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Spring 1994Volume 1, Number 1 |
The use of Total Parenteral Nutrition (TPN) has significantly improved the management of patients with intestinal failure. However, TPN-related complications such as liver dysfunction, cirrhosis, major vessel thrombosis, and sepsis have limited the benefits of TPN. Patients suffering from these complications can now be helped with intestinal transplantation (ITx). Although clinical trials of this procedure performed between 1964 and 1987 resulted in almost total failure (Transplant Proc 1989;21: 2869-2871), the results of recent trials are encouraging.
A clinical trial of ITx with FK506 immunosuppression began at the University of Pittsburgh in May, 1990. The intestine was transplanted alone or in combination with other abdominal organs, depending on the etiology of the intestinal failure and its associated effects on other organ systems (Annals of Surgery 1992;216:223-234). Table 1 lists the indications for ITx performed at the University of Pittsburgh between May 1990 and September 1993. During this period 60 patients (27 males and 33 females) received either isolated intestinal transplants (n=22), combined liver and intestinal transplants (n=27), or multivisceral transplants (n=11) (see illustrations). There were 27 adults ranging in age from 19 to 58 years, and 32 children ranging in age from six months to 16 years. There were 4 graft retransplants, 17 deaths (29%), and 8 intestinal graft removals (including one patient who was retransplanted, and three patients who later died). Of the 42 survivors, 34 (81%) are presently off TPN; four require partial TPN support, and four had TPN reinstituted after graft removal.
| INDICATIONS FOR INTESTINAL TRANSPLANTATION
AT THE UNIVERSITY OF PITTSBURGH (5/90 - 1/93) | |
| CHILDREN | ADULTS |
| Necrotizing enterocolitis | Crohn's disease |
| Gastroschisis | Thrombolytic disorder |
| Volvulus | Trauma |
| Pseudo-obstruction | Pseudo-obstruction |
| Hirschsprung's disease | Radiation enteritis |
| Intestinal atresia | Desmoid tumor |
| Microvillus inclusion disease | Familial polyposis |
| Malrotation | Volvulus |
Successful weaning from TPN support requires gradual advancement of oral or enteral feedings (via gastric or jejunal tube); results have varied among adult and pediatric populations. Recipients of combined liver-intestinal and multivisceral grafts require a mean of 60 post-transplant days to become independent of TPN, whereas recipients of isolated intestinal grafts require only about 30 post-transplant days. Some pediatric recipients who had never been exposed to an oral diet tended to resist oral feedings post-transplant. On an unrestricted oral or enteral diet, pediatric recipients showed consistent growth in height and weight post-transplant, and most adults maintained normal or appropriate body weight post-transplant.
A. Isolated intestinal transplant. B. Combined liver and intestinal transplant. C. Multivisceral transplant. Clamps indicate the route used for endoscopic observation and endoscope-guided biopsies.
Intestinal allograft function can be adequately assessed using D-xylose absorption and fecal fat excretion. In patients receiving tacrolimus for immunosuppression, it is common to see reduced absorption of the drug if moderate to severe graft rejection occurs. Satisfactory absorption has been confirmed using these parameters in the first postoperative month. Monitoring of the intestinal graft involves clinical examination of the abdomen and stoma, analysis of stomal output, and endoscopic evaluation.
The postoperative course of intestinal recipients is stormy, with numerous complications and frequent readmissions. Patients were readmitted a mean of 4.7 times during the first year after transplant, typically for infection, rejection, or dehydration. Acute intestinal allograft rejection has occurred in 80% of isolated intestinal grafts and 77% of combined liver-intestine grafts. The incidence of acute liver allograft rejection in the combined liver-intestinal recipients has been about 55%. Four patients required graft replacement due to hepatic artery thrombosis (n=1) and graft rejection (n=3).
Intestinal transplantation has evolved into a feasible operation. However, strict candidate selection and a multidisciplinary team approach to patient management are critical. Although intestinal transplantation has become a practical surgical procedure, further investigations and new strategies are required, especially in terms of immunosuppressive therapy.
Jorge Reyes, MD
Pittsburgh Transplantation Institute
Pittsburgh, Pennsylvania
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