後腹膜アプローチか経腹膜アプローチか：腫瘍の部位に基づいてロボット支援腎部分切除術を適応すべきか、それとも術者の好みか？

Robotic-Assisted Partial Nephrectomy (RAPN) can be performed via a transperitoneal (t-RAPN) or retroperitoneal (r-RAPN) approach. Despite the retroperitoneal route being potentially more suitable for posterior renal tumors, most surgeons prefer the transperitoneal access due to greater familiarity. This study evaluated perioperative and functional outcomes of r-RAPN versus t-RAPN for posterior renal masses performed by a surgeon without prior retroperitoneal experience. We retrospectively analyzed patients undergoing RAPN for posterior renal tumors between September 2023 and April 2025. Patient and tumor characteristics, operative time (OT), warm ischemia time (WIT), ΔeGFR, length of stay (LOS), complications, and Trifecta rate were compared. Trifecta was defined as WIT < 25 min, negative margins, and absence of Clavien-Dindo ⩾ III complications. Twenty patients were included: eight underwent t-RAPN and 12 r-RAPN. Baseline features were comparable. r-RAPN showed significantly shorter OT (125 ± 29 min vs 168 ± 37 min, p = 0.01), time on console (72 min vs 110 min, p = 0.01), and WIT (12 min vs 18 min, p = 0.048). Trifecta was achieved in all cases. Multivariate analysis identified surgical approach as the only independent predictor of console time (p = 0.024), with r-RAPN reducing it by 39 min. In conclusion, r-RAPN is feasible and safe even without prior retroperitoneal experience, offering comparable outcomes to t-RAPN with shorter operative times.