AUA 2018: Tips and Tricks: Dissection of the Renal Mass with Hilar Fat Invasion

San Francisco, CA USA ( Monish Aron, MD, presented on the “enucleo-resection” of pT3a renal masses. Dr. Aron explained that pT3a renal masses are difficult to predict on pre-operative imaging and have the potential to lead to tumor violation and/or positive surgical margins with subsequent implications for prognosis.

The incidences of upstaging for cT1a, cT1b, and cT2 renal masses are 4.2%, 9.5%, and 19.5%, respectively, with upstaged pT3a renal masses having worse cancer-specific survival (Srivastava et al., 2018). Therefore, pre-operative planning is important and patients should receive high-quality multiphase computed tomography imaging with 2 mm slices, 3D reconstruction, and interpretation by an experienced radiologist. There has to be a high suspicion for possible pT3a masses, especially in those tumors with irregular margins, nodular or linear pattern of fat infiltration, and/or a tumor size greater than 75 mm (Kim et al., 2013).

Dr. Aron then proceeded to provide intraoperative tips and tricks with the goal of keeping the procedure simple in order to provide better outcomes, “the simpler the better.”

Dr. Aron uses two assistant ports so that his assistant can work using “two hands.” He tends to err on the side of more when mobilizing the kidney. When defatting the kidney, he suggests retaining strategic “handles of fat.” He doesn’t stay close to the tumor when enucleating as he “doesn’t want to work in a web.” Significant venous back bleeding can be managed by placing a bulldog clamp on the renal vein. During the enucleation, he prefers to incise circumferentially around the tumor before proceeding to the deep resection. He recommends adjusting the light intensity if needed to differentiate yellow renal cell carcinoma from sinus fat. He also suggests bagging the specimen immediately.

Dr. Aron then showed an illustrative case. He says he always prepares the hilum and always clamps. His dissection is done with a hook. Prior to enucleation, he uses intraoperative ultrasound to get a “lay of the land” and minimize the chance of a positive surgical margin. His scissors are always pointing away from the tumor to prevent tumor violation and he uses a combination of blunt and sharp dissection. He stresses the importance of maintaining good visualization and suggests that, in deep tumors, the venous branches can obscure vision. In such cases, clamping of the renal vein will significantly help. The fourth arm is used to provide counter-traction. He warns that there can be multiple tumor projections into the sinus fat and/or the renal vein and that it is important to recognize these projections and make the appropriate corrections. He also recommends resecting the calyceal and/or venous walls immediately adjacent to the tumor in order to provide a “buffer zone.”

Presented by: Monish Aron, MD

Written by: Michael Owyong, Department of Urology, University of California-Irvine at the 2018 AUA Annual Meeting - May 18 - 21, 2018 – San Francisco, CA USA