Introduction: Based on randomized trials, carotid endarterectomy (CEA) is the standard procedure for patients with a 50-99% symptomatic carotid stenosis and carefully selected patients with an asymptomatic high-grade carotid stenosis. Carotid artery stenting (CAS) is a technical alternative for patients with a high surgical risk or difficult anatomic conditions (e.g., recurrent stenosis). This study aims to provide an overview of anatomic factors associated with a higher risk of CEA complications.
Evidence acquisition: The current literature was analyzed using a hierarchical approach. Firstly, carotid guidelines published between 2010 and 2015 and their recommendations or statements concerning anatomic risks for CEA were examined. Secondly, the retrieved full-text articles of the cited literature were assessed in detail. Thirdly, we searched the MEDLINE databank using the key words "recurrent stenosis" OR "high carotid bifurcation" OR "irradiation" OR "tracheostomy" OR "neck dissection" OR "contralateral paralysis of the recurrent laryngeal nerve" AND "carotid endarterectomy" OR "carotid surgery". Finally, the available data were summarized, as was information on each defined anatomic risk factor for CEA complications. The whole analysis is descriptive; no statistics were used.
Evidence synthesis: No evidence was found for a higher incidence of cranial nerve injuries after carotid surgery due to a high carotid lesion. CEA can be performed if the carotid stenosis is accessible by ultrasound. Restenosis and irradiation were not associated with a higher risk of stroke or death, but were associated with a higher incidence of cranial nerve injuries. No literature is available on the influence of neck dissection, contralateral paralysis of the recurrent nerve, or tracheostomy on the CEA surgical risk.
Conclusions: Anatomic criteria determining high-risk carotid surgery patients have been defined as high or low carotid stenosis, restenosis after CEA, previous radical neck dissection or cervical irradiation, contralateral laryngeal nerve palsy, and tracheostomy. Most of the defined criteria are based on expert opinion. Therefore, individual treatment based on carotid imaging and the local skin and soft tissue conditions is recommended.