Reoperation on stentless aortic xenografts.

BACKGROUND: Stentless xenografts have been proposed as substitutes for the diseased aortic valve. Cases of valve failure requiring reoperation have thus far been sporadic. To establish the prevalence and outcome of reoperation on stentless aortic xenograft valves, all patients operated on between October 1992 and October 1996 were reviewed.

METHODS: One hundred ninety-nine patients, 94 men and 105 women aged 70+/-7 years, had stentless aortic valve replacement for aortic stenosis (in 139), insufficiency (19), or both (38). Three prostheses were used, including the Biocor PSB (Belo Horizonte, Brazil) (106), Toronto SPV (St. Jude Medical, Inc., St. Paul, MN) (52), and O'Brien-Angell (Cryolife, Atlanta, GA) (41). While the Biocor PSB and Toronto SPV prostheses are designed to be implanted freehand with inflow and outflow suture lines, the O'Brien-Angell valve requires a single suture line.

RESULTS: There were 7 (3.5%) total and 6 (3%) valve-related reoperative procedures during a follow-up extending up to 4 years (mean 26+/-20 months). All but one valve-related reoperation, due to endocarditis 36 months after implant, were early (less than 12 months after initial operation). Prevalence of valve-related reinterventions was 1%, 0%, and 12%, and freedom from reoperation at 3 years was 98%+/-2%, 100%, and 81%+/-8%, in patients receiving the Biocor PSB, Toronto SPV, and O'Brien-Angell valves, respectively (p = 0.0039). Cause of reoperation was technical in 3 (O'Brien-Angell), pannus in-growth in 1 (O'Brien-Angell), valve tear in 1 (O'Brien-Angell), and endocarditis in 1 (Biocor PSB). All patients survived replacement of the xenograft with a stented bioprosthesis (5) or homograft root (1) and were discharged after a mean hospital stay of 6+/-3 days (range, 4 to 12 days). At follow-up 15+/-8 months after reintervention (range, 6 to 34 months), all patients are symptom-free with no evidence of recurrent valve obstruction, regurgitation, or infection.

CONCLUSIONS: Reoperation for stentless xenograft failure is a rare overall event. Implant of the O'Brien-Angell valve may be associated with a higher prevalence of early reintervention because of nonstructural failure. When needed, reoperation on a stentless xenograft is generally a simple procedure and carries a low surgical risk.