Preclinical evaluation of Millipede 088 intracranial aspiration catheter in cadaver and in vitro thrombectomy models

BACKGROUND: Larger bore aspiration catheters are expected to significantly improve the speed and completeness of acute stroke revascularization. OBJECTIVE: To evaluate the navigability and clot retrieval performance of a novel 8Fr aspiration catheter, Millipede 088 (Perfuze Ltd), using fresh-frozen cadavers and an in vitro thrombectomy model, respectively. METHODS: Cadaveric study: Transfemoral catheterization of the intracranial arteries was performed in six cadavers, allowing evaluation of navigation to 12 middle cerebral arteries (MCAs) and six basilar arteries. Commercially available 6Fr aspiration catheters (SOFIA Plus, Microvention) were used as controls. In vitro study: Three human blood clot phenotypes were created; red blood cell-rich, mixed, and fibrin/platelets-rich. Two clot sizes, resulting in occlusion of the internal carotid artery (ICA) and MCA-M1 were investigated. Endpoints were first-pass effect (FPE), first-pass complete ingestion, and second-pass recanalization. RESULTS: Cadaveric study: Both the Millipede 088 and SOFIA Plus devices reached the distal MCA-M1 and the basilar artery in 10/12 and 2/2 of the navigation attempts, respectively. In the two instances of unsuccessful navigation, neither device was able to cross the ophthalmic artery. In vitro study: In 10 mm long M1 occlusions, Millipede 088 achieved 100% FPE versus 40% for 6Fr devices (p>0.001). In 20 mm long ICA occlusions, Millipede 088 achieved 100% removal success within two passes in each clot phenotype compared with an average of 27% for 6Fr devices (p>0.001). CONCLUSIONS: Navigation of the Millipede 088 catheter to the MCA-M1 and basilar artery is feasible in a cadaver model. Millipede 088 demonstrates superiority over 6Fr aspiration catheters for three representative clot phenotypes at the most common sites of occlusion in an in vitro vasculature model.