Minimal Learning Curve for Minimally Invasive Aortic Valve Replacement

Minimally invasive aortic valve replacement (MiAVR) is an established technique for surgical aortic valve replacement (AVR). Although MiAVR was first described in 1993 and has shown good results compared with full sternotomy AVR (FSAVR) only a minority of patients undergo MiAVR. We recently started using MiAVR via an upper hemisternotomy. We aimed to examine the early results of our initial experience with this technique.

We compared 55 MiAVR patients with a historical cohort of 142 isolated FSAVR patients (December 2016-December 2022). The primary outcome was in-hospital mortality. Secondary outcomes included cardiopulmonary bypass (CPB) and cross-clamp times, blood product intake, in-hospital morbidity, and length of intensive care unit and hospital stay.

There was no significant difference in preoperative characteristics, including age, laboratory values, and comorbidities. There was no significant difference between the groups regarding in-hospital mortality (FSAVR 3.52 vs. MiAVR 1.82%). There was no significant difference in CPB time (FSAVR 103.5 [interquartile range: 82-119.5] vs. MiAVR 107 min [92.5-120]), aortic cross-clamp time (FSAVR 81 [66-92] vs. MiAVR 90 min [73-99]), and valve size (FSAVR 23 [21-25] vs. MiAVR 23 [21-25]). The incidence of intraoperative blood products transfusion was significantly lower in the MiAVR group (10.91%) compared with the FSAVR group (25.35%, p = 0.03).

Our findings further establish the possibility of reducing invasiveness of AVR without compromising patient safety and clinical outcomes. This is true even in the learning curve period and without requiring any significant change in the operative technique and dedicated equipment.