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Graft Occlusion (graft + occlusion)
Selected AbstractsDoes off-pump coronary artery bypass surgery reduce secretion of plasminogen activator inhibitor-1?INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 5 2007C. Ozkara Summary Prior studies showed that postoperative increase in plasminogen activator inhibitor-1 (PAI-1) levels is associated with an increased risk of graft occlusion after coronary artery bypass surgery (CABG). This prospective study aimed to compare the changes of PAI-1 antigen levels after off-pump and on-pump CABG. Forty-four patients admitted for elective CABG were randomised to on-pump (n = 22) or off-pump (n = 22) surgery. Serum samples were collected for estimation of PAI-1 and tissue plasminogen activator (t-PA) antigen levels preoperatively and 2 h after the operation. The groups were similar in terms of age, weight, gender ratio and extent of coronary disease, left ventricular function and number of grafts per patient. Fibrinogen and t-PA levels increased postoperatively in both the groups when compared with baseline values. After operation, statistical analysis revealed that increase of PAI-1 values was higher in off-pump group (44.1 ± 9.1 vs. 25.3 ± 6.9) than on-pump group (37.2 ± 5.5 vs. 27.3 ± 7.8, p = 0.002). This study shows that increase in PAI-1 antigen values in patients who undergo off-pump (beating heart) CABG is significantly higher than in those who undergo conventional CABG with cardiopulmonary bypass. [source] Results of Treatment Methods in Cardiac Arrest Following Coronary Artery Bypass GraftingJOURNAL OF CARDIAC SURGERY, Issue 3 2009Mehmet R. Guney M.D. We evaluated the short- and long-term consequences of these two methods and discussed the indications for re-revascularization. Methods: Between 1998 and 2004, a total of 148 CABG patients, who were complicated with cardiac arrest, were treated with emergency re-revascularization (n = 36, group R) and ICU procedures (n = 112, group ICU). Re-revascularizations are mostly blind operations depending on clinical/hemodynamic criteria. These are: no response to resuscitation, recurrent tachycardia/fibrillation, and severe hemodynamic instability after resuscitation. Re-angiography could only be performed in 3.3% of the patients. Event-free survival of the groups was calculated by the Kaplan-Meier method. Events are: death, recurrent angina, myocardial infarction, functional capacity, and reintervention. Results: Seventy percent of patients, who were complicated with cardiac arrest, had perioperative myocardial infarction (PMI). This rate was significantly higher in group R (p = 0.013). The major finding in group R was graft occlusion (91.6%). During in-hospital period, no difference was observed in mortality rates between the two groups. However, hemodynamic stabilization time (p = 0.012), duration of hospitalization (p = 0.00006), and mechanical support use (p = 0.003) significantly decreased by re-revascularization. During the mean 37.1 ± 25.1 months of follow-up period, long-term mortality (p = 0.03) and event-free survival (p = 0.029) rates were significantly in favor of group R. Conclusion: Better short- and long-term results were observed in the re-revascularization group. [source] Crushed Clopidogrel Administered via Nasogastric Tube Has Faster and Greater Absorption than Oral Whole TabletsJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 4 2009M. UROOJ ZAFAR M.B.B.S. Objectives: To compare the absorption of 300 mg clopidogrel administered crushed via nasogastric (NG) tube versus whole tablets taken orally in healthy volunteers. Background: Earlier antiplatelet therapy has proven benefits in treatment of myocardial infarction and in patients undergoing PCI. Aspirin can be delivered early in crushed form via NG tube after CABG surgery to prevent graft occlusion. If clopidogrel given crushed via NG tube provides faster absorption, it could allow earlier clopidogrel loading. Methods: Nine healthy human subjects (34.7 ± 11.1 years, 5 males) were given 300 mg clopidogrel in crushed form via NG tube with 30 mL water after 8 hours of fasting. Plasma levels of the primary circulating inactive clopidogrel metabolite SR26334 were measured after 20 minutes, 40 minutes, 1, 2, 4, 8, 12, and 24 hours of dosing. Following ,2 week washout, same subjects swallowed 300 mg clopidogrel (four 75 mg tablets) after an 8-hour fasting and SR26334 levels were measured at the same time points. Results: Plasma SR26334 concentrations peaked earlier after crushed delivery than after oral intake (44 vs. 70 minutes, P = 0.023) and the median peak was 80% higher (13,083 vs. 7,255 ng/mL, respectively, P = 0.021). At 40 minutes, area under the curve was almost twofold greater with NG administration than oral administration (geometric means ratio = 0.5299, 95% CI = 0.28,0.99, P = 0.048), but was similar over the 24-hour period with both administration methods (geometric means ratio = 1.05, 95% CI = 0.84,1.32, P = 0.646). Conclusions: A 300 mg loading dose of crushed clopidogrel administered via NG tube provides faster and greater bioavailability than an equal dose taken orally as whole tablets. The clinical benefits of this strategy need to be investigated. [source] Computational Fluid Dynamics and Vascular AccessARTIFICIAL ORGANS, Issue 7 2002Ulf Krueger Abstract: Anastomotic intimal hyperplasia caused by unphysiological hemodynamics is generally accepted as a reason for dialysis access graft occlusion. Optimizing the venous anastomosis can improve the patency rate of arteriovenous grafts. The purpose of this study was to examine, evaluate, and characterize the local hemodynamics and, in particular, the wall shear stresses in conventional venous end-to-side anastomosis and in patch form anastomosis (Venaflo) by three-dimensional computational fluid dynamics (CFD). We investigated the conventional form of end-to-side anastomosis and a new patch form by numerical simulation of blood flow. The numerical simulation was done with a finite volume-based algorithm. The anastomotic forms were constructed with usual size and fixed walls. Subdividing the flow domain into multiple control volumes solved the fundamental equations. The boundary conditions were identical for both forms. The velocity profile of the patch form is better than that for the conventional form. The region of high static pressure caused by flow stagnation is reduced on the vein floor. The anastomotic wall shear stress is decreased. The results of this study strongly support patch form use to reduce the incidence of intimal hyperplasia and venous anastomotic stenoses. [source] Improving the Clinical Patency of Prosthetic Vascular and Coronary Bypass Grafts: The Role of Seeding and Tissue EngineeringARTIFICIAL ORGANS, Issue 4 2002Alexander M. Seifalian Abstract: In patients requiring coronary or peripheral vascular bypass procedures, autogenous vein is currently the conduit of choice. If this is unavailable, then a prosthetic material is used. Prosthetic graft is liable to fail due to occlusion of the graft. To prevent graft occlusion, seeding of the graft lumen with endothelial cells is undertaken. Recent advances have also looked at developing a completely artificial biological graft engineered from the patient's cells with properties similar to autogenous vessels. This review encompasses the developments in the two principal technologies used in developing hybrid coronary and peripheral vascular bypass grafts, that is, seeding and tissue engineering. [source] Influence of perioperative blood glucose levels on outcome after infrainguinal bypass surgery in patients with diabetesBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 11 2006J. Malmstedt Background: High glucose levels are associated with increased morbidity and mortality after coronary surgery and in intensive care. The influence of perioperative hyperglycaemia on the outcome after infrainguinal bypass surgery among diabetic patients is largely unknown. The aim was to determine whether high perioperative glucose levels were associated with increased morbidity after infrainguinal bypass surgery. Methods: Ninety-one consecutive diabetic patients undergoing primary infrainguinal bypass surgery were identified from a prospective vascular registry. Risk factors, indication for surgery, operative details and outcome data were extracted from the medical records. Exposure to perioperative hyperglycaemia was measured using the area under the curve (AUC) method; the AUC was calculated using all blood glucose readings during the first 48 h after surgery. Results: Multivariable analysis showed that the AUC for glucose (odds ratio (OR) 13·35, first versus fourth quartile), renal insufficiency (OR 4·77) and infected foot ulcer (OR 3·38) was significantly associated with poor outcome (death, major amputation or graft occlusion at 90 days). Similarly, the AUC for glucose (OR 14·45, first versus fourth quartile), female sex (OR 3·49) and tissue loss as indication (OR 3·30) was associated with surgical wound complications at 30 days. Conclusion: Poor perioperative glycaemic control was associated with an unfavourable outcome after infrainguinal bypass surgery in diabetic patients. Copyright © 2006 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source] Native chronic total occlusion recanalization after lower limb bypass graft occlusion: A series of nine cases,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 2 2010FSCAI, Osami Kawarada MD Abstract Objective: The aim of the study was to report the clinical utility of native chronic total occlusion (CTO) recanalization as an endovascular strategy in lower limb bypass graft occlusion. Background: There is no consensus on the best approach for threatened limbs in patients with graft occlusion. Methods: The subjects were nine consecutive patients with limb-threatening ischemia after bypass graft occlusion. Native CTO recanalization was attempted endovascularly using conventional intraluminal and subintimal angioplasty techniques supported by stents. Results: The mean age of the bypass grafts was 6.7 ± 7.3 (range: 1,24) months and the mean number of previous lower limb bypass surgeries was 1.4 ± 0.5 (range: 1,2). Native CTO recanalization was performed in the iliofemoral (n = 2), iliac (n = 2), superficial femoral (n = 3), popliteal (n = 1), and popliteal-tibial (n = 1) arteries. Technical success was achieved in 89% (8/9) of cases without complications or major adverse cardiovascular events. The ankle-brachial index and skin perfusion pressure of the foot significantly increased after revascularization, with marked improvement of clinical symptoms (Rutherford class: 4.5 ± 1.1,0.9 ± 1.4, P < 0.001). Limb salvage was achieved in all successful recanalization cases during the mean follow-up time of 25 ± 20 months (range: 9,60). Conclusions: In this preliminary study, endovascular recanalization of native CTO showed satisfactory outcomes in patients with bypass graft occlusion. © 2010 Wiley-Liss, Inc. [source] Antiplatelet therapy after endovascular intervention: Does combination therapy really work and what is the optimum duration of therapy?,,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue S1 2009Richard V. Milani MD Abstract The number of patients undergoing peripheral interventions has increased in recent years, highlighting the need for a safe and effective protective antithrombotic therapy. Platelet inhibition following coronary intervention is associated with a significantly reduced risk of graft occlusion, and has been acknowledged to be safe and effective in patients with peripheral arterial disease. Monotherapy with either aspirin or clopidogrel, reduces the rate of stroke, myocardial infarction, and cardiovascular death in patients suffering from peripheral arterial disease. Limited data from clinical trials investigating combination therapy of aspirin with ticlopidine or clopidogrel in patients undergoing endovascular interventions, have suggested the potential for a reduction in cardiovascular events. Nevertheless, the optimal duration of postintervention antiplatelet therapy remains to be defined. © 2009 Wiley-Liss, Inc. [source] | ||||||||||