Off-clamp robot-assisted partial nephrectomy for complex renal tumors, "Beyond the Abstract," by Eric H. Kim, MD, et al

BERKELEY, CA ( - Following an assessment of our initial experience performing off-clamp robot-assisted partial nephrectomy,[1] (RAPN) as well as a matched cohort study comparing off-clamp RAPN to traditional clamped RAPN,[2] we hypothesized that off-clamp RAPN could provide relatively greater renal functional preservation.

Subsequently, we began to design a prospective randomized controlled trial comparing renal functional outcomes as well as oncologic and perioperative outcomes between off-clamp RAPN and traditional clamped RAPN.

In order to define inclusion and exclusion criteria, we examined our single-institution trends for utilizing the off-clamp technique for RAPN and compared our off-clamp RAPN results for complex versus non-complex cases.[3] We found the number of RAPN cases we performed off-clamp as well as the number of tumors with complex features —defined as hilar location, endophytic growth, and/or ipsilateral multifocality—we treated with off-clamp RAPN increased dramatically over the last two years. Perioperative, renal functional, and oncologic outcomes were similar between our complex and noncomplex off-clamp RAPN groups, except with greater mean estimated blood loss in our complex group. Despite increased blood loss in our complex group, only one patient—who underwent resection of eight ipsilateral masses, of which two were hilar in location, and another was completely endophytic—required a blood transfusion postoperatively.

With evidence to suggest that off-clamp RAPN of complex tumors can be performed safely and without significant differences in complication rates or oncologic outcomes, as compared to patients with noncomplex tumors, tumor complexity will not be used as an exclusion criterion for our upcoming randomized controlled trial. All patients who are candidates for RAPN who consent to enrollment in our study will be randomized to either off-clamp or traditional clamped RAPN treatment arms.


  1. Tanagho YS, Bhayani SB, Kim EH, et al. Off-clamp robot-assisted partial nephrectomy: initial Washington University experience. J Endourol 2012 Oct; 26(10): 1284-9.
  2. Tanagho YS, Bhayani SB, Sandhu GS, et al. Renal functional and perioperative outcomes off off-clamp versus clamped robot-assisted partial nephrectomy: a matched cohort study. Urology 2012 Oct; 80(4): 838-43.
  3. Kim EH, Tanagho YS, Sandhu GS, et al. Off-clamp robot-assisted partial nephrectomy for complex renal tumors. J Endourol 2012 Sep; 26(9): 1177-82.


Written by:
Eric H. Kim, Youssef S. Tanagho, Gurdarshan S. Sandhu, Sam B. Bhayani, and R. Sherburne Figenshau as part of Beyond the Abstract on This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.

Division of Urology
Washington University School of Medicine
St. Louis, Missouri USA

Off-clamp robot-assisted partial nephrectomy for complex renal tumors - Abstract

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