Small Bowel Transplantation
The first small bowel transplantation in Kerala was performed in Amrita Institute of Medical Sciences on 05th January 2015.
A small bowel (intestinal) transplant is an operation to replace a diseased or shortened small bowel with a healthy bowel from a donor. It is a complicated and highly specialised operation that is not commonly performed, although the number of procedures carried out has increased in recent years. These procedures are carried out only at specialist centres.
The small intestine or small bowel is the part of the gastrointestinal tract between the stomach and the large intestine, and is where much of the digestion and absorption of food takes place. The small intestine has three distinct regions – the duodenum, jejunum, and ileum. It receives bile and pancreatic juice through the pancreatic duct, controlled by the sphincter of Oddi. The primary function of the small intestine is the absorption of nutrients and minerals from food.
Types of Intestinal Transplants
There are three major types of intestinal transplants that are described in detail below.
- Isolated intestinal (Small Bowel) Transplantation :
In an isolated intestinal transplant, the diseased portion of the small intestine is removed and replaced with a healthy small intestine from a donor. In an isolated intestinal transplant, the disease limited to the small bowel only without liver failure. This procedure can be lifesaving for patients with irreversible intestinal failure that has become life-threatening.
- Combined Liver and Intestinal Transplantation :
Combined liver and intestine transplantation is done for patients with both liver and intestinal failure. IN In this procedure, the diseased liver and intestine are removed and replaced with a healthy liver and intestine from an organ donor. Complications of intravenous nutrition (TPN) are the main cause of liver failure attendant to intestinal failure. Without a transplant, patients with intestinal and liver failure have an expected median survival of 6 - 12 months while continued on TPN.
- Multivisceral Transplantation :
Multivisceral transplantation is performed where two or more intra-abdominal organs (including the intestines) are failing. The transplanted organs may include the stomach, duodenum, pancreas, intestine, and liver. This complex procedure can be life-saving for patients with combined abdominal organ failure resulting diseases such as Gardner's syndrome (familial colorectal polyposis), a pre-malignant colorectal condition and intestinal pseudo-obstruction (decreased ability of the intestines to push food through).
Why small bowel transplants are carried out?
A small bowel transplant is an option for children and adults whose bowel has stopped working properly and who are being fed by total parenteral nutrition (TPN). This is where a person requires all their nutrition to be given through a drip into a vein because their bowel is unable to absorb nutrients from any food they eat.
While many people needing TPN can have this treatment at home without experiencing any significant problems, the long-term use of TPN can lead to serious complications such as liver disease and repeated infections.
A small bowel transplant may be considered when the person has a serious problem with their bowel, but have developed complications from TPN or are unable to tolerate this form of feeding.
This is a complicated and difficult operation that takes, on average, around 8-10 hours and is carried out under general anaesthesia. During the procedure, the surgeon will remove the bowel and connect the transplanted bowel to your blood vessels and digestive tract. They will also form an ileostomy, where part of the small bowel is diverted through an opening in the tummy, called a stoma. The stoma will allow digestive waste to pass out of your body into an external pouch, and lets the transplant team easily assess the health of your transplanted bowel. Although it is not always possible, the ileostomy may be reversed a few months later.
Some persons are born with or develop irreversible intestinal failure. Intestinal failure occurs when a person's intestines can't digest food and absorb the fluids, electrolytes and nutrients essential to life and normal development. Patients must then receive TPN, which provides liquid nutrition through a catheter or needle inserted into a vein in the arm, groin, neck or chest.
Total Parenteral Nutrition (TPN)
Patients with intestinal failure may receive all or most of their nutrients and calories intravenously through total parenteral nutrition, or TPN. TPN is given through a catheter placed in the arm, groin, neck or chest. Patients on TPN may live for many years, but long-term use of TPN can result in serious complications, such as bone disorders, central venous catheter infections and liver disease. If those complications become life-threatening, an intestinal transplant may be required.
Causes of Intestinal Failure
The most common cause of intestinal failure is short bowel syndrome where at least half or more of the small intestine has been removed. Short bowel syndrome is typically a postsurgical condition for treatment of conditions such as trauma or necrotizing enterocolitis.
Intestinal failure may also be caused by functional disorders such as Crohn's disease, a digestive disorder, or chronic idiopathic intestinal pseudo-obstruction syndrome. The conditions leading to intestinal failure are age-dependent. That is, some conditions are more closely associated with pediatric intestinal failure while others are more common with intestinal failure in adults.
Pediatric Conditions Causing Intestinal Failure
Congenital malformations such as small bowel atresia, gastroschisis, aganglionosis Infections of the gastrointestinal tract such as necrotizing enterocolitis)
Short bowel syndrome following extensive bowel surgeries secondary to mesenteric ischemia (e.g., midgut volvulus) Absorptive impairment (e.g., intestinal pseudo-obstruction, microvillus inclusion disease)
Adult Conditions Causing Intestinal Failure
- Short bowel syndrome following extensive surgeries secondary to mesenteric ischemia (following thrombosis, embolism, volvulus, or trauma)
- Inflammatory bowel disease such as Crohn's disease
- Small bowel tumors such as Gardner's syndrome (familial colorectal polyposis)
- Tumors of the mesenteric root and retroperitoneum (desmoid tumor)