Preoperative volume expansion improves tolerance to carotid artery cross-clamping during endarterectomy

The benefit of carotid endarterectomy for carotid artery stenosis relates to both appropriate patient selection and careful surgical technique. Critical to the latter is the ability to afford intraoperative neuroprotection during carotid cross-clamping, although the optimal strategy to assure this protection remains debated. This report describes the impact of adding preoperative colloid volume expansion to a surgical algorithm that includes electroencephalographic (EEG) monitoring and barbiturate-induced burst suppression for EEG lateralization refractory to hypertension.

The incidence of ischemic EEG change during carotid cross-clamping was observed. The results of an initial series of patients (n = 45) reported before incorporation of volume expansion were compared with the results of the current series (n = 155) of carotid endarterectomies, which included preoperative volume expansion with 6% hetastarch (500 or 1000 cc).

With preoperative volume expansion, there was a 40% decrease in the incidence of EEG lateralization during carotid cross-clamping (17.4 versus 28.9%, P < 0.05) and a 63% decrease in the EEG lateralization refractory to induced hypertension (5.8 versus 15.6%, P < 0.05). The combined perioperative stroke and death rate was 1.3%.

These results support the use of preoperative colloid volume expansion in carotid endarterectomy as a means of increasing the cerebral tolerance to carotid cross-clamping.