Minimally-invasive parasternal aortic valve replacement-A slow learning curve towards improved outcomes

Background: We report our starting experience with parasternal minimally-invasive aortic valve replacement.

Methods: From 7/14 to 8/18, 192 received classic aortic valve surgery using a 5 cm parasternal incision and percutaneous groin cannulation. Patients were selected based on anatomic feasibility judged by preoperative computed tomography-scan. Except for porcelain aorta, left-sided aortic location, or endocarditic abscess, there were no exclusions.

Results: Patients were divided into two groups (first and second half of experience). Demographics were equal. Patients' mean ejection fraction was 59%, with preoperative stroke (12%), severe chronic obstructive pulmonary disorder (11%), and endocarditis (2%). All cases were elective or urgent. The Euroscore II was 3.37 ± 3.31 in the first and 3.68 ± 3.97 in the second group (n.s.). Biological prostheses were implanted in 90%. Operating times in the first group were just under 3 hours, with bypass times of 129 ± 32 minutes and clamp times of 77 ± 20 minutes. In the second group, these times changed only minimally. There were three conversions to sternotomy in the first, but only one in the second group. Similarly, three patients died in the first and one in the second group. There were fewer complications in the second group regarding revision for bleeding (7 vs 1%), stroke (4 vs 0%) dialysis (3 vs 1%), and pericardial effusions (3 vs 1%). The O/E ratio dropped from 0.93 to 0.28.

Conclusions: Parasternal minimally-invasive aortic valve replacement is a feasible technique associated with a slow learning curve but the potential to achieve improved outcomes. Considering the transcatheter alternatives, the relative risk reduction may be worth investigating in future trials.