Purpose: The existence of an anatomic and functional separation between the puborectalis muscle and external anal sphincter permits the performance of an abdominoendoanal excision, instead of an abdominoperineal excision, of the rectum and levator muscles, with preservation of a functioning external sphincter, in selected patients with very low rectal cancer and limited infiltration of the levator muscles.
Methods: Seven patients (4 females; age, 48-69; mean, 60.7 +/- 7.8 years) with low posterior or posterolateral localized rectal cancers with infiltration of the puborectalis muscle (T4) were submitted to preoperative chemoradiation and excision of the rectum with the levator muscles, while the external sphincter and its innervation were preserved. A coloanal anastomosis was performed at the dentate line.
Results: At a median follow-up of 58 (range, 42-102) months, 6 patients (86 percent) were alive and disease free. No local recurrence was observed. Anorectal function, at three years from surgery was no worse than that of six patients of the same age and gender who had undergone more conventional coloanal anastomoses with preservation of the levator muscles.
Conclusion: Selected patients with very low rectal cancers infiltrating the levator muscles (T4) and responding to preoperative chemoradiation therapy can still be treated with an advanced sphincter-sparing procedure, instead of an abdominoperineal excision. Oncologic and functional results seem to be satisfactory.