Improving Microcatheter Navigation Through the Brain

1. Improving Microcatheter Navigation Through the Brain Matt Kergosien Holly Bonar Advisor : Dr. Ted Larson

2. Background • Medical conditions of concern : aneurysms, hemorrhages, and vascular malformations. • Aneurysm - a sac formed by the localized dilatation of the wall of an artery, a vein, or the heart • Traditional Surgical procedures – invasive using tiny surgical clip • New surgical procedures involving microcatheters and coils

3. Who’s Having This Done? • New technology : FDA approved since 1997 • Vanderbilt performed 35 of these procedures involving microcatheters in 2000 • ~ 250 physicians across the country utilize the microcatheter technology, a 100 more than a year and a half ago • Microcatheters cost around $150-$200

4. New procedure • Catheters start in groin • At the base of the brain, microcatheter begins to snake into tiny blood vessels of the brain • Once the aneurysm is reached, the tip of the microcatheter actually goes inside and releases the tiny coils.

5. Problems and Consequences • Difficulty in navigation • Catheters follow the natural contours of the vessels – Imagine a race car on a track • Very difficult to make turns against these natural contours • Microcatheter poking through vessel wall • Coils come out of aneurysm (3-4%)

6. Examples

7. Very Long Procedure • 7-9 Hour Surgical Times • A lot of this time is due to tedious trial and error work, trying again and again to manipulate the catheter into the correct vessel • Since X-rays provide the “eyes” for the surgeon, the patient incurs increased expoure • Increased risk due to longer anesthetic exposure

8. Project Description • Design of new navigation system • Goals: decrease risks and consequences • Create less expensive design than the one currently used • Steerable Flow Directed Catheter

9. Current Hopes for a New Design • Able to handle large turns ( < 90 ) • Vessel wall friendly • Surgeon guided mechanism • Cost efficient • User friendly • More efficient control while maintaining benefits of current catheter

10. We have… • Research current models and applications • Study successful and unsuccessful designs • Current model characteristics • Observed embolization surgery • Met with Dr. Larson to determine design approach • Narrowed design options down to two • Chose a design option – permeable balloon

11. Our Design • 2-4 saline filled chambers • One way semi-permeable membrane • Controls head movement of catheter • Placement of “hinge”