network and between the surface communication network and subsurface microcirculation network using in vivo two photon microscopy imaging. Occlusion of the pial arteriole apparently increased the diameter and collateral blood flow of its leptomeningeal anastomoses, which significantly reduced the cortical infarction size. This result suggests that the collateral flow via surface communicating network connected with leptomeningeal anastomoses could greatly impact on the extent of infarction. We then further occluded the target pial arteriole and all of its leptomeningeal anastomoses. Notably, this type of occlusion led to reversals of blood flow in the penetrating arterioles mainly proximal to the occluded pial arteriole in a direction from the subsurface microcirculation network to surface arterioles. Interesting, the cell death in the area of ischemic penumbra was accelerated when we performed occlusion to cease the reversed blood flow in those penetrating arterioles, suggesting that the collateral blood flow from subsurface microcirculation network exerts protective roles in delaying cell death in the ischemic penumbra. In conclusion, we provide the first experimental evidence that collateral blood vessels at different cerebrovascular hierarchy are endogenously compensatory mechanisms in brain ischemia. © 2016 International Society of

Clinical, angiographic and hemodynamic predictors of recruitable collateral flow assessed during balloon angioplasty coronary occlusion

NARCIS (Netherlands)

Piek, J. J.; van Liebergen, R. A.; Koch, K. T.; Peters, R. J.; David, G. K.

1997-01-01

We sought to determine the predictive value of factors influencing coronary collateral vascular responses in humans. There is limited information on the factors responsible for coronary collateral vascular development, despite the protective effect of collateral vessels in ischemic syndromes.

Decreased perfusion in myocardial region of normal donor artery secondary to collateral development

International Nuclear Information System (INIS)

Koga, Y.; Takahashi, M.; Kojima, A.; Takaki, Y.; Tomiguchi, S.; Hirota, Y.; Kugiyama, K.; Yasue, H.; Hayasaki, K.; Kumamoto Saiseikai Hospital

1992-01-01

Thirty-one patients suffering from single vessel exertional angina with collaterals (Group A) were evaluated by stress 201 Tl myocardial emission CT (Tl-SPECT) with 16 controls of severely stenotic single vessel exertional angina without collaterals (Group B). Group A included 21 patients (68%) who showed an extensive perfusion defect in double artery myocardial regions, including the normal donor artery myocardial region (DMR). However, there were no such cases in Group B, giving a significant difference between these 2 groups (p < 0.001). Four patients in Group A, having a perfusion defect both in DMR and in the collateral dependent myocardial region (CMR) underwent a successful percutaneous transluminal coronary angioplasty (PTCA) with disappearance of collaterals. Tl-SPECT findings after PTCA showed no perfusion defect either in CMR or in DMR. This has been explained on the basis that the coronary collaterals stole blood and produced perfusion defect in DMR. (orig.)

Coronary Collateral Growth—Back to the Future

OpenAIRE

Chilian, William M.; Penn, Marc S.; Pung, Yuh Fen; Dong, Feng; Mayorga, Maritza; Ohanyan, Vahagn; Logan, Suzanna; Yin, Liya

2011-01-01

The coronary collateral circulation is critically important as an adaptation of the heart to prevent the damage from ischemic insults. In their native state, collaterals in the heart would be classified as part of the microcirculation, existing as arterial-arterial anastomotic connections in the range of 30 to 100 μM in diameter. However, these vessels also show a propensity to remodel into components of the macrocirculation and can become arteries larger than a 1000 μM in diameter. This proc...

Stenting of the Superior Mesenteric Artery as a Preoperative Treatment for Total Pancreatectomy

International Nuclear Information System (INIS)

Tanigawa, Noboru; Kariya, Shuji; Komemushi, Atsushi; Satoi, Sohei; Kamiyama, Yasuo; Sawada, Satoshi; Kojima, Hiroyuki; Sougawa, Mitsuharu; Takai, Yuichirou

2004-01-01

The patient was a 58-year-old male with mucinous cyst adenocarcinoma of the pancreas. Prior to total pancreatectomy, preoperative CT and angiography showed a high-grade arteriosclerotic stenosis of about 1.0 cm in length in the ostium of the superior mesenteric artery (SMA), as well as the development of collateral vessels in the area around the head of the pancreas. A stent was placed in the SMA stenosis to preserve the intestinal blood flow in the SMA region after total pancreatectomy, which was performed 25 days after stent placement. The postoperative SMA blood flow was favorable, with no postoperative intestinal ischemia, and the patient had an uneventful postoperative course

Histomorphological changes of vessel structure in head and neck vessels following preoperative or postoperative radiotherapy

International Nuclear Information System (INIS)

Schultze-Mosgau, S.; Wehrhan, F.; Wiltfang, J.; Grabenbauer, G.G.; Sauer, R.; Roedel, F.; Radespiel-Troeger, M.

2002-01-01

Patients and Methods: In 348 patients (October 1995-March 2002) receiving primarly or secondarily 356 microvascular hard- and soft tissue reconstruction, a total of 209 vessels were obtained from neck recipient vessels and transplant vessels during anastomosis. Three groups were analysed: group 1 (27 patients) treated with no radiotherapy or chemotherapy; group 2 (29 patients) treated with preoperative irradiation (40-50 Gy) and chemotherapy (800 mg/m 2 /day 5-FU and 20 mg/m 2 /day cisplatin) 1.5 months prior to surgery; group 3 (20 patients) treated with radiotherapy (60-70 Gy) (median interval 78.7 months; IQR: 31.3 months) prior to surgery. From each of the 209 vessel specimens, 3 sections were investigated histomorphometrically, qualitatively and quantitatively (ratio media area/total vessel area) by NIH-Image-digitized measurements. To evaluate these changes as a function of age, radiation dose and chemotherapy, a statistical analysis was performed using an analysis of covariance and χ 2 tests (p > 0.05, SPSS V10). Results: In group 3, qualitative changes (intima dehiscence, hyalinosis) were found in recipient arteries significantly more frequently than in groups 1 and 2. For group 3 recipient arteries, histomorphometry revealed a significant decrease in the ratio media area/total vessel area (median 0.51, IQR 0.10) in comparison with groups 1 (p = 0.02) (median 0.61, IQR 0.29) and 2 (p = 0.046) (median 0.58, IQR 0.19). No significant difference was found between the vessels of groups 1 and 2 (p = 0.48). There were no significant differences in transplant arteries and recipient or transplant veins between the groups. Age and chemotherapy did not appear to have a significant influence on vessel changes in this study (p > 0.05). Conclusions: Following irradiation with 60-70 Gy, significant qualitative and quantitative histological changes to the recipient arteries, but not to the recipient veins, could be observed. In contrast, irradiation at a dose of 40-50 Gy

Insights into coronary collateral formation from a novel porcine semiacute infarction model.

Science.gov (United States)

Krackhardt, Florian; Harnoss, Jonathan M; Waliszewski, Matthias W; Ritter, Zully; Granzow, Susanne; Felsenberg, Dieter; Neumann, Konrad; Lerman, Lilian O; Hillmeister, Philipp; Gebker, Rolf; Paetsch, Ingo; Riediger, Fabian; Bramlage, Peter; Buschmann, Ivo R

2018-03-01

For patients with severe ischemic heart disease, complete revascularization by a percutaneous coronary intervention or coronary artery bypass grafting is often not achieved and may still cause residual angina. In case of progressive coronary artery occlusions, therapeutic arteriogenesis constitutes a promising strategy for increasing blood supply to the ischemic myocardium. Whether the formation of collaterals in the hypofused myocardium is angiogenetic in nature or based on preformed coronary artery anastomoses remains debatable. The objectives of this research were (i) the development of an appropriate research methodology to study a humanoid animal semiacute infarction model with low mortality and (ii) to answer the question of whether collateral revascularization follows a pre-existing 'blueprint'. A porcine model was chosen in which a step-wise vessel occlusion was performed by implantation of a copper stent into the distal left anterior descending artery. Vessel occlusion and collateral development were confirmed in vivo every 14 days up to day 56 by repeated coronary angiography and myocardial perfusion measurement using cardiac MRI. After the completion of the in-vivo imaging studies, animals were euthanized and collateral growth was evaluated using microcomputer tomography. Our porcine model of semiacute noninvasive coronary artery occlusion confirmed the existence of preformed coronary anastomoses and the proliferation of functional vessels in hypoperfused myocardium. Repetitive intra-animal MRIs showed the functional impact of these growing collaterals. The confirmation of preformed coronary anastomoses during the process of collateralization (natural bypasses) offers a preclinical avenue to carry out arteriogenetic pharmaceutical research in patients with ischemic heart disease.

Innate collateral segments are predominantly present in the subendocardium without preferential connectivity within the left ventricular wall

Science.gov (United States)

van Horssen, Pepijn; Siebes, Maria; Spaan, Jos A E; Hoefer, Imo E; van den Wijngaard, Jeroen P H M

2014-01-01

Functional collateral vessels often stem from outward remodelling of pre-existing connections between perfusion territories. Knowledge of the distribution and morphology of innate collateral connections may help in identifying myocardial areas with protection against risk for ischaemia. The coronary network of six healthy canine hearts was investigated with an imaging cryomicrotome. Innate collateral connections ranged from 286 to 1015 μm in diameter. Left ventricular collateral density (number per gram of tissue) was about five in the subendocardium vs. 2.5 in the mid-myocardium (P collateral connections were oriented parallel to the long axis of the heart. For the major coronary arteries, five times more intracoronary than intercoronary connections were found, while their median diameter and interquartile range were not significantly different, at 96.1 (16.9) vs. 94.7 (18.9) μm. Collateral vessels connecting crowns from sister branches from a stem are denoted intercrown connections and those within crowns intracrown connections. The number of intercrown connections was related to the mean tissue weight of the crowns (y = 0.73x − 0.33, r2 = 0.85, P collateral diameter and length were independent of the tissue volumes bridged. We conclude that connectivity and morphology of the innate collateral network are distributed with no preference for intra-or intercrown connections, independent of stem diameter, including epicardial arteries. This renders all sites of the myocardium equally protected in case of coronary artery disease. The orientation of subendocardial collateral vessels indicates the longitudinal direction of subendocardial collateral flow. PMID:24366260

Innate collateral segments are predominantly present in the subendocardium without preferential connectivity within the left ventricular wall.

Science.gov (United States)

van Horssen, Pepijn; Siebes, Maria; Spaan, Jos A E; Hoefer, Imo E; van den Wijngaard, Jeroen P H M

2014-03-01

Functional collateral vessels often stem from outward remodelling of pre-existing connections between perfusion territories. Knowledge of the distribution and morphology of innate collateral connections may help in identifying myocardial areas with protection against risk for ischaemia. The coronary network of six healthy canine hearts was investigated with an imaging cryomicrotome. Innate collateral connections ranged from 286 to 1015 μm in diameter. Left ventricular collateral density (number per gram of tissue) was about five in the subendocardium vs. 2.5 in the mid-myocardium (P collateral connections were oriented parallel to the long axis of the heart. For the major coronary arteries, five times more intracoronary than intercoronary connections were found, while their median diameter and interquartile range were not significantly different, at 96.1 (16.9) vs. 94.7 (18.9) μm. Collateral vessels connecting crowns from sister branches from a stem are denoted intercrown connections and those within crowns intracrown connections. The number of intercrown connections was related to the mean tissue weight of the crowns (y = 0.73x - 0.33, r2 = 0.85, P collateral diameter and length were independent of the tissue volumes bridged. We conclude that connectivity and morphology of the innate collateral network are distributed with no preference for intra- or intercrown connections, independent of stem diameter, including epicardial arteries. This renders all sites of the myocardium equally protected in case of coronary artery disease. The orientation of subendocardial collateral vessels indicates the longitudinal direction of subendocardial collateral flow.

The human coronary collateral circulation: development and clinical importance.

Science.gov (United States)

Seiler, Christian; Stoller, Michael; Pitt, Bertram; Meier, Pascal

2013-09-01

Coronary collaterals are an alternative source of blood supply to myocardium jeopardized by ischaemia. In comparison with other species, the human coronary collateral circulation is very well developed. Among individuals without coronary artery disease (CAD), there are preformed collateral arteries preventing myocardial ischaemia during a brief vascular occlusion in 20-25%. Determinants of such anastomoses are low heart rate and the absence of systemic arterial hypertension. In patients with CAD, collateral arteries preventing myocardial ischaemia during a brief occlusion are present in every third individual. Collateral flow sufficient to prevent myocardial ischaemia during coronary occlusion amounts to one-fifth to one-fourth the normal flow through the open vessel. Myocardial infarct size, the most important prognostic determinant after such an event, is the product of coronary artery occlusion time, area at risk for infarction, and the inverse of collateral supply. Well-developed coronary collateral arteries in patients with CAD mitigate myocardial infarcts and improve survival. Approximately one-fifth of patients with CAD cannot be revascularized by percutaneous coronary intervention or coronary artery bypass grafting. Therapeutic promotion of collateral growth is a valuable treatment strategy in those patients. It should aim at growth of large conductive collateral arteries (arteriogenesis). Potential arteriogenic approaches include the treatment with granulocyte colony-stimulating factor, physical exercise training, and external counterpulsation.

Stimulation of collateral artery growth: travelling further down the road to clinical application

NARCIS (Netherlands)

Schirmer, S. H.; van Nooijen, F. C.; Piek, J. J.; van Royen, N.

2009-01-01

Collateral artery growth is a potent natural defence mechanism to prevent death and myocardial infarction in occlusive artery disease. Given the high prevalence of arterial obstructive disease, a therapeutic compound stimulating collateral vessel growth could have a major impact on morbidity and

Leptomeningeal collateral status predicts outcome after middle cerebral artery occlusion

DEFF Research Database (Denmark)

Madelung, Christopher Fugl; Ovesen, C; Trampedach, C

2017-01-01

NCCT and according to European Cooperative Acute Stroke Study (ECASS) criteria. Modified Rankin Scale score was assessed at 90 days, and mortality at 1 year. RESULTS: At 90 days, median (IQR) modified Rankin Scale score in patients with poor collateral status was 4 (3-6) compared to 2 (1-4) in patients...... population (P = .001). CONCLUSIONS: Leptomeningeal collateral status predicts functional outcome, mortality, and hemorrhagic transformation following middle cerebral artery occlusion.......OBJECTIVES: Perfusion through leptomeningeal collateral vessels is a likely pivotal factor in the outcome of stroke patients. We aimed to investigate the effect of collateral status on outcome in a cohort of unselected, consecutive stroke patients with middle cerebral artery occlusion undergoing...

Quantification of collateral flow in humans: a comparison of angiographic, electrocardiographic and hemodynamic variables

NARCIS (Netherlands)

van Liebergen, R. A.; Piek, J. J.; Koch, K. T.; de Winter, R. J.; Schotborgh, C. E.; Lie, K. I.

1999-01-01

Evaluation of collateral vascular circulation according to hemodynamic variables and its relation to myocardial ischemia. There is limited information regarding the hemodynamic quantification of recruitable collateral vessels. Angiography of the donor coronary artery was performed before and during

Functional significance of coronary collateral circulation during dynamic exercise evaluated by thallium-201 myocardial scintigraphy

International Nuclear Information System (INIS)

Wainwright, R.J.; Maisey, M.N.; Edwards, A.C.; Sowton, E.

1980-01-01

Sixty-five patients with angiographically documented coronary artery disease were investigated by thallium-201 ( 201 Tl) scintigraphy to determine the role of the collateral circulation during dynamic exercise. Fifty-three patients had complete proximal occlusion of at least one major coronary artery. One patient had total occlusion of all three major coronary arteries. Sixty-four collateral channels were identified, graded, and compared with corresponding regions of the myocardial scintigram. Tracer uptake was also graded and classified as various degrees of protection from ischaemia. A significant correlation between good collaterals with complete protection and poor or absent collaterals with no protection was noted. Seventeen patients (20 occluded vessels) had total coronary occlusion without myocardial infarction. Collaterals conferred protection in 9/15 occlusions whereas no protection was seen in five occlusions without collaterals. There was no difference in the protective role of homocoronary and heterocoronary collateral vessels. Hypertrophy of the first septal left anterior descending perforator conferred significant protection from ischaemia in contrast to bridging collaterals and ghosting. During exercise the right coronary bed is preferentially protected from ischaemia, in contrast to the left anterior descending territory. This probably reflects the direction of a transmural flow gradient between left and right ventricles during exercise. (author)

Effect of nitroglycerin on myocardial collateral conductance in awake dogs

International Nuclear Information System (INIS)

Brazzamano, S.; Rembert, J.C.; Greenfield, J.C. Jr.

1988-01-01

Conductance of the coronary collateral circulation during the course of two abrupt circumflex coronary occlusions was measured in awake dogs ∼ 2 wk after collateral vessels were stimulated to develop. The pressure gradient from the central aorta to the distal circumflex coronary artery was measured, and myocardial blood flow was determined by 9-μm radioactive microspheres at 30 s and 4 min after coronary occlusions. Collateral conductance was calculated as mean collateral blood flow divided by the mean aorta-coronary pressure gradient. Before nitroglycerin, collateral conductance increased in all eight dogs from 30 s to 4 min. After nitroglycerin administration, the conductance at 30 s increased from the prenitroglycerin control value to 0.014 ± 0.012 ml·min -1 ·g -1 ·mmHg -1 . The mean change in conductance from 30 s to 4 min postnitroglycerin was significantly less than during prenitroglycerin. These data indicate that an increase in conductance during coronary occlusion occurs even in the immature collateral circulation. This effect presumably takes place in the arterial smooth muscle at the origin of the collateral vasculature

Relationship between collateral circulation and myocardial viability of 18F-FDG PET/CT subtended by chronic total occluded coronary arteries.

Science.gov (United States)

Dong, Wei; Li, Jianan; Mi, Hongzhi; Song, Xiantao; Jiao, Jian; Li, Quan

2018-04-01

To analyze the relationship between the collateral flow of coronary chronic total occlusion (CTO) and myocardial viability detected by 18 F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging. A prospective analysis of 104 patients diagnosed by coronary angiography. All patients underwent resting myocardial perfusion imaging and PET/CT within 1 week. The collateral circulation was graded with Rentrop classification as no or poor collateral circulation in 16 CTO vessels, moderate collateral circulation in 34 CTO vessels, and good collateral circulation in 69 CTO vessels. Myocardial viability was determined with myocardial perfusion imaging and PET. The patterns were interpreted as mismatch, match and normal perfusion and 18 F-FDG uptake. There was no significant correlation between the severity and extent of perfusion defect, myocardial viability and collateral circulation grade. The myocardial viability was normal in mild and moderate hypokinetic regions and decreased in severe hypokinetic and akinesis-dyskinesis regions. The presence of collateral circulation was a sensitive (89%) but not a specific (31%) sign of myocardial viability. In patients with CTO, collateral circulation does not seem to be an effective way for predicting myocardial viability. Further analysis of PET patterns of viable myocardium is needed to guide further revascularization and predict functional improvement and survival benefit.

The role of VEGF and KDR polymorphisms in moyamoya disease and collateral revascularization.

Directory of Open Access Journals (Sweden)

Young Seok Park

Full Text Available We conducted a case-control study to investigate whether vascular endothelial growth factor (VEGF -2578, -1154, -634, and 936 and kinase insert domain containing receptor (KDR -604, 1192, and 1719 polymorphisms are associated with moyamoya disease. Korean patients with moyamoya disease (n = 107, mean age, 20.9±15.9 years; 66.4% female and 243 healthy control subjects (mean age, 23.0±16.1 years; 56.8% female were included. The subjects were divided into pediatric and adult groups. Among the 64 surgical patients, we evaluated collateral vessel formation after 2 years and divided patients into good (collateral grade A or poor (collateral grade B and C groups. The frequencies and distributions of four VEGF (-2578, -1154, -634, and 936 and KDR (-604, 1192, and 1719 polymorphisms were assessed from patients with moyamoya disease and compared to the control group. No differences were observed in VEGF -2578, -1154, -634, and 936 or KDR -604, 1192, and 1719 polymorphisms between the control group and moyamoya disease group. However, we found the -634CC genotype occurred less frequently in the pediatric moyamoya group (p = 0.040 whereas the KDR -604C/1192A/1719T haplotype increased the risk of pediatric moyamoya (p = 0.024. Patients with the CC genotype of VEGF -634 had better collateral vessel formation after surgery. Our results suggest that the VEGF -634G allele is associated with pediatric moyamoya disease and poor collateral vessel formation.

Collateral Function in Patients with Coronary Occlusion Evaluated by 201Thallium Scintigraphy

Directory of Open Access Journals (Sweden)

Aida Hasanović

2008-11-01

Full Text Available The present study evaluated the impact of the angiographically documented collaterals on regional myocardial perfusion measured by 201thallium scintigraphy in patients with a chronic total occlusion.The study included 60 patients with chronic total occlusion who underwent rest-stress myocardial perfusion scintigraphy and coronary angiography. All patients had angiographic evidence of coronary collaterals. Patients were divided into two groups: group one had well-developed coronary collateral vessels (n=35 and group II had poor coronary collateral development (n=25.Patients with chronic total occlusion had severe and extensive stress-induced myocardial perfusion defects regardless of the grade of angiographic coronary collaterals. The perfusion defects in the group with good collaterals were predominantly reversible, suggesting that coronary collaterals preserved myocardial viability in the regions subtended by a total coronary occlusion. A significant correlation between good collaterals with complete protection and poor collaterals with no protection was noted.Our results demonstrate a protective effect of collaterals on myocardial perfusion during coronary occlusion. The effective angiographic collaterals may prevent resting regional wall motion abnormalities but do not appear to protect against stress-induced perfusion defect.

Acute development of collateral circulation and therapeutic prospects in ischemic stroke

Directory of Open Access Journals (Sweden)

Eri Iwasawa

2016-01-01

Full Text Available In acute ischemic stroke, collateral circulation plays an important role in maintaining blood flow to the tissue that is at risk of progressing into ischemia, and in increasing the successful recanalization rate without hemorrhagic transformation. We have reported that well-developed collateral circulation is associated with smaller infarct volume and better long-term neurological outcome, and it disappears promptly once the effective recanalization is achieved. Contrary to the belief that collateral vessels develop over time in chronic stenotic condition, there exists a phenomenon that collateral circulation develops immediately in acute stenosis or occlusion of the arteries and it seems to be triggered by fluid shear stress, which occurs between the territories of stenotic/occluded arteries and those fed by surrounding intact arteries. We believe that this acute development of collateral circulation is a target of novel therapeutics in ischemic stroke and refer our recent attempt in enhancing collateral circulation by modulating sphingosine-1-phosphate receptor 1, which is a known shear-stress mechanosensing protein.

Acute development of collateral circulation and therapeutic prospects in ischemic stroke.

Science.gov (United States)

Iwasawa, Eri; Ichijo, Masahiko; Ishibashi, Satoru; Yokota, Takanori

2016-03-01

In acute ischemic stroke, collateral circulation plays an important role in maintaining blood flow to the tissue that is at risk of progressing into ischemia, and in increasing the successful recanalization rate without hemorrhagic transformation. We have reported that well-developed collateral circulation is associated with smaller infarct volume and better long-term neurological outcome, and it disappears promptly once the effective recanalization is achieved. Contrary to the belief that collateral vessels develop over time in chronic stenotic condition, there exists a phenomenon that collateral circulation develops immediately in acute stenosis or occlusion of the arteries and it seems to be triggered by fluid shear stress, which occurs between the territories of stenotic/occluded arteries and those fed by surrounding intact arteries. We believe that this acute development of collateral circulation is a target of novel therapeutics in ischemic stroke and refer our recent attempt in enhancing collateral circulation by modulating sphingosine-1-phosphate receptor 1, which is a known shear-stress mechanosensing protein.

Acute development of collateral circulation and therapeutic prospects in ischemic stroke

Institute of Scientific and Technical Information of China (English)

Eri Iwasawa; Masahiko Ichijo; Satoru Ishibashi; Takanori Yokota

2016-01-01

In acute ischemic stroke, collateral circulation plays an important role in maintaining blood lfow to the tissue that is at risk of progressing into ischemia, and in increasing the successful recanalization rate with-out hemorrhagic transformation. We have reported that well-developed collateral circulation is associated with smaller infarct volume and better long-term neurological outcome, and it disappears promptly once the effective recanalization is achieved. Contrary to the belief that collateral vessels develop over time in chronic stenotic condition, there exists a phenomenon that collateral circulation develops immediately in acute stenosis or occlusion of the arteries and it seems to be triggered by lfuid shear stress, which occurs be-tween the territories of stenotic/occluded arteries and those fed by surrounding intact arteries. We believe that this acute development of collateral circulation is a target of novel therapeutics in ischemic stroke and refer our recent attempt in enhancing collateral circulation by modulating sphingosine-1-phosphate recep-tor 1, which is a known shear-stress mechanosensing protein.

Association between neutrophil/lymphocyte ratio and coronary collateral circulation

Directory of Open Access Journals (Sweden)

Mustafa Oylumlu

2012-03-01

Full Text Available Objectives: To investigate relation between neutrophil/lymphocyte ratio and coronary collateral flow.Material and methods: Eighty-two patients admittedDicle University Medical Faculty Hospital Cardiology Departmentwith diagnosis of coronary artery disease anddetected significant stenosis or occlusion at least one ofthe coronary arteries, were included to study. Age, sex,presence of diabetes mellitus and hypertension, acute/stable coronary disease, body mass index, neutrophil/lymphocyte ratio, white blood count, Rentrop scores andnumber of diseased vessel were recorded.Results: Well-developed coronary collateral circulationwas found in 33 of the patients. Forty-nine patients hadpoor coronary collateral circulation. Mean age, sex, bodymass index, presence of diabetes mellitus and hypertensionwere similar in two groups. Mean neutrophil/lymphocyteratio was lower in well-developed coronary collateralcirculation group than poor coronary collateral circulationgroup, but there was no significant differences (2.78 vs2.89, p=0.12.Conclusions: There was no association between neutron/hil lymphocyte ratio and coronary collateral circulationaccording to our data. J Clin Exp Invest 2012; 3(1:29-32

Studies on intracranial collateral circulation with multi-slice CT angiography in patients with symptomatic cerebral artery stenosis

Directory of Open Access Journals (Sweden)

Shu-qing ZHOU

2011-06-01

Full Text Available Objective To explore the features of intracranial collateral circulation in patients with symptomatic cerebral artery stenosis.Method Ninety-four patients with ischemic cerebrovascular disease admitted from Apr.2004 to Jun.2009 were involved in present study.All the patients were examined with cerebral multi-slice CT angiography,and the features of cerebral artery stenosis and intracranial collateral circulation were evaluated using maximum intensity projection(MIP and volume rendering(VR images of CT angiography.Result Of the 94 patients involved,48 were diagnosed as cerebral artery stenosis,including 29 cases of cerebral infarction,18 of transient ischemic attack(TIA and 1 of moyamoya disease(MMD.Among the 14 cases of severe cerebral artery stenosis or occlusion,cerebral infarction was found in 6 cases with lesser intracranial collateral vessels(including massive cerebral infarction in 4 cases and watershed infarction in 2 cases,and focal infarction of central semi-ovale in 1 case and TIA in 7 cases were found with abundant intracranial collateral vessels.Multiple lacunar infarction was found in 22 cases of mild or moderate cerebral artery stenosis,but there was no significant correlation between the stenosed arteries and infarction sites.Abundant intracranial collateral vessels were found in one patient with Moyamoya disease but no infarction was observed.Conclusions Intracranial collateral circulation plays an important role of compensation in patients with severe cerebral artery stenosis or occlusion.Cerebral angiography with multi-slice CT is of great significance in evaluation of cerebral artery stenosis and intracranial collateral circulation.

Prediction of infarction and reperfusion in stroke by flow- and volume-weighted collateral signal in MR angiography.

Science.gov (United States)

Ernst, M; Forkert, N D; Brehmer, L; Thomalla, G; Siemonsen, S; Fiehler, J; Kemmling, A

2015-02-01

In proximal anterior circulation occlusive strokes, collateral flow is essential for good outcome. Collateralized vessel intensity in TOF- and contrast-enhanced MRA is variable due to different acquisition methods. Our purpose was to quantify collateral supply by using flow-weighted signal in TOF-MRA and blood volume-weighted signal in contrast-enhanced MRA to determine each predictive contribution to tissue infarction and reperfusion. Consecutively (2009-2013), 44 stroke patients with acute proximal anterior circulation occlusion met the inclusion criteria with TOF- and contrast-enhanced MRA and penumbral imaging. Collateralized vessels in the ischemic hemisphere were assessed by TOF- and contrast-enhanced MRA using 2 methods: 1) visual 3-point collateral scoring, and 2) collateral signal quantification by an arterial atlas-based collateral index. Collateral measures were tested by receiver operating characteristic curve and logistic regression against 2 imaging end points of tissue-outcome: final infarct volume and percentage of penumbra saved. Visual collateral scores on contrast-enhanced MRA but not TOF were significantly higher in patients with good outcome. Visual collateral scoring on contrast-enhanced MRA was the best rater-based discriminator for final infarct volume 50% (area under the curve, 0.67; P = .04). Atlas-based collateral index of contrast-enhanced MRA was the overall best independent discriminator for final infarct volume of collateral index combining the signal of TOF- and contrast-enhanced MRA was the overall best discriminator for effective reperfusion (percentage of penumbra saved >50%; area under the curve, 0.89; P collateral assessment, TOF- and contrast-enhanced MRA both contain predictive signal information for penumbral reperfusion. This could improve risk stratification in further studies. © 2015 by American Journal of Neuroradiology.

Dll4-Notch signaling determines the formation of native arterial collateral networks and arterial function in mouse ischemia models.

Science.gov (United States)

Cristofaro, Brunella; Shi, Yu; Faria, Marcella; Suchting, Steven; Leroyer, Aurelie S; Trindade, Alexandre; Duarte, Antonio; Zovein, Ann C; Iruela-Arispe, M Luisa; Nih, Lina R; Kubis, Nathalie; Henrion, Daniel; Loufrani, Laurent; Todiras, Mihail; Schleifenbaum, Johanna; Gollasch, Maik; Zhuang, Zhen W; Simons, Michael; Eichmann, Anne; le Noble, Ferdinand

2013-04-01

Arteriogenesis requires growth of pre-existing arteriolar collateral networks and determines clinical outcome in arterial occlusive diseases. Factors responsible for the development of arteriolar collateral networks are poorly understood. The Notch ligand Delta-like 4 (Dll4) promotes arterial differentiation and restricts vessel branching. We hypothesized that Dll4 may act as a genetic determinant of collateral arterial networks and functional recovery in stroke and hind limb ischemia models in mice. Genetic loss- and gain-of-function approaches in mice showed that Dll4-Notch signaling restricts pial collateral artery formation by modulating arterial branching morphogenesis during embryogenesis. Adult Dll4(+/-) mice showed increased pial collateral numbers, but stroke volume upon middle cerebral artery occlusion was not reduced compared with wild-type littermates. Likewise, Dll4(+/-) mice showed reduced blood flow conductance after femoral artery occlusion, and, despite markedly increased angiogenesis, tissue ischemia was more severe. In peripheral arteries, loss of Dll4 adversely affected excitation-contraction coupling in arterial smooth muscle in response to vasopressor agents and arterial vessel wall adaption in response to increases in blood flow, collectively contributing to reduced flow reserve. We conclude that Dll4-Notch signaling modulates native collateral formation by acting on vascular branching morphogenesis during embryogenesis. Dll4 furthermore affects tissue perfusion by acting on arterial function and structure. Loss of Dll4 stimulates collateral formation and angiogenesis, but in the context of ischemic diseases such beneficial effects are overruled by adverse functional changes, demonstrating that ischemic recovery is not solely determined by collateral number but rather by vessel functionality.

Dll4-Notch signaling determines the formation of native arterial collateral networks and arterial function in mouse ischemia models

Science.gov (United States)

Cristofaro, Brunella; Shi, Yu; Faria, Marcella; Suchting, Steven; Leroyer, Aurelie S.; Trindade, Alexandre; Duarte, Antonio; Zovein, Ann C.; Iruela-Arispe, M. Luisa; Nih, Lina R.; Kubis, Nathalie; Henrion, Daniel; Loufrani, Laurent; Todiras, Mihail; Schleifenbaum, Johanna; Gollasch, Maik; Zhuang, Zhen W.; Simons, Michael; Eichmann, Anne; le Noble, Ferdinand

2013-01-01

Arteriogenesis requires growth of pre-existing arteriolar collateral networks and determines clinical outcome in arterial occlusive diseases. Factors responsible for the development of arteriolar collateral networks are poorly understood. The Notch ligand Delta-like 4 (Dll4) promotes arterial differentiation and restricts vessel branching. We hypothesized that Dll4 may act as a genetic determinant of collateral arterial networks and functional recovery in stroke and hind limb ischemia models in mice. Genetic loss- and gain-of-function approaches in mice showed that Dll4-Notch signaling restricts pial collateral artery formation by modulating arterial branching morphogenesis during embryogenesis. Adult Dll4+/- mice showed increased pial collateral numbers, but stroke volume upon middle cerebral artery occlusion was not reduced compared with wild-type littermates. Likewise, Dll4+/- mice showed reduced blood flow conductance after femoral artery occlusion, and, despite markedly increased angiogenesis, tissue ischemia was more severe. In peripheral arteries, loss of Dll4 adversely affected excitation-contraction coupling in arterial smooth muscle in response to vasopressor agents and arterial vessel wall adaption in response to increases in blood flow, collectively contributing to reduced flow reserve. We conclude that Dll4-Notch signaling modulates native collateral formation by acting on vascular branching morphogenesis during embryogenesis. Dll4 furthermore affects tissue perfusion by acting on arterial function and structure. Loss of Dll4 stimulates collateral formation and angiogenesis, but in the context of ischemic diseases such beneficial effects are overruled by adverse functional changes, demonstrating that ischemic recovery is not solely determined by collateral number but rather by vessel functionality. PMID:23533173

Internal Carotid Artery Stenosis and Collateral Recruitment in Stroke Patients.

Science.gov (United States)

Dankbaar, Jan W; Kerckhoffs, Kelly G P; Horsch, Alexander D; van der Schaaf, Irene C; Kappelle, L Jaap; Velthuis, Birgitta K

2017-04-24

Leptomeningeal collaterals improve outcome in stroke patients. There is great individual variability in their extent. Internal carotid artery (ICA) stenosis may lead to more extensive recruitment of leptomeningeal collaterals. The purpose of this study was to evaluate the association of pre-existing ICA stenosis with leptomeningeal collateral filling visualized with computed tomography perfusion (CTP). From a prospective acute ischemic stroke cohort, patients were included with an M1 middle cerebral artery (MCA) occlusion and absent ipsilateral, extracranial ICA occlusion. ICA stenosis was determined on admission CT angiography (CTA). Leptomeningeal collaterals were graded as good (>50%) or poor (≤50%) collateral filling in the affected MCA territory on CTP-derived vessel images of the admission scan. The association between ipsilateral ICA stenosis ≥70% and extent of collateral filling was analyzed using logistic regression. In a multivariable analysis the odds ratio (OR) of ICA stenosis ≥70% was adjusted for complete circle of Willis, gender and age. We included 188 patients in our analyses, 50 (26.6%) patients were classified as having poor collateral filling and 138 (73.4%) as good. Of the patients 4 with poor collateral filling had an ICA stenosis ≥70% and 14 with good collateral filling. Unadjusted and adjusted ORs of ICA stenosis ≥70% for good collateral filling were 1.30 (0.41-4.15) and 2.67 (0.81-8.77), respectively. Patients with poor collateral filling had a significantly worse outcome (90-day modified Rankin scale 3-6; 80% versus 52%, p = 0.001). No association was found between pre-existing ICA stenosis and extent of CTP derived collateral filling in patients with an M1 occlusion.

Innate collateral segments are predominantly present in the subendocardium without preferential connectivity within the left ventricular wall

NARCIS (Netherlands)

van Horssen, Pepijn; Siebes, Maria; Spaan, Jos A. E.; Hoefer, Imo E.; van den Wijngaard, Jeroen P. H. M.

2014-01-01

Functional collateral vessels often stem from outward remodelling of pre-existing connections between perfusion territories. Knowledge of the distribution and morphology of innate collateral connections may help in identifying myocardial areas with protection against risk for ischaemia. The coronary

Accuracy of preoperative CT T staging of renal cell carcinoma: which features predict advanced stage?

International Nuclear Information System (INIS)

Bradley, A.J.; MacDonald, L.; Whiteside, S.; Johnson, R.J.; Ramani, V.A.C.

2015-01-01

Aims: To characterise CT findings in renal cell carcinoma (RCC), and establish which features are associated with higher clinical T stage disease, and to evaluate patterns of discrepancy between radiological and pathological staging of RCC. Materials and methods: Preoperative CT studies of 92 patients with 94 pathologically proven RCCs were retrospectively reviewed. CT stage was compared with pathological stage using the American Joint Committee on Cancer (AJCC), 7 th edition (2010). The presence or absence of tumour necrosis, perinephric fat standing, thickening of Gerota's fascia, collateral vessels were noted, and correlated with pT stage. The sensitivity, specificity, and positive (PPV) and negative predictive values (NPV) for predicting pT stage ≥pT3a were derived separately for different predictors using cross-tabulations. Results: Twenty-four lesions were pathological stage T1a, 21 were T1b, seven were T2a, 25 were T3a, 11 were T3b, four were T3c, and two were T4. There were no stage T2b. Sixty-three (67%) patients had necrosis, 27 (29%) thickening of Gerota's fascia (1 T1a), 25 had collateral vessels (0 T1a), 28 (30%) had fat stranding of <2 mm, 20 (21%) of 2–5mm and one (1%) of >5 mm. For pT stage ≥pT3a, the presence of perinephric fat stranding had a sensitivity, specificity, PPV and NPV of 74%, 65%, 63%, and 76%, respectively. Presence of tumour necrosis had a sensitivity, specificity, PPV, and NPV of 81%, 44%, 54%, and 72%, respectively. Thickening of Gerota's fascia had a sensitivity, specificity, PPV, and NPV of 52%, 90%, 81% and 70%, respectively; and enlarged collateral vessels had a sensitivity, specificity, PPV, and NPV value of 52%, 94%, 88%, and 71% respectively. Conclusion: The presence of perinephric stranding and tumour necrosis were not reliable signs for pT stage >T3a. Thickening of Gerota's fascia and the presence of collateral vessels in the peri- or paranephric fat had 90% and 94% specificity, with 82% and 88

[Value of evaluating the coronary collateral circulation by transluminal attenuation gradient in patients with chronic total occlusion and related influencing factors].

Science.gov (United States)

Chen, Y L; Wang, R; He, Y; Li, J N; Yuan, F; Tian, R; Ge, C J; Zhou, Y; Huang, R C; Cui, S; Song, X T

2017-10-24

Objective: To observe the value of evaluating the coronary collateral circulation of chronic total occlusion (CTO) by transluminal attenuation gradient (TAG) and Rentrop grading, and analyze the influencing factors for coronary collateral circulation. Methods: A total of 179 CTO patients admitted to Beijing Anzhen hospital during June 2013 to August 2016 were included in this study.All patients received coronary computed tomographic angiography (CCTA) examination before coronary angiography.Finally, 75 patients (79 vessels) were enrolled.Patients were divided into two groups on the basis of Rentrop classification.The Rentrop 3 was defined as a well-developed coronary collateral circulation group, including 50 CTO vessels, Rentrop 2 or below was defined as poorly-developed collateral circulation group, including 29 vessels.TAG values in patients with various Rentrop grades were analyzed.Univariate and multivariate analysis were used to determine the predictors of collateral circulation. Results: TAG increased consistently in proportion to the angiographic extent of collateral flow (TAG was (-33.6±24.4), (-16.5±15.7) and (-12.8±15.8) HU/10 mm in patients with Rentrop grade 0 or 1, 2 and 3, respectively, P =0.007). Number of good collateral circulation vessels predicted by TAG≥15.6 HU/10 mm was 45(57.0%, 45/79), and 50 (63.3%, 50/79) by Rentrop grade ( P =0.383). Prevalence of diabetes was significantly lower (20.8%(10/48) vs. 48.1%(13/27), P =0.01), while history of previous myocardial infarction (MI) was significantly higher (35.4%(17/48) vs. 11.1%(3/27), P =0.02) in patients with good collateral circulation than in patients with poor collateral circulation.The TAG of the good collateral circulation group was significantly higher than in poorly collateral circulation group ((-12.8±15.8) HU/10 mm vs. (-21.2±19.6) HU/10mm, P =0.041). Multiple logistic regression analysis revealed that history of MI ( OR =0.196, 95% CI 0.041-0.936, P =0.041) and diabetes( OR =6

[Collateral score based on CT perfusion can predict the prognosis of patients with anterior circulation ischemic stroke after thrombectomy].

Science.gov (United States)

Wang, Qingsong; Zhang, Sheng; Zhang, Meixia; Chen, Zhicai; Lou, Min

2017-07-25

To evaluate the value of collateral score based on CT perfusion (CTP-CS) in predicting the clinical outcome of patients with anterior circulation ischemic stroke after thrombectomy. Clinical data of acute ischemic stroke patients with anterior artery occlusion undergoing endovascular treatment in the Second Affiliated Hospital, Zhejiang University School of Medicine during October 2013 and October 2016 were retrospectively reviewed. Collateral scores were assessed based on CTP and digital subtraction angiography (DSA) images, respectively. And DSA-CS or CTP-CS 3-4 was defined as good collateral vessels. Good clinical outcome was defined as a modified Rankin Scale (mRS) ≤ 2 at 3 months after stroke. The binary logistic regression model was used to analyze the correlation between the collateral score and clinical outcome, and the receiver operating characteristic (ROC) curve was used to analyze the value of DSA-CS and CTP-CS in predicting the clinical outcome. Among 40 patients, 33 (82.5%) acquired recanalization and 16 (40.0%) got good outcome. Compared with poor outcome group, the collateral score (all P collateral vessels were higher in good outcome group (all P collateral vessels were independent factor of good outcome (CTP-CS: OR =48.404, 95% CI :1.373-1706.585, P Collateral scores based on CTP and DSA had good consistency ( κ =0.697, P <0.01), and ROC curve showed that the predictive value of CTP-CS and DSA-CS were comparable (both AUC=0.726, 95% CI :0.559-0.893, P <0.05). CTP-CS can predict the clinical outcome of patients with anterior circulation ischemic stroke after thrombectomy.

Collateral flow as causative of good outcomes in endovascular stroke therapy.

Science.gov (United States)

Sheth, Sunil A; Sanossian, Nerses; Hao, Qing; Starkman, Sidney; Ali, Latisha K; Kim, Doojin; Gonzalez, Nestor R; Tateshima, Satoshi; Jahan, Reza; Duckwiler, Gary R; Saver, Jeffrey L; Vinuela, Fernando; Liebeskind, David S

2016-01-01

Endovascular reperfusion techniques are a promising intervention for acute ischemic stroke (AIS). Prior studies have identified markers of initial injury (arrival NIH stroke scale (NIHSS) or infarct volume) as predictive of outcome after these procedures. We sought to define the role of collateral flow at the time of presentation in determining the extent of initial ischemic injury and its influence on final outcome. Demographic, clinical, laboratory, and radiographic data were prospectively collected on a consecutive cohort of patients who received endovascular therapy for acute cerebral ischemia at a single tertiary referral center from September 2004 to August 2010. Higher collateral grade as assessed by the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) grading scheme on angiography at the time of presentation was associated with improved reperfusion rates after endovascular intervention, decreased post-procedural hemorrhage, smaller infarcts on presentation and discharge, as well as improved neurological function on arrival to the hospital, discharge, and 90 days later. Patients matched by vessel occlusion, age, and time of onset demonstrated smaller strokes on presentation and better functional and radiographic outcome if found to have superior collateral flow. In multivariate analysis, lower collateral grade independently predicted higher NIHSS on arrival. Improved collateral flow in patients with AIS undergoing endovascular therapy was associated with improved radiographic and clinical outcomes. Independent of age, vessel occlusion and time, in patients with comparable ischemic burdens, changes in collateral grade alone led to significant differences in initial stroke severity as well as ultimate clinical outcome. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Transvenous closure of large aortopulmonary collateral

Directory of Open Access Journals (Sweden)

Parag W Barwad

2014-01-01

Full Text Available Aortopulmonary collaterals (APCs are occluded either preoperatively or at the time of cardiac surgery in patients with pulmonary atresia and ventricular septal defect (PAVSD. If left untreated, APCs are an important cause of deterioration in the early postoperative period. We present here an unusual case with a large residual APC causing refractory low-output state in the early postoperative period. Usual arterial approach failed due to extensive angulation with ostial narrowing. The large residual APC was successfully closed with an Amplatzer duct occluder (ADO device delivered through the transvenous route.

The range of adaptation by collateral vessels after femoral artery occlusion

NARCIS (Netherlands)

Eitenmüller, Inka; Volger, Oscar; Kluge, Alexander; Troidl, Kerstin; Barancik, Miroslav; Cai, Wei-Jun; Heil, Matthias; Pipp, Frederic; Fischer, Silvia; Horrevoets, Anton J. G.; Schmitz-Rixen, Thomas; Schaper, Wolfgang

2006-01-01

Natural adaptation to femoral artery occlusion in animals by collateral artery growth restores only approximately 35% of adenosine-recruitable maximal conductance (C(max)) probably because initially elevated fluid shear stress (FSS) quickly normalizes. We tested the hypothesis whether this deficit

Correlation of angina pectoris and perfusion decrease by collateral circulation in single-vessel coronary chronic total occlusion using myocardial perfusion single-photon emssion computed tomography

Energy Technology Data Exchange (ETDEWEB)

Cho, Sang Geon; Park, Ki Seong; Kang, Sae Ryung [Chonnam National University Hospital, Gwangju (Korea, Republic of); and others

2016-03-15

To evaluate the perfusion decrease in donor myocardium by collateral circulation and its correlation with angina pectoris in patients with chronic total occlusion (CTO) using myocardial perfusion single-photon emission computed tomography (MPS). Thirty-six patients with single-vessel CTO without any other stenosis were included. All patients underwent MPS and coronary angiography (CAG) within 2 months. Total 72 donor arteries were evaluated for the grades of collaterals to the CTO artery using the Rentrop grading system on CAG. Perfusion defects and perfusion scores in donor and CTO territories were analyzed on MPS. Myocardial perfusion of donor and CTO territories were evaluated according to the presence of angina pectoris and the grades of collateral circulation. When the CTO territory was ischemic, symptomatic patients showed higher summed difference scores in the CTO territory compared to asymptomatic patients (3.5 ± 2.4 vs. 1.5 ± 0.8 for symptomatic and asymptomatic groups respectively; p = 0.034). However, when the CTO territory was nonischemic, symptomatic patients showed higher summed stress scores (SSS, 4.3 ± 2.9 vs. 1.6 ± 1.2; p = 0.032) and summed rest scores (SRS, 4.2 ± 2.5 vs. 1.5 ± 1.1; p = 0.003) in the donor territories. On the per-vessel analysis, perfusion defects in donor territories were more frequent (0 % vs. 53 % vs. 86 % for Rentrop 0, Rentrop 1–2 and Rentrop 3, respectively; p < 0.001) and showed higher SSS (0.0 ± 0.0, 1.3 ± 1.6 and 2.1 ± 1.1 for Rentrop 0, Rentrop 1–2 and Rentrop 3, respectively; p = 0.001) and SRS (0.0 ± 0.0, 1.0 ± 1.4 and 1.7 ± 1.2; p = 0.003) at higher Rentrop grades, but their patterns were variable. Angina pectoris was related to either ischemia of the myocardium beyond CTO or a perfusion decrease in the donor myocardium. The perfusion decrease in donor myocardium positively correlated with the collateral grades.

Evaluation of Collateral Source Characteristics With 3-Dimensional Analysis Using Micro-X-Ray Computed Tomography.

Science.gov (United States)

Arima, Yuichiro; Hokimoto, Seiji; Tabata, Noriaki; Nakagawa, Osamu; Oshima, Asahi; Matsumoto, Yosuke; Sato, Takahiro; Mukunoki, Toshifumi; Otani, Jun; Ishii, Masanobu; Uchikawa, Michie; Yamamoto, Eiichiro; Izumiya, Yasuhiro; Kaikita, Koichi; Ogawa, Hisao; Nishiyama, Koichi; Tsujita, Kenichi

2018-03-23

Collateral arteries provide an alternative blood supply and protect tissues from ischemic damage in patients with peripheral artery disease. However, the mechanism of collateral artery development is difficult to validate. Collateral arteries were visualized using micro-x-ray computed tomography. Developmental characteristics were assessed using confocal microscopy. We conducted a single-center, retrospective, observational study and assessed the dilatation of collateral arteries on ischemic sides. We quantified the vascular volume in both ischemic and nonischemic legs. A prominent increase in vascular volume was observed in the ischemic leg using a murine hind-limb ischemia model. We also performed qualitative assessment and confirmed that the inferior gluteal artery functioned as a major collateral source. Serial analysis of murine hind-limb vessel development revealed that the inferior gluteal artery was a remnant of the ischial artery, which emerged as a representative vessel on the dorsal side during hind-limb organogenesis. We retrospectively analyzed consecutive patients who were admitted for the diagnosis or treatment of peripheral artery disease. The diameter of the inferior gluteal artery on the ischemic side showed significant dilatation compared with that on the nonischemic side. Our findings indicate that an embryonic remnant artery can become a collateral source under ischemic conditions. Flow enhancement in the inferior gluteal artery might become a novel therapeutic approach for patients with peripheral artery disease. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Effects of nicorandil on coronary collateral circulation depend on the donor arteries

International Nuclear Information System (INIS)

Umezawa, Shigeo; Ogawara, Shigeko; Okamoto, Yoshihiro; Igawa, Masayuki; Aonuma, Kazutaka; Inada, Mihoe; Korenaga, Masayoshi; Hiroe, Michiaki; Marumo, Fumiaki.

1996-01-01

The effects of nicorandil on coronary collateral circulation during exercise-induced ischemia were compared between the different donor arteries in 13 patients with effort angina, 7 with complete obstruction of the left anterior descending artery (LAD) with well-developed collateral vessels from the right coronary artery (RCA) (LAD group), and 6 with complete occlusion of the RCA (segment 2-3) with well-developed collateral vessels from the LAD (RCA group). Initial percentage thallium (%Tl) uptake (thallium-201 single photon emission computed tomography) and washout rate were measured in the anterior, septal and posterior regions during ergometer exercise. The submaximal treadmill exercise test was also performed using a cardiopulmonary monitoring system to measure Vo 2 at anaerobic threshold (AT). After the controls were obtained, nicorandil (15 mg/day) was administered for 4 weeks, during which ergometer exercise and treadmill exercise tests were carried out repeatedly. A significant improvement of initial %Tl uptake on exercise was observed in the LAD group with nicorandil therapy, but no improvement was shown in the RCA group. The AT significantly increased after nicorandil treatment in the LAD group (13.9±0.38 → 16.8±1.18 ml/min/kg), reflecting the improvement of cardiac function through the increased collateral flow. However, in the RCA group, it remained unchanged, suggesting no improvement of cardiac function. Nicorandil was effective to increase collateral flow from the RCA, but ineffective on that from the LAD. Nicorandil is an effective coronary dilator and is reported to affect both large and small coronary arteries. The effect on the collateral circulation is dependent on the donor artery supplying different areas. The vasodilator effect of nicorandil is mainly on the LAD, which is large enough to supply blood to a wider area of the heart, rather than the RCA. (author)

Stimulation of collateral artery growth: travelling further down the road to clinical application

OpenAIRE

Schirmer, S.H.; van Nooijen, F.C.; Piek, J.J.; van Royen, N.

2009-01-01

Collateral artery growth is a potent natural defence mechanism to prevent death and myocardial infarction in occlusive artery disease. Given the high prevalence of arterial obstructive disease, a therapeutic compound stimulating collateral vessel growth could have a major impact on morbidity and mortality world wide. Although experimental studies on the stimulation of arteriogenesis have been promising, not a single drug has been proved to be applicable in clinical practice, either because of...

Influence of oxidative stress on the development of collateral circulation in total coronary occlusions.

Science.gov (United States)

Demirbag, Recep; Gur, Mustafa; Yilmaz, Remzi; Kunt, Alper Sami; Erel, Ozcan; Andac, M Halit

2007-03-02

The purpose of this study was to investigate whether the levels of total antioxidant capacity (TAC), total peroxide and oxidative stress index (OSI) are associated with the development of collaterals in total coronary occlusions. Our study group contained 176 consecutive men patients with single-vessel TCO, 94 of whom had poorly developed coronary collateral, while 82 had well-developed coronary collateral. TAC and total peroxide concentration were measured of plasma. The ratio of TAC to total peroxide was accepted as an indicator of oxidative stress. The values of total peroxide and OSI in the Group I were significantly lower than that in Group II (ptotal peroxide and OSI levels (ptotal peroxide and OSI were independent predictors of collaterals score (p=0.006 and ptotal coronary occlusion patients.

Leptomeningeal collateral status predicts outcome after middle cerebral artery occlusion.

Science.gov (United States)

Madelung, C F; Ovesen, C; Trampedach, C; Christensen, A; Havsteen, I; Hansen, C K; Christensen, H

2018-01-01

Perfusion through leptomeningeal collateral vessels is a likely pivotal factor in the outcome of stroke patients. We aimed to investigate the effect of collateral status on outcome in a cohort of unselected, consecutive stroke patients with middle cerebral artery occlusion undergoing reperfusion therapy. This retrospectively planned analysis was passed on prospectively collected data from 187 consecutive patients with middle cerebral artery occlusion admitted within 4.5 hours to one center and treated with intravenous thrombolysis alone (N = 126), mechanical thrombectomy alone (N = 5), or both (N = 56) from May 2009 to April 2014. Non-contrast CT (NCCT) and computed tomography angiography (CTA) were provided on admission and NCCT repeated at 24 hours. Collateral status was assessed based on the initial CTA. Hemorrhagic transformation was evaluated on the 24-hour NCCT and according to European Cooperative Acute Stroke Study (ECASS) criteria. Modified Rankin Scale score was assessed at 90 days, and mortality at 1 year. At 90 days, median (IQR) modified Rankin Scale score in patients with poor collateral status was 4 (3-6) compared to 2 (1-4) in patients with good collateral status (P collateral status were less likely to achieve a good 90-day outcome (modified Rankin Scale score 0-2) (Adjusted odds ratio 0.27, 95% CI: 0.09-0.86). During the first year, 40.9% of patients with poor collateral status died vs 18.2% of the remaining population (P = .001). Leptomeningeal collateral status predicts functional outcome, mortality, and hemorrhagic transformation following middle cerebral artery occlusion. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

[Synopsis about the hypothesis of "information channel" of channel-collateral system].

Science.gov (United States)

Chang, Xi-Lang

2008-10-01

The author of the present paper founded a theorem about the "incompleteness of single channel structure" (nerve, blood vessel, lymphatic, interspace, aperture, etc.) through quantitative and qualitative analysis about the economic information channel in the human body, which eliminates the probability of single channel structure in the information channel of channel (meridian)-collateral system. After comprehensive analysis on the current researches, the author puts forward a neodoxy, i.e., the body "information channel" structure of the channel-collateral system, mainly follows the distribution regularity of systemic statistics, and is not a single specific entity; various layers of the information channel in the main stems of the channel-collaterals are composed of optimized structure tissues. Hence, the structure of this information channel of channel-collateral system is an overall-optimized, sequential and compatible systemic structure. From this neodoxy, the author brings forward a working principle of channel-collaterals, which is supported theoretically by bio-auxology. The longitudinal distribution of the main stems of meridian-collaterals is considered to result from that in the process of the animal evolution, in the animals moving forward, the microscopic complicated movement of intracorporeal information and energy molecules is related to the forward macroscopic and non-uniform movement of organism in trans-measure. Its impulse and kinetic momentum forms a main vector in the longitudinal direction of the body (the direction of the main stem of channel-collaterals). In order to adapt to and utilize natural regularities, the main stems of the channel-collaterals gradually differentiate and evolve in the living organism, forming a whole system. The "hypothesis of biological origin of channel-collateral system" and "that of information channel of the channel-collaterals in the body" constitute a relatively complete theoretical system framework.

Computed tomographic diagnosis for hepatofugal collaterals in portal hypertension

International Nuclear Information System (INIS)

Iida, Akihiko; Sano, Akira; Imanaka, Kazufumi; Nishizawa, Sadahiko; Sasai, Keisuke

1984-01-01

This paper deals with the diagnostic capability of CT scan for hepatofugal collaterals in 22 patients with portal hypertension. The patients studied were those who underwent percutaneous transhepatic portography (PTP) and CT scan within a short period. Each collateral vein demonstrated by PTP was classified into three grades according to its caliber (d) : (1) Grade I, d<5mm, (2) Grade II, 5mm< d<10mm and (3) Grade III, 10mm< d. Based on the PTP finding, the demonstrability of these collaterals on the CT images was analysed comparatively. Most collaterals in Grade I failed to demonstrate on CT images, while Grade II and III well coincided with CT images, at the rate of 64% and 100% respectively. CT features of these vascular structures showed multiformity: rounded, ovoid comma-shaped, tubular or beaded, etc.. To get an accurate diagnosis, each image must be analysed together with the adjacent upper and lower ones on the fully-performed contrast enhancement technique. Image deterioration of CT was concerned with Partial Volume Phenomenon for small vessels, and motion artifacts produced by intestinal peristalses, cardiac beats and occasionally by difficulty of breath holding. In spite of such diagnostic Iimitation, CT scan provides much qualified images than conventional angiographic procedures in evaluating hepatofugal collaterals. CT scan, which is widely applied to clinical workup for cirrhosis of the liver with special reference to hepatoma, allows incidental diagnostic information about collaterals in size and course. Such simplicity of the procedure contributes to the follow-up and repeat study after sclerotherapy for esophageal varices. (author)

The Relation between Collateral Circulation and 99mTc-MIBI Heart SPECT

International Nuclear Information System (INIS)

Kim, Jae Man; Na, Deug Young; Park, Eun Kyung

1994-01-01

The coronary collateral vessels have revealed their significance in terms of reduction of infarct size, preservation left ventricular function, and prevention of left ventricular aneurysm in patients with myocardial infarction. The purpose of this study were to evaluated the relation between collateral circulation and 99m Tc-MIBI Heart SPECT in patient with acute myocardial infarction and their clinical significance. The fifty six MI patients with antegrade TIMI perfusion grade 0 and 1 were studied. The patients were classified into two groups; Group I included 30 patients with grade 2, 3 Collateral flow. Group II included 26 patients with grade 0, 1 Collateral flow. Collateral filling were graded from 0 to 3; 0- none, 1- Filling of side branch only, 2- Partial filling of the epicardial segment, 3- Complete filling of epicardial segment. Clinical variables, left ventricular function, 99m Tc-MIBI Heart SPECT were analyzed with angiographic finding. Results were following: 1) Collateral visualization was found to be greater in patient with involvement of right coronary artery (RCA). The collateral development site of infarct related artery was RCA 15 cases, left anterior descending artery (LAD) 10 cases, left circumflex artery (LCX) 5 cases, and the collateral circulation from LAD to RCA was 13 cases (40.6%). 2) There was a tendency to be decreased in peak CK activity with group I . 3) The presence of good collateral channels was more frequently 99m Tc-MIBI reversible perfusion defect (83.4% vs 15.3%, p 99m Tc-MlBI reversible perfusion defect.

Monocytic microRNA profile associated with coronary collateral artery function in chronic total occlusion patients.

Science.gov (United States)

Hakimzadeh, Nazanin; Elias, Joëlle; Wijntjens, Gilbert W M; Theunissen, Ruud; van Weert, Angela; Smulders, Martijn W; van den Akker, Nynke; Moerland, Perry D; Verberne, Hein J; Hoebers, Loes P; Henriques, Jose P S; van der Laan, Anja M; Ilhan, Mustafa; Post, Mark; Bekkers, Sebastiaan C A M; Piek, Jan J

2017-05-08

An expansive collateral artery network is correlated with improved survival in case of adverse cardiac episodes. We aimed to identify cellular microRNAs (miRNA; miR) important for collateral artery growth. Chronic total occlusion (CTO) patients (n = 26) were dichotomized using pressure-derived collateral flow index (CFI p ) measurements; high collateral capacity (CFI p  > 0.39; n = 14) and low collateral (CFI p  collateral capacity patients. Validation by real-time polymerase chain reaction demonstrated significantly decreased expression of miR339-5p in all stimulated monocyte phenotypes of low collateral capacity patients. MiR339-5p showed significant correlation with CFI p values in stimulated monocytes. Ingenuity pathway analysis of predicted gene targets of miR339-5p and differential gene expression data from high versus low CFI p patients (n = 20), revealed significant association with STAT3 pathway, and also suggested a possible regulatory role for this signaling pathway. These results identify a novel association between miR339-5p and coronary collateral function. Future work examining modulation of miR339-5p and downstream effects on the STAT3 pathway and subsequent collateral vessel growth are warranted.

The Collateral Trap

OpenAIRE

Frédéric Boissay; Russell Cooper

2014-01-01

Active wholesale financial markets help reallocate deposits across heterogeneous banks. Because of incentive problems these flows are constrained and collateral is needed. The composition of collateral matters. The use of inside assets (loans) creates a “collateral pyramid” in that cash flows from one loan can be pledged to secure another. Through collateral pyramids the financial sector creates safe assets, but at the cost of exposing the economy to systemic panics. Outside collateral (treas...

Acquired portosystemic collaterals: anatomy and imaging

Energy Technology Data Exchange (ETDEWEB)

Leite, Andrea Farias de Melo; Mota Junior, Americo, E-mail: andreafariasm@gmail.com [Instituto de Medicina Integral Professor Fernando Figueira de Pernambuco (IMIP), Recife, PE (Brazil); Chagas-Neto, Francisco Abaete [Universidade de Fortaleza (UNIFOR), Fortaleza, CE (Brazil); Teixeira, Sara Reis; Elias Junior, Jorge; Muglia, Valdair Francisco [Universidade de Sao Paulo (FMRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina

2016-07-15

Portosystemic shunts are enlarged vessels that form collateral pathological pathways between the splanchnic circulation and the systemic circulation. Although their causes are multifactorial, portosystemic shunts all have one mechanism in common - increased portal venous pressure, which diverts the blood flow from the gastrointestinal tract to the systemic circulation. Congenital and acquired collateral pathways have both been described in the literature. The aim of this pictorial essay was to discuss the distinct anatomic and imaging features of portosystemic shunts, as well as to provide a robust method of differentiating between acquired portosystemic shunts and similar pathologies, through the use of illustrations and schematic drawings. Imaging of portosystemic shunts provides subclinical markers of increased portal venous pressure. Therefore, radiologists play a crucial role in the identification of portosystemic shunts. Early detection of portosystemic shunts can allow ample time to perform endovascular shunt operations, which can relieve portal hypertension and prevent acute or chronic complications in at-risk patient populations. (author)

Acquired portosystemic collaterals: anatomy and imaging

International Nuclear Information System (INIS)

Leite, Andrea Farias de Melo; Mota Junior, Americo; Chagas-Neto, Francisco Abaete; Teixeira, Sara Reis; Elias Junior, Jorge; Muglia, Valdair Francisco

2016-01-01

Portosystemic shunts are enlarged vessels that form collateral pathological pathways between the splanchnic circulation and the systemic circulation. Although their causes are multifactorial, portosystemic shunts all have one mechanism in common - increased portal venous pressure, which diverts the blood flow from the gastrointestinal tract to the systemic circulation. Congenital and acquired collateral pathways have both been described in the literature. The aim of this pictorial essay was to discuss the distinct anatomic and imaging features of portosystemic shunts, as well as to provide a robust method of differentiating between acquired portosystemic shunts and similar pathologies, through the use of illustrations and schematic drawings. Imaging of portosystemic shunts provides subclinical markers of increased portal venous pressure. Therefore, radiologists play a crucial role in the identification of portosystemic shunts. Early detection of portosystemic shunts can allow ample time to perform endovascular shunt operations, which can relieve portal hypertension and prevent acute or chronic complications in at-risk patient populations. (author)

Impact of collateral circulation on early outcome and risk of hemorrhagic complications after systemic thrombolysis.

Science.gov (United States)

Brunner, Freimuth; Tomandl, Bernd; Hanken, Katrin; Hildebrandt, Helmut; Kastrup, Andreas

2014-12-01

In stroke patients, collateral flow can rapidly be assessed on computed tomography angiography (CTA). In this study, the impact of baseline collaterals on early outcome and risk of symptomatic intracerebral hemorrhages after systemic thrombolysis in patients with proximal arterial occlusions within the anterior circulation were analyzed. Collateralization scores were determined on the CT angiography source images (0 = absent; 1 ≤ 50%, 2 > 50% but collateral filling) of patients with distal intracranial carotid artery and/or M1 segment occlusions treated from 2008 to December 2011. A collateral score of 0 to 1 was designated as poor and 2 to 3 as good collateral vessel status. Outcome variables included in hospital mortality, favorable outcome at discharge (modified Rankin score ≤ 2), and rates of symptomatic intracerebral hemorrhage based on the European-Australasian Acute Stroke Study II definition. Among 246 subjects (mean age of 74 years; median National Institutes of Health Stroke Scale N at admission 14), 205 patients (83%) had good collaterals, whereas 41 patients (17%) had poor collaterals, respectively. Patients with poor collaterals had significantly higher rates of in-hospital mortality (41% vs. 12%, P collaterals. The grade of collateralization was independently associated with in-hospital mortality (P collaterals have a poor early functional outcome and high rates of symptomatic intracerebral hemorrhage after systemic thrombolysis. Since similar findings have also been reported after endovascular therapy, strategies to improve collateral blood flow should be assessed in this patient population. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

Physiologic capacity of well-developed collaterals in patients with isolated left anterior descending artery disease

International Nuclear Information System (INIS)

Sakata, Kazuyuki; Yoshida, Hiroshi; Ono, Norihisa; Ohtani, Seiji; Mori, Noriko; Yokoyama, Shoichi; Hoshino, Tsuneo; Kaburagi, Tsuneo; Kurata, Chinori.

1992-01-01

To assess the physiologic significance of well-developed collaterals, 34 patients, with isolated left anterior descending artery disease (LAD) and without overt prior myocardial infarction, underwent cardiac catheterization and exercise thallium-201 emission computed tomography. The patients were divided into 3 groups: 11 patients with 90% stenosis of the proximal LAD and without collaterals (group 1), 11 with 99% stenosis of the proximal LAD, and without collaterals (group 2) and 12 with a total occlusion of the proximal LAD which was completely filled by well-developed collaterals (group 3). On left ventriculography, shortening fractions of the anterior wall were significantly reduced in group 2 as compared to groups 1 and 3 (group 1 vs group 2: p<0.01, group 2 vs group 3: p<0.05), which reflected the lower ejection fraction of group 2 (p<0.01 and p<0.05, respectively). The perfusion defects of the anterior wall on both the initial and the delayed images were severer in groups 2 and 3 than in group 1 (group 1 vs group 2 and group 1 vs group 3 on the initial image: p<0.01, for both, group 1 vs group 2 and group 1 vs group 3 on the delayed image: p<0.05, for both). However, recovery of the perfusion defects from the initial image to the delayed image was better in group 3 than in groups 1 and 2 (group 1 vs group 2 and group 1 vs group 3: p<0.05, for both). Therefore, coronary blood flow through well-developed collaterals was considered to be comparable to the flow through a diseased vessel with 90% stenosis at rest. During maximal exercise, blood flow through well-developed collaterals was considered to be comparable to the flow through a diseased vessel with 99% stenosis, although the blood flow through well-developed collaterals was considered to be better than that through 99% stenosis during the recovery period. These findings suggest that patients with well-developed collaterals must be treated like those with severe stenosis. (author)

Thallium-201 single photon emission tomography of myocardium. Additional information in reinjection studies is dependent on collateral circulation

International Nuclear Information System (INIS)

Bartenstein, P.; Schober, O.; Schaefers, M.; Matheja, P.; Hasfeld, M.; Breithardt, G.

1992-01-01

A second thallium-201 injection under resting conditions is able to improve the differentiation between myocardial scar and ischaemia when compared with simple redistribution imaging. The aim of this study was to evaluate the dependence of this improvement on the degree of stenosis and the presence of collaterals. Single photon emission tomography (SPET) studies under exercise, redistribution and reinjection conditions were performed on 84 patients with 181 stenotic vessels (70 left anterior descending, 47 left circumflex, 64 right coronary artery) and compared with angiography. An improvement of the 201 Tl uptake in the reinjection image was observed in 53% of the myocardial areas served by a coronary artery with a stenosis of over 90%. This is compared with 13% of the areas served by a vessel with a stenosis between 50% and 90%. Some 90% of the collateralized areas showed a fill-in effect, but only 7 of the 118 without angiographically visible collateralization (6%). The dependence of the fill-in effect, collateralization and >90% stenosis was highly significant (χ 2 test, P 90% narrowing. The fill-in effect was closely correlated to the presence of collaterals. In these cases, the fill-in may be an indication for hibernating myocardium. (orig.)

Loan collaterals and collateral substitutes in rural finance: a review ...

African Journals Online (AJOL)

Loan collaterals and collateral substitutes in rural finance: a review. ... have difficulties in obtaining loans from banks and other financial institutions because ... The limited availability of conventional collaterals in rural financial markets has led ...

Measuring the collateral network pressure to minimize paraplegia risk in thoracoabdominal aneurysm resection.

Science.gov (United States)

Etz, Christian D; Zoli, Stefano; Bischoff, Moritz S; Bodian, Carol; Di Luozzo, Gabriele; Griepp, Randall B

2010-12-01

To minimize paraplegia during thoracoabdominal aortic aneurysm repair, the concept of the collateral network was developed. That is, spinal cord perfusion is provided by an interconnecting complex of vessels in the intraspinal, paraspinous, and epidural space and in the paravertebral muscles, including intercostal and lumbar segmental as well as subclavian and hypogastric arteries. Collateral network pressure was measured with a catheter in the distal end of a ligated segmental artery in pigs and human beings. In the pig, collateral network pressure was 75% of the simultaneous mean aortic pressure. With complete segmental arterial ligation, it fell to 27% of baseline, recovering to 40% at 24 hours and 90% at 120 hours. Spinal cord injury occurred in approximately 50% of animals. When all segmental arteries were taken in 2 stages a week apart, collateral network pressure fell only to 50% to 70% of baseline, and spinal cord injury was rare. In human beings, baseline collateral network pressure also was 75% of mean aortic pressure, fell in proportion to the number of segmental arteries ligated, and began recovery within 24 hours. Collateral network pressure was lower with nonpulsatile distal bypass than with pulsatile perfusion. After subtraction of a measure of spinal cord outflow pressure (cerebrospinal fluid pressure or central venous pressure), collateral network pressure provides a clinically useful estimate of spinal cord perfusion pressure. Copyright © 2010. Published by Mosby, Inc.

The Changing Collateral Space

OpenAIRE

Manmohan Singh

2013-01-01

This paper highlights the changing collateral landscape and how it may shape the global demand/supply for collateral. We first identify the key collateral pools (relative to the “old” collateral space) and associated collateral velocities. Post-Lehman and continuing into the European crisis, some aspects of unconventional monetary policies pursued by central banks are significantly altering the collateral space. Moreover, regulatory demands stemming from Basel III, Dodd Frank, EMIR etc., new ...

Influence of angiographic collateral circulation on myocardial perfusion in patients with chronic total occlusion of a single coronary artery and no prior myocardial infarction.

Science.gov (United States)

Aboul-Enein, Fatma; Kar, Saibal; Hayes, Sean W; Sciammarella, Maria; Abidov, Aiden; Makkar, Raj; Friedman, John D; Eigler, Neal; Berman, Daniel S

2004-06-01

The functional role of various angiographic grades for coronary collaterals remains controversial. The aim of this study was to assess the influence of the Rentrop angiographic grading of coronary collaterals on myocardial perfusion in patients with single-vessel chronic total occlusion (CTO) and no prior myocardial infarction (MI). The study included 56 patients with single-vessel CTO and no prior MI who underwent rest-stress myocardial perfusion SPECT and coronary angiography within 6 mo. All patients had angiographic evidence of coronary collaterals. Patients were divided according to the Rentrop classification: Group I had grade 1 or 2 (n = 25) and group II had grade 3 collaterals (n = 31). Group I had a higher frequency of resting regional wall motion abnormalities on left ventriculography (52.6% vs. 19.2% [P = 0.019]). The mean perfusion scores of the overall population showed severe and extensive stress perfusion defects (summed stress score of 14.1 +/- 7.1 and summed difference score of 12.9 +/- 6.9) but minimal resting perfusion defects (summed rest score of 1.0 +/- 2.7). No perfusion scores differed between the 2 groups. The perfusion findings suggested that chronic stunning rather than hibernation is the principal cause of regional wall motion abnormalities in these patients. In the setting of single-vessel CTO and no prior MI, coronary collaterals appear to protect against resting perfusion defects. Excellent angiographic collaterals may prevent resting regional wall motion abnormalities but do not appear to protect against stress-induced perfusion defects.

Intra-renal localised reno-renal collaterals in the dog after tying of the main renal artery

International Nuclear Information System (INIS)

Rosenbusch, G.; Vincent, J.; Douveren, W. van; Sktonicki, S.; Arts, T.H.M.; Katholieke Univ. Nijmegen; Katholieke Univ. Nijmegen

1984-01-01

In 7 kidneys of 6 dogs one of the main stem of the renal artery was ligated. The development of the renorenal collaterals could be followed in 5, as two dogs died after the operation. In all cases intrarenal collaterals could be demonstrated, even in the postoperative dead dogs. The vessels responsible for the collateral circulation are preformed interarterial anastomoses, belonging to the extraglomerular arterial system. From the results of these and former experimental studies it can be concluded, that the renal artery of the dog when entering the renal sinus cannot be regarded as an anatomic, but at most as a functional end artery. (orig.) [de

Intra-renal localised reno-renal collaterals in the dog after tying of the main renal artery

Energy Technology Data Exchange (ETDEWEB)

Rosenbusch, G.; Vincent, J.; Douveren, W. van; Sktonicki, S.; Arts, T.H.M.

1984-01-01

In 7 kidneys of 6 dogs one of the main stem of the renal artery was ligated. The development of the renorenal collaterals could be followed in 5, as two dogs died after the operation. In all cases intrarenal collaterals could be demonstrated, even in the postoperative dead dogs. The vessels responsible for the collateral circulation are preformed interarterial anastomoses, belonging to the extraglomerular arterial system. From the results of these and former experimental studies it can be concluded, that the renal artery of the dog when entering the renal sinus cannot be regarded as an anatomic, but at most as a functional end artery.

Relationship Between Collateral Status, Contrast Transit, and Contrast Density in Acute Ischemic Stroke.

Science.gov (United States)

Kawano, Hiroyuki; Bivard, Andrew; Lin, Longting; Spratt, Neil J; Miteff, Ferdinand; Parsons, Mark W; Levi, Christopher R

2016-03-01

Collateral circulation is recognized to influence the life expectancy of the ischemic penumbra in acute ischemic stroke. The best method to quantify collateral status on acute imaging is uncertain. We aimed to determine the relationship between visual collateral status, quantitative collateral assessments, baseline computed tomographic perfusion measures, and tissue outcomes on follow-up imaging. Sixty-six consecutive patients with acute ischemic stroke clinically eligible for recanalization therapy and with M1 or M2 middle cerebral artery occlusion were evaluated. We compared the visual collateral scoring with measures of contrast peak time delay and contrast peak density. We also compared these measures for their ability to predict perfusion lesion and infarct core volumes, final infarct, and infarct growth. Shorter contrast peak time delay (P=0.041) and higher contrast peak density (P=0.002) were associated with good collateral status. Shorter contrast peak time delay correlated with higher contrast peak density (β=-4.413; P=0.037). In logistic regression analysis after adjustment for age, sex, onset-computed tomographic time, and occlusion site, higher contrast peak density was independently associated with good collateral status (P=0.009). Multiple regression analysis showed that higher contrast peak density was an independent predictor of smaller perfusion lesion volume (P=0.029), smaller ischemic core volume (P=0.044), smaller follow-up infarct volume (P=0.005), and smaller infarct growth volume (P=0.010). Visual collateral status, contrast peak density, and contrast peak time delay were inter-related, and good collateral status was strongly associated with contrast peak density. Contrast peak density in collateral vessel may be an important factor in tissue fate in acute ischemic stroke. © 2016 American Heart Association, Inc.

Conservative Management of an Epicardial Collateral Perforation During Retrograde Chronic Total Occlusion Percutaneous Coronary Intervention.

Science.gov (United States)

Ngo, Christian; Christopoulos, George; Brilakis, Emmanouil S

2016-01-01

Coronary artery perforation is a highly feared complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) and can lead to pericardial effusion, tamponade, and, rarely, emergent cardiac surgery. Perforation of epicardial collaterals during retrograde CTO-PCI may be particularly challenging to treat, as embolization from both sides of the perforation may be required to control the bleeding. However, conservative measures can occasionally be effective. We present a case of epicardial collateral vessel perforation that was managed conservatively with anticoagulation reversal.

Observed Influence of Nitroglycerine on Myocardial Perfusion Scintigraphy in Patients with Multiple Vessel Coronary Artery Disease and Well-Developed Collaterals

International Nuclear Information System (INIS)

Rasulova, Nigora; Nazirova, Lyudmila; Akhmedov, Khasan; Akhmedova, Dilyafruz; Djalalov, Farrukh; Seydaliev, Amet; Iskandarov, Farkhod; Kok, T. Y.

2012-01-01

� 0.3. However, these changes were not statistically significant (P = 0.3, P = 0.4, and P = 0.2, respectively). There was also statistically significant improvement of perfusion in the recipient territories from mean severity score at rest of 2.67 ± 0.08 to 1.6 ± 0.09 with nitroglycerine (P < 0.0001), in territories of poorly collateralized arteries from mean severity score at rest of 1.5 ± 0.14 to 0.8 ± 0.12 with nitroglycerine (P < 0.0008), as well as significant deterioration of myocardial perfusion in donor artery territories from mean severity score at rest of 1.7 ± 0.06 to 2.4 ± 0.06 with nitroglycerine (P < 0.0001). Based on the results of the study, we concluded that nitroglycerine administration in patients with multiple vessel coronary artery disease and well-developed collaterals can reduce myocardial perfusion to the areas supplied by donor arteries, even resulting in apparent absent perfusion, probably due to “steal syndrome,” although these arteries were less stenosed angiographically and deemed viable on MPS at rest. It appears that MPS in patients on nitroglycerine medication may result in an inappropriate decision by interventionists and surgeons to forgo revascularization. Hence, in cases where large and severe perfusion abnormalities are noted, MPS should be repeated after omitting nitrates

The "moving valgus stress test" for medial collateral ligament tears of the elbow.

Science.gov (United States)

O'Driscoll, Shawn W M; Lawton, Richard L; Smith, Adam M

2005-02-01

The diagnosis of a painful partial tear of the medial collateral ligament in overhead-throwing athletes is challenging, even for experienced elbow surgeons and despite the use of sophisticated imaging techniques. The "moving valgus stress test" is an accurate physical examination technique for diagnosis of medial collateral ligament attenuation in the elbow. Cohort study (diagnosis); Level of evidence, 2. Twenty-one patients underwent surgical intervention for medial elbow pain due to medial collateral ligament insufficiency or other abnormality of chronic valgus overload, and they were assessed preoperatively with an examination called the moving valgus stress test. To perform the moving valgus stress test, the examiner applies and maintains a constant moderate valgus torque to the fully flexed elbow and then quickly extends the elbow. The test is positive if the medial elbow pain is reproduced at the medial collateral ligament and is at maximum between 120 degrees and 70 degrees. The moving valgus stress test was highly sensitive (100%, 17 of 17 patients) and specific (75%, 3 of 4 patients) when compared to assessment of the medial collateral ligament by surgical exploration or arthroscopic valgus stress testing. The mean shear range (ie, the arc within which pain was produced with the moving valgus stress test) was 120 degrees to 70 degrees. The mean angle at which pain was at a maximum was 90 degrees of elbow flexion. The moving valgus stress test is an accurate physical examination technique that, when performed and interpreted correctly, is highly sensitive for medial elbow pain arising from the medial collateral ligament.

Prominent porto-systemic collateral pathways in patients with portal hypertension: demonstration by gadolinium-enhanced magnetic resonance angiography

International Nuclear Information System (INIS)

Caldana, Rogerio Pedreschi; Bezerra, Alexandre Araujo Sergio; Cecin, Alexnadre Oliveira; Souza, Luis Ronan Marques Ferreira de; Goldman, Susan Menasce; D'Ippolito, Giuseppe; Szejnfeld, Jacob

2003-01-01

To demonstrate the usefulness of gadolinium-enhanced magnetic resonance angiography in the evaluation of prominent porto-systemic collateral pathways. We reviewed the images from 40 patients with portal hypertension studied with gadolinium-enhanced magnetic resonance angiography and selected illustrative cases of prominent porto-systemic collateral pathways. The scans were performed using high field equipment (1.5 Tesla) and a 3 D volume technique. Image were obtained after intravenous injection of paramagnetic contrast media using a power injector. Magnetic resonance angiography demonstrated with precision the porto-systemic collateral pathways, particularly when investigating extensive territories or large vessels. The cases presented show the potential of this method in the investigation of patients with portal hypertension. Gadolinium-enhanced magnetic resonance angiography is a useful method for the evaluation of patients with portal hypertension and prominent collateral pathways. (author)

Differential impact of diabetes mellitus type II and arterial hypertension on collateral artery growth and concomitant macrophage accumulation.

Science.gov (United States)

Ito, Wulf D; Lund, Natalie; Sager, Hendrik; Becker, Wiebke; Wenzel, Ulrich

2015-01-01

Diabetes mellitus type II and arterial hypertension are major risk factors for peripheral arterial disease and have been considered to reduce collateral growth (arteriogenesis). Collateral growth proceeds through different stages. Vascular proliferation and macrophage accumulation are hallmarks of early collateral growth. We here compare the impact of arterial hypertension and diabetes mellitus type II on collateral proliferation (Brdu incorporation) and macrophage accumulation (ED 2 staining) as well as collateral vessel function (collateral conductance) in a rat model of peripheral vascular disease (femoral artery occlusion), diabetes mellitus type II (Zucker fatty diabetic rats and Zucker lean rat controls) and arterial hypertension (induced via clip placement around the right renal arteriy). We furthermore tested the impact of monocyte chemoattractant protein-1 (MCP‑1) on collateral proliferation and macrophage accumulation in these models Diabetic animals showed reduced vascular proliferation and macrophage accumulation, which however did not translate into a change of collateral conductance. Hypertensive animals on the contrary had reduced collateral conductances without altered macrophage accumulation and only a marginal reduction in collateral proliferation. Infusion of MCP‑1 only enhanced vascular proliferation in diabetic animals. These findings illustrate that impaired monocyte/macrophage recruitment is responsible for reduced collateral growth under diabetic conditions but not in arterial hypertension suggesting that diabetes mellitus in particular affects early stages of collateral growth whereas hypertension has its impact on later remodeling stages. Successful pro-arteriogenic treatment strategies in a patient population that presents with diabetes mellitus and arterial hypertension need to address different stages of collateral growth and thus different molecular and cellular targets simultaneously.

Value of Quantitative Collateral Scoring on CT Angiography in Patients with Acute Ischemic Stroke.

Science.gov (United States)

Boers, A M M; Sales Barros, R; Jansen, I G H; Berkhemer, O A; Beenen, L F M; Menon, B K; Dippel, D W J; van der Lugt, A; van Zwam, W H; Roos, Y B W E M; van Oostenbrugge, R J; Slump, C H; Majoie, C B L M; Marquering, H A

2018-06-01

Many studies have emphasized the relevance of collateral flow in patients presenting with acute ischemic stroke. Our aim was to evaluate the relationship of the quantitative collateral score on baseline CTA with the outcome of patients with acute ischemic stroke and test whether the timing of the CTA acquisition influences this relationship. From the Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR CLEAN) data base, all baseline thin-slice CTA images of patients with acute ischemic stroke with intracranial large-vessel occlusion were retrospectively collected. The quantitative collateral score was calculated as the ratio of the vascular appearance of both hemispheres and was compared with the visual collateral score. Primary outcomes were 90-day mRS score and follow-up infarct volume. The relation with outcome and the association with treatment effect were estimated. The influence of the CTA acquisition phase on the relation of collateral scores with outcome was determined. A total of 442 patients were included. The quantitative collateral score strongly correlated with the visual collateral score (ρ = 0.75) and was an independent predictor of mRS (adjusted odds ratio = 0.81; 95% CI, .77-.86) and follow-up infarct volume (exponent β = 0.88; P quantitative collateral score showed areas under the curve of 0.71 and 0.69 for predicting functional independence (mRS 0-2) and follow-up infarct volume of >90 mL, respectively. We found significant interaction of the quantitative collateral score with the endovascular therapy effect in unadjusted analysis on the full ordinal mRS scale ( P = .048) and on functional independence ( P = .049). Modification of the quantitative collateral score by acquisition phase on outcome was significant (mRS: P = .004; follow-up infarct volume: P quantitative collateral scoring in patients with acute ischemic stroke is a reliable and user-independent measure of the collateral

Impact of Admission Blood Glucose on Coronary Collateral Flow in Patients with ST-Elevation Myocardial Infarction.

Science.gov (United States)

Kurmus, Ozge; Aslan, Turgay; Ekici, Berkay; Baglan Uzunget, Sezen; Karaarslan, Sukru; Tanindi, Asli; Erkan, Aycan Fahri; Akgul Ercan, Ebru; Kervancıoglu, Celal

2018-01-01

In patients with acute myocardial infarction, glucose metabolism is altered and acute hyperglycemia on admission is common regardless of diabetes status. The development of coronary collateral is heterogeneous among individuals with coronary artery disease. In this study, we aimed to investigate whether glucose value on admission is associated with collateral flow in ST-elevation myocardial infarction (STEMI) patients. We retrospectively evaluated 190 consecutive patients with a diagnosis of first STEMI within 12 hours of onset of chest pain. Coronary collateral development was graded according to Rentrop classification. Rentrop 0-1 was graded as poor collateral development, and Rentrop 2-3 was graded as good collateral development. Admission glucose was measured and compared between two groups. Mean admission glucose level was 173.0 ± 80.1 mg/dl in study population. Forty-five (23.7%) patients had good collateral development, and 145 (76.3%) patients had poor collateral development. There were no statistically significant differences in demographic characteristics between two groups. Three-vessel disease was more common in patients with good collateral development ( p =0.026). Mean admission glucose level was higher in patients with poor collateral than good collateral (180.6 ± 84.9 mg/dl versus 148.7 ± 56.6 mg/dl, resp., p =0.008). In univariate analysis, higher admission glucose was associated with poor collateral development, but multivariate logistic regression analysis revealed a borderline result (odds ratio 0.994, 95% CI 0.989-1.000, p =0.049). Our results suggest that elevated glucose on admission may have a role in the attenuation of coronary collateral blood flow in acute myocardial infarction. Further studies are needed to validate our results.

Axonal collateral-collateral transport of tract tracers in brain neurons: false anterograde labelling and useful tool.

Science.gov (United States)

Chen, S; Aston-Jones, G

1998-02-01

It is well established that some neuroanatomical tracers may be taken up by local axonal terminals and transported to distant axonal collaterals (e.g., transganglionic transport in dorsal root ganglion cells). However, such collateral-collateral transport of tracers has not been systematically examined in the central nervous system. We addressed this issue with four neuronal tracers--biocytin, biotinylated dextran amine, cholera toxin B subunit, and Phaseolus vulgaris-leucoagglutinin--in the cerebellar cortex. Labelling of distant axonal collaterals in the cerebellar cortex (indication of collateral-collateral transport) was seen after focal iontophoretic microinjections of each of the four tracers. However, collateral-collateral transport properties differed among these tracers. Injection of biocytin or Phaseolus vulgaris-leucoagglutinin in the cerebellar cortex yielded distant collateral labelling only in parallel fibres. In contrast, injection of biotinylated dextran amine or cholera toxin B subunit produced distant collateral labelling of climbing fibres and mossy fibres, as well as parallel fibres. The present study is the first systematic examination of collateral-collateral transport following injection of anterograde tracers in brain. Such collateral-collateral transport may produce false-positive conclusions regarding neural connections when using these tracers for anterograde transport. However, this property may also be used as a tool to determine areas that are innervated by common distant afferents. In addition, these results may indicate a novel mode of chemical communication in the nervous system.

Discounting with Imperfect Collateral

OpenAIRE

Lou, Wujiang

2017-01-01

Cash collateral is perfect in that it provides simultaneous counterparty credit risk protection and derivatives funding. Securities are imperfect collateral, because of collateral segregation or differences in CSA haircuts and repo haircuts. Moreover, the collateral rate term structure is not observable in the repo market, for derivatives netting sets are perpetual while repo tenors are typically in months. This article synthesizes these effects into a derivative financing rate that replaces ...

Effect of dehydration on the development of collaterals in acute middle cerebral artery occlusion.

Science.gov (United States)

Chang, S-W; Huang, Y-C; Lin, L-C; Yang, J-T; Weng, H-H; Tsai, Y-H; Lee, T-H

2016-03-01

Recent large series studies have demonstrated that dehydration is common amongst stroke subjects and is associated with poor outcome. However, the effects of hydration status on the development of collaterals have never been discussed. In this study, the hypothesis that hydration status is an important factor for developing collaterals after acute middle cerebral artery (MCA) infarction was tested. Eighty-seven patients with acute infarction due to occlusion of the MCA were enrolled. Two collateral markers, posterior cerebral artery (PCA) laterality and fluid-attenuated inversion recovery hyperintense vessels (HVs) were assessed from magnetic resonance imaging. Dehydration status was defined by a nitrogen to creatinine ratio ≧ of 15. The associations between dehydration status and the development of collaterals were estimated. Sixty-one of 87 patients (70.1%) were identified as dehydrated. The development of PCA laterality and HVs shows a significant difference between dehydrated and euhydrated patients. A serum nitrogen to creatinine ratio Dehydration remained an independent negative predictor for the development of PCA laterality and HVs in the multivariate analysis. Hydration status is associated with the development of collateral flow after acute MCA occlusion. This preliminary study provides an imaging clue that hydration status and early hydration therapy could be important for acute stroke management. © 2016 EAN.

Using collateral to secure loans

OpenAIRE

Yaron Leitner

2006-01-01

In “Using Collateral to Secure Loans,” Yaron Leitner asks: Why is collateral used to secure some loans, but not others? And why does collateral potentially involve more risk? He considers these questions, looking at some of the explanations for using collateral, focusing on its benefits and drawbacks.

7 CFR 1980.331 - Collateral.

Science.gov (United States)

2010-01-01

... 7 Agriculture 14 2010-01-01 2009-01-01 true Collateral. 1980.331 Section 1980.331 Agriculture... REGULATIONS (CONTINUED) GENERAL Rural Housing Loans § 1980.331 Collateral. (a) General. The entire loan must... borrower. (c) All collateral must secure the entire loan. The Lender will not take separate collateral...

Retrograde approach for the recanalization of coronary chronic total occlusion: collateral selection and collateral related complication.

Science.gov (United States)

Ma, Jian-Ying; Qian, Ju-Ying; Ge, Lei; Fan, Bing; Wang, Qi-Bing; Yan, Yan; Zhang, Feng; Yao, Kang; Huang, Dong; Ge, Jun-Bo

2013-03-01

The retrograde approach through collaterals has been applied in the treatment of chronic total occlusion (CTO) lesions during percutaneous recanalization of coronary arteries. This study was to investigate the success rate of recanalization and collateral related complications in patients when using the retrograde approach. Eighty-four cases subjected to retrograde approach identified from July 2005 to July 2012 were included in this study. Patient characteristics, procedural outcomes and in-hospital clinical events were evaluated. Mean age of the patient was (59.6 ± 11.2) years old and 91.7% were men. The target CTO lesions were distributed among the left anterior descending artery in 45 cases (53.5%), left circumflex artery in one case (1.2%), right coronary artery in 34 cases (40.5%), and left main in four cases (4.8%). The overall success rate of recanalization was 79.8%. The septal collateral was three times more frequently used for retrograde access than the epicardial collateral, 68/84 (81%) vs. 16/84 (19%). Successful wire passage through the collateral channel was achieved in 58 (72.6%) patients. The success rate of recanalization was 93.1% (54/58) in patients with and 50% (13/26) in patients without successful retrograde wire passage of the collateral channel (P collaterals was achieved in 49 of 68 septal collaterals (72.1%) and in 9 of 16 epicardial collaterals (56.3%) (P = NS). There was no significant difference between the septal collateral group and the epicardial group in the success rate of recanalization after retrograde wire crossing the collaterals (91.8% vs. 100%, P > 0.05). CART or reverse CART technique was used in 15 patients, and 14 patients (93.3%) were recanalized successfully. Collateral related perforation occurred in three (18.8%) cases with the epicardial collateral as the first choice (compared with the septal collateral group (0), P collaterals. The retrograde approach is an effective technique to recanalize CTO lesions, the septal

The Dual Role of Cerebral Autoregulation and Collateral Flow in the Circle of Willis After Major Vessel Occlusion.

Science.gov (United States)

Kennedy McConnell, Flora; Payne, Stephen

2017-08-01

Ischaemic stroke is a leading cause of death and disability. Autoregulation and collateral blood flow through the circle of Willis both play a role in preventing tissue infarction. To investigate the interaction of these mechanisms a one-dimensional steady-state model of the cerebral arterial network was created. Structural variants of the circle of Willis that present particular risk of stroke were recreated by using a network model coupled with: 1) a steady-state physiological model of cerebral autoregulation; and 2) one wherein the cerebral vascular bed was modeled as a passive resistance. Simulations were performed in various conditions of internal carotid and vertebral artery occlusion. Collateral flow alone is unable to ensure adequate blood flow ([Formula: see text] normal flow) to the cerebral arteries in several common variants during internal carotid artery occlusion. However, compared to a passive model, cerebral autoregulation is better able to exploit available collateral flow and maintain flows within [Formula: see text] of baseline. This is true for nearly all configurations. Hence, autoregulation is a crucial facilitator of collateral flow through the circle of Willis. Impairment of this response during ischemia will severely impact cerebral blood flows and tissue survival, and hence, autoregulation should be monitored in this situation.

The preoperative venogram in planning extended craniectomies

International Nuclear Information System (INIS)

Lanzieri, C.F.; Duchesneau, P.M.; Rosenbloom, S.A.; Weinstein, M.A.; Sacher, M.

1987-01-01

A technique of extended craniectomy sometimes allows removal of large central or transtentorial mass lesions at a single operative sitting because it affords better exposure and control of normal structures. While seeking to avoid multiple craniotomies, this method requires permanent ligation of the transverse venous sinus. Unless there is adequate collateral venous drainage from the ipsilateral hemisphere, the patient is at risk for venous infarction in the post-craniectomy period. The purpose of this study is to propose a method of establishing the presence of collateral venous drainage preoperatively. Each carotid artery is injected with the head in a neutral position and with the head turned to the side ipsilateral to the carotid artery injection in an attempt to divert the venous flow. Fifty patients were examined using this method; seven were being evaluated for possible craniectomies. The technique identified nine patients with potential venous collaterals (20%). They would otherwise have been considered nonoperable: two of the six patients eventually operated upon (33%) fell into this category. In general, the operative procedure may be safe more often on the left than the right (45%) vs (20%). Particular attention must be given to the pattern of venous drainage from the posterior temporal lobe to avoid isolation of the venous drainage from this area. (orig.)

TEVAR and covering the celiac artery. Is it safe or not?

DEFF Research Database (Denmark)

Falkenberg, Morten; Lönn, Lars Birger; Schroeder, Torben Veith

2010-01-01

artery. In the latter case, adequate collateral supply to the upper gastrointestinal tract is crucial. Collateral arteries joining the celiac and the superior mesenteric arteries are well characterized in patients with chronic celiac stenosis or occlusion. Are these collateral pathways sufficient also...... for sudden iatrogenic closure of the celiac artery? By performing a preoperative angiography of the superior mesenteric artery with temporary balloon occlusion of the celiac artery, collateral capacity between the two vessels can be tested in advance. Exact positioning of the distal end of a large thoracic...... together, in the large majority of patients, it appears that intentional celiac coverage can be done safely provided that sufficient collateral function have been demonstrated in advance....

A protective role of early collateral blood flow in patients with ST-segment elevation myocardial infarction.

Science.gov (United States)

Kim, Eun Kyoung; Choi, Jin-Ho; Song, Young Bin; Hahn, Joo-Yong; Chang, Sung-A; Park, Sung-Ji; Lee, Sang-Chol; Choi, Seung-Hyuk; Choe, Yeon Hyeon; Park, Seung Woo; Gwon, Hyeon-Cheol

2016-01-01

Conflict persists regarding whether the presence of early collateral blood flow to the infarct-related artery has an effective role in reducing infarct size and improving myocardial salvage in patients with ST-segment elevation myocardial infarction (STEMI). We sought to investigate the impact of the collateral circulation on myocardial salvage and infarct size in STEMI patients. In 306 patients who were diagnosed with STEMI and underwent cardiac magnetic resonance within 1 week after revascularization, initial collateral flow to the infarct-related artery was assessed by coronary angiography. Using cardiac magnetic resonance imaging, myocardial infarct size and salvage were measured. Among 247 patients with preprocedural Thrombolysis in Myocardial Infarction flow 0/1, 54 (22%) patients had good collaterals (Rentrop grade ≥ 2, Collateral Connection Score ≥ 2). Infarct size and area at risk were significantly smaller in patients with good collaterals than those with poor collaterals (infarct size: 17.1 ± 10.1 %LV vs 21.8 ± 10.5 %LV, P = .003, area at risk: 33.8 ± 16.8 %LV vs 38.8 ± 15.5 %LV, P = .039). There was a significant difference of myocardial salvage index between 2 groups (50.9% ± 15.0% vs 43.8% ± 18.5%, P = .005). Poor collateralization was an independent predictor for large infarct size (odd ratio 2.48 [1.28-4.80], P = .007). In patients with STEMI, the presence of well-developed collaterals to occluded coronary artery from the noninfarct vessel and its extent were independently associated with reduced infarct burden and improved myocardial salvage. Our results help explain why MI patients with well-developed collateralization have reduced mortality and morbidity. Copyright © 2015 Elsevier Inc. All rights reserved.

Role of contrast-enhanced MR venography in the preoperative evaluation of parasagittal meningiomas

Energy Technology Data Exchange (ETDEWEB)

Bozzao, Alessandro; Finocchi, Vanina; Romano, Andrea; Ferrante, Michele; Fasoli, Fabrizio; Fantozzi, Luigi Maria [S. Andrea Hospital, Neuroradiological Section, Rome (Italy); Trillo, Giuseppe; Ferrante, Luigi [S. Andrea Hospital, Neurosurgical Section, Rome (Italy)

2005-09-01

Parasagittal meningiomas (PSM) may pose a difficult surgical challenge since venous patency and collateral anastomoses have to be clearly defined for correct surgical planning. The aim of this study was to assess the diagnostic value of contrast-enhanced (CE) magnetic resonance venography (MRV) in the preoperative evaluation of venous infiltration and collateral venous anastomoses in patients with PSM. CE-MRV was compared with phase-contrast (PC) magnetic resonance (MR) angiography, conventional angiography (when available), and surgery as a reference. Twenty-three patients undergoing surgery for meningiomas located adjacent to the superior sagittal sinus were prospectively evaluated. All the patients underwent both conventional MR examination and MRV. This was performed by means of PC and CE techniques. Both sets of angiograms (CE and PC) were evaluated by two expert neuroradiologists to assess (1) patency of the sinus (patent/occluded), (2) the extent of occlusion (in centimeters), and (3) the number of collateral anastomoses close to the insertion of the meningioma. Eight patients underwent digital subtraction angiography (DSA). All patients were operated on, and intraoperative findings were taken as the gold standard to evaluate the diagnostic value of MRA techniques. PC-MRV showed a flow void inside the sinus compatible with its occlusion in 15 cases, whereas CE-MRV showed the sinus to be occluded in five cases. CE-MRV data were confirmed by surgery, showing five patients to have an occlusion of the superior sagittal sinus. The PC-MRV sensitivity was thus 100% with a specificity of 50%. In those cases in which both MRV techniques documented occlusion of the sinus, the extent of occlusion was overestimated by PC compared with CE and surgery. CE-MRV depicted 87% of collateral venous anastomoses close to the meningioma as subsequently confirmed by surgery, while PC showed 58%. In the preoperative planning for patients with meningiomas located close to a venous

Role of contrast-enhanced MR venography in the preoperative evaluation of parasagittal meningiomas

International Nuclear Information System (INIS)

Bozzao, Alessandro; Finocchi, Vanina; Romano, Andrea; Ferrante, Michele; Fasoli, Fabrizio; Fantozzi, Luigi Maria; Trillo, Giuseppe; Ferrante, Luigi

2005-01-01

Parasagittal meningiomas (PSM) may pose a difficult surgical challenge since venous patency and collateral anastomoses have to be clearly defined for correct surgical planning. The aim of this study was to assess the diagnostic value of contrast-enhanced (CE) magnetic resonance venography (MRV) in the preoperative evaluation of venous infiltration and collateral venous anastomoses in patients with PSM. CE-MRV was compared with phase-contrast (PC) magnetic resonance (MR) angiography, conventional angiography (when available), and surgery as a reference. Twenty-three patients undergoing surgery for meningiomas located adjacent to the superior sagittal sinus were prospectively evaluated. All the patients underwent both conventional MR examination and MRV. This was performed by means of PC and CE techniques. Both sets of angiograms (CE and PC) were evaluated by two expert neuroradiologists to assess (1) patency of the sinus (patent/occluded), (2) the extent of occlusion (in centimeters), and (3) the number of collateral anastomoses close to the insertion of the meningioma. Eight patients underwent digital subtraction angiography (DSA). All patients were operated on, and intraoperative findings were taken as the gold standard to evaluate the diagnostic value of MRA techniques. PC-MRV showed a flow void inside the sinus compatible with its occlusion in 15 cases, whereas CE-MRV showed the sinus to be occluded in five cases. CE-MRV data were confirmed by surgery, showing five patients to have an occlusion of the superior sagittal sinus. The PC-MRV sensitivity was thus 100% with a specificity of 50%. In those cases in which both MRV techniques documented occlusion of the sinus, the extent of occlusion was overestimated by PC compared with CE and surgery. CE-MRV depicted 87% of collateral venous anastomoses close to the meningioma as subsequently confirmed by surgery, while PC showed 58%. In the preoperative planning for patients with meningiomas located close to a venous

Predicting ischemic mitral regurgitation in patients with acute ST-elevation myocardial infarction: Does time to reperfusion really matter and what is the role of collateral circulation?

Science.gov (United States)

Valuckiene, Zivile; Budrys, Povilas; Jurkevicius, Renaldas

2016-01-15

Ischemic mitral regurgitation (MR) is an adverse prognostic factor. We aimed to assess the role of time delay from symptom onset to reperfusion, and the impact of collateral circulation to incidence of MR in relation to established echocardiographic and clinical risk factors. Patients with STEMI presenting within 12 h from symptom onset and treated with primary percutaneous coronary intervention (PPCI) at Hospital of Lithuanian University of Health Sciences were enrolled. Echocardiography was performed after PPCI. Based on MR grade, patients were divided into no significant MR (NMR, grade 0-I MR, N = 102) and ischemic MR (IMR, grade ≥ 2 MR, N = 71) groups. Well-developed collaterals were defined as grade ≥ 2 by Rentrop classification. Continuous variables were compared by independent samples Student's T-test. Multivariate logistic regression analysis was used to identify independent predictors of ischemic MR. Time to reperfusion, MI localization, TIMI flow before/after PCI was similar between the groups. IMR group patients were elder, more often females and non-smokers, had lower body mass index, higher prevalence of multi-vessel coronary artery disease (CAD), better-developed collateral supply, greater left ventricular end-diastolic diameter index, left atrial index, pulmonary artery systolic pressure and lower ejection fraction. Multivariate logistic regression analysis revealed that ischemic MR is predicted by female gender, well-developed collateral supply, presence of multi-vessel CAD, and lower EF. In acute STEMI significant MR is unrelated to ischemic time and is predicted by female gender, lower EF, multi-vessel CAD and well-developed collateral supply to the infarct region.

FEATURES OF FORMATION OF COLLATERAL CIRCULATION IN PATIENTS WITH SUBCLAVIAN STEAL SYNDROME.

Science.gov (United States)

Kopolovets, I; Štefanič, P; Rusyn, V; Tóth, Š; Mashura, V; Berek, P

2017-12-01

To date in patients with subclavian steal syndrome diagnosis is only grade of stenosis or localization of occlusion described. Authors recommend to take into account also type of a collateral compensation of cerebral circulation for selection of an optimal treatment The objective of the research was to study the features of formation of collateral circulation in patients with subclavian steal syndrome. The authors described changes in the direction of blood flow in the extracranial vessels of 42 patients with subclavian steal syndrome. Latent subclavian steal syndrome was detected in 26.2% of patients, transient subclavian steal syndrome was found in 54.8% of patients, and a persistent course of the disease was observed in 19.9% of patients. Symptoms of vertebrobasilar insufficiency were detected in 26.6% of patients, and combination of chronic upper extremity ischemia and vertebrobasilar insufficiency was diagnosed in 73.8% of patients. When analyzing the features of collateral circulation in 64.3% of patients the extracranial compensatory mechanism was observed being provided by three main groups of collateral hemodynamic reallocation: the occipito-vertebral hemodynamic mechanism of compensation was detected in 38.1% of cases, the thyroid compensatory mechanism was found in 16.7% of cases, and the brain stem-occipital compensatory mechanism was observed in 9.5% of cases. In 35.7% of patients the intracranial compensatory mechanism was observed being provided by two main groups of collateral hemodynamic reallocation: the vertebro-vertebral compensatory mechanism was found in 21.4% of cases and cerebrobasilar compensatory mechanism was detected in 14.3% of cases. Consideration of the features of collateral circulation in patients with subclavian steal syndrome may serve as a prognostic criterion for selecting an optimal treatment tactics.Each of compensatory mechanisms has its own hemodynamic peculiarities. The occipito- vertebral compensatory mechanism has the

24 CFR 330.10 - Eligible collateral.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Eligible collateral. 330.10 Section... SECURITIES § 330.10 Eligible collateral. The Association, in its discretion, shall determine what collateral is eligible for inclusion in the Multiclass Securities program. Eligible collateral may include GNMA...

7 CFR 1779.48 - Collateral.

Science.gov (United States)

2010-01-01

... 7 Agriculture 12 2010-01-01 2010-01-01 false Collateral. 1779.48 Section 1779.48 Agriculture... (CONTINUED) WATER AND WASTE DISPOSAL PROGRAMS GUARANTEED LOANS § 1779.48 Collateral. (a) Lender responsibility. The lender is responsible for obtaining and maintaining proper and adequate collateral to protect...

Genetic Dissection of the Canq1 Locus Governing Variation in Extent of the Collateral Circulation

Science.gov (United States)

Wang, Shiliang; Zhang, Hua; Wiltshire, Tim; Sealock, Robert; Faber, James E.

2012-01-01

Background Native (pre-existing) collaterals are arteriole-to-arteriole anastomoses that interconnect adjacent arterial trees and serve as endogenous bypass vessels that limit tissue injury in ischemic stroke, myocardial infarction, coronary and peripheral artery disease. Their extent (number and diameter) varies widely among mouse strains and healthy humans. We previously identified a major quantitative trait locus on chromosome 7 (Canq1, LOD = 29) responsible for 37% of the heritable variation in collateral extent between C57BL/6 and BALB/c mice. We sought to identify candidate genes in Canq1 responsible for collateral variation in the cerebral pial circulation, a tissue whose strain-dependent variation is shared by similar variation in other tissues. Methods and Findings Collateral extent was intermediate in a recombinant inbred line that splits Canq1 between the C57BL/6 and BALB/c strains. Phenotyping and SNP-mapping of an expanded panel of twenty-one informative inbred strains narrowed the Canq1 locus, and genome-wide linkage analysis of a SWRxSJL-F2 cross confirmed its haplotype structure. Collateral extent, infarct volume after cerebral artery occlusion, bleeding time, and re-bleeding time did not differ in knockout mice for two vascular-related genes located in Canq1, IL4ra and Itgal. Transcript abundance of 6 out of 116 genes within the 95% confidence interval of Canq1 were differentially expressed >2-fold (p-valuecollateral formation. Conclusions These findings refine the Canq1 locus and identify several genes as high-priority candidates important in specifying native collateral formation and its wide variation. PMID:22412848

Supplemental Transcatheter Arterial Chemoembolization Through a Collateral Omental Artery: Treatment for Hepatocellular Carcinoma

International Nuclear Information System (INIS)

Won, Jong Yun; Lee, Do Yun; Lee, Jong Tae; Park, Sung Il; Kim, Myeong-Jin; Yoo, Hyung Sik; Suh, Sang-Hyun; Park, Sang Joon

2003-01-01

Purpose: To evaluate the therapeutic efficacy and safety of supplemental transcatheter arterialchemoembolization (TACE) through the extrahepatic collateral omentalartery (OA) for the treatment of hepatocellular carcinoma (HCC). Methods: We studied 21 patients with extrahepatic collaterals of the OA, among 1,512 patients with HCC who had undergone angiography. HCCs supplied by collateral OAs were located at: segment IV in seven, segment V in five, segment III in three, segment VI in three and segment VIII in three patients (Couinaud classification of segments). On preoperative CT scans, every HCC was abutting the liver surface. Adjacent omental infiltration or engorgement was noted in 11 patients. Celiac and hepatic arteriograms showed hypertrophy of the feeding OA in all patients. TACE of the OA was performed in 19 patients with an emulsion of iodized oil and doxorubicin hydrochloride.Embolization with gelatin sponge particles was added in five patients. Results: Collaterals of the OA to the HCC were found on the first to seventeenth sessions of TACE. On follow-up CT scans, five patients showed complete uptake of iodized oil in the tumor. Partial uptake of iodized oil was noted in 13 patients and no uptake in one patient. There was no serious complication that related to the omental embolization, such as omental or bowel ischemia. The cumulative survival rates from the time of the TACE of the OA were 81% at 6 months and 68% at 12 months. Conclusion: TACE of the OA is safe and has a potential therapeutic effect in the treatment of HCC

13 CFR 120.934 - Collateral.

Science.gov (United States)

2010-01-01

... Loan Program (504) 504 Loans and Debentures § 120.934 Collateral. The CDC usually takes a second lien position on the Project Property to secure the 504 loan. Sometimes additional collateral is required. (In... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Collateral. 120.934 Section 120...

Computed tomographic diagnosis for hepatofugal collaterals in portal hypertension. Comparative study of CT with percutaneous transhepatic portography

Energy Technology Data Exchange (ETDEWEB)

Iida, Akihiko; Sano, Akira; Imanaka, Kazufumi; Nishizawa, Sadahiko; Sasai, Keisuke

1984-08-01

This paper deals with the diagnostic capability of CT scan for hepatofugal collaterals in 22 patients with portal hypertension. The patients studied were those who underwent percutaneous transhepatic portography (PTP) and CT scan within a short period. Each collateral vein demonstrated by PTP was classified into three grades according to its caliber (d): (1) Grade I, d<5mm, (2) Grade II, 5mmcollaterals on the CT images was analyzed comparatively. Most collaterals in Grade I failed to demonstrate on CT images, while Grade II and III well coincided with CT images, at the rate of 64% and 100% respectively. CT features of these vascular structures showed multiformity: rounded, ovoid comma-shaped, tubular or beaded, etc. To get an accurate diagnosis, each image must be analyzed together with the adjacent upper and lower ones on the fully-performed contrast enhancement technique. Image deterioration of CT was concerned with Partial Volume Phenomenon for small vessels, and motion artifacts produced by intestinal peristalses, cardiac beats and occasionally by difficulty of breath holding. In spite of such diagnostic Iimitation, CT scan provides much qualified images than conventional angiographic procedures in evaluating hepatofugal collaterals.

Renovascular hypertension due to insufficient collateral flow in segmental artery occulusion

International Nuclear Information System (INIS)

Park, Y. H.; Lee, S. Y.; Kim, S. H.; Sohn, H. S.; Chung, S. K.

2001-01-01

We report a case in which a 33-year-old woman with renovascular hypertension due to insufficient collateral flow in segmental renal artery occlusion demonstrated abnormality on captopril renal scintigram. Baseline renal scintigram with DTPA showed normal perfusion and excretion in left kidney and captopril renal scintigram with DTPA showed a focal area of decreased perfusion and delayed clearance in lower half of left kidney, suggesting segmental renal artery stenosis. Selective left renal arteriography showed complete obstruction in proximal portion of anterior segmental artery with multiple small collateral vessels from posterior segmental artery and capsular artery and delayed opacification in lower half of left kidney. These findings are suggestive of segmental hypoperfusion due to insufficient collateral blood flow resulting to positive captopril response. Patient's blood pressure have been controlled well with ACE (angiotensin converting enzyme) inhibitor and calcium channel blocker for 2 year. Follow-up baseline renal scintigram with MAG3 showed normal perfusion and excretion in left kidney and captopril renal scintigram with MAG3 showed a focal area of decreased perfusion and delayed clearance in lower lateral portion of left kidney, which was smaller size than that of previous renal scintigram. And captopril renal scintigram with DMSA demonstrated a small area of decreased DMSA uptake on this lesion compared to baseline DMSA scintigram

Reexamining the empirical relation between loan risk and collateral: The roles of collateral characteristics and types

OpenAIRE

Berger, Allen N.; Frame, Scott; Ioannidou, Vasso

2011-01-01

This paper offers a possible explanation for the conflicting empirical results in the literature concerning the relation between loan risk and collateral. Specifically, we posit that different economic characteristics or types of collateral pledges may be associated with the empirical dominance of the four different risk-collateral channels implied by economic theory. For our sample, collateral overall is associated with lower loan risk premiums and a higher probability of ex post loan nonper...

12 CFR 950.7 - Collateral.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Collateral. 950.7 Section 950.7 Banks and... Advances to Members § 950.7 Collateral. (a) Eligible security for advances to all members. At the time of... interest in collateral that meets the requirements of one or more of the following categories: (1) Mortgage...

Ulnar Collateral Ligament Injuries of the Thumb

Science.gov (United States)

McKeon, Kathleen E.; Gelberman, Richard H.; Calfee, Ryan P.

2013-01-01

Background: The clinical diagnosis of thumb ulnar collateral ligament disruption has been based on joint angulation during valgus stress testing. This report describes a definitive method of distinguishing between complete and partial ulnar collateral ligament injuries by quantifying translation of the proximal phalanx on the metacarpal head during valgus stress testing. Methods: Sixty-two cadaveric thumbs underwent standardized valgus stress testing under fluoroscopy with the ulnar collateral ligament intact, following an isolated release of the proper ulnar collateral ligament, and following a combined release of both the proper and the accessory ulnar collateral ligament (complete ulnar collateral ligament release). Following complete ulnar collateral ligament release, the final thirty-seven thumbs were also analyzed after the application of a valgus force sufficient to cause 45° of valgus angulation at the metacarpophalangeal joint to model more severe soft-tissue injury. Two independent reviewers measured coronal plane joint angulation (in degrees), ulnar joint line gap formation (in millimeters), and radial translation of the proximal phalanx on the metacarpal head (in millimeters) on digital fluoroscopic images that had been randomized. Results: Coronal angulation across the stressed metacarpophalangeal joint progressively increased through the stages of the testing protocol: ulnar collateral ligament intact (average [and standard deviation], 20° ± 8.1°), release of the proper ulnar collateral ligament (average, 23° ± 8.3°), and complete ulnar collateral ligament release (average, 30° ± 8.9°) (p collateral ligament release (5.7 ± 1.5 mm), to that following complete ulnar collateral ligament release (7.2 ± 1.5 mm) (p collateral ligament (1.6 ± 0.8 mm vs. 1.5 ± 0.9 mm in the intact state). There was a significant increase in translation following release of the complete ulnar collateral ligament complex (3.0 ± 0.9 mm; p collateral ligament

Medial collateral ligament tear entrapped within a proximal tibial physeal separation: imaging findings and operative reduction

Energy Technology Data Exchange (ETDEWEB)

McAnally, James L.; Eberhardt, Steven C.; Mlady, Gary W. [University of New Mexico, Department of Radiology, Albuquerque, NM (United States); Fitzpatrick, Jennifer; Bosch, Patrick [University of New Mexico, Department of Orthopaedics and Rehabilitation, Albuquerque, NM (United States)

2008-10-15

Entrapped soft tissues such as periosteum and tendons have been described within joints and physeal fractures in the literature and frequently result in irreducible fractures and posttraumatic growth disturbances. We believe this case represents a novel presentation of acute, preoperative, magnetic resonance (MR) imaging diagnosis of a torn medial collateral ligament entrapped within a proximal tibial physeal separation. This case is presented with MR imaging and operative correlation of the findings. (orig.)

Medial collateral ligament tear entrapped within a proximal tibial physeal separation: imaging findings and operative reduction

International Nuclear Information System (INIS)

McAnally, James L.; Eberhardt, Steven C.; Mlady, Gary W.; Fitzpatrick, Jennifer; Bosch, Patrick

2008-01-01

Entrapped soft tissues such as periosteum and tendons have been described within joints and physeal fractures in the literature and frequently result in irreducible fractures and posttraumatic growth disturbances. We believe this case represents a novel presentation of acute, preoperative, magnetic resonance (MR) imaging diagnosis of a torn medial collateral ligament entrapped within a proximal tibial physeal separation. This case is presented with MR imaging and operative correlation of the findings. (orig.)

Lateral collateral ligament (image)

Science.gov (United States)

The lateral collateral ligament connects the end of the femur (thigh) to the top of the fibula (the thin bone that runs next to the shin bone). The lateral collateral ligament provides stability against varus stress. Varus stress ...

Computed tomographic manifestations of abdominal and pelvic venous collaterals

International Nuclear Information System (INIS)

Pagani, J.J.; Thomas, J.L.; Bernardino, M.E.

1982-01-01

Obstruction of blood flow through the inferior vena cava and portal vein may produce venous collaterals. These include the paravertebral venous system and its communications with the ascending lumbar veins and azygous/hemiazygous system; gonadal, periureteric, and other retroperitoneal veins; abdominal wall veins; hemorrhoidal venous plexus; and the portal venous system. The anatomic location of these vessels is discussed. Computed tomography demonstrates them as round or tubular structures that are isodens when compared with other venous structures following contrast material administration. Techniques of examination and methods of differentiation of these vascular structures from other abnormalities, especially lymphadenopathy, are discussed

12 CFR 950.10 - Collateral valuation; appraisals.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Collateral valuation; appraisals. 950.10...-BALANCE SHEET ITEMS ADVANCES Advances to Members § 950.10 Collateral valuation; appraisals. (a) Collateral valuation. Each Bank shall determine the value of collateral securing the Bank's advances in accordance with...

12 CFR 615.5060 - Special collateral requirement.

Science.gov (United States)

2010-01-01

... AFFAIRS, LOAN POLICIES AND OPERATIONS, AND FUNDING OPERATIONS Collateral § 615.5060 Special collateral... be withdrawn from collateral upon the expiration of 1 year from the date of the loan closing, unless... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Special collateral requirement. 615.5060...

A Framework for Collateral Risk Control Determination

OpenAIRE

Didier Cossin; Zhijiang Huang; Daniel Aunon-Nerin; Fer nando González

2002-01-01

This paper derives a general framework for collateral risk control determination in repurchase transactions or repos. The objective is to treat consistently heterogeneous collateral so that the collateral taker has a similar risk exposure whatever the collateral pledged. The framework measures the level of risk with the probability of incurring a loss higher than a pre-specified level given two well-known parameters used to manage the intrinsic risk of collateral: marking to market and haircu...

27 CFR 17.104 - Deposit of collateral.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Deposit of collateral. 17... PRODUCTS Bonds and Consents of Sureties § 17.104 Deposit of collateral. Except as otherwise provided by law... as collateral security in lieu of bonds obtained from surety companies. Deposit of collateral...

7 CFR 4287.113 - Release of collateral.

Science.gov (United States)

2010-01-01

... Loans § 4287.113 Release of collateral. (a) All releases of collateral with a value exceeding $100,000... loan. The Agency may, at its discretion, require an appraisal of the remaining collateral in cases... (a) of this section, lenders may, over the life of the loan, release collateral (other than personal...

Anterior mediastinal paraganglioma: A case for preoperative embolization

Directory of Open Access Journals (Sweden)

Shakir Murtaza

2012-07-01

Full Text Available Abstract Background Paraganglioma is a rare but highly vascular tumor of the anterior mediastinum. Surgical resection is a challenge owing to the close proximity to vital structures including the heart, trachea and great vessels. Preoperative embolization has been reported once to facilitate surgical treatment. Case presentation We report a case of anterior mediastinal paraganglioma that was embolized preoperatively, and was resected without the need for cardiopulmonary bypass and without major bleeding complications. Conclusion We make a case to further the role of preoperative embolization in the treatment of mediastinal paragangliomas.

29 CFR 20.32 - Liquidation of collateral.

Science.gov (United States)

2010-07-01

... 29 Labor 1 2010-07-01 2010-07-01 true Liquidation of collateral. 20.32 Section 20.32 Labor Office... collateral. An agency holding security or collateral which may be liquidated and the proceeds applied on... demand, unless the cost of disposing of the collateral will be disproportionate to its value or special...

25 CFR 502.5 - Collateral agreement.

Science.gov (United States)

2010-04-01

... 25 Indians 2 2010-04-01 2010-04-01 false Collateral agreement. 502.5 Section 502.5 Indians NATIONAL INDIAN GAMING COMMISSION, DEPARTMENT OF THE INTERIOR GENERAL PROVISIONS DEFINITIONS OF THIS CHAPTER § 502.5 Collateral agreement. Collateral agreement means any contract, whether or not in writing...

30 CFR 800.21 - Collateral bonds.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Collateral bonds. 800.21 Section 800.21 Mineral... FOR SURFACE COAL MINING AND RECLAMATION OPERATIONS UNDER REGULATORY PROGRAMS § 800.21 Collateral bonds. (a) Collateral bonds, except for letters of credit, cash accounts, and real property, shall be...

Diabetes diminishes the portal-systemic collateral vascular response to vasopressin via vasopressin receptor and Gα proteins regulations in cirrhotic rats.

Directory of Open Access Journals (Sweden)

Jing-Yi Lee

Full Text Available Liver cirrhosis may lead to portal-systemic collateral formation and bleeding. The hemostatic effect is influenced by the response of collateral vessels to vasoconstrictors. Diabetes and glucose also influence vasoresponsiveness, but their net effect on collaterals remains unexplored. This study investigated the impact of diabetes or glucose application on portal-systemic collateral vasoresponsiveness to arginine vasopressin (AVP in cirrhosis. Spraque-Dawley rats with bile duct ligation (BDL-induced cirrhosis received vehicle (citrate buffer or streptozotocin (diabetic, BDL/STZ. The in situ collateral perfusion was done after hemodynamic measurements: Both were perfused with Krebs solution, D-glucose, or D-glucose and NaF, with additional OPC-31260 for the BDL/STZ group. Splenorenal shunt vasopressin receptors and Gα proteins mRNA expressions were evaluated. The survival rate of cirrhotic rats was decreased by STZ injection. The collateral perfusion pressure changes to AVP were lower in STZ-injected groups, which were reversed by OPC-31260 (a V2R antagonist and overcome by NaF (a G protein activator. The splenorenal shunt V2R mRNA expression was increased while Gα proteins mRNA expressions were decreased in BDL/STZ rats compared to BDL rats. The Gαq and Gα11 mRNA expressions also correlated with the maximal perfusion pressure changes to AVP. Diabetes diminished the portal-systemic collateral vascular response to AVP in rats with BDL-induced cirrhosis, probably via V2 receptor up-regulation and Gα proteins down-regulation.

Sex Differences in the Cerebral Collateral Circulation.

Science.gov (United States)

Faber, James E; Moore, Scott M; Lucitti, Jennifer L; Aghajanian, Amir; Zhang, Hua

2017-06-01

Premenopausal women and intact female rodents sustain smaller cerebral infarctions than males. Several sex-dependent differences have been identified as potential contributors, but many questions remain unanswered. Mice exhibit wide variation in native collateral number and diameter (collateral extent) that is dependent on differences in genetic background, aging, and other comorbidities and that contributes to their also-wide differences in infarct volume. Likewise, variation in infarct volume correlates with differences in collateral-dependent blood flow in patients with acute ischemic stroke. We examined whether extent of pial collateral arterioles and posterior communicating collateral arteries (PComAs) differ depending on sex in young, aged, obese, hypertensive, and genetically different mice. We combined new data with meta-analysis of our previously published data. Females of C57BL/6J (B6) and BALB/cByJ (BC) strains sustained smaller infarctions than males after permanent MCA occlusion. This protection was unchanged in BC mice after introgression of the B6 allele of Dce1, the major genetic determinant of variation in pial collaterals among mouse strains. Consistent with this, collateral extent in these and other strains did not differ with sex. Extent of PComAs and primary cerebral arteries also did not vary with sex. No dimorphism was evident for loss of pial collateral number and/or diameter (collateral rarefaction) caused by aging, obesity, and hypertension, nor for collateral remodeling after pMCAO. However, rarefaction was greater in females with long-standing hypertension. We conclude that smaller infarct volume in female mice is not due to greater collateral extent, greater remodeling, or less rarefaction caused by aging, obesity, or hypertension.

28 CFR 94.25 - Collateral sources.

Science.gov (United States)

2010-07-01

... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Collateral sources. 94.25 Section 94.25... Victim Expense Reimbursement Program Coverage § 94.25 Collateral sources. (a) The amount of expenses... collateral source in connection with the same act of international terrorism. In cases in which a claimant...

12 CFR 615.5050 - Collateral requirements.

Science.gov (United States)

2010-01-01

... provided in this paragraph, the collateral value of notes and other obligations representing loans made... allowance for loan losses (except as provided for in § 615.5090). (2) The collateral value of loans in... loans, judgments, and contracts adjusted for any allowance for losses. (3) The collateral value of loans...

Military Robotics and Collateral Damage

National Research Council Canada - National Science Library

Kott, Robert Douglass ;Alexander

2004-01-01

.... Such concepts raise important questions in terms of their impact on collateral damage. In a broader context, western warfare in general places a continuously growing emphasis on issues of collateral damage...

Evaluation of portosystemic collaterals by MDCT-MPR imaging for management of hemorrhagic esophageal varices

International Nuclear Information System (INIS)

Kodama, Hideaki; Aikata, Hiroshi; Takaki, Shintaro; Azakami, Takahiro; Katamura, Yoshio; Kawaoka, Tomokazu; Hiramatsu, Akira; Waki, Koji; Imamura, Michio; Kawakami, Yoshiiku; Takahashi, Shoichi; Toyota, Naoyuki; Ito, Katsuhide; Chayama, Kazuaki

2010-01-01

Objective: To study the correlation between changes in portosystemic collaterals, evaluated by multidetector-row computed tomography imaging using multiplanar reconstruction (MDCT-MPR), and prognosis in patients with hemorrhagic esophageal varices (EV) after endoscopic treatment. Methods: Forty-nine patients with primary hemostasis for variceal bleeding received radical endoscopic treatment: endoscopic injection sclerotherapy (EIS) or endoscopic variceal ligation (EVL). Patients were classified according to the rate of reduction in feeding vessel diameter on MDCT-MPR images, into the narrowing (n = 24) and no-change (n = 25) groups. We evaluated changes in portosystemic collaterals by MDCT-MPR before and after treatment, and determined rebleeding and survival rates. Results: The left gastric and paraesophageal (PEV) veins were recognized as portosystemic collaterals in 100 and 80%, respectively, of patients with EV on MDCT-MPR images. The rebleeding rates at 1, 2, 3, and 5 years after endoscopic treatment were 10, 15, 23, and 23%, respectively, for the narrowing group, and 17, 24, 35, and 67%, respectively, for the no-change group (P = 0.068). Among no-change group, the rebleeding rate in patients with large PEV was significantly lower than that with small PEV (P = 0.027). The rebleeding rate in patients with small PEV of the no-change group was significantly higher than that in the narrowing group (P = 0.018). There was no significant difference in rebleeding rates between the no-change group with a large PEV and narrowing group (P = 0.435). Conclusion: Changes in portosystemic collaterals evaluated by MDCT-MPR imaging correlate with rebleeding rate. Evaluation of portosystemic collaterals in this manner would provide useful information for the management of hemorrhagic EV.

[Hemodynamic phenomena in retrobulhar and eyeball vessels].

Science.gov (United States)

Modrzejewska, Monika

2011-01-01

The purpose of this review was to evaluate factors connected with blood flow and indices regulating vascular diameter and some parameters influencing retrobulbar circulation such as type of vascular resistance, anatomical structure of vascular wall and vessel lumen. Neurogenic and angiogenic factors, rheological blood composition, presence of anatomical and pathological obstructions on blood flow pathway as well as degree of development of collateral circulation pathways--have influence on the volume and blood flow velocity in eyeball. There were discussed bulbar circulation hemodynamics, emphasizing the importance of perfusion pressure. The role of risk factors was underlined for pathological lesions in vessels supplying blood to eyeball and in ophthalmic artery (OA) and its collaterals, in central retinal artery (CRA) as well as posterior ciliary arteries (PCAs), and in venous system carrying away blood from eye. IN CONCLUSION--the results of many studies of retrobulbar blood flow in different types of ophthalmic diseases of the vascular etiopathogenesis indicate that registry of the mean values of blood flow parameters and vascular resistance indices parallel to measurement of blood flow spectrum in OA, CRA, PCAs arteries, might contribute much information to explain or to evaluate nature of pathological changes in retinal and choroidal circulation.

The relationship between fasting blood glucose variability and coronary artery collateral formation in type 2 diabetes patients with coronary artery disease.

Science.gov (United States)

Cheng, Gang; Mahmoudi, Hilda; Chokshi, Binna; Fernandez, Marlena; Kazemi, Vahid; Lamaa, Nader

2017-09-01

Coronary collaterals are an alternative source of blood supply to ischemic myocardium. Well-developed coronary collateral arteries in patients with coronary artery disease (CAD) limit the size of acute myocardial infarction and improves survival. The aim of this study was to investigate the relationship between glycemic variability and coronary collateral formation in patients with type 2 diabetes mellitus and CAD. Consecutive patients undergoing percutaneous coronary intervention or coronary artery bypass grafting procedures were studied. Multivariate logistic regression models were used to examine the association between coronary artery collateral formation graded by Rentrope classification and glycemic variability, measured by coefficient variation of fasting blood glucose. In our study, we retrospectively enrolled 300 patients, of whom 239 were diabetic (age: 70.1±11.9, 56% men) and 61 were nondiabetic (age: 71.5±11.5, 72% men). Diabetic patients were further stratified as follows: those with poor coronary collateral artery development (n=171, age: 69.7±12.4, 55% men) and those with good coronary collateral artery development (n=68, age 71.1±10.8, 59% men) according to the Rentrope classification. Our findings did not show association between glycemic variability and coronary collateral vessels development after controlling for potential confounders (odds ratio: 2.51; 95% confidence interval: 0.57-11.03; P=0.22). The culprit lesion (≥75% stenosis) in the left anterior descending artery and the right coronary artery was more frequent in the good collateral group compared with the poor collateral group (66 vs. 50%, P=0.02; 63 vs. 45%, P=0.01 respectively). Glycemic variability is not associated with coronary collateral artery formation in patients with type 2 diabetes mellitus and CAD.

Angiopoietin-2 impairs collateral artery growth associated with the suppression of the infiltration of macrophages in mouse hindlimb ischaemia

Directory of Open Access Journals (Sweden)

Xiaoyong Tan

2016-10-01

Full Text Available Abstract Background Angiopoietin-2 (Ang-2, a ligand of the Tie-2 receptor, plays an important role in maintaining endothelial cells and in destabilizing blood vessels. Collateral artery growth (arteriogenesis is a key adaptive response to arterial occlusion. It is unknown whether the destabilization of blood vessels by Ang-2 can affect arteriogenesis and modulate mononuclear cell function. This study aimed to investigate the effects of Ang-2 on collateral artery growth. Methods Hindlimb ischaemia model was produced in C57BL/6 mice by femoral artery ligation. Blood flow perfusion was measured using a laser Doppler perfusion imager quantitative RT-PCR analysis was applied to identify the level of angiogenic factors. Results After the induction of hindlimb ischaemia, blood flow recovery was impaired in mice treated with recombinant Ang-2 protein; this was accompanied by a reduction of peri-collateral macrophage infiltration. In addition, quantitative RT-PCR analysis revealed that Ang-2 treatment decreased monocyte chemotactic protein-1 (MCP-1, platelet-derived growth factor-BB (PDGF-BB mRNA levels in ischaemic adductor muscles. Ang-2 can lead to macrophage M1/M2 polarization shift inhibition in the ischaemic muscles. Furthermore, Ang-2 reduced the in vitro inflammatory response in macrophages and vascular cells involved in arteriogenesis. Conclusions Our results demonstrate that Ang-2 is essential for efficient arteriogenesis, which controls macrophage infiltration.

Understanding Collateral Evolution in Linux Device Drivers

DEFF Research Database (Denmark)

Padioleau, Yoann; Lawall, Julia Laetitia; Muller, Gilles

2006-01-01

no tools to help in this process, collateral evolution is thus time consuming and error prone.In this paper, we present a qualitative and quantitative assessment of collateral evolution in Linux device driver code. We provide a taxonomy of evolutions and collateral evolutions, and use an automated patch......-analysis tool that we have developed to measure the number of evolutions and collateral evolutions that affect device drivers between Linux versions 2.2 and 2.6. In particular, we find that from one version of Linux to the next, collateral evolutions can account for up to 35% of the lines modified in such code....

Portosystemic collateral circulation in the falciform ligament: evaluation with three dimensional dynamic contrast enhanced MR angiography in patients with portal hypertension

International Nuclear Information System (INIS)

Wu Zhuo; Liang Biling; Li Yong; Zhong Jinglian; Ye Ruixin; Zhang Rong

2009-01-01

Objective: The purpose of our study was to investigate three dimensional dynamic contrast enhanced MR angiography(3D DCE MRA) in the detection of portosystemic collateral circulation in the falciform ligament in patients with portal hypertension. Methods: From April 2003 to July 2008, 53 portal hypertension patients with varices in the falciform ligament were evaluated with 3D DCE MRA. Two radiologists independently assessed the number, diameter, location and drainages of the portosystemic collateral circulation in the falciform ligament according to the information on the 3D DCE MRA. Results: The veins in the falciform ligament were classified into the superior and inferior groups, and both groups arise from the left trunk of the portal vein. In our study, the number of varices detected on 3D DCE MRA images varied from 1 to 3, and the diameters of these vessels varied from 0.4 to 2.6 cm. The inferior group consisted of paraumbilical/umbilical veins (47 cases), which flowed toward umbilicus and then drained upwards (n=16) including deep superior epigastric veins (n=7), superficial superior epigastric veins (n=9), downwards (n=40) including deep inferior epigastric veins (n=7), superficial inferior epigastric veins (n=33), or upwards and downwards at the same time (n=9). The superior group of vessels in the falciform ligament were directly anastomosed with the internal thoracic vessels (n=6). Conclusion: In patients with portal hypertension, 3D DCE MRA can optimally demonstrate the portosystemic collateral circulation in the falciform ligament, which includes the superior and inferior drainage groups. (authors)

Large intracranial vessel occlusion arising after radiotherapy for craniopharingioma. A case report and review of the literature

Energy Technology Data Exchange (ETDEWEB)

Noguchi, Osamu; Iwasa, Satoshi; Kohno, Norio; Nozaki, Miwako (Kiryu Kohsei General Hospital, Gunma (Japan))

1994-10-01

We report a patient who developed occlusion of the intracranial major arteries induced by radiation therapy for craniopharyngioma. The patient, a 9-year-old boy, presented with deterioration of vision, nausea and vomiting. He underwent a right ventriculo-peritoneal shunt operation, and the tumor was partially removed. Postoperatively, he received focal radiation therapy with total of 60 Gy. Preoperative cerebral angiography, cerebral vessels had no sigh of occlusive lesion or stenosis. One year after irradiation, he started to have repeated cerebral ischemic attacks. But no regrowth of the tumor was detected on CT scans. Two years and 8 months after irradiation, he suddenly had right hemiparesis. Cerebral angiography revealed severe stenosis of the right anterior cerebral artery (precommunicating segment), middle cerebral artery (horizontal portion) and terminal portion of the right carotid artery. Left carotid angiography showed complete occlusion of the terminal portion of the internal carotid artery and collateral vessels from the middle meningeal artery to the middle cerebral artery through the shunt burr hole. He has been treated conservatively and is doing well except for slight right hemiparesis. Our experience shows that the risk of occlusive cerebrovasculopathy after radiation therapy should be taken into account, especially in children. (author).

Reexamining the empirical relation between loan risk and collateral:the roles of collateral liquidity and types

OpenAIRE

Berger, Allen N.; Frame, W. Scott; Ioannidou, Vasso

2016-01-01

This paper offers a possible explanation for the conflicting results in the literature concerning the empirical relation between collateral and loan risk. We posit that differences in collateral characteristics, such as liquidity, may be associated with the empirical dominance of different risk-collateral relations implied by economic theory. Using credit registry data and a novel identification strategy to control for borrower and lender selection effects allows us to differentiate between t...

How Collateral Laws Shape Lending and Sectoral Activity

OpenAIRE

Calomiris, Charles W.; Larrain, Mauricio; Liberti, José; Sturgess, Jason

2015-01-01

This paper investigates the effect of cross-country differences in collateral laws regarding movable assets on lending and sectoral allocation of resources. Using micro-level loan data for a sample of emerging market countries we show that loan-to-values of loans collateralized with movable assets are on average 21 percentage points higher in countries with strong-collateral laws relative to immovable assets. Further, stronger collateral laws tilt collateral composition away from immovable to...

The Impact of Conscious Sedation versus General Anesthesia for Stroke Thrombectomy on the Predictive Value of Collateral Status: A Post Hoc Analysis of the SIESTA Trial.

Science.gov (United States)

Schönenberger, S; Pfaff, J; Uhlmann, L; Klose, C; Nagel, S; Ringleb, P A; Hacke, W; Kieser, M; Bendszus, M; Möhlenbruch, M A; Bösel, J

2017-08-01

Radiologic selection criteria to identify patients likely to benefit from endovascular stroke treatment are still controversial. In this post hoc analysis of the recent randomized Sedation versus Intubation for Endovascular Stroke TreAtment (SIESTA) trial, we aimed to investigate the impact of sedation mode (conscious sedation versus general anesthesia) on the predictive value of collateral status. Using imaging data from SIESTA, we assessed collateral status with the collateral score of Tan et al and graded it from absent to good collaterals (0-3). We examined the association of collateral status with 24-hour improvement of the NIHSS score, infarct volume, and mRS at 3 months according to the sedation regimen. In a cohort of 104 patients, the NIHSS score improved significantly in patients with moderate or good collaterals (2-3) compared with patients with no or poor collaterals (0-1) ( P = .011; mean, -5.8 ± 7.6 versus -1.1 ± 10.7). Tan 2-3 was also associated with significantly higher ASPECTS before endovascular stroke treatment (median, 9 versus 7; P collateral status (0.1 versus 2.3), the sedation modes conscious sedation and general anesthesia were not associated with significant differences in the predictive value of collateral status regarding infarction size or functional outcome. The sedation mode, conscious sedation or general anesthesia, did not influence the predictive value of collaterals in patients with large-vessel occlusion anterior circulation stroke undergoing thrombectomy in the SIESTA trial. © 2017 by American Journal of Neuroradiology.

Change in the collateral and accessory collateral ligament lengths of the proximal interphalangeal joint using cadaveric model three-dimensional laser scanning.

Science.gov (United States)

Sandhu, S S; Dreckmann, S; Binhammer, P A

2016-05-01

The purpose of this study was to assess the lengths of the index and middle finger proximal interphalangeal joint ligaments and determine the relative changes in the collateral and accessory collateral ligament lengths at 0°, 45° and 90° flexion. We generated three-dimensional scans of 16 finger (eight index and eight middle) proximal interphalangeal joints to assess relative changes in ligament length. Significant changes were found between 45°-90° and 0°-90° for the ulnar collateral ligament of the index finger and both collateral ligaments of the middle finger between 45°-90° and 0°-90°. No significant changes in length were found for the radial collateral ligament of the index finger or the accessory collateral ligaments of the index and middle fingers. Overall, it was found that the collateral ligament length changed significantly, but there was no significant change in the accessory collateral ligaments. Therapeutic IV. © The Author(s) 2015.

27 CFR 24.159 - Release of collateral security.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Release of collateral... § 24.159 Release of collateral security. Collateral security pledged and deposited will be released only in accordance with the provisions of 31 CFR part 225. The collateral security will not be released...

22 CFR 213.17 - Liquidation of collateral.

Science.gov (United States)

2010-04-01

... Liquidation of collateral. Where the CFO holds a security instrument with a power of sale or has physical possession of collateral, he may liquidate the security or collateral and apply the proceeds to the overdue... circumstances require judicial foreclosure. However, collection from other businesses, including liquidation of...

7 CFR 3.15 - Liquidation of collateral.

Science.gov (United States)

2010-01-01

... 7 Agriculture 1 2010-01-01 2010-01-01 false Liquidation of collateral. 3.15 Section 3.15... and Compromise of Claims § 3.15 Liquidation of collateral. (a) In accordance with applicable statutes and regulations, agencies may liquidate security or collateral through a sale or a nonjudicial...

40 CFR 13.16 - Liquidation of collateral.

Science.gov (United States)

2010-07-01

... STANDARDS Collection § 13.16 Liquidation of collateral. Where the Administrator holds a security instrument with a power of sale or has physical possession of collateral, he may liquidate the security or... businesses, including liquidation of security or collateral, is not a prerequisite to requiring payment by a...

32 CFR 536.51 - Collateral source rule.

Science.gov (United States)

2010-07-01

... 32 National Defense 3 2010-07-01 2010-07-01 true Collateral source rule. 536.51 Section 536.51... AGAINST THE UNITED STATES Investigation and Processing of Claims § 536.51 Collateral source rule. Where permitted by applicable state or maritime law, damages recovered from collateral sources are payable under...

10 CFR 1015.210 - Liquidation of collateral.

Science.gov (United States)

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Liquidation of collateral. 1015.210 Section 1015.210... for the Administrative Collection of Claims § 1015.210 Liquidation of collateral. (a) DOE may liquidate security or collateral through the exercise of a power of sale in the security instrument or a...

Multiple coil closure of isolated aortopulmonary collateral

Directory of Open Access Journals (Sweden)

Padhi Sumanta

2010-01-01

Full Text Available A 7-month-old girl was diagnosed to have large aortopulmonary collateral during evaluation for congestive heart failure. There was no other evidence of cardiopulmonary disease. The collateral was successfully closed with multiple coils delivered sequentially. We describe the issues associated during closure of the aortopulmonary collateral in this case. To the best of our knowledge, this is the first reported case of large aortopulmonary collateral presenting with heart failure in an otherwise structurally normal heart that was closed successfully with multiple coils delivered sequentially.

Longitudinal anterior-to-posterior shift of collateral channels in patients with moyamoya disease: an implication for its hemorrhagic onset.

Science.gov (United States)

Yamamoto, Shusuke; Hori, Satoshi; Kashiwazaki, Daina; Akioka, Naoki; Kuwayama, Naoya; Kuroda, Satoshi

2018-03-23

OBJECTIVE This study aimed to assess longitudinal changes in the collateral channels originating from the lenticulostriate artery (LSA), posterior communicating artery (PCoA), and anterior and posterior choroidal arteries (AChA and PChA, respectively) during disease progression and/or aging. The impact of collateral channels on onset type was also examined. METHODS This study included 71 involved hemispheres in 41 patients with moyamoya disease. The disease was categorized into 6 stages according to Suzuki's angiographic staging system. The degree of development of each moyamoya vessel was categorized into 3 grades. RESULTS The LSA started to dilate in stage 2, showed the most prominent development in stage 3, and decreased in more advanced stages (p PCoA started to dilate in stage 3 and showed the most prominent development in stage 4 (p = 0.03). The PChA started to dilate in stage 3 and showed the most prominent development in stages 4 to 5 (p PCoA (p = 0.02, R = 0.28) and PChA (p PCoA, AChA, and PChA more distinctly developed in hemispheres with intracerebral or intraventricular hemorrhage than in hemispheres with ischemic stroke or transient ischemic attack (p < 0.001, p = 0.03, and p = 0.03, respectively). CONCLUSIONS This study suggests that the collateral channels through moyamoya vessels longitudinally shift from the anterior to posterior component during disease progression and aging, which may be closely related to the onset of hemorrhagic stroke in adult moyamoya disease.

27 CFR 17.114 - Release of collateral.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Release of collateral. 17... PRODUCTS Bonds and Consents of Sureties Termination of Bonds § 17.114 Release of collateral. The release of collateral security pledged and deposited to satisfy the bond requirement of this part is governed by the...

26 CFR 403.29 - Deposit of collateral.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Deposit of collateral. 403.29 Section 403.29... ADMINISTRATION DISPOSITION OF SEIZED PERSONAL PROPERTY Seizures and Forfeitures § 403.29 Deposit of collateral... principal by the United States, may be pledged and deposited by claimants as collateral security in lieu of...

27 CFR 72.25 - Deposit of collateral.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Deposit of collateral. 72... Seizures and Forfeitures § 72.25 Deposit of collateral. (a) Bonds or notes of the United States, or other... be pledged and deposited by claimants as collateral security in lieu of corporate sureties in...

Reexamining the Empirical Relation between Loan Risk and Collateral : The Role of the Economic Characteristics of Collateral

OpenAIRE

Berger, A.N.; Frame, W.S.; Ioannidou, V.

2012-01-01

Abstract: This paper offers a possible explanation for the conflicting results in the literature concerning the empirical relation between collateral and loan risk. We posit that certain economic characteristics of collateral may be associated with the empirical dominance of different risk-collateral channels implied by economic theory, namely the “lender selection,” “borrower selection,” “risk-shifting,” and “loss mitigation” channels. Each of these four channels has different predictions re...

13 CFR 120.343 - Collateral.

Science.gov (United States)

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Collateral. 120.343 Section 120.343 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Special Purpose Loans Export Working Capital Program (ewcp) § 120.343 Collateral. A Borrower must give SBA a first security...

Collateral in Loan Classification and Provisioning

OpenAIRE

In W Song

2002-01-01

Adequate loan classification practices are an essential part of a sound and effective credit risk-management process in a bank. Failure to identify deterioration in credit quality in a timely manner can aggravate and prolong the problem. Two key issues arise with regard to the use of collateral in the context of loan classification and provisioning. In particular, the questions arise whether collateral should be taken into account in classifying a collateralized loan, and whether it should be...

46 CFR 308.509 - Collateral deposit fund.

Science.gov (United States)

2010-10-01

... 46 Shipping 8 2010-10-01 2010-10-01 false Collateral deposit fund. 308.509 Section 308.509... Risk Cargo Insurance Ii-Open Policy War Risk Cargo Insurance § 308.509 Collateral deposit fund. (a) Requirements. An assured electing to use a cash collateral deposit fund pursuant to § 308.507 shall comply with...

Corruption of coronary collateral growth in metabolic syndrome: Role of oxidative stress.

Science.gov (United States)

Pung, Yuh Fen; Chilian, William M

2010-12-26

The myocardium adapts to ischemic insults in a variety of ways. One adaptation is the phenomenon of acute preconditioning, which can greatly ameliorate ischemic damage. However, this effect wanes within a few hours and does not confer chronic protection. A more chronic adaptation is the so-called second window of preconditioning, which enables protection for a few days. The most potent adaptation invoked by the myocardium to minimize the effects of ischemia is the growth of blood vessels in the heart, angiogenesis and arteriogenesis (collateral growth), which prevent the development of ischemia by enabling flow to a jeopardized region of the heart. This brief review examines the mechanisms underlying angiogenesis and arteriogenesis in the heart. The concept of a redox window, which is an optimal redox state for vascular growth, is discussed along with signaling mechanisms invoked by reactive oxygen species that are stimulated during ischemia-reperfusion. Finally, the review discusses of some of the pathologies, especially the metabolic syndrome, that negatively affect collateral growth through the corruption of redox signaling processes.

12 CFR 263.17 - Collateral attacks on adjudicatory proceeding.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Collateral attacks on adjudicatory proceeding... Collateral attacks on adjudicatory proceeding. If an interlocutory appeal or collateral attack is brought in... shall be excused based on the pendency before any court of any interlocutory appeal or collateral attack. ...

12 CFR 1780.16 - Collateral attacks on adjudicatory proceeding.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Collateral attacks on adjudicatory proceeding... Rules § 1780.16 Collateral attacks on adjudicatory proceeding. If an interlocutory appeal or collateral... subpart shall be excused based on the pendency before any court of any interlocutory appeal or collateral...

12 CFR 509.17 - Collateral attacks on adjudicatory proceeding.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Collateral attacks on adjudicatory proceeding....17 Collateral attacks on adjudicatory proceeding. If an interlocutory appeal or collateral attack is... shall be excused based on the pendency before any court of any interlocutory appeal or collateral attack. ...

[Comprehension and explanation of meridians and collaterals theory in the background of the spread of western medicine into the East in the Ming and Qing Dynasties].

Science.gov (United States)

Li, Su-Yun

2010-06-01

In the background of the spread of western medicine into the East in the Ming and Qing Dynasties, Chinese doctors who had accepted western medicine referred to western medical knowledge and began to use the methods of anatomical observation and demonstrating to explain the objective structure of meridians and collaterals. They tried to adopt the artery and vessel explaining the shape of meridian and the blood circle and pulmonary respiration explaining the circulation of Ying-Wei. When the anatomy structures could not perfectly equal to meridians and collaterals, some doctors put forward the gasification feature of meridian to explain the reason. These results suggest that there are difference between meridians and collaterals and pure anatomy concepts, which serves as significant reference and edification for later generations.

Adenocarcinoma of the pancreatic head: preoperative helical CT. Criteria of resectability

International Nuclear Information System (INIS)

Kozima, Shigeru; Szelagowski, Carlos; Tisserand, Guy L.; Ocampo, Carlos; Zandalazini, Hugo; Silva, Walter; Oria, Alejandro; Vidovic, Gustavo; Varas, Pablo

2001-01-01

Objective: The purpose of this study is to determine the accuracy of biphasic helical CT scanning in predicting resectability of adenocarcinoma of the head of the pancreas by staying tumor involvement of the portal and superior mesenteric veins. Material and methods: 46 patients with proven adenocarcinoma of the head of the pancreas who underwent curative or palliative surgery were studied with preoperative biphasic helical CT scanning. Tumor involvement of the portal and mesenteric veins was graduated on a 1-3 scale based on circumferential contiguity of the tumor vessel. Grade 1: without contact; grade 2: tumor involvement of less than 50% of the vessel; grade 3: tumor involvement of more than 50%. Results: The total number of vessels evaluated was 92. In our series the preoperative biphasic helical CT was accurate in 77% for resectability and unresectability. Conclusion: Our experience of staging in 3 grades with biphasic helical CT, vessel involvement the portal and superior mesenteric veins of adenocarcinoma of the head of the pancreas is highly specific for unresectable tumor in patients who were graded 2 and 3. (author)

Collateral and its Substitutes in Emerging Markets' Lending

OpenAIRE

Lukas Menkhoff; Doris Neuberger; Ornsiri Rungruxsirivorn

2011-01-01

Due to opaque information and weak enforcement in emerging loan markets, the need for collateral is high, whereas borrowers lack adequate assets to pledge as collateral. How is this puzzle solved? We find for a representative sample from Northeast Thailand that indeed most loans do not include any tangible assets as collateral. Instead, lenders enforce collateral-free loans through third-party guarantees and relationship lending, but also through modifying loan terms, such as reducing loan si...

Lateral collateral ligament of the elbow joint

DEFF Research Database (Denmark)

Olsen, Bo Sanderhoff; Vaesel, M T; Søjbjerg, Jens Ole

1996-01-01

The structure and kinematics of the lateral collateral ligament of the elbow joint were investigated in 10 cadaveric specimens. The lateral collateral ligament was observed to be a distinct part of the lateral collateral ligament complex. It contains posterior fibers that pass through the annular....... Division of the posterolateral capsule caused no further laxity. Cutting the lateral collateral ligament induced a maximum laxity of 11.8 degrees at 110 degrees of flexion in forced varus and a maximum laxity of 20.6 degrees at 110 degrees of flexion in forced external rotation. The corresponding maximal...... posterior radial head translation was observed at 80 degrees to 100 degrees of flexion and was 5.7 mm in forced varus and 8.1 mm in forced external rotation. This study suggests the lateral collateral ligament to be an important stabilizer of the humeroulnar joint and the radial head in forced varus...

Moral hazard in the credit market when the collateral value is stochastic

OpenAIRE

Niinimäki, Juha-Pekka

2010-01-01

This theoretical paper explores the effects of costly and non-costly collateral on moral hazard, when collateral value may fluctuate. Given that all collateral is costly, stochastic collateral will entail the same positive incentive effects as nonstochastic collateral, provided the variation in collateral value is modest. If it is large, the incentive effects are smaller under stochastic collateral. With non-costly collateral, stochastic collateral entails positive incentive effects or no eff...

The application of preoperative computed tomography angiogram for hemispherectomy

Directory of Open Access Journals (Sweden)

Jiqing Qiu

2017-10-01

Full Text Available Hemispherectomy is an established neurosurgical procedure for unilateral refractory epilepsy . Even though the surgical approach has evolved greatly, prevention of catastrophic intraoperative bleeding is a challenge. It is important that surgeons know the abnormal blood vessel before surgery. Herein, we report our experience with two patients in whom computed tomographic angiography (CTA was used in the preoperative evaluation for hemispherectomy. CTA allowed for precise anatomical delineation of the hemispheric vascular abnormalities. Preoperative CTA showed that the specific cerebral arteries and their branches ipsilateral to the lesion were slender. Elaborate preoperative planning for the surgical approach helped prevent catastrophic intraoperative bleeding. Favorable outcomes were achieved in both children. CTA appears to confer a considerable advantage in the preoperative vascular and anatomical delineation in patients scheduled for hemispherectomy. To our knowledge, this is the first report about the application of CTA for hemispherectomy preoperative planning.

41 CFR 105-55.014 - Liquidation of collateral.

Science.gov (United States)

2010-07-01

... collateral. 105-55.014 Section 105-55.014 Public Contracts and Property Management Federal Property... Administration 55-COLLECTION OF CLAIMS OWED THE UNITED STATES § 105-55.014 Liquidation of collateral. (a) The General Services Administration (GSA) will liquidate security or collateral through the exercise of a...

48 CFR 48.104-3 - Sharing collateral savings.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Sharing collateral savings... CONTRACT MANAGEMENT VALUE ENGINEERING Policies and Procedures 48.104-3 Sharing collateral savings. (a) The Government shares collateral savings with the contractor, unless the head of the contracting activity has...

48 CFR 2448.104-3 - Sharing collateral savings.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Sharing collateral savings... DEVELOPMENT CONTRACT MANAGEMENT VALUE ENGINEERING 2448.104-3 Sharing collateral savings. (a) The authority of the HCA to determine that the cost of calculating and tracking collateral savings will exceed the...

Collateral circulations in inferior vena cava obstruction

International Nuclear Information System (INIS)

Lee, Jong Beum; Park, Jae Hyung; Han, Man Chung; Park, Soo Soung

1985-01-01

Obstruction of the inferior vena cava (IVC) is an uncommon condition, and the collateral pathway varies according to the level, extent, duration and the cause of obstruction. Membranous obstruction of IVC in its hepatic portion might be one of the principle cause among Korean, though not reported till now. Analytical study was performed in 26 cases of IVC obstruction with various cause. 1. The level of the obstruction showed relatively even distribution as follows, upper caval in 11 cases, middle caval in 6 cases and infrarenal in 9 cases. 2. The main cause of upper caval obstruction was membranous obstruction. 3. As a whole, the main collateral pathway was the central route (22 cases: 85%). 4. Characteristic collateral pathway unique to upper caval obstruction was transhepatic venous collateral, developed between the obstructed segment and unobstructed segment of IVC. 5. Scalloping of left cardiac border produced by pericardiophrenic venous collateral was characteristic simple chest x-ray finding in IVC obstruction

Electroacupuncture improves neurovascular unit reconstruction by promoting collateral circulation and angiogenesis

Directory of Open Access Journals (Sweden)

Lei Shi

2017-01-01

Full Text Available Acupuncture at Shuigou (GV26 shows good clinical efficacy for treating stroke, but its mechanism remains poorly understood. In this study, a cerebral infarction model of ischemia/reperfusion injury received electroacupuncture at GV26 (15 Hz and 1 mA, continuous wave [biphasic pulses], for 5 minutes. Electroacupuncture effectively promoted regional cerebral blood flow on the infarct and non-infarct sides, increased infarct lesions, lectin, and number of blood vessels, upregulated von Willebrand factor and cell proliferation marker Ki67 expression, and diminished neurological severity score. These findings confirm that electroacupuncture at GV26 promotes establishment of collateral circulation and angiogenesis, and improves neurological function.

Reexamining the Empirical Relation between Loan Risk and Collateral : The Role of the Economic Characteristics of Collateral

NARCIS (Netherlands)

Berger, A.N.; Frame, W.S.; Ioannidou, V.

2012-01-01

Abstract: This paper offers a possible explanation for the conflicting results in the literature concerning the empirical relation between collateral and loan risk. We posit that certain economic characteristics of collateral may be associated with the empirical dominance of different

Collateral Circulation in Chronic Total Occlusions - An Interventional Perspective

Science.gov (United States)

Choo, Gim-Hooi

2015-01-01

Human coronary collaterals are inter-coronary communications that are believed to be present from birth. In the presence of chronic total occlusions, recruitment of flow via these collateral anastomoses to the arterial segment distal to occlusion provide an alternative source of blood flow to the myocardial segment at risk. This mitigates the ischemic injury. Clinical outcome of coronary occlusion ie. severity of myocardial infarction/ischemia, impairment of cardiac function and possibly survival depends not only on the acuity of the occlusion, extent of jeopardized myocardium, duration of ischemia but also to the adequacy of collateral circulation. Adequacy of collateral circulation can be assessed by various methods. These coronary collateral channels have been used successfully as a retrograde access route for percutaneous recanalization of chronic total occlusions. Factors that promote angiogenesis and further collateral remodeling ie. arteriogenesis have been identified. Promotion of collateral growth as a therapeutic target in patients with no suitable revascularization option is an exciting proposal.

Collateral Circulation in Chronic Total Occlusions - an interventional perspective.

Science.gov (United States)

Choo, Gim-Hooi

2015-09-09

Human coronary collaterals are inter-coronary communications that are believed to be present from birth. In the presence of chronic total occlusions, recruitment of flow via these collateral anastomoses to the arterial segment distal to occlusion provide an alternative source of blood flow to the myocardial segment at risk. This mitigates the ischemic injury. Clinical outcome of coronary occlusion ie. severity of myocardial infarction/ischemia, impairment of cardiac function and possibly survival depends not only on the acuity of the occlusion, extent of jeopardized myocardium, duration of ischemia but also to the adequacy of collateral circulation. Adequacy of collateral circulation can be assessed by various methods. These coronary collateral channels have been used successfully as a retrograde access route for percutaneous recanalization of chronic total occlusions. Factors that promote angiogenesis and further collateral remodeling ie. arteriogenesis have been identified. Promotion of collateral growth as a therapeutic target in patients with no suitable revascularization option is an exciting proposal.

Medial collateral ligament healing one year after a concurrent medial collateral ligament and anterior cruciate ligament injury: an interdisciplinary study in rabbits.

Science.gov (United States)

Yamaji, T; Levine, R E; Woo, S L; Niyibizi, C; Kavalkovich, K W; Weaver-Green, C M

1996-03-01

The optimal treatment for concurrent injuries to the medial collateral and anterior cruciate ligaments has not been determined, despite numerous clinical and laboratory studies. The objective of this study was to examine the effect of surgical repair of the medial collateral ligament on its biomechanical and biochemical properties 52 weeks after such injuries. In the left knee of 12 skeletally mature New Zealand White rabbits, the medial collateral ligament was torn and the anterior cruciate ligament was transected and then reconstructed. This is an experimental model previously developed in our laboratory. In six rabbits, the torn ends of the medial collateral ligament were repaired, and in the remaining six rabbits, the ligament was not repaired. Fifty-two weeks after injury, we examined varus-valgus and anterior-posterior knee stability; structural properties of the femur-medial collateral ligament-tibia complex; and mechanical properties, collagen content, and mature collagen crosslinking of the medial collateral ligament. We could not detect significant differences between repair and nonrepair groups for any biomechanical or biochemical property. Our data support clinical findings that when the medial collateral and anterior cruciate ligaments are injured concurrently and the anterior cruciate ligament is reconstructed, conservative treatment of the ruptured medial collateral ligament can result in successful healing.

24 CFR 1005.107 - What is eligible collateral?

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false What is eligible collateral? 1005... URBAN DEVELOPMENT LOAN GUARANTEES FOR INDIAN HOUSING § 1005.107 What is eligible collateral? (a) In general. A loan guaranteed under section 184 may be secured by any collateral authorized under and not...

Pleiotrophin levels are associated with improved coronary collateral circulation.

Science.gov (United States)

Türker Duyuler, Pinar; Duyuler, Serkan; Gök, Murat; Kundi, Harun; Topçuoğlu, Canan; Güray, Ümit

2018-01-01

Elucidation of the underlying mechanisms of angiogenesis and arteriogenesis in coronary collateral formation is necessary for new therapies. Pleiotrophin is a secreted multifunctional cytokine and associated with the formation of functional cardiovascular neovascularization in a series of experimental animal models. We aimed to evaluate the serum levels of pleiotrophin in patients with chronic total coronary artery occlusion and poor or good collateral development. We included 88 consecutive patients (mean age of the entire population: 63.7±12.1 years, 68 male patients) with stable angina pectoris who underwent coronary angiography and had chronic total occlusion in at least one major coronary artery. Collateral grading was performed according to the Rentrop classification. After grading, patients were divided into poor collateral circulation (Rentrop grade 0 and 1) and good collateral circulation (Rentrop grades 2 and 3) groups. Serum pleiotrophin levels were measured using a commercial human ELISA kit. Fifty-eight patients had good and 30 patients had poor coronary collaterals. The good collateral group had higher serum pleiotrophin levels than the poor collateral group (690.1±187.9 vs. 415.3±165.9 ng/ml, Pcollateral development (odds ratio: 1.007; confidence interval: 1.003-1.012; P=0.002). This study showed that increased serum pleiotrophin levels are associated with better developed coronary collateral circulation. Further studies are needed to better understand the relationship.

45 CFR 160.532 - Collateral estoppel.

Science.gov (United States)

2010-10-01

... 45 Public Welfare 1 2010-10-01 2010-10-01 false Collateral estoppel. 160.532 Section 160.532 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES ADMINISTRATIVE DATA STANDARDS AND RELATED REQUIREMENTS GENERAL ADMINISTRATIVE REQUIREMENTS Procedures for Hearings § 160.532 Collateral estoppel. When a...

Collaterals 2016: Translating the collaterome around the globe.

Science.gov (United States)

Liebeskind, David S; Woolf, Graham W; Shuaib, Ashfaq

2017-06-01

Collaterals 2016 (third International Symposium on Collaterals to the Brain) was a multidisciplinary scientific conference focused on collateral circulation in acute ischemic stroke. Decisive challenges include generalizability of optimal triage and selection paradigms based on collateral status for definitive treatment of acute ischemic stroke, rapid dissemination of expert methods, and the urgent need to leverage networking opportunities for stroke science related to the hemodynamics of collaterals. The collaterome, or individual capacity to offset ischemia in the brain, and determination of a favorable collateral profile have become pivotal factors in consideration of the precision medicine of stroke decision-making. The conference convened over 50 invited faculty from around the world to connect on-site participants at a state-of-the-art facility with remote audiences in more than 22 countries and regions. The 2½-day program was structured into 40-min sessions devoted to key issues in translating the collaterome in acute stroke therapy across the globe. This unique forum of expertise emphasized the timely impact of collaterals on a monumental scale, encouraging maximal participation, rapid diffusion and added value of a diverse networking resource. The meeting format established a model geographical framework and innovative videoconferencing platform for future scientific conferences.

42 CFR 402.15 - Collateral estoppel.

Science.gov (United States)

2010-10-01

... 42 Public Health 2 2010-10-01 2010-10-01 false Collateral estoppel. 402.15 Section 402.15 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS CIVIL MONEY PENALTIES, ASSESSMENTS, AND EXCLUSIONS General Provisions § 402.15 Collateral estoppel...

20 CFR 498.114 - Collateral estoppel.

Science.gov (United States)

2010-04-01

... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Collateral estoppel. 498.114 Section 498.114 Employees' Benefits SOCIAL SECURITY ADMINISTRATION CIVIL MONETARY PENALTIES, ASSESSMENTS AND RECOMMENDED EXCLUSIONS § 498.114 Collateral estoppel. In a proceeding under section 1129 of the Social Security Act that...

Dynamics of the Collateral Encyclopedia

DEFF Research Database (Denmark)

Thellefsen, Torkild Leo; Sørensen, Bent; Thellefsen, Martin Muderspach

2015-01-01

Both Umberto Eco and Charles S. Peirce have been concerned with the notion of background knowledge. Eco refers to background knowledge as the encyclopedia; Peirce’s term of reference is collateral experience. The aim of this article is to investigate the degree to which these two concepts...... are comparable. We focus on one major metaphysical issue, viz. the fact that Eco defines collateral experience, which is the first step in any process of cognition, as private, whereas Peirce, as a realist, would never accept the concept of private thoughts, feelings, etc. We suggest that freeing collateral...... experience from its nominalistic nomenclature makes possible a comparison and synthesis of Eco’s and Peirce’s conceptions when seen from the perspectives of their cognitive type, nuclear type, and molar content....

42 CFR 3.532 - Collateral estoppel.

Science.gov (United States)

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Collateral estoppel. 3.532 Section 3.532 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS PATIENT SAFETY ORGANIZATIONS AND PATIENT SAFETY WORK PRODUCT Enforcement Program § 3.532 Collateral estoppel. When a final...

42 CFR 1003.114 - Collateral estoppel.

Science.gov (United States)

2010-10-01

... 42 Public Health 5 2010-10-01 2010-10-01 false Collateral estoppel. 1003.114 Section 1003.114 Public Health OFFICE OF INSPECTOR GENERAL-HEALTH CARE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OIG AUTHORITIES CIVIL MONEY PENALTIES, ASSESSMENTS AND EXCLUSIONS § 1003.114 Collateral estoppel. (a) Where a...

All-inside arthroscopic lateral collateral ligament repair for ankle instability with a knotless suture anchor technique.

Science.gov (United States)

Vega, Jordi; Golanó, Pau; Pellegrino, Alexandro; Rabat, Eduard; Peña, Fernando

2013-12-01

Recently, arthroscopic-assisted techniques have been described to treat lateral ankle instability with excellent results. However, complications including neuritis of the superficial peroneal or sural nerve, and pain or discomfort due to a prominent anchor or suture knot have been reported. The aim of this study was to describe a novel technique, the "all-inside arthroscopic lateral collateral ankle ligament repair," and its results for treating patients with ankle instability. Sixteen patients (10 men and 6 women, mean age 29.3 years, 17-46) with lateral ankle instability were treated with an arthroscopic procedure. Using a suture passer and a knotless anchor, the ligaments were repaired with an all-inside technique. The right ankle was affected in 10 cases. Mean follow-up was 22.3 (12-35) months. On arthroscopic examination, 13 patients had an isolated anterior talofibular ligament (ATFL) injury, and in 3 patients, both the ATFL and calcaneofibular ligament (CFL) were affected. All-inside arthroscopic anatomic repair of the lateral collateral ligament complex was performed in all cases. All patients reported subjective improvement of their ankle instability. The mean AOFAS score increased from 67 preoperatively to 97 at final follow-up. No major complications were reported. The all-inside arthroscopic ligament repair was a safe, reliable, and reproducible technique that both provided an anatomic repair of the lateral collateral ligament complex and restored ankle stability while preserving all the advantages of an arthroscopic technique. Level IV, retrospective case series.

Blood pressure and collateral circulation in acute ischemic stroke.

Science.gov (United States)

Wufuer, A; Mijiti, P; Abudusalamu, R; Dengfeng, H; Jian, C; Jianhua, M; Xiaoning, Z

2018-03-20

This study aimed to evaluate the effect of different blood pressure (BP) parameters on the collateral circulation in a retrospective cohort of patients with acute ischemic stroke and ipsilateral internal carotid artery (ICA) occlusion. The degree of intracranial collaterals was graded according to the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) Collateral Flow Grading System. At 12-72 h after stroke onset, six BP measurements were obtained in 124 patients with ICA occlusion. Baseline clinical and imaging characteristics were collected. Group comparisons were performed, and the collateral score (CS) was assessed and entered into a logistic regression analysis. In all, 80 (64.5%) patients displayed good collateral filling (CS ≥ 2). Good intracranial collaterals were more frequently associated with the development of collaterals in the anterior communicating artery, posterior communicating artery, and leptomeningeal artery. The systolic blood pressure (SBP; p = 0.018), diastolic blood pressure (DBP; p = 0.013), and mean arterial pressure (MAP; p = 0.016) were significantly associated with good CS. Median CS was highest when SBP was 120-130 mm Hg (p = 0.034). Logistic regression analysis showed that hypertension (p = 0.026, OR: 0.380, 95% CI: 0.163-0.890) was a significant predictor of poor CS. The development of collateral circulation in patients with acute ischemic stroke with ICA occlusion may be influenced by BP. A moderately decreased SBP is associated with good integrity of the collateral circulation in patients with acute ischemic stroke with occlusion of the ICA.

Zinc release from Schaffer collaterals and its significance.

Science.gov (United States)

Takeda, Atsushi; Nakajima, Satoko; Fuke, Sayuri; Sakurada, Naomi; Minami, Akira; Oku, Naoto

2006-02-15

On the basis of the evidence that approximately 45% of Schaffer collateral boutons are zinc-positive, zinc release from Schaffer collaterals and its action were examined in hippocampal slices. When zinc release from Schaffer collaterals was examined using ZnAF-2, a membrane-impermeable zinc indicator, ZnAF-2 signal in the stratum radiatum of the CA1 was increased by tetanic stimuli at 100 Hz for 1s, suggesting that zinc is released from Schaffer collaterals in a calcium- and impulse-dependent manner. An in vivo microdialysis experiment indicated that the perfusion with 10 microM zinc significantly decreases extracellular glutamate concentration in the CA1. When tetanic stimuli at 100 Hz for 5s were delivered to the dentate granule cells, the increase in calcium signal in the stratum radiatum of the CA1, as well as in the stratum lucidum of the CA3, was attenuated by addition of 10 microM zinc, while enhanced by addition of 1mM CaEDTA, a membrane-impermeable zinc chelator. The increase in calcium signal in the CA1, in which Schaffer collateral synapses exist, during delivery of tetanic stimuli at 100 Hz for 1s to the Schaffer collateral-commissural pathway was also significantly enhanced by addition of 1mM CaEDTA. These results suggest that zinc released from Schaffer collaterals suppressively modulates presynaptic and postsynaptic calcium signaling in the CA1, followed by the suppression of glutamate release.

Prominent porto-systemic collateral pathways in patients with portal hypertension: demonstration by gadolinium-enhanced magnetic resonance angiography; Vias colaterais porto-sistemicas exuberantes em portadores de hipertensao portal: demonstracao pela angiografia por ressonancia magnetica com gadolinio

Energy Technology Data Exchange (ETDEWEB)

Caldana, Rogerio Pedreschi; Bezerra, Alexandre Araujo Sergio; Cecin, Alexnadre Oliveira; Souza, Luis Ronan Marques Ferreira de; Goldman, Susan Menasce; D' Ippolito, Giuseppe; Szejnfeld, Jacob [Universidade Federal de Sao Paulo (UNIFESP/EPM), Sao Paulo, SP (Brazil). Dept. de Diagnostico por Imagem]. E-mail: rogercal@uol.com.br

2003-03-01

To demonstrate the usefulness of gadolinium-enhanced magnetic resonance angiography in the evaluation of prominent porto-systemic collateral pathways. We reviewed the images from 40 patients with portal hypertension studied with gadolinium-enhanced magnetic resonance angiography and selected illustrative cases of prominent porto-systemic collateral pathways. The scans were performed using high field equipment (1.5 Tesla) and a 3 D volume technique. Image were obtained after intravenous injection of paramagnetic contrast media using a power injector. Magnetic resonance angiography demonstrated with precision the porto-systemic collateral pathways, particularly when investigating extensive territories or large vessels. The cases presented show the potential of this method in the investigation of patients with portal hypertension. Gadolinium-enhanced magnetic resonance angiography is a useful method for the evaluation of patients with portal hypertension and prominent collateral pathways. (author)

12 CFR 308.17 - Collateral attacks on adjudicatory proceeding.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Collateral attacks on adjudicatory proceeding... PRACTICE RULES OF PRACTICE AND PROCEDURE Uniform Rules of Practice and Procedure § 308.17 Collateral attacks on adjudicatory proceeding. If an interlocutory appeal or collateral attack is brought in any...

12 CFR 19.17 - Collateral attacks on adjudicatory proceeding.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Collateral attacks on adjudicatory proceeding... OF PRACTICE AND PROCEDURE Uniform Rules of Practice and Procedure § 19.17 Collateral attacks on adjudicatory proceeding. If an interlocutory appeal or collateral attack is brought in any court concerning all...

Radiologic analysis of the medical collateral ligament rupture

International Nuclear Information System (INIS)

Cho, Chung Che; Lee, Chang Jun; Kim, Kun Sang; Park, Soo Soung

1979-01-01

The medical collateral ligament rupture is the most common injury involving the knee joint ligaments. The ruptured medical collateral ligaments of 73 cases with clinical and surgical confirmations were radiologically analyzed. The results were obtained as follows: 1. The most risky age for tearing of the medical collateral ligament was third to fifth decades (50 cases of male and 23 of females). 2. The most common cause of the medical collateral ligament rupture was traffic accident (82.2%). 3. The mean distance of medial knee joint space was 7.9 ± 2.0 mm on the normal side and 13.7 ± 4.2 mm on the affected side. 4. The mean degree of knee joint space was 10.1 ± 2.5 on the normal side and 14.7 ± 3.8 on the affected side. 5. The fibula was the bone fractured most frequently in association with the medial collateral ligament rupture (30.6%).

A computational fluid dynamics study on hemodynamics for different locations of the distal anastomosis of a bypass nearby a collateral vessel in the femoropopliteal area.

Science.gov (United States)

Rivera, J; van der Graaf, G B; Escudero, J R; Bellmunt, S; van de Vosse, F

2014-11-01

Revascularization of the femoropopliteal sector is often performed by the placement of a bypass. In this paper, we have studied the effects of hemodynamics on patency of the bypass for different positions of the distal anastomosis close to a collateral artery. Computational fluid dynamics (CFD) are used for this study. The cardiac cycle-averaged wall shear stress (WSS) and oscillation index (OSI) have been analyzed. Low WSS and high OSI may increase the risk of intimal hyperplasia (IH), which may reduce bypass patency. From the CFD simulations, spots of low WSS and high OSI are found within and near the entrance of the collateral artery, near the suture line, at the floor, toe, and heel. We regarded flow ratios of 20:80 and of 35:65. It is found that for the high flow ratio anastomosis located proximal to the collateral artery is clearly more advantageous. However for the low flow ratio anastomosis located distal to the collateral artery seems to be slightly more advantageous, the results are less conclusive. One of the studied flow geometries has been validated by in vitro experiments using a time resolved particle image velocimetry technique. Velocity fields from these experiments are in good agreement with the CFD results. Copyright © 2014 John Wiley & Sons, Ltd.

12 CFR 747.17 - Collateral attacks on adjudicatory proceeding.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Collateral attacks on adjudicatory proceeding... INVESTIGATIONS Uniform Rules of Practice and Procedure § 747.17 Collateral attacks on adjudicatory proceeding. If an interlocutory appeal or collateral attack is brought in any court concerning all or any part of an...

Portosystemic pressure reduction achieved with TIPPS and impact of portosystemic collaterals for the prediction of the portosystemic-pressure gradient in cirrhotic patients

Energy Technology Data Exchange (ETDEWEB)

Grözinger, Gerd, E-mail: gerd.groezinger@med.uni-tuebingen.de [Department of Diagnostic Radiology, Department of Radiology, University of Tübingen (Germany); Wiesinger, Benjamin; Schmehl, Jörg; Kramer, Ulrich [Department of Diagnostic Radiology, Department of Radiology, University of Tübingen (Germany); Mehra, Tarun [Department of Dermatology, University of Tübingen (Germany); Grosse, Ulrich; König, Claudius [Department of Diagnostic Radiology, Department of Radiology, University of Tübingen (Germany)

2013-12-01

Purpose: The portosystemic pressure gradient is an important factor defining prognosis in hepatic disease. However, noninvasive prediction of the gradient and the possible reduction by establishment of a TIPSS is challenging. A cohort of patients receiving TIPSS was evaluated with regard to imaging features of collaterals in cross-sectional imaging and the achievable reduction of the pressure gradient by establishment of a TIPSS. Methods: In this study 70 consecutive patients with cirrhotic liver disease were retrospectively evaluated. Patients received either CT or MR imaging before invasive pressure measurement during TIPSS procedure. Images were evaluated with regard to esophageal and fundus varices, splenorenal collaterals, short gastric vein and paraumbilical vein. Results were correlated with Child stage, portosystemic pressure gradient and post-TIPSS reduction of the pressure gradient. Results: In 55 of the 70 patients TIPSS reduced the pressure gradient to less than 12 mmHg. The pre-interventional pressure and the pressure reduction were not significantly different between Child stages. Imaging features of varices and portosystemic collaterals did not show significant differences. The only parameter with a significant predictive value for the reduction of the pressure gradient was the pre-TIPSS pressure gradient (r = 0.8, p < 0.001). Conclusions: TIPSS allows a reliable reduction of the pressure gradient even at high pre-interventional pressure levels and a high collateral presence. In patients receiving TIPSS the presence and the characteristics of the collateral vessels seem to be too variable to draw reliable conclusions concerning the portosystemic pressure gradient.

Portosystemic pressure reduction achieved with TIPPS and impact of portosystemic collaterals for the prediction of the portosystemic-pressure gradient in cirrhotic patients

International Nuclear Information System (INIS)

Grözinger, Gerd; Wiesinger, Benjamin; Schmehl, Jörg; Kramer, Ulrich; Mehra, Tarun; Grosse, Ulrich; König, Claudius

2013-01-01

Purpose: The portosystemic pressure gradient is an important factor defining prognosis in hepatic disease. However, noninvasive prediction of the gradient and the possible reduction by establishment of a TIPSS is challenging. A cohort of patients receiving TIPSS was evaluated with regard to imaging features of collaterals in cross-sectional imaging and the achievable reduction of the pressure gradient by establishment of a TIPSS. Methods: In this study 70 consecutive patients with cirrhotic liver disease were retrospectively evaluated. Patients received either CT or MR imaging before invasive pressure measurement during TIPSS procedure. Images were evaluated with regard to esophageal and fundus varices, splenorenal collaterals, short gastric vein and paraumbilical vein. Results were correlated with Child stage, portosystemic pressure gradient and post-TIPSS reduction of the pressure gradient. Results: In 55 of the 70 patients TIPSS reduced the pressure gradient to less than 12 mmHg. The pre-interventional pressure and the pressure reduction were not significantly different between Child stages. Imaging features of varices and portosystemic collaterals did not show significant differences. The only parameter with a significant predictive value for the reduction of the pressure gradient was the pre-TIPSS pressure gradient (r = 0.8, p < 0.001). Conclusions: TIPSS allows a reliable reduction of the pressure gradient even at high pre-interventional pressure levels and a high collateral presence. In patients receiving TIPSS the presence and the characteristics of the collateral vessels seem to be too variable to draw reliable conclusions concerning the portosystemic pressure gradient

Documenting and automating collateral evolutions in Linux device drivers

DEFF Research Database (Denmark)

Padioleau, Yoann; Hansen, René Rydhof; Lawall, Julia

2008-01-01

. Manually performing such collateral evolutions is time-consuming and unreliable, and has lead to errors when modifications have not been done consistently. In this paper, we present an automatic program transformation tool, Coccinelle, for documenting and automating device driver collateral evolutions...... programmer. We have evaluated our approach on 62 representative collateral evolutions that were previously performed manually in Linux 2.5 and 2.6. On a test suite of over 5800 relevant driver files, the semantic patches for these collateral evolutions update over 93% of the files completely...

Propranolol modulates the collateral vascular responsiveness to vasopressin via a G(α)-mediated pathway in portal hypertensive rats.

Science.gov (United States)

Lee, Jing-Yi; Huo, Teh-Ia; Huang, Hui-Chun; Lee, Fa-Yauh; Lin, Han-Chieh; Chuang, Chiao-Lin; Chang, Ching-Chih; Wang, Sun-Sang; Lee, Shou-Dong

2011-12-01

Gastro-oesophageal variceal haemorrhage is one of the most dreadful complications of portal hypertension and can be controlled with vasoconstrictors. Nevertheless, sympathetic tone abnormality and vascular hyporesponsiveness in portal hypertension may impede the haemostatic effects of vasoconstrictors. Propranolol, a β-blocker binding the G-protein-coupled adrenoceptor, is a portal hypotensive agent. However, whether propranolol influences the collateral vasoresponse is unknown. Portal hypertension was induced by PVL (portal vein ligation) in Sprague-Dawley rats. In an acute study with an in situ perfusion model, the collateral responsiveness to AVP (arginine vasopressin) was evaluated with vehicle, propranolol (10 μmol/l), propranolol plus suramin (100 μmol/l, a G(α) inhibitor) or suramin pre-incubation. G(α) mRNA expression in the splenorenal shunt, the most prominent intra-abdominal collateral vessel, was measured. In the chronic study, rats received DW (distilled water) or propranolol (10 mg x kg(-1) of body weight x day(-1)) for 9 days. Then the concentration-response relationship of AVP and G(α) mRNA expression were assessed. Propranolol pre-incubation elevated the perfusion pressure changes of collaterals in response to AVP, which was inhibited by suramin. The splenorenal shunt G(αq) and G(α11) mRNA expression were enhanced by propranolol. The group treated with propranolol plus suramin had a down-regulation of G(α11) as compared with the propranolol group. Chronic propranolol treatment reduced mean arterial pressure, PP (portal pressure) and the perfusion pressure changes of collaterals to AVP. G(αs) expression was up-regulated. In conclusion, propranolol pre-incubation enhanced the portal-systemic collateral AVP responsiveness in portal hypertensive rats, which was related to G(αq) and G(α11) up-regulation. In contrast, the attenuated AVP responsiveness by chronic propranolol treatment was related to G(αs) up-regulation. The G(α) signalling

Noninvasive assessment of coronary collaterals in man by PET perfusion imaging

International Nuclear Information System (INIS)

Demer, L.L.; Gould, K.L.; Goldstein, R.A.; Kirkeeide, R.L.

1990-01-01

At present, coronary collateralization cannot be identified or assessed noninvasively in patients. In animal studies, coronary collaterals are associated with coronary steal, defined as a regional fall in perfusion during coronary arteriolar vasodilation. To determine the effect of coronary arteriolar vasodilation on collateral bed perfusion in man, myocardial perfusion imaging was performed before and after pharmacologic coronary vasodilation in patients with coronary artery disease (CAD). Regional myocardial activity of 82 Rb or 13 N ammonia was measured by positron emission tomography (PET) at rest and with intravenous dipyridamole/handgrip stress in 28 patients with angiographic collaterals and in 25 control patients with similar CAD severity by quantitative arteriography. Regional myocardial activity decreased after dipyridamole, indicating coronary steal, in 25 of 28 patients with angiographic collaterals and in only 4 of 25 control patients without angiographic collaterals. These findings suggest that developed collaterals are associated with myocardial steal in patients with CAD, allowing potential use of PET for non-invasive identification of coronary collateralization

Vertebrocarotid collateral in extracranial carotid artery occlusions: digital subtraction angiography findings

International Nuclear Information System (INIS)

Oguzkurt, Levent; Kizilkilic, Osman; Tercan, Fahri; Tuerkoez, Riza; Yildirim, Tuelin

2005-01-01

The internal and external carotid arteries are usually considered occluded distal to a common carotid artery occlusion but some collateral vessels may provide blood keeping the internal and external carotid arteries patent distal to the occlusion. Most common communication in such a case is diversion of blood from muscular branches of the vertebral artery to occipital branch of the external carotid artery which in turn could maintain blood flow into the internal carotid artery, a condition called carotid steal. We encountered vertebrocarotid anastomoses maintaining the patency of carotid circulation in six patients. Patients were four females and two males, ages ranging from 40 to 67 (mean age: 56) years. Five of the patients had ischemic cerebral symptoms. The origin of the external carotid artery was occluded in two and the whole common carotid artery in the remaining four patients. Two patients had double steal, carotid and subclavian at the same time. There was also severe stenosis or occlusion of at least one other major extracranial cerebral artery in all the cases. This concomitant involvement of the second extracranial cerebral artery was thought to be the main reason for the development of vertebrocarotid collateral. In contrast to most of the previously published reports claiming the inadequacy of angiography when compared with colour Doppler ultrasonography, angiography finely depicted the distal patency of the carotid circulation and all the collaterals in detail in every case. Selective injection of the vertebral artery ipsilateral to the occlusion, is the key to demonstrate distal patency of the carotid circulation in cases of proximal carotid occlusion. Demonstration of patency of the distal circulation is very important because some of the patients might get benefit from a reconstructive surgery

Vertebrocarotid collateral in extracranial carotid artery occlusions: digital subtraction angiography findings

Energy Technology Data Exchange (ETDEWEB)

Oguzkurt, Levent; Kizilkilic, Osman; Tercan, Fahri; Tuerkoez, Riza; Yildirim, Tuelin

2005-02-01

The internal and external carotid arteries are usually considered occluded distal to a common carotid artery occlusion but some collateral vessels may provide blood keeping the internal and external carotid arteries patent distal to the occlusion. Most common communication in such a case is diversion of blood from muscular branches of the vertebral artery to occipital branch of the external carotid artery which in turn could maintain blood flow into the internal carotid artery, a condition called carotid steal. We encountered vertebrocarotid anastomoses maintaining the patency of carotid circulation in six patients. Patients were four females and two males, ages ranging from 40 to 67 (mean age: 56) years. Five of the patients had ischemic cerebral symptoms. The origin of the external carotid artery was occluded in two and the whole common carotid artery in the remaining four patients. Two patients had double steal, carotid and subclavian at the same time. There was also severe stenosis or occlusion of at least one other major extracranial cerebral artery in all the cases. This concomitant involvement of the second extracranial cerebral artery was thought to be the main reason for the development of vertebrocarotid collateral. In contrast to most of the previously published reports claiming the inadequacy of angiography when compared with colour Doppler ultrasonography, angiography finely depicted the distal patency of the carotid circulation and all the collaterals in detail in every case. Selective injection of the vertebral artery ipsilateral to the occlusion, is the key to demonstrate distal patency of the carotid circulation in cases of proximal carotid occlusion. Demonstration of patency of the distal circulation is very important because some of the patients might get benefit from a reconstructive surgery.

Screening in the credit market when the collateral value is stochastic

OpenAIRE

Niinimäki, Juha-Pekka

2009-01-01

This theoretical paper explores screening with loan collateral when both the collateral value and the probability of project success fluctuate. Some model versions challenge the classic findings of Bester (1985) by showing that high-risk borrowers may in such case be more willing to pledge collateral than low-risk borrowers. Abundant collateral then would not signal low risk. The results may help explain the mixed empirical findings on the role of collateral. The paper also extends the analys...

Collateral Intimate Partner Homicide

Directory of Open Access Journals (Sweden)

Emily Meyer

2013-04-01

Full Text Available Collateral intimate partner homicide (CIPH is an underinvestigated genre of intimate partner violence (IPV where an individual(s connected to the IPV victim is murdered. We conducted a content analysis of a statewide database of CIPH newspaper articles (1990-2007. Out of 111 collateral murder victims, there were 84 IPV female focal victims and 84 male perpetrators. The most frequently reported CIPH decedent was the focal victim’s new partner (30%; 45% of focal victims were themselves killed. News reports framed CIPH as the unexpected result of interpersonal conflict, despite evidence of a systematic pattern of coercion and violence that capitulated in murder.

Detection of human collateral circulation by vasodilation-thallium-201 tomography

International Nuclear Information System (INIS)

Nienaber, C.A.; Salge, D.; Spielmann, R.P.; Montz, R.; Bleifeld, W.

1990-01-01

Coronary arteriolar vasodilation may provoke redistribution of flow to collateral-dependent jeopardized myocardium. To assess the physiologic significance of collaterals, 80 consecutive post-infarction patients (age 58 +/- 8 years) underwent vasodilation-redistribution thallium-201 tomographic imaging after administration of 0.56 mg of intravenous dipyridamole/kg body weight. Circumferential profile analysis of thallium-201 uptake and redistribution in representative left ventricular tomograms provided quantitative assessment of transient and fixed defects and separation between periinfarctional and distant inducible hypoperfusion. Tomographic perfusion data were correlated to wall motion and collateral circulation between distinct anatomic perfusion territories. Patients were grouped according to presence (59%) or absence (41%) of angiographically visible collateral channels to jeopardized myocardium. In the presence of collaterals, distant reversible defects were larger than in absence of collaterals (p less than 0.05); the extent of combined periinfarctional and distant redistribution was also larger in collateralized patients (p less than 0.025), whereas the size of the persistent perfusion defect was similar in both groups. By prospective analysis the tomographic perfusion pattern of combined periinfarctional and distant redistribution revealed a sensitivity of 85% and a specificity of 78% for the detection of significant collateral circulation in this group of patients. Thus, using the exhausted flow reserve as a diagnostic tool, vasodilation-thallium-201 tomography has the potential to identify and quantitate collateralized myocardium in post-infarction patients and may guide diagnostic and therapeutic decision-making

Internal carotid artery stenosis or occlusion: study of collateral circulation pathways on DSA and MRA

International Nuclear Information System (INIS)

Zhao Yunhui; Ma Zhubin; Xu Yikai

2004-01-01

Objectives: To evaluate the collateral pathways of internal carotid artery (ICA) stenosis or occlusion on digital subtraction angiography (DSA) and magnetic resonance angiography (MRA), and to compare these two methods in the study for collateral pathways. Methods: Seventy-four patients with ICA stenosis or occlusion were included as the study group. Sixty persons with normal findings on DSA or MRA each served as the control group. DSA, MRA, MRI, CT findings, and clinicall materials were analyzed in the two groups. Results: Stenosis or occlusion over ICA bifurcation was showed clearly in all patients on DSA or MRA. On DSA, the presence rate of ipsilateral posterior communicating artery (PCoA) in the study group (82.5%) was lower significantly than that of the control group (94.2%) (P=0.025). On MRA (3D-TOF), the rate in the study group (59.3%) was higher significantly than that of the controls (30.0%) (P=0.000). On DSA and MRA, the diameter of ipsilateral PCoA in the study group was larger than that of the control group (P=0.000). On DSA, the presence rate of OPhA in the study group was significantly different from that of the control group, and its diameter was larger than that of the control group (P=0.003). On MRA, its presence rate was lower than that of the control group. The presence rate of anterior communicating artery (ACoA) in the study group showed no statistical difference between DSA and MRA. In the study group, the presence rate of PCoA on DSA was significantly higher than that on MRA (P 0.05). The diameters of the three arteries showed no significant differences between DSA and MRA (P>0.05). Conclusion: DSA is highly valuable for the evaluation of collateral pathways of ICA stenosis or occlusion, and it is necessary for preoperative examination. MRA is a non-invasive angiographic method and can evaluate collateral circulation in both morphology and function, and can be the preferred method for the disease. (authors)

Collateral circulation on perfusion-computed tomography-source images predicts the response to stroke intravenous thrombolysis.

Science.gov (United States)

Calleja, A I; Cortijo, E; García-Bermejo, P; Gómez, R D; Pérez-Fernández, S; Del Monte, J M; Muñoz, M F; Fernández-Herranz, R; Arenillas, J F

2013-05-01

Perfusion-computed tomography-source images (PCT-SI) may allow a dynamic assessment of leptomeningeal collateral arteries (LMC) filling and emptying in middle cerebral artery (MCA) ischaemic stroke. We described a regional LMC scale on PCT-SI and hypothesized that a higher collateral score would predict a better response to intravenous (iv) thrombolysis. We studied consecutive ischaemic stroke patients with an acute MCA occlusion documented by transcranial Doppler/transcranial color-coded duplex, treated with iv thrombolysis who underwent PCT prior to treatment. Readers evaluated PCT-SI in a blinded fashion to assess LMC within the hypoperfused MCA territory. LMC scored as follows: 0, absence of vessels; 1, collateral supply filling ≤ 50%; 2, between> 50% and < 100%; 3, equal or more prominent when compared with the unaffected hemisphere. The scale was divided into good (scores 2-3) vs. poor (scores 0-1) collaterals. The predetermined primary end-point was a good 3-month functional outcome, while early neurological recovery, transcranial duplex-assessed 24-h MCA recanalization, 24-h hypodensity volume and hemorrhagic transformation were considered secondary end-points. Fifty-four patients were included (55.5% women, median NIHSS 10), and 4-13-23-14 patients had LMC score (LMCs) of 0-1-2-3, respectively. The probability of a good long-term outcome augmented gradually with increasing LMCs: (0) 0%; (1) 15.4%; (2) 65.2%; (3) 64.3%, P = 0.004. Good-LMCs was independently associated with a good outcome [OR 21.02 (95% CI 2.23-197.75), P = 0.008]. Patients with good LMCs had better early neurological recovery (P = 0.001), smaller hypodensity volumes (P < 0.001) and a clear trend towards a higher recanalization rate. A higher degree of LMC assessed by PCT-SI predicts good response to iv thrombolysis in MCA ischaemic stroke patients. © 2012 The Author(s) European Journal of Neurology © 2012 EFNS.

13 CFR 120.1850 - Will the Collateral be held by SBA?

Science.gov (United States)

2010-01-01

... Loan Program) § 120.1850 Will the Collateral be held by SBA? Yes, SBA or its expressly authorized agent... all Collateral for SISMBD Loans in a custodial account. Certificates held as Collateral must be in... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Will the Collateral be held by SBA...

Significance and function of different spinal collateral compartments following thoracic aortic surgery: immediate versus long-term flow compensation.

Science.gov (United States)

Meffert, Philipp; Bischoff, Moritz S; Brenner, Robert; Siepe, Matthias; Beyersdorf, Friedhelm; Kari, Fabian A

2014-05-01

Iatrogenic paraplegia has been accompanying cardiovascular surgery since its beginning. As a result, surgeons have been developing many theories about the exact mechanisms of this devastating complication. Thus, the impact of single arteries that contribute to the spinal perfusion is one of the most discussed subjects in modern surgery. The subsequent decision of reattachment or the permanent disconnection of these intercostal arteries divides the surgical community. On the one hand, the anatomical or vascular approach pleads for the immediate reimplantation to reconstruct the anatomical situation. On the other hand, the decision of the permanent disconnection aims at avoiding stealing phenomenon away from the spinal vascular network. This spinal collateral network can be described as consisting of three components-the intraspinal and two paraspinal compartments-that feed the nutrient arteries of the spinal cord. The exact functional impact of the different compartments of the collateral network remains poorly understood. In this review, the function of the intraspinal compartment in the context of collateral network principle as an immediate emergency backup system is described. The exact structure and architectural principles of the intraspinal compartment are described. The critical parameters with regard to the risk of postoperative spinal cord ischaemia are the number of anterior radiculomedullary arteries (ARMAs) and the distance between them in relation to the longitudinal extent of aortic disease. The paraspinal network as a sleeping reserve is proposed as the long-term backup system. This sleeping reserve has to be activated by arteriogenic stimuli. These are presented briefly, and prior findings regarding arteriogenesis are discussed in the light of the collateral network concept. Finally, the role of preoperative visualization of the ARMAs in order to evaluate the risk of postoperative paraplegia is emphasized.

10 CFR 609.15 - Default, demand, payment, and collateral liquidation.

Science.gov (United States)

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Default, demand, payment, and collateral liquidation. 609... PROJECTS THAT EMPLOY INNOVATIVE TECHNOLOGIES § 609.15 Default, demand, payment, and collateral liquidation... Guaranteed Obligation. Such assignment shall include all related liens, security, and collateral rights to...

Status of systemic to pulmonary arterial collateral flow after the fontan procedure.

Science.gov (United States)

Whitehead, Kevin K; Harris, Matthew A; Glatz, Andrew C; Gillespie, Matthew J; DiMaria, Michael V; Harrison, Neil E; Dori, Yoav; Keller, Marc S; Rome, Jonathan J; Fogel, Mark A

2015-06-15

The investigators recently validated a method of quantifying systemic-to-pulmonary arterial collateral flow using phase-contrast magnetic resonance imaging velocity mapping. Cross-sectional data suggest decreased collateral flow in patients with total cavopulmonary connections (TCPCs) compared with those with superior cavopulmonary connections (SCPCs). However, no studies have examined serial changes in collateral flow from SCPCs to TCPCs in the same patients. The aim of this study was to examine differences in collateral flow between patients with SCPCs and those with TCPCs. Collateral flow was quantified by 2 independent measures from 250 single-ventricle studies in 219 different patients (115 SCPC and 135 TCPC studies, 31 patients with both) and 18 controls, during routine studies using through-plane phase-contrast magnetic resonance imaging. Collateral flow was indexed to body surface area, aortic flow, and pulmonary venous flow. Regardless of indexing method, SCPC patients had significantly higher collateral flow than TCPC patients (1.64 ± 0.8 vs 1.03 ± 0.8 L/min/m(2), p <0.001). In 31 patients who underwent serial examinations, collateral flow as a fraction of aortic flow increased early after TCPC completion. In TCPC patients, indexed collateral flow demonstrated a significant negative correlation with time from TCPC. In conclusion, SCPC and TCPC patients demonstrate substantial collateral flow, with SCPC patients having higher collateral flow than TCPC patients overall. On the basis of the paired subset analysis, collateral flow does not decrease in the short term after TCPC completion and trends toward an increase. In the long term, however, collateral flow decreases over time after TCPC completion. Copyright © 2015 Elsevier Inc. All rights reserved.

7 CFR 1421.106 - Warehouse-stored marketing assistance loan collateral.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Warehouse-stored marketing assistance loan collateral... Marketing Assistance Loans § 1421.106 Warehouse-stored marketing assistance loan collateral. (a) A commodity may be pledged as collateral for a warehouse-stored marketing assistance loan in the quantity...

12 CFR 614.4250 - Collateral evaluation standards.

Science.gov (United States)

2010-01-01

..., personal, or intangible property is taken as security for a loan or is the subject of a lease, an evaluation of such property shall be performed in accordance with § 614.4260 and the institutions' policies and procedures. Such a collateral evaluation shall be identified as either a collateral valuation or a...

Intrahepatic Left to Right Portoportal Venous Collateral Vascular Formation in Patients Undergoing Right Portal Vein Ligation

Energy Technology Data Exchange (ETDEWEB)

Lienden, K. P. van, E-mail: k.p.vanlienden@amc.uva.nl [Academic Medical Center, University of Amsterdam, Department of Interventional Radiology (Netherlands); Hoekstra, L. T. [Academic Medical Center, University of Amsterdam, Department of Surgery (Netherlands); Bennink, R. J. [Academic Medical Center, University of Amsterdam, Department of Nuclear Medicine (Netherlands); Gulik, T. M. van [Academic Medical Center, University of Amsterdam, Department of Surgery (Netherlands)

2013-12-15

Purpose: We investigated intrahepatic vascular changes in patients undergoing right portal vein ligation (PVL) or portal vein embolization (PVE) in conjunction with the ensuing hypertrophic response and function of the left liver lobe. Methods: Between December 2008 and October 2011, 7 patients underwent right PVL and 14 patients PVE. Computed tomographic (CT) volumetry to assess future remnant liver (FRL) and functional hepatobiliary scintigraphy were performed in all patients before and 3 weeks after portal vein occlusion. In 18 patients an intraoperative portography was performed to assess perfusion through the occluded portal branches. Results: In all patients after initially successful PVL, reperfused portal veins were observed on CT scan 3 weeks after portal occlusion. This was confirmed in all cases during intraoperative portography. Intrahepatic portoportal collaterals were identified in all patients in the PVL group and in one patient in the PVE group. In all other PVE patients, complete occlusion of the embolized portal branches was observed on CT scan and on intraoperative portography. The median increase of FRL volume after PVE was 41.6 % (range 10-305 %), and after PVL was only 8.1 % (range 0-102 %) (p = 0.179). There were no differences in FRL function between both groups. Conclusion: Preoperative PVE and PVL are both methods to induce hypertrophy of the FRL in anticipation of major liver resection. Compared to PVE, PVL seems less efficient in inducing hypertrophy of the nonoccluded left lobe. This could be caused by the formation of intrahepatic portoportal neocollateral vessels, through which the ligated portal branches are reperfused within 3 weeks.

Effect of collateral circulation on myocardial protection in patients with acute myocardial infarction. Comparison of technetium-99m-tetrofosmin myocardial single photon emission computed tomography and coronary angiography

International Nuclear Information System (INIS)

Yoshida, Michi; Kondo, Makoto; Abe, Yoshiteru; Kubota, Tomoyuki; Matsuoka, Ryota; Araki, Makoto; Tanio, Hitoshi; Doyama, Kiyoshi

2006-01-01

Evaluation of myocardial blood flow from collateral vessels into the infarct area has been estimated by coronary angiography. In patients with acute myocardial infarction with Thrombolysis in Myocardial Infarction (TIMI) 0 flow, myocardial tracer uptake on single photon emission computed tomography (SPECT) images can predict the collateral blood flow in the infarct area if technetium (Tc)-99m-tetrofosmin was administered before recanalization. The present study investigated whether collateral blood flow evaluated by myocardial scintigraphy is a good predictor of myocardial salvage in patients with acute myocardial infarction. The study group consisted of 30 patients (mean age 65±14 years, 23 males, 7 females) with first acute myocardial infarction and coronary angiography evidence of total occlusion (TIMI 0) within 12 hr after the onset. All patients had one vessel disease related to infarction and TIMI 3 flow after percutaneous coronary intervention (PCI). Tc-99m-tetrofosmin was injected intravenously before the PCI. The regional severity score index (RSSI) was obtained from SPECT using the 17 segment method with the four-point scoring system. Myocardial viability was evaluated by the RSSI obtained from thallium-glucose-insulin infusion SPECT after 1 week and regional wall motion score index obtained from echocardiography during the chronic phase. The patients were divided into two groups according to the angiographic collateral finding. There were no differences in RSSI on thallium-glucose-insulin SPECT and regional wall motion score between the good collateral group (n=8) and poor collateral group (n=22). Myocardial Tc-99m-tetrofosmin RSSI was similar in these groups. On the other hand, the patients were divided according to Tc-99m-tetrofosmin scintigraphic evaluation before PCI. RSSI on thallium-glucose-insulin SPECT was significantly greater (0.7±0.5 vs 1.5±0.4, p<0.01) and regional wall motion score was significantly less (1.46±0.50 vs 2.08±0.78, p<0

7 CFR 1980.444 - Appraisal of property serving as collateral.

Science.gov (United States)

2010-01-01

... 7 Agriculture 14 2010-01-01 2009-01-01 true Appraisal of property serving as collateral. 1980.444... Program § 1980.444 Appraisal of property serving as collateral. (a) Appraisal reports prepared by independent qualified fee appraisers will be required on all property that will serve as collateral. In the...

12 CFR 615.5090 - Reduction in carrying value of collateral.

Science.gov (United States)

2010-01-01

... FISCAL AFFAIRS, LOAN POLICIES AND OPERATIONS, AND FUNDING OPERATIONS Collateral § 615.5090 Reduction in carrying value of collateral. When the bank or Farm Credit Administration determines that a loan did not... withdrawn from collateral until the cause of ineligibility is remedied. When a loan has been classified as a...

Exercise promotes collateral artery growth mediated by monocytic nitric oxide.

Science.gov (United States)

Schirmer, Stephan H; Millenaar, Dominic N; Werner, Christian; Schuh, Lisa; Degen, Achim; Bettink, Stephanie I; Lipp, Peter; van Rooijen, Nico; Meyer, Tim; Böhm, Michael; Laufs, Ulrich

2015-08-01

Collateral artery growth (arteriogenesis) is an important adaptive response to hampered arterial perfusion. It is unknown whether preventive physical exercise before limb ischemia can improve arteriogenesis and modulate mononuclear cell function. This study aimed at investigating the effects of endurance exercise before arterial occlusion on MNC function and collateral artery growth. After 3 weeks of voluntary treadmill exercise, ligation of the right femoral artery was performed in mice. Hindlimb perfusion immediately after surgery did not differ from sedentary mice. However, previous exercise improved perfusion restoration ≤7 days after femoral artery ligation, also when exercise was stopped at ligation. This was accompanied by an accumulation of peri-collateral macrophages and increased expression of endothelial nitric oxide synthase and inducible nitric oxide synthase (iNOS) in hindlimb collateral and in MNC of blood and spleen. Systemic monocyte and macrophage depletion by liposomal clodronate but not splenectomy attenuated exercise-induced perfusion restoration, collateral artery growth, peri-collateral macrophage accumulation, and upregulation of iNOS. iNOS-deficient mice did not show exercise-induced perfusion restoration. Transplantation of bone marrow-derived MNC from iNOS-deficient mice into wild-type animals inhibited exercise-induced collateral artery growth. In contrast to sedentary controls, thrice weekly aerobic exercise training for 6 months in humans increased peripheral blood MNC iNOS expression. Circulating mononuclear cell-derived inducible nitric oxide is an important mediator of exercise-induced collateral artery growth. © 2015 American Heart Association, Inc.

10 CFR 611.111 - Default, demand, payment, and collateral liquidation.

Science.gov (United States)

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Default, demand, payment, and collateral liquidation. 611... collateral liquidation. (a) In the event that the Borrower has defaulted in the making of required payments.... Attorney General, may seek to foreclose on the collateral assets and/or take such other legal action as...

Assessment of peripheral vessels and of the lymphatic system by means of gamma-camera scintiscan (gamma-scintigraphy of the whole body)

Energy Technology Data Exchange (ETDEWEB)

Ennis, J T

1981-01-01

For diagnosing pathologies of the peripheric vessels or of the lymphatic system, albumin aggregates marked with sup(99m) technetium (MAA) or antimonocolloids were used. The radionuclide venography is useful in diagnosing thrombosis, venous insufficiency, and permits a high degree of accuracy, comparable with that of phlebography. In the most cases the radionuclide lymphoscintigraphy is required for the diagnosis of lymphoedema and allows by distribution analysis an adequate morphological representation of the lymphatic ducts and glands. Contrary to lymphography, lymphoscintigraphy presents a completely physiological radionuclide transport and does not cause any reactive lymphatic node hyperplasia by contrast media. Increased capillary perfusion is found in collateral vessel formation in cases of arterial obstruction and ischaemic ulcus, whereas hypoperfusion is seen in obstructions of the larger arteries having no collateral vessels, and in bad circulatory states. Particularly in diabetics with microangiopathy, a peripheral distribution with hyperfusion of the skon presents itself as piece-meal necrosis. The importance and relevance of the perfusion scans of the extremities for the diagnostic assessment within the field of resection surgery is explained.

Atraumatic medial collateral ligament oedema in medial compartment knee osteoarthritis

International Nuclear Information System (INIS)

Bergin, D.; Keogh, C.; O'Connell, M.; Zoga, A.; Rowe, D.; Shah, B.; Eustace, S.

2002-01-01

Objective: To describe and determine the prevalence of atraumatic medial collateral oedema identified in patients with medial compartment osteoarthritis. Design and patients: Sixty patients, 30 patients with medial compartment knee osteoarthritis (Kellgren and Lawrence grade 2 to 4) and 30 age-matched patients with atraumatic knee pain without osteoarthritis, referred for MR imaging over a 2 year period were included in the study. In each case, severity of osteoarthritis was recorded on radiographs and correlated with the presence or absence of medial collateral ligament oedema at MR imaging. Results: Medial collateral oedema was identified in 27 of the 30 patients with osteoarthritis, of whom 14 had grade 1 oedema and 13 had grade 2 oedema compared with the presence of medial collateral ligament oedema (grade 1) in only two of the 30 control patients without osteoarthritis (P<<0.0001). Conclusion: Medial collateral oedema is common in patients with osteoarthritis in the absence of trauma. When identified, medial collateral ligament oedema should be considered to be a feature of osteoarthritis and should not be incorrectly attributed to an acute traumatic injury. (orig.)

Measuring the quality of eligible collateral

OpenAIRE

Lehmbecker, Philipp; Missong, Martin

2008-01-01

Recently, the U. S. subprime crisis has shown that a weak collateralization of credits may have massive economic implications, entailing severe perturbations of the international financial system. We focus on central bank lending and try to pin down the quantitative impact of the collateralization of central banks' credits. A questionnaire on national monetary frameworks was used to collect data from central banks. Drawing on these data we derive an index of the quality of eligible assets mea...

48 CFR 32.304-6 - Other collateral security.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Other collateral security. 32.304-6 Section 32.304-6 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION... collateral security. The following are examples of other forms of security that, although seldom invoked...

Collateral circulation alters downstream hemodynamic stress caused by intracranial atherosclerotic stenosis.

Science.gov (United States)

Liu, Xin; Dornbos, David; Pu, Yuehua; Leng, Xinyi; Song, Ligang; Jia, Baixue; Pan, Yuesong; Wang, David; Miao, Zhongrong; Wang, Yilong; Liu, Liping; Wang, Yongjun

2017-06-01

Fractional flow reserve (FFR) accurately predicts the degree of stenosis and is now widely used to identify clinically significant severe coronary artery lesions. In the current study, we utilized a similar indicator, fractional flow (FF), to determine the hemodynamic impact of symptomatic intracranial atherosclerotic stenosis (ICAS) and to assess the correlation of FF with the severity of stenosis and collateral circulation. Patients with symptomatic ICAS (70-99% stenosis) confirmed on digital subtraction angiography (DSA) were consecutively recruited. FF was obtained during DSA examination with the use of pressure sensors and was measured as a ratio, comparing measurements distal to an ICAS lesion (Pd) and within the aorta (Pa). The degree of leptomeningeal collateralization was graded from zero (absent) to four (complete compensatory). The correlation between FF, anatomical stenosis, and collateral status was then analyzed. Twenty-five patients with a mean age of 55.6 years were analyzed. The median percentage of stenosis and median FF were 82.3 and 0.68%, respectively. Eleven patients were found to have poor collateralization (grade 0-2), and fourteen patients were identified with good collateral circulation (grade 3-4). Overall, the hemodynamic impact of an atherosclerotic lesions worsened (decreased FF) as the percentage of stenosis increased, although this did not reach statistical significance (r = -0.398, p = 0.06). However, the status of collateralization significantly altered this correlation, worsening the hemodynamic impact in patients with poor collateral circulation (r = -0.677, p = 0.032). There was no difference in patients with good collateral circulation (r = -0.279, p = 0.356). An anatomically severe (70-99%) symptomatic ICAS lesion may generate significant hemodynamic stress downstream as assessed by the indicator FF, particularly in patients with poor collateral circulation. Further, good collateralization may mitigate this

Subtracted dynamic MR perfusion source images (sMRP-SI) provide collateral blood flow assessment in MCA occlusions and predict tissue fate

International Nuclear Information System (INIS)

Villringer, Kersten; Serrano-Sandoval, Rafael; Galinovic, Ivana; Ostwaldt, Ann-Christin; Brunecker, Peter; Fiebach, Jochen B.; Grittner, Ulrike; Schneider, Alice; Rocco, Andrea

2016-01-01

Collateral blood flow is accepted as a predictive factor of tissue fate in ischemic stroke. Thus, we aimed to evaluate a new method derived from MR perfusion source images to assess collateral flow in patients with ICA/MCA occlusions. A total of 132 patients of the prospective 1000+ study were examined. MR perfusion source images were assessed according to Δimg n = img n + 1 - img n - 1 using the five-grade Higashida collateral flow rating system. Higashida scores were correlated to mismatch (MM) volume, mismatch ratio, day 6 FLAIR lesion volumes and day 90 mRS. Patients with Higashida scores 3 and 4 had significantly lower admission NIHSS, smaller FLAIR day 6 lesion volumes (p < 0.001) and higher rates of better long-term outcome (mRS 0-2, p = 0.002). There was a linear trend for the association of Higashida grade 1 (p = 0.002) and 2 (p = 0.001) with unfavourable outcome (day 90 mRS 3-6), but no significant association was found for MM volume, MM ratio and day 90 mRS. Inter-rater agreement was 0.58 (95 % CI 0.43-0.73) on day 1, 0.70 (95 % CI 0.58-0.81) on day 2. sMRP-SI Higashida score offers a non-invasive collateral vessel and tissue perfusion assessment of ischemic tissue. The predictive value of Higashida rating proved superior to MM with regard to day 90 mRS. (orig.)

Subtracted dynamic MR perfusion source images (sMRP-SI) provide collateral blood flow assessment in MCA occlusions and predict tissue fate

Energy Technology Data Exchange (ETDEWEB)

Villringer, Kersten; Serrano-Sandoval, Rafael; Galinovic, Ivana; Ostwaldt, Ann-Christin; Brunecker, Peter; Fiebach, Jochen B. [Charite-Universitaetsmedizin, Academic Neuroradiology, Center for Stroke Research (CSB), Berlin (Germany); Grittner, Ulrike [Charite, Universitaetsmedizin Berlin, Center for Stroke Research, Berlin (Germany); Charite, Department for Biostatistics and Clinical Epidemiology, Berlin (Germany); Schneider, Alice [Charite, Universitaetsmedizin Berlin, Center for Stroke Research, Berlin (Germany); Rocco, Andrea [Charite, Department of Neurology and Center for Stroke Research, Berlin (Germany)

2016-05-15

Collateral blood flow is accepted as a predictive factor of tissue fate in ischemic stroke. Thus, we aimed to evaluate a new method derived from MR perfusion source images to assess collateral flow in patients with ICA/MCA occlusions. A total of 132 patients of the prospective 1000+ study were examined. MR perfusion source images were assessed according to Δimg{sub n} = img{sub n} + 1 - img{sub n} - 1 using the five-grade Higashida collateral flow rating system. Higashida scores were correlated to mismatch (MM) volume, mismatch ratio, day 6 FLAIR lesion volumes and day 90 mRS. Patients with Higashida scores 3 and 4 had significantly lower admission NIHSS, smaller FLAIR day 6 lesion volumes (p < 0.001) and higher rates of better long-term outcome (mRS 0-2, p = 0.002). There was a linear trend for the association of Higashida grade 1 (p = 0.002) and 2 (p = 0.001) with unfavourable outcome (day 90 mRS 3-6), but no significant association was found for MM volume, MM ratio and day 90 mRS. Inter-rater agreement was 0.58 (95 % CI 0.43-0.73) on day 1, 0.70 (95 % CI 0.58-0.81) on day 2. sMRP-SI Higashida score offers a non-invasive collateral vessel and tissue perfusion assessment of ischemic tissue. The predictive value of Higashida rating proved superior to MM with regard to day 90 mRS. (orig.)

Collateral and debt maturity choice: A signaling model

NARCIS (Netherlands)

Lensink, B.W.; Pham, 27735

2005-01-01

This paper derives optimal loan policies under asymmetric information where banks offer loan contracts of long and short duration, backed or unbacked with collateral. The main novelty of the paper is that it analyzes a setting in which high quality firms use collateral as a complementary device

Negative modulation of presynaptic activity by zinc released from Schaffer collaterals.

Science.gov (United States)

Takeda, Atsushi; Fuke, Sayuri; Tsutsumi, Wataru; Oku, Naoto

2007-12-01

The role of zinc in excitation of Schaffer collateral-CA1 pyramidal cell synapses is poorly understood. Schaffer collaterals stained with ZnAF-2 or ZnAF-2DA, a membrane-impermeable or a membrane-permeable zinc indicator, respectively, were treated by tetanic stimulation (200 Hz, 1 sec). Extracellular and intracellular ZnAF-2 signals were increased in the stratum radiatum of the CA1, in which Schaffer collateral synapses exist. Both the increases were completely blocked in the presence of 1 mM CaEDAT, a membrane-impermeable zinc chelator, suggesting that 1 mM CaEDTA is effective for chelating zinc released from Schaffer collaterals. The role of Schaffer collateral zinc in presynaptic activity was examined by using FM4-64, a fluorescent indicator for vesicular exocytosis. The decrease in FM4-64 signal during tetanic stimulation (10 Hz, 180 sec) was enhanced in Schaffer collaterals in the presence of 1 mM CaEDTA but suppressed in the presence of 5 microM ZnC1(2), suggesting that zinc released from Schaffer collaterals suppresses presynaptic activity during tetanic stimulation. When Schaffer collateral synapses stained with calcium orange AM, a membrane-permeable calcium indicator, were regionally stimulated with 1 mM glutamate, calcium orange signal was increased in the CA1 pyramidal cell layer. This increase was enhanced in the presence of CaEDTA and attenuated in the presence of zinc. These results suggest that zinc attenuates excitation of Schaffer collateral synapses elicited with glutamate via suppression of presynaptic activity. (c) 2007 Wiley-Liss, Inc.

Coronary collateralization shows sex and racial-ethnic differences in obstructive artery disease patients.

Directory of Open Access Journals (Sweden)

Zhi Liu

Full Text Available Coronary collateral circulation protects cardiac tissues from myocardial infarction damage and decreases sudden cardiac death. So far, it is unclear how coronary collateralization varies by race-ethnicity groups and by sex.We assessed 868 patients with obstructive CAD. Patients were assessed for collateral grades based on Rentrop grading system, as well as other covariates. DNA samples were genotyped using the Affymetrix 6.0 genotyping array. To evaluate genetic contributions to collaterals, we performed admixture mapping using logistic regression with estimated local and global ancestry.Overall, 53% of participants had collaterals. We found difference between sex and racial-ethnic groups. Men had higher rates of collaterals than women (P-value = 0.000175. White Hispanics/Latinos showed overall higher rates of collaterals than African Americans and non-Hispanic Whites (59%, 50% and 48%, respectively, P-value = 0.017, and especially higher rates in grade 1 and grade 3 collateralization than the other two populations (P-value = 0.0257. Admixture mapping showed Native American ancestry was associated with the presence of collaterals at a region on chromosome 17 (chr17:35,243,142-41,251,931, β = 0.55, P-value = 0.000127. African ancestry also showed association with collaterals at a different region on chromosome 17 (chr17: 32,266,966-34,463,323, β = 0.38, P-value = 0.00072.In our study, collateralization showed sex and racial-ethnic differences in obstructive CAD patients. We identified two regions on chromosome 17 that were likely to harbor genetic variations that influenced collateralization.

Single minimum incision endoscopic radical nephrectomy for renal tumors with preoperative virtual navigation using 3D-CT volume-rendering

Directory of Open Access Journals (Sweden)

Shioyama Yasukazu

2010-04-01

Full Text Available Abstract Background Single minimum incision endoscopic surgery (MIES involves the use of a flexible high-definition laparoscope to facilitate open surgery. We reviewed our method of radical nephrectomy for renal tumors, which is single MIES combined with preoperative virtual surgery employing three-dimensional CT images reconstructed by the volume rendering method (3D-CT images in order to safely and appropriately approach the renal hilar vessels. We also assessed the usefulness of 3D-CT images. Methods Radical nephrectomy was done by single MIES via the translumbar approach in 80 consecutive patients. We performed the initial 20 MIES nephrectomies without preoperative 3D-CT images and the subsequent 60 MIES nephrectomies with preoperative 3D-CT images for evaluation of the renal hilar vessels and the relation of each tumor to the surrounding structures. On the basis of the 3D information, preoperative virtual surgery was performed with a computer. Results Single MIES nephrectomy was successful in all patients. In the 60 patients who underwent 3D-CT, the number of renal arteries and veins corresponded exactly with the preoperative 3D-CT data (100% sensitivity and 100% specificity. These 60 nephrectomies were completed with a shorter operating time and smaller blood loss than the initial 20 nephrectomies. Conclusions Single MIES radical nephrectomy combined with 3D-CT and virtual surgery achieved a shorter operating time and less blood loss, possibly due to safer and easier handling of the renal hilar vessels.

The impact of coronary chronic total occlusion percutaneous coronary intervention upon donor vessel fractional flow reserve and instantaneous wave-free ratio: Implications for physiology-guided PCI in patients with CTO.

Science.gov (United States)

Mohdnazri, Shah R; Karamasis, Grigoris V; Al-Janabi, Firas; Cook, Christopher M; Hampton-Till, James; Zhang, Jufen; Al-Lamee, Rasha; Dungu, Jason N; Gedela, Swamy; Tang, Kare H; Kelly, Paul A; Davies, Justin E; Davies, John R; Keeble, Thomas R

2018-03-22

To investigate the immediate and short term impact of right coronary artery (RCA) chronic total coronary occlusion (CTO) percutaneous coronary intervention (PCI) upon collateral donor vessel fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR). CTO PCI influences collateral donor vessel physiology, making the indication and/or timing of donor vessel revascularization difficult to determine. In patients with RCA CTO, FFR, iFR, and collateral function index (FFR coll ) were measured in LAD and LCx pre-CTO PCI, immediately post and at 4 month follow-up. 34 patients underwent successful PCI. In the predominant donor vessel immediately post PCI, FFR, and FFR coll did not change (0.76 ± 0.12 to 0.75 ± 0.13, P = 0.267 and 0.31 ± 0.10 vs. 0.34 ± 0.11, P = 0.078), but iFR increased significantly (0.86 ± 0.10 to 0.88 ± 0.10, P = 0.012). At follow-up, there was a significant increase in predominant donor FFR and iFR (0.76 ± 0.12 to 0.79 ± 0.11, P = 0.047 and 0.86 ± 0.10 to 0.90 ± 0.07, P = 0.003), accompanied by a significant reduction in FFR coll (0.31 ± 0.10 to 0.18 ± 0.07 P PCI in the case of iFR and at 4-month follow-up for FFR and iFR compared to pre-PCI with a concomitant reduction in collateral function. © 2018 Wiley Periodicals, Inc.

The utility of collateral student drinking reports: Evidence from a biomarker study.

Science.gov (United States)

Fendrich, Michael; Fuhrmann, Daniel; Berger, Lisa; Plate, Charles; Lewis, Douglas; Jones, Joseph

2015-11-01

Researchers have increasingly used collateral informants to validate the reports provided by primary research subjects. We assessed the utility of collateral informants for college students in a study that incorporates biomarkers to validate student reports of recent drinking behavior. Students from a Midwestern university were randomly selected for a study in which they provided 90-day Timeline Followback data, hair and fingernail specimens for ethylglucuronide (EtG) testing, and information about collateral (friends or peers) informants who were familiar with their drinking behavior. We compared summary measures of recent drinking to collateral informant reports for the subset of 72 students who were selected to participate in the collateral validation process who had complete measures. Kappa, weighted kappa, and McNemar tests were performed to evaluate levels of agreement. We compared levels of use indicated by each informant within the context of EtG findings. We also compared respondent and collateral reports with respect to heavy drinking directly to EtG test results. There was considerable overlap between the reports provided by the student participants and their collateral informants. Within the context of EtG-informed analyses, collaterals rarely provided new information about heavy use beyond that provided by the study subjects. Collateral informants have limited utility in non-clinical studies of heavy drinking in randomly selected college students. Copyright © 2015. Published by Elsevier Ltd.

27 CFR 25.105 - Release of collateral security.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Release of collateral security. 25.105 Section 25.105 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE... of Bonds Or Consents of Surety § 25.105 Release of collateral security. Bonds, notes, and other...

12 CFR 615.5335 - Bank net collateral ratio.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Bank net collateral ratio. 615.5335 Section 615.5335 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM FUNDING AND FISCAL AFFAIRS, LOAN POLICIES AND OPERATIONS, AND FUNDING OPERATIONS Surplus and Collateral Requirements § 615.5335 Bank net...

10 CFR 609.16 - Perfection of liens and preservation of collateral.

Science.gov (United States)

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Perfection of liens and preservation of collateral. 609.16... THAT EMPLOY INNOVATIVE TECHNOLOGIES § 609.16 Perfection of liens and preservation of collateral. (a... to perfect and maintain liens, as applicable, on assets which are pledged as collateral for the...

10 CFR 611.108 - Perfection of liens and preservation of collateral.

Science.gov (United States)

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Perfection of liens and preservation of collateral. 611... of collateral. (a) The Agreement and other documents related thereto shall provide that: (1) DOE and... necessary to perfect and maintain liens, as applicable, on assets which are pledged as collateral for the...

Value of CT angiography in anterior circulation large vessel occlusive stroke: Imaging findings, pearls, and pitfalls

Energy Technology Data Exchange (ETDEWEB)

Power, Sarah, E-mail: drsarahpower@gmail.com [Department of Neuroradiology, Beaumont Hospital, P.O. Box 1297, Beaumont Rd, Dublin 9 (Ireland); McEvoy, Sinead H., E-mail: sineadmcevoy@beaumont.ie [Department of Neuroradiology, Beaumont Hospital, P.O. Box 1297, Beaumont Rd, Dublin 9 (Ireland); Cunningham, Jane, E-mail: janecunningham0708@gmail.com [Department of Radiology, Beaumont Hospital, P.O. Box 1297, Beaumont Rd, Dublin 9 (Ireland); Ti, Joanna P., E-mail: joannapearlyti@gmail.com [Department of Neuroradiology, Beaumont Hospital, P.O. Box 1297, Beaumont Rd, Dublin 9 (Ireland); Looby, Seamus, E-mail: seamuslooby@beaumont.ie [Department of Neuroradiology, Beaumont Hospital, P.O. Box 1297, Beaumont Rd, Dublin 9 (Ireland); O' Hare, Alan, E-mail: alanohare@beaumont.ie [Department of Neuroradiology, Beaumont Hospital, P.O. Box 1297, Beaumont Rd, Dublin 9 (Ireland); Williams, David, E-mail: davidwilliams@rcsi.ie [Department of Geriatrics and Stroke Medicine, Royal College of Surgeons in Ireland (RCSI) and Beaumont Hospital, P.O. Box 1297, Beaumont Rd, Dublin 9 (Ireland); Brennan, Paul, E-mail: paulbrennan@beaumont.ie [Department of Neuroradiology, Beaumont Hospital, P.O. Box 1297, Beaumont Rd, Dublin 9 (Ireland); Thornton, John, E-mail: johnthornton@beaumont.ie [Department of Neuroradiology, Beaumont Hospital, P.O. Box 1297, Beaumont Rd, Dublin 9 (Ireland)

2015-07-15

Highlights: • Site of occlusion determines potential collateralization routes and impacts outcome. • Multifocality of arterial occlusion is common, seen in approximately 20% of cases. • ICA false occlusion sign can be seen in setting of ICA stenosis or carotid T occlusion. • False patency sign: hyperdense thrombus/calcified occlusive plaque misinterpreted as patent vessel. • Additional abnormalities on CTA may infer stroke mechanism or alter decision making. - Abstract: Hyperacute stroke imaging is playing an increasingly important role in determining management decisions in acute stroke patients, particularly patients with large vessel occlusive stroke who may benefit from endovascular intervention. CT angiography (CTA) is an important tool in the work-up of the acute stroke patient. It reliably detects large occlusive thrombi in proximal cerebral arteries and is a quick and highly accurate method in identifying candidates for endovascular stroke treatment. In this article we review the imaging findings on CTA in acute large vessel occlusive stroke using a pictorial case based approach. We retrospectively reviewed CTA studies in 48 patients presenting with acute anterior circulation large vessel occlusive stroke who were brought for intra-arterial acute stroke intervention. We discuss and illustrate patterns of proximal intracranial arterial occlusion, collateralization to the occluded territory, as well as reviewing some important pearls, pitfalls and teaching points in CTA assessment of the acute stroke patient. Performed from the level of the aortic arch CTA also gives valuable information regarding the state of other vessels in the acute stroke patient, identifying additional significant vascular stenoses or occlusions, and as we illustrate, can demonstrate other clinically significant findings which may impact on patient management and outcome.

Value of CT angiography in anterior circulation large vessel occlusive stroke: Imaging findings, pearls, and pitfalls

International Nuclear Information System (INIS)

Power, Sarah; McEvoy, Sinead H.; Cunningham, Jane; Ti, Joanna P.; Looby, Seamus; O'Hare, Alan; Williams, David; Brennan, Paul; Thornton, John

2015-01-01

Highlights: • Site of occlusion determines potential collateralization routes and impacts outcome. • Multifocality of arterial occlusion is common, seen in approximately 20% of cases. • ICA false occlusion sign can be seen in setting of ICA stenosis or carotid T occlusion. • False patency sign: hyperdense thrombus/calcified occlusive plaque misinterpreted as patent vessel. • Additional abnormalities on CTA may infer stroke mechanism or alter decision making. - Abstract: Hyperacute stroke imaging is playing an increasingly important role in determining management decisions in acute stroke patients, particularly patients with large vessel occlusive stroke who may benefit from endovascular intervention. CT angiography (CTA) is an important tool in the work-up of the acute stroke patient. It reliably detects large occlusive thrombi in proximal cerebral arteries and is a quick and highly accurate method in identifying candidates for endovascular stroke treatment. In this article we review the imaging findings on CTA in acute large vessel occlusive stroke using a pictorial case based approach. We retrospectively reviewed CTA studies in 48 patients presenting with acute anterior circulation large vessel occlusive stroke who were brought for intra-arterial acute stroke intervention. We discuss and illustrate patterns of proximal intracranial arterial occlusion, collateralization to the occluded territory, as well as reviewing some important pearls, pitfalls and teaching points in CTA assessment of the acute stroke patient. Performed from the level of the aortic arch CTA also gives valuable information regarding the state of other vessels in the acute stroke patient, identifying additional significant vascular stenoses or occlusions, and as we illustrate, can demonstrate other clinically significant findings which may impact on patient management and outcome

Determinants of leptomeningeal collateral flow in stroke patients with a middle cerebral artery occlusion

International Nuclear Information System (INIS)

Seeters, Tom van; Velthuis, Birgitta K.; Biessels, Geert Jan; Kappelle, L.J.; Graaf, Yolanda van der

2016-01-01

Poor leptomeningeal collateral flow is related to worse clinical outcome in acute ischemic stroke, but the factors that determine leptomeningeal collateral patency are largely unknown. We explored the determinants of leptomeningeal collateral flow and assessed their effect on the relation between leptomeningeal collateral flow and clinical outcome. We included 484 patients from the Dutch acute stroke study (DUST) with a middle cerebral artery (MCA) occlusion. The determinants of poor leptomeningeal collateral flow (≤50 % collateral filling) were identified with logistic regression. We calculated the relative risk (RR) of poor leptomeningeal collateral flow in relation to poor clinical outcome (90-day modified Rankin Scale 3-6) using Poisson regression and assessed whether the determinants of leptomeningeal collateral flow affected this relation. Leptomeningeal collateral flow was poor in 142 patients (29 %). In multivariable analyses, higher admission glucose level (odds ratio (OR) 1.1 per mmol/L increase (95 % CI 1.0-1.2)), a proximal MCA occlusion (OR 1.9 (95 % CI 1.3-3.0)), and an incomplete posterior circle of Willis (OR 1.7 (95 % CI 1.1-2.6)) were independently related to poor leptomeningeal collateral flow. Poor leptomeningeal collateral flow was related to poor clinical outcome (unadjusted RR 1.7 (95 % CI 1.4-2.0)), and this relation was not affected by the determinants of leptomeningeal collateral flow. Our study shows that admission glucose level, a proximal MCA occlusion, and an incomplete ipsilateral posterior circle of Willis are determinants of leptomeningeal collateral flow that represent a combination of congenital, acquired, and acute factors. After adjustment for these determinants, leptomeningeal collateral flow remains related to clinical outcome. (orig.)

Determinants of leptomeningeal collateral flow in stroke patients with a middle cerebral artery occlusion

Energy Technology Data Exchange (ETDEWEB)

Seeters, Tom van; Velthuis, Birgitta K. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Biessels, Geert Jan; Kappelle, L.J. [University Medical Center Utrecht, Department of Neurology, Brain Center Rudolf Magnus, Utrecht (Netherlands); Graaf, Yolanda van der [University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands); Collaboration: on behalf of the Dutch acute stroke study (DUST) investigators

2016-10-15

Poor leptomeningeal collateral flow is related to worse clinical outcome in acute ischemic stroke, but the factors that determine leptomeningeal collateral patency are largely unknown. We explored the determinants of leptomeningeal collateral flow and assessed their effect on the relation between leptomeningeal collateral flow and clinical outcome. We included 484 patients from the Dutch acute stroke study (DUST) with a middle cerebral artery (MCA) occlusion. The determinants of poor leptomeningeal collateral flow (≤50 % collateral filling) were identified with logistic regression. We calculated the relative risk (RR) of poor leptomeningeal collateral flow in relation to poor clinical outcome (90-day modified Rankin Scale 3-6) using Poisson regression and assessed whether the determinants of leptomeningeal collateral flow affected this relation. Leptomeningeal collateral flow was poor in 142 patients (29 %). In multivariable analyses, higher admission glucose level (odds ratio (OR) 1.1 per mmol/L increase (95 % CI 1.0-1.2)), a proximal MCA occlusion (OR 1.9 (95 % CI 1.3-3.0)), and an incomplete posterior circle of Willis (OR 1.7 (95 % CI 1.1-2.6)) were independently related to poor leptomeningeal collateral flow. Poor leptomeningeal collateral flow was related to poor clinical outcome (unadjusted RR 1.7 (95 % CI 1.4-2.0)), and this relation was not affected by the determinants of leptomeningeal collateral flow. Our study shows that admission glucose level, a proximal MCA occlusion, and an incomplete ipsilateral posterior circle of Willis are determinants of leptomeningeal collateral flow that represent a combination of congenital, acquired, and acute factors. After adjustment for these determinants, leptomeningeal collateral flow remains related to clinical outcome. (orig.)

Collateral veins in inferior caval vein occlusion demonstrated via CT

International Nuclear Information System (INIS)

Lien, H.H.; Lund, G.

1983-01-01

CT-scans of 12 patients with tumour-induced occlusion of the inferior vena cava were studied with regard to collateral veins. A comparison was performed with findings at phlebography in 10 patients and at autopsy in 2. The site and appearance of the main collateral pathway are presented. A close study of vascular structures renders useful information on collateral circulation in occlusion of the inferior vena cava. (orig.)

The cerebral collateral circulation: Relevance to pathophysiology and treatment of stroke.

Science.gov (United States)

Ginsberg, Myron D

2017-08-09

The brain's collateral circulation consists of arterial anastomotic channels capable of providing nutrient perfusion to brain regions whose normal sources of flow have become compromised, as occurs in acute ischemic stroke. Modern CT-based neuroimaging is capable of providing detailed information as to collateral extent and sufficiency and is complemented by magnetic resonance-based methods. In the present era of standard-of-care IV thrombolysis for acute ischemic stroke, and following the recent therapeutic successes of randomized clinical trials of acute endovascular intervention, the sufficiency of the collateral circulation has been convincingly established as a key factor influencing the likelihood of successful reperfusion and favorable clinical outcome. This article reviews the features of the brain's collateral circulation; methods for its evaluation in the acute clinical setting; the relevance of collateral circulation to prognosis in acute ischemic stroke; the specific insights into the collateral circulation learned from recent trials of endovascular intervention; and the major influence of genetic factors. Finally, we emphasize the need to develop therapeutic approaches to augment collateral perfusion as an adjunctive strategy to be employed along with, or prior to, thrombolysis and endovascular interventions, and we highlight the possible potential of inhaled nitric oxide, albumin, and other approaches. Copyright © 2017 Elsevier Ltd. All rights reserved.

Collateral pathways in lumbar epidural venography

International Nuclear Information System (INIS)

Thijssen, H.O.M.; Ike, B.W.; Chevrot, A.; Bijlsma, R.

1982-01-01

Opacification of collateral pathways other than the central channels is very rare in lumbar epidural venography. Two cases of opacification of the inferior mesenteric vein following extravasation of contrast medium at the tip of the lateral sacral vein catheter are reported. One case is presented in which filling of normal parametrial venous plexuses and the left ovarian vein occurred as a consequence of incompetent or absent valves in the internal iliac vein. The literature containing comparable collateral flow patterns in disease is reviewed. The significance of the phlebographic features in our cases is discussed. (orig.)

Sphingosine-1-Phosphate Receptor-1 Selective Agonist Enhances Collateral Growth and Protects against Subsequent Stroke.

Directory of Open Access Journals (Sweden)

Masahiko Ichijo

CCAO. Administration of the S1PR1 selective agonist significantly increased cerebral blood flow (CBF and the diameter of leptomeningeal collateral vessels (42.9 ± 2.6 μm compared with the controls (27.6 ± 5.7 μm; P < 0.01. S1PR1 inverse agonist administration diminished the effect of the S1PR1 agonist (P < 0.001. After pMCAO, S1PR1 agonist pretreated animals showed significantly smaller infarct volume (17.5% ± 4.0% vs. 7.7% ± 4.0%, P < 0.01 and better functional recovery than vehicle-treated controls.These results suggest that S1PR1 is one of the principal regulators of leptomeningeal collateral recruitment at the site of increased shear stress and provide evidence that an S1PR1 selective agonist has a role in promoting collateral growth and preventing of ischemic damage and neurological dysfunction after subsequent stroke in patients with intracranial major artery stenosis or occlusion.

Alternative Evolutionary Paths to Bacterial Antibiotic Resistance Cause Distinct Collateral Effects.

Science.gov (United States)

Barbosa, Camilo; Trebosc, Vincent; Kemmer, Christian; Rosenstiel, Philip; Beardmore, Robert; Schulenburg, Hinrich; Jansen, Gunther

2017-09-01

When bacteria evolve resistance against a particular antibiotic, they may simultaneously gain increased sensitivity against a second one. Such collateral sensitivity may be exploited to develop novel, sustainable antibiotic treatment strategies aimed at containing the current, dramatic spread of drug resistance. To date, the presence and molecular basis of collateral sensitivity has only been studied in few bacterial species and is unknown for opportunistic human pathogens such as Pseudomonas aeruginosa. In the present study, we assessed patterns of collateral effects by experimentally evolving 160 independent populations of P. aeruginosa to high levels of resistance against eight commonly used antibiotics. The bacteria evolved resistance rapidly and expressed both collateral sensitivity and cross-resistance. The pattern of such collateral effects differed to those previously reported for other bacterial species, suggesting interspecific differences in the underlying evolutionary trade-offs. Intriguingly, we also identified contrasting patterns of collateral sensitivity and cross-resistance among the replicate populations adapted to the same drug. Whole-genome sequencing of 81 independently evolved populations revealed distinct evolutionary paths of resistance to the selective drug, which determined whether bacteria became cross-resistant or collaterally sensitive towards others. Based on genomic and functional genetic analysis, we demonstrate that collateral sensitivity can result from resistance mutations in regulatory genes such as nalC or mexZ, which mediate aminoglycoside sensitivity in β-lactam-adapted populations, or the two-component regulatory system gene pmrB, which enhances penicillin sensitivity in gentamicin-resistant populations. Our findings highlight substantial variation in the evolved collateral effects among replicates, which in turn determine their potential in antibiotic therapy. © The Author 2017. Published by Oxford University Press on

12 CFR 908.32 - Collateral attacks on proceedings under this part.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Collateral attacks on proceedings under this... Rules § 908.32 Collateral attacks on proceedings under this part. If a respondent files in any court a collateral attack that purports to challenge all or any portion of a proceeding under this part, the hearing...

Clinical application of preoperative TAE in the nasopharyngeal angiofibromas

International Nuclear Information System (INIS)

Liu Yu'e; Zhang Jingxian; Tang Wenheng; Yan Zhiping

2006-01-01

Objective: To evaluate the clinical value of the preoperative intra-arterial embolization of the nasopharyngeal angiofibromas. Methods: The treatment group of 7 male patients with the nasopharyngeal angiofibromas were undergone angiographic evaluation and embolization of tumor-feeding vessels before surgery. All patients were embolized with gelfoam particles and PVA. The control group of 7 patients received surgical treatment without preoperative embolization. The authors compared the volumes of intraoperative bleeding and the blood transfusions during operations between the two groups. Results: All patients achieved symptomatic remission, with no complications. Comparing with the control group, the amount of intraoperative bleeding and the blood transfusions during operations were much less in the treatment group submitted to endovascular embolization. Marked edema in the peripheral region of tumor of the treatment group made the tumor easy to be dissociated. Conclusion: The intraoperative bleeding can be reduced significantly by preoperative embolization of supplying arteries to the nasopharyngeal angiofibromas, therefore it should be used routinely as an adjunct to surgery. (authors)

Use of collateral sensitivity networks to design drug cycling protocols that avoid resistance development

DEFF Research Database (Denmark)

Imamovic, Lejla; Sommer, Morten

2013-01-01

collateral sensitivity and resistance profiles, revealing a complex collateral sensitivity network. On the basis of these data, we propose a new treatment framework-collateral sensitivity cycling-in which drugs with compatible collateral sensitivity profiles are used sequentially to treat infection...... pathogens. These results provide proof of principle for collateral sensitivity cycling as a sustainable treatment paradigm that may be generally applicable to infectious diseases and cancer....

Efficacy of collateral types used by financial intermediaries in KwaZulu-Natal

OpenAIRE

Kuhn, M.E.; Darroch, Mark A.G.; Ortmann, Gerald F.

1997-01-01

Collateral is an important incentive device used by lenders to encourage loan repayment. However, collateral must have secure and transferable title, it must be marketable, have low lender liquidation costs and lenders must be able to attach the collateral. Study results for rural and micro-enterprise finance institutions in KwaZulu-Natal showed that assets such as vehicles and equipment were not effective as collateral due to high costs in attaching the asset. Cessions on crops were often co...

Nox2 and p47phox modulate compensatory growth of primary collateral arteries

Science.gov (United States)

DiStasi, Matthew R.; Unthank, Joseph L.

2014-01-01

The role of NADPH oxidase (Nox) in both the promotion and impairment of compensatory collateral growth remains controversial because the specific Nox and reactive oxygen species involved are unclear. The aim of this study was to identify the primary Nox and reactive oxygen species associated with early stage compensatory collateral growth in young, healthy animals. Ligation of the feed arteries that form primary collateral pathways in rat mesentery and mouse hindlimb was used to assess the role of Nox during collateral growth. Changes in mesenteric collateral artery Nox mRNA expression determined by real-time PCR at 1, 3, and 7 days relative to same-animal control arteries suggested a role for Nox subunits Nox2 and p47phox. Administration of apocynin or Nox2ds-tat suppressed collateral growth in both rat and mouse models, suggesting the Nox2/p47phox interaction was involved. Functional significance of p47phox expression was assessed by evaluation of collateral growth in rats administered p47phox small interfering RNA and in p47phox−/− mice. Diameter measurements of collateral mesenteric and gracilis arteries at 7 and 14 days, respectively, indicated no significant collateral growth compared with control rats or C57BL/6 mice. Chronic polyethylene glycol-conjugated catalase administration significantly suppressed collateral development in rats and mice, implying a requirement for H2O2. Taken together, these results suggest that Nox2, modulated at least in part by p47phox, mediates early stage compensatory collateral development via a process dependent upon peroxide generation. These results have important implications for the use of antioxidants and the development of therapies for peripheral arterial disease. PMID:24633549

Angiotensin-converting enzyme DD polymorphism is associated with poor coronary collateral circulation in patients with coronary artery disease.

Science.gov (United States)

Ceyhan, Koksal; Kadi, Hasan; Celik, Atac; Burucu, Turgay; Koc, Fatih; Sogut, Erkan; Sahin, Semsettin; Onalan, Orhan

2012-01-01

Although association between angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism and cardiovascular diseases was reported by many studies, the relation between ACE I/D polymorphism and coronary collateral circulation (CCC) has not been studied yet. The aim of the present study was to investigate a possible relationship between ACE I/D polymorphism and CCC. Patients who were subjected to coronary angiography in the 2006 to 2009 period and had at least a completely occluded major artery were included in this study. To classify collateral circulation, we used the Rentrop classification. Patients were classified as having poor CCC (Rentrop grades 0 to 1) or good CCC (Rentrop grades 2 to 3). Gene polymorphism was detected through the detailed melting curve analysis of polymerase chain reaction products after amplification using real-time polymerase chain reaction method and LightCycler 1.5 apparatus. We prospectively studied 113 patients who had at least 1 totally occluded major epicardial coronary artery. Forty-seven patients had poor CCC and 67 patients had good CCC. There were no differences among groups in age, sex, risk factors, lipid profile, uses of cardiovascular drugs, and number of diseased vessels. Plasma ACE levels were significantly higher in poor CCC group (P DD polymorphism was higher in the poor CCC group (P DD genotype (95% CI, 2.55-12.79; P = 0.001), presence of diabetes (95% CI, 1.03-3.16; P = 0.005), and pulse pressure (95% CI, 1.04-1.56; P = 0.045) were independent determinants of poor coronary collateral development. This study showed that ACE DD polymorphism is associated with poor CCC. Poor collateral circulation in patients carrying the D allele may be associated with endothelial dysfunction and elevated blood ACE levels in these patients.

47 CFR 1.1907 - Return of property or collateral.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Return of property or collateral. 1.1907 Section 1.1907 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Collection of Claims Owed the United States General Provisions § 1.1907 Return of property or collateral...

Aging causes collateral rarefaction and increased severity of ischemic injury in multiple tissues

Science.gov (United States)

Faber, James E.; Zhang, Hua; Lassance-Soares, Roberta M.; Prabhakar, Pranay; Najafi, Amir H.; Burnett, Mary Susan; Epstein, Stephen E.

2011-01-01

Objective Aging is a major risk factor for increased ischemic tissue injury. Whether collateral rarefaction and impaired remodeling contribute to this is unknown. We quantified the number and diameter of native collaterals, and their remodeling in 3-, 16-, 24-, and 31-months-old mice. Methods and Results Aging caused an “age-dose-dependent” greater drop in perfusion immediately after femoral artery ligation, followed by a diminished recovery of flow and increase in tissue injury. These effects were associated with a decline in collateral number, diameter and remodeling. Angiogenesis was also impaired. Mechanistically, these changes were not accompanied by reduced recruitment of T-cells or macrophages to remodeling collaterals. However, eNOS signaling was dysfunctional, as indicated by increased protein nitrosylation and less phosphorylated eNOS and VASP in collateral wall cells. The cerebral circulation exhibited a similar age-dose-dependent loss of collateral number and diameter and increased tortuosity, resulting in an increase in collateral resistance and infarct volume (e.g., 6- and 3-fold, respectively, in 24-months-old mice) after artery occlusion. This was not associated with rarefaction of similarly-sized arterioles. Collateral remodeling was also reduced. Conclusions Our findings demonstrate that aging causes rarefaction and insufficiency of the collateral circulation in multiple tissues, resulting in more severe ischemic tissue injury. PMID:21617137

Historical aspects and relevance of the human coronary collateral circulation.

Science.gov (United States)

Seiler, Christian; Meier, Pascal

2014-02-01

In 1669, anastomoses between the right and left coronary artery were first documented by Richard Lower of Amsterdam. Using post-mortem imaging, a debate followed on the existence of structural inter-coronary anastomoses, which was not resolved before the first half of the 20 ieth century in case of the presence of coronary artery disease (CAD), and not before the early 1960 ies in case of the normal human coronary circulation by William Fulton. Functional coronary collateral measurements during coronary interventions were first performed only in the 1970 ies, respectively in the early 1980 ies. In humans, the existence of functional coronary collaterals in the absence of CAD has not been documented before 2003. Though the coronary collateral circulation has been recognized as an alternative source of blood supply to ischemic myocardium, its prognostic significance for the CAD population as a whole has been controversial until recently. The debate was due to different populations examined (acute versus chronic CAD, varying severity of CAD), to variable definitions of the term "prognosis", to insufficient statistical power of the investigation with rare occurrence of prognostic endpoints, to short duration of follow-up and to blunt instruments employed for collateral assessment. Individually, it has been acknowledged that a well functioning collateral supply to a myocardial area at risk for necrosis reduces infarct size, preserves ventricular function, prevents ventricular remodelling and aneurysm formation. Collectively, evidence has accumulated only recently that an extensive coronary collateral circulation is a beneficial prognosticator quoad vitam. In a recent meta-analysis on the topic, the risk ratio to die from any cause for high vs low or absent collateralization in patients with subacute myocardial infarction was 0.53 (95% confidence interval 0.15-1.92; p=0.335), and for patients with acute myocardial infarction, it was 0.63 (95% confidence interval 0

Tissue-engineered collateral ligament composite allografts for scapholunate ligament reconstruction: an experimental study.

Science.gov (United States)

Endress, Ryan; Woon, Colin Y L; Farnebo, Simon J; Behn, Anthony; Bronstein, Joel; Pham, Hung; Yan, Xinrui; Gambhir, Sanjiv S; Chang, James

2012-08-01

In patients with chronic scapholunate (SL) dissociation or dynamic instability, ligament repair is often not possible, and surgical reconstruction is indicated. The ideal graft ligament would recreate both anatomical and biomechanical properties of the dorsal scapholunate ligament (dorsal SLIL). The finger proximal interphalangeal joint (PIP joint) collateral ligament could possibly be a substitute ligament. We harvested human PIP joint collateral ligaments and SL ligaments from 15 cadaveric limbs. We recorded ligament length, width, and thickness, and measured the biomechanical properties (ultimate load, stiffness, and displacement to failure) of native dorsal SLIL, untreated collateral ligaments, decellularized collateral ligaments, and SL repairs with bone-collateral ligament-bone composite collateral ligament grafts. As proof of concept, we then reseeded decellularized bone-collateral ligament-bone composite grafts with green fluorescent protein-labeled adipo-derived mesenchymal stem cells and evaluated them histologically. There was no difference in ultimate load, stiffness, and displacement to failure among native dorsal SLIL, untreated and decellularized collateral ligaments, and SL repairs with tissue-engineered collateral ligament grafts. With pair-matched untreated and decellularized scaffolds, there was no difference in ultimate load or stiffness. However, decellularized ligaments revealed lower displacement to failure compared with untreated ligaments. There was no difference in displacement between decellularized ligaments and native dorsal SLIL. We successfully decellularized grafts with recently described techniques, and they could be similarly reseeded. Proximal interphalangeal joint collateral ligament-based bone-collateral ligament-bone composite allografts had biomechanical properties similar to those of native dorsal SLIL. Decellularization did not adversely affect material properties. These tissue-engineered grafts may offer surgeons another

Collateral flow predicts outcome after basilar artery occlusion : The posterior circulation collateral score

NARCIS (Netherlands)

van der Hoeven, Erik J R J; McVerry, Ferghal; Vos, Jan Albert; Algra, Ale; Puetz, Volker; Kappelle, L. Jaap; Schonewille, Wouter J.

2016-01-01

BACKGROUND AND AIM: Our aim was to assess the prognostic value of a semiquantitative computed tomography angiography-based grading system, for the prediction of outcome in patients with acute basilar artery occlusion, based on the presence of potential collateral pathways on computed tomography

Importance of preoperative imaging in acetabular revision surgery - a case report.

Science.gov (United States)

Schmitz, Hc; Egidy, Cc; Al-Khateeb, H; Cárdenas, G; Gehrke, T; Kendoff, D

2012-01-01

Acetabular defects, particularly as a result of protrusion of acetabular components into the hemipelvis, may cause serious complications during revision procedures as a result of iatrogenic injury to surrounding anatomical structures. In these challenging cases, we advocate the utilisation of preoperative three dimensional imaging. MRI and CT- imaging offer superior understanding of the three-dimensional quality of bony defects and the relationship of implants to important anatomical structures. Appropriate preoperative planning may also prevent major complications during the removal of the pre-existing hardware, prior to re-implantation of implants. Potential complications include injury of nerves, blood vessels and other intrapelvic structures.In our case, a major bony defect of the acetabulum was a result of the protrusion of an implanted reinforcement ring. A preoperative, contrast-enhanced CT scan showed that the urethra was in close proximity to the hook of the reinforcement ring.The preoperative imaging aided in identifying and understanding the potential complications that could occur intraoperatively. Additionally, it delineated the intact anatomic structures prior to surgery, which could have medico-legal implications.The importance of preoperative imaging and the existing literature is discussed within this case description.

Non-bronchial collateral supply from the left gastric artery in massive haemoptysis

International Nuclear Information System (INIS)

Sellars, N.; Belli, A.M.

2001-01-01

Two patients presented with recurrent, massive haemoptysis. Arteriography, including thoracoabdominal aortograms, revealed in both cases large non-bronchial collaterals arising from the left gastric artery. In the first case the non-bronchial collateral supplied the upper left lobe and in the second case it supplied the middle right lobe. Percutaneous embolisation of bronchial and non-bronchial collateral branches has become an accepted procedure in controlling massive or recurrent haemoptysis. Accurate identification of the non-bronchial collateral arterial feeders is essential for successful embolotherapy. (orig.)

Laparoscopic prototype for optical sealing of renal blood vessels

Science.gov (United States)

Hardy, Luke A.; Hutchens, Thomas C.; Larson, Eric R.; Gonzalez, David A.; Chang, Chun-Hung; Nau, William H.; Fried, Nathaniel M.

2017-02-01

Energy-based, radiofrequency and ultrasonic devices provide rapid sealing of blood vessels during laparoscopic procedures. We are exploring infrared lasers as an alternative for vessel sealing with less collateral thermal damage. Previous studies demonstrated vessel sealing in an in vivo porcine model using a 1470-nm laser. However, the initial prototype was designed for open surgery and featured tissue clasping and light delivery mechanisms incompatible with laparoscopic surgery. In this study, a laparoscopic prototype similar to devices in surgical use was developed, and tests were conducted on porcine renal blood vessels. The 5-mm-OD prototype featured a traditional Maryland jaw configuration. Laser energy was delivered through a 550-μm-core fiber and side-delivery from the lower jaw, with beam dimensions of 18-mm-length x 1.2-mm-width. The 1470-nm diode laser delivered 68 W with 3 s activation time. A total of 69 porcine renal vessels with mean diameter of 3.3 +/- 1.7 mm were tested, ex vivo. Vessels smaller than 5 mm were consistently sealed (48/51) with burst pressures greater than malignant hypertension blood pressure (180 mmHg), averaging 1038 +/- 474 mmHg. Vessels larger than 5 mm were not consistently sealed (6/18), yielding burst pressures of only 174 +/- 221 mmHg. Seal width, thermal damage zone, and thermal spread averaged 1.7 +/- 0.8, 3.4 +/- 0.7, and 1.0 +/- 0.4 mm. A novel optical laparoscopic prototype with 5-mm- OD shaft integrated within a standard Maryland jaw design consistently sealed vessels less than 5 mm with minimal thermal spread. Further in vivo studies are planned to test performance across a variety of vessels and tissues.

13 CFR 120.395 - What is SBA's collateral position?

Science.gov (United States)

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false What is SBA's collateral position? 120.395 Section 120.395 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Special Purpose Loans Builders Loan Program § 120.395 What is SBA's collateral position? SBA will require...

FFTF thermal-hydraulic testing results affecting piping and vessel component design in LMFBR's

International Nuclear Information System (INIS)

Stover, R.L.; Beaver, T.R.; Chang, S.C.

1983-01-01

The Fast Flux Test Facility completed four years of pre-operational testing in April 1982. This paper describes thermal-hydraulic testing results from this period which impact piping and vessel component design in LMFBRs. Data discussed are piping flow oscillations, piping thermal stratification and vessel upper plenum stratification. Results from testing verified that plant design limits were met

Coronary collateral circulation: clinical significance and influence on survival in patients with coronary artery occlusion

DEFF Research Database (Denmark)

Hansen, J F

1989-01-01

In a consecutive series of 96 patients with coronary artery occlusion, 67 had good and 29 had no or poor collateral circulation. Patients with good collaterals had the severest degree of coronary artery disease. Good collaterals are associated with a higher incidence of angina pectoris and normal...... electrocardiogram and with lower incidence of Q-waves, positive exercise tests, heart failure, previous myocardial infarction, and dyskinesia at ventriculography. Survival rates after 10 years were (1) 51.5% with good and 34.5% with poor collaterals (p less than 0.1), (2) 59.4% with angina pectoris and good...... collaterals and 41.2% with angina pectoris and poor collaterals (p less than 0.05), (3) 64.8% without and 24.4% with heart failure and good collaterals (p less than 0.001), and (4) 58.3% without and 16.1% with heart failure and poor collaterals (p less than 0.01). Good collaterals protect the myocardium...

Congenital absence of infrarenal IVC and iliac venous system : Unusual collateral Pathways

International Nuclear Information System (INIS)

Lee, Jin Joo; Lee, Byung Hee; Kim, Kie Hwan; Do, Young Soo; Chin, Soo Yil

1994-01-01

We present a case with congenital absence of the infrarenal portion of inferior vena cava and iliac venous system, showing unusual venous collaterals including the left ovarian venous collateral via parametrial venous complex, and a mesenteric-periureteric venous connection. The venous collateral pathways were demonstrated by computed tomography and venography

Preoperative evaluation of hilar vessel anatomy with 3-D computerized tomography in living kidney donors.

Science.gov (United States)

Tombul, S T; Aki, F T; Gunay, M; Inci, K; Hazirolan, T; Karcaaltincaba, M; Erkan, I; Bakkaloglu, A; Yasavul, U; Bakkaloglu, M

2008-01-01

Digital subtract angiography is the gold standard for anatomic assessment of renal vasculature for living renal donors. However, multidetector-row computerized tomography (MDCT) is less invasive than digital subtract angiography and provides information of kidney stones and other intra-abdominal organs. In this study, preoperative MDCT angiography results were compared with the peroperative findings to evaluate the accuracy of MDCT for the evaluation of renal anatomy. From December 2002 to May 2007, all 60 consecutive living kidney donors were evaluated with MDCT angiography preoperatively. We reported the number and origin of renal arteries, presence of early branching arteries, and any intrinsic renal artery disease. Renal venous anatomy was evaluated for the presence of accessory, retroaortic, and circumaortic veins using venous phase axial images. The calyces and ureters were assessed with delayed topograms. The results of the MDCT angiography were compared with the peroperative findings. A total of 67 renal arteries were seen peroperatively in 60 renal units. Preoperative MDCT angiography detected 64 of them. The two arteries not detected by MDCT had diameters less than 3 mm. Anatomic variations were present in nine veins, five of which were detected by CT angiography. Sensitivity of MDCT angiography for arteries and veins was 95% and 93%, respectively. Positive predictive values were 100% for both arteries and veins. MDCT angiography offers a less invasive, rapid, and accurate preoperative investigation modality for vascular anatomy in living kidney donors. It also provides sufficient information about extrarenal anatomy important for donor surgery.

Relationship between haemodynamic impairment and collateral blood flow in carotid artery disease.

Science.gov (United States)

Hartkamp, Nolan S; Petersen, Esben T; Chappell, Michael A; Okell, Thomas W; Uyttenboogaart, Maarten; Zeebregts, Clark J; Bokkers, Reinoud Ph

2017-01-01

Collateral blood flow plays a pivotal role in steno-occlusive internal carotid artery (ICA) disease to prevent irreversible ischaemic damage. Our aim was to investigate the effect of carotid artery disease upon cerebral perfusion and cerebrovascular reactivity and whether haemodynamic impairment is influenced at brain tissue level by the existence of primary and/or secondary collateral. Eighty-eight patients with steno-occlusive ICA disease and 29 healthy controls underwent MR examination. The presence of collaterals was determined with time-of-flight, two-dimensional phase contrast MRA and territorial arterial spin labeling (ASL) imaging. Cerebral blood flow and cerebrovascular reactivity were assessed with ASL before and after acetazolamide. Cerebral haemodynamics were normal in asymptomatic ICA stenosis patients, as opposed to patients with ICA occlusion, in whom the haemodynamics in both hemispheres were compromised. Haemodynamic impairment in the affected brain region was always present in symptomatic patients. The degree of collateral blood flow was inversely correlated with haemodynamic impairment. Recruitment of secondary collaterals only occurred in symptomatic ICA occlusion patients. In conclusion, both CBF and cerebrovascular reactivity were found to be reduced in symptomatic patients with steno-occlusive ICA disease. The presence of collateral flow is associated with further haemodynamic impairment. Recruitment of secondary collaterals is associated with severe haemodynamic impairment.

De-novo Collateral Formation Following Acute Myocardial Infarction: Dependence on CCR2+ Bone Marrow Cells

Science.gov (United States)

Zhang, Hua; Faber, James E

2015-01-01

Wide variation exists in the extent (number and diameter) of native pre-existing collaterals in tissues of different strains of mice, with supportive indirect evidence recently appearing for humans. This variation is a major determinant of the wide variation in severity of tissue injury in occlusive vascular disease. Whether such genetic-dependent variation also exists in the heart is unknown because no model exists for study of mouse coronary collaterals. Also owing to methodological limitations, it is not known if ischemia can induce new coronary collaterals to form (“neo-collaterals”) versus remodeling of pre-existing ones. The present study sought to develop a model to study coronary collaterals in mice, determine whether neo-collateral formation occurs, and investigate the responsible mechanisms. Four strains with known rank-ordered differences in collateral extent in brain and skeletal muscle were studied: C57BLKS>C57BL/6>A/J>BALB/c. Unexpectedly, these and 5 additional strains lacked native coronary collaterals. However after ligation, neo-collaterals formed rapidly within 1-to-2 days, reaching their maximum extent in ≤ 7 days. Rank-order for neo-collateral formation differed from the above: C57BL/6>BALB/c>C57BLKS>A/J. Collateral network conductance, infarct volume−1, and contractile function followed this same rank-order. Neo-collateral formation and collateral conductance were reduced and infarct volume increased in MCP1−/− and CCR2−/− mice. Bone-marrow transplant rescued collateral formation in CCR2−/− mice. Involvement of fractalkine→CX3CR1 signaling and endothelial cell proliferation were also identified. This study introduces a model for investigating the coronary collateral circulation in mice, demonstrates that neocollaterals form rapidly after coronary occlusion, and finds that MCP→CCR2-mediated recruitment of myeloid cells is required for this process. PMID:26254180

Associations Between Collateral Status and Thrombus Characteristics and Their Impact in Anterior Circulation Stroke.

Science.gov (United States)

Alves, Heitor C; Treurniet, Kilian M; Dutra, Bruna G; Jansen, Ivo G H; Boers, Anna M M; Santos, Emilie M M; Berkhemer, Olvert A; Dippel, Diederik W J; van der Lugt, Aad; van Zwam, Wim H; van Oostenbrugge, Robert J; Lingsma, Hester F; Roos, Yvo B W E M; Yoo, Albert J; Marquering, Henk A; Majoie, Charles B L M

2018-02-01

Thrombus characteristics and collateral score are associated with functional outcome in patients with acute ischemic stroke. It has been suggested that they affect each other. The aim of this study is to evaluate the association between clot burden score, thrombus perviousness, and collateral score and to determine whether collateral score influences the association of thrombus characteristics with functional outcome. Patients with baseline thin-slice noncontrast computed tomography and computed tomographic angiography images from the MR CLEAN trial (Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands) were included (n=195). Collateral score and clot burden scores were determined on baseline computed tomographic angiography. Thrombus attenuation increase was determined by comparing thrombus density on noncontrast computed tomography and computed tomographic angiography using a semiautomated method. The association of collateral score with clot burden score and thrombus attenuation increase was evaluated with linear regression. Mediation and effect modification analyses were used to assess the influence of collateral score on the association of clot burden score and thrombus attenuation increase with functional outcome. A higher clot burden score (B=0.063; 95% confidence interval, 0.008-0.118) and a higher thrombus attenuation increase (B=0.014; 95% confidence interval, 0.003-0.026) were associated with higher collateral score. Collateral score mediated the association of clot burden score with functional outcome. The association between thrombus attenuation increase and functional outcome was modified by the collateral score, and this association was stronger in patients with moderate and good collaterals. Patients with lower thrombus burden and higher thrombus perviousness scores had higher collateral score. The positive effect of thrombus perviousness on clinical outcome was only present in patients with

Relationship between haemodynamic impairment and collateral blood flow in carotid artery disease

DEFF Research Database (Denmark)

Hartkamp, Nolan S; Petersen, Esben T; Chappell, Michael A

2018-01-01

Collateral blood flow plays a pivotal role in steno-occlusive internal carotid artery (ICA) disease to prevent irreversible ischaemic damage. Our aim was to investigate the effect of carotid artery disease upon cerebral perfusion and cerebrovascular reactivity and whether haemodynamic impairment...... is influenced at brain tissue level by the existence of primary and/or secondary collateral. Eighty-eight patients with steno-occlusive ICA disease and 29 healthy controls underwent MR examination. The presence of collaterals was determined with time-of-flight, two-dimensional phase contrast MRA and territorial....... In conclusion, both CBF and cerebrovascular reactivity were found to be reduced in symptomatic patients with steno-occlusive ICA disease. The presence of collateral flow is associated with further haemodynamic impairment. Recruitment of secondary collaterals is associated with severe haemodynamic impairment....

Recovery of testicular blood flow following ligation of testicular vessels

International Nuclear Information System (INIS)

Pascual, J.A.; Villanueva-Meyer, J.; Salido, E.; Ehrlich, R.M.; Mena, I.; Rajfer, J.

1989-01-01

To determine whether initial ligation of the testicular vessels of the high undescended testis followed by a delayed secondary orchiopexy is a viable alternative to the classical Fowler-Stephens procedure, a series of preliminary experiments were conducted in the rat in which testicular blood flow was measured by the 133-xenon washout technique before, and 1 hour and 30 days after ligation of the vessels. In addition, testicular histology, and testis and sex-accessory tissue weights were measured in 6 control, 6 sham operated and 6 testicular vessel ligated rats 54 days after vessel ligation. The data demonstrate that ligation and division of the testicular blood vessels produce an 80 per cent decrease in testicular blood flow 1 hour after ligation of the vessels. However, 30 days later testis blood flow returns to the control and pre-treatment value. There were no significant changes in testis or sex-accessory tissue weights 54 days after vessel ligation. Histologically, 4 of the surgically operated testes demonstrated necrosis of less than 25 per cent of the seminiferous tubules while 1 testis demonstrated more than 75 per cent necrosis. The rest of the tubules in all 6 testes demonstrated normal spermatogenesis. From this study we conclude that initial testicular vessel ligation produces an immediate decrease in testicular blood flow but with time the collateral vessels are able to compensate and return the testis blood flow to its normal pre-treatment value. These preliminary observations lend support for the concept that initial ligation of the testicular vessels followed by a delayed secondary orchiopexy in patients with a high undescended testis may be a possible alternative to the classical Fowler-Stephens approach

The sural artery and vein as recipient vessels in free flap reconstruction about the knee.

Science.gov (United States)

Johnson, P E; Harris, G D; Nagle, D J; Lewis, V L

1987-04-01

The sural artery and vein were used successfully as recipient vessels in nine patients who required free flap reconstruction about the knee. The anatomy of the sural vessels and the potential advantages of their use as free flap recipients are reviewed and discussed. Indications include popliteal vessels that are absent or severely damaged, as determined by preoperative angiography. No anastomotic complications were encountered in this series, indicating that the sural artery and vein can be used successfully as recipient vessels.

[Key vessels assessment and operation highlights in laparoscopic extended right hemicolectomy].

Science.gov (United States)

Wang, Hao; Zhao, Quanquan

2018-03-25

Laparoscopic radical colectomies have been more widely used gradually, among which laparoscopic extended right hemicolectomy is considered as the most difficult procedure. The difficulty of extended right hemicolectomy lies in the need to dissect lymph nodes along the superior mesenteric vein (SMV) and disconnect numerous and possible aberrant vessels. To address this problem, we emphasize two points in key vessel assessment: getting familiar with the anatomy along the medial-to-lateral approach and having a good understanding about the preoperative imaging presentations. An accurately preoperative imaging assessment by abdominal enhanced CT can help the surgeon understand the relative position of the key vessels to be dealt with during operation and the situation of the possible aberrant vessels so as to guide the procedure more effectively and facilitate the prevention and management of the intraoperative complications. During operation, the operator should pay special attention to the management of the vessels in the ileocolic vessel region, Henle's trunk and middle colon vessels. The operation highlights of the key vessels are as follows: (1) The ileocolic vessels: identifying the Toldt's gap correctly and opening the vascular sheath of the SMV securely; making sure that the duodenum is well protected. (2) Henle's trunk: dissecting along the surface of the Henle's trunk; preserving the anterior superior pancreaticoduodenal vein (ASPDV) and main trunk of the Henle's trunk; disconnecting the roots of the right colic vein (RCV) and right gastroepiploic vein (RGEV), and then dissecting lymph nodes along the surface of the pancreas. (3) The middle colon vessels: identifying the root of the middle colon vessel along the lower edge of the pancreas; avoiding entering behind the pancreas; mobilizing the transverse mesocolon sufficiently along the surface of the pancreas. Finally, we discuss and analyze the disputes currently existing in laparoscopic extended right

Coronary collaterals and risk for restenosis after percutaneous coronary interventions: a meta-analysis

Directory of Open Access Journals (Sweden)

Meier Pascal

2012-06-01

Full Text Available Abstract Background The benefit of the coronary collateral circulation (natural bypass network on survival is well established. However, data derived from smaller studies indicates that coronary collaterals may increase the risk for restenosis after percutaneous coronary interventions. The purpose of this systematic review and meta-analysis of observational studies was to explore the impact of the collateral circulation on the risk for restenosis. Methods We searched the MEDLINE, EMBASE and ISI Web of Science databases (2001 to 15 July 2011. Random effects models were used to calculate summary risk ratios (RR for restenosis. The primary endpoint was angiographic restenosis > 50%. Results A total of 7 studies enrolling 1,425 subjects were integrated in this analysis. On average across studies, the presence of a good collateralization was predictive for restenosis (risk ratio (RR 1.40 (95% CI 1.09 to 1.80; P = 0.009. This risk ratio was consistent in the subgroup analyses where collateralization was assessed with intracoronary pressure measurements (RR 1.37 (95% CI 1.03 to 1.83; P = 0.038 versus visual assessment (RR 1.41 (95% CI 1.00 to 1.99; P = 0.049. For the subgroup of patients with stable coronary artery disease (CAD, the RR for restenosis with 'good collaterals' was 1.64 (95% CI 1.14 to 2.35 compared to 'poor collaterals' (P = 0.008. For patients with acute myocardial infarction, however, the RR for restenosis with 'good collateralization' was only 1.23 (95% CI 0.89 to 1.69; P = 0.212. Conclusions The risk of restenosis after percutaneous coronary intervention (PCI is increased in patients with good coronary collateralization. Assessment of the coronary collateral circulation before PCI may be useful for risk stratification and for the choice of antiproliferative measures (drug-eluting stent instead bare-metal stent, cilostazol.

Incidentally diagnosed Takayasu arteritis on thyroid ultrasonography showing prominent collateral vessels of thyroidal arteries and common carotid artery occlusion

Energy Technology Data Exchange (ETDEWEB)

Nam, Se Jin; Kim, Eun Kyung [Dept. of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul (Korea, Republic of)

2014-10-15

We report a case of middle-aged woman incidentally diagnosed with Takayasu arteritis during the ultrasonography of a thyroid gland nodule. Prominent collaterals of the thyroidal arteries and a thin common carotid artery with mural thickening and deficient intraluminal flow signals were initially depicted on the ultrasonography with color Doppler. Subsequent magnetic resonance angiography and computed tomography aortography confirmed the diagnosis with the imaging features of a bilateral long segment common carotid artery occlusion and segmental stenosis of the left subclavian artery in addition to the suggestive physical findings.

Pricing a Collateralized Derivative Trade with a Funding Value Adjustment

Directory of Open Access Journals (Sweden)

Chadd B. Hunzinger

2015-01-01

Full Text Available The 2008 credit crisis changed the manner in which derivative trades are conducted. One of these changes is the posting of collateral in a trade to mitigate the counterparty credit risk. Another is the realization that banks are not risk-free and, as a result, cannot borrow at the risk-free rate any longer. The latter led banks to introduced the controversial adjustment to derivative prices, known as a funding value adjustment (FVA, which is interlinked with the posting of collateral. In this paper, we extend the Cox, Ross and Rubinstein (CRR discrete-time model to include collateral and FVA. We prove that this derived model is a discrete analogue of Piterbarg’s partial differential equation (PDE, which describes the price of a collateralized derivative. The fact that the two models coincide is also verified by numerical implementation of the results that we obtain.

Collateral flow after extracorporeal membrane oxygenation

International Nuclear Information System (INIS)

Smith, A.S.; Wiznitzer, M.; Haacke, E.M.

1990-01-01

MR angiography was used to evaluate collateral flow after extracorporal membrane oxygenation (ECMO) in patients with permanent ligation of the right common carotid artery (RCCA). One year after ECMO, MR angiography of the cerebral circulation was performed in 11 survivors and MR angiography of the neck in seven. The diameters of the left common carotid (LCCA) and vertebral (Vert) arteries in the neck and of the basilar (Bas) and internal carotid arteries in the head were measured. Ratios of the artery diameters were compared with those of seven children (aged 6 months - 17 years) who had normal MR angiographic and brain MR imaging studies. Compared with carotid artery diameter, the ECMO population had proportionately larger vertebral (RVert/LCCA, -0.82 ± 0.12 vs 0.56 ± 0.20 [<.02], LVert/LCCA, -0.86 ± 0.15 vs 0.67 ± 0.05 [P < .02] and basilar artery diameters (LICA/Bas, -0.91 ± 0.15 vs 1.49 ± 0.48 [p < .003]) than did control subjects. Ratios in five children with enlarged RPComA after ECMO were not significantly different from those in controls. The RICA was present and smaller than the LICA in the ECMO population, but not in control subjects (RICA/LICA, -0.75 ± 0.06 vs 0.91 ± 0.23 [p < .05]). Increased vertebral and basilar artery flow is a response to RCCA ligation in the neonate and is independent of RPComA collateral flow. This suggests the presence of more extensive parenchymal collaterals from posterior cerebral arteries, from the vertebrobasilar circulation to the external carotid artery or other collaterals. Consequently, later abnormalities of vertebrobasilar flow might adversely affect right hemispheric function in this children

Injuries to the Collateral Ligaments of the Metacarpophalangeal Joint of the Thumb, Including Simultaneous Combined Thumb Ulnar and Radial Collateral Ligament Injuries, in National Football League Athletes.

Science.gov (United States)

Werner, Brian C; Belkin, Nicole S; Kennelly, Steve; Weiss, Leigh; Barnes, Ronnie P; Rodeo, Scott A; Warren, Russell F; Hotchkiss, Robert N

2017-01-01

Thumb collateral ligament injuries occur frequently in the National Football League (NFL). In the general population or in recreational athletes, pure metacarpophalangeal (MCP) abduction or adduction mechanisms yield isolated ulnar collateral ligament (UCL) and radial collateral ligament (RCL) tears, respectively, while NFL athletes may sustain combined mechanism injury patterns. To evaluate the incidence of simultaneous combined thumb UCL and RCL tears among all thumb MCP collateral ligament injuries in NFL athletes on a single team. Case series; Level of evidence, 4. A retrospective review of all thumb injuries on a single NFL team from 1991 to 2014 was performed. All players with a thumb MCP collateral ligament injury were included. Collateral ligament injuries were confirmed by review of both physical examination findings and magnetic resonance imaging. Player demographics, surgical details, and return-to-play data were obtained from the team electronic medical record and surgeons' records. A total of 36 thumbs in 32 NFL players were included in the study, yielding an incidence of 1.6 thumb MCP collateral ligament injuries per year on a single NFL team. Of these, 9 thumbs (25%) had a simultaneous combined UCL and RCL tear injury pattern confirmed on both physical examination and MRI. The remaining 27 thumbs (75%) were isolated UCL injuries. All combined UCL/RCL injuries required surgery due to dysfunction from instability; 63.0% of isolated UCL injuries required surgical repair ( P = .032) due to continued pain and dysfunction from instability. Repair, when required, was delayed until the end of the season. All players with combined UCL/RCL injuries and isolated UCL injuries returned to play professional football the following season. Simultaneous combined thumb UCL and RCL tear is a previously undescribed injury pattern that occurred in 25% of thumb MCP collateral ligament injuries on a single NFL team over a 23-year period. All players with combined thumb UCL

Collateral Informant Assessment in Alcohol Use Research Involving College Students

Science.gov (United States)

Hagman, Brett T.; Cohn, Amy M.; Noel, Nora E.; Clifford, Patrick R.

2010-01-01

Objective: This study examined the associations between college students' self-reported alcohol use and corresponding collateral reports and identified factors that influence agreement between both sets of reports. Participants/Methods: Subject-collateral pairs (N = 300) were recruited from undergraduate psychology courses. Results: Data yielded…

Collateral veins in left renal vein stenosis demonstrated via CT

Energy Technology Data Exchange (ETDEWEB)

Lien, H.H.; Lund, G.; Talle, K.

1983-02-01

Twelve patients with left renal vein stenosis from tumor compression were studied with CT. All had distended collateral veins in the perirenal space which either formed a radiating or a cobweb pattern or appeared as marked longitudinal veins. Inferior phrenic vein branches were seen in seven patients and were considerably enlarged in two. Other major veins possibly taking part in collateral circulation could not be recognized due to obliteration of fat planes. The renal fascia was thickened in eleven patients, probably due to edema. A close study of the perirenal space with CT may give valuable information about collateral development.

Collateral veins in left renal vein stenosis demonstrated via CT

International Nuclear Information System (INIS)

Lien, H.H.; Lund, G.; Talle, K.

1983-01-01

Twelve patients with left renal vein stenosis from tumor compression were studied with CT. All had distended collateral veins in the perirenal space which either formed a radiating or a cobweb pattern or appeared as marked longitudinal veins. Inferior phrenic vein branches were seen in seven patients and were considerably enlarged in two. Other major veins possibly taking part in collateral circulation could not be recognized due to obliteration of fat planes. The renal fascia was thickened in eleven patients, probably due to edema. A close study of the perirenal space with CT may give valuable information about collateral development. (orig.)

Collateral and SME financing in Bangladesh: An analysis across bank size and bank ownership types

OpenAIRE

Rahman, Ashiqur; Rahman, Mosiqure Twyeafur; Ključnikov, Aleksandr

2016-01-01

We examine the issue of pledging collateral and its effect on access to credit, interest rates and credit risk of SMEs financing in Bangladesh with respect to bank size. We also examine the collateral classification (fixed assets collateral, personal guarantee and third-party guarantee) by bank ownership types to find what types of collateral are preferred by public, private and foreign banks in Bangladesh for lending to firms. In addition to that, we examine whether collateral requirements a...

Collateral status affects the onset-to-reperfusion time window for good outcome.

Science.gov (United States)

Kim, Byung Moon; Baek, Jang-Hyun; Heo, Ji Hoe; Nam, Hyo Suk; Kim, Young Dae; Yoo, Joonsang; Kim, Dong Joon; Jeon, Pyoung; Baik, Seung Kug; Suh, Sang Hyun; Lee, Kyung Yol; Kwak, Hyo Sung; Roh, Hong Gee; Lee, Young-Jun; Kim, Sang Heum; Ryu, Chang-Woo; Ihn, Yon-Kwon; Kim, Byungjoon; Jeon, Hong Jun; Kim, Jin Woo; Byun, Jun Soo; Suh, Sangil; Park, Jeong Jin; Lee, Woong Jae; Roh, Jieun; Shin, Byoung-Soo; Bang, Oh Young

2018-03-08

To characterise the time window in which endovascular thrombectomy (EVT) is associated with good outcome, and to test the differential relationship between functional outcome and onset-to-reperfusion time (ORT), depending on collateral status. This was a retrospective analysis of clinical and imaging data of 554 consecutive patients, who had recanalisation success by EVT for anterior circulation large artery occlusion, from the prospectively maintained registries of 16 comprehensive stroke centres between September 2010 and December 2015. The patients were dichotomised into good and poor collateral groups, based on CT angiography. We tested whether the likelihood of good outcome (modified Rankin Scale, 0-2) by ORT was different between two groups. ORT was 298 min±113 min (range, 81-665 min), and 84.5% of patients had good collaterals. Age, diabetes mellitus, previous infarction, National Institutes of Health Stroke Scale, good collaterals (OR 40.766; 95% CI 10.668 to 155.78; pcollateral group (OR 0.305 for every 30 min; 95% CI 0.113 to 0.822) than in good collateral group (OR 0.926 for every 30 min; 95% CI 0.875 to 0.980). Earlier successful recanalisation was strongly associated with good outcome in poor collateral group; however, this association was weak during the tested time window in good collateral group. This suggests that the ORT window for good outcome can be adjusted according to collateral status. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Blood pool SPECT for visualization of portosystemic collaterals in portal hypertension

International Nuclear Information System (INIS)

Kroiss, A.; Auinger, C.

1990-01-01

In 46 patients, 26 male and 20 female, age from 32 to 71 years (mean 47,4 ± 11 years) a bloodpool-scintigraphy (BSP) with SPECT (single photon emission computed tomography) was performed. The in-vivo labelling of the erythrocytes with pyrophosphate and Tc99m was performed in the usual way. The SPECT investigations were performed with a digital Anger-Camera (Elscint; Apex 401). In 14 patients without collaterals BPS was performed to compare the method with patients with liver diseases and collaterals. 29 patients with liver cirrhosis and portal hypertension were investigated with the BSP and additionaly a scintisplenoportography (SSP) was performed. In patients with only cephalad collaterals all the results were concordant. In just 1 patient with cephalad and caudad collaterals we found a discordant result. In 8 patients we performed BSP, SSP and a katheterangiography (KA). Taking the KA as the 'golden standard' we found a concordant result with the 3 methods in all patients with cephalad collaterals. In patients with cephalad and caudad collaterals we once found a discordant result with the SSP and twice with the BSP. In 2 patients the patency of surgical shunts were proved. 2 patients after sclerosis of the oesophageal varices have been proved by BPS and SSP and both patients showed good therapeutical results. (Authors)

Usefulness of computed tomography (CT) in the diagnosis of portosystemic collaterals in liver cirrhosis

International Nuclear Information System (INIS)

Tsukune, Yoshihiko

1984-01-01

This study assesses the usefulness of computed tomography (CT) in the diagnosis of portosystemic collaterals in liver cirrhosis. Seventy-eight patients with liver cirrhosis underwent both CT and angiography. Comparison was made between CT and angiography on eleven types of collaterals, and many of them were demonstrated on CT scans better than angio. Especially, esophageal varices, paraesophageal varices, umbilical pathway and caput medusa were diagnostic on CT scans. Gastrorenal collaterals, splenorenal collaterals, retroperitoneal pathway are also well demonstrated. Dilatation of azygos systems and small veins in the liver surface are only observed on CT scans. However, coronary varices and short gastric varices are well diagnostic in angiography. But considering all types of collaterals, it was stressed that angiography can be eliminated by CT in evaluation of collaterals in liver cirrhosis. (author)

Retrospective analysis of intravertebral collateral enhancement in patients with central venous obstruction

International Nuclear Information System (INIS)

Simeone, F.J.; Chang, Connie Y.; Huang, Ambrose J.; Kattapuram, Susan V.; Bredella, Miriam A.; Torriani, Martin; Bennett, Debbie L.

2016-01-01

To compare prevalence and patterns of intravertebral collateral enhancement in patients with and without central venous obstruction (CVO). Chest CTs performed between 1/1/2000 and 12/15/2012 with reports containing terms indicating CVO were identified. All contrast enhanced CTs were examined for the presence of CVO and collateral venous pathways. If intravertebral collateral enhancement was present, the pattern was recorded as nodular, linear, or both. In 209 suspected cases of CVO, 53 (25 %) were confirmed with obstruction and 156 (75 %) were without obstruction. In patients with CVO, 47 % (25/53) demonstrated collateral venous flow through an intravertebral marrow pathway compared to 5 % (8/156) of patients without CVO (P < 0.0001). The most common level of enhancement was the upper thoracic spine, involving only the vertebral body. Nodular, linear, and combined nodular-linear enhancement patterns were seen with similar frequency. Nodular intravertebral collateral enhancement was mistaken for sclerotic metastases in 33 % (3/9) of cases. Intravertebral collateral enhancement was seen in almost half the patients with CVO and when nodular enhancement is present, it is important to differentiate between metastatic lesions and enhancement related to CVO. (orig.)

Retrospective analysis of intravertebral collateral enhancement in patients with central venous obstruction

Energy Technology Data Exchange (ETDEWEB)

Simeone, F.J.; Chang, Connie Y.; Huang, Ambrose J.; Kattapuram, Susan V.; Bredella, Miriam A.; Torriani, Martin [Massachusetts General Hospital and Harvard Medical School, Division of Musculoskeletal Imaging and Intervention, Department of Radiology, Boston, MA (United States); Bennett, Debbie L. [Saint Louis University School of Medicine, Department of Radiology, Saint Louis, MO (United States)

2016-02-15

To compare prevalence and patterns of intravertebral collateral enhancement in patients with and without central venous obstruction (CVO). Chest CTs performed between 1/1/2000 and 12/15/2012 with reports containing terms indicating CVO were identified. All contrast enhanced CTs were examined for the presence of CVO and collateral venous pathways. If intravertebral collateral enhancement was present, the pattern was recorded as nodular, linear, or both. In 209 suspected cases of CVO, 53 (25 %) were confirmed with obstruction and 156 (75 %) were without obstruction. In patients with CVO, 47 % (25/53) demonstrated collateral venous flow through an intravertebral marrow pathway compared to 5 % (8/156) of patients without CVO (P < 0.0001). The most common level of enhancement was the upper thoracic spine, involving only the vertebral body. Nodular, linear, and combined nodular-linear enhancement patterns were seen with similar frequency. Nodular intravertebral collateral enhancement was mistaken for sclerotic metastases in 33 % (3/9) of cases. Intravertebral collateral enhancement was seen in almost half the patients with CVO and when nodular enhancement is present, it is important to differentiate between metastatic lesions and enhancement related to CVO. (orig.)

Pattern of venous collateral development after splenic vein occlusion in an extended Whipple procedure : comparison with collateral vein pattern in cases of sinistral portal hypertension.

Science.gov (United States)

Strasberg, Steven M; Bhalla, Sanjeev; Sanchez, Luis A; Linehan, David C

2011-11-01

The risks of developing sinistral portal hypertension as a result of occlusion of the splenic vein close to its termination during a Whipple procedure are unclear. Our purpose was to compare the pattern of venous collateral development after splenic vein ligation in an extended Whipple procedure with the pattern of collateral development in cases of sinistral portal hypertension. Five patients underwent an extended Whipple procedure in which the splenic vein was divided and not reconstructed. Six to eight months later detailed mapping of venous return from the spleen was determined by contrast-enhanced multidetector computed tomography or in one case by 3D contrast-enhanced MRI. Spleen size and length of residual patent splenic vein were also measured. The literature on sinistral portal hypertension was evaluated to ascertain whether the venous collateral pattern in cases of left-sided portal hypertension was similar to the pattern that developed when the splenic vein was ligated at its termination in the Whipple procedure. A length of splenic vein remained patent in all five patients, measuring 4.5 to 11.5 cm from the spleen. Splenomegaly did not develop. Blood returned from the spleen by multiple collaterals including collaterals in the omentum and mesocolon. These types of collaterals do not develop in sinistral portal hypertension, nor is residual patent splenic vein seen. Ligation of the splenic vein close to its termination in five patients resulted in a pattern of venous return different from patients that have developed left-sided portal hypertension.

Cognitive assessment of older adults in general practice: the collateral history.

Science.gov (United States)

Dyer, Adam H; Foley, Tony; O'Shea, Brendan; Kennelly, Sean P

2017-12-02

The collateral (or informant) history is a key component in the assessment of older adults presenting with a memory problem or concern over cognition. Despite this, it rarely features in medical literature and academic curricula. Its role in general practice has never been assessed. The aim of this study is to assess the role of the collateral history in the investigation of cognitive impairment in general practice. An online survey distributed to three nationally representative cohorts of GPs in Ireland (n = 692). Ninety-five (14%; 52.2% male) responded. Nearly all (87%; 83/95) indicate that it is most often a family member who brings possible cognitive impairment to the attention of their GP. The vast majority obtain a collateral history in > 90% of cases (72.6%; 69/95) and rate it very useful in their clinical assessment of cognition. GPs report the collateral history as readily available and rarely refused, with the general practice environment well-suited to obtaining collateral histories. A small minority routinely use the GPCOG informant section (3.2%; 3/95). Nearly all (92.6%; 88/95) report having received no training in obtaining collateral histories with most (79%; 75/95) welcoming of further training in this area. Despite recognition of the utility and importance of the collateral history, the vast majority of GPs report having never received training in obtaining one and do not use structured tools to guide their interview. Further emphasis on the informant history as a distinct clinical entity on medical curricula and increasing emphasis on the availability of structured informant tools are warranted.

The medial collateral ligament of the elbow joint

DEFF Research Database (Denmark)

Floris, S; Olsen, Bo Sanderhoff; Dalstra, Michel

1998-01-01

Eighteen osteoligamentous elbow joint specimens were included in a study of the medial collateral ligament complex (MCL). The morphologic characteristics of the MCL were examined, and three-dimensional kinematic measurements were taken after selective ligament dissections were performed. On morph......Eighteen osteoligamentous elbow joint specimens were included in a study of the medial collateral ligament complex (MCL). The morphologic characteristics of the MCL were examined, and three-dimensional kinematic measurements were taken after selective ligament dissections were performed...

De-novo collateral formation following acute myocardial infarction: Dependence on CCR2⁺ bone marrow cells.

Science.gov (United States)

Zhang, Hua; Faber, James E

2015-10-01

Wide variation exists in the extent (number and diameter) of native pre-existing collaterals in tissues of different strains of mice, with supportive indirect evidence recently appearing for humans. This variation is a major determinant of the wide variation in severity of tissue injury in occlusive vascular disease. Whether such genetic-dependent variation also exists in the heart is unknown because no model exists for study of mouse coronary collaterals. Also owing to methodological limitations, it is not known if ischemia can induce new coronary collaterals to form ("neo-collaterals") versus remodeling of pre-existing ones. The present study sought to develop a model to study coronary collaterals in mice, determine whether neo-collateral formation occurs, and investigate the responsible mechanisms. Four strains with known rank-ordered differences in collateral extent in brain and skeletal muscle were studied: C57BLKS>C57BL/6>A/J>BALB/c. Unexpectedly, these and 5 additional strains lacked native coronary collaterals. However after ligation, neo-collaterals formed rapidly within 1-to-2 days, reaching their maximum extent in ≤7 days. Rank-order for neo-collateral formation differed from the above: C57BL/6>BALB/c>C57BLKS>A/J. Collateral network conductance, infarct volume(-1), and contractile function followed this same rank-order. Neo-collateral formation and collateral conductance were reduced and infarct volume increased in MCP1(-/-) and CCR2(-/-) mice. Bone-marrow transplant rescued collateral formation in CCR2(-/-) mice. Involvement of fractalkine➔CX3CR1 signaling and endothelial cell proliferation were also identified. This study introduces a model for investigating the coronary collateral circulation in mice, demonstrates that neo-collaterals form rapidly after coronary occlusion, and finds that MCP➔CCR2-mediated recruitment of myeloid cells is required for this process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Collateralized debt obligations (CDOs

Directory of Open Access Journals (Sweden)

Dragosavac Miloš

2012-01-01

Full Text Available Collateralized debt obligations (CDOs were issued in 1987 by bankers at Drexel Burnham Lambert Inc. A decade later, CDOs became the leading power on the credit derivative markets, on which the value of derivative assets was derived from the value of other assets. However, unlike options and credit swamps, CDOs are not real, which means that they are constructed, and sometimes even the construction of their construction. CDOs were made to satisfy different types of investors, at one end, there is low-risk with low-income, and at the other, high-risk with high-income. By 2007, following the bubble burst on the US real estate market, losses on the CDO market started to expand. By 2008, the crisis on the CDO market turned into what we call today 'the global financial crisis.' CDOs are 'in the heart' of the crisis, and even wider. Our attempt is to reveal the mechanism of collateralized debt obligations (CDOs and the way in which CDOs expanded the negative effects of the present global financial crisis.

75 FR 64710 - Public Roundtable on Individual Customer Collateral Protection

Science.gov (United States)

2010-10-20

... related to individual customer collateral protection in the context of the CFTC's rulemaking efforts... customer collateral protection in the context of the Act, may do so via: paper submission to David Stawick... be in English or be accompanied by an English translation. All submissions provided to the CFTC in...

46 CFR 308.522 - Collateral deposit fund, letter of transmittal, Form MA-302.

Science.gov (United States)

2010-10-01

... 46 Shipping 8 2010-10-01 2010-10-01 false Collateral deposit fund, letter of transmittal, Form MA... Collateral deposit fund, letter of transmittal, Form MA-302. The standard form of letter of transmittal for use in establishing a collateral deposit fund, may be obtained from the American War Risk Agency or...

Determinants of leptomeningeal collateral flow in stroke patients with a middle cerebral artery occlusion

NARCIS (Netherlands)

van Seeters, Tom; Biessels, Geert Jan; Kappelle, L. Jaap; van der Graaf, Yolanda; Velthuis, Birgitta K.

2016-01-01

INTRODUCTION: Poor leptomeningeal collateral flow is related to worse clinical outcome in acute ischemic stroke, but the factors that determine leptomeningeal collateral patency are largely unknown. We explored the determinants of leptomeningeal collateral flow and assessed their effect on the

12 CFR 725.19 - Collateral requirements.

Science.gov (United States)

2010-01-01

... CREDIT UNION ADMINISTRATION CENTRAL LIQUIDITY FACILITY § 725.19 Collateral requirements. (a) Each... applicable Facility advance or Agent loan, or by guarantee of the National Credit Union Share Insurance Fund...

A case of reocclusion of the renal artery diagnosed by the color Doppler method with evaluation of blood flow direction in the collateral circulation of the kidney in addition to the non-detectable blood signal in the renal artery.

Science.gov (United States)

Hirano, Megumi; Ohta, Tomoyuki; Nakata, Norio; Kawakami, Reina; Takamura, Kimihiro; Matsuda, Tosiharu; Nishioka, Makiko; Sakurai, Tomoo; Matsuo, Kouichi; Miyamoto, Yukio

2014-10-01

A 23-year-old woman was referred to our hospital for an interventional procedure for chronic total occlusion of the right renal artery, probably due to fibromuscular dysplasia (FMD), and for control of renal vascular hypertension. Before percutaneous transluminal renal angioplasty (PTRA), aortography revealed collateral circulation to the right kidney from the lower lumbar artery. After PTRA, however, blood flow in the renal side of the collateral circulation flowed outside from the right renal parenchyma. 4 months later, we could not find a blood flow signal in the right renal artery, and there was a contrary flow signal in the right kidney parenchyma continuously from the extrahilar vessel, possibly a collateral artery. These findings indicated reocclusion of the right artery. We confirmed reocclusion of the renal artery and collateral feeding by contrast dynamic computed tomography (CT), and PTRA was performed again without any complications or reocclusion for 5 months. This is the first case report showing that a back-flowing signal in the right renal parenchyma from the extrahilar artery is useful as an indirect finding suggesting reocclusion.

13 CFR 123.513 - Does SBA require collateral on its Military Reservist EIDL?

Science.gov (United States)

2010-01-01

..., or both. SBA will not decline a loan if you do not have a particular amount of collateral so long as SBA is reasonably sure that you can repay the loan. If you refuse to pledge the available collateral... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Does SBA require collateral on its...

Predicting Collateral Status With Magnetic Resonance Perfusion Parameters: Probabilistic Approach With a Tmax-Derived Prediction Model.

Science.gov (United States)

Lee, Mi Ji; Son, Jeong Pyo; Kim, Suk Jae; Ryoo, Sookyung; Woo, Sook-Young; Cha, Jihoon; Kim, Gyeong-Moon; Chung, Chin-Sang; Lee, Kwang Ho; Bang, Oh Young

2015-10-01

Good collateral flow is an important predictor for favorable responses to recanalization therapy and successful outcomes after acute ischemic stroke. Magnetic resonance perfusion-weighted imaging (MRP) is widely used in patients with stroke. However, it is unclear whether the perfusion parameters and thresholds would predict collateral status. The present study evaluated the relationship between hypoperfusion severity and collateral status to develop a predictive model for good collaterals using MRP parameters. Patients who were eligible for recanalization therapy that underwent both serial diffusion-weighted imaging and serial MRP were enrolled into the study. A collateral flow map derived from MRP source data was generated through automatic postprocessing. Hypoperfusion severity, presented as proportions of every 2-s Tmax strata to the entire hypoperfusion volume (Tmax≥2 s), was compared between patients with good and poor collaterals. Prediction models for good collaterals were developed with each Tmax strata proportion and cerebral blood volumes. Among 66 patients, 53 showed good collaterals based on MRP-based collateral grading. Although no difference was noted in delays within 16 s, more severe Tmax delays (Tmax16-18 s, Tmax18-22 s, Tmax22-24 s, and Tmax>24 s) were associated with poor collaterals. The probability equation model using Tmax strata proportion demonstrated high predictive power in a receiver operating characteristic analysis (area under the curve=0.9303; 95% confidence interval, 0.8682-0.9924). The probability score was negatively correlated with the volume of infarct growth (P=0.030). Collateral status is associated with more severe Tmax delays than previously defined. The present Tmax severity-weighted model can determine good collaterals and subsequent infarct growth. © 2015 American Heart Association, Inc.

COLLATERAL IN SMES’ LENDING: BANKS’ REQUIREMENTS VS CUSTOMERS’ EXPECTATIONS

OpenAIRE

Daniel BADULESCU

2011-01-01

SMEs’ support and importance in developing economies should not be only declarative. Searching for funding, managers encounter various obstacles arising from information asymmetry, lack of experience, severe market conditions, and insufficient or unsatisfactory collaterals for banks (OECD 2006; Badulescu and Badulescu 2010; OECD 2000 and 2004; Lin and Sun 2006; Toivanen and Cresy, 2000). The collateral issue is extensively discussed in literature – preventing moral hazard, the alignment the i...

Quantification of myocardial area at risk in the absence of collateral flow: the validation of angiographic scores by myocardial perfusion single-photon emission computed tomography.

Science.gov (United States)

Rodríguez-Palomares, José F; Alonso, Albert; Martí, Gerard; Aguadé-Bruix, Santiago; González-Alujas, M T; Romero-Farina, Guillermo; Candell-Riera, Jaume; García del Blanco, Bruno; Evangelista, Artur; García-Dorado, David

2013-02-01

Our study aimed to compare the area at risk (AAR) determined by single-photon emission computed tomography (SPECT) with the Bypass Angioplasty Revascularization Investigation (BARI) and modified Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) angiographic scores in the setting of patients undergoing coronary angioplasty for either unstable angina or an STEMI. Radionuclide myocardial perfusion imaging prior to reperfusion has classically been the most widely practised technique for assessing the AAR and has been successfully used to compare the efficacy of various reperfusion strategies in patients with an ST-segment elevation myocardial infarction (STEMI). The BARI and modified APPROACH scores are angiographic methods widely used to provide a rapid estimation of the AAR; however, they have not been directly validated with myocardial perfusion single-photon emission computed tomography (SPECT). Fifty-five patients with no previous myocardial infarction who underwent coronary angioplasty for single-vessel disease (unstable angina: n = 25 or an STEMI: n = 30) with no evidence of collaterals (Rentrop Collateral Score collateral flow, BARI and APPROACH scores constitute valid methods for AAR estimation in current clinical practice, with more accurate results when used for the LAD territory; both are useful not only in STEMI patients but also in patients with unstable angina.

Probabilistic atlas based labeling of the cerebral vessel tree

Science.gov (United States)

Van de Giessen, Martijn; Janssen, Jasper P.; Brouwer, Patrick A.; Reiber, Johan H. C.; Lelieveldt, Boudewijn P. F.; Dijkstra, Jouke

2015-03-01

Preoperative imaging of the cerebral vessel tree is essential for planning therapy on intracranial stenoses and aneurysms. Usually, a magnetic resonance angiography (MRA) or computed tomography angiography (CTA) is acquired from which the cerebral vessel tree is segmented. Accurate analysis is helped by the labeling of the cerebral vessels, but labeling is non-trivial due to anatomical topological variability and missing branches due to acquisition issues. In recent literature, labeling the cerebral vasculature around the Circle of Willis has mainly been approached as a graph-based problem. The most successful method, however, requires the definition of all possible permutations of missing vessels, which limits application to subsets of the tree and ignores spatial information about the vessel locations. This research aims to perform labeling using probabilistic atlases that model spatial vessel and label likelihoods. A cerebral vessel tree is aligned to a probabilistic atlas and subsequently each vessel is labeled by computing the maximum label likelihood per segment from label-specific atlases. The proposed method was validated on 25 segmented cerebral vessel trees. Labeling accuracies were close to 100% for large vessels, but dropped to 50-60% for small vessels that were only present in less than 50% of the set. With this work we showed that using solely spatial information of the vessel labels, vessel segments from stable vessels (>50% presence) were reliably classified. This spatial information will form the basis for a future labeling strategy with a very loose topological model.

In vivo metacarpophalanageal joint collateral ligament length changes during flexion.

Science.gov (United States)

Sun, Y C; Sheng, X M; Chen, J; Qian, Z W

2017-07-01

We investigated the in vivo length changes of the collateral ligaments of metacarpophalangeal joint during flexion. We obtained computed tomography scans of index, middle, ring and little fingers at 0°, 30°, 60° and 90° of joint flexion from six hands of six healthy adult volunteers. Three of them had their dominant right hand studied, and the other three had their non-dominant left hand studied. We measured and analysed the radial and ulnar collateral ligaments of each metacarpophalangeal joint from the reconstructed images. We found that the dorsal and middle portions of the both radial and ulnar collateral ligament lengthened progressively during digital flexion and reached the maximum at 90° flexion. The length of the volar portion increased from 0° to 30° flexion and then decreased from 30° to 60° flexion, reaching the minimum at 90°. In conclusion, three portions of collateral ligaments on both sides of the metacarpophalangeal joint have variable length changes during flexion, which act to stabilize the joint through its flexion arc.

Redistribution of thallium-201 into right ventricle through collateral circulation

International Nuclear Information System (INIS)

Kataoka, Hajime; Ohkubo, Toshitaka; Takaoka, Shigeru; Ohshige, Tamao; Miyahara, Kenkichi.

1984-01-01

The cases of reversible right ventricular ischemia, which demonstrated redistribution of thallium (Tl)-201 into the right ventricular free wall (RVFW) through collateral channels, were reported. Two cases with complete obstruction in the proximal right coronary artery accompanied by collateral channels (left coronary artery to distal right coronary artery) underwent submaximal exercise stress Tl-201 myocardial imaging. Although the RVFW was not visualized on immediate myocardial images in one or both of the 30 0 and 60 0 left anterior oblique views in each case, three-hour delayed myocardial images showed redistribution of Tl-201 into the RVFW. It was concluded that collateral circulation affects the occurrence of redistribution of Tl-201 into the RVFW. (author)

Treatment of hepatic neoplasm through extrahepatic collaterals

Energy Technology Data Exchange (ETDEWEB)

Soo, C.S.; Chuang, V.P.; Wallace, S.; Charnsangavej, C.; Carrasco, H.

1983-04-01

Twenty-nine patients with hepatic artery occlusion were treated with additional hepatic infusion or embolization through extrahepatic collaterals. Seventeen courses of hepatic infusion were performed in 13 patients through the inferior pancreaticoduodenal artery, left gastric artery, or right gastric artery. Twenty-five hepatic embolization procedures were performed in 16 patients through the right and left phrenic arteries, left and right gastric arteries, pancreaticoduodenal artery, gastroduodenal artery, or omentoepiploic artery. In one patient gastric ulcers developed following left gastric artery infusion. No complication related to the embolization procedure was observed in the embolization group. The extrahepatic collaterals are important alternative routes for continuous transcatheter management of hepatic neoplasms following hepatic artery occlusion.

Treatment of hepatic neoplasm through extrahepatic collaterals

International Nuclear Information System (INIS)

Soo, C.S.; Chuang, V.P.; Wallace, S.; Charnsangavej, C.; Carrasco, H.

1983-01-01

Twenty-nine patients with hepatic artery occlusion were treated with additional hepatic infusion or embolization through extrahepatic collaterals. Seventeen courses of hepatic infusion were performed in 13 patients through the inferior pancreaticoduodenal artery, left gastric artery, or right gastric artery. Twenty-five hepatic embolization procedures were performed in 16 patients through the right and left phrenic arteries, left and right gastric arteries, pancreaticoduodenal artery, gastroduodenal artery, or omentoepiploic artery. In one patient gastric ulcers developed following left gastric artery infusion. No complication related to the embolization procedure was observed in the embolization group. The extrahepatic collaterals are important alternative routes for continuous transcatheter management of hepatic neoplasms following hepatic artery occlusion

A novel flow-based parameter of collateral function assessed by intracoronary thermodilution.

Science.gov (United States)

Lindner, Markus; Felix, Stephan B; Empen, Klaus; Reffelmann, Thorsten

2014-04-01

Currently, many methods for quantitation of coronary collateral function are based on intracoronary pressure measurements distal of an occluded balloon, which do not fully account for the dynamic nature of collateral flow. Therefore, a flow-based parameter of coronary collateral function based upon principles of thermodilution was evaluated. In 26 patients with a high-grade coronary artery stenosis, intracoronary hemodynamics were analyzed by the RadiAnalyzer system (St Jude Medical), including fractional flow reserve (FFR), index of microcirculatory resistance (IMR), and the pressure-based collateral flow index (CFI) during balloon occlusion and hyperemia (intravenous adenosine). Moreover, immediately after an intracoronary bolus of room-temperature saline, the balloon was occluded and the intracoronary temperature distal to the balloon was analyzed over time. The slope of the temperature-time curve was calculated after logarithmic transformation as an index of collateral blood flow (CBFI). The coefficient of variation between two measurements of CBFI amounted to 11 ± 2%. In patients with CFI ≥0.25, CBFI amounted to 0.55 ± 0.09, whereas in those with CFI function, and should be evaluated in further studies.

Collateral Consequences and Effectiveness of Sex Offender Registration and Notification: Law Enforcement Perspectives.

Science.gov (United States)

Cubellis, Michelle A; Walfield, Scott M; Harris, Andrew J

2018-03-01

A growing body of research has examined the collateral effects of sex offender registration and notification (SORN), particularly those related to offenders' social and economic reintegration into society. Although studies have examined public, offender, treatment provider, and other criminal justice perspectives on SORN's collateral impacts, few have elicited the views of law enforcement (LE) professionals who have contact with registered offenders. This study presents results from a mixed method study examining LE perspectives on collateral consequences and effectiveness of SORN. Results indicate that, although overall LE concern regarding collateral impacts is limited, those who are most engaged in SORN-related duties are significantly more likely to indicate such concern, and also more likely to believe that SORN was an effective public safety tool. Importantly, respondents in states with larger registries expressed greater concern over collateral consequences, and less belief in SORN's public safety efficacy. Implications for policy and practice are discussed.

Cardiovascular risk factors cause premature rarefaction of the collateral circulation and greater ischemic tissue injury.

Science.gov (United States)

Moore, Scott M; Zhang, Hua; Maeda, Nobuyo; Doerschuk, Claire M; Faber, James E

2015-07-01

Collaterals lessen tissue injury in occlusive disease. However, aging causes progressive decline in their number and smaller diameters in those that remain (collateral rarefaction), beginning at 16 months of age in mice (i.e., middle age), and worse ischemic injury-effects that are accelerated in even 3-month-old eNOS(-/-) mice. These findings have found indirect support in recent human studies. We sought to determine whether other cardiovascular risk factors (CVRFs) associated with endothelial dysfunction cause collateral rarefaction, investigate possible mechanisms, and test strategies for prevention. Mice with nine different models of CVRFs of 4-12 months of age were assessed for number and diameter of native collaterals in skeletal muscle and brain and for collateral-dependent perfusion and ischemic injury after arterial occlusion. Hypertension caused collateral rarefaction whose severity increased with duration and level of hypertension, accompanied by greater hindlimb ischemia and cerebral infarct volume. Chronic treatment of wild-type mice with L-N (G)-nitro-arginine methylester caused similar rarefaction and worse ischemic injury which were not prevented by lowering arterial pressure with hydralazine. Metabolic syndrome, hypercholesterolemia, diabetes mellitus, and obesity also caused collateral rarefaction. Neither chronic statin treatment nor exercise training lessened hypertension-induced rarefaction. Chronic CVRF presence caused collateral rarefaction and worse ischemic injury, even at relatively young ages. Rarefaction was associated with increased proliferation rate of collateral endothelial cells, effects that may promote accelerated endothelial cell senescence.

Collateral findings during computed tomography scan for atrial fibrillation ablation: Let's take a look around.

Science.gov (United States)

Perna, Francesco; Casella, Michela; Narducci, Maria Lucia; Dello Russo, Antonio; Bencardino, Gianluigi; Pontone, Gianluca; Pelargonio, Gemma; Andreini, Daniele; Vitulano, Nicola; Pizzamiglio, Francesca; Conte, Edoardo; Crea, Filippo; Tondo, Claudio

2016-04-26

The growing number of atrial fibrillation catheter ablation procedures warranted the development of advanced cardiac mapping techniques, such as image integration between electroanatomical map and cardiac computed tomography. While scanning the chest before catheter ablation, it is frequent to detect cardiac and extracardiac collateral findings. Most collateral findings are promptly recognized as benign and do not require further attention. However, sometimes clinically relevant collateral findings are detected, which often warrant extra diagnostic examinations or even invasive procedure, and sometimes need to be followed-up over time. Even though reporting and further investigating collateral findings has not shown a clear survival benefit, almost all the working groups providing data on collateral findings reported some collateral findings eventually coming out to be malignancies, sometimes at an early stage. Therefore, there is currently no clear agreement about the right strategy to be followed.

12 CFR 221.7 - Supplement: Maximum loan value of margin stock and other collateral.

Science.gov (United States)

2010-01-01

... value of margin stock and other collateral. (a) Maximum loan value of margin stock. The maximum loan... nonmargin stock and all other collateral. The maximum loan value of nonmargin stock and all other collateral... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Supplement: Maximum loan value of margin stock...

Collateralization, Bank Loan Rates and Monitoring : Evidence from a Natural Experiment

NARCIS (Netherlands)

Cerqueiro, G.M.; Ongena, S.; Roszbach, K.

2011-01-01

Collateral is one of the most important features of a debt contract. A substantial theoretical literature motivates the use of collateral as a means to alleviate ex-ante and ex-post information asymmetries between borrowers and lenders and the incidence of credit rationing. Through its seniority

Kinematics of partial and total ruptures of the medial collateral ligament of the elbow

DEFF Research Database (Denmark)

Eygendaal, D; Olsen, Bo Sanderhoff; Jensen, Steen Lund

2000-01-01

In this study the kinematics of partial and total ruptures of the medial collateral ligament of the elbow are investigated. After selective transection of the medial collateral ligament of 8 osteoligamentous intact elbow preparations was performed, 3-dimensional measurements of angular displacement......, increase in medial joint opening, and translation of the radial head were examined during application of relevant stress. Increase in joint opening was significant only after complete transection of the anterior part of the medial collateral ligament was performed. The joint opening was detected during...... valgus and internal rotatory stress only. After partial transection of the anterior bundle of the medial collateral ligament was performed, there was an elbow laxity to valgus and internal rotatory force, which became significant after transection of 100% of the anterior bundle of the medial collateral...

Independent predictors of retrograde failure in CTO-PCI after successful collateral channel crossing.

Science.gov (United States)

Suzuki, Yoriyasu; Muto, Makoto; Yamane, Masahisa; Muramatsu, Toshiya; Okamura, Atsunori; Igarashi, Yasumi; Fujita, Tsutomu; Nakamura, Shigeru; Oida, Akitsugu; Tsuchikane, Etsuo

2017-07-01

To evaluate factors for predicting retrograde CTO-PCI failure after successful collateral channel crossing. Successful guidewire/catheter collateral channel crossing is important for the retrograde approach in percutaneous coronary intervention (PCI) for chronic total occlusion (CTO). A total of 5984 CTO-PCI procedures performed in 45 centers in Japan from 2009 to 2012 were studied. The retrograde approach was used in 1656 CTO-PCIs (27.7%). We investigated these retrograde procedures to evaluate factors for predicting retrograde CTO-PCI failure even after successful collateral channel crossing. Successful guidewire/catheter collateral crossing was achieved in 77.1% (n = 1,276) of 1656 retrograde CTO-PCI procedures. Retrograde procedural success after successful collateral crossing was achieved in 89.4% (n = 1,141). Univariate analysis showed that the predictors for retrograde CTO-PCI failure were in-stent occlusion (OR = 1.9829, 95%CI = 1.1783 - 3.3370 P = 0.0088), calcified lesions (OR = 1.9233, 95%CI = 1.2463 - 2.9679, P = 0.0027), and lesion tortuosity (OR = 1.5244, 95%CI = 1.0618 - 2.1883, P = 0.0216). On multivariate analysis, lesion calcification was an independent predictor of retrograde CTO-PCI failure after successful collateral channel crossing (OR = 1.3472, 95%CI = 1.0614 - 1.7169, P = 0.0141). The success rate of retrograde CTO-PCI following successful guidewire/catheter collateral channel crossing was high in this registry. Lesion calcification was an independent predictor of retrograde CTO-PCI failure after successful collateral channel crossing. Devices and techniques to overcome complex CTO lesion morphology, such as lesion calcification, are required to further improve the retrograde CTO-PCI success rate. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Retrograde Wiring of Collateral Channels of the Heart in Chronic Total Occlusions: A Systematic Review and Meta-Analysis of Safety, Feasibility, and Incremental Value in Achieving Revascularization.

Science.gov (United States)

Khand, Aleem; Patel, Bilal; Palmer, Nicholas; Jones, Julia; Andron, Mohammed; Perry, Raph; Mehrotra, Sanjay; Mitsudo, Kazuaki

2015-11-01

To conduct a systematic review and meta-analysis on retrograde wiring in chronic total occlusions (CTOs) with focus on its safety and feasibility. We searched publications from 1990 to December 2013 in PubMed, Ovid, EMBASE, and the Cochrane database inserting a number of terms relating to the collateral circulation of the heart in CTOs. A total of 18 case series (n range17-462) with a total of 2280 CTO revascularization attempts fulfilled criteria for a study of retrograde wiring of collateral channels in CTOs. There were no randomized studies comparing a primary antegrade with a primary retrograde approach. Procedural CTO revascularization rates ranged from 67% to 90.6% with a large proportion having previously failed an "antegrade" approach. The septal perforator collaterals and epicardial channels were used in 73.2% (n = 1670) and 21.7% (n = 495) of cases. Although collateral/coronary perforation was not infrequent (n = 90, 5%), serious acute complications were uncommon; in the combined population 18 cases of cardiac tamponade (0.8%) and 3 deaths (0.1%). Septal perforating wiring (79.3%) was significantly more likely to be successful compared to epicardial coronary artery wiring (72.5%) when chosen by the operator as a route of retrograde access to the CTO body (relative risk 1.11 [95% confidence interval: 1.02-1.20; P = .013]). Successful retrograde wiring of collateral channels in selected patients undertaken by "CTO dedicated" operators can significantly enhance the chances of revascularization of complex CTOs with a low risk of acute serious complications. Septal perforator channels are significantly more likely to be successfully retrogradely wired compared to epicardial vessels when either is selected, by reference to their anatomical suitability by the operator, as a route of access. © The Author(s) 2015.

7 CFR 1434.16 - Release of the honey pledged as collateral for a loan.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Release of the honey pledged as collateral for a loan... MARKETING ASSISTANCE LOAN AND LDP REGULATIONS FOR HONEY § 1434.16 Release of the honey pledged as collateral for a loan. (a)(1) A producer shall not move or dispose of any honey pledged as collateral for a loan...

Computed tomographic characteristics of collateral venous pathways in dogs with caudal vena cava obstruction.

Science.gov (United States)

Specchi, Swan; d'Anjou, Marc-André; Carmel, Eric Norman; Bertolini, Giovanna

2014-01-01

Collateral venous pathways develop in dogs with obstruction or increased blood flow resistance at any level of the caudal vena cava in order to maintain venous drainage to the right atrium. The purpose of this retrospective study was to describe the sites, causes of obstruction, and configurations of venous collateral pathways for a group of dogs with caudal vena cava obstruction. Computed tomography databases from two veterinary hospitals were searched for dogs with a diagnosis of caudal vena cava obstruction and multidetector row computed tomographic angiographic (CTA) scans that included the entire caudal vena cava. Images for each included dog were retrieved and collateral venous pathways were characterized using image postprocessing and a classification system previously reported for humans. A total of nine dogs met inclusion criteria and four major collateral venous pathways were identified: deep (n = 2), portal (n = 2), intermediate (n = 7), and superficial (n = 5). More than one collateral venous pathway was present in 5 dogs. An alternative pathway consisting of renal subcapsular collateral veins, arising mainly from the caudal pole of both kidneys, was found in three dogs. In conclusion, findings indicated that collateral venous pathway patterns similar to those described in humans are also present in dogs with caudal vena cava obstruction. These collateral pathways need to be distinguished from other vascular anomalies in dogs. Postprocessing of multidetector-row CTA images allowed delineation of the course of these complicated venous pathways and may be a helpful adjunct for treatment planning in future cases. © 2014 American College of Veterinary Radiology.

31 CFR 363.176 - May a converted savings bond be pledged or used as collateral?

Science.gov (United States)

2010-07-01

... pledged or used as collateral? 363.176 Section 363.176 Money and Finance: Treasury Regulations Relating to... a converted savings bond be pledged or used as collateral? A converted savings bond may not be pledged or used as collateral for the performance of an obligation. ...

Evaluation of computed tomography on diagnosis of portosystemic collaterals in portal hypertension

International Nuclear Information System (INIS)

Ohe, Takashi; Kuronuma, Yukio; Fujiwara, Hiromichi; Ibuki, Yoshikazu; Maehara, Misao; Sugaya, Hitoshi; Harada, Takashi; Iwasaki, Naoya; Hyodo, Haruo

1987-01-01

We analyzed the diagnostic capability of CT to demonstrate the eight types of portosystemic collaterals in patient with portal hypertension. A total of 62 patients with portal hypertension underwent both CT and conventional angiography. All of these eight types of collaterals, such as esophageal varices, paraesophageal varices, coronary and short gastric pathway, dilated vein in splenic hilus, splenorenal and splenoretroperitoneal pathway, paraumbilical pathway and small veins on liver surface, caput medusa, azygos system, were demonstrated on CT better than angiography, except coronary and short gastric pathyway. And we also made comparative study of CT with per-rectal portal scintigraphy in 9 patients who underwent both studies. In 7 of these 9 patients, portosystemic collaterals were recognized on scintigram less than CT. In conclusion, CT provides much qualified images than conventional angiography or per-rectal portal scintigraphy in evaluating portosystemic collaterals. (author)

Evaluation of computed tomography on diagnosis of portosystemic collaterals in portal hypertension

Energy Technology Data Exchange (ETDEWEB)

Ohe, T; Kuronuma, Y; Fujiwara, H; Ibuki, Y; Maehara, M; Sugaya, H; Harada, T; Iwasaki, N; Hyodo, H

1987-04-01

We analyzed the diagnostic capability of CT to demonstrate the eight types of portosystemic collaterals in patient with portal hypertension. A total of 62 patients with portal hypertension underwent both CT and conventional angiography. All of these eight types of collaterals, such as esophageal varices, paraesophageal varices, coronary and short gastric pathway, dilated vein in splenic hilus, splenorenal and splenoretroperitoneal pathway, paraumbilical pathway and small veins on liver surface, caput medusa, azygos system, were demonstrated on CT better than angiography, except coronary and short gastric pathyway. And we also made comparative study of CT with per-rectal portal scintigraphy in 9 patients who underwent both studies. In 7 of these 9 patients, portosystemic collaterals were recognized on scintigram less than CT. In conclusion, CT provides much qualified images than conventional angiography or per-rectal portal scintigraphy in evaluating portosystemic collaterals.

[As cardioprotective and angiogenic biomarker, can ghrelin predict coronary collateral development and severity of coronary atherosclerosis?

Science.gov (United States)

Akboğa, Mehmet Kadri; Taçoy, Gülten; Yılmaz Demirtaş, Canan; Türkoğlu, Sedat; Boyacı, Bülent; Çengel, Atiye

2017-06-01

Ghrelin exerts protective effects on cardiovascular system by inhibiting progression of atherosclerosis, supression of vascular inflammation, and stimulating angiogenesis. Thus, the aim of this study was to investigate the effect of serum ghrelin on coronary collateral development and SYNTAX score in patients with severe coronary artery disease. Total of 91 patients who had ≥90% stenosis in at least one major coronary artery were prospectively included in this cross-sectional, observational study. Collateral degree was graded according to Rentrop-Cohen classification. Patients with grade 2 or 3 collateral degree were allocated to Good Collateral Group and patients with grade 0 or 1 collateral degree were included in Poor Collateral Group. Ghrelin and vascular endothelial growth factor A (VEGF-A) levels were measured using radioimmunoassay and ELISA kits. Serum ghrelin and VEGF-A levels were significantly higher in Good Collateral Group. Furthermore, ghrelin level showed significant inverse correlation with SYNTAX score (r=0.348; p=0.001). In multivariable regression analysis, ghrelin (Odds ratio, 1.013; 95% confidence interval, 1.011-1.017; p=0.013), VEGF-A, fasting plasma glucose and presence of chronic total occlusion were independent predictors of good collateral development. In receiver operating characteristic curve analysis, ghrelin value cut-off point of ≥781 pg/mL predicted good collateral development with sensitivity of 73.1% and specificity of 67.7%. Findings suggested that ghrelin has antioxidant and antiinflammatory properties that protect endothelial functions and also stimulate angiogenesis, which results in development of good coronary collateral and inhibition of progression of coronary atherosclerosis.

Preoperative surgical planning and simulation of complex cranial base tumors in virtual reality

Institute of Scientific and Technical Information of China (English)

YI Zhi-qiang; LI Liang; MO Da-peng; ZHANG Jia-yong; ZHANG Yang; BAO Sheng-de

2008-01-01

@@ The extremely complex anatomic relationships among bone,tumor,blood vessels and cranial nerves remains a big challenge for cranial base tumor surgery.Therefore.a good understanding of the patient specific anatomy and a preoperative planning are helpful and crocial for the neurosurgeons.Three dimensional (3-D) visualization of various imaging techniques have been widely explored to enhance the comprehension of volumetric data for surgical planning.1 We used the Destroscope Virtual Reality (VR) System (Singapore,Volume Interaction Pte Ltd,software:RadioDexterTM 1.0) to optimize preoperative plan in the complex cranial base tumors.This system uses patient-specific,coregistered,fused radiology data sets that may be viewed stereoscopically and can be manipulated in a virtual reality environment.This article describes our experience with the Destroscope VR system in preoperative surgical planning and simulation for 5 patients with complex cranial base tumors and evaluates the clinical usefulness of this system.

Significance of collateral circulation on peri-infarct zone: assessment with stress thallium-201 scintigraphy

International Nuclear Information System (INIS)

Imamura, T.; Araki, H.; Fukuyama, T.; Maruoka, Y.; Ootsubo, H.; Nakamura, M.; Koiwaya, Y.; Tanaka, K.

1986-01-01

To evaluate the significance of collateral circulation on peri-infarct zone, stress myocardial scintigraphy and contrast left ventriculography (LVG) were performed in 38 patients with recent myocardial infarction (MI). All patients had at least one completely occluded coronary artery corresponding to the infarct area. In patients with good collaterals, stress induced transient enlargement of the perfusion defect, however, in those with poor or no collaterals the enlargement did not occur (p less than 0.05). Wall motion abnormality on LVG was significantly milder in the former patients than in the latter (p less than 0.001). Transient enlargement of the perfusion defect after stress and milder left ventricular asynergy were more frequently observed in patients with anterior MI and good collaterals. These observations indicate that good collaterals may keep some myocardium in the peri-infarct zone viable

Impact of Collateral Status on Successful Revascularization in Endovascular Treatment: A Systematic Review and Meta-Analysis.

Science.gov (United States)

Leng, Xinyi; Fang, Hui; Leung, Thomas W H; Mao, Chen; Xu, Yuming; Miao, Zhongrong; Liu, Liping; Wong, K S Lawrence; Liebeskind, David S

2016-01-01

Pre-treatment collateral status may be associated with the rates of successful revascularization in acute ischemic stroke patients receiving endovascular treatment (EVT). We conducted a systematic review and meta-analysis to synthesize relevant evidence currently available. Relevant full-text articles published in English since January 1, 2000, reporting associations between collateral status and successful reperfusion and/or recanalization in acute ischemic stroke patients receiving EVT in cohort or case-control studies, or randomized clinical trials, were retrieved through search of PubMed. Study selection, data extraction and study quality assessment were carried out by 2 investigators. Risk ratios (RR) were pooled for good vs. poor collaterals for the outcomes of successful reperfusion and recanalization, based on random-effects models. Subgroup analyses were conducted to explore for potential factors that might interfere with the effects of pre-treatment collateral status on reperfusion by EVT. In total, 27 studies (2,366 subjects) were included in qualitative analysis, among which 24 studies (2,239 subjects) were quantitatively analyzed. Overall, good pre-treatment collaterals significantly increased the rate of both successful reperfusion (RR 1.28, 95% CI 1.17-1.40; p collaterals. Subgroup analyses revealed that the effects of collateral status on successful reperfusion by EVT might be different between populations with different ethnicities. Good pre-treatment collaterals may enhance the rates of successful reperfusion and recanalization in EVT for acute ischemic stroke. This may partly explain the favorable effects of good pre-treatment collaterals on clinical outcomes of stroke patients receiving EVT. Thus, it would be valuable to assess the collateral status prior to EVT in acute ischemic stroke. But studies are needed to further verify if the positive effects of good collaterals on revascularization by EVT are restricted to certain subgroups of patients

Collateral Determinats In Bank Risk Mananagement: The Regional Case

Directory of Open Access Journals (Sweden)

A. M. Karminsky

2018-01-01

Full Text Available Regional banks are struggling with significant obstacles in the modern Russian economy. Among them are strong competition with major big banks, strong resource restrictions, tightening the Bank of Russia’s requirements, and quite rapid expansion of financial technologies. Thus, the reduction of regional banks occurs, that produces both a negative impact on the development of small and medium enterprises (SMEs and challenges for balanced competition on the Russian market. Basically, these banks provide the settlement of region’s social and economic problems while maintaining local companies and enterprises. Collateral, as a source for losses covering, became the essential element of credit risk management in banks. Providing lenders to implement such instruments, it helps to reduce bank losses under borrower’s default. The purpose of the article relates to revealing of collateral determinants with higher impact on bank risk with the application of empirical methods (including regional level. This study is based on linear regression models evaluated by the least square method. Private data of secured small and medium business loans is used. This article presents LTV (loan-to-value as a major collateral determinant. The empirical evidence of interlinkage between collateral requirements, by the means of LTV, and risk premium is provided for loan portfolio of Russian regional banks. The hypothesis that LTV conversely correlates with risk premium is statistically proved.

Coronary collateral circulation and its effect on myocardial infarction

International Nuclear Information System (INIS)

Fukuyama, Takaya; Ashihara, Toshiaki; Ogata, Ikuo

1995-01-01

The purpose of this study was to examine the influence of coronary collateral circulation, which grows after acute myocardial infarction (MI), on infarct size and prognosis. Study subjects were 47 patients who had arteriographic evidence of 99-100% constricture of the infarct-related artery approximately one month after the onset of the first MI. Coronary collateral circulation was analyzed by a four-point scoring (grade 0-3). Furthermore, the patients underwent thallium-201 myocardial imaging one month and two years after the onset to evaluate infarct size. Infarct size was analyzed using extent score (ES) and severity score (SS). ES tended to be decreased during chronic MI stage. Coronary collateral circulation was judged as grade 1 (n=9), grade 2 (n=12), and grade 3 (n=26). There was no difference in infarct size among the three groups. In groups of grades 1 and 2, there was no difference in ES and SS between acute and chronic MI stages. In the group of grade 3, however, ES decreased from 41% to 27% and SS decreased from 68% to 38%, showing remarkable decrease during chronic MI stage. Although coronary collateral circulation one month after the onset is not always responsible for infarct size during acute MI stage, it is considered rsponsible for inhibiting the remodeling of infarction through the long term process. (N.K.)

Embolization for Thoracic Duct Collateral Leakage in High-Output Chylothorax After Thoracic Surgery

International Nuclear Information System (INIS)

Kariya, Shuji; Nakatani, Miyuki; Yoshida, Rie; Ueno, Yutaka; Komemushi, Atsushi; Tanigawa, Noboru

2017-01-01

PurposeThis study was designed to investigate thoracic duct collateral leakage and the supply route of lymphatic fluid by lymphangiography and transcatheter thoracic ductography and to evaluate the results of embolization for thoracic duct collateral leakage performed to cut off this supply route.MethodsData were retrospectively collected from five patients who underwent embolization for thoracic duct collateral leakage in persistent high-output chylothorax after thoracic surgery. Extravasation of lipiodol at the ruptured thoracic duct collaterals was confirmed in all patients on lymphangiography. Transcatheter thoracic ductography was used to identify extravasation of iodinated contrast agent and to identify communication between the thoracic duct and leakage site. Thoracic duct embolization (TDE) was performed using the percutaneous transabdominal approach to cut off the supply route using N-butyl cyanoacrylate (NBCA) mixed with lipiodol (1:5–1:20).ResultsClinical success (drainage volume ≤10 mL/kg/day within 7 days after TDE) was achieved in all patients. The collateral routes developed as consequence of surgical thoracic duct ligation. In three patients, NBCA-Lipiodol reached the leakage site through direct communication between the thoracic duct and the ruptured lymphatic duct. In the other two patients, direct communication and extravasation was not detected on thoracic ductography, and NBCA-Lipiodol did not reach the leakage site. However, NBCA-Lipiodol did reach the cisterna chyli, lumbar trunks, and some collateral routes via the cisterna chyli or lumbar lymphatics. As a result, leakage was stopped.ConclusionsTDE was effective for the management of leakage of the collaterals in high-output chylothorax after thoracic surgery.

Embolization for Thoracic Duct Collateral Leakage in High-Output Chylothorax After Thoracic Surgery

Energy Technology Data Exchange (ETDEWEB)

Kariya, Shuji, E-mail: kariyas@hirakata.kmu.ac.jp; Nakatani, Miyuki, E-mail: nakatanm@hirakata.kmu.ac.jp; Yoshida, Rie, E-mail: yagir@hirakata.kmu.ac.jp; Ueno, Yutaka, E-mail: uenoyut@hirakata.kmu.ac.jp; Komemushi, Atsushi, E-mail: komemush@takii.kmu.ac.jp; Tanigawa, Noboru, E-mail: tanigano@hirakata.kmu.ac.jp [Kansai Medical University, Department of Radiology (Japan)

2017-01-15

PurposeThis study was designed to investigate thoracic duct collateral leakage and the supply route of lymphatic fluid by lymphangiography and transcatheter thoracic ductography and to evaluate the results of embolization for thoracic duct collateral leakage performed to cut off this supply route.MethodsData were retrospectively collected from five patients who underwent embolization for thoracic duct collateral leakage in persistent high-output chylothorax after thoracic surgery. Extravasation of lipiodol at the ruptured thoracic duct collaterals was confirmed in all patients on lymphangiography. Transcatheter thoracic ductography was used to identify extravasation of iodinated contrast agent and to identify communication between the thoracic duct and leakage site. Thoracic duct embolization (TDE) was performed using the percutaneous transabdominal approach to cut off the supply route using N-butyl cyanoacrylate (NBCA) mixed with lipiodol (1:5–1:20).ResultsClinical success (drainage volume ≤10 mL/kg/day within 7 days after TDE) was achieved in all patients. The collateral routes developed as consequence of surgical thoracic duct ligation. In three patients, NBCA-Lipiodol reached the leakage site through direct communication between the thoracic duct and the ruptured lymphatic duct. In the other two patients, direct communication and extravasation was not detected on thoracic ductography, and NBCA-Lipiodol did not reach the leakage site. However, NBCA-Lipiodol did reach the cisterna chyli, lumbar trunks, and some collateral routes via the cisterna chyli or lumbar lymphatics. As a result, leakage was stopped.ConclusionsTDE was effective for the management of leakage of the collaterals in high-output chylothorax after thoracic surgery.

Cerebral collateral therapeutics in acute ischemic stroke: A randomized preclinical trial of four modulation strategies.

Science.gov (United States)

Beretta, Simone; Versace, Alessandro; Carone, Davide; Riva, Matteo; Dell'Era, Valentina; Cuccione, Elisa; Cai, Ruiyao; Monza, Laura; Pirovano, Silvia; Padovano, Giada; Stiro, Fabio; Presotto, Luca; Paternò, Giovanni; Rossi, Emanuela; Giussani, Carlo; Sganzerla, Erik P; Ferrarese, Carlo

2017-10-01

Cerebral collaterals are dynamically recruited after arterial occlusion and highly affect tissue outcome in acute ischemic stroke. We investigated the efficacy and safety of four pathophysiologically distinct strategies for acute modulation of collateral flow (collateral therapeutics) in the rat stroke model of transient middle cerebral artery (MCA) occlusion. A composed randomization design was used to assign rats (n = 118) to receive phenylephrine (induced hypertension), polygeline (intravascular volume load), acetazolamide (cerebral arteriolar vasodilation), head down tilt (HDT) 15° (cerebral blood flow diversion), or no treatment, starting 30 min after MCA occlusion. Compared to untreated animals, treatment with collateral therapeutics was associated with lower infarct volumes (62% relative mean difference; 51.57 mm 3 absolute mean difference; p Collateral therapeutics acutely increased cerebral perfusion in the medial (+40.8%; p collaterals is feasible and provides a tissue-saving effect in the hyperacute phase of ischemic stroke prior to recanalization therapy.

31 CFR 363.58 - May book-entry savings bonds be pledged or used as collateral?

Science.gov (United States)

2010-07-01

... pledged or used as collateral? 363.58 Section 363.58 Money and Finance: Treasury Regulations Relating to...Direct General § 363.58 May book-entry savings bonds be pledged or used as collateral? Bonds may not be pledged or used as collateral for the performance of an obligation. ...

Moya moya: étiologie rare d'accident vasculaire cérébral ...

African Journals Online (AJOL)

Moya moya disease is an angiogenic disease characterized by the narrowing of the distal internal carotid artery extending to the proximal segments of the middle and anterior cerebral arteries, inducing collateral vessels formation. These vessels come from the collateral parenchymal vessels, the perforating vessels, ...

31 CFR 363.146 - May a certificate of indebtedness be pledged or used as collateral?

Science.gov (United States)

2010-07-01

... pledged or used as collateral? 363.146 Section 363.146 Money and Finance: Treasury Regulations Relating to... certificate of indebtedness be pledged or used as collateral? A certificate of indebtedness may not be pledged or used as collateral for the performance of an obligation. [69 FR 50309, Aug. 16, 2004. Redesignated...

Influence of risk area size and location on native collateral resistance and ischemic zone perfusion

International Nuclear Information System (INIS)

Gumm, D.C.; Cooper, S.M.; Thompson, S.B.; Marcus, M.L.; Harrison, D.C.

1988-01-01

To examine the effect of risk area size on collateral resistance and ichemic region perfusion, the authors produced different sized risk areas by occluding either the left anterior descending (LAD) or the circumflex (Cx) coronary artery at different sites. The most proximal occlusion of the LAD and Cx produced risk areas of 43 ± 5 and 36 ± 2% of left ventricular (LV) mass, respectively, whereas distal LAD and Cx occlusions produced risk areas of 13 ± 2 and 17 ± 2% of LV weight, respectively. Although total collateral flow was highest to the largest risk areas, collateral flow per 100 g of ischemic myocardium was 80% higher to the small LAD risk area compared with the large LAD risk area and 43% higher to the small Cx risk area compared with the large Cx risk area. Collateral resistance, calculated from the transcollateral pressure and perfusion per 100 g of myocardium was significantly lower in the small risk areas than in the large ones. They examined the effect of risk area location on collateral perfusion and resistance. These experiments show that collateral resistance is influenced both by ischemic region size and location. Small risk areas receive more collateral flow per mass of tissue than large risk areas, and apical risk areas receive greater quantities of collateral flow than those located at the base. These data may explain why small risk areas often do not develop infarction after coronary occlusion

Impaired Leptomeningeal Collateral Flow Contributes to the Poor Outcome following Experimental Stroke in the Type 2 Diabetic Mice

Science.gov (United States)

Akamatsu, Yosuke; Nishijima, Yasuo; Lee, Chih Cheng; Yang, Shih Yen; Shi, Lei; An, Lin; Wang, Ruikang K.; Tominaga, Teiji

2015-01-01

Collateral status is an independent predictor of stroke outcome. However, the spatiotemporal manner in which collateral flow maintains cerebral perfusion during cerebral ischemia is poorly understood. Diabetes exacerbates ischemic brain damage, although the impact of diabetes on collateral dynamics remains to be established. Using Doppler optical coherent tomography, a robust recruitment of leptomeningeal collateral flow was detected immediately after middle cerebral artery (MCA) occlusion in C57BL/6 mice, and it continued to grow over the course of 1 week. In contrast, an impairment of collateral recruitment was evident in the Type 2 diabetic db/db mice, which coincided with a worse stroke outcome compared with their normoglycemic counterpart db/+, despite their equally well-collateralized leptomeningeal anastomoses. Similar to the wild-type mice, both db/+ and db/db mice underwent collateral growth 7 d after MCA stroke, although db/db mice still exhibited significantly reduced retrograde flow into the MCA territory chronically. Acutely induced hyperglycemia in the db/+ mice did not impair collateral flow after stroke, suggesting that the state of hyperglycemia alone was not sufficient to impact collateral flow. Human albumin was efficacious in improving collateral flow and outcome after stroke in the db/db mice, enabling perfusion to proximal MCA territory that was usually not reached by retrograde flow from anterior cerebral artery without treatment. Our results suggest that the impaired collateral status contributes to the exacerbated ischemic injury in mice with Type 2 diabetes, and modulation of collateral flow has beneficial effects on stroke outcome among these subjects. PMID:25740515

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.

Minimally Invasive Approach for Spleen-Preserving Distal Pancreatectomy: a Comparative Analysis of Postoperative Complication Between Splenic Vessel Conserving and Warshaw's Technique.

Science.gov (United States)

Lee, Lip Seng; Hwang, Ho Kyoung; Kang, Chang Moo; Lee, Woo Jung

2016-08-01

Spleen-preserving distal pancreatectomy with Warshaw's technique (WT) was reported to have higher spleen-related complication. The aim of this study was to evaluate the postoperative complication between the splenic vessel-conserving technique (SVC) and the WT when they were performed by the minimally invasive approach. From January 2006 to June 2015, data of the patients who had laparoscopic or robotic-assisted spleen-preserving distal pancreatectomy for benign or borderline malignant tumors were retrospectively reviewed. Patients were divided into SVC and the WT group for comparison. Of the 89 patients who had the spleen-preserving distal pancreatectomy, 63 were SVC, whereas 26 were WT. The CT scans showed that patients who had WT were found to have higher rate of splenic infarction (P < 0.001) and had significantly higher rate of collateral vessel formation at 1 year (P < 0.001). All the splenic infarctions were low grade and asymptomatic which resolved spontaneously. None of the patients with collateral formation experienced gastrointestinal bleeding. The postoperative complication of SVC and WT did not differ significantly. SVC and WT were found to have comparable outcome. Both techniques can be used to achieve higher spleen-preserving rate.

Portographic Evaluation for Recurrent Esophagogastric Varices Following Devascularization Surgery

International Nuclear Information System (INIS)

Hsieh, J.-S.; Huang, C.-J.; Wang, J.-Y.; Huang, T.-J.

1996-01-01

Purpose: To investigate, by transhepatic portography, the changes in portosystemic collaterals and recurrent esophagogastric varices after devascularization surgery. Methods: Thirty-five patients, who had undergone devascularization surgery 2 - 8 years previously, underwent follow-up portography and the collaterals and drainage routes were compared with preoperative portography results. Results: Newly formed collaterals were present in 30 of 35 patients and the origins and drainage routes differed from preoperative ones. Most common were new collaterals arising from the junction of the portal and superior mesenteric veins; the next most frequent arose from a main portal branch, the portal trunk, or the superior mesenteric vein. New collaterals with recurrent varices were seen in 20 patients and without varices in 10; 5 patients had no collaterals or varices.Conclusion: Since the development of new collaterals is common in portal hypertensive patients following devascularization surgery, regular follow-up for recurrent varices is necessary

The future of collateral artery research

NARCIS (Netherlands)

Hakimzadeh, Nazanin; Verberne, Hein J.; Siebes, Maria; Piek, Jan J.

2014-01-01

In the event of obstructive coronary artery disease, collateral arteries have been deemed an alternative blood source to preserve myocardial tissue perfusion and function. Monocytes play an important role in modulating this process, by local secretion of growth factors and extracellular matrix

28 CFR 104.47 - Collateral sources.

Science.gov (United States)

2010-07-01

... determining the appropriate collateral source offset for future benefit payments, the Special Master may employ an appropriate methodology for determining the present value of such future benefits. In... compensation, including life insurance, pension funds, death benefits programs, and payments by Federal, State...

Resiliency and collateral learning in science in some students of cree ancestry

Science.gov (United States)

Sutherland, Dawn

2005-07-01

In the context of schooling, resiliency refers to the ability to thrive academically despite adverse circumstances. In this study the relationship between academic resilience and student's collateral learning is explored in 20 students of Cree ancestry. The individual resilience of each student was examined by identifying protective factors for school leaving within the microsystem of each student's ecological framework. Student responses to questions related to motivation and engagement were ranked. In addition, students' perception of the influence of family and peers on individual attributes toward schooling was ranked.To gain insight into the collateral learning aspects of science learning in Cree students, the participants in this study were asked to reflect on their learning strategies through the use of critical incidents. The relationship between collateral learning and resiliency was also explored.This study found that students possessing a greater number of protective factors were more likely to learn science in a way described by Jegede's collateral learning theory. Responses to critical incidents indicate some Cree students hold at least two sources of knowledge to explain some science concepts and therefore may adopt a collateral learning strategy. The importance these students place on earned or experiential knowledge is evident in the interviews. Some suggestions for classroom instruction are offered in conclusion.

Leptomeningeal collateralization in acute ischemic stroke: Impact on prominent cortical veins in susceptibility-weighted imaging

International Nuclear Information System (INIS)

Verma, Rajeev K.; Hsieh, Kety; Gratz, Pascal P.; Schankath, Adrian C.; Mordasini, Pasquale; Zubler, Christoph; Kellner-Weldon, Frauke; Jung, Simon; Schroth, Gerhard; Gralla, Jan; El-Koussy, Marwan

2014-01-01

Background: The extent of hypoperfusion is an important prognostic factor in acute ischemic stroke. Previous studies have postulated that the extent of prominent cortical veins (PCV) on susceptibility-weighted imaging (SWI) reflects the extent of hypoperfusion. Our aim was to investigate, whether there is an association between PCV and the grade of leptomeningeal arterial collateralization in acute ischemic stroke. In addition, we analyzed the correlation between SWI and perfusion-MRI findings. Methods: 33 patients with acute ischemic stroke due to a thromboembolic M1-segment occlusion underwent MRI followed by digital subtraction angiography (DSA) and were subdivided into two groups with very good to good and moderate to no leptomeningeal collaterals according to the DSA. The extent of PCV on SWI, diffusion restriction (DR) on diffusion-weighted imaging (DWI) and prolonged mean transit time (MTT) on perfusion-imaging were graded according to the Alberta Stroke Program Early CT Score (ASPECTS). The National Institutes of Health Stroke Scale (NIHSS) scores at admission and the time between symptom onset and MRI were documented. Results: 20 patients showed very good to good and 13 patients poor to no collateralization. PCV-ASPECTS was significantly higher for cases with good leptomeningeal collaterals versus those with poor leptomeningeal collaterals (mean 4.1 versus 2.69; p = 0.039). MTT-ASPECTS was significantly lower than PCV-ASPECTS in all 33 patients (mean 1.0 versus 3.5; p < 0.00). Conclusions: In our small study the grade of leptomeningeal collateralization correlates with the extent of PCV in SWI in acute ischemic stroke, due to the deoxyhemoglobin to oxyhemoglobin ratio. Consequently, extensive PCV correlate with poor leptomeningeal collateralization while less pronounced PCV correlate with good leptomeningeal collateralization. Further SWI is a very helpful tool in detecting tissue at risk but cannot replace PWI since MTT detects significantly more ill

Why is coronary collateral growth impaired in type II diabetes and the metabolic syndrome?

Science.gov (United States)

Rocic, Petra

2012-01-01

Type II diabetes and the metabolic syndrome are strong predictors of severity of occlusive coronary disease and poorer outcomes of coronary revascularization therapies. Coronary collateral growth can provide an alternative or accessory pathway of revascularization. However, collateral growth is impaired in type II diabetes and the metabolic syndrome. Although many factors necessary for collateral growth are known and many interventions have shown promising results in animal studies, not a single attempt to induce coronary collateral growth in human clinical trials has led to satisfactory results. Accordingly, the first part of this review outlines the known deleterious effects of diabetes and the metabolic syndrome on factors necessary for collateral growth, including pro-angiogenic growth factors, endothelial function, the redox state of the coronary circulation, intracellular signaling, leukocytes and bone marrow-derived progenitors cells. The second section highlights the gaps in our current knowledge of how these factors interact with the radically altered environment of the coronary circulation in diabetes and the metabolic syndrome. The interplay between these pathologies and inadequately explored areas related to the temporal regulation of collateral remodeling and the roles of the extracellular matrix, vascular cell phenotype and pro-inflammatory cytokines are emphasized with implications to development of efficient therapies. PMID:22342811

An elevated level of BNP in plasma is related to the development of good collateral circulation in coronary artery disease.

Science.gov (United States)

Xi, Wei-Wei; Cheng, Gang; Lv, Shumin; Gao, Qinqin; Bu, Gang; Zhou, Ying; Xu, Geng

2011-12-01

B-type natriuretic peptide (BNP) was recently demonstrated to be a potential stimulator of angiogenesis and arteriogenesis. The correlation between BNP level and collateral formation in patients with coronary artery disease (CAD) has not been reported. The study included 311 consecutive patients who underwent coronary angiography were divided into three groups according to coronary angiography and collateral formation: normal group (100 patients with normal coronary angiographic findings); poor collateral group (116 patients with at least one coronary stenosis of ≥75% without visible collateral circulation); and good collateral group (95 patients with at least one coronary stenosis of ≥75% with well-developed collateral circulation). Collateral score was analyzed using the Cohen-Rentrop classification. Plasma BNP levels were 45.77 ± 4.66 pg/ml, 116.40 ± 28.15 pg/ml, and 254.20 ± 42.85 pg/ml for patients in normal, poor collateral, and good collateral groups, respectively. Plasma BNP levels in the latter were significantly higher than in the normal group (p collateral group (p collateral group and poor collateral group when compared with left ventricular ejection fraction (LVEF), left ventricular dimensions at end diastole (LVEDd), age, severity of angiographic disease, and other cardiovascular risk factors. After adjustment in the multiple ordinal logistic regression model, plasma BNP levels showed a strong independent association with collateral Cohen-Rentrop score (χ(2 )= 5.636, OR = 1.002, 95% CI 1.000-1.004, p = 0.018). An elevated level of BNP in plasma is independently associated with collateral development; patients with good collaterals tend to have a higher BNP level.

Collateral Ligament Knee Injuries in Pediatric and Adolescent Athletes.

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Kramer, Dennis E; Miller, Patricia E; Berrahou, Iman K; Yen, Yi-Meng; Heyworth, Benton E

2017-12-08

The majority of research on medial (MCL) and lateral (LCL) collateral ligament injuries has focused on adults and combined collateral/cruciate injuries. The purpose of this study was to determine characteristics associated with isolated collateral ligament injuries in adolescents, and assess timing for return to sports. Electronic medical records were queried to identify patients aged below 17 years who sustained a magnetic resonance imaging-confirmed isolated MCL or LCL injury over an 8-year period. Retrospective review then documented patient and injury characteristics and clinical course. General linear modeling was used to analyze risk factors for prolonged return to sports, continued pain or reinjury. Fifty-one knees (33 in males, 65%), mean age 13.8 years (range, 5 to 17), were identified, of which 40 (78%) had MCL injuries. Over half (29, 57%) of knees had an open distal femoral physis including all 5 bony avulsion injuries. Eleven (22%) had LCL injuries of which 3 (6%) had concurrent posterolateral corner injuries. Forty-two (82%) knees had injuries that occurred during sports. Eleven knees (28%) with MCL tears had a simultaneous patellar instability episode. Knee injuries that occurred during sports had 37% shorter recovery time (P=0.02). Eight knees (16%) experienced a reinjury and 12 (24%) were followed over an extended period of time for various knee issues. Football injuries were more likely to be grade 3 (P=0.03), and football and soccer accounted for all grade III injuries. The mean return to sports was 2.2 months, with grade III cases returning at 2.4 months, and 95% of cases within 4 months. Isolated collateral ligament injuries are rare in adolescent athletes. MCL injuries, one-quarter of which occurred in conjunction with patellar instability events, were 4 times more common than LCL injuries, one quarter of which have other posterolateral corner structures involved. Grade III injuries represent 20% to 25% of collateral ligament injuries and

The March of Extrahepatic Collaterals: Analysis of Blood Supply to Hepatocellular Carcinoma Located in the Bare Area of the Liver After Chemoembolization

International Nuclear Information System (INIS)

Miyayama, Shiro; Yamashiro, Masashi; Okuda, Miho; Yoshie, Yuichi; Nakashima, Yoshiko; Ikeno, Hiroshi; Orito, Nobuaki; Matsui, Osamu

2010-01-01

The purpose of this study was to evaluate changes in vascular supply to hepatocellular carcinoma (HCC) located in the bare area of the liver in patients who were mainly treated with chemoembolization. Twenty-six patients with HCC showing a mean diameter of 3.1 ± 1.4 cm (mean ± standard deviation) were mainly treated with chemoembolization. All patients underwent 2.7 ± 2.3 chemoembolization sessions over 40.1 ± 25.2 months. Tumor feeding branches demonstrated in each chemoembolization session were retrospectively evaluated. Initially, 18 tumors (59.2%) were supplied by the hepatic artery (H) and 8 (30.8%) by both the hepatic and the extrahepatic arteries (H + C). Fourteen tumors (53.8%) recurred at the posterior aspect of the tumor and were supplied by H (n = 4), H + C (n = 5), and extrahepatic collaterals (C) (n = 5). Several tumors recurred despite repeated chemoembolization, and these were supplied by H (n = 1), H + C (n = 7), and C (n = 2) at the second recurrence, by H (n = 1), H + C (n = 2), and C (n = 3) at the third, by H + C (n = 2) and C (n = 2) at the fourth, by H + C (n = 2) and C (n = 2) at the fifth, and by H (n = 1) and C (n = 1) at the sixth. One tumor was supplied by H at the seventh and by H + C at the eighth recurrence. As the number of local recurrences increased, the feeding vessel shifted from H to C. Especially, the right inferior phrenic artery (IPA) and renal capsular artery (RCA) supplied the tumor early, while the small right RCAs, adrenal arteries, and intercostal and lumbar artery supplied late recurrences in turns. In conclusion, HCCs located in the bare area are frequently supplied by extrahepatic vessels initially, while recurrence after chemoembolization is mainly due to extrahepatic blood supply. The right IPA and RCA are common feeding vessels demonstrated early, while other extrahepatic collateral supply from the retroperitoneal circulation occurs in turns during the later course.

Tl myocardial SPECT demonstrates importance of collateral circulation in patients with myocardial infarction

International Nuclear Information System (INIS)

Hattori, Fukunori

1997-01-01

The influence of collateral circulation on the preservation of myocardial viability and the efficacy of drug therapy and PTCA were evaluated by exercise 201 Tl myocardial SPECT before and after treatment. Thirty-five patients with a history of myocardial infarction resulting from total or subtotal obstruction of the responsible coronary artery were divided into four groups, according to the method of the treatment and the degree of collateral blood flow. Patients in groups A and B received drug therapy and displayed developed and undeveloped collateral circulation, respectively. Groups C and D received PTCA and displayed developed and undeveloped collateral circulation, respectively. Tl myocardial SPECT was performed before treatment to record the extent of redistribution to the occluded region, the degree of myocardial viability and the nature and extent of the ischemic lesion. In group A, myocardial perfusion improved, although redistribution remained in all cases, while in group B, 4 of 7 cases improved after drug therapy. In group C, myocardial perfusion improved in all cases, and redistribution disappeared in 7 of 12 cases. 5 of 6 cases improved in group D after PTCA. After drug therapy, the %Tl uptake in the infarcted region improved significantly in initial and delayed images of patients in group A. The differences in initial and delayed images in group B before and after drug therapy were not significant. In contrast, groups C and D both registered significant improvement in initial and delayed images after PTCA. The washout rate improved significantly in groups A, C and D after their respective treatments. These results suggest that developed collateral circulation helps to preserve myocardial viability in cases of myocardial infarction. Myocardial perfusion improved after drug therapy in cases with developed collateral circulation, and in patients with developed and undeveloped collateral circulation receiving PTCA. (K.H.)

31 CFR 202.6 - Collateral security.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Collateral security. 202.6 Section 202.6 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE DEPOSITARIES AND FINANCIAL AGENTS OF THE FEDERAL...

12 CFR 614.4240 - Collateral definitions.

Science.gov (United States)

2010-01-01

... following definitions shall apply: (a) Abundance of caution, when used to describe decisions to require... income and/or other collateral, absent the real estate, and the decision to extend credit was, in fact... normal consideration for the property sold unaffected by special or creative financing or sales...

Breast varices: imaging findings of an unusual presentation of collateral pathways in superior vena caval syndrome

International Nuclear Information System (INIS)

Oezdemir, Ayseguel; Ilgit, Erhan T.; Konus, Oeznur L.; Cetin, Meltem; Oezsunar, Yelda

2000-01-01

Imaging findings are presented of an unusual pathway of collateral circulation consisting of bilateral and diffuse dilated breast veins from a patient with long standing superior vena caval syndrome. The main importance of this case is the extent of the collateral development through the breast veins, serving as the major pathway of collateral circulation. Identification of this unusual collateral development, which resembles breast varices, was performed with contrast-enhanced chest CT scans, digital subtraction venography, color Doppler ultrasonography, and mammographic studies. Collateral development was secondary to a long segment idiopathic venous occlusion involving bilateral subclavian and brachiocephalic veins as well as vena cava superior. We conclude that dilated breast veins when detected on any imaging modality should raise the suspicion of central venous obstruction

Assessment of jeopardized myocardium in patients with one-vessel disease

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Iskandrian, A.S.; Lichtenberg, R.; Segal, B.L.; Mintz, G.S.; Mundth, E.D.; Hakki, A.-H.; Kimbiris, D.; Bemis, C.E.; Croll, M.N.; Kane, S.A.

1982-01-01

The size of the perfusion defect was assessed from a quantitative analysis of exercise thallium-201 images. Quantitative analysis was determined by measuring the area and the perimeter of the perfusion defect and expressing it as a percentage of the total left ventricular area or perimeter in three projections. Using this technique, we studied 50 patients with one-vessel disease of 50% or greater diameter narrowing. The planimetric and the perimetric methods correlated well (p<0.001, r=0.97). Of the 11 patients with less than 70% diameter narrowing, only one patient had abnormal exercise thallium-201 images. Of the remaining 39 patients with 70% or greater diameter narrowing, 35 had abnormal exercise images. The defects were larger in patients with left anterior descending coronary artery disease (33 +/- 10%; mean +/- SD by perimetry) than in patients with left circumflex coronary artery disease (19 +/- 14%, p<0.01) or right coronary artery disease (17 +/- 11%, p<0.01). There was also significant variation in the sizes of the defects in the three projections in patients with left circumflex and right coronary artery disease, but not in patients with left anterior descending coronary artery disease. Patients with left anterior descending coronary artery disease with collaterals had smaller defects than their counterparts without collaterals

Severe Degeneration of the Medial Collateral Ligament in Hallux Valgus: A Histopathologic Study in 12 Consecutive Patients

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Prasitdumrong, Ittipol; Rungprai, Chamnanni; Reeboonlarb, Nitit; Poonpracha, Tara; Phisitkul, Phinit

2013-01-01

Objective To determine the degree and location of degenerative changes of the medial collateral ligament of the first metatarsophalangeal joint, using the lateral collateral ligament as a control, in patients undergoing hallux valgus correction. Materials and Methods A strip of medial and lateral collateral ligaments were biopsied from 12 consecutive patients (age 45 ± 4.8 years) with symptomatic hallux valgus. A blinded analysis of histopathology was performed by an experienced pathologist. Results The medial collateral ligament was significantly more degenerated compared to the lateral collateral ligament (x2 = 23.41, DF = 2, p hallux valgus correction. The Authors received no financial support for this study. PMID:24027461

Selective cyclooxygenase-1 inhibition improves collateral vascular reactivity in biliary cirrhotic rats

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Ching-Chih Chang

2013-10-01

Conclusion: There was no significant hemodynamic change and renal toxicity after acute administration of COX inhibitor in the FBDL-induced cirrhotic rats. Preincubation of selective COX-1, but not COX-2, inhibitor could enhance collateral vascular response to AVP, indicating that COX-1 plays a major role in the collateral vascular reactivity.

Micro-angiographic system using synchrotron radiation and conventional x-ray source for visualizing angiogenic vessels induced by cardiovascular regeneration therapy

International Nuclear Information System (INIS)

Mori, H.; Chiku, M.; Nishigami, K.; Tanaka, E.; Kimura, K.; Kawai, T.; Suzuki, K.; Mochizuki, R.; Okawa, Y.

2004-01-01

Therapeutic angiogenesis improved critical limb and myocardial ischemia in human, however, angiogenic vessels were not visualized well by conventional angiography, because of its limited spatial resolution of 200 μm. Recently, synchrotron radiation system characterized by high brightness, monochromatic and collimated nature revealed the micro-vessels of heart and lower limb in situ. We developed also an in-house microangiographic system with a relatively low cost. Limb ischemia models were made by ligature of femoral artery and treated by angiogenic growth factor genes and so on. One month after the treatment, we evaluated collateral micro-vessels by using the conventional and micro-angiographic systems. The approach was left femoral artery, and catheter was located in abdominal aorta. Iodine contrast (300 mg/ml) was injected 5 ml by 3 ml/sec with auto-injection system. The imaging was recorded by digital source in 1000 x 1000 pixels. The micro-angiographic system could detect the micro-vessels more precisely than conventional angiographic system and evaluate their function. (author)

Collateral sensitivity between aminoglycosides and beta-lactam antibiotics depends on active proton pumps.

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Azimi, Leila; Rastegar Lari, Abdolaziz

2017-11-01

Selection inversion is the hypothesis for antibiotic resistant inhabitation in bacteria and collateral sensitivity is one of the proposed phenomena for achievement of this hypothesis. The presence of collateral sensitivity associated with the proton motivation pump between the aminoglycosides and beta-lactam group of antibiotics is one of the examples of collateral sensitivity in some studies. The aim of this study was to demonstrate that collateral sensitivity between aminoglycosides and beta-lactam antibiotics associated with proton motivation pump may not be true in all cases. In this study, 100 Pseudomonas aeruginosa were surveyed. Gentamicin and imipenem-resistant strains were confirmed by disc diffusion method and MIC. Active proton motivation pumps were screened by pumps inhibitor. Semi-quantitative Real-Time PCR assay was used to confirm gene overexpression. Seventy-six and 79 out of 100 strains were resistant to gentamicin and imipenem, respectively. Seventy-five strains were resistant to both gentamicin and imipenem. The results of proton pump inhibitor test showed the involvement of active proton motivation pump in 22 of 75 imipenem- and gentamicin-resistant strains. According to Real - Time PCR assay, mexX efflux gene was overexpressed in the majority of isolates tested. The collateral sensitivity effect cannot explain the involvement of active proton motivation pumps in both imipenem and gentamicin-resistant strains simultaneously. Active and/or inactive proton pump in gentamicin-sensitive and/or resistant strains cannot be a suitable example for explanation of collateral sensitivity between aminoglycosides and beta-lactam antibiotics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Aberrant internal carotid artery presenting as a retrotympanic vascular mass

International Nuclear Information System (INIS)

Nicolay, Simon; De Foer, Bert; Bernaerts, Anja; Van Dinther, Joost; Parizel, Paul M

2014-01-01

We report a case of a young woman with an aberrant right internal carotid artery (ICA) presenting as a retrotympanic reddish mass. This variant of the ICA represents the collateral pathway that is formed as a result of an embryological agenesis of the cervical segment of the ICA. The embryonic inferior tympanic artery is recruited to bypass the absent carotid segment. This hypertrophied vessel may be seen otoscopically and wrongfully considered to be a vascular middle ear tumor. Informing the otorhinolaryngologist of this important vascular variant not only obviates biopsy but also helps in careful preoperative planning of eventual middle ear procedures

COLLATERAL'S IMPORTANCE IN SMES FINANCING: WHAT IS THE BANKS RESPONSE? SOME EVIDENCE FOR ROMANIA

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Petria Nicolae

2011-07-01

Full Text Available Searching for funding, SMEs managers face various obstacles arising from information asymmetry, lack of experience, severe market conditions, and insufficient or unsatisfactory collaterals for banks (OECD 2006; Badulescu and Badulescu 2010; OECD 2000 and 2004; Lin and Sun 2006; Toivanen and Cresy, 2000. The collateral issue is extensively discussed in literature preventing moral hazard, the alignment the interests (Stiglitz and Weiss 1981:393-410; Chan and Thakor 1987:345-363; Jimenez and Saurina 2004, a means to discipline the borrowers behaviour (ex post given the existence of a credible threat (Aghion and Bolton 1992:473-494, or even banking behaviour on the market (Manove et al. 2001:726-744, Argentiero 2009. In the same time we find that the perception of firms, revealed by National Bank of Romania (NBR 2010 survey data, show that banks still use the collateral as a measure of pressure, in special in crisis times. For an important part of managers, the bank increased the level of required collateral for existing, renewing or new credits, asking for new covenants, revealing a paradox of crisis time: while the bank loans remained the favourite method of external financing needs of business, the banks often reduce their availability. Although the bank loan remains the favorite mean to support the growth ambitions, the higher level of collateral or lending costs are seen as principal obstacles by the majority of manager in EU. According to NBR survey, the influence of risk factors related to collateral had a climax at the end of 2008 and 2009, when the banks have tightened the requirement for loan guarantee. Using National Bank of Romania (NBR 2010 survey data, we show that the banks still use the collateral as a measure of pressure, in special in crisis times. For an important part of managers, the bank increased the level of required collateral for existing, renewing or new credits, asking for new covenants, revealing a paradox of crisis time

Comparison of four different collateral scores in acute ischemic stroke by CT angiography.

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Seker, Fatih; Potreck, Arne; Möhlenbruch, Markus; Bendszus, Martin; Pham, Mirko

2016-11-01

Multiple scores have been described for the assessment of collateralization in acute ischemic stroke. Currently, there is no gold standard for collateral assessment by CT angiography (CTA). This study compared four frequently used collateral scores with regard to their correlation with early infarct core and mismatch ratio. 30 consecutive patients with acute occlusion of the M1 segment or terminal carotid artery were reviewed retrospectively. Collaterals were assessed using dynamic and also single-phase CTA according to grading systems by the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR), Alberta Stroke Program Early CT Score (ASPECTS) (on collaterals), Christoforidis et al and Miteff et al. The Christoforidis and ASITN/SIR scores, which were initially designed for conventional angiography, were adapted to be applicable to CTA. The scores were compared with respect to early infarct core and mismatch ratio in perfusion CT estimated by RAPID software using Spearman correlation. ASITN/SIR and ASPECTS collateral scores showed good correlation with early infarct core (rho=-0.696, p<0.001 and rho=-0.677, p<0.001) and mismatch ratio (rho=0.609, p<0.001 and rho=0.581, p<0.001). In contrast, the Christoforidis and Miteff scores correlated less well with infarct core (rho=0.245, p=0.191 and rho=-0.272, p=0.145, respectively) and mismatch ratio (rho=-0.329, p=0.075 and rho=0.279, p=0.135, respectively). ASPECTS and ASITN/SIR showed excellent cross-correlation (rho=0.901, p<0.001). Compared with the Christoforidis and Miteff scores, the modified ASITN/SIR and ASPECTS collateral scores showed consistently higher correlation with the extent of early infarct core and mismatch volume. This is probably because these scores evaluate the extent and delay of vascular enhancement in the affected territory rather than the backflow of contrast medium to the occlusion. Published by the BMJ Publishing Group Limited. For

Multidetector computed tomography arteriography in the preoperative assessment of patients with ureteropelvic junction obstruction

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Braun, Petra [Department of Radiology, Hospital de la Plana, Ctra. de Vila-real a Borriana KM. 0.5, 12540 Vila-real (Spain)]. E-mail: PetraBraun@gmx.de; Guilabert, Jose Pamies [Department of Radiology, Hospital de la Plana, Ctra. de Vila-real a Borriana KM. 0.5, 12540 Vila-real (Spain); Kazmi, Faaiza [Department of Radiology, Penn State Milton S. Hershey Medical Center (United States)

2007-01-15

Background: Nowadays, endoscopic management of ureteropelvic junction (UPJ) obstruction is the treatment of choice. However, in the presence of crossing vessels, the success rate of endoscopic management decreases and the risk of hemorrhagic and vascular complications rises. The purpose of this study is to evaluate patients with UPJ obstruction using contrast enhanced multidetector computed tomography (CT) angiography to aid in surgical planning and management. Patients and methods: Between 2001 and 2005, 27 patients (mean age: 43 years; age range: 17-75 years) with UPJ obstruction were studied with multidetector CT angiography. Identification and characterization of crossing vessels was performed with multidirectional images and three-directional reconstructions. Results: 12 patients (44%) were found to have 16 crossing vessels (vessels in contact with the UPJ or within a vicinity of less than 2 mm). Nine of these vessels were arteries and seven were veins. Nine vessels crossed anteriorly, two posteriorly, and one anteromedially. Endopyelotomy was contraindicated in these 12 patients due to the presence of crossing vessels. Eleven out of the 12 patients underwent a pyeloplasty by open surgery or laparoscopy, where the presence of crossing vessels was confirmed. One of the 12 patients did not undergo surgery. Conclusion: Multidetector CT angiography permits an adequate preoperative assessment of patients with UPJ obstruction as it is able to identify the presence and location of crossing vessels. Furthermore, it allows to study in detail the anatomy of the renal area and its vascular variants.

Integration of functional and morphological MR data for preoperative 3D visualisation of tumours. Cervical carcinoma

International Nuclear Information System (INIS)

Evers, H.; Meinzer, H.P.; Hawighorst, H.; Kaick, G. van; Knapstein, P.G.

1998-01-01

Purpose: The goal of this exemplary study was to integrate morphological and functional MRI to establish computer-based, preoperative therapy planning for tumors, instancing cervical carcinoma. Results: Segmentation of organs and vessels as well as tissue differentiation yielded a morphological visualisation of anatomical structures that were overlaid with pharmacokinetic parameters derived from dynamic MRI, subsequently. Thereby, three-dimensional, arbitrary views on the functional data were displayed. Conclusions: Image analysis and visualisation of the acquired MR data establishes both a morphologic and functional evaluation of suspect lesions and adjacent organs. By integrating morphologic and functional MRI additional information can be gathered that possibly impinge on preoperative planning. (orig./AJ) [de

Collateral status and tissue outcome after intra-arterial therapy for patients with acute ischemic stroke.

Science.gov (United States)

Boers, Anna Mm; Jansen, Ivo Gh; Berkhemer, Olvert A; Yoo, Albert J; Lingsma, Hester F; Slump, Cornelis H; Roos, Yvo Bwem; van Oostenbrugge, Robert J; Dippel, Diederik Wj; van der Lugt, Aad; van Zwam, Wim H; Marquering, Henk A; Majoie, Charles Blm

2017-11-01

Intra-arterial therapy (IAT) for ischemic stroke aims to save brain tissue. Collaterals are thought to contribute to prolonged penumbra sustenance. In this study, we investigate the effect of collateral status on brain tissue salvage with IAT. In 500 patients randomized between IAT and standard care, collateral status was graded from 0 (absent) to 3 (good). Final infarct volumes (FIV) were calculated on post-treatment CT. FIVs were compared between treatment groups per collateral grade. Multivariable linear regression with interaction terms was performed to study whether collaterals modified IAT effect on FIV. Four-hundred-forty-nine patients were included in the analysis. Median FIV for the IAT group was significantly lower with 54.5 mL (95% IQR: 21.8-145.0) than for the controls with 81.8 mL (95% IQR: 40.0-154.0) ( p = 0.020). Treatment effect differed across collateral grades, although there was no significant interaction (unadjusted p = 0.054; adjusted p = 0.105). For grade 3, IAT resulted in a FIV reduction of 30.1 mL ( p = 0.024). For grade 2 and 1, this difference was, respectively, 28.4 mL ( p = 0.028) and 28.4 mL ( p = 0.29). For grade 0, this was 88.6 mL ( p = 0.28) in favour of controls. IAT saves substantially more brain tissue as compared to standard care. We observed a trend of increasing effect of IAT with higher collateral grades.

Internal thoracic artery collateral to the external iliac artery in chronic aortoiliac occlusive disease

International Nuclear Information System (INIS)

Kim, Jinna; Won, Jong Yun; Park, Sung Il; Lee, Do Yun

2003-01-01

To evaluate the incidence and angiographic findings of the collateral pathway involving the internal thoracic artery in patients with chronic aortoiliac occlusive disease. Between March 2000 and Februrary 2001, 124 patients at our hospital underwent angiographic evaluation of chronic aortoiliac occlusive disease, and in 15 of these complete obstruction or severe stenosis of the aortoiliac artery was identified. The aortograms and collateral arteriograms obtained, including internal thoracic arteriograms, as well as the medical records of the patients involved, were evaluated. In nine patients there was complete occlusion of the infrarenal aorta, or diffuse stenosis of 75% or more in the descending thoracic aorta, and in the other six, a patent aorta but complete occlusion or stenosis of 75% or more of the common iliac artery was demonstrated. Collateral perfusion via hypertrophied internal thoracic arteries and rich anastomoses between the superior and inferior epigastric arteries, reconstituting the external iliac artery, were noted in all fifteen patients, regardless of symptom duration, which ranged from six months to twelve years. In patients with chronic aortoiliac occlusive disease, the internal thoracic artery, along with visceral collaterals and those from the contralateral side, is one of the major parietal collateral pathways

PENGEMBANGAN HAK KEKAYAAN INTELEKTUAL SEBAGAI COLLATERAL (AGUNAN UNTUK MENDAPATKAN KREDIT PERBANKAN DI INDONESIA

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Sri Mulyani

2012-09-01

Full Text Available Intellectual Property Rights is granted the exclusive rights to creators, inventors or designers for the creation or invention that has commercial value, either directly or through the automatic registration of the relevant agencies as awards, recognition should be given the protection of the rights of the community development law. Globally, the IPR will be used as collateral to obtain a bank loan internasional. In this law is necessary to realize the concept of legislation in each country who are willing to apply that regulate substance loading, binding, and registration of intellectual property as collateral. Key words: development of intellectual property rights, collateral, bank credit in Indonesia

Preoperative embolization of facial angiomas

International Nuclear Information System (INIS)

Causmano, F.; Bruschi, G.; De Donatis, M.; Piazza, P.; Bassi, P.

1988-01-01

Preoperative embolization was performed on 27 patients with facial angiomas supplied by the external carotid branches. Sixteen were males and 11 females; 13 of these angiomas were high-flow arterio-venous (A-V), 14 were low-flow capillary malformations. Fourteen patients underwent surgical removal after preoperative embolization; in this group embolization was carried out with Spongel in 3 cases and with Lyodura in 11 cases. In 12 of these patients the last angiographic examination was performed 3-6 years later: angiography evidenced no recurrence in 8 cases (67%), while in 3 cases (25%) there was capillary residual angioma of negligible size. Treatment was unsuccessful in one patient only, due to the large recurrent A-V angioma. Thirteen patients underwent embolization only, which was carried out with Lyodura in 10 cases, and with Ivalon in 3 cases. On 12 of these patients the last angiographic study was performed 2-14 months later: there was recurrent A-V angioma in 5 patients (42%), who underwent a subsequent embolization; angiography evidenced no recurrence in the other 7 patients (58%). In both series, the best results were obtained in the patients with low-flow capillary angiomas. Embolization and subsequent surgical removal are the treatment of choice for facial angiomas; embolization alone is useful in the management of surgically inacessible vascular malformations, and it can be the only treatment in patients with small low-flow angiomas when distal occlusion of the feeding vessel with Lyodura or Ivalon particles is performed

Improved evaluation of the coronary collateral circulation measuring the regional blood flow with 133Xe

International Nuclear Information System (INIS)

Franz, N.; Strangfeld, D.; Romaniuk, P.; Heublein, B.

1988-01-01

In 40 patients with angina pectoris catheter diagnostic measurements of the myocardial flow were carried out after intracoronary application of 133 Xe at rest and after oral application of Curantyl in order to obtain a better evaluation of coronary collaterals. The results show relations between angiographically detected coronary collaterals and the reduced coronary reserve. A quantitative measurement of collaterals from the angiogram facilitates a more precise evaluation of the relation between coronary sclerosis and myocardial flow. (author)

Collateral Flow and White Matter Disease in Patients with Internal Carotid Artery Occlusion.

Science.gov (United States)

Ishikawa, Mami; Sugawara, Hitoshi; Nagai, Mutsumi; Kusaka, Gen; Tanaka, Yuichi; Naritaka, Heiji

2017-01-01

When an internal carotid artery (ICA) occludes, a patient may develop cerebral infarction (CI). We investigated whether CI caused by ICA occlusion (ICAO) is associated with collateral flow through the anterior and posterior communicating arteries (ACoA and PCoA). In 100 patients with ICAO, we investigated CI and white matter disease by performing an MRI and the anatomy of the ACoA and PCoA were investigated by performing magnetic resonance angiography. All patients were divided into the symptomatic CI group or the no-CI group. The collateral flow pathway was estimated by the anterior cerebral artery (ACA)-PCoA score and the collateral flow volume after ICAO was estimated by the middle cerebral artery (MCA) flow score, based on how well the MCA was visualized. Of 100 patients with ICAO, the symptomatic CI group included 36 patients. ACA-PCoA score and white matter disease grades were significantly higher in the CI group (indicating poor collateral flow). More than 80% of patients with an ACA-PCoA score of 4 (poor collateral) experienced symptomatic CI. Thirty-one symptomatic CI patients (86%) had an MCA flow score of 1 or 2 (decreased MCA flow). The ACA-PCoA score and white matter disease grade may suggest an increased risk of CI following ICAO. © 2016 S. Karger AG, Basel.

MR imaging and MR angiography in preoperative evaluation of intracranial meningiomas

International Nuclear Information System (INIS)

Goldmann, A.; Kunz, U.; Bader, C.; Leibing, U.; Friedrich, J.M.; Oldenkott, P.

1994-01-01

A group of 41 patients with intracranial meningiomas were examined by MR imaging (MRI) and MR angiography (MRA) to assess the clinical value of MRA in the preoperative evaluation of these patients. The results of MRA were compared with the results of intraarterial cerebral catheter X-ray angiography (XRA; n 19) and with the operative findings (n = 41). Our results showed a good correlation between MRA and XRA/surgery in demonstrating the relationship between the tumor and adjacent venous and arterial structures. Use of MRA was also helpful in demonstrating the degree of intrinsic tumor vascularity. It also supplied important information for operative planning. Adjunct XRA was mandatory if detailed information about tumor-feeding vessels was requested by the neurosurgeon, especially in highly vascularized angiomatous meningiomas and in meningiomas suspected of tumor feeding by vessels of the internal carotid artery. (orig.)

MR imaging and MR angiography in preoperative evaluation of intracranial meningiomas

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Goldmann, A. [Dept. of Diagnostic Radiology, Univ. of Ulm (Germany); Kunz, U. [Dept. of Neurosurgery, Military Hospital, Academic Hospital of the University, Ulm (Germany); Bader, C. [Dept. of Diagnostic Radiology, Univ. of Ulm (Germany); Leibing, U. [Dept. of Diagnostic Radiology, Univ. of Ulm (Germany); Friedrich, J.M. [Dept. of Diagnostic Radiology, Univ. of Ulm (Germany); Oldenkott, P. [Dept. of Neurosurgery, Military Hospital, Academic Hospital of the University, Ulm (Germany)

1994-12-01

A group of 41 patients with intracranial meningiomas were examined by MR imaging (MRI) and MR angiography (MRA) to assess the clinical value of MRA in the preoperative evaluation of these patients. The results of MRA were compared with the results of intraarterial cerebral catheter X-ray angiography (XRA; n = 19) and with the operative findings (n = 41). Our results showed a good correlation between MRA and XRA/surgery in demonstrating the relationship between the tumor and adjacent venous and arterial structures. Use of MRA was also helpful in demonstrating the degree of intrinsic tumor vascularity. It also supplied important information for operative planning. Adjunct XRA was mandatory if detailed information about tumor-feeding vessels was requested by the neurosurgeon, especially in highly vascularized angiomatous meningiomas and in meningiomas suspected of tumor feeding by vessels of the internal carotid artery. (orig.)

Tests of ex ante ex post theories of collateral using private and public information

NARCIS (Netherlands)

Berger, A.N.; Frame, W.S.; Ioannidou, V.

2011-01-01

Collateral is a widely used, but not well understood, debt contracting feature. Two broad strands of theoretical literature explain collateral as arising from the existence of either ex ante private information or ex post incentive problems between borrowers and lenders. However, the extant

The PLAU P141L single nucleotide polymorphism is associated with collateral circulation in patients with coronary artery disease.

Science.gov (United States)

Duran, Joan; Sánchez-Olavarría, Pilar; Mola, Marina; Götzens, Víctor; Carballo, Julio; Martín-Pelegrina, Eva; Petit, Màrius; García Del Blanco, Bruno; García-Dorado, David; de Anta, Josep M

2014-07-01

Urokinase-type plasminogen activator, which is encoded by the PLAU gene, plays a prominent role during collateral arterial growth. We investigated whether the PLAU P141L (C > T) polymorphism, which causes a mutation in the kringle domain of the protein, is associated with coronary collateral circulation in a cohort of 676 patients with coronary artery disease. The polymorphism was genotyped in blood samples using a TaqMan-based genotyping assay, and collateral circulation was assessed by the Rentrop method. Multivariate logistic regression models adjusted by clinically relevant variables to estimate odds ratios were used to examine associations of PLAU P141L allelic variants and genotypes with collateral circulation. Patients with poor collateral circulation (Rentrop 0-1; n = 547) showed a higher frequency of the TT genotype than those with good collateral circulation (Rentrop 2-3; n = 129; P = .020). The T allele variant was also more common in patients with poor collateral circulation (P = .006). The odds ratio of having poorly developed collaterals in patients bearing the T allele (adjusted for clinically relevant variables) was statistically significant under the dominant model (odds ratio = 1.83 [95% confidence interval, 1.16-2.90]; P = .010) and the additive model (odds ratio = 1.73 [95% confidence interval, 1.14-2.62]; P = .009). An association was found between coronary collateral circulation and the PLAU P141L polymorphism. Patients with the 141L variant are at greater risk of developing poor coronary collateral circulation. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

Collateral circulation as a marker of the presence of viable myocardium in patients with recent myocardial infarction

International Nuclear Information System (INIS)

Fujita, M.; Ohno, A.; Wada, O.; Miwa, K.; Nozawa, T.; Yamanishi, K.; Sasayama, S.

1991-01-01

The relationship between the presence of viable myocardium and the extent of coronary collateral circulation to the infarct area was evaluated in 20 patients with a recent anterior myocardial infarction who had complete obstruction of the left anterior descending coronary artery. The viability of myocardial tissue was assessed by exercise thallium-201 myocardial scintigraphy, and the collateral circulation was angiographically evaluated by means of a collateral index ranging from 0 to 3. Patients were divided into two groups according to the presence (group 1, n = 10) or absence (group 2, n = 10) of viable myocardium in the perfusion territory of the infarct-related artery. The collateral index in group 1 was 2.5 ± 0.5 (SD), which was significantly higher than the 0.7 ± 0.8 in group 2. These findings indicate that the presence of ischemic but viable myocardium is intimately related to the development of collateral circulation in patients with myocardial infarction, and the existence of well-developed collateral channels predicts the presence of viable myocardium in the infarct area

12 CFR 614.4245 - Collateral evaluation policies.

Science.gov (United States)

2010-01-01

... directors of each Farm Credit System institution that engages in lending or leasing secured by collateral... descriptive and detailed to provide ample support to the institution's related credit decisions; (2) Performed... Section 614.4245 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM LOAN POLICIES AND...

Trade credit, collateral liquidation and borrowing constraints

NARCIS (Netherlands)

Fabbri, D.; Menichini, A.M.C.

2009-01-01

The paper proposes a model of collateralized bank and trade credit. Firms use a two-input technology. Assuming that the supplier is better able to extract value from existing assets and has an information advantage over other creditors, the paper derives a series of predictions. (1) Financially

31 CFR 203.21 - Collateral security requirements.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Collateral security requirements. 203.21 Section 203.21 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued... hereunder; or (iv) The depositary is closed for business by regulatory action or by proper corporate action...

SmPL: A Domain-Specific Language for Specifying Collateral Evolutions in Linux Device Drivers

DEFF Research Database (Denmark)

Padioleau, Yoann; Lawall, Julia Laetitia; Muller, Gilles

2007-01-01

identifying the affected files and modifying all of the code fragments in these files that in some way depend on the changed interface. We have studied the collateral evolution problem in the context of Linux device drivers. Currently, collateral evolutions in Linux are mostly done manually using a text...

Abnormal monocyte recruitment and collateral artery formation in monocyte chemoattractant protein-1 deficient mice

NARCIS (Netherlands)

Voskuil, Michiel; Hoefer, Imo E.; van Royen, Niels; Hua, Jing; de Graaf, Stijn; Bode, Christoph; Buschmann, Ivo R.; Piek, Jan J.

2004-01-01

Monocyte chemoattractant protein 1 (MCP-1) has been shown to be effective for the stimulation of collateral artery formation in small and large animal models. The availability of a genetic knockout mouse enables evaluation of the importance of the role of MCP-1 in the natural course of collateral

Absent collateral function of the circle of Willis as risk factor for ischemic stroke

NARCIS (Netherlands)

Hoksbergen, A. W. J.; Legemate, D. A.; Csiba, L.; Csáti, G.; Síró, P.; Fülesdi, B.

2003-01-01

Background. Autopsy studies show a higher prevalence of circle of Willis anomalies in brains with signs of ischemic infarction. Our goal was to examine the collateral function of the circle of Willis in ischemic stroke patients and to assess in a case-control study if a collateral deficient circle

Diagnosis of hepatic encephalopathy with magentic resonance imaging; With special reference to portal system encephalopathy

Energy Technology Data Exchange (ETDEWEB)

Inoue, Etsuo; Narumi, Yoshifumi; Kadota, Tsuyoshi; Fujita, Makoto; Kuriyama, Keiko; Kuroda, Chikazumi (Osaka Prefectural Center for Adult Diseases (Japan))

1993-01-01

Cranial magnetic resonance (MR) images were examined in 16 patients with liver cirrhosis. The findings of MR imaging were correlated with portal-systemic collateral vessel shown on angiograms. In 9 of 16 patients, basal ganglia was hyperintense compared with white matter on T1-weighted images. These 9 patients had portal-systemic collateral vessel 10 mm or more in diameter that was suppied by superior mesenteric vein (SMV), and 4 of the 9 patients had portal-systemic encephalopathy on angiograms. In the remaining 7 patients, no hyperintense lesions were seen in basal ganglia relative to white matter on T1-weighted images; angiography revealed that 2 patients had portal-systemic collateral vessel that was supplied by SMV but was 5 mm or less in diameter, 3 had bood supplies from splenic vein, and 2 had no collateral vessel. There was no change in signal intensity on T2-weighted images. In conclusion, a large portal-systemic collateral vessel supplied by SMV may be shown as a high intensity lesion in basal ganglia, thus making it possible to diagnose hepatic encephalopathy even if there was no psychoneurologic symptoms or signs. (N.K.).

Diagnosis of hepatic encephalopathy with magentic resonance imaging

International Nuclear Information System (INIS)

Inoue, Etsuo; Narumi, Yoshifumi; Kadota, Tsuyoshi; Fujita, Makoto; Kuriyama, Keiko; Kuroda, Chikazumi

1993-01-01

Cranial magnetic resonance (MR) images were examined in 16 patients with liver cirrhosis. The findings of MR imaging were correlated with portal-systemic collateral vessel shown on angiograms. In 9 of 16 patients, basal ganglia was hyperintense compared with white matter on T1-weighted images. These 9 patients had portal-systemic collateral vessel 10 mm or more in diameter that was suppied by superior mesenteric vein (SMV), and 4 of the 9 patients had portal-systemic encephalopathy on angiograms. In the remaining 7 patients, no hyperintense lesions were seen in basal ganglia relative to white matter on T1-weighted images; angiography revealed that 2 patients had portal-systemic collateral vessel that was supplied by SMV but was 5 mm or less in diameter, 3 had bood supplies from splenic vein, and 2 had no collateral vessel. There was no change in signal intensity on T2-weighted images. In conclusion, a large portal-systemic collateral vessel supplied by SMV may be shown as a high intensity lesion in basal ganglia, thus making it possible to diagnose hepatic encephalopathy even if there was no psychoneurologic symptoms or signs. (N.K.)

Recruitable collateral blood flow index predicts coronary instent restenosis after percutaneous coronary intervention

DEFF Research Database (Denmark)

Jensen, Lisette Okkels; Thayssen, Per; Lassen, Jens Flensted

2007-01-01

AIMS: Collateral flow may influence long-term results after percutaneous coronary intervention (PCI) because of haemodynamic forces compete with the antegrade flow through the dilated lesion. The aim of the study was to assess the influence of recruitable collateral blood flow on restenosis...... in patients undergoing PCI with bare metal stents and using optimal antithrombotic treatment. METHODS AND RESULTS: In 95 patients, 95 de novo lesions were treated with PCI and a bare metal stent. Fractional flow reserve (FFR) at maximum hyperaemia induced by intravenous adenosine was determined. The pressure.......02-1.12, P = 0.016). CONCLUSION: Recruitable collateral blood flow measured during balloon inflation predicts angiographic instent restenosis in PCI patients treated with bare metal stents. Udgivelsesdato: 2007-Aug...

45 CFR 30.16 - Liquidation of collateral.

Science.gov (United States)

2010-10-01

... fails to pay the debt(s) within a reasonable time after demand and if such action is in the best interests of the United States. (2) Collection from other sources, including liquidation of security or... will liquidate security or collateral through the exercise of a power of sale in the security...

Impact of collateral circulation status on favorable outcomes in thrombolysis treatment: A systematic review and meta-analysis.

Science.gov (United States)

Wufuer, Alimu; Wubuli, Atikaimu; Mijiti, Peierdun; Zhou, Jun; Tuerxun, Shabier; Cai, Jian; Ma, Jianhua; Zhang, Xiaoning

2018-01-01

Collateral circulation affects the prognosis of patients with acute ischemic stroke (AIS) treated by thrombolysis. The present study performed a systematic assessment of the impact of the collateral circulation status on the outcomes of patients receiving thrombolysis treatment. Relevant full-text articles from the Cochrane Library, Ovid, Medline, Embase and PubMed databases published from January 1, 2000 to November 1, 2016 were retrieved. The quality of the studies was assessed and data were extracted by 2 independent investigators. The random-effects model was used to estimate the impact of good vs. poor collateral circulation, as well as baseline characteristics, on the outcome within the series presented as risk ratios. Subgroup analyses explored the potential factors that may interfere with the effects of the collateral circulation status on the outcome. A total of 29 studies comprising 4,053 patients were included in the present meta-analysis. A good collateral circulation status was revealed to have a beneficial effect on favorable functional outcome (modified Rankin scale, 0-3 at 3-6 months; Pcollateral circulation. Good collateral circulation was also associated with a lower rate of symptomatic intracranial hemorrhage (Pcollateral circulation was demonstrated to have a favorable prognostic value regarding the outcome for patients with AIS receiving thrombolysis treatment. Assessment of collateral circulation and penumbra area during pre-treatment imaging within an appropriate time-window prior to thrombolytic therapy will therefore improve the identification of AIS patients who may benefit from thrombolysis treatment.

Excimer laser coronary atherectomy in septal collaterals during retrograde recanalization of a chronic total occlusion

Directory of Open Access Journals (Sweden)

Bernward Lauer

2011-09-01

Full Text Available Management of chronic total occlusions has been refined through the development of a retrograde approach via collateral pathways. We describe the use of Excimer Laser Coronary Atherectomy in the septal collaterals. This appraoch was not yet described in the literature.

Tests of Ex Ante Versus Ex Post Theories of Collateral Using Private and Public Information

NARCIS (Netherlands)

Berger, A.N.; Frame, W.S.; Ioannidou, V.

2010-01-01

Collateral is a widely used, but not well understood, debt contracting feature. Two broad strands of theoretical literature explain collateral as arising from the existence of either ex ante private information or ex post incentive problems between borrowers and lenders. However, the extant

13 CFR 123.11 - Does SBA require collateral for any of its disaster loans?

Science.gov (United States)

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Does SBA require collateral for any of its disaster loans? 123.11 Section 123.11 Business Credit and Assistance SMALL BUSINESS...? Generally, SBA will not require that you pledge collateral to secure a disaster home loan or a physical...

MR imaging in chronic rupture of the ulnar collateral ligament of the thumb

International Nuclear Information System (INIS)

Lohman, M.; Kivisaari, A.; Kivisaari, L.; Vasenius, J.

2000-01-01

MR imaging has been shown as the best radiologic method for verifying and classifying acute ulnar collateral ligament (UCL) ruptures of the thumb. Our aim was to analyse the usefulness of MR also in old ruptures and to establish the most useful sequences. Ten patients with an old UCL rupture of the thumb were preoperatively imaged using 1.5 T MR. Three radiologists blinded to the findings separately analysed the MR images of these patients and of 10 age-and sex-matched voluntary controls. MR findings of the patients were compared with those of surgery. The consensus diagnosis of an UCL rupture was accurate in all 10 patients. All controls were classified as having no UCL rupture. In 5 of the 7 patients with a surgically defined Stener or non-Stener lesion, the consensus diagnosis was the same as the operative diagnosis. Due to excessive scarring it was not possible to verify any Stener lesion intra-operatively in 3 patients. The most informative MR sequence was T2 TSE in the coronal plane, the second most informative was T1 SE with fat suppression in the coronal plane. An old UCL rupture is well verified by MR but typing of the lesion as either a Stener or non-Stener type is not always possible

Superior vena cava syndrome associated with right-to left shunt through systemic-to-pulmonary venous collaterals

International Nuclear Information System (INIS)

Juan, Yu Hsiang; Saboo, Sachin S.; Anand, Vishal; Chatzizisis, Yiannis S.; Steigner, Michael L.; Lin, Yu Ching

2014-01-01

Superior vena cava (SVC) obstruction is associated with the gradual development of venous collaterals. We present a rare form of systemic-to-pulmonary subpleural collateral pathway that developed in the bridging subpleural pulmonary veins in a 54-year-old woman with complete SVC obstruction. This uncommon collateral pathway represents a rare form of acquired right-to-left shunt due to previous pleural adhesions with an increased risk of stroke due to right-to-left venous shunting, which requires lifelong anticoagulation.

31 CFR 901.7 - Liquidation of collateral.

Science.gov (United States)

2010-07-01

... reasonable time after demand and if such action is in the best interest of the United States. Collection from... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Liquidation of collateral. 901.7 Section 901.7 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FEDERAL...

The collateral venous system in late pregnancy: A systematic review of the literature.

Science.gov (United States)

Humphries, Aimee; Stone, Peter; Mirjalili, S Ali

2017-11-01

Recent literature has reported an association between maternal supine sleep position and stillbirth during late pregnancy. In this position the gravid uterus almost completely obstructs the inferior vena cava. A small number of women experience supine hypotension, thought to be due in part to inadequate collateral venous circulation. The aim of this paper is to review the literature describing the anatomy of the collateral venous system and in particular the azygos system, the abdominal portion of which has not been well studied. A systematic review was conducted using the electronic databases: Medline, Embase, Scopus, and Google Scholar. Relevant anatomical and radiological literature concerning the azygos system in particular was reviewed. The search was limited to adult human studies only. The collateral venous system can be divided into superficial, intermediate and deep systems. The azygos system in particular provides immediate collateral venous circulation in the event of acute inferior vena caval obstruction. The abdominal portion of this pathway, including the ascending lumbar vein, has not been well studied and there are certain variations that can render it ineffective. In conclusion, the collateral venous system provides an alternative route for blood to flow back to the systemic circulation when acute occlusion of the inferior vena cava occurs in the supine position during late pregnancy. However, certain anatomical variations can render this pathway ineffective, and this could have implications for the development of supine hypotension and stillbirth in late pregnancy. Clin. Anat. 30:1087-1095, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Role of collateral circulation in the course of coronary heat disease (10-year clinical and angiographic follow-up)

International Nuclear Information System (INIS)

Tsapaeva, N.L.

1999-01-01

Results of the 10-year prospective follow-up of 59 ischemia patients with stenocardia are presented. Coronarography was made in all the patients whose coronary arteries and collateral blood flow were assessed. The experimental group comprised 37 patients with ischemia and collateral circulatory insufficiency. The control group included 22 patients with effective collateral circulation. The experimental group showed a worse prognosis than did the control one. Myocardial infarction developed in 54 and 27 % of cases, ischemia mortality was 29.7 and 9 % in the experimental and control groups, respectively. Effective collateral circulation is prerequisite of successful surgical myocardial revascularization [ru

Clinical Results of Arteriovenous Fistulas Constructed Using Autologous Vessels in End-Stage Renal Disease Patients on Hemodialysis

Directory of Open Access Journals (Sweden)

Ki Tae Kim

2018-04-01

Full Text Available Background: For hemodialysis patients with end-stage renal disease (ESRD, it is important to construct an efficient vascular access with a superior patency rate. This study investigated the factors influencing the efficiency of arteriovenous fistulas (AVFs constructed using an autologous vessel and evaluated the necessity of ultrasonography as a preoperative tool for AVF construction. Methods: A retrospective analysis was performed of 250 patients in whom an AVF was constructed using an autologous vessel due to ESRD at our institution from January 2009 to April 2016. Results: The 1-, 3-, and 5-year patency rates for all subjects were 87.6%, 85.6%, and 84.4%, respectively. The patients who underwent a preoperative evaluation of their vessels via ultrasonography had better patency rates than those who did not. Superior patency rates were found in patients under 65 years of age or with an anastomotic vein diameter of 3 mm or more. The 1-year patency rate and the diameter of the anastomotic vein showed a positive relationship. Conclusion: Ultrasonography is strongly recommended for AVF construction, and efforts should be made to increase the patency rate in patients over 65. Superior clinical results can be expected when an AVF is made using an autologous vessel with an anastomotic vein diameter of at least 3 mm.

Study of radiation damage of steels for light water pressure vessels at UJV

International Nuclear Information System (INIS)

Vacek, N.; Stoces, B.

1980-01-01

Preoperational determination of radiation resistance of pressure vessel steels is performed at accelerated neutron exposure in a test or materials research reactor. The results obtained at accelerated and operating exposure are not fully identical and surveillance bodies are therefore used manufactured from the pressure vessel material. Currently, the following steels are used for the manufacture of light water reactor pressure vessels: Mn-Mo-Ni (ASTM-A533-B, ASTM-A508), Cr-Mo-V (15Kh2M1FA). At UJV Rez, for irradiation Chanca-M probes imported from France are used featuring electric temperature control. Almost identical radiation embrittlement was measured for all three steels after irradiation with a neutron fluence of 3x10 23 n.m -2 at a temperature of 290 degC. (H.S.)

Inflammatory processes during arteriogenesis : the contribution of the innate immune system to collateral artery growth

NARCIS (Netherlands)

de Groot, D.

2011-01-01

The central theme of the work presented in the thesis is restoration of tissue perfusion by collateral artery growth. During collateral artery growth, or arteriogenesis, unused pre-existing vascular anastomoses remodel into functional arteries. These arteries are able to take over the perfusion of

Collateral effects of antibiotics on mammalian gut microbiomes

Science.gov (United States)

Antibiotics are an essential component of the modern lifestyle. They improve our lives by treating disease, preventing disease, and in the case of agricultural animals by improving feed efficiency. However, antibiotic usage is not without collateral effects. The development and spread of antibiot...

Preoperative evaluation of myocardial viability by thallium-201 imaging in patients with old myocardial infarction who underwent coronary revascularization

International Nuclear Information System (INIS)

Naruse, Hitoshi; Ohyanagi, Mitsumasa; Iwasaki, Tadaaki; Miyamoto, Takashi; Fukuchi, Minoru

1992-01-01

The myocardial uptake and redistribution in thallium scintigraphy and the regional wall motion by echocardiography were evaluated by a semi-quantitative method in 42 patients who previously had myocardial infarction (50 target vessels) and underwent coronary revascularization. The aim of this study was to elucidate the significance of the initial image, delayed image and redistribution on thallium-201 scintigraphy for clinical diagnosis of the myocardial viability. As a semi-quantitative analysis, we used a bull's-eye display for thallium image and centerline method for echocardiographic wall motion, and compared the results before and after revascularization. As a result, the thallium grade improved postoperatively in all 17 areas which preoperatively had showed redistribution, and also in 11 of the 32 areas without preoperative redistribution. The sensitivity, specificity and accuracy of preoperative thallium redistribution for predicting myocardial viability were 61%, 100% and 78%, respectively, when the postoperative improvement in the thallium grade was used as the standard. The postoperative probability of improvement in the thallium grade increased in proportion to the preoperative grade (delayed image)(p<0.01). There was no correlation between the preoperative thallium delayed image and postoperative improvement in wall motion. Postoperative improvement in thallium image and wall motion could not be predicted from the preoperative wall motion. Thus, postoperative improvement in thallium images can be anticipated if redistribution is present on the preoperative thallium image, and the preoperative thallium delayed image is useful for predicting myocardial viability. Improvement in wall motion could not be predicted preoperatively by these methods. (author)

Collateral Learning and Mathematical Education of Teachers

Science.gov (United States)

Abramovich, Sergei

2012-01-01

This article explores the notion of collateral learning in the context of classic ideas about the summation of powers of the first "n" counting numbers. Proceeding from the well-known legend about young Gauss, this article demonstrates the value of reflection under the guidance of "the more knowledgeable other" as a pedagogical method of making…

38 CFR 1.913 - Liquidation of collateral.

Science.gov (United States)

2010-07-01

... security or collateral through the exercise of a power of sale in the security instrument or a nonjudicial foreclosure, and apply the proceeds to the applicable debt, if the debtor fails to pay the debt within 180 days after demand and if such action is in the best interest of the United States. Collection from...

Effective preoperative irradiation of highly vascular cerebellopontine angle neurinomas

International Nuclear Information System (INIS)

Ikeda, K.; Ito, H.; Kashihara, K.; Fujisawa, H.; Yamamoto, S.

1988-01-01

Three cases of large cerebellopontine angle neurinoma with marked vascularity and tumor staining on the angiogram were treated with effective preoperative irradiation. The radiotherapy was given before the second operation in two cases and before the first operation in the other case. Irradiation doses administered with a linear accelerator were 2.34 to 3.0 Gy for 3 to 3.5 weeks, and radical operations were done 1.5 to 2 months after irradiation. After the irradiation, vertebral angiography showed moderate to marked decrease of the hypervascular capsular stain and disappearance of the early draining vein. Computed tomographic scan showed enlargement of the central necrotic area within the heterogeneously enhanced tumor, which was unchanged in size. Radical operations, which had been impossible because of uncontrollable massive bleeding, were successful without any intraoperative bleeding after radiotherapy. Postirradiation radiological findings corresponded well with those of histopathological examination, which showed decrease in cellularity and in vascularity and diffuse coagulation necrosis around the collapsed tumoral vessels as radiation effects. Preoperative irradiation of the hypervascular neurinoma was though to facilitate radical surgery by abolishing or diminishing the risk of intraoperative bleeding

13 CFR 120.1882 - What happens if funds to make required loan payments are not generated from the Collateral?

Science.gov (United States)

2010-01-01

... required loan payments are not generated from the Collateral? 120.1882 Section 120.1882 Business Credit and... to make required loan payments are not generated from the Collateral? (a) The SISMBD is responsible... Collateral as set forth in the Loan Agreements, related documents and applicable law. (b) An SISMBD will have...

13 CFR 120.1881 - How are payments on the Collateral allocated between the SISMBD borrower and repayment of the...

Science.gov (United States)

2010-01-01

... are payments on the Collateral allocated between the SISMBD borrower and repayment of the SISMBD Loan? Unless otherwise provided in the Loan Agreements for a particular SISMBD Loan, any payment on Collateral... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false How are payments on the Collateral...

13 CFR 120.545 - What are SBA's policies concerning the liquidation of collateral and the sale of business loans...

Science.gov (United States)

2010-01-01

... the liquidation of collateral and the sale of business loans and physical disaster assistance loans... policies concerning the liquidation of collateral and the sale of business loans and physical disaster.... SBA or the Lender may liquidate collateral securing a loan if the loan is in default or there is no...

[Associated vessel heteromorphosis in laparoscopic complete mesocolic excision and solutions to intraoperative hemorrhage].

Science.gov (United States)

Jiao, Yurong; He, Jinjie; Li, Jun; Xu, Dong; Ding, Kefeng

2018-03-25

Vessel identification and dissection are the key processes of laparoscopic complete mesocolic excision (CME). Vascular injury will lead to complications such as prolonged operative time, intraoperative hemorrhage and ischemia of anastomotic stoma. Superior mesenteric artery (SMA), superior mesenteric vein(SMV), gastrointestinal trunk, left colic artery(LCA), sigmoid artery and marginal vessels in the mesentery have been found with possibility of heteromorphosis, which requires better operative techniques. Surgeons should recognize those vessel heteromorphosis carefully during operations and adjust strategies to avoid intraoperative hemorrhage. Preoperative abdominal computed tomography angiography(CTA) with three-dimensional reconstruction can find vessel heteromorphosis within surgical area before operation. Adequate dissection of veins instead of violent separation will decrease intraoperative bleeding and be helpful for dealing with the potential hemorrhage. When intraoperative hemorrhage occurs, surgeons need to control the bleeding by simple compression or vascular clips depending on the different situations. When the bleeding can not be stopped by laparoscopic operation, surgeons should turn to open surgery without hesitation.

25 CFR 166.223 - Can I use a permit as collateral for a loan?

Science.gov (United States)

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Can I use a permit as collateral for a loan? 166.223... PERMITS Permit Requirements Permit (leasehold) Mortgage § 166.223 Can I use a permit as collateral for a loan? We may approve a permit containing a provision that authorizes the permittee to encumber the...

Concurrent patellar fracture and lateral collateral ligament avulsion as a result of trauma in three horses.

Science.gov (United States)

McLellan, Jonathan; Plevin, Sarah; Taylor, Elizabeth

2012-05-15

3 horses were evaluated because of lameness and swelling of the stifle joint subsequent to trauma. All horses had characteristic clinical signs of stifle joint pain and effusion. A medial patellar fracture and lateral collateral ligament avulsion fracture were visible ultrasonographically in each. Radiography, including standard as well as flexed lateromedial, cranioproximal-craniodistal oblique (skyline patellar), and laterally stressed caudocranial views, revealed similar findings. Arthroscopic surgery to remove the patellar fracture was attempted in 1 horse with severe desmitis of the lateral collateral ligament; it remained lame afterward. The other 2 horses, with less severe collateral ligament damage, were managed conservatively and returned to athletic use, despite the lack of surgical intervention to repair the patellar fractures. Special radiographic views were necessary for diagnosis of medial patellar fracture and lateral collateral ligament avulsion fracture in the 3 horses. Ultrasonographic findings pertaining to the collateral ligament may be prognostically important in such situations. The severity of a fracture involving ligament avulsion may be the limiting factor in horses with this combined injury, and this factor should be considered prior to attempting surgical correction of patellar fractures.

[Association between collateral circulation and myocardial viability evaluated by cardiac magnetic resonance imaging in patients with coronary artery chronic total occlusion].

Science.gov (United States)

Li, J N; Zhang, L J; He, Y; Chen, Y L; Huang, R C; Lyu, S Z; Song, X T

2017-07-24

Objective: Late gadolinium enhancement(LGE) cardiac magnetic resonance imaging(CMR) was used to evaluate the myocardial viability of chronic total occlusion(CTO) in patients with coronary heart disease and to observe the relationship between collateral circulation and myocardium viability in these patients. Methods: This retrospective study included 40 patients with CTO diagnosed by invasive coronary angiography (CAG) from September 2015 to June 2016 in our department, all patients performed CMR examination within one week after CAG.The collateral circulation of CTO was graded with Rentrop classification as follows: poor or no collateral circulation group, moderate collateral circulation group and good collateral circulation group.According to CMR images, the delayed enhancement transmural extent of myocardial segments were scored, the ventricular wall motion of the myocardial segment were graded, and the wall motion score index (WMSI) was calculated.Spearman correlation analysis was used to analyze the relationship between the delayed enhancement transmural extent of myocardial segments and WMSI. Results: In the no or poor collateral group of 6 myocardial regions, 1 myocardial region had viable myocardium and 3 myocardial regions had no viable myocardium; in the moderate collateral group of 16 myocardial regions, 11 myocardial regions had viable myocardium and 5 myocardial regions had no viable myocardium; in the good collateral group of 24 myocardial regions, 21 myocardial regions had viable myocardium and 3 myocardial regions had no viable myocardium, there was significant difference between the groups ( P =0.002). The WMSI of poor or no collateral circulation group, moderate collateral circulation group and good collateral circulation group were 1.54±0.50, 1.21±0.34 and 1.26±0.40, respectively, there was no significant difference between the groups ( P =0.063). Spearman correlation analysis showed that the extent of delayed enhancement transmural extent of

Incidence of and Risk Factors for Knee Collateral Ligament Injuries With Proximal Tibia Fractures: A Study of 32,441 Patients.

Science.gov (United States)

Samuel, Andre M; Diaz-Collado, Pablo J; Szolomayer, Lauren K; Wiznia, Daniel H; Chan, Wayne W; Lukasiewicz, Adam M; Basques, Bryce A; Bohl, Daniel D; Grauer, Jonathan N

2018-03-01

Proximal tibia fractures are associated with concurrent collateral ligament injuries. Failure to recognize these injuries may lead to chronic knee instability. The purpose of this study was to identify risk factors for concurrent collateral ligament injuries with proximal tibia fractures and their association with inpatient outcomes. A total of 32,441 patients with proximal tibia fractures were identified in the 2011-2012 National Trauma Data Bank. A total of 1445 (4.5%) had collateral ligament injuries, 794 (2.4%) had injuries to both collateral ligaments, 456 (1.4%) had a medial collateral ligament injury only, and 195 (0.6%) had a lateral collateral ligament injury only. On multivariate analysis, risk factors found to be associated with collateral ligament injuries included distal femur fracture (odds ratio, 2.1), pedestrian struck by motor vehicle (odds ratio, 2.0), obesity (odds ratio, 1.6), young age (odds ratio, 1.9 for 18 to 29 years vs 40 to 49 years), motorcycle accident (odds ratio, 1.5), and Injury Severity Score of 20 or higher (odds ratio, 1.4). In addition, patients with simultaneous injuries to both collateral ligaments had higher odds of inpatient adverse events (odds ratio, 1.51) and longer hospital stay (mean, 2.27 days longer). The risk factors reported by this study can be used to identify patients with proximal tibia fractures who may warrant more careful and thorough evaluation and imaging of their knee collateral ligaments. [Orthopedics. 2018; 41(2):e268-e276.]. Copyright 2018, SLACK Incorporated.

Correlation of cerebrovascular reserve as measured by acetazolamide-challenged perfusion CT with collateral circulation in unilateral high grade carotid stenosis

International Nuclear Information System (INIS)

Hong, Doran; Lee, Young Hen; Seo, Hyung Suk; Je, Bo Kyoung; Suh, Sang Il; Seol, Hae Young; Kim, Jung Hyuk; Lee, Nam Joon; Yang, Kyung Sook

2014-01-01

We correlated cerebrovascular reserve in unilateral high grade carotid artery stenosis or occlusion with a type of collateral circulation using acetazolamide-challenged perfusion CT (ACZ-PCT). Among the patients who underwent ACZ-PCT in our institution, we retrospectively selected the patients with unilateral high grade internal carotid artery or middle cerebral artery stenosis (> 70%) or occlusion; we verified the types of their dominant collateral circulation by digital subtraction angiography or 3T MR-angiography; first, the primary collaterals flow through the circle of Willis; second, the secondary collaterals that flow through the opthalmic artery, the basal artery or other external carotid artery. Using ACZ-PCT, we measured the difference in percentage change of cerebral blood flow of the stenotic hemisphere against contralateral normal hemisphere and compared cerebrovascular reserves of lesional hemisphere, according to the type of collaterals. A total of 28 patients were included. The percentage changes of cerebral blood flow were significantly lower in the stenotic hemisphere than the contralateral hemisphere (14.34 ± 36.43% and 34.53 ± 47.82%, p < 0.001), and in the hemisphere predominantly supplied by secondary collaterals than primary (7.03 ± 32.71% and 24.37 ± 42.03%, p < 0.05), respectively. Cerebrovascular reserves in the ipsilateral hemisphere predominantly supplied by secondary collaterals were more impaired than primary collaterals in patients with unilateral high grade carotid stenosis or occlusion.

Dynamic knee alignment and collateral knee laxity and its variations in normal humans

Directory of Open Access Journals (Sweden)

Kamal eDeep

2015-11-01

Full Text Available Alignment of normal, arthritic and replaced human knees is a much debated subject as is the collateral ligamentous laxity. Traditional quantitative values have been challenged. Methods used to measure these are also not without flaws. Authors review the recent literature and a novel method of measurement of these values has been included. This method includes use of computer navigation technique in clinic setting for assessment of the normal or affected knee before the surgery. Computer navigation has been known for achievement of alignment accuracy during knee surgery. Now its use in clinic setting has added to the inventory of measurement methods. Authors dispel the common myth of straight mechanical axis in normal knees and also look at quantification of amount of collateral knee laxity. Based on the scientific studies it has been shown that the mean alignment is in varus in normal knees. It changes from lying non weight bearing position to standing weight bearing position in both coronal and the sagittal planes. It also varies with gender and race. The collateral laxity is also different for males and females. Further studies are needed to define the ideal alignment and collateral laxity which the surgeon should aim for individual knees.

Preoperative assessment of trigeminal neuralgia and hemifacial spasm using constructive interference in steady state-three-dimensional fourier transformation magnetic resonance imaging

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Yamakami, Iwao; Kobayashi, Eiichi; Hirai, Shinji; Yamaura, Akira [Chiba Univ. (Japan). School of Medicine

2000-11-01

Results of microvascular decompression (MVD) for trigeminal neuralgia (TN) and hemifacial spasm (HFS) may be improved by accurate preoperative assessment of neurovascular relationships at the root entry/exit zone (REZ). Constructive interference in steady state (CISS)-three-dimensional Fourier transformation (3DFT) magnetic resonance (MR) imaging was evaluated for visualizing the neurovascular relationships at the REZ. Fourteen patients with TN and eight patients with HFS underwent MR imaging using CISS-3DFT and 3D fast inflow with steady-state precession (FISP) sequences. Axial images of the cerebellopontine angle (CPA) obtained by the two sequences were reviewed to assess the neurovascular relationships at the REZ of the trigeminal and facial nerves. Eleven patients subsequently underwent MVD. Preoperative MR imaging findings were related to surgical observations and results. CISS MR imaging provided excellent contrast between the cranial nerves, small vessels, and cerebrospinal fluid (CSF) in the CPA. CISS was significantly better than FISP for delineating anatomic detail in the CPA (trigeminal and facial nerves, petrosal vein) and abnormal neurovascular relationships responsible for TN and HFS (vascular contact and deformity at the REZ). Preoperative CISS MR imaging demonstrated precisely the neurovascular relationships at the REZ and identified the offending artery in all seven patients with TN undergoing MVD. CISS MR imaging has high resolution and excellent contrast between cranial nerves, small vessels, and CSF, so can precisely and accurately delineate normal and abnormal neurovascular relationships at the REZ in the CPA, and is a valuable preoperative examination for MVD. (author)

Preoperative assessment of trigeminal neuralgia and hemifacial spasm using constructive interference in steady state-three-dimensional fourier transformation magnetic resonance imaging

International Nuclear Information System (INIS)

Yamakami, Iwao; Kobayashi, Eiichi; Hirai, Shinji; Yamaura, Akira

2000-01-01

Results of microvascular decompression (MVD) for trigeminal neuralgia (TN) and hemifacial spasm (HFS) may be improved by accurate preoperative assessment of neurovascular relationships at the root entry/exit zone (REZ). Constructive interference in steady state (CISS)-three-dimensional Fourier transformation (3DFT) magnetic resonance (MR) imaging was evaluated for visualizing the neurovascular relationships at the REZ. Fourteen patients with TN and eight patients with HFS underwent MR imaging using CISS-3DFT and 3D fast inflow with steady-state precession (FISP) sequences. Axial images of the cerebellopontine angle (CPA) obtained by the two sequences were reviewed to assess the neurovascular relationships at the REZ of the trigeminal and facial nerves. Eleven patients subsequently underwent MVD. Preoperative MR imaging findings were related to surgical observations and results. CISS MR imaging provided excellent contrast between the cranial nerves, small vessels, and cerebrospinal fluid (CSF) in the CPA. CISS was significantly better than FISP for delineating anatomic detail in the CPA (trigeminal and facial nerves, petrosal vein) and abnormal neurovascular relationships responsible for TN and HFS (vascular contact and deformity at the REZ). Preoperative CISS MR imaging demonstrated precisely the neurovascular relationships at the REZ and identified the offending artery in all seven patients with TN undergoing MVD. CISS MR imaging has high resolution and excellent contrast between cranial nerves, small vessels, and CSF, so can precisely and accurately delineate normal and abnormal neurovascular relationships at the REZ in the CPA, and is a valuable preoperative examination for MVD. (author)

Local Cytokine Concentrations and Oxygen Pressure Are Related to Maturation of the Collateral Circulation in Humans

NARCIS (Netherlands)

Schirmer, Stephan H.; van Royen, Niels; Moerland, Perry D.; Fledderus, Joost O.; Henriques, José P.; van der Schaaf, René J.; Vis, Marije M.; Baan, Jan; Koch, Karel T.; Horrevoets, Anton J. G.; Hoefer, Imo E.; Piek, Jan J.

2009-01-01

Objectives Our aim was to determine cytokine and oxygen gradients over the collateral circulation in humans. Background The molecular background of the maturation of the collateral circulation in response to coronary narrowing is poorly understood in humans, partly because of difficulties in

Preoperative evaluation

International Nuclear Information System (INIS)

Murphy, C.H.; Murphy, M.R.

1987-01-01

The value of a preoperative chest radiograph is twofold. The examination may reveal unsuspected pathology that would alter the approach to surgery of anesthesia. Secondly, it provides a baseline or reference from which to evaluate subsequent post-operative films. The percentage of detection of unsuspected pathology on preoperative chest radiographs has been shown to be exceedingly small in certain patient populations. The authors do not recommend routine use of preoperative chest radiographs in children or in adults under the age of 40 who do not smoke, unless (1) the surgical disease has chest manifestations; (2) there is historic or clinical evidence of a coexisting disease with chest involvement; or (3) there is a likelihood that post-operative management will require follow-up films

Relationship between availability of the collateral circulation and ischemic time for myocardial viability in patients with acute myocardial infarction. Assessment by technetium-99m tetrofosmin single photon emission computed tomography

International Nuclear Information System (INIS)

Kanamori, Norio; Kondo, Makoto; Fukuoka, Yoshitomo; Higuchi, Hirokazu; Kubota, Tomoyuki; Matsuoka, Ryota; Araki, Makoto; Tanio, Hitoshi; Doyama, Kiyoshi

2007-01-01

Myocardial accumulation before reperfusion therapy of a radioactive tracer in the completely occluded region, conceivably reflects the viability of myocytes and degree of collateral circulation. To confirm this, the present study examined the relationship in the title. Subjects were 33 patients (F 7, M 26; average age 65 y) of the first 1-branch acute myocardial infarction and of TIMI (thrombolysis in myocardial infarction trial) grade 0 who recovered to TIMI 3 within 12 hr after attack: 99m Tc-tetrofosmin, 740 MBq, was intravenously injected before reperfusion and just after which, SPECT imaging (TF-SPECT) was conducted with Toshiba E. CAM, and regional severity score index (RSSI) (0-3) was calculated. About 1 week later, to see the myocardial viability in the chronic phase, GITl (Glucose-Insulin- 201 Tl) (111 MBq) SPECT was performed 30 min after its injection to calculate RSSI as above, and the echocardiography with ALOKA Pro Sound SSD-4000 or SIEMENS Acuson SEQUOIA C256 was done to calculate the regional wall motion score index (RWMSI) (0-4). RWMSI was found significantly correlated with TF-RSSI, the group with the better collateral circulation (TF-RSSI, 1.9 or less) exhibited significantly lower GITl-RSSI and RWMSI, and correlation between the ischemic time and neither TF-RSSI, GITl-RSSI nor RWMSI was found. Thus under these conditions, the development of collateral vessels was found to have potential protective effects on myocardium independently on the ischemic time. (T.I.)

Correlation between GDF-15 gene polymorphism and the formation of collateral circulation in acute ST-elevation myocardial infarction.

Science.gov (United States)

Chen, Xiao-Ping; Shang, Xiao-Sen; Wang, Yan-Bin; Fu, Zhi-Hua; Gao, Yu; Feng, Tao

2017-12-01

To explore the correlation between growth differentiation factor 15 (GDF-15) -3148C/G polymorphism and the formation of collateral circulation in acute ST-elevation myocardial infarction (STEMI) in Han population of Taiyuan area. The present study included 92 STEMI patients and 56 normal controls based on coronary angiography; STEMI group was divided into collateral group and non-collateral group according to Rentrop's grading method. Polymerase chain reaction (PCR) and DNA sequencing methods were used to detect and analyze the GDF-15 -3148C/G polymorphism in all participants. There was significant difference in GDF-15 -3148C/G CC and GC distribution between STEMI group and control group (p=0.009); the allele frequencies between these two groups were also significant different (p=0.016); and the risk genotype for STEMI was CC with increased OR=2.660. For STEMI group, GDF-15 -3148C/G CC and GC distribution was also significantly different between patients with and without collateral (p=0.048), and CC genotype significantly promote the formation of collateral circulation. However, there were no significant differences in allele frequencies between these two subgroups of STEMI. There was correlation between GDF-15-3148C/G polymorphism and the formation of collateral circulation in patients with acute STEMI.

Collateral abdominal circulation in patient with Leriche's syndrome diagnosed with 64-row multislice computed tomography (MSCT)

International Nuclear Information System (INIS)

Staskiewicz, G.; Drop, A.

2008-01-01

Leriche's syndrome results from slowly developing occlusion of the abdominal aorta. It affects mainly middle-aged males. The blood flow distal to the occlusion site is secured by collateral circulation. Signs of Leriche's syndrome include claudication, gluteal pain and impotence. The paper presents a patient with Leriche's syndrome, in whom a detailed visualization of collateral circulation was obtained with multislice computed tomography angiography. Patient underwent surgical recanalization of the aorta with an excellent result. To our knowledge, the presented case is the first description of collateral circulation in Leriche's syndrome obtained with 64-row computed tomography. (author)

Aberrant Ovarian Collateral Originating from External Iliac Artery During Uterine Artery Embolization

Energy Technology Data Exchange (ETDEWEB)

Kwon, Joon Ho; Kim, Man Deuk, E-mail: mdkim@yuhs.ac; Lee, Kwang-hun; Lee, Myungsu; Lee, Mu Sook; Won, Jong Yun; Park, Sung Il; Lee, Do Yun [Yonsei University College of Medicine, Department of Radiology, Research Institute of Radiological Science, Severance Hospital (Korea, Republic of)

2013-02-15

We report a case of a 35-year-old woman who underwent uterine artery embolization (UAE) for symptomatic multiple uterine fibroids with collateral aberrant right ovarian artery that originated from the right external iliac artery. We believe that this is the first reported case in the literature of this collateral uterine flow by the right ovarian artery originated from the right external iliac artery. We briefly present the details of the case and review the literature on variations of ovarian artery origin that might be encountered during UAE.

Aberrant Ovarian Collateral Originating from External Iliac Artery During Uterine Artery Embolization

International Nuclear Information System (INIS)

Kwon, Joon Ho; Kim, Man Deuk; Lee, Kwang-hun; Lee, Myungsu; Lee, Mu Sook; Won, Jong Yun; Park, Sung Il; Lee, Do Yun

2013-01-01

We report a case of a 35-year-old woman who underwent uterine artery embolization (UAE) for symptomatic multiple uterine fibroids with collateral aberrant right ovarian artery that originated from the right external iliac artery. We believe that this is the first reported case in the literature of this collateral uterine flow by the right ovarian artery originated from the right external iliac artery. We briefly present the details of the case and review the literature on variations of ovarian artery origin that might be encountered during UAE.

An isolated left subclavian artery supplied by a collateral artery from the abdominal aorta

International Nuclear Information System (INIS)

Ming, Zhu; Qian, Wang

2009-01-01

An isolated left subclavian artery is a rare anomaly. We report a 9-month-old boy with an isolated left subclavian artery associated with tetralogy of Fallot and the right aortic arch. MRI and angiography show that the blood supply through the left subclavian artery was maintained by a large tortuous collateral artery from the abdominal aorta. This type of collateral artery structure is unique. (orig.)

An isolated left subclavian artery supplied by a collateral artery from the abdominal aorta

Energy Technology Data Exchange (ETDEWEB)

Ming, Zhu; Qian, Wang [Shanghai Jiaotong University School of Medicine, Department of Radiology, Shanghai Children' s Medical Center, Shanghai (China)

2009-08-15

An isolated left subclavian artery is a rare anomaly. We report a 9-month-old boy with an isolated left subclavian artery associated with tetralogy of Fallot and the right aortic arch. MRI and angiography show that the blood supply through the left subclavian artery was maintained by a large tortuous collateral artery from the abdominal aorta. This type of collateral artery structure is unique. (orig.)

Clinical study of the hypothesis of endogenous collateral wind on acute coronary syndrome: a review.

Science.gov (United States)

Wang, Xian; Zhang, Cong; Yang, Ran; Zhu, Haiyan; Zhao, Huaibing; Li, Xiaoming

2014-01-01

Acute Coronary Syndrome (ACS), is a serious threat to people's health, and life, and in recent years, the incidence has increased yearly. This study was to propose the hypothesis of "endogenous collateral wind" based on the patho-mechanism of thrombogenesis complicated by ruptured plaque on ACS, and the theory of traditional Chinese medicine. Through successful coronary angiography (CAG), and intravascular ultrasound (IVUS), patients with coronary artery disease were made the differential diagnosis such as blood stasis, blood stasis due to phlegm obstruction, and endogenous collateral wind. The levels of plasma inflammatory marker were measured to study on the characteristics of "endogenous collateral wind". Luo heng dripping pills with promoting blood circulation to expel wind-evil, and remove wetness were made based on the hypothesis of "endogenous collateral wind" on ACS. Patients with unstable angina were randomly divided into 3, groups based on therapeutic methods: conventional therapy group, Luo Heng dripping pills group and Tongxinluo caps. Differences among groups were compared. There were great changes in number and degree of coronary arteriostenosis confirmed by CAG, the types of ACC/AHA lesion and Levin lesion confirmed by CAG, remodeling index, positive or negative remodeling percentage measured by IVUS, the plasma levels of plasma inflammatory marker measured by ELLSA in the patients with endogenous collateral wind, compared with patients with blood stasis and blood stasis due to phlegm obstruction. The total effective rate of improved angina in Luo Heng dripping pills group was significantly higher than those in other two groups. The levels of plasma inflammatory marker were significantly lower in Luo Heng dripping pills group. There were some pathological basis which were found about the hypothesis of "endogenous collateral wind" on acute coronary syndrome. It provided evidences for patients with coronary artery disease treated by medicines with

31 CFR 380.4 - What collateral may I pledge instead of a surety bond under 31 CFR part 225, and what value will...

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false What collateral may I pledge instead..., DEPARTMENT OF THE TREASURY BUREAU OF THE PUBLIC DEBT COLLATERAL ACCEPTABILITY AND VALUATION Acceptable Collateral and Its Valuation § 380.4 What collateral may I pledge instead of a surety bond under 31 CFR part...

Collateral Circles in Carotid Artery Occlusion. A Comparative Study between CW Doppler and contrast angiography

Energy Technology Data Exchange (ETDEWEB)

Giraldi, C; Marconi, F; Parenti, G; Lenzi, B; Canapicchi, R; Padolecchia, R

1986-01-01

In order to evaluate the presence and efficacy of the different collateral circles, 98 patients with occlusion of the internal carotid artery between its origin and the origin of the ophtalmic artery, has been examined. Before contrast angiography, each patients was submitted to a Doppler examination with test of compression on the exsternal and common carotid arteries. The information on the collateral circles (Willis and pre-Willis) deriving from the Doppler examination seems to be interesting and more accurate. On the contrary, angiography allows a better visualisation of the extention of intercranial circles. These data show that the Doppler and angiographic techniques are complementary one to the other in the study of the collateral circles.

The Prognostic Value of a Four-Dimensional CT Angiography-Based Collateral Grading Scale for Reperfusion Therapy in Acute Ischemic Stroke Patients.

Science.gov (United States)

Zhang, Sheng; Chen, Weili; Tang, Huan; Han, Quan; Yan, Shenqiang; Zhang, Xiaocheng; Chen, Qingmeng; Parsons, Mark; Wang, Shaoshi; Lou, Min

2016-01-01

Leptomeningeal collaterals, which affects tissue fate, are still challenging to assess. Four-dimensional CT angiography (4D CTA) originated from CT perfusion (CTP) provides the possibility of non-invasive and time-resolved assessment of leptomeningeal collateral flow. We sought to develop a comprehensive rating system to integrate the speed and extent of collateral flow on 4D CTA, and investigate its prognostic value for reperfusion therapy in acute ischemic stroke (AIS) patients. We retrospectively studied 80 patients with M1 ± internal carotid artery (ICA) occlusion who had baseline CTP before intravenous thrombolysis. The velocity and extent of collaterals were evaluated by regional leptomeningeal collateral score on peak phase (rLMC-P) and temporally fused intensity projections (tMIP) (rLMC-M) on 4D CTA, respectively. The cutoffs of rLMC-P and rLMC-M score for predicting good outcome (mRS score ≤ 2) were integrated to develop the collateral grading scale (CGS) (rating from 0-2). The CGS score was correlated with 3-months mRS score (non-recanalizers: ρ = -0.495, p = 0.01; recanalizers: ρ = -0.671, p < 0.001). Patients with intermediate or good collaterals (CGS score of 1 and 2) who recanalized were more likely to have good outcome than those without recanalization (p = 0.038, p = 0.018), while there was no significant difference in outcome in patients with poor collaterals (CGS score of 0) stratified by recanalization (p = 0.227). Identification of collaterals based on CGS may help to select good responders to reperfusion therapy in patients with large artery occlusion.

Immunohistochemical study of the growth factors, aFGF, bFGF, PDGF-AB, VEGF-A and its receptor (Flk-1) during arteriogenesis.

Science.gov (United States)

Wu, Song; Wu, Xiaoqiong; Zhu, Wu; Cai, Wei-Jun; Schaper, Jutta; Schaper, Wolfgang

2010-10-01

Growth factors are viewed as main arteriogenic stimulators for collateral vessel growth. However, the information about their native expression and distribution in collateral vessels is still limited. This study was designed to profile expression of acidic and basic FGF, platelet-derived growth factor (PDGF-AB) and vascular endothelial growth factor (VEGF-A) and its receptor, fetal liver kinase-1 (Flk-1) during arteriogenesis by confocal immunofluorescence in both dog ameroid constrictor model and rabbit arteriovenous shunt model of arteriogenesis. We found that: (1) in normal arteries (NA) in dog heart, aFGF, bFGF, and PDGF-AB all were mainly expressed in endothelial cells (EC) and media smooth muscle cells (SMC), but the expression of aFGF was very weak, with those of the other two being moderate; (2) in collateral arteries (CAs), aFGF, bFGF, and PDGF-AB all were significantly upregulated (P growth factors, aFGF, bFGF, and PDGF-AB are significantly upregulated in collateral vessels in dog heart, and enhanced VEGF-A and its receptor, Flk-1, are associated with rapid and lasting increased shear stress. These findings suggest that endogenous production of growth factors could be an important factor promoting collateral vessel growth.

7 CFR 762.142 - Servicing related to collateral.

Science.gov (United States)

2010-01-01

... necessary to properly service the loan. (4) Ensure the borrower does not convert loan security. (5) Ensure... collateral. (b) Partial releases. (1) A lender may release guaranteed loan security without FSA concurrence... applied as extra payments and not as a regular installment on the loan. (ii) The security item will be...

Standardization of MIP technique in three-dimensional CT portography: usefulness in evaluation of portosystemic collaterals in cirrhotic patients

International Nuclear Information System (INIS)

Kim, Jong Gi; Kim, Yong; Kim, Chang Won; Lee, Jun Woo; Lee, Suk Hong

2003-01-01

To assess the usefulness of three-dimensional CT portography using a standardized maximum intensity projection (MIP) technique for the evaluation of portosystemic collaterals in cirrhotic patients. In 25 cirrhotic patients with portosystemic collaterals, three-phase CT using a multide-tector-row helical CT scanner was performed to evaluate liver disease. Late arterial-phase images were transferred to an Advantage Windows 3.1 workstation (Gener Electric). Axial images were reconstructed by means of three-dimensional CT portography, using both a standardized and a non-standardized MIP technique, and the respective reconstruction times were determined. Three-dimensional CT portography with the standardized technique involved eight planes, namely the spleno-portal confluence axis (coronal, lordotic coronal, lordotic coronal RAO 30 .deg. C, and lordotic coronal LAO 30 .deg. C), the left renal vein axis (lordotic coronal), and axial MIP images (lower esophagus level, gastric fundus level and splenic hilum). The eight MIP images obtained in each case were interpreted by two radiologists, who reached a consensus in their evaluation. The portosystemic collaterals evaluated were as follows: left gastric vein dilatation; esophageal, paraesophageal, gastric, and splenic varix; paraumbilical vein dilatation; gastro-renal, spleno-renal, and gastro-spleno-renal shunt; mesenteric, retroperitoneal, and omental collaterals. The average reconstruction time using the non-standardized MIP technique was 11 minutes 23 seconds, and with the standardized technique, the time was 6 minutes 5 seconds. Three-dimensional CT portography with the standardized technique demonstrated left gastric vein dilatation (n=25), esophageal varix (n=18), paraesophageal varix (n=13), gastric varix (n=4), splenic varix (n=4), paraumbilical vein dilatation (n=4), gastro-renal shunt (n=3), spleno-renal shunt (n=3), and gastro-spleno-renal shunt (n=1). Using three-dimensional CT protography and the non

Collateral Projections Innervate the Mammillary Bodies and Retrosplenial Cortex: A New Category of Hippocampal Cells

Science.gov (United States)

O’Mara, Shane M.

2018-01-01

To understand the hippocampus, it is necessary to understand the subiculum. Unlike other hippocampal subfields, the subiculum projects to almost all distal hippocampal targets, highlighting its critical importance for external networks. The present studies, in male rats and mice, reveal a new category of dorsal subiculum neurons that innervate both the mammillary bodies (MBs) and the retrosplenial cortex (RSP). These bifurcating neurons comprise almost half of the hippocampal cells that project to RSP. The termination of these numerous collateral projections was visualized within the medial mammillary nucleus and the granular RSP (area 29). These collateral projections included subiculum efferents that cross to the contralateral MBs. Within the granular RSP, the collateral projections form a particularly dense plexus in deep Layer II and Layer III. This retrosplenial termination site colocalized with markers for VGluT2 and neurotensin. While efferents from the hippocampal CA fields standardly collateralize, subiculum projections often have only one target site. Consequently, the many collateral projections involving the RSP and the MBs present a relatively unusual pattern for the subiculum, which presumably relates to how both targets have complementary roles in spatial processing. Furthermore, along with the anterior thalamic nuclei, the MBs and RSP are key members of a memory circuit, which is usually described as both starting and finishing in the hippocampus. The present findings reveal how the hippocampus simultaneously engages different parts of this circuit, so forcing an important revision of this network. PMID:29527569

Traditional cardiovascular risk factors and coronary collateral circulation: Protocol for a systematic review and meta-analysis of case-control studies.

Science.gov (United States)

Xing, Zhenhua; Pei, Junyu; Tang, Liang; Hu, Xinqun

2018-04-01

Well-developed coronary collateral circulation usually results in fewer infarct size, improved cardiac function, and fewer mortality. Traditional coronary risk factors (diabetes, hypertension, and smoking) have some effects on coronary collateral circulation. However, the association between these risk factors and coronary collateral circulation are controversial. Given the confusing evidences regarding traditional cardiovascular risk factors on coronary collateral circulation, we performed this meta-analysis protocol to investigate the relationship between traditional risk factors of coronary artery disease and coronary collateral circulation. MEDINE, EMBASE, and Science Citation Index will be searched to identify relevant studies. The primary outcomes of this meta-analysis are well-developed coronary collateral circulation. Meta-analysis was performed to calculate the odds ratio (OR) and 95% confidence interval (CI) of traditional coronary risk factors (diabetes, smoking, hypertriton). Pooled ORs were computed as the Mantel-Haenszel-weighted average of the ORs for all included studies. Sensitivity analysis, quality assessment, publication bias analysis, and the Grading of Recommendations Assessment, Development and Evaluation approach (GRADE) will be performed to ensure the reliability of our results. This study will provide a high-quality synthesis of current evidence of traditional risk factors on collateral circulation. This conclusion of our systematic review and meta-analysis will provide evidence to judge whether traditional risk factors affects coronary collateral circulation.Ethics and dissemination: Ethical approval is not required because our systematic review and meta-analysis will be based on published data without interventions on patients. The findings of this study will be published in a peer-reviewed journal.

Does well maintained graft provide consistent return to play after medial ulnar collateral ligament reconstruction of the elbow joint in elite baseball players?

Science.gov (United States)

Park, Jin-Young; Oh, Kyung-Soo; Bahng, Seung-Chul; Chung, Seok-Won; Choi, Jin-Ho

2014-06-01

Several studies have reported the clinical outcomes of medial ulnar collateral ligament (MUCL) reconstruction of the elbow joint in throwing athletes, including the rate of return to sports. However, little has been known about the imaging outcomes after MUCL reconstruction. The aim of this study is to report the clinical and imaging outcomes after MUCL reconstruction using figure of eight fashion in the elite and professional baseball players. This study included 17 baseball players, who underwent MUCL reconstruction between July 2007 and May 2010. The average follow-up period was 48.6 months. Imaging assessment consisted of preoperative plain and stress radiographs, magnetic resonance imaging, and postoperative serial ultrasonography. The clinical assessments were composed of visual analogue scale (VAS) for pain, range of motion, and the Conway scale. The mean VAS score was 6.4 (range, 3 to 8) preoperatively and 2.2 (range, 0 to 4) postoperatively (p returned to sports at the same or higher level compared to preinjury. Serial ultrasonography revealed well-maintained grafts at 3 and 12 months in all of the players. Five out of 17 players showed decreased echogenecity in the common flexor tendon at 3 months, which was considered as remaining tissue swelling and resolved completely at 12 months. All grafts are well-maintained until 12-months based on the ultrasonographic findings, although only 53% of the players returned to preinjury level.

Correlation between GDF-15 gene polymorphism and the formation of collateral circulation in acute ST-elevation myocardial infarction

Directory of Open Access Journals (Sweden)

Xiao-ping Chen

Full Text Available Summary Objective: To explore the correlation between growth differentiation factor 15 (GDF-15 -3148C/G polymorphism and the formation of collateral circulation in acute ST-elevation myocardial infarction (STEMI in Han population of Taiyuan area. Method: The present study included 92 STEMI patients and 56 normal controls based on coronary angiography; STEMI group was divided into collateral group and non-collateral group according to Rentrop's grading method. Polymerase chain reaction (PCR and DNA sequencing methods were used to detect and analyze the GDF-15 -3148C/G polymorphism in all participants. Results: There was significant difference in GDF-15 -3148C/G CC and GC distribution between STEMI group and control group (p=0.009; the allele frequencies between these two groups were also significant different (p=0.016; and the risk genotype for STEMI was CC with increased OR=2.660. For STEMI group, GDF-15 -3148C/G CC and GC distribution was also significantly different between patients with and without collateral (p=0.048, and CC genotype significantly promote the formation of collateral circulation. However, there were no significant differences in allele frequencies between these two subgroups of STEMI. Conclusion: There was correlation between GDF-15-3148C/G polymorphism and the formation of collateral circulation in patients with acute STEMI.

The challenges of measuring in vivo knee collateral ligament strains using ultrasound.

Science.gov (United States)

Slane, Laura C; Slane, Josh A; D'hooge, Jan; Scheys, Lennart

2017-08-16

Ultrasound-based methods have shown promise in their ability to characterize non-uniform deformations in large energy-storing tendons such as the Achilles and patellar tendons, yet applications to other areas of the body have been largely unexplored. The noninvasive quantification of collateral ligament strain could provide an important clinical metric of knee frontal plane stability, which is relevant in ligament injury and for measuring outcomes following total knee arthroplasty. In this pilot cadaveric experiment, we investigated the possibility of measuring collateral ligament strain with our previously validated speckle-tracking approach, but encountered a number of challenges during both data acquisition and processing. Given the clinical interest in this type of tool, and the fact that this is a developing area of research, the goal of this article is to transparently describe this pilot study, both in terms of methods and results, while also identifying specific challenges to this work and areas for future study. Some challenges faced relate generally to speckle-tracking of soft tissues (e.g. the limitations of using a 2D imaging modality to characterize 3D motion), while others are specific to this application (e.g. the small size and complex anatomy of the collateral ligaments). This work illustrates a clear need for additional studies, particularly relating to the collection of ground-truth data and more thorough validation work. These steps will be critical prior to the translation of ultrasound-based measures of collateral ligament strains into the clinic. Copyright © 2017 Elsevier Ltd. All rights reserved.

FLAIR vascular hyperintensities and dynamic 4D angiograms for the estimation of collateral blood flow in posterior circulation occlusion

International Nuclear Information System (INIS)

Foerster, Alex; Wenz, Holger; Kerl, Hans Ulrich; Al-Zghloul, Mansour; Habich, Sonia; Groden, Christoph

2014-01-01

The objectives of this paper are to assess collateral blood flow in posterior circulation occlusion by MRI-based approaches (fluid-attenuated inversion recovery (FLAIR) vascular hyperintensities (FVHs), collateralization on dynamic 4D angiograms) and investigate its relation to ischemic lesion size and growth. In 28 patients with posterior cerebral artery (PCA) and 10 patients with basilar artery (BA) occlusion, MRI findings were analyzed, with emphasis on distal FVH and collateralization on dynamic 4D angiograms. In PCA occlusion, distal FVH was observed in 18/29 (62.1 %), in BA occlusion, in 8/10 (80 %) cases. Collateralization on dynamic 4D angiograms was graded 1 in 8 (27.6 %) patients, 2 in 1 (3.4 %) patient, 3 in 12 (41.4 %) patients, and 4 in 8 (27.6 %) patients with PCA occlusion and 0 in 1 (10 %) patient, 2 in 3 (30 %) patients, 3 in 1 (10 %) patient, and 4 in 5 (50 %) patients with BA occlusion. FVH grade showed neither correlation with initial or follow-up diffusion-weighted image (DWI) lesion size nor DWI-perfusion-weighted imaging (PWI) mismatch ratio. Collateralization on dynamic 4D angiograms correlated inversely with initial DWI lesion size and moderately with the DWI-(PWI) mismatch ratio. The combination of distal FVH and collateralization grade on dynamic 4D angiograms correlated inversely with initial as well as follow-up DWI lesion size and highly with the DWI-PWI mismatch ratio. In posterior circulation occlusion, FVH is a frequent finding, but its prognostic value is limited. Dynamic 4D angiograms are advantageous to examine and graduate collateral blood flow. The combination of both parameters results in an improved characterization of collateral blood flow and might have prognostic relevance. (orig.)

46 CFR 308.526 - Certificate for repayment of decrease of collateral deposit fund, Form MA-306.

Science.gov (United States)

2010-10-01

... 46 Shipping 8 2010-10-01 2010-10-01 false Certificate for repayment of decrease of collateral... TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Cargo Insurance Ii-Open Policy War Risk Cargo Insurance § 308.526 Certificate for repayment of decrease of collateral deposit fund, Form MA-306. The...

The Power of Collateral : How Problems in Securing Transections Limit Private Credit from Movable Property

OpenAIRE

Fleisig, Heywood

1995-01-01

In many developing countries, faulty laws and regulations make it hard to use livestock, machines, equipment, standing crops, and other movable property as collateral. The resulting constraints on access to credit hurt economies. In Bolivia, for example, a faulty legal and regulatory framework for the use of movable property as collateral has led to a loss in GDP estimated at between 5 and...

A novel method to assess pial collateralization from stroke perfusion MRI: subdividing Tmax into anatomical compartments

International Nuclear Information System (INIS)

Potreck, Arne; Seker, Fatih; Hoffmann, Angelika; Pfaff, Johannes; Bendszus, Martin; Heiland, Sabine; Pham, Mirko; Nagel, Simon

2017-01-01

To develop and validate a quantitative and observer-independent method to evaluate pial collateral circulation by DSC-perfusion MRI and test whether this novel method delivers diagnostic information which is redundant to or independent from conventional penumbra imaging by the mismatch approach. We retrospectively identified 47 patients with M1 occlusion who underwent MR diffusion/perfusion imaging and mechanical thrombectomy at our facility. By automated registration and segmentation, T max delays were attributed specifically to the pial, cortical and parenchymal compartments. The resulting pial volumes at delay were defined as the pial T max map-assessed collateral score (TMACS) and correlated with gold standard digital subtraction angiography (DSA). Mismatch ratio was assessed by conventional penumbra defining MRI criteria. Strong correlation was found between TMACS and angiographically assessed collateral score (Pearson ρ = -0.74, p < 0.001). In multiple logistic regression, both good collaterals according to TMACS [OR 4.3 (1.1-19, p = 0.04)] and mismatch ratio ≥ 3.5 [OR 12.3 (1.88-249, p = 0.03)] were independent predictors of favourable clinical outcome. Perfusion delay in the pial compartment, as evaluated by TMACS, closely reflects the extent of pial collaterals in gold-standard DSA. TMACS and mismatch ratio were found to be complementary predictors of a favourable clinical outcome, each adding independent predictive information. (orig.)

COLLATERAL'S IMPORTANCE IN SMES FINANCING: WHAT IS THE BANKS' RESPONSE? SOME EVIDENCE FOR ROMANIA

OpenAIRE

Badulescu Daniel; Petria Nicolae

2011-01-01

Searching for funding, SMEs' managers face various obstacles arising from information asymmetry, lack of experience, severe market conditions, and insufficient or unsatisfactory collaterals for banks (OECD 2006; Badulescu and Badulescu 2010; OECD 2000 and 2004; Lin and Sun 2006; Toivanen and Cresy, 2000). The collateral issue is extensively discussed in literature - preventing moral hazard, the alignment the interests (Stiglitz and Weiss 1981:393-410; Chan and Thakor 1987:345-363; Jiménez and...

46 CFR 308.525 - Application for decrease in amount of cash collateral fund, Form MA-305.

Science.gov (United States)

2010-10-01

... 46 Shipping 8 2010-10-01 2010-10-01 false Application for decrease in amount of cash collateral... TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Cargo Insurance Ii-Open Policy War Risk Cargo Insurance § 308.525 Application for decrease in amount of cash collateral fund, Form MA-305. Application for...

Relationship of myocardial hibernation, scar, and angiographic collateral flow in ischemic cardiomyopathy with coronary chronic total occlusion.

Science.gov (United States)

Wang, Li; Lu, Min-Jie; Feng, Lei; Wang, Juan; Fang, Wei; He, Zuo-Xiang; Dou, Ke-Fei; Zhao, Shi-Hua; Yang, Min-Fu

2018-03-07

The relationship between myocardial viability and angiographic collateral flow is not fully elucidated in ischemic cardiomyopathy (ICM) with coronary artery chronic total occlusion (CTO). We aimed to clarify the relationship between myocardial hibernation, myocardial scar, and angiographic collateral flow in these patients. Seventy-one consecutive ICM patients with 122 CTOs and 652 dysfunctional segments within CTO territories were retrospectively analyzed. Myocardial hibernation (perfusion-metabolism mismatch) and the extent of 18 F-fluorodeoxyglucose (FDG) abnormalities were assessed using 99m Tc-sestamibi and 18 F-FDG imaging. Myocardial scar was evaluated by late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging. Collateral flow observed on coronary angiography was assessed using Rentrop classification. In these patients, neither the extent nor frequency of myocardial hibernation or scar was related to the status of collateral flow. Moreover, the matching rate in determining myocardial viability was poor between any 2 imaging indices. The extent of 18 F-FDG abnormalities was linearly related to the extent of LGE rather than myocardial hibernation. Of note, nearly one-third (30.4%) of segments with transmural scar still had hibernating tissue. Hibernation and non-transmural scar had higher sensitivity (63.0% and 66.7%) than collateral flow (37.0%) in predicting global functional improvement. Angiographic collateral cannot accurately predict myocardial viability, and has lower sensitivity in prediction of functional improvement in CTO territories in ICM patients. Hence, assessment of myocardial viability with non-invasive imaging modalities is of importance. Moreover, due to the lack of correlation between myocardial hibernation and scar, these two indices are complementary but not interchangeable.

Targeting pathogen metabolism without collateral damage to the host

NARCIS (Netherlands)

Haanstra, J.R.; Gerding, A.; Dolga, A.M.; Sorgdrager, F.J.H.; Buist-Homan, M.; du Toit, F.; Faber, K.N.; Holzhütter, H.-G.; Szöör, B.; Matthews, K.R.; Snoep, J.L.; Westerhoff, H.V.; Bakker, B.M.

2017-01-01

The development of drugs that can inactivate disease-causing cells (e.g. cancer cells or parasites) without causing collateral damage to healthy or to host cells is complicated by the fact that many proteins are very similar between organisms. Nevertheless, due to subtle, quantitative differences

Are the anatomy textbooks wrong? A clinical patho-anatomic study of foveal vessels in the round ligament of the hip.

Science.gov (United States)

Barrington, John W; Sodhi, Nipun; Ali, Muzaffar; Khlopas, Anton; Sultan, Assem A; Kee, James R; Holmes, Kristopher A; Hariri, Omar; Newman, Jared M; Mont, Michael A

2017-12-01

The foveal vessels of the ligamentum teres are an anterior branch of the posterior division of the obturator artery, providing blood to the capitis of the femoral head. However, the basic anatomic description of foveal vasculature in the ligamentum teres of the hip is widely variable, with some studies reporting that the vessels are not patent in roughly one third of all adults. Therefore, the purpose of this study was to evaluate the status of foveal vessels in primary total hip arthroplasty (THA) patients. Specifically, we evaluated: (I) if the foveal vessels were intact; and we (II) correlated foveal vessel status with (i) patient demographics, including gender and age; as well as (ii) perioperative data, such as operative time and blood loss. The macroscopic status of the foveal vessels in the ligamentum teres femoris was documented in 266 patients at the time of primary unilateral THA performed between August 2015 and April 2017. The vessels were considered to be intact if active bleeding was directly visible from the acetabular stump of the severed ligamentum teres femoris. Demographics including age, gender, and preoperative diagnosis were collected. The perioperative outcome variables included estimated blood loss (EBL) and operative time. Foveal vessel status defined as intact or not intact, was also correlated with patient demographics and perioperative data. A student's t -test was used to compare the continuous variables and a chi square test was used for categorical variables. The foveal vessels were intact in 161 patients (61%) and not intact in 105 patients (39%). The mean age for patients with intact foveal vessels was found to be 64 years (range, 18 to 94 years) vs. 65 years (range, 29 to 94 years) (P>0.05) for not intact. No correlation was found between preoperative diagnosis, gender, operative time, and EBL and foveal vessel status. The results of this clinical patho-anatomic study of the foveal vessels in the ligamentum teres femoris of the hip

PRINSIP 6C (CHARACTER, CAPACITY, CAPITAL, CONDITION OF ECONOMY, COLLATERAL DAN CONSTRAINT DALAM WIRAUSAHA MAHASISWA

Directory of Open Access Journals (Sweden)

Henny Sri Astuty

2015-04-01

Full Text Available Abstrak: Prinsip 6C (Character, Capacity, Capital, Condition of Economy, Collateral dan Constraint dalam Wirausaha Mahasiswa. Kegiatan wirausaha yang sekarang banyak dilakukan oleh mahasiswa memiliki sisi positif maupun negatif, dari yang berhasil kuliah dan wirausahanya hingga yang gagal semuanya. Untuk ini diperlukan pemahaman tentang prinsip enam C (character, capacity, capital, condition of economy, collateral and constraint yang akan membantu mahasiswa sebagai bekal dalam melakukan kegiatan usahanya. Banyak faktor yang diperoleh dalam prinsip ini yaitu aspek manajemen, pemasaran, produksi, dan keuangan. Kata Kunci: prinsip 6c, wirausaha, mahasiswa Abstract: 6C Principles (Character, Capacity, Capital, Condition of Economy, Collateral and Constraint in Entrepreneurial Students. Entrepreneurial activity that is widely performed by students has two different stories. Some of them are successful on the other hand, the rest of them are fail. Accordingly, it is required an understanding of the 6C principles of the six C (character, capacity, capital, condition of economy, collateral and constraints which will help the students as a preparation in conducting their business activities. Many factors obtained in this principle namely: management, marketing, production, and financial aspects. Keywords: 6C principles, entrepreneurs, students

The Features of Extrahepatic Collateral Arteries Related to Hepatic Artery Occlusion and Benefits in the Transarterial Management of Liver Tumors