Obstruction of mechanical valve prostheses: clinical diagnosis and surgical or nonsurgical treatment.

Twenty patients underwent nonsurgical and/or surgical treatment for obstruction of mechanical prosthetic valves. The obstructed prosthetic valve was in the aortic position in 11 patients, in the mitral position in 5, and in the tricuspid position in 4. Twelve patients had a bileaflet valve (3 aortic, 5 mitral, 4 tricuspid), and 8 had a tilting disk valve (all aortic). The diagnosis of prosthetic valve obstruction was made by cineradiography and echocardiography. Thrombolytic therapy was instituted in a series of our 10 most recent patients (11 cases), except for one patient with acute renal failure, regardless of the position of the obstructed prosthetic valve. Successful thrombolysis was achieved in 6 cases (54.5%). Six patients required surgical treatment subsequent to either failed or incomplete thrombolysis, and one patient died of congestive heart failure 1 month after surgery. Nonfatal neurologic events occurred in 2 cases (18.2%). A total of 16 patients underwent surgical treatment. Two (12.6%) of the 16 patients died of causes unrelated to the operative procedures before discharge from the hospital. These results suggest that thrombolytic therapy appears to be an attractive nonsurgical alternative for valve thrombosis when the patient's clinical condition is not critical, and thus surgical treatment should only be performed in an emergency on seriously ill patients.