S2831 Acute on Chronic Mesenteric Ischemia: A Unique Presentation

Abstract

INTRODUCTION: Acute on chronic mesenteric ischemia resulting in cecal/terminal ileum perforation in a symptomatic patient. This is an important differential to consider with unknown etiology of abdominal pain, weight loss, and diarrhea. CASE DESCRIPTION/METHODS: A 61 year-old man initially presented with diarrhea (up to 15 bowel movements per day, non-bloody with nocturnal episodes), intermittent abdominal pain, weight loss (40 pounds), and dyspepsia. He had a history of reflux symptoms for a couple years, and was recently started on a proton pump inhibitor with minimal improvement. Initial EGD and colonoscopy were unremarkable including normal biopsies of the stomach. Labs consisted of normal celiac serologies, negative stool cultures and Clostridium difficile, and normal TSH, hemoglobin, pancreatic elastase, and ESR/CRP. A CT abdomen/pelvis was also unremarkable except for atherosclerotic calcifications within the celiac axis and SMA. He was placed on a combination of a proton pump inhibitor, dicyclomine, diphenoxylate/atropine, loperamide, duloxetine, and eluxadoline. A repeat CT scan of the abdomen revealed small splenic infarcts, with unremarkable hematologic work-up. Repeat EGD and colonoscopy were negative including biopsies. Video capsule endoscopy showed multiple ulcerations in the jejunum which were subsequently biopsied. Histology revealed superficial ulceration, active inflammation, and eosinophilia. Tissue culture including AFB was unremarkable. Worsening abdominal pain prompted a CT scan which showed a dilated cecum and pneumatosis in the setting of sepsis. Exploratory laparotomy was performed which revealed a necrotic cecum and distal ileum with an absent SMA pulse. Resection of necrotic small bowel and cecum with SMA bypass and antegrade anastomosis was completed. Final pathology of the resected tissue showed ischemic enterocolitis with focal mucosal ulceration, transmural acute and chronic inflammation, and acute serositis. DISCUSSION: The clinical presentation of weight loss, diarrhea, dyspepsia and abdominal pain was initially treated as GERD and IBS (diarrhea predominant). The patient presented to the emergency room prior to the final diagnosis of acute on chronic mesenteric ischemia, which is usually made by CT or MR angiography. In a patient with risk factors for mesenteric ischemia, including atherosclerosis and splenic infarcts, this should prompt additional work-up accordingly.Figure 1.: Ischemic enterocolitis: mucosal ulceration and associated purulent exudate, transmural acute and chronic inflammation, and acute serositis.Figure 2.: Cecal dilation with pneumatosis.Figure 3.: Ulcerated lesion with central clean base and adjacent erythema and dilated lacteals located in the jejunum.