The value of mucosal biopsies in evaluating small bowel rejection is c
ontroversial, In this study, the value of mucosal biopsies was estimat
ed in unmodified porcine small bowel rejection. Ten animals received t
he distal half of the small bowel as a heterotopic loop (Thiry-Vella l
oop), The allografts were followed by proximally and distally harveste
d Pull-thickness and mucosal biopsies every other day, starting from t
he 3rd day and continuing until the grafts became necrotic. The histol
ogical parameters in both types of biopsies were semiquantitatively sc
ored from 0 to 3 and compared with each other. The difference in mean
values on subsequent days was not remarkable. the results favoring sli
ghtly higher values in full-thickness than in mucosal biopsies, Our re
sults suggest that multiple mucosal biopsies are adequate in monitorin
g morphological changes of small bowel grafts during rejection and tha
t the proximal and distal ileum are similarly affected by acute reject
ion.