RS08 - The ENROUTE Transcarotid Neuroprotection System (ENROUTE Transcarotid NPS) DW-MRI Evaluation

Objectives: The goal of this study is to evaluate the incidence and volume of diffusion-weighted magnetic resonance imaging (DW-MRI) new white lesions (NWLs) occurring within 30 days after transcarotid artery revascularization (TCAR)

Methods: This a prospective, open label, single arm multicenter study. Between June 2019 and November 2021, 52 patients requiring carotid revascularization were enrolled in the DW-MRI protocol at 5 centers in the United States and 2 centers in the European Union and completed 30 day follow-up. Patients eligible for TCAR underwent serial DW-MRI of the brain pre-, post- and at 30-days following the procedure to assess the number, location, and volume of NWLs. All patients met at least one high risk criteria for carotid endarterectomy (CEA). Aggregate data were pooled across sites, stratified by demographics, and analyzed using descriptive statistics. The primary endpoint was incidence of ipsilateral NWLs by DW-MRI post procedure. Secondary endpoints were rates of stroke, neurological death, and rate of contralateral NWLs as well as the volume and location by DW-MRI.

Results: 52 patients completed the 30-day follow-up as of 01Nov2021, 16 were symptomatic (30.8%) and 36 were asymptomatic (69.2%). There were no differences in the demographics or medical history by symptom status. At least one NWL was detected in the ipsilateral hemisphere in 11 (21.2%) of 52 patients at post procedure DW-MRI, None of the patients experienced a clinical stroke by NIH stroke scale with no mortality. A summary of the NWLs post-procedure is shown in Table 1, followed by NWLs stratified by symptom status in Table 2. 5/16 (31.2%) of Symptomatic patients and 6/36 (16.7%) had NWLs. Symptomatic patients averaged 1.4 (7/5) NWLs while asymptomatic patients averaged 7.2 (43/6) NWLs. The mean lesion volume was 0.11 CC. (Symptomatic 0.02 CC and Asymptomatic 0.03 CC). There were no predictive variables found for NWLs

Conclusions: This multi-center evaluation suggests DW-MRI NWLs are uncommon following TCAR, indicating the importance of high flow rate reversal. These imaging findings do not manifest as clinical neurological events. Furthermore, the outcomes of this analysis should serve as the benchmark for future comparisons evaluating carotid revascularization strategies on cerebral NWLs and the degree of neuroprotection offered by high flow rate flow reversal