The Value of the Intraoperative OPG Monitoring in Carotidendarterectomy

One of the most important aspects of carotidendarterectomy is to maintain adequate cerebral blood flow during carotid clamping. Various methods have been reported to assess the cerebral circulation during carotidendarterectomy; e.g. electroencephalogram, stump pressure measurement, etc. The purpose of this paper is to analyze the value of the intraoperative OPG monitoring during carotidendarterectomy with emphasis on its value during carotid shunting. Using the Zira-OPG, 15 patients who underwent carotidendarterectomy were studied. Baseline OPG was done in the operating room after anesthesia. Serial recordings were obtained during sequential clamping of the common, internal and external carotid arteries. Another OPG was obtained during ca rotid shunting and every three minutes until the shunt was removed and after completion of the procedure. The pulse delay information obtained was used as indicator of what the expected delays would be in the event of shunt occlusion. The test was valid and helpful in eight and invalid and useless in the other seven patients. We concluded that this method was only helpful in 53% of the cases.