Pharmacological Management of GI Bleed Secondary to Arteriovenous Malformations: A Systematic Review

Introduction: Arteriovenous malformations (AVMs) are tangles of blood vessels that cause abnormal artery-to-vein connections, bypassing capillaries. AVMs of the gastrointestinal (GI) tract can remain silent or cause GI bleed. They are mostly seen in elderly population and treatment is challenging because barium contrast studies and endoscopy fail to demonstrate the lesion. There is no definite medical therapy for GI bleeds secondary to AVM. We present a systematic review exploring the management of GI bleeds due to AVMs.

Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, a comprehensive literature search was conducted on PubMed, Cochrane, and Clinical trials.gov using MeSH terms and keywords for " Arteriovenous Malformations" AND " Drug Therapy " AND "Hemorrhage" in July 2022. We did not place any time constraints. Our search produced a total of 47 records, and duplicates were removed. After screening and removing irrelevant and review articles, we included a total of 6 original articles and case reports reporting drug therapy for treatment of AVMs in adult patients. The data were collected for baseline characteristics of the participants and efficacy and safety of the intervention.

Results: A total of 46 patients from 6 articles were evaluated. (Table 1) The mean age of participants was 70 years and 36.9% (n=17/46) were males. AVMs were secondary to various underlying abnormalities including angiodysplasia, left ventricular assist devices and hereditary hemorrhagic telangiectasia. Octreotide, thalidomide and ethinyl estradiol are the drugs reported in literature for GI bleed secondary to AVMs. Octreotide was effective in helping to resume oral anticoagulation (OAC) for atrial fibrillation (AFib) without further serious GI bleeds and helped in reduced transfusion requirements in 100% of the patients. Thalidomide and estradiol were also effective in reducing transfusion requirements and further GI bleeds in 100% of patients. Commonly observed side effects with thalidomide were constipation, rash, dizziness, and peripheral neuropathy. Thalidomide had to be stopped due to peripheral neuropathy and dizziness in one patient each.

Conclusion: Thalidomide, octreotide and ethinyl estradiol have shown positive outcomes in GI bleeds secondary to AVMs. They help reduce further GI bleeds as well as transfusion requirements. Octreotide also helps in resuming OAC in AFib patients having AVMs. Initial studies favor the safety and efficacy of these drugs, but more randomized control trials are required to consolidate these findings.

No relevant conflicts of interest to declare.