Guidewire

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List of terms related to Guidewire

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 several feet away, and this is called torquability. When the operator rotates the guidewire outside the body, the ability of the guidewire to intern translate this motion into a similar motion at the tip is called torquability.

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

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

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)

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

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

link title

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

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.

COMMON TERMS USED TO DESCRIBE CLINICO-PHYSICAL PROPERTIES OF GUIDEWIRES

SUPPORT

Is a measure of

• Overall performance
• Smooth traverse through complex lesions
• Smooth device tracking.

STIFFNESS

Is a combination of diameter, trackability and torque control. Stiffer wires give better torque control and straighten the vectors of forces pushing the wire, balloon or a stent.

This quality 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 bury in to the intima in a “cheese cutter” effect. ( Eg Iron man wire)

MALLEABILITY

Ability to be shaped or bent without breaking

TORQUE CONTROL

Is the ability to transmit rotational forces from the operators hand to the tip. Directly proportional to diameter, May be assisted with the use of a “torquer” or a “pin vise” or “steering tool”.

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

TRACKABILITY

Is the ability of the wire to follow the wire tip without bucking or kinking. The term may also refer to a stent or a balloon.

TACTILE FEEDBACK

Is the “feel” of the wire tip’s behavior perceived by the operator. This is better appreciated with coil tipped wires, whereas polymer tipped wires it may be minimal or absent, making inadvertent perforation, dissection or traversing a plaque more likely.

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

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 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

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.

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 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

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.

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)

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

References

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