Full Versus Mini-Sternotomy for Isolated Aortic Valve Replacement: Single Center Retrospective Cohort

Abstract

Background: Mini-sternotomy (MS) is a minimally invasive surgical technique used as an alternative to the conventional full sternotomy (FS) for surgical aortic valve replacement (SAVR). Existing literature on clinical outcomes, morbidity and mortality after MS remains scarce and inconsistent. This study aims to compare intraoperative and early and mid-term postoperative clinical outcomes, in patients who underwent elective isolated AVR through MS vs. FS. Materials and Methods: In this retrospective, single-center study, patients who underwent elective isolated AVR through MS from 2011 to 2019 were included. An optimal 1:1 Mahalanobis Distance matching was implemented to compare FS with MS. Absolute standardized mean difference was used to compare preoperative variables between groups. Hospital mortality was defined as in-hospital or within the first 30 days after surgery. Survival and need for reoperation were accessed in December 2023. Immediate postoperative outcomes were assessed using conditional logistic regressions and time-to-event outcomes were assessed through Kaplan-Meier curves and stratified Cox proportional hazard models. Results: A total of 136 patients were analyzed (68 in each group), with a mean age of 73 ± 7 years, 62% being male. MS showed high risk of prolonged aortic cross-clamp time (OR: 3.57, 95% CI: 1.49-8.55, p=0.004) and cardiopulmonary bypass time (OR: 3.16, 95% CI: 1.47-6.81, p=0.003). There were no differences between groups regarding early postoperative outcomes, as well as long-term mortality (HR: 1.13, 95% CI: 0.37-3.45, p=0.829) and freedom from prosthesis-related reoperation (HR: 0.20, 95% CI: 0.02-1.74, p=0.145). Conclusion: There were no survival differences between MS and FS, despite prolonged intraoperative times. Limited sternotomy may be a comparable, alternative approach for SAVR, although this study and available evidence are still lacking in power to demonstrate significant differences in most clinical outcomes.