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. There is only one tool commonly used today, the En Snare. Very limited maneuverability; only useful if the foreign body floats freely in the vessel and is not adherent to the vascular wall Very limited maneuverability; only useful if the foreign body floats freely in the vessel and is not adherent to the vascular wall

3. Background Over 70,000 foreign body retrieval procedures are performed per year. Over 70,000 foreign body retrieval procedures are performed per year. Items retrieved from the vascular system include wire and catheter fragments and stents. Items retrieved from the vascular system include wire and catheter fragments and stents. Removal of a centrally embolized forgein body is imperative because of the high incidence of complications Removal of a centrally embolized forgein body is imperative because of the high incidence of complications According to Grabenwoeger, in 163 cases where these bodies were left untreated, the average mortality was 37.4% According to Grabenwoeger, in 163 cases where these bodies were left untreated, the average mortality was 37.4%

4. 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. 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; one end must be freely accessible. Using a wire snare, like the En Snare, is only successful when there is a free floating end to the foreign body; one end must be freely accessible. 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. 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.

5. 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) 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 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 Less damage to the endothelium or vascular wall when removing sharp dislodged objects

6. 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 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. 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 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). 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

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

8. 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.

9. Performance Criteria This tool will be used to perform intravascular retrieval from peripheral arterial or venous access sites. 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. 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. 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. Current techniques do not allow for effective reorientation and subsequent alignment with a catheter for retrieval.

10. Work Completed Received funding for materials needed – materials for large scale model. Received funding for materials needed – materials for large scale model. Establish project specifics pertaining to tool constraints Establish project specifics pertaining to tool constraints Gained access to the cath lab and related materials Gained access to the cath lab and related materials Created basic concept drawings, and performed literature searches to compare with existing designs. Created basic concept drawings, and performed literature searches to compare with existing designs. Completed animations demonstrating basic functionality of device. Completed animations demonstrating basic functionality of device. Built stationary model Built stationary model

11. 3D Modeling  Titanium head  Nitinol wiring  Platinum lining and patterning - imaging

12. Stationary Model Better estimation of size restraints Three Prongs Claw is still inexact

13. Current Work Looking for ways to enhance the large-scale model’s functionality Looking for ways to enhance the large-scale model’s functionality Clamp size Clamp size Opening mechanism Opening mechanism Anchor claws better Anchor claws better Collect more data Collect more data

14. Current Work – Opening Mech

15. Future Work Complete construction of a large-scale prototype demonstrating En Snare and other device functionality. Complete construction of a large-scale prototype demonstrating En Snare and other device functionality. Development of additional 3D models as necessary. Development of additional 3D models as necessary. We consider success in the overall academic year to be the completion of an acceptable large- scale model which demonstrates full functionality. This includes sheathing/unsheathing the claw, opening and closing of claw, and demonstration of functionality. We consider success in the overall academic year to be the completion of an acceptable large- scale model which demonstrates full functionality. This includes sheathing/unsheathing the claw, opening and closing of claw, and demonstration of functionality. Hope for future groups to continue our work.