Impact of warm ischaemia time on postoperative renal function after partial nephrectomy for clinical T1 renal cell carcinoma: a propensity score‐matched study

Abstract

ObjectivesTo analyse the effect of prolonged warm ischaemia time (WIT) on long-term renal function after partial nephrectomy (PN), as controversy still exists as to whether prolonged WIT adversely affects the incidence of chronic kidney disease (CKD) after PN. Patients and MethodsWe reviewed data from 1816 patients who underwent PN for a clinical T1 renal tumour. The propensity scores for prolonged WIT were calculated with the shorter WIT group (<30 min) matched to the longer WIT group (≥30 min) in a 2:1 ratio. Multivariate analysis was used to determine independent predictors for occurrence of postoperative CKD [defined as an estimated glomerular filtration rate (eGFR) of <60 mL/min/ 1.73 m 2 ] and major renal function deterioration (MRFD; defined as an eGFR decrease of ≥25% postoperatively). ResultsAfter propensity score matching, there was no significant difference in CKD-free survival between the two WIT groups (P = 0.787). Furthermore, longer WIT did not show any significant associations with postoperative CKD-free survival [hazard ratio (HR) 1.002, 95% confidence interval (CI) 0.989-1.015; P = 0.765) and MRFD-free survival (HR 1.014, 95% CI 1.000-1.028; P = 0.055). From further subgroup analyses using more specific WIT thresholds (≤20, 21-30, 31-40, 41-50, ≥50 min) and status of preoperative CKD, no significant differences were noted in CKD and MRFD-free survival amongst the subgroups (all P > 0.05). ConclusionsProlonged WIT was not associated with increased incidence of CKD or MRFD after PN.

Acute kidney injury and intermediate‐term renal function after clampless partial nephrectomy

“…We defined postoperative renal impairment as a ≥25% ultimate eGFR decrease from preoperative eGFR, which was consistent with previous studies. 5,17 The impact of AKI on renal impairment was evaluated. A temporary ≥25% eGFR decrease, which recovered thereafter, was not considered renal impairment.…”

Impact of warm ischaemia time during partial nephrectomy on renal function – is it really a matter of time?

“…Tumour size and renal function are vital determinants of suitability for PN . This publication clearly demonstrates that although large tumour size equated with prolonged clamp time, this was not the sole determinant of impaired long‐term renal function.…”

“…In the latest edition of the BJUI , Lee et al. have revisited the question of defining the ideal limit of warm ischaemia time (WIT) and its impact on postoperative renal function in patients undergoing partial nephrectomy (PN).…”

“…In addition to this, patients were further sub‐stratified into five subgroups, critiquing the effect of WIT up to 50 min. A key feature of this paper is the use of propensity score matching to adjust for any potential preoperative confounders affecting postoperative renal function, a technique also allowing matching of the two groups.…”

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

“…Recent studies have revealed that medical CKD rather than surgically induced CKD is a more important driver of postoperative renal function [7]. Propensity-matched data for almost 2000 patients comparing the effects of shorter and longer WIT (<30 vs >30 min) revealed no significant differences between the groups and confirmed that prolonged WIT is not associated with CKD or renal function deterioration [8]. It is clear from these studies that it is overly simplistic to consider a single IT cutoff as a dichotomous marker for renal injury.…”