Excision of the levator muscles with external sphincter preservation in the treatment of selected low T4 rectal cancers.

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.