Classification of spontaneous isolated superior mesenteric artery dissection: correlation with multi-detector CT...

The purpose of the study is to propose a computed tomography (CT) classification of spontaneous isolated superior mesenteric artery dissection (SISMAD) correlated with clinical presentation METHODS: We retrospectively reviewed CT images of 40 patients with SISMAD at our institution from 2006 to 2015 and proposed a new classification: type I, patent false lumen with both entry and re-entry; type II, patent false lumen without re-entry; type III, completely or partially thrombosed false lumen; and type IV, thrombosed false lumen with ulcer-like projection. Additionally, we included a subtype (S) at each type when there was either a long segment of dissection and/or significant true lumen stenosis. CT features were statistically analyzed using Fisher's exact and Mann-Whitney test.

The CT findings classified patients as type I (15%), type II (12.5%), type III (35%), and type IV (37.5%). Of the 40 patients, 25 (62.5%) were symptomatic. There was a significantly different proportion of each type between symptomatic and asymptomatic patients (p = 0.005). There were 25 patients with subtype (S); no type I or II, 12 type III, and 13 type IV. The symptomatic patients showed longer dissection tendency and more severe true lumen stenosis (78% vs. 53%, p = 0.000) compared with asymptomatic patients.

The proposed multi-detector CT classification of SISMAD correlates with clinical presentation. This new classification could be helpful for treatment planning.