A Rare Case of Extensive Colonic Vascular Malformation Leading to Chronic Disabling Gastrointestinal Bleeding 1579

• Published in: The American journal of gastroenterology Vol. 113; no. Supplement; pp. S908 - S910
• Main Authors: Zivari, Kaveh, Niknam, Negar, Waintraub, Daniel J., Mayer, Ira E., Rahmani, Rabin
• Format: Journal Article
• Language: English
• Published: New York Wolters Kluwer Health Medical Research, Lippincott Williams & Wilkins 01.10.2018
• Subjects: Anemia; Colon; Colonoscopy; Constipation; Embolization; Gastroenterology
• ISSN: 0002-9270; 1572-0241
• DOI: 10.14309/00000434-201810001-01579

Introduction:Large arteriovenous malformations (AVM) of the gastrointestinal (GI) tract are rarely encountered. Many of these malformations are present at birth but the diagnosis usually occurs after 2 months of life. This entity can lead to chronic, debilitating rectal bleeding and severe anemia. Here we present a case of a young man with chronic disabling GI bleeding due to extensive left colon AVMs. Case Presentation: 21 year old man presented with chronic constipation, rectal bleeding, and large colonic AVMs since childhood. Prior workup included multiple colonoscopies without definitive treatment. The patient presented in 2016 with painless rectal bleeding and Hemoglobin 5g/dL. Colonoscopy showed an inflamed left colon with erythematous and bluish, congested mucosa up to 55-60cm from the anal verge. Biopsies noted edema of the lamina propria with dilated capillaries. MRA/MRV of abdomen & pelvis showed a tangle of vessels identified in the arterial phase which persisted throughout all phases of the injection in the distal descending colon, consistent with vascular malformation. Patient was admitted in 2018 with symptomatic anemia and rectal bleeding. CT Angio of the abdomen/pelvis revealed circumferential thickening of the rectum to the level of descending colon and engorged vessels around the rectum to the level of distal descending colon. Colonoscopy showed engorged external and internal hemorrhoids in continuation with enlarged rectal vessels that extended to the descending colon, causing luminal narrowing. The enlarged vessels were not amenable to endoscopic intervention. IR guided embolization of a branch of the left colic artery was performed, but the patient continued to have constipation and intermittent rectal bleeding. Discussion:AVMs arise from embryologic mesoderm, where an endothelial cell defect and secretion of growth factors leads to smooth muscle proliferation. A case series reported 10 large AVMs with the largest malformation reported up to 30cm in length. Patients primarily exhibit painless rectal bleeding. Due to luminal narrowing in larger lesions, constipation is often seen. Angiography may allow embolization of a feeding vessel, however this is not a definitive treatment. While smaller lesions have been treated with cautery and coagulation, the treatment of choice is surgical resection. Large colonic AVMs are a challenging entity and require multidisciplinary collaboration and psychosocial support especially in the young adult.