Comparison of Near-Infrared Spectroscopy and Somatosensory Evoked Potentials for the Detection of Cerebral Ischemia During Carotid Endarterectomy

Abstract

Background and Purpose-We sought to assess the clinical value of regional cerebral saturation (rSO 2 ) obtained by means of the cerebral oximeter INVOS 3100A (Somanetics) in comparison to monitoring of somatosensory evoked potentials (SEP) for the reliable detection of severe cerebral ischemia requiring shunt placement in the individual patient undergoing carotid surgery under general anesthesia. Methods-In 317 patients undergoing reconstructive surgery on the internal carotid artery, simultaneous recordings of SEP and rSO 2 were obtained throughout the operation. Results-All 287 patients with preserved cortical SEP remained neurologically intact. Shunt placement was performed in 27 patients (9%) after flattening of cortical SEP during cross-clamping of the internal carotid artery. A stable rSO 2 value just before cross-clamping and the lowest value after cross-clamping were registered, and the decrease was calculated. A statistically significant (PϽ0.01) decrease of rSO 2 after cross-clamping could be found in patients without (64.9Ϯ8.3% to 60.9Ϯ9.9%) as well as in patients with consecutive loss of cortical SEP (65.8Ϯ9.1% to 56.1Ϯ13.4%).The difference of the decrease of rSO 2 in both groups was highly significant (6.9Ϯ9.0% versus 15.6Ϯ14.0%; PϽ0.001).However, substantial interindividual variability of rSO 2 and derived change of rSO 2 did not allow the definition of a threshold value indicating need of shunt placement. Conclusions-The

Detection of cerebral ischemia in neurovascular surgery using quantitative frequency-domain near-infrared spectroscopy

“…Twenty-five patients were monitored throughout the neurosurgery. In all cases with evidence of ischemic events (brain edema, slowing of electroencephalography, postoperative stroke, and failure of balloon occlusion testing), there was a decrease in HbO 2 and tHb concentrations and brain tissue SO 2 , with an increase in HHb concentrations.…”

“…Calderon-Arnulphi et al 2 , and HHb during a right CEA. Oxygenation baseline was lower on the affected side.…”

“…19,42 Moreover, Beese et al 2 used semiquantitative NIRS to study patients with restricted cerebral circulation, as indicated by the loss of cortical SSEPs; their results showed that severe cerebral ischemia, as indicated by cortical potential loss, occurred in some patients with minimal or even no change of the regional cerebral oxygenation displayed using semiquantitative NIRS. Data from previous studies demonstrated that absolute numbers of regional SO 2 are of little value in interpreting results obtained by semiquantitative NIRS.…”

Noninvasive cerebral oximetry during carotid endarterectomy: application and results

“…However, it still carries a 5-7.5% risk of perioperative cerebral infarction (14). The main reason for cerebrovascular events is hypoperfusion during carotid clamping.…”

Cerebral Hyperperfusion Syndrome After Angioplasty

“…When compared with SPECT, the sensitivity and specificity of transcranial regional cerebral oxygen saturation for the detection of hyperperfusion were 100%. Transcranial near-infrared spectroscopy can demonstrate decreased cerebral oxygenation resulting from ICA clamping (Beese et al, 1998;Duncan et al, 1995;Kirkpatrick et al, 1995;Samra et al, 1996) and can predict post-CEA CHS. Matsumoto et al (2009) used transcranial near-infrared spectroscopy to study 64 patients undergoing CAS, two of whom developed CHS (diagnosed by increased CBF at SPECT the day after treatment).…”