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. 2024 Feb 2;15(3):1355-1369.
doi: 10.1364/BOE.507730. eCollection 2024 Mar 1.

Measuring pulsatile cortical blood flow and volume during carotid endarterectomy

Alexander I Zavriyev  1 , Kutlu Kaya  1 , Kuan Cheng Wu  1 , Eric T Pierce  2 , Maria Angela Franceschini  1 , Mitchell B Robinson  1
Affiliations

Measuring pulsatile cortical blood flow and volume during carotid endarterectomy

Alexander I Zavriyev et al. Biomed Opt Express. .

Abstract

Carotid endarterectomy (CEA) involves removal of plaque in the carotid artery to reduce the risk of stroke and improve cerebral perfusion. This study aimed to investigate the utility of assessing pulsatile blood volume and flow during CEA. Using a combined near-infrared spectroscopy/diffuse correlation spectroscopy instrument, pulsatile hemodynamics were assessed in 12 patients undergoing CEA. Alterations to pulsatile amplitude, pulse transit time, and beat morphology were observed in measurements ipsilateral to the surgical side. The additional information provided through analysis of pulsatile hemodynamic signals has the potential to enable the discovery of non-invasive biomarkers related to cortical perfusion.

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Conflict of interest statement

At the time of the study, MAF had a financial interest in 149 Medical, Inc., a company developing DCS technology for assessing and monitoring CBF in newborn infants, which is now dissolved. MAF’s interests were reviewed and managed by Massachusetts General Hospital and Mass General Brigham in accordance with their conflict-of-interest policies. A.I.Z., K.K., K.C.W., E.T.P., and M.B.R. have nothing to report.

Figures

Fig. 1.
Fig. 1.
a) Optical probe used in this study (enlarged). Short separation (blue square) has colocalized outputs to DCS and NIRS. b) Image of both optical probes on a subject’s forehead along with EEG probes (standard institutional monitoring).
Fig. 2.
Fig. 2.
Box plots showing the changes in pulsatile BFi (left) and BVi (right) amplitude for measurements ipsilateral (top) and contralateral (bottom) to the surgical side for both long (top of each quadrant) and short (bottom of each quadrant) source-detector separations during different surgical phases. Individual patient changes are displayed with lines, with shunted patients in green and non-shunted patients in orange.
Fig. 3.
Fig. 3.
Large separation pulsatile waveforms of blood flow (top) and blood volume (bottom) on the ipsilateral (left) and contralateral (right) sides of a non-shunted patient (#18). During the clamping period, the side ipsilateral to the clamp had a reduced pulsatile signal amplitude in both NIRS and DCS measurements, and the peak of the waveform was delayed relative to the pre-clamp period. Upon the release of the clamp, in this patient, the blood flow amplitude and peak time on the side ipsilateral to the clamp returned to baseline, although with a slightly modified shape. Changes during the recovery period were variable between subjects.
Fig. 4.
Fig. 4.
Large separation pulsatile waveforms of blood flow (top) and blood volume (bottom) on the ipsilateral (left) and contralateral (right) sides of a patient (#20) who required carotid shunting. For the NIRS measurement ipsilateral to clamping, before shunt placement, amplitude of the pulsatile signals is reduced more than is seen in patients not requiring shunt placement. Upon placement of the shunt, the pBVi signal amplitude returned to levels that are observed in pBVi amplitude of patients not requiring a shunt, though the pBFi increase was seen to reach pre-clamp level.
Fig. 5.
Fig. 5.
Box plots showing the changes in peak arrival time relative to the pre-clamp period for pulsatile BFi (left) and BVi (right) amplitude ipsilateral (top) and contralateral (bottom) to clamping for both long (top of each quadrant) and short (bottom of each quadrant) source-detector separations during different surgical phases. For all signals ipsilateral to the clamp, we observed an increase in the delay of arrival, consistent with an increase in travel time through collateral circulation. Signals contralateral to the clamped side have considerable variability.
Fig. 6.
Fig. 6.
Comparison of the distribution of the pulsatility index for (A.) DCS long source-detector separation measurements and (B.) NIRS long source-detector separation measurements. Values for DCS PI are within the range of previously reported normative values of PI [37], with slight elevations observed on the side ipsilateral to clamping. Ipsilateral signals for both DCS and NIRS are seen to, on average, increase following the surgical procedure, while the response is more variable in the contralateral signals.
Fig. 7.
Fig. 7.
Comparison of the distribution of the resistive index for (A.) DCS long source-detector separation measurements and (B.) NIRS long source-detector separation measurements. The NIRS results presented in (B.) are seen to be very similar to the results presented in Fig. 6.B, owing to the relatively small pulsation amplitude. As was the case for the PI, following the surgical procedure, the values of RI ipsilateral to the clamping were seen to increase on average while the values contralateral had a more varied response.
Fig. 8.
Fig. 8.
Comparison of the distribution of (A.) pCVRi for the long source-detector separation measurements and (B.) pCVCi for the long source-detector separation measurements. On average, decreases in the pCVRI are observed for both ipsilateral and contralateral measurements, while on average modest increases in pCVCi are observed for both ipsilateral and contralateral measurements.
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References

    1. Biller J., Feinberg W. M., Castaldo J. E., et al. , “Guidelines for carotid endarterectomy,” Circulation 97(5), 501–509 (1998).10.1161/01.CIR.97.5.501 - DOI - PubMed
    1. Kim K. H., Lee C. H., Son Y. J., et al. , “Post-carotid endarterectomy cerebral hyperperfusion syndrome: is it preventable by strict blood pressure control?” J Korean Neurosurg Soc 54(3), 159 (2013).10.3340/jkns.2013.54.3.159 - DOI - PMC - PubMed
    1. Smith M., “Cerebral perfusion pressure,” BJA: British Journal of Anaesthesia 115(4), 488–490 (2015).10.1093/bja/aev230 - DOI - PubMed
    1. van der Jagt M., “Fluid management of the neurological patient: a concise review,” Critical Care 20(1), 126 (2016).10.1186/s13054-016-1309-2 - DOI - PMC - PubMed
    1. Taccone F. S., Citerio G., Le Roux P., et al. , “Advanced monitoring of systemic hemodynamics in critically ill patients with acute brain injury,” Neurocrit Care 21(S2), 38–63 (2014).10.1007/s12028-014-0033-5 - DOI - PubMed

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