A modified combined approach to operative carotid and coronary artery disease: 82 Cases in 8 years
ABSTRACT A significant number of patients undergoing coronary artery surgery have severe carotid artery disease. It is also true that up to half of the patients undergoing carotid endarterectomy (CEA) have severe treatable coronary lesions. This study aims to review data regarding 82 patients of combined approach in 8 years; the second half consists of 44 patients whose CEA was performed under local anesthesia. It compares results of the conventional and the modified approaches to simultaneous surgery.
All 82 patients who planned to have a concomitant procedure were recorded prospectively between 1995 and 2003. From 1998, the surgical technique has been modified to switch to local anesthesia for CEA, rather than perform under a single general anesthetic period. All pre-and perioperative data as well as in-hospital and outpatient control (mid- to long-term) data were recorded. A P-value of less than .05 was considered as significant. Analysis of survival was performed by using the Kaplan-Meier method and the log-rank test.
The 30-day follow-up was 100% complete for all patients. All patients were followed for 59.59 to 114 months) months postoperatively. Three patients (6.8%) in the modified and 2 (5.2%) in the standard group had intraluminal shunting (P > .05). In the standard group, 3 patients expired and 3 had perioperative stroke; only 1 patient had a stroke in the modified group and two expired (P > .05). Mean survival time according to Kaplan-Meier test was 109.97, SE 2.84, 95% CI (104.41-115.52) months for the former group, whereas it was 62.79, SE 1.20, 95% CI (60.4565.13) months for the latter. Actuarial estimates of survival during ten-year follow up were 94.44% SE 3.83 in ten-year follow-ups and 97.67% SE 2.30 in 5-year follow-ups for the modified group (P > .05).
Avoidance from extended periods of general anesthesia and cardiopulmonary bypass periods as well as immediate recognition of impaired cerebral flow during CEA and the time it provides to take preventive measures are the most important benefits of the modified technique without significantly changing hospital and long-term mortality and stroke. It may also reduce the cost and the waiting period for the suffering patient.
Conference Paper: Foundations of Probabilistic Logic.01/1987
Conference Paper: Algorithm comparison for manufacturing scheduling problems[Show abstract] [Hide abstract]
ABSTRACT: The performance of heuristic algorithms for combinatorial optimization is often highly sensitive to problem instances. A specialized heuristic algorithm may perform exceptionally well on a particular set of instances while fail to produce acceptable solutions on others. This paper proposes a formal method for comparing and selecting heuristic algorithms in real-time given a desired confidence level and a particular set of problem instances. We formulate this algorithm selection problem as a stochastic optimization problem. Two approaches for optimization, ordinal optimization and computing budget allocation, are applied to solve this algorithm selection problem. Computational testing on a set of statistical clustering algorithms in the IMSL library is conducted, which demonstrates that our method can effectively compare and select algorithms that are expected to perform well on given problem instancesDecision and Control, 1997., Proceedings of the 36th IEEE Conference on; 01/1998