Small intestine transplantation is the removal of the small intestine from a recently decreased person and then the transfer of the small intestine, sometimes with other organs, into a person who cannot get enough nutrients because of a disorder of their small intestine.
(See also Overview of Transplantation.)
Transplantation of the small intestine may be done when people cannot get enough nutrients because
They have a severe disorder that prevents the intestine from absorbing nutrients.
The intestine had to be removed because of a disorder or injury.
They have multiple tumors, chronic abscesses, or other problems that block the intestine.
They need to be fed intravenously (total parenteral nutrition) but no longer can be because of problems, such as liver failure or recurring infections.
Small intestine transplantations are done less frequently because there are treatments and techniques that make transplantation less necessary.
After 3 years, more than 50% of small intestine transplants are still functioning, and about 65% of people who have had an intestinal transplant are still alive.
Both donors and recipients undergo pretransplantation screening. This screening is done to be sure that the organ is healthy enough for transplantation and the recipient does not have any medical conditions that would prohibit transplantation.
Procedure
The small intestine can be transplanted alone or with other organs—a liver, stomach, and/or pancreas. These procedures can be very complicated.
A surgeon removes the diseased part of the recipient's small intestine and replaces it with a healthy piece of small intestine from the donor. The blood vessels of the recipient and the transplant are connected, and the donor's intestine is connected to the recipient's digestive tract.
Part of the transplanted small intestine is connected to an opening through the abdominal wall to the skin—called an ileostomy. This opening enables doctors to monitor how well the transplant is functioning and to check for problems. Usually, the opening can be closed after a period of time. While the ileostomy is present, body wastes pass through it and empty into a pouch.
Complications
Transplantation can cause various complications. Intestinal transplants are particularly prone to both infection and rejection.
Rejection
Even if tissue types are closely matched, transplanted organs, unlike transfused blood, are usually rejected unless measures are taken to prevent rejection. Rejection results from an attack by the recipient's immune system on the transplanted organ, which the immune system recognizes as foreign material. Rejection can be mild and easily controlled or severe, resulting in destruction of the transplanted organ.
Rejection occurs at least once in about 30 to 50% of people within a year after small intestine transplantation. Symptoms include diarrhea, fever, and abdominal cramps.
After transplantation, doctors use a viewing tube (endoscope) to check the intestine for signs of rejection. This test is done frequently, sometimes once a week, at first. Then the test is done every few weeks, then every few months.
Graft-versus-host disease
Because the small intestine contains a large amount of lymphatic tissue, the new intestinal tissue may produce cells that attack the recipient’s cells, causing graft-versus-host disease.
Other complications
Sometimes the new intestinal tissue develops problems with blood vessels and thus lacks enough blood supply. The tissue needs to be surgically removed. People may also eventually develop a blood cancer called lymphoma.
