An Unusual Location for Arteriovenous Malformations

Abstract

Arteriovenous malformations (AVMs) are lesions in the gastrointestinal (GI) tract which are frequently encountered in older patients. They account for up to 6% of lower GI bleeding and up to 8% of upper GI bleeding with presentation ranging from occult to overt bleeding. AVMs most frequently occur in the stomach, small intestine, and proximal colon. Esophageal AVMs are rare and have been reported twice in literature in the presence of Barrett's esophagus mucosa. We present the 3rd reported case of esophageal AVMs. A 79-year-old man was admitted to the hospital with shortness of breath and fatigue. His medical history includes long segment Barrett's esophagus and esophageal adenocarcinoma (EAC). His EAC was diagnosed 2 years ago and treated with radiation monotherapy due to other comorbidities including coronary artery disease and congestive heart failure. He denied any overt gastrointestinal bleeding, weight loss, or dysphagia. His vital signs on admission were normal. His physical exam was only significant for conjunctival pallor. Laboratory data was significant for a hemoglobin level of 7.8 g/dL with his prior hemoglobin levels being normal. Iron studies demonstrated a low serum iron and ferritin. An upper endoscopy was performed which showed a long segment of salmon colored mucosa proximal to the GEJ consistent with Barrett's esophagus. There were numerous AVMs throughout the Barrett's mucosa in a diffuse pattern that abruptly stopped where the squamous tissue began. There was no mass or lesion in the esophagus, and the stomach and duodenum were normal. Radiofrequency ablation was performed to prevent further blood loss. Our case highlights a diffuse presence of AVMs leading to occult bleeding, in contrast to the single AVMs reported in prior literature. This patient's history of radiation exposure for treatment of EAC also differentiates his case from others. Radiation changes to the esophagus typically involve an acute ulcerative process followed by a chronic fibrosis. The presence of metaplastic mucosa and lack of squamous mucosa may have caused atypical reactions to the radiation in the esophagus, analogous to rectal AVMs. Thermal therapy was the most efficacious modality for achieving hemostasis due to its shallow penetration depth and wide contact area.1826_A Figure 1. Esophageal AVM 11826_B Figure 2. Esophageal AVM 2