Diagnosis
AVMs can be found incidentally, or present with a wide variety of symptoms depending on location and size. On physical examination, auscultation typically demonstrates a bruit, which is due to abnormally high blood flow. Pulsation is a feature of AVMs as well (72). In this patient, an ultrasound revealed a vascular malformation in the musculature of the right neck/shoulder, with a clear communication with the right common carotid artery. The malformation exhibited venous flow, while the vascular connection demonstrated arterial waveforms. MRI with and without contrast showed an abnormal hypervascular lesion at the C2 level in the retropharyngeal space, extending inferiorly posterior to the carotid space. The arterial supply appeared to arise from the right subclavian artery and a small branch from the external carotid artery. She had no evidence of intra-cranial AVMs or steal syndrome.
When an AVM is diagnosed in a child, a complete family history and physical examination is warranted to assess the possibility for a systemic genetic syndrome such as hereditary hemorrhagic telangiectasia (HHT). HHT is inherited in an autosomal dominant fashion with variable penetrance. AVMs can occur in the brain, lungs, or liver in addition to mucosal telangiectasia. Early diagnosis is crucial so appropriate screening can be completed to avoid complications (73). In patients with AVMs, routine monitoring for high output heart failure is necessary depending on the degree of shunting across the AVM (74).