In Vitro Testing of a New Aspiration Thrombus Device

Background

Mechanical thrombectomy can restore blood flow to the brain after acute ischemic stroke, but may be associated with risks, such as breakage of moving parts and clot fragmentation. The aim of this study was to evaluate a new aspiration thrombus device (ATD), the GP ATD, which has no moving parts and extracts clots by suction in a vortex flow pattern.

Methods

The GP ATD is used to extract porcine blood clots inserted into the middle cerebral artery (MCA) of a model of the circle of Willis, and from porcine aorta.

Results

The GP ATD is navigable around the acute angles of the circle of Willis model and successfully extracts clots that cause complete occlusion of the MCA. There is a strong correlation between the pressure required for clot extraction (mean 31.8, range 30-34 kPa) and its mass (mean 0.08, range 0.03-0.13g). Complete clot extraction can be demonstrated by computed tomography scanning. Lysis of a 0.15-g thrombus using alteplase at a concentration of 3.4μg/mL was more effective when delivered and extracted via the GP ATD than via a catheter without the GP ATD or delivered systemically in our circle of Willis model and extracted without suction (clot mass after extraction 0.07, 0.09, and 0.11g, respectively). Histologic examination does not show evidence of damage of the arterial wall caused by clot extraction at suction pressures of up to 30 kPa via the GP ATD.

Conclusion

The GP ATD appears to effectively extract blood clots from models of the MCA without significant clot fragmentation and damage to the arterial wall. Further experiments using arteries in situ are required to confirm these findings.

Key Words: Aspiration thrombus device, GP device, blood clot