O-052 Sticky stents: a clot-adhesive coating on stent-retrievers reduces distal emboli

• Published in: Journal of neurointerventional surgery Vol. 15; no. Suppl 1; pp. A41 - A42
• Main Authors: Anagnostakou, V, Skarbek, C, Epshtein, M, Propocio, E, Raskett, C, Romagnoli, R, Iviglia, G, Morra, M, Antonucci, M, Nicoletti, A, Caligiuri, G, Gounis, M
• Format: Journal Article
• Language: English
• Published: BMA House, Tavistock Square, London, WC1H 9JR BMJ Publishing Group Ltd 30.07.2023; BMJ Publishing Group LTD
• Subjects: Medical research; SNIS 20th annual meeting oral abstracts; Stents
• ISSN: 1759-8478; 1759-8486
• DOI: 10.1136/jnis-2023-SNIS.52

BackgroundThe first-pass, complete recanalization by mechanical thrombectomy (MT) for the treatment of large vessel occlusion remains limited. Currently, stent-retrievers come with a variety of different designs with the goal of better clot integration, but there are no coatings available that can attract elements of the clot. Co-aspiration techniques can help retrieval of the main clot, but does not always prevent distal emboli, or emboli to a new territory (ENT). Clot specimens retrieved with MT have been shown to have dense meshes of extracellular DNA (neutrophil extracellular traps: NETs) on histology. We hypothesized that stent retrievers modified with coatings that bind to NETs will reduce distal emboli by anchoring the clot to the device.MethodsNickel-titanium plates were coated with 15 different substrates. Extensive characterization of candidate coatings was performed including X-Ray Photoelectron Spectroscopy, Atomic Force Microscopy and ζ - potential measurement. The plates were then exposed to both NETs and human peripheral whole blood in vitro. The amount of chromatin and platelet binding was measured with immunohistochemistry. The two best candidate coatings were then applied to the Solitaire device and tested in a validated simulated use experiment of MCA occlusion. Briefly, an aged clot that was confirmed to have NETs was introduced into a vascular replica of the entire circle of Willis. The two coated devices and two control devices (bare metal stent and stent with only the base polydopamine (PDA) film) were block randomized for mechanical thrombectomy in the model with 10 replicate experiments for each device. All effluent was collected from the MCA and ACA territories separately for emboli analysis to the distal vasculature and ENT, respectively. We also measured the number of passes required to achieve complete recanalization.ResultsChromatin binding was increased with all compounds tested as compared to the bare metal alloy; however, the two best candidates were mustard benzo[b]furan (MBF) and a piperaquine derivative (Pipe-2) that showed a 3-fold and almost 2-fold affinity for chromatin, respectively. MBF and Pipe-2 also has reduced affinity for binding platelets compared to bare metal plates. These candidate compounds were tested in the simulated use experiment. The control devices had similar numbers of total fragmented emboli >200µm (bare metal: 55, PDA 49). Both candidate NETs binding coatings had a statistically significant reduction in total clot fragments released during MT as compared to the bare metal stent (MBF: 19; Pipe-2: 25; p=0.042). Although the final complete reperfusion was equivalent for all devices tested, in 70% of the thrombectomies the clot became dislodged from the bare metal stent in the ICA (which was then successfully aspirated). With the coating technologies, both MBF and Pipe-2, showed a dramatic reduction in the clot rolling off the stent, becoming dislodged in 20% or fewer of the MT procedures.ConclusionThese experiments have shown that coating technologies targeting NETs of clots causing large vessel occlusion lead to fewer clot fragments during stent-retriever thrombectomy. It was also observed that the clot ‘rolling’ off the surface of the stent was reduced with chromatin binding surface modification.Disclosures V. Anagnostakou: None. C. Skarbek: None. M. Epshtein: None. E. Propocio: None. C. Raskett: None. R. Romagnoli: None. G. Iviglia: None. M. Morra: None. M. Antonucci: None. A. Nicoletti: 4; C; Kapto. G. Caligiuri: 4; C; Kapto. M. Gounis: 1; C; NIH, the United States – Israel Binational Science Foundation, Anaconda, ApicBio, Arsenal Medical, Axovant, Balt, Cerenovus, Ceretrieve, CereVasc LLC, Cook Medical, Galaxy Therapeutics, Gentuity, Gilb. 2; C; Alembic LLC, Astrocyte Pharmaceuticals, BendIt Technologies, Cerenovus, Imperative Care, Jacob’s Institute, Medtronic Neurovascular, Mivi Neurosciences, phenox GMbH, Q’Apel, Route 92 Medical, Scientia. 4; C; Imperative Care, InNeuroCo, Galaxy Therapeutics, Neurogami and Synchron.