Chapter 24. Operative Management of Rectal Tumors

Transanal Excision of Tumor

• Stage T1 tumors:
  • Mobile and < 4 cm in diameter.
  • Involving < 40% of the rectal wall circumference.
  • Located within 6 cm of the anal verge.
• Well or moderately differentiated histology only.
• Absence of vascular and lymphatic invasion.
• No evidence of nodal involvement on preoperative rectal ultrasound or MRI.

Low Anterior Resection (LAR) with Total Mesorectal Excision

• Malignant lesion of the rectum diagnosed by evaluation of a tissue biopsy specimen obtained within 2 cm of the anal sphincter in moderately or well-differentiated tumors or within 5 cm for poorly differentiated tumors.

Abdominoperineal Resection (APR) with Total Mesorectal Excision

• Malignant lesion of the rectum diagnosed by evaluation of a tissue biopsy specimen obtained < 2 cm from the anal sphincter for moderately or well-differentiated tumors or < 5 cm for poorly differentiated tumors.

Transanal Excision of Tumor

• Tumors stage greater than T1N0M0.
• Fixed tumors.
• Tumors > 4 cm in diameter or involving > 40% of the circumference of the rectal wall.
• Tumors located > 6 cm from the anal verge.
• Tumors with poorly differentiated histology or angiolymphatic invasion, or those that show evidence of nodal involvement on preoperative rectal ultrasound or MRI.

LAR with Total Mesorectal Excision

• Malignant lesion of the rectum diagnosed by evaluation of a tissue biopsy specimen obtained < 2 cm from the anal sphincter for moderately or well-differentiated tumors or < 5 cm for poorly differentiated tumors.

APR with Total Mesorectal Excision

• Malignant lesion of the lower rectum diagnosed by evaluation of a tissue biopsy specimen showing local invasion into the pelvic sidewall or pelvis that could benefit from neoadjuvant treatment to facilitate possible curative resection.

Transanal Excision of Tumor

Expected Benefits

• Removal of tumor with preservation of anus.
• Avoidance of radical surgery.

Potential Risks

• Bleeding requiring reoperation.
• Rectal stricture.
• Need for further resection based on pathologic findings.
• Fistula to prostate or vagina.
• Injury to the urethra for distal anterior tumors in men.

LAR or APR with Total Mesorectal Excision

Expected Benefits

• Treatment of rectal cancer.
• Potential prevention of colonic obstruction, tenesmus, and invasion of adjacent pelvic structures.

Potential Risks

• Bleeding requiring reoperation from presacral or splenic injuries (LAR or APR) or from the anastomosis (LAR).
• Infection, including intra-abdominal or pelvic abscesses resulting from anastomotic leaks (LAR) or infected intra-abdominal or pelvic fluid collections (LAR or APR).
• Fistula formation from anastomotic leak (LAR).
• Postoperative ileus (LAR or APR).
• Ureteral injury (LAR or APR).
• Need for a permanent or temporary stoma (LAR).
• Bladder or sexual dysfunction (LAR or APR).
• Fecal incontinence (LAR).
• Clustering of bowel movements (LAR).