Laparoscopic Low Anterior Resection with Ureterectomy and Ileal Ureter Interposition for Ureter-Invading Locally Recurrent Rectal Cancer: A Case Report.

introductionLocally recurrent rectal cancer (LRRC) with ureteral invasion is surgically demanding because curative-intent resection often requires en bloc ureterectomy, and urinary diversion may be considered. Although ileal interposition for ureteral reconstruction can preserve renal function when direct ureterocystostomy or uretero-ureterostomy is not possible, reports of this procedure for LRRC remain scarce. CASE PRESENTATION: An 81-year-old man underwent laparoscopic high anterior resection for rectosigmoid adenocarcinoma (pT3N1bM0, pStage IIIB) in March 2020, and adjuvant chemotherapy was not administered because of the patient's preference. Twenty months later, a metachronous liver metastasis was detected and resected by laparoscopic partial hepatectomy. Surveillance imaging in 2023 revealed an approximately 20-mm tumor consistent with recurrence located anterior to the left iliac bifurcation, involving the left ureter at the common iliac crossing and causing hydronephrosis, for which percutaneous nephrostomy was performed for decompression. The tumor was RAS-mutant, BRAF wild-type, and microsatellite stable. FOLFOX plus bevacizumab was selected as a standard systemic treatment option for recurrent colorectal cancer with RAS mutation, but the treatment was discontinued due to toxicity, mainly fatigue. Because the disease remained confined to the pelvis without distant metastasis on PET/CT and first-line chemotherapy became difficult to continue, curative-intent resection was planned. Curative-intent laparoscopic low anterior resection with en bloc ureterectomy was performed. Because tension-free ureterocystostomy or uretero-ureterostomy was considered difficult due to limited tissue mobility, a short-segment isoperistaltic ileal ureter interposition was constructed. Postoperative paralytic ileus resolved conservatively (Clavien-Dindo grade II). The urinary catheter, ureteral stent, and nephrostomy tube were removed on PODs 8, 32, and 49, respectively, without deterioration of renal function. No adjuvant therapy was administered. The patient remained free of clinical and radiological recurrence 12 months after surgery.

conclusionsLaparoscopic salvage resection with en bloc ureterectomy and ileal ureter interposition may be a feasible renal-preserving option for selected patients with ureter-invading LRRC.