Pathologic findings after cardiac valve replacement with glutaraldehyde-fixed porcine valves

Abstract

Although approximately 20,000 glutaraldehyde-fixed porcine cardiac valve prostheses have been implanted in patients there is a lack of detailed pathologic studies of valves removed surgically or examined at necropsy. In this study, of 363 valves implanted in 311 patients, 26 valves (7 percent) from 23 patients (7 percent) were examined morphologically. Of the 23 patients, 14 died intraoperatively or less than 1 month after valve replacement—3 from coronary artery disease, 4 from hemorrhagic myocardial necrosis, 2 from postoperative hemorrhage, 2 from pulmonary disease and 1 from phycomycosis of the prosthesis; in 2 patients no anatomic cause of death was found. Six patients died 1 to 9 months after valve replacement—one from prosthetic thrombotic stenosis, one from prosthetic endocarditis and four from causes unrelated to their prosthesis. Three patients underwent surgical excision of a malfunctioning valve 12 to 31 months after implantation; incompetence was due to infective endocarditis in two patients and to a torn cusp in one. Fourteen of 15 valves implanted for 1 month or less were normal. Eight of 11 valves implanted for more than 1 month were abnormal: 3 were infected, 2 (from one patient) had focal calcification and thrombosis, 1 had only focal thrombosis, 1 had diffuse thrombosis causing stenosis and 1 had a torn cusp. In our experience, clinical cardiovascular deterioration in the early postoperative period in patients with glutaraldehyde-fixed porcine valves is unlikely to be related to dysfunction due to pathologic processes affecting the implanted valve. Although postoperative valve dysfunction has been unusual to date, clinical cardiovascular deterioration in the late postoperative period may be related to pathologic processes (infection, thrombosis or degeneration) affecting the implanted valve.