Design Award

• Tong Biomedical Design Award Winner

News About this Project

• Patent: US11207171B2, Catheter apparatus and method (April 29, 2019)

Project Overview

Venous thromboembolic disease (VTE, includes deep venous thrombosis and pulmonary embolism) is a common condition associated with significant morbidity and mortality. There are over 500k cases of VTE each year in the United States, which account for approximately 300k deaths. The standard treatment for VTE is anticoagulation (ie, blood thinners). However, many patients cannot be put on anticoagulation or fail it (ie develop new blood clots despite being on it). In those patients, inferior vena cava (IVC) filters are often placed. There are many different types or designs of IVC filters. The purpose of an IVC filter is to catch large blood clots that break off from the lower extremities and prevent them from going to the lungs. The number of IVC filters placed has doubled in the past decade with >250k being placed in 2012. Historically, IVC filters were left in place indefinitely. However, filters that have been in place for a long time are associated with complications, including filter fracture, migration, penetration through the caval wall, and caval thrombosis/occlusion. For that reason, we now seek to remove filters as soon as the patient no longer needs it (preferably within the first 3 months). Filters that have only been in for a short period of time are usually easily removed with standard technique (a long sheath and a snare device). Those that have been in for a long time or filters designed to be permanent require much more complicated techniques including wire loop snare, rigid forceps or an excimer laser. One of the more difficult steps in removing a chronically embedded filter is engaging or capturing the filter, generally the first step before attempting to collapse the filter into a sheath. Some filters have a hook, which facilitates this. However, many filters do not have a hook, have a hook that is bent/broken, or have hooks that are covered in scar tissue. Those filters require formation of a wire loop snare, which can be a complex or tedious task involving looping a wire through/under the filter, snaring it, and bringing it back through the puncture site to form a loop. This can be difficult and time consuming. The goal of this project would be to design a device that engages or latches onto all or most IVC filters such that this step in a retrieval becomes easier and faster. Depending on the design, it could be used for both standard and complex filter retrievals. Several filter retrieval sets on are on the market, but only work with specific filter types and can only be used for simple retrievals, not complex retrievals.

Team Picture

Contact Information

Team Members

• Joseph Ashley - Team Leader
• Emily Foran - Communicator
• Lexi Doersch - BSAC
• Brett Struthers - BWIG
• Will Flanigan - BPAG

Advisor and Client

• Prof. Paul Thompson - Advisor
• Dr. Paul Laeseke - Client
• Dr. Michael Woods - Alternate Contact

Related Projects

• Spring 2018: Device for capturing IVC filters
• Fall 2017: Device for capturing IVC filters