Laparoscopic extraperitoneal radical prostatectomy: impact of the learning curve on perioperative outcomes and margin status.

OBJECTIVE After improved technical modifications that followed the original reports by pioneering laparoscopic surgeons, the impact of the learning curve has not been objectively assessed for laparoscopic extraperitoneal radical prostatectomy (LERP). In this study, we assessed the impact of the learning curve on operative and oncologic outcomes at a high surgical volume institution. METHODS AND MATERIAL We prospectively analyzed 400 consecutive patients with localized prostate cancer treated with LERP between January 2004 and July 2006. Patients were divided into 4 equal groups (1-100, 101-200, 201-300, and 301- 400). Kruskal-Wallis test was performed to determine whether all the preoperative variables were comparable among groups. Fisher's exact test was performed to determine the association of margin status with pathological stage. Chi-square test was performed to determine whether margin status was associated with groups (1 vs. 2, 3, & 4). Wilcoxon rank-sum test was used to determine whether operative time was statistically different in group 1 (1-100) compared with groups 2, 3, and 4. RESULTS All groups were comparable with respect to preoperative data. Positive margin rate significantly decreased after the first 200 cases for patients with pT2a-c disease (28.4% to 31.9% vs. 11.6% to 11.5%). Margin status was significantly associated with groups (Group 1 & 3: P=0.0044 and group 1 & 4: P=0.0021). Operative time significantly decreased after the first 100 cases (350 min vs. 218 min, 192 min, and 223 min) (P<0.0001). CONCLUSIONS In a tertiary care academic institution, the operative and pathologic outcomes improved significantly with increased surgical experience. At our institution, the operative and pathologic outcomes improved after 100 and 200 cases, respectively.