Laparoscopic resection of rectal cancer: A comparison of surgical and oncologic outcomes between extraperitoneal and intraperitoneal disease locations

PURPOSE: The extraperitoneal rectum is anatomically and biologically different from the intraperitoneal rectum, therefore, the surgical outcomes may be different. This study was designed to assess operative outcomes of laparoscopic resection of extraperitoneal (≤7 cm from the anal verge) vs. intraperitoneal rectal cancer. METHODS: Prospective data were collected from 312 patients with rectal cancer who underwent laparoscopic resection. Patients were divided into two groups: extraperitoneal (EP, n=138) vs. intraperitoneal (IP, n=174). Mean follow-up was 33 months. RESULTS: Patients with pT3/pT4 accounted for 69.6 percent of EP and 74.1 percent of IP. Circumferential margin was positive in 8.7 percent of EP and 0.6 percent of IP (P=0.0004). Anastomotic leakage developed in 9.7 percent of EP vs. 4.6 percent of IP (P=0.1081, overall 6.4 percent). Local recurrence rate at three years was 7.6 percent in EP and 0.7 percent in IP (P=0.0011, overall 4 percent). By multivariate analysis, extraperitoneal location was a risk factor for local recurrence. CONCLUSIONS: Laparoscopic resection of rectal cancer, regardless of EP or IP, provided acceptable operative outcomes. There was an increasing tendency for positive circumferential margin, leakage, and local recurrence in EP vs. IP. A multicenter, prospective study is ongoing to identify the high-risk group for local recurrence who may really benefit from neoadjuvant therapy in the era of laparoscopy.