Improving Microcatheter Navigation Through the Brain

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Improving Microcatheter Navigation Through the
Brain

• Matt Kergosien
• Holly Bonar
• Advisor Dr. Ted Larson

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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

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Whos 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

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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.

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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)

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Examples
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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

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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

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Current Hopes for a New Design

• Able to handle large turns ( lt 90? )
• Vessel wall friendly
• Surgeon guided mechanism
• Cost efficient
• User friendly
• More efficient control while maintaining benefits
  of current catheter

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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

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Our Design

• 2-4 saline filled chambers
• One way semi-permeable membrane
• Controls head movement of catheter
• Placement of hinge