First-in-man near-infrared spectroscopy proof of lipid-core embolization during carotid artery stenting

Intravascular near-infrared spectroscopy (NIRS), which has been used in over 5,000 patients to identify the lipid-core plaques (LCP) that cause coronary events, may also assist in the characterization of the carotid atherosclerotic lesions predisposing to stroke. To our knowledge, this is the first report of the use of NIRS in a patient undergoing carotid artery stenting (CAS).
In the coronary arteries NIRS seems to be capable of firstly assisting with coronary interventions by predicting distal embolization and stent failure and possibly also to identify lesions at higher risk of causing spontaneous coronary events [1–9]. While NIRS has been cleared by the FDA for detection of LCP in the coronary arteries, it has not been validated or approved for use in carotid arteries [10]. A multimodality catheter (TVC System, Infraredx, Inc, Burlington, MA) that contains intravascular ultrasound (IVUS) and NIRS was used in this carotid case.
The NIRS-IVUS imaging was performed in a 62-year-old man with a history of coronary stent placement. Angiography demonstrated an occlusion of the right carotid artery and an asymptomatic 90% stenosis of the left carotid artery for which stenting was indicated (Figure 1 A). The carotid stenting was performed according to the common practice in our center [11]. A distal filter protection device (Emboshield NAV6, Abbott, Santa Clara, CA) was placed in the left carotid. As shown in Figure 2, NIRS detected two LCP. The first lipid core disappeared after a self-expandable 6/9X40 mm stent (sinus-Carotid-RX, OptiMed-Medizinische Instrumente GmbH, Ettlingen, Germany) was deployed. Subsequently, post-dilation of the lesion was performed with a 5/14 mm balloon (Falcon grande, INVATEC, Roncadelle, Italy) with 8 atm. The second LCP disappeared after the post-dilation. The filter filled with material which presumably embolized during the dilation of the LCP (Figure 2). The patient experienced a slight transient decline in consciousness, but returned to normal mentation immediately after the protection filter was removed. Transcranial Doppler monitoring indicated that some of the semi-liquid lipid debris embolized to the brain despite the use of the filter, and documented a decline in the middle cerebral artery flow during the procedure and its restoration to normal levels immediately after filter removal (Figure 3).
To our knowledge, this is the first case report of the use of NIRS during CAS. We believe that detection of...


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