Gary B. Nackman

Cost-effectiveness of carotid endarterectomy in asymptomatic patients ☆ ☆☆

PURPOSE The purpose of this study was to determine the cost-effectiveness of carotid endarterectomy for treating asymptomatic patients with > or = 60% internal carotid stenosis, based on outcomes reported in the Asymptomatic Carotid Atherosclerosis Study (ACAS). METHODS A cost-effectiveness analysis was performed using a Markov decision model in which the probabilities for base-case analysis (average age, 67 years; 66% male; perioperative stroke plus death rate, 2.3%; ipsilateral stroke rate during medical management, 2.3% per year) were based on ACAS. The model assumed that patients who had TIAs or minor strokes during medical management crossed over to surgical treatment, and used the NASCET data to model the outcome of these now-symptomatic patients. Average cost of surgery (

Thrombolysis of occluded infrainguinal vein grafts: predictors of outcome.

8500), major stroke (

Endovascular management of ureteroarterial fistula

34,000 plus

Effective use of human simulators in surgical education1

18,000 per year), and other costs were based on local cost determinations plus a review of the published literature. Cost-effectiveness was calculated as the incremental cost of surgery per quality-adjusted life year (QALY) saved when compared with medical treatment, discounting at 5% per year. Sensitivity analysis was performed to determine the impact of key variables on cost-effectiveness. RESULTS In the base-case analysis, surgical treatment improved quality-adjusted life expectancy from 7.87 to 8.12 QALYs, at an incremental lifetime cost of

Convergence of nanotechnology and cardiovascular medicine : progress and emerging prospects.

2041. This yielded an incremental cost-effectiveness ratio of

Experiments show importance of flow-induced pressure on endothelial cell shape and alignment

8,000 per QALY saved by surgical compared with medical treatment. The high cost of care after major stroke during medical management largely offset the initial cost of endarterectomy in the surgical group. Furthermore, 26% of medically managed patients eventually underwent endarterectomy because of symptom development, which also decreased the cost differential. Sensitivity analysis demonstrated that the relative cost of surgical treatment increased substantially with increasing age, increasing perioperative stroke rate, and decreasing stroke rate during medical management. CONCLUSION For the typical asymptomatic patient in ACAS with > or = 60% carotid stenosis, our results indicate that carotid endarterectomy is cost-effective when compared with other commonly accepted health care practices. Surgery does not appear cost-effective in very elderly patients, in settings where the operative stroke risk is high, or in patients with very low stroke risk without surgery.

Flow bioreactor design for quantitative measurements over endothelial cells using micro-particle image velocimetry

PURPOSE The purpose of this study was to identify factors that influence graft patency and limb salvage rates after thrombolysis of occluded infrainguinal vein grafts. METHODS The records of patients who underwent percutaneous catheter-directed thrombolysis of occluded infrainguinal vein bypass grafts at our institution between 1985 and 1995 were reviewed. Life table analysis was used to determine survival and patency differences. Univariate and multivariate analyses were used to identify the patient-specific factors that affected outcomes. RESULTS Forty-four patients with 44 thrombosed infrainguinal vein grafts underwent thrombolysis with urokinase. The thrombolysis-related mortality rate was 2%, and nonfatal complications occurred in 16%. Thrombolysis was unable to restore graft patency in 25% of grafts (11 of 44). Of the remaining 33 successfully lysed grafts, 88% required adjunctive surgery or percutaneous transluminal angioplasty after thrombolysis. Overall, the primary graft patency rate was 25% at 1 year and 19% at 2 years after thrombolysis. Considering only successfully lysed grafts, the primary patency rate improved to 34% at 1 year and 25% at 2 years. Multivariate analysis revealed that the graft patency rate was substantially better in patients without diabetes and in vein grafts that had been in place for longer than 12 months (p < 0.01). The limb salvage rate was significantly improved by successful thrombolysis (63% at 2 years vs 31% if lysis failed; p < 0.01). The patient survival rate was high-89% 2 years after thrombolysis. CONCLUSIONS Even with adjunctive therapy, vein graft thrombolysis is unlikely to yield durable patency overall. However, successful thrombolysis improves limb salvage rates and may be beneficial in patients without diabetes who have mature vein grafts but who do not have options for other autogenous revascularization procedures.

Flow patterns through vascular graft models with and without cuffs

Ureteroarterial fistulas, although rare, appear to be increasing in frequency. Because open surgical repair may be difficult and associated with significant risk for complications, endovascular intervention may provide an attractive treatment alternative. We review the diagnosis and management of a ureteroarterial fistula and iliac pseudoaneurysm that presented with massive hematuria during ureteral stent removal. The patient was treated by means of the percutaneous embolization of the right hypogastric artery and placement of an expanded polytetrafluoroethylene stent-graft. Endovascular stent-graft placement may serve as a safe and practical alternative in the treatment of these patients, whose cases are challenging.

Practicing Evidence-Based Surgery

BACKGROUND We initiated a teaching module utilizing a human simulator midway through 2001-2002 to improve student skills specific to the evaluation of patients in shock during a required clerkship in surgery for fourth-year medical students. We tested the hypothesis that student skills would improve after implementation of this module and identified factors that predicted student performance. MATERIALS AND METHODS Students (n = 86) chose one of two hospital sites for a clerkship that focuses on the care of acutely ill surgical patients. A case-based lecture focusing on the diagnosis and management of a patient in shock was replaced midway through the academic year by a simulator session with a computerized life-sized mannequin. A standardized clinical final evaluation (OSCE) was used to assess student skills. We evaluated the effect of the simulator session and other factors on student exam performance using univariate and multivariate analysis. RESULTS The site of the clerkship and the simulator session were significant factors affecting the OSCE score identified by ANOVA, P < 0.05. A stepwise multiple regression analysis testing the effect of simulator module, site, time of year, prior NBME subject exam, and prior OSCE during the third year clerkship identified that the simulator module was the only independent factor that modeled performance on all shock stations, P < 0.01. CONCLUSIONS In a clerkship that already emphasized faculty facilitated case-based learning, the use of a teaching module employing a human simulator significantly improved test scores. This study supports the efficacy of human simulators to improve student skills related to the management of complex critically ill patients.

Phlegmasia Cerulea Dolens in a Patient with Ulcerative Colitis Treated by Iliofemoral Venous Thrombectomy A Case Report

Advances in the emergence of biological probes, materials, and analytical tools limited to the nanoscale size range, collectively referred to as ‘nanotechnology’, are increasingly being applied to the understanding and treatment of the major pathophysiological problems in cardiovascular medicine. Analytical techniques based on high-resolution microscopy and molecular-level fluorescence excitation processes capable of detecting nanoscale interactions have been used to elucidate cardiovascular pathology. Nanotechnology has also significantly impacted diagnostic intervention in cardiology, with the use of nanoparticles as contrast agents, for targeted biomedical imaging of vulnerable plaques, for detection of specific pathologic targets signaling the onset of atherosclerosis, and for tracking inflammatory events. Real-time nanoscale biosensors can be used to measure cardiovascular biomarkers, and nanopore sequencing has the potential to speed up the analysis of gene expression in cardiovascular disease. Potential therapeutic applications include the use of nanomaterials in cardiovascular devices, for delivery of drugs and bioactive molecules, or in novel technologies for reducing cholesterol accumulation and for dissolving clots.