Transition in the Treatment of Carotid Stenosis with Emphasis on Cerebral Blood Flow and Plaque Characteristics

Abstract

  The treatment of carotid artery stenosis has been proven in randomized controlled trials (RCTs). First, the superiority of carotid endarterectomy (CEA) over medical therapy and the non-inferiority of carotid artery stenting (CAS) in high-risk patients with CEA were demonstrated. More recently, an RCT on asymptomatic lesions has been underway. The therapeutic risks of carotid artery lesions include postoperative hyperperfusion syndrome in patients with severely impaired cerebral hemodynamic reserve, and postoperative thromboembolic complications in patients with vulnerable plaques. For the former, using shunt system reportedly shortens the ischemic time in CEA, and staged angioplasty demonstrably reduces the ischemic time in CAS. For the latter, the usefulness of various plaque imaging techniques, including MRI, CT, and US, has been reported. Recently, new plaque imaging techniques using optical coherence tomography and near-infrared spectroscopy have been reported. Furthermore, micromesh stents, which can reduce thromboembolic complications in CAS, have been introduced as a new device in Japan. Regarding medical treatment strategies, improvements in blood pressure and lifestyle factors, antithrombotic drugs, statins, and other medications are also evolving. In the future, strategies to reduce the complications of CEA and CAS, optimization of medical therapy, and further investigations into the best treatment option according to disease background including age, previous history, and the pathology of the lesion, are warranted.