Silzone-coated St. Jude Medical valves: six-year experience in 46 patients

The Silzone-coated St. Jude Medical valve was developed to reduce prosthetic valve endocarditis, but in the Artificial Valve Endocarditis Trial (AVERT) was recalled following reports of major paravalvular leaks. A separate study suggested an increased risk of thromboembolic complications associated with the Silzone valve. Herein is reviewed the present authors' experience in patients with Silzone valves.

Between April 1998 and November 1999, 46 patients (28 males, 18 females; mean age 62.6 years; range: 41-78 years) received a total of 49 Silzone valves. Seven of the patients were in NYHA class IV, and 29 in class III; four patients had active endocarditis. Twenty-one patients underwent aortic valve replacement, 22 mitral valve replacement, and three had both mitral and aortic valve replacement. Concomitant procedures were performed in nine patients.

The 30-day mortality was 6.5 % (n = 3). At post-mortem examination, the valves were found to be seated well, with no evidence of malfunction, thrombotic occlusion or infection. Follow up examinations were conducted initially at six months after surgery, and annually thereafter. All patients underwent transthoracic echocardiography. Follow up was 100% complete; the mean follow up period was 73.5 months (range: 62-81 months). Six late deaths have occurred; five deaths were due to non-cardiac causes, and one cardiac death was unrelated to the valve prosthesis. No cases of paravalvular leak have been identified. Two patients had postoperative thromboembolic complications, but echocardiography did not demonstrate the presence of thrombus or paravalvular leakage.

In this single-center, non-randomized study of 46 patients, the findings of increased paravalvular leak with the Silzone valve, as identified in AVERT study, could not be confirmed. Moreover, the incidence of thromboembolic complications reported was modest.