Design, Fabrication, and Testing of an Endovascular Mechanical Thrombectomy Device

Abstract

Stroke is a leading cause of death and debilitation in the United States, with ischemic stroke in particular affecting hundreds of thousands of people every year. Treatment options for ischemic stroke have several limitations. Among ischemic stroke treatment options, mechanical thrombectomy offers significant advantages, including a longer time window for treatment. However, these devices also have limiting factors such as limited maneuverability and poor performance in certain vessel geometries. The focus of this work is to discuss the design and testing of an alternative mechanical thrombectomy device to be used for ischemic stroke treatment. This device will aim to remove some of the limiting factors that currently affect mechanical thrombectomy devices.

Fabrication of the device was accomplished through a combination of shape memory polymer foam and nitinol tubing attached to a guidewire. Characterization of the device was achieved by utilizing a set of tensile testing procedures and a set of in vitro mechanical thrombectomy procedures. Retraction force was recorded during some of the in vitro procedures for comparison to the tensile data. Average tensile force required to cause device failure was more than 2.75 times the peak retraction force seen in any trial. In vitro thrombectomy was performed successfully in all attempted trials for a specific geometry, suggesting that this device has potential as an alternative treatment option. Further in vitro thrombectomy trials to compare the design to current FDA-approved mechanical thrombectomy devices and a set of preclinical tests to show effectiveness in an animal model would validate the design and pave the way for clinical studies.