EMBOLESS MECHANICAL CLOT REMOVAL DEVICE: POSSIBILITY FOR IMPROVING THE OUTCOMES OF ISCHEMIC STROKE PATIENTS

摘要

Ischemic stroke affects nearly 690,000 patients a year in the United States and is the leading cause of long-term disability and the third leading cause of death [1, 2]. Acute ischemic stroke occurs when a clot becomes lodged in a cerebral vessel, cutting off blood supply to areas of the brain. There are two treatment options for acute ischemic stroke: tissue plasminogen activator (beneficial within the first 4 hours of stroke onset), and mechanical removal (beneficial from 4 to 8 hours after stroke onset). The two FDA approved clot removal devices (MERCI and Penumbra) for ischemic stroke are capable of achieving revascularization rates between 48% and 80% [3,4].rnThe EmboLess includes a whisk laser-cut from a nitinol sheet and shape-set to a bulbous form with a filter made of liquid polymer material attached to its distal half. The whisk is attached to a guidewire and the entire device is compressed into a sheath. It treats ischemic stroke by removing clots in occluded arterial vessels that are typically 2-4 mm in diameter and allow only non-harmful embolic fragments less than 100 jxm in diameter to pass through the filter. The EmboLess operates as shown in figure 1. First, the entire device encased in a sheath is passed through the center of the clot. Next, the ensnaring whisk is deployed out of sheath distal to the clot. Following this, the sheath is removed from the center of the clot. Of utmost importance are the shape memory and elastic properties of the nitinol. The nitinol whisk is compressed into the catheter and when released, obtains the bulbous shape that it was set to. The elastic properties allow it to expand to the diameter of the vessel wall, thus capturing the full diameter of the clot.