Post-Surgical Outcomes of Kidney-Sparing Surgery vs. Radical Nephroureterectomy for Upper-Tract Urothelial Cancer in a Propensity-Weighted Cohort

Objectives: In localized upper-tract urothelial carcinoma (UTUC), radical nephroureterectomy (RNU) represents the surgical gold standard, but kidney-sparing surgery (KSS) offers an alternative. The surgical perspective, including complications, remains understudied in this context. This study aimed to compare KSS and RNU, assess kidney function and survival, and identify the surgical risk factors. Methods: This retrospective analysis included UTUC patients undergoing KSS (n = 46) or RNU (n = 46) at a single center from 2016 to April 2024, matched by propensity scores. The primary endpoint was Clavien–Dindo complications. Other endpoints included Days Alive and Out of the Hospital within 30 days (DAOH30), changes in the eGFR, cancer-specific survival (CSS), and disease-free survival (DFS). A UTUC Surgery Risk Score was developed to identify the surgical risk factors for severe complications. Results: KSS was significantly associated with higher rates of Clavien–Dindo grades ≥ 3 (KSS: 14; RNU: 3). DAOH30 was significantly longer following RNU. The UTUC Surgery Risk Score, based on a non-endoscopic KSS approach, an ASA score ≥ 3, and preoperative creatinine > 0.9 mg/dL, was significantly associated with overall and severe complications and DAOH30 (both p < 0.001). KSS showed significantly better early postoperative eGFR preservation (+0.55 mL/min vs. −4.3 mL/min for RNU, p = 0.015). No significant differences were observed in the median CSS or DFS between the groups. Conclusions: KSS is associated with a higher rate of certain postoperative complications, but offers superior kidney function preservation, with comparable oncological outcomes to RNU. The novel UTUC Surgery Risk Score can aid in patient counseling and personalized decision-making prior to surgery.