1. Michael J. Cowley, MD, MSCAI
Selection and Use of Basic Equipment: Guide Catheters, Wires and Balloons
Michael J. Cowley, MD, MSCAI
NIC Mid-term Meeting, Hyderabad
April 15, 2016

2. Basic Guiding Catheter Functions
Supportive conduit for advancement of guidewires and devices
Vehicle for contrast injection
Measure blood pressure

3. Important Guiding Catheter Features
Atraumatic tip
Proper preformed shape
co-axial with vessel
Torque control
Kink resistance
Radiopacity

4. Guide Catheter Construction

5. Guide Catheter Sizing Diameter Length Lumen size required
Access site & prox coronary size
5-7 F femoral; 5-6F radial
Length
100 cm standard
>100 cm in tortuous aorta or radial access in tall patient
<100 cm for distal sites (snake graft, tortuous IMA)

6. Proper Left Guide Catheter Position

7. Guide Catheter Selection
Aortic Configuration
Normal
Dilated
Narrow or Short
Coronary Orientation (take off)
Normal, Upward (high), Downward
SVG Orientation
RCA: horizontal or downward
LCA: Horizontal or superior

8. Guiding Catheter Support

9. Possible Solutions when the RCA Originates More Anteriorly
Right Judkins
Right Judkins or Hockey Stick
Left Amplatz or Hockey Stick
Left Amplatz or Left Judkins (out of plane)

10. Guide Catheter Options for Difficult Right Coronary Cannulation
Hockey Stick
Amplatz
EBU or Left Graft
LIMA or XBRCA
LIMA catheter useful for upward - oriented RCA origin or Shepherd’s Crook Curve

11. Guide Selection for Vein Grafts
Left Bypass; Hockey Stick or Amplatz Left
Multipurpose; Right Bypass
Right Judkins or Multipurpose
Hockey Stick
Right Judkins (JR4) will cannulate most grafts

12. Physics of Guide Catheters for Left Coronary Artery in Transfemoral and Transradial PCI
Ikari et al J Invas Cardiol 2005;17:

13. Radial vs Femoral Access

14. Guide Selection and Use Influence Support
h q Angle provides greater Backup Support

15. Backup Force with Various Guide ShapesJL
JL deep
BL 3.5
IL 4
IL4 Power

16. Guide Catheter Support
Approach
Femoral > L Radial > R Radial
Power support angle ( q )
Contralateral aortic wall angle q
Deep seating vs power curves
XB, EBU, Amplatz, Ikari
Coaxial alignment
Larger French size

17. Guide Wires

18. Basic Characteristics
Coronary Guide Wires
Basic Characteristics
Steerable “Deliverable”
Atraumatic Tip
Adequate Rail Support
Smooth Coating
Tip
Polymer sleeve or
Coil-Spring Tip
Platinum,Tungsten, steel
Central Core
Stainless steel Durasteel™
nitinol/Elastinite®
Lubricious Coating
Silicone
PTFE
Hydrophilic

19. Guidewire Construction
3 Basic Components
Central Core
Stainless steel Durasteel™
nitinol/Elastinite®
Tip
Polymer sleeve or
Coil-Spring Tip
Platinum
Tungsten
Stainless Steel
Lubricious
Coating
Silicone
PTFE
Hydrophilic

20. Tip Coil with Shaping Ribbon Design
Guidewires
Tip Coil with Shaping Ribbon Design

21. Guidewires
Core-to-Tip Design

22. Smooth Taper Core Grind Design
Guidewires
Smooth Taper Core Grind Design

23. Guidewires Core Diameter Smaller Diameter: More Flexibility
Diameter affects flexibility, support and torque
Smaller Diameter: More Flexibility
Larger Diameter : More Support & Torque
Larger Diameter – mor e support for tracking bulky devices; more supportive rail; however, takes away from overall performance

24. Guidewires
Core Taper
Longer taper: better wire tracking, less prolapse
Shorter taper: better support, more prolapse

25. Core Taper
Short tapers produce h longitudinal support but also h tendency to prolapse
Prolapse

26. Core Taper
Long or gradual tapers provide greater tracking and less tendency to prolapse
Successful
Tracking

27. Affects flexibility, support, steering and tracking
Guidewires
Core Material
Affects flexibility, support, steering and tracking
Stainless Steel
Nitinol/Elastinite®

28. Guidewires Core Material Stainless steel
Original core material technology
Good support, push force and torque
Less flexible than newer core materials

29. Guidewires Core Wire: Coil Spring:
Ground and tapered on the distal end to increase flexibility
Coil Spring:
Typically soldered to core wire at point where inside diameter of coil spring matches the outside diameter of the core wire

30. Guidewires Core Material Nitinol / Elastinite®
Super-elastic alloy designed for kink resistance
Excellent flexibility and steering

31. Work-Horse Guide Wire Characteristics
Intermediate Core Diameter
Gentle Core Taper
Resilient Core with good torque control
Soft Tip
Coils or Covers
Smooth Coating

32. Ideal Workhorse Wire Soft, flexible and atraumatic tip
Excellent torque transfer (1:1)
Good tactile feel
Excellent steerability and pushability
Supportive but tracks well in tortuous vessels
Facilitates balloon and stent delivery

33. Coronary Guidewires Workhorse Hydrophilic CTO Extra Support
HTF, BMW, Prowater, Runthrough, ATW
Hydrophilic
Whisper, Choice PT
CTO
Fielder XT, Miracle Bros, Confianza
Extra Support

34. Coronary Guide Wire Characteristics
Unfavorable Features
Steerable “Deliverable”
Stiff Tip
Increased Rail Support
Hydrophilic Coating
Atraumatic Spring Tip
Adequate Rail Support
Smooth Coating
Dissections & Perforations
Straightening Artifacts
Perforation

35. Pseudo-lesion
Safian et al

36. Balloon Angioplasty

37. Current Clinical Usage
Balloon Angioplasty
Current Clinical Usage
Pre-dilation
Stent Deployment
Post-dilation
gioplasty

38. Anatomy of a Balloon Catheter
Over-The-Wire (OTW) Balloon Catheter
Monorail (Rx) Balloon Catheter

39. Balloon Catheter Performance
Handling
Inflation
Trackability
Pushability
Crossability
Entry profile
Crossing profile
Compliance
Compliant
Semi-compliant
Non-compliant
Dilating Force
Nonimal Pressure
Rated burst pressure

40. Balloon Catheter Characteristics
Trackability
Pushability
Crossability
Entry profile
Crossing profile

41. Key Performance Characteristics
Balloon Angioplasty
Key Performance Characteristics
Compliance
Dilatation force
Presenter
When talking about balloon materials and performance, we need to consider compliance and dilatation force.
First, let’s talk about compliance.

42. Balloon Angioplasty Compliance
The rate of the change in balloon diameter over a range of inflation pressures
Determined in unconstrained environment
Does not address resistance to expansion

43. Balloon Materials & Performance
Compliance
Compliant
Semi-Compliant
Diameter (mm)
Presenter
This chart illustrates the different types of balloon materials and their relative growth as pressure increases.
Non-Compliant
Atmospheres (ATM)

44. Balloon Compliance Material Growth Above Nominal Compliant Polyolofin
~20%
Semi-compliant
Polyethylene or Nylon
~10%
Non Compliant
PET
~0-5%

45. Balloon Performance Compliance Chart Derived from bench testing
3.0 mm Balloon
Derived from bench testing
In vitro, 37º in water bath
Unreliable in vivo
Significant overestimation of actual MLD by IVUS
~20% less than stated chart size

46. Balloon Compliance Charts
3.0 mm Balloon RB RB
Diam (mm) RB N N N

47. Materials & Performance
Balloon Angioplasty
Materials & Performance
Dilatation force
The radial force exerted by the balloon on the coronary lesion or metal stent
Dilatation force is a function of
Inflation pressure
Balloon material (compliance)
Presenter
Dilatation force is the radial force exerted by the balloon on the coronary lesion or metal stent. Dilatation force is a combined measure of:
Inflation Pressure: The pressure applied to inflate the balloon.
Balloon Material: A more compliant balloon material results in reduced dilatation force at the lesion. More non-compliant balloon material provides greater dilatation force at the lesion.

48. Balloons grow in areas of least resistance
Growth is more significant as pressure increases
Balloons grow in areas of least resistance
Low and focal growth as pressure increases
Designed for dilatation of calcified or resistant lesions

49. Dilatation Force (Straw Test)
Balloon Performance
Dilatation Force (Straw Test)
Semi-compliant
Low-compliant
Non-compliant
Dilatation Force NC LC SC
Presenter
This chart illustrates the test you just saw.
The lines show the growth of each type of balloon material, and the dots indicate at which ATM that material popped the straw.
As you can see, the low compliant balloon required four more ATM of pressure than the non-compliant balloon to apply the same amount of dilatation force to the straw.
The semi-compliant balloon required twice as much pressure to equal the dilatation force of the non-compliant balloon.
Pressure (ATM)

50. Materials & Performance
Compliant & Semi-compliant Balloons
Better flexibility & trackability
Better cross and recross performance
Limited durability
Increased diameter and longitudinal growth variance
Limited dilatation force
Presenter
Because the compliant balloon is softer and more flexible, it has the ability to more easily traverse through the twists and turns of difficult anatomy.
The thin compliant material is also able to cross difficult or tight lesions because of these soft, flexible traits.
The soft, flexible material however, limits the balloon’s durability and allows for greater variance in diameter and longitudinal growth.

51. Materials & Performance
Compliant & Semi-Compliant Balloons
Used for Pre-dilatation
Gain lesion access/ prepare vessel for stent
Determine lesion length/diameter
Determine lesion morphology
Trade-offs
Potential growth outside lesion
Unwanted vessel expansion
Presenter
Compliant and semi-compliant balloons are used primarily for pre-dilatation of a vessel prior to stent implantation.
More compliant balloons are typically made of a softer and more flexible material. In these balloons, pressure migrates to the area of the balloon with the least resistance which can be outside the lesion area or metal stent. This can cause a “dog-boning” effect which could result in damage of healthy tissue outside the intended treatment area, as shown in the illustration.

52. Materials & Performance
Non-Compliant Balloons
Durability
“Focused” radial force to lesion / stent
Less diameter / longitudinal growth variance
Reduced flexibility, trackability
Limited cross and re-cross performance
Limited sizing flexibility
Presenter
The non-compliant balloon is typically stiffer and thicker for added durability, making it more difficult to traverse this balloon through tortuous anatomy.
The non-compliant balloon will likely be more difficult to cross or recross a lesion due to its thickness and profile characteristics. Yet, this type of balloon material provides more “focused” dilating force because it has less diameter and longitudinal growth variance.

53. Materials & Performance
Non-Compliant Balloons
Used for Post-dilatation
Maximum dilatation force
Focal stent expansion
Lowest longitudinal growth
Presenter
Less compliant balloons are typically stiffer, thicker and less susceptible to growth outside of a lesion. In this case, the less compliant balloon holds its shape despite added ATM pressure. This results in the balloon’s ability to exert more force against a hard lesion or metal stent, potentially increasing dilatation success.
The size growth and pressure characteristics of a less compliant balloon are similar to a basketball. As a basketball is inflated, it will form its shape at a relatively low pressure. However, the basketball can still be deformed if you push into it. As you continue to inflate the basketball to higher and higher pressures, the shape and size of the ball does not change but it becomes increasingly more difficult to deform its shape by squeezing it.

54. Device Delivery Problems
Inability to Pass Balloon/stent around bend
Better Guide support
Stiffer guide wire
Buddy wire
Guideliner
More flexible stent
Shorter stent

55. Pre-PCI Planning Access site and guide catheter selection ?
Guidewire characteristics desired ?
Strategies to be used
balloon, modified balloon, direct stent ?
BMS, DES ?
Alternative equipment / techniques (Plan B)

56. Balloon Angioplasty Alone
Treatment of focal in-stent restenosis (especially BMS or multiple layers )
Anastomosis lesions soon after surgery
Bifurcations (treatment of daughter limb )
Small vessels ( <2mm )

57. Balloon Angioplasty Role with Stenting Pre-dilatation Post-dilatation
Gain lesion access / prepare vessel for stenting
Determine lesion length / diameter
Determine lesion morphology
Post-dilatation
Ensure full stent expansion / apposition of stent
Optimize Minimum Lumen Diameter (MLD)
Presenter
Balloon usage in PTCA procedures has changed with the development and widespread adoption of stent technology.
Currently, there are three main uses for a balloon during PTCA procedures:
Plain Old Balloon Angioplasty, or POBA: A procedure where the balloon is used alone to dilate the vessel. Because this procedure has been associated with higher restenosis rates, the percentage of pure POBA procedures has decreased significantly in the last five to 10 years and is now estimated to be less than 10% of all PTCA procedures.
Pre-Dilatation: The use of the balloon before the implantation of a stent, to gain access to the lesion, to prepare the vessel for the stent, or to determine the attributes of the lesion to aid in stent selection.
Post-Dilatation: The use of a balloon inside an already deployed stent. Post-dilatation is used by physicians to ensure that the stent is fully expanded or apposed in the vessel, ensure MLD, and help avoid complications such as SAT (Source: Cheneau, et al. Circulation 2003;108;43-47), that have been associated with unapposed stents. With the introduction of drug-eluting stents, proper stent apposition also ensures that the drug is in contact with the artery wall.

58. Summary Proper choice of equipment facilitates best results with PCI:
Shortens procedure times
Improves succss rates
Reduces complications and adverse events

60. Selection and Use of Basic Equipment : Guiding Catheters, Wires and Balloons
Michael J. Cowley, MD, MSCAI
Professor of Medicine Virginia Commonwealth University
Feb 19, 2016