Subclavian-carotid bypass to an "isolated" carotid bifurcation: a retrospective analysis.

Most patients with occlusion of the common carotid artery will have concomitant occlusion of the internal and external carotid arteries. A few, however, will maintain antegrade internal carotid flow via retrograde flow from the ipsilateral external carotid artery. These patients remain at risk for hemispheric transient ischemic attacks (TIAs), ischemic stroke, or vertebrobasilar insufficiency/global cerebral ischemia. Historically, diagnosis of this condition has relied on cerebral arteriography and/or blind exploration of the carotid bifurcation. More recently, color-enhanced duplex ultrasonography has been used to facilitate the diagnosis and has allowed focused, delayed arteriographic views of the appropriate carotid bifurcation, making blind exploration unnecessary. From 1985 to 1994, nine patients with TIAs (n = 5), completed stroke with minimal residual deficit (n = 2), or vertebrobasilar insufficiency (n = 2) were found to have occlusion of the common carotid artery with a patent carotid bifurcation on duplex ultrasound images. All nine had this particular anatomic condition confirmed by arteriography and were subsequently treated by subclavian-carotid bypass using autologous reversed saphenous vein (n = 5) or synthetic (n = 4) grafts. Five of nine patients required concomitant bifurcation endarterectomy. There were no perioperative strokes or TIAs and no operative deaths. Six of eight survivors remain asymptomatic at 1 to 92 months' follow-up (mean 37.1 months). Symptomatic patients with occluded common carotid arteries and patent bifurcations can be treated surgically with low operative morbidity and good long-term results.