The indication for intestinal transplant is intestinal failure. This is defined as an inability to maintain greater than 75% of essential nutrition through the enteric delivery of nutrients11 and is commonly the result of previous extensive small bowel resections, although severe malabsorption or dysmotility syndromes can also produce this situation. The short bowel syndrome, which manifests in these individuals, consists of massive diarrhea or stomal output, electrolyte abnormalities, fat malabsorption, gastric hypersecretion, Vitamin B12 deficiency, hyperbi-lirubinemia, and hepatic steatosis.12

While in the past patients with intestinal failure would not survive, these patients can now be kept alive with parenteral nutrition. Over the long term parenteral nutritional support can be provided at home, and many individuals with intesti-

Organ Transplantation, 2nd edition, edited by Frank P. Stuart, Michael M. Abecassis and Dixon B. Kaufman. ©2003 Landes Bioscience.

nal failure have done very well for many years with home parenteral nutrition (HPN). However, HPN is a very expensive therapy, costing $250 to $500 US dollars a day. Furthermore, HPN can be associated with potentially life-threatening complications such as catheter-related sepsis, catheter-related thrombosis, metabolic derangements, liver dysfunction, and bone disorders. In the pediatric population and in adults with extremely short guts (i.e., < 50 cm with colon, <100 cm without colon), gross impairment in liver function is seen in up to 50% of patients. Because central venous access is required for administration of TPN, and recurrent central line placements often lead to venous stenosis or occlusion, long term HPN often results in a loss of sites for vascular access.13

Since in some patients HPN may only be needed temporarily, before considering intestinal transplantation attempts at establishing enteral feeding should be pursued since there can be significant adaptation in intestinal function. Adaptation of the intestine is a result of both an increased absorptive surface due to hypertrophy and an increase in the efficiency of absorption. Generally, if an individual with intestinal failure remains HPN-dependent after 1 year, intestinal transplantation should be considered. If life-threatening complications of HPN develop prior to 1 year, intestinal transplantation should be considered earlier. If during the intestinal transplant assessment evidence of irreversible liver disease [cirrhosis, fibrosis, portal hypertension] is discovered, a liver/intestine transplant should be performed. If the underlying disease process compromises the organs supplied by both the mesenteric and celiac arterial systems, or if it mandates replacement of other sections of the alimentary tract, a multivisceral transplant (i.e., stomach, duodenum, pancreas, liver, small intestine, and colon) should be considered.

Although no specific disease entity, in and of itself, is an indication for intestinal transplant, in the intestinal transplants performed to date the primary diseases which have most commonly led to consideration of an intestinal transplant are, in adults: mesenteric thrombosis, Crohn's disease, trauma, volvulus, desmoid tumor, Gardner's syndrome/familial polyposis; and in children: volvulus, gas-troschisis, necrotizing enterocolitis, pseudo-obstruction, intestinal astresia, and Hirschsprung's disease.10

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