Periadrenal Volume is a Better Predictor of Prolonged Operative Time in Laparoscopic Retroperitoneal Adrenalectomy than BMI.

Background: Retroperitoneal laparoscopic adrenalectomy is gaining traction as a minimally invasive technique. One of the purported relative contraindications is BMI given the smaller working space. We hypothesize that other anthropometric measurements may be better predictors of operative time.

Methods: An IRB-approved, single-institution, retrospective study of 83 patients who underwent laparoscopic retroperitoneal adrenalectomy evaluated the association of anthropometric measurements taken from cross-sectional imaging and the primary outcome of operative time. Descriptive statistics were performed with Wilcoxon rank-sum test for continuous variables (median; IQR) and Chi-square (n; %) for categorical variables. A linear random effects model was used to model operative time.

Results: The majority of the patients were white (40; 48.2%) women (46; 55.4%) with a median age of 54 with interquartile range (IQR) of 43-63 and a median BMI of 27.8 (IQR 21.2-38.6). On univariable analysis, factors that led to longer operative time included right-sided operation (p = 0.04), male gender (p < 0.01), clinical diagnosis (p < 0.01), waist area (p < 0.01), waist/hip ratio (p < 0.01), periadrenal volume (p < 0.01), posterior adiposity index (PAI) (p < 0.01) and BMI (p < 0.01). Only side, order of operation, and periadrenal fat volume (p < 0.01, p = 0.02 and p < 0.01, respectively) remained independent predictors of increased operative time on multivariable analysis.

Conclusion: This study demonstrates that anthropometric measurements, specifically periadrenal fat volume, and side of operation, are better predictors for increased operative time in laparoscopic retroperitoneal adrenalectomies than BMI. This information can help facilitate appropriate patient selection for this operative approach.