A Comparative Study of Aortic Valve Neocuspidization Techniques: Formula vs. Template Methods of Neocusp Formation

The template method (TM), pioneered by Ozaki for aortic valve neocuspidization (AVNeo), has been widely adopted for aortic valve replacement, though it requires specialized instruments. This study introduces a novel formula method (FM), which uses the diameter of the aortic valve fibrous ring (AV-D) to determine the dimensions of the neocusps to be trimmed from autologous without the need for templates, potentially reducing costs and complexity. We aimed to compare the clinical outcomes of the FM with the established TM in patients undergoing AVNeo.

A retrospective and prospective study was conducted on 31 patients who underwent isolated AVNeo between January 21, 2019 and December 15, 2022. Patients were divided into two groups: FM (n = 17) and TM (n = 14). The formula for the cusp free margin horizontal length is L1 = AV-D + 10 mm, cusp height is H = AV-D, cusp suture margin is L2 is a parabola that joins L1 and H, and cusp wings to be secured to aortic sinus = 3mm. The primary endpoints were major adverse valve-related events, including cardiac death, reoperation, and infective endocarditis. Secondary endpoints included significant aortic regurgitation, peak pressure gradients, aortic valve area, and New York Heart Association (NYHA) functional class. Intraoperative times, early postoperative outcomes, and mid-term hemodynamic performance were evaluated for both techniques.

Both the FM and TM demonstrated comparable intraoperative and postoperative outcomes. The cardiopulmonary bypass time, myocardial ischemia time, and blood loss were similar between the groups. Mid-term outcomes also showed no significant differences in valve function or hemodynamic parameters, with both groups exhibiting substantial reverse left ventricular remodeling. The FM group had a peak pressure gradient of 14.1 ± 4.3 mmHg compared to 18.4 ± 12.0 mmHg in the TM group (p = 0.219). The aortic valve area was 2.43 ± 0.3 cm² in the FM and 2.4 ± 0.2 cm² in the TM (p = 0.890). No significant differences were observed in freedom from reoperation or adverse events.

Both techniques showed excellent mid-term hemodynamic performance and comparable intraoperative and postoperative outcomes. The FM for AVNeo provides a cost-effective and practical alternative to the TM, offering similar clinical outcomes without the need for expensive templates; it has the potential to improve the accessibility of AVNeo, particularly in resource-limited settings. However, further research with larger cohorts and long-term follow-up is needed to fully assess the durability and long-term benefits of the FM.