Determinants of Pneumoperitoneum Duration During Laparoscopic Living-Donor Nephrectomy

Pure laparoscopic donor nephrectomy (LDN) and hand-assisted LDN (HALDN) are widely performed in living donor kidney transplantation. However, the relative contribution of donor-related factors to operative complexity remains incompletely understood, particularly in Japan, where surgical practices differ from those in Western countries.

A retrospective analysis was conducted on 152 donors who underwent LDN or HALDN between 2006 and 2024. Perioperative outcomes and pneumoperitoneal duration were evaluated. A random forest machine-learning model combined with SHapley Additive exPlanations analysis was used to identify the predictors associated with pneumoperitoneum duration.

The overall perioperative complication rate was low, and no mortality was observed. The pneumoperitoneum duration was significantly longer in the HALDN group than in the LDN group. SHapley Additive exPlanations analysis identified the surgical approach, body mass index, donor kidney volume adjusted for body surface area, visceral adipose tissue, and donor age as the strongest predictors of pneumoperitoneum duration. Obesity-related factors exerted a greater influence than anatomical complexity. Postoperative renal function in the donor and recipient graft survival was not significantly associated with the duration of pneumoperitoneum.

Both LDN and HALDN are safe procedures with minimal perioperative risks. Machine learning analysis demonstrated that, among donor-related factors, obesity-related parameters and kidney size were the principal determinants of operative complexity, exceeding the impact of anatomical factors. These findings may facilitate individualized surgical planning and contribute to the development of Japan-specific standards for donor nephrectomy.