This paper describes the detection of microembolism in the ophthalmic artery during carotid artery stenting (CAS). Methods: During the CAS procedure, the ophthalmic artery was examined by color Doppler flow imaging (CDFI) in 18 patients with internal carotid artery stenosis. Ophthalmic artery CDFI provided high intensity transient signals (HITS) and flow direction. Results: Fifteen patients (83%) showed HITS, and HITS was seen in every CAS phase. During the post-dilatation phase with a distal protection system, HITS was significantly more frequent in patients who underwent saline irrigation than in patients who did not (p<0.05). The ophthalmic artery flow direction was abnormal in 10 patients before the CAS procedure. During CAS, the ophthalmic artery flow direction changed in relation to the CAS phase. After CAS, the ophthalmic artery flow direction was normalized significantly in all patients (p<0.05). Conclusion: The presence of microemboli in the ophthalmic artery was proved during the CAS procedure as HITS, and it was clarified that the microemboli entered the intracranial or retinal circulation via the ophthalmic artery. During the post-dilatation phase, saline irrigation was a significant risk factor for embolism even with a distal protection system.
