[Reoperations for prosthetic heart valves: operation techniques and determinant factors of operative mortality]

Between 1982 and 1993, 93 patients underwent reoperation for prosthetic heart valves at our hospital. There were 41 male and 52 female patients who ranged in age 2 to 70 years with a mean age of 47 years. Twenty-four patients were in New York Heart Association (NYHA) functional class II, 52 in class III, and 17 in class IV, preoperatively. The indications of reoperative valve surgery were primary tissue failure of a bioprosthesis in 57 patients, valve thrombosis in 10, nonstructural valve dysfunction in 12, cloth wear of a ball valve in 5, endocarditis in 5, and others in 4. In reoperation, the heart was not mobilized from the pericardium to prevent tearing the heart and great vessels. All operative procedures were performed through the pericardium which adhered tightly to the heart. Adequate myocardial protection was obtained without total dissection of the heart with cold crystalloid cardioplegic solution and topical cooling which was accomplished by filling the left pleural space with cold saline. The operative mortality was 7 of the 93 patients (7.5%), falling from 4/36 (11.1%) in 1982 through 1987 to 3/57 (5.3%) in 1988 through 1993. Advanced New York Heart Association functional class, prolonged cardiopulmonary bypass and aortic cross clamping times were the determinant factors of operative mortality. These results suggest that reoperation for dysfunctioning prosthetic heart valves should be performed before deterioration of the hemodynamic condition of the patient.