[Important recommendations of the German-Austrian S3 guidelines on management of extracranial carotid artery stenosis].

Background: Lesions of the extracranial carotid artery are the cause of 10-15 % of all cases of cerebral ischemia. The aims of the updated S3 guidelines are evidence-based and consensus-based recommendations for action on comprehensive care of patients with extracranial carotid stenosis in Germany and Austria.

Methods: A systematic literature search (1990-2019) and methodical assessment of existing guidelines and systematic reviews were carried out. Consensus answers to 37 key questions with evidence-based recommendations.

Results: The prevalence of extracranial carotid stenosis is approximately 4% and increases after the age of 65 years. The most important examination method is duplex sonography. Randomized controlled studies (RCT) have shown that carotid endarterectomy (CEA) of an asymptomatic 60-99% carotid artery stenosis reduces the absolute risk of stroke (absolute risk reduction, ARR) within 5 years in comparison to drug treatment alone by 4.1%. Due to an improved pharmaceutical prevention of arteriosclerosis, the S3 guidelines recommend a prophylactic CEA of a 60-99% stenosis only for patients without an increased surgical risk. Additionally, one or more clinical or imaging results should be present, which indicate an increased risk of carotid-related stroke in the follow-up. For medium-grade (50-69 %) and high-grade (70-99 %) symptomatic stenoses the ARRs after 5 years are 4.6% and 15.6%, respectively. Systematic reviews of RCTs have shown that CEA is associated with a ca. 50% lower periprocedural risk of stroke compared to carotid artery stenting (CAS). There are no differences in the long-term course. The CEA is recommended for high-grade asymptomatic, medium-grade and high-grade symptomatic carotid stenosis as a standard procedure, alternatively CAS can be considered. For both procedures the periprocedural stroke rate/mortality during hospitalization should be a maximum of 2% (asymptomatic stenosis) or 4% (symptomatic stenosis).

Conclusion: Both CEA and CAS necessitate a critical evaluation of the indications and strict quality criteria. Future studies should evaluate even better selection criteria for an individual, optimal, conservative, operative or endovascular treatment.