Objective: The purpose of this study is to identify the imaging characteristics of segmental arterial mediolysis (SAM) at presentation and establish the longitudinal course of disease.
Materials and methods: We retrospectively identified patients with SAM at a single institution from 2000 through 2015. Diagnosis was based on published guidelines with multidisciplinary consensus. Imaging studies obtained at initial evaluation were reviewed to evaluate imaging findings and vascular territory distribution. All subsequent follow-up imaging studies were reviewed to assess for progression, stability, or regression.
Results: We identified 111 patients (79 men and 32 women; median age, 51 years) who met the diagnostic criteria for SAM. Abdominal pain was the most common presentation (74%), followed by flank pain (21%). SAM most commonly affected the renal arteries (47%), superior mesenteric artery (46%), celiac trunk (46%), hepatic artery (23%), iliac arteries (18%), and splenic artery (14%). The most common imaging findings were dissection (86%), aneurysm (57%), beading or webs (28%), occlusion (19%), and a rind or wall thickening (15%). The 247 available follow-up imaging studies for 97 patients (median follow-up, 12 months) showed progression in 19 patients (20%), with either stability or regression observed in the remaining patients.
Conclusion: SAM most commonly affects the renal arteries, superior mesenteric artery, and celiac artery. Dissections and aneurysms are the most common imaging findings. Follow-up imaging studies show stability or regression in most patients.
Keywords: aneurysm; dissection; hemorrhage; segmental arterial mediolysis; vasculopathy.