Segmental Arterial Mediolysis: Clinical and Imaging Features at Presentation and during Follow-up

Purpose: To review clinical and imaging features at presentation and during follow-up of patients with a suspected diagnosis of segmental arterial mediolysis (SAM). Materials and Methods: All cases of SAM diagnosed at a single institution from 2000 to 2010 were included. Diagnosis was based on characteristic radiologic features in the absence of other plausible diagnoses. Medical records were reviewed for demographics, presenting symptoms, and laboratory and imaging findings at presentation and during follow-up. Results: Fourteen patients (nine men; mean age, 53 y +/- 15) were diagnosed with SAM. Initial presentation included abdominal or flank pain (n = 8) and chest pain, headache, stroke, or suprapubic fullness (n = 1 each). Two patients were asymptomatic. Inflammatory markers were negative in all cases. Imaging at presentation revealed involvement of celiac (n = 7), common hepatic (n = 3), splenic (11 = 2), superior mesenteric (n = 5), renal (n = 5), and iliac (n = 2) arteries and the abdominal aorta (n = 1). Imaging demonstrated arterial dissections (n = 10), fusiform aneurysms (n = 6), arterial wall thickening (n = 2), and artery occlusion (n = 1). Clinical follow-up was available in 13 patients (median, 25 mo). Symptoms improved (n = 4), resolved (n = 3), or remained stable (n = 2), and four patients experienced new symptoms. Follow-up imaging, available in 10 patients at a median of 33 months, demonstrated new dissections, aneurysms, or arterial occlusions in five patients, including carotid artery dissection in three. Imaging findings remained stable (n = 3), improved (n = 1), or resolved (n = 1). Conclusions: SAM affects middle-aged and elderly patients. Visceral artery dissections and aneurysms are common. The disease progresses in nearly half the patients. Serial follow-up with computed tomographic angiography and/or magnetic resonance angiography may be necessary to monitor disease progression.