Occipital Artery to Extradural Vertebral Artery Bypass for Posterior Circulation Ischemia.

BACKGROUND

Posterior circulation ischemic strokes can have devastating consequences, despite medical therapies. Extracranial-intracranial bypass for the augmentation of flow is a treatment option for selected patients with hemodynamic compromise and recurrent ischemia. However, posterior circulation bypass carries a higher risk and lower patency rate than bypass with anterior circulation.

OBJECTIVE

To present the occipital artery to the extradural vertebral artery (OA-eVA) bypass for posterior circulation ischemia.

METHODS

We retrospectively reviewed our experience of the OA-eVA bypass surgery in the treatment of bilateral vertebral steno-occlusive disease.

RESULTS

Seventeen patients were identified. Thirteen patients had bilateral vertebral artery (VA) occlusion (type I), while 4 patients had VA occlusion with contralateral VA severe stenosis (type II). All patients had cerebellar or pons infarction, for which the postoperative bypass patency rate was 100%, with carotid angiogram demonstrating excellent filling of the rostral basilar system or the posterior inferior cerebellar artery territory. The long-term follow-up outcome was favorable (modified Rankin score of 0-2) in 82% of patients (7 patients had complete resolution and 7 had improvement of symptoms) and unfavorable in 18%. One type II case without previous endovascular therapy developed recurrent ischemic onset associated with bypass occlusion.

CONCLUSION

OA-eVA bypass is a minimally invasive and effective alternative to posterior circulation ischemia. It provides sufficient blood flow augmentation to the vertebrobasilar territory. The advantages of this novel therapeutic strategy include avoiding performing craniotomy and deep bypass and achieving shorter operative times compared to conventional bypass surgery.