Redo Aortic Valve Replacement following Root Replacement with a Homograft: Open Surgery or TAVI?

Objectives: Aortic valved allografts (homografts) have in the past been used alternatively to mechanical or biological valve prostheses in expectation of better durability, resistance to infection, and to avoid long-term anticoagulation. Homograft valves do degenerate, however, and patients return for redo aortic procedures between 10 and 20 years later. These redo procedures have proven challenging, that is, due to heavy wall calcification. TAVI as a ViV procedure presents a treatment alternative in these patients. Aim of the study was to compare outcome between the two treatment strategies.

Methods: Between 1993 and 2018, 81 patients underwent redo aortic valve procedures having previously received an aortic homograft. The redo had become necessary due to degeneration in 72 (94%) and infection in 5 (6%) patients. Sixty (74%, mean age 57 ± 14 years; 82% male) procedures were performed conventionally (SAVR) and 21 (26%; mean age 66 ± 10 years; 71% male) as TAVI. The transfemoral approach was chosen in 15 (71%), transapical in 6 (29%).

Results: Conventional isolated valve replacement was possible in 48 (80%), complete redo root replacement was necessary in six (13%) cases. Six (10%) required root patch plasty. Concomitant procedures including CABG, mitral, and tricuspid repair was performed in 21 (35%). Mean cardiopulmonary bypass and cross-clamp times were 166 ± 76 min and 106 ± 52 min, respectively. Prosthetic valve size was 23 ± 2 mm in the SAVR and 26 ± 2 in the TAVI group.

TAVI showed a significantly better postoperative outcome concerning prolonged ventilation (0 vs. 29, p = 0.004), low–cardiac output (0 vs. 19%, p = 0.031), SIRS (0 vs. 24%, p = 0.016), and renal failure (0 vs. 24%) compared to SAVR. ICU (p = 0.000) and in hospital stay (p = 0.038) were 3 days shorter in the TAVI group. However, operative mortality and 5-year survival were comparable. SAVR showed no valvular or paravalvular leakage, while TAVI resulted in paravalvular leakage I° in 5 (24%) and II° in 1 (5%).

Conclusion: We present the largest study to date. SAVR following previous aortic valved homograft implantation shows excellent results but the perioperative risk remains substantial and poorly predictable. TAVI present a reasonable and more easily accessible alternative and is associated with good short-term results. In the absence of relevant contraindications TAVI is presently the preferred treatment option in our center for these patients.