PATIENTS WITH LOW STUMP PRESSURE AND POSSIBLE PRESSURE FALL IN THE MIDDLE CEREBRAL-ARTERY DURING CAROTID SURGERY MAY BE IDENTIFIED PREOPERATIVELY BY TRANSCRANIAL DOPPLER

Although it has now been established that surgery is the best way to t reat patients with symptomatic tight carotid stenosis, the fact remain s that perioperative risks are not negligible. Patients with significa nt contralateral stenosis and/or no collateral flow capacity through t he anterior communicating artery are likely to be at higher risk durin g surgery. We examined a series of 52 patients pre- and postoperativel y with transcranial Doppler (TCD) and compared the results to perioper ative stump pressures. Our intention was to find out whether the resul ts of the TCD examination of the circle of Willis could be correlated to the perioperative stump pressures, and whether TCD gives reliable i nformation about the collateral flow. We found relatively high stump p ressures in patients with potential function of any communicating arte ry, and in the group with no collateral function most patients had low stump pressures. We also found that preoperative flow velocity fall i n the middle cerebral artery (MCA) on compression of the ipsilateral i nternal carotid artery correlated with perioperative stump-pressure in dices. However, we were unable to predict stump pressures in individua l patients by flow velocity measurements in the MCA preoperatively.