Rectal Cancer Surgery

The surgery for rectal cancer has some unique considerations from that performed for colon cancer. First is that it is generally more technically challenging and therefore requires someone with good training and experience. Because of proximity to pelvic nerves that affect sexual and bladder function, there is higher risk of injury to those nerves. Consequences of removing the rectum have more of an effect on bowel control, because the rectum is very important in sensing, storing and allowing appropriate elimination. Removing most or all of it will affect those functions, because the colon which is used to replace the rectum does not have those unique abilities. For that reason patients will have more bowel frequency, smaller bowel movements, and possibly some affects on continence. Usually these troubling symptoms can improve with time and dietary management. Many find these struggles far better than living with a colostomy.

As mentioned earlier in the work-up of rectal cancer, when it is found prior to surgery that the tumor has grown through the rectal muscle wall and/or involves the surrounding lymph nodes (Stage II or III), it is recommended that patients undergo neoadjuvant chemo radiation to shrink the cancer. This enhances the results in terms of the oncologic outcome (curing the cancer) and function of the new rectum. However, it is important to realize that unlike colon cancer surgery, most operations for rectal cancer entail a temporary ileostomy. That does mean that patients typically wear a bag for 3-6 months to collect their waste. Usually the end of the small intestine (aka the ileum) is brought up to create the ostomy, hence the name ileostomy. The primary reason for this additional step is that there is much higher risk of anastomotic leak from the bowel connection deep in the pelvis. The ostomy “protects” the healing bowel anastomosis.

The basic surgical techniques of rectal cancer surgery are similar to colon cancer, i.e. laparoscopic or open. Often surgeons elect to do the majority of the surgery laparoscopically, and then the delicate pelvic dissection and construction of the new rectum is done in open fashion, but through a much smaller incision. Robotic surgery has also been introduced for these procedures, but for now is purely investigational and does not seem to offer much advantage. Because of the anatomic location of rectal cancer near the anal opening, the option exists to remove the cancer trans-anally. This is much better tolerated and preserves the rectum, but recurrence risks are much higher. This kind of approach is only acceptable for patients who will not tolerate a major operation or for those lucky few with very early cancers.

Although more risky and often requiring two steps (cancer surgery and then ostomy reversal), the oncologic results of rectal cancer are quite similar to those with colon cancer. Most patients have prednisone to learn to adjust after rectal cancer surgery to the changes in sensation and function, but they can go on to enjoy life with rarely the need for a permanent colostomy. The main exceptions being those patients with advanced tumors involving the anal sphincter muscles or those with pre-existing fecal incontinence.