ROLE OF TRANSCRANIAL DOPPLER AND STUMP PRESSURE DURING CAROTID ENDARTERECTOMY

Background and Purpose The aim of our study was to clarify the pathoph ysiology of perioperative cerebral complications during carotid endart erectomy in our series. Methods By means of transcranial Doppler ultra sonography and slump pressure measurement, we monitored 112 patients w ho underwent carotid endarterectomy under general anesthesia for sympt omatic or asymptomatic severe carotid stenosis. Results Of 18 patients who underwent carotid endarterectomy with intra-arterial shunt, 2 (11 .1%) developed an ischemic stroke. Of the other 94 patients, one suffe red a nucleocapsular hemorrhage and 5 had cerebral ischemic complicati ons. In these 5 patients, the duration of clamping was significantly l onger (mean +/- SD, 16.4 +/- 1.1 versus 12.7 +/- 2.6 minutes; P = .001 9). and the decrease of middle cerebral artery mean velocity on clampi ng was significantly greater (mean +/- SD, 56.4 +/- 4.9% versus 28.8 /- 20.2%; P = .0031), while stump pressure was not significantly diffe rent, Microembolic signals were recorded in 70 patients (62.5%) and we re not associated with cerebral ischemic complications. The 7 patients who developed cerebral ischemic complications had a significantly hig her percentage of stenosis in the contralateral internal carotid arter y (mean +/- SD, 82.0 +/- 17.8% versus 29.3 +/- 36.4%; P = .0018). Conc lusions The results of our study suggest that the major complications of carotid endarterectomy may be due to hemodynamic factors. Stump pre ssure alone is not a reliable indicator of hemodynamic changes that pr edict cerebral ischemia. Particulate microembolism may cause more subt le changes in cerebral parenchyma, but further studies are needed to c larify this point.