Intersphincteric Resection: A Silver Lining in Rectal Cancer Surgery

Dr Suneel Kaushik Komanduri, Surgical Oncologist, Onco Cancer Care Centre,  explains how an intersphincteric resection can be used to avoid a permanent colostomy bag in some cases. 

Surgical management of low rectal cancers is challenging due to higher rates of local recurrence and inferior survival rates. These are related to the anatomical constraints of the anorectal region.

Abdominoperineal resection, commonly called  APR, has been the standard surgical procedure for all patients with low rectal cancer. This surgery involves removal of rectum and anal canal, with anal sphincter complex, and creation of a permanent stoma in lower abdomen for passing stools.

However, the procedure is not easily accepted by patients because of the need for a permanent colostomy.

Can permanent colostomy be avoided for low rectal cancer surgery?

With advances in surgical techniques, radiation techniques and chemotherapeutic options, organ conserving surgeries for rectal cancer are now possible.

It is now possible to avoid this mutilating surgery. Considering various tumor factors oncologists are now able to conserve the natural anal passage of stools while preserving the sphincter mechanism to prevent incontinence.

What is the anal – sphincter complex?

Rectal cancer arises in the last few inches of the large intestine called rectum.

Rectum begins as a continuation of the sigmoid colon, and reaches the short, narrow passage leading to anus.

Anal sphincter is a ring of muscle, surrounding the anus, that opens and closes the anus and plays a large role in controlling bowel emptying. This maintains a seal that can be opened to discharge the body waste.

This sphincter complex has an inner ring and an outer ring of muscles. An injury to this sphincter complex can result in stool incontinence.

Can all tumours of rectum be treated by Intersphincteric resection?

 While tumors located high up in the rectum can be safely treated without disturbing the structure of anal sphincter, management of those in the lower part of rectum can be challenging due to proximity to sphincter.

For those tumors not penetrating very deep into the layers of rectum an Intersphincteric resection is the ultimate sphincter-preserving operation.

For those tumors involving the muscle complex, a priming treatment with combination of radiation and chemotherapy can help reduce the size and extent of disease, and makes the tumor amenable for a sphincter sparing surgery..

Is Intersphincteric resection safe?

Oncologists observed similar outcomes in terms of the chances of disease recurring, while reducing the need for permanent colostomy.

Intersphincteric resection involves removal of the internal sphincter in toto or in part.

Studies found that continence was satisfactory for most patients. A quarter of those who underwent this surgery may have incontinence to flatus and liquid stools.

Not everyone with a low rectal can undergo this procedure. Several factors including the tumour location and depth of penetration, preexisting anal tone, patients expectations are considered by oncologists while deciding the feasibility of this surgery.

Read more about screening tests for colorectal cancer here.