External sphincter resection for lower rectal and anal canal adenocarcinoma: achieving anal preservation with oncological and functional satisfaction.

Intersphincteric resection (ISR) has recently been performed for very low rectal cancer, whereas abdominoperineal resection (APR) is typically reserved for cancers extremely close to the anal verge and/or when the depth of tumor invasion is suspected to involve the intersphincteric space. This is because impairment of anal function is considered unavoidable if the external sphincter (ES) is excised. We describe our technique of ISR with ES resection and discuss its outcomes. This surgical technique may offer major clinical advantages to selected patients and should be considered as an alternative to APR, although careful consideration of anal function is required.