[Spontaneous arteriovenous fistulas of the vertebral artery. Apropos of a case--review of the literature].

Spontaneous arteriovenous fistulae of the vertebral artery are rare (only 41 cases in French and English-language literature). Auscultation regularly discloses a cervical bruit which was found by systematic examination in 30 p. 100 of the cases. Otherwise, the fistula was revealed by unilateral pulsatile tinnitus (30 p. 100) or by a transient vertebro-basilar ischaemic accident (20 p. 100). The main complications, which occurred in 40 p. 100 of the cases, were ischaemic accidents in the vertebro-basilar territory and, primarily in children, heart failure. Prognosis seems to be governed by the patient's age at the time of diagnosis: 6 out of 7 cardiac complications occurred before the age of 10, and only 2 beyond the age of 50; in contrast, the duration and complexity of the fistula do not appear to be prognostic factors. Doppler examination of the neck and head, based on clinical findings, confirms the diagnosis and provides information on a possible blood steal. Arteriography by the arterial route is mandatory before surgery, but it also represents a first therapeutic measure (embolization, or even spontaneous obliteration of the fistula during the procedure, as seen in 4 cases). Asymptomatic forms, for which embolization and surgery may be postponed, can be monitored by ultrasounds.