Intravascular Foreign Body Retrieval System Nathan Luibrand, Nicholas Luibrand, Lukas Richards, and Elise Adcock-Hinojosa Advised by Dr. Michael Barnett Problem Statement There is only one tool commonly used today, the En Snare. Very limited maneuverability. Background Over 70,000 foreign body retrieval procedures are performed per year. Items retrieved from the vascular system include wire and catheter fragments and stents. Unable to retrieve medical statistics for use due to company privacy. The En Snare Device A system of 3 interlocked loops of wire which when pulled into the catheter cause the loops to close and catch the targeted foreign body. Using a wire snare, like the En Snare, is only successful when there is a free floating end to the foreign body Some foreign bodies are caught at awkward angles and require a better orientation in order to be pulled inside the catheter to reduce damage to the vessels during retrieval. Advantages There are some advantages to using a forcep-like device over using wire snares for foreign object retrieval: Greater maneuverability (rotational and “grasping” area) The ability to dislodge a foreign body trapped with no free end: the ability to grab the foreign body in the middle of the object Less damage to the endothelium or vascular wall when removing sharp dislodged objects How can this tool be used? The En Snare, as well as any future devices foreign body removal devices can be used in: Indwelling Venous Catheter Repositioning An indwelling venous catheter allows for venous access for long periods of time (months to years), and it is more easily repositioned with a retrieval device. Snare Assisted Guide Wire Capture When introducing a wire into the body, the use of a snare entered through a different incision can aid in guiding the wire where it needs to go (i.e. capturing a wire over the aortic bifurcation). http://www.saintfrancis.com/hearthospital/services/heartsurgery.aspx How can this tool be used? Foreign Body Removal Stents, wires, thrombi, etc. http://www.mayoclinic.org/cardiothoracicsurgery-jax/diseases.html Primary Objective To design a device which can not only “grab” foreign bodies, but which can also manipulate them in such a way as for easier removal. Construct multiple different prototypes and/or 3D models to represent functionality. Performance Criteria This tool will be used to perform intravascular retrieval from peripheral arterial or venous access sites. Its size could range from 1-8 mm in diameter and 160190 cm long. The goal is to be able to use the tool to reorient and remove debris –both natural and synthetic- from vasculature of small to large radii through a catheter. Current techniques do not allow for effective reorientation and subsequent alignment with a catheter for retrieval. Work Completed Received funding for materials needed – engineering kit w/ nitinol and supplies for prototype construction. Establish project specifics pertaining to tool constraints Gained access to the cath lab and related materials Created basic concept drawings, and performed literature searches to compare with existing designs. Completed animations demonstrating basic functionality of device. 3D Modeling Titanium head Nitinol wiring Platinum lining - imaging Current Work Brainstorming of additional ideas. Looking for appropriate materials to construct a large-scale En Snare device from. Demonstrate a mock surgery in the cath lab Hands-on experience with a variety of tools – potential to translate ideas into our project. Developing addition 3D models of potential designs Future Work Determination of the best design sketched Complete construction of a large-scale prototype demonstrating En Snare and other device functionality. We consider success in the overall academic year to be the completion of an acceptable largescale model which demonstrates full functionality. We wish to be at a stage where this model appears promising enough for someone else to be willing to take the design to completion should we choose to conclude our work at graduation.