Perioperative Efficacy of Laparoscopic Partial Nephrectomy for Tumors Larger than 4 cm

Background: Laparoscopic partial nephrectomy (LPN) is typically reserved for kidney tumors ≤4 cm in size. The use of LPN in patients with larger tumors (>4 cm) has not been systematically evaluated. Objective: To examine technical feasibility and perioperative safety and efficacy of LPN for clinical stage pT1b-T2 tumors >4 cm. Design, setting, and participants: This is a retrospective review of data from an Institutional Review Board-approved, prospectively maintained database of 425 LPN procedures over a 6-yr period (September 1999 through December 2005). Patients were grouped according to tumor size: control group1: <2 cm (n = 89; 21% of patients); control group 2: 2-4 cm (n = 278; 65% of patients); and study group 3: >4 cm (n = 58; 14% of patients). Intervention: Retroperitoneal and transperitoneal LPN. Measurements: Serum creatinine levels, estimated glomerular filtration rates. Results and limitations: For groups 1, 2, and 3, mean tumor size was 1.5 cm, 2.9 cm, and 6 cm in diameter, respectively (p < 0.001). Study group 3 patients more often had an American Society of Anesthesiologists score ≥3 (p < 0.05), central tumors (p < 0.001), pelvicalyceal repair (p = 0.004), and heminephrectomy (p < 0.001). Total operative time, estimated blood loss, and duration of hospital stay were equivalent. Mean warm ischemia time was 30 min, 32 min, and 38 min in groups 1, 2, and 3, respectively (p = 0.007). Tumor size >4 cm did not increase significant risk for positive tumor margins, intraoperative complications, or postoperative genitourinary complications. In each group preoperative stage ≥3 chronic kidney disease (CKD) was present in 31%, 35%, and 44% of patients in groups 1, 2, and 3, respectively (p = 0.15); postoperatively, stage 3-5 CKD incidence increased to 52%, 52%, and 63% in groups 1, 2, and 3, respectively (p = 0.20). Patients with tumor size >4 cm and preoperative stage 3-5 CKD had an 8-fold increase in risk for CKD stage progression. Limitations of the study include retrospective analysis and a relatively low number of patients in group 3. Conclusions: Given laparoscopic expertise and appropriate patient selection, LPN is feasible and efficacious for kidney tumors >4 cm. Indications for LPN should be expanded to include patients with amenable tumors >4 cm in order to maximally preserve kidney function in these patients.