To compare between the effects of cold and warm ischemia on the risk of deterioration of renal insufficiency in patients with T1 renal tumor managed by partial nephrectomy.

This prospective randomized study was performed on 120 patients with chronic kidney disease, all having T1 renal tumors. Renal function was estimated by estimated glomerular filtration rate (eGFR), using the Modification of Diet in Renal Disease formula. Patients were randomly divided into 2 groups: in group A, warm ischemia was used, and in group B, cold ischemia was used. All patients were treated by open partial nephrectomy. Patients were followed up for 2 years. The primary outcome of the study was eGFR at 2 years. Secondary outcomes were tumor recurrence, loss of follow-up, or patient death.

Mean age of patients was 60.7 ± 5.3 years. Associated chronic disease (diabetes and/or hypertension) was present in 93 patients. Worsening of renal insufficiency occurred within 1 month of surgery in 38 patients (27 in group A and 11 in group B). At 3 months follow-up, 21 of these 38 patients returned to their baseline eGFR. Warm ischemia rendered patients more prone to a decrease in eGFR after partial nephrectomy, with relative risk of 1.34 and 2 times at 3 months and 2 years of follow-up, respectively.

Warm ischemia increases the risk of deterioration of renal functions in patients with renal insufficiency undergoing open partial nephrectomy for renal tumors.