An innovative method for detecting surgical errors using indocyanine green angiography during carotid endarterectomy: a preliminary investigation

Carotid endarterectomy (CEA) is the most effective treatment method of carotid stenosis or occlusion. Surgeons typically check the blood flow in each vessel using Duplex Doppler ultrasonography or radiocontrast angiography in order to prevent postoperative complications. Embolic cerebral infarction on the ipsilateral side has been reported in 4-7% of patients undergoing CEA despite a tolerable blood flow reported by Duplex ultrasonography. This study was designed to evaluate a new intraoperative method for detecting technical errors during CEA using indocyanine green (ICG) angiography.Six consecutive patients with severe carotid stenosis or occlusion underwent CEA. Both ICG angiography and Doppler ultrasonography were performed before the carotid arterial incision and after the carotid arterial suture. After injecting ICG dye via an intravenous route, the internal surface, atheroma, and flow defect were visualized with a microscope.In ICG angiography, stenotic lesions could be identified as regions of relatively dark signal intensity. Magnified real-time images could be created using a microscope with an infrared filter, including three-dimensional images and detailed images of the inner lumen. These images could then be compared with the results of Doppler ultrasonography. In the six cases assessed by both ICG angiography and Doppler ultrasonography, all Doppler results were acceptable. However, one patient underwent revision surgery because a fluttering atheroma was detected by ICG angiography. ICG angiography could assume the extent of severe stenotic area. ICG angiography could also detect mobile lesions such as a fluttering atheroma.Intraoperative ICG angiography before arteriotomy is useful to determine the precise stenotic area and the shape of the associated plaque. ICG angiography after an arteriotomy site is sutured is also useful for detecting residual stenosis or fluttering atheroma. ICG angiography could be an alternative method to Doppler ultrasonography for ensuring a complete and successful operation and preventing complications.