Abstract Number: Esoc2026a964 Microplastics Not Detected in Cerebral Thrombi from Cardioembolic Stroke: Detection Using Pyrolysis–gc/ms

Abstract Background and aims Recent reports have described the detection of microplastics in human tissues, raising concerns about their potential health effects. The human body has mechanisms that promote thrombus formation in response to foreign materials, and if plastics are present in the bloodstream, they may contribute to thrombus formation leading to ischemic stroke. The purpose of this study was to analyze thrombi retrieved from patients with cardioembolic stroke to investigate the presence of plastics and to clarify their constituent components. Methods This was a single-center prospective study including patients with cardioembolic stroke who underwent mechanical thrombectomy. Retrieved thrombi were analyzed using pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS), and the obtained spectra were compared with databases of polyethylene (PE), polystyrene (PS), and other microplastics. Results Linear alkanes were detected in all cases and were initially considered to be derived from PE; however, they did not match the spectra of PE reference standards. For PS, a styrene monomer peak was observed, but PS-specific oligomers were not detected, and the presence of PS was therefore excluded. No other plastics were detected. Conclusions Conventional detection methods have largely relied on visual assessment; in contrast, Py-GC/MS enables comprehensive analysis of constituent components and is considered one of the most reliable techniques for trace-level analysis of contained substances. In thrombi from patients with cardioembolic stroke, no plastics, including PE or PS, were detected, indicating that recent reports should be interpreted with caution. Conflict of interest Yuya Kobayashi: nothing to disclose