Surgical management of prosthetic valve obstruction with the Sorin tilting disc prosthesis

Thrombotic occlusion is a potentially fatal complication of heart valve replacement surgery. The purpose of this report is to present our experience in the treatment of this group of patients, with emphasis on valve debridement as an effective surgical cure.

Of 299 operative survivors undergoing valve replacement with Sorin Carbocast tilting disc prostheses at our institution 270 could be followed up: 18 of them (6.7%) developed thrombosis within 26 months. All thrombotic blocks occurred in the mitral position. Anticoagulation was sub-therapeutic in 13 patients. Clinically, the patients presented with dyspnea, congestive cardiac failure, acute pulmonary edema or chest pain. Prosthetic valve closure sounds were absent or muffled in all patients and new murmurs developed in two. The average duration of symptoms was 3.0 days (range eight hours to 15 days). Diagnosis was made on physical examination alone, and echocardiographic confirmation was possible in 11 patients. Ten underwent emergency surgery, all by valve debridement with retention of the prosthesis.

Of the operated patients, eight survived with restoration of prosthetic valve function. Complications including hypoxic encephalopathy and acute renal failure occurred in two patients (20%). One death occurred 13 months later due to renal failure. At a follow up of 18 to 32 months (mean 21.3 months), seven patients are alive and well, and in NYHA functional class I or II. One patient developed a recurrent prosthetic valve thrombotic occlusion, and underwent successful surgical debridement for a second time. Thrombolysis was attempted in two cases with early success, but recurrent prosthetic valve thrombosis occurred.

The incidence of PVT was 6.7% in 270 patients with Sorin tilting disc valves implanted and followed up for 26 months. Though thrombolysis is initially successful, recurrent valve thrombosis is a risk. Emergency surgical treatment allowed 70% mid term survival after valve debridement alone. Adequate anticoagulation and regular medical follow up postoperatively need to be strongly emphasized.