Colin W. Mccord

Aortic Replacement Clinical Experience with a Semirigid Ball-Valve Prosthesis

A ball-valve prosthesis for aortic replacement has been described which, while it is similar to the mitral ball valve in terms of materials and construction, is quite different in sewing margin and internal geometry. Implantation is greatly facilitated by the flexibility of the prosthesis in terms of external diameter, and by the availability of a full set of varying sizes for obtaining a proper fit. Widening of the aortic root by patch grafting has not been necessary. Long-term survival has been achieved in the dog, and early clinical results are most promising.While the selection of the ideal aortic valvular replacement must await further experience with all types of prostheses, continued evaluation of the ball valve in the aortic position, in carefully chosen patients, is indicated.

Serial Cardiac Output and Blood Volume Studies Following Cardiac Valve Replacement

The cardiac output and blood volume were measured preoperatively and sequentially during the early postoperative period in 45 patients undergoing cardiac valve replacement. Most patients showed a prompt, highly significant increase in cardiac output. Those with uncorrected valvular disease, even though apparently trivial, had lower cardiac outputs. The blood volume was sharply reduced from the preoperative level in almost every patient. When this was associated with low cardiac output, replacement of the blood volume deficit was usually accompanied by a prompt increase in cardiac output. Failure to respond in this way occurred only in patients with residual valvular lesions or myocardial disease.

Cardiac Catheterization Studies after Combined Tricuspid, Mitral, and Aortic Valve Replacement

Postoperative cardiac catheterizations were performed in eight patients within the first year following replacement of the tricuspid, mitral, and aortic valves with Starr-Edwards ball-valve prostheses. Two additional patients were studied who had mitral and tricuspid replacement. Before surgery the patients characteristically had distinct elevation of right and left atrial pressures, and markedly reduced cardiac outputs. Four individuals had marked pulmonary hypertension. At the postoperative catheterizations, consistent changes were an increase in cardiac output, a decrease in right and left atrial pressures, and a decrease in right ventricular systolic pressure. The last change was particularly notable in those individuals who had marked pulmonary hypertension before surgery.

Rupture of the Infarcted Interventricular Septum Surgical Repair with Survival

Successful surgical closure of a ruptured interventricular septum following myocardial infarction is reported. The patient developed the loud pansystolic parasternal murmur characteristic of septal perforation, and cardiac catheterization confirmed an unusually large left-to-right shunt. The patients course was not the typical rapid deterioration with shock or intractable heart failure, but when myocardial insufficiency developed insidiously 5 weeks postinfarction, surgical closure with a Teflon patch was accomplished during cardiac bypass. Since early death ensues so frequently, surgical repair has been attempted in only a small number of instances; this patient is one of the very few with successful closure and long-term survival. The pathology, clinical course, and cardiac catheterization data of this entity are reviewed from previously reported cases.

Clinical and Hemodynamic Observations After Combined Aortic and Mitral Replacement

Twelve patients have been observed from 6 to 19 months after combined aortic and mitral valvular replacement with Starr-Edwards prostheses. Eleven patients have had postoperative right- and left-heart catheterizations. The clinical and hemodynamic findings are described. Nine patients are well. Three others have less than satisfactory results, although one of these is improved. It is concluded that bivalvular replacement is now practical in selected patients and provides gratifying results in most individuals so treated.

Prevention of Excess Hemolysis During Cardiopulmonary Bypass by the Use of Mannitol

Mannitol infusion has significantly decreased plasma hemoglobin build-up rate in mitral and aortic valvular replacement. This occurred before hemoglobin appeared in the urine, and was unrelated to the binding of hemoglobin by haptoglobin. The mechanism by which mannitol decreases the build-up rate of plasma hemoglobin is unknown, but seems to be other than by renal excretion of hemoglobin.

Mitral commissurotomy with pump standby

Abstract Mitral commissurotomy has been performed on twenty-six patients, eight of whom have required mitral valve replacement as a result of incomplete opening or dilator injury. There was one death. It is believed that the essential pathologic condition in dilator injuries or incomplete commissurotomy is due to the subvalvular fusion of the chordae tendineae. With open commissurotomy the fusion can be relieved under direct vision without injury to the mitral leaflets. The greatest hazard from open commissurotomy is air embolus. This can be obviated by using the technic outlined. The long-term results from open commissurotomy remain to be determined.

Transposition of the great vessels: Recent experience with the Blalock-Hanlon procedure☆☆☆

Abstract An experience with twenty-one patients undergoing emergency palliative surgery for transposition of the great vessels with pulmonary overcirculation is presented. Banding of the pulmonary artery was performed as the only operative procedure in three patients and as the initial operative procedure in six patients. All but one failed to survive operation. The creation of an atrial septal defect by the Blalock-Hanlon operation was performed as the only operative procedure in fourteen patients with four deaths and a satisfactory late clinical result in all survivors. Thus, while the over-all results of palliative surgery for transposition are far from satisfactory, those patients suffering predominantly from severe cyanosis may expect a good result from a Blalock-Hanlon operation in terms of exercise tolerance, growth and development and the ease of subsequent medical management. Those patients suffering predominantly from associated cardiac defects with massive pulmonary overcirculation and only minimal cyanosis are poor candidates for palliative surgery and must be considered for total correction if survival is to be obtained.