S3319 An Unusual Presentation of Segmental Artery Mediolysis

Abstract

Introduction: Segmental Arterial Mediolysis (SAM) is a rare non-atherosclerotic and non-inflammatory disease that often mimics vasculitis. It most commonly affects celiac artery and superior mesenteric artery. Here we describe an unusual presentation of SAM in an elderly woman. Case Description/Methods: A 65-year-old female with history of smoking presented with sudden onset dull epigastric pain, radiating to the back, nausea, vomiting and decreased oral intake for three days. Review of system was negative for other symptoms. Vital signs upon presentation were blood pressure 140/87 mm Hg, heart rate 92 beats per minute, respiratory rate 16 per minute and saturating 96% on room air. Physical examination revealed epigastric tenderness without rebound tenderness or guarding. Initial labs showed WBC 15,200/mL, CRP 9.4 mg/L and ESR 92 mm/hour. LFTs revealed AST 2173 U/L, ALT 2013 U/L, total bilirubin 0.6 mg/dl, albumin 3.7 and INR 1.1 Further labs ruled out infectious etiology for her presentation. Rheumatologic work up was negative for ANA, ANCA or abnormalities in complement proteins. Computed tomographic angiography (CTA) of the abdomen demonstrated multiple large aneurysms involving bilateral hepatic arteries with diffuse irregularity and ectasia of the hepatic arterial system and blood products surrounding the left hepatic artery aneurysm. (Figure A) She subsequently underwent coil embolization of left hepatic artery. (Figure B) The procedure was complicated by complete occlusion of left hepatic artery and spontaneous thrombosis of right hepatic artery upon catheterization. CTA abdomen after procedure showed reconstitution of flow within hepatic arterial supply via collaterals. Post procedure investigations revealed down trending inflammatory markers and transaminitis with levels returning to baseline within a week. Discussion: To the best of our knowledge, this is the first reported case with multiple pseudoaneurysms involving both hepatic arteries. Although, in our case, histologic confirmation was not done, clinical presentation, laboratory findings and radiologic pattern, led to the diagnosis of SAM. Early detection is the key in the prognosis of SAM, as clinical course tends to be unpredictable and complications of vascular injury including stenosis, dissection, aneurysm or rupture may occur.Figure 1.: A) Computed tomographic angiography (CTA) of the abdomen demonstrated left hepatic artery aneurysm (arrowhead) and right hepatic artery aneurysm (arrow). B) Angiogram showing coil embolization of left hepatic artery (arrow).