Intravascular Foreign Body Retrieval System

1. Intravascular Foreign Body Retrieval System Nathan Luibrand, Nicholas Luibrand, Lukas Richards, and Elise Adcock-Hinojosa Advised by Dr. Michael Barnett

2. Problem Statement • There is only one tool commonly used today, the En Snare. • Very limited maneuverability.

3. 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. 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.

4. 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

5. 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

6. How can this tool be used? • Foreign Body Removal • Stents, wires, thrombi, etc. http://www.mayoclinic.org/cardiothoracicsurgery-jax/diseases.html

7. Primary Objective • The current tool being used for foreign body retrieval has limited maneuverability • 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.

8. 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 160-190 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.

9. Work Completed • Met with Michael Barnett about project specifics, discussing most common current methods. • Established project goals and timeline (proposal) • Establish project specifics pertaining to constraints for tool • Created basic concept drawings, and performed literature searches to compare with existing designs.

10. Current Work • Researching information on En Snare, mainly looking for ways to improve the design. Brainstorming and drawing rough sketches of different ways to allow reorientation of foreign bodies and threading them into the device. • Meet with Dr. Barnett and to watch related surgery. • Catheter Lab

11. Future Work • Determine what budget is necessary by discussing with advisor • Determination of the best design sketched • Designing the best determined model using an autoCAD tool. • In a week or two, our goal is to have one or more feasible foreign body retrieval tools completely designed. • We consider success in the overall academic year to be the completion of an acceptable prototype. We wish to be at a stage where the prototype appears promising enough for someone else to be willing to take the design to completion should we choose to conclude our work at graduation.