Intraoperative tumor capsule injury in patients with renal cell carcinoma receiving partial nephrectomy.

Objective: We investigated the impact of intraoperative tumor capsule injury (TCI) during robot-assisted partial nephrectomy (RAPN) or laparoscopic partial nephrectomy (LPN) on oncological outcomes, as well as underlying factors of intraoperative TCI for improving surgical outcomes.
Methods: A total of 253 patients who underwent RAPN or LPN between 2010 and 2022 were retrospectively analyzed and were divided into two groups: non-TCI and TCI groups. The background was compared between two groups. We investigated the surgical records or video to evaluate TCI and seek the possible causes for TCI. Multivariate logistic regression analysis was performed to identify prognostic factors for cancer recurrence.
Results: Of the 253 patients, 227 have renal cell carcinoma (RCC), with 29 patients having TCI. The TCI group had larger tumors, a lower rate of trifecta achievement, higher bleeding, higher T stage, and a lower rate of clear cell RCC (ccRCC) histological types as compared to non-TCI group. Disease recurrence rate was 13.8% with TCI and 1.0% with non-TCI (odds ratio 15.7; 95% confidence interval, 2.73-90.1; p = 0.003). Univariate and multivariate analyses confirmed TCI as an independent prognostic factor for disease-free survival. Compared with ccRCC, non-clear cell RCC (non-ccRCC) was found to have a higher probability of TCI and a significantly thinner capsule thickness on pathological evaluation.
Conclusion: TCI had a negative impact on oncological outcomes. Surgeons should consider thickness of tumor capsules, especially in cases with non-ccRCC, to minimize the risk of TCI during partial nephrectomy.
(© 2025 The Japanese Urological Association.)