Validation of the Automated Electronic Microemboli Detection System in Patients Undergoing Carotid Endarterectomy

Abstract

To assess the diagnostic value of automatic embolus detection software (AEDS) in transcranial Doppler (TCD) monitoring for the detection of solid microemboli in patients at risk for perioperative stroke during carotid endarterectomy (CEA). In 50 patients undergoing CEA, perioperative TCD registration was recorded. All recorded events, identified and saved by the AEDS, were analyzed off-line doubly by two human experts (HEs) within a time frame of> 4 months. The inter- and intraobserver variability was assessed. The overall agreement with the HEs, the sensitivity, specificity, negative and positive predictive values (NPV and PPV) of the AEDS were computed for different cut-offs (patient displaying perioperative 5, 10, 20, 25, or 50 microemboli). 77 233 events were analyzed. The inter- and intraobserver variability was good (min κ = 0.72, max κ = 0.79). AEDS and the HEs identified 760 and 470 solid emboli, respectively. The agreement between AEDS and the HEs for solid emboli detection was poor (κ = 0.24, SE = 0.016). The specificity and NPV were high (99.2 % and 99.6 %) but the sensitivity and PPV were low (30.6 % and 19.8 %). Applying a threshold of> 20 microemboli resulted in the best sensitivity (100.0 %), specificity (84.4 %), PPV (42.7 %), NPV (100.0 %) and area under the curve (0.898). However, 58.3 % of the patients were false positive as classified by AEDS. In this validation cohort, AEDS has insufficient agreement with HEs in the identification of solid emboli. AEDS and HEs disagree with respect to the identification of specific patients at risk. Therefore, AEDS cannot be used as a standalone system to identify patients at risk for perioperative stroke during CEA.

A Time-Frequency Approach for Cerebral Embolic Load Monitoring

“…Our reference annotations may thus be interpreted as reliable [35]. Similar kappa values (72%, and 90%) have previously been reported in the literature for embolus annotations by human experts [36], [37].…”

Flow Cytometry Based Platelet Reactivity Testing to Predict the Occurrence of Per-operative Solid Microemboli During Carotid Endarterectomy

“…20 solid MES as at high risk of peri-operative stroke. 19,20 Within the study, eight of 190 patients met this criterium. They were prescribed aspirin monotherapy (n ¼ 1), aspirin and dipyridamole (n ¼ 5), clopidogrel (n ¼ 1), or aspirin and an oral anticoagulant (n ¼ 1).…”

“…18 Classification of solid emboli was performed once for each patient. 19 Before induction of anaesthesia, arterial blood was collected into 0.105 M trisodium citrate vacuum tubes (Becton Dickinson, Temse, Belgium) for flow cytometric platelet reactivity analysis.…”

Ultrasound detection of cerebral microembolism in carotid stenoses: progress and perspective (A review of the literature)

“…Так, T. Leunissen зі співавт. (2018) [18] за результатами порівняння даних розробленого програмного забезпечення електронної системи емболодетекції та отриманих експертами в 50 пацієнтів під час КЕА не виявили узгодженості між автоматизованою та візуальною оцінкою, чутливість автоматизованої системи була нижчою з 53,8 % хибнопозитивних результатів.…”