Segmental arterial mediolysis (SAM) is a rare vasculopathy of unknown etiology characterized by disruption of the arterial layer, which can result in vessel dissection, hemorrhage and ischemia. Literature review has demonstrated a varied presentation ranging from benign abdominal pain to life threatening hemorrhage. We report a case of 58 year old female with past medical history of deep vein thrombosis/pulmonary embolism secondary to Protein C and S deficiency on Coumadin who presented with right flank pain for 3 days. Complete blood count and complete metabolic panel were within normal limits. CT scan of abdomen and MRI showed ischemia of segment 5 of liver secondary to intrahepatic arterial pseudo-aneurysm measuring 3cm with compression of anterior branch of right portal vein. Infectious workup and Antinuclear antibody(ANA) were negative. Antineutrophil cytoplasmic antibody(ANCA), complement level, myeloperoxidase antibody and PR3 antibody were negative. Hepatitis B was negative. ESR was 73 and CRP was 224. SAM was diagnosed on the basis of the patient’s clinical history, clinical examination, CT angiogram findings and ruling out of other etiology. She underwent embolization of hepatic pseudo aneurysm that improved the pain. After 5 days, she again reports abdominal pain. Repeat CT scan of abdomen showed large perihepatic hematoma with enhancing structure in right hepatic lobe near prior embolization site concerning for re-bleeding from known pseudo aneurysm. So, reembolization of gastroduodenal artery and hepatic artery was done. Despite reembolization, she developed gall bladder necrosis with rupture and underwent exploratory laparotomy with cholecystectomy. She developed worsening transaminitis. Liver transplant workup was done. She ultimately developed sepsis, and unfortunately we lost our patient. Though segmental arterial mediolysis is rare, it is an important cause of unexplained vascular lesion. It should be considered when aneurysms, stenosis and occlusions are identified in medium and large vessel, especially when limited to one anatomical location. When segmental arterial mediolysis is suspected, multidisciplinary approach should be pursued.
Pokharel A, Reinhold L, Pokharel A, Bateman J. A rare case of segmental arterial mediolysis. Poster presented at: The American College of Physicians Michigan Chapter Residents Day / Medical Students Day; 2022 May 13; Dearborn, MI.