Favorable Pathologic and Long-Term Outcomes From the Conventional Approach to Abdominoperineal Resection

Abstract

Suboptimal oncologic outcomes from abdominoperineal resection have been related to high rates of circumferential margin involvement. The extralevator approach has gained popularity as a means of reducing circumferential margin involvement, but it remains unknown whether comparable outcomes are achievable with a conventional approach to abdominoperineal resection. This study aimed to determine the rate of circumferential margin involvement, to identify factors predictive for a positive circumferential margin, and to relate these findings to long-term outcomes. This is a retrospective analysis of a prospective clinical database. This study was conducted at a single center, Mount Sinai Hospital, Toronto. Patients were included who underwent abdominoperineal resection for low rectal adenocarcinoma between 1997 and 2006. The main outcome measures included the rate of circumferential margin involvement, local recurrence, and disease-free survival. A total of 115 patients underwent abdominoperineal resection for primary adenocarcinoma of the rectum. A positive circumferential margin was demonstrated in 18 patients (15.7%). Intraoperative perforations occurred in 7 patients (6.1%). Tumors located anteriorly had a higher rate of circumferential margin involvement (31.6%) compared with lateral (13%), posterior (10%), and circumferential tumors (0%) (P = .024). This finding was reflected by a reduced median distance to the circumferential margin in anterior tumors. Curative resections (n = 108) were followed up for a median of 55.5 months. The 5-year local recurrence rate was 10.6% and the 5-year disease-free survival was 67.4%. Cox regression analysis revealed that circumferential margin involvement was an independent predictor for local recurrence; and T-category, N-category, and circumferential margin involvement for disease-free survival. This study was limited by its sample size and the number of outcome events. The conventional approach to abdominoperineal resection can produce oncologic outcomes comparable to the extralevator approach. However, the rate of circumferential margin involvement is higher than in restorative procedures and may be related to difficulties in obtaining adequate clearance in anterior tumors.