Surgical factors affecting return of renal function after partial nephrectomy

Nephron-sparing surgery is becoming the standard treatment for small renal tumors. In this study, we investigate the relationship between operative factors and recovery of renal function after partial nephrectomy. Records of 141 partial nephrectomy patients at the University of Alabama Medical Center at Birmingham between 1999 and 2008 were reviewed retrospectively. Renal function was assessed preoperatively, at 1 day (early) and 6 months (late) postoperatively by calculated creatinine clearance (CC). Anesthesia time, arterial clamp time, use of ice slush, tumor size, and change in hematocrit following surgery were assessed for their impact on change in early and late renal function after adjusting for patient age, gender, race, co-morbidities, preoperative renal function and operative approach. Descriptive statistics are presented for independent predictors and research outcome by time points. Multivariate regression model was used to identify independent predictors of renal function. Increasing anesthesia time, clamp time, and postoperative hematocrit were associated with decreased renal function (CC) at 1 day postoperative. At 6 months, tumor size and change in early postoperative hematocrit predicted a decline in CC. In multivariate analysis, decreased renal function at 6 months was predicted by change in postoperative hematocrit level. Long hilar clamp times and anesthesia times adversely affect early postoperative renal function but not late renal function. Intraoperative bleeding adversely affected renal function at both early and late time points. Limiting intraoperative blood loss may be more important than clamp times or renal cooling in the recovery of renal function after partial nephrectomy.