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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 ...

  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. Stenting in the treatment of acute ischemic stroke: literature review.

    Directory of Open Access Journals (Sweden)

    EdgarASamaniego

    2011-12-01

    Full Text Available Recanalization of acute large artery occlusions is a strong predictor of good outcome. The development of thrombectomy devices resulted in a significant improvement in recanalization rates compared to thrombolytics alone. However, clinical trials and registries with these thrombectomy devices in acute ischemic stroke (AIS have shown recanalization rates in the range of 40-81%. The last decade has seen the development of nickel titanium self-expandable stents (SES. These stents, in contrast to balloon-mounted stents, allow better navigability and deployment in tortuous vessels and therefore are optimal for the cerebral circulation. SES were initially used for stent-assisted coil embolization of intracranial aneurysms and for treatment of intracranial stenosis. However, a few authors have recently reported feasibility of deployment of SES in AIS. The use of these devices yielded higher recanalization rates compared to traditional thrombectomy devices. Encouraged by these results, retrievable SES systems have been recently used in AIS. These devices offer the advantage of resheathing and retrieving of the stent even after full deployment. Some of these stents can also be detached in case permanent stent placement is needed. Retrievable SES are being used in Europe and currently tested in clinical trials in the United States. We review the recent literature in the use of stents for the treatment of AIS secondary to large vessel occlusion.

  5. 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

  6. 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.

  7. Simultaneous endovascular stent and renal stent placement for acute type B aortic dissection with malperfusion of kidney

    OpenAIRE

    Dagdelen, Sinan; Aydın, Ebuzer; Karabulut, Hasan

    2012-01-01

    Acute aortic dissection frequently causes life-threatening organ ischemia. The optimal therapy for acute type-B aortic dissection is still controversial. Surgery for acute dissection with organ malperfusion is known to carry a high morbidity and mortality; however endovascular treatment is becoming an alternative form of treatment. We report a clinical case of emergency percutaneous thoracal aorta endovascular stenting and renal artery stenting in a patient who had renal malperfusion and acut...

  8. Acute Coronary Stent Thrombosis in Cancer Patients: A Case Series Report

    OpenAIRE

    Lee, Joo Myung; Yoon, Chang-Hwan

    2012-01-01

    There have been a growing numbers of patients diagnosed with malignancy and coronary artery disease simultaneously or serially. In the era of percutaneous coronary intervention (PCI), stent thrombosis has been a rare but challenging problem. Recently, we experienced two unique cases of acute stent thrombosis in patients with malignancy. The first case showed acute and subacute stent thrombosis after PCI. The second case revealed simultaneous thromboses in stent and non-treated native coronary...

  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. 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.

  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. 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...... intervention (PCI) for ST-segment elevation myocardial infarction significantly reduced major bleeding compared with heparin with or without glycoprotein IIb/IIIa inhibitors (GPI), but it was associated with an increase in AST. METHODS: We compared patients with (n = 12) or without AST (n = 2,184) regarding...

  13. 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-

  14. Oclusão arterial aguda de stent fêmoro-poplíteo Acute femoropopliteal artery stent obstruction

    OpenAIRE

    Fabio Henrique Rossi; Milton Kiyonory Uehara; Juliana Chen; Thiago Emilio Burza Maia; Eduardo Mulinari Darold; Andréia Silveira Martins; Akash Kuzhiparambil Prakasan; Nilo Mitsuro Izukawa

    2009-01-01

    A oclusão aguda de stent fêmoro-poplíteo pode ser causa de isquemia crítica dos membros inferiores. A terapia fibrinolítica pode não ser a forma de tratamento mais indicada para o grupo de pacientes com esse quadro clínico. Neste artigo, apresentamos um caso em que a retirada de um fragmento de stent por endarterectomia tornou possível a revascularização do membro.Femoropopliteal stent obstruction may be responsible for acute lower limb ischemia. Fibrinolytic treatment may not be the best the...

  15. Oclusão arterial aguda de stent fêmoro-poplíteo Acute femoropopliteal artery stent obstruction

    Directory of Open Access Journals (Sweden)

    Fabio Henrique Rossi

    2009-09-01

    Full Text Available A oclusão aguda de stent fêmoro-poplíteo pode ser causa de isquemia crítica dos membros inferiores. A terapia fibrinolítica pode não ser a forma de tratamento mais indicada para o grupo de pacientes com esse quadro clínico. Neste artigo, apresentamos um caso em que a retirada de um fragmento de stent por endarterectomia tornou possível a revascularização do membro.Femoropopliteal stent obstruction may be responsible for acute lower limb ischemia. Fibrinolytic treatment may not be the best therapeutic approach in this group of patients. We report a clinical case in which stent fragmentation and endarterectomy enabled femoropopliteal below knee bypass and limb revascularization.

  16. 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.

  17. 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

  18. Refinement of a thrombectomy technique to treat acute ischemic stroke: Technical note on microcatheter advance during retrieving self expandable stent

    International Nuclear Information System (INIS)

    Temporary stenting and thrombectomy by use of the Solitaire stent (ev3, Irvine, CA, USA) has shown prompt and successful recanalization of the acutely occluded major cerebral artery. However, even if rarely reported, inadvertent stent detachment may occur as an innate drawback and full deployment of the stent was considered to increase the risk. In our patients, the Solitaire stent did not fully unfold to prevent inadvertent detachment. Before retrieval of the stent, the tip of the microcatheter was advanced forward carefully under fluoroscopic observation until it met the presumed thrombus segment and a subtle sense of resistance was felt in the fingers guiding the stent. After retrieval, complete recanalization was achieved, and the thrombus was trapped between the tip of the microcatheter and the stent strut. We present 2 cases of successful thrombi captures by advancing a microcatheter during Solitaire stent retrieval, and we suggest that advancing the microcatheter can be a useful refinement to the thrombectomy technique for acute ischemic stroke

  19. 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.

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

    International Nuclear Information System (INIS)

    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

  1. 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....

  2. Acute coronary stent thrombosis in cancer patients: a case series report.

    Science.gov (United States)

    Lee, Joo Myung; Yoon, Chang-Hwan

    2012-07-01

    There have been a growing numbers of patients diagnosed with malignancy and coronary artery disease simultaneously or serially. In the era of percutaneous coronary intervention (PCI), stent thrombosis has been a rare but challenging problem. Recently, we experienced two unique cases of acute stent thrombosis in patients with malignancy. The first case showed acute and subacute stent thrombosis after PCI. The second case revealed simultaneous thromboses in stent and non-treated native coronary artery. We believe that we need rigorous precautions in the treatment of patients with coronary artery disease and malignancy, especially with regards to deciding how and whether to revascularize, as well as which anti-platelet agents to select. PMID:22870083

  3. Factors influencing recurrent reflux acute pyelonephritis in patients with JJ ureteral stent after discharge

    Directory of Open Access Journals (Sweden)

    Pricop Catalin

    2014-01-01

    Full Text Available The vesicoureteral reflux (VUR after the insertion of a JJ stent is a pathological entity characterized by the impossibility of the vesicoureteric junction (VUJ to exhibit its sphincterian functioning that allows the unidirectional flow of urine from the ureter to the bladder. This happens as long as the catheter is in place, and after its suppression due to traumatization of the ureterovesical junction, which loses its tonicity and ability to ensure urinary unidirectional flow. Reflux acute pyelonephritis is the acute inflammation of the renal tract and parenchyma resulting from stagnation of infected urine for long periods of time due to vesicoureteral reflux. We have noted multiple cases which, after the insertion of a JJ stent, presented reflux acute pyelonephritis due VUR, we considered the causes favoring these aspects. We focused on the frequency of reflux acute pyelonephritis and identified factors that could be used to advise patients with JJ stents.

  4. 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.

  5. 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

  6. Efficacy of Solitaire™ Stent Arterial Embolectomy in Treating Acute Cardiogenic Cerebral Embolism in 17 Patients.

    Science.gov (United States)

    Fu, Maolin; He, Wenqin; Dai, Weizheng; Ye, Yingan; Ruan, Zhifang; Wang, Shuanghu; Xie, Huifang

    2016-01-01

    BACKGROUND Thrombolysis with rtPA is the only accepted drug therapy for acute ischemic stroke. Since acute cerebral stroke is so pervasive, newly developed recanalization methods have the potential for wide-ranging impacts on patient health and safety. We explored the efficacy and safety of Solitaire stent arterial embolectomy in the treatment of acute cardiogenic cerebral embolism. MATERIAL AND METHODS Between October 2012 and June 2015, 17 patients underwent Solitaire stent arterial embolectomy, either alone or in combination with rtPA intravenous thrombolysis, to treat acute cardiogenic cerebral embolism. Sheath placement time, vascular recanalization time, number of embolectomy attempts, and IV rtPA dose and time were recorded. Success and safety of the recanalization procedure, as well as clinical outcomes, were assessed. These results were compared to 16 control patients who were treated using only rtPA IV thrombolysis. RESULTS Full recanalization of the occluded arteries was achieved in 15 (88.2%) of the Solitaire stent patients. NIH Stroke Scale scores of embolectomy patients improved by an average of 12.59±8.24 points between admission and discharge, compared to 5.56±5.96 in the control group (PComa Score improvement between admission and discharge was also significantly higher in the embolectomy group (P0.05). CONCLUSIONS Solitaire stent embolectomy is a safe and effective alternative to simple venous thrombolytic therapy, and it can significantly improve short-term neurological function and long-term prognosis in acute cardiogenic cerebral embolism. PMID:27090916

  7. ”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.

  8. An evaluation of short and long-term outcomes of TAXUS stent in patient with acute coronary syndrome

    International Nuclear Information System (INIS)

    Objective: To investigate the effect and security of TAXUS stent (paclitaxel-eluting stent) in patients with acute coronary syndrome (ACS). Methods: From November 2002 to December 2004, 94 patients with ACS had 120 TAXUS stents placed. Twenty -seven out of 95 had ST- segment elevation myocardial infarction; 8 had non- ST-segment elevation myocardial infarction and 59 had unstable angina. As for lesion characteristics, diffuse disease was found in 19 case, bifurcation lesions in 21 cases, chronic severe occlusion lesions in 19 cases, in-stent restenosis in 5 cases and ostial lesions in 6 case. The immediate angiographic outcome, six mouth follow-up results with major cardiac evrdiac event (MACE) and follow-up angiography in 6-7th mouth had been assessed. Results: Successful stent- placing procedure was achieved in 99% patients with ACS. Sub- acute stent thrombosis occurred in 1 patient, late stent thrombosis leading to AMI occurred in 1 patient. There was no death during the procedure and 6 -month follow -up. The MACE rate during hospitalization was 0.0% and was 7.4% during 6 month follow -up. Follow -up study performed in 6-7th month showed that restenosis rate (ISR) was 13.0% (in-stent restenosis rate was 2.7%). And the target vessel revascularization (TLR) rate was 2.7%. Conclusion: TAXUS stent implantation in the treatment of ACS is safe and effective, providing a significantly lower ISR rate than the convetional metal stents. (authors)

  9. Feasibility and safety of endovascular stent and Guglielmi detachable coils for treating acute ruptured wide-necked intracranial aneurysms

    International Nuclear Information System (INIS)

    Objective: To discuss the feasibility and safety of treatment on acute ruptured wide-necked intracranial aneurysms with endovascular stent and Guglielmi detachable coils (GDS). Methods: The coronary stents were first implanted across the neck of 57 acute ruptured wide-necked intracranial aneurysms with microcatheters introducing into the aneurysm sac through the stent mesh. GDCs were used to embolize the aneurysms. Results: 56 procedures were successful with only one failure of stent implantation due to tortuous vessel. Over 90% occlusion were achieved in 56 embolized aneurysms. The patients recovered well with patency of the parent arteries. Conclusion: Endovascular therapy with stent implantation and GDC placement is a safe and feasible approach for the treatment of acute ruptured wide-necked intracranial aneurysms. (authors)

  10. Endovascular stent-assisted thrombolysis in acute occlusive carotid artery dissection

    Energy Technology Data Exchange (ETDEWEB)

    Mourand, Isabelle [Hopital Gui de Chauliac, Department of Neurology, CHU Montpellier, Montpellier, Cedex 5 (France); Hopital Gui de Chauliac, Department of Neurology, Service de Neurologie, Montpellier, Cedex 5 (France); Brunel, Herve; Vendrell, Jean-Francois; Bonafe, Alain [Hopital Gui de Chauliac, Department of Neuroradiology, CHU Montpellier, Montpellier, Cedex 5 (France); Thouvenot, Eric [Hopital Gui de Chauliac, Department of Neurology, CHU Montpellier, Montpellier, Cedex 5 (France)

    2010-02-15

    Internal carotid artery dissection with tandem internal carotid and middle cerebral artery occlusion may be responsible for large cerebral infarction that carries a general poor prognosis. Recanalization of internal carotid artery (ICA) dissection by stent-assisted thrombolysis has been recently proposed. We report two cases of acute symptomatic ICA dissection with tandem occlusion successfully treated with emergent endovascular stent-assisted thrombolysis using new self-expandable intracranial stents. A 37-year-old woman and a 59-year-old man were admitted in our hospital after acute severe symptoms of right-hemispheric stroke with National Institutes of Health Stroke Scale (NIHSS) scores of 15 and 18, respectively. In both cases, magnetic resonance angiography showed tandem occlusion and angiography confirmed tandem occlusion with ICA dissection. An extensive mismatch region was diagnosed by Perfusion-diffusion MRI of the brain within 3 h after symptoms onset. Treatment was initiated 4 h after symptom onset by implantation of self-expandable intracranial stents into the dissected ICA and administration of intra-arterial recombinant tissue plasminogen activator. Recanalization of the ICA and middle cerebral artery (MCA) was accomplished within 6 h after symptoms onset. In both cases, no periprocedural complication was observed and follow-up CT scan showed only a mild brain infarct in the MCA territory. After, respectively, 12 and 10 months follow-up, patients had a favorable outcome with NIHSS 0 and mRS {<=}1. Endovascular stent-assisted thrombolysis appears to be a promising treatment in tandem occlusion due to ICA dissection. Our work underline the potential use of self-expandable intracranial stents in symptomatic acute ICA dissection. (orig.)

  11. 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

  12. Outcomes after revascularisation with everolimus- and sirolimus-eluting stents in patients with acute coronary syndromes and stable angina pectoris

    DEFF Research Database (Denmark)

    Antonsen, Lisbeth; Thayssen, Per; Hansen, Henrik S; Maeng, Michael; Tilsted, Hans-Henrik; Bøtker, Hans E; Ravkilde, Jan; Madsen, Morten; Sørensen, Henrik T; Thuesen, Leif; Lassen, Jens F; Jensen, Lisette O

    2014-01-01

    Aims: The aim of this substudy of the SORT OUT IV trial was to compare clinical outcomes among patients with acute coronary syndromes (ACS) and stable angina pectoris (SAP) treated with everolimus-eluting stents (EES) or sirolimus-eluting stents (SES). Methods and results: We performed a post hoc...

  13. 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

  14. Stent-assisted mechanical recanalization for the treatment of acute ischemic stroke

    International Nuclear Information System (INIS)

    Objective: to evaluate the safety and efficacy of stent-assisted mechanical recanalization technique in treating acute ischemic stroke. Methods: Stent-assisted mechanical recanalization procedure was carried out in 12 patients with acute ischemic stroke. The lesions were located at the anterior circulation in 10 cases and at posterior circulation in 2 cases. The clinical data were retrospectively analyzed. The technical success rate, the vascular recanalization, the occurrence of symptomatic intracranial hemorrhage, the clinical improvement and mortality were observed and evaluated. Results: The stent was successfully deployed in 11 patients (92%). After the treatment, different degrees of vascular recanalization were obtained in all patients. The complete (TIMI 3), partial (TIMI 2) and minor (TIMI 1) recanalization rate was 58.3% (7/12), 25% (3/12) and 8.3% (1/12), respectively. Postoperative symptomatic intracranial hemorrhage occurred in one patient (8.3%). Stroke-related death occurred in one patient (8.3%) and eight patients had their modified Rankin Score ≤ 2. Conclusion: For the treatment of acute ischemic stroke, stent-assisted mechanical recanalization technique is clinically feasible and safe with high vascular recanalization rate although further studies with larger sample to clarify its clinical usefulness are still needed. (authors)

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    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......-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...... patient management is central to achieve good clinical outcome....

  16. 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.

  17. [Absorbable coronary stents. New promising technology].

    Science.gov (United States)

    Erbel, Raimund; Böse, Dirk; Haude, Michael; Kordish, Igor; Churzidze, Sofia; Malyar, Nasser; Konorza, Thomas; Sack, Stefan

    2007-06-01

    Coronary stent implantation started in Germany 20 years ago. In the beginning, the progress was very slow and accelerated 10 years later. Meanwhile, coronary stent implantation is a standard procedure in interventional cardiology. From the beginning of permanent stent implantation, research started to provide temporary stenting of coronary arteries, first with catheter-based systems, later with stent-alone technology. Stents were produced from polymers or metal. The first polymer stent implantation failed except the Igaki-Tamai stent in Japan. Newly developed absorbable polymer stents seem to be very promising, as intravascular ultrasound (IVUS) and optical coherence tomography have demonstrated. Temporary metal stents were developed based on iron and magnesium. Currently, the iron stent is tested in peripheral arteries. The absorbable magnesium stent (Biotronik, Berlin, Germany) was tested in peripheral arteries below the knee and meanwhile in the multicenter international PROGRESS-AMS (Clinical Performance and Angiographic Results of Coronary Stenting with Absorbable Metal Stents) study. The first magnesium stent implantation was performed on July 30, 2004 after extended experimental testing in Essen. The magnesium stent behaved like a bare-metal stent with low recoil of 5-7%. The stent struts were absorbed when tested with IVUS. Stent struts were not visible by fluoroscopy or computed tomography (CT) as well as magnetic resonance imaging (MRI). That means, that the magnesium stent is invisible and therefore CT and MRI can be used for imaging of interventions. Only using micro-CT the stent struts were visible. The absorption process could be demonstrated in a patient 18 days after implantation due to suspected acute coronary syndrome, which was excluded. IVUS showed a nice open lumen. Stent struts were no longer visible, but replaced by tissue indicating the previous stent location. Coronary angiography after 4 months showed an ischemia-driven target lesion

  18. 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.

  19. 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

  20. 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

  1. Direct oral anticoagulant use and stent thrombosis following an acute coronary syndrome: A potential new pharmacological option?

    Science.gov (United States)

    Welsh, Robert C; Zeymer, Uwe; Tarrantini, Giuseppe

    2016-05-01

    With the evolution of techniques and pharmacological strategies in percutaneous coronary intervention, significant advances have been made towards reducing the risk of in-stent restenosis and improving patient outcomes. However, in spite of these advances, stent thrombosis remains a deadly complication of stent implantation. The fundamental challenge in implementing a combined anticoagulant and antiplatelet strategy is balancing the risk of bleeding with the enhanced efficacy of therapy on both pathways. Results from the ATLAS ACS 2-TIMI 51 trial suggest that the addition of rivaroxaban 2.5mg twice daily to standard antiplatelet therapy may achieve this desired balance alongside careful patient selection. This review considers the clinical burden and pathology of stent thrombosis, oral antithrombotic strategies to reduce stent thrombosis, and what findings from recent trials could mean for the long-term management of patients with an acute coronary syndrome. PMID:27020515

  2. 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...

  3. Efficacy and Safety of Endoscopic Gallbladder Stenting for Acute Cholecystitis in Patients with Concomitant Unresectable Cancer.

    Science.gov (United States)

    Hatanaka, Takeshi; Itoi, Takao; Ijima, Masashi; Matsui, Ayako; Kurihara, Eishin; Okuno, Nozomi; Kobatake, Tsutomu; Kakizaki, Satoru; Yamada, Masanobu

    2016-01-01

    Objective Endoscopic gallbladder stenting (EGBS) is an alternative treatment option for high-risk surgical patients with acute cholecystitis. However, there are no reports focusing on EGBS in patients with concomitant unresectable cancer. The aim of this study was thus to evaluate EGBS in such patients. Methods Twenty-two consecutive patients with acute cholecystitis and unresectable cancer were enrolled between September 2010 and December 2014. Their median age was 74.5 years (range: 51-95). Thirteen patients were men and nine were women. The primary cancers of the patients were biliary tract cancer (9), pancreas cancer (9), lung cancer (2), gastric cancer (1), and colon cancer (1). The causes of cholecystitis were calculus cholecystitis (7), obstruction by malignant tumor (13), and obstruction by fully covered stent (2). Results EGBS was successfully performed in 17 patients (77.2%). The technical success rates for calculus cholecystitis, obstruction by malignant tumor, and obstruction by fully covered stent were 85.7% (6/7), 69.2% (9/13), and 100% (2/2), respectively. No complications were observed. Percutaneous transhepatic gallbladder drainage was conducted on two patients in whom EGBS had failed and then we performed EGBS by a rendezvous approach. Of the 19 patients in whom we finally deployed EGBS, the median follow-up period was 229 days (range: 14-880 days). A recurrence of acute cholecystitis occurred in three (15.7%) patients 14, 130, and 440 days after EGBS placement. The rates of recurrence of cholecystitis at one and two years were 10.5% and 18.7%, respectively. Conclusion Our study demonstrated that EGBS is a safe and effective method for acute cholecystitis in patients with concomitant unresectable cancer. PMID:27250045

  4. 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

  5. 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.

  6. Abciximab in the treatment of acute in-stent thrombosis in patient with intracranial aneurysm

    International Nuclear Information System (INIS)

    A case of endovascular therapy via embolization of aneurysm in patient with SAH is performed selective brain angiography and find 3 aneurysms. The first is in right segment M1-M2 with diameter 5 mm, the second with wide neck is in supraclinoid portion of right internal carotid artery and the third in left M1-M2 segment. One month after embolization of ruptured aneurysm with coils BALT (Montmorency, France) and previous anticoagulation therapy was applied Leo stent (SALT) intraluminal in left internal carotid artery. Developed acute instent thrombosis recanalized with intraarterial use of abciximab. (authors)

  7. Power-Pulse Thrombolysis and Stent Recanalization for Acute Post-Liver Transplant Iliocaval Venous Thrombosis

    International Nuclear Information System (INIS)

    Postoperative inferior vena cava (IVC) thrombosis is a potentially lethal complication in a liver transplant recipient. We report the case of a 57-year-old liver transplant recipient, who developed acute, postoperative, markedly symptomatic complete IVC, ilial-femoral-caval, and left renal vein thrombosis. After treatment with power-pulse tissue plasminogen activator thrombolysis, thrombectomy, and stent placement, the IVC and iliac veins were successfully recanalized. At 2.5-year imaging and laboratory follow-up, the IVC, iliac, and renal veins remained patent and graft function was preserved.

  8. Outcomes of emergent carotid artery stenting within 6 hours of symptom onset in patients with acute ischemic stroke

    International Nuclear Information System (INIS)

    To investigate clinical outcomes following the emergent carotid artery stenting for treatment of acute ischemic stroke. Twenty-eight consecutive patients with acute stroke due to atherosclerotic steno-occlusive diseases of extracranial internal carotid artery underwent emergent carotid artery stenting. Of these, 23 patients had tandem intracranial arterial occlusions. Extracranial carotid stenting was successful in all patients. From the 13 patients who underwent intracranial recanalization procedures, successful recanalization occurred in 84.6% (11/13). 57% of patients (16/28) had a good clinical outcome (modified Rankin Scale 0-2) after 3 months. Patients with successful intracranial/extracranial recanalization had a significantly higher rate of good outcome than those without recanalization after 3 months (75% vs. 33%, p = 0.027). Patients without intracranial tandem occlusions had a more favorable clinical outcome than those with intracranial tandem occlusions (100% vs. 48%, p = 0.033). Symptomatic intracerebral hemorrhage occurred in one patient (3.6%). Mortality rate was 0% (0/28) after 3 months. Emergent carotid artery stenting in setting of acute stroke was a safe and effective treatment modality. Successful recanalization (extracranial and intracranial) and absence of intracranial tandem occlusion are significantly associated with a good outcome for our cohort of patients whom undergone emergent carotid artery stenting.

  9. 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...

  10. Long-Term Safety and Efficacy of Sirolimus- and Paclitaxel-Eluting Stents in Patients With Acute Myocardial Infarction: Four-Year Observational Study

    OpenAIRE

    Min, Gye-Sik; Lee, Jae-Hwan; Park, Jae-Ho; Choi, Ung-Lim; Lee, Young-Dal; Seong, Seok-Woo; Jin, Seon-Ah; Park, Soo-Jin; Kim, Jun-Hyeong; Park, Jae-Hyeong; Choi, Si Wan; Jeong, Jin-Ok; Seong, In-Whan

    2012-01-01

    Background and Objectives The comparison of long-term clinical effects between Sirolimus-eluting stent (SES) and Paclitaxel-eluting stents (PES) for treatment of acute myocardial infarction (AMI) remains unclear. Seeking to clarify this issue, we performed a retrospective analysis to evaluate four-year clinical outcomes of SES compared to PES treated AMI patients. Subjects and Methods From January 2004 to August 2006, all patients with acute ST-segment elevation myocardial infarction and acut...

  11. The effects of delayed percutaneous transluminal coronary angioplasty plus intracoronary stents on myocardial perfusion in patients with acute myocardial infarction

    International Nuclear Information System (INIS)

    Objective: To assess the myocardial perfusion in patients with acute myocardial infarction (AMI) after delayed percutaneous transluminal coronary angioplasty (PTCA) and intracoronary stent implanting. Methods: Fifty-six patients with AMI were divided into delayed PTCA + stent group (treatment group, n=30) and control group (n=26). The treatment group were received delayed PTCA and coronary artery stents 15-30 d after AMI. The first 99Tcm-MIBI was performed 1-3 d before PTCA + stent (treatment group) and 15-30 d after AMI (control group), and followed by the second (1 month later), and the third (6 months later) 99Tcm-MIBI. Results: One month and six months after the treatment procedure (PTCA + stent), the blood flow deficit degree of myocardial infarction area in treatment group was much improved comparing with that before the procedure (treatment group, P0.05). Conclusions: There is residual myocardial viability in the AMI regions and PTCA + stent implantation keeps more jeopardize myocardium viable. Active therapy after AMI can significantly improve myocardial perfusion

  12. 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

  13. 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.

  14. 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...

  15. 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.

  16. Mechanical thrombectomy with solitaire stent retrieval for acute ischemic stroke in a Brazilian population

    Directory of Open Access Journals (Sweden)

    Luis Henrique de Castro-Afonso

    2012-12-01

    Full Text Available OBJECTIVE: Large vessel occlusion in acute ischemic stroke is associated with low recanalization rates under intravenous thrombolysis. We evaluated the safety and efficacy of the Solitaire AB stent in treating acute ischemic stroke. METHODS: Patients presenting with acute ischemic stroke were prospectively evaluated. The neurological outcomes were assessed using the National Institutes of Health Stroke Scale and the modified Rankin Scale. Time was recorded from the symptom onset to the recanalization and procedure time. Recanalization was assessed using the thrombolysis in cerebral infarction score. RESULTS: Twenty-one patients were evaluated. The mean patient age was 65, and the National Institutes of Health Stroke Scale scores ranged from 7 to 28 (average 17±6.36 at presentation. The vessel occlusions occurred in the middle cerebral artery (61.9%, distal internal carotid artery (14.3%, tandem carotid occlusion (14.3%, and basilarartery (9.5%. Primary thrombectomy, rescue treatment and a bridging approach represented 66.6%, 28.6%, and 4.8% of the performed procedures, respectively. The mean time from symptom onset to recanalization was 356.5±107.8 minutes (range, 80-586 minutes. The mean procedure time was 60.4±58.8 minutes (range, 14-240 minutes. The overall recanalization rate (thrombolysis in cerebral infarction scores of 3 or 2b was 90.4%, and the symptomatic intracranial hemorrhage rate was 14.2%. The National Institutes of Health Stroke Scale scores at discharge ranged from 0 to 25 (average 6.9±7. At three months, 61.9% of the patients had a modified Rankin Scale score of 0 to 2, with an overall mortality rate of 9.5%. CONCLUSIONS: Intra-arterial thrombectomy with the Solitaire AB device appears to be safe and effective. Large randomized trials are necessary to confirm the benefits of this approach in acute ischemic stroke.

  17. A comparative study of primary coronary stenting with intravenous thrombolysis for acute myocardial infarction using 99mTc-MIBI SPECT imaging

    International Nuclear Information System (INIS)

    To evaluate and compare the therapeutic effectiveness of primary coronary stenting with that of intravenous thrombolysis for acute myocardial infarction (AMI) using 99mTc-MIBI myocardial SPECT imaging. A total of 42 patients with AMI was undergoing primary coronary stenting (stenting group, 23 patients) or intravenous thrombolysis therapy (thrombolysis groups 19 patients). 99mTc-MIBI myocardium SPECT imaging was performed before and 1 week after stenting or thrombolysis therapy. The left ventricular myocardium of each patient was divided into 20 segments. The semiquantitative score of myocardial 99mTc-MIBI uptake was expressed with a five-point scoring system. The scores of scanning before stenting or intravenous thrombolysis was SBS. The scores of scarring after stenting or intravenous thrombolysis was SAS. Deducting SAS from SBS was SDS. Make a comparison between the SAS. stenting group and fhrombolysis group: SBS was 41.3±9.8 and 39.4±7.9 (t=1.2, P>0.05); SAS was 17.8±6.4 and 27.3±6.7 (t=5.8, P99mTc-MIBI myocardial SPECT imaging has been proved to be an objective parameter for evaluating the therapeutic effectiveness of the stenting and intravenous thrombolysis in treatment of AMI. At the same time;, the results indicate that primary coronary stenting seems to be more effective than intravenous thrombolysis

  18. 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

  19. 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

    International Nuclear Information System (INIS)

    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.

  20. 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.

  1. The use of Solitaire AB stent in mechanical thrombectomy for acute cerebral artery occlusion: the initial experience in 31 cases

    International Nuclear Information System (INIS)

    Objective: To evaluate the safety and effectiveness of Solitaire AB stent in performing mechanical thrombectomy for acute cerebral artery occlusion. Methods: During the period from May 2010 to May 2011, arterial embolectomy by using Solitaire AB stent was carried out in 31 patients with acute cerebral artery occlusion. The obstructed arteries included internal carotid artery (ICA, n=6), middle cerebral artery (MCA, n=12), basal artery (BA, n=9), MCA plus BA (n=1) and distal segment of ICA plus MCA (n=3). The immediate effect after the treatment and the occurrence of postoperative bleeding were retrospectively analyzed. Modified Rankin scale (MRS) scores at 90 days after the treatment were determined. Results: Successful recanalization was obtained in MCA and BA. Recanalization of ICA was seen in 6 cases. Residual luminal stenosis after recanalization was found in 12 cases and stent implantation had to be employed. Postoperative intracranial hemorrhage occurred in 4 patients (12.9%), and death occurred in 8 patients (25.8%). In five of the eight fatal cases the responsible artery was the ICA, while in the other three fatal cases the responsible artery was the BA. The time from the onset of the symptoms to recanalization was over 8 hours in 8 patients, amongst them death occurred in two who suffered from ICA occlusion. During the follow-up period lasting 90 days, 15 patients (48.4%) had a good MRS scores (< 2) at the time of discharge. Conclusion: The results of this study suggest that the Solitaire AB device can get high recanalization rate and good clinical outcome in patients with MCA and BA occlusion, although Solitaire AB stent thrombectomy for IAC occlusion is not satisfactory as its revascularization rate is lower and its mortality is higher. (authors)

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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.

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

    International Nuclear Information System (INIS)

    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.

  9. Comparison of biolimus eluted from an erodible stent coating with bare metal stents in acute ST-elevation myocardial infarction (COMFORTABLE AMI trial): rationale and design

    OpenAIRE

    Räber, Lorenz; Kelbaek, Henning; Ostoijc, Miodrag; Baumbach, Andreas; Tüller, David; von Birgelen, Clemens; Roffi, Marco; Pedrazzini, Giovanni; Kornowski, Ran; Weber, Klaus; Heg, Dik; Matter, Christian; Lüscher, Thomas; Taniwaki, Masanori; Meier, Bernhard

    2012-01-01

    Compared with bare metal stents (BMS), early generation drug-eluting stents (DES) reduce the risk of revascularisation in patients with ST-elevation myocardial infarction (STEMI) at the expense of an increased risk of very late stent thrombosis (ST). Durable polymer coatings for controlled drug release have been identified as a potential trigger for these late adverse events and this has led to the development of newer generation DES with durable and biodegradable polymer surface coatings wit...

  10. Urgent stenting for patients with acute stroke due to atherosclerotic occlusive lesions of the cervical internal carotid artery

    International Nuclear Information System (INIS)

    Acute symptomatic occlusion of the cervical internal carotid artery (ICA) can be treated by intravenous administration of tissue plasminogen activator, percutaneous transluminal angioplasty, and carotid endarterectomy. Carotid artery stenting (CAS) is now indicated for cervical ICA stenosis, but the safety and the efficacy of urgent CAS have not been established. We retrospectively reviewed 10 patients treated by urgent CAS for atherosclerotic occlusive lesions of cervical ICA with acute stroke. Five patients had complete occlusions and five had near total occlusions. Five of the 10 patients had intracranial tandem occlusions. Indication for urgent CAS was determined by mismatch of diffusion-weighted and perfusion-weighted magnetic resonance imaging findings. Stents were successfully deployed in all lesions. Three of five patients with concomitant intracranial tandem occlusions were treated by additional intraarterial fibrinolysis after the CAS. Intracranial artery occlusions were completely recanalized in one patient, and partially recanalized in two by fibrinolysis. Hyperperfusion syndrome did not occur in any of the patients. A favorable outcome (modified Rankin Scale ≤1) was obtained in all of the five patients with isolated cervical ICA occlusion and one of the five patients with intracranial tandem occlusions. Urgent CAS is a safe and effective treatment in patients with isolated cervical ICA occlusion. Treatment of intracranial tandem occlusions is an issue that must be resolved. (author)

  11. 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.

  12. First- Versus Second-Generation Drug-Eluting Stents in Acute Coronary Syndromes (Katowice-Zabrze Registry)

    Science.gov (United States)

    Kawecki, Damian; Morawiec, Beata; Dola, Janusz; Waha, Wojciech; Smolka, Grzegorz; Pluta, Aleksandra; Marcinkiewicz, Kamil; Ochała, Andrzej; Nowalany-Kozielska, Ewa; Wojakowski, Wojciech

    2016-01-01

    Background There are sparse data on the performance of different types of drug-eluting stents (DES) in acute and real-life setting. Objective The aim of the study was to compare the safety and efficacy of first- versus second-generation DES in patients with acute coronary syndromes (ACS). Methods This all-comer registry enrolled consecutive patients diagnosed with ACS and treated with percutaneous coronary intervention with the implantation of first- or second-generation DES in one-year follow-up. The primary efficacy endpoint was defined as major adverse cardiac and cerebrovascular event (MACCE), a composite of all-cause death, nonfatal myocardial infarction, target-vessel revascularization and stroke. The primary safety outcome was definite stent thrombosis (ST) at one year. Results From the total of 1916 patients enrolled into the registry, 1328 patients were diagnosed with ACS. Of them, 426 were treated with first- and 902 with second-generation DES. There was no significant difference in the incidence of MACCE between two types of DES at one year. The rate of acute and subacute ST was higher in first- vs. second-generation DES (1.6% vs. 0.1%, p < 0.001, and 1.2% vs. 0.2%, p = 0.025, respectively), but there was no difference regarding late ST (0.7% vs. 0.2%, respectively, p = 0.18) and gastrointestinal bleeding (2.1% vs. 1.1%, p = 0.21). In Cox regression, first-generation DES was an independent predictor for cumulative ST (HR 3.29 [1.30-8.31], p = 0.01). Conclusions In an all-comer registry of ACS, the one-year rate of MACCE was comparable in groups treated with first- and second-generation DES. The use of first-generation DES was associated with higher rates of acute and subacute ST and was an independent predictor of cumulative ST. PMID:27058257

  13. 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

  14. 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.

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

    International Nuclear Information System (INIS)

    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

  16. 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.

  17. 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

  18. 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

  19. 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

  20. 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...

  1. 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

  2. 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.

  3. Biocompatibility of Coronary Stents

    Directory of Open Access Journals (Sweden)

    Thamarasee M. Jeewandara

    2014-01-01

    Full Text Available Cardiovascular disease is the dominant cause of mortality in developed countries, with coronary artery disease (CAD a predominant contributor. The development of stents to treat CAD was a significant innovation, facilitating effective percutaneous coronary revascularization. Coronary stents have evolved from bare metal compositions, to incorporate advances in pharmacological therapy in what are now known as drug eluting stents (DES. Deployment of a stent overcomes some limitations of balloon angioplasty alone, but provides an acute stimulus for thrombus formation and promotes neointimal hyperplasia. First generation DES effectively reduced in-stent restenosis, but profoundly delay healing and are susceptible to late stent thrombosis, leading to significant clinical complications in the long term. This review characterizes the development of coronary stents, detailing the incremental improvements, which aim to attenuate the major clinical complications of thrombosis and restenosis. Despite these enhancements, coronary stents remain fundamentally incompatible with the vasculature, an issue which has largely gone unaddressed. We highlight the latest modifications and research directions that promise to more holistically design coronary implants that are truly biocompatible.

  4. 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

  5. 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.

  6. 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

  7. Acute effects of liver vein occlusion by stent-graft placed in transjugular intrahepatic portosystemic shunt channel: An experimental study

    OpenAIRE

    Keussen, Inger; Bergqvist, Lennart; Rissler, Pehr; Cwikiel, W

    2006-01-01

    The purpose of this study was to evaluate the effects of hepatic vein occlusion by stent-graft used in transjugular intrahepatic portosystemic shunt (TIPS). The experiments were performed in six healthy pigs under general anesthesia. Following percutaneous transhepatic implantation of a port-a-cath in the right hepatic vein, TIPS was created with a stent-graft (Viatorr; W L Gore, Flagstaff, AZ, USA). The outflow from the hepatic vein, blocked by the stent-graft was documented by injection of ...

  8. 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...

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

    International Nuclear Information System (INIS)

    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.

  10. 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.

  11. The Study of Factors Associated with Severity of In-Stent Restenosis in Patients Treated with PCI for Acute Coronary Syndromes

    Directory of Open Access Journals (Sweden)

    Blendea Ciprian

    2016-03-01

    Full Text Available Introduction: The management of in stent restenosis represents a topic of great actuality and interest, especially since the interventional treatment with stent implantation became largely accepted as the metod of choice in patients with acute coronary syndromes. Identification of certain risk factors that could predict the development of an in stent restenosis and its severity could be extremely useful for the clinical management of these patients. Methods: We retrospectively analyzed a total of 60 stent restenoses encountered in 57 patients admitted and treated in the Cardiology Clinic of Tirgu Mures. The interval of occurrence of restenosis ranged between 2 months and 37 months postintervention. We monitored the demographic characteristics (age, gender, colesterol, presence of renal insufficiency and we realized a descriptive qualitative analysis of the angiographic procedural aspects. The in stent restenosis occurred most frequently on left anterior descending artery (63%, followed by the circumflex artery (22.15% and right coronary artery (14.8%, regardless of the degree of stenosis prior to revascularization. Results: Statistical analysis using Chi square test revealed no statistically significant differences in terms of the correlation between the incidence of restenosis and gender (p=0.14, treatment with ACE inhibitors (p=0.16, implanted stent diameter (p=0.22 or the type of procedure (ram crossing over a secondary branch being considered as a procedure involved in the genesis of severe restenosis (p=0.2. We used the t-student test for comparative analysis of the correlation between the continuous variables related to initial native lesion diameter and the degree of restenosis, without finding any a statistically significant correlation between them (p=0.226. However, a statistically significant correlation was found between cholesterol levels and the degree of stenosis (p=0.039. Descriptive analysis of restenosis lesions did not find

  12. 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

  13. 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 ...

  14. 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

  15. Stent graft placement for dysfunctional arteriovenous grafts

    International Nuclear Information System (INIS)

    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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. The HERMES Recoil Detector

    Science.gov (United States)

    Kaiser, R.

    2006-07-01

    The HERMES Collaboration is installing a new Recoil Detector to upgrade the spectrometer for measurements of hard exclusive electron/positron scattering reactions, in particular deeply virtual Compton scattering. These measurements will provide access to generalised parton distributions and hence to the localisation of quarks inside hadrons and to their orbital angular momentum. The HERMES Recoil Detector consists of three active components: a silicon detector surrounding the target cell inside the beam vacuum, a scintillating fibre tracker and a photon detector consisting of three layers of tungsten/scintillator. All three detectors are located inside a solenoidal magnetic field of 1 Tesla. The Recoil Detector was extensively tested with cosmic muons over the summer of 2005 and is being installed in the winter of 2005/6 for data taking until summer 2007.

  1. The HERMES Recoil Detector

    International Nuclear Information System (INIS)

    The HERMES Collaboration is installing a new Recoil Detector to upgrade the spectrometer for measurements of hard exclusive electron/positron scattering reactions, in particular deeply virtual Compton scattering. These measurements will provide access to generalised parton distributions and hence to the localisation of quarks inside hadrons and to their orbital angular momentum. The HERMES Recoil Detector consists of three active components: a silicon detector surrounding the target cell inside the beam vacuum, a scintillating fibre tracker and a photon detector consisting of three layers of tungsten/scintillator. All three detectors are located inside a solenoidal magnetic field of 1 Tesla. The Recoil Detector was extensively tested with cosmic muons over the summer of 2005 and is being installed in the winter of 2005/6 for data taking until summer 2007

  2. 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.

  3. High acceptance recoil polarimeter

    International Nuclear Information System (INIS)

    In order to detect neutrons and protons in the 50 to 600 MeV energy range and measure their polarization, an efficient, low-noise, self-calibrating device is being designed. This detector, known as the High Acceptance Recoil Polarimeter (HARP), is based on the recoil principle of proton detection from np→n'p' or pp→p'p' scattering (detected particles are underlined) which intrinsically yields polarization information on the incoming particle. HARP will be commissioned to carry out experiments in 1994

  4. Acute Effects of Liver Vein Occlusion by Stent-Graft Placed in Transjugular Intrahepatic Portosystemic Shunt Channel: An Experimental Study

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the effects of hepatic vein occlusion by stent-graft used in transjugular intrahepatic portosystemic shunt (TIPS). The experiments were performed in six healthy pigs under general anesthesia. Following percutaneous transhepatic implantation of a port-a-cath in the right hepatic vein, TIPS was created with a stent-graft (Viatorr; W L Gore, Flagstaff, AZ, USA). The outflow from the hepatic vein, blocked by the stent-graft was documented by injection of contrast medium and repeated injections of 99Tcm-labeled human serum albumin through the port-a-cath. After 2 weeks, the outflow was re-evaluated, the pigs were sacrificed, and histopathologic examination of the liver was performed. Occlusion of the hepatic vein by a stent-graft had a short and temporary effect on the outflow. Histopathological examination from the affected liver segment showed no divergent pattern. Stent-grafts used in TIPS block the outflow from the liver vein, but do not have a prolonged circulatory effect and do not affect the liver parenchyma

  5. 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

  6. 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...

  7. 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.)

  8. 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).

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. Carotid stenting

    International Nuclear Information System (INIS)

    Full text: The annual incidence of stroke is estimated around 2 cases per 1000 in the general population and 80% of strokes are ischemic. [1] Atherosclerotic disease resulting in stenosis of common and/or internal carotid arteries is an established risk factor for acute cerebrovascular events. [2] In the majority of the cases ischemic stroke is caused by atherosclerotic plaque rupture and subsequent thrombus formation resulting in carotid occlusion or/and distal thromboembolization. Today, two invasive methods are available in order to reduce the risk of severe ischemic events: surgical carotid artery endarterectomy (CEA) and percutaneous carotid artery stenting (CAS). More recently amassed high-level scientific data coming from randomized controlled trials (RCTs) and meta-analysis comparing CAS with CEA have emerged. [3] Initial RTCs included the French EVA 3S, which investigated 527 symptomatic patients in 30 different centers, the German SPACE investigating 1.200 patients and the International ICSS which randomized 1710 patients. In EVA 3S the 30-day rate of any stroke death was significantly lower in the CEA group (3.9 vs. 9.6%, HR: 2.5). However the trial was prematurely stopped and severely criticized. [4] The SPACE trial resulted in a similar rate of ipsilateral stroke or death at 30-days and 2 years follow-up (6.8% CAS vs. 6.3% CEA), while in the ICSS trial the primary endpoint of all strokes, death and myocardial infarction (MI) was significantly lower in the CAS group (5.2% vs. 8.5%). Finally, the most recent CREST (Carotid Revascularization Endarterectomy vs. Stenting) trial randomized 2.502 patients (1.321 symptomatic). The composite primary endpoint of any stroke, death and MI was similar between the two methods (CAS: 7.2% vs. CEA: 6.8%; HR=1.11), while both methods demonstrated similar short- and longer-term outcomes. However significant differences between the components were detected (stroke 4.1% vs. 2.3%, P=0.012; and MI 1.1% vs. 2.3%, p=0.032, CAS

  14. Stent intracoronario. Intracoronary stent.

    OpenAIRE

    Lorenzo D. Llerena Rojas; Luis Roberto Llerena Rojas

    2000-01-01

    Diez años después de introducida la angioplastia coronaria por vía transluminal percutánea (ACTP), fue implantada la primera prótesis metálica intracoronaria en el hombre con lo que se redujeron 2 de los inconvenientes de la ACTP: la oclusión súbita del vaso recién dilatado y la reestenosis que aparece en los 6 meses que siguen a una ACTP exitosa y que se presenta aproximadamente en el 30 % de los pacientes. El uso del stent se ha difundido rápidamente en el mundo incluyendo nuestro país dond...

  15. 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

  16. 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 ...

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. 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. 

  4. 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.

  5. 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.

  6. Acute Vertebral Artery Origin Occlusion Leading to Basilar Artery Thrombosis Successfully Treated by Angioplasty with Stenting and Thrombectomy

    OpenAIRE

    Abe, Arata; Okubo, Seiji; Onozawa, Shiro; Nakajima, Masataka; Suzuki, Kentaro; Harada-Abe, Mina; Ueda, Masayuki; Katsura, Ken-ichiro; Katayama, Yasuo

    2014-01-01

    Few reports have described the successful treatment of stroke caused by acute vertebral artery (VA) origin occlusion by endovascular surgery. We describe the case of a 68-year-old man who experienced stroke due to left acute VA origin occlusion. Cerebral angiography showed that the left VA was occluded at its origin, the right VA had hypoplastic and origin stenosis, and the basilar artery was occluded by a thrombus. The VA origin occlusion was initially passed through with a 0.035-inch guide ...

  7. 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

  8. 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’ ...

  9. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... paves the path so we can pass the metal stent. And then we take a stent and ... open up that balloon, and it expands that metal stent, which is generally stainless steel in compound, ...

  10. 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...

  11. 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,...

  12. 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...

  13. 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.

  14. Drug-eluting stents in renal artery stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Zaehringer, M. [Marienhospital Stuttgart, Department of Radiology, Stuttgart (Germany); Pattynama, P.M.T. [Erasmus MC-University Medical Center Rotterdam, Rotterdam (Netherlands); Talen, A. [genae associates nv, Antwerp (Belgium); Sapoval, M. [Hopital Europeen Georges Pompidou, Service de Radiologie Cardio-Vasculaire, Paris (France); Inserm U 780 epidemiologie Cardio Vasculaire, Paris (France)

    2008-04-15

    Because of higher acute and long-term success rates compared with balloon angioplasty alone, percutaneous stent implantation has become an accepted therapy for the treatment of atherosclerotic renal artery stenosis. Restenosis rates after successful renal stent placement vary from 6 up to 40%, depending on the definition of restenosis, the diameter of the treated vessel segment and comorbidities. The safety and efficacy of drug-eluting stents for the treatment of renal-artery stenosis is poorly defined. The recently published GREAT study is the only prospective study, comparing bare-metal and sirolimus-coated low profile stent systems in renal artery stenosis, showing a relative risk reduction of angiographic binary in-stent restenosis by 50%. This is an opinion paper on indications, current treatment options and restenosis rates following renal artery stenting and the potential use of drug-eluting stents for this indication. (orig.)

  15. 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

    International Nuclear Information System (INIS)

    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

  16. 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.

  17. 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.

  18. 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...

  19. Electromagnetic separators for recoiling reaction products

    International Nuclear Information System (INIS)

    This chapter describes the use of magnetic spectrometers and spectrographs, recoil mass spectrometers, and velocity filters as standard tools in many heavy-ion investigations. Topics considered include ion optics, examples of recoil selectors with static fields (the SHIP, the MIT-BNL energy-mass spectrometer, the MIT-BNL recoil-mass selector, the recoil-mass spectrometer at Michigan State University, the recoil-mass spectrometer at the University of Rochester, the Daresbury recoil separator, the MIT-ORNL recoil-mass selector), examples of recoil selectors with RF fields (the Munich RF separator, an RF separator proposed for GSI), magnetic spectrometers combined with time of flight (the GSI spectrometer, mirror-symmetric magnetic spectrometers), spectrometers for spallation products (the BEVALAC spectrometers, a proposed time-of-flight spectrometer for LAMPF), and technical aspects of electromagnetic separators (electric-field limitations, beam scattering)

  20. 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 ...

  1. 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.

  2. Renal Artery Stenting in Patients with a Solitary Functioning Kidney

    International Nuclear Information System (INIS)

    Purpose: To retrospectively evaluate the results of renal artery stenting in patients with renovascular disease and a solitary functioning kidney.Methods: Palmazstents were placed in 16 patients with a solitary functioning kidney,renal artery stenosis, hypertension and renal failure. Stenoses were evaluated with color Doppler ultrasound, MR angiography and digital subtraction angiography (DSA). Indications for stenting were: recoil after percutaneous transluminal renal angioplasty (PTRA) (63%),arterial dissection after PTRA (13%) and primary stenting (25%).Immediate results were evaluated by DSA. On follow-up (6-36 months),patients underwent periodical evaluation of clinical conditions (blood pressure and serum creatinine level) and stent patency, by means of color Doppler ultrasound.Results: Stent placement was successful in all patients (100%). Cumulative primary patency rate was: 100% at 1 day, 93.75% at 6 months, 81.25% at 12 months and 75% at 24 months. A significant reduction in diastolic blood pressure occurred (mean ± SD 104 ± 6 vs 92 ± 3;p 0.05).Conclusion: Renal artery stenting, both after PTRA and as primary stenting, represents a safe procedure, able to preserve renal function in patients with a solitary functioning kidney

  3. 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...

  4. 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.

  5. 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...

  6. 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

  7. 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.

  8. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... from the heart, and then there are other issues as well. It 5 could be a pinched ... prevents these stents from clotting off. The real issue between a bare metal stent and a drug- ...

  9. 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.)

  10. 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

  11. 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

  12. 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.

  13. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... and very difficult to get to the 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. And I ...

  14. 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. ...

  15. Coronary artery and myocardial inflammatory reaction induced by intracoronary stent

    Directory of Open Access Journals (Sweden)

    Gomes Walter J.

    2002-01-01

    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.

  16. 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

  17. 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

  18. 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

  19. Recoil-ion momentum spectroscopy

    International Nuclear Information System (INIS)

    High-resolution recoil-ion momentum spectroscopy (RIMS) is a novel technique to determine the charge state and the complete final momentum vector PR of a recoiling target ion emerging from an ionising collision of an atom with any kind of radiation. It offers a unique combination of superior momentum resolution in all three spatial directions of ΔPR = 0.07 a.u. with a large detection solid angle of ΔΩR/4π≥ 98%. Recently, low-energy electron analysers based on rigorously new concepts and reaching similar specifications were successfully integrated into RIM spectrometers yielding so-called ''reaction microscopes''. Exploiting these techniques, a large variety of atomic reactions for ion, electron, photon and antiproton impact have been explored in unprecedented detail and completeness. Among them first kinematically complete experiments on electron capture, single and double ionisation in ion-atom collisions at projectile energies between 5 keV and 1.4 GeV. Double photoionisation of He has been investigated at energies Eγ close to the threshold (Eγ = 80 eV) up to Eγ = 58 keV. At Eγ>8 keV the contributions to double ionisation after photoabsorption and Compton scattering were kinematically separated for the first time. These and many other results will be reviewed in this article. In addition, the experimental technique is described in some detail and emphasis is given to envisage the rich future potential of the method in various fields of atomic collision physics with atoms, molecules and clusters. (orig.)

  20. 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.

  1. 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.

  2. Rational minimally invasive treatment of pAOD: when should a conservative approach, PTA, or stent be chosen?

    International Nuclear Information System (INIS)

    In order to obtain optimal results and satisfied patients, rational therapy of pAOD should strictly follow national and international society guidelines. In particular cases an individual therapeutic concept seems justified beyond these guidelines. Based on clinical data and driven by costs, aortic and iliac lesions may be treated by PTA or selective stent placement with equal results; however, long-term data justify also primary, direct stenting. For treatment of infrainguinal and popliteal stenotic lesions primary stenting should be restricted to PTA failure (dissection, recoil, occlusion); except for treatment of extended lesions, primary stenting compared to PTA alone seems beneficial in terms of midterm patency. Endovascular procedures below the knee and at the toe should be limited to existing limb-threatening ischemia in order to save the extremity; whether PTA or stenting is advantageous has not yet determined. (orig.)

  3. Treatment of splenic artery aneurysm with double overlapping bare stents: case report

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Hyo Sung; Han, Young Min; Jin, Gong Yong [School of Medicine, Chonbuk National Univ., Chonju (Korea, Republic of)

    2004-09-01

    The traditional treatment of splenic artery aneurysm (SAA) is generally surgery and/or transcatheter arterial embolization, but recently, the treatment of SAA using a stent graft has been reported. However, the acute angle of the celiac axis, as well as the tortuous path of the splenic artery makes the use of stent graft difficult for treatment of aneurysma. We report here a case of SAA treated with the technique of double overlapping metallic stents.

  4. 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

  5. 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...... 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 was obtained via laser cutting, and surface treatment was performed with acid pickling and electropolishing, followedby an annealing process. In vitro mechanical analysis was performed to analyze the mechanical performance of the auxetic coronary stent. Scanning electronic microscopy (SEM) was...

  6. 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

  7. 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

  8. 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.

  9. 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...

  10. Palliative stent implantation for coarctation in neonates and young infants

    International Nuclear Information System (INIS)

    In selected neonates and infants, primary palliative stent implantation may be indicated for coarctation of the aorta. We describe our experience with this approach in five consecutive patients. Five neonates and infants (age range 6 to 68 days, gestation 33 to 38 weeks, weight range at procedure of between 1650 to 4000 g) underwent palliative stent implantation as primary therapy for coarctation of the aorta. Indications for primary stent implantation were varied. All procedures were performed by elective surgical cut down of the axillary artery. Standard coronary stents (diameter 4.5 to 5 mm, length 12 to 16 mm) were delivered via a 4F sheath. The axillary artery was repaired after removal of the sheath. All procedures were acutely successful, and without procedural complications. All patients survived to hospital discharge. Four patients have subsequently undergone elective stent removal and surgical repair of the arch, at between 38 and 83 days following stent implantation. Complete stent removal was achieved in three patients. Over a follow-up ranging between 8 weeks and 36 months, none of the patients has had any further complications. This palliative approach is warranted in carefully selected patients. Long-term follow-up is required

  11. 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.

  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. The basic research on different intra-tracheal stent placement in experiment dogs

    International Nuclear Information System (INIS)

    Objective: On the basic research of different intra-tracheal stent placement in dogs, we try to further explore the application value of membrane covered stent. Methods: Totally 18 healthy, matured and hybrid dogs were randomly divided into 3 groups with different type of intra-tracheal stent placement. Group A (n=6): with whole membrane covered stent (6 cm, length covered) placement. Group B (n=6): with middle segment membrane covered stent (4 cm in length with either 1 cm uncovered at the upper and lower terminal). Group C(n=6): with uncovered stent (6 cm in length). After intra-tracheal stent placement, all clogs were monitored with recording of clinical assessment of food intake, expectoration and respiration. Twenty weeks later, all dogs were sacrificed and their tracheal specimen were inspected grossly and HE examination. The further investigation included PCNA stain, the positive expression of proliferative cells by quantification analysis. Results: After intra-tracheal stent placement, all dogs showed no acute dyspnea but with a mild to moderate cough with no obvious difference in expectoration. All animals were normal in drinking, taking food and bark, and only a part of them seemed to be in low activity. The proliferation of endotracheal wall was more prominent at the non-membrane covered stent placement sites, together with more severe sterotic lumens than those of the membrane covered stent placement sites. All groups demonstrated individually the inflammatory change, squamous metaplasia of low columnal epithelial cells, granulomatosis and fibrous proliferation under HE stain examination. The positive expression of mucosal proliferative cells involved all the groups showed statistical significant differences (P<0.05), with higher preoportional rates for non-membrane covered stent placement site. Conclusion: Short term intra-tracheal placement with membrane covered or non-covered stent shows no significant influence clinically. The outcome of membrane

  14. Spectral Imaging for Intracranial Stents and Stent Lumen.

    Directory of Open Access Journals (Sweden)

    Chi-Lun Weng

    Full Text Available Application of computed tomography for monitoring intracranial stents is limited because of stent-related artifacts. Our purpose was to evaluate the effect of gemstone spectral imaging on the intracranial stent and stent lumen.In vitro, we scanned Enterprise stent phantom and a stent-cheese complex using the gemstone spectral imaging protocol. Follow-up gemstone spectral images of 15 consecutive patients with placement of Enterprise from January 2013 to September 2014 were also retrospectively reviewed. We used 70-keV, 140-keV, iodine (water, iodine (calcium, and iodine (hydroxyapatite images to evaluate their effect on the intracranial stent and stent lumen. Two regions of interest were individually placed in stent lumen and adjacent brain tissue. Contrast-to-noise ratio was measured to determine image quality. The maximal diameter of stent markers was also measured to evaluate stent-related artifact. Two radiologists independently graded the visibility of the lumen at the maker location by using a 4-point scale. The mean of grading score, contrast/noise ratio and maximal diameter of stent markers were compared among all modes. All results were analyzed by SPSS version 20.In vitro, iodine (water images decreased metallic artifact of stent makers to the greatest degree. The most areas of cheese were observed on iodine (water images. In vivo, iodine (water images had the smallest average diameter of stent markers (0.33 ± 0.17mm; P < .05 and showed the highest mean grading score (2.94 ± 0.94; P < .05 and contrast/noise ratio of in-stent lumen (160.03 ±37.79; P < .05 among all the modes.Iodine (water images can help reduce stent-related artifacts of Enterprise and enhance contrast of in-stent lumen. Spectral imaging may be considered a noninvasive modality for following-up patients with in-stent stenosis.

  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. Tracheomalatia, to stent or not to stent

    Directory of Open Access Journals (Sweden)

    Irena Perić

    2015-01-01

    Full Text Available Benign thyroid disorders such as goiter, especially retrosternal, can cause tracheostenosis by extrinsic tracheal compression, which is due to the lack of specific symptoms often misdiagnosed. Tracheomalatia develops as a result to long term tracheal compression and refers to weakness of the trachea characterized by softness of the tracheal cartilage arches and by loss of regular tracheal structure. Tracheomalatia is characterized by reduction of the endotracheal lumen and may affect the entire trachea or may be localized to one portion of it. We present the case of a 72-year old patient with distinct tracheostenosis and tracheomalatia, caused by long term pressure by the retrosternal goiter. We have been monitoring the patient for last 20 years after the second endotracheal stent had been placed. The first one was placed 34 years ago, in 1981. On both occasions granulation tissue and colonization of bacteria occurred. In the end the placed stents were rejected and migrated to the main carina. Despite the tracheal diameter narrower than 5 mm the patient has been living normally without the stent for 17 years, with the exception of no hard physical labor. He had a few short term antibiotic therapies and bronchial toilets during symptomatic deteriorations. Diagnosing retrosternal goiter and surgical treatment on time is of crucial importance in cases such as this one. Considering the complications caused by the stent, our opinion is that the majority of patients may require conservative treatment with closely monitoring during respiratory infections.

  17. Hyperperfusion syndrome after carotid stent angioplasty

    International Nuclear Information System (INIS)

    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.)

  18. 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.)

  19. 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 ...

  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

    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 ...

  3. 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 ...

  4. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... putting in a bare metal stent. The whole theory behind that is you have a lesser chance ... a stress test in a year, with the knowledge that this last stress test was a false ...

  5. 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 ...

  6. 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 ...

  7. 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 ...

  8. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... against the wall, but what happens is scar tissue forms, so it’s literally scarring in there. That ... secreted from the metal stent and prevents scar tissue from forming. So at one time it was ...

  9. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... long-term,” that has changed as a moving target. But at one point it was a year. ... deploy and very difficult to get to the target lesion. Now with the stents being as flexible ...

  10. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... metal stent, which is generally stainless steel in compound, and it opens it up, and we take ... wire and pass a little tiny ultrasound catheter down where we can actually look at the plaque ...

  11. 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 ...

  12. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... putting in a bare metal stent. The whole theory behind that is you have a lesser chance ... time, very important. Oh, I think in the interest of the patient who has been laying on ...

  13. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... is associated with accelerated hardening of the arteries. Diabetes Mellitus is a very serious cause of particularly ... one that came in from Art. He said, “Two weeks ago I had a drug-eluting stent ...

  14. 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 ...

  15. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... you can have a lesser plaque, 30 percent, 40 percent, which does not reduce blood flow, which ... That occurs in anywhere from 20 up to 40 percent of lesions. That’s why Medicated stents were ...

  16. Preliminary report on a new concept stent prototype designed for venous implant.

    Science.gov (United States)

    Lugli, M; Maleti, O

    2015-08-01

    Venous obstruction at iliocaval level in both forms, primary and secondary, is a significant cause of severe chronic venous insufficiency. A new therapeutic approach to this pathology emerged with the introduction of stenting procedures that proved effective, leading to good long-term results. However, at present, the majority of implanted stents have been designed for arterial implant and this can pose a limit in particular districts. The purpose of this preliminary acute study was to verify the deliverability and safety of a new stent specially designed for venous-vessel implant. We assess the safety and deliverability of two braided, self-expanding, nickel-titanium stents (Jotec GmbH, Hechingen, Germany) specially designed for endovascular implant in veins. The two stents, despite being based on the same concept, have a different design: stent A presents a proximal tapering shape specially designed to reduce migration, while stent B does not. Both of them are enlarged at their distal extremity and present variable radial force the length of the stent itself, the said force becoming very high in the intermediate segment. Stents were implanted in the internal jugular vein of a sheep, showing optimal deliverability. The completion venography showed the migration of stent B into the right atrium. Stent A maintained its location, confirmed by intravascular ultrasound examination. No scaffolding effect was detected and an adequate adherence and adaptability to the vein wall was obtained. In conclusions, the stent A design matches the characteristics required by vein implants. Stability is achieved even where difficult anatomical conditions apply, such as in the jugular vein. Deployment is easy and precise in a given landing zone. Radial resistive force is very high, as required in specific vein districts, but is also associated with good flexibility. Following this preliminary acute report, further studies are required. PMID:24920424

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

    International Nuclear Information System (INIS)

    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

  18. 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

  19. 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...

  20. 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.

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

    International Nuclear Information System (INIS)

    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

  2. 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.

  3. 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

  4. Average charge of superheavy recoil ion in helium gas

    Energy Technology Data Exchange (ETDEWEB)

    Kaji, D.; Morita, K.; Morimoto, K.; Haba, H. [RIKEN, Wako, Saitama (Japan). Nishina Center for Accelerator Based Science; Kudo, H. [Niigata Univ. (Japan). Dept. of Chemistry

    2011-07-01

    The average equilibrium charges q{sub ave} of heavy recoil ions moving in helium gas were measured by a gasfilled recoil ion separator (GARIS). A new empirical formula to calculate q{sub ave} for superheavy recoil ions with a low velocity was derived. This formula was applicable to the search for a superheavy nuclide of {sup 266}Bh. (orig.)

  5. Average charge of superheavy recoil ion in helium gas

    International Nuclear Information System (INIS)

    The average equilibrium charges qave of heavy recoil ions moving in helium gas were measured by a gasfilled recoil ion separator (GARIS). A new empirical formula to calculate qave for superheavy recoil ions with a low velocity was derived. This formula was applicable to the search for a superheavy nuclide of 266Bh. (orig.)

  6. 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.

  7. 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.

  8. 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

  9. Mechanical Recanalization of Cerebral Artery Embolic Occlusion Using a Self-Expanding Stent: Experimental Analysis in Canine Model

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin Woo; Kim, Snag Joon; Lee, Deok Hee; Suh, Dae Chul [Dept. of Radiology and Research Institute of Radiology, Asan Medical Center, Ulsan University College of Medicine, Seoul (Korea, Republic of)

    2011-07-15

    To evaluate the feasibility of a self-expanding stent for acute embolic occlusion, and recanalization mechanism by histologic examination. Five mongrel dogs were used as study subjects. Each vertebral artery was occluded, and a self-expanding stent was used for recanalization. We evaluated the technical success rate for the placement of the stent to the targeted vessel, the recanalization rate, and residual stenosis. We obtained two specimens of the stented vertebral arteries for histologic evaluation. One dog died of an unknown cause during the induction of anesthesia. In two dogs, only one side of the vertebral artery was used, whereas both vertebral arteries were used in the remaining dogs. A total of six vertebral arteries were successfully occluded. The technical success rate for stenting without complication was 66.7%. The immediate recanalization rate after stenting was 100%. The residual stenosis was 35.6 {+-} 18.6%. On microscopic examination, the stent concentrically displaced the clot and the clot was captured between the stent mesh and arterial wall. Self-expanding stents were effective in revascularizing the cerebrovascular embolic occlusion. The self-expanding stent seemed to achieve recanalization by pushing the clot to the arterial wall and capturing the clot between the stent mesh and arterial wall.

  10. Ionization and scintillation of nuclear recoils in gaseous xenon

    International Nuclear Information System (INIS)

    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. 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.

  12. Clinical observation on coronary heart disease treated with carbon stent

    International Nuclear Information System (INIS)

    Objective: To discuss the security of carbon stent in the percutaneous coronary intervention, especially the effectiveness of preventing thrombus formation in the carbo stent and effect on reducing the rate of restenosis. Methods: 10 cases with coronary heart disease. 6 cases suffered from acute myocardial infarction (AMI), including 2 on the anterior wall, 4 on the inferior and 4 with unstable angina pectoris. 8 cases were undergone emergent direct PCI and other 2 with rescue PCI. There were 12 diseased blood vessels and 13 lesions of pathologic changes. The ratio of the diameter of selective stent and target blood vessel was 1.0-1.1:1. The authors began to expend the diseased vascular lumen with the lower pressure and gradually increased the pressure to obtain only 5% of the original narrowing. Results: The authors used 13 carbo stents. After the procedure, all of diseased blood vessles reached forward TIMI III grade of blood flow. Anticoagulants were carried on continuously after the procedure. The follow-up survey continued for 2-18 months (average 10.3±6.33 months) without any cardiovascular events. Conclusion: Carbo stent covered with a layer of carbofilm separates the metal from contact with blood and tissues, and thus reduced the rate of acute thrombus formation and the re-narrowing rate. The exact therapeutic effect is still in need of further research and observation. (authors)

  13. Self-expandable stent loaded with 125I seeds: Feasibility and safety in a rabbit model

    International Nuclear Information System (INIS)

    Objective: To evaluate technical feasibility and acute and subacute radiotolerance of a self-expandable stent loaded with 125I seeds in the rabbit esophagus. Methods: A self-expandable stent designed for esophageal application was made of 0.16 mm nitinol wire and loaded with 125I seeds (CIAE-6711). Twenty-seven stents with three different radioactive dosages (n = 9 in each dosage group) were implanted in the esophagus of healthy rabbits, while nine stents alone were used as controls. The stents were perorally deployed into the esophagus under fluoroscopic guidance. Radiological follow-up included plain chest film, CT scan, and barium esophagography which were undertaken in all rabbits of each group at 2, 4, and 8 weeks, respectively, which were correlated to histopathological findings. The stented esophageal segments along with their adjacent tissues were harvested for histopathological examinations. Results: The stent was successfully deployed into the targeted esophageal segment in all rabbits. Neither 125I seeds dislodged from the stent during the deployment, nor they did during the follow-up period. The greatest (16.2 Gy) absorbed dose was found in the tissue 10 mm from 125I seeds at 8 weeks. Slight epithelial hyperplasia on the stent surface and submucosal inflammatory process developed at 2 weeks, which reached the peak at 8 weeks after the procedure. Significant thickness of the esophageal muscular layer was found at 8 weeks only in the groups with 125I seeds. On radiologic follow-up, moderate strictures on both ends of the stents developed at 4 weeks and became severe at 8 weeks after the procedure in all groups. Conclusion: Deployment of a self-expandable stent loaded with 125I seeds is technically feasible and safe within the first 8 weeks. Acute and subacute radiotolerance of the treated esophagus and its adjacent tissues by 125I seeds is well preserved in a healthy rabbit model

  14. Esophageal stents: when and how.

    Science.gov (United States)

    Kachaamy, Toufic; Pannala, Rahul

    2016-06-01

    Esophageal stents are devices used to alleviate dysphagia and treat leaks and perforations. Successful esophageal stenting requires definition of the abnormal anatomy such as stricture length or location of the leak, proper stent selection and deployment. This requires detailed knowledge of characteristics of the currently available stents. Self-expanding metal stents whether fully or partially covered have become the mainstay of treatment of esophageal cancer-related dysphagia as they provide quick relief of symptoms and have a favorable safety and efficacy profile, compared to other modalities such as radiation, laser, and argon plasma coagulation. They are also the initial treatment of choice for both malignant and benign fistulae. Stents are also used in benign refractory strictures but long-term stricture resolution rates are low in this setting. Fully covered metal stents are relatively easier to remove compared to partially covered stents; optimal time interval for removal depends on the indication for stenting and the clinical status of the patient. Stent related adverse events include chest pain, reflux, migration, and recurrent obstruction. Serious adverse events occur in less than 5% with procedure-related mortality of less than 2%. Techniques such as placement of hemostatic clips, Over The Scope clips, and endoscopic suturing are being used to decrease the migration risk but the optimal approach has not been defined. Antireflux measures are needed when a stent is placed across the gastroesophageal junction. Stents with antireflux designs do not appear to offer additional benefit compared to the conventional stent designs. Newer stent designs including biodegradable, drug eluting and radioactive stents are currently being investigated. PMID:26824424

  15. Stenting the ductus arteriosus: Case selection, technique and possible complications

    International Nuclear Information System (INIS)

    Ductal stenting is an attractive alternative to conventional shunt surgery in duct dependent congenital heart disease as it avoids thoracotomy and its related problems. With today's generation of coronary stents which have better profile, flexibility and trackability, ductal stenting may be achieved safely and with considerably less difficulty than previously described. As in Blalock-Taussig (BT) shunt, ductal stenting is indicated mainly in duct-dependent cyanotic lesions chiefly in the neonatal period. Unlike the Patent ductus arteriosus (PDA) as an isolated lesion, the ductus in cyanotic heart disease has a remarkable morphologic variability. The ductus tends to arise more proximally under the aortic arch, giving rise to a vertical ductus or occasionally it may arise from the subclavian artery. It also tends to be long and sometimes very tortuous, rendering stent implantation technically impossible. The ductus in these patients may also insert onto one of the branch pulmonary arteries with some stenosis at the site of insertion. The ductus in Tetralogy of Fallot with pulmonary atresia (TOF-PA) tend to exhibit these morphologic features and to a lesser degree in transposition of great arteries with ventricular septal defect and pulmonary atresia (TGA-VSD-PA) and the more complex forms of univentricular hearts. In the preliminary angiographic evaluation, it is important to delineate these morphologic features as the basis for case selection. Ductal stenting may be done by the retrograde femoral artery route or the antegrade transvenous route depending on the ductus morphology and the underlying cardiac lesion. The detailed techniques and essential hardware are described. Finally, major potential complications of the procedure are described. Acute stent thrombosis is the most serious and potentially catastrophic. Emergent treatment with thrombolytic therapy and mechanical disruption of thrombus are required. With proper case selection, appropriate technique

  16. Long-Term Clinical Outcome after Sirolimus-Stent Implantation for in Sirolimus-Eluting Stent Restenosis

    Directory of Open Access Journals (Sweden)

    Alain Guidon

    2008-01-01

    Full Text Available Restenosis after sirolimus-eluting stents (SES remains a clinical problem. We report our experience with the use a second SES in the fi rst SES to treat in-SES restenosis. Twenty-seven patients with in-SES restenosis were included in the registry. In-SES restenosis was focal in 34%, diffuse in 59% and proliferative in 7%. The procedure was successful in all patients without any acute in-hospital complications. During a mean follow-up of 14 ± 7 months MACE occurred in 8 patients (30%, (1 death, 1 myocardial infarction, 4 target lesion revascularisation, 1 target vessel revascularisation and 1 patient underwent CABG. Nineteen patients (70% had an event-free outcome. In conclusion SES placement to treat in-SES is safe and feasible and could be considered as a therapeutic option. However the incidence of MACE remains high on a long-term period. The use of stents has significantly improved the outcome of percutaneous coronary interventions (PCI (1,2. However, despite major advances in angioplasty and stenting, in-stent restenosis remains a major limitation. Recently, drug-eluting stents and especially sirolimus-eluting stents (SES have emerged as a very promising approach in preventing restenosis, and several different compounds have been shown to have a major impact on both the angiographic and the clinical outcome (6–9. However, even after drug eluting stents implantation in-stent restenosis (ISR remains and represents a clinical challenge. Several approaches have been proposed to deal with ISR like plain old balloon angioplasty (POBA, rotational atherectomy, brachytherapy (1–3. Few reports are actually available about the use of SES in SES for ISR treatment. We report our experience about the use SES for treating an ISR after SES implantation.

  17. Cavity cooling below the recoil limit.

    Science.gov (United States)

    Wolke, Matthias; Klinner, Julian; Keßler, Hans; Hemmerich, Andreas

    2012-07-01

    Conventional laser cooling relies on repeated electronic excitations by near-resonant light, which constrains its area of application to a selected number of atomic species prepared at moderate particle densities. Optical cavities with sufficiently large Purcell factors allow for laser cooling schemes, avoiding these limitations. Here, we report on an atom-cavity system, combining a Purcell factor above 40 with a cavity bandwidth below the recoil frequency associated with the kinetic energy transfer in a single photon scattering event. This lets us access a yet-unexplored regime of atom-cavity interactions, in which the atomic motion can be manipulated by targeted dissipation with sub-recoil resolution. We demonstrate cavity-induced heating of a Bose-Einstein condensate and subsequent cooling at particle densities and temperatures incompatible with conventional laser cooling. PMID:22767925

  18. Elastic recoil detection using heavy ion beams

    International Nuclear Information System (INIS)

    Elastic Recoil Detection using heavy ion projectile beams allows compositional depth-profiling of materials to a depth of about 2.5 μm. The technique is sensitive to all chemical elements including hydrogen. It is particularly suited for the analysis of thin film materials. Large solid-angle position-sensitive gas ionization detectors have been developed for the efficient detection of the recoil ions. With the set-up at the Australian National University, measurement and analysis are greatly simplified by using a new detector design. A grid electrode allows a direct determination of the ion energy, while a divided anode enables the simultaneous detection of ions with largely different atomic numbers and also provides linear position information. A diverse spectrum of materials has been analyzed including photosensitive doped silica, high-Tc superconductors and dielectric films

  19. 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

  20. 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; Lassen, Jens Flensted; Harnek, Jan; Olivecrona, Göran K; Erglis, Andrejs; Fossum, Eigil; Niemelä, Matti; Kervinen, Kari; Ylitalo, Antti; Pietilä, Mikko; Aaroe, Jens; Kellerth, Thomas; Saunamäki, Kari; Thayssen, Per; Hellsten, Lars; Thuesen, Leif; Niemelä, Kari

    2012-01-01

    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...

  1. 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.

  2. 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...

  3. 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.

  4. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... be more difficult to open up, and that leads to more techniques that we’ll discuss. 6 ... ahead with stenting?” And I think that may lead to some of the questions. We don’t ...

  5. Coronary Angioplasty Stent Placement

    Medline Plus

    Full Text Available ... There’s a thing we call “balanced ischemia.” Ischemia meaning lack of blood flow, and sometimes those tests ... most patients that have a drug-eluting stent should be on Plavix or a similar type of ...

  6. Discrimination between Nuclear Recoils and Electron Recoils by Simultaneous Detection of Phonons and Scintillation Light

    CERN Document Server

    Meunier, P; Bruckmayer, M; Giordano, S; Loidl, M; Meier, O; Pröbst, F; Seidel, W; Sisti, M; Stodolsky, L; Uchaikin, S V; Zerle, L

    1999-01-01

    We have developed a detector, consisting of a cryogenic calorimeter with a scintillating crystal as absorber, and a second calorimeter for the detection of the scintillation light, both operated at 12 mK. Using a CaWO4 crystal with a mass of 6g as scintillating absorber, we have achieved a discrimination of nuclear recoils against electron recoils with a suppression factor of 99.7% at energies above 15 keV. This novel method will be applied for background rejection in the CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) experiment looking for dark matter Weakly Interacting Massive Particles (WIMPs).

  7. Mechanical Characteristics of Composite Knitted Stents

    International Nuclear Information System (INIS)

    We used metal wires and fibers to fabricate a composite knitted stent and then compare the mechanical characteristics of this stent with those of a pure metallic stent of the same construction in order to develop a stent that offers a comparable degree of expandability as metallic stents but can be used for highly curved lesions that cannot be treated using metallic stents. We fabricated two types of composite knitted stent (N-Z stents), using nitinol wire with a diameter of 0.12 mm and polypara-phenylene-benzobisoxazole (PBO) multifilament fiber (Zyron AS; Toyobo, Osaka, Japan). Stents were knitted into a cylindrical shape using the same textile pattern as a Strecker stent. Two loop lengths (L) of nitinol wire were used in the N-Z stents: L = 1.84 mm (N-Z stent L = 1.84) and L = 2.08 mm (N-Z stent L = 2.08). For the sake of comparison, we fabricated a metallic stent of nitinol using the same textile pattern (N-N stent L = 1.92). We applied a radial compression force diametrically to each stent and applied a bending force diametrically at the free end of a stent with one end fixed in order to evaluate the relationship between stent elasticity and load values. In addition, we macroscopically evaluated the generation of kinks when the stent was bent 180o. The radial compressive force when the stent diameter was reduced by 53% was 6.44 N in the case of N-Z stent L = 1.84, 6.14 N in the case of N-Z stent L = 2.08, and 4.96 N in the case of N-N stent L = 1.92 mm. The composite stent had a radial compressive force higher than that of a metallic stent. The restoring force to longitudinal direction at a 90o bending angle was 0.005 N for N-Z stent L = 1.84, 0.003 N for N-Z stent L = 2.08, and 0.034 N for N-N stent L = 1.92. The restoring force of the composite stent was significantly lower. Finally, the composite stent generated no definitive kinks at a bending angle of 180o, regardless of loop length. However, the N-N stent clearly produced kinks, causing blockage of the

  8. 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)

  9. Endovascular therapy for atherosclerotic renovascular disease: technical results with the Palmaz {sup trademark} -Corinthian{sup TM} stent; Endovaskulaere Therapie der Nierenarterienstenose: technische Ergebnisse mit dem Palmaz {sup trademark} -Corinthian{sup TM}-Stent

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, C.W.; Hahn, U.; Tepe, G.; Pereira, P.L.; Duda, S.H. [Tuebingen Univ. (Germany). Abt. Radiologische Diagnostik; Erley, M. [Medizinische Klinik III, Univ. Tuebingen (Germany); Schneider, W. [Abt. Thorax-, Herz- und Gefaesschirurgie, Univ. Tuebingen (Germany); Ritter, W. [Inst. fuer Diagnostische und Interventionelle Radiologie, Klinikum Neurnberg-Sued (Germany); Beregi, J.P. [Service de Radiologie Vasculaire, Hopital Cardiologique, CHRU de Lille (France); Goffette, P. [Radiologie Vasculaire et Interventionnelle, Cliniques Univ. Saint-Luc, Dept. de Radiologie, Unite de Radiodiagnostic, Univ. Catholique de Louvain, Bruxelles (Belgium)

    2001-05-01

    To evaluate the technical performance and delivery characteristics of the Palmaz-Corinthian stent for endovascular therapy of atherosclerotic renovascular disease. Methods: 61 patients underwent implantation of 76 Palmaz-Corinthian (PC) stents in 72 arteries. 50 original PC and 26 PC stents with the modified IQ-design were employed. The indications comprised primary stenting of ostial (n = 49) or truncal (n = 1) stenosis or occlusion (n = 3), and selective stenting following complicated (dissection, n = 4) or unsuccessful (n = 8) angioplasty. The remaining stents were placed in patients with recurrent stenosis (n = 5) or acute aortic dissection (n = 2) involving the renal artery. Mean severity and length of stenosis were 81,3% and 9.8 mm, respectively. 39 lesions were rated eccentric or calcified. Data on technical success, complication rate, delivery characteristics and ease of placement compared to standard renal stents were retrieved from a prospective multicenter registry. Results: stent delivery was successful in all patients, major complications were not reported. Stent placement was suboptimal in 7 of 72 cases: 4 stents were located too distally in the renal artery, necessitating proximal coaxial overstenting in 2 cases. The distal part of the stenosis was incompletely covered and the orifice of a segmental branch inappropriately overstented in one case each. One stent was dislodged from the balloon, resulting in stent protrusion in the aortic lumen. Significnt residual stenosis after stenting was not observed. Overall stent deliverability, trackability and potential repositioning inside the stenosis were rated positive, radioopacity was rated superior for the IQ design. Conclusion: technical performance and delivery characteristics of the Palmaz-Corinthian stent have been significantly improved compared to the Palmaz design, allowing mostly correct placement in renal artery stenoses with a low complication rate. (orig.) [German] Untersuchung der

  10. 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

    endpoint, and clinically indicated target vessel revascularisation (TVR) and stent thrombosis. Compared to patients with BMS, those treated with SES and EES had a strong trend towards lower two-year rates of the primary endpoint (HR: 0.31 [CI: 0.11-0.90], p=0.03, and HR: 0.74 [CI: 0.44-1.24], p=0.25), and...... implantation in large vessels was associated with a reduction in both TVR and the combined endpoint consisting of cardiovascular death/MI. Thus, DES use improves both efficacy and safety. These findings support the use of DES in NSTE-ACS patients.......AIMS: The use of drug-eluting stents (DES) in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) is controversial and not yet endorsed in clinical guidelines. METHODS AND RESULTS: This was an a priori planned post hoc analysis involving 754 NSTE-ACS patients from the...

  11. 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

  12. 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

  13. 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

  14. Neutron electric form factor via recoil polarimetry

    International Nuclear Information System (INIS)

    The ratio of the electric to the magnetic form factor of the neutron, GEn/GMn, was measured via recoil polarimetry from the quasielastic d((pol-e),e(prime)(pol-n)p) reaction at three values of Q2 [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 GEn follows the Galster parameterization up to Q2 = 1.15 (GeV/c)2 and appears to rise above the Galster parameterization at Q2 = 1.47 (GeV/c)2

  15. 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.

  16. Triple focussing recoil separator CARP at RCNP

    International Nuclear Information System (INIS)

    A reaction product mass separator (CARP) which is now being constructed for use with the AVF cyclotron at RCNP is described. This device is intended to separate unslowed recoiling products in nuclear reactions from the primary beam and to analyze them according to their charge-to-mass ratio. The use as a mass-spectrograph or as a mass-separator is available according to the experimental requirements. The solid angle and the energy range of acceptance will be 10 msr and 20%, respectively. (orig.)

  17. 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.

  18. 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...

  19. 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...

  20. 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)

  1. Noninvasive correction of a fractured endoluminal nitinol tracheal stent in a dog.

    Science.gov (United States)

    Ouellet, Mathieu; Dunn, Marilyn E; Lussier, Bertrand; Chailleux, Nadège; Hélie, Pierre

    2006-01-01

    An 11-year-old, castrated male Pomeranian was presented for intractable cough and dyspnea secondary to severe tracheal collapse. An endoluminal nitinol tracheal stent was placed with good results. Five months following placement of the prosthesis, clinical signs acutely recurred and failure of the implant was noted. A second stent was superimposed over the fractured stent and resulted in resolution of all clinical signs. The dog died several months later from progression of the tracheal collapse to the carina and mainstem bronchi. PMID:17088395

  2. Contralateral Cerebral Infarction after Stent Placement in Carotid Artery: An Unexpected Complication

    OpenAIRE

    Park, Seong-Ho; Lee, Chang Young

    2008-01-01

    Stenting is a useful alternative treatment modality in carotid artery stenosis patients who are too high-risk to undergo carotid endarterectomy (CEA). We report a case of contralateral cerebral infarction after stenting for extracranial carotid stenosis. A 78-year-old woman was admitted to the hospital with left-sided weakness. Based on magnetic resonance imaging (MRI) of the brain and conventional angiography, she was diagnosed with an acute watershed infarct of the right hemisphere secondar...

  3. 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.

  4. 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

  5. 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

    randomly allocated to treatment with the Absorb BVS or a metallic EES 1:1. The primary endpoint is the neointimal healing (NIH) score, which is calculated based on a score taking into consideration the presence of uncovered and malapposed stent struts, intraluminal filling defects and excessive neointimal...

  6. 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.

  7. Synchrotron-radiation experiments with recoil ions

    Energy Technology Data Exchange (ETDEWEB)

    Levin, J.C.

    1989-01-01

    Studies of atoms, ions and molecules with synchrotron radiation have generally focused on measurements of properties of the electrons ejected during, or after, the photoionization process. Much can also be learned, however, about the atomic or molecular relaxation process by studies of the residual ions or molecular fragments following inner-shell photoionization. Measurements are reported of mean kinetic energies of highly charged argon, krypton, and xenon recoil ions produced by vacancy cascades following inner-shell photoionization using white and monochromatic synchrotron x radiation. Energies are much lower than for the same charge-state ions produced by charged-particle impact. The results may be applicable to design of future angle-resolved ion-atom collision experiments. Photoion charge distributions are presented and compared with other measurements and calculations. Related experiments with synchrotron-radiation produced recoil ion, including photoionization of stored ions and measurement of shakeoff in near-threshold excitation, are briefly discussed. 24 refs., 6 figs., 1 tab.

  8. 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.)

  9. Stents and statins: history, clinical outcomes and mechanisms.

    Science.gov (United States)

    Nair, Pradeep K; Mulukutla, Suresh R; Marroquin, Oscar C

    2010-09-01

    The 1980s witnessed the inception of both stents and 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors (statins). While they evolved separately, it was soon realized that they each offered a unique and powerful mechanism for targeting the major offender in cardiovascular disease, namely atherosclerosis. Coincidentally, the first statin was approved by the US FDA in 1987, the same year that the coronary stent was conceived. Since that time, stents and statins have revolutionized the field of cardiovascular medicine and their paths have been intertwined. Several pivotal randomized clinical trials have established statins as an effective therapy for improving clinical outcomes after percutaneous coronary intervention (PCI) among patients presenting with stable coronary artery disease and acute coronary syndromes. In addition, chronic statin therapy and acute loading of statins prior to PCI has consistently been shown to limit periprocedural myocardial necrosis. The mechanism for improved clinical outcomes with statins has clearly been associated with statin-induced reductions in LDL. In addition, statins may also exert 'pleiotropic' effects, independent of LDL lowering, that might counteract the inflammatory and prothrombotic mileu created with PCI. This article provides a brief historical perspective of the evolution of the use of statins and stents in patients with coronary artery disease, an evaluation of the available clinical data supporting the use of statins in patients undergoing PCI across a wide spectrum of clinical scenarios, and a discussion of the potential mechanisms of the benefit of statins in these patients. PMID:20828351

  10. 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.)

  11. 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

  12. Rational minimally invasive treatment of pAOD: when should a conservative approach, PTA, or stent be chosen?; Rationale minimal-invasive Therapie der pAVK: wann konservativ, wann PTA, wann Stent

    Energy Technology Data Exchange (ETDEWEB)

    Mueller-Huelsbeck, S. [Universitaetsklinikum Schleswig-Holstein der Christian-Albrechts-Universitaet zu Kiel, Klinik fuer Diagnostische Radiologie, Kiel (Germany)

    2006-11-15

    In order to obtain optimal results and satisfied patients, rational therapy of pAOD should strictly follow national and international society guidelines. In particular cases an individual therapeutic concept seems justified beyond these guidelines. Based on clinical data and driven by costs, aortic and iliac lesions may be treated by PTA or selective stent placement with equal results; however, long-term data justify also primary, direct stenting. For treatment of infrainguinal and popliteal stenotic lesions primary stenting should be restricted to PTA failure (dissection, recoil, occlusion); except for treatment of extended lesions, primary stenting compared to PTA alone seems beneficial in terms of midterm patency. Endovascular procedures below the knee and at the toe should be limited to existing limb-threatening ischemia in order to save the extremity; whether PTA or stenting is advantageous has not yet determined. (orig.) [German] Die rationale Therapie der peripheren arteriellen Verschlusskrankheit (pAVK) sollte in Anlehnung an Richtlinien der nationalen und internationalen Fachgesellschaften erfolgen, um in hohem Masse ein klinisch optimales und zufrieden stellendes Behandlungsergebnis fuer den Patienten zu erreichen. Im Einzelfall muss allerdings eine individuelle Therapiestrategie ausserhalb der Richtlinien entwickelt werden. Basierend auf gleichwertigen klinischen Daten und Kostengruenden sind aortal und in besonderem Masse iliakal die alleinige perkutane transluminale Angioplastie (PTA) und/oder selektive Stentimplantation zu bevorzugen, wenngleich ausgezeichnete Langzeitergebnisse auch eine direkte, primaere Stentimplantation rechtfertigen. Infrainguinal und popliteal hingegen sollten Stents nicht primaer zur Behandlung stenosierender Veraenderungen eingesetzt werden, sondern nur nach fehlgeschlagener PTA (Dissektion, Recoil, Verschluss); lediglich zur Behandlung langstreckiger Veraenderungen koennte eine Stentimplantation Vorteile gegenueber einer

  13. 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)

  14. 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.

  15. Self-Expanding Metal Stents for Palliative Treatment of Superior Vena Caval Syndrome

    International Nuclear Information System (INIS)

    Purpose: Two stent types (a new Wallstent and a Z-stent) were investigated in 30 patients with recurrent malignant superior vena caval syndrome (SVCS). Methods: Eligibility requirements were that the patient had recurrent symptoms after appropriate radiation therapy, chemotherapy, or both; ≥75% of the vessel was occluded; and there was collateral flow. Because of the limited availability of stents, it was not possible to perform a prospectively randomized study. Results: In the Z-stent group (17 patients), occlusion of the stent due to acute thrombosis occurred within 12 hr in 4 patients (24%), but in the other 13 patients (76%) symptoms disappeared completely. After 2 weeks the cavogram in these patients showed no signs of thrombosis, and 12 (71%) of the patients remained symptom-free. There was partial occlusion in 5 patients (29%), without relevant clinical symptoms. Of the 13 patients who received Wallstents, only 1 had an acute immediate thrombosis (8%). Symptoms disappeared completely in the other 12 patients and no signs of thrombosis were seen. However, after 2 weeks complete stent occlusion with SVCS was found in 3 patients (23%) and partial occlusion with minor clinical symptoms in 6 (46%). Only 3 patients (23%) had complete relief of their SVCS. The difference between the rates of occlusion of the two stents after 2 weeks was highly significant (p= 0.008). Conclusions: The overall clinical success rate for long-term patency was 100% for the Z-stents and 69% for the new Wallstent. These results suggest that when used for this purpose, the new Wallstent is more thrombogenic at 2 weeks than the Z-stent

  16. 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; Lassen, Jens Flensted; Tilsted, Hans-Henrik; Hansen, Knud Noerregaard; Maeng, Michael; Thuesen, Leif; Thayssen, Per

    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 or...... restenosis after DES implantation for treatment of restenosis....

  17. Are Aortic Stent Grafts Safe in Pregnancy?

    OpenAIRE

    Nader Khandanpour; Mehta, Tapan A.; Adiseshiah, M; Meyer, Felicity J.

    2015-01-01

    Aortic stent grafts are increasingly used to treat aortic aneurysms and also other aortic pathologies. The safety of aortic stent grafts in pregnancy has never been studied or reported. We report on two cases of aortic stent grafts in pregnant women and discuss the effect of pregnancy on these aortic stent grafts.

  18. Treatment of symptomatic intracranial arterial stenosis with Wingspan stent system

    International Nuclear Information System (INIS)

    Objective: To discuss the safety of Gateway-Wingspan stent system in treating symptomatic intracranial atherosclerotic stenosis and its effect of preventing and treating cerebral ischemic events. Methods: Interventional treatment by using Gateway-Wingspan sent system was carried out in 36 patients with symptomatic intracranial atherosclerotic arterial stenosis (a total of 38 lesions) who had failed to response the medication. Of the 32 cases, elective surgery was performed in 32 and emergent surgery in 4. Of the total 38 stenotic sites, 22 were located at the posterior cerebral blood circulation region, while 16 at the anterior circulation region. Results: The average degree of stenosis before stenting procedure was 72.6%±12.6%, the residual stenosis degree after balloon dilatation and stenting was 33.8%±15.2% and 23.6%±13.9%, respectively. The successful rate of treatment was 97.4%. Perioperative complications occurred in 4 patients, two from 32 cases who received elective surgery and other two from 4 cases who received emergent stent implantation. In cases receiving elective surgery, one suffered from perforating arterial branch occlusion and one occurred cerebral bleeding due to the rupture of middle cerebral artery caused by guide-wire. In patients receiving emergent stent implantation, acute stent thrombosis occurred in 2 cases during the interventional management (n=1) or 24 hours after stent placement (n=1). The overall complication rate was 11.1% (4/36). The 30-day composite ipsilateral stroke rate was 5.5% and the frequency of ipsilateral stroke within 30 days or ipsilateral stroke between 30 days and 12 months was 11.1% (4/36) during a mean follow-up time of 9.6 months (ranged between 1-24 months). DSA check-up was conducted in 10 cases and restenosis at the middle cerebral artery was detected in 2 cases. Conclusion: It is quite safe to use Gateway-Wingspan stent system for the treatment of symptomatic intracranial stenosis and its short-term clinical

  19. 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

  20. 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.

  1. 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

  2. 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

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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. ...

  8. 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

  9. 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 ...

  10. 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...

  11. 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...

  12. Carotid artery stenting

    International Nuclear Information System (INIS)

    An ipsilateral stenosis of the internal carotid artery is found in 10 - 15 % of all ischemic strokes and indicates an increased risk of a second stroke. Carotid artery stenting (CAS) is a therapy that is established for many years. CAS reveals complication rates and long-term efficacy comparable to carotid endarterectomy (TEA). Especially younger patients seem to benefit from CAS. Abilities and experiences of the therapist and the choice of the techniques used are critical for patient safety. The efficacy of CAS for treatment of asymptomatic carotid stenosis is probable but still unproven in prospective-randomized trial. (orig.)

  13. Carotid artery stenting; Karotisangioplastie

    Energy Technology Data Exchange (ETDEWEB)

    Fiehler, Jens [Universitaetsklinikum Eppendorf, Hamburg (Germany). Klinik und Poliklinik fuer Neuroradiologische Diagnostik und Intervention, Diagnostikzentrum

    2009-09-15

    An ipsilateral stenosis of the internal carotid artery is found in 10 - 15 % of all ischemic strokes and indicates an increased risk of a second stroke. Carotid artery stenting (CAS) is a therapy that is established for many years. CAS reveals complication rates and long-term efficacy comparable to carotid endarterectomy (TEA). Especially younger patients seem to benefit from CAS. Abilities and experiences of the therapist and the choice of the techniques used are critical for patient safety. The efficacy of CAS for treatment of asymptomatic carotid stenosis is probable but still unproven in prospective-randomized trial. (orig.)

  14. Biodegradable, elastomeric coatings with controlled anti-proliferative agent release for magnesium-based cardiovascular stents.

    Science.gov (United States)

    Gu, Xinzhu; Mao, Zhongwei; Ye, Sang-Ho; Koo, Youngmi; Yun, Yeoheung; Tiasha, Tarannum R; Shanov, Vesselin; Wagner, William R

    2016-08-01

    Vascular stent design continues to evolve to further improve the efficacy and minimize the risks associated with these devices. Drug-eluting coatings have been widely adopted and, more recently, biodegradable stents have been the focus of extensive evaluation. In this report, biodegradable elastomeric polyurethanes were synthesized and applied as drug-eluting coatings for a relatively new class of degradable vascular stents based on Mg. The dynamic degradation behavior, hemocompatibility and drug release were investigated for poly(carbonate urethane) urea (PCUU) and poly(ester urethane) urea (PEUU) coated magnesium alloy (AZ31) stents. Poly(lactic-co-glycolic acid) (PLGA) coated and bare stents were employed as control groups. The PCUU coating effectively slowed the Mg alloy corrosion in dynamic degradation testing compared to PEUU-coated, PLGA-coated and bare Mg alloy stents. This was confirmed by electron microscopy, energy-dispersive x-ray spectroscopy and magnesium ion release experiments. PCUU-coating of AZ31 was also associated with significantly reduced platelet adhesion in acute blood contact testing. Rat vascular smooth muscle cell (rSMC) proliferation was successfully inhibited when paclitaxel was released from pre-loaded PCUU coatings. The corrosion retardation, low thrombogenicity, drug loading capacity, and high elasticity make PCUU an attractive option for drug eluting coating on biodegradable metallic cardiovascular stents. PMID:27085049

  15. 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.

  16. 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)

  17. Minimonoka Stent for Canalicular Reconstruction

    Directory of Open Access Journals (Sweden)

    Sunil G Biradar,

    2015-04-01

    Full Text Available Objective: Canalicular injuries are relatively common and accounts for 16-26% of all lid tears. There are different techniques for reconstructing traumatic canalicular lacerations. The most favorable intervention would be one that is simple, less invasive with reduced postoperative complications/recovery time. The aim of this study is to report the surgical outcome with the Mini-Monoka monocanalicular stent. Material and Methods: Patients with traumatic canalicular lacerations who underwent surgical reconstruction using the Mini-Monoka monocanalicular stent were included. The surgical outcome was based on subjective (epiphora and objective (tear meniscus level, and lacrimal irrigation findings after stent removal. Result: Ten patients (mean age: 9.7 years of lower canaliculus injury were included. Successful stenting was accomplished in all cases. Postoperative eyelid position was satisfactory in most patients. The mean postoperative follow-up period was 6 months. There were no cases of premature stent extrusion. Functional drainage after stent removal was normal in all of patients. Syringing showed full patency. Conclusion:The MiniMonoka monocanalicular stent is an effective tool in reconstructing traumatic canalicular lacerations. Easy to use, carries a minimal risk of infection and injury to the non-lacerated canaliculus, and results in high anatomical and functional success rates.

  18. 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)....

  19. Fabrication and testing of recoil mass spectrometer at Mumbai Pelletron

    International Nuclear Information System (INIS)

    The main motivation for the recoil mass separator, which has been designed and constructed at the Mumbai Pelletron, has been to study the exotic nuclei far off from the line of β-stability, produced through fusion-evaporation reactions. These have very low cross sections, of the order of a few microbarns and the reaction products recoil in the forward direction along with the beam particles. The recoil mass separator enables one to study these reaction products by separating them from the main beam and from each other

  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. Treatment of arterial femoropopliteal obstructions with Palmaz midsize stents

    International Nuclear Information System (INIS)

    Purpose: To evaluate effectiveness, success and patency rates after endovascular treatment with mid-size Palmaz stents in high-grade stenoses or short-distance occlusions of femoral arteries. Materials and methods: 27 patients with 10 occlusions (average length 3.2±1.4 cm) and 17 severe stenoses of the superficial femoral artery were treated with 33 mid-size Palmaz stents. The follow-up included Doppler ultrasound at one, three, 6 and 12 months and an angiography at 6 months. Mean follow-up was 6.5 months. Results: Technical success was 100%. The ankle-brachial index improved from 0.57±0.28 pretreatment to 0.87±0.13 within 24 hours. Acute stent thrombosis occurred in two patients (50%, n=2). Life-table analysis according to Kaplan-Meier revealed 6-month primary and secondary patency rates of 84% and 91%. Conclusion: with regard to our limited data, the implantation of mid-size Palmaz stents in femoral arteries seems promising in treatment of short-distance occlusions and stenoses of the femoral artery. (orig.)

  2. Endovascular stent-graft management of thoracic aortic diseases

    Energy Technology Data Exchange (ETDEWEB)

    Dake, Michael D. E-mail: mddake@stanford.edu

    2001-07-01

    The traditional standard therapy for descending thoracic aortic aneurysm (TAA) is open operative repair with graft replacement of the diseased aortic segment. Despite important advances in surgical techniques, anesthetic management, and post-operative care over the last 30 years, the mortality and morbidity of surgery remains considerable, especially in patients at high risk for thoracotomy because of coexisting severe cardiopulmonary abnormalities or other medical diseases. The advent of endovascular stent-graft technology provides an alternative to open surgery for selected patients with TAA. The initial experience suggests that stent-graft therapy potentially may reduce the operative risk, hospital stay and procedural expenses of TAA repair. These potential benefits are especially attractive for patients at high risk for open TAA repair. Current results of endovascular TAA therapy document operative mortalities of between 0 and 4%, aneurysm thrombosis in 90 and 100% of cases, and paraplegia as a complication in 0 and 1.6% of patients. The early success of stent-graft repair of TAA has fostered the application of these devices for the management of a wide variety of thoracic aortic pathologies, including acute and chronic dissection, intramural hematoma, penetrating ulcer, traumatic injuries, and other diseases. The results of prospective controlled trials that compare the outcomes of stent-graft therapy with those of surgical treatment in patients with specific types of aortic disease are anxiously awaited before recommendations regarding the general use of these new devices can be made with confidence.

  3. 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.)

  4. 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.)

  5. 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...

  6. Treatment of arterial femoropopliteal obstructions with Palmaz midsize stents; Behandlung arterieller femoropoplitealer Obstruktionen mit mittleren Palmaz-Stents

    Energy Technology Data Exchange (ETDEWEB)

    Mueller-Huelsbeck, S.; Schwarzenberg, H.; Steffens, J.C.; Kopp, U.; Link, J.; Kutzner, D.; Glueer, C.C.; Heller, M. [Kiel Univ. (Germany). Klinik fuer Radiologische Diagnostik

    1998-06-01

    Purpose: To evaluate effectiveness, success and patency rates after endovascular treatment with mid-size Palmaz stents in high-grade stenoses or short-distance occlusions of femoral arteries. Materials and methods: 27 patients with 10 occlusions (average length 3.2{+-}1.4 cm) and 17 severe stenoses of the superficial femoral artery were treated with 33 mid-size Palmaz stents. The follow-up included Doppler ultrasound at one, three, 6 and 12 months and an angiography at 6 months. Mean follow-up was 6.5 months. Results: Technical success was 100%. The ankle-brachial index improved from 0.57{+-}0.28 pretreatment to 0.87{+-}0.13 within 24 hours. Acute stent thrombosis occurred in two patients (<3 weeks). Angiography at 6 months revealed restenosis rates of 7.4% (>50%, n=2). Life-table analysis according to Kaplan-Meier revealed 6-month primary and secondary patency rates of 84% and 91%. Conclusion: with regard to our limited data, the implantation of mid-size Palmaz stents in femoral arteries seems promising in treatment of short-distance occlusions and stenoses of the femoral artery. (orig.) [Deutsch] Ziel: Ueberpruefung von Wirksamkeit, Erfolg und Offenheitsrate des mittleren Palmaz-Stents zur Behandlung kurzstreckiger Verschluesse und hochgradiger Stenosen der A. femoralis superficialis. Material und Methode: 27 Patienten mit 10 Verschluessen (3,2{+-}1,4 cm Laenge) und 17 hochgradigen Stenosen der Femoralarterien wurden mit 33 mittleren Palmaz-Stents behandelt. Die Kontrolluntersuchungen setzten sich aus klinischen und Doppler-sonographischen Untersuchungen nach einen, drei, 6 und 12 Monaten sowie einer zusaetzlichen Kontrollangiographie nach 6 Monaten zusammen. Das mittlere Nachuntersuchungsintervall betrug 6,5 Monate. Ergebnisse: Die Stentimplantation war in allen Faellen erfolgreich. Der Arm-Knoechel-Index verbesserte sich von 0,57{+-}0,28 vor auf 0,87{+-}0,13 24 Stunden nach Stentimplantation. Akute Verschluesse der Stents traten bei zwei Patienten auf (<3

  7. Recoil distance lifetime measurements in 118Xe

    International Nuclear Information System (INIS)

    Lifetimes of the excited states of the ground state band in 118Xe are newly measured using the recoil-distance Doppler-shift technique. The reaction 93Nb(29Si,p3n)118Xe at a beam energy of 135 MeV was used for this experiment. The lifetimes of the 2+, 4+, 6+, 8+, and 10+ states of the ground state band were extracted using the computer code LIFETIME which includes the corrections due to the side feeding and the nuclear deorientation effects. The present B(E2) values are in good agreement with the extracted B(E2) values from the Hartee-Fock-Bogoliubov calculations. The measured B(E2) values are also compared with the standard algebraic and the geometrical models. The B(E2) values for the 2+ state for this nucleus and the other Xe nuclei as a function of the neutron number are well reproduced in the framework of the algebraic model IBA-1 with O(6) symmetry and the geometrical finite range droplet model

  8. 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...

  9. 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)

  10. 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...

  11. 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.

  12. 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...

  13. 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 ...

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. Anticoagulation in patients with atrial fibrillation undergoing coronary stent implantation.

    Science.gov (United States)

    Bernard, A; Fauchier, L; Pellegrin, C; Clementy, N; Saint Etienne, C; Banerjee, A; Naudin, D; Angoulvant, D

    2013-09-01

    In patients with atrial fibrillation (AF) undergoing coronary stent implantation, the optimal antithrombotic strategy is unclear. We evaluated whether use of oral anticoagulation (OAC) was associated with any benefit in morbidity or mortality in patients with AF, high risk of thromboembolism (TE) (CHA2DS2-VASC score ≥ 2) and coronary stent implantation. Among 8,962 unselected patients with AF seen between 2000 and 2010, a total of 2,709 (30%) had coronary artery disease and 417/2,709 (15%) underwent stent implantation while having CHA2DS2-VASC score ≥ 2. During follow-up (median=650 days), all TE, bleeding episodes, and major adverse cardiac events (i.e. death, acute myocardial infarction, target lesion revascularisation) were recorded. At discharge, 97/417 patients (23%) received OAC, which was more likely to be prescribed in patients with permanent AF and in those treated for elective stent implantation. The incidence of outcome event rates was not significantly different in patients treated and those not treated with OAC. However, in multivariate analysis, the lack of OAC at discharge was independently associated with increased risk of death/stroke/systemic TE (relative risk [RR] =2.18, 95% confidence interval [CI] 1.02-4.67, p=0.04), with older age (RR =1.12, 1.04-1.20, p=0.003), heart failure (RR =3.26, 1.18-9.01, p=0.02), and history of stroke (RR =18.87, 3.11-111.11, p=0.001). In conclusion, in patients with AF and high thromboembolic risk after stent implantation, use of OAC was independently associated with decreased risk of subsequent death/stroke/systemic TE, suggesting that OAC should be systematically used in this patient population. PMID:23846210

  19. Myocardial bridging is a potential risk factor of very late stent thrombosis of drug eluting stent

    OpenAIRE

    Jiang, Qixia; Liang, Chun; Wu, Zonggui

    2012-01-01

    Summary Drug eluting stents have been implanted worldwide and used in nearly 90% of percutaneous coronary interventions in China. Although many randomized trials have confirmed the efficacy and safety profile of drug eluting stents, they were not powered to detect or exclude the effect of drug eluting stents on rare events such as stent thrombosis. Several mechanisms of very late stent thrombosis have been postulated, but are not widely accepted. Virchow’s triad describes the 3 main factors o...

  20. Late Stent Thrombosis Associated with Heavy Exercise

    OpenAIRE

    Simsek, Ziya; Arslan, Sakir; Gundogdu, Fuat

    2009-01-01

    Bare-metal stents are commonly used in the treatment of coronary artery disease. Stent thrombosis usually occurs within the first 48 hours after stent deployment. After a week, the incidence of thrombosis is low. Late stent thrombosis (after 30 days) is rarely seen; however, its clinical outcomes are severe 30-day mortality rates of 20% to 48% and myocardial infarction rates of 60% to 70%. Herein, we present the case and discuss the treatment of a patient who, after heavy exercise, experience...

  1. 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)

  2. 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...

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. One Year Clinical Outcomes of Renal Artery Stenting: The Results of ODORI Registry

    International Nuclear Information System (INIS)

    The safety, efficacy and long term clinical benefits of renal artery revascularization by stenting are still a matter of debate. The aim of our study was to define the safety and efficacy of renal artery stenting with the Tsunami peripheral stent (Terumo Corporation, Tokyo, Japan). The ODORI was a prospective, multicentre registry which enrolled 251 consecutive patients, (276 renal arteries) in 36 centres across Europe. The primary endpoint was acute procedural success defined as <30% residual stenosis after stent placement. Secondary endpoints included major adverse events, blood pressure control, serum creatinine level, and target lesion revascularization (TLR) at 6 and 12 months. Patients were 70 ± 10 years old, 59% were male, 33% had diabetes, and 96% hypertension. The main indications for renal stent implantation were hypertension in 83% and renal salvage in 39%. Direct stent implantation was performed in 76% of the cases. Acute success rate was 100% with residual stenosis of 2.5 ± 5.4%. Systolic/diastolic blood pressure decreased from a mean of 171/89 at baseline to 142/78 mmHg at 6 months (p < 0.0001 vs. baseline), and 141/80 mmHg at 12 months (p < 0.0001 vs. baseline). Mean serum creatinine concentration did not change significantly in the total population. However, there was significant improvement in the highest tercile (from 283 μmol/l at baseline to 205 and 209 μmol/l at 6 and 12 months respectively). At 12-months, rates of restenosis and TLR were 6.6 and 0.8% respectively. The 12 month cumulative rate of all major clinical adverse events was 6.4% while the rate of device or procedure related events was 2.4%. In hypertensive patients with atherosclerotic renal artery stenosis Tsunami peripheral balloon-expandable stent provides a safe revascularization strategy, with a potential beneficial impact on hypertension control and renal function in the highest risk patients.

  8. Palliation of malignant gastric obstruction : fluoroscopic guided covered metallic stent placement

    International Nuclear Information System (INIS)

    To demonstrate the feasibility and clinical efficacy of self-expanding, covered metallic stent placement for the palliative treatment of malignant gastric obstruction. Under fluoroscopic guidance, the placement of self-expanding, covered stents was attempted in 23 patients (age range, 31-78 years) with inoperable or recurrent gastric malignancies. All 23 suffered dysphagia and/or vomiting after the ingestion of soft foods, or swallowing difficulty. Three different types of self-expanding, covered metallic stents were used and in all patients, these were placed perorally using over the guide wire technique. Success was defined both technically and clinically. Stent placement was technically successful in 19 patients (82.6%) but because the guidewire failed to successfully negotiate the sites at which there was obstruction, was unsuccessful in four (17.4%). Stent placement was well tolerated in all patients except one, in whom an acutely angled efferent loop from remnant stomach was present. In this case, stent placement required a strong metallic guidewire. After placement, 17 of the 19 patients (89.5%) were able to ingest solid and/or soft foods without dysphagia and showed a markedly decreased incidence of vomiting. Two others showed some improvement in the frequency of vomiting but were able to ingest only a liquid diet. In one patient, the stent migrated two days after the procedure. During the follow-up period of 2-7 months (mean, 74 days), there were no clinically significant complications. For the short-term palliative treatment of patients with gastric inlet or outlet obstruction, the placement of self-expanding metallic stents has proven relatively easy and safe, as well as reasonably effective. (author)

  9. Graft occlusion after coronary artery bypass grafting and stent deformation and in-stent restenosis after succedent stenting in a patient with deep position myocardial bridging

    OpenAIRE

    Zou, Yi-Xi; Huang, Fang-Jiong; Wu, Qiang; Zhu, En-jun

    2012-01-01

    We present a case of deep position myocardial bridging in a patient who had early graft occlusion after coronary artery bypass grafting and had stent deformation and in-stent restonesis after succedent stenting.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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...

  15. Recoil release of fission products from nuclear fuel

    Science.gov (United States)

    Wise, C.

    1985-10-01

    An analytical approximation is developed for calculating recoil release from nuclear fuel into gas filled interspaces. This expression is evaluated for a number of interspace geometries and shown to be generally accurate to within about 10% by comparison with numerical calculations. The results are applied to situations of physical interest and it is demonstrated that recoil can be important when modelling fission product release from low temperature CAGR pin failures. Furthermore, recoil can contribute significantly in experiments on low temperature fission product release, particularly where oxidation enhancement of this release is measured by exposing the fuel to CO 2. The calculations presented here are one way of allowing for this, other methods are suggested.

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. 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

  1. Ureteral Stent Coatings: What's Here and What's Coming

    Science.gov (United States)

    Razvi, Hassan

    2008-09-01

    Ureteral stents have become an indispensable tool to the urologist in the management of various disorders afflicting the urinary tract. While the ideal stent remains elusive, novel technical advances in stent coating technology offer the potential of enhancing stent biocompatibility and clinical application. Currently available stent coatings as well as new and emerging devices will be reviewed.

  2. 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

  3. 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.

  4. Drug eluting biliary stents to decrease stent failure rates: A review of the literature.

    Science.gov (United States)

    Shatzel, Joseph; Kim, Jisoo; Sampath, Kartik; Syed, Sharjeel; Saad, Jennifer; Hussain, Zilla H; Mody, Kabir; Pipas, J Marc; Gordon, Stuart; Gardner, Timothy; Rothstein, Richard I

    2016-01-25

    Biliary stenting is clinically effective in relieving both malignant and non-malignant obstructions. However, there are high failure rates associated with tumor ingrowth and epithelial overgrowth as well as internally from biofilm development and subsequent clogging. Within the last decade, the use of prophylactic drug eluting stents as a means to reduce stent failure has been investigated. In this review we provide an overview of the current research on drug eluting biliary stents. While there is limited human trial data regarding the clinical benefit of drug eluting biliary stents in preventing stent obstruction, recent research suggests promise regarding their safety and potential efficacy. PMID:26839648

  5. 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.

  6. 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...

  7. 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...

  8. 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.

  9. The fast neutron spectrum unfolding from measured proton recoil spectrum

    International Nuclear Information System (INIS)

    This paper presents the method of fast neutron spectrum unfolding from measured pulse-height data produced by recoil protons in a scintillation detector. Computer code PULNE which is described use the algorithm with approximate corrections for effects of second scattering of neutrons by hydrogen and the loss of recoil protons through the detector surface. In that way the most important physical effect influenced the final results are taken in consideration, and the computer code is made to be easily adapted for use on a small computer. Results of analysis of pulse height data from measuring the spectrum of americium-berylium source are presented. (author)

  10. 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 ...

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. Deferred versus conventional stent implantation in patients with ST-segment elevation myocardial infarction (DANAMI 3-DEFER)

    DEFF Research Database (Denmark)

    Kelbæk, Henning; Høfsten, Dan Eik; Køber, Lars; Helqvist, Steffen; Kløvgaard, Lene; Holmvang, Lene; Jørgensen, Erik; Pedersen, Frants; Saunamäki, Kari; De Backer, Ole; Bang, Lia E; Kofoed, Klaus F; Lønborg, Jacob; Ahtarovski, Kiril; Vejlstrup, Niels; Bøtker, Hans E; Terkelsen, Christian J; Christiansen, Evald H; Ravkilde, Jan; Tilsted, Hans-Henrik; Villadsen, Anton B; Aarøe, Jens; Jensen, Svend E; Raungaard, Bent; Jensen, Lisette O; Clemmensen, Peter; Grande, Peer; Madsen, Jan K; Torp-Pedersen, Christian; Engstrøm, Thomas

    2016-01-01

    to assess the clinical outcomes of deferred stent implantation versus standard PCI in patients with STEMI. METHODS: We did this open-label, randomised controlled trial at four primary PCI centres in Denmark. Eligible patients (aged >18 years) had acute onset symptoms lasting 12 h or less, and ST...... stent implantation (hazard ratio 0·99, 95% CI 0·76-1·29; p=0·92). Procedure-related myocardial infarction, bleeding requiring transfusion or surgery, contrast-induced nephopathy, or stroke occurred in 28 (5%) patients in the conventional PCI group versus 27 (4%) patients in the deferred stent...... implantation group, with no significant differences between groups. INTERPRETATION: In patients with STEMI, routine deferred stent implantation did not reduce the occurrence of death, heart failure, myocardial infarction, or repeat revascularisation compared with conventional PCI. Results from ongoing...

  16. 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 differe...

  17. Stent placement for tracheobronchial disease

    Energy Technology Data Exchange (ETDEWEB)

    Walser, Eric M. [Department of Radiology, Rt 0709, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-0709 (United States)]. E-mail: emwalser@utmb.edu

    2005-09-01

    Early treatment for airway stenoses or occlusions involved open repair with the attendant risks of thoracotomy or sternotomy. With the advent of rigid and, more recently, flexible bronchoscopy, the placement of airway stents has come to the forefront in the treatment of benign and malignant tracheobronchial disease. This paper describes the history of surgical and endoluminal treatment of airway disease and discusses the indications and contraindications for airway stent placement. The advantages and limitations of such therapy are reviewed as well as the procedural details and the imaging evaluation and follow-up of patients undergoing endoluminal treatment. Although the placement of tracheobronchial stents is now primarily performed by interventional pulmonologists, imaging anatomically complex airway disease also requires the skills of an accomplished cross-sectional radiologist. Additionally, interventional radiologists using fluoroscopic guidance and alternative access routes to the airways can salvage failed bronchoscopic procedures and primarily treat selected cases. Due to the importance of pre- and post-procedural imaging in these patients, radiologists should be aware of airway anatomy suitable for stent placement and the appearance of various complications of this procedure.

  18. 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.

  19. 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.)

  20. Tritium recoil reactions in inorganic solid compounds. Chapter 22

    International Nuclear Information System (INIS)

    The behavior of recoil tritium produced in inorganic solid compounds is an esoteric chapter of the already esoteric field of Hot Atom Chemistry. A very small group of investigators have devoted their attention to this problem. The author summarizes the results of their studies. (Auth.)

  1. 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.

  2. Scintillation response of liquid xenon to low energy nuclear recoils

    International Nuclear Information System (INIS)

    Liquid Xenon (LXe) is expected to be an excellent target and detection medium to search for dark matter in the form of Weakly Interacting Massive Particles (WIMPs). We have measured the scintillation efficiency of nuclear recoils with kinetic energy between 10.4 and 56.5 keV relative to that of 122 keV gamma rays from 57Co. The scintillation yield of 56.5 keV recoils was also measured as a function of applied electric field, and compared to that of gamma rays and alpha particles. The Xe recoils were produced by elastic scattering of 2.4 MeV neutrons in liquid xenon at a variety of scattering angles. The relative scintillation efficiency is 0.130±0.024 and 0.227±0.016 for the lowest and highest energy recoils, respectively. This is about 15% less than the value predicted by Lindhard, based on nuclear quenching. Our results are in good agreement with more recent theoretical predictions that consider the additional reduction of scintillation yield due to biexcitonic collisions in LXe

  3. Gravitational recoil from spinning binary black hole mergers

    CERN Document Server

    Herrmann, F; Laguna, P; Matzner, R A; Shoemaker, D; Herrmann, Frank; Hinder, Ian; Laguna, Pablo; Matzner, Richard A.; Shoemaker, Deirdre

    2007-01-01

    The inspiral and merger of binary black holes will likely involve black holes with both unequal masses and arbitrary spins. The gravitational radiation emitted by these binaries will carry angular as well as linear momentum. A net flux of emitted linear momentum implies that the black hole produced by the merger will experience a recoil or kick. Previous studies have focused on the recoil velocity from unequal mass, non-spinning binaries. We present results from simulations of equal mass but spinning black hole binaries and show how a significant gravitational recoil can also be obtained in these situations. We consider the case of black holes with opposite spins aligned with the orbital angular momentum. For the initial setups under consideration, we find a recoil velocity of $V = 475 \\KMS |a| $, with $a$ the dimensionless spin parameters of the individual holes. Supermassive black hole mergers producing kicks of this magnitude could result in the ejection from the cores of dwarf galaxies of the final hole p...

  4. 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

  5. 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 ...

  6. Parametric study of recoil proton spectrometer with permanent magnets

    International Nuclear Information System (INIS)

    The role played by the main physical and geometrical parameters on the characteristics of a recoil proton spectrometer has been analysed. The optimization has been done in the case of a permanent magnet magnetic sector. Some examples of optimized geometries in the case of neutron spectra (by using n, p reaction) around 14 MeV are given

  7. 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...

  8. Modeling gravitational recoil from black-hole binaries using numerical relativity

    International Nuclear Information System (INIS)

    We review the developments in modeling gravitational recoil from merging black-hole binaries and introduce a new set of 20 simulations to test our previously proposed empirical formula for the recoil. The configurations are chosen to represent generic binaries with unequal masses and precessing spins. Results of these simulations indicate that the recoil formula is accurate to within a few km s-1 in the similar mass-ratio regime for the out-of-plane recoil.

  9. 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

  10. Effects of tongxinluo on C-reactive protein and clinical prognosis in patients after coronary stenting

    International Nuclear Information System (INIS)

    Objective: To investigate the effects of Tongxinluo on C reactive protein(CRP)and clinical prognosis in patients after coronary stenting. Methods: From January 2003 to December 2004, 132 patients in our department diagnosed as coronary artery disease (including acute myocardial infarction, unstable angina pectoris and stable angina pectoris)were divided into two groups: Tongxinluo group and control group. The control group received routine treatment, while Tongxinluo group based on routine treatment was administrated with Tongxinluo capsule in combination for 6 months. Results: CRP level was much lower in Tongxinluo group together with apparent decrease of the major adverse cardiac event (MACE)rate in 6 months' follow-up than those of the control group, but showing no difference in coronary arterial restenosis between the two groups at 6 months after coronary stenting. Conclusion: Tongxinluo has favorable effects to decrease the CRP level and improve clinical efficiency together with prognosis for patients after coronary stenting. (authors)

  11. iStent trabecular micro-bypass stent for open-angle glaucoma

    OpenAIRE

    Saheb, Hady

    2014-01-01

    Kim Le, Hady Saheb Department of Ophthalmology, McGill University, Montreal, QC, Canada Abstract: Trabecular micro-bypass stents, commonly known as iStents, are micro-invasive glaucoma surgery (MIGS) devices used to treat open-angle glaucoma. Like other MIGS procedures that enhance trabecular outflow, the iStent lowers intraocular pressure (IOP) by creating a direct channel between the anterior chamber and Schlemm’s canal. iStents are typically implanted at the time of phacoemulsif...

  12. iStent trabecular micro-bypass stent for open-angle glaucoma

    OpenAIRE

    Le K; Saheb H

    2014-01-01

    Kim Le, Hady Saheb Department of Ophthalmology, McGill University, Montreal, QC, Canada Abstract: Trabecular micro-bypass stents, commonly known as iStents, are micro-invasive glaucoma surgery (MIGS) devices used to treat open-angle glaucoma. Like other MIGS procedures that enhance trabecular outflow, the iStent lowers intraocular pressure (IOP) by creating a direct channel between the anterior chamber and Schlemm’s canal. iStents are typically implanted at the time of phacoemulsificat...

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

    Science.gov (United States)

    Jiang, Yongfei; Zhang, Jun; Zhao, Wanhua

    2016-04-01

    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.

  14. 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

  15. [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

  16. [Drug-eluting stents: long-term safety].

    Science.gov (United States)

    Karpov, Iu A; Samko, A N; Buza, V V

    2009-01-01

    The review concerns the problem of late thromboses of drug-eluting stents and their influence on late prognosis of the patients; presents long-term results of the trial of sirolimus-eluting stents implanted to patients with coronary heart disease; analyses mechanisms of development of late stent thrombosis, data from different meta-analyses and registers comparing long-term outcomes in patients with implanted sirolimus-eluting stents and metallic stents; suggests risk factors of late thromboses of drug-eluting stents; presents original evidence on 3.5-year follow-up of patients with implanted sirolimus-eluting stents and metallic stents. PMID:19537584

  17. Endoscopic management of pancreatic duct injury by endoscopic stent placement: a case report and literature review

    Directory of Open Access Journals (Sweden)

    Ito Yasuhiro

    2012-07-01

    Full Text Available Abstract Recently, the diagnostic evaluation of pancreatic injury has improved dramatically. On the other hand, it is occasionally difficult to diagnose pancreatic injury, because there are no specific signs, symptoms, or laboratory findings. Radiological imaging also often fails to identify pancreatic injury in the acute phase. Delayed diagnosis results in significant morbidity and mortality. Most cases of pancreatic injury with suspicion or pancreatic duct disruption require surgery. Endoscopic retrograde cholangiopancreatography is one of the most accurate modalities for ductal evaluation and therapy and might enable one to avoid unnecessary surgery. We describe endoscopic management of pancreatic duct injury by endoscopic stent placement. A 45-year-old woman was admitted after a traffic accident. A computed tomography scan showed pancreatic parenchyma disruption at the pancreatic head. Endoscopic retrograde cholangiopancreatography demonstrated disruption of the pancreatic duct with extravasation into the peripancreatic fluid collection. A 5-French endoscopic nasopancreatic drainage (ENPD tube was placed. Her symptoms dramatically improved. ENPD tube was exchanged for a 5-French 5-cm pancreatic stent. Subsequent follow-up CT revealed remarkable improvement. On the 26th day, the patient was discharged from the hospital without symptoms or complications. In this report, a pancreatic stent may lead to rapid clinical improvement and enable surgery to be avoided. On the other hand, the reported complications of long-term follow-up make the role of stenting uncertain. Thus, close attention should be paid to stenting management in the follow-up period. A pancreatic stent is useful for pancreatic ductal injury. If pancreatic ductal injury is managed appropriately, a pancreatic stent may improve the clinical condition, and also prevent unnecessary surgery.

  18. Bare metal stenting of the iliac arteries.

    Science.gov (United States)

    Kim, Tanner I; Schneider, Peter A

    2016-06-01

    A significant subset of patients with peripheral artery disease (PAD) has iliac artery involvement that requires treatment. The development of bare metal stents has improved the short- and long-term outcomes of endovascular repair and has become first line therapy. Open surgical bypass has been reserved for extremely complex anatomic morphologies or endovascular failures. It is unclear whether primary stenting is superior to angioplasty with provisional stenting but if angioplasty is used alone, it is likely only appropriate for the most focal lesions. Self-expanding and balloon-expandable stents have unique characteristics that are suitable to different lesion morphologies. Both stent-types have demonstrated similar outcomes. Herein, we review the practice and results of bare metal stents in the iliac arteries. PMID:27035892

  19. 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.

  20. 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

    2016-01-01

    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.

  1. 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.

  2. 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...

  3. 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...

  4. In vitro Coronary Stent Implantation: Vessel Wall-Stent Interaction

    Czech Academy of Sciences Publication Activity Database

    Horný, L.; Chlup, Hynek; Vesely, J.; Gultová, E.; Kronek, J.; Žitný, R.; Voňavková, T.; Adámek, T.; Lanzer, P.; Hromádka, D.

    Berlín : Springer, 2011 - (Jobbágy, Á.), s. 795-798 ISBN 978-3-642-23507-8. ISSN 1680-0737. [European Conference of the International Federation for Medical and Biological Engineering /5./. Budapest (HU), 14.09.2011-18.09.2011] R&D Projects: GA ČR(CZ) GA106/08/0557 Institutional research plan: CEZ:AV0Z20760514 Keywords : edge detection * coronary stent * over-stretching Subject RIV: JJ - Other Materials

  5. 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.

  6. 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 ...

  7. Predictive Factors of In-Stent Restenosis in Renal Artery Stenting: A Retrospective Analysis

    International Nuclear Information System (INIS)

    Purpose. To retrospectively evaluate the role of clinical and procedural factors in predicting in-stent restenosis in patients with renovascular disease treated by renal artery stenting. Methods. From 1995 to 2002, 147 patients underwent renal artery stenting for the treatment of significant ostial atherosclerotic stenosis. Patients underwent strict clinical and color-coded duplex ultrasound follow-up. Ninety-nine patients (111 stents), with over 6 months of continuous follow-up (mean 22±12 months, range 6-60 months), were selected and classified according to the presence (group A, 30 patients, 32 lesions) or absence (group B, 69 patients, 79 lesions) of significant in-stent restenosis. A statistical analysis was performed to identify possible preprocedural and procedural predictors of restenosis considering the following data: sex, age, smoking habit, diabetes mellitus, hypertension, serum creatinine, cholesterol and triglyceride levels, renal artery stenosis grade, and stent type, length and diameter. Results. Comparing group A and B patients (χ2 test), a statistically significant relation was demonstrated between stent diameter and length and restenosis: the risk of in-stent restenosis decreased when the stent was ≥6 mm in diameter and between 15 and 20 mm in length. This finding was confirmed by multiple logistic regression analysis. Stent diameter and length were proved to be significantly related to in-stent restenosis also when evaluating only patients treated by Palmaz stent (71 stents). Conclusion. Although it is based on a retrospective analysis, the present study confirms the importance of correct stent selection in increasing long-term patency, using stents of at least 6 mm in diameter and with a length of approximately 15-20 mm

  8. 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.

  9. 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%.

  10. 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)

  11. 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.

  12. α decay and recoil decay tagging studies of 183Tl

    International Nuclear Information System (INIS)

    High-spin states in the nucleus 183Tl have been studied using the recoil decay tagging and recoil tagging techniques. The data have enabled new structures to be identified which are believed to be based on prolate f7/2, h9/2, and oblate h9/2 configurations. In addition, the prolate i3/2 structure has also been extended. The systematics of the newly identified structures will be discussed. The α decay of 183Tl has also been investigated. Examination of both delayed and prompt γ rays in coincidence with the prominent 6333-keV α decay, together with an investigation of the effects of the summing of L electrons, allow assignment of transitions and the construction of tentative low-spin decay schemes for 179Au and 175Ir

  13. 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.

  14. Time-dependent isotope effect in recoil implantation Pt. 2

    International Nuclear Information System (INIS)

    A typical case of time-dependent isotope effect was found in recoil implantation of technetium in tetraphenylporphyrin. When a mixture of metallic molybdenum and tetraphenylporphyrin (free base) was bombarded with 15 MeV deuterons, the difference of chemical distribution between sup(99m)Tc and 95Tc (or 96Tc) was pronounced in the sample which was stored one day after irradiation, whereas no difference was observed just after the irradiation. This effect was ascribed to decay-induced decomposition, by observing behaviours of the purified system of 99Mo-sup(99m)Tc-TPP. The decomposition was not derived directly from the β-decay recoil but from internal excitation associated with the decay. (author)

  15. 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.

  16. 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.

  17. Radiation pressure in SFA theory: retardation and recoil corrections

    CERN Document Server

    Krajewska, K

    2015-01-01

    Radiation pressure effects in ionization by short linearly-polarized laser pulses are investigated in the framework of strong-field approximation, in both nonrelativistic and relativistic formulations. Differences between both approaches are discussed, and retardation and recoil corrections are defined. It is demonstrated how these corrections can be incorporated into the nonrelativistic approach, leading to the so-called quasi-relativistic formulation. These three approaches are further applied to the analysis of signatures of radiation pressure in energy-angular distributions of photoelectrons. It is demonstrated that, for Ti:Sapphire laser pulses of intensities up to $10^{16}\\mathrm{W/cm}^2$, predictions of the quasi-relativistic formulation agree well with those of the full relativistic one, and that the recoil corrections contribute predominantly to the radiation pressure effects.

  18. Modernization of the detector system at the recoil separator VASSILISSA

    International Nuclear Information System (INIS)

    Within the past ten years, the recoil separator VASSILISSA has been used for the investigations of evaporation residues produced in heavy ion induced complete fusion reactions. In the course of experimental work in the region of the elements with 92≤Z≤94, fourteen new isotopes have been identified by the parent-daughter correlations. For further experiments aimed at the synthesis of the superheavy element isotopes (Z≥110) with intensive 48Ca extracted beams, improvements in the focal plane detector system have been made. As a result, energy and position resolutions of the detectors have been significantly improved, the detection efficiency for the α-particles, emitted from the implanted into the focal plane detector recoil nuclei, has been increased to 85%. The decay properties of the new isotope of element 112 and the isotope of the new element 114 with mass 287 have been measured in two-nuclei decay

  19. 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.

  20. 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...

  1. Recoil corrected bag model calculations for semileptonic weak decays

    International Nuclear Information System (INIS)

    Recoil corrections to various model results for strangeness changing weak decay amplitudes have been developed. It is shown that the spurious reference frame dependence of earlier calculations is reduced. The second class currents are generally less important than obtained by calculations in the static approximation. Theoretical results are compared to observations. The agreement is quite good, although the values for the Cabibbo angle obtained by fits to the decay rates are somewhat to large

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. Revealing Compressed Stops Using High-Momentum Recoils

    CERN Document Server

    Macaluso, Sebastian; Shih, David; Tweedie, Brock

    2015-01-01

    Searches for supersymmetric top quarks at the LHC have been making great progress in pushing sensitivity out to higher mass, but are famously plagued by gaps in coverage around lower-mass regions where the decay phase space is closing off. Within the common stop-NLSP / neutralino-LSP simplified model, the line in the mass plane where there is just enough phase space to produce an on-shell top quark remains almost completely unconstrained. Here, we show that is possible to define searches capable of probing a large patch of this difficult region, with S/B ~ 1 and significances often well beyond 5 sigma. The basic strategy is to leverage the large energy gain of LHC Run 2, leading to a sizable population of stop pair events recoiling against a hard jet. The recoil not only re-establishes a MET signature, but also leads to a distinctive anti-correlation between the MET and the recoil jet transverse vectors when the stops decay all-hadronically. Accounting for jet combinatorics, backgrounds, and imperfections in ...

  8. 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.

  9. 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.

  10. 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

  11. 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...

  12. 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.

  13. 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.

  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. 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.

  16. 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

  17. Direct coronary stenting in reducing radiation and radiocontrast consumption

    International Nuclear Information System (INIS)

    Coronary stenting is the primary means of coronary revascularization. There are two basic techniques of stent implantation: stenting with balloon predilatation of stenosis and stenting without predilatation (direct stenting). Limiting the time that a fluoroscope is activated and by appropriately managing the intensity of the applied radiation, the operator limits radiation in the environment, and this saves the exposure to the patient and all personnel in the room. Nephrotoxicity is one of the most important properties of radiocontrast. The smaller amount of radiocontrast used also provides multiple positive effects, primarily regarding the periprocedural risk for the patients with the reduced renal function. The goal of the study was to compare fluoroscopy time, the amount of radiocontrast, and expenses of material used in direct stenting and in stenting with predilatation. In a prospective study, 70 patients with coronary disease were randomized to direct stenting, or stenting with predilatation. Fluoroscopy time and radiocontrast use were significantly reduced in the directly stented patients in comparison to the patients stented with balloon-predilatation. The study showed a significant reduction of expenses when using a direct stenting method in comparison to stenting with predilatation. If the operator predicts that the procedure can be performed using direct stenting, he is encouraged to do so. Direct stenting is recommended for all percutaneous coronary interventions when appropriate conditions have been met. If direct stenting has been unsuccessful, the procedure can be converted to predilatation

  18. [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

  19. Resection of thrombosed femoral artery over-dimensional stent-graft placed due to multiple arteriovenous fistulas following gunshot wounds

    Directory of Open Access Journals (Sweden)

    Radak Đorđe

    2010-01-01

    Full Text Available Introduction. Though surgical approach is common in arteriovenous (AV fistula treatment, endovascular procedures such as stent-graft placement has become more popular in recent years. We aim to present a case of thrombosed femoral artery stent-graft which was placed one year earlier due to multiple AV fistulas following gunshot wounds. Case Outline. A 43-year-old patient was admitted to the Institute for Cardiovascular Diseases 'Dedinje', Belgrade, Serbia, for arteriography. Five years before, he had suffered from six gunshot wounds in his right leg and one year before, in the health centre in Vienna, stent-graft had been placed in the right superficial femoral artery due to multiple AV fistulas. Because of artery dilation proximal to AV fistula location, a large dimensional stent-graft had to be placed (24 mm. After admission, arteriography and Multislice CT (MSCT angiography revealed thrombotic masses in the stent-graft with intraluminal stenosis of 50%. Extirpation of thrombosed stent-graft was performed followed by Dacron tubular graft 10 mm interposition. On the fifth postoperative day, the patient was discharged from the clinic, and after 3 months, the right leg vascularisation was well preserved. Conclusion. Large dimensional stent-graft placement in patients with mutiple AV fistulas and blood vessel dilation proximal to AV site of communication carries an increased risk of thrombotic events due to turbulent blood flow and parietal thrombosis occurrence. Though stent-graft placement can be a very useful solution in acute AV fistula treatment, the very same thrombosis should be thought of when surgical management is the only treatment choice.

  20. 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.

  1. 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

  2. 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

  3. 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...

  4. 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.

  5. Stent insertion in patients with malignant biliary obstruction: problems of the Hanaro stent

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Jae Hyun; Seong, Chang Kyu; Shin, Tae Beom; Kim, Yong Joo [School of Medicine, Kyungpook National Univ., Daegu (Korea, Republic of); Jung, Gyoo Sik [School of Medicine, Kosin National Univ., Pusan (Korea, Republic of); Park, Byeung Ho [School of Medicine, Donga National Univ., Pusan (Korea, Republic of)

    2002-07-01

    To investigate the problems of the Hanaro stent (Solco Intermed, Seoul, Korea) when used in the palliative treatment of patients with inoperable malignant biliary obstruction. Between January 2000 and May 2001, the treatment of 46 patients with malignant biliary obstruction involved percutaneous placement of the Hanaro stent. Five patients encountered problems during removal of the stent's introduction system. The causes of obstruction were pancreatic carcinoma (n=2), cholangiocarcinoma (n=2), and gastric carcinoma with biliary invasion (n=1). In one patient, percutaneous transhepatic cholangiography and stent insertion were performed as a one-step procedure, while the others underwent conventional percutaneous transhepatic biliary drainage for at least two days prior to stent insertion. A self-expandable Hanaro stent, 8-10 mm in deameter and 50-100 mm in lengh, and made from a strand of nitinol wire, was used in all cases. Among the five patients who encountered problems, breakage of the olive tip occourred in three, upward displacement of the stent in two, and improper expansion of the distal portion of the stent, unrelated with the obstruction site, in one. The broken olive tip was pushed to the duodenum in two cases and to the peripheral intrahepatic duct in one. Where the stent migrated during withdrawal of its introduction system, an additional stent was inserted. In one case, the migrated stent was positioned near the liver capsule and the drainage catheter could not be removed. Although the number of patients in this study was limited, some difficulties were encountered in withdrawing the stent's introduction system. To prevent the occurrence of this unusual complication, the stent should be appropriately expansile, and shape in the olive tip should be considered.

  6. Stent insertion in patients with malignant biliary obstruction: problems of the Hanaro stent

    International Nuclear Information System (INIS)

    To investigate the problems of the Hanaro stent (Solco Intermed, Seoul, Korea) when used in the palliative treatment of patients with inoperable malignant biliary obstruction. Between January 2000 and May 2001, the treatment of 46 patients with malignant biliary obstruction involved percutaneous placement of the Hanaro stent. Five patients encountered problems during removal of the stent's introduction system. The causes of obstruction were pancreatic carcinoma (n=2), cholangiocarcinoma (n=2), and gastric carcinoma with biliary invasion (n=1). In one patient, percutaneous transhepatic cholangiography and stent insertion were performed as a one-step procedure, while the others underwent conventional percutaneous transhepatic biliary drainage for at least two days prior to stent insertion. A self-expandable Hanaro stent, 8-10 mm in deameter and 50-100 mm in lengh, and made from a strand of nitinol wire, was used in all cases. Among the five patients who encountered problems, breakage of the olive tip occourred in three, upward displacement of the stent in two, and improper expansion of the distal portion of the stent, unrelated with the obstruction site, in one. The broken olive tip was pushed to the duodenum in two cases and to the peripheral intrahepatic duct in one. Where the stent migrated during withdrawal of its introduction system, an additional stent was inserted. In one case, the migrated stent was positioned near the liver capsule and the drainage catheter could not be removed. Although the number of patients in this study was limited, some difficulties were encountered in withdrawing the stent's introduction system. To prevent the occurrence of this unusual complication, the stent should be appropriately expansile, and shape in the olive tip should be considered

  7. 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...

  8. 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...

  9. New stent developments for peripheral arterial occlusive disease

    International Nuclear Information System (INIS)

    Infrainguinal peripheral occlusive disease is increasingly being treated by endovascular techniques. Bare metal stainless steel, self-expanding nitinol stents, drug-eluting and covered stents (stent grafts) are becoming increasingly more important adjuncts to percutaneous translumninal angioplasty in the treatment of peripheral artery disease. In this article the available evidence supporting the use of stents in the femoropopliteal and tibial arteries will be described as well as their limitations. Future stent developments will also be discussed. (orig.)

  10. 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.

  11. 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. PMID:23597097

  12. 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.)

  13. 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.)

  14. Percutaneous transfemoral placement of a new flexible stent-graft into the thoracic aorta followed by a percutaneous suture-mediated closure of the access site - initial experience

    International Nuclear Information System (INIS)

    To evaluate the transfemoral placement of a new, flexible stent-graft into the thoracic aorta and the suture-mediated closure of the femoral access. Patients and Methods: five patients were treated endovascularly with a stent-graft for an aneurysm (n = 3) or acute dissection (n = 2) of the thoracic aorta via a femoral 24 F sheath. The femoral access site was closed with two suture-mediated closure devices after placement of the stent-graft. Results: the aneurysm or the false lumen was excluded from perfusion by the placement of the stent-graft in all patients. Hemostasis at the femoral access site was successful in all patients with the percutaneous suture device. A minor stenosis of the femoral artery was found angiographically in four patients after suture-mediated closure. Besides a reversible renal failure due to the medically induced hypotension for the treatment of an acutely ruptured aneurysm, no complications resulted from the stent-graft placement or the percutaneous suture. Conclusion: the percutaneous transfemoral placement of stent-grafts in the thoracic aorta using a suture-mediated closure of the access site is technically feasible. Long-term results of the technique have to be awaited. (orig.)

  15. 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

  16. 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.

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

    International Nuclear Information System (INIS)

    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

  18. 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

  19. 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.

  20. 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...

  1. 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)

  2. 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...

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Multiple scattering problems in heavy ion elastic recoil detection analysis

    International Nuclear Information System (INIS)

    A number of groups use Heavy Ion Elastic Recoil Detection Analysis (HIERDA) to study materials science problems. Nevertheless, there is no standard methodology for the analysis of HIERDA spectra. To overcome this deficiency we have been establishing codes for 2-dimensional data analysis. A major problem involves the effects of multiple and plural scattering which are very significant, even for quite thin (∼100 nm) layers of the very heavy elements. To examine the effects of multiple scattering we have made comparisons between the small-angle model of Sigmund et al. and TRIM calculations. (authors)

  8. Bolometric detection of the recoil spectrum in the alpha decay of 210Po

    International Nuclear Information System (INIS)

    Bolometers at low temperature are being developed as particle spectrometers and potential detectors of dark matter particles through the measurement of recoil energies. A successful observation of the recoil spectrum from a Po electrodeposited source was made for the first time with the use of a 2 mm3 composite-composite diamond bolometer operated in a 300 mK cryostat. The measured recoil ratio is 0.98±0.06 recoil/alpha above 50 keV, with the well defined peak in the spectrum at 101±2.5 keV. ((orig.))

  9. 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...

  10. 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)

  11. 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...

  12. 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

  13. Treatment of Post-Stent Gastroesophageal Reflux by Anti-Reflux Z-Stent

    International Nuclear Information System (INIS)

    Severe symptoms of heartburn and retrosternal pain consistent with gastro-esophageal reflux (GER) developed in a patient following placement of a conventional self-expanding 16-24-mm-diameter x 12-cm-long esophageal stent across the gastroesophageal junction to treat an obstructing esophageal carcinoma. A second 18-mm-diameter x 10-cm-long esophageal stent with anti-reflux valve was deployed coaxially and reduced symptomatic GER immediately. Improvement was sustained at 4-month follow-up. An anti-reflux stent can be successfully used to treat significant symptomatic GER after conventional stenting

  14. Clinical application of mouth-retrofitted stent in prevention of esophageal restenosis after esophageal stent implantation

    International Nuclear Information System (INIS)

    Objective: to evaluate the mouth-retrofitted stent in preventing esophageal restenosis after esophageal stent implantation, and to discuss its safety in clinical use. Methods: Mouth-retrofitted stent implantation was carried out in 10 patients with pathologically and radiologically confirmed esophageal carcinoma. The mouth part of the stent used in the treatment was covered with silica gel membrane. After the treatment, the patients were followed up monthly to determine the severity of dysphagia, which was assessed by using Stooler's score, X-ray. Chest CT scanning and esophagography were performed to observe the location of the stent and to clarify if there was any obstruction. The gastroscopy was bimonthly performed in all patients to see whether or not stent restenosis occurred. If stent restenosis occurred, biopsy examination was used in order to determine its etiology. During the follow-up period, the related complications such as serious chest pain, hemorrhage, pneumonia, trancheoesophageal fistula, etc. were closely observed. Results: All the 10 patients were followed up for 4∼10 months. The Stooler's score for dysphagia was 0 to 1 grade in 9 cases. The severity of dysphagia was gradually increased in one case and its grade reached 3 at 5 months after the procedure. After operation, no stent migration occurred in 9 cases; in 1 case who had received treatment with the stent loaded with 125I seeds the stent migrated into the stomach after 8 months although both esophagography and gastroscopy showed that the esophageal inner wall of the former stenotic lumen was smooth with no stenosis. In the patient who had gradual increased dysphagia, chest CT scanning showed that the lesion exceeded the superior edge of stent, and both esophagography and gastroscopy confirmed that the restenosis was caused by tumor proliferation. In the remaining 8 patients, the length of lesions was not obviously increased, and the mouth part of the stent showed no stenosis

  15. Self-expanding stents in transjugular intrahepatic portosystemic shunt: experience with nitinol Strecker stents.

    Science.gov (United States)

    Rossi, P; Bezzi, M; Salvatori, F M; Broglia, L; Maccioni, F; Pizzi, G; Abbondanza, S; Bonomo, G

    1996-01-01

    The aim of our study was to evaluate the performance and efficacy of a new self-expanding stent (nitinol Strecker stent) in the transjugular intrahepatic portosystemic shunt (TIPS) procedure. We have successfully placed 64 nitinol Strecker stents in 48 patients. The average portosystemic gradient decreased from 22 to 11 mm Hg. Balloon dilatation was necessary in 12 of 35 angiographically controlled cases at 5 days (34%), because of incomplete stent expansion, small thrombi within the stent or obstruction. At 1-6 months stent malfunctions occurred in 8 of 23 patients who underwent control angiography (34%) and at 6-24 months in 6 of 7 patients (85%). Rebleeding occurred in 2 of 39 patients (follow-up > 1 month) (5%) and temporary crises of de novo encephalopathy were observed in 11 of 48 patients (23%). Refractory ascites completely resolved in 4 of 6 patients (66%) and improved in the remaining 2 cases. Compared with other self-expanding stents, nitinol Strecker stents seem to be equally effective in TIPS; no increase in complication rate was observed, either clinical or stent-related. PMID:8934143

  16. Randomized comparison of a sirolimus-eluting Orsiro stent with a biolimus-eluting Nobori stent in patients treated with percutaneous coronary intervention

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Thayssen, Per; Maeng, Michael; Ravkilde, Jan; Hansen, Henrik Steen; Jensen, Svend Eggert; Bøtker, Hans Erik; Berencsi, Klára; Lassen, Jens Flensted; Christiansen, Evald Høj

    2015-01-01

    BACKGROUND: Third-generation coronary drug-eluting stents (DES) with biodegradable polymers have been designed to improve safety and efficacy. We designed a large scale registry-based randomized clinical trial to compare 2 third-generation DES: a thin strut, cobalt-chromium DES with silicon carbide-coating...... releasing sirolimus from a biodegradable polymer (O-SES, Orsiro; Biotronik, Bülach, Switzerland) with the stainless steel biodegradable polymer biolimus-eluting Nobori stents (N-BES, Nobori; Terumo, Tokyo, Japan) in an all-comer patient population. DESIGN: The multicenter SORT OUT VII trial (NCT01879358......) randomly assigned 2,530 patients to treatment with biodegradable polymer O-SES or biodegradable polymer N-BES at 3 sites in Western Denmark. Patients were eligible, if they were ≥18 years old; had chronic stable coronary artery disease or acute coronary syndromes; and ≥1 coronary lesion with >50% diameter...

  17. Development and assessment of 316LVM cardiovascular stents

    Energy Technology Data Exchange (ETDEWEB)

    Raval, Ankur [Research and Development Division, Sahajanand Medical Technologies, Surat 395003 (India)]. E-mail: ankur.med@sahmed.com; Choubey, Animesh [Research and Development Division, Sahajanand Medical Technologies, Surat 395003 (India); Engineer, Chhaya [Research and Development Division, Sahajanand Medical Technologies, Surat 395003 (India); Kothwala, Devesh [Research and Development Division, Sahajanand Medical Technologies, Surat 395003 (India)

    2004-11-25

    One of the most common causes for heart failure is vasoconstriction. The medical procedure for alleviating vasoconstriction, angioplasty, calls for intracoronary stents. And the manufacture of intracoronary stents demands absolutely unmatched precision. Current study investigates CNC controlled pulsed Nd:YAG (neodymium:yttrium aluminium garnet) laser for cutting complex geometry of a stent on 316LVM tubings. It has been shown that surface quality of cardiovascular stents has a significant influence on biocompatibility. Therefore, optimal method and parameters for acid pickling of these slotted tube laser cut stents were explored, as a pretreatment for electropolishing. Pickling was necessary prior to electropolishing for removing the oxide films covering the stent surface. An optimal condition for electrochemical polishing could also be established and it caused a smooth stent surface. Passivation of these electropolished stents was done. Furthermore, materials characterization of stents was performed by means of composition and microstructural analysis.

  18. Tracheal stent placement for the emergency management of tracheal collapse in dogs.

    Science.gov (United States)

    Beal, Matthew W

    2013-08-01

    Dogs with tracheal collapse may present with life-threatening upper airway obstruction. In most instances, a conservative approach to treatment including oxygen support coupled with sedation and cooling measures will relieve respiratory effort and thus relieve airway obstruction. Dogs that fail this conservative approach require endotracheal intubation to ensure a patent airway. This population of patients would benefit from a more definitive, yet palliative treatment option to acutely relieve upper airway obstruction. Placement of a self-expanding metallic stent that spans the affected portion of the trachea will acutely provide the patient with a sustained patent airway and optimize the likelihood of a positive outcome. PMID:24182999

  19. 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

  20. 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

  1. Physician-initiated prospective Italian Registry of carotid stenting with the C-Guard mesh-stent: the IRON-Guard registry. Rationale and design.

    Science.gov (United States)

    Setacci, C; Speziale, F; De Donato, G; Sirignano, P; Setacci, F; Capoccia, L; Galzerano, G; Mansour, W

    2015-10-01

    According to the World Health Organization, every year, 5 million peoples die for stroke and another 5 million are permanently disabled. Although there are many causes of acute stroke, a common treatable cause of acute stroke is atheromatous narrowing at the carotid bifurcation. Carotid endarterectomy is still the standard of car, even if carotid artery stenting (CAS) has become an effective, less invasive alterantive. Unfortunately, CAS procedure is not yet perfect; regardless the use of an embolic protection device (EPD), percutaneous treatment has been correlated with a risk of cerebral ischemic events related to distal embolization. The objective of the IRON-Guard Registry is to evaluate the clinical outcome of treatment by means of stenting with the C-Guard (InspireMD, Boston, MA, USA) in subjects requiring CAS due to significant extracranial carotid artery stenosis with a physician-initiated, Italian, prospective, multicenter, single-arm study. A total of 200 enrolled subjects divided over different centers are planned to be enrolled. CAS will performed by implanting of C-Guard stent. Procedure will be performed according to the physician's standard of care. Standard procedures will be followed based on the Instructions for Use, for the C-Guard device of Inspire. The primary endpoint of this study is the 30-day rate of major adverse events (MAE), defined as the cumulative incidence of any periprocedural (≤30 days postprocedure) death, stroke or myocardial infarction. Secondary endpoints are rate of late ipsilateral stroke (31 through 365 days), system technical success, device malfunctions, major adverse events (MAEs), serious device-related and procedure-related adverse events, target lesion revascularization, and in-stent restenosis rates. PMID:25996843

  2. Heavy-to-light baryonic form factors at large recoil

    CERN Document Server

    Mannel, Thomas

    2011-01-01

    We analyze heavy-to-light baryonic form factors at large recoil and derive the scaling behavior of these form factors in the heavy quark limit. It is shown that only one universal form factor is needed to parameterize Lambda_b to p and Lambda_b to Lambda matrix elements in the large recoil limit of light baryons, while hadronic matrix elements of Lambda_b to Sigma transition vanish in the large energy limit of Sigma baryon due to the space-time parity symmetry. The scaling law of the soft form factor eta(P^{\\prime} \\cdot v), P^{\\prime} and v being the momentum of nucleon and the velocity of Lambda_b baryon, responsible for Lambda_b to p transitions is also derived using the nucleon distribution amplitudes in leading conformal spin. In particular, we verify that this scaling behavior is in full agreement with that from light-cone sum rule approach in the heavy-quark limit. With these form factors, we further investigate the Lambda baryon polarization asymmetry alpha in Lambda_b to Lambda gamma and the forward-...

  3. Binary Black Holes: Spin Dynamics and Gravitational Recoil

    CERN Document Server

    Herrmann, Frank; Shoemaker, Deirdre M; Laguna, Pablo; Matzner, Richard A

    2007-01-01

    We present a study of spinning black hole binaries focusing on the spin dynamics of the individual black holes as well as on the gravitational recoil acquired by the black hole produced by the merger. We consider two series of initial spin orientations away from the binary orbital plane. In one of the series, the spins are anti-aligned; for the second series, one of the spins points away from the binary along the line separating the black holes. We find a remarkable agreement between the spin dynamics predicted at 2nd post-Newtonian order and those from numerical relativity. For each configuration, we compute the kick of the final black hole. We use the kick estimates from the series with anti-aligned spins to fit the parameters in the Kidder kick formula, and verify that the recoil along the direction of the orbital angular momentum is proportional to $\\sin\\theta$ and on the orbital plane to $\\cos\\theta$, with $\\theta$ the angle between the spin directions and the orbital angular momentum.

  4. 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.

  5. 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...

  6. 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.

  7. 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.

  8. 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

  9. Renal artery stent angioplasty for renovascular hypertension

    International Nuclear Information System (INIS)

    Objective: To evaluate the therapeutic results of expandable stent for treatment of atherosclerotic renovascular obstructive disease. Methods: 15 patients (10 men and 5 women, 41-75 years old; mean age, 52 years) with renal arterial hypertension underwent renal stent angioplasty including renal arterial stenosis 89%(n=13) and fully obstruction without function in 2, of which 2 patients had bilateral involvement. The stenotic range of all arterial segments showed 60% to 90% width of the normal arterial diameter. 16 stents were implanted under the guidance of fluoroscopy. The most of stents implanted were Palmaz (n=12, 75%) with regular clinical and angiographic follow up. Results: Technical success (residual stenosis <30%) was achieved in all patients without serious complication. During the follow-up (6-15 months; mean, 8 ± 4 months), hypertension was improved in 9 patients and cured in 4 patients with a total benefit of 86% and no efficacy in 2(13%). The average systolic blood pressure decreased from 27.12 ± 3.09 kPa to 18.62 ± 3.12 kPa and the average diastolic blood pressure decreased from 17.73 ± 1.92 kPa to 11.12 ± 2.43 kPa after stent treatment (P<0.05). Serum creatinine remained stable in 60% (n=9) patients with improvement in 33% (n=5) and worsened in 6% (n=1) patients. Follow-up angiography was performed in all patients with 1 case of a restenosis. 6 months after expanding through stent by using balloon, the two follow up angiographies showed a stable restenosis about 20%. Conclusions: Percutaneous transluminal stent placement is highly beneficial for patients who had renal arterial obstructive disease. The success of stent angioplasty of complete obstructive renal arteries reveals wide prospects for interventional method. (authors)

  10. 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...

  11. 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) ...

  12. 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

  13. 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

  14. 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.  

  15. 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

  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. 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)

  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. iStent trabecular micro-bypass stent for open-angle glaucoma

    Directory of Open Access Journals (Sweden)

    Le K

    2014-09-01

    Full Text Available Kim Le, Hady Saheb Department of Ophthalmology, McGill University, Montreal, QC, Canada Abstract: Trabecular micro-bypass stents, commonly known as iStents, are micro-invasive glaucoma surgery (MIGS devices used to treat open-angle glaucoma. Like other MIGS procedures that enhance trabecular outflow, the iStent lowers intraocular pressure (IOP by creating a direct channel between the anterior chamber and Schlemm’s canal. iStents are typically implanted at the time of phacoemulsification for patients with open-angle glaucoma and visually significant cataracts. This review summarizes the published data regarding the efficacy, safety, and cost considerations of trabecular micro-bypass stents. Most studies found statistically significant reductions in mean IOP and ocular medication use after combined phacoemulsification with single or double iStent implantation. The devices were found to be very safe, with a safety profile similar to that of cataract surgery. Complications were infrequent, with the most common complications being temporary stent obstruction or malposition, which resolved with observation or secondary procedures. Future studies are needed to evaluate long-term outcomes, patient satisfaction, cost effectiveness, and expanded indications. Keywords: iStent, trabecular micro-bypass, glaucoma, MIGS, ab interno, surgery

  20. 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

  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. 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)

  3. 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.

  4. 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.)

  5. Recoil-distance lifetime measurements in some sd-shell nuclei

    International Nuclear Information System (INIS)

    The investigation reported in this thesis consisted of three parts: the design and development of a recoil-distance apparatus, the development and application of computer programs for the analysis of recoil-distance γ-ray spectra, and the measurement of the lifetimes of one or more excited states in 24Na, 26Al, and 28Al. (G.T.H.)

  6. Monitoring of physics performance of ILC Software based on Higgs Recoil Mass

    Science.gov (United States)

    Volkova, E.; Voutsinas, G.

    2016-02-01

    We discuss a part of ILC software development, that allow us to make automated testing of ILC results. The testing code consists of automated everyday Higgs recoil mass analysis and compares Higgs recoil mass with one of the previous day result. This code uses the result of generation, Mokka simulation and Marlin reconstruction of ILC events.

  7. Use of nuclear recoil for separating 228Ra, 224Ra, and 233Pa from colloidal thorium

    International Nuclear Information System (INIS)

    By using α-recoil it is possible to separate by dialysis the α disintegration products (224 Ra; 228 Ra) of thorium from colloidal thorium hydroxide.The use of n, γ recoil allows the separation of 233Pa produced by the neutron irradiation of thorium, on condition that the colloidal thorium hydroxide is irradiated in the presence of a dispersing. (author)

  8. Current status of radioactive stents for the prevention of in-stent restenosis

    International Nuclear Information System (INIS)

    Purpose: The objective of this paper was to provide an update on the clinical and experimental evaluation of radioactive stents for the prevention of restenosis. Materials and Methods: Direct ion implantation of 32P onto the surface of a 15-mm length balloon expandable stainless-steel Palmaz-Schatz stent was employed to render this commercially available vascular stent radioactive. 32Phosphorous, a pure beta-particle-emitting radioisotope, was selected because of its short half-life (14.3 days) and limited range of tissue penetration (3-4 mm). The vascular response to radioactive 7-mm length Palmaz-Schatz stents with activities 0.14 to 23 μCi of 32P were evaluated in animal models of arterial injury and restenosis. The Phase-1 isostent for restenosis intervention study (IRIS trial) was a nonrandomized safety trial designed to evaluate the use of a low activity 32P (0.5 to 1.5 μCi) 15-mm length Palmaz-Schatz stent for the treatment of de novo or restenosis native coronary arterial lesions. Results: In the porcine coronary restenosis model, at ≤0.5 μCi and ≥3.0 μCi stent activities, there was a 30% reduction in the neointimal and percent area stenosis as compared to nonradioactive stents. The 1.0 μCi stents, however, had nearly 2-fold greater neointimal formation and more luminal narrowing than the control stents. In the Phase 1 IRIS trial, 57 patients with symptomatic de novo or restenosis native coronary lesions have been treated with low activity (0.5 to 1.5 μCi) 32P Palmaz-Schatz coronary stents. Fifty-seven stents were successfully implanted without a major procedural complication (death, urgent coronary bypass, Q-wave myocardial infarction). There were no cases of stent thrombosis, target vessel revascularization, or other adverse events in the first 30 days after implant. Conclusion: The early clinical results with a low-activity 32P Palmaz-Schatz radioactive stent demonstrate sufficient procedural and 30-day event-free survival to warrant

  9. 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

  10. 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

  11. Self-expanding stent-assisted middle cerebral artery recanalization: technical note

    Energy Technology Data Exchange (ETDEWEB)

    Sauvageau, Eric [State University of New York, Department of Neurosurgery, School of Medicine and Biomedical Sciences, Buffalo, NY (United States); State University of New York, Toshiba Stroke Research Center, School of Medicine and Biomedical Sciences, Buffalo, NY (United States); Levy, Elad I. [State University of New York, Department of Neurosurgery, School of Medicine and Biomedical Sciences, Buffalo, NY (United States); State University of New York, Department of Radiology, School of Medicine and Biomedical Sciences, Buffalo, NY (United States); State University of New York, Toshiba Stroke Research Center, School of Medicine and Biomedical Sciences, Buffalo, NY (United States)

    2006-06-15

    Investigation into pharmacological and mechanical means of improving recanalization rates by intraarterial therapy has led to technological development. Angiographic recanalization has been associated with improvement in clinical outcome. A clot retriever has recently joined an imperfect armamentarium for intraarterial stroke therapy. In this report, we describe successful recanalization of an acute thrombotic occlusion of the inferior division of the middle cerebral artery (MCA) achieved with a self-expanding stent. An 82-year-old woman with a history of coronary atherosclerosis and previous cerebellar hemorrhage presented with a National Institutes of Health Stroke Scale (NIHSS) score of 11. Perfusion computed tomography imaging showed a left MCA territory deficit. Diffusion-weighted magnetic resonance (MR) imaging revealed a small punctiform insular hyperintensity. Angiography documented occlusion of the inferior division of the left MCA (Thrombolysis in Myocardial Infarction or Thrombolysis in Cerebral Infarction, TIMI/TICI, grade 0). Intraarterial delivery of eptifibatide to the occlusion site failed to recanalize the vessel. Deployment of a self-expanding stent in the occluded segment resulted in complete revascularization of the distal vascular bed. Angiography performed on the next day confirmed patency of the stented vessel segment (TIMI/TICI 3). The patient was discharged 3 days after the procedure (NIHSS 3). MR angiography obtained 3 months after the procedure documented left MCA patency. This technique may have a role worthy of further investigation in acute stroke therapy. (orig.)

  12. 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.

  13. 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.

  14. 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

  15. Electron recombination in low-energy nuclear recoils tracks in liquid argon

    International Nuclear Information System (INIS)

    This paper presents an analysis of electron-ion recombination processes in ionization tracks of recoiled atoms in liquid argon (LAr) detectors. The analysis is based on the results of computer simulations which use realistic models of electron transport and reactions. The calculations reproduce the recent experimental results of the ionization yield from 6.7 keV nuclear recoils in LAr. The statistical distribution of the number of electrons that escape recombination is found to deviate from the binomial distribution, and estimates of recombination fluctuations for nuclear recoils tracks are obtained. A study of the recombination kinetics shows that a significant part of electrons undergo very fast static recombination, an effect that may be responsible for the weak drift-field dependence of the ionization yield from nuclear recoils in some noble liquids. The obtained results can be useful in the search for hypothetical dark matter particles and in other studies that involve detection of recoiled nuclei

  16. Linear momentum transfer in complete and incomplete fusion of 16O with 175Lu: forward recoil range distribution measurements

    International Nuclear Information System (INIS)

    In the present work, forward recoil range distributions of some evaporation residues recoiled in thin Al-catcher foils, have been measured and the results are interpreted in terms on complete fusion (CF) and incomplete fusion (ICF) reactions

  17. 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 ($

  18. 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

  19. 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

  20. 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. ...

  1. 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 ...

  2. Innovations in Stroke Prevention: An Update on Carotid Stenting

    Medline Plus

    Full Text Available ... called a sheath, we can then place a filter, or cerebral protection device, to prevent any small ... very stable environment to pass balloon stents and filters during the carotid stent angioplasty. The cerebral protection ...

  3. Safety and Efficacy of Thoracic External Beam Radiotherapy After Airway Stenting in Malignant Airway Obstruction

    International Nuclear Information System (INIS)

    Purpose: We retrospectively evaluated the outcome and toxicity of external beam radiotherapy (EBRT) after airway stents were placed in patients treated for malignant airway obstruction. Methods and Materials: Between 2004 and 2009, we performed airway stenting followed by EBRT in 43 patients for symptomatic primary lung cancer (n = 31) or other thoracic malignancies (n = 12). The median time interval between stent placement and first irradiation was 14 days. A median total dose of 50 Gy was delivered. Sixty-seven percent of the patients had reduced performance status (Karnofsky performance score, ≤70). Results: EBRT had to be stopped prematurely in 16 patients (37%), at a median total dose of 17 Gy, for various reasons. In this group of patients, the survival was poor, with a median overall survival (OS) of only 21 days. Twenty-seven patients (63%) completed radiotherapy as planned, with a median OS of 8.4 months. Fourteen of 43 patients (33%) developed at least one Common Terminology Criteria for Adverse Event of grade 3 to 5. The most common event was a malignant restenosis of the stent leading to asphyxia (n = 7), followed by fistula formation (n = 4), necrosis (n = 3), mediastinitis with abscess (n = 1), secondary nonmalignant airway stenosis (n = 1), and hemoptysis (n = 1). With the exception of one event, all events were associated with a local progression of the tumor. Conclusions: Although the long-term prognosis for patients with malignant airway obstruction is poor, airway stenting combined with EBRT offers a possible therapeutic option, achieving fast relief of acute respiratory distress with an associated antitumor effect, resulting in a potential survival benefit. However, due to local advanced tumor growth, increased rates of adverse events are to be expected, necessitating careful monitoring.

  4. 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 ...

  5. Spectroscopy of 144Ho using recoil-isomer tagging

    International Nuclear Information System (INIS)

    Excited states in the proton-unbound odd-odd nucleus 144Ho have been populated using the 92Mo(54Fe,pn)144Ho reaction and studied using the recoil-isomer-tagging technique. The alignment properties and signature splitting of the rotational band above the Iπ=(8+)144mHo isomer have been analyzed and the isomer confirmed to have a πh11/2 x νh11/2 two-quasiparticle configuration. The configuration-constrained blocking method has been used to calculate the shapes of the ground and isomeric states, which are both predicted to have triaxial nuclear shapes with |γ|≅24 deg.

  6. Recoil Polarization for Delta Excitation in Pion Electroproduction

    Energy Technology Data Exchange (ETDEWEB)

    J. J. Kelly; R. E. Roche; Z. Chai; M. K. Jones; O. Gayou; A. J. Sarty; S. Frullani; K. Aniol; E. J. Beise; F. Benmokhtar; W. Bertozzi; W. U. Boeglin; T. Botto; E. J. Brash; H. Breuer; E. Brown; E. Burtin; J. R. Calarco; C. Cavata; C. C. Chang; N. S. Chant; J.-P. Chen; M. Coman; D. Crovelli; R. De Leo; S. Dieterich; S. Escoffier; K. G. Fissum; V. Garde; F. Garibaldi; S. Georgakopoulus; S. Gilad; R. Gilman; C. Glashausser; J.-O. Hansen; D. W. Higinbotham; A. Hotta; G. M. Huber; H. Ibrahim; M. Iodice; C. W. de Jager; X. Jiang; A. Klimenko; A. Kozlov; G. Kumbartzki; M. Kuss; L. Lagamba; G. Laveissiere; J. J. LeRose; R. A. Lindgren; N. Liyanage; G. J. Lolos; R. W. Lourie; D. J. Margaziotis; F. Marie; P. Markowitz; S. McAleer; D. Meekins; R. Michaels; B. D. Milbrath; J. Mitchell; J. Nappa; D. Neyret; C. F. Perdrisat; M. Potokar; V. A. Punjabi; T. Pussieux; R. D. Ransome; P. G. Roos; M. Rvachev; A. Saha; S. Sirca; R. Suleiman; S. Strauch; J. A. Templon; L. Todor; P. E. Ulmer; G. M. Urciuoli; L. B. Weinstein; K. Wijesooriya; B. Wojtsekhowski; X. Zheng; and L. Zhu

    2005-08-01

    We measured angular distributions of recoil-polarization response functions for neutral pion electroproduction for W=1.23 GeV at Q{sup 2}=1.0 (GeV/c){sup 2}, obtaining 14 separated response functions plus 2 Rosenbluth combinations; of these, 12 have been observed for the first time. Dynamical models do not describe quantities governed by imaginary parts of interference products well, indicating the need for adjusting magnitudes and phases for nonresonant amplitudes. We performed a nearly model-independent multipole analysis and obtained values for Re(S1+/M1+)=-(6.84+/-0.15)% and Re(E1+/M1+)=-(2.91+/-0.19)% that are distinctly different from those from the traditional Legendre analysis based upon M1+ dominance and sp truncation.

  7. 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.

  8. 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.

  9. Measurement of the neutron electric form factor via recoil polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    T. Reichelt; R. Madey; A.Yu. Semenov; S. Taylor; A. Aghalarian; E. Crouse; G. MacLachlan; B. Plaster; S. Tajima; W. Tireman; C.Y. Yan; A. Ahmidouch; B.D. Anderson; R. Asaturian; O. Baker; A.R. Baldwin; H. Breuer; R. Carlini; E. Christy; S. Churchwell; L. Cole; S. Danagulian; D. Day; M. Elaasar; R. Ent; M. Farkhondeh; H. Fenker; J.M. Finn; L. Gan; K. Garrow; P. Gueye; C. Howell; B. Hu; M.K. Jones; J.J. Kelly; C. Keppel; M. Khandaker; W.Y. Kim; S. Kowalski; A. Lung; D. Mack; D.M. Manley; P. Markowitz; J. Mitchell; H. Mkrtchian; A.K. Opper; C. Perdrisat; V. Punjabi; B. Raue; J. Reinhold; J. Roche; Y. Sato; W. Seo; N. Simicevic; G. Smith; S. Stepanian; V. Tadevosian; L. Tang; P. Ulmer; W. Vulcan; J.W. Watson; S. Wells; F. Wesselmann; S. Wood; C. Yan; S. Yang; L. Yuan; W.M. Zhang; H. Zhu; X. Zhu; H. Arenhovel

    2003-10-22

    The ratio G{sub c}{sup n}/G{sub m}{sup n} of the electric to the magnetic form factor of the neutron has been measured by analyzing the polarization of the recoiling neutron in quasi-elastic scattering of longitudinally polarized electrons from deuterium at the Q{sup 2} values of 0.45, 1.15, and 1.47 (GeV/c){sup 2}. The experiment has been performed in Hall C of the Thomas Jefferson National Accelerator Facility. With G{sub m}{sup n} being known G can be deduced. The preliminary results show that the lowest Q{sup 2} points follow the Galster parameterization and that the 1.47 (GeV/c){sup 2} point rises above this parameterization.

  10. Calibration of a compact magnetic proton recoil neutron spectrometer

    Science.gov (United States)

    Zhang, Jianfu; Ouyang, Xiaoping; Zhang, Xianpeng; Ruan, Jinlu; Zhang, Guoguang; Zhang, Xiaodong; Qiu, Suizheng; Chen, Liang; Liu, Jinliang; Song, Jiwen; Liu, Linyue; Yang, Shaohua

    2016-04-01

    Magnetic proton recoil (MPR) neutron spectrometer is considered as a powerful instrument to measure deuterium-tritium (DT) neutron spectrum, as it is currently used in inertial confinement fusion facilities and large Tokamak devices. The energy resolution (ER) and neutron detection efficiency (NDE) are the two most important parameters to characterize a neutron spectrometer. In this work, the ER calibration for the MPR spectrometer was performed by using the HI-13 tandem accelerator at China Institute of Atomic Energy (CIAE), and the NDE calibration was performed by using the neutron generator at CIAE. The specific calibration techniques used in this work and the associated accuracies were discussed in details in this paper. The calibration results were presented along with Monte Carlo simulation results.

  11. Recoil distance lifetimes of rotational states in 236U

    International Nuclear Information System (INIS)

    Half-lives for members of the 236U ground-state rotational band have been measured by the recoil-distance method following Coulomb excitation with 40Ar8+ projectiles. The B (E2, I→I-2) values in units of e2 b2 determined from the half-lives of the 4+, 6+, 8+, 10+, and 12+ states are 3.03+-0.20, 3.28+-0.19, 3.42+-0.28, 3.11+-0.30, and 3.34+2.23/sub em-dash//sub 0//sub .9//sub 5/, respectively. Transition quadrupole moments Q20(I/subi/→I/subf/) deduced from the lifetimes are constant within experimental error and thus support the characterization of 236U as a good rotor to spin 12+

  12. 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...

  13. Mechanisms of chemical reaction initiated by recoil implantation

    International Nuclear Information System (INIS)

    Mechanisms of chemical reactions initiated by recoil implantation were studied in the systems 51Cr+M(acac)3 yields 51Cr(acac)3 where M is a trivalent metal. The yield of 51Cr(acac)3 increased linearly with an increase of inverse of the force constant of metal-oxygen bonding K(M-O). This indicates that there is competition between the implanted 51Cr atom and M. However, exception for this trend was the case of Co(acac)3 catcher, for which the yield of 51Cr(acac)3 was much higher than that expected for a competition reaction. Complex features of the replacement reaction caused by implantation are discussed

  14. Investigation of fractional momentum transfer: measurement of forward recoil ranges in 16O + natTm collisions

    International Nuclear Information System (INIS)

    For better understanding of complete fusion and incomplete fusion in heavy ion reactions a programme of precise measurements of excitation functions, recoil range distribution and angular distributions of recoils has been undertaken. In the present contribution the recoil range distribution for the residues have been measured at ≅ 6 MeV/nucleon, using recoil-catcher technique followed by off-line gamma-spectroscopy

  15. 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.

  16. 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...

  17. 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 (...

  18. 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...

  19. Monitoring the Wall Mechanics During Stent Deployment in a Vessel

    OpenAIRE

    Steinert, Brian D.; Zhao, Shijia; Gu, Linxia

    2012-01-01

    Clinical trials have reported different restenosis rates for various stent designs1. It is speculated that stent-induced strain concentrations on the arterial wall lead to tissue injury, which initiates restenosis2-7. This hypothesis needs further investigations including better quantifications of non-uniform strain distribution on the artery following stent implantation. A non-contact surface strain measurement method for the stented artery is presented in this work. ARAMIS stereo optical su...

  20. 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.