Surgical and oncologic outcomes of laparoscopic partial nephrectomy: A Japanese multi-institutional study of 1375 patients

Background and Purpose: Despite clear trends toward minimally invasive surgery, information about laparoscopic partial nephrectomy (LPN) in Japan is sparse. We conducted a retrospective survey to clarify time trends for LPN and analyze surgical and oncologic outcomes. Patients and Methods: A nationwide survey was performed. Between 1998 and 2008, 1375 patients underwent LPN at 54 institutions. Complications, patterns of tumor recurrence, and recurrence-free survival were analyzed. Results: Renal pedicle clamping was used in 1031 (75%) cases, and renal cooling was performed in 64%. Median warm/cold ischemic time was 37/53 minutes. Median tumor size was 2.26 cm (interquartile range 1.6 to 2.7). Multivariate analysis identified total operative time, operative blood loss, and surgical margin status as independently associated with high grade (grade 3-5) urologic and nonurologic complications. Despite increases in central tumor, a trend was seen toward shorter warm/cold ischemic time in recent cases, and the overall complication rate did not change throughout the study period. With a median follow-up of 26 months for 1193 malignancies, recurrence occurred in 22 (1.7%) patients, including local recurrence in 7 (0.5%), lung in 8 (0.7%), lymph nodes in 2 (0.1%), and bone in 4 (0.3%). Of the 26 cases with positive surgical margins, local tumor recurrence occurred in only one. Conclusions: This is the first nationwide survey of LPN in Japan to be reported. LPN could be performed with acceptable positive margins and complication rates. Most tumor recurrences occur as metastases, and surgical margin status appears to have little impact on oncologic outcomes.