The impact of a minimally invasive approach on reoperative aortic valve replacement

The advantages of minimally invasive aortic valve replacement (AVR) are well documented, but whether the benefits extend to subsequent reoperative aortic valve surgery and beyond is unknown. The study aim was to compare in-hospital outcomes and long-term survival following reoperative AVR between patients who had previous undergone either minimally invasive AVR (mini-AVR) or full sternotomy AVR (sAVR).

All reoperative, isolated AVRs performed between July 1997 and September 2013 at the authors' institution, with or without non-complex aortic surgery, were identified. Patients were excluded if AVR was not isolated, had occurred prior to July 1997, or if the initial AVR was performed before the patient was aged 18 years. All reoperations were performed through a full sternotomy. The main outcomes of interest were operative results and long-term survival.

A total of 101 patients was identified, of which 34 had undergone previous mini-AVR and 67 previous sAVR. The time from the previous AVR was similar in both groups (median 7.6 years overall). Of previous valve implants, 57 were bioprostheses and 44 mechanical; structural valve degeneration was the most common indication for surgery (43/101). Mini-AVR and sAVR patients did not differ significantly with regards to patient demographics and preoperative risk factors. A strong trend towards shorter skin-to-skin operative times was observed for mini-AVR (330 min versus 356 min; p = 0.053). Postoperatively, mini-AVR patients had a shorter ventilation time (5.7 h versus 8.4 h; p = 0.005), intensive care unit stay (37 h versus 63 h; p ≤ 0.001) and hospital length of stay (6.5 days versus 8.0 days; p = 0.038). There was one operative mortality in the sAVR, and none in the mini-AVR group. Mid-term survival at one and five years for mini-AVR was 100% (95% CI 100-100) and 100% (95% CI 100-100), and for sAVR was 93.9% (95% CI 88.2-99.7) and 85.0% (95% CI 75.1-94.9), respectively (p = 0.041).

Mini-AVR confers benefits during subsequent reoperative AVR, with shorter hospital stays and improved long-term survival. These findings suggest that mini-AVR should be considered for patients at risk for aortic valve reoperation, and describes a previously unreported advantage of this well-established technique.