EARLY RESULTS OF MINIMALLY INVASIVE AORTIC VALVE REPLACEMENT VIA PARTIAL STERNOTOMY OR RIGHT THORACOTOMY: INSIGHTS IN ACUTE KIDNEY INJURY

Background and Aim: Minimally Invasive Aortic Valve Replacement (MI-AVR) offers outcomes comparable to conventional sternotomy, with increased adoption due to fewer complications. Comparisons between partial sternotomy (PS) and right thoracotomy (RT) in MI-AVR are limited. This study aims to compare the short-term clinical outcomes of these two approaches. Methods: We retrospectively reviewed patients who underwent isolated MI-AVR at Santa Maria Hospital, Bari, from 2017-2023. The primary outcome was 30-day mortality. Secondary outcomes included early postoperative results, acute kidney injury (AKI) as per KDIGO classification, and other complications. Multivariate logistic regression identified predictors of AKI, presented as odds ratios (OR) with 95% confidence intervals (CI). Results: Among 334 patients, 289 (86.5%) underwent PS, and 45 (13.5%) received RT. The overall 30-day mortality was 0.9%, with no difference between groups. AKI occurred in 40 cases (12.0%): 39 in the PS (13.5%) and 1 in the RT groups (2.2%) (p=0.026). Most AKIs (60%) were stage 1. The multivariate model showed a borderline non-significant association between PS and AKI (OR 6.77, p=0.064). The PS group had a higher median area under the creatinine concentration-time curve (AUC) (1.64 vs. 1.21 mg/dL, p=0.005) and C-Reactive Protein AUC, despite shorter cardiopulmonary bypass (73 vs. 86 min, p=0.029) and cross- clamp times (50 vs. 63 min, p=0.001). Other major complications did not differ between groups. Conclusion: MI-AVR is safe and has satisfactory short-term outcomes. A non-significant trend suggested an association between PS and AKI, potentially due to higher postoperative inflammation, warranting further investigation.