A Large High-Flow Arteriovenous Malformation of the Distal Third of the Right Upper Arm (Cho Type IIIb): A Case Report and Literature Review
Year: 2026
Type: article
Study design: Case Report
Abstract: Background. Peripheral arteriovenous malformations (AVMs) are rare congenital high-flow vascular lesions defined by a direct arteriovenous shunt lacking an intervening capillary bed. Misdiagnosis or inappropriate management may lead to catastrophic haemorrhage, high-output cardiac failure, trophic ulceration and functional loss of the limb. The angiographic Cho–Do–Yakes classification directly determines the endovascular strategy. Case presentation. A patient was referred for imaging evaluation of a slowly enlarging, pulsatile swelling of the distal third of the right arm. Clinical examination revealed a palpable thrill, local warmth, a continuous systolo-diastolic bruit and dilated tortuous superficial veins, with mildly diminished ipsilateral distal pulses suggesting a moderate steal phenomenon (Schöbinger stage II). Triphasic CT angiography demonstrated a bulky dysplastic soft-tissue vascular network measuring 107 × 46 mm, organised around a complex nidus, fed predominantly by the distal brachial artery, with early venous opacification during the arterial phase through two dominant outflow axes — the cephalic vein and the ulnar venous network. Multiple intralesional phleboliths were present, without cortical erosion or medullary involvement of the distal humerus. The lesion was classified as Cho type IIIb. Conclusion. This case illustrates the diagnostic power of multiphasic CT angiography in mapping a high-flow AVM and the necessity of rigorous classification to guide endovascular therapy. A painless, slowly progressive upper-limb mass may harbour a potentially devastating high-flow shunt whose control relies on the combined expertise of the diagnostic radiologist, the interventional radiologist and the vascular surgeon. ________________________________________
Source: MedPeer publisher
Institution: Mohammed V University
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W7224847477