The International experience of small bowel transplantation since 1985 has been compiled and analyzed through the International Intestinal Transplant Registry (IITR). As of May 2001, the Registry reported that 55 intestine transplant programs have been established, with 696 intestine transplants performed in 656 patients.
Combined intestine-liver transplantation was the most common type performed (44%), followed by isolated intestine transplantation (42%) and multivisceral transplantation (15%).
The most common indications in adults are:
- Ischemia (22%)
- Crohn’s disease (13%)
- Trauma (12%)
- Desmoid tumor (10%)
The most common indications in pediatrics are:
- Gastroschisis (21%)
- Volvulus (18%)
- Necrotizing enterocolitis (12%)
The intestine is a muscular tube that moves food from the stomach to the anus. As food travels through the small and large intestines, fluids and nutrients are absorbed through the intestinal wall. People become dehydrated and malnourished when the intestine does not function well. Symptoms of intestinal failure include: persistent diarrhea, dehydration, muscle wasting, poor growth, frequent infections, weight loss, and fatigue.
Bowel transplantation was first attempted in humans during the 1960s. At that time, patients were dying of starvation after having a large portion of their bowel removed because of disease or trauma. Parenteral (intravenous) feeding was not yet available, and surgeons hoped that the transplanted bowel would function normally. These first intestinal transplant patients died, however, from technical complications such as: rejection, or infection. Successful intestinal transplants were not performed until the mid-1980s when better immune suppressive drugs became available along with better methods to prevent infections. As a result of these improvements, today almost 1000 patients have been able to stop total parenteral nutrition (TPN), resume a normal diet, and enjoy a healthy lifestyle after intestinal transplantation.
The intestine has been more difficult to transplant than other solid organs and some of the possible reasons include:
• the large number of white cells in the bowel provides a strong stimulus for rejection
• the large number of bacteria in the gut increases the risk of infection after transplantation
Patients must take anti-rejection drugs to suppress their immune system so their body will accept the transplanted bowel. They must take enough drugs to prevent rejection, but not too many or they may have problems with infection and drug toxicity. Prograf® (FK506, tacrolimus) is the most common anti-rejection drug used in intestinal transplantations.
Patients with poor intestinal function who cannot be maintained on intravenous feedings are potential candidates for transplantation. Sometimes, most of the bowel has been surgically removed to treat a disease. This produces the “short-gut syndrome”, which is the most common cause of intestinal failure. Sometimes, the entire intestine is present, but it is unable to absorb enough fluids and nutrients.
Diseases leading to intestinal transplantation include:
- Short-gut syndrome caused by volvulus, gastroschisis, trauma, necrotizing enterocolitis, ischemia, or Crohn’s disease
- Poor absorption caused by microvillus inclusion, secretory diarrhea, or autoimmune enteritis
- Poor motility caused by pseudo-obstruction, aganlionosis (Hirschprung’s disease), or visceral neuropathy
- Tumors or cancer such as desmoid tumors, or familial polyposis (Gardner’s disease)
Many children and adults do well on total parenteral nutrition (TPN), and transplantation may not be indicated for these patients. Transplantation, however, is a potentially life-saving option for patients with intestinal failure who cannot tolerate TPN or who present with limited venous access. Because patients’ survival rates are better after isolated bowel transplants, this is the preferred type of transplant. However, combined intestinal-liver transplants (or cluster transplants) are the best options for patients who developed liver failure on TPN or for patients who have large, local tumors that can only be removed by removing several organs.
Most intestinal grafts come from cadaver donors— people who have been declared dead in a hospital while attached to a ventilator (artificial breathing machine). Consent is given by the next of kin for organ removal and transplant. Occasionally, a portion of the bowel is taken from a living donor— usually a relative such as a parent or sibling.
Improved anti-rejection drugs, refined surgical procedures, better prevention of infection, and a greater understanding of immunology have all contributed to successful intestinal transplants. Survival rates are now comparable to, or better than, the results of lung transplantation. Of the surviving patients, three-fourths have stopped total parenteral nutrition (TPN) resuming on a normal oral diet. Because most of the patients in the international Intestinal Transplant Registry have been followed for a brief period time; it will take several years to obtain reliable data on long-term results.
To become the standard treatment for intestinal failure, transplantation must offer better survival, better quality of life, and lower costs than TPN. Considerable progress has been made towards these goals, but further refinements are needed before bowel transplantation becomes a routine surgical procedure.
After intestinal transplant the patients may experience postoperative complication(s). The commonest complications include infections, rejection, intestinal ischemia, and leaks from the anastomoses. Because of the high doses of immunosuppressive medications, intestinal transplant recipients are at higher risk of infection compared to other surgery patients. Rejection is another complication in which body reacts against the transplanted intestine. Intestinal ischemia and leak are mostly related to due to surgical technical difficulty in reconnection of the intestine and the vessels. There are treatment options for all of the above-mentioned complications but in some cases they result in graft loss or even death of the patient.
Information was credited from:
Intestinal Transplant Association (C)2011
Beverly Kosmach Park, MSN, CRNP, Clinical Nurse Specialist, Department of Transplant Surgery, Starzl Transplantation Institute, Children’s Hospital of Pittsburgh, Pennsylvania-
Medscape Article: http://www.medscape.com/viewarticle/436543