The impact of warm ischemia time on short-term renal function after partial nephrectomy: a systematic review and meta-analysis

PURPOSE: This study aimed to assess the impact of warm ischemia time on short-term renal function in individuals undergoing partial nephrectomy. METHODS: We conducted a comprehensive search for primary research articles from 1990 to October 15, 2024 across several databases, including MEDLINE, Embase and the Cochrane Library. A random effects model was applied to determine multivariable adjusted odds ratios (ORs) and their corresponding 95% confidence intervals (CIs). Country and study design were utilised as outcome indicators in the regression model. RESULTS: Ten studies including 4,993 patients who underwent partial nephrectomy met the inclusion criteria. The threshold of potentially harmful ischemia time for renal artery occlusion ranges between 10 and 45 min. Our results revealed that long warm ischemia time was associated with decreased postoperative eGFR and poor short-term renal function (OR = 1.08; 95% CI = 1.02-1.15; P = 0.006) after partial nephrectomy. Sensitivity and meta-regression analyses demonstrated the robustness of the study's findings. CONCLUSIONS: Extended periods of warm ischemia, specifically exceeding 25-30 min, can inflict damage on kidneys undergoing surgical treatment. Minimising the duration of warm ischemia while simultaneously prioritising surgical safety and achieving clear margins is imperative. Moreover, ischemia time remains a modifiable risk factor and must be reduced to maintain overall short-term renal function. Relevant prospective and randomised controlled trials must be conducted to validate these findings. PROSPERO REGISTRATION NUMBER: CRD42024560051.