Rectal Arteriovenous Malformation Masquerading As Rectal Varices

We report a case of a bleeding rectal arteriovenous malformation (AVM), initially diagnosed as a rectal varix, which was ultimately treated with staged transarterial embolization.A 67-year-old man with a past medical history significant for hypertension, type 2 diabetes mellitus, and rectal varices presented with progressive hematochezia resulting in a drop in his hemoglobin from 11 g/dL to 8 g/dL.His medication history was notable for chronic ibuprofen use, ginkgo biloba, and ginseng supplementation.Flexible sigmoidoscopy revealed active bleeding from a lesion that was initially thought to be a rectal varix at the rectosigmoid junction and was subsequently treated with an endoscopic clip.Repeated episodes of bleeding led to computed tomography angiography (CTA), which demonstrated tortuous perirectal vasculature concerning for an AVM.The diagnosis of a complex rectal AVM was made, and imaging showed that this vascular lesion was supplied by the inferior mesenteric artery (IMA) with early venous drainage into the internal iliac venous systems bilaterally.Following an initial embolization, the patient experienced recurrent bleeding 38 days later and underwent repeat embolization to achieve hemostasis.The targeted vessels included the superior rectal arterial branches, hemorrhoidal arteries, and AVM nidus.The patient was discharged without complications the following day.In this patient, a rectal AVM was an important diagnostic consideration after recurrent hematochezia despite presumed rectal varices in the absence of portal hypertension.In this case, staged transarterial embolization achieved hemostasis after endoscopic management was unsuccessful.