Compare the rates of major intra- and postoperative complications, surgical conversion and mortality between transperitoneal versus retroperitoneal laparoscopic adrenalectomy.

In a series of 344 consecutive unilateral laparoscopic adrenalectomies, performed from January 1997 to December 2017, we evaluated the rates of major intra- and postoperative complications (Clavien-Dindo≥III) and surgical conversion of the two approaches.

The retroperitoneal laparoscopic route was used in 259 patients (67.3%) and the transperitoneal laparoscopic route in 85 patients (22.1%). A total of 12 (3.5%) major postoperative complications occurred, with no statistically significant difference between the two approaches (P=0.7). In univariate analysis, the only predictor of major postoperative complication was Cushing's syndrome (P=0.03). The surgical conversion rate was higher in the transperitoneal route group (10/85 (11.8%) compared to 6/259 (2.3%), P=0.0003) in the retroperitoneal route group. One death occurred in each group. Independent predictors of surgical conversion in multivariate analysis included the transperitoneal laparoscopic approach (OR 1.7, 95% CI 1.3–1.9, P=0.02), advanced age (OR 1.2, 95% CI 1.1–1.6, P=0.04) and large tumor size (OR 1.3, 95% CI 1.1–1.7, P=0.01).

Both transperitoneal and retroperitoneal approaches for laparoscopic adrenalectomy are safe, with an equivalent rate of major complications and mortality. The surgical conversion rate was higher for the transperitoneal route. The retroperitoneal approach should be reserved for small adrenal lesions.