Duodenal compression defect and the "superior mesenteric artery syndrome" 1.

Forty-two cases of progressive systemic sclerosis were reviewed. A compression defect of the duodenum was found at the site where the superior mesenteric artery crossed the duodenum in all patients with duodenal dilatation. A similar observation was made in patients with small-intestinal obstruction and pancreatitis. Both the defect and dilatation may spontaneously disappear and return. The author concludes that in the cases studied, the compression produced by the superior mesenteric artery is secondary to dilatation and loss of muscle tone of the duodenum. It does not cause obstruction, and its presence per se does not warrant a diagnosis of "superior mesenteric artery syndrome."