Abstract: PD73-06
Sources of Funding: None

Introduction

The duration of renal ischemia is the largest modifiable risk factor during partial nephrectomy. The shorter the warm ischemia time during LPN the lower the effect on long-term renal function. Real advantages of off-clamping LPN compared with clamping surgery are not yet sufficiently studied. Few studies reported results of off-clamping LPN for high RENAL score cases. We compared Trifecta outcomes of the LPN with and without clamping stratifying cases through nephrometric RENAL score.

Methods

A total of 109 cases classified as low-complexity (54), intermediate-complexity (33) and high-complexity (22) underwent clamping (55) or off-clamping (54) laparoscopic partial nephrectomy and were compared in each group (clamping x off-clamping LPN). Clamping technique was performed with cold scissors intended to obtain 0.5cm of free surgical margins. Off-clamp technique was performed with harmonic scalpel close to the plane of enucleating to achieve minimal surgical margins. Renal function was measured at 1, 6 and 12 months postoperatively. All enrolled patients had normal contra-lateral kidney. Trifecta (Trifecta criteria: Clavien ≤ 2, negative-margins, and warm ischemia time ≤ 20 min) outcomes were analyzed and compared between the groups stratified by the nephrometric RENAL score.

Results

Trifecta achievement was similar in both groups for low complexity tumors (p < 0.31). The off-clamping group achieved higher trifecta rates for the intermediate (87.5% x 23.5%, p < 0.001) and high (83% x 0%, p < 0.005) complexity tumors. Patients with off-clamp technique had higher mean blood loss (150 X 400 ml) with no difference in blood transfusions. In the clamping group, significant higher proportion did not achieve trifecta (45.5% x 7.4%, p < 0.001). After 1 year, the difference of remnant renal function was 10% more for patients with off clamp surgery with high complexity RENAL score

Conclusions

Off-clamping pure LPN was associated to accomplish higher trifecta rates for intermediate and high complexity RENAL score tumors. Long-term renal function was slightly better for off clamp group. It is unclear if off-clamp technique or differences in the amount resected of renal parenchyma were responsible for observed differences.

Funding

None