Two-for-one Stroke Thrombectomy: A novel Dual DAC to enhance navigability, lumen size, aspiration efficiency, and persistent flow arrest in mechanical thrombectomy

PROJECT SUMMARY/ABSTRACT The long-term goal of this proposal is to improve the care of patients suffering from Large Vessel Occlusion Acute Ischemic stroke. Currently, mechanical thrombectomy techniques can achieve revascularization in over 70% of cases, and physicians are rapidly adoption aspiration thrombectomy over stent-trievers. Aspiration maintains equivalent angiographic and clinical outcomes to stent-retrieval, but larger catheters and new combinatorial techniques have given rise to promises of faster, cheaper, more effective “Super Bore” devices. The way to improve aspiration technologies is to expand the inner diameter (ID) of distal access catheters (DACs): in vitro studies have shown that catheters with ID of 0.088” have near-perfect rates of clot ingestion in a single pass, spurring development of multiple Super Bore 088 DAC systems. While the enthusiasm for the 088DACs remains extremely high among the interventional stroke community, limitations in recent clinical reports point to key aspects that could readily be improved with novel design features. First, a “one-size- fits- all” approach may not be ideal for many patients, especially women with smaller intracranial arteries. Specifically, the middle cerebral artery (MCA), where most clots reside, has variable width. Second, the promise of “localized flow arrest” with the large bore catheters, where the catheter itself is large enough to stop forward flow, falls apart if the clot is not ingested immediately and “corked” clots as the tip must be pulled into the guiding catheter, risking downstream emboli. Third, the 0.088” ID is still too small for clots that lodge in the internal carotid artery. Finally, most of the currently proposed 088DACs are incompatible with 8Fr access sheaths, and thus cannot be used on-label with arterial closure devices, increasing the risk of hemorrhage. In response to these challenges, we have designed a novel, two-component, telescoping “Dual DAC” system that, as a unit, has the same ID of other “Super Bore” DACs while achieving 8Fr short sheath compatibility. The inner DAC provides the target 0.088” ID, yet fits into the outer DAC’s 0.101”ID. By thinning the walls of the two nested DACs, we provide all of the performance features, and much more, of the other Super Bore 088 DACs. Our system can be placed in the MCA, but instead of a single, thick-walled 0.088” catheter, our system allows placement of both DACs simultaneously in most patients. The inner DAC is used for aspiration, while the outer DAC remains in the MCA for persistent local flow arrest during retrieval of the inner DAC. Further, our inner DAC, with an OD almost 1Fr smaller than other Super Bore 088 DACs, will fit even into narrow MCAs in smaller women. To date, we have constructed prototypes and demonstrated outstanding trackability of the Dual DAC system in leading neurovascular simulators. In this Phase 1 STTR we propose to refine and test the system to achieve design freeze. If successful, this research program will provide the next generation system for clot ingestion, which we will drive forward to commercialization through GLP animal and other testing required to achieve regulatory clearance in our Phase II.