Transcranial Duplex Evaluation of Internal Carotid Artery Flow Direction during Transcarotid Artery Revacularisation with Integrated Embolic Protection

The aim of this study was to report the findings of transcranial duplex (TCD) evaluation of petrous internal carotid artery (ICA) flow during transcarotid artery revascularisation (TCAR). Thirty day clinical results were also evaluated. A two centre database of all consecutive patients who had TCD evaluation of the petrous segment of the ICA during TCAR with a modified approach using the Neuroguard IEP (Contego Medical, Raleigh, NC, USA) three in one device and selective flow reversal was reviewed retrospectively. This novel carotid stent has an integrated embolic protection (IEP) system, and the procedure has been termed TCAR-IEP. The study primary endpoint was the achievement or not of flow reversal, and secondary endpoints were procedural technical success and 30 day stroke and or death. Between January and May 2023, 22 consecutive patients (mean age 72 years; 16 [73%] males) underwent TCAR-IEP with concomitant TCD evaluation of the ipsilateral petrous ICA. In 16 of these patients (73%) there was a sufficient temporal bone window to allow for an adequate peri-operative duplex scan of the petrous segment of the ICA. After common carotid artery (CCA) clamping and side port opening for pressure differential augmentation and despite the presence of retrograde flow in an 8 F carotid artery sheath in all patients, only eight patients (50%) demonstrated flow reversal in the ipsilateral petrous ICA. Technical success was 100%. No major strokes or death were observed in the first 30 days post-intervention. In this study, distal ICA flow reversal was not present during TCAR for a significant proportion of patients despite retrograde flow being visually observed in the CCA sheath. Addition of distal embolic protection in all patients appears reasonable for effective stroke risk reduction.