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

Background Medical conditions of concern : aneurysms, hemorrhages, and vascular malformations. 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 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 Traditional Surgical procedures – invasive using tiny surgical clip New surgical procedures involving microcatheters and coils New surgical procedures involving microcatheters and coils

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

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

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

Examples

Very Long Procedure 7-9 Hour Surgical Times 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 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 Since X-rays provide the “eyes” for the surgeon, the patient incurs increased expoure Increased risk due to longer anesthetic exposure Increased risk due to longer anesthetic exposure

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

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

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

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