The morphologic relationship of sinus and fistula formation to intestinal stenoses in children with Crohn's disease.

Sinus and fistula (SF) formation in adults with Crohn's disease has been ascribed to increased intraluminal pressure from stenotic lesions or to inflammation. We retrospectively evaluated 55 surgically resected specimens from 30 children with Crohn's disease for stenotic lesions, sinuses, fistulas, and inflammation. Eighteen of 30 children had one operation, and there were 12 multiple surgeries. Thirty-one of 55 specimens (56%) contained stenoses. SF formation was seen in 16 of 31 specimens with stenosis; it developed proximal to the stenosis in seven patients, distal in five, and both proximal and distal in four. SF formation was also noted in 12/24 specimens without stenosis. In 93% of the cases, the SF was associated with moderate to severe inflammation. Although 56% of the patients had stenoses, SF frequently developed independent of stenosis. All SF were associated with inflammation. Therefore, inflammation rather than increased intraluminal pressure appears to be the primary factor in SF formation in children with Crohn's disease.