Purpose: In this article we will review some of the issues surrounding the relationship between TCD-detected emboli and brain function and architecture, both during conventional surgical carotid endarterectomy (CEA) and carotid angioplasty and stenting (CAS).
Material and methods: In both procedures, the cerebral embolic load was semi quantitatively assessed and associated with clinical outcome during the procedure and after a symptom free interval within 7 days.
Results: In CEA, particulate emboli that occurred during the wound closure stage were associated with intraoperative stroke and stroke related death, odds ratios [OR] 2.3 95% CI 1.2-4.4, p = 0.007. In CAS, showers of microemboli that appeared at postdilatation of the stent (OR 3.2, 95% CI 1.5-6.9, p = 0.002), particulate macroembolism (relative risk [RR] 10.2, 95% CI 5.9-17.3, p < 0.001), and massive air embolism (RR 10.2, 95%CI 5.8-17.7, p < 0.001) were associated with new transient and persistent cerebral deficits.
Conclusion: In both CEA and CAS, recording of cerebral emboli by TCD ultrasonography provides insight in the pathogenesis of procedure related adverse cerebral outcome. In several centres TCD monitoring during CEA is now accepted as a clinically relevant tool that helps the surgeon to make the operation safer. In CAS more research is needed, particularly with respect to the impact of cerebral protection devices.