SHM Converge Scientific Abstract ePoster Gallery-Sam

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This case describes a 46-year-old man with 8 days of sudden epigastric pain radiating across the abdomen. An initial CT abdomen/pelvis was read as unremarkable, and he was discharged on a PPI. However, the final radiology review identified possible vascular inflammatory changes, prompting a CT angiogram that showed inflammatory changes around the celiac artery extending into the splenic and common hepatic arteries, with a short segment focal dissection and a 6 mm pseudoaneurysm. Because vasculitis was suspected, he received 3 days of pulse-dose methylprednisolone before transfer for further evaluation.<br /><br />At the receiving hospital, the patient’s pain had resolved and he was hemodynamically stable. Laboratory evaluation showed normal ESR and CRP, positive ANA at 1:160 with homogeneous pattern, normal complement levels, negative ANCA, and negative hepatitis testing. Rheumatology and vascular surgery reviewed the case. Imaging showed no involvement of other arteries. Based on the clinical and imaging findings—especially the dissection—segmental arterial mediolysis (SAM) was felt to be more likely than vasculitis.<br /><br />SAM is a non-inflammatory, non-atherosclerotic vasculopathy that often affects splanchnic vessels and can mimic vasculitis on imaging. A key distinguishing feature is arterial dissection, which is more characteristic of SAM. Importantly, immunosuppressive therapy used for vasculitis is not effective in SAM and may worsen outcomes. The patient was managed conservatively with blood pressure control and repeat imaging. Five days later, the pseudoaneurysm and wall thickening were stable, and at 3-month follow-up he remained asymptomatic with improved arterial wall thickening and a smaller pseudoaneurysm.<br /><br />This case highlights the importance of recognizing SAM as a vasculitis mimicker to avoid unnecessary immunosuppression and ensure appropriate follow-up.

Asset Subtitle

Khushboo Singh

Meta Tag

Author List Khushboo Singh, Sebastian C. Sattui, Tissa Bijoy George

Category Clinical Vignettes

Concept Segmental Arterial Mediolysis

Concept Arterial Dissection

Concept Pseudoaneurysm

Concept Immunosuppressive Therapy

Concept Vasculitis

Distinguished Non-Finalist

Presenter Organization Upmc

Presenting Author Khushboo Singh

Track Adult

Keywords

segmental arterial mediolysis

celiac artery dissection

pseudoaneurysm

splanchnic vasculopathy

vasculitis mimicker

abdominal pain

CT angiogram

arterial dissection

immunosuppression

blood pressure control

Segmental Arterial Mediolysis

Arterial Dissection

Pseudoaneurysm

Immunosuppressive Therapy

Vasculitis