Role of cerebral oximetry in prediction of hyperperfusion syndrome after carotid endarterectomy

Shchanitsyn I.N., Larin I.V., Bakharev R.M., Lukin O.Yu.

Scientific Research Institute for Traumatology, Orthopaedics and Neurosurgery, Saratov State Medical University named after V.I. Razumovsky under the RF Ministry of Public Health, Saratov, Russia

Objective. The purpose of the study was to carry out a retrospective analysis of alterations in regional oxygenation (rSO₂) of the brain at all stages of carotid endarterectomy (CEA) in order to detect predictors of ischaemia and hyperperfusion of the brain.

Patients and methods. In a total of 169 patients during CEA under general anaesthesia we registered rSO₂ after induction of narcosis, prior to carotid artery cross-clamping, at 2 minutes and each 10 minutes after cross-clamping, before re-establishing blood flow, at 2 and 5 minutes thereafter, and finally at the end of the operation. We evaluated the baseline parameters and intraoperative alterations in regional oxygenation depending on clinical and instrumental data. We also carried out a multivariate regression analysis in order to reveal significant risk factors for ischaemia and hyperperfusion. We analysed the ROC curves in order to determine the threshold value of a decrease and increase of rSO₂ in ischaemia and hyperperfusion of the brain.

Results. After the multivariate analysis, an independent predictor turned out to be grade III arterial hypertension (OR 9.5, 95% CI: 1.1-82.7). It was revealed that the most significant predictor of the development of hyperperfusion syndrome was the absolute increase in rSO₂ after re-establishing blood flow by more than 11.3. Sensitivity, specificity, positive and negative prognostic value of the parameter revealed amounted to 87.4, 83, 35 and 98.4%, respectively.

Conclusions. The multivariate analysis performed demonstrated that only long-standing grade III arterial hypertension was a significant risk factor for the development of hyperperfusion syndrome after CEA. In our study, the most accurate parameter for the Fore-Sight oximeter was the maximum increase of the absolute value of rSO₂ after re-establishing blood flow above 11.3 Cerebral oximetry is a non-invasive, simple to use and interpreter method making it possible to evaluate not only ischaemia but hyperperfusion of the brain during CEA and in the early postoperative period.

KEY WORDS: carotid endarterectomy, cerebral oximetry, parainfrared spectroscopy, hyperperfusion syndrome.

P. 26

« Back