Jejunal versus ileal segmental allografts in the dog: comparison of immunologic and functional results

Segmental small-bowel grafts have been advocated as a means of reducing the incidence of rejection and graft-versus-host disease in small-bowel transplant recipients. This study compared the results achieved with heterotopic segmental allografts of the jejunum and the ileum that used 120 cm Thiry-Vella loops in a dog model. Immunosuppressive therapy consisted of 25 mg cyclosporine/kg/day. Results were monitored by histologic examinations, function tests (maltose and xylose absorption), and brush-border enzyme assays. Thirty-three dogs were randomized for use as a donor (n = 11) or recipient of a jejunal allograft (n = 11) or an ileal allograft (n = 11). Eight allografts were technical failures and were excluded from analysis. Fourteen allografts were successful (eight ileal, six jejunal). No case of graft-versus-host disease was observed. Six allografts (42.5%, three jejunal [50%] and three ileal [37.5%]) were rejected during the first 3 months (not statistically significant). Eight allografts (five ileal, three jejunal) were tolerated for up to 3 months and were removed. Two ileal and two jejunal allografts appeared grossly normal at surgical removal, but two ileal and one jejunal allografts exhibited signs of chronic rejection, and one ileal allograft showed advanced rejection. The jejunal and ileal allografts had similar clinical courses, as were revealed by immunologic reactions and functional parameters. We conclude that there is no major difference between jejunal allografts and ileal allografts in the dog.