Evaluation of oncological outcomes of robotic partial nephrectomy according to the type of hilar control approach (On-clamp vs Off-clamp), a multicentric study of the French network of research on kidney cancer-UROCCR 58-NCT03293563

Abstract

Purpose: To compare off-clamp vs on-clamp robotic partial nephrectomy (RPN) for renal cell carcinoma (RCC) in terms of oncological outcomes, and to assess the impact of surgical experience (SE).

Methods: We extracted data of a contemporary cohort of 1359 patients from the prospectively maintained database of the French national network of research on kidney cancer (UROCCR). The primary objective was to assess the positive surgical margin (PSM) rate. We also evaluated the oncological outcomes regardless of the surgical experience (SE) by dividing patients into three groups of SE as a secondary endpoints. SE was defined by the caseload of RPN per surgeon per year. For the continuous variables, we used Mann-Whitney and Student tests. We assessed survival analysis according to hilar control approach by Kaplan-Meier curves with log rank tests. A logistic regression multivariate analysis was used to evaluate the independent factors of PSM.

Results: Outcomes of 224 off-clamp RPN for RCC were compared to 1135 on-clamp RPN. PSM rate was not statistically different, with 5.6% in the off-clamp group, and 11% in the on-clamp group (p = 0.1). When assessing survival analysis for overall survival (OS), local recurrence-free survival (LR), and metastasis-free survival (MFS) according to hilar clamping approach, there were no statistically significant differences between the two groups with p value log rank = 0.2, 0.8, 0.1, respectively. In multivariate analysis assessing SE, hilar control approach, hospital volume (HV), RENAL score, gender, Age, ECOG, EBL, BMI, and indication of NSS, age at surgery was associated with PSM (odds ratio [OR] 1.03 (95% CI 1.00-1.04), 0.02), whereas SE, HV, and type of hilar control approach were not predictive factors of PSM.

Conclusion: Hilar control approach seems to have no impact on PSM of RPN for RCC. Our findings were consistent with randomized trials.

Keywords: Hilar control approach; Kidney cancer; Oncological outcomes; Positive surgical margins; Robotic partial nephrectomy.