Selective clamping during robot-assisted partial nephrectomy in patients with a solitary kidney: is it safe and does it help?

Objectives: To obtain the most accurate assessment of the risks and benefits of selective clamping in robot-assisted partial nephrectomy (RAPN) we evaluated outcomes of this technique vs those of full clamping in patients with a solitary kidney undergoing RAPN.

Patients And Methods: Data from institutional review board-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. Both groups were analysed with regard to demographics, risk factors, intra-operative complications, and postoperative outcomes using chi-squared tests, Fisher's exact tests, t-tests and Mann-Whitney U-tests.

Results: Our initial cohort consisted of 4112 patients, of whom 72 had undergone RAPN in a solitary kidney (51 with full clamping and 21 with selective clamping). There were no significant differences in demographics, tumour size, baseline estimated glomerular filtration rate (eGFR), or warm ischaemia time (WIT) between the groups (Table 1). Intra-operative outcomes, including estimated blood loss, operating time, and intra-operative complications were similar in the two groups. Short- and long-term postoperative percentage change in eGFR, frequency of acute kidney injury (AKI), and frequency of de novo chronic kidney disease (CKD) were also not significantly different between the two techniques.

Conclusion: In a large cohort of patients with solitary kidney undergoing RAPN, selective clamping resulted in similar intra-operative and postoperative outcomes compared to full clamping and conferred no additional risk of harm. However, selective clamping did not appear to provide any functional advantage over full clamping as there was no difference observed in the frequency of AKI, CKD or change in eGFR. Short WIT in both groups (<15 min) may have prevented identification of benefits in the selective clamping group; a similar study analysing cases with longer WIT may elucidate any beneficial effects of selective clamping.