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Sample records for acute stent recoil

  1. Acute stent recoil in the left main coronary artery treated with additional stenting.

    Science.gov (United States)

    Battikh, Kais; Rihani, Riadh; Lemahieu, Jean Michel

    2003-01-01

    We report a case of acute stent recoil occurring after the stenting of an ostial left main coronary artery lesion. The marked recoil after high-pressure balloon inflation confirmed that the radial force of the first stent was unable to ensure vessel patency. The addition of a second stent provided the necessary support to achieve a good final result. This case illustrates a possible complication of aorto-ostial angioplasty that could be treated with double stenting. PMID:12499528

  2. Comparison of in vivo acute stent recoil between the bioabsorbable everolimus-eluting coronary stent and the everolimus-eluting cobalt chromium coronary stent: insights from the ABSORB and SPIRIT trials

    DEFF Research Database (Denmark)

    Tanimoto, Shuzou; Serruys, Patrick W; Thuesen, Leif;

    2007-01-01

    OBJECTIVES: This study sought to evaluate and compare in vivo acute stent recoil of a novel bioabsorbable stent and a metallic stent. BACKGROUND: The bioabsorbable everolimus-eluting coronary stent (BVS) is composed of a poly-L-lactic acid backbone, coated with a bioabsorbable polymer containing...... the antiproliferative drug, everolimus, and expected to be totally metabolized and absorbed in the human body. Because the BVS is made from polymer, it may have more acute recoil than metallic stents in vivo. METHODS: A total of 54 patients, who underwent elective stent implantation for single de novo native coronary...... artery lesions, were enrolled: 27 patients treated with the BVS and 27 patients treated with the everolimus-eluting cobalt chromium stent (EES). Acute absolute recoil, assessed by quantitative coronary angiography, was defined as the difference between mean diameter of the last inflated balloon...

  3. Acute stent thrombosis after bifurcation stenting with the crush technique visualized with 64-slice computed tomography

    DEFF Research Database (Denmark)

    Kristensen, T.S.; Engstrom, T.; Kofoed, Klaus Fuglsang

    2008-01-01

    Acute stent thrombosis remains a potential complication after stent implantation. With the introduction of electrocardiographic gated multidetector row computed tomography (MDCT), a new nonnvasive imaging modality has become available that may contribute to the detection of complications after co...... complex interventional procedures. We present a case where CT angiography was performed just prior to the clinical presentation of acute stent thrombosis in a 55-year-old male who was treated with the crush technique in a bifurcation lesion Udgivelsesdato: 2008/7...

  4. Acute stent thrombosis after primary percutaneous coronary intervention

    DEFF Research Database (Denmark)

    Clemmensen, Peter; Wiberg, Sebastian; Van't Hof, Arnoud;

    2015-01-01

    OBJECTIVES: This study sought to determine clinical, procedural, and treatment factors associated with acute stent thrombosis (AST) in the EUROMAX (European Ambulance Acute Coronary Syndrome Angiography) trial. BACKGROUND: Bivalirudin started during transport for primary percutaneous coronary int...

  5. Rescue coronary stenting in acute myocardial infarction

    Science.gov (United States)

    Barbieri, Enrico; Meneghetti, Paolo; Molinari, Gionata; Zardini, Piero

    1996-01-01

    Failed rescue coronary angioplasty is a high risk situation because of high mortality. Coronary stent has given us the chance of improving and maintaining the patency of the artery. We report our preliminary experience of rescue stenting after unsuccessful coronary angioplasty.

  6. Is Acute Carotid Artery Stent Thrombosis an Avoidable Complication?

    Science.gov (United States)

    Köklü, Erkan; Yüksel, İsa Öner; Bayar, Nermin; Arslan, Şakir

    2015-10-01

    The most serious complication of carotid artery stenting (CAS) is acute carotid artery stent thrombosis (ACAST). ACAST is a very rare complication, but it may lead to dramatic and catastrophic consequences. The most important cause is inadequate or ineffective antiaggregant therapy. It is very important to identify, before CAS, those patients who might be candidates for ACAST and to start antiplatelet therapy for them. Testing patients who are candidates for CAS for acetylsalicylic acid and clopidogrel resistance may prevent this complication. PMID:26303788

  7. One year clinical follow up of paclitaxel eluting stents for acute myocardial infarction compared with sirolimus eluting stents

    NARCIS (Netherlands)

    S.H. Hofma (Sjoerd); M. Valgimigli (Marco); C.A.G. van Mieghem (Carlos); P.J. de Feyter (Pim); P.W.J.C. Serruys (Patrick); W.J. van der Giessen (Wim); P.P.T. de Jaegere (Peter); E.S. Regar (Eveline); G. Sianos (Georgios); J. Aoki (Jiro); G.A. Rodriguez-Granillo (Gaston); E.P. McFadden (Eugene); A.T.L. Ong (Andrew); R.T. van Domburg (Ron)

    2005-01-01

    textabstractOBJECTIVE: To compare clinical outcome of paclitaxel eluting stents (PES) versus sirolimus eluting stents (SES) for the treatment of acute ST elevation myocardial infarction. DESIGN AND PATIENTS: The first 136 consecutive patients treated exclusively with PES in the setting of primary pe

  8. Acute Carotid Artery Stent Thrombosis Due to Dual Antiplatelet Resistance

    Energy Technology Data Exchange (ETDEWEB)

    Köklü, Erkan, E-mail: drerkankoklu@gmail.com; Arslan, Şakir; Yüksel, İsa Öner; Bayar, Nermin [Antalya Education and Research Hospital, Clinic of Cardiology (Turkey); Koç, Pınar [Antalya Education and Research Hospital, Clinic of Radiology (Turkey)

    2015-08-15

    Carotid artery stenting (CAS) is a revascularization modality that is an alternative to carotid endarterectomy. The efficacy of CAS in primary and secondary prevention from ischemic stroke has been demonstrated in various trials. Acute thrombosis of CAS is a rare complication that can lead to dramatic and catastrophic consequences. We discuss a case of acute CAS thrombosis in a patient who had previously undergone successful CAS. CAS was performed in a 73-year-old man who had had dysarthria lasting 2 weeks with 95 % stenosis in his left internal carotid artery. An acute cerebrovascular event resulting in right-sided hemiplegia developed 24 h after the procedure. Computed tomographic carotid angiography revealed complete occlusion of the stent with thrombus. The cause of stent thrombosis was thought to be antiaggregant resistance to both acetylsalicylic acid and clopidogrel. The most important cause of acute CAS thrombosis is inadequate or ineffective antiaggregant therapy. Evaluating patients who are candidates for CAS for acetylsalicylic acid and clopidogrel resistance may preclude this complication.

  9. Acute Carotid Artery Stent Thrombosis Due to Dual Antiplatelet Resistance

    International Nuclear Information System (INIS)

    Carotid artery stenting (CAS) is a revascularization modality that is an alternative to carotid endarterectomy. The efficacy of CAS in primary and secondary prevention from ischemic stroke has been demonstrated in various trials. Acute thrombosis of CAS is a rare complication that can lead to dramatic and catastrophic consequences. We discuss a case of acute CAS thrombosis in a patient who had previously undergone successful CAS. CAS was performed in a 73-year-old man who had had dysarthria lasting 2 weeks with 95 % stenosis in his left internal carotid artery. An acute cerebrovascular event resulting in right-sided hemiplegia developed 24 h after the procedure. Computed tomographic carotid angiography revealed complete occlusion of the stent with thrombus. The cause of stent thrombosis was thought to be antiaggregant resistance to both acetylsalicylic acid and clopidogrel. The most important cause of acute CAS thrombosis is inadequate or ineffective antiaggregant therapy. Evaluating patients who are candidates for CAS for acetylsalicylic acid and clopidogrel resistance may preclude this complication

  10. Life-threatening Cerebral Edema Caused by Acute Occlusion of a Superior Vena Cava Stent

    Energy Technology Data Exchange (ETDEWEB)

    Sofue, Keitaro, E-mail: keitarosofue@yahoo.co.jp; Takeuchi, Yoshito, E-mail: yotake62@qg8.so-net.ne.jp; Arai, Yasuaki, E-mail: arai-y3111@mvh.biglobe.ne.jp [National Cancer Center Hospital, Department of Diagnostic Radiology (Japan); Sugimura, Kazuro, E-mail: sugimura@med.kobe-u.ac.jp [Kobe University, Department of Radiology, Graduate School of Medicine (Japan)

    2013-02-15

    A71-year-old man with advanced lung cancer developed a life-threatening cerebral edema caused by the acute occlusion of a superior vena cava (SVC) stent and was successfully treated by an additional stent placement. Although stent occlusion is a common early complication, no life-threatening situations have been reported until now. Our experience highlights the fact that acute stent occlusion can potentially lead to the complete venous shutdown of the SVC, resulting in life-threatening cerebral edema, after SVC stent placement. Immediate diagnosis and countermeasures are required.

  11. The Evolution and Current Utility of Esophageal Stent Placement for the Treatment of Acute Esophageal Perforation.

    Science.gov (United States)

    Herrera, Argenis; Freeman, Richard K

    2016-08-01

    Esophageal stent placement was used primarily for the treatment of malignant strictures until the development of a new generation of biomaterials allowed the production of easily removable, occlusive stents in 2001. Since then, thoracic surgeons have gained experience using esophageal stents for the treatment of acute esophageal perforation. As part of a hybrid treatment strategy, including surgical drainage of infected spaces, enteral nutrition, and aggressive supportive care, esophageal stent placement has produced results that can exceed those of traditional surgical repair. This review summarizes the evolution of esophageal stent use for acute perforation and provides evidence-based recommendations for the technique. PMID:27427525

  12. Combined use of transmyocardial stents with gene therapy in the treatment of acute myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    王永武

    2006-01-01

    Objective To determine the efficacy of combined use of transmyocardial stent with gene therapy to treat acute myocardial infarction in porcine model. Methods 24 Chinese mini swines have been devided into 4 groups randomly: group myocardial infarction (group MI n1 = 6), group transmyocardial stent (group ST n2 = 6) , group vascular endothelial growth factor (group VEGF n3 = 6) , group transmyocardial stent and VEGF (group ST + VEGF n4 = 6). In group MI,acute myocardial infarc-

  13. Stent-graft repair for acute traumatic thoracic aortic rupture.

    Science.gov (United States)

    Neuhauser, B; Czermak, B; Jaschke, W; Waldenberger, P; Fraedrich, G; Perkmann, R

    2004-12-01

    Traumatic rupture of the thoracic aorta is potentially life-threatening and leads to death in 75 to 90 per cent of cases at the time of injury. In high-risk patients, as traumatic injuries of the aorta combine with multiple associated injuries, endoluminal repair is now reported as a promising therapeutic strategy with encouraging results. This study determined the outcome of patients with traumatic thoracic aortic injury treated endovascularly during the past 7 years at our institution. Thirteen patients, 11 males and 2 females (mean age, 39 years; range, 19-82), with traumatic rupture of the otherwise unremarkable descending aorta (10 acute, 3 chronic), out of a series of 64 endovascular thoracic stent-graft procedures, were treated by implantation of Talent (n = 8), Vanguard (n = 5), and Excluder (n = 2) self-expanding devices between January 1996 and August 2003. The immediate technical success rate was 92 per cent (12/13). One patient showed a proximal endoleak type I, which was treated successfully by an additional stent-graft procedure. Secondary success rate was 100 per cent. The mortality rate was 0 per cent. Two additional stent-graft procedures were performed due to type I endoleaks after 18 and 28 months. There was no other intervention-related morbidity or mortality during the mean follow-up time of 26.4 months' (range, 6-86). Endovascular stent-graft repair of traumatic thoracic aortic injuries is a safe, effective, and low-morbidity alternative to open thoracic surgery and has promising midterm results.

  14. Acute Cholecystitis Caused by Malignant Cystic Duct Obstruction: Treatment with Metallic Stent Placement

    International Nuclear Information System (INIS)

    We report the successful management of acute cholecystitis using cystic duct stent placement in 3 patients with inoperable malignant cystic duct obstruction (2 cholangiocarcinoma and 1 pancreatic carcinoma). All patients underwent stent placement in the bile duct, using an uncovered stent in 2 and a covered stent in 1, to relieve jaundice occurring 8-184 days (mean 120 days) before the development of acute cholecystitis. The occluded cystic duct was traversed by a microcatheter and a stent was implanted 4-17 days (mean 12 days) after cholecystostomy. Acute cholecystitis was improved after the procedure in all patients. Two patients died 3 and 10 months later, while 1 has survived without cholecystitis for 22 months after the procedure to date.

  15. Acute Duodenal Obstruction After Percutaneous Placement of Metallic Biliary Stents: Peroral Treatment with Enteral Stents

    International Nuclear Information System (INIS)

    Three patients with malignant biliary obstruction were treated with placement of metallic biliary stents. Two patients had known partial duodenal stenosis but had no symptoms of gastrointestinal obstruction. The patients developed symptomatic duodenal obstruction early after biliary metallic stent placement. The symptomatic duodenal obstructions were successfully treated with peroral placement of duodenal stents, which obviated the need for surgical intervention

  16. ST-elevated acute myocardial infarction happening 1 month post stent implantation: late thrombosis in-stents or new lesions?

    Institute of Scientific and Technical Information of China (English)

    SONG Guang-yuan; YANG Yue-jin; XU Bo; LI Jian-jun; GAO Run-lin; QIAO Shu-bin; YUAN Jin-qing; TANG Yi-da; YOU Shi-jie; PEI Han-jun; ZHAO Zhen-yan; WANG Xi-mei; WU Yong-jian

    2009-01-01

    Background ST-elevated acute myocardial infarction (STEAMI) happening in the first month post percutaneous coronary intervention (PCI) is almost related to acute thrombosis or subacute thrombosis in-stents. This study aimed to investigate the possible causes of myocardial infarction one month later. Methods Patients who had a history of successful PCI, and received coronary angiography or re-PCI due to STEAMI were included in this study. The AMI-related lesions and previous angiographic findings such as the number of lesions, the degree of the stenosis, the type of stents and acute results of last PCI were recorded. If the AMI-related lesion was localized in-stents or at the edge of stents (distance apart from the edge <5 mm), it was defined to be late thrombosis; otherwise as a new-lesion induced AMI. Results One hundred and ninety-two patients aged 40-79 years were included in this study. New lesions, as the cause of STEAMI, were found in 144 patients (Group A, 75%), and late thrombosis in 48 patients (Group B, 25%). Almost all newly built thromboses were found at the sites of previous insignificant lesions (diameter stenosis <50%). There was a significant difference in the average time from previous PCI to AMI ((30.1+12.4) vs (20.3+11.9) months) between the two groups. Diabetes mellitus (DM) and drug-eluting stent (DES) utilization were associated with markedly higher morbidity of late thrombosis in adjusted Logistic regression (hazard ratio (HR) 3.4, 95% confidence interval (CI) 1.1-10.9 and 5.3, 95% CI 1.1-26.5). Conclusions STEAMIs happening 1 month after PCI are more likely to develop from previous insignificant lesion rupture than from late thrombosis in-stents. Moreover, DM and DES are associated with the high incidence of latethrombosis, which may indicate that intensive antiplatelet therapy should be considered in patients with diabetes.

  17. Hepatic artery stent-grafts for the emergency treatment of acute bleeding

    Energy Technology Data Exchange (ETDEWEB)

    Bellemann, Nadine, E-mail: nadine.bellemann@med.uni-heidelberg.de [Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, INF 110, 69120 Heidelberg (Germany); Sommer, Christof-Matthias; Mokry, Theresa; Kortes, Nikolas; Gnutzmann, Daniel; Gockner, Theresa; Schmitz, Anne [Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, INF 110, 69120 Heidelberg (Germany); Weitz, Jürgen [Department of Surgery, University Hospital Heidelberg, INF 110, 69120 Heidelberg (Germany); Department for Visceral, Thoracic and Vascular Surgery at the University Hospital, Technical University Dresden (Germany); Kauczor, Hans-Ulrich; Radeleff, Boris; Stampfl, Ulrike [Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, INF 110, 69120 Heidelberg (Germany)

    2014-10-15

    Highlights: • We report our experiences with stent-grafts for the treatment of acute hemorrhage from the hepatic artery or the stump of the gastroduodenal artery. • The technical success of stent-graft implantation was 88%. • The bleeding ceased immediately after stent-graft implantation in 88%. • The complication rate was 21%. - Abstract: Purpose: We evaluated the technical success and clinical efficacy of stent-graft implantation for the emergency management of acute hepatic artery bleeding. Methods: Between January 2010 and July 2013, 24 patients with hemorrhage from the hepatic artery were scheduled for emergency implantation of balloon expandable stent-grafts. The primary study endpoints were technical and clinical success, which were defined as successful stent-graft implantation with sealing of the bleeding site at the end of the procedure, and cessation of clinical signs of hemorrhage. The secondary study endpoints were complications during the procedure or at follow-up and 30-day mortality rate. Results: In 23 patients, hemorrhage occurred after surgery, and in one patient hemorrhage occurred after trauma. Eight patients had sentinel bleeding. In most patients (n = 16), one stent-graft was implanted. In six patients, two overlapping stent-grafts were implanted. The stent-grafts had a target diameter between 4 mm and 7 mm. Overall technical success was 88%. The bleeding ceased after stent-graft implantation in 21 patients (88%). The mean follow-up was 137 ± 383 days. In two patients, re-bleeding from the hepatic artery occurred during follow-up after 4 and 29 days, respectively, which could be successfully treated by endovascular therapy. The complication rate was 21% (minor complication rate 4%, major complication rate 17%). The 30-day mortality rate was 21%. Conclusions: Implantation of stent-grafts in the hepatic artery is an effective emergency therapy and has a good technical success rate for patients with acute arterial hemorrhage.

  18. Biolimus-eluting stents with biodegradable polymer versus bare-metal stents in acute myocardial infarction

    DEFF Research Database (Denmark)

    Räber, Lorenz; Kelbæk, Henning; Taniwaki, Masanori;

    2014-01-01

    BACKGROUND: This study sought to determine whether the 1-year differences in major adverse cardiac event between a stent eluting biolimus from a biodegradable polymer and bare-metal stents (BMSs) in the COMFORTABLE trial (Comparison of Biolimus Eluted From an Erodible Stent Coating With Bare Meta......, BES continued to improve cardiovascular events compared with BMS beyond 1 year. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NTC00962416....

  19. Microvascular Coronary Flow Comparison in Acute Myocardial Infarction Angioplasty treated with a mesh covered stent (MGUARD Stent) versus Bare Metal Stent

    Energy Technology Data Exchange (ETDEWEB)

    Lindefjeld, Dante S., E-mail: dslindef@puc.cl [Hospital Clínico, Pontificia Universidad Católica de Chile (Chile); Hospital Dr. Sótero del Río, Santiago-Chile (Chile); Guarda, Eduardo [Hospital Clínico, Pontificia Universidad Católica de Chile (Chile); Méndez, Manuel [Hospital Clínico, Pontificia Universidad Católica de Chile (Chile); Hospital Dr. Sótero del Río, Santiago-Chile (Chile); Martínez, Alejandro [Hospital Clínico, Pontificia Universidad Católica de Chile (Chile); Pérez, Osvaldo [Hospital Clínico, Pontificia Universidad Católica de Chile (Chile); Hospital Dr. Sótero del Río, Santiago-Chile (Chile); Fajuri, Alejandro; Marchant, Eugenio [Hospital Clínico, Pontificia Universidad Católica de Chile (Chile); Aninat, Mauricio; Torres, Humberto [Hospital Dr. Gustavo Fricke, Viña del Mar-Chile (Chile); Dussaillant, Gastón [Hospital Clínico Universidad de Chile, Santiago-Chile (Chile)

    2013-01-15

    Background: Distal embolization of thrombus/platelet aggregates decreases myocardial reperfusion during primary percutaneous coronary intervention (PCI), and is associated with worse immediate and long-term prognosis of patients with ST-elevation myocardial infarction (STEMI). Objective: Assess the efficacy of a mesh covered stent (MGuard™ stent, MGS) in preventing distal embolization and microvascular reperfusion impairment during primary PCI, compared with a bare metal stent (BMS). Methods: Forty patients with STEMI referred for primary PCI were randomized for stenting the culprit lesion with the MGS (n = 20) or a BMS (n = 20). Blinded experts performed off-line measurements of angiographic epicardial and microvascular reperfusion criteria: TIMI flow grade, myocardial blush, corrected TIMI frame count (cTFC). Results: At baseline clinical, angiographic and procedural variables were not different between groups. Post PCI TIMI flow grade was similar in both groups. We observed better myocardial Blush grade in group MGS compared to BMS (median value 3.0 vs 2.5, 2p = 0.006) and cTFC (mean cTFC: MGS 19.65 ± 4.07 vs BMS 27.35 ± 7.15, 2p < 0.001, cTFC mean difference MGS-BMS: 7.7, CI 95%: 3.94 to 11.46). MGS stent group had a higher percentage of successful angioplasty (cTFC ≤ 23: MGS 85% vs BMS 30%, 2p < 0.001). We had two cases of acute stent thrombosis (one for each group) at 30 days follow up, but no clinical events at 6 months follow up. Conclusions: In this exploratory study, MGS significantly improved microvascular reperfusion criteria compared with a BMS in primary PCI. However its safety and impact on clinical outcomes should be verified in larger randomized clinical trials.

  20. Emergency placement of stent-graft for symptomatic acute carotid artery occlusion after endarterectomy.

    Science.gov (United States)

    Ko, Jun Kyeung; Choi, Chang Hwa; Lee, Sang Weon; Lee, Tae Hong

    2016-03-01

    A patient underwent a left-sided carotid endarterectomy (CEA) for an asymptomatic 80% carotid artery (CA) stenosis. There were no signs of intolerance during the carotid cross-clamping and an initially uneventful awakening was observed. However, in the third postoperative hour he experienced left amaurosis and dysarthria. An urgent MRI showed an occluded internal CA on the operated site without evidence of acute infarction. To recanalize the occluded internal CA and minimize leakage from the arteriotomy site, a self-expandable stent-graft was placed, covering the dissection and the distal atherosclerotic lesions. Complete recanalization of the left internal CA was achieved and the patient showed a dramatic improvement of his preoperative deficits. To our knowledge, this is the first case of stent-graft implantation for a symptomatic acute CA occlusion following CEA. Stent-graft placement should be considered as an alternative method of treatment for acute CA occlusion or dissection following CEA. PMID:25653229

  1. Heparin-induced thrombocytopenia with abdominal aortic stent-graft acute thrombosis.

    Science.gov (United States)

    Canaud, Ludovic; Hireche, Kheira; Marty-Ané, Charles; Alric, Pierre

    2013-08-01

    We report a case of heparin-induced thrombocytopenia in a patient on low molecular weight heparin bridge therapy who developed acute abdominal aortic stent-graft thrombosis 1 week after uncomplicated endovascular abdominal aortic aneurysm repair. The diagnosis was confirmed by a computed tomographic scan of the abdomen. The patient was successfully treated by conversion to open repair. The postoperative course was marked by subacute left limb ischemia related to an in vivo cross-reactivity of danaparoid with the heparin immune complex. To our knowledge, this is the first case report of heparin-induced thrombocytopenia with acute abdominal aortic stent-graft thrombosis. PMID:23711968

  2. [Rescue treatment in acute thrombosis of intracranial stents].

    Science.gov (United States)

    Pumar, José M; Banguero, Alexandra; Arias-Rivas, Susana; Blanco, Miguel; Rodríguez-Yáñez, Manuel; Sucasas, Paula; Blanco, Miguel; Castiñeira-Mourenza, José A; Vázquez-Herrero, Fernando

    2014-02-01

    Introduccion. La trombosis aguda intrastent es una complicacion potencialmente grave en el stenting intracraneal. Es primordial determinar cual es la terapia mas adecuada en las trombosis intrastent. Caso clinico. Mujer de 58 años, el primer caso de trombosis aguda de un stent intracraneal, que fue tratada con exito mediante fibrinolisis tras la implantacion de un dispositivo diversificador de flujo (Silk) en un aneurisma basilar fusiforme. Conclusion. La administracion de abciximab como tratamiento de rescate parece segura en los casos de formaciones de trombos agudos intrastent.

  3. ”Missing clot” during mechanical thrombectomy in acute stroke using Solitaire stent retrieval system

    Directory of Open Access Journals (Sweden)

    Vikram Huded

    2016-01-01

    Full Text Available Stent retrieval system is an established treatment modality in acute ischemic stroke with large vessel occlusion. Here, we describe a complication which occurred during mechanical thrombectomy in three cases where the clot dislodged during retrieval. There was a possibility of the clot getting reinjected into the artery with possible dire consequences.

  4. Acute and subacute stent thrombosis after primary percutaneous coronary intervention for ST-segment elevation myocardial infarction : incidence, predictors and clinical outcome

    NARCIS (Netherlands)

    Hesstermans, A. A. C. M.; van Werkum, J. W.; Zwart, B.; van der Heyden, J. A.; Kelder, J. C.; Breet, N. J.; van't Hof, A. W. J.; Koolen, J. J.; Brueren, B. R. G.; Zijlstra, F.; ten Berg, J. M.; Dambrink, Jan Hendrik Everwijn

    2010-01-01

    Background: Early coronary stent thrombosis occurs most frequent after primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). Objectives: To identify the specific predictors of, respectively, acute and subacute stent thrombosis in patients after prim

  5. Predictive value of antiplatelet resistance on early stent thrombosis in patients with acute coronary syndrome

    Institute of Scientific and Technical Information of China (English)

    LI Lei; LI Hai-yan; QIAO Rui; YU Hai-yi; ZENG Hui; GAO Wei; ZHANG Jie

    2013-01-01

    Background Despite outstanding antiplatelet properties of aspirin and clopidogrel,some patients taking these drugs continue to suffer complications.Antiplatelet resistance appears to be a new prognostic factor in acute coronary syndrome patients for clinical events associated with stent thrombosis (ST).However,there is no optimal method to identify it and assess its correlation to clinical outcomes.This study sought to evaluate the predictive value of antiplatelet resistance assessed by whole blood impedance aggregometry for the risk of early ST in patients with acute coronary syndrome who underwent coronary stenting.Methods Platelet responses to aspirin and clopidogrel in 86 patients with acute coronary syndrome were measured by whole blood impedance aggregometry.Spontaneous platelet aggregation was defined as antiplatelet resistance identified by the increased electrical impedance.The clinical endpoint was early stent thrombosis during 30-day follow-up after coronary stenting.Results The prevalence of aspirin resistance,clopidogrel resistance and dual resistance of combined clopidogrel and aspirin resistance were 19.8%,12.8% and 5.8% respectively.Diabetes,female and higher platelet counts were more frequently detected in clopidogrel-resistant and dual-resistant patients.During 30-day follow-up,the patients with clopidogrel resistance and dual resistance had higher incidence of early stent thrombosis (18.2% vs.1.3%,40.0% vs.1.2%,P <0.05).Binary Logistic Regression analysis indicated that dual resistance remained an independent predicator for early stent thrombosis (odds ratio 34.064,95% CI 1.919-604.656,P=-0.016).Conclusions Antiplatelet resistance assessed by whole blood impedance aggregometry is paralleled to clinical events,and dual antiplatelet resistance is an independent predicator for early stent thrombosis in patients with acute coronary syndrome.As a physiological assessment of platelet reactivity,whole blood impedance aggregometry is a

  6. Vascular Response to Experimental Stent Malapposition and Under-Expansion.

    Science.gov (United States)

    O'Brien, Caroline C; Lopes, Augusto C; Kolandaivelu, Kumaran; Kunio, Mie; Brown, Jonathan; Kolachalama, Vijaya B; Conway, Claire; Bailey, Lynn; Markham, Peter; Costa, Marco; Ware, James; Edelman, Elazer R

    2016-07-01

    Up to 80% of all endovascular stents have malapposed struts, and while some impose catastrophic events others are inconsequential. Thirteen stents were implanted in coronary arteries of seven healthy Yorkshire pigs, using specially-designed cuffed balloons inducing controlled stent malapposition and under-expansion. Optical coherence tomography (OCT) imaging confirmed that 25% of struts were malapposed (strut-wall distance 51 ± 0.05 mm vs. apposed group 0.09 ± 0.05 mm, p = 2e-3). Imaging at follow-up revealed malapposition acutely resolved (areas (slope = 0.86, p area and lumen area (R (2) = 0.96) suggesting all lumen loss was related to contraction of elastic lamina with negligible plaque/intimal hyperplasia growth. Simulation showed this vascular recoil could be partially explained by the non-uniform strain environment created from sub-optimal expansion of device and balloon, and the inability of stent support in the malapposed region to resist recoil. Malapposition as a result of stent under-expansion is resolved acutely in healthy normal arteries, suggesting existing animal models are limited in replicating clinically observed persistent stent malapposition. PMID:26732391

  7. Endovascular stent graft treatment of acute thoracic aortic transections due to blunt force trauma.

    LENUS (Irish Health Repository)

    Bjurlin, Marc A

    2012-02-01

    Endovascular stent graft treatment of acute thoracic aortic transections is an encouraging minimally invasive alternative to open surgical repair. Between 2006 and 2008, 16 patients with acute thoracic aortic transections underwent evaluation at our institution. Seven patients who were treated with an endovascular stent graft were reviewed. The mean Glasgow Coma Score was 13.0, probability of survival was .89, and median injury severity score was 32. The mean number of intensive care unit days was 7.7, mean number of ventilator support days was 5.4, and hospital length of stay was 10 days. Mean blood loss was 285 mL, and operative time was 143 minutes. Overall mortality was 14%. Procedure complications were a bleeding arteriotomy site and an endoleak. Endovascular treatment of traumatic thoracic aortic transections appears to demonstrate superior results with respect to mortality, blood loss, operative time, paraplegia, and procedure-related complications when compared with open surgical repair literature.

  8. Efficacy of recombinant tissue-type plasminogen activator thrombolysis and primary coronary stenting after acute myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    陈步星; 王伟民; 赵红; 胡大一; 徐成斌; 赵明中; 卢明瑜; 刘健; 吴淳

    2003-01-01

    Objective To compare the efficacy of low dose recombinant tissue-type plasminogen activator (rt-PA) thrombolysis with primary coronary stenting after acute myocardial infarction.Methods Of 261 patients with first acute myocardial infarction, 131 were given low dose rt-PA intravenous thrombolysis, and 130 primary coronary stenting.Results The age, time from onset of chest pain to hospital presentation and infarct location between these two groups were comparable. The patency rate of the infarct-related artery (IRA) in patients in the thrombolysis group was significantly lower than that of patients in the primary stenting group (P0.05).Conclusion Comparing with low dose rt-PA thrombolytic therapy after acute myocardial infarction, primary coronary stenting has a higher patency rate of the IRA, better cardiac function and shorter hospitalization time.

  9. Thrombectomy assisted by carotid stenting in acute ischemic stroke management

    DEFF Research Database (Denmark)

    Steglich-Arnholm, Henrik; Holtmannspötter, Markus; Kondziella, Daniel;

    2015-01-01

    -term outcome (mRS ≤ 2). Harms included complications during and following EVT. Mean age was 64.3 years (standard deviation ±12.5), 40 (85%) patients received IVT initially. Median NIHSS was 16 (inter-quartile range 14-19). Mean time from stroke onset to recanalization was 311 min (standard deviation ±78......Extracranial carotid artery occlusion or high-grade stenosis with concomitant intracranial embolism causes severe ischemic stroke and shows poor response rates to intravenous thrombolysis (IVT). Endovascular therapy (EVT) utilizing thrombectomy assisted by carotid stenting was long considered risky......-center analysis of 47 consecutive stroke patients with carotid occlusion or high-grade stenosis and concomitant intracranial embolus treated between September 2011 and December 2014. Benefits included early improvement of stroke severity (NIHSS ≥ 10) or complete remission within 72 h and favorable long...

  10. Drug-eluting stents for acute coronary syndrome: a meta-analysis of randomized controlled trials.

    Directory of Open Access Journals (Sweden)

    Lishan Wang

    Full Text Available Drug-eluting stents (DES are increasingly used for treatment of acute coronary syndrome (ACS. However, clinical efficacy and safety of various types of DES is not well established in these subjects. We therefore evaluated clinical utility of second-generation and first-generation DES in patients with ACS by conducting a meta-analysis.A search of Medline, Embase, the Cochrane databases, and Web of Science was made. Randomized controlled trials (RCTs which compared second-generation DES (everolimus-eluting stents [EES] or zotarolimus-eluting stents [ZES] versus first-generation DES (sirolimus-eluting stents [SES] or paclitaxe-eluting stents [PES] in patients with ACS and provided data on clinical efficacy or safety endpoints were included. Pooled estimates were calculated using random-effects model.A total of 2,757 participants with ACS in 6 RCTs were included. Compared with first-generation one, second-generation DES trended to be associated with the decreased incidence of definite or probable stent thrombosis in ACS patients (risk ratio [RR]  = 0.60, 95% confidence intervals [CI] 0.33 to 1.07, p = 0.09. However, the rate of target lesion revascularization (TLR significantly increased in second-generation DES (RR = 2.08, 95%CI 1.25 to 3.47, p = 0.005. There were no significant differences in the incidence of major adverse cardiac events (MACEs, all-cause death, cardiac death, and recurrent myocardial infarction between the two arms (all p>0.10. The second-generation EES showed a tendency towards lower risk of MACEs (p = 0.06 and a beneficial effect on reducing stent thrombosis episodes (p = 0.009, while the second-generation ZES presented an increased occurrence of MACEs (p = 0.02 and TLR (p = 0.003.Second-generation DES, especially EES, appeared to present a lower risk of stent thrombosis, whereas second-generation ZES might increase the need for repeat revascularization in ACS patients. During coronary

  11. The History of Primary Angioplasty and Stenting for Acute Myocardial Infarction.

    Science.gov (United States)

    Smilowitz, Nathaniel R; Feit, Frederick

    2016-01-01

    The evolution of the management of acute myocardial infarction (MI) has been one of the crowning achievements of modern medicine. At the turn of the twentieth century, MI was an often-fatal condition. Prolonged bed rest served as the principal treatment modality. Over the past century, insights into the pathophysiology of MI revolutionized approaches to management, with the sequential use of surgical coronary artery revascularization, thrombolytic therapy, and percutaneous coronary intervention (PCI) with primary coronary angioplasty, and placement of intracoronary stents. The benefits of prompt revascularization inspired systems of care to provide rapid access to PCI. This review provides a historical context for our current approach to primary PCI for acute MI.

  12. EFFICACY AND SAFETY OF GLYCOPROTEIN IIB/IIIA BLOCKER MONOFRAM IN CORONARY STENTING IN PATIENTS WITH ACUTE MYOCARDIAL INFARCTION

    Directory of Open Access Journals (Sweden)

    E. I. Makhiyanova

    2011-01-01

    Full Text Available  Aim. To study of efficacy and safety of glycoprotein IIb/IIIa blocker monafram in acute ST-segment elevation myocardial infarction (STEMI patients, underwent coronary stenting. Material and methods. 220 STEMI patients were included in the trial; they were split into two groups. 109 patients of the first group were underwent coronary stenting with i/v monafram therapy. Coronary stenting without monafram therapy was performed in 111 patients of the second group. Bare metal stents were used in all patients. Deaths, stent thrombosis, individual intolerance, allergic reactions, bleeding were registered during hospitalization. Results. There were 3 (2.75% cases of stent thrombosis in monafram group and 4 (3.6% ones - in the control group. Good tolerance of monafram was observed in all patients. There were no allergic reactions, major and minor bleedings. Reinfarction rate was similar in both groups during 30 days observational period. Conclusions. Monafram therapy is effective and safe in acute STEMI patients underwent coronary stenting.  

  13. Early prediction of acute kidney injury biomarkers after endovascular stent graft repair of aortic aneurysm: a prospective observational study

    OpenAIRE

    Ueta, Kazuyoshi; Watanabe, Michiko; Iguchi, Naoya; Uchiyama, Akinori; Shirakawa, Yukitoshi; Kuratani, Toru; Sawa, Yoshiki; Fujino, Yuji

    2014-01-01

    Background Acute kidney injury (AKI) is a common and serious condition usually detected some time after onset by changes in serum creatinine (sCr). Although stent grafting to repair aortic aneurysms is associated with AKI caused by surgical procedures or the use of contrast agents, early biomarkers for AKI have not been adequately examined in stent graft recipients. We studied biomarkers including urinary neutrophil gelatinase-associated lipocalin (NGAL), blood NGAL, N-acetyl-β-d-glucosaminid...

  14. Coronary Stents: The Impact of Technological Advances on Clinical Outcomes.

    Science.gov (United States)

    Mennuni, Marco G; Pagnotta, Paolo A; Stefanini, Giulio G

    2016-02-01

    Percutaneous coronary interventions (PCI) were proposed in the late 1970s as an alternative to surgical coronary artery bypass grafting for the treatment of coronary artery disease. Important technological progress has been made since. Balloon angioplasty was replaced by bare metal stents, which allowed to permanently scaffold the coronary vessel avoiding acute recoil and abrupt occlusion. Thereafter, the introduction of early generation drug-eluting stents (DES) has significantly improved clinical outcomes, primarily by markedly reducing the risk of restenosis. New generation DES with thinner stent struts, novel durable or biodegradable polymer coatings, and new limus antiproliferative agents, have further improved upon the safety and efficacy profile of early generation DES. The present article aims to review the impact of technological advances on clinical outcomes in the field of PCI with coronary stents, and to provide a brief overview on clinical margins of improvement and unmet needs of available DES.

  15. Colonic stenting as bridge to surgery versus emergency surgery for management of acute left-sided malignant colonic obstruction: a multicenter randomized trial (Stent-in 2 study

    Directory of Open Access Journals (Sweden)

    Scholten Pieter

    2007-07-01

    Full Text Available Abstract Background Acute left-sided colonic obstruction is most often caused by malignancy and the surgical treatment is associated with a high mortality and morbidity rate. Moreover, these operated patients end up with a temporary or permanent stoma. Initial insertion of an enteral stent to decompress the obstructed colon, allowing for surgery to be performed electively, is gaining popularity. In uncontrolled studies stent placement before elective surgery has been suggested to decrease mortality, morbidity and number of colostomies. However stent perforation can lead to peritoneal tumor spill, changing a potentially curable disease in an incurable one. Therefore it is of paramount importance to compare the outcomes of colonic stenting followed by elective surgery with emergency surgery for the management of acute left-sided malignant colonic obstruction in a randomized multicenter fashion. Methods/design Patients with acute left-sided malignant colonic obstruction eligible for this study will be randomized to either emergency surgery (current standard treatment or colonic stenting as bridge to elective surgery. Outcome measurements are effectiveness and costs of both strategies. Effectiveness will be evaluated in terms of quality of life, morbidity and mortality. Quality of life will be measured with standardized questionnaires (EORTC QLQ-C30, EORTC QLQ-CR38, EQ-5D and EQ-VAS. Morbidity is defined as every event leading to hospital admission or prolonging hospital stay. Mortality will be analyzed as total mortality as well as procedure-related mortality. The total costs of treatment will be evaluated by counting volumes and calculating unit prices. Including 120 patients on a 1:1 basis will have 80% power to detect an effect size of 0.5 on the EORTC QLQ-C30 global health scale, using a two group t-test with a 0.05 two-sided significance level. Differences in quality of life and morbidity will be analyzed using mixed-models repeated measures

  16. The Impact of the Acute Results on the Long - Term Outcome after the Treatment of In- stent Restenosis: A Serial Intravascular Ultrasound Study

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ Stenting reduces acute complications and restenosis compared to balloon angioplasty and other devices. However, in- stent restenosis (ISR) is an important clinical problem. The current serial intravascular ultrasound (IVUS)analysis was undertaken to determine whether the acute results obtained during the treatment of ISR influence the long term results and whether this is true for patients treated with and without adjunct brachytherapy.

  17. Longitudinal stent deformation during coronary bifurcation stenting.

    Science.gov (United States)

    Vijayvergiya, Rajesh; Sharma, Prafull; Gupta, Ankush; Goyal, Praveg; Panda, Prashant

    2016-03-01

    A distortion of implanted coronary stent along its longitudinal axis during coronary intervention is known as longitudinal stent deformation (LSD). LSD is frequently seen with newer drug eluting stents (DES), specifically with PROMUS Element stent. It is usually caused by impact of guide catheter tip, or following passage of catheters like balloon catheter, IVUS catheter, guideliner, etc. We hereby report a case of LSD during coronary bifurcation lesion intervention, using two-stents technique. Patient had acute stent thrombosis as a complication of LSD, which was successfully managed. PMID:26811144

  18. Vascular Response to Experimental Stent Malapposition and Under-Expansion.

    Science.gov (United States)

    O'Brien, Caroline C; Lopes, Augusto C; Kolandaivelu, Kumaran; Kunio, Mie; Brown, Jonathan; Kolachalama, Vijaya B; Conway, Claire; Bailey, Lynn; Markham, Peter; Costa, Marco; Ware, James; Edelman, Elazer R

    2016-07-01

    Up to 80% of all endovascular stents have malapposed struts, and while some impose catastrophic events others are inconsequential. Thirteen stents were implanted in coronary arteries of seven healthy Yorkshire pigs, using specially-designed cuffed balloons inducing controlled stent malapposition and under-expansion. Optical coherence tomography (OCT) imaging confirmed that 25% of struts were malapposed (strut-wall distance strut thickness) to variable extent (max. strut-wall distance malapposed group 0.51 ± 0.05 mm vs. apposed group 0.09 ± 0.05 mm, p = 2e-3). Imaging at follow-up revealed malapposition acutely resolved (struts remained malapposed at day 5), with strong correlation between lumen and the stent cross-sectional areas (slope = 0.86, p < 0.0001, R (2) = 0.94). OCT in three of the most significantly malapposed vessels at baseline showed high correlation of elastic lamina area and lumen area (R (2) = 0.96) suggesting all lumen loss was related to contraction of elastic lamina with negligible plaque/intimal hyperplasia growth. Simulation showed this vascular recoil could be partially explained by the non-uniform strain environment created from sub-optimal expansion of device and balloon, and the inability of stent support in the malapposed region to resist recoil. Malapposition as a result of stent under-expansion is resolved acutely in healthy normal arteries, suggesting existing animal models are limited in replicating clinically observed persistent stent malapposition.

  19. A modified total arch replacement combined with a stented elephant trunk implantation for acute type A dissection under deep hypothermic circulatory arrest and selective antegrade cerebral perfusion

    OpenAIRE

    Yang, Su-Min; Xu, Ping; Cheng-xiang LI; Huang, Qiang; Gao, Hong-Bo; Li, Zhen-Fu; Chang, Qing

    2014-01-01

    Objectives Since the optimal management of patients with acute aortic dissection is unclear, this study analyzed total arch replacement combined with stented elephant trunk implantation in the treatment of acute type A aortic dissection. Methods Between February 2008 and February 2013, 86 consecutive patients admitted to our hospital for acute type A dissection underwent total arch replacement combined with stented elephant trunk implantation under deep hypothermic circulatory arrest. The Ben...

  20. Persistent high levels of plasma oxidized low-density lipoprotein after acute myocardial infarction predict stent restenosis

    NARCIS (Netherlands)

    T. Naruko; M. Ueda; S. Ehara; A. Itoh; K. Haze; N. Shirai; Y. Ikura; M. Ohsawa; H. Itabe; Y. Kobayashi; H. Yamagishi; M. Yoshiyama; J. Yoshikawa; A.E. Becker

    2006-01-01

    Objective-Recently, elevated levels of plasma oxidized low-density lipoprotein (LDL) have been shown to relate to plaque instability in human atherosclerotic lesions. We investigated prospectively patients admitted with acute myocardial infarction (AMI) who underwent primary coronary stenting to eva

  1. A clinical evaluation of endoscopically placed self-expanding metallic stents in patients with acute large bowel obstruction

    DEFF Research Database (Denmark)

    Pommergaard, H C; Vilmann, P; Jakobsen, H L;

    2009-01-01

    BACKGROUND AND AIMS: Self-expanding metallic stents (SEMS) have since 1991 established themselves as an option in the treatment of large bowel obstruction. The aim of this study was to evaluate the use of SEMS in management of acute colorectal obstructions at a Danish Surgical Gastroenterology...

  2. Drug-eluting stents and acute myocardial infarction:A lethal combination or friends?

    Institute of Scientific and Technical Information of China (English)

    Shuji; Otsuki; Manel; Sabaté

    2014-01-01

    Primary percutaneous coronary intervention is the preferred reperfusion strategy for patients presenting with ST-segment elevation myocardial infarction(STEMI). First generation drug-eluting stents(DES),(sirolimus drug-eluting stents and paclitaxel drug-eluting stents), reduce the risk of restenosis and target vessel revascularization compared to bare metal stents. However, stent thrombosis emerged as a major safety concern with first generation DES. In response to these safety issues, second generation DES were developed with different drugs, improved stent platforms and more biocompatible durable or bioabsorbable polymeric coating. This article presents an overview of safety and efficacy of the first and second generation DES in STEMI.

  3. High versus low-pressure balloon inflation during multilinktrade mark stent implantation: acute and long-term angiographic results.

    Science.gov (United States)

    Caixeta, A M; Brito, F S; Rati, M; Perin, M A; da Luz, P L; Ramires, J A; Ambrose, J A; Martinez, E E

    2000-08-01

    We compared the impact of low and high-pressure balloon inflation on acute and late angiographic results of Multilink stent. Low-pressure balloon inflation (9.5 +/- 1.9 atm) was used in 43 stents and high pressure (17.1 +/- 1.5 atm) in 44. A larger immediate luminal gain was achieved in stents with high-pressure balloon inflation (1.80 +/- 0.26 vs. 1.47 +/- 0.62; P = 0.002), resulting in a larger mean diameter in this group (2.71 +/- 0.37 vs. 2.48 +/- 0.47; P = 0.017). At follow-up, a larger luminal diameter was achieved in the high pressure group (1.93 +/- 0.72 vs. 1.45 +/- 0.66; P = 0.002) and a trend to a lower rate of angiographic restenosis (15% vs. 38%, P = 0.08).

  4. Self-expanding metallic stents drainage for acute proximal colon obstruction

    Institute of Scientific and Technical Information of China (English)

    Li-Qin Yao; Yun-Shi Zhong; Mei-Dong Xu; Jian-Min Xu; Ping-Hong Zhou; Xian-Li Cai

    2011-01-01

    AIM: To clarify the usefulness of the self-expanding metallic stents (SEMS) in the management of acute proximal colon obstruction due to colon carcinoma before curative surgery. METHODS: Eighty-one colon (proximal to spleen flex) carcinoma patients (47 males and 34 females, aged 18-94 years, mean = 66.2 years) treated between September 2004 and June 2010 for acute colon obstruction were enrolled to this study, and their clinical and radiological features were reviewed. After a cleaning enema was administered, urgent colonoscopy was performed. Subsequently, endoscopic decompression using SEMS placement was attempted. RESULTS: Endoscopic decompression using SEMS placement was technically successful in 78 (96.3%) of 81 patients. Three patients' symptoms could not be relieved after SEMS placement and emergent operation was performed 1 d later. The site of obstruction was transverse colon in 18 patients, the hepatic flex in 42, and the ascending colon in 21. Following adequate cleansing of the colon, patients' abdominal girth was decreased from 88 ± 3 cm before drainage to 72 ± 6 cm 7 d later, and one-stage surgery after 8 ± 1 d (range, 7-10 d) was performed. No anastomotic leakage or postoperative stenosis occurred after operation. CONCLUSION: SEMS placement is effective ane in the management of acute proximal colon obstruction due to colon carcinoma, and is considered as a bridged method before curative surgery.

  5. Zotarolimus-eluting vs. sirolimus-eluting coronary stents in patients with and without acute coronary syndromes

    DEFF Research Database (Denmark)

    Thim, Troels; Maeng, Michael; Kaltoft, Anne Kjer;

    2012-01-01

    Eur J Clin Invest 2012 ABSTRACT: Objectives:  To compare clinical outcomes among patients with acute coronary syndrome treated with zotarolimus-eluting and sirolimus-eluting stents in the SORT OUT III trial. Background:  Currently, only limited data allow direct comparison of clinical outcomes......-eluting (n = 546) stents and followed for 18 months. The primary composite endpoint, major adverse cardiac events (MACE), was defined as a composite of cardiac death, myocardial infarction or target vessel revascularization. Results:  Zotarolimus-eluting stent treatment compared to sirolimus-eluting stent...... treatment was associated with increased rates of MACE (8·7% vs. 5·0%; hazard ratio (HR), 1·78; 95% confidence interval (CI), 1·10-2·88; P = 0·02) and TVR (6·8% vs. 3·9%; HR, 1·77; 95% CI, 1·03-3·04; P = 0·04), while all-cause death, cardiac death, myocardial infarction and definite stent thrombosis did not...

  6. Clinical application of self-expanding metallic stent in the management of acute left-sided colorectal malignant obstruction

    Institute of Scientific and Technical Information of China (English)

    You-Ben Fan; Ying-Sheng Cheng; Ni-Wei Chen; Hui-Min Xu; Zhe Yang; Yue Wang; Yu-Yao Huang; Qi Zheng

    2006-01-01

    AIM: To summarize our experience with the application of self-expanding metallic stent (SEMS) in the management of acute left-sided colorectal malignant obstruction.METHODS: A retrospective chart review of all patients undergoing placement of SEMS between April 2000 and January 2004 was performed.RESULTS: Insertion of SEMS was attempted in 26patients under fluoroscopic guidance with occasional endoscopic assistance. The sites of lesions were located in splenic flexure of two patients, left colon of seven patients, sigmoid colon of eight patients and rectum of nine patients. The intended uses of SEMS were for palliation in 7 patients and as a bridge to elective surgery in 19 patients. In the latter group, placement of SEMS allowed for preoperative systemic and bowel preparation and the following one-stage anastomosis. Successful stent placement was achieved in 22 (85%) of the 26patients. The clinical bowel obstruction resolved 24 hours after successful stent placement in 21 (95%) patients.Three SEMS-related minor complications occurred, two stents migrated and one caused anal pain.CONCLUSION: SEMS represents an effective and safe tool in the management of acute malignant colorectal obstruction. As a bridge to surgery, SEMS can provide time for systematic support and bowel preparation and obviate the need for fecal diversion or on-table lavage.As a palliative measure, SEMS can eliminate the need for emergent colostomy.

  7. Acute ischemic stroke in a child due to basilar artery occlusion treated successfully with a stent retriever.

    Science.gov (United States)

    Savastano, Luis; Gemmete, Joseph J; Pandey, Aditya S; Roark, Christopher; Chaudhary, Neeraj

    2016-08-01

    Ischemic strokes in childhood are rare. Thrombolytic therapy with intravenous (IV) tissue plasminogen activator (tPA) has been the main intervention for the management of pediatric stroke patients, but safety data are lacking and efficacy has been questioned. Recently, successful endovascular treatments for acute ischemic stroke in children have been reported with increasing frequency, suggesting that mechanical thrombectomy can be a safe and effective treatment. We present the case of a 22-month-old child with acute ischemic stroke due to basilar artery occlusion that was successfully treated with a stent retriever. PMID:26156170

  8. A recoil resilient lumen support, design, fabrication and mechanical evaluation

    Science.gov (United States)

    Mehdizadeh, Arash; Ali, Mohamed Sultan Mohamed; Takahata, Kenichi; Al-Sarawi, Said; Abbott, Derek

    2013-06-01

    Stents are artificial implants that provide scaffolding to a cavity inside the body. This paper presents a new luminal device for reducing the mechanical failure of stents due to recoil, which is one of the most important issues in stenting. This device, which we call a recoil-resilient ring (RRR), is utilized standalone or potentially integrated with existing stents to address the problem of recoil. The proposed structure aims to minimize the need for high-pressure overexpansion that can induce intra-luminal trauma and excess growth of vascular tissue causing later restenosis. The RRR is an overlapped open ring with asymmetrical sawtooth structures that are intermeshed. These teeth can slide on top of each other, while the ring is radially expanded, but interlock step-by-step so as to keep the final expanded state against compressional forces that normally cause recoil. The RRRs thus deliver balloon expandability and, when integrated with a stent, bring both radial rigidity and longitudinal flexibility to the stent. The design of the RRR is investigated through finite element analysis (FEA), and then the devices are fabricated using micro-electro-discharge machining of 200-µm-thick Nitinol sheet. The standalone RRR is balloon expandable in vitro by 5-7 Atm in pressure, which is well within the recommended in vivo pressure ranges for stenting procedures. FEA compression tests indicate 13× less reduction of the cross-sectional area of the RRR compared with a typical stainless steel stent. These results also show perfect elastic recovery of the RRR after removal of the pressure compared to the remaining plastic deformations of the stainless steel stent. On the other hand, experimental loading tests show that the fabricated RRRs have 2.8× radial stiffness compared to a two-column section of a commercial stent while exhibiting comparable elastic recovery. Furthermore, testing of in vitro expansion in a mock artery tube shows around 2.9% recoil, approximately 5-11

  9. A recoil resilient lumen support, design, fabrication and mechanical evaluation

    International Nuclear Information System (INIS)

    Stents are artificial implants that provide scaffolding to a cavity inside the body. This paper presents a new luminal device for reducing the mechanical failure of stents due to recoil, which is one of the most important issues in stenting. This device, which we call a recoil-resilient ring (RRR), is utilized standalone or potentially integrated with existing stents to address the problem of recoil. The proposed structure aims to minimize the need for high-pressure overexpansion that can induce intra-luminal trauma and excess growth of vascular tissue causing later restenosis. The RRR is an overlapped open ring with asymmetrical sawtooth structures that are intermeshed. These teeth can slide on top of each other, while the ring is radially expanded, but interlock step-by-step so as to keep the final expanded state against compressional forces that normally cause recoil. The RRRs thus deliver balloon expandability and, when integrated with a stent, bring both radial rigidity and longitudinal flexibility to the stent. The design of the RRR is investigated through finite element analysis (FEA), and then the devices are fabricated using micro-electro-discharge machining of 200-µm-thick Nitinol sheet. The standalone RRR is balloon expandable in vitro by 5–7 Atm in pressure, which is well within the recommended in vivo pressure ranges for stenting procedures. FEA compression tests indicate 13× less reduction of the cross-sectional area of the RRR compared with a typical stainless steel stent. These results also show perfect elastic recovery of the RRR after removal of the pressure compared to the remaining plastic deformations of the stainless steel stent. On the other hand, experimental loading tests show that the fabricated RRRs have 2.8× radial stiffness compared to a two-column section of a commercial stent while exhibiting comparable elastic recovery. Furthermore, testing of in vitro expansion in a mock artery tube shows around 2.9% recoil, approximately 5

  10. Long-term outcome of patients of over 85 years old with acute coronary syndrome undergoing percutaneous coronary stenting: a comparison of bare metal stent and drug eluting stent

    Institute of Scientific and Technical Information of China (English)

    MA Han-ying; ZHOU Yu-jie; Ronald J Dick; SHI Dong-mei; LIU Yu-yang; CHENG Wan-jun; GUO Yong-he; WANG Jian-long; GE Hai-long

    2008-01-01

    Background Patients aged over 85 years have been under-represented in percutaneous coronary intervention (PCI)trials despite an increase in referrals for PCI. The long-term safety and efficacy of percutaneous coronary stenting in patients aged over 85 years with acute coronary syndrome (ACS) remain unclear. Moreover it is unknown whether there are differences between bare metal stent (BMS) and drug eluting stent (DES) in this special population.Methods A total of 80 patients with ACS aged over 85 years undergoing stenting (BMS group n=21 vs DES group n=59)were retrospectively studied. In-hospital, one year and overall clinical follow-up (12-36 months) of major adverse cardiac events (MACEs) including cardiac deaths, myocardial infarction, target lesion revascularization (TLR) and target vessel revascularization (TVR) as well as stroke and other major bleeding were compared between the two groups.Results In the entire cohort, the procedure success rate was 93.8% with TIMI-3 coronary flow post-PCI in 93.8% of the vessels and the procedure related complication was 17.5%. The incidence of in-hospital MACEs in BMS group was higher (14.3% vs 6.8%, P=0.30). The 1-year incidence of MACEs in DES group was 7.0% while there was no MACE in the BMS group. Clinical follow-up for 12-36 months showed that the overall survival free from MACE was 82.9% and the incidence of MACE in the BMS group was lower (5.3% vs 21.1%, P=0.20). Multivariate regression analysis showed that the creatinine level (OR:1.013; 95%C1: 1.006-1.020; P=0.004) and hypertension (OR:3.201; 95%C1: 1.000-10.663;P=0.04) are two major factors affecting the long-term MACE.Conclusions Percutaneous coronary stenting in patients aged over 85 years is safe and provides good short and long-term efficacy. Patients with renal dysfunction and hypertension may have a relatively high incidence of MACE.

  11. Effect of biolimus-eluting stents with biodegradable polymer vs bare-metal stents on cardiovascular events among patients with acute myocardial infarction

    DEFF Research Database (Denmark)

    Räber, Lorenz; Kelbæk, Henning; Ostojic, Miodrag;

    2012-01-01

    The efficacy and safety of drug-eluting stents compared with bare-metal stents remains controversial in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).......The efficacy and safety of drug-eluting stents compared with bare-metal stents remains controversial in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI)....

  12. Mechanical Thrombectomy using a solitaire stent in acute ischemic stroke; The relationship between the visible antegrade flow on first device deployment and final success in revascularization

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sung Ho; Lee, Byung Hon; Hwang, Yoon Joon; Kim, Su Young; Lee, Ji Young; Hong, Keun Sik; Cho, Yong Jin [Ilsan Paik Hospital, Inje University College of Medicine, Goyang (Korea, Republic of)

    2015-05-15

    The purpose of the study was to evaluate the relationship between the successful revascularization on the first Solitaire stent deployment and the successful revascularization on the final angiography in acute ischemic stroke. From February 2012 to April 2014, 24 patients who underwent Solitaire stent thrombectomy as the first thrombectomy method for treatment of acute ischemic strokes were retrospectively reviewed. When the first Solitaire stent was deployed, 9 patients showed revascularization (Group 1) and 15 patients did not show revascularization (Group 2). Revascularization immediately after the first Solitaire stent removal and on the final angiography were comparatively assessed between the 2 groups. Statistical analysis was performed by the Fisher exact test and Student's t-test. The rates of revascularization maintenance immediately after the first Solitaire stent removal were 89% in Group 1 and 27% in Group 2, respectively (p = 0.009), and the rates of final successful revascularization were 100% in Group 1 and 47% in Group 2, respectively (p = 0.009). There was a statistically significant difference between the 2 groups. Revascularization on the first Solitaire stent deployment can be a useful predictor in evaluating the success of final revascularization in the treatment of acute ischemic stroke.

  13. Successful treatment of cardiogenic shock by stenting of the left main coronary artery in acute myocardial infarction

    Directory of Open Access Journals (Sweden)

    Knežević Božidarka

    2008-01-01

    Full Text Available Introduction. Patients with non-ST elevation acute coronary syndromes (NSTE-ACS are sometimes severely hemodynamicly compromised. Urgent coronary angiography should be performed in these patients in percutaneous coronary intervention (PCI centers according to the ESC NSTE-ACS guidelines to determine suitabilty for percutaneous or surgical revascularization. Case report. We reported a 62-year-old male with chest pain admitted to the Coronary Care Unit. ST segment depression of 2 mm in leads I, L and V4-6 was revealed at electrocardiogram. After following 6 hours the patient had chest pain and signs of cardiogenic shock despite of the therapy. Chest x-ray showed pulmonary edema. Echocardiographic examination showed dyskinetic medium and apical segments of septum. The patient underwent coronary angiography immediately which revealed 75% stenosis of the left main coronary artery with thrombus. The use of a GPIIb/III inhibitor-tirofiban and stent implantation resulted in TIMI III flow. After that the patient had no chest pain and acute heart failure subsided in the following days Echocardiography done at the fourth day from PCI showed only hypokinesis medium and apical segment of septum. The patient was discharged at day 11 from admission in a stable condition. Conclusion. Stenting of left main coronary artery stenosis in patients with cardiogenic shock and non- ST segment elevation acute coronary syndromes may be a life saving procedure.

  14. Coronary stenting with cardiogenic shock due to acute ascending aortic dissection

    Institute of Scientific and Technical Information of China (English)

    Yuichi; Hanaki; Kazuhiko; Yumoto; Seigen; I; Hajime; Aoki; Tomoyuki; Fukuzawa; Takahiro; Watanabe; Kenichi; Kato

    2015-01-01

    A 65-year-old man developed chest pain under cardiogenic shock. Coronary angiography revealed severe stenosis from the ostium of the left main coronary artery(LMCA) to the left anterior descending artery(LAD). Intravascular ultrasound(IVUS) identified a large hematoma that originated from the aorta and extended into the LAD, thereby compressing the true lumen. Type A aortic dissection(TAAD) that involved the LMCA was diagnosed by IVUS. Coronary stenting was performed via the LMCA to the proximal LAD, which resulted in coronary blood flow restoration and no further propagation of dissection. Elective surgical aortic repair was performed 2 wk after the stenting. LMCA stenting under IVUS guidance is effective for prompt diagnosis and precise stent deployment in patients with cardiogenic shock due to TAAD with LMCA dissection.

  15. Gender difference in patients with acute myocardial infarction treated by primary percutaneous coronary intervention in drug-eluting stent era

    Institute of Scientific and Technical Information of China (English)

    GE Jun-bo

    2010-01-01

    @@ Primary percutaneous coronary intervention (PCI) has been the standard of care for patients with acuteST-elevation myocardial infarction (STEMI) within 12 hours of symptom onset in modern era.~(1,2) The advances and applications of robust anti-platelet and anti-coagulation medicines further improve the outcome of STEMI patients undergoing primary PCI,~3 and drug-eluting stent (DES) has also been proven to be effective and safe when applying in primary PCI.~4 Historical data indicated that women undergoing PCI exerted worse outcomes than male patients, and the gender differences in outcome after PCI are still topical and of interest, especially the outcome after primary PCI.

  16. A randomized, prospective, two-center comparison of sirolimus-eluting stent and zotarolimus-eluting stent in acute ST-elevation myocardial infarction: The SEZE trial

    Institute of Scientific and Technical Information of China (English)

    Woo-Young Chung; Sang-Hyun Kim; In-Ho Chae; Joo-Hee Zo; Myung-A Kim; Dong-Ju Choi; Jeehoon Kang; Young-Seok Cho; Hae-Jun Park; Han-Mo Yang; Jae-Bin Seo; Jung-Won Suh; Kwang-Il Kim; Tae-Jin Youn

    2012-01-01

    Background The zotarolimus-eluting stent has shown larger in-stent late lumen loss compared to sirolimus-eluting stents in previous studies.However,this has not been thoroughly evaluated in ST elevation myocardial infarction.Methods This was a prospective,randomized,controlled trial evaluating angiographic outcomes in patients presenting with ST elevation myocardial infarction,treated with zotarolimus-eluting stents or sirolimus-eluting stents.From March 2007 to February 2009,122 patients were randomized to zotarolimus-eluting stents or sirolimus-eluting stents in a 1:1 fashion.The primary endpoint was 9-month in-stent late lumen loss confirmed by coronary angiography,and secondary endpoints were percent diameter stenosis,binary restenosis rate,major adverse cardiac events (a composite of cardiac death,non-fatal myocardial infarction,and target vessel revascularization),and late-acquired incomplete stent apposition.Results Angiographic in-stent late lumen loss was significantly higher in the zotarolimus-eluting stent group compared to the sirolimus-eluting stent group ((0.49±0.65) mm vs.(0.10±0.46) mm,P=0.001).Percent diameter stenosis at 9-month follow-up was also larger in the zotarolimus-eluting stent group ((30.0±17.9)% vs.(17.6±14.0)%,P <0.001).In-segment analysis showed similar findings.There were no significant differences in binary restenosis rate,major adverse cardiac events,and late-acquired incomplete stent apposition.Conclusions Compared to sirolimus-eluting stents,the zotarolimus-eluting stent is associated with significantly higher in-stent late lumen loss at 9-month angiographic follow-up in the treatment of ST elevation myocardial infarction.Although there was no significant difference in 1-year clinical outcomes,the clinical implication of increased late lumen loss should be further studied.

  17. Endovascular Mechanical Recanalisation After Intravenous Thrombolysis in Acute Anterior Circulation Stroke: The Impact of a New Temporary Stent

    Energy Technology Data Exchange (ETDEWEB)

    Fesl, Gunther, E-mail: gunther.fesl@med.uni-muenchen.de; Patzig, Maximilian; Holtmannspoetter, Markus [University of Munich, Department of Neuroradiology (Germany); Mayer, Thomas E. [University of Jena, Department of Neuroradiology (Germany); Pfefferkorn, Thomas; Opherk, Christian [University of Munich, Department of Neurology (Germany); Brueckmann, Hartmut [University of Munich, Department of Neuroradiology (Germany); Wiesmann, Martin [University Hospital, Department of Diagnostic and Interventional Neuroradiology (Germany)

    2012-12-15

    Purpose: Treatment of acute stroke by endovascular mechanical recanalisation (EMR) has shown promising results and continues to be further refined. We evaluated the impact of a temporary stent compared with our results using other mechanical devices. Materials and Methods: We analysed clinical and radiological data of all patients who were treated by EMR after intravenous thrombolysis for acute carotid T- and middle-cerebral artery (M1) occlusions at our centre between 2007 and 2011. A comparison was performed between those patients in whom solely the stent-retriever was applied (group S) and those treated with other devices (group C). Results: We identified 14 patients for group S and 16 patients for group C. Mean age, National Institute of Health Stroke Scale score, and time to treatment were 67.1 years and 16.5 and 4.0 h for group S and 61.1 years and 17.6 and 4.5 h for group C, respectively. Successful recanalisation (thrombolysis in cerebral infarction scores {>=}IIb) was achieved in 93% of patients in group S and 56% of patients in group C (P < 0.05). Mean recanalisation times for M1 occlusions were 23 min (group S) and 29 min (group C) and for carotid-T occlusions were 39 min (group S) and 50 min (group C), and 45% of the patients in group S and 33% in group C had a favourable outcome (Modified Rankin Scale score {<=}2). Conclusion: The findings suggest an improvement in recanalisation success by the application of a temporary stent compared with previously used devices. These results are to be confirmed by larger studies.

  18. Antithrombotic therapy in anticoagulated patients with atrial fibrillation presenting with acute coronary syndromes and/or undergoing percutaneous coronary intervention/stenting

    Directory of Open Access Journals (Sweden)

    Benjamin J. Wrigley

    2010-07-01

    Full Text Available The management of antithrombotic therapy in atrial fibrillation patients presenting with acute coronary syndrome and/or undergoing percutaneous coronary inter vention/stenting cannot be done according to a regimented common protocol, and stroke and bleeding risk stratification schema should be employed to individualize treatment options. A delicate balance is needed between the prevention of thromboembolism, against recurrent cardiac ischemia or stent thrombosis, and bleeding risk. New guidance from a consensus document of the European Society of Cardiology Working Group on Thrombosis, endorsed by the European Heart Rhythm Association and the European Association ofPercutaneous Cardiovascular Interventions on the management of Antithrombotic Therapy in Atrial Fibrillation Patients Presenting with Acute Coronary Syndrome and/or Undergoing Percutaneous Coronary Intervention/Stenting has sought to clarify some of the major issues and problems surrounding this practice, and will allow clinicians to make much more informed decisions when faced with treating such patients.

  19. The HERMES Recoil Detector

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Weilin [II. Physikalisches Institut, JLU Giessen, Heinrich-Buff-Ring 16, 35392 Giessen (Germany)

    2008-07-01

    The HERMES Collaboration at HERA constructed and installed a new Recoil Detector to upgrade the existed spectrometer. This detector is designed to measure recoil protons in hard exclusive processes which provide access to the orbital angular momentum of quarks. The Recoil Detector consists of a silicon detector surrounding the target cell inside the beam vacuum, a scintillating fiber tracker and a photon detector. All three detectors are located inside a solenoidal magnet which provides a 1 T longitudinal magnetic field. The Recoil Detector was installed in January 2006 and data taking lasted until the end of HERA operation in June 2007. Results on the detector performance will be presented here.

  20. Fate of side branches after intracoronary implantation of the Gianturco-Roubin flex-stent for acute or threatened closure after percutaneous transluminal coronary angioplasty.

    Science.gov (United States)

    Mazur, W; Grinstead, W C; Hakim, A H; Dabaghi, S F; Abukhalil, J M; Ali, N M; Joseph, J; French, B A; Raizner, A E

    1994-12-15

    Side branch occlusion may occur in the course of percutaneous transluminal coronary angioplasty (PTCA), particularly if complicated by site dissection. Concern that the additional placement of a stent may further jeopardize side branches is logical. Consequently, this study analyzed pre-PTCA, post-PTCA, poststent, and 6-month follow-up angiograms of 100 consecutive patients in whom 103 Gianturco-Roubin stents were implanted for acute or threatened closure after PTCA. Side branches were defined as major (> 50% of the stented vessel diameter) and minor ( 50% stenosis), and 129 minor branches were analyzed. Seven major branches (6%), all of which were diseased before PTCA, and 23 minor branches (18%) were lost after PTCA. Immediately after stent insertion, only 1 additional major and 1 minor branch were lost, whereas 2 of 7 major (29%) and 9 of 23 minor (39%) branches reappeared. At follow-up angiography, 7 major branches (6%) were more stenosed and 6 (6%) were improved compared with the angiogram before PTCA. Only 2 major (2%) and 5 minor (4%) branches remained occluded. Additionally, 2 major and 1 minor branch, which were patent after PTCA and stenting, were occluded at follow-up as a result of total occlusion of the stented segment.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7977091

  1. Bioresorbable microporous stents deliver recombinant adenovirus gene transfer vectors to the arterial wall.

    Science.gov (United States)

    Ye, Y W; Landau, C; Willard, J E; Rajasubramanian, G; Moskowitz, A; Aziz, S; Meidell, R S; Eberhart, R C

    1998-01-01

    The use of intravascular stents as an adjunct for percutaneous transluminal revascularization is limited by two principal factors, acute thrombosis and neointimal proliferation, resulting in restenosis. To overcome these limitations, we have investigated the potential of microporous bioresorbable polymer stents formed from poly(L-lactic acid) (PLLA)/poly(epsilon-caprolactone) (PCL) blends to function both to provide mechanical support and as reservoirs for local delivery of therapeutic molecules and particles to the vessel wall. Tubular PLLA/PCL stents were fabricated by the flotation-precipitation method, and helical stents were produced by a casting/winding technique. Hybrid structures in which a tubular sheath is deposited on a helical skeleton were also generated. Using a two-stage solvent swelling technique, polyethylene oxide has been incorporated into these stents to improve hydrophilicity and water uptake, and to facilitate the ability of these devices to function as drug carriers. Stents modified in this manner retain axial and radial mechanical strength sufficient to stabilize the vessel wall against elastic recoil caused by vasoconstrictive and mechanical forces. Because of the potential of direct gene transfer into the vessel wall to ameliorate thrombosis and neointimal proliferation, we have investigated the capacity of these polymer stents to function in the delivery of recombinant adenovirus vectors to the vessel wall. In vitro, virus stock was observed to readily absorb into, and elute from these devices in an infectious form, with suitable kinetics. Successful gene transfer and expression has been demonstrated following implantation of polymer stents impregnated with a recombinant adenovirus carrying a nuclear-localizing betaGal reporter gene into rabbit carotid arteries. These studies suggest that surface-modified polymer stents may ultimately be useful adjunctive devices for both mechanical support and gene transfer during percutaneous

  2. Outcome of endoscopic self-expandable metal stents in acute malignant colorectal obstruction at a tertiary center

    Directory of Open Access Journals (Sweden)

    Eduardo Rodrigues-Pinto

    2015-09-01

    Full Text Available Background: Malignant colorectal obstruction (MCRO by advanced colonic cancer occurs in 8-13% of colonic cancer patients. Emergent surgery carries a high mortality and morbidity risk. Endoscopic self-expanding metal stents (SEMS may be used in acute MCRO. Aim: Evaluate clinical outcome of SEMS in acute MCRO and efficacy of SEMS placement considering fluoroscopy guidance. Methods: Retrospective study of patients with acute MCRO that placed SEMS in a 3 years period. Results: SEMS were placed in 47 patients, followed-up for a median time of 150 days. The intent of stenting was bridge to definitive surgery in 40% of the patients (n = 19 and palliation in the remaining 60% (n = 28. The location of the tumor did not influence the presence of lymph node involvement (p = 0.764 nor metastasis (p = 0.885. Mortality rate at year 1 was 61%. Survival was significantly higher in patients submitted later to combination therapy compared to chemotherapy, surgery or symptomatic treatment (p < 0.001. Fluoroscopy was used in 57% of the procedures. Clinical success was 79%. A second SEMS was needed during the procedure in 6% of the patients. Rate of early and late complications was 11% and 5%, respectively. Fluoroscopy guidance did not influence the occurrence of immediate (p = 0.385, early (p = 0.950 or late complications (p = 0.057. Thirty-three percent of patients underwent surgery at a later stage, with neo-adjuvant therapy in 18%. Conclusions: SEMS provide a relative safe and successful treatment in a palliative or bridge-to-surgery indication. No significant differences were found in SEMS placement success, early complications or late complications considering fluoroscopy guidance.

  3. Recanalization and Mortality Rates of Thrombectomy With Stent-Retrievers in Octogenarian Patients with Acute Ischemic Stroke

    Energy Technology Data Exchange (ETDEWEB)

    Parrilla, G., E-mail: gpr1972@gmail.com [Hospital Clínico Universitario Virgen de la Arrixaca, Service of Interventional Neuroradiology (Spain); Carreón, E. [Service of Neurology Hospital Clínico Universitario Virgen de la Arrixaca (Spain); Zamarro, J.; Espinosa de Rueda, M.; García-Villalba, B. [Hospital Clínico Universitario Virgen de la Arrixaca, Service of Interventional Neuroradiology (Spain); Marín, F. [Hospital Clínico Universitario Virgen de la Arrixaca, Department of Cardiology (Spain); Hernández-Fernández, F. [Hospital Clínico Universitario Virgen de la Arrixaca, Service of Interventional Neuroradiology (Spain); Morales, A. [Service of Neurology Hospital Clínico Universitario Virgen de la Arrixaca (Spain); Fernández-Vivas, M.; Núñez, R. [Hospital Clínico Universitario Virgen de la Arrixaca, Intensive Care Unit (Spain); Moreno, A. [Hospital Clínico Universitario Virgen de la Arrixaca, Service of Interventional Neuroradiology (Spain)

    2015-04-15

    BackgroundOur objective was to evaluate the effect of treatment with stent-retrievers in octogenarians suffering an acute ischemic stroke.MethodsA total of 150 consecutive patients with acute stroke who were treated with stent-retrievers between April 2010 and June 2012 were retrospectively reviewed. Patients were divided into those <80 years old (n = 116) and those ≥80 (n = 34). Baseline characteristics, procedure data, and endpoints (postprocedural NIHSS, death, and mRS at 3 months) were compared.ResultsHigh blood pressure, atrial fibrillation, and anticoagulation were more frequent in octogenarians (p = 0.01, 0.003, and 0.04 respectively). There were no differences between both groups regarding previous intravenous thrombolysis (32.4 vs. 48.3 %, p = 0.1), preprocedural NIHSS (18.1 vs. 16.8, p = 0.3), procedure time (74.5 (40–114) min vs. 63 (38–92) min, p = 0.2), revascularization time (380.5 (298–526.3) min vs. 350 (296.3–452.8), p = 0.3), TICI ≥ 2B (88.2 vs. 93.9 %, p = 0.1), and symptomatic haemorrhage (5.9 vs. 2.6 %, p = 0.3). Discharge NIHSS was higher in octogenarians (9.7 vs. 6.5, p = 0.03). Death and 3-month mRS ≥3 were more frequent in octogenarians (35.3 vs. 17.2 %, p = 0.02 and 73.5 vs. 37.1 %, p = 0.02). ICA-involvement and prolonged revascularization involved higher mortality (66.7 vs. 27.6 %, p = 0.03) and worse mRS (50 vs. 24.4 %, p = 0.06) in octogenarians.ConclusionsIn our series, treatment with stent-retrievers in octogenarians with acute ischemic stroke achieved good rates of recanalization but with a high mortality rate. ICA involvement and revascularization times beyond 6 hours associated to a worse prognosis. These data might be of value in the design of prospective studies evaluating the clinical efficacy of the endovascular treatments in octogenarians.

  4. Thrombectomy assisted by carotid stenting in acute ischemic stroke management: benefits and harms.

    Science.gov (United States)

    Steglich-Arnholm, Henrik; Holtmannspötter, Markus; Kondziella, Daniel; Wagner, Aase; Stavngaard, Trine; Cronqvist, Mats E; Hansen, Klaus; Højgaard, Joan; Taudorf, Sarah; Krieger, Derk Wolfgang

    2015-12-01

    Extracranial carotid artery occlusion or high-grade stenosis with concomitant intracranial embolism causes severe ischemic stroke and shows poor response rates to intravenous thrombolysis (IVT). Endovascular therapy (EVT) utilizing thrombectomy assisted by carotid stenting was long considered risky because of procedural complexities and necessity of potent platelet inhibition-in particular following IVT. This study assesses the benefits and harms of thrombectomy assisted by carotid stenting and identifies factors associated with clinical outcome and procedural complications. Retrospective single-center analysis of 47 consecutive stroke patients with carotid occlusion or high-grade stenosis and concomitant intracranial embolus treated between September 2011 and December 2014. Benefits included early improvement of stroke severity (NIHSS ≥ 10) or complete remission within 72 h and favorable long-term outcome (mRS ≤ 2). Harms included complications during and following EVT. Mean age was 64.3 years (standard deviation ±12.5), 40 (85%) patients received IVT initially. Median NIHSS was 16 (inter-quartile range 14-19). Mean time from stroke onset to recanalization was 311 min (standard deviation ±78.0). Early clinical improvement was detected in 22 (46%) patients. Favorable outcome at 3 months occurred in 32 (68%) patients. Expedited patient management was associated with favorable clinical outcome. Two (4%) patients experienced symptomatic hemorrhage. Eight (17%) patients experienced stent thrombosis. Four (9%) patients died. Thrombectomy assisted by carotid stenting seems beneficial and reasonably safe with a promising rate of favorable outcome. Nevertheless, adverse events and complications call for additional clinical investigations prior to recommendation as clinical standard. Expeditious patient management is central to achieve good clinical outcome. PMID:26345413

  5. Successful treatment of post-exertion acute myocardial infarction by primary angioplasty and stenting in a patient with antiphospholipid antibody syndrome.

    Science.gov (United States)

    Musuraca, Gerardo; Imperadore, Ferdinando; Terraneo, Clotilde; De Girolamo, Piergiuseppe; Cemin, Claudio; Bonmassari, Roberto; Vergara, Giuseppe

    2004-01-01

    Antiphospholipid syndrome is a disorder characterized by arterial and venous thromboses, thrombocytopaenia and stroke. Acute myocardial infarction is rarely associated with this syndrome. The treatment of these patients is a clinical challenge. This report is about a patient with antiphospholipid syndrome presenting with an acute myocardial infarction after an exercise test. The infarct-related coronary artery was successfully revascularized by primary angioplasty and stenting without any major bleeding complications. We think that the physical exertion could have favoured acute coronary thrombosis in this particular setting.

  6. Outcomes after primary coronary intervention with drug eluting stent implantation in diabetic patients with acute ST elevation myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qi; HU Jian; YANG Zhen-kun; ZHENG Ai-fang; ZHANG Xian; SHEN Wei-feng; SHEN Jie; ZHANG Rui-yan; QIU Jian-ping; LU Ji-de; ZHANG Yu; CHEN Yue-hua; ZHANG Jun-feng; ZHANG Jian-sheng

    2007-01-01

    Background Drug-eluting stent (DES) has been used widely for the treatment of patients with acute coronary syndrome with or without diabetes mellitus during percutaneous coronary intervention (PCI), but its long-term safety and efficacy in diabetic patients with acute ST elevation myocardial infarction (STEMI) remain uncertain. This study aimed to investigate the clinical outcomes after primary coronary intervention with DES implantation for diabetic patients with acute STEMI, compared with non-diabetic counterparts.Methods From December 2004 to March 2006, 56 consecutive diabetic patients (diabetic group) and 170 non-diabetic patients (non-diabetic group) with acute STEMI who underwent primary PCI with DES implantation in 3 hospitals were enrolled. Baseline clinical, angiographic, and procedural characteristics, as well as occurrence of major adverse cardiac event (MACE) including cardiac death, non-fatal recurrent myocardial infarction (re-MI) and target vessel revascularization (TVR) during hospitalization and one-year clinical follow-up were compared between the two groups.Results Patients in diabetic group were more hyperlipidemic (69.6% and 51.8%, P=0.03) and had longer time delay from symptom onset to admission ((364±219) minutes and (309±223) minutes,P=0.02) than those in non-diabetic group.The culprit vessel distribution, reference vessel diameter, and baseline TIMI flow grade were similar between the two groups, but multi-vessel disease was more common in diabetic than in non-diabetic group (82.1% and 51.2%, P<0.001).Despite similar TIMI flow grades between the two groups after stenting, the occurrence of TIMI myocardial perfusion grade (TMPG)≥2 was lower in diabetic group (75.0% vs 88.8% in non-diabetic groups, P=0.02). The MACE rate was similar during hospitalization between the two groups (5.4% vs 3.5%, P=0.72), but it was significantly higher in diabetic group (16.1%) during one-year follow-up, as compared with non-diabetic group (6.5%, P=0

  7. The HERMES Recoil Detector

    OpenAIRE

    Airapetian, A.; Aschenauer, E.C.; S. Belostotski(St. Petersburg, INP); Borissov, A; Borisenko, A.; Bowles, J; Brodski, I.; Bryzgalov, V.; Burns, J; Capitani, G.P.; V. Carassiti; Ciullo, G.; Clarkson, A.; Contalbrigo, M; R.Leo

    2013-01-01

    For the final running period of HERA, a recoil detector was installed at the HERMES experiment to improve measurements of hard exclusive processes in charged-lepton nucleon scattering. Here, deeply virtual Compton scattering is of particular interest as this process provides constraints on generalised parton distributions that give access to the total angular momenta of quarks within the nucleon. The HERMES recoil detector was designed to improve the selection of exclusive events by a direct ...

  8. Impact of baseline characteristics on outcomes of carotid artery stenting in acute ischemic stroke patients

    Directory of Open Access Journals (Sweden)

    Yu CS

    2016-03-01

    Full Text Available Cheng-Sheng Yu,1,* Chih-Ming Lin,2,3,* Chi-Kuang Liu,4 Henry Horng-Shing Lu1 1Institute of Statistics and Big Data Research Center, National Chiao Tung University, Hsinchu, 2Stroke Centre and Department of Neurology, Chunghua Christian Hospital, Chunghua, 3Graduate Institute of Biological Science and Technology, National Chiao Tung University, Hsinchu, 4Department of Medical Imaging, Chunghua Christian Hospital, Chunghua, Taiwan, Republic of China *These authors contributed equally to this work Abstract: Carotid artery stenting is an effective treatment for ischemic stroke patients with moderate-to-severe carotid artery stenosis. However, the midterm outcome for patients undergoing this procedure varies considerably with baseline characteristics. To determine the impact of baseline characteristics on outcomes following carotid artery stenting, data from 107 eligible patients with a first episode of ischemic stroke were collected by retrospective chart review. A modified Rankin Scale (mRS was used to divide patients into two baseline groups, mRS ≤2 and mRS >2. A three-step decision-tree statistical analysis was conducted. After weighting the decision-tree parameters, the following impact hierarchy was obtained: admission low-density lipoprotein, gouty arthritis, chronic kidney disease, ipsilateral common carotid artery resistance index, contralateral ophthalmic artery resistance index, sex, and dyslipidemia. The finite-state machine model demonstrated that, in patients with baseline mRS ≤2, 46% had an improved mRS score at follow-up, whereas 54% had a stable mRS score. In patients with baseline mRS >2, a stable mRS score was observed in 75%, improved score in 23%, and a poorer score in 2%. Admission low-density lipoprotein was the strongest predictive factor influencing poststenting outcome. In addition, our study provides further evidence that carotid artery stenting can be of benefit in first-time ischemic stroke patients with baseline m

  9. Emergency Use of Stent and rtPA with Mechanical Cloth Defragmentation for a Thromboembolic Complication during GDC Coil Treatment of an Acutely Ruptured Basilar Tip Aneurysm.

    Science.gov (United States)

    Poncyljusz, W; Falkowski, A; Kojder, I; Sagan, L

    2006-11-30

    Thrombotic occlusion of both posterior cerebral arteries occurred during embolization of an acutely ruptured basilar tip aneurysm. Intracranial stenting and continuous superselective infusion of rtPA was administered combined with mechanical clot fragmentation to reestablish normal vessel flow. DSA disclosed that normal vessel patency was achieved within 30 min. There were no adverse events related to rtPA administration and the patient recovered from the embolization with minor neurologic deficit as present before the procedure. PMID:24351269

  10. Impact of plaque components on no-reflow phenomenon after stent deployment in patients with acute coronary syndrome: a virtual histology-intravascular ultrasound analysis

    OpenAIRE

    Hong, Young Joon; Jeong, Myung Ho; Choi, Yun Ha; Ko, Jum Suk; Lee, Min Goo; Kang, Won Yu; Lee, Shin Eun; Kim, Soo Hyun; Park, Keun Ho; Sim, Doo Sun; Yoon, Nam Sik; Youn, Hyun Ju; Kim, Kye Hun; Park, Hyung Wook; Kim, Ju Han

    2009-01-01

    Aims We used virtual histology-intravascular ultrasound (VH-IVUS) to evaluate the relation between coronary plaque characteristics and no-reflow in acute coronary syndrome (ACS) patients. Methods and results A total of 190 consecutive ACS patients were imaged using VH-IVUS and analysed retrospectively. Angiographic no-reflow was defined as TIMI flow grade 0, 1, and 2 after stenting. Virtual histology-intravascular ultrasound classified the colour-coded tissue into four major components: fibro...

  11. The HERMES recoil detector

    Energy Technology Data Exchange (ETDEWEB)

    Airapetian, A. [Giessen Univ. (Germany). Physikalisches Inst.; Michigan Univ., Ann Arbor, MI (United States). Randall Laboratory of Physics; Aschenauer, E.C. [DESY, Zeuthen (Germany); Belostotski, S. [B.P. Konstantinov Petersburg Nuclear Physics Insitute, Gatchina (Russian Federation)] [and others; Collaboration: HERMES Recoil Detector Group

    2013-02-15

    For the final running period of HERA, a recoil detector was installed at the HERMES experiment to improve measurements of hard exclusive processes in charged-lepton nucleon scattering. Here, deeply virtual Compton scattering is of particular interest as this process provides constraints on generalised parton distributions that give access to the total angular momenta of quarks within the nucleon. The HERMES recoil detector was designed to improve the selection of exclusive events by a direct measurement of the four-momentum of the recoiling particle. It consisted of three components: two layers of double-sided silicon strip sensors inside the HERA beam vacuum, a two-barrel scintillating fibre tracker, and a photon detector. All sub-detectors were located inside a solenoidal magnetic field with an integrated field strength of 1Tm. The recoil detector was installed in late 2005. After the commissioning of all components was finished in September 2006, it operated stably until the end of data taking at HERA end of June 2007. The present paper gives a brief overview of the physics processes of interest and the general detector design. The recoil detector components, their calibration, the momentum reconstruction of charged particles, and the event selection are described in detail. The paper closes with a summary of the performance of the detection system.

  12. The HERMES recoil detector

    Science.gov (United States)

    Airapetian, A.; Aschenauer, E. C.; Belostotski, S.; Borisenko, A.; Bowles, J.; Brodski, I.; Bryzgalov, V.; Burns, J.; Capitani, G. P.; Carassiti, V.; Ciullo, G.; Clarkson, A.; Contalbrigo, M.; De Leo, R.; De Sanctis, E.; Diefenthaler, M.; Di Nezza, P.; Düren, M.; Ehrenfried, M.; Guler, H.; Gregor, I. M.; Hartig, M.; Hill, G.; Hoek, M.; Holler, Y.; Hristova, I.; Jo, H. S.; Kaiser, R.; Keri, T.; Kisselev, A.; Krause, B.; Krauss, B.; Lagamba, L.; Lehmann, I.; Lenisa, P.; Lu, S.; Lu, X.-G.; Lumsden, S.; Mahon, D.; Martinez de la Ossa, A.; Murray, M.; Mussgiller, A.; Nowak, W.-D.; Naryshkin, Y.; Osborne, A.; Pappalardo, L. L.; Perez-Benito, R.; Petrov, A.; Pickert, N.; Prahl, V.; Protopopescu, D.; Reinecke, M.; Riedl, C.; Rith, K.; Rosner, G.; Rubacek, L.; Ryckbosch, D.; Salomatin, Y.; Schnell, G.; Seitz, B.; Shearer, C.; Shutov, V.; Statera, M.; Steijger, J. J. M.; Stenzel, H.; Stewart, J.; Stinzing, F.; Trzcinski, A.; Tytgat, M.; Vandenbroucke, A.; Van Haarlem, Y.; Van Hulse, C.; Varanda, M.; Veretennikov, D.; Vilardi, I.; Vikhrov, V.; Vogel, C.; Yaschenko, S.; Ye, Z.; Yu, W.; Zeiler, D.; Zihlmann, B.

    2013-05-01

    For the final running period of HERA, a recoil detector was installed at the HERMES experiment to improve measurements of hard exclusive processes in charged-lepton nucleon scattering. Here, deeply virtual Compton scattering is of particular interest as this process provides constraints on generalised parton distributions that give access to the total angular momenta of quarks within the nucleon. The HERMES recoil detector was designed to improve the selection of exclusive events by a direct measurement of the four-momentum of the recoiling particle. It consisted of three components: two layers of double-sided silicon strip sensors inside the HERA beam vacuum, a two-barrel scintillating fibre tracker, and a photon detector. All sub-detectors were located inside a solenoidal magnetic field with a field strength of 1T. The recoil detector was installed in late 2005. After the commissioning of all components was finished in September 2006, it operated stably until the end of data taking at HERA end of June 2007. The present paper gives a brief overview of the physics processes of interest and the general detector design. The recoil detector components, their calibration, the momentum reconstruction of charged particles, and the event selection are described in detail. The paper closes with a summary of the performance of the detection system.

  13. The HERMES recoil detector

    International Nuclear Information System (INIS)

    For the final running period of HERA, a recoil detector was installed at the HERMES experiment to improve measurements of hard exclusive processes in charged-lepton nucleon scattering. Here, deeply virtual Compton scattering is of particular interest as this process provides constraints on generalised parton distributions that give access to the total angular momenta of quarks within the nucleon. The HERMES recoil detector was designed to improve the selection of exclusive events by a direct measurement of the four-momentum of the recoiling particle. It consisted of three components: two layers of double-sided silicon strip sensors inside the HERA beam vacuum, a two-barrel scintillating fibre tracker, and a photon detector. All sub-detectors were located inside a solenoidal magnetic field with an integrated field strength of 1Tm. The recoil detector was installed in late 2005. After the commissioning of all components was finished in September 2006, it operated stably until the end of data taking at HERA end of June 2007. The present paper gives a brief overview of the physics processes of interest and the general detector design. The recoil detector components, their calibration, the momentum reconstruction of charged particles, and the event selection are described in detail. The paper closes with a summary of the performance of the detection system.

  14. Minimally invasive direct coronary artery bypass plus coronary stent for acute coronary syndrome: a case report

    Institute of Scientific and Technical Information of China (English)

    Caiyi Lu; Gang Wang; Qi Zhou; Jinwen Tian; Lei Gao; Shenhua Zhou; Jinyue Zhai; Rui Chen; Zhongren Zhao; Cangqing Gao; Shiwen Wang; Yuxiao Zhang; Ming Yang; Qiao Xue; Cangsong Xiao; Wei Gao; Yang Wu

    2008-01-01

    A 69-year old female patient was admitted because of 3 days of worsened chest pain.Coronary angiography showed60% stenosis of distal left main stem,chronic total occlusion of left anterior descending (LAD),70% stenosis at the ostium of a smallleft circumflex,70-90%stenosis at the paroxysmal and middle part of a dominant fight coronary artery (RCA),and a normal left internalmammary artery (LIMA) with normal origination and orientation.Percutaneous intervention was attempted but failed on the occludedlesion of LAD.The patient received minimally invasive direct coronary artery bypass (MIDCAB) with left LIMA isolation by Davincirobot.Eleven days later,the RCA lesion was treated by Sirolimus Rapamicin eluting stents implantation percutaneously.Then thepatient was discharged uneventfully after 3 days hospitalization.Our experience suggests that two stop shops of hybrid technique befeasible and safe in the treatment of elderly patient with multiple coronary diseases.

  15. Acute coronary syndrome with unusual form of right coronary artery aneurysm and treated with overlapping two covered stents across coronary aneurysm: case report

    Directory of Open Access Journals (Sweden)

    Naresh Sen

    2016-04-01

    Full Text Available A 27-year old male presented with acute inferior wall myocardial infarction. Coronary angiogram revealed normal left coronary arteries and a giant coronary aneurysm in Right coronary artery (RCA. Primary angioplasty of RCA was performed. Large thrombus burden was retrieved with aspiration device and coronary flow restored. However, despite best efforts some thrombus remained and decision to stent was deferred to a later date. Dimensions of aneurysm on quantitative coronary angiogram were 16 mm in width and 43 mm in length. Two weeks later coronary angiogram revealed normal flow in RCA without any angiographically visible thrombus. PCI was performed with two 3.0 and times; 28 mm covered stents, graft master (JoStent deployed across the aneurysm, overlapping each other. This completely sealed the aneurysm and intravascular ultrasound confirmed no leakage through the covered stents. Patient remains asymptomatic 2 months post procedure on triple antiplatelet therapy. [Int J Res Med Sci 2016; 4(4.000: 1295-1297

  16. Finite element analyses for design evaluation of biodegradable magnesium alloy stents in arterial vessels

    Energy Technology Data Exchange (ETDEWEB)

    Wu Wei [Laboratory of Biological Structure Mechanics, Structural Engineering Department, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan (Italy); Gastaldi, Dario, E-mail: dario.gastaldi@polimi.it [Laboratory of Biological Structure Mechanics, Structural Engineering Department, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan (Italy); Yang Ke; Tan Lili [Division of Specialized Materials and Devices, Institute of Metal Research, Chinese Academy of Sciences, Shenyang (China); Petrini, Lorenza; Migliavacca, Francesco [Laboratory of Biological Structure Mechanics, Structural Engineering Department, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan (Italy)

    2011-12-15

    Biodegradable magnesium alloy stents (MAS) can provide a great benefit for diseased vessels and avoid the long-term incompatible interactions between vessels and permanent stent platforms. However, the existing MAS showed insufficient scaffolding to the target vessels due to short degradation time. In this study, a three dimensional finite element model combined with a degradable material model of AZ31 (Al 0.03, Zn 0.01, Mn 0.002 and Mg balance, mass percentage) was applied to three different MAS designs including an already implanted stent (Stent A), an optimized design (Stent B) and a patented stent design (Stent C). One ring of each design was implanted through a simulation in a vessel model then degraded with the changing interaction between outer stent surface and the vessel. Results showed that a proper stent design (Stent B) can lead to an increase of nearly 120% in half normalized recoil time of the vessel compared to the Stent A; moreover, the expectation that the MAS design, with more mass and optimized mechanical properties, can increase scaffolding time was verified numerically. The Stent C has more materials than Stent B; however, it only increased the half normalized recoil time of the vessel by nearly 50% compared to the Stent A because of much higher stress concentration than that of Stent B. The 3D model can provide a convenient design and testing tool for novel magnesium alloy stents.

  17. Acute thrombosis during left main stenting using tap technique in a patient presenting with non-ST-segment elevation acute coronary syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Natarajan, Deepak, E-mail: deepaknatarajan@me.com

    2015-06-15

    This case reports the sudden development of large burden of thrombi in the left anterior descending coronary artery immediately following distal left main stenting using TAP technique in a middle aged man who presented with non ST-segment elevation acute coronary syndrome despite having been administered 7,500 units of unfractionated heparin and being given 325 mg of aspirin and 60 mg of prasugrel prior to the procedure. The thrombi were managed effectively by giving an intra-coronary high bolus dose of tirofiban (25 mcg/kg) without the need for catheter thrombus extraction. Tirofiban intra-venous infusion was maintained for 18 hours, and the patient was discharged in stable condition on the third day. Importantly there is no controlled study on upstream administration of glycoprotein IIb/IIIa inhibitors in addition to the newer more potent anti-platelet agents in patients with unprotected distal left main disease presenting with non ST-segment elevation acute coronary syndrome, nor is there any data on safety and efficacy of mandatory usage of injectable anti-platelet agents at the start of a procedure in a catheterization laboratory in such a setting.

  18. Acute thrombosis during left main stenting using tap technique in a patient presenting with non-ST-segment elevation acute coronary syndrome

    International Nuclear Information System (INIS)

    This case reports the sudden development of large burden of thrombi in the left anterior descending coronary artery immediately following distal left main stenting using TAP technique in a middle aged man who presented with non ST-segment elevation acute coronary syndrome despite having been administered 7,500 units of unfractionated heparin and being given 325 mg of aspirin and 60 mg of prasugrel prior to the procedure. The thrombi were managed effectively by giving an intra-coronary high bolus dose of tirofiban (25 mcg/kg) without the need for catheter thrombus extraction. Tirofiban intra-venous infusion was maintained for 18 hours, and the patient was discharged in stable condition on the third day. Importantly there is no controlled study on upstream administration of glycoprotein IIb/IIIa inhibitors in addition to the newer more potent anti-platelet agents in patients with unprotected distal left main disease presenting with non ST-segment elevation acute coronary syndrome, nor is there any data on safety and efficacy of mandatory usage of injectable anti-platelet agents at the start of a procedure in a catheterization laboratory in such a setting

  19. Endonasal DCR with Silicon Tube Stents: A Better Management for Acute Lacrimal Abscesses

    OpenAIRE

    Sudhir M Naik; Appaji, Mohan K.; S Ravishankara; Mushannavar, Annapurna S.; Sarika S Naik

    2012-01-01

    Acute dacryocystitis, or inflammation of the lacrimal sac with lacrimal abscess, is almost always secondary to nasolacrimal duct obstruction. The standard practice for the treatment is incision and drainage because of concerns about the risks of exacerbation and spread of infection. Here we tried to evaluate primary EnDCR as a treatment for acute dacryocystitis with abscess formation. Department of ENT, Head and Neck Surgery, KVG Medical College, Sullia. This is comparative case series analys...

  20. The HERMES Recoil Detector

    CERN Document Server

    Airapetian, A; Belostotski, S; Borissov, A; Borisenko, A; Bowles, J; Brodski, I; Bryzgalov, V; Burns, J; Capitani, G P; Carassiti, V; Ciullo, G; Clarkson, A; Contalbrigo, M; De Leo, R; De Sanctis, E; Diefenthaler, M; Di Nezza, P; Düren, M; Ehrenfried, M; Guler, H; Gregor, I M; Hartig, M; Hill, G; Hoek, M; Holler, Y; Hristova, I; Jo, H S; Kaiser, R; Keri, T; Kisselev, A; Krause, B; Krauss, B; Lagamba, L; Lehmann, I; Lenisa, P; Lu, S; Lu, X -G; Lumsden, S; Mahon, D; de la Ossa, A Martinez; Murray, M; Mussgiller, A; Nowak, W -D; Naryshkin, Y; Osborne, A; Pappalardo, L L; Perez-Benito, R; Petrov, A; Pickert, N; Prahl, V; Protopopescu, D; Reinecke, M; Riedl, C; Rith, K; Rosner, G; Rubacek, L; Ryckbosch, D; Salomatin, Y; Schnell, G; Seitz, B; Shearer, C; Shutov, V; Statera, M; Steijger, J J M; Stenzel, H; Stewart, J; Stinzing, F; Trzcinski, A; Tytgat, M; Vandenbroucke, A; Van Haarlem, Y; Van Hulse, C; Varanda, M; Veretennikov, D; Vilardi, I; Vikhrov, V; Vogel, C; Yaschenko, S; Ye, Z; Yu, W; Zeiler, D; Zihlmann, B

    2013-01-01

    For the final running period of HERA, a recoil detector was installed at the HERMES experiment to improve measurements of hard exclusive processes in charged-lepton nucleon scattering. Here, deeply virtual Compton scattering is of particular interest as this process provides constraints on generalised parton distributions that give access to the total angular momenta of quarks within the nucleon. The HERMES recoil detector was designed to improve the selection of exclusive events by a direct measurement of the four-momentum of the recoiling particle. It consisted of three components: two layers of double-sided silicon strip sensors inside the HERA beam vacuum, a two-barrel scintillating fibre tracker, and a photon detector. All sub-detectors were located inside a solenoidal magnetic field with an integrated field strength of 1 Tm. The recoil detector was installed in late 2005. After the commissioning of all components was finished in September 2006, it operated stably until the end of data taking at HERA end...

  1. Endonasal DCR with Silicon Tube Stents: A Better Management for Acute Lacrimal Abscesses.

    Science.gov (United States)

    Naik, Sudhir M; Appaji, Mohan K; Ravishankara, S; Mushannavar, Annapurna S; Naik, Sarika S

    2013-08-01

    Acute dacryocystitis, or inflammation of the lacrimal sac with lacrimal abscess, is almost always secondary to nasolacrimal duct obstruction. The standard practice for the treatment is incision and drainage because of concerns about the risks of exacerbation and spread of infection. Here we tried to evaluate primary EnDCR as a treatment for acute dacryocystitis with abscess formation. Department of ENT, Head and Neck Surgery, KVG Medical College, Sullia. This is comparative case series analysis study done in our medical college hospital during the study period 61 months from January 2007 to November 2011. 31 cases of acute dacryocystitis with lacrimal abscess managed were included in the study. 13 cases were operated primarily with EnDCR. Rest of the 18 cases was managed conventionally by incision and drainage and later by an external approach of DCR. Swelling disappeared intraoperatively in all EnDCR cases while medial canthal edema and erythema completely reduced within 2-3 days post-operatively. While in incision and drainage swelling disappeared partially intraoperatively and repeated draining was needed on the 2nd and 3rd day. The mean VAS score on first post operative day was 3.14 in group A and was 4.64 in group B. Group A had faster pain relief with 92.3% improvement in epiphora while group B had slower pain relief but epiphora remained. Mean intraoperative blood was 65 ml in group A and minimal in group B. Primary EnDCR is successful as a procedure of choice for acute dacryocystitis with abscess preventing further episodes of abscess formation and epiphora in the patients. We recommend EnDCR as the treatment of choice for acute dacryocystitis with lacrimal abscesses. PMID:24427674

  2. Stent graft placement for dysfunctional arteriovenous grafts

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Gyeong Sik [Dept. of Radiology, CHA Bundang Medical Center, College of Medicine, CHA University, Seongnam (Korea, Republic of); Shin, Byung Seok; Ohm, Joon Young; Ahn, Moon Sang [Chungnam National University Hospital, Daejeon (Korea, Republic of)

    2015-07-15

    This study aimed to evaluate the usefulness and outcomes of stent graft use in dysfunctional arteriovenous grafts. Eleven patients who underwent stent graft placement for a dysfunctional hemodialysis graft were included in this retrospective study. Expanded polytetrafluoroethylene covered stent grafts were placed at the venous anastomosis site in case of pseudoaneurysm, venous laceration, elastic recoil or residual restenosis despite the repeated angioplasty. The patency of the arteriovenous graft was evaluated using Kaplan-Meier analysis. Primary and secondary mean patency was 363 days and 741 days. Primary patency at 3, 6, and 12 months was 82%, 73%, and 32%, respectively. Secondary patency at the 3, 6, 12, 24, and 36 months was improved to 91%, 82%, 82%, 50%, and 25%, respectively. Fractures of the stent graft were observed in 2 patients, but had no effect on the patency. Stent graft placement in dysfunctional arteriovenous graft is useful and effective in prolonging graft patency.

  3. Six Versus Twelve Months Clopidogrel Therapy After Drug-Eluting Stenting in Patients With Acute Coronary Syndrome: An ISAR-SAFE Study Subgroup Analysis.

    Science.gov (United States)

    Lohaus, Raphaela; Michel, Jonathan; Mayer, Katharina; Lahmann, Anna Lena; Byrne, Robert A; Wolk, Annabelle; Ten Berg, Jurrien M; Neumann, Franz-Josef; Han, Yaling; Adriaenssens, Tom; Tölg, Ralph; Seyfarth, Melchior; Maeng, Michael; Zrenner, Bernhard; Jacobshagen, Claudius; Wöhrle, Jochen; Kufner, Sebastian; Morath, Tanja; Ibrahim, Tareq; Bernlochner, Isabell; Fischer, Marcus; Schunkert, Heribert; Laugwitz, Karl-Ludwig; Mehilli, Julinda; Kastrati, Adnan; Schulz-Schüpke, Stefanie

    2016-01-01

    In patients presenting with acute coronary syndrome (ACS) the optimal duration of dual-antiplatelet therapy after drug-eluting stent (DES) implantation remains unclear. At 6 months after intervention, patients receiving clopidogrel were randomly assigned to either a further 6-month period of placebo or clopidogrel. The primary composite endpoint was death, myocardial infarction, stent thrombosis, stroke, or major bleeding 9 months after randomization. The ISAR-SAFE trial was terminated early due to low event rates and slow recruitment. 1601/4000 (40.0%) patients presented with ACS and were randomized to 6 (n = 794) or 12 months (n = 807) clopidogrel. The primary endpoint occurred in 14 patients (1.8%) receiving 6 months of clopidogrel and 17 patients (2.2%) receiving 12 months; hazard ratio (HR) 0.83, 95% confidence interval (CI) 0.41-1.68, P = 0.60. There were 2 (0.3%) cases of stent thrombosis in each group; HR 1.00, 95% CI 0.14-7.09, P = >0.99. Major bleeding occurred in 3 patients (0.4%) receiving 6 months clopidogrel and 5 (0.6%) receiving 12 months; HR 0.60, 95% CI 0.15-2.49, P = 0.49. There was no significant difference in net clinical outcomes after DES implantation in ACS patients treated with 6 versus 12 months clopidogrel. Ischaemic and bleeding events were low beyond 6-months. PMID:27624287

  4. Transient ST-segment elevation in precordial leads by acute marginal branch occlusion during stent implantation.

    Science.gov (United States)

    Arzola, Leidimar Carballo; Esteban, Marcos T Rodríguez; Niebla, Javier García

    2016-01-01

    The isolated right ventricular infarction is a rare entity. Our case presented a selective occlusion of an acute marginal branch that supplies the right ventricular free wall with isolated ST elevation in precordial leads simulating an occlusion of the left anterior descending artery and without pseudonormalization in inferior due to the non-involvement of the main branch in the ischemic process. Our case clearly illustrates a rare differential diagnosis when a new ST segment elevation appears in earlier precordial leads in patients with symptoms of myocardial ischemia.

  5. Implanted central venous catheter-related acute superior vena cava syndrome: management by metallic stent and endovascular repositioning of the catheter tip

    Energy Technology Data Exchange (ETDEWEB)

    Qanadli, S.D.; Mesurolle, B.; Sissakian, J.F.; Chagnon, S.; Lacombe, P. [Service de Radiologie, Hopital Ambroise Pare, 92 - Boulogne (France)

    2000-08-01

    We describe a case of a 49-year-old woman with stage-IIIB lung adenocarcinoma who experienced an acute superior vena cava syndrome related to an implanted central venous catheter without associated venous thrombosis. The catheter was surgically implanted for chemotherapy. Superior vena cava syndrome appeared after the procedure and was due to insertion of the catheter through a subclinical stenosis of the superior vena cava. Complete resolution of the patient's symptoms was obtained using stent placement and endovascular repositioning of the catheter tip. (orig.)

  6. Bronchial stents

    Directory of Open Access Journals (Sweden)

    Ibrahim Emad

    2006-01-01

    Full Text Available Bronchial stents are mostly used as a Palliative relief of symptoms often caused by airway obstruction, It is also used for sealing of stump fistulas after pneumonectomy and dehiscence after bronchoplastic operations. Advances in airway prosthetics have provided a variety of silicone stents, expandable metal stents, and pneumatic dilators, enabling the correction of increasingly complex anatomical problems. Several series have been published describing the application and results of these techniques. This manuscript reviews the historical development of stents, types, indication, outcome, and complications. Alternative therapies for tracheobronchial stenting were also reviewed

  7. Very late bare-metal stent thrombosis, rare but stormy!

    LENUS (Irish Health Repository)

    Ali, Mohammed

    2011-08-01

    Recurrent in-stent thrombosis is rarely reported, with catastrophic clinical consequences of either acute coronary syndrome or death. We present a case of recurrent in-stent thrombosis with its outcome and a concise literature review.

  8. Characteristic mechanical properties of balloon-expandable peripheral stent systems

    International Nuclear Information System (INIS)

    Purpose: To measure in vitro geometric-mechanical characteristics of balloon-expandable peripheral stent systems for determining suitability for specific vascular regions. Materials and Methods: Balloon-expandable stents including their delivery systems manufactured by Guidant (OTW MegalinkTM), Inflow Dynamics (Antares), Medtronic (AVE BridgeTM), Biotronik (PeironTM) and Cordis (Corinthian IQTM) were selected for this study. When expanded, all stents had a nominal diameter of 8 mm. The length was 38-40 mm. Stent profile, trackability, length change on expansion, stiffness, elastic recoil, and radio-opacity in the crimped and expanded state of these stent systems were determined with specially developed test methods. Results: The Corinthian IQTM, MegalinkTM and PeironTM required the smallest force to pass through the vascular model. While the BridgeTM system had the largest profile with a diameter of 2.430 mm, all other stent systems had a significantly smaller diameter ranging from 1.970 mm for the PeironTM to 2.078 mm for the Corinthian IQTM. In the distal region of the stent delivery system, the MegalinkTM was the most flexible and the BridgeTM system the stiffest. Elastic recoil for all stents was in the range of 2.5% to 3.5%, with the exception of the BridgeTM stent, which had an elastic recoil of 4.79%. The Corinthian IQTM stent had noticeably the highest radial stiffness. In the expanded condition, the PeironTM was the most flexible while the Corinthian IQTM and AntaresTM were found to be the stiffest. Length change (shrinkage on expansion) ranged from 0.54 to 6.57%, with the exception of the Corinthian IQ, which shrunk >7 mm (18.5%) on expansion. All stent systems in the crimped and expanded state were readily visible radiographically. (orig.)

  9. Impact of admission creatinine level on clinical outcomes of patients with acute ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention with drug-eluting stent implantation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qi; ZHANG Rui-yan; SHEN Jie; ZHANG Jian-sheng; HU Jian; YANG Zheng-kun; ZHANG Xian; ZHENG Ai-fang; SHEN Wei-feng

    2008-01-01

    Background Prognosis of patients with acute ST-elevation myocardial infarction (STEMI) and renal dysfunction (RD) who received primary percutaneous coronary intervention (PCI) has not been fully investigated in the drug-eluting stent (DES) era.This study aimed to evaluate the impact of admission serum creatinine level on short-term outcomes in patients with acute STEMI undergoing DES-based primary PCI.Methods Primary PCI with DES implantation was attempted in 619 consecutive STEMI patients within 12 hours of symptom onset.Among them,86 patients had a serum creatinine level >115 μmol/L on admission (RD group),and the remaining 533 patients had normal renal function (non-RD group).The primary endpoint was 30-day major adverse cardiac events (MACE,including death,non-fatal reinfarction,and target vessel revascularization),and the secondary endpoint was subacute stent thrombosis.Results Patients in the RD group were older than those in the non-RD group.There are more female patients in the RD group and they had a history of hypertension,myocardial infarction and revascularization.The occurrence rates of Killip class ≥2 (29.1% vs 18.6%,P=0.02) and multi-vessel (62.8% vs 44.5%,P=0.001) and triple vessel disease (32.6% vs 18.2%,P=0.002),in-hospital mortality (9.3% vs 3.8%,P=0.03),and MACE rate during hospitalization (17.4% vs 7.7%,P=0.006) were higher in the RD group than those in the non-RD group.At a 30-day clinical follow-up,the MACE-free survival rate was significantly reduced in the RD group (76.7% vs 89.9%,P=0.0003).Angiographic stent thrombosis occurred in 3 (3.5%) and 7 (1.3%) of patients in the RD group and non-RD group,respectively (P=0.15).Multivariate analysis revealed that the serum creatinine level≥115 μmol/L on admission was an independent predictor for MACE rate at a 30-day follow-up (Hazard ratio (HR) 3.31,95% CI 1.19-9.18,P<0.001).Conclusion Despite similar prevalence of stent thrombosis at a 30-day clinical follow-up,the short-term prognosis of

  10. Recoiling Black Holes in Quasars

    CERN Document Server

    Bonning, E W; Salviander, S

    2007-01-01

    Recent simulations of merging black holes with spin give recoil velocities from gravitational radiation up to several thousand km/s. A recoiling supermassive black hole can retain the inner part of its accretion disk, providing fuel for a continuing QSO phase lasting millions of years as the hole moves away from the galactic nucleus. One possible observational manifestation of a recoiling accretion disk is in QSO emission lines shifted in velocity from the host galaxy. We have examined QSOs from the Sloan Digital Sky Survey with broad emission lines substantially shifted relative to the narrow lines. We find no convincing evidence for recoiling black holes carrying accretion disks. We place an upper limit on the incidence of recoiling black holes in QSOs of 4% for kicks greater than 500 km/s and 0.35% for kicks greater than 1000 km/s line-of-sight velocity.

  11. The HERMES recoil detector

    Energy Technology Data Exchange (ETDEWEB)

    Van Hulse, Charlotte, E-mail: charlotte@inwfsun1.UGent.b [Gent University Department of Subatomic and Radiation Physics, Proeftuinstraat 86, 9000 Gent (Belgium)

    2010-11-01

    In order to allow for the detection of low momentum particles, originating from the scattering of a 27.6 GeV lepton beam off a fixed gaseous target at the HERMES experiment at DESY in Hamburg (Germany), a dedicated recoil detector was installed. It consists of a silicon strip detector, located inside the beam vacuum, a scintillating fiber tracker and a photon detector, around a 150 mm long target cell made out of a 75{mu}m thick aluminum tube. The full detector assembly is mounted inside a 1 T super-conducting solenoid and is able to detect protons and pions with momenta up to 1.40 GeV/c and photons in the region surrounding the target cell. The detector has been operational from February 2006 until June 2007. The commissioning and performance of the detector are presented in this paper.

  12. Subacute coronary stent thrombosis in a patient with angina treated with double antiplatelet drugs for six days

    Institute of Scientific and Technical Information of China (English)

    XUE Feng; YANG Xiang-jun; CHENG Xu-jie; HUI Jie; JIANG Ting-bo; CHEN Tan; LIU Zhi-hua; SONG Jian-ping; JIANG Wen-ping

    2009-01-01

    @@ Stent implantation has been a great advance in percutaneous coronary intervention (PCI), decreasing the frequency of acute closure and restenosis. But stent thrombosis is a severe complication of this therapy regardless of the stent type: bare-metal stent (BMS) and drug-eluting stent (DES).

  13. Impact of Dual Antiplatelet Therapy with Proton Pump Inhibitors on the Outcome of Patients with Acute Coronary Syndrome Undergoing Drug-Eluting Stent Implantation

    Science.gov (United States)

    Macaione, Francesca; Montaina, Carla; Evola, Salvatore; Novo, Giuseppina; Novo, Salvatore

    2012-01-01

    This study aimed to assess if proton pump inhibitors (PPIs) may reduce the effectiveness of clopidogrel, than H2 antagonist (anti-H2) in order to determine rehospitalization for acute coronary syndrome (re-ACS), target vessel revascularization (TVR) and cardiac death. This case-control study included 176 patients with ACS undergoing angioplasty (PCI) with drug-eluting stent implantation. The population was divided into two groups: PPI group (n = 121) consisting of patients receiving at discharge dual antiplatelet therapy (DAT) plus PPI and anti-H2 group (n = 55), consisting of patients receiving at discharge DAT + H2 receptor antagonist (H2RA). In a followup of 36 months the prevalence of ACS event (P = 0.014), TVR (P = 0.031) was higher in the PPI group than in the anti-H2 group; instead there was no statistically significant difference between groups for death. The variables independently associated with ACS were the diabetes, omeprazole, and esomeprazole; instead the variables independently associated with TVR were only omeprazole. Our data shows that the use of omeprazole and esomeprazole, with clopidogrel, is associated with increased risk of adverse outcomes after PCI with drug-eluting stent implantation. PMID:22792485

  14. Very Late Bare Metal Stent Thrombosis

    Directory of Open Access Journals (Sweden)

    Mariana Soto Herrera

    2013-01-01

    Full Text Available Very late stent thrombosis is a rare and not-well-understood complication after bare metal stent implantation. It usually presents as an ST elevation acute coronary syndrome and it is associated with high rates of morbidity and mortality. Pathophysiologic mechanisms are not well defined; nevertheless, recent studies have proposed a neoatherosclerotic process as the triggering mechanism. We present the case of a patient with bare metal very late stent thrombosis 12 years after implantation.

  15. Very Late Bare Metal Stent Thrombosis

    Science.gov (United States)

    Soto Herrera, Mariana; Restrepo, José A.; Felipe Buitrago, Andrés; Gómez Mejía, Mabel; Díaz, Jesús H.

    2013-01-01

    Very late stent thrombosis is a rare and not-well-understood complication after bare metal stent implantation. It usually presents as an ST elevation acute coronary syndrome and it is associated with high rates of morbidity and mortality. Pathophysiologic mechanisms are not well defined; nevertheless, recent studies have proposed a neoatherosclerotic process as the triggering mechanism. We present the case of a patient with bare metal very late stent thrombosis 12 years after implantation. PMID:24829831

  16. Maximizing benefit of drug-eluting stent by direct coronary stenting because of further reduction of inflammatory response

    Institute of Scientific and Technical Information of China (English)

    LI Jian-jun; GAO Run-lin

    2009-01-01

    @@ Coronary stents have been used as standard mechanical devices for percutaneous coronary intervention (PCI) in patients with coronary artery disease (CAD).1-3 They provide vessel wall scaffolding and prevent early elastic recoil and restenosis, which are major limitations of balloon angioplasty.4,5 Consequently, coronary stenting has a higher successful rate of PCI and improves the clinical outcome of the patients with CAD.6

  17. Ballon angioplasty and stenting for acute ischemic stroke%急性缺血性卒中患者的球囊血管成形和支架置入术治疗

    Institute of Scientific and Technical Information of China (English)

    石明超; 王守春

    2009-01-01

    药物溶栓治疗急性缺血性卒中存在一定的局限性,球囊血管成形和支架置入术已成为急性缺血性卒中治疗的研究热点.文章综述了球囊血管成形和支架置入术治疗急性缺血性卒中的有效性和安全性.%Thrombolytic agents for the treatment of acute ischemic stroke have some limitations. Balloon angioplasty and stenting have become the research hotspot in the treatment of acute ischemic stroke. 1his article reviews the effectiveness and safety of balloon angioplasty and stenting in the treatment of acute ischemic stroke.

  18. Comparison of Safety between Yinyi Micropole Drug Coated Stent and PARTNER in Patients with Acute Myocardial Infarction%垠艺TM支架与PARTNER支架治疗急性心肌梗死的安全性比较

    Institute of Scientific and Technical Information of China (English)

    王书林; 党群; 李永健; 赵凯

    2011-01-01

    目的:探讨垠艺TM微肓孔载药支架在急性心肌梗死(AMI)经皮冠状动脉介入(PCI)治疗中应用的安全性.方法:选拟行PCI治疗的AMI患者190例,并按植入支架类型分为垠艺TM微盲孔载药支架组(A组,100例)和国产雷帕霉素洗脱支架(PARTNER)组(B组,90例),对2组患者住院期间、术后30 d及术后6个月的主要心血管不良事件(MACE)和支架内血栓的发生情况进行随访和对比分析.结果:住院期间A组无急性、亚急性及晚期血栓发生,B组发生1例亚急性支架内血栓.住院期间、术后30d及6个月时2组MACE的发生率差异均无统计学意义(P>0.05).结论:垠艺TM微盲孔载药支架在治疗AMI中与PARTNER支架一样有较好的安全性.%Objective: To investigate the safety of Yinyi micropole drug coated stent in percutaneous coronary intervention (PCI) in patients with acute myocardial infarction(AMI). Methods:One hundred and ninety consecutive patients with AMI underwent PCI were divided into Yinyi micropole drug coated stent group (Group A, n= 100) and domestic produced rapamycin-eluting stent (PARTNER) group (Group B,n= 90)according to the type of the stents. The incidence of major adverse cardiovascular event (MACE) and stent thrombosis was evaluated during in-hospital, 30 days and 6 months follow up after PCI in patients of two groups. Results: There was no acute, subacute and late in-stent thrombosis during the hospital stay in group A, but one case stent thrombosis in group B (P > 0.05). There were no significant differences in rates of MACE during the hospital stay, 30 days and 6 months after operation between the 2 groups(P > 0.05). Conclusion: Implantation of Yinyi micropole drug coated stent after PCI is as safe as PARTNER stent in patients with AMI.

  19. Acute Portal Vein Thrombosis and Massive Necrosis of the Liver. An Unusual Complication After Stenting for Chronic Pancreatitis

    Directory of Open Access Journals (Sweden)

    Velayutham Vimalraj

    2006-11-01

    Full Text Available Context ERCP can provide information which is invaluable in managing chronic pancreatitis but it is associated withinfrequent, although significant, complications and rare mortality. The complications uniquely associated withdiagnostic ERCP include pancreatitis and sepsis (primary cholangitis. Case report A 32-year-old man presented with severe upper abdominal pain radiating to the back, associated with vomiting and abdominal distension. The patient was diagnosed as having had chronic calcific pancreatitis recently and had undergone ERCP with pancreatic duct stenting elsewhere. Two days after the procedure, the patient developed severe abdominal pain, vomiting and abdominal distention, and patient was referred to our hospital 7 days after the procedure. Investigation revealed massive liver necrosis and portal vein thrombosis. This patient had a life-threatening complication following pancreatic duct stenting for chronic pancreatitis and was managed medically.Conclusion Therapeutic pancreatic endoscopy procedures are technically demanding and should be restricted to highvolume centers. There is a continuing need for evaluation and comparison with alternative strategies. In a good surgical candidate, it is better to avoid stenting.

  20. Early double stent thrombosis associated with clopidogrel hyporesponsivenesss

    OpenAIRE

    Rademakers, L. M.; Dewilde, W.; van de Kerkhof, D

    2011-01-01

    A 57-year-old male patient without cardiovascular history suffered an acute myocardial infarction and underwent drug-eluting stent implantation in the left anterior descending artery. A few days later, the right coronary artery was also stented (drug-eluting stent). Three days later, he was re-admitted to our hospital in cardiogenic shock. Emergent coronary angiography showed total occlusion of both stents. Platelet function analysis (PFA) showed attenuated platelet inhibition in response to ...

  1. Stent malapposition, as a potential mechanism of very late stent thrombosis after bare-metal stent implantation: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Higuma, Takumi, E-mail: higuma@cc.hirosaki-u.ac.jp; Abe, Naoki; Hanada, Kenji; Yokoyama, Hiroaki; Tomita, Hirofumi; Okumura, Ken

    2014-04-15

    A 90-year-old man was admitted to our hospital with acute ST-segment elevation myocardial infarction. He had a history of post-infarction angina pectoris 79 months ago and had a bare-metal stent (BMS) implanted in the proximal left anterior descending artery at our hospital. Emergent coronary angiography demonstrated thrombotic occlusion in the previously stented segment. After catheter thrombectomy, antegrade flow was restored, but 90% stenosis with haziness persisted in the proximal and distal portions of the previously stented segment. Intravascular ultrasound imaging showed interstrut cavities or stent malapposition at the proximal and distal sites of stented segment. In close proximity to the sites, residual thrombi were also observed. Optical coherence tomography (OCT) demonstrated neither lipid-laden neointimal tissue nor rupture but clearly demonstrated residual thrombus adjacent to the malapposed region in addition to the stent malapposition. PCI with balloon was successfully performed and stent apposition was confirmed by OCT. Stent malapposition is an unusual mechanism of very late stent thrombosis after BMS implantation. OCT can clearly reveal the etiology of stent thrombosis.

  2. Very late stent thrombosis of bare-metal coronary stent nine years after primary percutaneous coronary intervention

    Directory of Open Access Journals (Sweden)

    Đurić Predrag

    2016-01-01

    Full Text Available Introduction. Stent thrombosis (ST in clinical practice can be classified according to time of onset as early (0–30 days after stent implantation, which is further divided into acute ( 30 days and very late (> 12 months. Myocardial reinfaction due to very late ST in a patient receiving antithrombotic therapy is very rare, and potentially fatal. The procedure alone and related mechanical factors seem to be associated with acute/subacute ST. On the other hand, in-stent neoathero-sclerosis, inflammation, premature cessation of antiplatelet therapy, as well as stent fracture, stent malapposition, un-covered stent struts may play role in late/very late ST. Some findings implicate that the etiology of very late ST of bare-metal stent (BMS is quite different from those following drug-eluting stent (DES implantation. Case report. We presented a 56-year old male with acute inferoposterior ST segment elevation myocardial infarction (STEMI related to very late stent thrombosis, 9 years after BMS implantation, despite antithrombotic therapy. Thrombus aspiration was successfully performed followed by percutaneous coronary intervention (PCI with implantation of DES into the pre-viously implanted two stents to solve the in-stent restenosis. Conclusion. Very late stent thrombosis, although fortu-nately very rare, not completely understood, might cause myocardial reinfaction, but could be successfully treated with thrombus aspiration followed by primary PCI. Very late ST in the presented patient might be connected with neointimal plaque rupture, followed by thrombotic events.

  3. Effect of cause of iliac vein stenosis and extent of thrombus in the lower extremity on patency of iliac venous stent placed after catheter-directed thrombolysis of acute deep venous thrombosis in the lower extremity

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Sung Il; Choi, Young Ho; Yoon, Chang Jin; Lee, Min Woo; Chung, Jin Wook; Park, Jae Hyung [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    2003-10-01

    To assess the CT findings of acute deep venous thrombosis (DVT) in a lower extremity prior to catheter-directed thrombolysis, and to evaluate their relevance to the patency of an iliac venous stent placed with the help of CT after catheter-directed thrombolysis of DVT. Fourteen patients [M:F=3:11; age, 33-68 (mean, 50.1) years] with acute symptomatic DVD of a lower extremity underwent CT before and after catheter-directed thrombolysis using an iliac venous stent. The mean duration of clinical symptoms was 5.0 (range, 1-14 days. The CT findings prior to thrombolysis were evaluated in terms of their anatomic cause and the extent of the thrombus, and in all patients, the patency of the iliac venous stent was assessed at CT performed during a follow-up period lasting 6-31 (mean, 18.9) months. All patients were assigned to the patent stent group (n=9) or the occluded stent group (n=5). In the former, the anatomic cause of patency included typical iliac vein compression (May-Thurner syndrome) (n=9), and a relatively short segmental thrombus occurring between the common iliac and the popliteal vein (n=8). Thrombi occurred in the iliac vein (n=3), between the common iliac and the femoral vein (n=3), and between the common iliac and the popliteal vein (n=2). In one case, a relatively long segmental thrombus occurred between the common iliac vein and the calf vein. In the occluded stent group, anatomic causes included atypical iliac vein compression (n=3) and a relatively long segmental thrombus between the common iliac and the calf vein (n=4). Typical iliac vein compression (May-Thurner syndrome) occurred in two cases, and a relatively short segmental thrombus between the external iliac and the common femoral vein in one. Factors which can affect the patency of an iliac venous stent positioned after catheter-directed thrombolysis are the anatomic cause of the stenosis, and the extent of a thrombus revealed at CT of acute DVT and occurring in a lower extremity prior to

  4. Comparison of long-term clinical outcome between patients with chronic versus acute type B aortic dissection treated by implantation of a stent graft: a single-center report

    Directory of Open Access Journals (Sweden)

    Chen SL

    2013-04-01

    Full Text Available Shao-Liang Chen, Jian-Cheng Zhu, Xiao-Bo Li, Fei Ye, Jun-Jie Zhang, Zhi-Zhong Liu, Nai-Liang Tian, Song Lin, Cheng-Yu Lv Nanjing First Hospital, Nanjing Medical University, Nanjing, People's Republic of China Background: Stent grafting for treatment of type B aortic dissection has been extensively used. However, the difference in the long-term clinical outcome between patients with chronic versus acute type B aortic dissection remains unknown. This study aimed to analyze the difference in long-term clinical outcome after endovascular repair for patients with chronic (93% complete false-lumen thrombosis. Untreated tear and type I endoleak were predictors of clinical events during follow-up. Conclusion: Comparable long-term clinical results were achieved in patients with chronic or acute type B aortic dissection after implantation of a stent graft. Keywords: aortic dissection, endovascular repair, procedure-related events, propensity score matching

  5. Consequences of gravitational radiation recoil

    CERN Document Server

    Merritt, D; Favata, M; Hughes, S A; Holz, D E; Merritt, David; Milosavljevic, Milos; Favata, Marc; Hughes, Scott A.; Holz, Daniel E.

    2004-01-01

    Coalescing binary black holes experience an impulsive kick due to anisotropic emission of gravitational waves. We discuss the dynamical consequences of the recoil accompanying massive black hole mergers. Recoil velocities are sufficient to eject most coalescing black holes from dwarf galaxies and globular clusters, which may explain the apparent absence of massive black holes in these systems. Ejection from giant elliptical galaxies would be rare, but coalescing black holes are displaced from the center and fall back on a time scale of order the crossing time. Displacement of the black holes transfers energy to the stars in the nucleus and can convert a steep density cusp into a core. Radiation recoil calls into question models that grow supermassive black holes from hierarchical mergers of stellar-mass precursors.

  6. Recoiling DNA Molecule Simulation & Experiment

    CERN Document Server

    Neto, J C; Mesquita, O N; Neto, Jose Coelho; Dickman, Ronald

    2002-01-01

    Many recent experiments with single DNA molecules are based on force versus extension measurements and involve tethering a microsphere to one of its extremities and the other to a microscope coverglass. In this work we show that similar results can also be obtained by studying the recoil dynamics of the tethered microspheres. Computer simulations of the corresponding Langevin equation indicate which assumptions are required for a reliable analysis of the experimental recoil curves. We have measured the persistence length A of single naked DNA molecules and DNA-Ethidium Bromide complexes using this approach.

  7. Late stent thrombosis: a not negligible issue after drug-eluting stent implantation

    Institute of Scientific and Technical Information of China (English)

    GAO Run-lin

    2007-01-01

    @@ Drug-eluting stent (DES) has markedly reduced restenosis and the need for target lesion revascularization (TLR). The safety profile of DES does not seem to differ from that of bare metal stent in the acute and subacute phases following coronary intervention.

  8. Acute non ST segment elevation myocardial infarction (mi) relations with drug-eluting stents%急性非ST段抬高型心肌梗死与药物洗脱支架植入的关系

    Institute of Scientific and Technical Information of China (English)

    李英

    2015-01-01

    目的:研究急性非ST段抬高型心肌梗死与药物洗脱支架植入的影响关系,根据不同种药物洗脱支架对患者的疗效情况,得出有效结论。方法:随机选择急性非S T段抬高型心肌梗死患者115例,分为观察组60例,采用雷帕霉素、紫杉醇等药物洗脱支架植入术,对照组55例,未植入支架,对比两组患者支架植入后肌酐激酶、心肌肌钙蛋白指标数据,查看其12导联心电图是否正常,分析急性非ST段抬高型心肌梗死与药物洗脱支架植入的影响关系。结果:观察组患者两种药物洗脱支架植入术均成功,随访12个月,患者死亡、支架内血栓、疾病病变等不良事件的产生均可判定无差异影响,观察组随访调查中,患者肌酐激酶、心肌肌钙蛋白指标数据趋向正常,再狭窄率为7.59%,明显低于对照组,10.61%,差异具有统计学意义(P<0.05)。结论:药物洗脱支架植入与急性非ST段抬高型心肌梗死患者疾病变化有一定关联影响,在患者的预后治疗中,可设为独立预后指标,参考病情发展及变化情况。%Objective To study the acute non ST segment elevation myocardial infarction (mi) and the influence of the drug-eluting stent, according to the curative effect of different kinds of drug-eluting stents to patients condition and draw valid conclusions.Methods Randomly selected 115 patients with acute non ST segment elevation myocardial infarction patients, divided into observation group and control group, 60 cases with rapamycin, paclitaxel drug-eluting stents (des) implantation, such as the control group 55 cases, stent placement, compared two groups of patients after stenting creatinine kinase, myocardial troponin index data, check whether the 12-lead electrocardiogram is normal, analysis of acute non ST segment elevation myocardial infarction and the effect of drug-eluting stents.Results Observation group of patients with

  9. Silicon Carbide Coating Ñ A Semiconducting Hybrid Design of Coronary Stents Ñ A Feasibility Study.

    Science.gov (United States)

    Heublein; Pethig; Elsayed

    1998-06-01

    OBJECTIVE: To determine the rates of subacute and acute thrombotic stent occlusion in patients with normal and high risk for stent thrombosis and to assess the 6 month follow-up with respect to in-stent restenosis, using a new principle of semiconductor coating (active passivating as metallic hybrid design). DESIGN: Open, non-randomized, prospective, observational, feasibility study. PATIENTS: One hundred sixty-five patients (215 stents) were scheduled consecutively with respect to lesions suitable for slotted tube stent implantation. Two subgroups of patients (stents) were identified based on the local thrombotic risk (common indications for stent implantation Ñ group I; lesions with high(er) risk for stent implantation (group II). A closed clinical 3Ð12 (mean 6.5 +/- 2.3) months follow-up was done in 126 (92.6%) eligible patients [164 (97.6%) stents]. Angiographic and/or IVUS data were available in 96 of 136 eligible patients (70.6%) after stenting 6.0 +/- 2.1 months). STENT-MATERIAL/MEDICATION: Balloon expandable tantalum three segment slotted tube stents which were coated with silicon carbide, diameter ranged from 2.5 to 4.0 mm were used. Stent deployment was limited by inflation pressure (12Ð16 Bar). Apart from patients with acute myocardial infarction (n = 15 stents) patients received heparin loading dose during the procedure only, no oral anticoagulation except aspirin (300 mg p.d.) and ticlopidine (250Ð500mg p.d.) given over 1 month. RESULTS: Acute complications. No in-hospital mortality occurred, stent-related myocardial infarction was 1.9%; major bleedings 0.5% of implanted stents. Acute stent thrombosis 1.4%, subacute stent thrombosis occurred in 0.5% (no significant difference between group I and II). Late events: From 136 eligible patients (range 15 daysÐ14 months) (187 stents) 92 patients (67.6%) with 142 stents (75.9%) were event-free. In-stent restenosis. Thirty-six percent (biased group of patients with events) resp. 26.8% (including negative

  10. ANALYSIS OF OUTPATIENT PHYSICIANS, PRESCRIPTION OF DISAGGREGANT THERAPY FOR PATIENTS AFTER ACUTE MYOCARDIAL INFARCTION AND/OR CORONARY ANGIOPLASTY WITH STENT IMPLANTATION WITHIN THE RECVAD REGISTRY

    Directory of Open Access Journals (Sweden)

    A. V. Zagrebelnyi

    2015-01-01

    Full Text Available Objective: to estimate the quality of antiaggregants therapy in patients with coronary heart disease in outpatient settings. Materials and methods. The data of the retrospective outpatient RECVAD registry (3690 patients who lived in Ryazan and its Region and had evidence in their outpatient medical records for one of the diagnoses, such as coronary heart disease, hypertension, chronic heart failure, atrial fibrillation, or their concurrence, were used. Forty­nine patients after acute myocardial infarction (AMI and/or percutaneous coro­ nary interventions (PCI with stenting ≤ 1 year before their inclusion in the registry, who were to undergo dual antiaggregant therapy (DAT according to current clinical guidelines (CG, were identified among 427 patients after AMI and/or PCI with coronary angioplasty. Contra­ indications to DAT were simultaneously revealed and a relationship of the use of therapy to their presence was compared. Results. Among the 49 patients who had indications for DAT that was used in 15 (30.6 % cases and that was not in 3 (6.1 % patients in the presence of contraindications, 25 (51.0 % did not receive DAT in the absence of contraindications and 6 (12.3 % patients received the therapy in the presence of contraindications. Conclusion. DAT prescribed by outpatient physicians does not always meet the current CG. There are cases of not using DAT in the presence of obvious indications for DAT and, on the contrary, those of its use in the presence of contraindications. 

  11. Comparing coronary stent material performance on a common geometric platform through simulated bench testing.

    Science.gov (United States)

    Grogan, J A; Leen, S B; McHugh, P E

    2012-08-01

    Absorbable metallic stents (AMSs) are a newly emerging cardiovascular technology which has the potential to eliminate long-term patient health risks associated with conventional permanent stents. AMSs developed to date have consisted of magnesium alloys or iron, materials with inferior mechanical properties to those used in permanent stents, such as stainless steel and cobalt-chromium alloys. However, for AMSs to be feasible for widespread clinical use it is important that their performance is comparable to modern permanent stents. To date, the performances of magnesium, iron, and permanent stent materials have not been compared on a common stent platform for a range of stent performance metrics, such as flexibility, radial strength, and recoil. In this study, this comparison is made through simulated bench testing, based on finite-element modelling. The significance of this study is that it allows potential limitations in current AMS performance to be identified, which will aid in focusing future AMS design. This study also allows the identification of limitations in current AMS materials, thereby informing the on-going development of candidate biodegradable alloys. The results indicate that the AMSs studied here can match the recoil characteristics and radial strength of modern permanent stents; however, to achieve this, larger strut dimensions are required. It is also predicted that the AMSs studied are inferior to permanent stents in terms of maximum absolute curvature and longitudinal stiffness.

  12. Crush implantation of a self-expanding interwoven stent over a subintimally recanalized standard stent in a TASC D lesion of the superficial femoral artery.

    Science.gov (United States)

    Vogel, B; Strothmeyer, A; Cebola, R; Katus, H; Blessing, E

    2012-11-01

    We demonstrate feasibility of implantation of a self-expanding interwoven nitinol stent in a claudicant, where recanalization attempt of a heavily calcified, occluded superficial femoral artery (TASC D lesion) was complicated by a previously implanted, fractured standard stent. Wire passage through the occlusion and beyond the fractured stent could only be achieved through the subintimal space. A dedicated reentry device was used to allow distal wire entry into the true lumen at the level of the popliteal artery. Despite crushing of the fractured stent with a series of increasingly sized standard balloons, a significant recoil remainded in the area of the crushed stent. To secure patency of the femoro-popliteal artery we therefore decided to implant the novel self-expanding interwoven nitinol stent (Supera Veritas (TM), IDEV), whose unique feature is an exceptional high radial strength. Patient presented asymptomatic without any impairment of his walking capacity at three month follow up and duplex ultrasound confirmed patency of the stent. Subintimal recanalizations can be complicated by previously implanted stents, in particular in the presence of stent fracture, where intraluminal wire passage often can not be achieved. Considering the high radial strength and fracture resistance, interwoven nitinol stents represent a good treatment option in those challenging cases and they can be used to crush standard nitinol and ballonexpandable stents. PMID:23129042

  13. 冠状动脉介入术后反复支架内血栓形成一例%Sub-acute Stent Thrombosis after Percutaneous Coronary Intervention:A Case Report

    Institute of Scientific and Technical Information of China (English)

    张倩; 王春梅; 朱小玲

    2012-01-01

    Stent thrombosis after percutaneous coronary intervention ( PCI ) is a serious complication that can be confusing to doctors. Clinical manifestations can be acute myocardial infarction, cardiac shock, unstable angina, etc. This article is a case about repeated stent thrombosis after PCI. Through the case, talk about treatments to repeated stent thrombosis in acute coronary syndrome patients with idiopathic platelet increasing disease.%经皮冠状动脉介入治疗(PCI)后支架内血栓形成一直是困扰医师的严重并发症,临床可表现为急性心肌梗死、心源性休克、不稳定心绞痛等.本文报道1例PCI术后反复支架内血栓形成和心源性休克的患者,通过此例探讨急性冠脉综合征患者合并原发性血小板增多症反复支架内血栓形成的治疗.

  14. Assessment of the safety and performance of the STENTYS self-expanding coronary stent in acute myocardial infarction: Results from the APPOSITION I study

    NARCIS (Netherlands)

    G. Amoroso (Giovanni); R.J.M. van Geuns (Robert Jan); C.M. Spaulding (Christian); S. Manzo-Silberman (Stephane); K. Hauptmann (Karl); R. Spaargaren (René); H.M. Garcia-Garcia (Hector); P.W.J.C. Serruys (Patrick); S. Verheye (Stefan)

    2011-01-01

    textabstractAims: In the setting of ST-elevation myocardial infarction (STEMI), epicardial vasoconstriction and throm- bus load may lead to stent undersizing and malapposition after primary percutaneous coronary intervention (PPCI), which can both be responsible for stent thrombosis or restenosis. A

  15. A comparative study of short- and medium-term outcomes comparing emergent surgery and stenting as a bridge to surgery in patients with acute malignant colonic obstruction.

    LENUS (Irish Health Repository)

    Kavanagh, Dara O

    2013-04-01

    The use of self-expanding metal stents as a bridge to surgery in the setting of malignant colorectal obstruction has been advocated as an acceptable alternative to emergency surgery. However, concerns about the safety of stenting have been raised following recent randomized studies.

  16. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... of the bare metal stent versus the drug-coated stents is an ongoing debate. And I think ... that with putting in a bunch of drug-coated stents, and it looks very pretty when we’ ...

  17. A high maintenance dose of clopidogrel improves short-term clinical outcomes in patients with acute coronary syndrome undergoing drug-eluting stent implantation

    Institute of Scientific and Technical Information of China (English)

    HAN Ya-ling; WANG Bin; LI Yi; XU Kai; WANG Shou-li; JING Quan-min; WANG Zu-lu; WANG Dong-mei; MA Ying-yan; WANG Geng

    2009-01-01

    Background Recurrent ischemic events occurred even during routine use of 75 mg clopidogrel in addition to aspirin,that indicated a potentially insufficient maintenance dosage of clopidogrel.The aim of the present study was to evaluate the short-term efficacy and safety of a 150 mg maintenance dose of clopidogrel following a 600 mg loading dose in patients with an acute coronary syndrome (ACS) undergoing drug eluting stent (DES) implantation.Methods Between November 2005 and November 2006,a total of 813 consecutive ACS patients undergoing DES implantation were enrolled.A 600 mg loading dose was administered before percutaneous coronary intervention (PCI) nd patients were randomized to receive clopidogrel 75 mg or 150 mg for 30 days in addition to 300 mg aspidn daily.Primary end points were the composite of cardiac death,non-fatal myocardial infarction (MI) and urgent target vessel revascularization (UTVR).Secondary end points included stent thrombosis (ST),major and minor bleeding events at 30days.Results At a follow-up period of 30 days,4 (1.0%) patients in the 150 mg group and 9 (2.2%) patients in the 75 mg group (P >0.05) reached the primary end points.There was no significant difference in the incidences of MI (0.5% vs1.2%,P >0.05),UTVR (0.7% vs 2.0%,P >0.05),and cardiac death (0.2% vs 0.2%,P >0.05) between the two groups.The incidence of ST (0 vs 1.5%,P <0.05) was significantly lower in the 150 mg group than that in the 75 mg group.There were no significant differences between both groups regarding the risk of major (0.2% vs 0,P >0.05) or minor (0.5% vs 0.2%,P >0.05) bleedings.Conclusion A high clopidogrel maintenance dose of 150 mg daily following a 600 mg loading dose for the first month after PCI procedure reduces the risk of ST and appears to be safe in patients with ACS undergoing DES implantation.

  18. Recoiling DNA Molecule: Simulation & Experiment

    OpenAIRE

    Neto, Jose Coelho; Dickman, Ronald; Mesquita, O. N.

    2002-01-01

    Single molecule DNA experiments often generate data from force versus extension measurements involving the tethering of a microsphere to one end of a single DNA molecule while the other is attached to a substrate. We show that the persistence length of single DNA molecules can also be measured based on the recoil dynamics of these DNA-microsphere complexes if appropriate corrections are made to the friction coefficient of the microsphere in the vicinity of the substrate. Comparison between co...

  19. Symptomatic stent cast.

    LENUS (Irish Health Repository)

    Keohane, John

    2012-02-03

    Biliary stent occlusion is a major complication of endoscopic stent insertion and results in repeat procedures. Various theories as to the etiology have been proposed, the most frequently studied is the attachment of gram negative bacteria within the stent. Several studies have shown prolongation of stent patency with antibiotic prophylaxis. We report the case of stent occlusion from a cast of a previously inserted straight biliary stent; a "stent cast" in an 86-year-old woman with obstructive jaundice. This was retrieved with the lithotrypter and she made an uneventful recovery. This is the first reported case of a biliary stent cast.

  20. Symptomatic stent cast.

    Science.gov (United States)

    Keohane, John; Moore, Michael; O'Mahony, Seamus; Crosbie, Orla

    2008-02-01

    Biliary stent occlusion is a major complication of endoscopic stent insertion and results in repeat procedures. Various theories as to the etiology have been proposed, the most frequently studied is the attachment of gram negative bacteria within the stent. Several studies have shown prolongation of stent patency with antibiotic prophylaxis. We report the case of stent occlusion from a cast of a previously inserted straight biliary stent; a "stent cast" in an 86-year-old woman with obstructive jaundice. This was retrieved with the lithotrypter and she made an uneventful recovery. This is the first reported case of a biliary stent cast.

  1. Risk of Post-ERCP Pancreatitis after placement of Covered versus Uncovered Self-Expandable Biliary Metal Stents: A Systematic Review and Meta-Analysis

    OpenAIRE

    Yaseen Alastal; Tariq Hammad; Muhammad Ali Khan; Khalil, Basmah W.; Sobia Khan; Mohammad Kashif Ismail; Ali Nawras; Aijaz Sofi

    2008-01-01

    Background Self-expandable metal stents are commonly used in the management of malignant biliary obstruction due to higher patency rates compared to plastic stents. Development of covered self-expandable metal stents has led to extended stent patency compared to uncovered self-expandable metal stents. However, there are concerns that deployment of covered self-expandable metal stents may be associated with higher risk of post-endoscopic retrograde cholangio-pancreatography pancreatitis, acute...

  2. Primary stenting of an anomalous left main coronary artery originating from the right sinus of Valsalva during acute myocardial infarction

    OpenAIRE

    Gökhan Çiçek; Servet Altay; Seçkin Satılmış; Zekeriya Nurkalem

    2015-01-01

    Anomalous origin of left and right coronary arteries from a single coronary ostium in the right sinus of Valsalva is rare. Previously, few reports have described percutaneous coronary interventions (PCI) in this anomaly. We report a case of a 78-year-old female who had acute inferior myocardial infarction with a severe lesion in the anomalous left main coronary artery (LMCA) arising from a single ostium in the right sinus of Valsalva.Key words: Coronary artery anomaly, single coronary artery,...

  3. Preventive PCI versus culprit lesion stenting during primary PCI in acute STEMI: a systematic review and meta-analysis

    OpenAIRE

    Pandit, Anil; Aryal, Madan Raj; Aryal Pandit, Aashrayata; Hakim, Fayaz Ahmad; Giri, Smith; Mainali, Naba Raj; Sharma, Prashant; Lee, Howard R.; Fortuin, F. David; Mookadam, Farouk

    2014-01-01

    Aim The benefit of preventive percutaneous coronary intervention (PCI) in ST elevation myocardial infarction (STEMI) has been shown in randomised trials. However, all the randomised trials are underpowered to detect benefit in cardiac death. We aim to systematically review evidence on the cardiac mortality benefit of preventive PCI in patients presenting with acute STEMI in randomised patient populations. Methods PubMed, Scopus, Cochrane and clinicaltrials.gov databases were searched for stud...

  4. Comparison of a new stent and Wallstent for transjugular intrahepatic portosystemic shunt in a porcine model

    Institute of Scientific and Technical Information of China (English)

    Gao Jun Teng; Michael A. Bettmann; P. Jack Hoopes; Li Yang

    2001-01-01

    AIM To evaluate a new balloon-expandablestainless steel stent (Cordis stent ) in atransjugular intrahepatic portosystemic shunt(TIPS) porcine model and compared withWallstent.METHODS TIPS was performed in 26 normaldomestic pigs weighing 20 kg-30 kg using aCordis stent or Wallstent (13 pigs in each stent).All pigs were sacrificed at the 14th day afterTIPS. The stent deployment delivery system,stent patency, and stent recoil after placementwere evaluated. Proliferative response inrepresentative histological sections from thecenter, hepatic and portal regions of the twostent designs were quantified.RESULTS The shunt was widely patent in 4pigs in the Cordis stent group (4/12, prematuredead in 1 pig), and in 5 pigs in the Wallstentgroup (5/13). All remaining stents of bothdesigns were occluded or stenotic. The meanquantified proliferation including thickness ofthe proliferation and the ratio of proliferation:total area in three assayed regions in Cordisstent and Wallstent was 2.18 mm:2.00 mm, and59.18 mm2: 51.66 mm2, respectively (P >0.05).The delivery system and mechanical propertiesof the Cordis stent fuctioned well.CONCLUSION The new Cordis stent isappropriate for TIPS procedure.

  5. Computer Simulation of the Mechanical Behaviour of Implanted Biodegradable Stents in a Remodelling Artery

    Science.gov (United States)

    Boland, Enda L.; Grogan, James A.; Conway, Claire; McHugh, Peter E.

    2016-04-01

    Coronary stents have revolutionised the treatment of coronary artery disease. While coronary artery stenting is now relatively mature, significant scientific and technological challenges still remain. One of the most fertile technological growth areas is biodegradable stents; here, there is the possibility to generate stents that will break down in the body once the initial necessary scaffolding period is past (6-12 months) (Grogan et al. in Acta Biomater 7:3523, 2011) and when the artery has remodelled (including the formation of neo-intima). A stent angioplasty computational test-bed has been developed by the authors, based on the Abaqus software (DS-SIMULIA, USA), capable of simulating stent tracking, balloon expansion, recoil and in vivo loading in a atherosclerotic artery model. Additionally, a surface corrosion model to simulate uniform and pitting corrosion of biodegradable stents and a representation of the active response of the arterial tissue following stent implantation, i.e. neointimal remodelling, has been developed. The arterial neointimal remodelling simulations with biodegradable stent corrosion demonstrate that the development of new arterial tissue around the stent struts has a substantial effect on the mechanical behaviour of degrading stents.

  6. Safety and effectiveness of the Genous™ endothelial progenitor cell-capture stent in the first year following ST-elevation acute myocardial infarction: A single center experience and review of the literature

    Energy Technology Data Exchange (ETDEWEB)

    Pereira-da-Silva, Tiago, E-mail: tiagopsilva@sapo.pt; Bernardes, Luís; Cacela, Duarte; Fiarresga, António; Sousa, Lídia; Patrício, Lino; Ferreira, Rui Cruz

    2013-11-15

    Purpose: The Genous™ stent (GS) is designed to accelerate endothelization, which is potentially useful in the pro-thrombotic environment of ST-elevation acute myocardial infarction (STEMI). We aimed to evaluate the safety and effectiveness of the GS in the first year following primary percutaneous coronary intervention (PCI) and to compare our results with the few previously published studies. Methods and Materials: All patients admitted to a single center due to STEMI that underwent primary PCI using exclusively GS, between May 2006 and January 2012, were enrolled. The primary study endpoints were major adverse cardiac events (MACEs), defined as the composite of cardiac death, acute myocardial infarction and target vessel revascularization, at one and 12 months. Results: In the cohort of 109 patients (73.4% male, 59 ± 12 years), 24.8% were diabetic. PCI was performed in 116 lesions with angiographic success in 99.1%, using 148 GS with median diameter of 3.00 mm (2.50–4.00) and median length of 15 mm (9–33). Cumulative MACEs were 2.8% at one month and 6.4% at 12 months. Three stent thromboses (2.8%), all subacute, and one stent restenosis (0.9%) occurred. These accounted for the four target vessel revascularizations (3.7%). At 12 months, 33.9% of patients were not on dual antiplatelet therapy. Conclusions: GS was safe and effective in the first year following primary PCI in STEMI, with an apparently safer profile comparing with the previously published data. Summary: We report the safety and effectiveness of the Genous™ stent (GS) in the first year following primary percutaneous coronary intervention in ST-elevation acute myocardial infarction. A comprehensive review of the few studies that have been published on this subject was included and some suggest a less safe profile of the GS. Our results and the critical review included may add information and reinforce the safety and effectiveness of the GS in ST-elevation in acute myocardial infarction.

  7. Use of the Viabil Covered Stent in the Treatment of a Benign Biliary Stricture with the Subsequent Development of Acute Pancreatitis

    OpenAIRE

    Burke, Charles T.; Stavas, Joseph M.

    2007-01-01

    The use of bare metal stents for benign biliary strictures is typically avoided due to historically poor long-term patency. Thus, in patients who are not surgical candidates, the management of benign biliary strictures can be a frustrating process. This article describes a patient who developed a common bile duct stricture following a complex endovascular thoracoabdominal aneurysm repair. The stricture was treated with the placement of a covered metallic biliary stent; a procedure complicated...

  8. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... put in, versus medicated or what’s known as drug-eluding stents. And there has been a lot ... Both bare metal stents and medicated stents, or drug-eluting stents, have their role, and we often ...

  9. Interpreting Recoil Motion for Undergraduate Students

    CERN Document Server

    Mokhiemer, Tarek Ahmed

    2007-01-01

    In this paper, I outline some problems in the students' understanding of the reason of recoil motion when introduced to them in the context of Newton's third law. I propose to explain the origin of recoil and the fundamental mechanism which produces this motion when presenting recoil to students to give them more insight into the physical processes involved. This mechanism differs from one system to another. Several examples that can be easily implemented in the classroom environment are given in this paper. Such a deep understanding of recoil may reflect on the level of understanding of other physical phenomena sought by students.

  10. Primary reactions of recoiling germanium atoms

    International Nuclear Information System (INIS)

    75Ge recoils are made using the (n,2n) reaction. By analogy with Si recoils, two divalent species are suggested as intermediates in the recoil-germane reaction, one formed by H abstraction and the other formed by insertion only. A series of moderator and competition experiments were conducted. Of the noble gases, Kr is the most efficient moderator at removing kinetic energy from the recoils. Xe has a special effect due to its low ionization potential. A reaction scheme is proposed with two routes to digermane, one from a hot neutral atom and the other from a positive ion. 8 figures

  11. Safety and efficacy of coronary stent implantation. Acute and six month outcomes of 1,126 consecutive patients treated in 1996 and 1997

    Directory of Open Access Journals (Sweden)

    Luiz Alberto Mattos

    1999-07-01

    Full Text Available PURPOSE: The authors analyzed the 30-day and 6-month outcomes of 1,126 consecutive patients who underwent coronary stent implantation in 1996 and 1997. METHODS: The 30-day results and 6-month angiographic follow-up were analyzed in patients treated with coronary stents in 1996 and 1997. All patients underwent coronary stenting with high-pressure implantation (>12 atm and antiplatelet drug regimen (aspirin plus ticlopidine. RESULTS: During the study period, 1,390 coronary stents were implanted in 1,200 vessels of 1,126 patients; 477 patients were treated in the year 1996 and 649 in 1997. The number of percutaneous procedures performed using stents increased significantly in 1997 compared to 1996 (64 % vs 48%, p=0.0001. The 30-day results were similar in both years; the success and stent thrombosis rates were equal (97% and 0.8%, respectively. The occurrence of new Q wave MI (1.3% vs 1.1%, 1996 vs 1997, p=NS, emergency coronary bypass surgery (1% vs 0.6%, 1996 vs 1997, p=NS and 30-day death rates (0.2% vs 0.5%, 1996 vs 1997, p=NS were similar. The 6-month restenosis rate was 25% in 1996 and 27% in 1997 (p= NS; the target vessel revascularization rate was 15% in 1996 and 16% in 1997 (p = NS. CONCLUSIONS: Intracoronary stenting showed a high success rate and a low incidence of 30-day occurrence of new major coronary events in both periods, despite the greater angiographic complexity of the patients treated with in 1997. These adverse variables did not have a negative influence at the 6-month clinical and angiographic follow-up, with similar rates of restenosis and ischemia-driven target lesion revascularization rates.

  12. Absence of gender disparity in short-term clinical outcomes in patients with acute ST-segment elevation myocardial infarction undergoing irolimus-eluting stent based primary coronary intervention: a report from Shanghai Acute Coronary Event (SACE) Registr

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qi; LIAO Min-lei; HU Jian; SHEN Wei-feng; QIU Jian-ping; ZHANG Rui-yan; LI Yi-gang; HE Ben; JIN Hui-gen; ZHANG Jun-feng; WANG Xiao-long; JIANG Li

    2010-01-01

    Background Randomized, controlled trials have demonstrated the superiority of sirolimus-eluting stent (SES) implantation during primary percutaneous coronary intervention (PCI), as opposed to bare-metal stents, in patients with ST-elevation myocardial infarction (STEMI). This study aimed to test the hypothesis that clinical benefits of SES treatment were independent of gender in this setting.Methods A total of 2042 patients with STEMI undergoing SES-based primary PCI were prospectively enrolled into Shanghai Acute Coronary Event (SACE) registry (1574 men and 468 women). Baseline demographics, angiographic and PCI features, and in-hospital and 30-day major adverse cardiac events (MACE) were analyzed as a function of gender. Results Compared with men, women were older and more frequently had hypertension, diabetes, and hypercholesterolemia. Use of platelet glycoprotein IIb/IIIa receptor inhibitor (GPI, 65.5% vs. 62.2%, P=0.10) and procedural success rate (95.0% vs. 94.2%, P=0.52) were similar in both genders. In-hospital death and MACE occurred in 3.8% and 7.6%, and 4.5% and 8.1% in the male and female patients, respectively (all P >0.05). At 30-day follow-up, survival (94.3% vs. 93.8%, P=0.66) and MACE-free survival (90.2% vs. 89.3%, P=0.52) did not significantly differ between men and women. After adjustment for differences in patient demographics, angiographic and proceduralfeatures, there were no significant difference in either in-hospital (OR=0.77, 95%C/ of 0.48 to 1.22, P=0.30) or 30-day mortality (OR=1.28, 95%C/ of 0.73 to 2.23, P=0.38) between women and men.Conclusion Despite more advanced age and clustering of risk factors in women, female patients with STEMI treated by SES-based primary PCI had similar in-hospital and short-term clinical outcomes as their male counterparts.

  13. High resolution elastic recoil detection

    International Nuclear Information System (INIS)

    The quantitative analysis of light elements in ultra thin films being thinner than 10 nm is still a nontrivial task. This paper will summarise the prospects of high resolution elastic recoil detection (ERD) using a Q3D magnetic spectrograph. It has been shown that subnanometer resolution can be achieved in ultra thin films and even monolayer resolution is possible close to the surface. ERD has best quantification possibilities compared to any other method. Sensitivity is sufficient to analyse main elements and impurities as e.g. being necessary for the characterisation of microelectronic materials. In addition, high resolution channeling ERD can be performed in order to get information on lattice location of light elements in crystalline ultra thin layers. The potential of high resolution ERD will be demonstrated by several applications where it is the most valuable tool for elemental profiling

  14. Factors Associated with the Use of Drug-Eluting Stents in Patients Presenting with Acute ST-Segment Elevation Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Jose F. Chavez

    2015-01-01

    Full Text Available Background. Drug-eluting stents (DES have proven clinical superiority to bare-metal stents (BMS for the treatment of patients with ST-segment elevation myocardial infarction (STEMI. Decision to implant BMS or DES is dependent on the patient’s ability to take dual antiplatelet therapy. This study investigated factors associated with DES placement in STEMI patients. Methods. Retrospective analysis was performed on 193 patients who presented with STEMI and were treated with percutaneous coronary intervention at an urban, tertiary care hospital. Independent factors associated with choice of stent type were determined using stepwise multivariate logistic regression. Odds ratio (OR was used to evaluate factors significantly associated with DES and BMS. Results. 128 received at least one DES, while 65 received BMS. BMS use was more likely in the setting of illicit drug or alcohol abuse ([OR] 0.15, 95% CI 0.05–0.48, p≤0.01, cardiogenic shock (OR 0.26, 95% CI 0.10–0.73, p=0.01, and larger stent diameter (OR 0.28, 95% CI 0.11–0.68, p≤0.01. Conclusions. In this analysis, BMS implantation was associated with illicit drug or alcohol abuse and presence of cardiogenic shock. This study did not confirm previous observations that non-White race, insurance, or income predicts BMS use.

  15. Next generation covered stents made from nanocomposite materials: A complete assessment of uniformity, integrity and biomechanical properties.

    Science.gov (United States)

    Farhatnia, Yasmin; Pang, Jun Hon; Darbyshire, Arnold; Dee, Ryan; Tan, Aaron; Seifalian, Alexander M

    2016-01-01

    Covered stents are stents wrapped with a thin polymeric membrane, and are typically used to treat vessel aneurysms and seal perforated arteries. Current covered stents suffer from restenosis due to limitations in material and fabrication methods which leaves metallic struts directly exposed to blood. We have developed a biocompatible and haemocompatible nanocomposite polymer, polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane (POSS-PCU). We devised a novel combination of ultrasonic spray atomisation system and dip-coating process to produce small calibre covered stents with metal struts fully embedded within the membrane, which also yields greater coating uniformity. Stent-polymer bonding was enhanced via silanisation and coating of reactive pre-polymer. Platelet studies supported the non-thrombogenicity of POSS-PCU. Biomechanical performances including diametrical compliance, bending strength, radial strength and recoil were evaluated and optimised. This proof-of-principle manufacturing technique could lead to the development of next-generation small calibre adult and paediatric covered stents. These stents are currently undergoing preclinical trial. From the Clinical Editor: The use of stents to treat vascular diseases is now the standard of care in the clinical setting. Nonetheless, a major problem of the current stents is the risk of restenosis and thrombosis. The authors developed a nanocomposite material using polyhedral oligomeric silsesquioxane and poly(carbonate-urea) urethane (POSS-PCU) and incorporated into metallic stents. Preliminary data have already shown promising results. It is envisaged that this would further lead to better stent technology in the future. PMID:26238080

  16. Gas powered fluid gun with recoil mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Grubelich, Mark C.; Yonas, Gerold

    2016-03-01

    A gas powered fluid gun for propelling a stream or slug of a fluid at high velocity toward a target. Recoil mitigation is provided that reduces or eliminates the associated recoil forces, with minimal or no backwash. By launching a quantity of water in the opposite direction, net momentum forces are reduced or eliminated. Examples of recoil mitigation devices include a cone for making a conical fluid sheet, a device forming multiple impinging streams of fluid, a cavitating venturi, one or more spinning vanes, or an annular tangential entry/exit.

  17. Gas powered fluid gun with recoil mitigation

    Science.gov (United States)

    Grubelich, Mark C; Yonas, Gerold

    2013-11-12

    A gas powered fluid gun for propelling a stream or slug of a fluid at high velocity toward a target. Recoil mitigation is provided that reduces or eliminates the associated recoil forces, with minimal or no backwash. By launching a quantity of water in the opposite direction, net momentum forces are reduced or eliminated. Examples of recoil mitigation devices include a cone for making a conical fluid sheet, a device forming multiple impinging streams of fluid, a cavitating venturi, one or more spinning vanes, or an annular tangential entry/exit.

  18. Portal Vein Occlusion after Biliary Metal Stent Placement in Hilar Cholangiocarcinoma

    OpenAIRE

    Woo, Kyung Hee; Kim, Jin Bae; Chang, Yoon Jung; Kim, Hyo Jung; Baek, Il Hyun; Ko, Jin Seok; Woo, Ji Young; Kim, Hong Dae; Lee, Myung Seok

    2008-01-01

    Acute symptomatic portal vein obstruction related to biliary stenting is an extremely rare but life-threatening complication. This usually occurs in patients with either tumor invasion into the portal vein or pre-existing portal vein thrombus. Therefore, the portal vein should be carefully evaluated before placing a biliary metallic stent in such patients. We describe a case of acute portal vein obstruction after placing metallic biliary stents in a patient with a periductal-infiltrating type...

  19. Portal vein occlusion after biliary metal stent placement in hilar cholangiocarcinoma.

    Science.gov (United States)

    Woo, Kyung Hee; Kim, Jin Bae; Chang, Yoon Jung; Kim, Hyo Jung; Baek, Il Hyun; Ko, Jin Seok; Woo, Ji Young; Kim, Hong Dae; Lee, Myung Seok

    2008-06-01

    Acute symptomatic portal vein obstruction related to biliary stenting is an extremely rare but life-threatening complication. This usually occurs in patients with either tumor invasion into the portal vein or pre-existing portal vein thrombus. Therefore, the portal vein should be carefully evaluated before placing a biliary metallic stent in such patients. We describe a case of acute portal vein obstruction after placing metallic biliary stents in a patient with a periductal-infiltrating type of hilar cholangiocarcinoma. PMID:20485610

  20. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... target lesion. Now with the stents being as flexible as they are, we can pretty much get to anywhere we want. The issue of the bare metal stent versus the drug-coated stents is an ongoing debate. ...

  1. Stenting plus coiling: dangerous or helpful?; Stenting plus Coiling bei akut rupturierten intrakraniellen Aneurysmen

    Energy Technology Data Exchange (ETDEWEB)

    Wanke, I.; Gizewski, E.; Doerfler, A.; Stolke, D.; Forsting, M. [Essen Univ. (Germany). Inst. fuer Radiologie und Neuroradiologie

    2005-09-01

    Purpose: the purpose of this study was to evaluate the procedural risk of treating acute ruptured aneurysms with a stentcoil combination. Material and methods: between August 2001 and January 2004 we treated nine acute subarachnoid hemorrhage (SAH) patients with a combination of stents and platinum coils. Results: six aneurysms were 100% eliminated; the residual three aneurysms had a 95% to 99% occlusion. A transient thrombosis in the stent in one patient could be recanalized by intravenous application of ReoPro {sup registered}. In another patient an occlusive vasospasm at the distal end of the stent was successfully treated with intraarterial Nimotop {sup registered}. Neurological complications occurred in none of the patients. Conclusion: in broad-based aneurysms which cannot be clipped or in which any neurosurgical treatment presents an unacceptably high risk (posterior circulation and paraophthalmic aneurysms), treatment using a combination of stent and platinum coils might be an option even in the acute phase of an SAH. Platelet aggregation can be treated with Aspirin registered and Plavix {sup registered} after placement of the first coil, vasospasms with intraarterial Nimotop {sup registered}, and acute stent thrombosis with GP IIa/IIIb-antagonists. (orig.)

  2. The interventional thrombolysis and stenting of acute internal carotid occlusion%颈内动脉急性闭塞的溶栓及支架置入治疗

    Institute of Scientific and Technical Information of China (English)

    廖凯兵; 祝望才; 郑传胜

    2014-01-01

    Objective:To investigate the efficacy and safety of the interventional thrombolysis and stenting in patients with acute internal carotid occlusion.Methods:Intra-arterial thrombolysis was carried out and followed by stent implantation for the residual vascular stenosis in 6 patients with acute internal carotid occlusion.The neurological impairment score be-fore the treatment and at 24 hours after the treatment were evaluated.The incidence of complications and the changes in limbs activity and consciousness were observed.Results:6 patients got arterial recanalization and the blood flow recovered. The clinical symptoms were improved rapidly.At 24 hours after the treatment,the muscle strength increased by 3 grades in 4 patients and 2 grades in 2 patients.Conclusion:The efficacy of the interventional thrombolysis and stenting in acute inter-nal carotid occlusion is positive.It is more effective and safer when the treatment is given earlier.%目的:探讨颈内动脉急性闭塞的溶栓及支架置入治疗的有效性及安全性。方法:对6例颈内动脉急性闭塞的患者行动脉内溶栓治疗,其后对残余狭窄行支架置入治疗。溶栓前及治疗后24 h 进行神经功能缺损评分,同时观察脑内及其他系统有无出血并发症,并观察肢体活动及意识改善情况。结果:6例患者颈内动脉完全再通,血流量恢复,临床症状改善迅速,24h后4例瘫痪肢体肌力提高3级,2例提高2级。结论:颈内动脉急性闭塞患者的溶栓及支架置入治疗的疗效是值得肯定的。治疗时间越早疗效越好,安全性越高。

  3. Drug-Eluting versus Bare-Metal Stent for Acute Myocardial Infarction%急性心肌梗死介入治疗:药物支架还是裸支架?

    Institute of Scientific and Technical Information of China (English)

    刘锡燕

    2011-01-01

    药物支架的出现是介入性心脏病学一个里程碑,但是由于其有增加晚期血栓形成的潜在风险,使其应用于病变血栓负荷重的急性心肌梗死受到质疑.近年来关于药物支架应用于急性心肌梗死的随机对照试验及临床注册试验显示其应用于急性心肌梗死患者与裸支架相比并不增加病死率、心肌梗死率及支架内血栓发生率,且明显降低靶病变及靶血管的血运重建,但已有研究的随访时间尚不够长,仍需要样本量更大、随访时间更长的研究以进一步证实药物支架的长期安全性与有效性.%The development of drug-eluting stents ( DES) was a critical milestone in the advancement of interventional cardiology. However, clinical stent thrombosis still poses a serious potential complication. In acute myocardial infarction (AMI) , acute total vessel occlusion has a larger thrombus burden, and the use of DES in this particular case raises safety concerns. Yet, in both registry and randomized studies that compare the use of DES and bare-metal stents (BMS) in AMI patients, DES show a consistent trend toward decreasing the risk of complications. However, these studies have limited study populations and follow-up periods, therefore longer-term follow-up studies are necessary. In this article we reviewed the findings of randomized and nonrandomized trials on the use of DES versus BMS in the setting of a-cute ST elevated myocardial infarction.

  4. SMART Control stents in femoropopliteal region

    Directory of Open Access Journals (Sweden)

    Jagić Nikola

    2008-01-01

    Full Text Available Introduction/Aim. Occlusive disease of lower limb arteries have been so far traditionally best treated with bypass surgery, but we want to find minimally invasive approach that should be at least as good as conventional surgery, and hopefully better. The aim of this study was to evaluate SMART Control stents (Cordis, J&J in Trans Atlantic Society Consensus (TASC B and C femoropopliteal lesions during one-year follow-up. Methods. Retrospective nonrandomized analysis included forty arteries in consecutive 40 patients who were stented with SMART Control stents. Primary patency at 12-month verified with Duplex Ultrasound and Acute Brachial Index (ABI as well as freedom from Target Vessel Revascularization (TVR were primary endpoints. Results. Primary technical success at stent implantation was 100%. Mean ABI values were preprocedurally 0.50, postprocedurally 0.83, at one month 0.86, at six months 0.84, at one year 0.78. After one year 39 stents were patent (97.5%. Conclusion. Excellent performance of the stent from technical point of view and a midterm results in vessel patency, as well as the absence of need for TVR were achieved. Yet, life expectancy in this cohort group of patients demands longer follow up data to draw a definite sustained positive conclusion.

  5. Circadian Variation in Coronary Stent Thrombosis

    NARCIS (Netherlands)

    Mahmoud, Karim D.; Lennon, Ryan J.; Ting, Henry H.; Rihal, Charanjit S.; Holmes, David R.

    2011-01-01

    Objectives We sought to determine the circadian, weekly, and seasonal variation of coronary stent thrombosis. Background Other adverse cardiovascular events such as acute myocardial infarction are known to have higher incidences during the early morning hours, Mondays, and winter months. Methods The

  6. Aortic stenting.

    Science.gov (United States)

    Droc, Ionel; Calinescu, Francisca Blanca; Droc, Gabriela; Blaj, Catalin; Dammrau, Rolf

    2015-01-01

    The approach to aortic pathology is nowadays more and more endovascular at both thoracic and abdominal levels. Thoracic stenting has gained worldwide acceptance as first intention to treat pathologies of the descending thoracic aorta. Indications have been extended to aortic arch aneurysms and also to diseases of the ascending aorta. The current devices in use for thoracic endovascular repair (TEVAR) are Medtronic Valiant, Gore TAG, Cook Tx2 and Jotec. The choice of the endograft depends on the thoracic aortic pathology and the anatomical suitability. The technological evolution of the abdominal aortic endografts was very rapid, arriving now at the fourth generation. We report the results of 55 elective cases of endovascular abdominal aortic repair (EVAR) performed in two vascular surgical centers in Romania and Germany. The prostheses used were 16 E-vita Abdominal XT, 12 Excluder, eight Talent, seven PowerLink, three Endurant and nine custom-made, fenestrated or branched from Jotec. The mean follow-up was 18 months with CT-scan, duplex ultrasound and contrast-enhanced ultrasound. The mortality was 2%. EVAR tends to become the gold standard for abdominal aortic aneurysm repair. Technological development of the devices with lowest profile introduction systems will permit to extend the anatomical indications to new frontiers. PMID:26200430

  7. Neoatherosclerosis in the stent

    Directory of Open Access Journals (Sweden)

    A. A. Komkov

    2015-01-01

    Full Text Available Achievements of interventional cardiology in the treatment of coronary artery disease are based on coronary balloon angioplasty with implanting bare metal stents and drug eluting stents. Questions of complications such as early stent thrombosis and restenosis of stent were solved in a considerable degree. However, with the lengthening of the followup period, the problem of late complications became obvious. Except endothelization and fibromuscular proliferation in stented coronary arteries the process of plaque formation has an important influence on later complications in follow-up period more than one year. This process was defined as neoatherosclerosis. This is verified by clinical manifestations of the disease, histological studies, angioscopy, intravascular ultrasound and optical-coherence tomography in stented patients. Dynamic observation of the condition in stentedcoronary arteries showed multistep proliferation with restenosis, its regression, and neoatherosclerosis development. Evidences of neoatherosclerosis formation in stented coronary arteries are considered in this review.

  8. Neutrino-recoil induced desorption

    International Nuclear Information System (INIS)

    Nuclear decay induced 37Cl ion desorption from the electron capture decay 37Ar→37Cl+ν is reported for the first time. A mixture of one part 36Ar and ∼5x10-5 parts 37Ar (36/37Ar) is physisorbed on a gold-plated Si wafer kept at 16 K under ultrahigh vacuum conditions. The time of flight (TOF) of recoiled 37Cl ions is measured using coincidence techniques. The observed kinetic energy distribution of the 37Cl ions is approximately Gaussian in shape, with a maximum at ∼9.0 eV and a full width at half-maximum of ∼3 eV. Considering the binding energy of physisorbed 37Ar is ∼80 meV, the 9-eV peak energy compares well with that of the gas-phase value, where conservation of the energy and momentum fixes the kinetic energy of 37Cl ions at 9.54 eV. Using a combination of TOF and retarding field energy analysis, the charge states of detected ions for 1 ML (monolayer) of 36/37Ar are determined as 53%+1e, 21%+2e, and 26%+ne, where n≥3. The fraction of decaying 37Ar atoms which emerge from the surface as positive 37Cl ions is found to be 10%. Finally, a strong charge exchange reaction between a 37Cl ion and near-neighbor atoms causes a Coulomb explosion within the multilayers, increasing the kinetic energy of desorbing ions by as much as ∼7 eV

  9. Firebird sirolimus eluting stent versus bare mental stent in patients with ST-segment elevation myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    GAO Hai; YAN Hong-bing; ZHU Xiao-ling; LI Nan; AI Hui; WANG Jian; LI Shi-ying; YANG Duo

    2007-01-01

    Background There are few evidences about the value of drug eluting stent in patients with ST-segment elevation myocardial infarction (STEMI). We prospectively designed a randomized controlled trial to compare the safety and efficacy of Firebird sirolimus eluting stent (Firebird stent) and bare metal stent (BMS).Methods Patients with STEMI enrolled during one year period were randomized to undergo implantation of Firebird stent or BMS, and clinical and angiographic follow-up. The primary endpoint of the present study was in-lesion late lumen loss (LLL) at 6 months, and secondary endpoint includes stent thrombosis and major adverse cardiac events (MACE) at 6 months.Results During one year period, 156 patients were randomized into the Firebird stent group (101 patients with an average age of 57.8 years) or the BMS group (55 patients with 59.7 years on average). Six-month angiographic follow-up was available in 66.3% and 63.7% of patients assigned to Firebird stent and BMS, respectively. At 6-month follow-up,mortality, target vessel revascularization (TVR) and MACE were 2.0%, 6.9% and 9.9% in the Firebird stent group, while 3.6%, 30.9% and 36.4% in the BMS group (P<0.05). Subacute thrombosis occurred in 1 patient in both groups,respectively. The mean LLL was 0.18 mm in the Firebird stent group versus 0.72 mm in the BMS group.Conclusion Implantation of Firebird sirolimus eluting stent for STEMI may greatly reduce TVR and MACE at 6 months with low incidence of acute/subacute stent thrombosis compared with BMS.

  10. The Development of Coronary Artery Stents: From Bare-Metal to Bio-Resorbable Types

    Directory of Open Access Journals (Sweden)

    Ming-Yun Ho

    2016-07-01

    Full Text Available Coronary artery disease is the leading cause of death worldwide. Conventional balloon angioplasty is associated with high rates of complications such as coronary dissection and vessel recoil. The deployment of bare-metal stents (BMSs can overcome these problems and achieve a better patency rate than simple balloon angioplasty. It has been shown that the stent design including structure platform, size, length, and strut thickness has a major influence on the clinical results. Even though angioplasty with BMS implantation is widely used in coronary interventions, the restenosis rate due to neointimal hyperplasia remains high. Therefore, drug-eluting stents (DESs coated with anti-proliferative agents and polymers have been developed to reduce the restenosis rate and improve the clinical outcomes. Although the repeat revascularization rate of DESs is lower than that of BMSs, the long-term stent thrombosis rate is higher than for BMSs. Therefore, new and emerging generations of stents, in which, for example, thinner struts and bioresorbable polymers are used, are available for clinical use. However, there are only a limited number of clinical trials, in which these newer stents have been compared with BMSs and first- and second-generation DESs. The purpose of this review was to provide up-to-date information on the evolution of coronary artery stents from BMSs to DESs to bioresorbable stents (BRSs.

  11. Choledochoduodenal Fistula after the Placement of a Partially Covered Metal Stent for Unresectable Pancreatic Cancer.

    Science.gov (United States)

    Masuda, Daisuke; Ogura, Takeshi; Imoto, Akira; Onda, Saori; Sano, Tatsushi; Takagi, Wataru; Okuda, Atsushi; Takeuchi, Toshihisa; Fukunishi, Shinya; Inoue, Takuya; Higuchi, Kazuhide

    2016-01-01

    A 75-year-old Japanese man with type 2 diabetes mellitus suffered from unresectable pancreatic head cancer and was admitted to our institution due to acute cholangitis. A partially covered metal stent was placed at that time. 11 months later, he was readmitted for acute cholangitis. Upper endoscopy revealed complete stent distal migration and a small hole on the oral side of the ampulla. While attempting cannulation into the hole, an upstream biliary tract was revealed. Accordingly, we diagnosed the patient to have a choledochoduodenal fistula. After metal stent removal and balloon dilation, we placed two 7 Fr plastic stents, which successfully relieved the patient's cholangitis. PMID:27301511

  12. Recoil and related effects in molecular photoemission

    Energy Technology Data Exchange (ETDEWEB)

    Kukk, E., E-mail: edwin.kukk@utu.fi [Dept. of Physics and Astronomy, University of Turku, FIN-20014 Turku (Finland); Ueda, K. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Miron, C. [Synchrotron SOLEIL, L' Orme des Merisiers, Saint-Aubin, BP 48, FR-91192 Gif-sur-Yvette Cedex (France)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer We present a overview of recoil-related effects for general audience of experimentalists working in the field of photoelectron spectroscopy. Black-Right-Pointing-Pointer Photoelectron recoil is shown to alter vibrational structure. Black-Right-Pointing-Pointer Photoelectron rotational recoil is shown to induce line shifts and broadenings. Black-Right-Pointing-Pointer Interference and scattering of the outgoing photoelectron wave(s) are shown to introduce oscillations of branching ratios in molecular photoelectron spectra. -- Abstract: Photoemission from free molecules in the gas phase results in a complex spectral structure of electronic, vibrational and rotational transitions. In this review, the effects that can alter this structure and particularly the branching ratios in photoelectron spectra at the kinetic energies well above the ionization thresholds are considered. Simplified models that have nevertheless been found to describe the observations well are presented for photoelectron vibrational and rotational recoil, rotational Doppler broadening, photoelectron scattering and Cohen-Fano type interference phenomena. Experimental examples are shown together with the models. Some future developments and applications of the recoil-related phenomena are briefly considered.

  13. Recoil and related effects in molecular photoemission

    International Nuclear Information System (INIS)

    Highlights: ► We present a overview of recoil-related effects for general audience of experimentalists working in the field of photoelectron spectroscopy. ► Photoelectron recoil is shown to alter vibrational structure. ► Photoelectron rotational recoil is shown to induce line shifts and broadenings. ► Interference and scattering of the outgoing photoelectron wave(s) are shown to introduce oscillations of branching ratios in molecular photoelectron spectra. -- Abstract: Photoemission from free molecules in the gas phase results in a complex spectral structure of electronic, vibrational and rotational transitions. In this review, the effects that can alter this structure and particularly the branching ratios in photoelectron spectra at the kinetic energies well above the ionization thresholds are considered. Simplified models that have nevertheless been found to describe the observations well are presented for photoelectron vibrational and rotational recoil, rotational Doppler broadening, photoelectron scattering and Cohen–Fano type interference phenomena. Experimental examples are shown together with the models. Some future developments and applications of the recoil-related phenomena are briefly considered.

  14. Auxetic coronary stent endoprosthesis

    DEFF Research Database (Denmark)

    Amin, Faisal; Ali, Murtaza Najabat; Ansari, Umar;

    2014-01-01

    BACKGROUND: Cardiovascular heart disease is one of the leading health issues in the present era and requires considerable health care resources to prevent it. The present study was focused on the development of a new coronary stent based on novel auxetic geometry which enables the stent to exhibit...... a negative Poisson's ratio. Commercially available coronary stents have isotropic properties, whereas the vascular system of the body shows anisotropic characteristics. This results in a mismatch between anisotropic-isotropic properties of the stent and arterial wall, and this in turn is not favorable...... for mechanical adhesion of the commercially available coronary stents with the arterial wall. It is believed that an auxetic coronary stent with inherent anisotropic mechanical properties and negative Poisson's ratio will have good mechanical adhesion with the arterial wall. METHODS: The auxetic design...

  15. New results from the HERMES Recoil Detector

    Energy Technology Data Exchange (ETDEWEB)

    Mussgiller, Andreas [DESY, 22603 Hamburg (Germany)

    2009-07-01

    Hard exclusive processes provide access to generalized parton distributions (GPDs), which extend our description of the nucleon structure beyond the standard parton distributions. The Deeply Virtual Compton Scattering (DVCS) process provides the theoretically cleanest access to the GPDs. For the final two years of data taking, a Recoil Detector had been installed at the HERMES experiment at HERA with the purpose of improving the ability to measure hard-exclusive processes. In addition the Recoil Detector allows to measure the individual background contributions which can be used to refine previously published results on DVCS. The Recoil Detector consisted of three sub-detectors inside a 1 T solenoidal magnetic field. A silicon detector operated inside the HERA vacuum, a scintillating fiber tracker, and a photon detector. The progress of the ongoing data analysis is presented.

  16. Vessel healings after stenting with different polymers in STEMI patients

    Science.gov (United States)

    Jin, Qin-Hua; Chen, Yun-Dai; Tian, Feng; Guo, Jun; Jing, Jing; Sun, Zhi-Jun

    2016-01-01

    Background Different stents implantation in ST-segment elevation myocardial infarction (STEMI) patients may influence the long term prognosis by affecting vessel healings after stenting. The aim of this study was to evaluate the vessel healings after implantation of drug eluting stents (DES) with biodegradable or durable polymer or of bare-metal stents (BMS) in patients with acute STEMI. Methods This study included 50 patients, who underwent follow up angiogram and optical coherence tomography (OCT) assessment about one year after percutaneous coronary intervention (PCI) for STEMI. According to the initial stents types, these patients were classified to durable (n = 19) or biodegradable polymer sirolimus-eluting stents (n = 15), or BMS (n = 16) groups. The conditions of stent struts coverage and malapposition were analyzed with OCT technique. Results A total of 9003 struts were analyzed: 3299, 3202 and 2502 from durable or biodegradable polymer DES, or BMS, respectively. Strut coverage rate (89.0%, 94.9% and 99.3%, respectively), malapposition presence (1.7%, 0.03% and 0 of struts, respectively) and average intimal thickness over struts (76 ± 12 µm, 161 ± 30 µm and 292 ± 29 µm, respectively) were significantly different among different stent groups (all P < 0.001). Conclusions Vessel healing status in STEMI patients is superior after implantation of biodegradable polymer DES than durable polymer DES, while both are inferior to BMS. PMID:27403139

  17. Proton recoils in organic liquid scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Winter, Juergen [Technische Universitaet Muenchen, Physik Department E15, Garching (Germany); Collaboration: LENA Working Group

    2012-07-01

    In liquid-scintillator detectors like the LENA (Low Energy Neutrino Astronomy) project, understanding the nature of proton recoils is vital. First of all concerning the observation of the diffuse Supernova anti {nu}{sub e} background with the inverse beta decay (IBD). This signature can be mimicked by the thermalization and capture of a knockout neutron originating from inelastic NC interactions of atmospheric neutrinos on {sup 12}C. However, with the help of pulse shape discrimination between the neutron-induced proton recoils and the prompt positron signal from the IBD, this background might be reduced effectively. Furthermore, elastic {nu}-p scattering is an important channel for neutrinos from a galactic core-collapse SN. In order to reconstruct the initial neutrino energy, the energy-dependent quenching factor of proton recoils has to be known. Therefore, a neutron scattering experiment at the Maier-Leibnitz-Laboratorium in Garching has been set up in order to understand the response of proton recoils in organic liquid scintillator.

  18. D-brane recoil and logarithmic operators

    CERN Document Server

    Kogan, I I; Wheater, John F; Kogan, Ian I; Mavromatos, Nick E; Wheater, John F

    1996-01-01

    We construct the pair of logarithmic operators associated with the recoil of a D-brane. This construction establishes a connection between a translation in time and a world-sheet rescaling. The problem of measuring the centre of mass coordinate of the D-brane is considered and the relation between the string uncertainty principle and the logarithmic operators is discussed.

  19. First results from the HERMES recoil detector

    Energy Technology Data Exchange (ETDEWEB)

    Yaschenko, Sergey [Physikalisches Institut II, Universitaet Erlangen-Nuernberg (Germany)

    2008-07-01

    For the last one and a half years of operation of HERA, a Recoil Detector was installed at the HERMES experiment to improve measurements of hard exclusive electron/positron scattering reactions in particular deeply virtual Compton scattering. These measurements can provide important constraints on models for generalized parton distributions and hence can lead to the determination of the angular momentum of quarks inside the nucleon. The HERMES Recoil Detector was designed to improve the selection of exclusive events by a direct measurement of the momentum and track direction of recoiling particles and allow the rejection of non-exclusive background events. The detector consisted of three main components: a silicon strip detector (SSD) placed inside the HERA vacuum, a scintillation fiber tracker (SFT), and a photon detector consisting of three layers of tungsten-scintillator sandwich. All the detectors were located in a solenoidal magnetic field of 1 Tesla. The detector was installed in the HERMES experiment in December 2005. The commissioning of the SFT was finished in February 2006 and the SSD commissioning could only be finished in September 2006 due to beam induced noise. The fully commissioned Recoil detector was working stable from September 2006 to the end of HERA operation on June 30 of 2007. Results on the detector performance are presented.

  20. QED theory of the nuclear recoil effect in atoms

    OpenAIRE

    Shabaev, V. M.

    1997-01-01

    The quantum electrodynamic theory of the nuclear recoil effect in atoms to all orders in \\alpha Z is formulated. The nuclear recoil corrections for atoms with one and two electrons over closed shells are considered in detail. The problem of the composite nuclear structure in the theory of the nuclear recoil effect is discussed.

  1. QED theory of the nuclear recoil effect in atoms

    CERN Document Server

    Shabaev, V M

    1998-01-01

    The quantum electrodynamic theory of the nuclear recoil effect in atoms to all orders in \\alpha Z is formulated. The nuclear recoil corrections for atoms with one and two electrons over closed shells are considered in detail. The problem of the composite nuclear structure in the theory of the nuclear recoil effect is discussed.

  2. Long-term outcomes after stenting as a "bridge to surgery"for the management of acute obstruction secondary tocolorectal cancer

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    Obstructive symptoms are present in 8% of cases atthe time of initial diagnosis in cases of colorectal cancer.Emergency surgery has been classically considered thetreatment of choice in these patients. However, in themajority of studies, emergency colorectal surgery isburdened with higher morbidity and mortality rates thanelective surgery, and many patients require temporalcolostomy which deteriorates their quality of life andbecomes permanent in 10%-40% of cases. The aim ofstenting by-pass to surgery is to transform emergencysurgery into elective surgery in order to improve surgicalresults, obtain an accurate tumoral staging and detectionof synchronous lesions, stabilization of comorbidities andperformance of laparoscopic surgery. Immediate resultswere more favourable in patients who were stentedconcerning primary anastomosis, permanent stoma,wound infection and overall morbidity, having the highersurgical risk patients the greater benefit. However, somefindings laid out the possible implication of stenting inlong-term results of oncologic treatment. Perforationafter stenting is related to tumoral recurrence. In studieswith perforation rates above 8%, higher recurrencesrates in young patients and lower disease free survivalhave been shown. On the other hand, after stentingthe number of removed lymph nodes in the surgicalspecimen is larger, patients can receive adjuvant chemotherapyearlier and in a greater percentage andthe number of patients who can be surgically treatedwith laparoscopic surgery is larger. Finally, there are noconsistent studies able to demonstrate that one strategyis superior to the other in terms of oncologic benefits. Atpresent, it would seem wise to assume a higher initialcomplication rate in young patients without relevantcomorbidities and to accept the risk of local recurrencein old patients (〉 70 years) or with high surgical risk (ASAⅢ/Ⅳ).

  3. Effects of coexisting polymorphisms of CYP2C19 and P2Y12 on clopidogrel responsiveness and clinical outcome in patients with acute coronary syndromes undergoing stent-based coronary intervention

    Institute of Scientific and Technical Information of China (English)

    TANG Xiao-fang; ZHANG Jia-hui; WANG Jing; HAN Ya-ling; XU Bo; QIAO Shu-bin; WU Yong-jian

    2013-01-01

    Background The CYP2C19 G681A single polymorphism has been proven to affect clopidogrel responsiveness.However,the effect of coexisting polymorphisms of other genes has not yet been reported in the Chinese population.This study investigated the effect of coexisting polymorphisms of CYP2C19 and P2Y12 on clopidogrel responsiveness and adverse clinical events in Chinese patients.Methods In 577 Han Chinese patients undergoing stent placement because of acute coronary syndrome had platelet reactivity assessed by thromboelastography,and the CYP2C19 G681A and P2Y12 C34T polymorphisms were detected by the ligase detection reaction.Primary clinical endpoints included cardiovascular death,nonfatal myocardial infarction,target vessel revascularization,and stent thrombosis.The secondary clinical endpoints were thrombolysis in myocardial infarction bleeding.The follow-up period was 12 months.Results Genotyping revealed 194 carriers of the wild type GG genotype of CYP2C19 and the wild type CC genotype of P2Y12 (group 1),102 carriers of the wild type GG genotype of CYP2C 19 and the mutational T allele of P2Y12 (group 2),163 carriers of the mutational A allele of CYP2C19 and the wild type CC genotype of P2Y12 (group 3),and 118 carriers of the mutational A allele of CYP2C19 and the mutational T allele of P2Y12 (group 4).Group 4 had the lowest ADP-inhibition (49.74±32.61) and the highest prevalence of clopidogrel low response (29.7%) of the four groups.The rate of the composite of primary clinical endpoints increased more in group 4 (8.5%) than in the other three groups; the rate of composite primary endpoints in group 2 (2.9%) and group 3 (3.7%) were not significantly different than that of group 1 (1.5%).Conclusion Coexisting polymorphisms of different genes affected clopidogrel responsiveness and clinical outcome more than single polymorphism in Chinese patients with acute coronary syndrome undergoing percutaneous coronary intervention.

  4. An Update to Hepatobiliary Stents

    OpenAIRE

    Moy, Brian T.; Birk, John W.

    2015-01-01

    Endoscopic stent placement is a common primary management therapy for benign and malignant biliary strictures. However, continuous use of stents is limited by occlusion and migration. Stent technology has evolved significantly over the past two decades to reduce these problems. The purpose of this article is to review current guidelines in managing malignant and benign biliary obstructions, current endoscopic techniques for stent placement, and emerging stent technology. What began as a simpl...

  5. Endoscopic pancreatic duct stent placement for inflammatory pancreatic diseases

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The role of endoscopic therapy in the management of pancreatic diseases is continuously evolving; at present most pathological conditions of the pancreas are successfully treated by endoscopic retrograde cholangiopancreatography (ERCP) or endoscopic ultrasound (EUS),or both. Endoscopic placement of stents has played and still plays a major role in the treatment of chronic pancreatitis, pseudocysts, pancreas divisum, main pancreatic duct injuries, pancreatic fistulae, complications of acute pancreatitis, recurrent idiopathic pancreatitis,and in the prevention of post-ERCP pancreatitis. These stents are currently routinely placed to reduce intraductal hypertension, bypass obstructing stones, restore lumen patency in cases with dominant, symptomatic strictures,seal main pancreatic duct disruption, drain pseudocysts or fluid collections, treat symptomatic major or minor papilla sphincter stenosis, and prevent procedure-induced acute pancreatitis. The present review aims at updating and discussing techniques, indications, and results of endoscopic pancreatic duct stent placement in acute and chronic inflammatory diseases of the pancreas.

  6. Role of colonic stents in the management of colorectalcancers

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    Colorectal cancer is one of the commonly encounteredcancers across the Western World. In United Kingdom,this constitutes third most common ranked cancer andsecond most common ranked cause of cancer relateddeaths. Its acute presentation as a malignant colonicobstruction imposes challenges in its management.Colonic stent has been used for many years to alleviateSubmit a Manuscript http://www.wjgnet.com/esps/Help Desk: http://www.wjgnet.com/esps/helpdesk.aspxDOI: 10.4253/wjge.v8.i4.198World J Gastrointest Endosc 2016 February 25; 8(4): 198-204ISSN 1948-5190 (online)? 2016 Baishideng Publishing Group Inc. All rights reserved.acute obstruction in such cases allowing optimisationof patient's physiological status and adequate stagingof cancer. In this review, current literature evidenceregarding use of colonic stent in acute malignant colonicobstruction is critically appraised and recommendationson the use of colonic stent are advocated.

  7. First-in-man (FIM) study of the Stentys™ bifurcation stent - 30 days results

    NARCIS (Netherlands)

    S. Verheye (Stefan); E. Grube (Eberhard); S. Ramcharitar (Steve); J. Schofer (Joachim); B. Witzenbichler (Bernhard); J. Kovac (Jan); K. Hauptmann (Karl); P. Agostoni (Pierfrancesco); M. Wiemer (Marcus); T. Lefèvre (Thierry); P.W.J.C. Serruys (Patrick); R.J.M. van Geuns (Robert Jan)

    2009-01-01

    textabstractAims: We report the acute and 30 day results of the OPEN I study, a multicentre prospective single arm study evaluating the safety and feasibility of the Stentys™ bifurcation stent. Methods and results: The Stentys™ stent is a provisional, self-expanding nitinol drug eluting or bare meta

  8. Wiktor stent implantation in patients with restenosis following balloon angioplasty of a native coronary artery

    NARCIS (Netherlands)

    P.W.J.C. Serruys (Patrick); M.E. Bertrand (Michel); V. Wiegand; G. Kober; J.F. Marquis; B. Valeix; R. Uebis; J. Piessen; P.P.T. de Jaegere (Peter)

    1992-01-01

    textabstractIntracoronary stenting has been introduced as an adjunct to balloon angioplasty aimed at overcoming its limitations, namely acute vessel closure and late restenosis. This study reports the first experience with the Wiktor stent implanted in the first 50 consecutive patients. All patients

  9. Ionization and scintillation of nuclear recoils in gaseous xenon

    CERN Document Server

    Renner, J; Goldschmidt, A; Matis, H S; Miller, T; Nakajima, Y; Nygren, D; Oliveira, C A B; Shuman, D; Álvarez, V; Borges, F I G; Cárcel, S; Castel, J; Cebrián, S; Cervera, A; Conde, C A N; Dafni, T; Dias, T H V T; Díaz, J; Esteve, R; Evtoukhovitch, P; Fernandes, L M P; Ferrario, P; Ferreira, A L; Freitas, E D C; Gil, A; Gómez, H; Gómez-Cadenas, J J; González-Díaz, D; Gutiérrez, R M; Hauptman, J; Morata, J A Hernando; Herrera, D C; Iguaz, F J; Irastorza, I G; Jinete, M A; Labarga, L; Laing, A; Liubarsky, I; Lopes, J A M; Lorca, D; Losada, M; Luzón, G; Marí, A; Martín-Albo, J; Martínez, A; Moiseenko, A; Monrabal, F; Monserrate, M; Monteiro, C M B; Mora, F J; Moutinho, L M; Vidal, J Muñoz; da Luz, H Natal; Navarro, G; Nebot-Guinot, M; Palma, R; Pérez, J; Aparicio, J L Pérez; Ripoll, L; Rodríguez, A; Rodríguez, J; Santos, F P; Santos, J M F dos; Seguí, L; Serra, L; Simón, A; Sofka, C; Sorel, M; Toledo, J F; Tomás, A; Torrent, J; Tsamalaidze, Z; Veloso, J F C A; Villar, J A; Webb, R C; White, J; Yahlali, N

    2014-01-01

    Ionization and scintillation produced by nuclear recoils in gaseous xenon at approximately 14 bar have been simultaneously observed in an electroluminescent time projection chamber. Neutrons from radioisotope $\\alpha$-Be neutron sources were used to induce xenon nuclear recoils, and the observed recoil spectra were compared to a detailed Monte Carlo employing estimated ionization and scintillation yields for nuclear recoils. The ability to discriminate between electronic and nuclear recoils using the ratio of ionization to primary scintillation is demonstrated. These results encourage further investigation on the use of xenon in the gas phase as a detector medium in dark matter direct detection experiments.

  10. Ionization and scintillation of nuclear recoils in gaseous xenon

    Energy Technology Data Exchange (ETDEWEB)

    Renner, J., E-mail: jrenner@lbl.gov [Lawrence Berkeley National Laboratory (LBNL), 1 Cyclotron Road, Berkeley, CA 94720 (United States); Department of Physics, University of California, Berkeley, CA 94720 (United States); Gehman, V.M.; Goldschmidt, A.; Matis, H.S.; Miller, T.; Nakajima, Y.; Nygren, D.; Oliveira, C.A.B.; Shuman, D. [Lawrence Berkeley National Laboratory (LBNL), 1 Cyclotron Road, Berkeley, CA 94720 (United States); Álvarez, V. [Instituto de Física Corpuscular (IFIC), CSIC & Universitat de València, Calle Catedrático José Beltrán, 2, 46980 Paterna, Valencia (Spain); Borges, F.I.G. [Departamento de Fisica, Universidade de Coimbra, Rua Larga, 3004-516 Coimbra (Portugal); Cárcel, S. [Instituto de Física Corpuscular (IFIC), CSIC & Universitat de València, Calle Catedrático José Beltrán, 2, 46980 Paterna, Valencia (Spain); Castel, J.; Cebrián, S. [Laboratorio de Física Nuclear y Astropartículas, Universidad de Zaragoza, Calle Pedro Cerbuna 12, 50009 Zaragoza (Spain); Cervera, A. [Instituto de Física Corpuscular (IFIC), CSIC & Universitat de València, Calle Catedrático José Beltrán, 2, 46980 Paterna, Valencia (Spain); Conde, C.A.N. [Departamento de Fisica, Universidade de Coimbra, Rua Larga, 3004-516 Coimbra (Portugal); and others

    2015-09-01

    Ionization and scintillation produced by nuclear recoils in gaseous xenon at approximately 14 bar have been simultaneously observed in an electroluminescent time projection chamber. Neutrons from radioisotope α-Be neutron sources were used to induce xenon nuclear recoils, and the observed recoil spectra were compared to a detailed Monte Carlo employing estimated ionization and scintillation yields for nuclear recoils. The ability to discriminate between electronic and nuclear recoils using the ratio of ionization to primary scintillation is demonstrated. These results encourage further investigation on the use of xenon in the gas phase as a detector medium in dark matter direct detection experiments.

  11. Biocompatibility evaluation of NiTi SMA stent via intervenient therapy

    Institute of Scientific and Technical Information of China (English)

    FENG; Jing-su; LIU; Kun-peng; KOU; Ya-ming

    2005-01-01

    NiTi shape memory alloy (SMA) stent with film are the long-term implanted medical devices which could be used in human's organ, such as esophagus, bile duct, urethra-prostate and blood vessel, by intervene therapy. It is very important to have a good biocompatibility for implanted device. According to standard ISO 10993, we completed biocompatibility evaluation of NiTi stent that included following tests: cytotoxicity, sensitization, genotoxicity, hemolysis and acute systemic toxicity, The results of tests qualify the NiTi stent, and provide an optimistic conclusion for the eventual use of NiTi stent as implanted medical devices.

  12. Experiments with recoil ions and other considerations

    Energy Technology Data Exchange (ETDEWEB)

    Cocke, C.L.

    1987-01-01

    Some opportunities in collisions physics with slow, multiply charged ions are addressed. A distinction between inner and outer shell collisions is drawn. The applicability of recoil ion sources to outer shell collision systems is discussed, with emphasis on the quality of the beam desired. An example of an inner shell collision is discussed, and the usefulness of not pushing the collision energy too low is pointed out. 13 refs., 14 figs.

  13. Elastic recoil detection analysis of ferroelectric films

    Energy Technology Data Exchange (ETDEWEB)

    Stannard, W.B.; Johnston, P.N.; Walker, S.R.; Bubb, I.F. [Royal Melbourne Inst. of Tech., VIC (Australia); Scott, J.F. [New South Wales Univ., Kensington, NSW (Australia); Cohen, D.D.; Dytlewski, N. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1996-12-31

    There has been considerable progress in developing SrBi{sub 2}Ta{sub 2}O{sub 9} (SBT) and Ba{sub O.7}Sr{sub O.3}TiO{sub 3} (BST) ferroelectric films for use as nonvolatile memory chips and for capacitors in dynamic random access memories (DRAMs). Ferroelectric materials have a very large dielectric constant ( {approx} 1000), approximately one hundred times greater than that of silicon dioxide. Devices made from these materials have been known to experience breakdown after a repeated voltage pulsing. It has been suggested that this is related to stoichiometric changes within the material. To accurately characterise these materials Elastic Recoil Detection Analysis (ERDA) is being developed. This technique employs a high energy heavy ion beam to eject nuclei from the target and uses a time of flight and energy dispersive (ToF-E) detector telescope to detect these nuclei. The recoil nuclei carry both energy and mass information which enables the determination of separate energy spectra for individual elements or for small groups of elements In this work ERDA employing 77 MeV {sup 127}I ions has been used to analyse Strontium Bismuth Tantalate thin films at the heavy ion recoil facility at ANSTO, Lucas Heights. 9 refs., 5 figs.

  14. Intravascular ultrasound assessed incomplete stent apposition and stent fracture in stent thrombosis after bare metal versus drug-eluting stent treatment the Nordic Intravascular Ultrasound Study (NIVUS)

    DEFF Research Database (Denmark)

    Kosonen, Petteri; Vikman, Saila; Jensen, Lisette Okkels;

    2013-01-01

    This prospective multicenter registry used intravascular ultrasound (IVUS) in patients with definite stent thrombosis (ST) to compare rates of incomplete stent apposition (ISA), stent fracture and stent expansion in patients treated with drug-eluting (DES) versus bare metal (BMS) stents. ST...... is a rare, but potential life threatening event after coronary stent implantation. The etiology seems to be multifactorial....

  15. [Stent implantation as initial coronary interventional therapy? A theoretical model on clinical and economical consequences of in-stent restenosis].

    Science.gov (United States)

    Pfund, A; Wendland, G; Baer, F; Lauterbach, K; Höpp, H W

    2000-08-01

    The reduction of acute complications and late restenosis compared to conventional PTCA has led to a rapid increase in stent implantation as initial treatment for coronary stenosis. As a result, in-stent restenosis has become an important clinical and economical problem, especially the diffuse form, which is much more likely to reappear. In order to compare the consequences of initial stenting and initial angioplasty, we developed an analytic model, considering the differences between diffuse and focal in-stent restenosis. The simulation based on the optimized therapeutic proceeding following an elective 1-vessel revascularization of a 60-year-old patient, dealing with probabilities for acute complications and late restenosis taken from the literature and in-hospital costs obtained from 200 elective interventions. In the stent group 71.0% of patients were free of any target lesion-related event, compared to 60.2% in the PTCA group. Catheter reintervention was necessary for 32.1% of the patients initially treated with angioplasty and for 17.6% of the initially stented patients, whereas 7.7% of the stent patients had to undergo elective bypass surgery as final treatment compared to 2.8% in the PTCA arm. Long-term medical costs for initial stenting (6,237 Euros) were 14% higher than for conventional PTCA (5,345 Euros). Taking also into consideration the indirect costs (loss of productivity) for a collective with an employment rate of 50%, the difference between stent implantation (9,067 Euros) and angioplasty (8,581 Euros) is smaller. Initial treatment of coronary stenosis by stent implantation decreases the rate of repeat revascularization compared to initial PTCA, but there is a greater likelihood that elective bypass surgery will become necessary. This difference in following treatment is related to the occurrence of diffuse in-stent restenosis. When calculating the long-term costs stenting still appeared to be more expensive than PTCAA because the savings in

  16. Hyperperfusion syndrome after carotid stent angioplasty

    Energy Technology Data Exchange (ETDEWEB)

    Grunwald, I.Q.; Politi, M.; Reith, W.; Krick, C.; Karp, K.; Zimmer, A.; Struffert, T.; Kuehn, A.L.; Papanagiotou, P. [University of the Saarland, Department for Interventional and Diagnostic Neuroradiology, Homburg (Germany); Roth, C.; Haass, A. [University of the Saarland, Clinic for Neurology, Homburg (Germany)

    2009-03-15

    This study assesses the incidence and causes of hyperperfusion syndrome occurring after carotid artery stenting (CAS). We retrospectively reviewed the clinical database of 417 consecutive patients who were treated with CAS in our department to identify patients who developed hyperperfusion syndrome and/or intracranial hemorrhage. Magnetic resonance imaging (MRI) including fluid-attenuated inversion recovery and diffusion-weighted imaging was performed before and after CAS in 269 cases. A Spearman's rho nonparametric correlation was performed to determine whether there was a correlation between the occurrence/development of hyperperfusion syndrome and the patient's age, degree of stenosis on the stented and contralateral side, risk factors such as diabetes, smoking, hypertension, adiposity, gender and fluoroscopy time, and mean area of postprocedural lesions as well as preexisting lesions. Significance was established at p < 0.05. Of the 417 carotid arteries stented and where MRI was also completed, we found hyperperfusion syndrome in 2.4% (ten cases). Patients who had preexisting brain lesions (previous or acute stroke) were at a higher risk of developing hyperperfusion syndrome (p = 0.022; Spearman's rho test). We could not validate any correlation with the other patient characteristics. Extensive microvascular disease may be a predictor of hyperperfusion syndrome after carotid stent placement. We believe that further studies are warranted to predict more accurately which patients are at greater risk of developing this often fatal complication. (orig.)

  17. The virtual histology intravascular ultrasound appearance of newly placed drug-eluting stents.

    Science.gov (United States)

    Kim, Sang-Wook; Mintz, Gary S; Hong, Young-Joon; Pakala, Rajbabu; Park, Kyung-Sook; Pichard, Augusto D; Satler, Lowell F; Kent, Kenneth M; Suddath, William O; Waksman, Ron; Weissman, Neil J

    2008-11-01

    Intravascular ultrasound (IVUS) is used before and after intervention and at follow-up to assess the quality of the acute result as well as the long-term effects of stent implantation. Virtual histology (VH) IVUS classifies tissue into fibrous and fibrofatty plaque, dense calcium, and necrotic core. Although most interventional procedures include stent implantation, VH IVUS classification of stent metal has not been validated. In this study, the VH IVUS appearance of acutely implanted stents was assessed in 27 patients (30 lesions). Most stent struts (80%) appeared white (misclassified as "calcium") surrounded by red (misclassified as "necrotic core"); 2% appeared just white, and 17% were not detectable (compared with grayscale IVUS because of the software-imposed gray medial stripe). The rate of "white surrounded by red" was similar over the lengths of the stents; however, undetectable struts were mostly at the distal edges (31%). Quantitatively, including the struts within the regions of interest increased the amount of "calcium" from 0.23 +/- 0.35 to 1.07 +/- 0.66 mm(2) (p stents have an appearance that can be misclassified by VH IVUS as "calcium with or without necrotic core." It is important not to overinterpret VH IVUS studies of chronically implanted stents when this appearance is observed at follow-up. A separate classification for stent struts is necessary to avoid these misconceptions and misclassifications.

  18. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... But there is clearly a huge body of data that shows that tobacco use is associated with ... medicated stents. I hear they’re bad.” The data that has come out since then has showed ...

  19. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... not to just ignore any kind of symptoms. Diabetics, in particular, are a subclass of patients who ... vessel disease or multiple vessel blockages, or a diabetic, we think that the drug-eluting stents are ...

  20. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... the equipment that we use from the early days has undergone a sea change. The catheters that ... the stent design has improved from the early days when they were very difficult to deploy and ...

  1. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available Coronary Angioplasty Stent Placement Shawnee Mission Heart & Vascular Center, Shawnee Mission, Kansas February 19, 2009 Welcome to this OR-Live westbound cast presentation, live from Shawnee Mission Medical Center ...

  2. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... care of the intravenous medications and any other medicines that need to be administered in monitoring his ... put in, versus medicated or what’s known as drug-eluding stents. And there has been a lot ...

  3. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... have accessed the femoral artery, which is the big blood vessel in the leg, through which we ... getting to the point where if it’s a big artery, a bare metal stent will work, a ...

  4. Coronary Angioplasty Stent Placement

    Science.gov (United States)

    ... 2009 Welcome to this OR-Live westbound cast presentation, live from Shawnee Mission Medical Center in Merriam, ... putting in a bare metal stent. The whole theory behind that is you have a lesser chance ...

  5. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... 2009 Welcome to this OR-Live westbound cast presentation, live from Shawnee Mission Medical Center in Merriam, ... putting in a bare metal stent. The whole theory behind that is you have a lesser chance ...

  6. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... the opening of the blood vessel. It’s a collagen plug, and that will help seal the opening. ... stent should be on Plavix or a similar type of anti-platelet drug lifelong. One of the ...

  7. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... a big artery, a bare metal stent will work, a smaller artery or in some of the ... the equipment that we use from the early days has undergone a sea change. The catheters that ...

  8. Drug-eluting stents to prevent stent thrombosis and restenosis.

    Science.gov (United States)

    Im, Eui; Hong, Myeong-Ki

    2016-01-01

    Although first-generation drug-eluting stents (DES) have significantly reduced the risk of in-stent restenosis, they have also increased the long-term risk of stent thrombosis. This safety concern directly triggered the development of new generation DES, with innovations in stent platforms, polymers, and anti-proliferative drugs. Stent platform materials have evolved from stainless steel to cobalt or platinum-chromium alloys with an improved strut design. Drug-carrying polymers have become biocompatible or biodegradable and even polymer-free DES were introduced. New limus-family drugs (such as everolimus, zotarolimus or biolimus) were adopted to enhance stent performances. As a result, these new DES demonstrated superior vascular healing responses on intracoronary imaging studies and lower stent thrombotic events in actual patients. Recently, fully-bioresorbable stents (scaffolds) have been introduced, and expanding their applications. In this article, the important concepts and clinical results of new generation DES and bioresorbable scaffolds are described.

  9. Stent Fracture after Everolimus-Eluting Stent Implantation

    Directory of Open Access Journals (Sweden)

    Ali S. Almasood

    2011-01-01

    Full Text Available Compared with bare-metal stents, drug-eluting stents (DES have greatly reduced the risk of in-stent restenosis (ISR by inhibiting neointimal growth. Nevertheless, DES are still prone to device failure, which may lead to cardiac events. Recently, stent fracture (SF has emerged as a potential mechanism of DES failure that is associated with ISR. Stent fracture is strongly related to stent type, and prior reports suggest that deployment of sirolimus eluting stents (SES may be associated with a higher risk of SF compared to other DES. Everolimus eluting stents (EESs represent a new generation of DES with promising results. The occurrence of SF with EES has not been well established. The present paper describes two cases of EES fracture associated with ISR.

  10. Drug-eluting stents to prevent stent thrombosis and restenosis.

    Science.gov (United States)

    Im, Eui; Hong, Myeong-Ki

    2016-01-01

    Although first-generation drug-eluting stents (DES) have significantly reduced the risk of in-stent restenosis, they have also increased the long-term risk of stent thrombosis. This safety concern directly triggered the development of new generation DES, with innovations in stent platforms, polymers, and anti-proliferative drugs. Stent platform materials have evolved from stainless steel to cobalt or platinum-chromium alloys with an improved strut design. Drug-carrying polymers have become biocompatible or biodegradable and even polymer-free DES were introduced. New limus-family drugs (such as everolimus, zotarolimus or biolimus) were adopted to enhance stent performances. As a result, these new DES demonstrated superior vascular healing responses on intracoronary imaging studies and lower stent thrombotic events in actual patients. Recently, fully-bioresorbable stents (scaffolds) have been introduced, and expanding their applications. In this article, the important concepts and clinical results of new generation DES and bioresorbable scaffolds are described. PMID:26567863

  11. Development of a dynamic in vitro model of a stented blood vessel to evaluate the effects of stent strut material selection and surface coating on smooth muscle cell response

    Science.gov (United States)

    Winn, Bradley Huegh

    Cardiovascular disease is the leading cause of mortality in The United States and Europe, accounting for approximately half of all deaths. The most common form of cardiovascular disease is atherosclerosis, which is characterized by the formation of fatty atheromatous plaques that can grow to occlude the vessel lumen, thus causing ischemia distal to the occlusion. This is commonly treated using balloon angioplasty, which is usually done in conjunction with the deployment of a stent. Stent deployment helps hold the vessel open following the local injury caused by balloon inflation and prevents elastic recoil and subsequent negative remodeling. Stenting has been shown to significantly reduce restenosis rates from approximately 20-50% without a stent to about 10-30% with stent deployment. However, restenosis still remains the main cause of long-term stent failure. In basic terms, a balloon angioplasty procedure is a forceful displacement of an atherosclerotic lesion serving to widen the vessel lumen to increase blood flow. This procedure causes stretching of the vessel wall, tears in the atherosclerotic plaques, and general damage to the vessel in turn signaling a complex cascade of thrombosis, inflammation, intimal thickening, and vascular remodeling. Stent deployment also further complicates the immunological response by triggering a foreign body response from the implantation of a biomaterial into the body. When performing an angioplasty procedure, particularly in conjunction with stent deployment, a certain degree of vascular injury is inevitable. However, the initial injury can be further complicated by the body's local reaction to the implanted biomaterial, the severity of which can ultimately dictate the degree of restenosis and subsequently affect procedural success. The proliferative response of VSMCs to the various afore mentioned stimuli results in the formation of often copious amounts of neointimal tissue, generally known as intimal hyperplasia. The

  12. Hemodynamics in Idealized Stented Coronary Arteries: Important Stent Design Considerations

    OpenAIRE

    Beier, Susann; Ormiston, John; Webster, Mark; Cater, John; Norris, Stuart; Medrano-Gracia, Pau; Young, Alistair; Cowan, Brett

    2015-01-01

    Stent induced hemodynamic changes in the coronary arteries are associated with higher risk of adverse clinical outcome. The purpose of this study was to evaluate the impact of stent design on wall shear stress (WSS), time average WSS, and WSS gradient (WSSG), in idealized stent geometries using computational fluid dynamics. Strut spacing, thickness, luminal protrusion, and malapposition were systematically investigated and a comparison made between two commercially available stents (Omega and...

  13. Clinical results from first use of prostate stent as fiducial for radiotherapy of prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Carl, Jesper; Nielsen, Jane (Dept. of Medical Physics, Dept. of Oncology, Aalborg Hospital, Aarhus Univ. Hospital, Aalborg (Denmark)), e-mail: jhc@rn.dk; Holmberg, Mats (Dept. of Oncology, Aalborg Hospital, Aarhus Univ. Hospital, Aalborg (Denmark)); Larsen, Erik Hoejkjaer; Fabrin, Knud (Dept. of Urology, Aalborg Hospital, Aarhus Univ. Hospital, Aalborg (Denmark)); Fisker, Rune V. (Dept. of Radiology, Aalborg Hospital, Aarhus Univ. Hospital, Aalborg (Denmark))

    2011-05-15

    Purpose. A clinical feasibility study using a removable prostate stent as fiducial for image-guided radiotherapy (IGRT) of localized prostate cancer (PC). Material and methods. The study included patients with local or locally advanced PC. The clinical target volume (CTV) was outlined on magnetic resonance (MR) images co-registered to planning computer tomography (CT) images. Daily online IGRT was delivered using the stent as fiducial. Risk of migration was estimated using multiple MR. Acute urinary toxicity was scored using the international prostate symptom score (IPSS). Late gastro-intestinal (GI) and genito-urinary (GU) toxicity was scored using the Radio Therapy Oncology Group (RTOG) score, biochemical failure (BF) was defined as an elevation of prostate specific antigen (PSA) above nadir plus 2 ng/ml after radiotherapy. Results. One hundred men were enrolled in the study. Ninety completed radiotherapy with the stent as fiducial. No migration of the stent was seen, but three cases of dislocation of the stent to the bladder were observed. Acute urinary toxicity based on IPSS was comparable to toxicity in patients who had gold markers (GM) as fiducials. Removal of the stent was associated with a high frequency of urinary retention. Late GI and GU toxicity and BF were comparable to those of other studies, but longer observation time is needed. Conclusions. This study reports the first clinical results of using a prostate stent as fiducial. No migration of the stent observed. Dislocation of the stent to the urinary bladder was observed in three cases, requiring removal of the stent and insertion of a new fiducial. Acute toxicity during radiotherapy evaluated from IPSS was comparable to toxicity in patients with GM. Removal of the stent was associated with a high frequency of post procedural urinary retention. Late toxicity and BF were comparable to those of other studies, though longer observation time is needed

  14. The risk and prognostic impact of definite stent thrombosis or in-stent restenosis after coronary stent implantation

    DEFF Research Database (Denmark)

    Thayssen, Per; Jensen, Lisette Okkels; Lassen, Jens Flensted;

    2012-01-01

    Aims: Data are limited on the prognostic impact of stent thrombosis and in-stent restenosis in patients treated with coronary stents. We examined the prognostic impact of stent thrombosis and in-stent restenosis in patients treated with percutaneous coronary intervention (PCI). Methods and results......: All patients who underwent stent implantation from 2002 to 2005 were identified in the Western Denmark Heart Registry. The hazard ratio (HR) for death associated with stent thrombosis or in-stent restenosis was estimated with a Cox regression analysis with stent thrombosis or in-stent restenosis...... as time-dependent variables. A total of 12,277 patients were treated with stent implantation. Stent thrombosis was observed in 111 (0.9%) patients and in-stent restenosis in 503 (4.1%) patients within 12 months after the index PCI. Occurrence of stent thrombosis was associated with an increased risk...

  15. Nanomaterial coatings applied on stent surfaces.

    Science.gov (United States)

    Bagheri, Mahsa; Mohammadi, Marzieh; Steele, Terry Wj; Ramezani, Mohammad

    2016-05-01

    The advent of percutaneous coronary intervention and intravascular stents has revolutionized the field of interventional cardiology. Nonetheless, in-stent restenosis, inflammation and late-stent thrombosis are the major obstacles with currently available stents. In order to enhance the hemocompatibility of stents, advances in the field of nanotechnology allow novel designs of nanoparticles and biomaterials toward localized drug/gene carriers or stent scaffolds. The current review focuses on promising polymers used in the fabrication of newer generations of stents with a short synopsis on atherosclerosis and current commercialized stents, nanotechnology's impact on stent development and recent advancements in stent biomaterials is discussed in context.

  16. Nanomaterial coatings applied on stent surfaces.

    Science.gov (United States)

    Bagheri, Mahsa; Mohammadi, Marzieh; Steele, Terry Wj; Ramezani, Mohammad

    2016-05-01

    The advent of percutaneous coronary intervention and intravascular stents has revolutionized the field of interventional cardiology. Nonetheless, in-stent restenosis, inflammation and late-stent thrombosis are the major obstacles with currently available stents. In order to enhance the hemocompatibility of stents, advances in the field of nanotechnology allow novel designs of nanoparticles and biomaterials toward localized drug/gene carriers or stent scaffolds. The current review focuses on promising polymers used in the fabrication of newer generations of stents with a short synopsis on atherosclerosis and current commercialized stents, nanotechnology's impact on stent development and recent advancements in stent biomaterials is discussed in context. PMID:27111467

  17. Treatment of Malignant Biliary Obstruction with a PTFE-Covered Self-Expandable Nitinol Stent

    Energy Technology Data Exchange (ETDEWEB)

    Han, Young-Min; Kwak, Hyo-Sung; Jin, Gong-Yong; Lee, Seung-Ok; Chung, Gyung-Ho [Chonbuk National University Medical School and Hospital, Chonju (Korea, Republic of)

    2007-10-15

    We wanted to determine the technical and clinical efficacy of using a PTFE-covered self-expandable nitinol stent for the palliative treatment of malignant biliary obstruction. Thirty-seven patients with common bile duct strictures caused by malignant disease were treated by placing a total of 37 nitinol PTFE stents. These stents were covered with PTFE with the exception of the last 5 mm at each end; the stent had an unconstrained diameter of 10 mm and a total length of 50 80 mm. The patient survival rate and stent patency rate were calculated by performing Kaplan-Meier survival analysis. The bilirubin, serum amylase and lipase levels before and after stent placement were measured and then compared using a Wilcoxon signed-rank test. The average follow-up duration was 27.9 weeks (range: 2 81 weeks). Placement was successful in all cases. Seventy-six percent of the patients (28/37) experienced adequate palliative drainage for the remainder of their lives. There were no immediate complications. Three patients demonstrated stent sludge occlusion that required PTBD (percutaneous transhepatic biliary drainage) irrigation. Two patients experienced delayed stent migration with stone formation at 7 and 27 weeks of follow-up, respectively. Stent insertion resulted in acute elevations of the amylase and lipase levels one day after stent insertion in 11 patients in spite of performing endoscopic sphincterotomy (4/6). The bilirubin levels were significantly reduced one week after stent insertion (p < 0.01). The 30-day mortality rate was 8% (3/37), and the survival rates were 49% and 27% at 20 and 50 weeks, respectively. The primary stent patency rates were 85%, and 78% at 20 and 50 weeks, respectively. The PTFE-covered self-expandable nitinol stent is safe to use with acceptable complication rates. This study is similar to the previous studies with regard to comparing the patency rates and survival rates.

  18. Therapeutic effect and safety of Firebird stent combined tirofiban on acute myocardial infarction%Firebird 支架联合替罗非班用于急性心肌梗死中的疗效及安全性

    Institute of Scientific and Technical Information of China (English)

    刘远萍; 郝亚荣

    2015-01-01

    目的:评价Firebird支架联合替罗非班用于急性心肌梗死(AMI)中的疗效及安全性。方法:选择2011年8月至2013年8月我院收治的86例AMI患者,依据随机数字表法患者被分为:联合治疗组(50例, Firebird支架联合替罗非班)和常规治疗组(36例,裸金属支架)。对患者进行12~18个月的随访,比较两组临床疗效、临床事件发生率。结果:PCI术后,与常规治疗组比较,联合治疗组患者TIMI分级1-2级比例(13.9%比4.0%)明显减少,3~4级比例(86.1%比96.0%)明显增加,校正TIMI计帧数[(29.2±4.4)比(21.4±5.1)]明显减少, P均<0.05;术后6个月,与常规治疗组比较,联合治疗组的亚急性血栓(2.8%比0%)、心肌梗死(2.8%比0%)发生率均明显降低( P均<0.05),术后12个月,与常规治疗组比较,联合治疗组的心绞痛(16.7%比6.0%)、亚急性血栓(11.1%比0%)、心肌梗死(8.3%比0%)、心力衰竭(2.8%比0%)、再入院(11.1%比0%)发生率均明显降低(P<0.05或<0.01)。结论:Firebird支架联合替罗非班用于急性心肌梗死中的疗效显著,且安全可靠,值得推广。%Objective:To evaluate therapeutic effect and safety of Firebird stent combined tirofiban on acute myocar‐dial infarction (AMI) .Methods :A total of 86 AMI patients treated in our hospital from Aug 2011 to Aug 2013 were selected .According to random number table method ,patients were divided into combined treatment group (n=50 , received Firebird stenting combined tirofiban treatment ) and routine treatment group (n=36 ,received bare metal stenting) .Patients were followed up for 12~18 months ,therapeutic effects ,incidence rates of clinical events were compared between two groups .Results:After PCI ,compared with routine treatment group ,there were significant reductions in percentage of TIMI class 1~2 (13.9% vs .4

  19. Molecular sieves analysis by elastic recoil detection

    International Nuclear Information System (INIS)

    The opportunity of water determination in zeolites via hydrogen detection using the elastic recoil detection analysis (ERDA) was investigated. The radiation effect upon the desorption rate of hydrogen in miscellaneous types of zeolites, e.g. Y-Faujasite, ZSM-5, SK, etc. and in a natural clay, e.g. an Algerian bentonite was discussed. Quantitative measurements were carried out in order to determine the amount and distribution shape of hydrogen in each material. Various explanations dealing with hydration and constitution water in such a crystalline framework were proposed. The experimental results are in a good agreement with the corresponding theoretical values

  20. Neutron electric form factor via recoil polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    Madey, Richard; Semenov, Andrei; Taylor, Simon; Aghalaryan, Aram; Crouse, Erick; MacLachlan, Glen; Plaster, Bradley; Tajima, Shigeyuki; Tireman, William; Yan, Chenyu; Ahmidouch, Abdellah; Anderson, Brian; Asaturyan, Razmik; Baker, O; Baldwin, Alan; Breuer, Herbert; Carlini, Roger; Christy, Michael; Churchwell, Steve; Cole, Leon; Danagoulian, Samuel; Day, Donal; Elaasar, Mostafa; Ent, Rolf; Farkhondeh, Manouchehr; Fenker, Howard; Finn, John; Gan, Liping; Garrow, Kenneth; Gueye, Paul; Howell, Calvin; Hu, Bitao; Jones, Mark; Kelly, James; Keppel, Cynthia; Khandaker, Mahbubul; Kim, Wooyoung; Kowalski, Stanley; Lung, Allison; Mack, David; Manley, D; Markowitz, Pete; Mitchell, Joseph; Mkrtchyan, Hamlet; Opper, Allena; Perdrisat, Charles; Punjabi, Vina; Raue, Brian; Reichelt, Tilmann; Reinhold, Joerg; Roche, Julie; Sato, Yoshinori; Seo, Wonick; Simicevic, Neven; Smith, Gregory; Stepanyan, Samuel; Tadevosyan, Vardan; Tang, Liguang; Ulmer, Paul; Vulcan, William; Watson, John; Wells, Steven; Wesselmann, Frank; Wood, Stephen; Yan, Chen; Yang, Seunghoon; Yuan, Lulin; Zhang, Wei-Ming; Zhu, Hong Guo; Zhu, Xiaofeng

    2003-05-01

    The ratio of the electric to the magnetic form factor of the neutron, G_En/G_Mn, was measured via recoil polarimetry from the quasielastic d({pol-e},e'{pol-n)p reaction at three values of Q^2 [viz., 0.45, 1.15 and 1.47 (GeV/c)^2] in Hall C of the Thomas Jefferson National Accelerator Facility. Preliminary data indicate that G_En follows the Galster parameterization up to Q^2 = 1.15 (GeV/c)^2 and appears to rise above the Galster parameterization at Q^2 = 1.47 (GeV/c)^2.

  1. Future developments in biliary stenting

    Directory of Open Access Journals (Sweden)

    Hair CD

    2013-06-01

    Full Text Available Clark D Hair,1 Divyesh V Sejpal21Department of Medicine, Section of Gastroenterology and Hepatology, Baylor College of Medicine, Houston, TX, USA; 2Department of Medicine, Section of Gastroenterology, Hofstra North Shore-LIJ School of Medicine, North Shore University Hospital, Manhasset, NY, USAAbstract: Biliary stenting has evolved dramatically over the past 30 years. Advancements in stent design have led to prolonged patency and improved efficacy. However, biliary stenting is still affected by occlusion, migration, anatomical difficulties, and the need for repeat procedures. Multiple novel plastic biliary stent designs have recently been introduced with the primary goals of reduced migration and improved ease of placement. Self-expandable bioabsorbable stents are currently being investigated in animal models. Although not US Food and Drug Administration approved for benign disease, fully covered self-expandable metal stents are increasingly being used in a variety of benign biliary conditions. In malignant disease, developments are being made to improve ease of placement and stent patency for both hilar and distal biliary strictures. The purpose of this review is to describe recent developments and future directions of biliary stenting.Keywords: plastic stents, self-expandable metal stents, drug eluting stents, bioabsorbable stents, malignant biliary strictures, benign biliary strictures

  2. Recoil-decay tagging spectroscopy of 162 74 W 88

    OpenAIRE

    Li, H. J.; Cederwall, B.; Bäck, T.; Qi, C.; Doncel, M.; Jakobsson, Ulrika; Auranen, Kalle; Bönig, S; Drummond, M. C.; Grahn, Tuomas; Greenlees, Paul; Herzan, Andrej; Julin, Rauno; Juutinen, Sakari; Konki, Joonas

    2015-01-01

    Excited states in the highly neutron-deficient nucleus 162W have been investigated via the 92Mo(78Kr, 2α) 162W reaction. Prompt γ rays were detected by the JUROGAM II high-purity germanium detector array and the recoiling fusion-evaporation products were separated by the recoil ion transport unit (RITU) gas-filled recoil separator and identified with the gamma recoil electron alpha tagging (GREAT) spectrometer at the focal plane of RITU. γ rays from 162W were identified uniquel...

  3. Thermal recoil force, telemetry, and the Pioneer anomaly

    International Nuclear Information System (INIS)

    Precision navigation of spacecraft requires accurate knowledge of small forces, including the recoil force due to anisotropies of thermal radiation emitted by spacecraft systems. We develop a formalism to derive the thermal recoil force from the basic principles of radiative heat exchange and energy-momentum conservation. The thermal power emitted by the spacecraft can be computed from engineering data obtained from flight telemetry, which yields a practical approach to incorporate the thermal recoil force into precision spacecraft navigation. Alternatively, orbit determination can be used to estimate the contribution of the thermal recoil force. We apply this approach to the Pioneer anomaly using a simulated Pioneer 10 Doppler data set.

  4. Recoil 18F-chemistry in fluoroalkanes

    International Nuclear Information System (INIS)

    This thesis describes the study of the chemical reactions of recoil 18F-atoms in gaseous fluoromethanes and fluoroethanes. A brief survey of the organic hot atom chemistry is given in Chapter I. Chapter II deals with the experimental procedures used in this investigation. The irradiation facilities, the vapour phase radio-chromatography and the identification, including the synthesis of some fluorocarbons, are described in detail. Chapter III consists of a study on the applicability of perfluoropropene, C3F6, as scavenger for thermal 18F-atoms and radicals. Chapters IV, V, VI and VII deal with 18F-recoil chemistry in gaseous fluoroethanes, using H2S as scavenger. Chapter VIII is a short discussion on the hot 18F-atom based production of 18F-labeled organic compounds via decay of the intermediate 18Ne. A target system is proposed for production of this isotope in high energy and ultra high flux particle beams, which possibly would become available in fast breeders and fusion reactors. (Auth.)

  5. Nitinol Stent Oversizing in Patients Undergoing Popliteal Artery Revascularization: A Finite Element Study.

    Science.gov (United States)

    Gökgöl, Can; Diehm, Nicolas; Nezami, Farhad Rikhtegar; Büchler, Philippe

    2015-12-01

    Nitinol stent oversizing is frequently performed in peripheral arteries to ensure a desirable lumen gain. However, the clinical effect of mis-sizing remains controversial. The goal of this study was to provide a better understanding of the structural and hemodynamic effects of Nitinol stent oversizing. Five patient-specific numerical models of non-calcified popliteal arteries were developed to simulate the deployment of Nitinol stents with oversizing ratios ranging from 1.1 to 1.8. In addition to arterial biomechanics, computational fluid dynamics methods were adopted to simulate the physiological blood flow inside the stented arteries. Results showed that stent oversizing led to a limited increase in the acute lumen gain, albeit at the cost of a significant increase in arterial wall stresses. Furthermore, localized areas affected by low Wall Shear Stress increased with higher oversizing ratios. Stents were also negatively impacted by the procedure as their fatigue safety factors gradually decreased with oversizing. These adverse effects to both the artery walls and stents may create circumstances for restenosis. Although the ideal oversizing ratio is stent-specific, this study showed that Nitinol stent oversizing has a very small impact on the immediate lumen gain, which contradicts the clinical motivations of the procedure.

  6. Neoatherosclerosis:Coronary stents seal atherosclerotic lesions but result in making a new problem of atherosclerosis

    Institute of Scientific and Technical Information of China (English)

    Hidenori; Komiyama; Masamichi; Takano; Noritake; Hata; Yoshihiko; Seino; Wataru; Shimizu; Kyoichi; Mizuno

    2015-01-01

    Chronic inflammation of the native vessel wall with infiltration of lipid-laden foamy macrophages through impaired endothelium results in atherosclerosis. Percutaneous coronary intervention, including metallic stent implantation, is now widely utilized for the treatment of atherosclerotic lesions of the coronary artery. Baremetal stents and the subsequently developed drugeluting stents seal the atherosclerosis and resolve lumen stenosis or obstruction of the epicardial coronary artery and myocardial ischemia. After stent implantation, neointima proliferates within the stented segment. Chronic inflammation caused by a foreign body reaction to the implanted stent and subsequent neovascularization, which is characterized by the continuous recruitment of macrophages into the vessel, result in the transformation of the usual neointima into an atheromatous neointima. Neointima with an atherosclerotic appearance, such as that caused by thin-cap fibroatheromas, is now recognized as neoatherosclerosis, which can sometimes cause in-stent restenosis and acute thrombotic occlusion originating from the stent segment following disruption of the atheroma. Neoatherosclerosis is emerging as a new coronary stent-associated problem that has not yet been resolved. In this review article, we will discuss possible mechanisms, clinical challenges, and the future outlook of neoatherosclerosis.

  7. 左半结直肠癌急性梗阻采用肠道支架与梗阻导管治疗的临床体会%Clinical Experience of the Treatment of Acute Obstruction of the Left Colon Cancer With the Use of the Intestinal Stent and the Obstruction Catheter

    Institute of Scientific and Technical Information of China (English)

    王新刚; 王光辉

    2015-01-01

    Objective To explore the therapeutic effect of the treatment of acute obstruction of the left colon cancer with the use of the intestinal stent and the obstruction of the catheter. Methods 39 cases with intestinal stents as stent group,39 cases treated by catheter obstruction as catheter group,and the operation effect and the therapeutic effects of two groups were analyzed. Results Two groups of abdominal pain abdominal distension relief time and obstruction of the proximal bowel contrast of inner diameter had difference(P 0.05. Conclusion Compared with the obstruction catheter,metal stent can improve the symptoms of intestinal obstruction in a certain extent.%目的:探究左半结直肠癌急性梗阻采用肠道支架与梗阻导管的疗效。方法39例采用肠道支架治疗作为支架组,39例采用梗阻导管治疗作为导管组,并分析两组的手术治疗效果。结果两组腹痛腹胀缓解时间与梗阻近端肠管内径差值的对比,P <0.05;两组患者术后疗效对比, P >0.05。结论与梗阻导管相比,金属支架能够在某种程度上改善肠梗阻症状。

  8. Drug-eluting stents: current issues

    NARCIS (Netherlands)

    P.W.J.C. Serruys (Patrick); A.T.L. Ong (Andrew)

    2005-01-01

    textabstractEarly stent thrombosis occurs in about 1% to 1.5% of patients with drug-eluting stents, very similar to the rate with bare-metal stents. Late stent thrombosis is more of a concern with drug-eluting stents, with an incidence of at least 0.35%. I would urge caution if you feel you have to

  9. Recent advances in the field of recoil chemistry

    International Nuclear Information System (INIS)

    Recent advances in the field of recoil chemistry are summarized and discussed. As important aids to furthering our knowledge of complex systems, the role is emphasized of new techniques such as vapour-phase chromatography, ion exchange and paper electrophoresis. An attempt is made to relate current work in recoil chemistry to other fields of investigation. (author)

  10. Comparison of the Recoil of Conventional and Electromagnetic Cannon

    Directory of Open Access Journals (Sweden)

    Edward M. Schmidt

    2001-01-01

    Full Text Available The recoil from an electromagnetic (EM railgun is discussed and compared with that from conventional, propellant gas driven cannon. It is shown that, under similar launch conditions, the recoil of the EM gun is less than that of the powder gun; however, use of a muzzle brake on a powder gun can alter this relative behavior.

  11. Comparison of the incidence of late stent thrombosis after implantation of different drug-eluting stents in the real world coronary heart disease patients: three-year follow-up results

    Institute of Scientific and Technical Information of China (English)

    CHEN Ji-lin; LIU Hai-bo; WU Yong-jian; YUAN Jin-qing; CHEN Jue; YOU Shi-jie; DAI Jun; GAO Run-lin; GAO Li-jian; YANG Yue-jin; LI Jian-jun; QIAO Shu-bin; XU Bo; HUANG Jing-han; YAO Min; QIN Xue-wen

    2010-01-01

    Background Late stent thrombosis (LST) is still concerned by interventions cardiologists in daily clinical practice. This study aimed to compare the incidence of LST after implantation of different drug-eluting stents (DES) in coronary heart disease (CHD) patients in the real world.Methods From December 2001 to February 2009, a total of 11 875 consecutive CHD patients undergone DES implantation were enrolled in this single-center registery study. Patients with acute ST-segment elevation myocardial infarction, mixed DES implantation, restenosis lesions, and patients who could not take dual antiplatlet medication and those who were contraindicated for coronary interventional treatment were excluded. All patients were treated with completed dual antiplatelet medications for at least 9 months after DES deployment. The follow-up was completed by outpatient visits, letter correspondence, phone calls and coronary angiography. Definite LST was diagnosed auording to the Academic Research Consortium (ARC) definition.Results Cypher or Cypher Select stents were implanted in 4104 cases, Taxus or Taxus Liberty stents in 2271 cases and Firebird stents (Chinese rapamycin-eluting stents) in 5500 cases. One-year follow-up was completed in 9693 patients, including 3346 cases with Cypher or Cypher Select stents, 1529 cases with Taxus or Taxus Liberty stents and 4818 cases with Firebird stents. Two- and three-year follow-up results were obtained in 7133 and 4353 patients, respectively, including 2410 and 1760 cases with Cypher or Cypher Select stents, 1285 and 900 cases with Taxus or Taxus Liberty stents as well as 3438 and 1693 cases with Firebird stents. One-year follow-up results showed that the incidence of LST was 1.08% in patients with Cypher or Cypher Select stents, 1.24% in those with Taxus or Taxus Liberty stents and 0.71% in those with Firebird stents; there was no significant difference between those with Cypher or Cypher Select and Firebird stents, but there was significant

  12. A Unique Use of a Double-Pigtail Plastic Stent: Correction of Kinking of the Common Bile Duct Due to a Metal Stent

    OpenAIRE

    Kuwatani, Masaki; Kawakami, Hiroshi; Abe, Yoko; Kawahata, Shuhei; Kawakubo, Kazumichi; Kubo, Kimitoshi; Sakamoto, Naoya

    2015-01-01

    A 72-year-old man with jaundice by ampullary adenocarcinoma was treated at our hospital. For biliary decompression, a transpapillary, fully covered, self-expandable metal stent (FCSEMS) was deployed. Four days later, the patient developed acute cholangitis. Endoscopic carbon dioxide cholangiography revealed kinking of the common bile duct above the proximal end of the FCSEMS. A 7-F double-pigtail plastic stent was therefore placed through the FCSEMS to correct the kink, straightening the comm...

  13. Lithium recoil measurement without a subrecoil sample

    CERN Document Server

    Cassella, Kayleigh; Estey, Brian; Feng, Yanying; Lai, Chen; Müller, Holger

    2016-01-01

    We report both the first atom interferometer with a low-mass, laser-cooled atom (lithium-7) and the first simultaneous conjugate Ramsey-Bord\\'e interferometers with an atomic ensemble not cooled or selected to subrecoil speeds. Above the recoil temperature, fast thermal motion of atoms leads to overlapped interferometers whose outputs tend to cancel. We avoid such cancellation using the two-photon detuning from Raman resonance to control the relative phase between these conjugate interferometers. To prevent magnetic dephasing, we present optical pumping to the magnetically-insensitive state using the well-resolved $D_1$ line. These techniques allow the use of "warm" atoms for Ramsey-Bord\\'e interferometers, which broadens the choice of species, simplifies cooling, increases available atom number and reduces cycle time for faster integration.

  14. Early and long-term outcome of elective stenting of the infarct-related artery in patients with viability in the infarct-area: Rationale and design of the Viability-guided Angioplasty after acute Myocardial Infarction-trial (The VIAMI-trial

    Directory of Open Access Journals (Sweden)

    Visser Cees A

    2004-11-01

    Full Text Available Abstract Background Although percutaneous coronary intervention (PCI is becoming the standard therapy in ST-segment elevation myocardial infarction (STEMI, to date most patients, even in developed countries, are reperfused with intravenous thrombolysis or do not receive a reperfusion therapy at all. In the post-lysis period these patients are at high risk for recurrent ischemic events. Early identification of these patients is mandatory as this subgroup could possibly benefit from an angioplasty of the infarct-related artery. Since viability seems to be related to ischemic adverse events, we initiated a clinical trial to investigate the benefits of PCI with stenting of the infarct-related artery in patients with viability detected early after acute myocardial infarction. Methods The VIAMI-study is designed as a prospective, multicenter, randomized, controlled clinical trial. Patients who are hospitalized with an acute myocardial infarction and who did not have primary or rescue PCI, undergo viability testing by low-dose dobutamine echocardiography (LDDE within 3 days of admission. Consequently, patients with demonstrated viability are randomized to an invasive or conservative strategy. In the invasive strategy patients undergo coronary angiography with the intention to perform PCI with stenting of the infarct-related coronary artery and concomitant use of abciximab. In the conservative group an ischemia-guided approach is adopted (standard optimal care. The primary end point is the composite of death from any cause, reinfarction and unstable angina during a follow-up period of three years. Conclusion The primary objective of the VIAMI-trial is to demonstrate that angioplasty of the infarct-related coronary artery with stenting and concomitant use of abciximab results in a clinically important risk reduction of future cardiac events in patients with viability in the infarct-area, detected early after myocardial infarction.

  15. Comparison of recoil-induced resonances and the collective atomic recoil laser

    CERN Document Server

    Berman, P R

    1999-01-01

    The theories of recoil-induced resonances (RIR) [J. Guo, P. R. Berman, B. Dubetsky and G. Grynberg, Phys. Rev. A {\\bf 46}, 1426 (1992)] and the collective atomic recoil laser (CARL) [ R. Bonafacio and L. De Salvo, Nucl. Instrum. Methods A {\\bf 341}, 360 (1994)] are compared. Both theories can be used to derive expressions for the gain experienced by a probe field interacting with an ensemble of two-level atoms that are simultaneously driven by a pump field. It is shown that the RIR and CARL formalisms are equivalent. Differences between the RIR and CARL arise because the theories are typically applied for different ranges of the parameters appearing in the theory. The RIR limit considered in this paper is $qP_{0}/M\\omega_{q}\\gg 1$, while the CARL limit is $qP_{0}/M\\omega_{q}\\lesssim 1$, where $% q $ is the magnitude of the difference of the wave vectors of the pump and probe fields, $P_{0}$ is the width of the atomic momentum distribution and $% \\omega_{q}$ is a recoil frequency. The probe gain for a probe-pu...

  16. An unusual case of ST-segment elevation myocardial infarction following a late bare-metal stent fracture in a native coronary artery: a case report

    Directory of Open Access Journals (Sweden)

    Minardi Giovanni

    2009-11-01

    Full Text Available Abstract Introduction A bare-metal stent fracture as a cause of acute coronary thrombosis and consequently of acute coronary syndrome is a rare clinical event that, to the best of our knowledge, has previously not been reported. A stent fracture is a rare complication arising from percutaneous coronary intervention. Case presentation We present, to the best of our knowledge, the first documented case of ST-segment elevation myocardial infarction in a patient following a late bare-metal stent fracture and thrombosis in a native coronary artery. The patient, a 51-year-old Caucasian man, was treated successfully with primary percutaneous coronary intervention and a new stent implantation. Conclusion A coronary stent fracture is a rare complication that has been described in venous bypass grafts deploying either a drug-eluting stent or a bare-metal stent. Stent fractures rarely occur in coronary arteries. In light of the non-specific presentation of stent fracture, it is also an easily missed complication. Patients may present with a non-specific symptom of angina. The angina could either be stable or unstable as a result of restenosis or in-stent thrombosis, or both. Our case demonstrates the most severe consequences of a bare-metal stent fracture (sudden coronary thrombosis and subsequent myocardial infarction in a native coronary artery. It was diagnosed angiographically and treated early and effectively.

  17. Self-expandable metalic endotracheal stent

    International Nuclear Information System (INIS)

    Six bare stents and six covered stents were inserted in the trachea of 12 dogs under general anesthesia. After 1-10 weeks of observation, the dogs were killed, and the trachea and lung were examined grossly and histologically. Pneumonia and stent migration were observed more frequently at covered stent group. Inflammatory change of the trachea was more severe at covered stent group. In conclusion, we believe that it is inadequate to insert silicone covered stent in the tracheobronchial tree. (Author)

  18. Delayed complications after flow-diverter stenting: reactive in-stent stenosis and creeping stents.

    Science.gov (United States)

    Cohen, José E; Gomori, John Moshe; Moscovici, Samuel; Leker, Ronen R; Itshayek, Eyal

    2014-07-01

    We assessed the frequency and severity of changes in stent configuration and location after the treatment of intracranial aneurysms, and patterns of in-stent stenosis. We retrospectively reviewed data for consecutive aneurysm patients managed with endovascular implantation of flow-diverter stents (Silk Flow Diverter [Balt Extrusion, Montmorency, France] and Pipeline Embolization Device [ev3/Coviden, Minneapolis, MN, USA]) from October 2011 to July 2012. Routine 2, 6, 9-12, and 16-20 month follow-up angiograms were compared, with a focus on changes in stent configuration and location from immediately after deployment to angiographic follow-up, and the incidence and development of in-stent stenosis. Thirty-four patients with 42 aneurysms met inclusion criteria. The Silk device was implanted in 16 patients (47%, single device in 15), the Pipeline device in 18 (53%, single device in 16). On first follow-up angiography, in-stent stenosis was observed in 38% of Silk devices and 39% of Pipeline devices. In-stent stenosis was asymptomatic in 12 of 13 patients. One woman presented with transient ischemic attacks and required stent angioplasty due to end tapering and mild, diffuse in-stent stenosis. Configuration and location changes, including stent creeping and end tapering were seen in 2/16 patients (13%) with Silk devices, and 0/18 patients with Pipeline devices. We describe stent creeping and end tapering as unusual findings with the potential for delayed clinical complications. In-stent stenosis, with a unique behavior, is a frequent angiographic finding observed after flow-diverter stent implant. The stenosis is usually asymptomatic; however, close clinical and angiographic monitoring is mandatory for individualized management.

  19. Successive breaks in biliary stents.

    Science.gov (United States)

    Espinel, Jesús; Pinedo, Eugenia; Ojeda, Vanesa; Guerra, María

    2016-04-01

    A 64 year-old male, was diagnosed with obstructive jaundice due to a well-differentiated pancreatic neuroendocrine tumor with liver metastases. The patient underwent endoscopic placement of covered self-expanding biliary stent (10x60 mm, Hanaro) by ERCP. He was admitted with cholangitis one year later. The following ERCP revealed a fractured stent with loss of the distal end (duodenal) and partial migration of the remaining stent to the common bile duct. The fragmented stent was removed from the common bile duct and a new, similar one was inserted. Four months later the patient was admitted with cholangitis. A new ERCP was done and biliary stent was also fragmented. It was removed and an uncovered stent (Wallflex) was inserted. PMID:27065248

  20. A gun recoil system employing a magnetorheological fluid damper

    International Nuclear Information System (INIS)

    This research aims to design and control a full scale gun recoil buffering system which works under real firing impact loading conditions. A conventional gun recoil absorber is replaced with a controllable magnetorheological (MR) fluid damper. Through dynamic analysis of the gun recoil system, a theoretical model for optimal design and control of the MR fluid damper for impact loadings is derived. The optimal displacement, velocity and optimal design rules are obtained. By applying the optimal design theory to protect against impact loadings, an MR fluid damper for a full scale gun recoil system is designed and manufactured. An experimental study is carried out on a firing test rig which consists of a 30 mm caliber, multi-action automatic gun with an MR damper mounted to the fixed base through a sliding guide. Experimental buffering results under passive control and optimal control are obtained. By comparison, optimal control is better than passive control, because it produces smaller variation in the recoil force while achieving less displacement of the recoil body. The optimal control strategy presented in this paper is open-loop with no feedback system needed. This means that the control process is sensor-free. This is a great benefit for a buffering system under impact loading, especially for a gun recoil system which usually works in a harsh environment. (paper)

  1. Future developments in biliary stenting

    OpenAIRE

    Hair CD; Sejpal DV

    2013-01-01

    Clark D Hair,1 Divyesh V Sejpal21Department of Medicine, Section of Gastroenterology and Hepatology, Baylor College of Medicine, Houston, TX, USA; 2Department of Medicine, Section of Gastroenterology, Hofstra North Shore-LIJ School of Medicine, North Shore University Hospital, Manhasset, NY, USAAbstract: Biliary stenting has evolved dramatically over the past 30 years. Advancements in stent design have led to prolonged patency and improved efficacy. However, biliary stenting is still affected...

  2. Metallic stent placement in hemodialysis graft patients after insufficient balloon dilation

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Huei-Lung; Pan, Huay-Ben; Lin, Yih-Huie; Chen, Chiung-Yu; Lai, Pin-Hong; Yang, Chien-Fang [Kaohsiung Veterans General Hospital, Kaohsiung (China); Chung, Hsiao-Min; Wu, Tung-Ho; Chou, Kang-Ju [National Yangming University, Taipei (China)

    2006-06-15

    We wanted to report our experience of metallic stent placement after insufficient balloon dilation in graft hemodialysis patients. Twenty-three patients (13 loop grafts in the forearm and 10 straight grafts in the upper arm) underwent metallic stent placement due to insufficient flow after urokinase thrombolysis and balloon dilation. The indications for metallic stent deployment included 1) recoil and/or kinked venous stenosis in 21 patents (venous anastomosis: 17 patients, peripheral outflow vein: four patients); and 2) major vascular rupture in two patients. Metallic stents 8-10mm in diameter and 40-80 mm in length were used. Of them, eight stents were deployed across the elbow crease. Access patency was determined by clinical follow-up and the overall rates were calculated by Kaplan-Meier survival analysis. No procedure-related complications (stent fracture or central migration) were encountered except for a delayed Wallstent shortening/migration at the venous anastomosis, which resulted in early access failure. The overall primary and secondary patency rates ({+-}standard error) of all the vascular accesses in our 23 patients at 3, 6, 12 and 24 months were 69%{+-}9 and 88%{+-}6,41% {+-}10 and 88%{+-}6, 30%{+-}10 and 77%{+-}10, and 12%{+-}8 and 61%{+-}13, respectively. For the forearm and upper-arm grafts, the primary and secondary patency rates were 51%{+-}16 and 86%{+-}13 vs 45%{+-}15 and 73%{+-}13 at 6 months, and 25%{+-}15 and 71%{+-}17 vs 23%{+-}17 and 73%{+-}13 at 12 months ({rho} = .436 and .224), respectively. Metallic stent placement is a safe and effective means for treating peripheral venous lesions in dialysis graft patients after insufficient balloon dilation. No statistically difference in the patency rates between the forearm and upper-arm patient groups was seen.

  3. Angioplasty and stent - heart - discharge

    Science.gov (United States)

    Drug-eluting stents - discharge; PCI - discharge; Percutaneous coronary intervention - discharge; Balloon angioplasty - discharge; Coronary angioplasty - discharge; Coronary artery angioplasty - discharge; Cardiac ...

  4. Role of self expandable stents in management of colorectalcancers

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    Acute malignant colorectal obstruction is a complicationof colorectal cancer that can occur in 7%-29% of patients. Self-expanding metallic stent placement formalignant colorectal obstruction has gained popularity asa safe and effective procedure for relieving obstruction.This technique can be used in the palliation of malignantcolorectal obstruction, as a bridge to elective surgery forresectable colorectal cancers, palliation of extracolonicmalignant obstruction, and for nonmalignant etiologiessuch as anastomotic strictures, Crohn's disease, radiationtherapy, and diverticular diseases. Self-expandingmetallic stent has its own advantages and disadvantagesover the surgery in these indications. During the insertionof the self-expanding metallic stent, and in the followup,short term and long term morbidities should be keptin mind. The most important complications of the stentsare perforation, stent obstruction, stent migration, andbleeding. Additionally, given the high risk of perforation,if a patient is treated or being consideredfortreatmentwithantiangiogenic agents such as bevacizumab, it isnot recommended to use self-expanding metallic stentas a palliative treatment for obstruction. Therefore, thereis a need for careful clinical evaluation for each patientwho is a candidate for this procedure. The purpose ofthis review was to evaluate self-expanding metallic stentin the management of the obstruction of the colon dueto the colorectal and extracolonic obstruction.

  5. Endoscopic transpapillary gallbladder drainage with replacement of a covered self-expandable metal stent.

    Science.gov (United States)

    Kawakubo, Kazumichi; Isayama, Hiroyuki; Sasahira, Naoki; Nakai, Yousuke; Kogure, Hirofumi; Sasaki, Takashi; Hirano, Kenji; Tada, Minoru; Koike, Kazuhiko

    2011-02-16

    Endoscopic self-expandable metal stent (SEMS) placement has become a standard palliative therapy for patients with malignant biliary obstruction. Acute cholecystitis after SEMS placement is a serious complication. We report a patient with an acute cholecystitis after covered SEMS placement, who was managed successfully with endoscopic transpapillary gallbladder drainage (ETGBD) and replacement of the covered SEMS. An 85-year-old man with pancreatic cancer suffered from acute cholecystitis after covered SEMS placement. It was impossible to perform percutaneous transhepatic gallbladder drainage. After removal of the covered SEMS with a snare, a 7Fr double pigtail stent was placed between the gallbladder and duodenum, subsequently followed by another covered SEMS insertion into the common bile duct beside the gallbladder stent. The cholecystitis improved immediately after ETGBD. ETGBD with replacement of the covered SEMS thus proved to be effective for treatment of patients with acute cholecystitis after covered SEMS placement. PMID:21403817

  6. Hemobilia into a metallic biliary stent due to pseudoaneurysm. A case report

    International Nuclear Information System (INIS)

    A 48-year-old man with locally advanced pancreatic cancer underwent combined treatment with gemcitabine and proton radiation therapy. Because of subsequent obstruction of the common bile duct, a metallic biliary stent was placed and he received further gemcitabine chemotherapy. During chemotherapy, he developed an acute abdomen with a sudden-onset of tarry stool and jaundice. Gastroduodenoscopy revealed hemobilia from the biliary metallic stent. Contrast-enhanced abdominal computed tomography revealed the presence of a pseudoaneurysm arising from the right hepatic artery adjacent to the top of the stent. Hemostasis of the right hepatic artery pseudoaneurysm was achieved via transcatheter arterial embolization using cyanoacrylate. (author)

  7. Delayed aortic regurgitation caused by a right coronary stent protruding into the aorta.

    Science.gov (United States)

    Quintana, Eduard; Mestres, Carlos A; Congiu, Stefano; Josa, Miguel; Cartañá, Ramon

    2009-11-01

    Aortic valve perforation is an extremely rare complication after percutaneous coronary intervention. The case is presented of a 49-year-old male with aortic valve regurgitation secondary to the intra-aortic protrusion of a right coronary stent. The patient had undergone an apparently successful rescue percutaneous transluminal coronary angioplasty with a drug-eluting stent following failed fibrinolysis, but one month later was readmitted for acute pulmonary edema. Further investigations demonstrated new-onset aortic regurgitation. Medical stabilization was achieved and an elective aortic valve replacement and coronary revascularization performed. Intraoperatively, the stent was found to be partially deployed within the aortic lumen, causing perforation to the non-coronary cusp.

  8. Nasal packing and stenting

    Directory of Open Access Journals (Sweden)

    Weber, Rainer K.

    2009-01-01

    Full Text Available Nasal packs are indispensable in ENT practice. This study reviews current indications, effectiveness and risks of nasal packs and stents. In endoscopic surgery, nasal packs should always have smooth surfaces to minimize mucosal damage, improve wound healing and increase patient comfort. Functional endoscopic endonasal sinus surgery allows the use of modern nasal packs, since pressure is no longer required. So called hemostatic/resorbable materials are a first step in this direction. However, they may lead to adhesions and foreign body reactions in mucosal membranes. Simple occlusion is an effective method for creating a moist milieu for improved wound healing and avoiding dryness. Stenting of the frontal sinus is recommended if surgery fails to produce a wide, physiologically shaped drainage path that is sufficiently covered by intact tissue.

  9. 药物洗脱支架术后急性亚急性血栓发生的原因及救治分析%Analysis of the factors and treatment of the acute and subacute thrombosis in the coronary drug-eluting stent

    Institute of Scientific and Technical Information of China (English)

    李志立; 曹义战; 艾永飞; 马文帅; 薛玉生; 杨欣国; 汤雁玲; 金葵花

    2014-01-01

    Objective To analyze the Factors and treatment of the acute and subacute thrombosis in the coronary drug -eluting stent ( DES ) and to evaluate the efficacy of the emergent percutaneous coronary intervention (PCI)for it.Methods baseline and follow-up data of 5320 patients who underwent PCI and implanted DES in our hospital from December 2007 to December 2012 , in which 43 patients suffered from acute and subacute thrombosis Results ①43 acute and subacute coronary in-stent thrombosis was confirmed in 5320 patients ( 0.81%) and 9 patients died ( mortality 20.93%).The thrombosis occurred from 6 hours to 11 days after PCI (4.2 ±4.6)d.②Target vessel of the thrombosis:33 in the left anterior descending artery (LAD), 3 in the left cicumlex artery(LCX) and 7 in the right coronary artery ( RCA);The lesions type:39 cases were type B/C and 4 cases were type A;Artery diameter of thrombosis:19 in 2.5 mm,22 in 3.0 mm and 3 in 3.5 mm artery respectively;The length and the number of the stents in the target vessel:38 were more than 2 stents (2.87 ±0.40) mm ×(32.39 ±7.72) mm and 5 were only one stent (3.18 ±0.39) mm ×(19.87 ±4.66) mm.③Among the 43 cases, 19 caused by stent malapposition , 14 by small vessel and long lesion , 5 by endothelial tear of overdistension and 3 by clopidogre resistant .④35 patients were treated by high pressure balloon dilatation and 5 patients were treated by planting more stent .Conclusion The risk factors of developing in -stent thrombosis were lesion type , intervention operating factors , the length and diameter of the stents and clopidogre resistant . It occurred higher in patients with diabetes , hypertension ,multi-vessel disease , target lesion in LAD and suffuse lesion .Emergency PCI are the most effective methods for treating acute and subacute thrombosis .%目的:分析冠状动脉药物洗脱支架(drug-eluting stent, DES)置入术后支架内急性、亚急性血栓形成的原因及救治

  10. Carotid stenting and endarterectomy.

    Science.gov (United States)

    Yip, Hon-Kan; Sung, Pei-Hsun; Wu, Chiung-Jen; Yu, Cheuk-Man

    2016-07-01

    Stroke, either ischemic or hemorrhagic, remains the second commonest cause of death worldwide in the last decade. Etiologies for ischemic stroke (IS) vary widely. Atherothrombotic occlusion is an essential cause to which carotid artery stenosis (CAS) is a major contributor. Administration of anti-platelet agent to patients with CAS has been shown to reduce incidence of long-term IS. In additional, in patients with symptomatic CAS, clinical trials have demonstrated that carotid endarterectomy (CEA) is superior to medical therapy for prevention of future CAS-related IS. However, CEA is not suitable for CAS post-radiotherapy or those located at higher level of the internal carotid artery; and major complications of this procedure including cranial nerve injuries have stimulated the interest of using percutaneous transfemoral carotid stenting as an alternative approach. Although transfemoral arterial approach of carotid stenting is not inferior to CEA in improving clinical outcomes, it has been reported to be associated with vascular complication and has its limitations in patients with athero-occlusive disease of abdominal aorta or bilateral iliac arteries, level II or III aortic arch, or bovine type carotid arterial anatomy. Therefore, transradial/transbrachial arterial approach has emerged as a novel method for carotid stenting. This article provides a critical review on interventional approaches for the treatment of CAS. PMID:27061654

  11. Clinical results of carotid artery stenting with a nitinol self-expanding stent (SMART stent)

    Energy Technology Data Exchange (ETDEWEB)

    Drescher, Robert; Mathias, Klaus D.; Jaeger, Horst J.; Bockisch, Georg; Demirel, Eren; Gissler, Martin H.; Hauth, Elke [Department of Radiology, Staedtische Kliniken Dortmund, Beurhausstrasse 40, 44139 Dortmund (Germany); Department of Radiology and Microtherapy, University Witten/Herdecke (Germany)

    2002-10-01

    Our objective was to assess the technical feasibility and the clinical results of internal carotid artery (ICA) stenting using a nitinol self-expanding stent (SMART stent). In 13 patients 13 high-grade stenoses of the internal carotid artery were treated via an implantation of a SMART stent. In all cases a predilation of the stenosis and a postdilation within the stent were performed. Follow-up examinations were carried out in all patients after a period of 6 months. In each case the implantation of the stent was performed without technical complications. In 12 of 13 cases the stent was placed in the patients' internal carotid artery, in 1 case from the internal to the common carotid artery (CCA). The average degree of stenosis of 78% (70-95%) was reduced to an average of 2.8% (0-21%). The 6-month follow-up angiography showed an average degree of restenosis of 11.8% (0-29%) in 8 of 13 patients. Duplex sonography in the remaining 5 patients demonstrated patent stents. One patient showed brief neurological symptoms during the intervention. No further complications occurred during follow-up time. Treatment of internal carotid artery stenosis with the SMART stent seems technically feasible, safe, and promises long-term patency. (orig.)

  12. Two-Photon Collective Atomic Recoil Lasing

    Directory of Open Access Journals (Sweden)

    James A. McKelvie

    2015-11-01

    Full Text Available We present a theoretical study of the interaction between light and a cold gasof three-level, ladder configuration atoms close to two-photon resonance. In particular, weinvestigate the existence of collective atomic recoil lasing (CARL instabilities in differentregimes of internal atomic excitation and compare to previous studies of the CARL instabilityinvolving two-level atoms. In the case of two-level atoms, the CARL instability is quenchedat high pump rates with significant atomic excitation by saturation of the (one-photoncoherence, which produces the optical forces responsible for the instability and rapid heatingdue to high spontaneous emission rates. We show that in the two-photon CARL schemestudied here involving three-level atoms, CARL instabilities can survive at high pump rateswhen the atoms have significant excitation, due to the contributions to the optical forces frommultiple coherences and the reduction of spontaneous emission due to transitions betweenthe populated states being dipole forbidden. This two-photon CARL scheme may form thebasis of methods to increase the effective nonlinear optical response of cold atomic gases.

  13. Hemodynamics in Idealized Stented Coronary Arteries: Important Stent Design Considerations.

    Science.gov (United States)

    Beier, Susann; Ormiston, John; Webster, Mark; Cater, John; Norris, Stuart; Medrano-Gracia, Pau; Young, Alistair; Cowan, Brett

    2016-02-01

    Stent induced hemodynamic changes in the coronary arteries are associated with higher risk of adverse clinical outcome. The purpose of this study was to evaluate the impact of stent design on wall shear stress (WSS), time average WSS, and WSS gradient (WSSG), in idealized stent geometries using computational fluid dynamics. Strut spacing, thickness, luminal protrusion, and malapposition were systematically investigated and a comparison made between two commercially available stents (Omega and Biomatrix). Narrower strut spacing led to larger areas of adverse low WSS and high WSSG but these effects were mitigated when strut size was reduced, particularly for WSSG. Local hemodynamics worsened with luminal protrusion of the stent and with stent malapposition, adverse high WSS and WSSG were identified around peak flow and throughout the cardiac cycle respectively. For the Biomatrix stent, the adverse effect of thicker struts was mitigated by greater strut spacing, radial cell offset and flow-aligned struts. In conclusion, adverse hemodynamic effects of specific design features (such as strut size and narrow spacing) can be mitigated when combined with other hemodynamically beneficial design features but increased luminal protrusion can worsen the stent's hemodynamic profile significantly.

  14. The median recoil direction as a WIMP directional detection signal

    CERN Document Server

    Green, Anne M

    2010-01-01

    Direct detection experiments have reached the sensitivity required to detect dark matter WIMPs. Demonstrating that a putative signal is due to WIMPs, and not backgrounds, is a major challenge however. The direction dependence of the WIMP scattering rate provides a potential WIMP `smoking gun'. If the WIMP distribution is predominantly smooth, the Galactic recoil distribution is peaked in the direction opposite to the direction of Solar motion. Previous studies have found that, for an ideal detector, of order 10 WIMP events would be sufficient to reject isotropy, and rule out an isotropic background. We examine how the median recoil direction could be used to confirm the WIMP origin of an anisotropic recoil signal. Specifically we determine the number of events required to reject the null hypothesis that the median direction is random (corresponding to an isotropic Galactic recoil distribution) at 95% confidence. We find that for zero background 31 events are required, a factor of roughly 2 more than are requi...

  15. Direct Measurement of Photon Recoil from a Levitated Nanoparticle

    CERN Document Server

    Jain, Vijay; Moritz, Clemens; Dellago, Christoph; Quidant, Romain; Novotny, Lukas

    2016-01-01

    The momentum transfer between a photon and an object defines a fundamental limit for the precision with which the object can be measured. If the object oscillates at a frequency $\\Omega_0$, this measurement back-action adds quanta $\\hbar\\Omega_0$ to the oscillator's energy at a rate $\\Gamma_{\\rm recoil}$, a process called photon recoil heating, and sets bounds to quantum coherence times in cavity optomechanical systems. Here, we use an optically levitated nanoparticle in ultrahigh vacuum to directly measure $\\Gamma_{\\rm recoil}$. By means of a phase-sensitive feedback scheme, we cool the harmonic motion of the nanoparticle from ambient to micro-Kelvin temperatures and measure its reheating rate under the influence of the radiation field. The recoil heating rate is measured for different particle sizes and for different excitation powers, without the need for cavity optics or cryogenic environments. The measurements are in quantitative agreement with theoretical predictions and provide valuable guidance for th...

  16. Recoil effects in the electroproduction of the delta

    International Nuclear Information System (INIS)

    Two quark-meson soliton models - the Linear Sigma Model and the Chromodielectric Model - are used to describe the nucleon and delta excitation. Treating the delta as a bound state, we obtain its electroproduction amplitudes corrected for recoil effects. (author)

  17. Stenting of the Cystic Duct in Benign Disease: A Definitive Treatment for the Elderly and Unwell

    Energy Technology Data Exchange (ETDEWEB)

    Hersey, N., E-mail: naomi.hersey@sth.nhs.uk [Sheffield Teaching Hospitals NHS Trust, Department of Radiology, Northern General Hospital (United Kingdom); Goode, S. D., E-mail: s.goode@sheffield.sc.uk [Sheffield Teaching Hospitals NHS Trust, Sheffield Vascular Institute (United Kingdom); Peck, R. J., E-mail: robert.peck@sth.nhs.uk; Lee, F., E-mail: fred.lee@sth.nhs.uk [Sheffield Teaching Hospitals NHS Trust, Department of Radiology, Northern General Hospital (United Kingdom)

    2015-08-15

    PurposeThere have been few case reports describing cystic duct stent insertion in the management of acute cholecystitis secondary to benign disease with no case series published to date. We present our series demonstrating the role of cystic duct stents in managing benign gallbladder disease in those patients unfit for surgery.Materials and MethodsThirty three patients unfit for surgery in our institution underwent cystic duct stent insertion for the management of acute cholecystitis in the period June 2008 to June 2013. Patients underwent a mixture of transperitoneal and transhepatic gallbladder puncture. The cystic duct was cannulated with a hydrophilic guidewire which was subsequently passed through the common bile duct and into the duodenum. An 8Fr 12-cm double-pigtail stent was placed with the distal end lying within the duodenum and the proximal end within the gallbladder.ResultsTen patients presented with gallbladder perforation, 21 patients with acute cholecystitis, 1 with acute cholangitis and 1 with necrotising pancreatitis. The technical success rate was 91 %. We experienced a 13 % complication rate with 3 % mortality rate at 30 days.ConclusionCystic duct stent insertion can be successfully used to manage acute cholecystitis, gallbladder empyema or gallbladder perforations in those unfit for surgery and should be considered alongside external gallbladder drainage as a definitive mid-term treatment option.

  18. Arterial healing following primary PCI using the Absorb everolimus-eluting bioresorbable vascular scaffold (Absorb BVS) versus the durable polymer everolimus-eluting metallic stent (XIENCE) in patients with acute ST-elevation myocardial infarction

    DEFF Research Database (Denmark)

    Räber, Lorenz; Onuma, Yoshinobu; Brugaletta, Salvatore;

    2015-01-01

    AIMS: The Absorb bioresorbable vascular scaffold (Absorb BVS) provides similar clinical outcomes compared with a durable polymer-based everolimus-eluting metallic stent (EES) in stable coronary artery disease patients. ST-elevation myocardial infarction (STEMI) lesions have been associated...

  19. Four-Year Follow-Up of TYPHOON (Trial to Assess the Use of the CYPHer Sirolimus-Eluting Coronary Stent in Acute Myocardial Infarction Treated With BallOON Angioplasty)

    NARCIS (Netherlands)

    Spaulding, Christian; Teiger, Emmanuel; Commeau, Philippe; Varenne, Olivier; Bramucci, Ezio; Slama, Michel; Beatt, Keavin; Tirouvanziam, Ashok; Polonski, Lech; Stella, Pieter R.; Clugston, Richard; Fajadet, Jean; de Boisgelin, Xavier; Bode, Christophe; Carrie, Didier; Erglis, Andrejs; Merkely, Bela; Hosten, Stefan; Cebrian, Ana; Wang, Patrick; Stoll, Hans-Peter; Henry, Patrick

    2011-01-01

    Objectives The aim of this study was to assess the long-term safety and efficacy of the CYPHER (Cordis, Johnson and Johnson, Bridgewater, New Jersey) sirolimus-eluting coronary stent (SES) in percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). Background

  20. A Novel Source of Tagged Low-Energy Nuclear Recoils

    OpenAIRE

    Joshi, Tenzing H. Y.

    2011-01-01

    For sufficiently wide resonances, nuclear resonance fluorescence behaves like elastic photo-nuclear scattering while retaining the large cross-section characteristic of resonant photo-nuclear absorption. We show that NRF may be used to characterize the signals produced by low-energy nuclear recoils by serving as a novel source of tagged low-energy nuclear recoils. Understanding these signals is important in determining the sensitivity of direct WIMP dark-matter and coherent neutrino-nucleus s...

  1. Dynamic Simulation of the Tank Gun Recoil Response

    Institute of Scientific and Technical Information of China (English)

    XING Jun-wen; WANG Liang-xi; SHI Yan; CHEN Chun-liang

    2005-01-01

    By using the ATV module of MSC. ADAMS, the dynamic simulation of recoil response of tank gun is analyzed.How the recoil force affects the bodywork and the suspension during gun firing, as well as the changing status of the gun muzzle's velocity are gained. All results and analyzing methods are offered for the designing basis of optimizing tank vehicle-gun match. The constructive exploration is beneficial to improving the general capability of tank.

  2. Direct Measurement of Photon Recoil from a Levitated Nanoparticle

    OpenAIRE

    Jain, Vijay; Gieseler, Jan; Moritz, Clemens; Dellago, Christoph; Quidant, Romain; Novotny, Lukas

    2016-01-01

    The momentum transfer between a photon and an object defines a fundamental limit for the precision with which the object can be measured. If the object oscillates at a frequency $\\Omega_0$, this measurement back-action adds quanta $\\hbar\\Omega_0$ to the oscillator's energy at a rate $\\Gamma_{\\rm recoil}$, a process called photon recoil heating, and sets bounds to quantum coherence times in cavity optomechanical systems. Here, we use an optically levitated nanoparticle in ultrahigh vacuum to d...

  3. Incidence of definite stent thrombosis or in-stent restenosis after drug-eluting stent implantation for treatment of coronary in-stent restenosis

    DEFF Research Database (Denmark)

    Jensen, Jesper Khedri; Jensen, Lisette Okkels; Terkelsen, Christian Juhl;

    2013-01-01

    There are limited data on the optimal management of in-stent restenosis after percutaneous coronary intervention (PCI) with bare metal stent (BMS) or drug-eluting stent (DES) implantations. We assessed the clinical presentation, the incidence, and prognosis of definite stent thrombosis...

  4. Polymers for Cardiovascular Stent Coatings

    Directory of Open Access Journals (Sweden)

    Anne Strohbach

    2015-01-01

    Full Text Available Polymers have found widespread applications in cardiology, in particular in coronary vascular intervention as stent platforms (scaffolds and coating matrices for drug-eluting stents. Apart from permanent polymers, current research is focussing on biodegradable polymers. Since they degrade once their function is fulfilled, their use might contribute to the reduction of adverse events like in-stent restenosis, late stent-thrombosis, and hypersensitivity reactions. After reviewing current literature concerning polymers used for cardiovascular applications, this review deals with parameters of tissue and blood cell functions which should be considered to evaluate biocompatibility of stent polymers in order to enhance physiological appropriate properties. The properties of the substrate on which vascular cells are placed can have a large impact on cell morphology, differentiation, motility, and fate. Finally, methods to assess these parameters under physiological conditions will be summarized.

  5. Percutaneous biliary drainage and stenting

    International Nuclear Information System (INIS)

    Full text: Percutaneous transhepatic cholangiography (PTC) is an X-ray or US guided procedure that involves the injection of a contrast material directly into the bile ducts inside the liver to produce pictures of them. If a blockage or narrowing is found, additional procedures may be performed: 1. insertion of a catheter to drain excess bile out of the body or both - internal and external; 2. plastic endoprothesis placement; 3. self-expandable metal stents placement to help open bile ducts or to bypass an obstruction and allow fluids to drain. Current percutaneous biliary interventions include percutaneous transhepatic cholangiography (PTC) and biliary drainage to manage benign and malignant obstructions. Internal biliary stents are either plastic or metallic, and various types of each kind are available. Internal biliary stents have several advantages. An external tube can be uncomfortable and have a psychological disadvantage. An internal stent prevents the problems related to external catheters, for example, pericatheter leakage of bile and the need for daily flushing. The disadvantages include having to perform endoscopic retrograde cholangiopancreatography (ERCP) or new PTC procedures to obtain access in case of stent obstruction. Better patency rates are reported with metallic than with plastic stents in cases of malignant obstruction, though no effect on survival is noted. Plastic internal stents are the cheapest but reportedly prone to migration. Metallic stents are generally not used in the treatment of benign disease because studies have shown poor long-term patency rates. Limited applications may include the treatment of patients who are poor surgical candidates or of those in whom surgical treatment fails. Most postoperative strictures are treated surgically, though endoscopic and (less commonly) percutaneous placement of nonmetallic stents has increasingly been used in the past few years. Now there are some reports about use of biodegradable biliary

  6. Technical overview on the MiStent coronary stent.

    Science.gov (United States)

    McCLAIN, James B; Carlyle, Wenda C; Donohoe, Dennis J; Ormiston, John A

    2016-10-01

    Drug-eluting stents (DES) have dramatically improved the long-term efficacy of percutaneous coronary intervention (PCI). Over the last decade there have been numerous advances in DES platforms, however, all but one currently approved DES in the United States and many of the approved DES worldwide still have 3 common features: a metal stent platform, an anti-proliferative drug, and a permanent polymer. In this context, the polymer is critical to control drug release, but the polymer serves no purpose after the drug is eluted. While designed to be completely biocompatible, synthetic polymers have the potential to illicit an inflammatory response within the vessel including but not limited to delayed healing and hypersensitivity. Adverse vascular reactions to these polymers have been implicated as a cause of very late stent thrombosis, ongoing intimal hyperplasia and late "catch-up" in addition to neoatherosclerosis. To avoid the long-term risks associated with prolonged polymer exposure, DES with bioabsorbable polymers have been developed. The MiStent® Sirolimus-Eluting Absorbable Polymer Coronary Stent System (MiStent SES) (MiCell Technologies, Durham, NC, USA) combines crystalline sirolimus, a rapidly absorbing polylactide-co-glycolic acid (PLGA) coating and a thin-strut cobalt chromium alloy stent platform (Genius MAGIC® Stent System, EuroCor GmbH, Germany). MiCell's supercritical fluid technology allows a rigorously controlled, solvent-free drug and polymer coating to be applied to a bare-metal stent. This solvent-free application of drug uniquely allows a crystalline form of sirolimus to be used on the MiStent SES potentially providing improved clinical benefits. It avoids the uncontrolled burst of drug seen with other DES, provides uniform drug delivery around and between the stent struts, and allows the anti-inflammatory and anti-restenotic drug (sirolimus) to be present in the tissue through the entire polymer absorption period and for months after the

  7. Coronary stent technology: a narrative review.

    Science.gov (United States)

    Chen, Daniel; Jepson, Nigel

    2016-09-19

    Coronary angioplasty and coronary artery stents have revolutionised interventional cardiology. Contemporary coronary stent technology continues to seek to improve on the outcomes of the preceding generation of devices by refining their design, structure and component materials. These technologies include new generations of drug-eluting stents, non-polymeric stents, bioresorbable polymer-coated stents, and fully bioresorbable scaffolds. This review discusses the evolution of coronary stent technology, the efficacy and safety of currently available devices, and the rationale for new generation platforms as efforts continue to design the ideal coronary stent technology. PMID:27627940

  8. Cardiomiopatia isquêmica terminal associada à complicação do uso de stent no tratamento de infarto agudo do miocárdio Terminal ischemic cardiomyopathy associated with complication of stenting in the treatment of acute myocardial infarction

    Directory of Open Access Journals (Sweden)

    Renato Braulio

    2011-09-01

    Full Text Available Uma complicação grave, como a dissecção do tronco de coronária esquerda, com redução relevante do fluxo sanguíneo coronário pela luz verdadeira, requer ação rápida. Diante disso, a escolha imediata do stent no comprimento e calibre adequados para tratar a complicação se faz necessária.A serious complication such as dissection of the left main coronary artery, with significant reduction in coronary blood flow by the true light, requires quick action. Therefore, the immediate choice of stent with appropriate length and size to treat the complication is necessary.

  9. Safety and efficacy of everolimus-eluting stents compared with first-generation drug-eluting stents in patients undergoing primary percutaneous coronary intervention

    International Nuclear Information System (INIS)

    Objective: To assess the safety and efficacy everolimus-eluting stents (EES) compared with first-generation drug-eluting stents (DES) in patients with acute myocardial infarction (MI) undergoing primary percutaneous coronary intervention (PCI). Background: EES have been associated with improved clinical outcomes compared to paclitaxel-eluting stents (PES) and with similar outcomes compared to sirolimus-eluting stents (SES). Methods: A total of 520 patients who presented with ST-elevation myocardial infarction (STEMI) from 2003 to 2013, who underwent primary PCI with DES, were retrospectively analyzed. Of these, 247 received SES, 136 PES, and 137 EES. Patients were followed up to 2 years for major adverse cardiac events (MACE). Univariate and multivariate models detected correlates to outcome. Results: EES implantation, compared with PES and SES, resulted in comparable rates of MACE (8.8% vs. 16.2%, p = 0.06 and 8.8% vs. 12.6%, respectively, p = 0.26), stent thrombosis, MI, and target lesion revascularization. Patients who received EES had lower rates of all-cause mortality (3.7% vs. 12.6% vs. 9.4%, p = 0.03) at 1-year follow up. However, in the univariate and multivariate analyses, stent type was not independently associated with the primary outcome or with all-cause mortality. Diabetes mellitus and number of stents implanted were independently associated with the primary outcome. Conclusion: While EES seem to be associated with better outcome when compared to PES, the main correlates of STEMI patients are the presence of diabetes and number of stents implanted, and not the type of stent used for intervention

  10. Safety and efficacy of everolimus-eluting stents compared with first-generation drug-eluting stents in patients undergoing primary percutaneous coronary intervention

    Energy Technology Data Exchange (ETDEWEB)

    Escárcega, Ricardo O.; Baker, Nevin C.; Magalhaes, Marco A.; Lipinski, Michael J.; Minha, Sa’ar; Torguson, Rebecca; Satler, Lowell F.; Pichard, Augusto D.; Suddath, William O.; Waksman, Ron, E-mail: ron.waksman@medstar.net

    2014-09-15

    Objective: To assess the safety and efficacy everolimus-eluting stents (EES) compared with first-generation drug-eluting stents (DES) in patients with acute myocardial infarction (MI) undergoing primary percutaneous coronary intervention (PCI). Background: EES have been associated with improved clinical outcomes compared to paclitaxel-eluting stents (PES) and with similar outcomes compared to sirolimus-eluting stents (SES). Methods: A total of 520 patients who presented with ST-elevation myocardial infarction (STEMI) from 2003 to 2013, who underwent primary PCI with DES, were retrospectively analyzed. Of these, 247 received SES, 136 PES, and 137 EES. Patients were followed up to 2 years for major adverse cardiac events (MACE). Univariate and multivariate models detected correlates to outcome. Results: EES implantation, compared with PES and SES, resulted in comparable rates of MACE (8.8% vs. 16.2%, p = 0.06 and 8.8% vs. 12.6%, respectively, p = 0.26), stent thrombosis, MI, and target lesion revascularization. Patients who received EES had lower rates of all-cause mortality (3.7% vs. 12.6% vs. 9.4%, p = 0.03) at 1-year follow up. However, in the univariate and multivariate analyses, stent type was not independently associated with the primary outcome or with all-cause mortality. Diabetes mellitus and number of stents implanted were independently associated with the primary outcome. Conclusion: While EES seem to be associated with better outcome when compared to PES, the main correlates of STEMI patients are the presence of diabetes and number of stents implanted, and not the type of stent used for intervention.

  11. Mechanical thrombectomy using Rotarex system and stent-in-stent placement for treatment of distal femoral artery occlusion secondary to stent fracture – a case report and literature review

    International Nuclear Information System (INIS)

    Treatment of peripheral arterial diseases may be distinguished into conservative and interventional management; the latter is divided into surgical and endovascular procedures. Management of peripheral artery stenosis and occlusion with vascular stents is associated with the risk of late complications such as restenosis, stent fracture or dislocation. A 62-year-old woman with generalized atherosclerosis, particularly extensive in lower limb arteries, was admitted to the Department of Angiology 11 months after having an endovascular procedure performed due to critical ischemia of left lower limb. Because of stent occlusion, a decision to perform angiographic examination of lower limb arteries was made. Examination revealed occlusion of the superficial femoral artery along its entire length, including previously implanted stents. Distal stent was fractured with slight dislocation of the proximal segment. A decision was made to perform mechanical thrombectomy using a Rotarex system followed by a stent-in-stent placement procedure. Follow-up angiography and ultrasound scan performed 24 hours after the procedure revealed a patent vessel with satisfactory blood flow. Nowadays, imaging diagnostics of peripheral artery stenosis involves non-invasive examinations such as ultrasound, minimally invasive examinations such as angio-MRI and MDCT, or invasive examinations such as DSA and IVUS. DSA examinations are used to confirm significant stenosis or occlusion of a vessel, particularly when qualifying a patient for endovascular treatment. Due to their anatomic location, the superficial femoral artery and the popliteal artery are subject to various forces e.g. those exerted by the working muscles. Mechanical thrombectomy and atherectomy are efficient methods of arterial recanalization used in the treatment of acute, subacute or even chronic occlusions or stenosis of peripheral vessels. Frequency of angioplasty and vascular stent implantation procedures is increased in patients

  12. Risk of Post-ERCP Pancreatitis after placement of Covered versus Uncovered Self-Expandable Biliary Metal Stents: A Systematic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Yaseen Alastal

    2008-09-01

    Full Text Available Background Self-expandable metal stents are commonly used in the management of malignant biliary obstruction due to higher patency rates compared to plastic stents. Development of covered self-expandable metal stents has led to extended stent patency compared to uncovered self-expandable metal stents. However, there are concerns that deployment of covered self-expandable metal stents may be associated with higher risk of post-endoscopic retrograde cholangio-pancreatography pancreatitis, acute cholecystitis and stent migration. Objective We performed this meta-analysis to assess the risk of post-endoscopic retrograde cholangio-pancreatography pancreatitis and other adverse events (acute cholecystitis and stent migration with biliary covered self-expandable metal stents compared to uncovered self-expandable metal stents. We also assessed the proportion of stent patency at 6 and 12 months between the two groups. Methods We searched MedLine, EMBASE, Cochrane database, ISI Web of Science and Scopus from January 1989 through June, 2014, to identify randomized controlled trials and observational studies that provided data on the risk of post-endoscopic retrograde cholangio-pancreatography pancreatitis and other adverse events following the placement of covered self-expandable metal stents versus uncovered self-expandable metal stents in patients with biliary obstruction. The Mantel–Haenszel method was used to pool data of post-endoscopic retrograde cholangio- pancreatography pancreatitis, acute cholecystitis, stent migration and proportion of stent patency over 6 and 12 months into fixed or random effect model of meta-analyses. Odds ratio was used to generate an overall effect estimate of the outcome. Results Eight studies (6 randomized controlled trials and 2 observational studies with a total of 1078 patients were included in the meta-analysis. The pooled odds ratio with 95% confidence intervals for risk of post-endoscopic retrograde cholangio

  13. Current Status of Biliary Metal Stents

    OpenAIRE

    Nam, Hyeong Seok; Kang, Dae Hwan

    2016-01-01

    Many advances have been achieved in biliary stenting over the past 30 years. Endoscopic stent placement has become the primary management therapy to relieve obstruction in patients with benign or malignant biliary tract diseases. Compared with plastic stents, a self-expandable metallic stent (SEMS) has been used for management in patients with malignant strictures because of a larger lumen and longer stent patency. Recently, SEMS has been used for various benign biliary strictures and leaks. ...

  14. In vitro evaluation of 56 coronary artery stents by 256-slice multi-detector coronary CT

    Energy Technology Data Exchange (ETDEWEB)

    Steen, Henning, E-mail: henning.steen@med.uni-heidelberg.de [University of Heidelberg, Department of Cardiology, Im Neuenheimer Feld 410, Heidelberg 69120 (Germany); Andre, Florian, E-mail: Florian.Andre@med.uni-heidelberg.de [University of Heidelberg, Department of Cardiology, Im Neuenheimer Feld 410, Heidelberg 69120 (Germany); Korosoglou, Grigorios, E-mail: Grigorios.Korosoglou@med.uni-heidelberg.de [University of Heidelberg, Department of Cardiology, Im Neuenheimer Feld 410, Heidelberg 69120 (Germany); Mueller, Dirk, E-mail: Dirk.Mueller@philips.com [Philips GmbH Healthcare Division, Luebeckertordamm 5, Hamburg 20099 (Germany); Hosch, Waldemar, E-mail: Waldemar.Hosch@med.uni-heidelberg.de [University of Heidelberg, Department of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 410, Heidelberg 69120 (Germany); Kauczor, Hans-Ulrich, E-mail: Hans-Ulrich.Kauczor@med.uni-heidelberg.de [University of Heidelberg, Department of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 410, Heidelberg 69120 (Germany); Giannitsis, Evangelos, E-mail: Evangelos.Giannitsis@med.uni-heidelberg.de [University of Heidelberg, Department of Cardiology, Im Neuenheimer Feld 410, Heidelberg 69120 (Germany); Katus, Hugo A., E-mail: Hugo.Katus@med.uni-heidelberg.de [University of Heidelberg, Department of Cardiology, Im Neuenheimer Feld 410, Heidelberg 69120 (Germany)

    2011-10-15

    Objective: We sought to investigate stent lumen visibility of 56 coronary stents with the newest 256-multi-slice-CT (256-MDCT) technology for different reconstruction algorithms in an in vitro model. Background: Early identification of in-stent restenosis (ISR) is important to avoid recurrent ischemia and prevent acute myocardial infarction (AMI). Since angiography has the disadvantage of high costs and its invasiveness, MDCT could be a convenient and safe non-invasive alternative for detection of ISR. Material and methods: Percentages of in-stent lumen diameter and in-stent signal attenuation (measured as contrast-to-noise ratio (CNR)) of 56 coronary stents (group A {<=}2.5 mm; group B = 2.75-3.0 mm; group C = 3.5-4.0 mm) were evaluated in a coronary vessel in vitro phantom (iodine-filled plastic tubes) employing four different reconstruction algorithms (XCD, CC, CD, XCB) on a novel 256-MDCT (Philips-iCT, collimation = 128 mm x 0.625 mm; rotation time = 270 ms; tube current = 800 mA s with 120 kV). Analysis was conducted with the semi-automatical full-width-at-half-maximum (FWHM) method. P-values <0.05 were regarded statistically significant. Results: In-stent lumen diameter >60% for group C stents was significantly larger and CNR was significantly lower (both p < 0.05) for sharp kernels (CD; XCD) when compared to groups A/B. The FWHM-method showed significantly smaller in-stent lumen diameter (p < 0.05) when compared to the manual method. Conclusion: 256-MDCT could potentially be employed for clinical assessment of stent patency in stents >3.0 mm when analysed with cardio-dedicated sharp kernels, although clinical studies corroborating this claim should be performed. However, stents {<=}3.0 mm reconstructed by soft kernels revealed insufficient in-stent lumen visualisation and should not be used in clinical practice. Further improvements in spatial and temporal image resolution as well as reductions of radiation exposure and image noise have to be accomplished

  15. Endoscopic Removal of a Proximally Migrated Metal Stent during Balloon Sweeping after Stent Trimming

    OpenAIRE

    Cho, Nam Jun; Lee, Tae Hoon; Park, Sang-Heum; Lee, Han Min; Hyun, Kyung Hee; Lee, Suck-Ho; Chung, Il-Kwun; Kim, Sun-Joo

    2013-01-01

    Placement of a self-expanding metal stent (SEMS) is an effective method for palliation of a malignant biliary obstruction. However, metal stents can cause various complications, including stent migration. Distally migrated metal stents, particularly covered SEMS, can be removed successfully in most cases. Stent trimming using argon plasma coagulation may be helpful in difficult cases despite conventional methods. However, no serious complications related to the trimming or remnant stent remov...

  16. Endoscopic pancreatic duct stent placement for inflammatory pancreatic diseases

    OpenAIRE

    Testoni, Pier Alberto

    2007-01-01

    The role of endoscopic therapy in the management of pancreatic diseases is continuously evolving; at present most pathological conditions of the pancreas are successfully treated by endoscopic retrograde cholangio-pancreatography (ERCP) or endoscopic ultrasound (EUS), or both. Endoscopic placement of stents has played and still plays a major role in the treatment of chronic pancreatitis, pseudocysts, pancreas divisum, main pancreatic duct injuries, pancreatic fistulae, complications of acute ...

  17. 光学相干断层成像评价植入不同药物洗脱架后的血管愈合情况%Evaluation by optical coherence tomography of vascular healing after drug-eluting stents implantation in acute myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    范春雨; Kim Jung-Sun; Kim Tae-Hoon; 吕吉元

    2011-01-01

    目的 应用光学相干断层成像(OCT)比较急性心肌梗死(AMI)患者植入不同药物洗脱支架(DES)后的新生内膜覆盖和支架贴壁情况以评估血管愈合.方法 49例AMI患者植入不同DES后9个月时进行OCT检查.其中20个雷帕霉素药物洗脱支架(SES,Cypher),12个紫杉醇药物洗脱支架(PES,Taxus)和17个雷帕霉素衍生物药物洗脱支架(ZES,Endeavor).每隔1 mm评估OCT横断面影像每个支架柱的新生内膜覆盖和贴壁情况,同时观察每个支架内的血栓发生情况.结果 总计对12 378个支架柱进行了分析.SES的新生内膜增生最少,新生内膜厚度:SES(77±60)μm、PES(153±82)μm、ZES(265±130)μm,且新生内膜增生面积百分比最低,SES(10±8)%、PES(19±8)%、ZES28±9)%,但SES和PES有更多未被新生内膜覆盖的支架柱,SES(15.1±16)%、PES(7.1±10)%、ZES(0.6±1.5)%,且贴壁不良支架柱的发生率也高于ZES,SES(3.8±7.2)%、PES(2.1±4.4)%、ZES(0±0)%,而有完全新生内膜覆盖的支架比例以ZES为高,SES 5%、PES33.3%、ZES 82.4%.血栓的发生率SES和PES高于ZFS,SES 34%、PES 33%、ZES 6%.结论 AMI患者植入不同类型DES后,其支架的新生内膜覆盖程度和贴壁不良的发生率是显著不同的,因此DES的类型可能影响了AMI血栓性病变的血管愈合过程.%Objective To compare neointimal coverage and stent malapposition after DESs implantation in patients with acute myocardial infarction using optical coherence tomography (OCT).Methods OCT was analyzed at 9-month after DESs implantation in 49 AMI patients [20 sirolimus eluting stent (SES, Cypher), 12 paclitaxel eluting stent (PES, Taxus) and 17 zotarolimus eluting stent (ZES,Endeavor)].Neointimal thickness and strut apposition were measured at each stent strut and every 1 mm corss section.Presence of thrombus was observed in each stent.Results In total, 12 378 stent struts were analyzed.SES had the least neointimal thickness (SES 77 ±60 μm vs PES 153 ±82 μ,m vs ZES

  18. Safety and efficacy of limus-eluting stents and balloon angioplasty for sirolimus-eluting in-stent restenosis

    Energy Technology Data Exchange (ETDEWEB)

    Ota, Hideaki [Division of Interventional Cardiology, MedStar Washington Hospital Center, Washington, DC 20010 (United States); Mahmoudi, Michael [University of Surrey, Guildford Road, Surrey, GU2-7XH (United Kingdom); Kitabata, Hironori; Torguson, Rebecca; Chen, Fang; Satler, Lowell F.; Suddath, William O.; Pichard, Augusto D. [Division of Interventional Cardiology, MedStar Washington Hospital Center, Washington, DC 20010 (United States); Waksman, Ron, E-mail: ron.waksman@medstar.net [Division of Interventional Cardiology, MedStar Washington Hospital Center, Washington, DC 20010 (United States)

    2015-03-15

    Objectives: The aim of this study was to compare the safety and efficacy of everolimus-eluting stent (EES), sirolimus-eluting stent (SES), and plain old balloon angioplasty (POBA) for the treatment of SES in-stent restenosis (S-ISR). Background: The optimal treatment for drug-eluting in-stent restenosis remains controversial. Methods: The study cohort comprised 310 consecutive patients (444 lesions) who presented with S-ISR to our institution and underwent treatment with EES (43 patients), SES (102), or POBA (165). The analyzed clinical parameters were the 1-year rates of death, Q-wave myocardial infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), definite stent thrombosis (ST) and major adverse cardiac event (MACE) defined as the composite of death, MI, or TLR at 1-year. Results: The three groups were well matched for the conventional risk factors for coronary artery disease except for smoking. The 1-year analyzed clinical parameters were similar in the three groups: MACE (EES = 14%, SES = 18%, POBA = 20%; p = 0.65), death (EES = 2.3%, SES = 6.2%, POBA = 6.1%; p = 0.61), MI (EES = 4.8%, SES = 2.1%, POBA = 2.5%; p = 0.69), TLR (EES = 11.9%, SES = 12.1%, POBA = 24%; p = 0.78), and TVR (EES = 11.9%, SES = 24.8%, POBA = 22.2%; p = 0.23). There were no cases of definite ST. MACE-free rate was significantly lower in patients with recurrent in-stent restenosis (log-rank p = 0.006). Presentation with acute MI, number of treated lesions and a previous history of MI were found to be independent predictors of MACE. Conclusions: In patients presenting with S-ISR, treatment with implantation of an EES, SES, or POBA is associated with similar clinical outcomes. Patients presenting with recurrent ISR may have a poorer clinical outcome.

  19. Endoscopic transpapillary gallbladder drainage with replacement of a covered self-expandable metal stent

    OpenAIRE

    Kawakubo, Kazumichi; Isayama, Hiroyuki; Sasahira, Naoki; Nakai, Yousuke; Kogure, Hirofumi; Sasaki, Takashi; Hirano, Kenji; Tada, Minoru; Koike, Kazuhiko

    2011-01-01

    Endoscopic self-expandable metal stent (SEMS) placement has become a standard palliative therapy for patients with malignant biliary obstruction. Acute cholecystitis after SEMS placement is a serious complication. We report a patient with an acute cholecystitis after covered SEMS placement, who was managed successfully with endoscopic transpapillary gallbladder drainage (ETGBD) and replacement of the covered SEMS. An 85-year-old man with pancreatic cancer suffered from acute cholecystitis aft...

  20. Mechanisms of Biliary Plastic Stent Occlusion and Efforts at Prevention

    OpenAIRE

    Kwon, Chang-Il; Lehman, Glen A.

    2016-01-01

    Biliary stenting via endoscopic retrograde cholangiopancreatography has greatly improved the quality of patient care over the last 30 years. Plastic stent occlusion limits the life span of such stents. Attempts to improve plastic stent patency duration have mostly failed. Metal stents (self-expandable metal stents [SEMSs]) have therefore replaced plastic stents, especially for malignant biliary strictures. SEMS are at least 10 times more expensive than plastic stents. In this focused review, ...

  1. Evaluating Stent Optimisation Technique (StentBoost®) in a Dedicated Bifurcation Stent (the Tryton™)

    Energy Technology Data Exchange (ETDEWEB)

    Fysal, Zamil; Hyde, Thomas; Barnes, Edward; McCrea, William; Ramcharitar, Steve, E-mail: steve.ramcharitar@chem.ox.ac.uk

    2014-03-15

    Background/Purpose: To evaluate the use of StentBoost® in the Tryton™ dedicated SideBranch Stent. Methods and Results: The Tryton™ SideBranch Stent has been effectively used to manage complex bifurcations. However, the paucity of scaffolding in the proximal part of the stent makes it often difficult to visualise under standard radiographic imaging. We set out to evaluate whether by using an augmented radiographic imaging technique it was possible to aid visualisation of the stent. In particular the so call 'wedding ring' band which is crucial to the procedural success. We further evaluated whether it was possible to determine the apposition of the stent at the carina, its coverage and the ability to aid recrossing of the struts closest to the carina as well as the added radiation exposure. Conclusions: StentBoost® was found to be invaluable to the procedural success of the Tryton™ deployment without adding any extra cost to the procedure and with only a 3.7% increase in radiation to the patient. It allowed enhanced visualisation in all cases to aid apposition, recrossing and coverage.

  2. Endoscopic placement of pancreatic stents and drains in the management of pancreatitis.

    Science.gov (United States)

    Kozarek, R A; Patterson, D J; Ball, T J; Traverso, L W

    1989-01-01

    Although widely used in the biliary tree, little data is available on endoscopic placement of stents or drains within the pancreas. This report describes 17 patients, nine with acute relapsing pancreatitis and eight with chronic pancreatitis, who had drain or stent placement for hypertensive pancreatic duct (PD) sphincter, dominant ductal stenosis, duct disruption, or pseudocyst. Two patients have subsequently undergone surgery, and six other patients continue long-term stent placement with marked reduction of chronic pain or attacks of recurrent pancreatitis. All six pseudocysts resolved, although one recurred and required surgery. It is concluded that pancreatic drains or stents may obviate the need for surgery, temporize before definitive therapy, or direct a subsequent surgical procedure. Images Figs. 1A and B. Figs. 2A-C. Figs. 2A-C. Fig. 3. Figs. 4A-D. Figs. 5A and B. PMID:2923512

  3. Long-term outcome after drug-eluting versus bare-metal stent implantation in patients with ST-segment elevation myocardial infarction: 3-year follow-up of the randomized DEDICATION (Drug Elution and Distal Protection in Acute Myocardial Infarction) Trial

    DEFF Research Database (Denmark)

    Kaltoft, Anne; Kelbaek, Henning; Thuesen, Leif;

    2010-01-01

    The purpose of this study was to compare long-term clinical outcomes after implantation of drug-eluting stents (DES) and bare-metal stents (BMS) in patients with ST-segment elevation myocardial infarction (STEMI).......The purpose of this study was to compare long-term clinical outcomes after implantation of drug-eluting stents (DES) and bare-metal stents (BMS) in patients with ST-segment elevation myocardial infarction (STEMI)....

  4. Simultaneous Two-Vessel Subacute Stent Thrombosis Caused by Clopidogrel Resistance from CYP2C19 Polymorphism.

    Science.gov (United States)

    Afzal, Ashwad; Patel, Bimal; Patel, Neel; Sattur, Sudhakar; Patel, Vinod

    2016-01-01

    Clopidogrel resistance from CYP2C19 polymorphism has been associated with stent thrombosis in patients undergoing percutaneous coronary intervention with drug-eluting stents. We present a case of a 76-year-old male who received drug-eluting stents to the right coronary artery and left anterior descending artery for non-ST elevation myocardial infarction and was discharged on dual antiplatelet therapy with aspirin and clopidogrel. He subsequently presented with chest pain from anterior, anteroseptal, and inferior ST segment elevation myocardial infarction. An emergent coronary angiogram revealed acute stent thrombosis with 100% occlusion of RCA and LAD that was successfully treated with thrombus aspiration and angioplasty. Although he was compliant with his dual antiplatelet therapy, he developed stent thrombosis, which was confirmed as clopidogrel resistance from homozygous CYP2C19 polymorphism. PMID:27555873

  5. Nuclear Recoil Calibration of DarkSide-50

    Science.gov (United States)

    Edkins, Erin; DarkSide Collaboration

    2016-03-01

    DarkSide-50 dark matter experiment is a liquid argon time projection chamber (TPC) surrounded by a liquid scintillator active neutron veto, designed for the direct detection of Weakly Interacting Massive Particles (WIMPs). The success of such an experiment is dependent upon a detailed understanding of both the expected signal and backgrounds, achieved using radioactive calibration sources of known energies. Nuclear recoils provide a measurement of both the expected signal and the most dangerous background, as nuclear recoils from neutrons cannot be distinguished from a dark matter signal on an event-by-event basis in the TPC. In this talk, I will present the DS-50 calibration system, and analysis of the results of the calibration of DarkSide-50 to nuclear recoils using radioactive neutron sources. See also the DS-50 presentations by X. Xiang and G. Koh.

  6. Anatomy of the binary black hole recoil: A multipolar analysis

    CERN Document Server

    Schnittman, Jeremy D; van Meter, James R; Baker, John G; Boggs, William D; Centrella, Joan; Kelly, Bernard J; McWilliams, Sean T

    2007-01-01

    We present a multipolar analysis of the gravitational recoil computed in recent numerical simulations of binary black hole (BH) coalescence, for both unequal masses and non-zero, non-precessing spins. We show that multipole moments up to and including l=4 are sufficient to accurately reproduce the final recoil velocity (within ~2%) and that only a few dominant modes contribute significantly to it (within ~5%). We describe how the relative amplitudes, and more importantly, the relative phases, of these few modes control the way in which the recoil builds up throughout the inspiral, merger, and ringdown phases. We also find that the numerical results can be reproduced by an ``effective Newtonian'' formula for the multipole moments obtained by replacing the radial separation in the Newtonian formulae with an effective radius computed from the numerical data. Beyond the merger, the numerical results are reproduced by a superposition of three Kerr quasi-normal modes (QNMs). Analytic formulae, obtained by expressin...

  7. Rupture and recoil of bent-core liquid crystal filaments.

    Science.gov (United States)

    Salili, S M; Ostapenko, T; Kress, O; Bailey, C; Weissflog, W; Harth, K; Eremin, A; Stannarius, R; Jákli, A

    2016-05-25

    The recoil process of free-standing liquid crystal filaments is investigated experimentally and theoretically. We focus on two aspects, the contraction speed of the filament and a spontaneously formed undulation instability. At the moment of rupture, the filaments buckle similarly to the classical Euler buckling of elastic rods. The tip velocity decays with decreasing filament length. The wavelength of buckling affinely decreases with the retracting filament tip. The energy gain related to the decrease of the total length and surface area of the filaments is mainly dissipated by layer rearrangements during thickening of the fibre. A flow back into the meniscus is relevant only in the final stage of the recoil process. We introduce a model for the quantitative description of the filament retraction speed. The dynamics of this recoil behaviour may find relevance as a model for biology-related filaments. PMID:27140824

  8. Accounting for Recoil Effects in Geochronometers: A New Model Approach

    Science.gov (United States)

    Lee, V. E.; Huber, C.

    2012-12-01

    A number of geologically important chronometers are affected by, or owe their utility to, the "recoil effect". This effect describes the physical displacement of a nuclide due to energetic nuclear processes such as radioactive alpha decay (as in the case of various parent-daughter pairs in the uranium-series decay chains, and Sm-Nd), as well as neutron irradiation (in the case of the methodology for the 40Ar/39Ar dating method). The broad range of affected geochronometers means that the recoil effect can impact a wide range of dating method applications in the geosciences, including but not limited to: Earth surface processes, paleoclimate, volcanic processes, and cosmochemistry and planetary evolution. In particular, the recoil effect can have a notable impact on the use of fine grains (silt- and clay-sized particles) for geochronometric dating purposes. This is because recoil-induced loss of a nuclide from the surfaces of a grain can create an isotopically-depleted outer rind, and for small grains, this depleted rind can be volumetrically significant. When this recoil loss is measurable and occurs in a known time-dependent fashion, it can usefully serve as the basis for chronometers (such as the U-series comminution age method); in other cases recoil loss from fine particles creates an unwanted deviation from expected isotope values (such as for the Ar-Ar method). To improve both the accuracy and precision of ages inferred from geochronometric systems that involve the recoil of a key nuclide from small domains, it is necessary to quantify the magnitude of the recoil loss of that particular nuclide. It is also necessary to quantitatively describe the effect of geological processes that can alter the outer surface of grains, and hence the isotopically-depleted rind. Here we present a new mathematical and numerical model that includes two main features that enable enhanced accuracy and precision of ages determined from geochronometers. Since the surface area of the

  9. Powerful flares from recoiling black holes in quasars

    CERN Document Server

    Shields, G A

    2008-01-01

    Mergers of spinning black holes can give recoil velocities from gravitational radiation up to several thousand km/s. A recoiling supermassive black hole in an AGN retains the inner part of its accretion disk. Marginally bound material rejoining the disk around the moving black hole releases a large amount of energy in shocks in a short time, leading to a flare in thermal soft X-rays with a luminosity approaching the Eddington limit. Reprocessing of the X-rays by the infalling material gives strong optical and ultraviolet emission lines with a distinctive spectrum. Despite the short lifetime of the flare (~10^4 yr), as many as 100 flares may be in play at the present time in QSOs at redshifts ~ 1 to 3. These flares provide a means to identify high velocity recoils.

  10. First detection of tracks of radon progeny recoils by MIMAC

    CERN Document Server

    Riffard, Q; Bosson, G; Bourrion, O; Descombes, T; Fourel, C; Guillaudin, O; Muraz, J -F; Colas, P; Ferrer-Ribas, E; Giomataris, I; Busto, J; Fouchez, D; Tao, C; Lebreton, L; Maire, D

    2015-01-01

    The MIMAC experiment is a $\\mu$-TPC matrix project for directional dark matter search. Directional detection is a strategy based on the measurement of the WIMP flux anisotropy due to the solar system motion with respect to the dark matter halo. The main purpose of MIMAC project is the measurement of the energy and the direction of nuclear recoils in 3D produced by elastic scattering of WIMPs. Since June 2012 a bi-chamber prototype is operating at the Modane underground laboratory. In this paper, we report the first ionization energy and 3D track observations of nuclear recoils produced by the radon progeny. This measurement shows the capability of the MIMAC detector and opens the possibility to explore the low energy recoil directionality signature.

  11. How black holes get their kicks: Radiation recoil in binary black hole mergers

    CERN Document Server

    Hughes, S A; Holz, D E; Hughes, Scott A.; Favata, Marc; Holz, Daniel E.

    2004-01-01

    Gravitational waves from the coalescence of binary black holes carry linear momentum, causing center of mass recoil. This ``radiation rocket'' has important implications for systems with escape speeds of order the recoil velocity. We describe new recoil calculations using high precision black hole perturbation theory to estimate the magnitude of the recoil for the slow ``inspiral'' coalescence phase; coupled with a cruder calculation for the final ``plunge'', we estimate the total recoil imparted to a merged black hole. We find that velocities of many tens to a few hundred km/sec can be achieved fairly easily. The recoil probably never exceeds about 500 km/sec.

  12. Endothelial cell repopulation after stenting determines in-stent neointima formation: effects of bare-metal vs. drug-eluting stents and genetic endothelial cell modification.

    OpenAIRE

    Douglas, G; van Kampen, E.; Hale, AB; McNeill, E; Patel, J.; Crabtree, MJ; Ali, Z; Hoerr, RA; Alp, NJ; Channon, KM

    2013-01-01

    Aims Understanding endothelial cell repopulation post-stenting and how this modulates in-stent restenosis is critical to improving arterial healing post-stenting. We used a novel murine stent model to investigate endothelial cell repopulation post-stenting, comparing the response of drug-eluting stents with a primary genetic modification to improve endothelial cell function. Methods and results Endothelial cell repopulation was assessed en face in stented arteries in ApoE−/− mice with end...

  13. Nuclear recoil measurements in Superheated Superconducting Granule detectors

    OpenAIRE

    Schmiemann, K.

    1993-01-01

    The response of Superheated Superconducting Granule (SSG) devices to nuclear recoils has been explored by irradiating SSG detectors with a 70Me$\\!$V neutron beam. In the past we have tested Al SSG and more recently, measurements have been performed with Sn and Zn detectors. The aim of the experiments was to test the sensitivity of SSG detectors to recoil energies down to a few ke$\\!$V. In this paper, the preliminary results of the neutron irradiation of a SSG detector made of Sn granules 15-2...

  14. Massive Black Hole Recoil in High Resolution Hosts

    OpenAIRE

    Guedes, Javiera; Diemand, Jürg; Zemp, Marcel; Kuhlen, Michael; Madau, Piero; Mayer, Lucio; Stadel, Joachim

    2008-01-01

    The final inspiral and coalescence of a black hole binary can produce highly beamed gravitational wave radiation. To conserve linear momentum, the black hole remnant can recoil with "kick" velocity as high as 4000 km/s. We present two sets of full N-body simulations of recoiling massive black holes (MBH) in high-resolution, non-axisymmetric potentials. The host to the first set of simulations is the main halo of the Via Lactea I simulation (Diemand et al. 2007). The nature of the resulting or...

  15. Ionic recoil energies in the Coulomb explosion of metal clusters

    Science.gov (United States)

    Teuber, S.; Döppner, T.; Fennel, T.; Tiggesbäumker, J.; Meiwes-Broer, K. H.

    The photoionization of metal clusters in intense femtosecond laser fields has been studied. In contrast to an experiment on atoms, the interaction in this case leads to a very efficient and high charging of the particle where tens of electrons per atom are ejected from the cluster. The recoil energy distribution of the atomic fragment ions was measured which in the case of lead clusters exceeds 180 keV. Enhanced charging efficiency which we observed earlier for specific pulse conditions is not reflected in the recoil energy spectra. Both the average and the maximum energies decrease with increasing laser pulse width. This is in good agreement with molecular dynamics calculations.

  16. Ionization Efficiency Study for Low Energy Nuclear Recoils in Germanium

    CERN Document Server

    Barker, D; Mei, D -M; Zhang, C

    2013-01-01

    We used the internal conversion ($E_0$ transition) of germanium-72 to indirectly measure the low energy nuclear recoils of germanium. Together with a reliable Monte Carlo package, in which we implement the internal conversion process, the data was compared to the Lindhard ($k$=0.159) and Barker-Mei models. A shape analysis indicates that both models agree well with data in the region of interest within 4%. The most probable value (MPV) of the nuclear recoils obtained from the shape analysis is 17.5 keV with an average path-length of 0.014 $\\mu$m.

  17. Emergency and elective implantation of covered stent systems in iatrogenic arterial injuries

    Energy Technology Data Exchange (ETDEWEB)

    Goltz, J.P.; Kickuth, R. [Universitaetsklinikum Wuerzburg (Germany). Inst. fuer Roentgendiagnostik; Bastuerk, P.; Hoppe, H.; Triller, J. [Universitaetsspital Bern (Switzerland). Inst. fuer Diagnostische, Interventionelle und Paediatrische Radiologie

    2011-07-15

    Purpose: To evaluate the effectiveness and safety of covered stents for the management of iatrogenic arterial injury. Materials and Methods: Between 03/1998 and 12/2009, 31 patients underwent selective covered stent implantation after iatrogenic arterial injury. 12/31 of these patients (38.7 %) were hemodynamically unstable. Six different endovascular covered stent types were utilized. The primary endpoints of this study were technical and clinical success and rates of minor and major complications. Results: Initial angiograms demonstrated active extravasation in 19 (61.3 %) patients and pseudoaneurysms in 12 (38.7 %) patients. The following sites of bleeding origin were detected: axillary artery, subclavian artery, common iliac artery, external iliac artery, internal iliac artery, common femoral artery, superficial femoral artery, popliteal and fibular artery, femoro-popliteal and popliteo-crural bypasses, common hepatic artery, aberrant hepatic artery, cystic and gastroduodenal artery. In all patients bleeding was effectively controlled by covered stent implantation resulting in an immediate technical success of 100 %. Clinical success attributed to covered stent implantation was documented in 30 of the 31 patients (96.8 %). Major complications included death in four patients (11.1 %), acute thrombosis with arm ischemia in one patient (2.8 %) and stent fracture with associated pseudoaneurysm in another patient (2.8 %). In 2/31 patients (6.5 %) covered stent failure was detected and successfully treated by implantation of a second covered stent. Conclusion: Emergency and elective implantation of covered stents may be used for minimally invasive and effective management of iatrogenic arterial injury. (orig.)

  18. Emergency and elective implantation of covered stent systems in iatrogenic arterial injuries

    International Nuclear Information System (INIS)

    Purpose: To evaluate the effectiveness and safety of covered stents for the management of iatrogenic arterial injury. Materials and Methods: Between 03/1998 and 12/2009, 31 patients underwent selective covered stent implantation after iatrogenic arterial injury. 12/31 of these patients (38.7 %) were hemodynamically unstable. Six different endovascular covered stent types were utilized. The primary endpoints of this study were technical and clinical success and rates of minor and major complications. Results: Initial angiograms demonstrated active extravasation in 19 (61.3 %) patients and pseudoaneurysms in 12 (38.7 %) patients. The following sites of bleeding origin were detected: axillary artery, subclavian artery, common iliac artery, external iliac artery, internal iliac artery, common femoral artery, superficial femoral artery, popliteal and fibular artery, femoro-popliteal and popliteo-crural bypasses, common hepatic artery, aberrant hepatic artery, cystic and gastroduodenal artery. In all patients bleeding was effectively controlled by covered stent implantation resulting in an immediate technical success of 100 %. Clinical success attributed to covered stent implantation was documented in 30 of the 31 patients (96.8 %). Major complications included death in four patients (11.1 %), acute thrombosis with arm ischemia in one patient (2.8 %) and stent fracture with associated pseudoaneurysm in another patient (2.8 %). In 2/31 patients (6.5 %) covered stent failure was detected and successfully treated by implantation of a second covered stent. Conclusion: Emergency and elective implantation of covered stents may be used for minimally invasive and effective management of iatrogenic arterial injury. (orig.)

  19. Recoil-alpha-fission and recoil-alpha-alpha-fission events observed in the reaction Ca-48 + Am-243

    CERN Document Server

    Forsberg, U; Andersson, L -L; Di Nitto, A; Düllmann, Ch E; Gates, J M; Golubev, P; Gregorich, K E; Gross, C J; Herzberg, R -D; Hessberger, F P; Khuyagbaatar, J; Kratz, J V; Rykaczewski, K; Sarmiento, L G; Schädel, M; Yakushev, A; Åberg, S; Ackermann, D; Block, M; Brand, H; Carlsson, B G; Cox, D; Derkx, X; Dobaczewski, J; Eberhardt, K; Even, J; Fahlander, C; Gerl, J; Jäger, E; Kindler, B; Krier, J; Kojouharov, I; Kurz, N; Lommel, B; Mistry, A; Mokry, C; Nazarewicz, W; Nitsche, H; Omtvedt, J P; Papadakis, P; Ragnarsson, I; Runke, J; Schaffner, H; Schausten, B; Shi, Y; Thörle-Pospiech, P; Torres, T; Traut, T; Trautmann, N; Türler, A; Ward, A; Ward, D E; Wiehl, N

    2015-01-01

    Products of the fusion-evaporation reaction Ca-48 + Am-243 were studied with the TASISpec set-up at the gas-filled separator TASCA at the GSI Helmholtzzentrum f\\"ur Schwerionenforschung. Amongst the detected thirty correlated alpha-decay chains associated with the production of element Z=115, two recoil-alpha-fission and five recoil-alpha-alpha-fission events were observed. The latter are similar to four such events reported from experiments performed at the Dubna gas-filled separator. Contrary to their interpretation, we propose an alternative view, namely to assign eight of these eleven decay chains of recoil-alpha(-alpha)-fission type to start from the 3n-evaporation channel 115-288. The other three decay chains remain viable candidates for the 2n-evaporation channel 115-289.

  20. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... On occasion, if somebody comes in with an acute heart attack, they have clot in the vessel, we’ll ... question about that. People who have having an acute heart attack there is absolutely no question they need to ...

  1. Three-dimensional reconstruction of coronary stents in vivo based on motion compensated X-ray angiography

    Science.gov (United States)

    Schäfer, Dirk; Movassaghi, Babak; Grass, Michael; Schoonenberg, Gert; Florent, Raoul; Wink, Onno; Klein, Andrew J. P.; Chen, James Y.; Garcia, Joel; Messenger, John C.; Carroll, John D.

    2007-03-01

    The complete expansion of the stent during a percutaneous transluminal coronary angioplasty (PTCA) procedure is essential for treatment of a stenotic segment of a coronary artery. Inadequate expansion of the stent is a major predisposing factor to in-stent restenosis and acute thrombosis. Stents are positioned and deployed by fluoroscopic guidance. Although the current generation of stents are made of materials with some degree of radio-opacity to detect their location after deployment, proper stent expansion is hard to asses. In this work, we introduce a new method for the three-dimensional (3D) reconstruction of the coronary stents in-vivo utilizing two-dimensional projection images acquired during rotational angiography (RA). The acquisition protocol consist of a propeller rotation of the X-ray C-arm system of 180°, which ensures sufficient angular coverage for volume reconstruction. The angiographic projections were acquired at 30 frames per second resulting in 180 projections during a 7 second rotational run. The motion of the stent is estimated from the automatically tracked 2D coordinates of the markers on the balloon catheter. This information is used within a motion-compensated reconstruction algorithm. Therefore, projections from different cardiac phases and motion states can be used, resulting in improved signal-to-noise ratio of the stent. Results of 3D reconstructed coronary stents in vivo, with high spatial resolution are presented. The proposed method allows for a comprehensive and unique quantitative 3D assessment of stent expansion that rivals current X-ray and intravascular ultrasound techniques.

  2. Percutaneous cholangioscopy in obstructed biliary metal stents

    International Nuclear Information System (INIS)

    Purpose. To reevaluate the reasons for the occlusion of self-expanding biliary metal stents, on the basis of cholangioscopic findings. Methods. Percutaneous transhepatic cholangioscopy (PTCS) was performed in 15 patients with obstructed biliary Wallstents. The reason for stent insertion was a malignant obstruction in 14 patients; 1 had a benign biliary stricture. Conventional noncovered stents had been inserted in 12 patients; in 3 cases a polyurethane-covered prototype Wallstent had been used. Stent occlusions occurred after 1-55 months. PTCS was performed with a 2.3-mm endoscope through an 11 Fr sheath. Biopsies were taken via the working channel of the endoscope. Results. In all patients with noncovered stents the inner surface of the stent was highly irregular with seaweed-like protrusions (biopsy-proven granulation tissue). Stent incorporation varied from absent (n=1) to subtotal (n=8), but was always incomplete, no matter how long the stent had been in place. Tumor ingrowth was histologically proven in 2 patients. One patient had a large occluding concrement at the proximal end of the stent. In patients with covered stents, the inner surface appeared more regular; however, viable granulation tissue was found inside two stents and tumor ingrowth in one of them. Conclusion. PTCS showed that incorporation of the stent is virtually always incomplete. The factors contributing most to stent occlusion are the buildup of granulation tissue, bile sludge, and tumor overgrowth. Stone formation and tumor ingrowth can also be important, although less common causes of occlusion. A polyurethane stent covering could not prevent tumor ingrowth in one patient and the buildup of viable granulation tissue inside the stent in two further patients; mean stent patency in the three patients with such a stent was 3 months

  3. Coronary aneurysm and very late stent thrombosis formation associated with sirolimus-eluting stent implantation

    Institute of Scientific and Technical Information of China (English)

    XIE Hong-zhi; ZHANG Shu-yang; ZENG Yong; SHEN Zhu-jun; FANG Quan

    2009-01-01

    @@ Since drug-eluting stents (DES) can significantly reduce the risk of instant restenosis compared with bare-metal stents, they have been widely used in interventional therapy for coronary heart disease. With bare-metal stents being rapidly replaced by DES there is a great concern about the safety of DES due to stent thrombosis.~(1,2)

  4. Drug-eluting stents and bare metal stents in patients with NSTE-ACS

    DEFF Research Database (Denmark)

    Pedersen, Sune Haahr; Pfisterer, Matthias; Kaiser, Christoph;

    2014-01-01

    the randomised BASKET-PROVE trial (sirolimus-eluting stent vs. everolimus-eluting stent vs. bare metal stent in large-vessel stenting). The primary endpoint was the combined two-year rate of cardiovascular death or non-fatal myocardial infarction (MI). Secondary endpoints were each component of the primary...

  5. Very late coronary aneurysm formation with subsequent stent thrombosis secondary to drug-eluting stent

    Institute of Scientific and Technical Information of China (English)

    Ibrahim Akin,; Stephan Kische; Tim C Rehders; Henrik Schneider; G(o)kmen R Turan; Tilo Kleinfeldt; Jasmin Ortak; Christoph A. Nienaber; Hüseyin Ince

    2011-01-01

    Drug-eluting stents have changed the practice in interventional cardiology.With the widespread use of these stents important safety concerns regarding stent thrombosis and formation of coronary artery aneurysm have been expressed.While the majority of attention was focused on stent thrombosis,the formation of coronary aneurysm was only described in anecdotal reports.We report on a patient who suffered from very late stent thrombosis in association with coronary artery aneurysm formation secondary to drug-eluting stent but not to bare-metal stent.

  6. Mechanisms of Biliary Plastic Stent Occlusion and Efforts at Prevention.

    Science.gov (United States)

    Kwon, Chang-Il; Lehman, Glen A

    2016-03-01

    Biliary stenting via endoscopic retrograde cholangiopancreatography has greatly improved the quality of patient care over the last 30 years. Plastic stent occlusion limits the life span of such stents. Attempts to improve plastic stent patency duration have mostly failed. Metal stents (self-expandable metal stents [SEMSs]) have therefore replaced plastic stents, especially for malignant biliary strictures. SEMS are at least 10 times more expensive than plastic stents. In this focused review, we will discuss basic mechanisms of plastic stent occlusion, along with a systematic summary of previous efforts and related studies to improve stent patency and potential new techniques to overcome existing limitations. PMID:27000422

  7. Who is responsible for the consequences? A case of stent thrombosis subsequent to noncompliance with post angioplasty treatment regimen.

    Science.gov (United States)

    Sajwani, Salma Abdul Aziz; Allana, Saleema

    2014-01-01

    Coronary artery disease (CAD) is a major cause of mortality internationally and in Pakistan. Angioplasty has been proven to be an effective treatment for CAD. Stent thrombosis is a known but preventable complication of angioplasty. Several factors may lead to stent thrombosis with non-compliance with the prescribed drug regimen, being one of the most important factors. We report a case of stent thrombosis after four months of angioplasty. After exploring of patient's post angioplasty routines, it was found that the patient was non-compliant with the prescribed anti- platelets and other prescribed drugs. This time the patient presented with another acute myocardial infarction, and he went through angioplasty again.

  8. Time course, predictors and clinical implications of stent thrombosis following primary angioplasty. Insights from the DESERT cooperation

    DEFF Research Database (Denmark)

    De Luca, Giuseppe; Dirksen, Maurits T; Spaulding, Christian;

    2013-01-01

    on the timing of stent thrombosis (ST) with both DES and bare metal stents (BMS) and its prognostic significance in patients undergoing pPCI. The Drug-Eluting Stent in Primary Angioplasty (DESERT) cooperation is based on a pooled database including individual data of randomised trials that evaluate the long...... angioplasty with BMS or DES. At 1201 ± 440 days, ST occurred in 267 patients (4.25%). Most of the events were acute or subacute (within 30 days) and very late (> 1 years), with different distribution between DES vs BMS. Patients with ST were more often diabetic (21.7% vs 15.1%, p=0.005), more frequently had...

  9. Preventive role of palladium-103 radioactive stent on in-stent restenosis in rabbit iliac arteries

    Institute of Scientific and Technical Information of China (English)

    LUO Quan-Yong; CHEN Li-Bo; YUAN Zhi-Bin; LU Han-Kui; ZHU Rui-Sen

    2005-01-01

    The abilility of γ-emitting palladium-103 stent implantation to inhibit in-stent restenosis in rabbit iliac arteries was investigated. Quantitative histomorphometry of the stented iliac segments 28 days after the implantation indicated that palladium-103 stents made a significant reduction in neointimal area and percent area stenosis compared with the nonradioactive stents. Lumen area in the palladium-103 stents treatment group was larger than the control group. However, the reduction of neointima formation by palladium-103 stents implantation was in a non-dose-dependent fashion. Low ionizing radiation doses via γ-emitting palladiurn-103 stent are effective in preventing neointimal hyperplasia in iliac arteries of rabbits. Palladium-103 stents can be employed as a possible novel means to prevent in-stent restenosis.

  10. Angioplasty and stent placement - carotid artery

    Science.gov (United States)

    Carotid angioplasty and stenting; CAS; Angioplasty - carotid artery; Carotid artery stenosis - angioplasty; ... Carotid angioplasty and stenting (CAS) is done using a small surgical cut. Your surgeon will make a surgical cut ...

  11. Recoil studies of photonuclear reactions at intermediate energies

    CERN Document Server

    Haba, H

    2002-01-01

    A review is given on the recoil studies of photonuclear reactions on complex nuclei at intermediate energies. Recoils of 167 radionuclides formed in the photonuclear reactions of sup 2 sup 7 Al, sup n sup a sup t V, sup n sup a sup t Cu, sup 9 sup 3 Nb, sup n sup a sup t Ag, sup n sup a sup t Ta, and sup 1 sup 9 sup 7 Au, induced by bremsstrahlung of end-point energies (E sub 0) from 600 to 1100 MeV, have been investigated by the thick-target thick-catcher method. The recoil velocity from the first step and the mean kinetic energy of the residual nuclei in the second step were deduced based on the two-step vector velocity model and discussed by comparing with the reported results on proton-induced reactions. Recoils of sup 2 sup 4 Na produced from sup 2 sup 7 Al, sup n sup a sup t V, sup n sup a sup t Cu, sup n sup a sup t Ag, and sup 1 sup 9 sup 7 Au are of special interest from a viewpoint of a change in the production mechanism with respect to target mass. Reaction yields of 58 and 63 radionuclides produce...

  12. Direct Measurement of Photon Recoil from a Levitated Nanoparticle.

    Science.gov (United States)

    Jain, Vijay; Gieseler, Jan; Moritz, Clemens; Dellago, Christoph; Quidant, Romain; Novotny, Lukas

    2016-06-17

    The momentum transfer between a photon and an object defines a fundamental limit for the precision with which the object can be measured. If the object oscillates at a frequency Ω_{0}, this measurement backaction adds quanta ℏΩ_{0} to the oscillator's energy at a rate Γ_{recoil}, a process called photon recoil heating, and sets bounds to coherence times in cavity optomechanical systems. Here, we use an optically levitated nanoparticle in ultrahigh vacuum to directly measure Γ_{recoil}. By means of a phase-sensitive feedback scheme, we cool the harmonic motion of the nanoparticle from ambient to microkelvin temperatures and measure its reheating rate under the influence of the radiation field. The recoil heating rate is measured for different particle sizes and for different excitation powers, without the need for cavity optics or cryogenic environments. The measurements are in quantitative agreement with theoretical predictions and provide valuable guidance for the realization of quantum ground-state cooling protocols and the measurement of ultrasmall forces. PMID:27367388

  13. Direct Measurement of Photon Recoil from a Levitated Nanoparticle

    Science.gov (United States)

    Jain, Vijay; Gieseler, Jan; Moritz, Clemens; Dellago, Christoph; Quidant, Romain; Novotny, Lukas

    2016-06-01

    The momentum transfer between a photon and an object defines a fundamental limit for the precision with which the object can be measured. If the object oscillates at a frequency Ω0 , this measurement backaction adds quanta ℏΩ0 to the oscillator's energy at a rate Γrecoil, a process called photon recoil heating, and sets bounds to coherence times in cavity optomechanical systems. Here, we use an optically levitated nanoparticle in ultrahigh vacuum to directly measure Γrecoil. By means of a phase-sensitive feedback scheme, we cool the harmonic motion of the nanoparticle from ambient to microkelvin temperatures and measure its reheating rate under the influence of the radiation field. The recoil heating rate is measured for different particle sizes and for different excitation powers, without the need for cavity optics or cryogenic environments. The measurements are in quantitative agreement with theoretical predictions and provide valuable guidance for the realization of quantum ground-state cooling protocols and the measurement of ultrasmall forces.

  14. Gravitational recoil: signatures on the massive black hole population

    CERN Document Server

    Volonteri, M

    2007-01-01

    In the last stages of a black hole merger, the binary can experience a recoil due to asymmetric emission of gravitational radiation. Recent numerical relativity simulations suggest that the recoil velocity can be as high as a few thousands kilometers per second for particular configurations. We consider here the effect of this worst case scenario on the hierarchical evolution of the massive black hole (MBH) population, where sensible values for binaries mass ratios and spins are assumed. The orbital configuration is chosen to be the one yielding the highest possible kick. We explore two routes for MBH formation which lead to different ejection histories: either that MBHs are the remnants of the first generation of stars, or that MBHs form by direct collapse. We show that the gravitational recoil does not pose a threat to the evolution of the MBH population that we observe locally in either case. The gravitational recoil is instead a real hazard for (i) MBHs in biased halos at high-redshift, where mergers are ...

  15. Exclusive ρ0 production measured with the HERMES recoil detector

    International Nuclear Information System (INIS)

    The Hermes experiment (HERa MEasurement of Spin) at Desy was designed to study the spin structure of the nucleon in semi-inclusive deep inelastic scattering. The internal structure of the nucleon has been investigated in detail and it has been measured that the intrinsic quark spin contribution is only about 30% of the total spin of the nucleon. A formalism to describe the internal structure of the nucleon called Generalised Patron Distributions (GPDs) was developed recently to understand the fundamental structure of the nucleon. These GPDs can be accessed by the measurement of hard exclusive reactions and hard exclusive processes that can be understood in terms of GPDs. The accumulated Hermes data offer access to GPDs in different combinations of beam charge and beam and target helicity asymmetries. To improve exclusivity and to enhance the resolution of kinematic variables to study hard exclusive processes which provide access to the GPDs and hence to the orbital angular momentum of the quarks, in January 2006 a Recoil Detector was installed that surrounded the internal gas target of the Hermes experiment. The Hermes Recoil Detector consisted of three components: a silicon strip detector inside the vacuum, a scintillating fiber tracker and the photon detector. All three detectors were located inside a solenoidal magnet which provided a 1T longitudinal magnetic field. The Recoil Detector improves the selection of exclusive events by a direct measurement of the momentum and track position of the recoiling particle as well as by rejecting non-exclusive background. This detector was an ideal novel tool to combine energy and position measurements for charged particles in a momentum range of 0.1 to 1.4 GeV/c. The Recoil Detector was fully commissioned and operating. Data was taken continuously until the final Hera shutdown in July of 2007. In this thesis we report on the performance of the Recoil Detector and more specifically about the scintillating fiber tracker

  16. Some Reactions of Recoil Atoms in Solid Inorganic Phosphorus Compounds

    International Nuclear Information System (INIS)

    In connection with our interest in the recoil chemistry of radiophosphorus it was considered worthwhile to investigate systems in which tritium recoils can be produced and subsequently react with inorganic anions of phosphorus. One purpose of this investigation was to evaluate the possibility for tritium recoils to replace (''displace'') either an oxygen or a hydrogen atom bound to phosphorus. For instance, oxygen replacement in an orthophosphate ion (PO4)-3 could lead to a (TPO3)-2 ion (phosphite), hydrogen replacement in hypophosphite could lead to (HTPO2). A number of lithium salts of orthophosphoric, phosphorous and hypophosphorous acid were irradiated with neutrons, the nuclear reaction Li6 (n, α)H3 serving as the source for the energetic tritium atoms. Through a step-wise oxidation procedure tritium bound to phosphorus was converted into HTO and radio-assayed by means of liquid scintillation counting. The results indicate that replacement of oxygen by tritium in orthophosphates is highly unlikely. When phosphites and hypophosphites are the target material, an appreciable percentage of the tritium recoils end up bound to phosphorus. The second purpose of this investigation was to determine to what extent the labelling of the tripolyphosphate - P32 anion, formed by recoiling P32 particles in a number of crystalline phosphates, deviates from a uniform distribution. A number of phosphates were irradiated with neutrons. The tripolyphosphate - P32 formed was separated by precipitation as the tris (ethylenediamine) cobalt (III) salt. By means of a step-wise degradation into orthophosphate the distribution of the P32 among the two possible positions in the anion was measured. One result of this study is that when anhydrous orthophosphates are the target material, there is as predicted, a strong preference for the tripolyphosphate - P32 formed to be labelled at the centre. These and other results are discussed in the light of current concepts of ''hot

  17. Visualization of stent lumen in MR imaging. Relationship with stent design and RF direction

    International Nuclear Information System (INIS)

    Magnetic resonance imaging (MRI) visualization of metallic stent lumens is possible if the stent structure counteracts eddy currents in the lumen induced by the radio frequency magnetic field, B1. To examine the effectiveness of various stent designs in counteracting eddy currents, we anchored eight copper stent models and 2 commercially available nickel-titanium alloy (Nitinol) stents in a gel phantom, perpendicular or parallel to the direction of B1. A mesh stent lumen showed hypointensity irrespective of its alignment relative to B1. A solenoid stent lumen showed hypointensity with the stent axis parallel to B1, but it had the same signal intensity as outside the lumen when perpendicular to B1. A Moebius stent lumen showed no signal reduction, irrespective of alignment relative to B1. Lumens of the commercially available stents showed hypointensity regardless of alignment relative to B1. Computer simulation revealed that the signal intensities of the stents corresponded to magnetic flux densities of B1 in the stents, which are modified by the structure of the stent. While in vivo MRI viewing of a Moebius stent lumen is likely possible regardless of axis alignment, inherent structural weakness may be problematic. As a more practical choice, the solenoid stent is easier to manufacture and generates no hypointensive signal when the axis is parallel to B0. (author)

  18. 21 CFR 884.3900 - Vaginal stent.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vaginal stent. 884.3900 Section 884.3900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES... stent. (a) Identification. A vaginal stent is a device used to enlarge the vagina by stretching, or...

  19. Incidence and predictors of coronary stent thrombosis

    DEFF Research Database (Denmark)

    D'Ascenzo, Fabrizio; Bollati, Mario; Clementi, Fabrizio;

    2013-01-01

    Stent thrombosis remains among the most feared complications of percutaneous coronary intervention (PCI) with stenting. However, data on its incidence and predictors are sparse and conflicting. We thus aimed to perform a collaborative systematic review on incidence and predictors of stent...... thrombosis....

  20. Metallic stent placement for the management of acute colorectal obstruction caused by colorectal carcinomas: its effect on scheduled surgery%急性结肠梗阻支架置入对结直肠癌择期手术的作用

    Institute of Scientific and Technical Information of China (English)

    曹燕; 刘冰妍; 茅爱武; 殷响; 高中度

    2011-01-01

    Objective To prospectively evaluate the safety and clinical efficacy of a newly designed self-expandable metallic stent ( SEMS ) placement in the treatment of patients with acute malignant colorectal obstruction due to colorectal carcinomas. Methods During the period from April 2001 to October 2007 , a total of 52 patients with acute malignant colorectal obstruction were treated with stent placement by using a new designed SEMS, which was employed as a preoperative transit means. All the patients were followed up and the relevant data, including technical success rate, clinical efficacy, complications and overall survival rate, were documented. The results were analyzed. Results Stent placement was successfully carried out in all patients except for two patients who showed complete colorectal obstruction. No procedure-related complications occurred. Technical success rate was 96% ( 50/52 ). Two days after the treatment,, the relief rate of colorectal obstruction was 98% ( 49/50 ). Postoperative complications included stent migration ( n =4 ), anal pain ( n = 2 ) and stool impaction ( n = 1 ). The stool impaction seen in one patient was successfully removed away with endoscopic manipulation two days after stent placement. An elective one-stage surgical procedure was performed in all 50 patients who successfully received a SEMS placement within a mean interval of ( 8 ± 2 ) days ( ranged 4 - 11 days ) after stent placement. Mean follow-up time was ( 36 ± 12 ) months with a range of ( 3 - 70 ) months. All patients remained alive at the time of this report. Conclusion The newly designed SEMS placement used as a preoperative transit means is a safe and effective intervention for colonic decompression in patients with acute malignant colorectal obstruction due to colorectal carcinomas.It can reliably ensure most of patients with colorectal carcinomas to successfully accomplish an elective surgery. ( J Intervent Radiol, 2011, 20 : 799-802 )%目的 探讨自膨胀金

  1. Geometrical deployment for braided stent.

    Science.gov (United States)

    Bouillot, Pierre; Brina, Olivier; Ouared, Rafik; Yilmaz, Hasan; Farhat, Mohamed; Erceg, Gorislav; Lovblad, Karl-Olof; Vargas, Maria Isabel; Kulcsar, Zsolt; Pereira, Vitor Mendes

    2016-05-01

    The prediction of flow diverter stent (FDS) implantation for the treatment of intracranial aneurysms (IAs) is being increasingly required for hemodynamic simulations and procedural planning. In this paper, a deployment model was developed based on geometrical properties of braided stents. The proposed mathematical description is first applied on idealized toroidal vessels demonstrating the stent shortening in curved vessels. It is subsequently generalized to patient specific vasculature predicting the position of the filaments along with the length and local porosity of the stent. In parallel, in-vitro and in-vivo FDS deployments were measured by contrast-enhanced cone beam CT (CBCT) in idealized and patient-specific geometries. These measurements showed a very good qualitative and quantitative agreement with the virtual deployments and provided experimental validations of the underlying geometrical assumptions. In particular, they highlighted the importance of the stent radius assessment in the accuracy of the deployment prediction. Thanks to its low computational cost, the proposed model is potentially implementable in clinical practice providing critical information for patient safety and treatment outcome assessment. PMID:26891065

  2. A Survey of Surface Modification Techniques for Next-Generation Shape Memory Polymer Stent Devices

    Directory of Open Access Journals (Sweden)

    Tina Govindarajan

    2014-08-01

    Full Text Available The search for a single material with ideal surface properties and necessary mechanical properties is on-going, especially with regard to cardiovascular stent materials. Since the majority of stent problems arise from surface issues rather than bulk material deficiencies, surface optimization of a material that already contains the necessary bulk properties is an active area of research. Polymers can be surface-modified using a variety of methods to increase hemocompatibilty by reducing either late-stage restenosis or acute thrombogenicity, or both. These modification methods can be extended to shape memory polymers (SMPs, in an effort to make these materials more surface compatible, based on the application. This review focuses on the role of surface modification of materials, mainly polymers, to improve the hemocompatibility of stent materials; additional discussion of other materials commonly used in stents is also provided. Although shape memory polymers are not yet extensively used for stents, they offer numerous benefits that may make them good candidates for next-generation stents. Surface modification techniques discussed here include roughening, patterning, chemical modification, and surface modification for biomolecule and drug delivery.

  3. Vascular response after implantation of coated and non-coated coronary stents

    NARCIS (Netherlands)

    S.H. Hofma (Sjoerd)

    2005-01-01

    textabstractHet doel van dit proefschrift was het bestuderen van de vaatwandreactie na interventies in de kransslagader. Hierbij werd gekeken naar acute en chronische vaatwandbeschadiging, endotheeldysfunctie en naar het gedrag van de nieuwste generatie stents, de zogenaamde “drug-eluting stents” (D

  4. A Multicenter, Prospective Study of a New Fully Covered Expandable Metal Biliary Stent for the Palliative Treatment of Malignant Bile Duct Obstruction

    Directory of Open Access Journals (Sweden)

    Bret T. Petersen

    2013-01-01

    Full Text Available Background and Study Aims. Endoscopic placement of self-expanding metal stents (SEMSs is indicated for palliation of inoperable malignant biliary obstruction. A fully covered biliary SEMS (WallFlex Biliary RX Boston Scientific, Natick, USA was assessed for palliation of extrahepatic malignant biliary obstruction. Patients and Methods. 58 patients were included in this prospective, multicenter series conducted under an FDA-approved IDE. Main outcome measurements included (1 absence of stent occlusion within six months or until death, whichever occurred first and (2 technical success, need for reintervention, bilirubin levels, stent patency, time to stent occlusion, and adverse events. Results. Technical success was achieved in 98% (57/58, with demonstrated acute removability in two patients. Adequate clinical palliation until completion of followup was achievedin 98% (54/55 of evaluable patients, with 1 reintervention due to stent obstruction after 142 days. Mean total bilirubin decreased from 8.9 mg/dL to 1.2 mg/dL at 1 month. Device-related adverse events were limited and included 2 cases of cholecystitis. One stent migrated following radiation therapy. Conclusions. The WallFlex Biliary fully covered stent yielded technically successful placement with uncomplicated acute removal where required, appropriate reduction in bilirubin levels, and low rates of stent migration and occlusion. This SEMS allows successful palliation of malignant extrahepatic biliary obstruction.

  5. "Virtual" in-vivo bench test for bifurcation stenting with "StentBoost".

    Science.gov (United States)

    Agostoni, Pierfrancesco; Verheye, Stefan; Vermeersch, Paul; Cornelis, Kristoff; Van Langenhove, Glenn

    2009-04-01

    "StentBoost" is a new angiographic technique that allows improved angiographic visualization of stents deployed in coronary arteries, by enhancing the X-ray focus of the region where the stent is placed. Using this technique we were able to assess the deformation and the expansion of a stent deployed to treat a bifurcation lesion between the mid-left anterior descending (LAD) artery and a big second diagonal branch, during sequential inflations of: (1) the stent per se in the LAD, (2) the ostium of the diagonal branch through the stent struts, (3) the stent again with a non compliant balloon, and (4) both branches with the kissing balloon technique. "StentBoost" guided our clinical and angiographic decision-making process and allowed us to create a "virtual" bench test of the stent deployed at the level of the bifurcation treated.

  6. Current Status of Biliary Metal Stents.

    Science.gov (United States)

    Nam, Hyeong Seok; Kang, Dae Hwan

    2016-03-01

    Many advances have been achieved in biliary stenting over the past 30 years. Endoscopic stent placement has become the primary management therapy to relieve obstruction in patients with benign or malignant biliary tract diseases. Compared with plastic stents, a self-expandable metallic stent (SEMS) has been used for management in patients with malignant strictures because of a larger lumen and longer stent patency. Recently, SEMS has been used for various benign biliary strictures and leaks. In this article, we briefly review the characteristics of SEMS as well as complications of stent placement. We review the current guidelines for managing malignant and benign biliary obstructions. Recent developments in biliary stenting are also discussed. PMID:26911896

  7. Recent Advances of Biliary Stent Management

    International Nuclear Information System (INIS)

    Recent progress in chemotherapy has prolonged the survival of patients with malignant biliary strictures, leading to increased rates of stent occlusion. Even we employed metallic stents which contributed to higher rates and longer durations of patency, and occlusion of covered metallic stents now occurs in about half of all patients during their survival. We investigated the complication and patency rate for the removal of covered metallic stents, and found that the durations were similar for initial stent placement and re-intervention. In order to preserve patient quality of life, we currently recommend the use of covered metallic stents for patients with malignant biliary obstruction because of their removability and longest patency duration, even though uncovered metallic stents have similar patency durations.

  8. Current Status of Biliary Metal Stents

    Science.gov (United States)

    Nam, Hyeong Seok; Kang, Dae Hwan

    2016-01-01

    Many advances have been achieved in biliary stenting over the past 30 years. Endoscopic stent placement has become the primary management therapy to relieve obstruction in patients with benign or malignant biliary tract diseases. Compared with plastic stents, a self-expandable metallic stent (SEMS) has been used for management in patients with malignant strictures because of a larger lumen and longer stent patency. Recently, SEMS has been used for various benign biliary strictures and leaks. In this article, we briefly review the characteristics of SEMS as well as complications of stent placement. We review the current guidelines for managing malignant and benign biliary obstructions. Recent developments in biliary stenting are also discussed. PMID:26911896

  9. Recent advances of biliary stent management.

    Science.gov (United States)

    Kida, Mitsuhiro; Miyazawa, Shiro; Iwai, Tomohisa; Ikeda, Hiroko; Takezawa, Miyoko; Kikuchi, Hidehiko; Watanabe, Maya; Imaizumi, Hiroshi; Koizumi, Wasaburo

    2012-01-01

    Recent progress in chemotherapy has prolonged the survival of patients with malignant biliary strictures, leading to increased rates of stent occlusion. Even we employed metallic stents which contributed to higher rates and longer durations of patency, and occlusion of covered metallic stents now occurs in about half of all patients during their survival. We investigated the complication and patency rate for the removal of covered metallic stents, and found that the durations were similar for initial stent placement and re-intervention. In order to preserve patient quality of life, we currently recommend the use of covered metallic stents for patients with malignant biliary obstruction because of their removability and longest patency duration, even though uncovered metallic stents have similar patency durations. PMID:22563289

  10. Stenting in Malignant Biliary Obstruction.

    Science.gov (United States)

    Almadi, Majid A; Barkun, Jeffrey S; Barkun, Alan N

    2015-10-01

    Decompression of the biliary system in patients with malignant biliary obstruction has been widely accepted and implemented as part of the care. Despite a wealth of literature, there remains a significant amount of uncertainty as to which approach would be most appropriate in different clinical settings. This review covers stenting of the biliary system in cases of resectable or palliative malignant biliary obstruction, potential candidates for biliary drainage, technical aspects of the procedure, as well as management of biliary stent dysfunction. Furthermore, periprocedural considerations including proper mapping of the location of obstruction and the use of antibiotics are addressed. PMID:26431598

  11. Indications for stenting during thrombolysis

    DEFF Research Database (Denmark)

    Bækgaard, N; Broholm, R; Just, Sven Richardt Lundgren

    2013-01-01

    The most important vein segment to thrombolyse after deep venous thrombosis (DVT) is the outflow tract meaning the iliofemoral vein. Iliofemoral DVT is defined as DVT in the iliac vein and the common femoral vein. Spontaneous recanalization is less than 50%, particularly on the left side...... with catheter-directed thrombolysis of iliofemoral deep venous thrombosis....... of a stent in this position is the treatment of choice facilitating the venous flow into an unobstructed outflow tract either from the femoral vein or the deep femoral vein or both. The stent, made of stainless steel or nitinol, has to be self-expandable and flexible with radial force to overcome...

  12. Comparison of short- and mid-term outcomes between CYPHER and TAXUS stents in patients with complex lesions of the coronary arteries

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Background Drug-eluting stent (DES) could obviously reduce in-stent restenosis, which has been proved by international multi-center clinical trials. However, the types of the lesions for stenting were highly selected in these trials. Up to now, there has been no large scale study on the effect of DES in treating complex lesions in real world. Although REALITY trial was just reported during American College of Cardiology Congress 2005, the entry criteria for lesions were limited to one or two de novo lesions. This study was conducted to compare the short- and mid-term clinical outcomes between sirolimus-eluting stent (CYPHER stent) and paclitaxel-eluting stent (TAXUS stent) in patients with complex lesion. Methods This is a retrospective study. From April 2002 to June 2004, a total of 1061 patients were treated with DES in Fu Wai Hospital, of which, 611 patients (642 lesions with 698 CYPHER stents) were in CYPHER group,and 450 patients (534 lesions with 600 TAXUS stents) were in TAXUS group. There was no significant difference in clinical data and lesion types between CYPHER group and TAXUS group. Results Success rates of stent implantation were 99.2% and 98.8% in CYPHER and TAXUS stent groups respectively. The major adverse cardiac events (MACE) during in-hospital and 6-8-month follow-up were 0.7% and 2.3% in CYPHER stent group versus 1.3% and 3.2% in TAXUS stent group. There was no significant difference in MACE rate between these two groups. Restenosis rate was a little higher in TAXUS stent group than that in CYPHER stent group (14.0% vs 7.3%), but there was no significant difference. The incidence of acute occlusion of side branch after implanting DES in main vessel was 6.9% in CYPHER group and 11.9% in TAXUS group(P<0.05).Conclusions CYPHER and TAXUS DES were safe and effective in patients with complex lesion. Clinical outcomes of CYPHER stent were better than TAXUS stent in bifurcation lesions. There was an increasing tendency in restenosis rate and late

  13. Percutaneous unilateral biliary metallic stent placement in patients with malignant obstruction of the biliary hila and contralateral portal vein steno-occlusion

    Energy Technology Data Exchange (ETDEWEB)

    Son, Rak Chae; Gwon, Dong Il; Ko, Heung Kyu; Kim, Jong Woo; Ko, Gi Young [Dept. of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2015-06-15

    To investigate the outcomes of percutaneous unilateral metallic stent placement in patients with a malignant obstruction of the biliary hila and a contralateral portal vein steno-occlusion. Sixty patients with a malignant hilar obstruction and unilobar portal vein steno-occlusion caused by tumor invasion or preoperative portal vein embolization were enrolled in this retrospective study from October 2010 to October 2013. All patients were treated with percutaneous placement of a biliary metallic stent, including expanded polytetrafluoroethylene (ePTFE)-covered stents in 27 patients and uncovered stents in 33 patients. A total of 70 stents were successfully placed in 60 patients. Procedural-related minor complications, including self-limiting hemobilia (n = 2) and cholangitis (n = 4) occurred in six (10%) patients. Acute cholecystitis occurred in two patients. Successful internal drainage was achieved in 54 (90%) of the 60 patients. According to a Kaplan-Meier analysis, median survival time was 210 days (95% confidence interval [CI], 135-284 days), and median stent patency time was 133 days (95% CI, 94-171 days). No significant difference in stent patency was observed between covered and uncovered stents (p = 0.646). Stent dysfunction occurred in 16 (29.6%) of 54 patients after a mean of 159 days (range, 65-321 days). Unilateral placement of ePTFE-covered and uncovered stents in the hepatic lobe with a patent portal vein is a safe and effective method for palliative treatment of patients with a contralateral portal vein steno-occlusion caused by an advanced hilar malignancy or portal vein embolization. No significant difference in stent patency was detected between covered and uncovered metallic stents.

  14. Percutaneous unilateral biliary metallic stent placement in patients with malignant obstruction of the biliary hila and contralateral portal vein steno-occlusion

    International Nuclear Information System (INIS)

    To investigate the outcomes of percutaneous unilateral metallic stent placement in patients with a malignant obstruction of the biliary hila and a contralateral portal vein steno-occlusion. Sixty patients with a malignant hilar obstruction and unilobar portal vein steno-occlusion caused by tumor invasion or preoperative portal vein embolization were enrolled in this retrospective study from October 2010 to October 2013. All patients were treated with percutaneous placement of a biliary metallic stent, including expanded polytetrafluoroethylene (ePTFE)-covered stents in 27 patients and uncovered stents in 33 patients. A total of 70 stents were successfully placed in 60 patients. Procedural-related minor complications, including self-limiting hemobilia (n = 2) and cholangitis (n = 4) occurred in six (10%) patients. Acute cholecystitis occurred in two patients. Successful internal drainage was achieved in 54 (90%) of the 60 patients. According to a Kaplan-Meier analysis, median survival time was 210 days (95% confidence interval [CI], 135-284 days), and median stent patency time was 133 days (95% CI, 94-171 days). No significant difference in stent patency was observed between covered and uncovered stents (p = 0.646). Stent dysfunction occurred in 16 (29.6%) of 54 patients after a mean of 159 days (range, 65-321 days). Unilateral placement of ePTFE-covered and uncovered stents in the hepatic lobe with a patent portal vein is a safe and effective method for palliative treatment of patients with a contralateral portal vein steno-occlusion caused by an advanced hilar malignancy or portal vein embolization. No significant difference in stent patency was detected between covered and uncovered metallic stents.

  15. Dynamical Formation of Horizons in Recoiling D Branes

    CERN Document Server

    Ellis, Jonathan Richard; Nanopoulos, Dimitri V; Ellis, John

    2000-01-01

    A toy calculation of string/D-particle interactions within a world-sheet approach indicates that quantum recoil effects - reflecting the gravitational back-reaction on space-time foam due to the propagation of energetic particles - induces the appearance of a microscopic event horizon, or `bubble', inside which stable matter can exist. The scattering event causes this horizon to expand, but we expect quantum effects to cause it to contract again, in a `bounce' solution. Within such `bubbles', massless matter propagates with an effective velocity that is less than the velocity of light in vacuo, which may lead to observable violations of Lorentz symmetry that may be tested experimentally. The conformal invariance conditions in the interior geometry of the bubbles select preferentially three for the number of the spatial dimensions, corresponding to a consistent formulation of the interaction of D3 branes with recoiling D particles, which are allowed to fluctuate independently only on the D3-brane hypersurface.

  16. Velocity distribution in recoil-distance Doppler-shift experiments

    International Nuclear Information System (INIS)

    The Recoil-Distance Doppler-Shift (RDDS) technique is a well established method to measure lifetimes of excited nuclear states in the pico-second range. In standard RDDS experiments at non-relativistc beam-energies, the velocities of the emerging recoils are usually distributed narrowly around a mean velocity v = left angle v right angle v. Under these circumstances, the effect of the velocity distribution is neglectable and the assumption that all nuclei move with the average velocity is justified. In this poster we investigate the influence of broader velocity distributions on lifetimes determined using the standard lifetime analysis-method DDCM. This can be observed, e.g., in experiments with thick targets. In particular, it is shown that the effect of the velocity distribution on the deduced lifetime is minimised at the maximum amplitude of the derivative of the decay function.

  17. Gravitational wave recoil in Robinson-Trautman spacetimes

    International Nuclear Information System (INIS)

    We consider the gravitational recoil due to nonreflection-symmetric gravitational wave emission in the context of axisymmetric Robinson-Trautman spacetimes. We show that regular initial data evolve generically into a final configuration corresponding to a Schwarzschild black hole moving with constant speed. For the case of (reflection-)symmetric initial configurations, the mass of the remnant black hole and the total energy radiated away are completely determined by the initial data, allowing us to obtain analytical expressions for some recent numerical results that have appeared in the literature. Moreover, by using the Galerkin spectral method to analyze the nonlinear regime of the Robinson-Trautman equations, we show that the recoil velocity can be estimated with good accuracy from some asymmetry measures (namely the first odd moments) of the initial data. The extension for the nonaxisymmetric case and the implications of our results for realistic situations involving head-on collision of two black holes are also discussed.

  18. Elastic recoil detection analysis of hydrogen in polymers

    Energy Technology Data Exchange (ETDEWEB)

    Winzell, T.R.H.; Whitlow, H.J. [Lund Univ. (Sweden); Bubb, I.F.; Short, R.; Johnston, P.N. [Royal Melbourne Inst. of Tech., VIC (Australia)

    1996-12-31

    Elastic recoil detection analysis (ERDA) of hydrogen in thick polymeric films has been performed using 2.5 MeV He{sup 2+} ions from the tandem accelerator at the Royal Melbourne Institute of Technology. The technique enables the use of the same equipment as in Rutherford backscattering analysis, but instead of detecting the incident backscattered ion, the lighter recoiled ion is detected at a small forward angle. The purpose of this work is to investigate how selected polymers react when irradiated by helium ions. The polymers are to be evaluated for their suitability as reference standards for hydrogen depth profiling. Films investigated were Du Pont`s Kapton and Mylar, and polystyrene. 11 refs., 3 figs.

  19. Drug eluting biliary stents to decrease stent failure rates: Areview of the literature

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    Biliary stenting is clinically effective in relieving bothmalignant and non-malignant obstructions. However, thereare high failure rates associated with tumor ingrowth andepithelial overgrowth as well as internally from biofilmdevelopment and subsequent clogging. Within the lastdecade, the use of prophylactic drug eluting stents as ameans to reduce stent failure has been investigated. Inthis review we provide an overview of the current researchon drug eluting biliary stents. While there is limited humantrial data regarding the clinical benefit of drug elutingbiliary stents in preventing stent obstruction, recentresearch suggests promise regarding their safety andpotential efficacy.

  20. A case report of very late stent thrombosis after bare-metal stent implantation

    Directory of Open Access Journals (Sweden)

    Mustafa Adem Tatlısu

    2014-03-01

    Full Text Available Stent thrombosis is undesirable complication after percutaneous coronary interventions (PCI, despite contemporary concepts of stents and antiplatelet therapy. Stent thrombosis (ST is defined by the Academic Research Concortium as: early (1 year. Risk of very late stent thrombosis is considerably higher in patients with drug-eluting stents (DES, owing to delayed endothelialization. There are several cases very late ST after bare-metal stent (BMS implantation. Our patient presented with ST-elevation myocardial infarction on account of BMS thrombosis 14 years after the implantation.

  1. Recoil Correction to Hydrogen Energy Levels A Revision

    CERN Document Server

    Yelkhovsky, A S

    1997-01-01

    Recent calculations of the order (Z\\alpha)^4(m/M)Ry pure recoil correction to hydrogen energy levels are critically revised. The origins of errors made in the previous works are elucidated. In the framework of a successive approach, we obtain the new result for the correction to S levels. It amounts to -16.4 kHz in the ground state and -1.9 kHz in the 2S state.

  2. The median recoil direction as a WIMP directional detection signal

    OpenAIRE

    Green, Anne M; MORGAN, BEN

    2010-01-01

    Direct detection experiments have reached the sensitivity required to detect dark matter WIMPs. Demonstrating that a putative signal is due to WIMPs, and not backgrounds, is a major challenge however. The direction dependence of the WIMP scattering rate provides a potential WIMP `smoking gun'. If the WIMP distribution is predominantly smooth, the Galactic recoil distribution is peaked in the direction opposite to the direction of Solar motion. Previous studies have found that, for an ideal de...

  3. Recoiled Proton Tagged Knockout Reaction for 8He

    Institute of Scientific and Technical Information of China (English)

    曹中鑫; 叶沿林; 江栋兴; 郑涛; 李智焕; 华辉; 葛榆成; 李湘庆; 楼建玲; 肖军; 李奇特; 吕林辉; 李阔昂; 王赫; 乔锐; 游海波; 陈瑞九

    2012-01-01

    An experiment for knockout reaction induced by SHe beam at 82.5 MeV/nucleon on CH2 and C targets was carried out. The 6He and 4He core fragments at forward angles and the recoiled protons at large angles were detected coincidently. From this exclusive measurement the valence nucleon knockout mechanism and the core knockout mechanism are separated, which can be applied to the exclusive spectroscopic study on the structure of exotic nuclei.

  4. Three dimensional momentum distributions of recoil-ions and photoelectrons

    Energy Technology Data Exchange (ETDEWEB)

    Ullrich, J.; Schmitt, W. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Doerner, R.; Jagutzki, O.; Mergel, V.; Moshammer, R.; Schmidt-Boecking, H.; Spielberger, L.; Unverzagt, M.; Vogt, T. [Frankfurt Univ. (Germany). Inst. fuer Kernphysik

    1996-10-01

    A novel high-resolution technique, the Multi-Electron-Recoil-Ion Momentum Spectroscopy, allows to determine in coincidence the three dimensional momentum vectors of the ion and up to three electrons created in any photo ionization event. At a solid angle of 4 {pi} the energy-resolutions for ions and electrons are {+-}2{mu} eV and {+-}10 meV, respectively. (orig.)

  5. Discrimination of nuclear recoils from alpha particles with superheated liquids

    Energy Technology Data Exchange (ETDEWEB)

    Aubin, F; Auger, M; Genest, M-H; Giroux, G; Gornea, R; Faust, R; Leroy, C; Lessard, L; Martin, J-P; Morlat, T; Piro, M-C; Starinski, N; Zacek, V [Departement de Physique, Universite de Montreal, Montreal, H3C 3J7 (Canada); Beltran, B; Krauss, C B [Department of Physics, University of Alberta, Edmonton, T6G 2G7 (Canada); Behnke, E; Levine, I; Shepherd, T [Department of Physics and Astronomy, Indiana University South Bend, South Bend, IN 46634 (United States); Nadeau, P; Wichoski, U [Department of Physics, Laurentian University, Sudbury, P3E 2C6 (Canada)], E-mail: zacekv@lps.umontreal.ca (and others)

    2008-10-15

    The PICASSO collaboration observed for the first time a significant difference between the acoustic signals induced by neutrons and alpha particles in a detector based on superheated liquids. This new discovery offers the possibility of improved background suppression and could be especially useful for dark matter experiments. This new effect may be attributed to the formation of multiple bubbles on alpha tracks, compared to single nucleations created by neutron-induced recoils.

  6. B -> K(*) l+ l- @ Low Recoil and Physics Implications

    OpenAIRE

    Hiller, Gudrun

    2013-01-01

    This talk covers recent theoretical progress in exclusive semileptonic rare B-decays at low hadronic recoil. The efficient parametric suppression of the 1/mb corrections in this region provides opportunities to probe the Standard Model and beyond at precision level. Notably, angular analysis allows to simultaneously access electroweak flavor physics and hadronic matrix elements, the latter of which constitute the leading source of theoretical uncertainty. Ratios of B ->K* form factors can alr...

  7. Spallation recoil and age of presolar grains in meteorites

    Science.gov (United States)

    Ott, U.; Begemann, F.

    2000-01-01

    We have determined the recoil losses from silicon carbide grain size fractions of spallation neon produced by irradiation with 1.6 GeV protons. During the irradiation the SiC grains were dispersed in paraffin wax in order to avoid re-implantation into neighboring grains. Analysis for spallogenic 21Ne of grain size separates in the size range 0.3 μm to 6 μm and comparison with the 22Na activity of the SiC+paraffin mixture indicates an effective recoil range of 2-3 μm with no apparent effect from acid treatments such as routinely used in the isolation of meteoritic SiC grains. Our results indicate that the majority of presolar SiC grains in primitive meteorites, which are ~μm-sized, will have lost essentially all spallogenic Ne produced by cosmic ray interaction in the interstellar medium. This argues against the validity of previously published presolar ages of Murchison SiC (~10 to ~130 Ma; increasing with grain size; Lewis et al., 1994), where recoil losses had been based on calculated recoil energies. It is argued that the observed variations in meteoritic SiC grain size fractions of 21Ne/22Ne ratios are more likely due to the effects of nucleosynthesis in the He burning shell of the parent AGB stars which imposes new boundary conditions on nuclear parameters and stellar models. It is suggested that spallation-Xe produced on the abundant Ba and REE in presolar SiC, rather than spallogenic Ne, may be a promising approach to the presolar age problem. There is a hint in the currently available Xe data (Lewis et al., 1994) that the large (>1 μm) grains may be younger than the smaller (<1 μm) ones.

  8. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... such as non-cue wave heart attacks and myocardial infarctions, I think they need to be intervened upon. There is no question about that. People who have having an acute heart attack there is absolutely no question they ...

  9. An in Vitro Twist Fatigue Test of Fabric Stent-Grafts Supported by Z-Stents vs. Ringed Stents

    Directory of Open Access Journals (Sweden)

    Jing Lin

    2016-02-01

    Full Text Available Whereas buckling can cause type III endoleaks, long-term twisting of a stent-graft was investigated here as a mechanism leading to type V endoleak or endotension. Two experimental device designs supported with Z-stents having strut angles of 35° or 45° were compared to a ringed control under accelerated twisting. Damage to each device was assessed and compared after different durations of twisting, with focus on damage that may allow leakage. Stent-grafts with 35° Z-stents had the most severe distortion and damage to the graft fabric. The 45° Z-stents caused less fabric damage. However, consistent stretching was still seen around the holes for sutures, which attach the stents to the graft fabric. Larger holes may become channels for fluid percolation through the wall. The ringed stent-graft had the least damage observed. Stent apexes with sharp angles appear to be responsible for major damage to the fabrics. Device manufacturers should consider stent apex angle when designing stent-grafts, and ensure their devices are resistant to twisting.

  10. The recoil proton polarization in. pi. p elastic scattering

    Energy Technology Data Exchange (ETDEWEB)

    Seftor, C.J.

    1988-09-01

    The polarization of the recoil proton for ..pi../sup +/p and ..pi../sup -/p elastic scattering has been measured for various angles at 547 MeV/c and 625 MeV/c by a collaboration involving The George Washington University; the University of California, Los Angeles; and Abilene Christian University. The experiment was performed at the P/sup 3/ East experimental area of the Los Alamos Meson Physics Facility. Beam intensities varied from 0.4 to 1.0 x 10/sup 7/ ..pi../sup -/'s/sec and from 3.0 to 10.0 x 10/sup 7/ ..pi../sup +/'s/sec. The beam spot size at the target was 1 cm in the horizontal direction by 2.5 cm in the vertical direction. A liquid-hydrogen target was used in a flask 5.7 cm in diameter and 10 cm high. The scattered pion and recoil proton were detected in coincidence using the Large Acceptance Spectrometer (LAS) to detect and momentum analyze the pions and the JANUS recoil proton polarimeter to detect and measure the polarization of the protons. Results from this experiment are compared with previous measurements of the polarization, with analyzing power data previously taken by this group, and to partial-wave analysis predictions. 12 refs., 53 figs., 18 tabs.

  11. Anatomy of the Binary Black Hole Recoil: A Multipolar Analysis

    Science.gov (United States)

    Schnittman, Jeremy; Buonanno, Alessandra; vanMeter, James R.; Baker, John G.; Boggs, William D.; Centrella, Joan; Kelly, Bernard J.; McWilliams, Sean T.

    2007-01-01

    We present a multipolar analysis of the recoil velocity computed in recent numerical simulations of binary black hole coalescence, for both unequal masses and non-zero, non-precessing spins. We show that multipole moments up to and including 1 = 4 are sufficient to accurately reproduce the final recoil velocity (= 98%) and that only a few dominant modes contribute significantly to it (2 95%). We describe how the relative amplitude, and more importantly, the relative phase, of these few modes control the way in which the recoil builds up throughout the inspiral, merger, and ring-down phases. We also find that the numerical results can be reproduced, to a high level of accuracy, by an effective Newtonian formula for the multipole moments obtained by replacing in the Newtonian formula the radial separation with an effective radius computed from the numerical data. Beyond the merger, the numerical results are reproduced by a superposition of three Kerr quasi-normal modes. Analytic formulae, obtained by expressing the multipole moments in terms of the fundamental QNMs of a Kerr BH, are able to explain the onset and amount of '.anti-kick" for each of the simulations. Lastly, we apply this multipolar analysis to understand the remarkable difference between the amplitudes of planar and non-planar kicks for equal-mass spinning black holes.

  12. Recoiling Black Holes: Electromagnetic Signatures, Candidates, and Astrophysical Implications

    Directory of Open Access Journals (Sweden)

    S. Komossa

    2012-01-01

    Full Text Available Supermassive black holes (SMBHs may not always reside right at the centers of their host galaxies. This is a prediction of numerical relativity simulations, which imply that the newly formed single SMBH, after binary coalescence in a galaxy merger, can receive kick velocities up to several 1000 km/s due to anisotropic emission of gravitational waves. Long-lived oscillations of the SMBHs in galaxy cores, and in rare cases even SMBH ejections from their host galaxies, are the consequence. Observationally, accreting recoiling SMBHs would appear as quasars spatially and/or kinematically offset from their host galaxies. The presence of the “kicks” has a wide range of astrophysical implications which only now are beginning to be explored, including consequences for black hole and galaxy assembly at the epoch of structure formation, black hole feeding, and unified models of active galactic nuclei (AGN. Here, we review the observational signatures of recoiling SMBHs and the properties of the first candidates which have emerged, including follow-up studies of the candidate recoiling SMBH of SDSSJ092712.65+294344.0.

  13. The recoil proton polarization in πp elastic scattering

    International Nuclear Information System (INIS)

    The polarization of the recoil proton for π+p and π-p elastic scattering has been measured for various angles at 547 MeV/c and 625 MeV/c by a collaboration involving The George Washington University; the University of California, Los Angeles; and Abilene Christian University. The experiment was performed at the P3 East experimental area of the Los Alamos Meson Physics Facility. Beam intensities varied from 0.4 to 1.0 x 107 π-'s/sec and from 3.0 to 10.0 x 107 π+'s/sec. The beam spot size at the target was 1 cm in the horizontal direction by 2.5 cm in the vertical direction. A liquid-hydrogen target was used in a flask 5.7 cm in diameter and 10 cm high. The scattered pion and recoil proton were detected in coincidence using the Large Acceptance Spectrometer (LAS) to detect and momentum analyze the pions and the JANUS recoil proton polarimeter to detect and measure the polarization of the protons. Results from this experiment are compared with previous measurements of the polarization, with analyzing power data previously taken by this group, and to partial-wave analysis predictions. 12 refs., 53 figs., 18 tabs

  14. Carotid Artery Stenting Successfully Prevents Progressive Stroke Due to Mobile Plaque

    Directory of Open Access Journals (Sweden)

    Masahiro Oomura

    2015-05-01

    Full Text Available We report a case of progressive ischemic stroke due to a mobile plaque, in which carotid artery stenting successfully prevented further infarctions. A 78-year-old man developed acute multiple infarcts in the right hemisphere, and a duplex ultrasound showed a mobile plaque involving the bifurcation of the left common carotid artery. Maximal medical therapy failed to prevent further infarcts, and the number of infarcts increased with his neurological deterioration. Our present case suggests that the deployment of a closed-cell stent is effective to prevent the progression of the ischemic stroke due to the mobile plaque.

  15. Successful retrieval of an unexpanded coronary stent from the left main coronary artery during primary percutaneous coronary intervention

    Directory of Open Access Journals (Sweden)

    Šalinger-Martinović Sonja

    2011-01-01

    Full Text Available Introduction. Dislodgement and embolization of the new generation of coronary stents before their deployment are rare but could constitute a very serious complication. Case Outline. We report a case of a stent dislodgement into the left main coronary artery during the primary coronary intervention of infarct related left circumflex artery in a patient with acute myocardial infarction. The dislodged and unexpanded bare-metal stent FlexMaster 3.0x19 mm (Abbot Vascular was stranded and bended in the left main coronary artery (LMCA, probably by the tip of the guiding catheter, but stayed over the guidewire. It was successfully retrieved using a low-profile Ryujin 1.25x15 balloon catheter (Terumo that was passed through the stent, inflated and then pulled back into the guiding catheter. After that, the whole system was withdrawn through the 6 F arterial sheath via the transfemoral approach. After repeated cannulation via the 6F arterial sheath, additional BMW and ATW guidewires were introduced into the posterolateral and obtuse marginal branches and a bare-metal stent Driver (Medtronic Cardiovascular Inc 3.0x18 mm was implanted in the target lesion. Conclusion. Stent dislodgement is a rare but potentially life-threatening complication of the percutaneous coronary intervention. This incident occurring in the LMCA in particular during an acute myocardial infarction requires to be urgently resolved. The avoidance of rough manipulation with the guiding catheter and delivery system may help in preventing this kind of complications.

  16. Polymeric Biodegradable Stent Insertion in the Esophagus

    Directory of Open Access Journals (Sweden)

    Kai Yang

    2016-04-01

    Full Text Available Esophageal stent insertion has been used as a well-accepted and effective alternative to manage and improve the quality of life for patients diagnosed with esophageal diseases and disorders. Current stents are either permanent or temporary and are fabricated from either metal or plastic. The partially covered self-expanding metal stent (SEMS has a firm anchoring effect and prevent stent migration, however, the hyperplastic tissue reaction cause stent restenosis and make it difficult to remove. A fully covered SEMS and self-expanding plastic stent (SEPS reduced reactive hyperplasia but has a high migration rate. The main advantage that polymeric biodegradable stents (BDSs have over metal or plastic stents is that removal is not require and reduce the need for repeated stent insertion. But the slightly lower radial force of BDS may be its main shortcoming and a post-implant problem. Thus, strengthening support of BDS is a content of the research in the future. BDSs are often temporarily effective in esophageal stricture to relieve dysphagia. In the future, it can be expect that biodegradable drug-eluting stents (DES will be available to treat benign esophageal stricture, perforations or leaks with additional use as palliative modalities for treating malignant esophageal stricture, as the bridge to surgery or to maintain luminal patency during neoadjuvant chemoradiation.

  17. Treatment of malignant and benign biliary obstructions with metal stents

    International Nuclear Information System (INIS)

    The palliative treatment of malignant bilary tract obstructions using a metal stent is now an established procedure in clinical practice. An endoscopic, transpapillary approach is the first choice for implantation of the stent. If it is not possible to insert the stent in this way, which is often the case with high obstructions, a percutaneous approach is chosen. It appears to be beneficial to use a metal stent with a finemeshed net such as, for example, the Wall stent. Metal stents have a higher patency rate than plastic stents so that the primary choice of a metal stent is justified. Coated stents have not yet shown any major advantages. In cases of stent occlusion the coaxial implantation of a plastic stent seems to be the most efficient. In cases of benign biliary tract stenoses, a metal stent should only be implanted after a careful evaluation of all possible surgical modalities and exploitation of balloon dilatation and long-term splinting methods. (orig.)

  18. 支架内再狭窄的机制及防治进展%Mechanism of In-stent Restenosis and Progress of the Prevention and Treatment

    Institute of Scientific and Technical Information of China (English)

    刘雯

    2012-01-01

    In-stent restenosis is an important medical problem of coronary atherosclerotic heart disease ( coronary disease for short intervention. Its main mechanism includes: elastic recoil of vessels, formation of thrombus,hyperplasia of smooth muscle and inflammatory reaction and so on. According to the main mechanism there are several methods to prevent stent restenosis including antiplatelet drugs,drug-eluting stents and new material stents and so on. Here is to summarize the main mechanism and the progress of prevention and treatment of in-stent restenosis.%支架内再狭窄是冠状动脉粥样硬化性心脏病介入治疗技术中面临的重要医学难题.目前研究其主要发生机制有血管弹性回缩、血栓形成、平滑肌过度增生和炎性反应等.针对其主要机制的防治支架内再狭窄的方法有抗血小板药物的使用、药物涂层支架的使用和新型材料支架的使用等.现就支架内再狭窄发生机制及防治进展予以综述.

  19. Clinical safety and efficacy of a next-generation stent-graft device for thoracic endovascular aortic repair.

    Science.gov (United States)

    Eggebrecht, Holger; Schmermund, Axel; Voigtländer, Thomas

    2013-01-01

    Thoracic endovascular aortic repair has significantly improved the treatment of patients with acute and chronic diseases of the descending thoracic aorta. Retrograde transarterial implantation of a membrane-covered stent graft aims at excluding the aortic pathology at risk for complications (e.g., aneurysm, dissection) from the circulation to prevent expansion and ultimately rupture. Today, several stent grafts from different manufacturers are approved by the respective authorities and thus commercially available. The Medtronic Talent® stent graft used to be one of the initially available devices and has been broadly used to become the world-wide market leader at its time. In 2005, it has been replaced by the second-generation Medtronic Valiant® device, which features several technical improvements. In this article, we evaluate a recent publication investigating the clinical performance of this second-generation stent graft device, and discuss the results in the view of the current literature and developments. PMID:23259442

  20. Evaluation of a novel stent technology: the Genous EPC capturing stent

    NARCIS (Netherlands)

    M. Klomp

    2012-01-01

    Tegenwoordig gebruiken ziekenhuizen een nieuwe stent bij dotterbehandelingen van kransslagadervernauwingen. Deze Genous-stent heeft een laag met antistoffen waardoor het behandelde bloedvat snel bedekt raakt met lichaamseigen cellen. Zo wordt tegengegaan dat er opnieuw een vernauwing optreedt of dat

  1. An Evaluation of Magneto Rheological Dampers for Controlling Gun Recoil Dynamics

    Directory of Open Access Journals (Sweden)

    Mehdi Ahmadian

    2001-01-01

    Full Text Available The application of magneto rheological dampers for controlling recoil dynamics is examined, using a recoil demonstrator that includes a single-shot 50 caliber BMG rifle action and a MR damper. The demonstrator is selected such that it can adequately represent the velocities that commonly occur in weapons with a recoil system, and can be used for collecting data for analyzing the effects of MR dampers on recoil dynamics. The MR damper is designed so that it can work effectively at the large velocities commonly occurring in gun recoil, and also be easily adjusted to reasonably optimize the damper performance for the recoil demonstrator. The test results show that it is indeed possible to design and use MR dampers for recoil applications, which subject the damper to relative velocities far larger than the applications that such dampers have commonly been used for (i.e., vehicle applications. Further, the results indicate that the recoil force increases and the recoil stroke decreases nonlinearly with an increase in the damping force. Also of significance is the fact that the adjustability of MR dampers can be used in a closed-loop system such that the large recoil forces that commonly occur upon firing the gun are avoided and, simultaneously, the recoil stroke is reduced. This study points to the need for several areas of research including establishing the performance capabilities for MR dampers for gun recoil applications in an exact manner, and the potential use of such dampers for a fire out of battery recoil system.

  2. Influence of strut cross-section of stents on local hemodynamics in stented arteries

    Science.gov (United States)

    Jiang, Yongfei; Zhang, Jun; Zhao, Wanhua

    2016-05-01

    Stenting is a very effective treatment for stenotic vascular diseases, but vascular geometries altered by stent implantation may lead to flow disturbances which play an important role in the initiation and progression of restenosis, especially in the near wall in stented arterial regions. So stent designs have become one of the indispensable factors needed to be considered for reducing the flow disturbances. In this paper, the structural designs of strut cross-section are considered as an aspect of stent designs to be studied in details. Six virtual stents with different strut cross-section are designed for deployments in the same ideal arterial model. Computational fluid dynamics (CFD) methods are performed to study how the shape and the aspect ratio (AR) of strut cross-section modified the local hemodynamics in the stented segments. The results indicate that stents with different strut cross-sections have different influence on the hemodynamics. Stents with streamlined cross-sectional struts for circular arc or elliptical arc can significantly enhance wall shear stress (WSS) in the stented segments, and reduce the flow disturbances around stent struts. The performances of stents with streamlined cross-sectional struts are better than that of stents with non-streamlined cross-sectional struts for rectangle. The results also show that stents with a larger AR cross-section are more conductive to improve the blood flow. The present study provides an understanding of the flow physics in the vicinity of stent struts and indicates that the shape and AR of strut cross-section ought to be considered as important factors to minimize flow disturbance in stent designs.

  3. Rapid virtual stenting for intracranial aneurysms

    Science.gov (United States)

    Zhao, Liang; Chen, Danyang; Chen, Zihe; Wang, Xiangyu; Paliwal, Nikhil; Xiang, Jianping; Meng, Hui; Corso, Jason J.; Xu, Jinhui

    2016-03-01

    The rupture of Intracranial Aneurysms is the most severe form of stroke with high rates of mortality and disability. One of its primary treatments is to use stent or Flow Diverter to divert the blood flow away from the IA in a minimal invasive manner. To optimize such treatments, it is desirable to provide an automatic tool for virtual stenting before its actual implantation. In this paper, we propose a novel method, called ball-sweeping, for rapid virtual stenting. Our method sweeps a maximum inscribed sphere through the aneurysmal region of the vessel and directly generates a stent surface touching the vessel wall without needing to iteratively grow a deformable stent surface. Our resulting stent mesh has guaranteed smoothness and variable pore density to achieve an enhanced occlusion performance. Comparing to existing methods, our technique is computationally much more efficient.

  4. Esophageal stent migration leads to intestinal obstruction

    Directory of Open Access Journals (Sweden)

    Oguzhan Karatepe

    2009-07-01

    Full Text Available Background: Self-expanding metallic stents are the devices of choice in the treatment of malign or benign strictures of esophagus. Stent migration is a well-known complication of this procedure. Aims: We report a case of intestinal obstruction caused by esophageal stent migration, in which surgical intervention was used. Methods: A 65-year-old woman, who had a medical history of gastric cancer operation and esophageal stent application admitted to our emergeny department with a 48-hour history of abdominal pain, nausea and vomiting. An emergeny laparotomy was performed and the migrated stent leading to intestinal obstruction was removed. Results: The patient recovered without incident and was discharged on postoperative day 3. Conclusion: This case illustrates that esophageal stent migration has to be considered as a potential life-threatening complication.

  5. Mechanical behavior of peripheral stents and stent-vessel interaction: A computational study

    Science.gov (United States)

    Dottori, Serena; Flamini, Vittoria; Vairo, Giuseppe

    2016-05-01

    In this paper stents employed to treat peripheral artery disease are analyzed through a three-dimensional finite-element approach, based on a large-strain and large-displacement formulation. Aiming to evaluate the influence of some stent design parameters on stent mechanics and on the biomechanical interaction between stent and arterial wall, quasi-static and dynamic numerical analyses are carried out by referring to computational models of commercially and noncommercially available versions of both braided self-expandable stents and balloon-expandable stents. Addressing isolated device models, opening mechanisms and flexibility of both opened and closed stent configurations are numerically experienced. Moreover, stent deployment into a stenotic peripheral artery and possible postdilatation angioplasty (the latter for the self-expandable device only) are simulated by considering different idealized vessel geometries and accounting for the presence of a stenotic plaque. Proposed results highlight important differences in the mechanical response of the two types of stents, as well as a significant influence of the vessel shape on the stress distributions arising upon the artery-plaque system. Finally, computational results are used to assess both the stent mechanical performance and the effectiveness of the stenting treatment, allowing also to identify possible critical conditions affecting the risk of stent fracture, tissue damage, and/or pathological tissue response.

  6. Hypersensitivity to drug-eluting stent and stent thrombosis: Kounis or not Kounis syndrome?

    Institute of Scientific and Technical Information of China (English)

    TAN Wei; CHENG Kang-lin; CHEN Qiu-xiong

    2009-01-01

    @@ With the utilization of coronary-stents, coronary remodeling and restenosis were reduced compared with balloon angioplasty alone.~1 However, the risk of restenosis is still in the range of 15% to 20%. Drug-eluting stents (DES), which could release antiproliferative pharmacological agents after deployment. were designed to inhibit the response to injury reaction after bare-metal stent (BMS) implantation.

  7. [Immediate and remote results of stenting of left coronary artery trunk in patients with ischemic heart disease].

    Science.gov (United States)

    Bokeriia, L A; Alekian, B G; Buziashvili, Iu I; Golukhova, E Z; Staferov, A V; Zakarian, N V; Al-Sharjabi, R M

    2006-01-01

    The aim of this investigation was assessment of efficacy of stenting in patients with ischemic heart disease with lesions of left coronary artery (LCA) trunk. In the A.N. Bakulev Scientific Center of Cardiovascular Surgery between June 1997 and March 2005 stenting of LCA trunk was carried out in 50 patients (33 with stable effort angina and 17 with acute coronary syndrome). Immediate success rate was 100% in patients with stable angina. In a group of patients with acute coronary syndrome angiographic success rate was 100%. Total lethality in this group was (3 cases) 17.7%. In remote period (6 to 60 months) 33 of 39 patients were examined and recurrence of angina was noted in 7 of them (21.1%). Control angiography was carried out in 16 patients and restenosis of LCA was revealed in 18.75% of cases. The authors believe that stenting of LCA trunk is an effective and safe method of treatment of patients with stable angina and sufficiently safe method in patients with acute coronary syndrome. Roentgenoendovascular treatment may serve as an alternative to aortocoronary bypass surgery especially in isolated lesions of LCA trunk. Application of stents with drug coating allows to cardinally improve long term results of stenting. PMID:16710248

  8. Stent implantation influence wall shear stress evolution

    Science.gov (United States)

    Bernad, S. I.; Totorean, A. F.; Bosioc, A. I.; Petre, I.; Bernad, E. S.

    2016-06-01

    Local hemodynamic factors are known affect the natural history of the restenosis critically after coronary stenting of atherosclerosis. Stent-induced flows disturbance magnitude dependent directly on the strut design. The impact of flow alterations around struts vary as the strut geometrical parameters change. Our results provide data regarding the hemodynamic parameters for the blood flow in both stenosed and stented coronary artery under physiological conditions, namely wall shear stress and pressure drop.

  9. Photodynamic therapy for occluded biliary metal stents

    Science.gov (United States)

    Roche, Joseph V. E.; Krasner, Neville; Sturgess, R.

    1999-02-01

    In this abstract we describe the use of photodynamic therapy (PDT) to recanalize occluded biliary metal stents. In patients with jaundice secondary to obstructed metal stents PDT was carried out 72 hours after the administration of m THPC. Red laser light at 652 nm was delivered endoscopically at an energy intensity of 50 J/cm. A week later endoscopic retrograde cholangiogram showed complete recanalization of the metal stent.

  10. Basic Knowledge about Metal Stent Development

    OpenAIRE

    Jeong, Seok

    2016-01-01

    Biliary self-expandable metal stents (SEMS), a group of non-vascular stents, have been used in the palliative management of biliary obstruction around the world. However, there are still unmet needs in the clinical application of biliary SEMS. Comprehensive understanding of the SEMS is required to resolve the drawbacks and difficulties of metal stent development. The basic structure of SEMS, including the materials and knitting methods of metal wires, covering materials, and radiopaque marker...

  11. Assessment of Coronary Stents by 64-slice Computed Tomography:In-stent Lumen Visibility and Patency

    Institute of Scientific and Technical Information of China (English)

    Ling-yan Kong; Zheng-yu Jin; Shu-yang Zhang; Zhu-hua Zhang; Yi-ning Wang; Lan Song; Xiao-na Zhang; Yun-qing Zhang

    2009-01-01

    Objective To assess lumen visibility of coronary stents by 64-slice computed tomography(CT)coronary angiography,and determine the value of 64-slice CT in non-invasive detecting of in-stent restenosis after coronary artery stent implantation.Methods Totally,60 patients(54 males,aged 57.0±12.7 years)and 105 stents were investigated by 64-slice CT at a mean interval of 20.0±16.6 months after coronary stents implantation.Axial multi-planar reconstruction images of the stents and curved-planar reconstruction images through the median of the stents were reconstructed for evaluating stent image quality on a 5-point scale(1=excellent,5=nonassessable),and stent lumen diameter was detected.Conventional coronary angiography was performed in 18 patients,and 32 stents were evaluated.Results Image quality was good to excellent on average(score 1.71±0.76).Stent image quality score was correlated to heart rate(r=0.281,P<0.01)and stent diameter(r=0.480,P<0.001).All the stents were assessable in lumen visibility with an average visible lumen diameter percentage of 60.7% ±13.6% .Visible lumen diameter percentage was correlated to heart rate(r=-0.193,P<0.05),stent diameter (r=0.403,P<0.001),and stent image quality score(r=-0.500,P<0.001).Visible lumen diameter percentage also varied depending on the stent type.In comparison with the conventional coronary angiography,4 of 6 in-stent stenoses were correctly detected.The sensitivity and specificity for the detection of in-stent stenosis were 66.7% and 84.6% ,respectively.Conclusions Using a 64-slice CT,the stent lumen is partly visible in most of the stents.And 64-slice CT may be useful in the assessment of stent patency.

  12. 53. Bilateral ductal stenting for nonconfluent pulmonary arteries in a newborn

    Directory of Open Access Journals (Sweden)

    K. Al Dhahri

    2016-07-01

    Full Text Available Bilateral PDA dependent pulmonary circulation with right and left pulmonary artery discontinuity is very rare. Limited data available for bilateral PDA stenting. Bilateral PDA stenting in nonconfluent pulmonary arteries is challenging procedure but can be considered as an option in the management of complex conditions like this. 12 days old Preterm (36 weeks gestation male baby with birth weight of 2.6 kg developed respiratory distress with severe cyanosis and desaturation upto 50%. Baby was intubated and started on Prostaglandin 0.05 mic/kg/mt. His saturation improved to 80%. Echocardiogram showed complex cyanotic heart disease, Situs ambiguous, dextrocardia, complete unbalanced AV septal defect, pulmonary atresia , nonconfluent small branch pulmonary arteries supplied by the bilateral patent ductus arteriosus (PDA from right aortic arch and all four pulmonary veins form a confluence and drain into superior vena cava(SVC through vertical vein with no obstruction. Baby was taken up for PDA stenting. descending aortogram showed right aortic arch with vertical tortuous duct to right pulmonary artery (RPA and another short duct with acute angle from left subclavian artery to left pulmonary artery (LPA . Both ducti stented with coronary stents. Vertical vein angiogram showed both lungs drain to a confluence and then to SVC via ascending vertical vein with no obstruction. After stenting lung perfusion improved and the baby was stable and maintained 80% saturation on room air. Bilateral PDA dependent pulmonary circulation with right and left pulmonary artery discontinuity is very rare. Our case is unique with Heterotaxy, TAPVC, Dextrocardia and double ducti. Eventhough bilateral ductal stenting is technically challenging it is successful through femoral artery approach.

  13. Treatment of gastric outlet and duodenal obstructions with uncovered expandable metal stents

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To investigate and evaluate the technical feasibility and clinical effectiveness of fluoroscopically guided peroral uncovered expandable metal stent placement to treat gastric outlet and duodenal obstructions. METHODS: Fifteen consecutive patients underwent peroral placement of WallstentTM Enteral Endoprosthesis to treat gastric outlet and duodenal obstructions (14 malignant, 1 benign). All procedures were completed under fluoroscopic guidance without endoscopic assistance. Follow-up was completed until the patients died or were lost, and the clinical outcomes were analyzed. RESULTS: The technique success rate was 100%, and the oral intake was maintained in 12 of 14 patients varying from 7 d to 270 d. Two patients remained unable to resume oral intake, although their stents were proven to be patent with the barium study. One patient with acute necrotizing pancreatitis underwent enteral stenting to treat intestinal obstruction, and nausea and vomiting disappeared. Ten patients died during the followup period, and their mean oral intake time was 50 d. No procedure-related complications occurred. Stent migration to the gastric antrum occurred in one patient 1 year after the procedure, a tumor grew at the proximal end of the stent in another patient 38 d post-stent insertion. CONCLUSION: Fluoroscopically guided peroral metal stent implantation is a safe and effective method to treat malignant gastrointestinal obstructions, and complications can be ignored based on our short-term study. Indications for this procedure should be discreetly considered because a few patients may not benefit from gastrointestinal insertion, but some benign gastrointestinal obstructions can be treated using this procedure.

  14. Update on Pancreatobiliary Stents: Stent Placement in Advanced Hilar Tumors

    OpenAIRE

    Jang, Sung Ill; Lee, Dong Ki

    2015-01-01

    Palliative drainage is the main treatment option for inoperable hilar cholangiocarcinoma to improve symptoms, which include cholangitis, pruritus, high-grade jaundice, and abdominal pain. Although there is no consensus on the optimal method for biliary drainage due to the paucity of large-scale randomized control studies, several important aspects of any optimal method have been studied. In this review article, we discuss the liver volume to be drained, stent type, techniques to insert self-e...

  15. Stenting:84 Cases of Clinical Application

    Institute of Scientific and Technical Information of China (English)

    GUANG Yongsong

    2002-01-01

    Objective To evaluate clinical application of therapeutic stenting. Methods 84 cases were managed with stents clinically, 136 procedures of intervention in all. The cases were suffering from portal hypertension of cirrhosis, stricture of inferior vana cava, superior vana cava syndrome, post- operative esophageal stricture, narrowig of femoral, common carotid, renal, superior mesentery arteries and biliary tract, etc. Results Therapeutic stenting achieves clinical effects completely different from conventional intemal medicine and surgery. Conclusion Therapeutic stenting is clinically unique, dramatically effective, with minor risks and worthy promoting.

  16. New stent delivery balloon: a technical note.

    Science.gov (United States)

    di Mario, C; Reimers, B; Reinhardt, R; Ferraro, M; Moussa, I; Colombo, A

    1997-12-01

    This study reports the first clinical application of a new noncompliant balloon composed of a middle polyurethane layer sandwiched between an inner layer of polyethylene terephtalate and an outer membrane that provides for consistent even expansion. With this balloon design, the very low compliance and high pressure resistance of polyethylene terephthalate are associated with the high elasticity of polyurethane, preventing balloon damage from stent crimping and expansion and allowing a firm embedding of the stent struts. Palmaz-Schatz stent implantation was successful in 33/35 stents (94%), and the two stents that could not be advanced up to the lesion were successfully withdrawn. High pressure expansion of the stent was obtained during deployment with no balloon ruptures at inflation pressures equal or lower than 16 atmospheres (atm). Accurate positioning of the stent was facilitated by the two markers at the balloon ends and by the optimal visualization after contrast injection, even with 6 Fr guiding catheters. This new delivery system maintains the advantages of hand-crimped stents on noncompliant balloons, reducing the risk of stent loss. PMID:9408637

  17. Nuclear recoil detection in liquid argon using a two-phase CRAD and DD neutron generator

    International Nuclear Information System (INIS)

    The detection of nuclear recoils in noble liquids using neutron elastic scattering off nuclei is relevant in the field of calibration of rare-event detectors for dark matter search and coherent neutrino-nucleus scattering experiments. We present here the first results on nuclear recoil detection in liquid Ar, using a two-phase Cryogenic Avalanche Detector (CRAD) and DD neutron generator. The technique to select the nuclear recoils for backward neutron scattering has been demonstrated

  18. Recoil ion charge state distribution following the beta(sup +) decay of {sup 21}Na

    Energy Technology Data Exchange (ETDEWEB)

    Scielzo, Nicholas D.; Freedman, Stuart J.; Fujikawa, Brian K.; Vetter, Paul A.

    2003-01-03

    The charge state distribution following the positron decay of 21Na has been measured, with a larger than expected fraction of the daughter 21Ne in positive charge states. No dependence on either the positron or recoil nucleus energy is observed. The data is compared to a simple model based on the sudden approximation. Calculations suggest a small but important contribution from recoil ionization has important consequences for precision beta decay correlation experiments detecting recoil ions.

  19. Szilard-Chalmers Recoil Reactions in Metalloporphines. Part I

    International Nuclear Information System (INIS)

    The chemical consequences of neutron capture in Co, Ni, Cu, Zn, Pd and Pt α, β, γ, δ -tetraphenylporphine complexes were investigated. The complexes were prepared in extremely pure form by new methods. Two types of retention values were determined: (a) retention in the parent molecules (Rc) obtained by chromatographing the irradiated porphines, and (b) retention in a mixture of parent molecules and the various complexing fragments produced from the parent molecules as a result of recoil and radiation damage. These retention values (R01N, R8N) were determined by extracting the irradiated and dissolved porphines with 0.1N and 8 N HCl. Large retention differences were observed between the isotopes in each of the three isotope pairs investigated. The isotope retention ratios observed in the parent molecules were Zn69m/Zn65 2.1, Pd109/Pd103 1.4, and Pt191/Pt197 2.2. The differences, R01N Rc and R8N-Rc, reflected the general order of divalent metal chelate stability constants, i.e. Pt > Pd > Cu> Ni > Co> Zn. The Co, Ni and Pd isotopes did not respond to isothermal annealing. The Zn65, Pt191 and Pt197 isotopes responded slightly, and the Zn69 and Cu64 exhibited a more pronounced effect. The results are discussed and interpreted on the basis of differences in the recoil energy spectrum and internal conversions effects. Parental retention is attributed in part to exchange reactions resulting from collision complex formation and in part to diffusion back to the point of origin of the recoil atom. (author)

  20. B -> D* l nu at zero recoil: an update

    CERN Document Server

    Bailey, Jon A; Bernard, C; Bouchard, C M; DeTar, C; El-Khadra, A X; Freeland, E D; Gámiz, E; Gottlieb, Steven; Heller, U M; Hetrick, J E; Kronfeld, A S; Laiho, J; Levkova, L; Mackenzie, P B; Oktay, M B; Simone, J N; Sugar, R; Toussaint, D; Van de Water, R S

    2010-01-01

    We present an update of our calculation of the form factor for B -> D* l nu at zero recoil, with higher statistics and finer lattices. As before, we use the Fermilab action for b and c quarks, the asqtad staggered action for light valence quarks, and the MILC ensembles for gluons and light quarks (L\\"uscher-Weisz married to 2+1 rooted staggered sea quarks). In this update, we have reduced the total uncertainty on F(1) from 2.6% to 1.7%. At Lattice2010 we presented a still-blinded result, but this writeup includes the unblinded result from the September 2010 CKM workshop.

  1. Low energy recoil detection with a spherical proportional counter

    OpenAIRE

    I. Savvidis; Katsioulas, I.; Eleftheriadis, C.; Giomataris, I.; Papaevangellou, T.

    2016-01-01

    We present low energy recoil detection results in the keV energy region, from measurements performed with the Spherical Proportional Counter (SPC). An ${}^{241}Am-{}^{9}{Be}$ fast neutron source is used in order to obtain neutron-nucleus elastic scattering events inside the gaseous volume of the detector. The detector performance in the $keV$ energy region was resolved by observing the $5.9\\ keV$ line of a ${}^{55}Fe$ X-ray source, with energy resolution of $9\\%$ ($\\sigma$). The toolkit GEANT...

  2. Collective Atomic Recoil Lasing Including Friction and Diffusion Effects

    CERN Document Server

    Robb, G R M; Ferraro, A; Bonifacio, R; Courteille, P W; Zimmermann, C; Courteille, Ph.W.

    2003-01-01

    We extend the Collective Atomic Recoil Lasing (CARL) model including the effects of friction and diffusion forces acting on the atoms due to the presence of optical molasses fields. The results from this model are consistent with those from a recent experiment by Kruse et al. [Phys. Rev. Lett. 91, 183601 (2003)]. In particular, we obtain a threshold condition above which collective backscattering occurs. Using a nonlinear analysis we show that the backscattered field and the bunching evolve to a steady-state, in contrast to the non-stationary behaviour of the standard CARL model. For a proper choice of the parameters, this steady-state can be superfluorescent.

  3. Observation of Lasing Mediated by Collective Atomic Recoil

    CERN Document Server

    Kruse, D; Zimmermann, C; Courteille, P W; Courteille, Ph.W.

    2003-01-01

    We observe the buildup of a frequency-shifted reverse light field in a unidirectionally pumped high-Q optical ring cavity serving as a dipole trap for cold atoms. This effect is enhanced and a steady state is reached, if via an optical molasses an additional friction force is applied to the atoms. We observe the displacement of the atoms accelerated by momentum transfer in the backscattering process and interpret our observations in terms of the collective atomic recoil laser. Numerical simulations are in good agreement with the experimental results.

  4. Microbeam recoil detection for hydration of minerals studies

    Energy Technology Data Exchange (ETDEWEB)

    Sie, S.H.; Suter, G.F. [CSIRO, North Ryde, NSW (Australia). Exploration and Mining Div.; Chekhmir, A.; Green, T.H. [Macquarie Univ., North Ryde, NSW (Australia)

    1993-12-31

    The glancing angle geometry is chosen to enable application of the elastic recoil detection microanalysis on thick geological samples, for hydrogen content determination. Simultaneous PIXE measurements can be used to eliminate the problem of uncertainties in beam charge collection. The method is applied to determine the hydration characteristics of silicates, produced experimentally at high pressure and temperature simulating the lower crust and upper mantle conditions. Preliminary results show that the technique can be applied readily on a microscopic (<100 {mu}m) scale for determination of H at fraction of atomic percent level. 9 refs., 3 figs.

  5. Is CHF triggered by the vapor recoil effect?

    CERN Document Server

    Nikolayev, Vadim S; Chatain, D

    2007-01-01

    This paper deals with the triggering mechanism of the boiling crisis, a transition from nucleate to film boiling. We observe the boiling crisis in pool saturated boiling experimentally at nearly critical pressure to take advantage of the slowness of the bubble growth and of the smallness of the Critical Heat Flux (CHF) that defines the transition point. Such experiments require the reduced gravity conditions. Close to the CHF, the slow growth of the individual dry spots and their subsequent fusion on the transparent heater are observed through the latter. As discussed in the paper, these observations are consistent with numerical results obtained with the vapor recoil model of the boiling crisis.

  6. Modeling of neutron elastic scattering energy deposition in proton recoil counters

    International Nuclear Information System (INIS)

    For the purpose of determining the neutron energy deposition in proton-recoil detectors, a model based on the multigroup transport theory is developed. The matrix of the averaged recoil nucleus energies represents the entire process of neutron kinetic energy transfer to the target nuclei. The averaged energy recoil nucleus receive is correspondent to the energy loss of a neutron that suffers collision within detector volume. The necessary algorithm for the matrix elements determination is developed. Computer code EESCAT is developed to calculate elastic scattering matrices and recoil nucleus energies received from elastically scattered neutrons. (author)

  7. Recoil-decay tagging spectroscopy of W-162(74)88

    OpenAIRE

    Li, Hongjie; Cederwall, Bo; Bäck, Torbjörn; Qi, Chong; Doncel, Maria; Jakobsson, Ulrika; Auranen, K; Boenig, S.; Drummond, M. C.; Grahn, T.; Greenlees, P.; Herzan, A.; Julin, R.; Juutinen, S.; Konki, J.

    2015-01-01

    Excited states in the highly neutron-deficient nucleus W-162 have been investigated via the Mo-92(Kr-78, 2 alpha) W-162 reaction. Prompt gamma rays were detected by the JUROGAM II high-purity germanium detector array and the recoiling fusion-evaporation products were separated by the recoil ion transport unit (RITU) gas-filled recoil separator and identified with the gamma recoil electron alpha tagging (GREAT) spectrometer at the focal plane of RITU. gamma rays from W-162 were identified uniq...

  8. An Evaluation of Magneto Rheological Dampers for Controlling Gun Recoil Dynamics

    OpenAIRE

    Mehdi Ahmadian; Poynor, James C.

    2001-01-01

    The application of magneto rheological dampers for controlling recoil dynamics is examined, using a recoil demonstrator that includes a single-shot 50 caliber BMG rifle action and a MR damper. The demonstrator is selected such that it can adequately represent the velocities that commonly occur in weapons with a recoil system, and can be used for collecting data for analyzing the effects of MR dampers on recoil dynamics. The MR damper is designed so that it can work effectively at the large ve...

  9. Measurements of the ballistic phonon component resulting from nuclear recoils in crystalline silicon

    International Nuclear Information System (INIS)

    We present evidence that nuclear recoils in silicon at cryogenic temperatures result in a larger ballistic component of phonons than do equal-energy electron recoils. A 300 μm thick crystal of pure silicon was instrumented on both sides with superconducting titanium transition-edge sensors, and the phonon ballistic energy fraction was determined by measuring phonon focusing effects. Comparison of the data with simulations indicates that this fraction is 1.49-0.26+0.34 times higher (at 68% confidence level) for nuclear recoils than for electron recoils

  10. Intravascular Stenting in Microvascular Anastomoses

    DEFF Research Database (Denmark)

    Assersen, Kristine; Sørensen, Jens

    2015-01-01

    Background The effect of intravascular stenting (IVaS) on microvascular anastomoses has given adverse results. For experienced microsurgeons the benefit of IVaS is doubtful. We have investigated the potential benefit of the IVaS technique for two groups of inexperienced microsurgeons with different...... surgical levels of experience (medical students and young residents). Experienced microsurgeons acted as a control group. Materials and Methods In an experimental crossover study, 139 microsurgical anastomoses were performed on the femoral artery in 70 rats by 10 surgeons. On one side of the rat, the IVaS...... spent on the anastomosis. Results No significant difference in patency rates was seen between the stenting and conventional technique in all three groups. The experienced microsurgeons had 100% patency rate with both techniques. The medical students had 20/28 in the IVaS and 19/28 conventional group...

  11. Aorta Segmentation for Stent Simulation

    CERN Document Server

    Egger, Jan; Setser, Randolph; Renapuraar, Rahul; Biermann, Christina; O'Donnell, Thomas

    2011-01-01

    Simulation of arterial stenting procedures prior to intervention allows for appropriate device selection as well as highlights potential complications. To this end, we present a framework for facilitating virtual aortic stenting from a contrast computer tomography (CT) scan. More specifically, we present a method for both lumen and outer wall segmentation that may be employed in determining both the appropriateness of intervention as well as the selection and localization of the device. The more challenging recovery of the outer wall is based on a novel minimal closure tracking algorithm. Our aortic segmentation method has been validated on over 3000 multiplanar reformatting (MPR) planes from 50 CT angiography data sets yielding a Dice Similarity Coefficient (DSC) of 90.67%.

  12. Delayed cerebral infarction due to stent folding deformation following carotid artery stenting

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Kwon Duk; Lee, Kyung Yul; Suh, Sang Hyun [Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); Kim, Byung Moon [Dept. of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2014-12-15

    We report a case of delayed cerebral infarction due to stent longitudinal folding deformation following carotid artery stenting using a self-expandable stent with an open-cell design. The stented segment of the left common carotid artery was divided into two different lumens by this folding deformation, and the separated lumens became restricted with in-stent thrombosis. Although no established method of managing this rare complication exists, a conservative approach was taken with administration of anticoagulant and dual antiplatelet therapy. No neurological symptoms were observed during several months of clinical follow-up after discharge.

  13. Late stent malapposition and marked positive vessel remodeling after sirolimus-eluting coronary stent implantation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Feng; QIAN Ju-ying; GE Jun-bo

    2006-01-01

    @@ It has been reported that positive remodeling, regression of neointimal hyperplasia, and late malapposition are associated with brachytherapy, one of the approaches to prevent first-time and recurrent in-stent restenosis.1,2 Recently, some drug-eluting stents have been demonstrated to dramatically reduce restenosis rates.3,4 Despite these promising results, these drug-eluting stents may have the same potential risks as brachytherapy, with some similarities between the 2 technologies in anti- proliferative effects on vascular smooth muscle cells and endothelial cells. We reported a case of late stent malapposition and marked positive vessel remodeling after sirolimus-eluting coronary stent implantation.

  14. Peri-stent contrast staining, major evaginations and severe malapposition after biolimus-eluting stent implantation

    DEFF Research Database (Denmark)

    Antonsen, Lisbeth; Thayssen, Per; Jensen, Lisette Okkels

    2014-01-01

    Peri-stent contrast staining and late acquired malapposition represent pathological vessel wall healing patterns following percutaneous coronary intervention with stent implantation. Earlier studies have described these abnormal vessel wall responses commonly present after implantation of first......-generation drug-eluting stents. These coronary vascular changes can cause flow disturbance and thereby dispose for later thrombotic events. This case report, based on coronary optical frequency domain imaging, describes peri-stent contrast staining, major evaginations and severe malapposition occurring 18months...... after third-generation biolimus-eluting stent implantation....

  15. Endoscopic ultrasound-guided pancreatic pseudocyst cystogastrostomy using a novel self-expandable metal stent with antimigration system: A case series

    OpenAIRE

    Nelsen, Eric M.; Johnson, Eric A.; Walker, Andrew J.; Pfau, Patrick; Gopal, Deepak V

    2015-01-01

    Background and Objectives: Development of symptomatic pseudocysts after acute pancreatitis is a common occurrence. Endoscopic ultrasound (EUS)-guided transmural drainage has become the treatment of choice for symptomatic pseudocysts. Following this procedure, stent migration can occur. A recently developed fully covered biliary metal stent with antimigration system has shown promise as an alternative endoprosthetic option for cystogastrostomy. The aim of this study is to describe the success ...

  16. Endovascular stent grafting: a review

    Energy Technology Data Exchange (ETDEWEB)

    Kribs, S. [Univ. of Western Ontario, Dept. of Vascular and Interventional Radiology, London, Ontario (Canada)

    2001-06-01

    Endovascular stent grafts are intravascular devices composed of surgical graft material and a metallic frame, (Fig. 1). Their main application has been to treat aneurysms, but they have been used in vascular trauma and are being investigated for use in occlusive disease. Their advantage in treating aneurysms over conventional surgical treatment is that they are loaded into relatively small delivery systems (Fig. 2) and can be introduced to the area of interest from a remote site - usually the femoral artery. This avoids the morbidity of surgical exposure in difficult sites, such as the thoracic aorta, and lessens the cardiovascular stress to patients by eliminating the need to surgically cross-clamp the vessel being treated. The first description of abdominal aortic aneurysm exclusion by an endovascular stent graft was provided by Parodi and colleagues in 1991. Much of the early clinical experience in endovascular stent grafting was obtained from centres in Australia and Europe, and they are now reporting midterm follow-up data. There are now many centres in Canada and the United States involved in endovascular research and practice. (author)

  17. Re-stenting treatment for esophagotracheal fistula caused by intrathoracic gastroesophageal anastomosis stent

    International Nuclear Information System (INIS)

    Objective: To evaluate the curative effect of stent replacement for the treatment of esophagotracheal fistula which occurred after the stent implantation for stenosis of intrathoracic gastroesophageal anastomotic stoma. Methods: Six patients with esophagotracheal fistula occurred after stent placement for stenosis of intrathoracic gastroesophageal anastomotic stoma were enrolled in this study. Under X-ray monitoring, the previous stent was taken out and a new, longer, covered stent was inserted into the esophagus in such a way that the stent would not be angled with the esophagus. Results: The previous stent was successfully taken out in all patients. No serious complications such as esophageal rupture, mediastinal abscess, hemorrhage, apnoea or dyspnea occurred. The replacement of the covered stent, which was 20-40 mm longer than the previous one, was also successfully performed. All the patients complained different degrees of, but tolerable, pharyngeal pain after the stenting procedure, however, the pain was markedly relieved after symptomatic treatment. Conclusion: Esophagotracheal fistula occurred after the stent implantation for stenosis of intrathoracic gastroesophageal anastomotic stoma can be effectively treated by replacing a longer covered stent. (authors)

  18. Iliocaval Confluence Stenting for Chronic Venous Obstructions

    Energy Technology Data Exchange (ETDEWEB)

    Graaf, Rick de, E-mail: r.de.graaf@mumc.nl [Maastricht University Medical Centre (MUMC), Department of Radiology (Netherlands); Wolf, Mark de, E-mail: markthewolf@gmail.com [Maastricht University Medical Centre (MUMC), Department of Surgery (Netherlands); Sailer, Anna M., E-mail: anni.sailer@mumc.nl [Maastricht University Medical Centre (MUMC), Department of Radiology (Netherlands); Laanen, Jorinde van, E-mail: jorinde.van.laanen@mumc.nl; Wittens, Cees, E-mail: c.wittens@me.com [Maastricht University Medical Centre (MUMC), Department of Surgery (Netherlands); Jalaie, Houman, E-mail: hjalaie@ukaachen.de [University Hospital Aachen, Department of Surgery (Germany)

    2015-10-15

    PurposeDifferent techniques have been described for stenting of venous obstructions. We report our experience with two different confluence stenting techniques to treat chronic bi-iliocaval obstructions.Materials and MethodsBetween 11/2009 and 08/2014 we treated 40 patients for chronic total bi-iliocaval obstructions. Pre-operative magnetic resonance venography showed bilateral extensive post-thrombotic scarring in common and external iliac veins as well as obstruction of the inferior vena cava (IVC). Stenting of the IVC was performed with large self-expandable stents down to the level of the iliocaval confluence. To bridge the confluence, either self-expandable stents were placed inside the IVC stent (24 patients, SECS group) or high radial force balloon-expandable stents were placed at the same level (16 patients, BECS group). In both cases, bilateral iliac extensions were performed using nitinol stents.ResultsRecanalization was achieved for all patients. In 15 (38 %) patients, a hybrid procedure with endophlebectomy and arteriovenous fistula creation needed to be performed because of significant involvement of inflow vessels below the inguinal ligament. Mean follow-up was 443 ± 438 days (range 7–1683 days). For all patients, primary, assisted-primary, and secondary patency rate at 36 months were 70, 73, and 78 %, respectively. Twelve-month patency rates in the SECS group were 85, 85, and 95 % for primary, assisted-primary, and secondary patency. In the BECS group, primary patency was 100 % during a mean follow-up period of 134 ± 118 (range 29–337) days.ConclusionStenting of chronic bi-iliocaval obstruction shows relatively high patency rates at medium follow-up. Short-term patency seems to favor confluence stenting with balloon-expandable stents.

  19. INTRAVASCULAR ULTRASOUND EVALUATING CORONARY STENTS FOR PATIENTS WITH CORONARY ARTERY DISEASE: COMPARED OLD WITH NEW MULTILINK STENTS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective.It was suggested that coronary stent design and coating may affect stent performance and hence induce varying degrees of thrombogenesis and neointimal hyperplasia.The purpose of this study is to compare the 6 month follow up results between old and new Multilink stents with the method of intravascular ultrasound (IVUS) imaging.Methods.We have performed old (n=40) and new (n=35) Multilink stent implantations on 75 patients with coronary artery disease.Coronary angiography was performed before,immediately after,and 6 months after the in stent procedure respectively.Six month follow up IVUS imaging was performed and analyzed off line.Results.Minimal lumen cross sectional area (CSA) of new Multilink stents was significantly larger than that of old Multilink stents (P=0.0053).Mean stent lumen area of new Multilink stents was significantly larger than that of old Multilink stents (P=0.040).Similarly,minimal lumen diameter (MLD) of new Multilink stents was larger than that of old Multilink stents (P= 0.011).Old Multilink stents had a higher percentage of plaque area than new Multilink stents.Conclusion.The new Multilink stent is obviously superior to old Multilink stents,in particular,in the stent MLD and lumen CSA- - major determinants of the restenosis.

  20. Silicon shallow doping by erbium and oxygen recoils implantation

    Science.gov (United States)

    Feklistov, K. V.; Cherkov, A. G.; Popov, V. P.

    2016-09-01

    In order to get shallow high doping of Si with optically active complexes ErOn, Er followed by O recoils implantation was realized by means of subsequent Ar+ 250-290 keV implantation with doses 2×1015-1×1016 cm-2 through 50-nm deposited films of Er and then SiO2, accordingly. High Er concentration up to 5×1020 cm-3 to the depth of 10 nm was obtained after implantation. However, about a half of the Er implanted atoms become part of surface SiO2 during post-implantation annealing at 950 °C for 1 h in the N2 ambient under a SiO2 cap. The mechanism of Er segregation into the cap oxide following the moving amorphous-crystalline interface during recrystallization was rejected by the transmission electron microscopy (TEM) analysis. Instead, the other mechanism of immobile Er atoms and redistribution of recoil-implanted O atoms toward cap oxide was proposed. It explains the observed formation of two Er containing phases: Er-Si-O phase with a high O content adjacent to the cap oxide and deeper O depleted Er-Si phase. The correction of heat treatments is proposed in order to avoid the above-mentioned problems.

  1. A Measurement of the Recoil Polarization of Electroproduced {Lambda}(1116)

    Energy Technology Data Exchange (ETDEWEB)

    Simeon McAleer

    2002-01-01

    The CEBAF Large Acceptance Spectrometer at the Thomas Jefferson National Laboratory was used to study the reaction e + p {yields} e{prime} + K{sup +} + {Lambda}(1116) for events where {Lambda}(1116) subsequently decayed via the channel {Lambda}(1116) {yields} p + {pi}{sup -}. Data were taken at incident electron beam energies of 2.5, 4.0, and 4.2 GeV during the 1999 E1C run period. They hyperon production spectra span the Q{sup 2} range from 0.5 to 2.8 GeV{sup 2} and nearly the entire range in the center of mass angles. The proton angular distribution in the {Lambda}(1116) rest frame is used to deduce the recoil polarization of the hyperon, and the W and cos {theta}{sub cm}{sup K+} dependence of the recoil polarization will be presented. The data show sizeable negative polarizations for the {Lambda}(1116) as a function of both cos {theta}{sub cm}{sup K+} and W.

  2. Low energy recoil detection with a spherical proportional counter

    CERN Document Server

    Savvidis, I; Eleftheriadis, C; Giomataris, I; Papaevangellou, T

    2016-01-01

    We present low energy recoil detection results in the keV energy region, from measurements performed with the Spherical Proportional Counter (SPC). An ${}^{241}Am-{}^{9}{Be}$ fast neutron source is used in order to obtain neutron-nucleus elastic scattering events inside the gaseous volume of the detector. The detector performance in the $keV$ energy region was resolved by observing the $5.9\\ keV$ line of a ${}^{55}Fe$ X-ray source, with energy resolution of $9\\%$ ($\\sigma$). The toolkit GEANT4 was used to simulate the irradiation of the detector by an ${}^{241}Am-{}^{9}{Be}$ source, while SRIM was used to calculate the Ionization Quenching Factor (IQF). The GEANT4 simulated energy deposition spectrum in addition with the SRIM calculated quenching factor provide valuable insight to the experimental results. The performance of the SPC in low energy recoil detection makes the detector a good candidate for a wide range of applications, including Supernova or reactor neutrino detection and Dark Matter (WIMP) searc...

  3. Risk Factors and Clinical Evaluation of Superficial Femoral Artery Stent Fracture: Prote'ge'GPS Stent

    International Nuclear Information System (INIS)

    To evaluate the occurrence of superficial femoral artery stent fractures, the risk factors of stent fracture, and the relationship between fractures and clinical findings. Of the 38 patients who underwent treatment with Prote'ge'GPS stenting due to arterial occlusions on the superficial femoral artery, 17 also underwent a clinical analysis. Forty-three stents were inserted in the 17 superficial femoral arteries, ranging between 15 and 50 cm in length, with a mean treated length of 26.4 cm (15-50 cm). A fracture was evaluated by taking a PA and lateral simple radiography, as well as a follow-up evaluation accompanied with a CT angiography, DSA, and a color Doppler sonography. The examination involved the assessment of the difference between bone fractures due to length, placement, and frequency. Fractures occurred in 13 of 43 stents (30.2%). A total of 10 (71.4%) occurred in the upper third, compared to 4 (28.6%) in the lower third of the superficial femoral artery. In addition, 10 stents (71.4%) had a single strut fracture, whereas 4 (28.6%) had multiple strut fractures. A stent fracture occurred more frequently when the stents and lesions were longer (p=0.021, 0.012) and the stents were inserted near the joint. However, there was no significant relationship between stent numbers and the fractures (p=0.126). When the stents were inserted along the popliteal artery, a stent fracture occurred more frequently in the lower third of the artery. The stent fractures did not significantly influence the patency rate of the stented artery (p=0.44) Prote'ge'GPS stents in the superficial femoral artery revealed a considerable number of fractures and the fracture frequency showed a significant relationship with the length of stents and lesions. The closer stent insertion was to the joints, the more frequently fractures occurred. There were no evident significant relationships between the presence of stent fractures and the patency of the stented arteries

  4. A computational study of the hemodynamic impact of open- versus closed-cell stent design in carotid artery stenting.

    Science.gov (United States)

    De Santis, Gianluca; Trachet, Bram; Conti, Michele; De Beule, Matthieu; Morbiducci, Umberto; Mortier, Peter; Segers, Patrick; Verdonck, Pascal; Verhegghe, Benedict

    2013-07-01

    The aim of this study is to analyze the shape and flow changes of a patient-specific carotid artery after carotid artery stenting (CAS) performed using an open-cell (stent-O) or a closed-cell (stent-C) stent design. First, a stent reconstructed from micro-computed tomography (microCT) is virtually implanted in a left carotid artery reconstructed from CT angiography. Second, an objective analysis of the stent-to-vessel apposition is used to quantify the lumen cross-sectional area and the incomplete stent apposition (ISA). Third, the carotid artery lumen is virtually perfused in order to quantify its resistance to flow and its exposure to atherogenic or thrombogenic hemodynamic conditions. After CAS, the minimum cross-sectional area of the internal carotid artery (ICA) (external carotid artery [ECA]) changes by +54% (-12%) with stent-O and +78% (-17%) with stent-C; the resistance to flow of the ICA (ECA) changes by -21% (+13%) with stent-O and -26% (+18%) with stent-C. Both stent designs suffer from ISA but the malapposed stent area is larger with stent-O than stent-C (29.5 vs. 14.8 mm(2) ). The untreated vessel is not exposed to atherogenic flow conditions whereas an area of 67.6 mm(2) (104.9) occurs with stent-O (stent-C). The area of the stent surface exposed to thrombogenic risk is 5.42 mm(2) (7.7) with stent-O (stent-C). The computer simulations of stenting in a patient's carotid artery reveal a trade-off between cross-sectional size and flow resistance of the ICA (enlarged and circularized) and the ECA (narrowed and ovalized). Such a trade-off, together with malapposition, atherogenic risk, and thrombogenic risk is stent-design dependent. PMID:23578331

  5. Removal of an embedded "covered" biliary stent by the "stent-in-stent" technique

    OpenAIRE

    Menon, Shyam

    2013-01-01

    A 46-year-old man was admitted with obstructive jaundice and cross-sectional imaging with computed tomography suggested distal biliary obstruction. A distal common bile duct stricture was found at endoscopic retrograde cholangiopancreatography (ERCP) and cytology was benign. A 6 cm fully covered self-expanding metal stent (SEMS) was inserted across the stricture to optimize biliary drainage. However, the SEMS could not be removed at repeat ERCP a few months later. A further fully covered SEMS...

  6. Crush stenting in treating coronary bifurcate lesions: paclitaxel eluting stents versus sirolimus eluting stents

    Institute of Scientific and Technical Information of China (English)

    CHEN Shao-liang; SUN Xue-wen; HU Da-yi; Tak W. Kwan; ZHANG Jun-jie; YE Fei; CHEN Yun-dai; ZHU Zhong-sheng; LIN Song; TIAN Nai-liang; LIU Zhi-zhong; FANG Wei-yi

    2008-01-01

    Background Because no data regarding the comparison of crush stenting with pactitaxel(PES)or sirolimus eluting stents(SES)for coronary bifurcate lesions have been reported,we compared the clinical outcomes of these two types of stents.Methods Two hundred and thirty patients with 242 bifurcate lesions were enrolled in a prospective,nonrandomized trial.Primary endpoints included myocardial infarction,cardiac death and target vessel revascularization at 8 months.Results All patients were followed up clinically and 82%angiographically at 8 months.Final kissing balloon inflation was performed in 72%in the PES and 75%in the SES groups(P>0.05).Compared to the SES group,PES group had a higher late loss and incidence of restenosis(P=0.04)in the prebifurcation vessel segment.The postbifurcation vessel segment in the PES group had a greater late loss((0.7+0.6)mm vs(0.3±0.4)mm,P<0.001)and higher restenosis in the side branch(25.5%vs 15.6%,P=0.04)when compared to the SES group.There was significant difference of insegment restenosis in the entire main vessel between PES and SES groups (P=0.004).Target lesion revascularization was more frequently seen in the PES group as compared to the SES group(P=0.01).There was significant difference in the accumulative MACE between these two groups(P=0.01).The survival rate free from target lesion revascularization was significantly higher in the SES group when compared to the PES group(P<0.001).Conclusion SES is superior to PES in reducing restenosis and target lesion revascularization by 8-month follow-up after crush stenting for bifurcate lesions.

  7. 21 CFR 876.4620 - Ureteral stent.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ureteral stent. 876.4620 Section 876.4620 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4620 Ureteral stent. (a) Identification. A ureteral...

  8. Stent placement for esophageal strictures : an update

    NARCIS (Netherlands)

    Hirdes, Meike Madeleine Catharine; Vleggaar, Frank Paul; Siersema, Peter Derk

    2011-01-01

    The use of stents for esophageal strictures has evolved rapidly over the past 10 years, from rigid plastic tubes to flexible self-expanding metal (SEMS), plastic (SEPS) and biodegradable stents. For the palliative treatment of malignant dysphagia both SEMS and SEPS effectively provide a rapid relief

  9. Nanophasic biodegradation enhances the durability and biocompatibility of magnesium alloys for the next-generation vascular stents

    Science.gov (United States)

    Mao, Lin; Shen, Li; Niu, Jialin; Zhang, Jian; Ding, Wenjiang; Wu, Yu; Fan, Rong; Yuan, Guangyin

    2013-09-01

    Biodegradable metal alloys emerge as a new class of biomaterials for tissue engineering and medical devices such as cardiovascular stents. Deploying biodegradable materials to fabricate stents not only obviates a second surgical intervention for implant removal but also circumvents the long-term foreign body effect of permanent implants. However, these materials for stents suffer from an un-controlled degradation rate, acute toxic responses, and rapid structural failure presumably due to a non-uniform, fast corrosion process. Here we report that highly uniform, nanophasic degradation is achieved in a new Mg alloy with unique interstitial alloying composition as the nominal formula Mg-2.5Nd-0.2Zn-0.4Zr (wt%, hereafter, denoted as JDBM). This material exhibits highly homogeneous nanophasic biodegradation patterns as compared to other biodegradable metal alloy materials. Consequently it has significantly reduced degradation rate determined by electrochemical characterization. The in vitro cytotoxicity test using human vascular endothelial cells indicates excellent biocompatibility and potentially minimal toxic effect on arterial vessel walls. Finally, we fabricated a cardiovascular stent using JDBM and performed in vivo long-term assessment via implantation of this stent in an animal model. The results confirmed the reduced degradation rate in vivo, excellent tissue compatibility and long-term structural and mechanical durability. Thus, this new Mg-alloy with highly uniform nanophasic biodegradation represents a major breakthrough in the field and a promising material for manufacturing the next generation biodegradable vascular stents.

  10. Drug eluting stents: Current status and new developments

    NARCIS (Netherlands)

    G. Ertaş; H.M.M. van Beusekom (Heleen)

    2012-01-01

    textabstractDespite the favorable impact of drug eluting stents on stent restenosis, their long-term reliability is considered worrisome by some because of stent thrombosis. Often attributed to adverse reactions to the stent platform, both the drugs and polymer characteristics have been further adva

  11. Stent Graft in Managing Juxta-Renal Aortoiliac Occlusion

    International Nuclear Information System (INIS)

    Endovascular procedures are frequently used as an alternative to surgical bypass in aortic and iliac occlusion. Stents have revolutionized the scope of such endovascular procedures, but there are few reports of stents or stent grafts in occlusive juxta-renal aortic occlusion. We present a case where such occlusion was managed by use of a stent graft with successful outcome

  12. Triple antithrombotic therapy in patients with atrial fibrillation undergoing coronary artery stenting: hovering among bleeding risk, thromboembolic events, and stent thrombosis

    Directory of Open Access Journals (Sweden)

    Menozzi Mila

    2012-10-01

    Full Text Available Abstract Dual antiplatelet treatment with aspirin and clopidogrel is the antithrombotic treatment recommended after an acute coronary syndrome and/or coronary artery stenting. The evidence for optimal antiplatelet therapy for patients, in whom long-term treatment oral anticoagulation is mandatory, is however scarce. To evaluate the safety and efficacy of the various antithrombotic strategies adopted in this population, we reviewed the available evidence on the management of patients receiving oral anticoagulation, such as a vitamin-k-antagonists, referred for coronary artery stenting. Atrial fibrillation is the most frequent indication for oral anticoagulation. The need of starting antiplatelet therapy in this clinical scenario raises concerns about the combination to choose: triple therapy with warfarin, aspirin, and a thienopyridine being the most frequent and advised. The safety of this regimen appeared suboptimal because of an increased risk in hemorrhagic complications. On the other hand, the combination of oral anticoagulation and an antiplatelet agent is suboptimal in preventing thromboembolic events and stent thrombosis; dual antiplatelet therapy may be considered only when a high hemorrhagic risk and low thromboembolic risk are perceived. Indeed, the need for prolonged multiple-drug antithrombotic therapy increases the bleeding risks when drug eluting stents are used. Since current evidence derives mainly from small, single-center and retrospective studies, large-scale prospective multicenter studies are urgently needed.

  13. Should antiplatelet therapy be interrupted in drug eluting stent recipients throughout the periendoscopic period? A very late stent thrombosis case re-port and review of the literature

    Institute of Scientific and Technical Information of China (English)

    Peng DONG; Xin-Chun YANG; Su-Yan BIAN

    2014-01-01

    In-stent thrombosis after cessation of antiplatelet medications in patients with drug-eluting stents (DES) is a significant problem in medical practice, particularly in the perioperative period. We report a case of an 87-year-old man with a medical history of hypertension, coronary artery disease and chronic atrophic gastritis. Very late thrombosis of a sirolimus-eluting stent occurred 1207 days after implantation, seven months after discontinuation of clopidogrel, and the interruption of aspirin 13 days in preparation of an elective endoscopic gastroin-testinal procedure presented with acute myocardial infarction. The patient was treated with thrombectomy and successfully revascularized with superimposition of two sirolimus-eluting stents. Medications administered in the catheterization laboratory included low molecular weight heparin and nitroglycerin. Flow was defined as grade 2 according to the thrombolysis in myocardial infarction scale. Electrocardio-gram after the procedure revealed persistent, but decreased, ST-segment elevation in the anterolateral leads. The patient recovered and was discharged on aspirin and clopidogrel indefinitely. There was no cardiac event during the two year follow-up period. This case underlines the importance of maintaining the balance of thrombosis and bleeding during perioperation of non-cardiac procedure and the possible need for continuation of aspirin therapy during periendoscopic procedures among patients with low bleeding risks who received DES.

  14. Should antiplatelet therapy be interrupted in drug eluting stent recipients throughout the periendoscopic period? A very late stent thrombosis case report and review of the literature.

    Science.gov (United States)

    Dong, Peng; Yang, Xin-Chun; Bian, Su-Yan

    2014-09-01

    In-stent thrombosis after cessation of antiplatelet medications in patients with drug-eluting stents (DES) is a significant problem in medical practice, particularly in the perioperative period. We report a case of an 87-year-old man with a medical history of hypertension, coronary artery disease and chronic atrophic gastritis. Very late thrombosis of a sirolimus-eluting stent occurred 1207 days after implantation, seven months after discontinuation of clopidogrel, and the interruption of aspirin 13 days in preparation of an elective endoscopic gastrointestinal procedure presented with acute myocardial infarction. The patient was treated with thrombectomy and successfully revascularized with superimposition of two sirolimus-eluting stents. Medications administered in the catheterization laboratory included low molecular weight heparin and nitroglycerin. Flow was defined as grade 2 according to the thrombolysis in myocardial infarction scale. Electrocardiogram after the procedure revealed persistent, but decreased, ST-segment elevation in the anterolateral leads. The patient recovered and was discharged on aspirin and clopidogrel indefinitely. There was no cardiac event during the two year follow-up period. This case underlines the importance of maintaining the balance of thrombosis and bleeding during perioperation of non-cardiac procedure and the possible need for continuation of aspirin therapy during periendoscopic procedures among patients with low bleeding risks who received DES. PMID:25278977

  15. Basic Knowledge about Metal Stent Development.

    Science.gov (United States)

    Jeong, Seok

    2016-03-01

    Biliary self-expandable metal stents (SEMS), a group of non-vascular stents, have been used in the palliative management of biliary obstruction around the world. However, there are still unmet needs in the clinical application of biliary SEMS. Comprehensive understanding of the SEMS is required to resolve the drawbacks and difficulties of metal stent development. The basic structure of SEMS, including the materials and knitting methods of metal wires, covering materials, and radiopaque markers, are discussed in this review. What we know about the physical and mechanical properties of the SEMS is very important. With an understanding of the basic knowledge of metal stents, hurdles such as stent occlusion, migration, and kinking can be overcome to develop more ideal SEMS. PMID:27000423

  16. Foreign body contamination during stent implantation.

    Science.gov (United States)

    Whelan, D M; van Beusekom, H M; van der Giessen, W J

    1997-03-01

    The treatment of coronary artery disease using stents has become a widely accepted technique. However, the inadvertent co-implantation of contaminating factors with the stent has received little attention. We studied histological cross-sections of stented porcine coronary arteries and observed contamination of some vessels with surgical glove powder and textile fibres. The contaminating particles were associated with a foreign body reaction. Such a reaction could delay the wound-healing response of a stented vessel and thereby prolong the period in which subacute thrombosis could occur. It is also proposed that air contamination could affect the thrombogenicity of the stent. Appropriate measures should be followed to reduce the chance of contamination occurring.

  17. Call for standards in technical documentation of intracoronary stents.

    Science.gov (United States)

    Lanzer, Peter; Gijsen, Frank J H; Topoleski, L D Timmie; Holzapfel, Gerhard A

    2010-01-01

    At present, the product information of intracoronary stents provided by the industry contains only limited technical data restricting judgments on the in vivo performance of individual products. Available experimental and clinical evidence suggests that interventional target sites display highly heterogeneous biomechanical behavior needed to be matched by specific stent and stent delivery system characteristics. To allow individualized stent-lesion matching, both, understanding of biomechanical properties of the atherosclerotic coronary artery lesions and expert knowledge of the intracoronary stent systems, are required. Here, the authors review some of the initial data on mechanical properties of coronary artery lesions potentially relevant to stenting and suggest standards for technical documentation of intracoronary stents. PMID:20140786

  18. Calculations of Total and Differential Solid Angles for a Proton Recoil Solid State Detector

    International Nuclear Information System (INIS)

    The solid angles have been computed for a proton recoil counter consisting of a circular hydrogenous foil viewed by an isotropic neutron point source at different distances from the target foil. Tables are given for the total subtended solid angle as well as the differential energy distribution function of the proton recoil spectrum. The influence of finite foil thickness has also been studied

  19. Optimal control of gun recoil in direct fire using magnetorheological absorbers

    International Nuclear Information System (INIS)

    Optimal control of a gun recoil absorber is investigated for minimizing recoil loads and maximizing rate of fire. A multi-objective optimization problem was formulated by considering the mechanical model of the recoil absorber employing a spring and a magnetorheological (MR) damper. The damper forces are predicted by evaluating pressure drops using a nonlinear Bingham-plastic model. The optimization methodology provides multiple optimal design configurations with a trade-off between recoil load minimization and increased rate of fire. The configurations with low or high recoil loads imply low or high rate of fire, respectively. The gun recoil absorber performance is also analyzed for perturbations in the firing forces. The adaptive control of the MR damper for varying gun firing forces provides a smooth operation by returning the recoil mass to its battery position (ready to reload and fire) without incurring an end-stop impact. Furthermore, constant load transmissions are observed with respect to the recoil stroke by implementing optimal control during the simulated firing events. (paper)

  20. Compton cross-section calculations in terms of recoil-ion momentum observables

    Energy Technology Data Exchange (ETDEWEB)

    Kaliman, Z. E-mail: kaliman@pefri.hr; Pisk, K

    2004-11-01

    We present a theoretical framework for the calculations of Compton scattering on bound electrons, based on recoil-ion observables. We show the results for Compton cross sections on He-atom, with respect to the recoil-ion momentum. The validity and the utility of this approach are discussed particularly in connection with the electron momentum density determination.

  1. Optimal control of gun recoil in direct fire using magnetorheological absorbers

    Science.gov (United States)

    Singh, Harinder J.; Wereley, Norman M.

    2014-05-01

    Optimal control of a gun recoil absorber is investigated for minimizing recoil loads and maximizing rate of fire. A multi-objective optimization problem was formulated by considering the mechanical model of the recoil absorber employing a spring and a magnetorheological (MR) damper. The damper forces are predicted by evaluating pressure drops using a nonlinear Bingham-plastic model. The optimization methodology provides multiple optimal design configurations with a trade-off between recoil load minimization and increased rate of fire. The configurations with low or high recoil loads imply low or high rate of fire, respectively. The gun recoil absorber performance is also analyzed for perturbations in the firing forces. The adaptive control of the MR damper for varying gun firing forces provides a smooth operation by returning the recoil mass to its battery position (ready to reload and fire) without incurring an end-stop impact. Furthermore, constant load transmissions are observed with respect to the recoil stroke by implementing optimal control during the simulated firing events.

  2. Chemical fate of a recoil atom as a function of the lattice conditions

    International Nuclear Information System (INIS)

    The author considers the fate of a recoil atom receiving a recoil as a result of a nuclear reaction, completely rupturing the bonds between the atom and its ligands, in the case of KMnO4- and KBrO3-crystal lattices. (Auth.)

  3. [Three case reports of the use of herbal combinations resulted in stent thrombosis: herbal combinations; friend or foe?].

    Science.gov (United States)

    Vatankulu, Mehmet Akif; Tasal, Abdurrahman; Erdoğan, Ercan; Göktekin, Ömer

    2012-04-01

    Nowadays, herbal combinations are commonly used in Turkey and around the world. In particular, an herbal combination including Tribulus terrestris (TT), Avena sativa (AS), and Panax Ginseng (PG), which may be effective in treatment of atherosclerosis and thrombosis, is used by patients with coronary artery disease. In this paper, we will report three cases with coronary stents who were diagnosed with acute coronary syndrome while using this herbal combination of TT, AS and PG together with anti-aggregant medications. A 45-year-old man presented with chest pain and coronary angiography confirmed a total occluded stent in left anterior descending artery which was implanted a year ago. Balloon dialation was performed to dilate the stent, resulting in full opening of the vessel. The second case, a 53-year-old woman, was admitted to the hospital with chest pain. Coronary angiography confirmed a total occluded stent, which had been implanted three months ago. A balloon was performed to dilate the stent and it was fully opened. The third case, a 62-year-old man, presented with chest pain. Coronary angiography was performed and there was a 98% stenosis of the circumflex stent, which was implanted three months ago. A balloon was performed to dilate the stent and it was fully opened. It was learnt that all three patients had used the same herbal combination (TT, AS and PG) with dual anti-aggregant therapy for three months ago to presentation in the clinic. Patients were discharged with the suggestion not to use this herbal combination with dual anti-aggregant therapy. There were no problems during the four month follow-up period. Stent thrombosis may be caused by interactions between herbal combination (TT, AS and PG) and clopidogrel in these patients under dual antiaggregant therapy. PMID:22864325

  4. Diagnostic accuracy of 64-slice multidetector CT for detection of in-stent restenosis in an unselected, consecutive patient population

    Energy Technology Data Exchange (ETDEWEB)

    Haraldsdottir, Sigurdis, E-mail: sigurdisha@gmail.com [Boston Medical Center, 72 East Concord Street (Evans 124), Boston, MA, 02118 (United States); Gudnason, Thorarinn, E-mail: thorgudn@landspitali.is [Landspitali University Hospital, Hringbraut, 101 Reykjavik (Iceland); Sigurdsson, Axel F., E-mail: axelfsig@landspitali.is [Landspitali University Hospital, Hringbraut, 101 Reykjavik (Iceland); Gudjonsdottir, Jonina, E-mail: jonina@rd.is [Rontgen Domus Medica, Egilsgata 3, 101 Reykjavik (Iceland); Lehman, Sam J., E-mail: slehman@partners.org [Massachusetts General Hospital, 165 Cambridge Street, Suite 400, Boston, MA 02114 (United States); Eyjolfsson, Kristjan, E-mail: kristey@landspitali.is [Landspitali University Hospital, Hringbraut, 101 Reykjavik (Iceland); Scheving, Sigurpall S., E-mail: sigurpal@landspitali.is [Landspitali University Hospital, Hringbraut, 101 Reykjavik (Iceland); Gibson, C. Michael, E-mail: mgibson@perfuse.org [Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02115 (United States); Hoffmann, Udo, E-mail: uhoffmann@partners.org [Massachusetts General Hospital, 165 Cambridge Street, Suite 400, Boston, MA 02114 (United States); Jonsdottir, Birna, E-mail: birna@rd.is [Rontgen Domus Medica, Egilsgata 3, 101 Reykjavik (Iceland); Andersen, Karl, E-mail: andersen@landspitali.is [Landspitali University Hospital, Hringbraut, 101 Reykjavik (Iceland)

    2010-11-15

    Objectives: To investigate the diagnostic accuracy of 64-slice multidetector computed tomography (64-CT) for detection of in-stent restenosis (ISR) in an unselected, consecutive patient population. Background: Detection of in-stent restenosis by cardiac CT would be a major advance for the evaluation of patients suspected of having ISR. However, the diagnostic accuracy of current generation 64-CT in this context is not fully established. Methods: We conducted a prospective study on patients with stable angina or acute coronary syndrome with no prior history of coronary artery disease. Six months after percutaneous coronary intervention (PCI) with stent placement they underwent a 64-CT scan (Toshiba Multi-Slice Aquilion 64) and consequently a repeat coronary angiography for comparison. Cardiac CT data sets were analyzed for the presence of in-stent restenosis by two independent expert readers blinded to the coronary angiographic data. Results: Ninety-three patients with a total of 140 stents were evaluated. Males comprised 82% of the study group and the mean age was 63 {+-} 10 years. The mean time from PCI to the repeat coronary angiography was 208 {+-} 37 days and the mean time from 64-CT to repeat coronary angiography was 3.7 {+-} 4.9 days. The restenosis rate according to coronary angiography was 26%. Stent diameter, strut thickness, heart rate and body mass index (BMI) significantly affected image quality. The sensitivity, specificity, positive and negative predictive values of 64-CT for detection of in-stent restenosis were 27%, 95%, 67% and 78%, respectively. Conclusions: Current generation, 64-slice CT, remains limited in its ability to accurately detect in-stent restenosis.

  5. Biliary stenting: indications, choice of stents and results: European Society of Gastrointestinal Endoscopy (ESGE) clinical guideline.

    Science.gov (United States)

    Dumonceau, J-M; Tringali, A; Blero, D; Devière, J; Laugiers, R; Heresbach, D; Costamagna, G

    2012-03-01

    This article is part of a combined publication that expresses the current view of the European Society of Gastrointestinal Endoscopy about endoscopic biliary stenting. The present Clinical Guideline describes short-term and long-term results of biliary stenting depending on indications and stent models; it makes recommendations on when, how, and with which stent to perform biliary drainage in most common clinical settings, including in patients with a potentially resectable malignant biliary obstruction and in those who require palliative drainage of common bile duct or hilar strictures. Treatment of benign conditions (strictures related to chronic pancreatitis, liver transplantation, or cholecystectomy, and leaks and failed biliary stone extraction) and management of complications (including stent revision) are also discussed. A two-page executive summary of evidence statements and recommendations is provided. A separate Technology Review describes the models of biliary stents available and the stenting techniques, including advanced techniques such as insertion of multiple plastic stents, drainage of hilar strictures, retrieval of migrated stents and combined stenting in malignant biliary and duodenal obstructions.The target readership for the Clinical Guideline mostly includes digestive endoscopists, gastroenterologists, oncologists, radiologists, internists, and surgeons while the Technology Review should be most useful to endoscopists who perform biliary drainage.

  6. Hybrid stent device of flow-diverting effect and stent-assisted coil embolization formed by fractal structure.

    Science.gov (United States)

    Kojima, Masahiro; Irie, Keiko; Masunaga, Kouhei; Sakai, Yasuhiko; Nakajima, Masahiro; Takeuchi, Masaru; Fukuda, Toshio; Arai, Fumihito; Negoro, Makoto

    2016-05-01

    This paper presents a novel hybrid medical stent device. This hybrid stent device formed by fractal mesh structures provides a flow-diverting effect and stent-assisted coil embolization. Flow-diverter stents decrease blood flow into an aneurysm to prevent its rupture. In general, the mesh size of a flow-diverter stent needs to be small enough to prevent blood flow into the aneurysm. Conventional flow-diverter stents are not available for stent-assisted coil embolization, which is an effective method for aneurysm occlusion, because the mesh size is too small to insert a micro-catheter for coil embolization. The proposed hybrid stent device is capable of stent-assisted coil embolization while simultaneously providing a flow-diverting effect. The fractal stent device is composed of mesh structures with fine and rough mesh areas. The rough mesh area can be used to insert a micro-catheter for stent-assisted coil embolization. Flow-diverting effects of two fractal stent designs were composed to three commercially available stent designs. Flow-diverting effects were analyzed using computational fluid dynamics (CFD) analysis and particle image velocimetry (PIV) experiment. Based on the CFD and PIV results, the fractal stent devices reduce the flow velocity inside an aneurism just as much as the commercially available flow-diverting stents while allowing stent-assisted coil embolization.

  7. Commissioning of the recoil silicon detector for the HERMES experiment

    Energy Technology Data Exchange (ETDEWEB)

    Pickert, N.C.

    2008-02-15

    The reconstruction of the missing mass is limited by the position and momentum resolution of the HERMES spectrometer. In order to reach a higher accuracy in the measurements the backscattered nucleon must also be detected. A detector suited for this must give the possibility, to determine the momentum of the particles over a very large range: from minimally ionizing particles up to protons, which are stopped in the detector. The detector must also be able to discriminate hadrons and mesons as well as cover the complete spatial region around the target. In the winter 2005-2006 such a recoil detector was installed in the HERMES experiment. The detector sonsists of three partial detectors, a silicon counter within the scattering chamber, a sintillating-fiber detector and a photon detector. Before the installation of the detector the silicon modules were tested in a bench test and checked together with the other particle detectors in a test experiment. A large part of this dissertation is dedicated to the planning and performance of these tests as well to the evaluation of them. It could be show, that the modules worked accordly to their specifications, however because of unexpectedly high noise a signal correction became necessary. Different models for the correction were developed and tested in the framework of these thesis. In spite of the high noise cosmic muons could be detected and their energy deposition measured with a signal-to-noise ratio of 2:1. In the winter break 2005-2006 the recoil detector was installed into the HERMES experiment. First diagnosis and analysis software was developed. The silicon detector measured successfully energy depositions of minimally ionizing particles up to protons stopped in the sensor. Minimally ionizing particles could be detected with a signal-to-noise ratio of 5:1. By means of track information of the scintillating-fiber detector protons could be discriminated from pions and other mesons by the silicon detector. The HERMES

  8. Commissioning of the recoil silicon detector for the HERMES experiment

    International Nuclear Information System (INIS)

    The reconstruction of the missing mass is limited by the position and momentum resolution of the HERMES spectrometer. In order to reach a higher accuracy in the measurements the backscattered nucleon must also be detected. A detector suited for this must give the possibility, to determine the momentum of the particles over a very large range: from minimally ionizing particles up to protons, which are stopped in the detector. The detector must also be able to discriminate hadrons and mesons as well as cover the complete spatial region around the target. In the winter 2005-2006 such a recoil detector was installed in the HERMES experiment. The detector sonsists of three partial detectors, a silicon counter within the scattering chamber, a sintillating-fiber detector and a photon detector. Before the installation of the detector the silicon modules were tested in a bench test and checked together with the other particle detectors in a test experiment. A large part of this dissertation is dedicated to the planning and performance of these tests as well to the evaluation of them. It could be show, that the modules worked accordly to their specifications, however because of unexpectedly high noise a signal correction became necessary. Different models for the correction were developed and tested in the framework of these thesis. In spite of the high noise cosmic muons could be detected and their energy deposition measured with a signal-to-noise ratio of 2:1. In the winter break 2005-2006 the recoil detector was installed into the HERMES experiment. First diagnosis and analysis software was developed. The silicon detector measured successfully energy depositions of minimally ionizing particles up to protons stopped in the sensor. Minimally ionizing particles could be detected with a signal-to-noise ratio of 5:1. By means of track information of the scintillating-fiber detector protons could be discriminated from pions and other mesons by the silicon detector. The HERMES

  9. Carbon cluster diagnostics-I: Direct Recoil Spectroscopy (DRS) of Ar+ and Kr+ bombarded graphite

    CERN Document Server

    Ahmad, Shoaib; Qayyum, A; Ahmad, B; Bahar, K; Arshed, W

    2016-01-01

    Measurements of the energy spectra of multiply charged positive and negative carbon ions recoiling from graphite surface under 100 and 150 keV argon and krypton ion bombardment are presented. With the energy spectrometer set at recoil angle of 79.5 degrees, direct recoil (DR) peaks have been observed with singly as well as multiply charged carbon ions , where n = 1 to 6. These monatomic and cluster ions have been observed recoiling with the characteristic recoil energy E(DR) . We have observed sharp DR peaks. A collimated projectile beam with small divergence is supplemented with a similar collimation before the energy analyzer to reduce the background of sputtered ions due to scattered projectiles.

  10. First measurement of surface nuclear recoil background for argon dark matter searches

    CERN Document Server

    Xu, Jingke; Westerdale, Shawn; Calaprice, Frank; Wright, Alexander; Shi, Zhiming

    2016-01-01

    One major background in direct searches for weakly interacting massive particles (WIMPs) comes from the deposition of radon progeny on detector surfaces. The most dangerous surface background is the $^{206}$Pb recoils produced by $^{210}$Po decays. In this letter, we report the first characterization of this background in liquid argon. The scintillation signal of low energy Pb recoils is measured to be highly quenched in argon, and we estimate that the 103keV $^{206}$Pb recoil background will produce a signal equal to that of a ~5keV (30keV) electron recoil ($^{40}$Ar recoil). In addition, we demonstrate that this dangerous $^{210}$Po surface background can be suppressed by a factor of ~100 or higher using pulse shape discrimination methods, which can make argon dark matter detectors near background-free and enhance their potential for discovery of medium- and high-mass WIMPs. We also discuss the impact on other low background experiments.

  11. Deconvoluting nonaxial recoil in Coulomb explosion measurements of molecular axis alignment

    Science.gov (United States)

    Christensen, Lauge; Christiansen, Lars; Shepperson, Benjamin; Stapelfeldt, Henrik

    2016-08-01

    We report a quantitative study of the effect of nonaxial recoil during Coulomb explosion of laser-aligned molecules and introduce a method to remove the blurring caused by nonaxial recoil in the fragment-ion angular distributions. Simulations show that nonaxial recoil affects correlations between the emission directions of fragment ions differently from the effect caused by imperfect molecular alignment. The method, based on analysis of the correlation between the emission directions of the fragment ions from Coulomb explosion, is used to deconvolute the effect of nonaxial recoil from experimental fragment angular distributions. The deconvolution method is then applied to a number of experimental data sets to correct the degree of alignment for nonaxial recoil, to select optimal Coulomb explosion channels for probing molecular alignment, and to estimate the highest degree of alignment that can be observed from selected Coulomb explosion channels.

  12. Gravitational Wave Recoil Oscillations of Black Holes: Implications for Unified Models of Active Galactic Nuclei

    CERN Document Server

    Komossa, S

    2008-01-01

    We consider the consequences of gravitational wave recoil for unified models of active galactic nuclei (AGNs). Spatial oscillations of supermassive black holes (SMBHs) around the cores of galaxies following gravitational wave (GW) recoil imply that the SMBHs spend a significant fraction of time off-nucleus, at scales beyond that of the molecular obscuring torus. Assuming reasonable distributions of recoil velocities, we compute the off-core timescale of (intrinsically type-2) quasars. We find that roughly one-half of major mergers result in a SMBH being displaced beyond the torus for a time of 30 Myr or more, comparable to quasar activity timescales. Since major mergers are most strongly affected by GW recoil, our results imply a deficiency of type 2 quasars in comparison to Seyfert 2 galaxies. Other consequences of the recoil oscillations for the observable properties of AGNs are also discussed.

  13. Retention studies of recoiling daughter nuclides of 225Ac in polymer vesicles

    International Nuclear Information System (INIS)

    Alpha radionuclide therapy is steadily gaining importance and a large number of pre-clinical and clinical studies have been carried out. However, due to the recoil effects the daughter recoil atoms, most of which are alpha emitters as well, receive energies that are much higher than the energies of chemical bonds resulting in decoupling of the radionuclide from common targeting agents. Here, we demonstrate that polymer vesicles (i.e. polymersomes) can retain recoiling daughter nuclei based on an experimental study examining the retention of 221Fr and 213Bi when encapsulating 225Ac. - Highlights: • First reported loading of 213Bi and 225Ac in polymer vesicles (i.e. polymersomes). • Encapsulating 225Ac in polymersomes results in up to 69 % recoil retention of 221Fr. • Encapsulating 225Ac in polymersomes results in up to 53 % recoil retention of 213Bi

  14. Recoiling black holes: prospects for detection and implications of spin alignment

    CERN Document Server

    Blecha, Laura; Kelley, Luke Zoltan; Torrey, Paul; Vogelsberger, Mark; Nelson, Dylan; Springel, Volker; Snyder, Gregory; Hernquist, Lars

    2015-01-01

    Supermassive black hole (BH) mergers produce powerful gravitational wave (GW) emission. Asymmetry in this emission imparts a recoil kick to the merged BH, which can eject the BH from its host galaxy altogether. Recoiling BHs could be observed as offset active galactic nuclei (AGN). Several candidates have been identified, but systematic searches have been hampered by large uncertainties regarding their observability. By extracting merging BHs and host galaxy properties from the Illustris cosmological simulations, we have developed a comprehensive model for recoiling AGN. Here, for the first time, we model the effects of BH spin alignment and recoil dynamics based on the gas-richness of host galaxies. For comparable assumptions, we find much higher rates of recoiling AGN than Volonteri & Madau (2008), indicating systematic differences between BH populations in semi-analytic models and cosmological simulations. We predict that if BH spins are not highly aligned, seeing-limited observations could resolve off...

  15. Impact of Low-Energy Response to Nuclear Recoils in Dark Matter Detectors

    CERN Document Server

    Mei, D -M; Wang, L

    2015-01-01

    We report an absolute energy response function to electronic and nuclear recoils for germanium and liquid xenon detectors. As a result, we show that the detection energy threshold of nuclear recoils for a dual-phase xenon detector can be $\\sim$ 6.8 keV for a given number of detectable photoelectrons. We evaluate the average energy expended per electron-hole pair to be $\\sim$8.9 eV, which sets a detection energy threshold of $\\sim$4.5 keV for a germanium detector at 50 mini-Kelvin at 69 volts with a primary phonon frequency of 2 THz. The Fano factors of nuclear and electronic recoils that constrain the capability for discriminating nuclear recoils below 2-3 keV recoil energy for both technologies are different.

  16. Indications and Problems of Intracranial Stenting: Report of Two Cases

    OpenAIRE

    Deguchi, J.; Kuroiwa, T; Nagasawa, S; Satoh, G.; T. Ohta

    2000-01-01

    There have been few reports of stenting in the intracranial arteries. We used coronary stents in the chronically occluded intracranial vertebral artery and stenosis of internal carotid artery by the external force, and good blood flow were resumed. Stenosis in the intracranial arteries is also a good indication for stent placement when it is due to chronic total occlusion or artery compression by external force. But stent placement in the intracranial arteries has some problems. Stent placeme...

  17. Functional Self-Expandable Metal Stents in Biliary Obstruction

    OpenAIRE

    Kwon, Chang-Il; Ko, Kwang Hyun; Hahm, Ki Baik; Kang, Dae Hwan

    2013-01-01

    Biliary stents are widely used not only for palliative treatment of malignant biliary obstruction but also for benign biliary diseases. Each plastic stent or self-expandable metal stent (SEMS) has its own advantages, and a proper stent should be selected carefully for individual condition. To compensate and overcome several drawbacks of SEMS, functional self-expandable metal stent (FSEMS) has been developed with much progress so far. This article looks into the outcomes and defects of each st...

  18. Transient coronary aneurysm formation after Nevo™ stent implantation versus persistent coronary aneurysm after Cypher Select™ stent implantation

    DEFF Research Database (Denmark)

    Christiansen, Evald Høj; Lassen, Jens Flensted; Jensen, Lisette Okkels

    2011-01-01

    We implanted a Cypher Select™ coronary stent and two months later a Nevo™ sirolimus-eluting coronary stent in another vessel. At a prescheduled angiographic follow-up, coronary aneurysms were seen in the two stented segments, 6 and 8 months after stent implantation, respectively. Six months later......, the aneurysm had healed in the Nevo, but was still present in the Cypher stented segment. We hypothesize that aneurysm formation was induced by sirolimus and the polymer of the implanted stents, and that subsequent healing was possible in the Nevo stent after degradation of the polymer....

  19. Measurement of the ionization produced by sub-keV silicon nuclear recoils in a CCD dark matter detector

    OpenAIRE

    Chavarria, A. E.; Collar, J. I.; Pena, J.; Privitera, P.; Robinson, A E; Scholz, B.; Sengul, C.; Zhou, J.; Estrada, J.; Izraelevitch, F.; Tiffenberg, J.; Neto, J. R. T. de Mello(Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil); Machado, D. Torres

    2016-01-01

    We report a measurement of the ionization efficiency of silicon nuclei recoiling with sub-keV kinetic energy in the bulk silicon of a charge-coupled device (CCD). Nuclear recoils were produced by low-energy neutrons ($

  20. The Supralimus sirolimus-eluting stent.

    Science.gov (United States)

    Lemos, Pedro A; Bienert, Igor

    2013-05-01

    The use of biodegradable polymeric coatings has emerged as a potential bioengineering target to improve the vascular compatibility of coronary drug-eluting stents (DESs). This review summarizes the main features and scientific facts about the Supralimus sirolimus-eluting stent (Sahajanand Medical Technologies Ltd, Surat, India), which is a biodegradable polymer-based, sirolimus-eluting metallic stent that was recently introduced for routine use in Europe. The novel stent is built on a stainless steel platform, coated with a blend of biodegradable polymers (poly-l-lactide, poly-dl-lactide-co-glycolide and polyvinyl pyrrolidone; coating thickness is 4-5 µm). The active agent is the antiproliferative sirolimus in a dose load of 1.4 µg/mm(2), which is released within 48 days. The Supralimus stent was initially evaluated in the single-arm SERIES-I study, which showed binary angiographic restenosis rates of 0% (in-stent) and 1.7% (in-segment) and an in-stent late lumen loss of 0.09 ± 0.28 mm. The multicenter randomized PAINT trial compared two DESs with identical metallic platforms and biodegradable polymer carriers, but different agents (Infinnium [Sahajanand Medical Technologies Pvt Ltd] paclitaxel-eluting stent or Supralimus sirolimus-eluting stent) against bare stents. After 3 years, the pooled DES population had similar rates of cardiac death or myocardial infarction (9 vs 7.1%; p = 0.6), but a lower risk of repeat interventions (10 vs 29.9%; p < 0.01) than controls with bare stents. The incidence of definite or probable stent thrombosis in the pooled DES group was 2.3% (1st year: 1.8%; 2nd year: 0.4% and 3rd year: 0%). These results demonstrate that the novel Supralimus stents are effective in reducing reintervention, while potentially improving the safety profile by decreasing the risk of late-term thrombosis, even though further studies would be necessary to confirm these findings.

  1. On the Superposition and Elastic Recoil of Electromagnetic Waves

    CERN Document Server

    Schantz, Hans G

    2014-01-01

    Superposition demands that a linear combination of solutions to an electromagnetic problem also be a solution. This paper analyzes some very simple problems: the constructive and destructive interferences of short impulse voltage and current waves along an ideal free-space transmission line. When voltage waves constructively interfere, the superposition has twice the electrical energy of the individual waveforms because current goes to zero, converting magnetic to electrical energy. When voltage waves destructively interfere, the superposition has no electrical energy because it transforms to magnetic energy. Although the impedance of the individual waves is that of free space, a superposition of waves may exhibit arbitrary impedance. Further, interferences of identical waveforms allow no energy transfer between opposite ends of a transmission line. The waves appear to recoil elastically one from another. Although alternate interpretations are possible, these appear less likely. Similar phenomenology arises i...

  2. B -> K(*) l+ l- @ Low Recoil and Physics Implications

    CERN Document Server

    Hiller, Gudrun

    2013-01-01

    This talk covers recent theoretical progress in exclusive semileptonic rare B-decays at low hadronic recoil. The efficient parametric suppression of the 1/mb corrections in this region provides opportunities to probe the Standard Model and beyond at precision level. Notably, angular analysis allows to simultaneously access electroweak flavor physics and hadronic matrix elements, the latter of which constitute the leading source of theoretical uncertainty. Ratios of B ->K* form factors can already be extracted from present data. A comparison with existing theoretical determinations by lattice QCD and light cone sum rules gives a consistent picture over the whole kinematic range. In the future improved analyses will advance our understanding of non-perturbative methods for QCD and of |Delta B|=1 transitions.

  3. Neutron absorbed dose determination by calculations of recoil energy.

    Science.gov (United States)

    Wrobel, F; Benabdesselam, M; Iacconi, P; Lapraz, D

    2004-01-01

    The aim of this work is to calculate the absorbed dose to matter due to neutrons in the 5-150 MeV energy range. Materials involved in the calculations are Al2O3, CaSO4 and CaS, which may be used as dosemeters and have already been studied for their luminescent properties. The absorbed dose is assumed to be mainly due to the energy deposited by the recoils. Elastic reactions are treated with the ECIS code while for the non-elastic ones, a Monte Carlo code has been developed and allowed to follow the nucleus decay and to determine its characteristics (nature and energy). Finally, the calculations show that the absorbed dose is mainly due to non-elastic process and that above 20 MeV this dose decreases slightly with the neutron energy. PMID:15353750

  4. The ANTARES recoil time-of-flight spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Martin, J.W.; Russell, G.J. [New South Wales Univ., Kensington, NSW (Australia); Cohen, D.D.; Dytlewski, N. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1996-12-31

    The Australian National Tandem for Applied Research (ANTARES), is a 8MV FN tandem particle accelerator at the Australian Nuclear Science and Technology Organisation. Research on the accelerator is divided between two groups, Accelerator Mass Spectrometry (AMS) and lon Beam Analysis (IBA). The IBA group carries out a range of research projects from nuclear physics to materials characterisation. The major IBA project on the accelerator is a recoil time-of-flight spectrometer which consists of two electrostatic time pulse generators and an ion-implanted surface barrier detector. The spectrometer is ideally suited to the profiling of layered multi-element materials, and has been used to characterise materials such as metal-germanides, optoelectronics, superconductors and catalytic converters. This paper will describe the time-of-flight system as well as some recent materials characterisation results. 1 refs., 3 figs.

  5. The influence of vascular anatomy on carotid artery stenting: a parametric study for damage assessment.

    Science.gov (United States)

    Iannaccone, F; Debusschere, N; De Bock, S; De Beule, M; Van Loo, D; Vermassen, F; Segers, P; Verhegghe, B

    2014-03-01

    Carotid artery stenting is emerging as an alternative technique to surgery for the treatment of symptomatic severe carotid stenosis. Clinical and experimental evidence demonstrates that both plaque morphology and biomechanical changes due to the device implantation can be possible causes of an unsuccessful treatment. In order to gain further insights of the endovascular intervention, a virtual environment based on structural finite element simulations was built to emulate the stenting procedure on generalized atherosclerotic carotid geometries which included a damage model to quantify the injury of the vessel. Five possible lesion scenarios were simulated by changing both material properties and vascular geometrical features to cover both presumed vulnerable and stable plaques. The results were analyzed with respect to lumen gain and wall stresses which are potentially related to the failure of the procedure according to previous studies. Our findings show that an elliptic lumen shape and a thinner fibrous cap with an underlying lipid pool result in higher stenosis reduction, while large calcifications and fibrotic tissue are more prone to recoil. The shielding effect of a thicker fibrous cap helps to reduce local compressive stresses in the soft plaque. The presence of a soft plaque reduces the damage in the healthy vascular structures. Contrarily, the presence of hard plaque promotes less damage volume in the fibrous cap and reduces stress peaks in this region, but they seem to increase stresses in the media-intima layer. Finally the reliability of the achieved results was put into clinical perspective.

  6. A Study of Nuclear Recoils in Liquid Argon Time Projection Chamber for the Direct Detection of WIMP Dark Matter

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Huajie [Princeton Univ., NJ (United States)

    2014-11-01

    Robust results of WIMP direct detection experiments depend on rm understandings of nuclear recoils in the detector media. This thesis documents the most comprehensive study to date on nuclear recoils in liquid argon - a strong candidate for the next generation multi-ton scale WIMP detectors. This study investigates both the energy partition from nuclear recoil energy to secondary modes (scintillation and ionization) and the pulse shape characteristics of scintillation from nuclear recoils.

  7. Retrograde Colonic Stent Implantation Assisted by Percutaneous Colostomy: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Hyoung Gun; Han, Hyun Young; Chun, Tong Jin [Eulji Medical Center, Seoul (Korea, Republic of)

    2009-10-15

    We present a patient with disseminated pancreatic cancer who presented with symptoms of acute obstruction of the sigmoid colon. It was not possible to pass the region of the obstruction with a guide wire under colonoscopy and fluoroscopy. Consequently retrograde implantation of stents was performed successfully with the assistance of a minimally-sized colostomy when compared with a previously described procedure in the literature.

  8. EMPREGO DE STENTS CEREBRAIS NAS PATOLOGIAS CEREBROVASCULARES

    Directory of Open Access Journals (Sweden)

    Laís Rocha Lopes

    2015-06-01

    Full Text Available Objective: To understand the applicability and characteristics of the stents for the treatment of cerebrovascular pathologies in order to understand its viability for the therapy. Methods: Scientific articles were used based on electronic search as PubMed, Scientific Electronic Library Online (SciELO, Intechopen, Medscape. An international and up to date source of articles was used. Results: Cerebrovascular diseases have emerged as the second most important cause of mortality worldwide, from this principle we observe the importance of this study. Recently, as a solution form, stents have become a major treatment option for difficult and not feasible cerebral aneurysms single winding. Intracranial stents serve as a bridge to the neo-endothelialization by providing a reduction in blood flow into the aneurysm. The use of stents for treatment should be seriously analyzed according to their feasibility, the knowledge of the professional about their brands, features and deployment techniques, and theoretical part of the professional needs to have dexterity to the application of an intracranial stent. Conclusions: This review raises an awareness of this subject, starts from the concept of cerebrovascular disease and aneurysms as well as the genesis of the stents, progressing to elucidate all product brands and specific characteristics of each, ending with its applicability, as well as making clear the purpose and mechanism of stents.

  9. Targeting In-Stent-Stenosis with RGD- and CXCL1-Coated Mini-Stents in Mice

    Science.gov (United States)

    Weinandy, Stefan; Schreiber, Fabian; Megens, Remco T. A.; Theelen, Wendy; Smeets, Ralf; Jockenhövel, Stefan; Gries, Thomas; Möller, Martin; Klee, Doris; Weber, Christian; Zernecke, Alma

    2016-01-01

    Atherosclerotic lesions that critically narrow the artery can necessitate an angioplasty and stent implantation. Long-term therapeutic effects, however, are limited by excessive arterial remodeling. We here employed a miniaturized nitinol-stent coated with star-shaped polyethylenglycole (star-PEG), and evaluated its bio-functionalization with RGD and CXCL1 for improving in-stent stenosis after implantation into carotid arteries of mice. Nitinol foils or stents (bare metal) were coated with star-PEG, and bio-functionalized with RGD, or RGD/CXCL1. Cell adhesion to star-PEG-coated nitinol foils was unaltered or reduced, whereas bio-functionalization with RGD but foremost RGD/CXCL1 increased adhesion of early angiogenic outgrowth cells (EOCs) and endothelial cells but not smooth muscle cells when compared with bare metal foils. Stimulation of cells with RGD/CXCL1 furthermore increased the proliferation of EOCs. In vivo, bio-functionalization with RGD/CXCL1 significantly reduced neointima formation and thrombus formation, and increased re-endothelialization in apoE-/- carotid arteries compared with bare-metal nitinol stents, star-PEG-coated stents, and stents bio-functionalized with RGD only. Bio-functionalization of star-PEG-coated nitinol-stents with RGD/CXCL1 reduced in-stent neointima formation. By supporting the adhesion and proliferation of endothelial progenitor cells, RGD/CXCL1 coating of stents may help to accelerate endothelial repair after stent implantation, and thus may harbor the potential to limit the complication of in-stent restenosis in clinical approaches. PMID:27192172

  10. Targeting In-Stent-Stenosis with RGD- and CXCL1-Coated Mini-Stents in Mice.

    Directory of Open Access Journals (Sweden)

    Sakine Simsekyilmaz

    Full Text Available Atherosclerotic lesions that critically narrow the artery can necessitate an angioplasty and stent implantation. Long-term therapeutic effects, however, are limited by excessive arterial remodeling. We here employed a miniaturized nitinol-stent coated with star-shaped polyethylenglycole (star-PEG, and evaluated its bio-functionalization with RGD and CXCL1 for improving in-stent stenosis after implantation into carotid arteries of mice. Nitinol foils or stents (bare metal were coated with star-PEG, and bio-functionalized with RGD, or RGD/CXCL1. Cell adhesion to star-PEG-coated nitinol foils was unaltered or reduced, whereas bio-functionalization with RGD but foremost RGD/CXCL1 increased adhesion of early angiogenic outgrowth cells (EOCs and endothelial cells but not smooth muscle cells when compared with bare metal foils. Stimulation of cells with RGD/CXCL1 furthermore increased the proliferation of EOCs. In vivo, bio-functionalization with RGD/CXCL1 significantly reduced neointima formation and thrombus formation, and increased re-endothelialization in apoE-/- carotid arteries compared with bare-metal nitinol stents, star-PEG-coated stents, and stents bio-functionalized with RGD only. Bio-functionalization of star-PEG-coated nitinol-stents with RGD/CXCL1 reduced in-stent neointima formation. By supporting the adhesion and proliferation of endothelial progenitor cells, RGD/CXCL1 coating of stents may help to accelerate endothelial repair after stent implantation, and thus may harbor the potential to limit the complication of in-stent restenosis in clinical approaches.

  11. Targeting In-Stent-Stenosis with RGD- and CXCL1-Coated Mini-Stents in Mice.

    Science.gov (United States)

    Simsekyilmaz, Sakine; Liehn, Elisa A; Weinandy, Stefan; Schreiber, Fabian; Megens, Remco T A; Theelen, Wendy; Smeets, Ralf; Jockenhövel, Stefan; Gries, Thomas; Möller, Martin; Klee, Doris; Weber, Christian; Zernecke, Alma

    2016-01-01

    Atherosclerotic lesions that critically narrow the artery can necessitate an angioplasty and stent implantation. Long-term therapeutic effects, however, are limited by excessive arterial remodeling. We here employed a miniaturized nitinol-stent coated with star-shaped polyethylenglycole (star-PEG), and evaluated its bio-functionalization with RGD and CXCL1 for improving in-stent stenosis after implantation into carotid arteries of mice. Nitinol foils or stents (bare metal) were coated with star-PEG, and bio-functionalized with RGD, or RGD/CXCL1. Cell adhesion to star-PEG-coated nitinol foils was unaltered or reduced, whereas bio-functionalization with RGD but foremost RGD/CXCL1 increased adhesion of early angiogenic outgrowth cells (EOCs) and endothelial cells but not smooth muscle cells when compared with bare metal foils. Stimulation of cells with RGD/CXCL1 furthermore increased the proliferation of EOCs. In vivo, bio-functionalization with RGD/CXCL1 significantly reduced neointima formation and thrombus formation, and increased re-endothelialization in apoE-/- carotid arteries compared with bare-metal nitinol stents, star-PEG-coated stents, and stents bio-functionalized with RGD only. Bio-functionalization of star-PEG-coated nitinol-stents with RGD/CXCL1 reduced in-stent neointima formation. By supporting the adhesion and proliferation of endothelial progenitor cells, RGD/CXCL1 coating of stents may help to accelerate endothelial repair after stent implantation, and thus may harbor the potential to limit the complication of in-stent restenosis in clinical approaches.

  12. Is provisional stenting the effective option? The WIDEST study (Wiktor stent in de novo stenosis)

    OpenAIRE

    Fluck, D.; Chenu, P; Mills, P; Davies, A; Street, J.; Paul, E; Balcon, R; Layton, C; Investigators', G

    2000-01-01

    AIM—To compare the immediate and late outcomes of patients treated by a policy of routine stent implantation with routine balloon angioplasty and the use of stents only when an ideal result has not been obtained.
METHODS—A nine centre, multinational, randomised study of 300 patients with coronary artery disease thought suitable for treatment of a single lesion by balloon angioplasty or stent implantation. Only new lesions in patients who had not undergone previous bypass surgery were included...

  13. Stent-retriever thrombectomy after intravenous t-PA vs. t-PA alone in stroke

    DEFF Research Database (Denmark)

    Saver, Jeffrey L; Goyal, Mayank; Bonafe, Alain;

    2015-01-01

    BACKGROUND: Among patients with acute ischemic stroke due to occlusions in the proximal anterior intracranial circulation, less than 40% regain functional independence when treated with intravenous tissue plasminogen activator (t-PA) alone. Thrombectomy with the use of a stent retriever, in addit......BACKGROUND: Among patients with acute ischemic stroke due to occlusions in the proximal anterior intracranial circulation, less than 40% regain functional independence when treated with intravenous tissue plasminogen activator (t-PA) alone. Thrombectomy with the use of a stent retriever......, in addition to intravenous t-PA, increases reperfusion rates and may improve long-term functional outcome. METHODS: We randomly assigned eligible patients with stroke who were receiving or had received intravenous t-PA to continue with t-PA alone (control group) or to undergo endovascular thrombectomy......: In patients receiving intravenous t-PA for acute ischemic stroke due to occlusions in the proximal anterior intracranial circulation, thrombectomy with a stent retriever within 6 hours after onset improved functional outcomes at 90 days. (Funded by Covidien; SWIFT PRIME ClinicalTrials.gov number, NCT01657461.)....

  14. Management of malignant biliary obstruction: Technical and clinical results using an expanded polytetrafluoroethylene fluorinated ethylene propylene (ePTFE/FEP)-covered metallic stent after 6-year experience

    International Nuclear Information System (INIS)

    To evaluate the efficacy and safety of an expanded polytetrafluoroethylene-fluorinated ethylene-propylene (ePTFE/FEP)-covered metallic stent in the management of malignant biliary obstruction. Eighty consecutive patients with malignant common bile duct strictures were treated by placement of 83 covered metallic stents. The stent-graft consists of an inner ePTFE/FEP lining and an outer supporting structure of nitinol wire. Clinical evaluation, assessment of serum bilirubin and liver enzyme levels were analyzed before biliary drainage, before stent-graft placement and during the follow-up period at 1, 3, 6, 9 and 12 months. Technical success was obtained in all cases. After a mean follow-up of 6.9±4.63 months, the 30-day mortality rate was 14.2%. Survival rates were 40% and 20.2% at 6 and 12 months, respectively. Stent-graft patency rates were 95.5%, 92.6% and 85.7% at 3, 6 and 12 months, respectively. Complications occurred in five patients (6.4%); among these, acute cholecystitis was observed in three patients (3.8%). A stent-graft occlusion rate of 9% was observed. The percentage of patients undergoing lifetime palliation (91%) and the midterm patency rate suggest that placement of this ePTFE/FEP-covered stent-graft is safe and highly effective in achieving biliary drainage in patients with malignant strictures of the common bile duct. (orig.)

  15. Management of malignant biliary obstruction: Technical and clinical results using an expanded polytetrafluoroethylene fluorinated ethylene propylene (ePTFE/FEP)-covered metallic stent after 6-year experience

    Energy Technology Data Exchange (ETDEWEB)

    Fanelli, Fabrizio; Orgera, Gianluigi; Bezzi, Mario; Rossi, Plinio; Allegritti, Massimiliano; Passariello, Roberto [University of Rome, Department of Radiological Sciences, Rome (Italy)

    2008-05-15

    To evaluate the efficacy and safety of an expanded polytetrafluoroethylene-fluorinated ethylene-propylene (ePTFE/FEP)-covered metallic stent in the management of malignant biliary obstruction. Eighty consecutive patients with malignant common bile duct strictures were treated by placement of 83 covered metallic stents. The stent-graft consists of an inner ePTFE/FEP lining and an outer supporting structure of nitinol wire. Clinical evaluation, assessment of serum bilirubin and liver enzyme levels were analyzed before biliary drainage, before stent-graft placement and during the follow-up period at 1, 3, 6, 9 and 12 months. Technical success was obtained in all cases. After a mean follow-up of 6.9{+-}4.63 months, the 30-day mortality rate was 14.2%. Survival rates were 40% and 20.2% at 6 and 12 months, respectively. Stent-graft patency rates were 95.5%, 92.6% and 85.7% at 3, 6 and 12 months, respectively. Complications occurred in five patients (6.4%); among these, acute cholecystitis was observed in three patients (3.8%). A stent-graft occlusion rate of 9% was observed. The percentage of patients undergoing lifetime palliation (91%) and the midterm patency rate suggest that placement of this ePTFE/FEP-covered stent-graft is safe and highly effective in achieving biliary drainage in patients with malignant strictures of the common bile duct. (orig.)

  16. Carotid Stent Fracture from Stylocarotid Syndrome

    Science.gov (United States)

    Hooker, Jeffrey D; Joyner, David A; Farley, Edward P; Khan, Majid

    2016-01-01

    Eagle syndrome is a rare condition resulting from elongation of the temporal styloid process or calcification of its associated stylohyoid ligaments. Although usually presenting with pain or odynophagia, Eagle syndrome has been reported to cause a multitude of neurologic symptoms or vascular complications, some of which can be life-threatening. We present a case in which an endovascularly placed internal carotid artery stent in close proximity to a calcified stylohyoid ligament resulted in stent fracture with subsequent stent and vessel occlusion. We review and discuss the presentation, diagnosis, etiology, complications and treatment options of the syndrome.

  17. A Novel method for modeling the recoil in W boson events at hadron collider

    Energy Technology Data Exchange (ETDEWEB)

    Abazov, Victor Mukhamedovich; /Dubna, JINR; Abbott, Braden Keim; /Oklahoma U.; Abolins, Maris A.; /Michigan State U.; Acharya, Bannanje Sripath; /Tata Inst.; Adams, Mark Raymond; /Illinois U., Chicago; Adams, Todd; /Florida State U.; Aguilo, Ernest; /Alberta U. /Simon Fraser U. /York U., Canada /McGill U.; Ahsan, Mahsana; /Kansas State U.; Alexeev, Guennadi D.; /Dubna, JINR; Alkhazov, Georgiy D.; /St. Petersburg, INP; Alton, Andrew K.; /Michigan U. /Augustana Coll., Sioux Falls /Northeastern U.

    2009-07-01

    We present a new method for modeling the hadronic recoil in W {yields} {ell}{nu} events produced at hadron colliders. The recoil is chosen from a library of recoils in Z {yields} {ell}{ell} data events and overlaid on a simulated W {yields} {ell}{nu} event. Implementation of this method requires that the data recoil library describe the properties of the measured recoil as a function of the true, rather than the measured, transverse momentum of the boson. We address this issue using a multidimensional Bayesian unfolding technique. We estimate the statistical and systematic uncertainties from this method for the W boson mass and width measurements assuming 1 fb{sup -1} of data from the Fermilab Tevatron. The uncertainties are found to be small and comparable to those of a more traditional parameterized recoil model. For the high precision measurements that will be possible with data from Run II of the Fermilab Tevatron and from the CERN LHC, the method presented in this paper may be advantageous, since it does not require an understanding of the measured recoil from first principles.

  18. Very late stent thrombosis following the placement of a crossing Y-stent with dual closed-cell stents for the coiling of a wide-necked aneurysm.

    Science.gov (United States)

    Lee, Chang-Young; Kim, Chang-Hyun

    2015-02-01

    The crossing Y-stent technique is a viable option for coiling of wide-necked bifurcation aneurysms. However, little is known about the long-term impact of this technique. Very late (>1 year) stent thrombosis following the placement of a crossing Y-stent with dual closed-cell stents for the coiling of a wide-necked basilar tip aneurysm, which has not been reported to date, is described.

  19. Retention studies of recoiling daughter nuclides of 225Ac in polymer vesicles.

    Science.gov (United States)

    Wang, G; de Kruijff, R M; Rol, A; Thijssen, L; Mendes, E; Morgenstern, A; Bruchertseifer, F; Stuart, M C A; Wolterbeek, H T; Denkova, A G

    2014-02-01

    Alpha radionuclide therapy is steadily gaining importance and a large number of pre-clinical and clinical studies have been carried out. However, due to the recoil effects the daughter recoil atoms, most of which are alpha emitters as well, receive energies that are much higher than the energies of chemical bonds resulting in decoupling of the radionuclide from common targeting agents. Here, we demonstrate that polymer vesicles (i.e. polymersomes) can retain recoiling daughter nuclei based on an experimental study examining the retention of (221)Fr and (213)Bi when encapsulating (225)Ac. PMID:24374072

  20. Nuclear recoil correction to the g factor of boron-like argon

    CERN Document Server

    Shchepetnov, Arseniy A; Volotka, Andrey V; Shabaev, Vladimir M; Tupitsyn, Ilya I; Plunien, Guenter

    2014-01-01

    The nuclear recoil effect to the g factor of boron-like ions is investigated. The one-photon-exchange correction to the nuclear recoil effect is calculated in the non-relativistic approximation for the nuclear recoil operator and in the Breit approximation for the interelectronic-interaction operator. The screening potential is employed to estimate the higher-order contributions. The updated g-factor values are presented for the ground 2P_1/2 and first excited 2P_3/2 states of B-like argon 40^Ar^13+, which are presently being measured by the ARTEMIS group at GSI.

  1. Improved measurement of the 'head-tail' effect in nuclear recoils

    Energy Technology Data Exchange (ETDEWEB)

    Dujmic, D; Fisher, P; Henderson, S; Kaboth, A; Kohse, G; Lanza, R; Monroe, J; Sciolla, G; Vanderspek, R; Yamamoto, R [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Ahlen, S; Lewandowska, M; Roccaro, A; Tomita, H [Boston University, Boston, MA 02215 (United States); Skvorodnev, N; Wellenstein, H [Brandeis University, Waltham, MA 02454 (United States)], E-mail: ddujmic@mit.edu

    2008-07-15

    We present new results with a prototype detector that is being developed by the DMTPC collaboration for the measurement of the direction tag ('head-tail') of dark matter wind. We use neutrons from a {sup 252}Cf source to create low-momentum nuclear recoils in elastic scattering with the residual gas nuclei. The recoil track is imaged in low-pressure time-projection chamber with optical readout. We measure the ionization rate along the recoil trajectory, which allows us to determine the direction tag of the incoming neutrons.

  2. Use of thin collodion films to prevent recoil-ion contamination of alpha-spectrometry detectors

    International Nuclear Information System (INIS)

    Recoil ions from alpha-particle emission can contaminate surface-barrier detection systems. This contamination results in increased measurement uncertainty, and may require the replacement of expensive detectors. Disposable thin Collodion films are easily prepared and effectively retard the recoil ions when either directly applied to the surface of alpha-sources or as catcher foils between the source and the detector. The thin films are particularly effective for relatively low-level sources, but can sustain structural damage when exposed to high levels of recoil ions (tens of thousands per second) over extended periods of time. (author)

  3. Primary Endonasal DCR Without Stent: Our Experience and Case Series Analysis.

    Science.gov (United States)

    Raghuwanshi, Shiv Kumar; Raghuwanshi, Sapna; Agarwal, Mohit; Batni, Gaurav

    2015-09-01

    Endonasal dacryocystorhinostomy is widely accepted and effective treatment option for nasolacrimal duct obstruction. It can be done with or without the use of stents. This study was carried out to evaluate the results of endonasal DCR surgery and to access efficacy of this procedure without stenting. This is a prospective clinical study conducted in Departments of ENT and Ophthalmology, L.N. Medical College and J.K. Hospital, Bhopal from October 2008 to April 2012. A total of 90 patients with epiphora as evidenced by nasolacrimal duct blockage on syringing were included in the study. These patients underwent endoscopic DCR without stenting. The cases were followed up to 18 months postoperative. Surgical success was defined as anatomical patency and symptomatic relief at the end of the follow up period. Failure was defined as no symptomatic relief, and/or acute dacryocystitis, and/or non patent lacrimal drainage system. Surgical success was observed in 80 of 90 (88.89 %) patients. Incidence of complication was low as only 6 patients had minor complication of bleeding, synechie and granulation tissue formation. It was concluded that high success rates could be achieved in case of nasolacrimal duct obstruction by endoscopic DCR. Thus, we can minimize complications, discomfort, the cost of stenting and follow up visits after endonasal DCR surgery. PMID:26405663

  4. Use of a covered stent modification to produce a transcatheter valve: laboratory and animal testing.

    Science.gov (United States)

    Levi, Daniel S; Raff, Evan; Stepan, Lenka; Liu, Jasen; Williams, Ryan J; Moore, John W; Carman, Greg

    2005-01-01

    Stent-based transcatheter valves continue to require large sheaths inappropriate for deployment in children. Low-profile covered stent valves (CSVs) were constructed by removing triangular sections from two sides of partially expanded Palmaz P308 stents before covering the stents with 0.1 mm polytetrafluoroethylene. Valves were carefully crimped onto balloon catheters and deployed in a pulsatile flow loop. With fixed afterload and pump output, flow, degree of stenosis, effect on pulse pressure, and ease of deployment were determined for each valve. In vivo transcatheter feasibility studies were then performed by disabling the aortic valve of two 25-kg pigs, and deploying transcatheter CSVs into their descending aorta. All transcatheter valves deployed consistently via sheaths three French sizes larger than the recommended sheath for their balloon and none created significant obstruction. With the bicuspid and supravalvar CSVs, the flow was 64% and 79% (respectively) of a commercially available valve. Angiograms revealed excellent acute CSV function after deployment with only mild regurgitation and without significant obstruction to systolic flow. Although long-term testing is required, a modified CSV design may have utility in low-profile pediatric transcatheter valve replacement. PMID:16340356

  5. FDA Approves First Fully Dissolvable Stent

    Science.gov (United States)

    ... newly approved stent is made from a biodegradable polymer that's commonly used in medical devices designed to ... the views of MedlinePlus, the National Library of Medicine, the National Institutes of Health, the U.S. Department ...

  6. Emerging Stent and Balloon Technologies in the Femoropopliteal Arteries

    Directory of Open Access Journals (Sweden)

    Georgios Pastromas

    2014-01-01

    Full Text Available Endovascular procedures for the management of the superficial femoral (SFA and popliteal artery disease are increasingly common. Over the past decade, several stent technologies have been established which may offer new options for improved clinical outcomes. This paper reviews the current evidence for SFA and popliteal artery angioplasty and stenting, with a focus on randomized trials and registries of nitinol self-expanding stents, drug-eluting stents, dug-coated balloons, and covered stent-grafts. We also highlight the limitations of the currently available data and the future routes in peripheral arterial disease (PAD stent and balloon technology.

  7. Focal stent collapse in a patient with systemic sclerosis.

    Science.gov (United States)

    Di Francesco, L; Finci, L; Reimers, B; Di Mario, C; Colombo, A

    1998-05-01

    We report a patient with systemic sclerosis having implantation of a 35 mm beStent with immediate success but developing angina at follow-up. A focal stent collapse with focal hyperplasia in and outside the stent was documented by ultrasound after 2 mos. A 14mm Palmaz-Schatz stent was successfully deployed into the collapsed beStent, with good 6-mo angiographic result. The stent collapse was probably due to unequal distribution of radial forces and possibly reactive hyperplasia in this unique patient with systemic sclerosis.

  8. Vessel wall reactions to endovascular stent implantation

    OpenAIRE

    van Beusekom, Heleen

    1993-01-01

    textabstractIn order to gain insight in the effects of stenting, we studied the process of wound healing and the short- and long-term effect of these permanently present foreign bodies. Both thrombogenic and less thrombogenic metals were evaluated with respect to thrombogenicity and tissue response. Synthetic polymers were evaluated with respect to improving the haemocompatibility and tissue-compatibility profile of these devices. Stenting of normal porcine arteries. In Chapter 2, a balloon-e...

  9. Nasolacrimal Polyurethane Stent: Complications with CT Correlation

    International Nuclear Information System (INIS)

    Purpose: To evaluate initial results in patients with epiphora secondary to obstruction of the nasolacrimal duct treated by placement of a polyurethane stent, and to discuss the technical problems and complications arising during the procedure, with visualization of the anatomy of the drainage apparatus using computed tomography (CT). Methods: We inserted 20 polyurethane Song stents under fluoroscopic guidance after dacryocystography in 19 patients with grade 3-4 epiphora caused by idiopathic obstruction of the nasolacrimal duct. CT scans were obtained following stent placement in all patients. Results: We focus on the technical problems and complications that arose during these procedures. During negotiation of the guidewire past the obstruction at the level of the junction of the duct with the lacrimal sac, the guidewire created a false passage in a posterior suborbital direction in two cases and towards the posterior midline in another. In all cases the guidewire was withdrawn and reinserted through the proper anatomic route without further difficulty or complications. In two cases the stent was improperly positioned wholly or partially outside the nasolacrimal system (one medially, one posteriorly). In one case the stent was removed and reinserted; in the other it remains in place and functional. CT was performed in all these cases to ensure proper anatomic alignment and determine what had gone wrong. The epiphora was completely resolved in 13 cases and partially relieved in four; there were three cases of stent obstruction. Epistaxis of short duration (1 hr) occurred in seven patients and headache in one. Conclusions: Treatment of epiphora with polyurethane stents is a technique that is well tolerated by patients and achieves a high success rate, yet problems in placement may be encountered. Though no major consequences for patients are involved, cognizance of such difficulties is important to avoid incorrect positioning of stents

  10. Bilateral Metallic Stenting in Malignant Hilar Obstruction

    OpenAIRE

    Lee, Tae Hoon; Moon, Jong Ho; Park, Sang-Heum

    2014-01-01

    Endoscopic palliative biliary drainage is considered as a gold standard treatment in advanced or inoperable hilar cholangiocarcinoma. Also, metal stents are preferred over plastic stents in patients with >3 months life expectancy. However, the endoscopic intervention of advanced hilar obstruction is often more challenging and complex than that of distal malignant biliary obstructions. In this literature review, we describe the issues commonly encountered during endoscopic unilateral (single) ...

  11. Malignant biliary obstruction treated with metallic stents

    International Nuclear Information System (INIS)

    Purpose: The outcome of 33 patients with malignant biliary obstruction treated with metallic stents is presented. Materials and methods: Thirty-eight biliary metallic stents were placed in 33 patients with malignant biliary obstruction. They were 52-71 years old (mean = 61.7); 23 were male and 10 were female. The biliary obstruction was caused by biliary carcinoma (n = 16), pancreatic carcinoma (n = 2), hepatoma (n = 2), metastasis in liver (n = 3) and lymph node metastasis (n = 10). Six types and 38 metallic stents were used. After stentering, 3 cases were treated with intrastent brachytherapy, 7 cases treated with external radiotherapy and 2 patients treated with interventional radiology. Patients were followed for 6-28 months, mean 11 months. Results: Stent placement was successful in all 33 cases. The same time, 4 patients were treated with plastic tube for external drainage only. The successful rate was 90%. Twenty-nine patients were placed in one time, 4 cases began with plastic tube which was replaced with metallic stents after 1-2 weeks. Nine had metallic stents and plastic tube, because of complicated obstruction. The external drainage catheters were removed after 15-200 days. Three patients had stents crossing the ampulla. In 28 cases (84.85%), jaundice was reduced satisfactorily while in 5 cases with complicated biliary obstruction, the result was unsatisfactory. The median survival was 7 months. After stentering, 12 cases were treated with locat chemotherapy, brachytherapy or radiotherapy. The median survival period was 10 months. Conclusion: The metallic stent provides good palliative drainage and is well tolerated by patients. It improves the survival rate when combined with radiotherapy, brachytherapy and chemotherapy in patients with malignant biliary obstruction

  12. Six-month clinical outcomes of Firebird 2TM sirolimus-eluting stent implantation in real-world patients with coronary artery diseases

    Institute of Scientific and Technical Information of China (English)

    GE Jun-bo; ZHANG Feng; QIAN Ju-ying; GE Lei; LIU Xue-bo; ZHOU Jun

    2011-01-01

    Background The Firebird 2TM sirolimus-eluting stent (Firebird 2 stent) is a second-generation sirolimus-eluting stent which has a cobalt-chromium alloy stent platform, a brand new bracket structure, and two layers of styrene-butylenes-styrene polymer coatings with better biocompatibility. The Firebird 2TM cObalt-Chromium alloy sirolimus-elUting Stent registry (FOCUS registry) aimed to evaluate the safety and efficacy of the Firebird 2 stent in patients with coronary artery disease in daily practice.Methods The FOCUS registry is a prospective, non-randomized, international multi-center, single-arm clinical registry.Between March 2009 and February 2010, 5084 patients receiving at least 1 Firebird 2 stent during daily clinical practice at 83 medical centers were enrolled.Results Of the 5084 patients enrolled in the registry, 5077 and 5058 were respectively available for 30 days and 6 months follow-up. The 30-day rate of major adverse cardiac events (MACE) was 1.20%, including 13 cardiac deaths, 46 non-fatal myocardial infarction (MI), and 6 target vessel revascularization (TVR). At 6 months follow-up, the rate of MACE was 1.80%. There were 32 cardiac deaths, 48 non-fatal MI, and 15 TVR. According to the Academic Research Consortium definition, definite/probable stent thrombosis (ST) occurred in 0.43% (22/5058) of patients, including 8 cases of acute ST, 11 subacute ST, and 3 late ST.Conclusion The Firebird 2 stent showed the promising efficacy and safety at 30 days and 6 months in a real-world population of patients with coronary artery diseases.

  13. Intracoronary stents: clinical and angiographic results.

    Science.gov (United States)

    Popma, J J; Ellis, S G

    1990-10-01

    Limitations of current forms of coronary angioplasty including abrupt vessel closure and delayed restenosis have led to the development of alternative nonsurgical methods of coronary revascularization. By scaffolding the arterial dissection and smoothing the endoluminal surface, intracoronary stenting may obviate the need for emergency coronary bypass surgery in patients who develop abrupt vessel closure following coronary angioplasty. As primary therapy, its use may prevent or delay restenosis in high-risk patients; however, due to potential patient selection bias, controlled studies are needed. Currently available intracoronary stents are limited by varying degrees of inflexibility, radiolucency, and thrombogenicity. These limitations have resulted in the development of innovative stent designs using radioopaque tantalum filaments and aggressive pharmacologic treatment with antiplatelet and anti-thrombotic therapy following stent deployment. Current experimental investigation into the feasibility of intracoronary stent coating with genetically engineered endothelial cells or slow release antiproliferative agents, such as colchicine or methotrexate, may further serve to lessen the frequency of late restenosis. The optimal patient selection criteria for the use of the intracoronary stent is currently the subject of intense clinical investigation. PMID:2227766

  14. Clinical Application of Stents in Digestive Diseases

    Institute of Scientific and Technical Information of China (English)

    GUAN Yongsong

    2002-01-01

    Objective To evaluate clinical application of therapeutic stenting of digestive diseases as a new approach from conventional management. Methods 115 cases of disorders in digestive system were managed with stents clinically, 148 procedures of intervention in all. The cases were suffering from portal hypertension of cirrhosis, post - operative esophageal stricture, Stricture resulted from esophageal carcinoma, Buddi - Chari syndrome, narrowing of superior mesentery arteries and biliary tract, etc. All had had the strictured or obliterated original natural tube lumen been dilated or recanalized under the guidance of monitoring of the fluoroscope before the stent placement except those receiving TIPS needing the creation of an artificial passage within the liver to place the stent. Results Therapeutic stenting achieves clinical effects completely different from conventional internal medicine and surgery such as portal hypertension by cirrhosis with esophageal varices, megalospleen, ascites improved; jaundis relived then resided and liver function improved and appetite better in postoperative stricture of bile duct; ascites and edema of lower limbs resided in Buddi - Chari syndrom; intestininal distention disappeared, appetite and digestive function improved in stricture in superior mesentery artery; and no dysphagia and easy food intake, appetite improved in patients of stricture of postoperative esophagus and stricture resulted from esophageal carcinoma. Conclusion Therapeutic stenting is clinically unique, dramatically effective, with minor risks and worthy promoting in the management of certain digestive disorders.

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

    International Nuclear Information System (INIS)

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

  16. 4D phase contrast flow imaging for in-stent flow visualization and assessment of stent patency in peripheral vascular stents – A phantom study

    International Nuclear Information System (INIS)

    Purpose: 4D phase contrast flow imaging is increasingly used to study the hemodynamics in various vascular territories and pathologies. The aim of this study was to assess the feasibility and validity of MRI based 4D phase contrast flow imaging for the evaluation of in-stent blood flow in 17 commonly used peripheral stents. Materials and methods: 17 different peripheral stents were implanted into a MR compatible flow phantom. In-stent visibility, maximal velocity and flow visualization were assessed and estimates of in-stent patency obtained from 4D phase contrast flow data sets were compared to a conventional 3D contrast-enhanced magnetic resonance angiography (CE-MRA) as well as 2D PC flow measurements. Results: In all but 3 of the tested stents time-resolved 3D particle traces could be visualized inside the stent lumen. Quality of 4D flow visualization and CE-MRA images depended on stent type and stent orientation relative to the magnetic field. Compared to the visible lumen area determined by 3D CE-MRA, estimates of lumen patency derived from 4D flow measurements were significantly higher and less dependent on stent type. A higher number of stents could be assessed for in-stent patency by 4D phase contrast flow imaging (n = 14) than by 2D phase contrast flow imaging (n = 10). Conclusions: 4D phase contrast flow imaging in peripheral vascular stents is feasible and appears advantageous over conventional 3D contrast-enhanced MR angiography and 2D phase contrast flow imaging. It allows for in-stent flow visualization and flow quantification with varying quality depending on stent type

  17. Frequency and consequences of early in-stent lesions after carotid artery stent placement.

    NARCIS (Netherlands)

    Jongen, L.M.; Hendrikse, J.; Waaijer, A.; Worp, H.B. van der; Leijdekkers, V.J.; Lo, R.T.; Mali, W.P.Th.; Prokop, M.

    2009-01-01

    PURPOSE: To examine the prevalence of in-stent lesions 1 month after carotid artery stent placement with multidetector computed tomography (CT) angiography and to evaluate their possible causes and their consequences during 1-year follow-up. MATERIALS AND METHODS: Sixty-nine patients with symptomati

  18. Computational Study of Axial Fatigue for Peripheral Nitinol Stents

    Science.gov (United States)

    Meoli, Alessio; Dordoni, Elena; Petrini, Lorenza; Migliavacca, Francesco; Dubini, Gabriele; Pennati, Giancarlo

    2014-07-01

    Despite their success as primary treatment for vascular diseases, Nitinol peripheral stents are still affected by complications related to fatigue failure. Hip and knee movements during daily activities produce large and cyclic deformations of the superficial femoral artery, that concomitant to the effects of pulsatile blood pressure, may cause fatigue failure in the stent. Fatigue failure typically occurs in cases of very extended lesions, which often require the use of two or more overlapping stents. In this study, finite element models were used to study the fatigue behavior of Nitinol stents when subjected to cyclic axial compression in different conditions. A specific commercial Nitinol stent was chosen for the analysis and subjected to cyclic axial compression typical of the femoral vascular region. Three different configurations were investigated: stent alone, stent deployed in a tube, and two overlapping stents deployed in a tube. Results confirm that stent oversizing has an influence in determining both the mean and amplitude strains induced in the stent and plays an important role in determining the fatigue response of Nitinol stents. In case of overlapping stents, numerical results suggest higher amplitude strains concentrate in the region close to the overlapping portion where the abrupt change in stiffness causes higher cyclic compression. These findings help to explain the high incidence of stent fractures observed in various clinical trials located close to the overlapping portion.

  19. Automation of experiments at Dubna Gas-Filled Recoil Separator

    Science.gov (United States)

    Tsyganov, Yu. S.

    2016-01-01

    Approaches to solving the problems of automation of basic processes in long-term experiments in heavy ion beams of the Dubna Gas-Filled Recoil Separator (DGFRS) facility are considered. Approaches in the field of spectrometry, both of rare α decays of superheavy nuclei and those for constructing monitoring systems to provide accident-free experiment running with highly radioactive targets and recording basic parameters of experiment, are described. The specific features of Double Side Silicon Strip Detectors (DSSSDs) are considered, special attention is paid to the role of boundary effects of neighboring p-n transitions in the "active correlations" method. An example of an off-beam experiment attempting to observe Zeno effect is briefly considered. Basic examples for nuclear reactions of complete fusion at 48Ca ion beams of U-400 cyclotron (LNR, JINR) are given. A scenario of development of the "active correlations" method for the case of very high intensity beams of heavy ions at promising accelerators of LNR, JINR, is presented.

  20. Moving towards first science with the St. George recoil separator

    Science.gov (United States)

    Meisel, Zachary; Berg, G. P. A.; Gilardy, G.; Moran, M.; Schmitt, J.; Seymour, C.; Stech, E.; Couder, M.

    2015-10-01

    The St. George recoil mass separator has recently been coupled to the 5MV St. Ana accelerator at the University of Notre Dame's Nuclear Science Lab. St. George is a unique tool designed to measure radiative alpha-capture reactions for nuclei up to A = 40 in inverse kinematics in order to directly obtain cross sections required for astrophysical models of stellar and explosive helium burning. Commissioning of St. George is presently taking place with primary beams of hydrogen, helium, and oxygen. In this presentation, results will be shown for the measured energy acceptance of St. George, which compare favorably to COSY results when employing the calculated optimal ion-optical settings. Additionally, future plans will be discussed, such as assessing the angular acceptance of St. George and the re-integration of HiPPO at the separator target position to provide a dense, windowless helium gas-jet target. The material presented in this work is partially supported by the National Science Foundation Grant No. 1419765.

  1. First Measurement of Beam-Recoil Observables Cx and Cz

    Energy Technology Data Exchange (ETDEWEB)

    R. Bradford; R.A. Schumacher; G. Adams; M.J. Amaryan; P. Ambrozewicz; E. Anciant; M. Anghinolfi; B. Asavapibhop; G. Asryan; G. Audit; H. Avakian; H. Bagdasaryan; N. Baillie; J.P. Ball; N.A. Baltzell; S. Barrow; V. Batourine; M. Battaglieri; K. Beard; I. Bedlinskiy; M. Bektasoglu; M. Bellis; N. Benmouna; B.L. Berman; N. Bianchi; A.S. Biselli; B.E. Bonner; S. Bouchigny; S. Boiarinov; D. Branford; W.J. Briscoe; W.K. Brooks; S. B¨ultmann; V.D. Burkert; C. Butuceanu; J.R. Calarco; S.L. Careccia; D.S. Carman; B. Carnahan; S. Chen; P.L. Cole; A. Coleman; P. Collins; P. Coltharp; D. Cords; † P. Corvisiero; D. Crabb; H. Crannell; V. Crede; J.P. Cummings; R. De Masi; E. De Sanctis; R. De Vita; P.V. Degtyarenko; H. Denizli; L. Dennis; A. Deur; K.V. Dharmawardane; R. Dickson; C. Djalali; G.E. Dodge; J. Donnelly; D. Doughty; P. Dragovitsch; M. Dugger; S. Dytman; O.P. Dzyubak; H. Egiyan; ; K.S. Egiyan; L. El Fassi; L. Elouadrhiri; A. Empl; P. Eugenio; R. Fatemi; G. Fedotov; G. Feldman; R.J. Feuerbach; T.A. Forest; H. Funsten; M. Garcon; G. Gavalian; ; G.P. Gilfoyle; K.L. Giovanetti; F.X. Girod; J.T. Goetz; A. Gonenc; R.W. Gothe; K.A. Griffioen; M. Guidal; M. Guillo; N. Guler; L. Guo; V. Gyurjyan; C. Hadjidakis; K. Hafidi; H. Hakobyan; R.S. Hakobyan; J. Hardie; D. Heddle; F.W. Hersman; K. Hicks; I. Hleiqawi; M. Holtrop; J. Hu; M. Huertas; C.E. Hyde-Wright; Y. Ilieva; D.G. Ireland; B.S. Ishkhanov; E.L. Isupov; M.M. Ito; D. Jenkins; H.S. Jo; K. Joo; H.G. Juengst; N. Kalantarians; J.D. Kellie; M. Khandaker; K.Y. Kim; K. Kim; W. Kim; A. Klein; F.J. Klein; M. Klusman; M. Kossov; L.H. Kramer; V. Kubarovsky; J. Kuhn; S.E. Kuhn; S.V. Kuleshov; J. Lachniet; J.M. Laget; J. Langheinrich; D. Lawrence; A.C.S. Lima; K. Livingston; H.Y. Lu; K. Lukashin; M. MacCormick; J.J. Manak; C. Marchand; N. Markov; S. McAleer; B. McKinnon; J.W.C. McNabb; B.A. Mecking; M.D. Mestayer; C.A. Meyer; T. Mibe; K. Mikhailov; M. Mirazita; R. Miskimen; V. Mokeev; K. Moriya; S.A. Morrow; M. Moteabbed; V. Muccifora; J. Mueller; G.S. Mutchler; P. Nadel-Turonski; J. Napolitano; R. Nasseripour; N. Natasha; S. Niccolai; G. Niculescu; I. Niculescu; B.B. Niczyporuk; M.R. Niroula; R.A. Niyazov; M. Nozar; G.V. O’Rielly; M. Osipenko; A.I. Ostrovidov; K. Park; E. Pasyuk; C. Paterson; S.A. Philips; J. Pierce; N. Pivnyuk; D. Pocanic; O. Pogorelko; E. Polli; I. Popa; S. Pozdniakov; B.M. Preedom; J.W. Price; Y. Prok; D. Protopopescu; L.M. Qin; B.P. Quinn; B.A. Raue; G. Riccardi; G. Ricco; M. Ripani; B.G. Ritchie; F. Ronchetti; G. Rosner; P. Rossi; D. Rowntree; P.D. Rubin; F. Sabatie; J. Salamanca; C. Salgado; J.P. Santoro; ; V. Sapunenko; V.S. Serov; A. Shafi; Y.G. Sharabian; J. Shaw; N.V. Shvedunov; S. Simionatto; A.V. Skabelin; E.S. Smith; L.C. Smith; D.I. Sober; D. Sokhan; M. Spraker; A. Stavinsky; S.S. Stepanyan; S. Stepanyan; B.E. Stokes; P. Stoler; I.I. Strakovsky; S. Strauch; M. Taiuti; S. Taylor; D.J. Tedeschi; U. Thoma; R. Thompson; A. Tkabladze; S. Tkachenko; L. Todor; C. Tur; M. Ungaro; M.F. Vineyard; A.V. Vlassov; K. Wang; D.P. Watts; L.B. Weinstein; H. Weller; D.P. Weygand; M. Williams; E. Wolin; M.H. Wood; A. Yegneswaran; J. Yun; L. Zana; J. Zhang; B. Zhao; and Z.W. Zhao

    2007-03-01

    Spin transfer from circularly polarized real photons to recoiling hyperons has been measured for the reactions $\\vec\\gamma + p \\to K^+ + \\vec\\Lambda$ and $\\vec\\gamma + p \\to K^+ + \\vec\\Sigma^0$. The data were obtained using the CLAS detector at Jefferson Lab for center-of-mass energies $W$ between 1.6 and 2.53 GeV, and for $-0.85<\\cos\\theta_{K^+}^{c.m.}< +0.95$. For the $\\Lambda$, the polarization transfer coefficient along the photon momentum axis, $C_z$, was found to be near unity for a wide range of energy and kaon production angles. The associated transverse polarization coefficient, $C_x$, is smaller than $C_z$ by a roughly constant difference of unity. Most significantly, the {\\it total} $\\Lambda$ polarization vector, including the induced polarization $P$, has magnitude consistent with unity at all measured energies and production angles when the beam is fully polarized. For the $\\Sigma^0$ this simple phenomenology does not hold. All existing hadrodynamic models are in poor agreement with these results.

  2. Fast thermometry for trapped atoms using recoil-induced resonance

    Science.gov (United States)

    Zhao, Yan-Ting; Su, Dian-Qiang; Ji, Zhong-Hua; Zhang, Hong-Shan; Xiao, Lian-Tuan; Jia, Suo-Tang

    2015-09-01

    We have employed recoil-induced resonance (RIR) with linewidth on the order of 10 kHz to demonstrate the fast thermometry for ultracold atoms. We theoretically calculate the absorption spectrum of RIR which agrees well with the experimental results. The temperature of the ultracold sample derived from the RIR spectrum is T = 84±4.5 μK, which is close to 85 μK that measured by the method of time-of-flight absorption imaging. To exhibit the fast measurement advantage in applying RIR to the ultracold atom thermometry, we study the dependence of ultracold sample temperature on the trapping beam frequency detuning. This method can be applied to determine the translational temperature of molecules in photoassociation dynamics. Project supported by the National Basic Research Development Program of China (Grant No. 2012CB921603), the National High Technology Research and Development Program of China (Grant No. 2011AA010801), the National Natural Science Foundation of China (Grant Nos. 61275209, 11304189, 61378015, and 11434007), and Program for Changjiang Scholars and Innovative Research Team in Universities of China (Grant No. IRT13076).

  3. Superconducting Nuclear Recoil Sensor for Directional Dark Matter Detection

    Science.gov (United States)

    Junghans, Ann; Baldwin, Kevin; Hehlen, Markus; Lafler, Randy; Loomba, Dinesh; Phan, Nguyen; Weisse-Bernstein, Nina

    The Universe consists of 72% dark energy, 23% dark matter and only 5% of ordinary matter. One of the greatest challenges of the scientific community is to understand the nature of dark matter. Current models suggest that dark matter is made up of slowly moving, weakly interacting massive particles (WIMPs). But detecting WIMPs is challenging, as their expected signals are small and rare compared to the large background that can mimic the signal. The largest and most robust unique signature that sets them apart from other particles is the day-night variation of the directionality of dark matter on Earth. This modulation could be observed with a direction-sensitive detector and hence, would provide an unambiguous signature for the galactic origin of WIMPs. There are many studies underway to attempt to detect WIMPs both directly and indirectly, but solid-state WIMP detectors are widely unexplored although they would present many advantages to prevalent detectors that use large volumes of low pressure gas. We present first results of a novel multi-layered architecture, in which WIMPs would interact primarily with solid layers to produce nuclear recoils that then induce measureable voltage pulses in adjacent superconductor layers. This work was supported by the U.S. Department of Energy through the LANL Laboratory Directed Research and Development Program.

  4. M-Guard Stent in Stemi Patients with High Thrombus Burden Lesions: A Prospective, Single Arm Study

    Directory of Open Access Journals (Sweden)

    Mohammad Zade Shabestari M

    2014-04-01

    Full Text Available Introduction: Primary PCI is the preferred modality to restore blood perfusion in STEMI patients, but myocardial reperfusion is sometimes lower than optimal. Distal embolization seems to play the leading role. There is rare evidence suggestive of M-Guard stents; a recent innovation which protects against distal embolization may be beneficial in this circumstance. Materials and Methods:This was a prospective single arm study. Patients with acute STEMI admitted at the Cardiac Emergency Unit of Imam Reza Hospital from July 2011 to November  2012 who had a large bulk of thrombus in their angiogram, underwent M-Guard stenting and were followed up for six months for chest pain and secondary revascularization. Results: The 23 patients, aged between 34 and 84; 65.2%, were male and had undergone primary PCI, mechanical thrombus aspiration, and M-Guard stenting. Left Anterior Descending (LAD (63.9% and Right Coronary Artery (RCA (39.1% were most commonly involved. 78.2%, 13.1%, and 8.9% of patients had primary Thrombolysis in Myocardial Infarction (TIMI Thrombus grade five, four, and three. Among them, 86.9% achieved TIMI Flow grade three and 13.04% TIMI Flow grade two. The rate of transient "no-reflow" phenomenon was 21%. One patient died after stenting in the setting of cardiogenic shock. There was one case of in-stent restenosis five months after the procedure. Of the other 15 accessible patients, after six months, none experienced a second angioplasty or any ischemic symptoms. Conclusion: Using M-Guard stents in acute STEMI patients having undergone primary PCI with high thrombus burden is probably associated with lower rates of the "no-reflow" phenomenon and improved vessel reperfusion.  

  5. About the importance of the nuclear recoil in \\alpha emission near the DNA

    CERN Document Server

    Rizzini, E Lodi; Corradini, M; Leali, M; Mascagna, V; Venturelli, L; Zurlo, N

    2011-01-01

    The effect of the energy deposition inside the human body made by radioactive substances is discussed. For the first time, we stress the importance of the recoiling nucleus in such reactions, particularly concerning the damage caused on the DNA structure.

  6. First measurement of the ionization yield of nuclear recoils in liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, T. [Univ. of California, Berkeley, CA (United States). Dept. of Nuclear Engineering; Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Sangiorgio, Samuele [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Bernstein, A. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Foxe, Michael P. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Pennsylvania State Univ., University Park, PA (United States). Dept. of Mechanical and Nuclear Engineering; Hagmann, Chris [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Jovanovic, Igor [Pennsylvania State Univ., University Park, PA (United States). Dept. of Mechanical and Nuclear Engineering; Kazkaz, K. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Mozin, Vladimir V. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Norman, E. B. [Univ. of California, Berkeley, CA (United States). Dept. of Nuclear Engineering; Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Pereverzev, S. V. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Rebassoo, Finn O. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Sorensen, Peter F. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)

    2014-05-01

    Liquid phase argon has long been used as a target medium for particle detection via scintillation light. Recently there has been considerable interest in direct detection of both hypothetical darkmatter particles and coherent elastic neutrino nucleus scattering. These as-yet unobserved neutral particle interactions are expected to result in a recoiling argon atom O(keV), generally referred to in the literature as a nuclear recoil. This prompts the question of the available electromagnetic signal in a liquid argon detector. In this Letter we report the first measurement of the ionization yield (Qy), detected electrons per unit energy, resulting from nuclear recoils in liquid argon, measured at 6.7 keV. This is also the lowest energy measurement of nuclear recoils in liquid argon.

  7. MIMAC low energy electron-recoil discrimination measured with fast neutrons

    CERN Document Server

    Riffard, Q; Guillaudin, O; Bosson, G; Bourrion, O; Bouvier, J; Descombes, T; Muraz, J -F; Lebreton, L; Maire, D; Colas, P; Giomataris, I; Busto, J; Fouchez, D; Brunner, J; Tao, C

    2016-01-01

    MIMAC (MIcro-TPC MAtrix of Chambers) is a directional WIMP Dark Matter detector project. Direct dark matter experiments need a high level of electron/recoil discrimination to search for nuclear recoils produced by WIMP-nucleus elastic scattering. In this paper, we proposed an original method for electron event rejection based on a multivariate analysis applied to experimental data acquired using monochromatic neutron fields. This analysis shows that a $10^{5}$ rejection power is reachable for electron/recoil discrimination. Moreover, the efficiency was estimated by a Monte-Carlo simulation showing that a $10^{5}$ electron rejection power is reached with a 85.1\\% nuclear recoil efficiency using the same detector gain that on the detectors running at Modane.

  8. Karakteristike trzanja elektromagnetskog topa / Recoil characteristics of an electromagnetic rail gun

    Directory of Open Access Journals (Sweden)

    Zoran B. Ristić

    2009-10-01

    Full Text Available U radu je razmatrano trzanje elektromagnetskog šinskog topa i upoređeno sa trzanjem konvencionalnog topa sa barutnim punjenjem. Zaključuje se da je kod elektromagnetskog topa trzanje manje nego kod topa sa barutnim punjenjem. Takođe, pokazano je da pri istim uslovima lansiranja upotreba gasne kočnice topa sa barutnim punjenjem može izmeniti karakteristike trzanja i više ih približiti ponašanju elektromagnetskog topa. / In this paper the electromagnetic rail gun recoil is discussed and compared with the recoil of a conventional, propellant gas driven gun. It is shown that, under similar launch conditions, the recoil of an electromagnetic gun is weaker than that of the powder-driven gun. The use of a muzzle brake on a powder-driven gun can alter its recoil characteristics and make its behavior closer to that of the electromagnetic rail gun.

  9. An preliminary clinical study of transbronchoscopic interventional treatment for severe emphysema with local made one-way valvular stents

    International Nuclear Information System (INIS)

    Objective: To evaluate the safety and efficiency of bronchoscopic interventional lung volume reduction with domestic-made stents. Methods: The target areas of 7 patients with severe emphysema for valvular stenting form May 2006 to Aug. 2007 were prospectively selected on the basis of CT scan. Under general anesthesia, one-way valvular stenting were carried out over a guidewire under flexible bronchoscopy and fluoroscopic control. The symptom, pulmonary function, blood gas analysis, B-ultrasonic wave, 6 minute walk distance and thoracic CT were undertaken. Results: 4-6 stents per patient took place in 136 ± 72.3 min to obstruct the upper-lobe segments unilaterally but without obvious atelectasis under imaging. The patients could walk 2 hours after the operation with relief of dyspnea. No major change in radiologic findings and lung function occurred in 2 weeks, only bronchi distal to the stents gathered together. 6-min walk distance, Borg dyspnea scale fell and the pulmonary arterial pressure showed significant (P<0.05)statistical discrepancy. No major life-threatening complications were noted in the 15-day study period and no conspicuous change in lung function, blood gas analysis and lung volume. Lower-lobe pneumonia of nontarget area developed in 1 patient and acute episode of COPD occurred in another. Conclusions: Bronchoscopic interventional lung volume reduction may improve dyspnea and quality of life, as a rather safety therapeutic measure. (authors)

  10. Multivariate techniques of analysis for ToF-E recoil spectrometry data

    International Nuclear Information System (INIS)

    Multivariate statistical methods are being developed by the Australian -Swedish Recoil Spectrometry Collaboration for quantitative analysis of the wealth of information in Time of Flight (ToF) and energy dispersive Recoil Spectrometry. An overview is presented of progress made in the use of multivariate techniques for energy calibration, separation of mass-overlapped signals and simulation of ToF-E data. 6 refs., 5 figs

  11. As-Al recoil implantation through Si 3N 4 barrier layer

    Science.gov (United States)

    Godignon, P.; Morvan, E.; Montserrat, J.; Jordà, X.; Flores, D.; Rebollo, J.

    1999-01-01

    Al recoil implantation have been shown to be a possible alternative to direct Al ion implantation to avoid usual problems linked with Al sources. Poor efficiency of the recoil + annealing process is observed if no barrier or an oxyde screen layers are used. This problem can be solved using a Si 3N 4 screen layer. Then, P-N and N +/P/N structures can be obtained with deep low doped P-well with reduced thermal budget.

  12. As-Al recoil implantation through Si3N4 barrier layer

    International Nuclear Information System (INIS)

    Al recoil implantation have been shown to be a possible alternative to direct Al ion implantation to avoid usual problems linked with Al sources. Poor efficiency of the recoil + annealing process is observed if no barrier or an oxyde screen layers are used. This problem can be solved using a Si3N4 screen layer. Then, P-N and N+/P/N structures can be obtained with deep low doped P-well with reduced thermal budget

  13. First analysis of hard exclusive data using the HERMES recoil scintillating fiber tracker

    Energy Technology Data Exchange (ETDEWEB)

    Keri, Tibor; Dueren, Michael; Perez-Benito, Roberto Francisco; Yu, Weilin [II.Physikalisches Institut, Justus-Liebig-Universitaet, Giessen (Germany)

    2008-07-01

    The HERMES experiment was upgraded by a recoil detector that contains a scintillating fiber tracker in order to measure recoiling protons and pions with low momentum and at large polar angle. The upgrade improves the event selections of hard-exclusive processes and helps to access Generalized Parton Distributions. Preliminary studies to extract single spin asymmetries of DVCS processes were carried out and first results are presented.

  14. Investigation on modeling and controability of a magnetorheological gun recoil damper

    Science.gov (United States)

    Hu, Hongsheng; Wang, Juan; Wang, Jiong; Qian, Suxiang; Li, Yancheng

    2009-07-01

    Magnetorheological (MR) fluid as a new smart material has done well in the vibration and impact control engineering fields because of its good electromechanical coupling characteristics, preferable dynamic performance and higher sensitivity. And success of MRF has been apparent in many engineering applied fields, such as semi-active suspension, civil engineering, etc. So far, little research has been done about MR damper applied into the weapon system. Its primary purpose of this study is to identify its dynamic performance and controability of the artillery recoil mechanism equipped with MR damper. Firstly, based on the traditional artillery recoil mechanism, a recoil dynamic model is developed in order to obtain an ideal rule between recoil force and its stroke. Then, its effects of recoil resistance on the stability and firing accuracy of artillery are explored. Because MR gun recoil damper under high impact load shows a typical nonlinear character and there exists a shear-thinning phenomenon, to establish an accurate dynamic model has been a seeking aim of its design and application for MR damper under high impact load. Secondly, in this paper, considering its actual bearing load, an inertia factor was introduced to Herschel-Bulkley model, and some factor's effect on damping force are simulated and analyzed by using numerical simulation, including its dynamic performance under different flow coefficients and input currents. Finally, both of tests with the fixed current and different On-Off control algorithms have been done to confirm its controability of MR gun recoil damper under high impact load. Experimental results show its dynamic performances of the large-scale single-ended MR gun recoil damper can be changed by altering the applied currents and it has a good controllability.

  15. High-purity germanium detector ionization pulse shapes of nuclear recoils, gamma interactions and microphonism

    OpenAIRE

    Baudis, L.; Hellmig, J.; Klapdor-Kleingrothaus, H. V.; Ramachers, Y.; Hammer, J. W.; Mayer, A.

    1999-01-01

    Nuclear recoil measurements with high-purity Germanium detectors are very promising to directly detect dark matter candidates. The main background sources in such experiments are natural radioactivity and microphonic noise. Digital pulse shape analysis is an encouraging approach to reduce the background originating from the latter. To study the pulse shapes of nuclear recoil events we performed a neutron scattering experiment, which covered the ionization energy range from 20 to 80 keV. We ha...

  16. Multivariate techniques of analysis for ToF-E recoil spectrometry data

    Energy Technology Data Exchange (ETDEWEB)

    Whitlow, H.J.; Bouanani, M.E.; Persson, L.; Hult, M.; Jonsson, P.; Johnston, P.N. [Lund Institute of Technology, Solvegatan, (Sweden), Department of Nuclear Physics; Andersson, M. [Uppsala Univ. (Sweden). Dept. of Organic Chemistry; Ostling, M.; Zaring, C. [Royal institute of Technology, Electrum, Kista, (Sweden), Department of Electronics; Johnston, P.N.; Bubb, I.F.; Walker, B.R.; Stannard, W.B. [Royal Melbourne Inst. of Tech., VIC (Australia); Cohen, D.D.; Dytlewski, N. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1996-12-31

    Multivariate statistical methods are being developed by the Australian -Swedish Recoil Spectrometry Collaboration for quantitative analysis of the wealth of information in Time of Flight (ToF) and energy dispersive Recoil Spectrometry. An overview is presented of progress made in the use of multivariate techniques for energy calibration, separation of mass-overlapped signals and simulation of ToF-E data. 6 refs., 5 figs.

  17. Stents

    Science.gov (United States)

    ... Topics Aneurysm Carotid Artery Disease Coronary Heart Disease Percutaneous Coronary Intervention Peripheral Artery Disease Send a link to NHLBI ... an artery as part of a procedure called percutaneous coronary intervention (PCI), also known as coronary angioplasty. PCI restores ...

  18. Axial stent strut angle influences wall shear stress after stent implantation: analysis using 3D computational fluid dynamics models of stent foreshortening

    Directory of Open Access Journals (Sweden)

    Warltier David C

    2005-10-01

    Full Text Available Abstract Introduction The success of vascular stents in the restoration of blood flow is limited by restenosis. Recent data generated from computational fluid dynamics (CFD models suggest that the vascular geometry created by an implanted stent causes local alterations in wall shear stress (WSS that are associated with neointimal hyperplasia (NH. Foreshortening is a potential limitation of stent design that may affect stent performance and the rate of restenosis. The angle created between axially aligned stent struts and the principal direction of blood flow varies with the degree to which the stent foreshortens after implantation. Methods In the current investigation, we tested the hypothesis that stent foreshortening adversely influences the distribution of WSS and WSS gradients using time-dependent 3D CFD simulations of normal arteries based on canine coronary artery measurements of diameter and blood flow. WSS and WSS gradients were calculated using conventional techniques in ideal (16 mm and progressively foreshortened (14 and 12 mm stented computational vessels. Results Stent foreshortening increased the intrastrut area of the luminal surface exposed to low WSS and elevated spatial WSS gradients. Progressive degrees of stent foreshortening were also associated with strut misalignment relative to the direction of blood flow as indicated by analysis of near-wall velocity vectors. Conclusion The current results suggest that foreshortening may predispose the stented vessel to a higher risk of neointimal hyperplasia.

  19. Coronary artery and myocardial inflammatory reaction induced by intracoronary stent Alterações inflamatórias das artérias coronárias e do miocárdio induzidas por stents coronários

    Directory of Open Access Journals (Sweden)

    Walter J. Gomes

    2002-12-01

    Full Text Available BACKGROUND: Intra-coronary stents have been extensively employed in percutaneous coronary revascularization. However, despite breakthroughs and developments associated to this new technology, novel complications and findings have emerged compelling the cardiac surgeon to cope with this new scenario. The presence of an intra-coronary foreign body (stent might induce an inflammatory reaction carrying functional and structural repercussions of the coronary artery and surrounding cardiac muscle. METHOD:Patients, who had previously undergone stent implantation (6 to 18 months and were submitted to coronary artery bypass surgery, had biopsies taken from the grafted coronary artery distal to the stent and from the adjacent muscle. The collected samples were processed and stained with hematoxylin-eosin and histologically studied. RESULTS:The histology of the coronary artery distal to the stent revealed chronic inflammatory processes and an intimal acute inflammatory infiltrate, with polymorphonuclear leukocytes even at long term follow-up, 12 months after stent implantation, disclosing an ongoing inflammatory process. The myocardium adjacent to the stent implantation site exhibited a significant chronic inflammatory infiltrate and fibrosis compatible with myocarditis. CONCLUSION:The presence of an intra-coronary stent induces an acute and chronic inflammatory reaction, even over the long term, with involvement of the distal coronary artery and surrounding myocardium. Further studies are necessary to assess the inflammatory process extension and its consequences.OBJETIVO: Stents intracoronários têm sido extensivamente utilizados na revascularização coronária percutânea. Entretanto, apesar dos avanços e desenvolvimento nessa área, novas complicação tem emergido obrigando o cirurgião cardíaco a enfrentar esta nova situação. A presença do stent poderia induzir reação inflamatória tipo corpo-estranho com repercussão funcional na art

  20. Innovations in Stroke Prevention: An Update on Carotid Stenting

    Medline Plus

    Full Text Available ... important thing also is that with the current role of using carotid stent angioplasty, we can get ... study results are pending, which will determine the role of carotid stenting in the healthier patients, the ...

  1. Fracture of Memotherm Metallic Stents in the Biliary Tract

    International Nuclear Information System (INIS)

    In a series of 66 patients who had palliation of malignant obstructive jaundice by percutaneous placement of Memotherm expanding metal stents, we report four cases of stent fracture. This has not been reported previously

  2. Trimming a Metallic Biliary Stent Using an Argon Plasma Coagulator

    International Nuclear Information System (INIS)

    Background. Distal migration is one of the common complications after insertion of a covered metallic stent. Stent repositioning or removal is not always possible in every patient. Therefore, trimming using an argon plasma coagulator (APC) may be a good alternative method to solve this problem. Methods. Metallic stent trimming by APC was performed in 2 patients with biliary Wallstent migration and in another patient with esophageal Ultraflex stent migration. The power setting was 60-100 watts with an argon flow of 0.8 l/min. Observations. The procedure was successfully performed and all distal parts of the stents were removed. No significant collateral damage to the nearby mucosa was observed. Conclusions. In a patient with a distally migrated metallic stent, trimming of the stent is possible by means of an APC. This new method may be applicable to other sites of metallic stent migration

  3. Innovations in Stroke Prevention: An Update on Carotid Stenting

    Medline Plus

    Full Text Available INNOVATIONS IN STROKE PREVENTION: AN UPDATE ON CAROTID STENTING NEW YORK-PRESBYTERIAN HOSPITAL NEW YORK, NY July ... MD: Good evening. Welcome to our webcast on innovations in stroke prevention: an update on carotid stenting. ...

  4. A Migrated Aortic Stent Graft Causing Erosive Spondylopathy

    Energy Technology Data Exchange (ETDEWEB)

    Gestrich, Christopher, E-mail: christopher.gestrich@ukb.uni-bonn.de; Probst, Chris, E-mail: chris.probst@ukb.uni-bonn.de [Universitaetsklinikum Bonn, Department of Cardiac Surgery (Germany); Wilhelm, Kai, E-mail: kai.wilhelm@ek-bonn.de [Johanniterkrankenhaus Bonn, Department of Radiology (Germany); Schiller, Wolfgang, E-mail: wolfgang.schiller@ukb.uni-bonn.de [Universitaetsklinikum Bonn, Department of Cardiac Surgery (Germany)

    2013-12-15

    We report about a patient presenting with back pain 4 months after an uneventful endovascular implantation of an aortic stent graft. Computed tomography scan revealed a migration of the stent with consecutive endoleakage, kink formation, and movement of the stent toward the spine, which caused destruction of the aortic wall as well as vertebral necrosis. Explantation of the stent and replacement of the native aorta relieved the patient of his symptoms.

  5. Radiotherapy Prolongs Biliary Metal Stent Patency in Malignant Pancreatobiliary Obstructions

    OpenAIRE

    Park, Semi; Park, Jeong Youp; Bang, Seungmin; Park, Seung Woo; Chung, Jae Bock; Song, Si Young

    2013-01-01

    Background/Aims Biliary stenting is the most effective decompressive method for treating malignant biliary obstructive jaundice. Although the main cause of stent occlusion is tumor growth, few studies have investigated whether stent patency is affected by the combination of cancer-treatment modalities. The aim of this study was to evaluate the effects of local radiotherapy on metal-stent patency in patients with malignant biliary obstruction. Methods Patients who underwent self-expandable bil...

  6. Evaluation of different percutaneous modalities for managing malfunctioning biliary stents

    OpenAIRE

    M. Alwarraky; A. Aljaky; E. Tharwa; Aziz, A.

    2015-01-01

    Background: There is no consensus regarding optimal management of biliary metal stent occlusion. Aim: To evaluate the efficacy of different percutaneous methods for managing biliary metal stent occlusion. Patients and methods: Thirty-eight patients were included in the study. Metal biliary stent occlusions were managed by insertion of another metal stent in 18 patients (group 1), insertion of an internal–external catheter in 15 patients (group 2), and mechanical cleaning in 5 patients (...

  7. Metal stents: a bridge to surgery in hilar cholangiocarcinoma

    OpenAIRE

    Grünhagen, Dirk J.; Dunne, Declan FJ; Sturgess, Richard P; Stern, Nick; Hood, Stephen; Fenwick, Stephen W; Poston, Graeme J; Malik, Hassan Z

    2012-01-01

    Background Obstructive jaundice in patients with hilar cholangiocarcinoma is a known risk factor for hepatic failure after liver resection. Plastic stents are most widely used for preoperative drainage. However, plastic stents are known to have limited patency time and therefore, in palliative settings, the self-expanding metal stent (SEMS) is used. This type of stent has been shown to be superior because it allows for rapid biliary decompression and a reduced complication rate after insertio...

  8. Simulation of stent deployment in a realistic human coronary artery

    OpenAIRE

    van der Steen Anton FW; Wentzel Jolanda J; Thury Attila; Petrini Lorenza; Socci Laura; Schievano Silvia; Migliavacca Francesco; Gijsen Frank JH; Serruys Patrick WS; Dubini Gabriele

    2008-01-01

    Abstract Background The process of restenosis after a stenting procedure is related to local biomechanical environment. Arterial wall stresses caused by the interaction of the stent with the vascular wall and possibly stress induced stent strut fracture are two important parameters. The knowledge of these parameters after stent deployment in a patient derived 3D reconstruction of a diseased coronary artery might give insights in the understanding of the process of restenosis. Methods 3D recon...

  9. Metallic Stents for Tracheobronchial Pathology Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, Carolina, E-mail: carolina.serrano@unizar.es [University of Zaragoza, Surgical Pathology Unit, Animal Pathology Department (Spain); Laborda, Alicia, E-mail: alaborda@unizar.es [University of Zaragoza, Minimally Invasive Techniques Research Group (GITMI) (Spain); Lozano, Juan M., E-mail: juamauloz@gmail.com [Marly Clinic, Radiology Department (Colombia); Caballero, Hugo, E-mail: hugocaballero2007@gmail.com [Marly Clinic, Pulmonology Department (Colombia); Sebastian, Antonio, E-mail: antonio.sebastian@ono.es [Lozano Blesa Clinical University Hospital, Pulmonology Department (Spain); Lopera, Jorge, E-mail: lopera@uthscsa.edu [Health Science Center, Interventional Radiology Deparment (United States); Gregorio, Miguel Angel de, E-mail: mgregori@unizar.es [University of Zaragoza, Minimally Invasive Techniques Research Group (GITMI) (Spain)

    2013-12-15

    Purpose: To present the 7-year experience of the treatment of benign and malignant tracheobronchial stenoses using metallic stents. Patients and Methods: One hundred twenty-three stents were inserted in 86 patients (74 benign and 12 malignant stenoses). Ninety-seven stents were placed in the trachea and 26 in the bronchi. The procedures were performed under fluoroscopic and flexible bronchoscopic guidance with the patient under light sedation. In cases of severe stenotic lesions or obstructions, laser resection was performed before stent placement. Clinical and functional pulmonary data were recorded before and 3 months after the procedure. Follow-up involved clinical data and radiographic techniques at 48 h and at 1-, 3-, 6-, and 12-month intervals. Results: The technical success was 100 %. Dyspnea disappearance, forced expiratory volume in the first second, and pulmonary functional data improvement was observed in all patients (p < 0.001). Complications were detected in 23 patients (26.7 %). Mean follow-up time was 6.3 {+-} 1.2 months in patients with malignant lesions and 76.2 {+-} 2.3 months patients with in benign lesions. By the end of the study, 100 % of patients with malignant pathology and 6.7 % of patients with benign lesions had died. Conclusion: Endoluminal treatment of tracheobronchial stenosis with metallic stents is a therapeutic alternative in patients who are poor candidates for surgery. In unresectable malignant lesions, the benefit of metallic stenting is unquestionable. In benign lesions, the results are satisfactory, but sometimes other interventions are required to treat complications. New stent technology may improve these results.

  10. Effects of cobalt-chromium everolimus eluting stents or bare metal stent on fatal and non-fatal cardiovascular events

    DEFF Research Database (Denmark)

    Valgimigli, Marco; Sabaté, Manel; Kaiser, Christoph;

    2014-01-01

    eluting stents with bare metal stents were selected. The principal investigators whose trials met the inclusion criteria provided data for individual patients. PRIMARY OUTCOMES: The primary outcome was cardiac mortality. Secondary endpoints were myocardial infarction, definite stent thrombosis, definite......OBJECTIVES: To examine the safety and effectiveness of cobalt-chromium everolimus eluting stents compared with bare metal stents. DESIGN: Individual patient data meta-analysis of randomised controlled trials. Cox proportional regression models stratified by trial, containing random effects, were...... or probable stent thrombosis, target vessel revascularisation, and all cause death. RESULTS: The search yielded five randomised controlled trials, comprising 4896 participants. Compared with patients receiving bare metal stents, participants receiving cobalt-chromium everolimus eluting stents had...

  11. Detection of exclusive reactions in the Hermes Recoil Fiber Tracker

    Energy Technology Data Exchange (ETDEWEB)

    Keri, Tibor

    2008-08-15

    the RD (Recoil Detector) with an unpolarized target at this position. This detector consists of the Silicon Strip Detector, the SFT (Scintillating Fiber Tracker), the Photon Detector and is surrounded by a 1T superconducting magnet. It provides several space points for tracking and thus momentum reconstruction. The energy deposition in the various detectors is used to achieve particle identification. The main part of the thesis work was the implementation of the SFT and the RD readout system. Before the installation of the RD a series of test runs were carried out to proof the concept of the detector, to measure the internal alignment and to prepare the installation. These test runs for the SFT are described and major results are shown. Furthermore a preliminary analysis of the latest data 06d/06d0 was carried out to show the performance of the installed Recoil Detector in combination with the HERMES forward spectrometer. (orig.)

  12. Modelling and simulating in-stent restenosis with complex automata

    NARCIS (Netherlands)

    A.G. Hoekstra; P. Lawford; R. Hose

    2010-01-01

    In-stent restenosis, the maladaptive response of a blood vessel to injury caused by the deployment of a stent, is a multiscale system involving a large number of biological and physical processes. We describe a Complex Automata Model for in-stent restenosis, coupling bulk flow, drug diffusion, and s

  13. 2-year patient-related versus stent-related outcomes

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Thayssen, Per; Christiansen, Evald Høj;

    2012-01-01

    OBJECTIVES: There are limited head-to-head randomized data on patient-related versus stent-related outcomes for everolimus-eluting stents (EES) and sirolimus-eluting stents (SES). BACKGROUND: In the SORT OUT IV (Scandinavian Organization for Randomized Trials With Clinical Outcome IV) trial, comp...

  14. Simulation of stent deployment in a realistic human coronary artery

    NARCIS (Netherlands)

    F.J.H. Gijsen (Frank); F. Migliavacca (Francesco); S. Schievano (Silvia); L. Socci (Laura); L. Petrini (Lorenza); A. Thury (Attila); J.J. Wentzel (Jolanda); A.F.W. van der Steen (Ton); P.W.J.C. Serruys (Patrick); G. Dubini (Gabriele)

    2008-01-01

    textabstractBackground: The process of restenosis after a stenting procedure is related to local biomechanical environment. Arterial wall stresses caused by the interaction of the stent with the vascular wall and possibly stress induced stent strut fracture are two important parameters. The knowledg

  15. Biocompatibility of phosphorylcholine coated stents in normal porcine coronary arteries

    NARCIS (Netherlands)

    D.M. Whelan (Deirdre); S.C. Krabbendam; P.D. Verdouw (Pieter); P.W.J.C. Serruys (Patrick); E.A. van Vliet (Erwin); W.J. van der Giessen (Wim); H.M.M. van Beusekom (Heleen)

    2000-01-01

    textabstractOBJECTIVE: To improve the biocompatibility of stents using a phosphorylcholine coated stent as a form of biomimicry. INTERVENTIONS: Implantation of phosphorylcholine coated (n = 20) and non-coated (n = 21) stents was performed in the coronary arteries of 25 pigs. The an

  16. Stenting and interventional radiology for obstructive jaundice in patients with unresectable biliary tract carcinomas

    OpenAIRE

    Tsuyuguchi, Toshio; Takada, Tadahiro; Miyazaki, Masaru; Miyakawa, Shuichi; Tsukada, Kazuhiro; Nagino, Masato; Kondo, Satoshi; Furuse, Junji; Saito, Hiroya; Suyama, Masafumi; Kimura, Fumio; Yoshitomi, Hideyuki; Nozawa, Satoshi; Yoshida, Masahiro; Wada, Keita

    2008-01-01

    Together with biliary drainage, which is an appropriate procedure for unresectable biliary cancer, biliary stent placement is used to improve symptoms associated with jaundice. Owing to investigations comparing percutaneous transhepatic biliary drainage (PTBD), surgical drainage, and endoscopic drainage, many types of stents are now available that can be placed endoscopically. The stents used are classified roughly as plastic stents and metal stents. Compared with plastic stents, metal stents...

  17. Local drug-delivery balloon for proliferative occlusive in-stent restenosis after drug-eluting stent

    Institute of Scientific and Technical Information of China (English)

    Gianluca Rigatelli; Paolo Cardaioli; Fabio Dell'Avvocata; Massimo Giordan

    2011-01-01

    Drug-coated balloon has been developed as an alternative to drug-eluting stents for in-stent restenosis but the performance of drug infusion balloon in such setting has not been previously described. We present a case of particularly aggressive in-stent restenosis after drug eluting stent implantation treated with a new kind of drug infusion balloon developed in order to overcome the impossibility to inflate regular drug-coated balloon for several dilatation.

  18. Sirolimus-eluting stent fractures associated with aneurysm and very late stent thrombosis in the right coronary artery

    Institute of Scientific and Technical Information of China (English)

    LIU Xuebo; Gary S.Mintz; Stéphane G.Carlier; Martin B.Leon

    2007-01-01

      Although the occurrence of coronary stent fracture is rare,recent reports showed that stent fracture after sirolimus-eluting stent(SES)implantation may be associated with neointimal hyperplasia and restenosis.We report two cases of stent fracture that occurred late after elective SES implantation into the right coronary artery(RCA)that were related to the aneurysm,restenosis,thrombosis,and vessel occlusion.……

  19. Shortening of Wallstent RP during carotid artery stenting requires appropriate stent placement.

    Science.gov (United States)

    Aikawa, Hiroshi; Nagata, Shun-ichi; Onizuka, Masanari; Tsutsumi, Masanori; Iko, Minoru; Kodama, Tomonobu; Nii, Kouhei; Matsubara, Shuko; Etou, Hosei; Go, Yoshinori; Kazekawa, Kiyoshi

    2008-06-01

    Changes in the location and length of the Wallstent RP during carotid artery stenting (CAS) were evaluated using intraoperative videos of 28 patients with carotid artery stenosis who underwent CAS with a 10/20 mm Wallstent RP to determine the appropriate stent placement. The stent was deployed after its midpoint was positioned over a virtual center line, the perpendicular line which crossed the most stenotic point of the lesion on the road mapping image. The length of the stenotic lesion, the changes in the locations of the distal and proximal ends of the stent, and the changes in stent length were examined. The distal end of the stent moved a maximum of 6.1 mm toward the proximal side to a point 19.9 mm from the virtual center line. The proximal end moved a maximum of 11.3 mm toward the distal side to a point 14.7 mm from the virtual center line. The stent length ranged from 37.7 to 44.5 mm (mean 41.2 mm). The 10/20 mm Wallstent RP placed by our technique covers the entire lesion with no less than 5.7 mm of margin over the segment distal to the lesion in patients with stenotic segments shorter than 29.4 mm.

  20. Partial stent-in-stent placement of biliary metallic stents using a short double-balloon enteroscopy

    Institute of Scientific and Technical Information of China (English)

    Koichiro Tsutsumi; Hironari Kato; Takeshi Tomoda; Kazuyuki Matsumoto; Ichiro Sakakihara; Naoki Yamamoto; Yasuhiro Noma

    2012-01-01

    Endoscopic intervention is less invasive than percutaneous or surgical approaches and should be considered the primary drainage procedure in most cases with obstructive jaundice.Recently,therapeutic endoscopic retrograde cholangiopancreatography (ERCP) using double-balloon enteroscopy (DBE) has been shown to be feasible and effective,even in patients with surgically altered anatomies.On the other hand,endoscopic partial stent-in-stent (PSIS) placement of selfexpandable metallic stents (SEMSs) for malignant hilar biliary obstruction in conventional ERCP has also been shown to be feasible,safe and effective.We performed PSIS placement of SEMSs for malignant hilar biliary obstruction due to liver metastasis using a short DBE in a patient with Roux-en-Y anastomosis and achieved technical and clinical success.This procedure can result in quick relief from obstructive jaundice in a single session and with short-term hospitalization,even in patients with surgically altered anatomies.