Recurrence of Crohn's lesions in the neoterminal ileum after ileal resection and ileocolonic anastomosis.

The recurrence rate after "curative" resection for Crohn's disease is variously reported to be between 17% and 81%. Endoscopic-histological studies in over 200 patients allowed us to demonstrate that 71% of the patients have endoscopic evidence of recurrence within the first year of surgery. The early lesions consist of small aphtoid ulcers. Later these lesions become confluent and result in large, often longitudinal ulcerations, separated by a thickened nodular mucosa with inflammatory cell infiltration. Eventually stenosis develops. These lesions are in 90% of the cases confined to the neoterminal ileum and around the anastomosis. Pre- and postoperative studies indicated that these ulcers do not develop from preexisting lesions left behind at surgery. However, the segment to be used as neoterminal ileum contains an increased number of HLA-DR+, ATPase + dendritic cells in the lamina propria. These findings suggest that immunological processes play a role in the development of recurrent lesions. We further showed that the severity of the early recurrence allows to predict the future course of the disease.