Spontaneous arteriovenous malformations in the cervical area.

Four patients with spontaneous arteriovenous malformations of cervical vessels have been presented. The embryology of these vessels has been discussed in order to suggest an explanation for the apparent difference in the incidence of arteriovenous malformations involving the internal carotid artery and those involving either the vertebral or the external carotid arteries. A fifth case (S.T.) is presented as a probable iatrogenic arteriovenous fistula and is to be added to the steadily growing reports of this phenomenon.