A major concern for people undergoing surgery for rectal cancer is whether they will require a stoma, and whether it will be a temporary or a permanent one. This article discusses the factors that determine the need for a stoma.
A stoma or ostomy (from the Greek word for “mouth” or “opening”) is an opening created in the body by the surgeon for one of several purposes. When this opening is made to collect stools from the large intestine, it is called a “colostomy”, and when it is made in the small intestine, it is called an “ileostomy” (ileum = last part of the small intestine). The stools are collected in an external stoma appliance (“stoma bag”), and the appliance is emptied of stools at regular intervals. The stoma could be temporary or permanent depending on the reason for its construction.
The principle of curative surgery for any cancer is achieving adequate cancer-free surgical margins. In the case of rectal cancer, critical margins during surgery are
- Margin beyond cancer (distal margin), and
- Margin around the cancer (radial margin)
In order to restore intestinal continuity (by joining back or “anastomosing” the ends of the intestine after removing the segment containing cancer), two conditions have to be fulfilled
- No compromise on the removal of cancer (adequate cancer-free margin achieved)
- Functional residual anal sphincter complex (ability to control the passage of stools via the normal passage after surgery)
In earlier days, the majority of surgeries for cancer of the lower third of the rectum involved surgical removal of the entire anal sphincter complex and making a permanent colostomy. Of late, more and more people with rectal cancer are able to undergo “function preserving” or “organ conserving” or “sphincter preserving” surgeries which avoids the need for a permanent stoma. This change is due to
- A better understanding of surgical anatomy and pathology in recent years.
- Use of neo-adjuvant therapies (radiation and chemotherapy prior to surgery).
- Improved surgical techniques and instrumentation.
- Use of devices like surgical staplers, which facilitates anastomosis deep in the pelvis.
- Use of minimally invasive techniques.
- Focus on surgical specialization and training.
Despite these advances, there is a subset of patients with rectal cancer in whom a permanent stoma may be required in order to achieve a cure. In addition, some patients may need a temporary stoma – this is usually done to “protect” the surgical anastomosis until it heals – such stomas are “reversed” (surgically closed) after a short interval, after which the patient passes stools through the normal passage.
In summary, most patients with rectal cancer are today able to undergo curative treatment without the need for a permanent stoma.