Yota Suzuki1, Tetsuya Goto2, Yu Fujii1, Yosuke Hara1, Kunihiko Kodama1, Atsushi Sato3, Tetsuyoshi Horiuchi1, Kazuhiro Hongo1. 1. Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan. 2. Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan; Department of Neurosurgery, St. Marianna University, Kawasaki, Japan. Electronic address: tegotou@shinshu-u.ac.jp. 3. Department of Neurosurgery, Ina Central Hospital, Ina, Japan.
Abstract
OBJECTIVE: Carotid revascularization surgery is known to carry a risk of postoperative visual deterioration associated with retinal ischemia. We checked intraoperative visual evoked potential (VEP) monitoring in carotid endarterectomy (CEA). METHODS: Ten consecutive patients who underwent CEA in Shinshu University Hospital under total intravenous anesthesia were checked by intraoperative VEP and electroretinogram (ERG) recording in addition to somatosensory evoked potential monitoring. RESULTS: Two of 10 patients presented decreased amplitude of VEP and ERG on the ipsilateral affected side by clamping the common carotid artery and persistent attenuation of VEP and ERG during external carotid artery occlusion, using an internal carotid shunt. These findings disappeared immediately after releasing the cervical carotid artery clamping. In the other 8 patients, VEP and ERG did not change throughout the surgery. CONCLUSIONS: Transient retinal ischemia during even brief carotid artery occlusion in the CEA procedure could be estimated by intraoperative VEP and ERG monitoring.
OBJECTIVE: Carotid revascularization surgery is known to carry a risk of postoperative visual deterioration associated with retinal ischemia. We checked intraoperative visual evoked potential (VEP) monitoring in carotid endarterectomy (CEA). METHODS: Ten consecutive patients who underwent CEA in Shinshu University Hospital under total intravenous anesthesia were checked by intraoperative VEP and electroretinogram (ERG) recording in addition to somatosensory evoked potential monitoring. RESULTS: Two of 10 patients presented decreased amplitude of VEP and ERG on the ipsilateral affected side by clamping the common carotid artery and persistent attenuation of VEP and ERG during external carotid artery occlusion, using an internal carotid shunt. These findings disappeared immediately after releasing the cervical carotid artery clamping. In the other 8 patients, VEP and ERG did not change throughout the surgery. CONCLUSIONS: Transient retinal ischemia during even brief carotid artery occlusion in the CEA procedure could be estimated by intraoperative VEP and ERG monitoring.