Fate of residual ureteral stump in patients undergoing robot-assisted radical nephroureterectomy for high-risk upper tract urothelial carcinoma

BACKGROUND: Management of the distal ureter in radical nephroureterectomy and bladder cuff excision (RNUBCE) is paramount, directly influencing oncologic outcomes. Herein, we analyze the natural history of patients who have undergone robotic radical nephroureterectomy without formal bladder cuff excision and retained ureteral stump and compare this cohort with patients undergoing formal RNUBCE for high-risk upper tract urothelial carcinoma (UTUC). METHODS: From February 2008 to October 2018, all patients who underwent robotic RNUBCE by multiple surgeons in a single institution for high-risk UTUC were reviewed. Preoperative, perioperative, and postoperative variables were investigated. Overall survival, cancer specific survival, local recurrence-free survival, distant recurrence-free survival, and bladder recurrence-free survival were compared between the two cohorts. Further management treatments were explored for patients with retained ureteral stump. Follow-up consisted of abdominopelvic/chest imaging and cystoscopy at regular intervals. RESULTS: A total of 105 patients underwent robotic RNU during the above time period. Of patients with documented 6-month follow-up, approximately 6.6% of patients had retained ureteral stump. Median follow-up for the entire cohort was 31.5 months with a range of 6 to 114.2 months. Factors that precluded formal BCE were densely, fibrotic reaction near the ureterovesical junction due to prior vascular or pelvic surgery in 5 patients, severe pyonephrosis and continued anesthetic risk in one patient, and surgeon choice (patient co-morbidities) in another patient. Three patients died with metastatic disease and one patient succumbed to cardiovascular compromise. Two additional patients developed local recurrence only at the level of the ureteral stump, with one patient undergoing eventual distal excision, contralateral RNUBCE and radical cystectomy. CONCLUSIONS: In these cases, responsibilities assumed by the surgeon demand the utmost in judgement and skill; however, at times, circumstances prevail such as patient factors and nature/biology of the disease. These factors may prevent adequate excision the complete ureter, ureterovesical junction, and bladder cuff at the time of RNU. In this robotic cohort of patients undergoing RNUBCE for UTUC, not excising the most distal part of the ureter directly translates to inferior oncologic outcomes. Complete ureteral excision with bladder cuff should be performed where possible as this is an integral part of the radical nephroureterectomy. Also, if feasible, adjunctive chemotherapy/immunotherapy treatments should be considered.