Wires

1. Guidewire and Balloon Selection
George S. Chrysant, M.D. FACC, FSCAI,
FSCCT
Chief Medical Officer
INTEGRIS Cardiovascular Physicians

2. The Function of a
Guidewire
• Safely access the coronary vessel
• Safely cross the lesion
• Deliver interventional devices
• Must do so without causing damage:
– Perforation, dissection, fracturing, tip
entrapment

3. Learning Objectives
• Describe the primary design features of guidewires
• Explain how design features affect performance
such as crossability, torqueability, etc.
• Understand the classes of wires and how to select
a combination of wire characteristics that will
enable advancement of the PCI

4. Guidewires

5. GUIDEWIRE CONSTRUCTION

7. STAINLESS STEEL
• Benefits: excellent torque response, rail support, pushability,
and shapeability
NITINOL ALLOY
• Benefits: excellent kink resistance, flexibility, and shape
retention
Guidewire Construction: Core Materials

8. • Less flexibility
• Better support
• Better torqueability in less
tortuous anatomy
Guidewire Construction: Core Diameter
• Better flexibility
• Less support
• Better torqueability in
highly tortuous anatomy
Small Diameter Large Diameter
• Core diameter influences the support, flexibility,
and torqueability of the wire.
0.014” 0.014”

9. Strength = Radius4
0.018” wire is 2.73 X stronger than 0.014”

11. UNIBODY or CORE-TO-TIP
• Core extends all the way to distal tip
• Good torqueability & tip control
SHAPING RIBBON
• Small, flat ribbon (typically steel)
• attached to distal core
• Ease of shapeability, decreased
torque transmission
COMPOSITE CORE or INNER COIL TECHNOLOGY (ICT)
Core wire
Inner Coil
Coil
Core wire
Inner coil Coil
Shaping ribbon
Guidewire Construction: Tip Styles
• Micro-coil wound around
core, inside outer spring
coil
• Good shape retention
and torque transmission

12. Guidewire Construction: Tip Coils & Covers
• Full Spring Coil Tip
– Spring coil covering distal core
– Benefits: Tip resiliency & tactile feel
• Polymer Jacket Over Spring Coil
– Polymer jacket covering spring coil
– Benefits: Spring coil promotes tip resiliency,
polymer jacket promotes crossability and smooth
device tracking
• Full Polymer Tip
– Polymer jacket covering distal core
– Benefits: Promotes crossability and smooth
device tracking
• Spring Coil Tip, Polymer Jacket
– Spring coil on distal tip, polymer jacket over core
– Benefits: Hybrid design promotes tactile feel
and resiliency at distal tip and smooth device
delivery
• Micro-cut Nitinol Sleeve
– Micro-cut nitinol sleeve covering distal core
– Benefits: Promotes precise steerability and
torque transmission

13. Guidewire Construction: Coatings
HYDROPHILIC (“water-loving”)
– Highly lubricious (slippery); bonds with water to
create slippery gel
– Promotes crossability and trackability
– Can reduce tactile feel
HYDROPHOBIC (“water-repelling”)
– Less lubricious than hydrophilic
– Promotes tactile feel with slightly increased
resistance
– Examples include silicone and PTFE

14. GUIDEWIRE PERFORMANCE

16. TIP LOAD is the standard
measurement for tip stiffness or
flexibility of guidewires.
– Tip load = the amount of
force (grams) required to
buckle the distal tip of the
guidewire
Wire Classification Tip Load
Workhorse
Wires
≤1 g
Secondline / Support 0.5 g – 3 g
Crossing
Wires
4 g – 14 g
MORE
ATRAUMATIC
LOWER TIP
LOAD
SMALLER
CORE
DIAMETER
STIFFER
HIGHER TIP
LOAD
LARGER
CORE
DIAMETER
Guidewire Performance: Crossability

17. Guidewire Performance: Crossability
• CROSSABILITY is the ability to cross a lesion with little or no resistance
• Three key features of a guidewire contribute to its ability to cross lesions:
– TIP STIFFNESS
– TIP PROFILE
– COATING & COVERING
A guidewire with these features will typically display
improved crossability:
HIGH TIP LOAD (≥4 g)
wires have a stiffer tip and
increased crossability
TAPERED TIP (≤0.010”)
wires have higher
penetration force than
similar tip load wires with
non-tapered tips
POLYMER JACKETED &
HYDROPHILIC coated wires
are less resistant & more
lubricious

18. Guidewire Performance: Trackability
Successful
Tracking
Unsuccessful
Tracking
Prolapse

19. Guidewire Performance: Rail Support
FLOPPY/LIGHT SUPPORT:
• Most flexible but least rail support
• Provides improved trackability because of flexibility
EXTRA SUPPORT:
• Long rail support region
MODERATE SUPPORT:
• Flexibility profile in between floppy & extra support
• Added support for stent delivery

20. Guidewire Performance: Tactile Feedback
TACTILE FEEL is the sensation of resistance that is transmitted from the
distal end of the guidewire to the physician’s hand at the proximal end of
the guidewire.
– Helps physician understand distal tip position and lesion
characteristics
Tactile Feedback
Lubricity
Polymer jacket
with hydrophilic
coating
Hydrophilic
coating
Silicone/
PTFE coating
No coating

24. GUIDEWIRE SELECTION

25. Workhorse Wires
Very atraumatic tip (≤1
gram)
Light to moderate rail
support
Hydrophobic coating for
tactile feel
Good
torqueability
TYPICAL
USE
• Straightforward anatomy
• Type A lesions
• Often first wire used in a case

26. Secondline Access
Wires
Non-tapered tip
Atraumatic tip (tip load
≤2 g)
• Good trackability
• Light to moderate rail
support
Full length hydrophilic
coating and/or polymer
jacket
• More challenging anatomy
• If workhorse has difficulty crossing
• More crossable than workhorse
TYPICAL
USE

27. Delivery Support Wires
Non-tapered tip with
hydrophobic coating
Atraumatic tip
(≤2.1 grams)
Increased rail support
• Tortuous anatomy
• Distal lesions
• Delivery support when workhorse isn’t enough
• Often used as a buddy wire or to straighten
anatomy
TYPICAL
USE

28. Specialty Crossing Wires
Hydrophilic or Jacketed
Low (<2 g) OR medium
(4-6g) tip load
Hydrophilic coating (or
jacketed)
• Complex (type B and C) lesions
• Small vessels and microchannels
• Subtotal lesions
• Ambiguous anatomy
• Knuckling
• Initial probing of lesion (often)
• Moderate rail support
• Highly torqueable
TYPICAL
USE
Tapered tip (typically
≤0.010”) OR non-tapered

29. Specialty Crossing Wires
Tapered, Non-Jacketed
Range of tip loads, from
atraumatic (≤1.7 g) to
medium (3-5 g)
• Complex (type B and C) lesions
• Small vessels and microchannels
• Subtotal lesions
• Ambiguous anatomy
Highly torqueable
TYPICAL
USE
Tapered tip (typically
≤0.010”)
No polymer jacket
With or without hydrophilic
coating

30. Specialty Crossing Wires
High Penetration Force Wires
Tapered tip (≤0.010”)
Stiff wire tip (8-14 grams)
• Hydrophilic coating for increased
crossability
• Sometimes with hydrophobic on distal
tip for increased tactile feel and safety
Typically larger core
diameters for increased
pushability and rail support
• Highly fibrotic or calcified complex lesions
• Total occlusions
• Puncturing proximal or distal cap
• Non-ambiguous anatomy
TYPICAL
USE

31. Guidewire Performance:
Radiopacity
• The RADIOPACITY of a guidewire affects its visibility under
fluoroscopy.
• The radiopaque section of a guidewire is typically made with a
radiopaque material like platinum
Radiopaque tip
Radiopaque
Less
radiopaque

32. Workflow for Workhorse wire (left) and High
Penetration wire (right)
Escalate as needed

33. Balloons

39. Power
Precisio
n
Safety
Rectangular edges
“lock” the device into
lesion
Leading edges drive
outward force 15-25 times
that of POBA
Post-scoring, outward
forces are designed to be
equivalent to POBA
Specialty Balloons
• Minimizes Slippage
• Scoring mechanism designed to reduce the risk of flow
-limiting dissections
• Multiple lesion morphologies including calcium

40. Ideal Balloon Characteristics
Low lesion entry
and crossing
profiles
Marker bands
Tight balloon
wrap and re-wrap
Lubricious
hydrophilic
coating
Flexible
catheter
Shoulder
Guidewire
Tip

41. Cutting and Scoring
Balloons
WOLVERINE™ Cutting Balloon
AngioSculpt™ Scoring Balloon
Chocolate™ PTCA Balloon Catheter
Atherotomes
• Blades affixed to balloons
• Expand radially as balloon
is inflated to score arterial
plaque
Scoring elements
• Spiral wires wrap around
balloon and score arterial
plaque as balloon expands
Dilatation pillows with plaque
channeling grooves
• Vessel dilatation without
cutting or scoring
Cut or score plaque while minimizing vessel wall injury

42. The POSTIT Trial
N=256 patients
p<0.0005 p<0.001
p<0.0001
Is post-dilatation necessary after coronary stent deployment?
More optimal stent deployment achieved when post-dilatation employed
Lumen Area Plaque Area Vessel Area
20.0
18.0
16.0
14.0
12.0
10.0
8.0
6.0
4.0
2.0
0.0
6.6
9.3
15.9
7.8
8.7
16.5
Before Post-
Dilatation
After Post-
Dilatation
Area
(mm
2
)
Before and After Post-dilatation
Using only the stent delivery balloon, over 70% of patients did
not achieve optimal stent deployment (MSD≥90% RLD)

43. Thank You