Identification of plaque location using intraoperative indocyanine green during carotid endarterectomy for patient with near occlusion.

INTRODUCTION: Microscope-integrated near-infrared indocyanine green (ICG) videoangiography (VA) is an effective method of intraoperative blood flow assessment and identification of plaque location during carotid endarterectomy (CEA). However, the validity of ICG-VA during CEA for patient with near occlusion has not been elucidated. PATIENTS AND METHODS: Thirty-four CEA procedures were performed between June 2009 and December 2017 for patient with near occlusion, which are more than 95% stenosis. The lesions were classified into three groups according to the diameter of distal ICA compared with ipsilateral external carotid artery (ECA), as normal diameter (>100%), moderate diameter reduction (50-100%), severe diameter reduction (<50%). 5 mg of ICG was injected intravenously before arteriotomy, and ICG-VA was taken to identify the distal end of the plaque. Depiction of the distal end and its accuracy were retrospectively reviewed. RESULTS: There were 18 cases with normal diameter group, 14 cases with moderate diameter reduction group, and 2 cases with severe diameter reduction group. All but one case in the severe diameter reduction group showed apparent distal end signal which were confirmed by arteriotomy afterward. CONCLUSIONS: The present study clearly denotes that ICG-VA can visualize the carotid plaque distal end during the CEA, even with the patient with near occlusion. However, it should be noted that there may be a difficulty in visualization of the distal plaque end for patient with severely collapsed distal ICA.