Background and purpose Vascular wall components (VWCs) are sometimes identified as collagen fibers in specimens retrieved by thrombectomy from acute stroke patients. However, their clinical significance and associated factors remain unclear. The purpose of this study was to clarify the factors associated with VWCs in retrieved thrombi.
Methods Consecutive acute stroke patients treated endovascularly using the Penumbra aspiration catheter or stent retrievers (SRs) at our institute from November 2013 to April 2016 were retrospectively reviewed, and the retrieved thrombi were evaluated histopathologically. VWCs were defined as banded collagen fibers with a distinct boundary observed at the rim or outside of the retrieved thrombi. Factors associated with the presence of VWCs were studied.
Results A total of 150 specimens (76 specimens retrieved by the Penumbra, 74 by SRs) from 101 patients (47 women, age 74.9±11.1 years) were investigated. Applied thrombectomy devices were aspiration catheters in 42 patients, SRs in 21 patients, and both in 38 patients. VWCs were observed in 24 specimens (16%) from 22 patients. A low proportion of erythrocyte components (41.7±24.8% vs 55.0±26.3%, P=0.01), a high frequency of the devices reaching the M2/P2 (75% vs 50%, P=0.02), and a high number of device passages (P for trend=0.02) were associated with VWC positive thrombi. Successful recanalization (Treatment in Cerebral Ischemia ≥2b) tended to be less frequent in patients with VWC positive thrombi than in those without (73% vs 89%, P=0.06).
Conclusions The histopathology of occlusive thrombi, arterial sites where devices reached, and number of device passages, might affect the presence of VWCs in retrieved thrombi.
- mechanical thrombectomy
- vascular damage
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Contributors Study conception and design: NF and MH. Drafting the article: NF. Revising the manuscript critically for important intellectual content: MH, HI-U, and KT. Acquisition of the data: all authors. Technical/material support: TH, HY, TS, JCT, KN, and HI-U. Analysis and interpretation of the data: all authors. Study supervision: HY, TI, and KT. Final approval of the version to be published: all authors.
Funding This work was supported by the Japan Society for the Promotion of Science, Grant in Aid for Scientific Research (C) 15K10381, and by the Japanese Society for Neuroendovascular Therapy.
Competing interests None declared.
Patient consent Not required.
Ethics approval The study was approved by the research ethics committee of the National Cerebral and Cardiovascular Center.
Provenance and peer review Not commissioned; externally peer reviewed.
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