Endoscopic and external bowel changes and histopathology in patients with Crohn's disease

The relationships between intraoperative endoscopic findings, exterior bowel wall changes and transmural histopathology were investigated in 23 patients with Crohn's disease (24 resections). Villous atrophy and leucocyte infiltration of the epithelium, lamina propria and submucosa were common in intestine without endoscopic lesions. Minor endoscopic ulcers were associated with leucocyte infiltration, ulcers and pyloric metaplasia, and large endoscopic ulcers and stricture with severe transmural inflammation, fibrosis and fissures. In ileal Crohn's disease (19 resections), correlation was close between endoscopic stage and histopathology (rs = 0.77, P < 0.0001), but an exterior lesion index showed worse correlations with endoscopy and histology (rs = 0.57 and rs = 0.59 respectively). The difference was attributable to patients with previous resection and/or fistula showing exterior lesions without concomitant histological or endoscopic abnormalities. Intraoperative surgical decisions should be guided by endoscopic observations rather than by assessment of exterior bowel wall changes.