Michael E. DeBakey

Successful Surgical Correction of Supravalvular Aortic Stenosis

Stenotic lesions in the aortic valve region may be acquired or congenital, and may be valvular, subvalvular, or supravalvular in location. As more of these patients are offered the benefits of surgical correction, cases of supravalvular aortic stenosis are being reported with increasing frequency. At least seven previous cases have been corrected successfully and another is reported.The diagnosis of supravalvular aortic stenosis usually cannot be made on clinical grounds alone. Definitive diagnostic technics are available, however, and allowed accurate delineation of the lesion in the case reported. Surgical correction consists of enlarging the aortic lumen in the area of supravalvular constriction. This usually is possible by longitudinal aortotomy through the area of constriction followed by patch angioplasty, as employed in this case in conjunction with modified endarterectomy. In most instances of supravalvular aortic stenosis, the valve itself is perfectly normal, and total correction is possible if the correct diagnosis is made.

The DeBakey/NASA Axial Flow Ventricular Assist Device

Summary. An implantable, nonpulsatile, axial flow venxad tricular assist device (V AD) is currently under development as a joint project between the Baylor College of Medicine and the NASA/Johnson Space Center. The project was initixad ated after a NASA engineer underwent a heart transplant in 1984. In 1989 a memorandum of understanding was signed, and 1993 was the first year of funding for this project. Since then, more than 50 configurations have been designed, fabrixad cated, and tested. To date, the pump has been optimized in terms of hydraulic efficiency, hemolysis, and thrombosis. The pump requires less than 10 W to deliver 5 Umin against 100mmHg. A normalized Index of Hemolysis of less than 0.003 mg/dl has been achieved and several configurations have been thrombus-free after 2 weeks ex vivo implantaxad tion. Following the success of the ex vivo experiments, a series of in vivo experiments has been initiated with the goal of 6 months, thrombus-free implantation.

Late Changes in Saphenous Vein Aorto-Coronary Bypass Grafts: Clinical, Angiographic, Lipid and Pathological Correlations

Coronary bypass surgery has become well established as the most effective form of treatment for relief of angina pectoris and has been shown, in a number of ramdomized studies, to prolong life in certain subsets of patients. Despite the extraordinary success of this operation and its durability in comparison to other forms of operations for atherosclerosis, there is need for enhancement of early and late graft patency and prevention of the late vein graft deterioration which has been observed in a significant portion of patients over a period of 10 to 15 years.