Selective renal parenchymal clamping in nephron-sparing surgery: an alternative to minimize renal ischemia

Abstract

ntroduction and objectives Nephron-sparing surgery (NSS) is thestandard of care for technically amenable small renal masses. Variousmethods have been described to achieve vascular control whileminimizing ischemia to the normal renal parenchyma. Apart fromsegmental artery clamping which requires high surgical and anestheticexpertise, selective renal parenchymal clamping (SRPC) by anadjustable kidney clamp with a snare and ratchet has been introducedto our institution since March 2012. This study aims to evaluate theperioperative outcome and oncological control after NSS for renaltumors using the SRPC technique vs conventional hilar clamping (HC).Materials and methods A retrospective, single-institution review ofall patients undergoing partial nephrectomy with conventional HC orSRPC technique from January 2009 to March 2016 was performed.The tumor characteristics, operative outcomes, oncological control andpostoperative renal function were compared between the two groups.Statistical analysis were performed using Mann-Whitney U test, Chisquared test and Fisher’s exact test.Results In 115 patients undergoing NSS in the period, 85 and 30were performed with HC and SRPC techniques respectively. The meanfollow-up durations were 34 months and 22 months for the HC and RPC groups respectively. Patient demographics were comparable inboth groups in terms of age and sex. Tumors in the SRPC group wereall exophytic and the majority of them were at polar regions (90%).PADUA score was significantly lower in the SRPC group compared tothe HC group (7.19  1.00 vs 8.42  1.33, P < 0.0001). The majority(68.2%) of HC group was performed with open approach, while 72%of NSS in SRPC group were performed with laparoscopic or robotic-assisted laparoscopic approach.Regarding the peri-operative outcomes, SRPC technique was associatedwith a significantly shorter operating time (211 0.3  64.9 vs294.9  81.2 min, P < 0.0001) and lower estimated blood loss(207.6  186.7 vs 336.0  265.1 mL, P = 0.016). There were nocases of acute kidney injury and both groups had no significant changein mean post-operative serum creatinine level on post-operative day 7,30 and 90.Conclusion Compared with conventional hilar clamping, selectiverenal parenchymal clamping technique for selected cases is safe andfeasible during NSS, with the advantages of shorter operative time andless blood loss, while maintaining a good post-operative renal function.