Background: Total mesorectal excision has been advocated in conjunction with low anterior or abdominoperineal resection as the optimal surgical treatment for rectal cancer. It involves removal of the entire rectal mesentery as an intact unit and maximizes the likelihood of obtaining a negative circumferential margin.
Objectives: To prospectively validate the efficacy of total mesorectal excision in obtaining locoregional control, to identify the perioperative factors influencing the selection of either a sphincter sparing or a sphincter ablating procedure, and to identify independent factors that may influence long-term prognosis in rectal cancers.
Settings: Tertiary referral center.
Patients: Seventy-three consecutive patients with rectal cancer located within 10 cm of the anal verge were treated from 1984 to 1997 by the senior author (F.M.). Sixty-five patients form the basis of our analysis after the exclusion of 7 patients who had their cancer removed transanally and 1 patient who had a permanent diverting stoma as the only procedure.
Results: Twenty-six patients underwent a sphincter ablating procedure; 39 underwent a sphincter sparing procedure. Operative mortality was 1.5%. Follow-up was complete in 64 patients (39+/-30 months; range, 3-126 months). Five-year actuarial survival rates were 88% for the 34 patients with stage I and II adenocarcinoma and 65% for the 22 patients with stage III adenocarcinoma. The local recurrence rate was 6.2% overall, but only 3.1% in the potentially curable group (stages I-III). When only patients who did not receive adjuvant chemoradiation therapy were considered (n=23), local recurrence rate was 8.3% overall and 0% in the potentially curable group. Tumor stage (P=.04) and vascular and/or lymphatic invasion (P=.002) were statistically significant in their association with survival. Circumferential lesions (P<.001), gross invasion of contiguous organs (P<.001) and distance from the anal verge of less than 5 cm (P=.01) were statistically significant in their association with the choice of a sphincter ablating procedure.
Conclusions: This study confirms the efficacy of total mesorectal excision in minimizing locoregional recurrence rates and confirms the well-established prognostic value of stage and microinvasion. Moreover, it indicates that circumferential lesions, distance from anal verge, and gross invasion of contiguous organs are significant perioperative factors in the selection of the type of surgical procedure.