How to improve guiding catheter back-up in TRI using the IKARI curve - physics of guide catheter -

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How to improve guiding catheter back-upin TRI
using the IKARI curve- physics of guide catheter
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The IKARI Curves
Technical aspects
Trans-radial approach
Trans-Radial Intervention

• Yuji Ikari, MD, PhD
• Tokai University, Japan

Yuji Ikari, MD
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Background

• We need sufficient backup support of guide
  catheters in TRI as well as TFI.
• We need to know the mechanism how the guide
  catheters generate backup force.

Technical aspects
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Ikari guide catheters
Ikari Curves
Ikari R (IR) 1.5 Ikari L (IL) 4
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Hypothesis

• If Fcosq l (static friction),
• the guiding catheter works.
• If Fcosq gt l, system collapses.

hypothesis

• Thus, Maximun backup force
• (Fmax) is

l Fmax ?? cosq
IKARI curve
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We try to explain several common findings using
the hypothesis in the following slides.
Experiments
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1. Role of q

• If q is larger and close to 90
• the backup force is greater.

Results
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Judkins L can generate greater backup force in
TFI than in TRI.
l Fmax ????
cosq
Judkins Left TFI vs TRI
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Judkins L 3.5 can generate greaterbackup force
in TRI than JL4.
Plt0.05
l Fmax ????
cosq
Judkins Left 3.5 vs 4
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Deep engagement increasesbackup force of Judkins
L
Plt0.05
l Fmax ????
cosq
Judkins Left Deep engage
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Ikari L can generate greaterbackup force than
Judkins L in TRI
Plt0.001
l Fmax ????
cosq
Ikari vs Judkins L
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Power Position of Ikari L generatesthe greatest
backup force
Plt0.05
Power position Of Ikari L
l Fmax ????
cosq
power position
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2. Role of static friction (l)
If the static friction is larger, the backup
force is greater.
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Considerations aboutthe static friction
l Fmax ????
cosq
Static friction
15mm
25mm
35mm
45mm
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Considerations aboutthe static friction
l Fmax ????
cosq
Plt0.05
Static friction
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3. Consideration about the brachiocephalic angle
Is the brachiocephalic angle responsible for
less backup in TRI?
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Considerations about the brachiocephalic angle
l Fmax ????
cosq
Brachio- Cephalic angle
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Considerations about the brachiocephalic angle
n.s.
Brachio- Cephalic angle
The brachiocephalic angle is not responsible for
less backup. However, JL3.5 with angle is easy to
engage in TRI.
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Summary
l Fmax ????
cosq

• This new hypothesis can explain
• several common observations in
• the manipulation of guiding catheters.

summary

• static friction within the aorta wall
• F back-up force

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Conclusion

• Ikari catheter can generate greater
• backup force in TRI.
• The hypothesis may explain several
• guiding catheter problems.

conclusion
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References

• Ikari Y, et al. Initial characterization of Ikari
  Guide catheter for transradial coronary
  intervention.J Invasive Cardiol. 2004
  Feb16(2)65-8.
• Ikari Y, et al. Novel guide catheter for left
  coronary intervention via a right upper limb
  approach.Cathet Cardiovasc Diagn. 1998
  Jun44(2)244-7.

references