Guidewire
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor-In-Chief: Priyantha Ranaweera [2];
Key Words and Synonyms: PCI guidewire, angioplasty guidewire, coronary guidewire, steerable wire, steerable guidewire
Overview
Angioplasty guidewires are small, soft, flexible, lubricated, wires that act as a rail over which equipment such as an angioplasty balloon, a stent, or an intravascular ultrasound device can be delivered over into the coronary artery.
Historical Perspective
Angioplasty guide wires were introduced in 1982 by doctors Simpson and Roberts. The introduction of coronary guidewires was a major advance as it allowed the angioplasty balloon to be a traumatically steered to the proper location.
Desirable Performance Characteristics of Coronary Guidewires
Steerability
The tip of a coronary guidewire must be curved and must be able to be turned or "torqued" to follow the course of the vessel down which it is being placed.
Trackability
A coronary guidewire must be capable of being readily advanced around curves in the coronary arteries, and must have sufficient strength or support to allow devices to likewise go around these curves in the coronary artery.
Torquability
The tip of the guidewire must be able to be pointed in different directions by the operator to change directions, to go into sidebranches, to cross asymmetric or eccentric lesions, to avoid stent struts and to go around corners and bends in the coronary artery. When the operator rotates the guidewire outside the body, the ability of the guidewire to translate this motion into a similar motion at the tip is called torquability. This is the ability of the coronary guidewire to transmit rotational forces from the operators hand to the tip and the optimal performance is for this rotation of the coronary guidewire to be translated to the tip in a one-to-one fashion. The operator will often use his hand to twist or maneuver the wire, however, the torquability of the wire may be further improved by the use of a “torquer” or a “pin vise” or “steering tool”.
Support
The support of coronary guidewire refers to the ability of the coronary guidewire to allow a bulky device to track through bends in the coronary artery and to be to be delivered across the blockage without buckling or kinking of the wire. If the operator is attempting to advance a balloon or stent down the artery, and if the guiding catheter backs out of the coronary artery and if the guidewire also works its way from a distal position to a proximal position and backs out of the body, then this may be a sign of a "lack of guidewire support". Calcified and tortuous right coronary arteries often require guidewires that offer improved support to maneuver a balloon or a stent to a distal lesion in the right coronary artery.
Tactile Feedback
Tactile feedback refers to the “feel” of the wire tip’s behavior as perceived by the operator. Tactile feedback is better appreciated with coil tipped wires, whereas polymer tipped wires it may be minimal or absent, making inadvertent perforation, dissection or subintimal diversion into a plaque more likely.
Stiffness
Stiffness of the guidewire depends upon the diameter, trackability and torque control of the guidewire. Stiffer wires give better torque control and straighten the vectors of forces pushing the wire, balloon or a stent. Stiff quagmires may allow devices to be delivered through tortuous and calcified vessels with greater ease. A stiffer wire can be useful in crossing chronic total occlusions as well as when delivering a stent or balloon in a straight segment and can work against delivering a stent or balloon in a tortuous or an angulated segment. Stiffer wires are more likely to cause pleating artefacts and also slice through the intima in a “cheese cutter” effect. This "cheese cutter" effect has been observed with the "Iron Man" wire.
MALLEABILITY
Ability to be shaped or bent without breaking
STEERABILITY
Is the ability of a guide wire tip to be delivered to the desired position in a vessel.
It is a combination of all of the physical properties of the guide wire combined with the skill of the operator.
STEERABLE GUIDE WIRES
FLEXIBILITY
Is the ability to bend with direct pressure.
Determined mainly by the distance from the tip of the central core to the distal tip of the wire.
Important in minimizing vascular trauma
RADIOOPACITY / VISIBILITY
Useful as a marker, measure of length, helps maintain focus on the lesion while the tip is in the peripheral visual field.
Platinum at the end of the wire gives radio-opacity
May mask anatomy, eg dissection
CORONARY GUIDE WIRES
SIZES
CORE DIAMETER
0.010” - 0.018” Commonest 0.014” Some wires have tapering ends (eg .014” tapering to .010 “)
TIP DIAMETER
Usually 0.014” – 0.009”
LENGTH
Standard length : 175-190 cm Exchange length : 270-400 cm
If using a standard length wire and need an exchange length wire, use a docking system to mount another standard length wire
(caution – docking joint is prone to “snapping” when bent, also the docking joint may give way)
When using an exchange length wire and delivering a balloon or a stent, a magnet may be used to hold the wire in place. (preferably this is a two operator procedure. )
PHYSICAL CHARACTERISTICS
Has three main components - Core, Tip and the lubricous coating.
Figure : Components of a guide wire (courtesy : Abbott vascular inc)
In some wires the core extends up to the tip. In others the tip is made of a different material
CORE
The core is usually ground to a taper towards the end for the tip to attach.
If core starts tapering more towards the tip, the wire as a whole becomes more rigid, steerable and torquable.
The opposite happens when the core tapers more proximally allowing for a longer tip.
The core may be continuous or joined (more likely to bend on wire advancement if joined)
COMPOSITION
Nitinol, stainless steel or similar metal
TYPES OF CORE MATERIAL
NITINOL
ADVANTAGES - NITINOL
Super-elastic alloy designed for kink resistance Excellent flexibility and steering Probably more durable nature Better trackability Less prolapse.
=DISADVANTAGES - NITINOL
Stores torque without necessarily transmitting it to the tip Wires with single nitinol cores could “ wind up”
Less torquable
CLINICAL CORRELATION - NITINOL
Nitinol wires are more likely to enter a retroflexed circumflex
STAINLESS STEEL
Original core material technology
ADVANTAGES – STAINLESS STEEL=
Gives more pushability, torquability, and good shapeability in “core-to-tip” wires. Good support, push force and torque
DISADVANTAGES – STAINLESS STEEL
- Tendency to kink
- Less flexible than newer core materials
OTHER MATERIAL USED IN THE CORE
High tensile strength stainless steel
- More durable than regular stainless steel
- Retains shape more
- Improved flexibility
- Improved steering and tracking
Asahi Tru Torque Steel
LUBRICIOUS COATING
One or both of
- Hydrophilic
- Hydrophobic
- Hydrophobic tip and hydrophilic distal end
- Affects lubricity, friction and wire tracking in crossing lesions as well as during stent and balloon delivery.
- Facilitate smooth movement
- Confined to the distal 30-35 cm
Commonly used coatings
1.PTFE (Polytetrafluroehylene) - commonest
2.Teflon
3.Silicone
4.Pro/Pel®, (Medtronic)
5.Hydro-track® (Medtronic)
6.Hydro-coat (Abbott vascular)
HYDROPHILIC COATING
- attracts water
- It is applied over polymer or stainless steel (including tip coils)
- Thin, non-slippery solid when dry, needs lubrication to perform
- Becomes gel when wet
- Reduces friction
- Increases trackability
HYDROPHOBIC COATING
- repels water
- Silicone on working area of wire, excluding tip
- No actuation/wetting required
- Reduces friction
- Increases trackability
Platinum in the tip for radio-opacity. (usually 3-25 cm length at the tip)
TIP OF THE INNER CORE WIRE
CORE TO TIP GUIDE WIRES
When the core is extended to the tip, that increases pushability, precise steering, tip control and torquability. This can be a useful feature for eg. in probing chronic total occlusions.
With unibody wires there is more torquability, pushability and tactile feel. With two piece tip wires shaping is easy and the wire is likely to retain the shape “wire memory”
SHAPING RIBBON
Softer tip allowing shape retention
TIP OF THE GUIDE WIRE
SPRING COIL TIP
1. Spring coil - Safer than hydrophilic coated or polymer tip wires - less risk of perforation
2. Distal weld
SPRING COILS
- Outer coils only
- Tip coil only
TIP COVER
- Polymer or plastic
- Provide lubricity
- Smooth tracking through tortuosity
POLYMER TIP (COVER)
Polymer instead of the spring coil with hydrophilic coating
Improved trackability with the compromise of reduced tactile feedback / feel
Eg: PT Graphix™ Intermediate Guide Wire, ChoICE PT wire
”COMBINATION” TIPS
- Tip coils plus
- Intermediate coils
- Bare core
- Plastic cover
- Polymer
- Polymer over tip coils
As lubricity increases the amount of tactile feedback decreases. This partly accounts for the increased risk of perforation with hydrophilic coated wires.
Courtesy: Abbott Vascular
TIP LOAD
One way of quantifying some of these physical features is by measuring with a strain gauge, the force needed to bend a wire when exerted on a straight guide wire tip, at 1 cm from the tip.
Using this method , the tip loads in ascending order are 3gm, 4.5 gm, 6gm, 9 gm and 12 gm (ultra stiff)
As stiffness increases the wire becomes prone to perforation
FLEXIBILITY OF TIP
DETERMINANTS OF TIP FLEXIBILITY
JOINT
There is one or more joints in the wires with tip material some different to core material.
The number of joints and the nature of them influence the clinical performance of the wires. The joints could serve as hinge points and bend during guide wire passage.
COMMONLY USED GUIDEWIRES
There is no uniform clinical classification of guide wires.
A commonly used somewhat crude classification is based on
1. Support ( steerability and trackability. )
Soft guide wires
- Asahi soft
- Hi-torque balance
moderate support
- Wizdom
- High torque balance middle weight
extra support
- ChoICE PT extra support
- PT Graphix intermediate
- Stabilizer
- Hi-torque balance heavy weight
Super extra support
- Iron man
- Asahi grand slam
2. Crossing profile
2.1 Simple lesions
2.2 Complex lesions and lesions in very tortuous vessels
- Prowater
- ChoICE PT
- PT graphix intermediate
2.3 Chronic total occlusions
- Cross it series
- Miracle bro series
- Shinobi
- Confianza
3. Device delivery wires
- Stablizier
- Wiggle
COMMONLY USED GUIDE WIRES
ASAHI SOFT / LIGHT GUIDE WIRE
- Hydrophobic Coating
- Soft tip
- Flexible body
- Support to deliver most interventional devices
- Tip load: 0.5 g
- Radiopaque length: 3 cm
- Outside diameter: 0.014"
- Total length: 180 cm – 300 cm
ASAHI PROWATER AND PROWATER FLEX
Relatively safe guide wire with moderate support.
Source : http://www.abbottvascular.com/
- Has a hybrid Coating: Soft hydrophobic tip & hydrophilic working coils. Hydrophilic coating maximizes lubricity to navigate anatomy and hydrophobic coating designed to enhance tactile feel.
- Uses “TruTorq” technology - a design that fuses stainless steel to platinum spring coils via a single-joint. (claimed to afford the improved torque response and steerability seen with this wire.)
- Tip load: 0.8 g
- Radiopaque length: 3 cm
- Outside diameter: 0.014"
- Total length: 180 cm, 300 cm
ACS HI TORQUE BALANCED MIDDLE WEIGHT (BMW)
ACS HIGH TORQE BALANCE MIDDLE WEIGHT (BMW) UNIVERSAL
Shaping ribbon provides reasonable provision for shape retention & tip softness
Intermediate coils at the tip maintain .014" diameter for smooth device delivery
- Hydrophobic or Hydrophilic coating for tracking
HI-TORQUE BALANCE MIDDLEWEIGHT UNIVERSAL
Durasteel shaping ribbon material provides added durability and shape retention
Intermediate section has both a hydrophilic coating and a polymer cover
PT GRAPHIX INTERMEDIATE
Figure Source http://www.bostonscientific.com
ChoICE PT
Excellent in crossing moderately difficult lesions and negotiating tortuous lesions.
Crossing guide wire with light rail support.
Unibody stainless steel Polymer tip Hydrophilic ICE coating Radioopaque length 35 cm Outside diameter 0.014” Available lengths182cm, 300 cm Compatible with magnet Exchange Device
ChoICE PT Extra support
Crossing guide wire with extra rail support
Figure CPT XS jpg
Unibody stainless steel Polymer tip Hydrophilic ICE coating Radioopaque length 35 cm Outside diameter 0.014” Available lengths 182cm, 300 cm Compatible with Magnet Exchange Device
ChoICE Floppy guide wire
Relatively atraumatic guide wire with light rail support.
Figure Choice jpg
Unibody stainless steel Spring tip, polymer sleeve ICE hydrophilic coating
Radioopaque length 3 cm Outside diameter 0.014” Available lengths 182cm, 300 cm Compatible with Magnet Exchange Device
ChoICE Extra support
Delivery support wire with extra rail support.
BASIC CONSTRUCTION
Unibody stainless steel core Spring tip, Polymer sleeve ICE hydrophilic coating Radioopaque length 3 cm Outside diameter 0.014” Available lengths 182cm, 300 cm Compatible with Magnet Exchange Device
WHISPER
Durasteel™ Core-to-tip designed to improve steering, durable shape retention and tactile feedback
Full Polymer cover with Hydrophilic coating intended for deliverability and smooth lesion access
Responsease™ “transitionless” core grind designed to provide improved tracking and better torque response
Tip coils designed to provide softer, shapeable tip and also improve tactile feedback
STABILIZER EXTRA SUPPORT
WIZDOM
:
:
WIGGLE WIRE
This wire has a niche role in delivering stents and balloons in to areas with poor transmission of proximal push. It works by shifting the direction of the pushing forces thus "stepping over" the :obstacle".
IRON MAN GUIDEWIRE
Stiff wire with poor steerability. Its rigidness is used to straighten vessel segements and allow better transmission of forces pushing balloons or stents. This property comes from the tendency of the wire to retain its shape rather than conform to the contours of the vessel. This feature makes “cheese cutter” effects on the vascular intima at their bends. This some times is demonstrated angiographically by a “pleating artifact” and in extreme situations could lead to a transient “no-reflow” state. ( Figure) Though this wire will allow transmit more force to the balloon or the stent, it could actually make device delivery more difficult in tortuous vessels.
GUIDE WIRES PRIMARILY USED FOR CHRONIC TOTAL OCCLUSIONS
CROSS IT GUIDE WIRES
1. CROSS IT XT 100
Cross it 100 xt
Figure source: http://www.abbottvascular.com
Tapered tip coil from 0.014" to 0.010" at distal 3 cm
Hydrocoat hydrophilic coating of distal 30 cm
:
2. Cross it 200 XT
Cross it 200 xt
3. Cross it 300 XT
Cross it 300 xt
PILOT WIRES
Pilot 50, 150, 200
Figure :
PERSUADER
These wires are mainly used to cross challenging chronic total occlusions
Core to tip family used mainly for CTOs
Figures source http://www.medtronic.com
=PERSUADER 3
Persuader 3jpg
PERSUADER 6
Persuader 6jpg
PERSUADER 9
Persuader 9jpg
ASAHI MIRACLE BRO
These wires are mainly used to cross challenging chronic total occlusions Core to tip guidewires
ASAHI MIRACLE BRO 3
1. Asahi miraclebros 3.JPG
Tip load: 3 g Radiopaque length: 11 cm Outside diameter: 0.014" Total length: 180 cm
2. Asahi Miraclebro 4.5
Asahi miraclebros 45.JPG
Tip load: 4.5 g
Radiopaque length: 11 cm
Outside diameter: 0.014"
Total length: 180 cm
3. Asahi Miraclebro 6
Asahi miraclebros 6.JPG
Tip load: 6 g Radiopaque length: 11 cm Outside diameter: 0.014" Total length: 180 cm
4. Asahi Miraclebro 12
Asahi miraclebros 12.JPG
Tip load: 12 g Radiopaque length: 11 cm Outside diameter: 0.014" Total length: 180 cm
STEEL CORE
ZINGER GUIDEWIRE
COUGAR GUIDEWIRE
THUNDER GUIDEWIRE
ASAHI GRAND SLAM
The tip is very flexible, hence less traumatic, but provides considerable support. Tip load: 0.7 g Radiopaque length: 3 cm Outside diameter: 0.014" Total length: 180 cm, 300 cm
Asahi grand slam jpg.
SPARTACORE
This wire is mainly used in peripheral interventions.
V 18
This is a .018” wire mainly used in the peripheral interventions. It is a stiff wire with excellent torque control, tendency to prolapse and perforation.
STEERABLE GUIDE WIRES
Cordis ATW™ All Track Wire
FIG CORDIS STEERABLE GUIDE WIRE
Moderate Support General Purpose Precision Control from Hand to Tip Precise steerability for lesion access Enhanced flexibility for tracking in tortuous vessels Highly lubricious, durable platform for smooth delivery of multiple devices The ATWTM Guidewire atraumatic floppy tip and integrated FLEX-JOINTTM Bond combine for distal flexibility and atraumatic vessel tracking
Torquer / steering tool
Used to maintain an achieved torque. There is a gradual inadvertent “unwinding” of torque with human fingers which can be effectively prevented by this tool.
Two types are commonly used.
TIPS IN CROSSING A LESION
1. Use a bend at the tip of the wire which is roughly the length of the diameter of the vessel proximal to the lesion. 2. If a wire repeatedly fails to cross a lesion, a. Adjust the guide, b. Use a balloon, transit, ultrafuse or twin pass catheter to direct the wire c. modify the bend at the tip. d. change the wire ( check the tip of the wire for evidence of wear and tear) 3. A wire in a balloon or a catheter ( ultrafuse, transit or exchelon) may help guide the wire through the lesion
SAFETY TIPS
1. Get used to a few wires to suit most situations 2. Always use the least traumatic wire for the lesion, >90% lesions could be crossed with standard “work horse” wires 3. Until familiar and comfortable, do not rush in to wires which are mote likely to perforate. 4. Avoid bending or buckling the wire 5. Never push a wire, let it find its “track” with 6. A ventricular premature beat could be a suggestion that the wire is off track, withdraw the wire immediately and redirect it. 7. Check every fluro and cine loop for evidence for perforation, embolization and dissection. If the picture quality is poor, then do not hesitate to increase the frame count/radiation to improve it. 8. If there is a suspicion of a perforation, then an emergent Echo should be performed on the table. ( link complications – perforation)
COMMON PITFALLS
TROUBLE SHOOTING
TRAPPED WIRE
May occur with
- calcified vessels ( eg RCA) at the tip.
May be prevented by avoiding using the same wire on multiple interventions or multiple crossing.
My need to advance a small profle balloon or a small caliber catheter (transit) to the “attachement” site and use traction. Caution : Perforation.
- May occur when a buddy wire gets trapped between a stent and the vessel wall. Gentle traction may bring the wire out of the stent. The coating of the tip may “deglove” and be left behind, which could be “pushed and pasted” against the vessel wall with another stent. May need surgery to retrieve it. The tip may completely detach, then the management is as above.
DETACHMENT OR EMBOLISATION OF END OF THE WIRE
Uncommon with most modern wires.
Management
There is no data to guide management. Clinical judgment should be used.
May have to snare it.
May be left in situ, speacially if small and unable to retrieve. Could use a stent to “push and paste” it to the vessel wall.
Surgery may be needed.
WIRE FRACTURE IN A CORONARY VESSEL
This should be identified immediately and the wire should be replaced. It could give rise to the situations mentioned above.
GUIDEWIRES BY MAJOR MANUFACTURERS
Abbott vascular
1.1 Asahi
- Asahi by Abbott vascular
- ASAHI Confianza Coronary Guide Wires
- ASAHI Grand Slam Coronary Guide Wires
- ASAHI Light Coronary Guide Wires
- ASAHI Medium Coronary Guide Wires
- ASAHI Miracle Bros Coronary Guide Wires (3g, 4.5g, 6g and 12g)
- ASAHI Prowater Coronary Guide Wires
- ASAHI Prowater Flex Coronary Guide Wires
- ASAHI Standard Coronary Guide Wires
1.2 Balance wires by Abbott vascular
BALANCE (HI-TORQUE BALANCE Coronary Guide Wire) BALANCE (HI-TORQUE BALANCE MIDDLEWEIGHT UNIVERSAL Coronary Guide Wire)
1.3 HI-TORQUE CROSS-IT XT Coronary Guide Wire by Abbott vascular
- 100 XT
- 200 XT
- 300 XT
Medtronic
- Cougar
- Zinger
- Persuader
- Thunder
Boston Scientific
Crossing guide wires
- ChoICE PT
- ChoICE PT Extra support
- PT
- PT Graphix Intermediate
- Forte
- IQ
- Luge
- Mailman
mailman.jpg, Delivery support guidewire super support rail for straightening of vessel. Spring tip with polymer sleeve, unibody stainless steel, hydrophilic coating 3 cm radioopacity, diameter .014”
cordis
- ATW™All Track Wire
- ATW™Marker Wire
- WIZDOM® Steerable Guidewires
- WIZDOM® ST Steerable Guidewires
- STABILIZER® Balanced Performance Steerable Guidewires
- STABILIZER® Plus Steerable Guidewires
- STABILIZER® XS Steerable Guidewires
- STABILIZER® Marker Wire
- SHINOBI® Steerable Guidewires
- SHINOBI® Plus Steerable Guidewires
- REFLEX® Steerable Guidewires
- Steer it Deflecting Tip Guidewire E-1
Steerable Guidewire Accessories
- CINCH® QR Extension Wire
- EASY TWIST® Torquing Device
Sources
1. Arce-Gonzalez JM, Schwartz L, Ganassin L, Henderson M, Aldridge H: Complications associated with the guide wire in percutaneous transluminal coronary angioplasty. J Am Coll Cardiol 10: 218-221, 1987.
2. Hartzler GO, Rutherford BD, McConahay DR: Retained percutaneous transluminal coronary angioplasty equipment components and their management. Am J Cardiol 60:1260-1264, 1987.
3. Serota H, Deligonul U, Lew B, Kern MJ, Aguirre F, Vandomael M: Improved method for transcatheter retrieval of intracoronary detached angioplasty guidewire segments. Cathet Cardiovasc Diagn 17:248-251, 1989. 218-221, 1987