Propensity score-matched analysis examining the role of obesity on outcomes in retroperitoneal laparoscopic adrenalectomy: a cohort study.

ABSTRACT

Background: There is inconsistent evidence regarding obesity's effect on surgical outcomes following retroperitoneal laparoscopic adrenalectomy (RLA). This study aimed to investigate the influence of obesity on surgical outcomes in patients undergoing RLA, with an emphasis on operative time, drainage tube removal time, postoperative hospital stays and perioperative complications. Methods: In this retrospective, single-center, observational study, all consecutive cases of unilateral RLA for adrenal disease from January 2012 to December 2021 were incorporated. The patients were divided into two groups based on their body mass index (BMI) of 28 kg/m2. To mitigate selection bias, propensity score matching (PSM) was conducted, using logistic regression to calculate propensity scores for balancing baseline characteristics. A multivariate logistic regression analysis was performed to assess how obesity affects operative time and intraoperative blood loss as well. The linear correlation between BMI and surgical outcomes, including prolonged operative time and increased intraoperative blood loss, was also examined using restricted cubic spline (RCS) analysis. Results: A total of 569 patients who underwent RLA were included. After PSM, 122 patients were apportioned to each group. Statistically significant differences were observed between the obese and non-obese group in operative time (97.5 vs. 115 min, P<0.001). There were no statistically significant differences between the two groups regarding hospital stay (6.7 vs. 6.8 days, P=0.58), drainage tube removal time (3.0 vs. 3.0 days, P=0.19), nor postoperative complications (9.0% vs. 12.3%, P=0.41). Furthermore, univariate logistic regression analysis revealed that, obese patients undergoing RLA were linked to prolonged operative time and increased intraoperative blood loss. After adjusting for potential confounders, the obese group showed a 67% increased risk of prolonged operative time and a 69% increased intraoperative blood loss. The RCS analysis revealed that BMI had a linear relationship with operative time (P for nonlinearity =0.47) and blood loss during surgery (P for linearity =0.89). Conclusions: In patients undergoing RLA, obesity exerts a significant influence on surgical outcomes, particularly with regard to operative time and intraoperative blood loss, as shown in multivariable logistic regression analysis and PSM to balance baseline characteristics.