The Role of Maintaining External Carotid Artery Flow in Graft Interposition After Carotid Endarterectomy

Surgical and endovascular treatment have been shown as effective treatment modalities in symptomatic and asymptomatic patients at high risk of stroke on medical therapy with significant carotid artery stenosis. Eversion carotid endarterectomy (eCEA) has proven effective as a surgical treatment modality. In highly selected instances carotid bypass may be indicated as a bailout procedure or primarily as a preoperatively planned maneuver. Usually, the decision for substitution of carotid bifurcation with a synthetic graft is made due to an extensive, severe atherosclerotic process on the distal part of the extracranial internal carotid artery, the presence of uncontrollable atherosclerotic plaque after endarterectomy, and in cases when an exceptionally thin artery wall remains after endarterectomy.

Several techniques have been described for substituting carotid bifurcation with a synthetic graft. The most common technique involves complete resection and excision of the carotid bifurcation and reconstruction with graft interposition between the undiseased segment of the common carotid artery (CCA) proximally and the internal carotid artery (ICA) distally by creating proximal and distal end-to-end anastomoses. This technique requires ligation and exclusion of the external carotid (ECA) and the superior thyroid artery from circulation. The less common techniques that preserve flow through the external carotid artery are performed as a primary option for treatment without previous endarterectomy and are seldom applied. Currently, there are no recommendations regarding the administration of carotid bypass, nor comparisons of these techniques.

In this study, the investigators are comparing a technique with graft interposition between endarterectomized CCA (creation of side-to-end anastomosis) and the distal segment of the ICA (end-to-end anastomosis) after failure of eCEA to provide technical success with the described common interposition by end-to-end anastomoses proximally and distally. Therefore, the role of flow preservation through the ECA could be defined.

Inclusion criteria

• symptomatic carotid stenosis (> 50%)
• unilateral asymptomatic carotid stenosis (> 60%)
• bilateral asymptomatic carotid stenosis (> 60%)

Exclusion criteria

• carotid restenosis
• "major surgery" in previous 6 months
• previous brain trauma or surgery
• malignant disease
• epilepsy
• carotid artery aneurysm