ロボット支援腎温存手術（尿管部分切除術）による遠位尿管癌の治療：日本における5例の初期経験

Management of distal ureteral urothelial carcinoma remains challenging, with kidney-sparing surgery (KSS) emerging as a viable alternative to radical nephroureterectomy in selected cases. We report our initial experience with robot-assisted partial ureterectomy using the da Vinci Xi surgical system.

Between 2024 and 2025, five patients underwent robot-assisted KSS for distal ureteral tumors. All procedures were performed using the da Vinci Xi system with a transperitoneal approach in lithotomy position. The surgical technique involved extensive proximal ureteral mobilization to the level just distal to the common iliac artery crossing, excision with adequate margins including bladder cuff, and neo-ureterocystostomy to intact bladder mucosa using V-Loc suture. Frozen section analysis of the proximal margin was performed with conversion to nephroureterectomy planned if positive. Written informed consent was obtained from all patients.

Median operative time was 205 min (range: 174-253) with median console time of 170 min. Median estimated blood loss was 65 mL (range: 5-215 mL). Pathological examination revealed urothelial carcinoma in all cases: two patients had pT3 disease and three had pTa disease. Surgical margins were negative in four cases and indeterminate in one. One patient (20%) experienced a Clavien-Dindo Grade 2 complication. All patients maintained stable renal function. At a median follow-up of 6 months, no local recurrence or upper tract recurrence was observed. Robot-assisted KSS with extensive proximal ureteral resection appears feasible and safe for selected patients with distal ureteral tumors. Longer follow-up and larger series are needed to confirm oncological efficacy.