Segmental arterial mediolysis: a vasculitis mimicker. A single centre experience.

Objectives: Segmental arterial mediolysis (SAM) is a rare vasculopathy of unknown aetiology. It is non-atherosclerotic, non-inflammatory, non-hereditary, non-infectious, large to medium-sized arteriopathy. SAM is a condition which in some circumstances behaves as a vasculitis mimicker and should be recognised in order to provide appropriate treatment and avoid unnecessary immune-suppressive therapy.

Methods: We report a single-centre experience of 6 consecutive SAM cases (3 males and 3 females). A literature search of cases reported with SAM was performed and data summarised.

Results: Abdominal or flank pain was the presenting symptom in 5 of the 6 patients. CT angiography (CTA) was the method of diagnosis in all 6 patients. 3 patients underwent therapeutic angiography; 2 with angiographic embolisation because of bleeding, and one patient needed a stent insertion because of left renal infarction. 2 patients underwent FDG-PET to rule out vasculitis. Serological tests were negative in all case, but C-reactive protein was elevated in 4 of them. 2 patients were treated with angiographic embolisation due to bleeding, 2 treated with anti-platelet therapy, one with stent insertion, and one with antihypertensive treatment. A medical literature review of 160 additional cases shows that abdominal or flank pain was the chief complaint in the vast majority of the cases. Renal and abdominal medium-sized arteries were the most commonly involved. CTA was the preferred method of diagnosis.

Conclusions: SAM should be suspected in cases presenting with abdominal or flank pain. Angiographic features should be carefully studied by experienced radiologists to rule out vasculitis.