Project Id: 2021-40
Background:
Inferior vena cava (IVC) filters are small, metal devices temporarily placed in the inferior vena cava that are designed to catch blood clots and stop the blood clots from traveling to the lungs. An average of 65,000 IVC filters are placed annually in the United States. About 15% of the time, the IVC filter becomes embedded in the intima of the vessel, rendering it irretrievable by conventional methods such as the snare method. These filters are needed in patients with a history or risk of deep vein thrombosis (DVT) or pulmonary embolism (PE), as well as trauma victims and immobile patients. Immobile patients may need IVC filters when other methods such as blood-thinning agents are unsuccessful. The snare method is the most popular method of retrieval and relies on the ability to grasp the retrieval hook on the end of the IVC filter. However, when the IVC filter is tilted at an angle, the snare is unable to grab the retrieval hook by itself. Additionally, the surgeon and/or radiologist needs to be able to see the hook clearly on the angiogram, which is a black and white two-dimensional image. These variables make the retrieval process more difficult and can significantly increase retrieval time.
Invention Summary:
Researchers at the University of Toledo have developed a novel IVC filter retrieval device configured to safely remove an IVC filter, including an IVC filter that is embedded in the intima of a vessel, in an efficient and cost-effective manner. The novel device is characterized by a hook deployed from an angled pig-tailed catheter which is encompassed by a slightly larger, outer sheath thereby reducing retrieval time over conventional methods. The hook on the retrieval device is designed large enough to secure the retrieval hook of the filter and/or the neck portion of the filter. This is ideal in cases when conventional methods such as snares and forceps are not successful. When the hook is deployed/embedded into the vessel, the surgeon is able to rotate around the entire circumference of the vessel until the IVC filter retrieval device engages with the IVC filter at the hook or the neck of the filter. The hook securely grabs the IVC filter and pulls it away from the intima of the vessel and into the retrievable sheath or to a position within the vessel that allows easier manipulation and retrieval. The hook can sweep around the entire boundary of the vessel until the IVC filter retrieval device makes contact with the IVC filter, at which point the IVC filter can be retrieved. The IVC filter retrieval device does not require the surgeon to specifically aim for only one IVC filter hook, which is a tiny target of just a few millimeters. Rather, advantageously, making initial contact with the neck portion or even a leg of the IVC filter may still result in successful retrieval of the IVC filter.
Applications:
Retrieval of IVC filters, foreign bodies, wires, etc.
Advantages:
IP Status: Patent Pending.