Abstract
BACKGROUND: Indications for partial nephrectomy (PN) in the treatment of renal cell carcinoma are evolving, particularly for larger, more complex tumors. OBJECTIVE: Compare single-institution outcomes for minimally invasive partial nephrectomy (MIPN) and open partial nephrectomy (OPN) for tumors>4-7 cm. DESIGN, SETTING, AND PARTICIPANTS: A total of 2290 patients underwent PN from 2002 to 2010 at Memorial Sloan-Kettering Cancer Center; 280 had >4-7 cm renal cortical tumors. Of these 280 patients, 230 had pT1b, 48 had pT3a, and 2 had angiomyolipomas; 226 underwent OPN and 54 underwent MIPN (16 robot-assisted and 37 laparoscopic procedures). Perioperative management was uniform on the clinical pathway. Perioperative data, clinicopathologic variables, complications within 30 d, and oncologic outcomes were reviewed. MEASUREMENTS: Estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. Complications were reported from prospectively collected data based on a modified Clavien system. The Fisher exact and Mann-Whitney U tests were used for descriptive statistical analysis. Kaplan-Meier methods were used to estimate survival. RESULTS AND LIMITATIONS: Median follow-up for OPN and MIPN was 29 and 13 mo, respectively. There were no statistically significant differences in age, gender, preoperative American Society of Anesthesiologists score, laterality, histologic subtype, tumor size, tumor stage, or margin status between procedures. Univariate analysis revealed significantly greater values in the OPN group for preoperative eGFR, renal artery clamp time, estimated blood loss, use of renal hypothermia, and length of stay. Differences in overall survival and recurrence-free survival were not statistically significant; however, short median follow-up times limit comparison. There was no significant difference in the number of complications grade≥3 (p=0.1) or urine leaks requiring intervention (p=0.7). Limitations include the retrospective nature of the study and the possibility of selection bias. CONCLUSIONS: OPN and MIPN procedures performed in patients with tumors>4-7 cm offer acceptable and comparable results in terms of operative, functional, and convalescence measures, regardless of approach.