Introduction High Frequency Optical Coherence Tomography (HF-OCT)¹ is an intra-vascular imaging technique to assess device-vessel interactions and neointimal tissue growth at unprecedented spatial resolution (~10µm). In this study, we tested the hypothesis that an adequately deployed (as visualized by HF-OCT) Woven EndoBridge (WEB, Microvention, Aliso Viejo, CA) will lead to a higher aneurysm occlusion rate at 12-week follow-up in an animal model of aneurysms.

Methods Elastase-induced rabbit aneurysms (n=24) were treated with the WEB device. HF-OCT (Vis-M; Gentuity LLC, Sudbury MA) and DSA were performed after WEB deployment and repeated at 4, 8, and 12 weeks. Protrusion and malapposition were binary coded (0- present, 1- absent; 0- malapposed, 1- neck apposition >50%), respectively, on HF-OCT and DSA. A device was considered adequately deployed if it was scored as 1 on both metrics. Aneurysm healing on DSA was interpreted using the 4-point WEB occlusion score (WOS)²; with A-B considered a positive outcome. HF-OCT images acquired at 12 weeks were analyzed and neointimal coverage quantified. Scanning electron microscopy (SEM) was performed of the explanted specimens.

Results Discrepancy between HF-OCT and DSA was found: HF-OCT classified as adequately deployed a total of 5 cases, whereas 8 cases were classified as adequately deployed by DSA images. Acceptable WOS grade at 12 weeks was seen in 21% of cases (n=5): 80% of those cases (n=4) were classified as adequately deployed based by HF-OCT; whereas only 60% of those cases (n=3) classified adequate by DSA. A significant interaction between adequate deployment on HF-OCT and positive outcome was confirmed (p= 0.007). However, there was no statistically significant relationship between good outcome and adequate deployment based on DSA images (p= 0.289). Based on HF-OCT images, the absence of the protrusion was related with a positive outcome (p= 0.006); however, malapposition had no significant interaction with positive outcome (p= 0.19). The area of neointimal tissue quantified by HF-OCT showed a strong correlation with SEM assessment (R²=0.96; p< 0.001). The mean neointimal coverage on ‘adequate deployment’ cases was 78%, whereas a mean neointimal coverage of 31% was found for the ‘not adequate deployment’ cases (p=0.001).

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Abstract O-014 Figure 1 Example of a ‘not adequately deployed’ device based on HF-OCT. (A-D) Baseline HF-OCT, 12 weeks final DSA, SEM, and 12 weeks HF-OCT, respectively, for a case with the presence of protrusion and absence of malapposition (white arrow, A). A large amount of uncovered device struts were found by both SEM and HF-OCT images (White arrow, D). (E-H) an example of ‘adequate deployment’: baseline HF-OCT, 12 weeks DSA, SEM image, and 12 weeks HF-OCT, respectively, for an animal without any protrusion or malapposition. A positive outcome (WOS-A) and completed neointimal coverage of the device is observed on SEM (G). Similarly, the device struts are completely covered by neointimal tissue as observed by HF-OCT (white arrow, H)

Conclusion HF-OCT may be valuable prognosticate adequate aneurysm occlusion with the WEB and can be used to monitor aneurysm healing longitudinally. Absence of protrusion was associated with subsequent aneurysm occlusion; however, malapposition alone did not show an effect on the rate of aneurysm healing.

Reference

1. Stroke. 2018:Nov29:STROKEAHA118022315 2. AJNR 2014;35:432–8.

Disclosures Z. Vardar: None. R. King: None. A. Kraitem: None. E. Langan: None. L. Peterson: None. B. Duncan: None. C. Raskett: None. V. Anagnostakou: None. M. Gounis: None. A. Puri: None. G. Ughi: None.