Pathological features of Crohn's disease determining perforation.

Even if Crohn's disease (CD) stenoses are related to perforating complications, such as abscess or fistula, it remains unclear why only some stenoses lead to such complications. We have studied the surgical specimens in 94 cases of CD to characterize the anatomical features of stenosis. We found no differences between group A (patients with perforation) and group B (noncomplicated patients) as far as extent of lesion, number of stenoses, and the caliber of the stenotic bowel. In CD of the ileum, the wall thickness of the stenoses was significantly different: 12.0 +/- 3.4 mm in group A and 7.6 +/- 3.1 mm in group B (p less than 0.001). In colonic CD, the length of stenosis was significantly greater in patients with perforation. Duration of symptoms, age at surgery, and sex did not correlate with the increased thickness or with perforating complications. These observations suggest that the fibrotic gastrointestinal tract, poorly distensible, may increase the intraluminal pressure above the stenosis and in this way squeeze bowel content through mucosal fissures of the inflamed bowel. Evaluation and monitoring of wall thickness may help in prompting surgery before the disease is complicated by perforation.