Comparison of Hemodynamic Cerebral Ischemia and Microembolic Signals Detected During Carotid Endarterectomy and Carotid Angioplasty

Abstract

Background and Purpose There has been concern about carotid percutaneous transluminal angioplasty (PTA) carrying a greater risk of cerebral ischemia than carotid endarterectomy. We set out to compare cerebral hemodynamics and microembolization during carotid PTA and CEA. Methods We used transcranial Doppler to monitor the middle cerebral artery of 28 patients undergoing carotid PTA (n=14) or carotid endarterectomy (CEA) with a shunt (n=14). Each period during which the internal carotid artery was occluded by PTA balloon or by clamp when the shunt was not in place was timed. Individual periods were summated to give a total occlusion time. Ischemic time was defined as the period for which mean middle cerebral artery velocity fell to a third or less of baseline. Microembolic signals were counted during each procedure. Results CEA resulted in significantly longer individual and total occlusion time than PTA (mean individual occlusion time, seconds), CEA, 168±51; PTA, 20±7; P <.001; mean total occlusion time; CEA, 337±70; PTA, 26±10; P <.001. Ischemic time was also significantly longer during CEA than during PTA (CEA, 165±40; PTA, 17±5; P =.001). There were significantly more microembolic signals during PTA than during CEA (mean number of microembolic signals during CEA, 52±64; during PTA, 202±119; P =.001). There was no correlation between any of the parameters measured and periprocedural stroke, which occurred in one patient in each group. Conclusion PTA results in less hemodynamic ischemia but more cerebral microembolism than CEA. In this small series, however, it is not possible to comment on the relations between ischemic time, microembolism, and stroke.