Management of Asymptomatic Spontaneous Isolated Superior Mesenteric Artery Dissection and Morphology Features and Variations on Abdominal Contrast-Enhanced Computed Tomography: A Single-Center Experience.

Background: Spontaneous isolated visceral artery dissection (SIVAD) is rare. Recently, appropriate treatment strategies for symptomatic SIVAD have been proposed. We aimed to determine the management of asymptomatic spontaneous isolated superior mesenteric artery dissection (ASISMAD), which is relatively frequently encountered in SIVAD.

Methods: We retrospectively reviewed abdominal contrast-enhanced computed-tomography (CE-CT) scans from January 2015 to December 2020 in our institution and identified 24 patients with ASISMAD. Patient characteristics, vascular risk factors, complications, morphology features on CE-CT images, changes in abdominal CE-CT, and treatments outcomes were analyzed.

Results: All patients were male. The mean age of the patients was 66.0 ± 8.9 (standard deviation) years, and the follow-up period was 24.8 ± 28.7 months. The CE-CT images revealed that 1 patient had periarterial fat stranding, 15 patients had aneurysmal dilatation, and 7 patients had branch vessel involvement. The mean length of the dissection was 19.9 ± 13.5 mm. The mean distance from the orifice of the superior mesenteric artery to the dissection origin point was 14.9 ± 8.8 mm. The mean branching angle was 54.8°± 19.7°. None of the patients had dissection-related abdominal symptoms or complications. Follow-up CE-CT scans showed progression of the dissection in 2 (8.3%), improvement in 2 (8.3%), stable dissection in 17 (70.9%), and complete remodeling in 3 (12.5%).

Conclusions: Patients with ASISMAD do not require hospitalization because the pathology does not usually progress to visceral ischemia. Nevertheless, follow-up CE-CT is required because of progression of the dissection in rare cases.