Anatomy of Contemporary CTO Guidewires and Selection Criteria Craig A. Thompson, M.D., MMSc. Director, Invasive Cardiology and Vascular Medicine Yale University School of Medicine New Haven, CT USA
Disclosure Statement of Financial Interest Within the past 12 months, I or my spouse/partner have had a financial interest/arrangement or affiliation with the organization(s) listed below. Affiliation/Financial Relationship Company Grant/Research Support Abbott Vascular, Boston Scientific, Cordis Consulting Fees/Honoraria Abbott Vascular, Bridgepoint Medical, InfraRedx, Medtronic, Sanofi-Aventis Major Stock Shareholder/Equity None Royalty Income None Ownership/Founder None Intellectual Property Rights None Other Financial Benefit None
Performance Characteristics Flexibility Tracking Steering Lubricity Prolapse tendency Support Visibility Tactile Feedback
Guide Wire Components 1. Core Material 1. Tip Style 2. Core Diameter 2. Covers and Coils 3. Core Taper 3. Coating Core Diameter Coatings Core Material Core Taper Covers & Coils Tip Style
Core Material Stainless steel Original core material technology Good support, push force and torque Less flexible than newer core materials
Core Material High Tensile Strength Stainless Steel More durable than regular stainless steel Retains shape Good flexibility Excellent steering and tracking
Core Material Nitinol Super-elastic alloy designed for kink resistance Excellent flexibility and steering Durable nature may facilitate treatment of multiple lesions and/or tortuous vessels
Core Taper Tracking Ability of wire body to follow tip around bends Degree of support Core Taper
Core Taper Longer taper Shorter taper
Core Taper Gradual or long tapers produce a wire with less support but which tracks successfully Successful Tracking
Core Taper Abrupt or short tapers produce a wire which provides greater support but also greater tendency to prolapse Prolapse
Tip Style Affects steering and tip softness Design options Shaping ribbon for softer tip allowing shape retention Core-to-tip for precise steering and tip control Shaping Ribbon Core-to-Tip
Spring Coils Affect support, trackability, and visibility Impact dimension of wire Provide tactile feedback Outer Coils Tip Coils Only
Covers Polymer or plastic Provide lubricity Smooth tracking through tortuosity Polymer Cover
Radiopacity Affected by coils and covers Tip Coils
Coatings Hydrophilic Hydrophobic Attracts water Repels water Becomes gel when wet Reduces friction No actuation required Increases trackability Reduces friction Increases trackability Coatings
Guide Wire Covers and Coatings Lubricity Polymer Cover with Hydrophilic Coating Hydrophilic Coating Hydrophobic Coating No Coating Tactile Feedback (related to coils)
Polymer-Coated (Hydrophilic) Wires plastic/polymer jacketed and coated Manufacturer Abbott Vascular Wire Shaft Diameter Stiffness Whisper 1 gram Pilot 50 1.6 gram Pilot 150 & 200 3 & 4.5 gram Asahi Intec Confianza Pro (tip 0.009 ) 9 & 12 Fielder, Fielder FC, XT ~1 gram (XT tip 0.009 ) Boston Scientific Choice PT & P2 1-2 gram PT Graphix & P2 3-4 gram Cordis Shinobi 7 gram Shinobi Plus 8 gram Medtronic Vascular Persuader (tip 0.011 ) 3 & 6 gram Persuader 9 9 gram
Non-Coated (Non-Lubricious) Coil Wires Manufacturer Abbott Vascular Medtronic Vascular Wire Shaft & Tip Diameter Stiffness Medium 3 gram Miraclebros 3, 4.5, 6, 12g Confianza 9 & 12 gram Cross-IT 100 (tip 0.010 ) 1.6 gram Cross-IT 200 (tip 0.010 ) 4.8 gram Cross-IT 300 (tip 0.010 ) 6.75 gram Cross-IT 400 (tip 0.010 ) 9 gram Persuader 3 & 6 gram Persuader 9 (tip 0.011 ) 9 gram
Conclusions Guidewire design dictates performance characteristics Core Material Core Diameter Core Taper Tip Style Covers and Coils Coating Newer generation guidewires design more well suited for CTO PCI Design characteristics dictate optimal technique for use Microchannel probing/sliding Controlled Drill Penetration