Intravascular Foreign
Body Retrieval System
Nathan Luibrand, Nicholas Luibrand,
Lukas Richards, and
Elise Adcock-Hinojosa
Advised by Dr. Michael Barnett
Problem Statement
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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.
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Advantages
There are some advantages to using a forcep-like device
over using wire snares for foreign object retrieval:
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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
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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
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
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
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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
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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.
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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
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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.