Analysis of Selective Clamping in Robotic Partial Nephrectomy for Patients with Solitary Kidney Finds Similar Outcomes with No Additional Risk of Harm

HUMC Recognized for Novel Approach of Examining Selective Clamping in Solitary Kidney at WCE 2019

An analysis of selective arterial clamping (SAC) during Robotic Partial Nephrectomy (RPN) recently presented at the World Congress of Endourology found that in a large cohort of solitary kidney patients undergoing RPN, selective clamping results in similar intraoperative and postoperative outcomes compared to full clamping and confers no additional risk of harm but no functional advantage.

This novel analysis of examining patients with solitary kidney who underwent RPN allows for better assessment of the effects of SAC on renal function due to lack of contralateral renal compensation.

The Department of Urology at Hackensack University Medical Center, in partnership with the Department of Urology at Hackensack Meridian School of Medicine and the Department of Urology at Mount Sinai Medical Center, presented results on November 1.

Temporary clamping of renal arterial flow is a standard component of robotic partial nephrectomy (RPN) as it improves operative visibility and reduces blood loss. However, increased renal hilar clamping duration may increase risk of adverse effects on short- and long-term renal function. Concern over this risk has led to new techniques to reduce length of warm ischemia time (WIT) during partial nephrectomy. Among these is selective arterial clamping (SAC), the isolation and clamping of renal arterial branches directly supplying the tumor; its use and efficacy of SAC during RPN remain controversial and in need of further study.

To more accurately assess the risks and benefits of selective clamping vs. full clamping in RPN, an analysis was conducted among patients with solitary kidney who had undergone RPN.

Patients with solitary kidneys allow for better appreciation of the effect of SAC on renal function due to lack of contralateral renal compensation. Such assessment can also elucidate if SAC in patients with solitary kidneys results in improved outcomes for such a population.

Data from IRB approved retrospective and prospective databases from 2006 to 2019 at multiple institutions with sharing agreements were evaluated. Patients with a solitary kidney were identified and stratified based on whether selective or full renal artery clamping was performed.

A total of 72 patients of 4,112 cases were identified, with 51 fully clamped, and 21 selectively clamped. The full clamping group was compared to selective clamping group to assess demographics, intraoperative, and postoperative outcomes. Analysis for statistical significance performed using Chi-square test, Fisher’s exact test, t-test, and Mann Whitney U’s test.

No significant differences were seen in demographics, tumor size, baseline estimated glomerular filtration rate (eGFR), warm ischemia time (WIT), estimated blood loss (EBL), operative time, intraoperative complications, short/long term change in eGFR, acute kidney injury (AKI), and de novo chronic kidney disease (CKD).

The analysis revealed that selective clamping results in similar intraoperative and postoperative outcomes compared to full clamping and confers no additional risk of harm but no functional advantage.

Short WIT in both groups (<15 minutes) may have prevented identification of benefits in selective clamping, demonstrating need for analysis of cases with longer WIT.