Perioperative and renal function outcomes of minimally invasive partial nephrectomy for T1b and T2a kidney tumors.

Purpose: To compare operative and functional outcomes of minimally invasive partial nephrectomy (MPN) and minimally invasive radical nephrectomy (MRN) for T(1b) and T(2a) renal tumors.

Patients And Methods: All patients who underwent MPN or MRN for a localized, solitary renal mass 4 to 10 cm were included. Perioperative and renal function outcomes were compared. Propensity analysis was used to account for selection bias in type of nephrectomy when evaluating complication rates.

Results: One hundred and eight patients underwent MRN and 45 underwent MPN between August 2004 and September 2010. Preoperative patient and tumor characteristics were similar between groups. Tumor size was larger in the MRN group (5.3 vs 6.8 cm, P<0.001). Operative times and positive margin rates were similar between the groups (P=0.956 and P=0.207, respectively). Estimated blood loss was higher in the MPN group (401.8 vs 157.1 mL, P<0.001), but transfusion rates were similar (P=0.225). Rates of intraoperative (P=0.724), postoperative (P=0.806), and high Clavien-grade postoperative complications (P=0.966) were similar. Propensity analysis indicated that the likelihood of any complication (odds ratio [OR] 0.810, confidence interval [CI] 0.331-1.982, P=0.645) or of a high-grade complication (OR 0.164, CI 0.011-2.513, P=0.194) was unrelated to type of nephrectomy. With similar preoperative renal function parameters, postoperative development of new stage III to V chronic kidney disease (CKD) was greater in the MRN group (58 vs 31%, P=0.011). Propensity analysis showed that the likelihood of new CKD was 2.8 times higher in the MRN group (P=0.048).

Conclusion: In selected patients and with appropriate surgical expertise, MPN can result in similar rates of complications but superior renal function outcomes in larger kidney tumors.