Cerebral circulation monitoring in carotid endarterectomy and carotid artery stenting.

In the near future it is likely that surgeons, anesthesiologists, and interventional radiologists and cardiologists will care for increasing numbers of patients undergoing carotid endarterectomy (CEA) and carotid angioplasty and stenting (CAS). Perhaps the most important factor in assuring technically acceptable interventions is the availability of an experienced team with demonstrable low periprocedural morbidity and mortality and a proper understanding of both vascular principles and cerebral physiology. Although different monitoring techniques have proven successful during both surgical and endovascular carotid interventions, the advantages of periprocedural transcranial Doppler (TCD) monitoring, such as its sensitivity for recording blood flow velocities and microembolism in real-time, are convincing. Because of its high temporal resolution, it provides additional information about the cerebral circulation, especially during cross-clamping, clamp release, and balloon inflation and deflation, respectively. If made audible during the procedure, it also provides unique information concerning cerebral micro-embolization. In CEA, TCD monitoring gives a better understanding of the pathophysiology of complications and makes the operation safer. In CAS, it gives insight into the clinical relevance of cerebral embolism and the possible effects of protection devices.