Innovative approaches to improving organ availability for small bowel transplant candidates

Choice of Allograft in Patients Requiring Intestinal Transplantation: A Critical Review

Intestinal transplantation (ITx) is indicated in patients with irreversible intestinal failure (IF) and life-threatening complications related to total parenteral nutrition (TPN). ITx can be classified into three main types. Isolated intestinal transplantation (IITx), that is, transplantation of the jejunoileum, is indicated in patients with preserved liver function. Combined liver-intestine transplantation (L-ITx), that is, transplantation of the liver and the jejunoileum, is indicated in patients with liver failure related to TPN. Thus, patients with cirrhosis or advanced fibrosis should receive a combined allograft, while patients with lower grades of liver fibrosis can usually safely undergo ITx. Reflecting their degree of sickness, the waitlist mortality rate and the early posttransplant outcomes of patients receiving L-ITx are worse than IITx. However, L-ITx is associated with better long-term graft and patient survival. Multivisceral transplantation (MVTx), that is, transplantation of the organs dependent on the celiac axis and superior mesenteric artery, can be classified into full MVTx if it includes the liver and modified MVTx if it does not. The most common indications for MVTx are extensive portomesenteric thrombosis and diffuse gastrointestinal pathology such as motility disorders and polyposis syndrome. Every patient with IF should undergo a multidisciplinary evaluation by an experienced ITx team.

Use of the aspartate aminotransferase to platelet ratio index to follow liver fibrosis progression in infants with short gut

BACKGROUND

Infants with parenteral nutrition dependence may develop liver dysfunction and progress to liver failure requiring transplantation. The aspartate aminotransferase-to-platelet ratio index (APRI) has good correlation with liver fibrosis progression in adults. This study applies APRI scoring to parenteral nutrition-dependant, short-gut infants to determine hepatic fibrosis progression.

METHODS

Laboratory values and biopsies were collected from initial intestinal resection (time 0) up to transplantation (end). Fibrosis scoring ranged from F0 (normal) to F4 (cirrhosis). Children were divided into 3 groups: (1) isolated intestine; and combined liver/intestine with gestational age (2) 34 weeks or greater and (3) 30 weeks or less. Liver function values over time, including calculated APRI, were analyzed as predictors of fibrosis.

RESULTS

Fifteen children who had 33 biopsies were included. Median APRI by fibrosis grade was F < or = 2: 1.88, F3: 3.23, and F4: 14.16 (P < .01). Median APRI at transplant by study group was (1) isolated intestine: 2.47, (2) liver/intestine 35 weeks or longer EGA: 14.16, and (3) liver/intestine 30 weeks or less EGA: 14.74 (P = .04).

CONCLUSION

Progression of APRI up to 60 days initially demonstrates similar values among study groups, but over time the score distinguishes those children with impending liver cirrhosis and differentiates fibrosis grade and study group.

Intestinal transplantation: current outcomes and opportunities

PURPOSE OF REVIEW

This review highlights current outcomes in intestinal transplantation and summarizes advances that have recently occurred in five interrelated areas: progress in intestinal rehabilitation, immunologic and technical modifications, awareness of opportunities for improved allograft monitoring, and better assessment of long-term complications and morbidities.

RECENT FINDINGS

Improved long-term management of patients with intestinal failure as well as improved outcomes with intestine transplant are changing the previously established paradigms of timing for referral. For those requiring transplant, use of monoclonal and polyclonal antibody induction protocols have been associated with improved outcomes. Experience at centers of excellence demonstrates 1 and 5 year patient survival rates of 93 and 78%, respectively with ongoing investigations focusing on lowering long-term causes of graft loss such as chronic rejection or morbidities such as renal dysfunction. Descriptions of tissue, proteomic and genomic technologies to complement traditional methodologies to monitor graft function are emerging.

SUMMARY

Optimal timing for referral of children with intestinal failure and improved medical and surgical therapies increase the opportunity for intestinal adaptation without the need for transplant. For those undergoing transplant, technical and immunologic modifications, developments in graft monitoring, and reduction of long-term morbidities are leading to improved outcomes.

Rapid reversal of parenteral-nutrition-associated cirrhosis following isolated intestinal transplantation

INTRODUCTION

Liver disease and the development of hepatic fibrosis are complications associated with total parenteral nutrition (TPN). Patients developing cirrhosis and portal hypertension in the setting of intestinal failure have a high mortality and may require combined liver and intestinal transplantation which carries much higher morbidity and mortality than isolated intestinal transplantation.

DISCUSSION

Recently, regression of hepatic fibrosis in patients with TPN liver disease has been described following intestinal transplantation. To date, there has been no demonstration of the reversal of established cirrhosis due to long-term TPN injury. Herein, we describe a patient with intestinal failure who developed cirrhosis from long-standing TPN injury and underwent isolated intestinal transplantation. He had no overt clinical stigmata of portal hypertension and had preserved liver function. Serial liver biopsies were reviewed and assessed with standard histology and quantitation of fibrosis using image analysis. Dramatic regression of fibrosis and reversal of cirrhosis were observed 17 months posttransplantation. Image analysis demonstrated a 14% total decrease in the percentage area of fibrosis.

CONCLUSIONS

Cirrhosis related to TPN may be rapidly reversible after isolated intestinal transplantation. Such patients may be able to undergo isolated intestinal transplantation if they do not have hepatic synthetic compromise or clinical stigmata of portal hypertension.

Current perspectives on pediatric intestinal transplantation

Irreversible intestinal failure in children is predominantly caused by surgical conditions such as volvulus, necrotizing enterocolitis, and gastroschisis. Functional intestinal failure from motility disorders such as intestinal pseudo-obstruction or enterocyte dysfunction with microvillus inclusion disease also may require intestine replacement. Approved indications for intestinal transplantation include liver dysfunction, loss of major venous access, frequent central line-related sepsis, and recurrent episodes of severe dehydration despite intravenous fluid management. Surgical options include transplantation of the isolated intestine, combined liver-intestine transplantation, or multivisceral transplantation of the stomach, duodenum, pancreas, and small bowel (with or without the liver). Immunosuppression for intestinal transplantation is based on tacrolimus therapy, often with induction immunosuppression using antilymphocyte antibodies (eg, antithymocyte antibody and alemtuzumab). Experience at centers of excellence demonstrates 1- and 5-year patient survival rates of 95% and 77%, respectively, with ongoing investigations focusing on lowering long-term causes of graft loss such as chronic rejection.