Imaging appearances and management of isolated spontaneous dissection of the superior mesenteric artery

Abstract Objective The objective of our study was to report the clinical and imaging features of isolated dissection of the superior mesenteric artery (SMA) and describe our imaging classification of this disease entity. Subjects and methods We retrospectively analyzed clinical presentation, imaging appearances and outcome of the 12 patients who were diagnosed as having spontaneous dissection of the SMA from 1991 to 2005 in our institution or its affiliated two hospitals. There were 11 males and 1 female with a mean age of 50 years (range, 43–61 years). The diagnosis of isolated dissection was established with CT within 24 h of the onset. Results We categorized SMA dissection into the following four types based on imaging appearances: type I, patent false lumen with both entry and re-entry (four patients), type II, ‘cul-de-sac’ shaped false lumen without re-entry (one patient), type III, thrombosed false lumen with ulcer like projection (ULP), which is defined as a localized blood-filled pouch protruding from the true lumen into the thrombosed false lumen (five patients) and type IV, completely thrombosed false lumen without ULP (two patients). One patient with type II underwent urgent surgery because of small bowel ischemia. One patient with type III underwent urgent embolotherapy for the treatment of rupture of a branch of the SMA. The remaining 10 patients were initially managed conservatively. In one of the conservatively treated patient, ULP had progressively dilated, and it was treated with stent placement and coil packing 22 months after the onset. The remaining nine patients were conservatively managed without any event during the follow-up period of 7–72 months. Conclusion Most of the patients with isolated SMA dissection can initially be managed conservatively if there are no clinical and imaging signs indicating ruptured SMA branches or bowel ischemia.