Arteriovenous fistula of the scalp secondary to punch autograft hair transplantation: angioarchitecture, histopathology, and endovascular and surgical therapy.

Arteriovenous fistula of the scalp secondary to punch autograft technique is a relatively uncommon occurrence, similar to traumatic scalp arteriovenous fistulas from other causes. A pulsatile subcutaneous mass with an associated thrill or bruit and symptoms including pain or headache is a common presentation. Angiography is required for full diagnostic evaluation. Angioarchitecture may appear complex, even with a single-hole fistula. Super-selective angiography and embolization facilitate surgery and provide essential information regarding angioarchitecture. Complete excision of the lesion is curative. Identification and resection of the draining vein is mandatory to ensure a complete resection. The lesion may extend across traditional anatomic planes. Ligation of proximal feeding arteries is inadequate and potentially harmful. Histopathology of the traumatic arteriovenous fistula may appear similar to that of an arteriovenous malformation. Acquired arteriovenous fistulas and congenital arteriovenous malformations are markedly similar in their ultimate histopathology, angioarchitecture, angiographic appearance, hemodynamics, and treatment requirements. They should be considered to represent a spectrum of the same disease state rather than discrete entities.