Influence of cardiopulmonary bypass set-up and management on clinical outcomes after minimally invasive aortic valve surgery

INTRODUCTION

Minimally invasive aortic valve replacement (MIAVR) requires changes in cannulation strategy and cardiopulmonary bypass (CPB) management when compared to the conventional approach (CAVR). We aimed at evaluating if these differences could influence perfusion-related quality parameters and impair postoperative outcomes.

METHODS

Overall, 339 consecutive patients underwent MIAVR or CAVR between 2014 and 2020 and were analyzed retrospectively. To account for baseline differences, a propensity-matching analysis was performed, obtaining two groups of 97 patients each.

RESULTS

MIAVR group had longer CPB time [107 (95-120) vs 95 (86-105) min, p = .003] than CAVR group. Of note, average pump flow rate index [2.4 (2.2-2.5) vs 2.7 (2.4-2.8) l/min/m², p = .004] was lower in the MIAVR group. Mean arterial pressure was 73 = 9 mmHg vs 62 = 11 mmHg for the MIAVR and CAVR group, respectively (p < .001). Cell-salvaged blood was most commonly used in the MIAVR group (25.8% vs 11.3%, p = .02). Finally, CPB temperature was 32.8°C (32.1-34.8) for MIAVR group vs 34.9°C (33.2-36.1) for the CAVR group (p = .02). Postoperative complications were similar between groups.

CONCLUSIONS

In conclusion, despite differences in CPB parameters in patients undergoing CAVR and MIAVR, the incidences of adverse outcomes were similar. However, compared to CAVR, MIAVR was associated with shorter durations of mechanical ventilation and hospital stay as well as less transfusion of blood products.

ACUTE KIDNEY INJURY AFTER OPEN-HEART SURGERY PROCEDURES

Cardiac surgery-associated acute kidney injury (CS-AKI) is a major complication associated with increased morbidity and mortality. There are multiple diagnostic criteria for CS-AKI. Despite many new investigations available for improved AKI diagnostics, creatinine and urea remain the cornerstone of diagnostics in everyday clinical practice. There are three major pathophysiological mechanisms that contribute to kidney injury, i.e. renal hypoperfusion, inflammation with oxidative stress, and use of nephrotoxic agents. Some risk factors have been identified that can be modified during the course of treatment (use of nephrotoxic agents, duration of cardiopulmonary bypass, type of extracorporeal circulation, postoperative low cardiac output or hypotension). The aim of AKI prevention should always be to prevent aggravation of renal failure and, if possible, to avoid progression to renal replacement therapy, which in turn brings worse long-term outcomes.