Introduction

The aim of this study was to compare the outcomes of on-clamp and off-clamp robotic partial nephrectomy (RPN).

Methods

The charts of all patients who underwent a RPN at 8 french departments between 2010 and 2014 were retrospectively reviewed. The patients who underwent an off-clamp RPN were matched to on-clamp RPN in a 1 to 4 fashion according to the following variables: RENAL SCORE, tumor size and surgeon’s experience. Pre, intra and postoperative datas were compared between the off-clamp and on-clamp groups.

Results

Among 525 RPN, 26 were performed off-clamp (5%). They were matched to 104 on-clamp RPN. In the off-clamp groups there were two types of tumors: small exophytic renal masses of low complexity (n=20; mean size=20 mm ; mean RENAL SCORE=4.7) and complex hilar tumors (n=6; mean size=50 mm ; mean RENAL SCORE=9.2). The complications rate (15.5% vs 7.7%, p=0.53), major complications rate (4.9% vs. 3.9%; p=0.82) and transfusions rate (0% vs. 4.9% ; p=0.58) did not differ significantly between the clamped and unclamped groups. Conversely, estimated blood loss was higher in the off-clamp group (266.4 vs 284.6 mL, p=0.048) and so was the rate of conversion to radical nephrectomy (0% vs 7.7%, p=0.04). There were no statistically significant differences between the on-clamp and off-clamp group in terms of preserving renal function in the early postoperative period (-6.9% vs. -0.2%; p=0.22) or at 6 months postoperatively (-5.7% vs. 0%; p=0.10).

Conclusions

Off-clamp RPN is feasible for a small subgroup of renal tumors without increased risk of post-operative complications but at the cost of higher estimated blood loss and increased risk of conversion to radical nephrectomy. This study did not show any significant differences between on-clamp and off-clamp RPN in terms of preserving postoperative renal function.

Funding

none