Thrombotic complications after valve replacement with porcine heterografts.

Abstract

AbstractThe incidence of thrombotic and thromboembolic (TE) complications after Hancock valve replacement was reviewed in 140 patients with mitral valve prostheses and 150 patients with aortic valve prostheses. In patients with aortic valves, 1 embolus occurred and another patient was found at autopsy to have thrombi on a degenerated valve. Both patients had been on aspirin treatment. There was no TE event in patients receiving no anticoagulant therapy.In patients with mitral valves, 16 showed pre‐ and/or postoperative low output syndrome (Group A); 8 of these patients died and 6 had autopsies that showed major thrombi in the heterograft. In 126 long‐term survivors, 9 thromboembolic events occurred (TE incidence 5.4% per patient year). All patients with emboli had atrial fibrillation. The majority (7/9) of emboli occurred during the first 3 postoperative months. Five occurred in patients who were not on anticoagulation (Group B), and 2 occurred in patients receiving warfarin therapy (Group C). There was no thromboembolic event in patients receiving aspirin treatment (Group D).It is concluded that patients with Hancock aortic valves have a very small risk of TE, and do not need anticoagulation. Patients with Hancock mitral valves with stable hemodynamics have a decreased risk of TE and do not require anticoagulation. Patients with atrial fibrillation have an increased risk of TE and should be on warfarin for 3 months after surgery and then on aspirin therapy.