Surgical Approaches for Rectal Cancer

Anatomical and Surgical Differences

The National Comprehensive Cancer Network recommends that Abdominoperineal Resection (APR) involves en bloc resection of the rectosigmoid, rectum, and anus, along with surrounding mesentery, mesorectum (TME), and perianal soft tissue, necessitating creation of a permanent colostomy 1, 2
The National Comprehensive Cancer Network suggests that Low Anterior Resection (LAR) preserves the anal sphincter and involves resection of the affected rectum with TME, followed by creation of a colorectal or coloanal anastomosis, maintaining intestinal continuity 2, 3
For mid to upper rectal lesions, LAR extends 4-5 cm below the distal edge of the tumor using TME technique, as recommended by the National Comprehensive Cancer Network 2, 3
Both procedures incorporate total mesorectal excision (TME), which involves en bloc removal of the mesorectum with associated vascular and lymphatic structures, according to the National Comprehensive Cancer Network 4, 3

APR is indicated when the tumor directly involves the anal sphincter or levator muscles, or when a margin-negative resection would result in loss of anal sphincter function and incontinence, as indicated by the National Comprehensive Cancer Network 1, 2
LAR is indicated when the tumor is located in the mid to upper rectum, and anal function is intact and adequate distal clearance (4-5 cm below tumor edge) can be achieved, according to the National Comprehensive Cancer Network 2, 3

The National Comprehensive Cancer Network reports that recent retrospective comparisons show that patients treated with APR have worse local control and overall survival compared to those treated with LAR 1
A retrospective study of 3,633 patients with T3-T4 rectal cancer suggests an association between the APR procedure itself and increased risks of recurrence and death, as reported by the National Comprehensive Cancer Network 1, 2

The National Comprehensive Cancer Network notes that patients who underwent APR reported worse body image, worse micturition symptoms, and less sexual enjoyment at 1-year post-surgery compared to those who had sphincter-preserving surgery 1, 2
Despite these differences, overall quality of life between patients with or without a permanent colostomy appears to be fairly comparable in some studies, according to the National Comprehensive Cancer Network 1, 2

An extralevator APR approach may offer benefits over conventional APR, including lower rates of intraoperative perforation, CRM involvement, and local recurrence, though results are inconsistent across studies, as reported by the National Comprehensive Cancer Network 1, 2
Both procedures can be performed via open, laparoscopic, or robotic approaches with comparable oncological outcomes, according to the National Comprehensive Cancer Network and Cancer Communications 1, 6