Pediatric Intestinal Transplantation: The Resected Allograft

Abstract

We reviewed the clinical and pathologic finding of 22 resected allografts from 19 of the 83 children who underwent a variety of small intestinal transplant procedures in the years 1990-2000 at the Children's Hospital of Pittsburgh. Resections were compared with prior mucosal biopsies because resections allow for evaluation of the entire bowel thickness, including the feeding vessels, and obviate the problems of limited sampling. Partial resections that were done soon after the transplant, or soon after additional surgery, were for surgical problems such as leaks, adhesions, and volvulus. None had biopsy features suggestive of rejection or infection. Partial resections done late (6 months or more) after transplantation were more likely to be related to allograft immune biology; two had a sclerosing peritonitis that was confined to the allograft, and one had an obstructing carcinoma arising in the allograft mucosa. One patient had a localized stricture, demonstrated to be due to graft vascular disease at partial resection, and this patient went on to have the allograft removed a year later for chronic rejection. Early complete allograft enterectomies were for refractory acute cellular rejection, 1-2 months following transplant. One was removed for pancreatitis and liver failure from operative complications. Late allograft enterectomies were generally for chronic rejection, some with residual acute rejection, but there were also a number of patients who had multiple superimposed conditions such as cytomegalovirus, Epstein-Barr virus, and post-transplant lymphoproliferative disorder in various combinations. One had idiopathic scarring and developed an adynamic bowel that remains unexplained. Examination of the resected specimens allows for dissection of the multiple contributions to graft failure, especially the vascular disease that can rarely be seen on mucosal biopsy. An unexpected finding was the impressive hypertrophy of neural elements, nerves, and ganglion cells in many of the patients, the significance of which requires further investigation.

Diffuse mesenterial sclerosis: a characteristic feature of chronic small-bowel allograft rejection

“…The majority of publications about the histopathology of experimental chronic intestinal allograft rejection has focused on structural abnormalities of the intestinal wall and -with a few exceptions -neglected the alterations of the allograft mesenteries [8,9,16,26,27]. However, these few morphologic descriptions point to alterations of the mesenteries which are similar to the changes described in the present study [5,17,21]. However, these few morphologic descriptions point to alterations of the mesenteries which are similar to the changes described in the present study [5,17,21].…”

Sclerosing peritonitis, a rare complication after intestinal transplant. Report of one case successfully treated with adjustment of immunosuppression

“…Published data show that the prevalence rates in the general population are low, between 0.54% and 0.9% . So far, SP cases related to IT have been treated with partial intestinal resection or enterectomy leading to retransplantation . In some of these cases, adjustment of immunosuppression including corticosteroid boluses as palliative treatment was used, but in all cases, surgical resections were performed to solve the intestinal obstruction with high mortality associated with the occurrence of SP.…”

Pathology of Pediatric Gastrointestinal and Liver Disease

“…Another striking feature that has been reported primarily in pediatric intestinal grafts is the development of a sclerosing or fi brosing peritonitis, wherein the serosa and subserosa of the entire allograft are markedly fi brotic and thickened with extensive areas of hyalinization and associated infl ammation (Noguchi Si et al 2002 ;Macedo et al 2005 ;Ramos et al 2007 ;Ruiz et al 2003 ). The clinical presentation is usually vomiting and features of bowel obstruction with abdominal pain.…”

“…It is therefore important to carefully evaluate any resection specimen or segments of bowel received that represent the allograft to exclude the possibility of small or early lesions of PTLD besides evaluating for vascular and other changes (Noguchi Si et al 2002 ). Areas of necrosis are frequently seen in these tumors, and perforation may be a complication.…”