Neurocognitive Function After Carotid Thrombendarterectomy

Perioperative Complications and Cognitive Outcome in Carotid Thrombendarterectomy With Multimodal Monitoring Cerebral Perfusion Optimisation

Previous studies did not reach a consensus on the influence of the type of anesthesiologic procedure and monitoring, during carotid thrombendarterectomy, on perioperative complications and cognitive outcomes. The aim of this study is the optimization of brain perfusion during the vascular carotid clamp using multimodal monitoring. We assume that standardized monitoring techniques and a better selection of cognitive tests will allow a more accurate assessment of subclinical cognitive deficits.

ABSTRACT: AIM OF THE STUDY: Effect of perioperative multimodal monitoring with transcranial doppler (TCD), near-infrared spectroscopy (NIRS), and Electroencephalography (EEG) in patients for carotid thrombendarterectomy (CEA) on perioperative complications and cognitive functions. PATIENTS AND METHODS: The prospective study will analyze 80 consecutive patients with an asymptomatic and symptomatic (transitory ischemic attack, TIA, in anamnesis) stenosis of the internal carotid artery in which CEA is indicated in general anesthesia. Cognitive tests will be analyzed for all patients preoperatively, first and eighth day postoperatively, and after 8 weeks. Breath-holding index (BHI) will be measured preoperatively and postoperatively. The first group of patients (n = 40) will have expanded intraoperative monitoring involving TCD, NIRS, and EEG, and the control group (n = 40) will have only standard anesthetic monitoring. EXPECTED CONTRIBUTION OF THE STUDY: Previous studies did not agree on the influence of the type of anesthesiologic procedure and monitoring of perioperative complications and cognitive outcomes. We assume that standardized monitoring techniques and a better selection of cognitive tests will allow a more accurate assessment of the effect.

Multimodal monitoring includes cerebral oxygenation (with NIRS) and EEG (with SEDLINE). During the carotic clamp, if cerebral oxygenation decreased for more than 12 % on the operating side from the baseline value, simple interventions as, increasing arterial blood pressure, increasing arterial carbon dioxide tension or increasing oxygen inspiration concentration will be performed.

The control arm does not have any monitor of cerebral perfusion and oxygenation, during the carotic clamp only intervention is regulating arterial blood pressure values.

During the carotic clamp, if cerebral oxygenation decreased for more than 12 % on the operating side from the baseline value, simple interventions as, increasing arterial blood pressure, increasing arterial carbon dioxide tension or increasing oxygen inspiration concentration will be performed.

A widely used screening assessment for detecting cognitive impairment. It was validated in the setting of mild cognitive impairment, and has subsequently been adopted in numerous other settings clinically. This test consists of 30 points and takes part in 10 minutes from the individual. The Montreal test is performed in seven steps. The basics of this test include short-term memory, executable performance, attention, focus and more.

Change in measurements (result is in numbers) done at four time points (before surgery, day after the surgery, on 7th day and after 8 weeks

Neuropsychological test that involves visual scanning and working memory. In the TMT-1 (rote memory) the subject is instructed to connect a set of 25 dots as quickly as possible (time is measured in seconds).

Changes in measurements (results are in seconds) done at four time points (before surgery, day after the surgery, on 7th day and after 8 weeks

TMT-2 (executive functioning) is a neuropsychological test that involves visual scanning and working memory. In this test the dots go from 1 to 13 and include letters from A to L.

Changes in measurements done at four time points (before surgery, day after the surgery, on 7th day and after 8 weeks

It is a rapid (< 2 min) and simple to administer test of cognitive function that is widely used at the bedside. The test requests the subject to recite the months of the year in reverse order starting with December, until the subject reaches January.

changes in measurements done at four time points (before surgery, day after the surgery, on 7th day and after 8 weeks

Difference in breath holding index before surgery , after the surgery and after eight weeks as a surrogate of brain perfusion in both groups of patients

Inclusion Criteria: patients with The North American Symptomatic Carotid Endarterectomy Trial (NASCET) stenosis of more than 70% symptomatic stenosis asymptomatic stenosis elective surgery patients signed informed consent initial MoCa test equal and more than 22 Exclusion Criteria: who refuse to participate previous stroke in anamnesis patient without bone window for BHI measurements comorbidities with aphasia and plegia, and the impossibility to solve cognitive tests