Management of rectal cancer resection has developed gradually an exceptional improvement in the operative techniques and adjuvant treatments during the past decades. The process of surgical development has played a key role in the potential curative prognosis of rectal cancer. Rectal cancer resection emphasizes preservation of anal sphincter with normal pelvic function and bowel. Type of surgery used to eliminate rectal cancer depends on the stage and location of cancer. Rectal cancer that detected well above the anus, the low anterior resection (LAR) can be done. This type of surgery permits a patient to pass stools normally. When the rectal cancer is detected close to the anus, an abdominoperineal resection (APR) is performed to remove the anus. A patient then has to use a colostomy bag that attached to the abdominal wall to collect the stool. Apart from these two, there is another operative option, sphincter-sparing treatment is also available at this moment.
Following are the different type rectal cancer resection:
Low Anterior Resection Surgery (LAR)
Cancer identified well above the anus is generally treated by LAR surgery. In this process, the entire rectal cancer including adjacent normal rectal tissue and surrounding lymph nodes are eliminated by an incision that made in the lower abdomen. After removal of cancer, the cut ends of the rectum are stitched back together. Thus the movement of stool from large intestine through the anus remains undisturbed. If the cancer is found in the lower region of the rectum, the cut end of the large intestine is directly joined with the anus, called as colo-anal anastomosis. During this procedure, a temporary colostomy is created to protect the delicate attachment of the large intestine to the anus. However, after patient’s recovery, this temporary colostomy is removed and allows normal movement of stool from large bowel to anus.
Abdominoperineal Resection Surgery (APR)
Cancer detected close to the anus commonly treated by APR surgery. While undergoing this operation, the entire rectal cancer including the adjacent normal rectum, rectal sphincter or anus, and also the surrounding lymph nodes are eliminated by an incision in the lower abdomen and perineum. Following the removal of cancer, the cut end of the perineum is stitched and shut. The cut end of the large intestine is however directly attached to an abdominal opening which is covered with a bag to collect the stool passed out from the large intestine. This is called colostomy and it is permanent contrary to LAR operation.
The inconvenience caused by a colostomy in APR surgery, the improvement in the surgical method is the advent of sphincter-sparing surgery. In this method, the surgery is designed to eliminate cancer and the circumferential resection margin (CRM) also called the radial margin of the normal bowel and not the anus. The guideline recommends that a positive margin of CRM should be more than 1 mm. for all the patients undergoing rectal cancer resection through sphincter-sparing surgery. This surgery preserves anal sphincter with normal pelvic function and bowel. This surgery is often followed by both the chemotherapy and the radiation therapy. The surgery is performed either through anus, coccyx or the tailbone.
Authored By Dr G Parthasarathy - Surgical Gastroenterologist, Hyderabad