No consensus exists for treatment of asymptomatic patients, and decisions for treatment of symptomatic patients are controversial and made according to each case 1). The 2011 American Heart Association guidelines recommend open surgery or endovascular intervention to treat symptomatic ischemic lesions affecting the anterior cerebral circulation caused by Common carotid artery occlusion 2) In contrast, the 2009 European Society of Cardiology Protocol has no specific recommendations on this matter, 3) which emphasizes the need for further studies.
A review of English-language medical literature from 1965 to 2012 was conducted using the PubMed and EMBASE databases to find all studies involving management of common carotid artery occlusion (CCAO). The search identified 21 articles encompassing 146 patients/arteries (73.2% men; mean age 65 ± 6.9 years).
The majority of the patients (93.8%) were symptomatic. Most of the patients (61.5%) had ipsilateral internal carotid artery (ICA) and external carotid artery (ECA) patent, while an occluded ICA and a patent ECA were found in 26.6% of the patients. Eighty per cent of the patients treated underwent a surgical bypass procedure, with the subclavian artery as the most common inflow vessel (64.1%). During the first 30 days of the procedure two strokes (1.5%) were reported. During a follow-up period spanning an average of 25.6 ± 11.2 months nine patients (6.6%) experienced a clinical cerebrovascular event. Seven restenoses (5.1%) and two reocclusions (1.5%) also occurred-eight after open surgical and one after endovascular repair.
The necessity to intervene to a CCAO remains controversial. Open surgical management of symptomatic CCA occlusive disease is a safe, durable, and effective therapeutic strategy with low perioperative cerebrovascular morbidity 4).
Hecht et al. from the Department of Neurosurgery and Center for Stroke Research Berlin (CSB), Charité and Department of Neurology, Aarhus, analyzed the experience with surgical revascularization of CCA-occlusion to develop an algorithm for selection of the most suitable bypass strategy according to the Riles classification.
During a 10-year period, 16 out of 288 patients with cerebrovascular disease and compromised hemodynamic reserve underwent revascularization for unilateral CCA-occlusion. The utilized bypass strategies included (1) a saphenous vein graft from the subclavian artery (SA) to the internal carotid artery (ICA), (2) a radial artery graft from the V3 segment of the vertebral artery (VA) to a superficial branch of the middle cerebral artery (MCA), or (3) a saphenous vein graft from the SA to a deep branch of the MCA.
In CCA-occlusion with maintained external carotid artery (ECA)/ICA patency (Riles type 1A), an SA-ICA bypass was performed (25%). In cases without ECA/ICA patency (Riles type 1B or 2) but suitable VA, a VA-MCA bypass was grafted (31%). In cases with unsuitable VA, a long SA-MCA interposition bypass was performed (38%). Transient postoperative neurological deficits occurred in 5 patients (31%) with 1 patient (6%) suffering permanent neurological worsening and 1 mortality (6%). Overall, no difference was found between the median preoperative mRS (2; range, 1-4) and the mRS at the time point of the last follow-up (2; range, 1-6; p = 0.75). The long-term graft patency was 94%.
Although surgical revascularization for CCA-occlusion is feasible, it is associated with a higher risk than standard bypass grafting. Considering the poor natural history of CCA-occlusion, however, this risk may be justified in carefully selected patients 5).
Eight patients with common carotid artery (CCA) occlusion underwent bypass with saphenous vein to either the carotid bifurcation (five), the internal carotid artery (two), or the external carotid artery (one). Indications included ipsilateral transient ischemic attack (two), recent nondisabling hemispheric stroke (two), and transient nonhemispheric cerebral symptoms (two). Two asymptomatic patients with CCA occlusion and contralateral internal carotid stenosis underwent prophylactic revascularization prior to planned aortic surgery. There were no perioperative strokes, occlusions, or deaths. Late ipsilateral stroke occurred in two patients, and one patient had a single transient ischemic attack after 2 years. The four patients with preoperative transient cerebral ischemia experienced relief of their symptoms. Duplex ultrasound is an accurate screening modality for distal patency. Collateral filling of the internal or external carotid artery can usually be demonstrated after aortic arch or retrograde brachial contrast injection. End-to-end distal anastomosis after endarterectomy eliminates the original occlusive plaque as a potential source of emboli. The subclavian artery is preferred for inflow on the left. The CCA origin is easily accessible for inflow on the right. Bypass of the occluded CCA is safe and may be effective in relieving transient cerebral ischemic symptoms, although long-term ipsilateral neurologic sequelae may still occur 6).