Treatment strategy based on the natural course for patients with spontaneous isolated superior mesenteric artery dissection

Objective: The optimal treatment of spontaneous isolated superior mesenteric artery dissection (SISMAD) is still not known, and we sought to determine an optimal treatment strategy for patients with SISMAD based on its natural clinical course. Methods: We retrospectively reviewed consecutive patients with SISMAD treated from 2001 through 2016. Diagnosis and angiographic type of SISMAD were determined with contrast-enhanced computed tomography (CT) scan, and the clinical features were obtained using a fixed form questionnaire. All patients were treated conservatively, except for five who unselectively underwent primary interventional treatment. For the follow-up examinations, clinical features and morphologic changes of superior mesenteric artery dissection were examined with CT angiography every 6 to 12 months. Results: During the past 15 years, 116 patients with SISMAD (male, 92%; mean age, 54.7 +/- 10.8 years; symptomatic, 76%) were encountered. Clinical features and morphologic changes on CT examinations were available in 100% and 88% of the patients, respectively, during the mean follow-up of 53 +/- 39 months (range, 1-173 months). Of 83 symptomatic patients managed conservatively, 96% achieved pain resolution; 4% experienced prolonged pain, including one patient with bowel gangrene. After pain resolution, 20% of patients developed late recurrence of abdominal pain, which was relieved with conservative management, whereas two patients (12%) required surgery to treat bowel stricture. Follow-up examinations (n = 102) by CT angiography revealed no change in 34%, partial or complete remodeling in 63%, aneurysmal change in 2%, and dissection progression in 1% of the patients. Antithrombotic therapy offered no beneficial effects on either clinical or morphologic outcomes. Conclusions: With conservative treatment, the majority of patients with SISMAD showed clinical improvement and no morphologic changes during long-term follow-up. We thus recommend a conservative management strategy as the first-line treatment for patients with SISMAD, regardless of angiographic type.