Embolization of a Mesenteric Arteriovenous Malformation Associated with Idiopathic Myointimal Hyperplasia: A Case Report and Literature Review

Abstract Background Idiopathic myointimal hyperplasia of the mesenteric vein (IMHMV) is a rare, often undiagnosed pathology affecting the colon. Patients typically present with severe abdominal pain and inflammation caused by smooth muscle proliferation of the veins, leading to arterialization, stenosis, and potential occlusion. The etiology remains unclear, but it has been hypothesized that an arteriovenous connection may be associated with the pathology. This is the first reported case supporting such an association. Endovascular embolization is generally a less invasive alternative to surgical resection in the treatment of such vascular disorders, and our case highlights the potential benefits of endovascular treatment. Case Presentation This report describes a 24-year-old female patient with findings of colitis and an abnormal arteriovenous connection of the inferior mesenteric arterial and venous system. Partial embolization of this arteriovenous connection temporarily improved symptoms, but the presence of multiple smaller feeder vessels not amenable to embolization ultimately necessitated colonic resection for definitive treatment. Although prior reports have hypothesized that arterial pressurization of the veins may cause myointimal hyperplasia, to the authors’ knowledge, this is the first report of IMHMV with an associated abnormal arteriovenous connection. Conclusions This case illustrates the possibility of a pathogenic relationship between an arteriovenous connection and IMHMV. It is presumable that early radiologic analysis for an abnormal arteriovenous connection in colitis patients may facilitate IMHMV diagnosis, and early diagnosis may even facilitate the success of embolization.