Wire Technology: How to Choose Based on Anatomy and Strategy NCVH New Cardiovascular Horizons KNOW YOUR OPTIONS Craig M. Walker, MD, FACC, FACP Clinical Professor of Medicine Tulane University School of Medicine New Orleans, LA Clinical Professor of Medicine LSU School of Medicine New Orleans, LA Founder, President, and Medical Director Cardiovascular InsAtute of the South Houma, LA
DISCLOSURES Consultant/Medical/Scientific Boards Abbott Boston Scientific Cardiva Cook Medical CR Bard Lake Regional Medical Medtronic Spectranetics PVD Training Abbott Bard Boston Scientific Spectranetics TriReme Medical Stockholders CardioProlific Cardiva Spectrane5cs Vasamed Speaker s Bureau Abbo= Bard Boehringer- ingelheim Bristol- Myers- Squibb/Sanofi Cardiva Cook Medical Cordis DSI/Lilly Gore ACHL/Merck Spectrane5cs
Guide Wire Usage Access lesions Cross lesions Facilitate delivery of interven5onal devices Why is this important? If you can t: 1. Access the lesion 2. Cross the lesion 3. Get your devices to and across the lesion You can t treat the patient!
Guidewire a.ributes affec3ng selec3on Wire length Wire diameter Tip penetrance Torquability Shaft support Shaft flexibility Visibility Coatings Sleeves Tip shapability Tip retention Device compatibility Cost Durability
Guide Wire Key Components Diameter Material Taper/Grind Func5onal Diameter (0.014 /0.018 /0.035 ) Coa5ngs Coils & Covers Tip Style The Building Blocks of All Guide Wires
The 6 Guide Wire Components 1 Material 2 Diameter 3 Taper 4 Tip Design 5 Coils and Covers 6 Coa5ngs A Balancing Act of Trade- offs Between Performance and Clinical A=ributes; by Changing the Different Building Blocks, We Change the Characteris5cs!
The 6 Guide Wire Components 1 Material 2 Diameter 3 Taper 4 Tip Design 5 Coils and Covers 6 Coa5ngs A Balancing Act of Trade- offs Between Performance and Clinical A=ributes; by Changing the Different Building Blocks, We Change the Characteris5cs!
1) Guide Wire Materials material affects flexibility, support, steering and tracking Stainless Steel (SS) Ni3nol (NiTi) More Torqueable and rigid More Flexible Be=er columnar support Won t kink Genera3on 1: Stainless Steel Genera3on 1: Ni3nol Genera3on 2: High Tensile Strength SS Genera3on 2: Stainless Steel+NiTi
The 6 Guide Wire Components 1 Material 2 Diameter 3 Taper 4 Tip Design 5 Coils and Covers 6 Coa5ngs A Balancing Act of Trade- offs Between Performance and Clinical A=ributes; by Changing the Different Building Blocks, We Change the Characteris5cs!
Guidewire Basics: Diameter Larger Diameter = Increased rail support & torque, may enable vessel straightening (i.e. sheath placement in a 5ght iliac bifurca5on) Smaller Diameter = Increased flexibility & trackability through the vessel Strength=Radius 4 Strength 0.018 = 2.73 X Strength of 0.014 Selec3on Considera3ons Clinical needs such as tortuosity (increased flexibility), crossing 5ght stenosis Device compa5bility and support.014 most atherectomy + need for column strength
The 6 Guide Wire Components 1 Material 2 Diameter 3 Taper 4 Tip Design 5 Coils and Covers 6 Coa5ngs A Balancing Act of Trade- offs Between Performance and Clinical A=ributes; by Changing the Different Building Blocks, We Change the Characteris5cs!
3) Tapers and Grinds Taper = The part of the wire where the diameter of the core changes over a set distance Grind = The part of the core with constant diameter Grind 1 Grind 2 Taper 1 Taper 2
3) Tapers and Grinds Broad, gradual, or long tapers Offers acute vessel access, improved tracking The wire follows itself well around bends Grind Longer Tapers Abrupt or short tapers Creates support in shorter distance Greater tendency to prolapse Shorter Taper Grind
Guide Wire Support Charts How to Read Them 450 400 350 S5ffness (grams force) 300 250 200 150 100 50 Taper Taper 0 5 10 15 20 25 30 35 40 Distance From Guide Wire Tip (cm)
The 6 Guide Wire Components 1 Material 2 Diameter 3 Taper 4 Tip Design 5 Coils and Covers 6 Coa5ngs A Balancing Act of Trade- offs Between Performance and Clinical A=ributes; by Changing the Different Building Blocks, We Change the Characteris5cs!
4) Guide Wire Tip Design Affects Steering and Durability Design Op3ons ü Force transmission ü Be=er steerability ü Tac5le feedback ü Ideal for peripheral vessels ü More durable - to- 5p ü Easy 5p shapeability ü Flexibility, soiness ü Ability to prolapse ü Ability to prolapse ü More delicate Shaping Ribbon
Guide Wire Penetra3on Power Understanding Tip Diameter and S3ffness Tip S3ffness = 4.0g Tip Diameter 0.012 Area of Guide Wire Tip r Penetra3on Power: (Pressure) Tip S5ffness / Area of Guide Wire Tip:.004kg/ (3.14*.006 2 ) Penetra5on Power = 40 Kg/in 2 Guide Wire Tip
The 6 Guide Wire Components 1 Material 2 Diameter 3 Taper 4 Tip Design 5 Coils and Covers 6 Coa5ngs A Balancing Act of Trade- offs Between Performance and Clinical A=ributes; by Changing the Different Building Blocks, We Change the Characteris5cs!
5) Guide Wire Tip Coils Affect support, steering, tracking and visibility (radiopacity) Impact dimension of wire Affect tac5le feedback Tip Coils Outer Coils Tip Coils Only
5) Guide Wire Covers Polymer or plas5c Provide Smooth tracking through tortuosity Not to be confused with Hydrophilic coa5ng Polymer Cover Polymer Tip
5) Guide Wire Tip Coils and Covers - Combina3ons Tip coils plus: Intermediate coils Bare core Plas5c cover Polymer Polymer Cover + Tip Coils Polymer over 5p coils Exposed Coils for Be=er Tac5le Response
The 6 Guide Wire Components 1 Material 2 Diameter 3 Taper 4 Tip Design 5 Coils and Covers 6 Coa5ngs A Balancing Act of Trade- offs Between Performance and Clinical A=ributes; by Changing the Different Building Blocks, We Change the Characteris5cs!
6) Guide Wire Coatings: Hydrophobic Coating Repeal water to create a smooth, wax- like surface No actua5on with water required Reduces fric5on & provides improved device trackability
6) Guide Wire Coatings: Hydrophyllic Coating Minimizes fric5on & provides be=er device trackability A=racts water to create a slippery gel- like surface
6) Guide Wire Coa3ngs: Lubricity vs. Tac3le Feedback THE TRADE- OFF Polymer Cover With Hydrophilic Coa5ng Guide wire Ap with: Lubricity Hydrophilic Coa5ng Hydrophobic Coa5ng No Coa5ng Tac5le Feedback
Coils: Impact on Visibility Platinum, Palladium, Tungsten, and Stainless Steel Type of material and Durometer (density) of material impacts visibility Platinum most radiopaque, Stainless steel least Length of radiopaque coils Clinical benefit of visibility:
Guidewire Tip Shaping Techniques Penetrating the lesion entry point Straight or small angle at the very distal tip Secondary bend for navigating tortuosity Small angle at the very distal tip, subtle secondary bend Re-entering true lumen from subintima More acute angle like a J-tip
How Guidewires Fail to Cross Wire tip prolapses at the cap à wire with higher tip gram load, sharp short angle, SC Proximal segment of tip buckles à wire with higher tip gram load; hydrophilic coating or advance a support catheter near tip Tip enters lesion, wire fails to follow à wire with higher rail support; lower profile; hydrophilic, or advance a support catheter Wire Crosses but device fails to cross à wire with higher rail support or lower profile system
Keys To Success: Selec3ng a guidewire for crossing Wire escala5on approach Frequent wire exchanges Wire selec5on for penetra5ng the cap, versus naviga5ng the middle of the lesion, versus device delivery Shaping of the 5p Use of a support catheter ACCESS Push, torque, reach, support Visualiza5on (hiberna5ng vessel and gepng closer to site to be imaged), minimiza5on of contrast use Approaching the soier cap or avoiding collateral vessels.
Conclusion Trea5ng complex lesions can be challenging. Wires can fail in many ways (failure to cross, to deliver a device, or cause distal injury). Familiarity with a mul5tude of wires can benefit in these cases. Understanding wire technical a=ributes and impact on clinical performance will help select the right wire for the right case. Non- wire factors affect wire success.
Closing Remarks / Thank You