Review of Intersphincteric Resections for Rectal Cancer Treatment

Abstract

Colorectal cancer is the third most common cancer, second most common cancer in women, and the fourth leading cause of death in the world. Radical surgical treatment with Total Mesorectal Excision (TME) is considered the best treatment for cancer found in the lower third of the rectum and has benefits of complete tumor removal to reduce risk of recurrence and to improve survival. Advances in preoperative chemoradiation therapy have increased chances of achieving a 1 cm distal margin and allowed successful sphincter-preserving surgery by intersphincteric resection (ISR) and Coloanal Anastomosis (CAA) that allows normal defecation. MRI is particularly useful in evaluating localization of the tumor, involvement of anal sphincter (internal and external sphincters), levator ani muscles, and adjacent structures to the anus, with an accuracy of 85%, sensitivity of 87%, and specificity of 75%. Performing ISR with TME oncologic principles achieves similar results to Low Anterior Resection (LAR), but depends on the presence of sufficient Distal Rectal Margin (DRM); if a sufficient DRM cannot be achieved, then patients are offered an Abdominoperineal Resection (APR) with permanent colostomy and poor quality-of-life results.