Impact of warm ischemia time on the change of split renal function after minimally invasive partial nephrectomy in Taiwanese patients.

BACKGROUND Nephron-sparing surgery has become the standard treatment for T1 renal tumors. However, relevant data on the Taiwanese population are lacking, and most of the current literature uses global instead of split renal function (SRF) for postoperative renal function follow-up. We evaluated the postoperative renal function after minimally invasive partial nephrectomy in Taiwanese patients. METHODS We retrospectively reviewed our database from April 2004 to July 2012 and enrolled patients who received laparoscopic partial nephrectomy (LPN) or robot-assisted partial nephrectomy (RPN). The estimated glomerular filtration rate (eGFR) and SRF were calculated as representatives of renal function. The preoperative and 6- and 12-month postoperative renal functions were assessed. Freidman test was used to evaluate pre- and postoperative renal function changes; Wilcoxon test was used for comparing the renal function of each period. RESULTS The 6- and 12-month postoperative SRF values were decreased compared with the preoperative values. Multivariate analysis revealed that older age was related to a lower postoperative eGFR, and a longer warm ischemia time was related to a decreased postoperative SRF. Patients with a warm ischemia time of >30 minutes were correlated with a larger mean tumor size, higher "preoperative aspects and dimensions used for an anatomical" score, greater amount of blood loss during the operation, longer postoperative hospital stay, and lower postoperative SRF compared with patients with a warm ischemia time of <30 minutes. Patients in the RPN group had shorter warm ischemia time and higher 6-month postoperative SRF compared with patients in the LPN group. CONCLUSION SRF is more sensitive for postoperative follow-up than eGFR. Longer warm ischemia time is associated with poorer postoperative renal function. RPN is a safe and feasible alternative to LPN.