Does Every Minute of Renal Ischemia Still Count in 2019? Unlocking the Chains of a Flawed Thought Process over Five Decades

Our understanding of the potential impact of ischemia time on renal function during nephron-sparing surgery (NSS) is based on decades of low-quality evidence. Recent studies have shown that the baseline quality of the renal parenchyma and the quantity of parenchyma remaining, rather than duration of ischemia, are more important in predicting renal functional recovery. A prospective clinical trial evaluating actual renal parenchyma under clamp conditions during NSS showed minimal structural and functional changes that were reversible and were not associated with duration of ischemia. Patients with known preoperative kidney disease should be optimized before surgery and care should be taken intraoperatively to preserve the maximum amount of healthy parenchyma. A thorough evaluation of evidence is warranted before setting or changing surgical practice and approach. Patient summary: This mini-review reveals that a limited duration of ischemia during nephron-sparing surgery for kidney cancer does not have a significant impact on renal function. Baseline renal function and the amount of parenchyma preserved appear to play a more important role in predicting postoperative renal function.