The value of CT findings for prognostic prediction of spontaneous superior mesenteric artery dissection

Spontaneous superior mesenteric artery (SMA) dissection is rare cause of acute abdomen. Time-dependent change of SMA dissection has not been established. To determine Sakamoto classification (SC) type of acute and chronic SMA dissection (aSMAD and cSMAD) to predict the treatment methods and outcome. From April 2003 to March 2017, unenhanced and contrast-enhanced CT were used to diagnose acute symptomatic or chronic asymptomatic SMA dissection in 25 consecutive patients without aortic dissection. Correlations between SCs and treatment methods and outcomes were investigated. All 13 patients with aSMAD initially received conservative treatment. Initial SCs in aSMAD were type I？=？1, type III？=？9, and type IV？=？3. Three of nine initial type III and two of three initial type IV changed to type I at follow-up. One of nine type III changed to type II at follow-up. Ohers did not change. One with initial type III required vascular repair, so the final SC was not available. Three patients required bowel resection. In cSMAD of 12 patients, the initial/final SC were type I and IV in ten and two patients, respectively, without change during follow-up. cSMAD was significantly older than aSMAD. The initial length of dissection of aSMAD was longer than in the cSMAD group. In aSMAD, the final length of dissection was significantly shorter than in the initial computed tomography scan. Initial SC differed significantly between aSMAD and cSMAD. Initial SC types in aSMAD were type III and IV mainly, and changed during the observation period. In cSMAD, SC types were I and IV without change