Purpose: To evaluate our initial outcomes of retroperitoneal partial nephrectomy (RPN) performed by off-clamp excision.
Patients and methods: Between January 2011 and October 2102, patients with T1 posterior renal masses or in the renal convexity were selected for RPN with the intent of performing the modified zero ischemia technique. Patient characteristics, operative details, complications, and long-term outcomes were analyzed.
Results: There were 19 patients included (mean age 60 years, range 37-81 years; body mass index 27.8 kg/m(2), range 25-34 kg/m(2)). Mean tumor size was 35 mm (20-50 mm), and preoperative aspects and dimensions used for an anatomical (PADUA) classification score was 9 (7-11). Surgical time was 182 minutes (110-255 min), and the series warm ischemia time was 4.9 minutes (0-28 min). The off-clamp procedure was performed in 15 (79%) patients. Mean estimated blood losses (EBL) were 414 mL (100-1600 mL). Transfusion was necessary in two cases, while one reoperation and one conversion to open surgery were needed. Mean hospital stay was 4.5 days (range 3-11). One (5.3%) case of positive margins was reported. Serum creatinine levels varied from 86 to 94 μmol/L (preoperative and 6-month follow-up). Considering the learning curve of the technique, separate analysis of the initial 9 and last 10 cases revealed that while tumor characteristics remained comparable (size 33 vs 37 mm; PADUA score 8.8 vs 9.2), no clamping was performed in the later cases with decreased EBL (544 vs 297 mL), surgical time (207 vs 159 min), and shorter hospital stay (5 vs 4 days).
Conclusion: Our preliminary results on off-clamp RPN are promising and may pave the way for a real zero ischemia nephron-sparing surgery. Larger and randomized studies should follow in to confirm our initial results.