Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Coronary guidewires

3,037 views

Published on

Cardiology- Coronary guidewires

Published in: Health & Medicine

Coronary guidewires

  1. 1. CORONARY GUIDEWIRES Dr. Raji Rajan & Dr. A. George Koshy Government Medical College, Trivandrum
  2. 2. •GRUNTZIG First performed Angioplasty in 1974 •1977 – First coronary angioplasty •Polyvinyl Chloride balloon catheter with short guidewire attached to its tip
  3. 3. •1982 – Simpson reported First experience with over the balloon system •It had an independently movable guidewire within the balloon dilation catheter
  4. 4. • To track through the vessel • To access the lesion • To cross the lesion atraumatically • To provide support for interventional devices
  5. 5. Guidewire main characteristics  Torque control Is an ability to apply rotational force at a proximalend of a guidewire and have that force transmitted efficiently to achieve proper control at the distal end  Trackability Is an ability of a wire to follow the wire tip around curves and bends without bucking or kinking, to navigate anatomy of vasculature  Steerability Is an ability of a guidewire tip to be delivered to the desired position in a vessel  Flexibility Is an ability to bend with direct pressure
  6. 6.  Prolapse tendency Tendency of the body of a wire not to follow the tip around bends  Radiopacity/visibility Is an ability to visualise a guidewire or guidewire tip under fluoroscopy.  Tactile feedback Is tactile sensation on a proximal end of a guide wire that physician has that tells him what the distal end of the guidewire is doing  Crossing Is an ability of a guidewire to cross lesion with little or no resistance  Support Is an ability of a guidewire to support a passage of another device or system over it
  7. 7. STRUCTURE  CORE-Material Diameter Core taper  TIP  COILS, COVERS & COATINGS
  8. 8. Core • Inner part of the guidewire • Extents through the shaft of the wire from the proximal to the distal part • Distal taper • Stiffest part of the wire that gives stability and steerability
  9. 9. Core Material Core material affects the flexibility, support, steering and trackability • Stainless steel – superior torque characteristics, can deliver more push, provides good shapeability and excellent support – more susceptible to kinking and is less flexible • Nitinol – pliable but supportive, less torquability than SS – generally considered kink resistant & have a tendency to return to their original shape, making them potentially less susceptible to deformation during prolonged use
  10. 10. Core Diameter • Influences the performance of the wire • Larger diameter improves support and allows 1:1 torque response • Smaller diameter enhances the flexibility Core taper • Variable length • Continuous/segmented • Short taper and smaller number of widely spaces gradual tapers increases support and transmission of push force • Longer tapers and larger numbers of segmented tapering increases flexibility
  11. 11. Tip • Tapers distally to a variable extent – 2-piece core- distal part of core does not reach distal tip of wire→ shaping ribbon, extends to distal tip – 1-piece core- tapered core reaches distal tip weld • 2-piece→ easy shaping & durable shape memory • 1-piece →better force transmission to tip & greater “tactile response” for operator
  12. 12. Coils, Covers & Coating Keeps the diameter at .014 inch • Coils – Stainless steel – Outer coil Design – Coils placed over tapered core and tip of the wire – Tip coil Design – Tip alone is covered with coils – Flexibility, support, steering, tracking, visibility & tactile feedback – Radio opaque platinum coils – Intermediate coils placed on the working length of the wire
  13. 13. Coils
  14. 14. • Covers – Polymer or plastic – Lubricity • Coating – Distal half – Affects lubricity and tracking – Creates tactile feel – Reduces friction – Facilitates movement of wire within the vessel and deliverability of intervention equipment
  15. 15. Hydrophobic • Applied over the entire working length except the distal tip • Require no activation by liquid • ↓friction, ↑trackability • Preserves tactile feel, allows easier anchorability / parking - esp CTO • Silicone, Teflon
  16. 16. Hydrophilic • Applied over the entire working length of wire including tip coils • Attracts water - needs lubrication • Thin, non slippery, solid when dry→ becomes a gel when wet – ↓friction – ↑trackability – ↓Thrombogenic ↓tactile feel- ↑risk of perforation Tendency to stick to angioplasty cath • Useful in negotiating tortuous lesions and in “finding microchannels” in total occlusions
  17. 17. Shapeability and shaping memory • Shapeability - allows to modify its distal tip conformation • Shaping memory - ability of tip to return back to its basal conformation after having been exposed to deformation & stress – Both do not necessarily go in parallel – SS core wires -easier to shape (↑memory- nitinol core) – 2-piece core + shaping ribbon - easier to shape & ↑memory
  18. 18. Classification Based on Tip Flexibility • Floppy – Eg:- Hi torque balance middle weight, Hi torque balance, Hi torque transvers • Intermediate – Eg:- Hi torque intermediate, Choice intermediate • Standard – Shinobi, Boston Scientific Based on Device support • Light – Eg:- Hi torque balance • Moderate – Eg:- Hi torque balance middle Weight • Extra support – Eg:- Hi torque whisper
  19. 19. Based on coating • Hydrophilic : Eg:- CholCETM PT Floppy • Hydrophobic : Eg:- Asahi soft Depending on tip load • Floppy, Balanced & Extra support • Tip load - force needed to bend a wire when exerted on a straight guide wire tip, at 1 cm from the tip – Floppy - <0.5g – Balanced – 0.5-0.9g – Extra support - >0.9g
  20. 20. Guidewire Manipulations • Two step process • Shaping the wire tip – It minimizes the amount of force applied to the wire – For steering into the vessel – For visualization of torquing effort
  21. 21. Shaping the Wire Tip
  22. 22. Steering of the wire • Small alternating rotations to left and right • Excessive rotations should be avoided to prevent wire tip fracture
  23. 23. Optimum guide wire positioning • Should be placed as distally as possible in the target vessel • Allows extra support when crossing with balloon/stent catheters • ↓ chance of the wire becoming displaced backwards across the lesion and necessitating re-crossing Avoid vessel perforation when positioning wires with hydrophilic coatings very distally
  24. 24. Strategies if Guidewire fails to cross • Make the guide more coaxial with the lumen of the artery • Use a balloon to direct the wire • Modify the bend at the tip of the wire • Change the wire
  25. 25. Complications • Vessel perforations – Uncommon <1% – Risk factors • Hydrophilic wires, core to tip • Chronic total occlusions – Diagnosis • Angiographic diagnosis • Small extraluminal extravasation of blush in the distribution of target vessel • Emergency echo to r/o pericardial effusion and tamponade – Prognosis • Extend of extravasation into pericardium
  26. 26. – Classification • Type I – Extraluminal crater without extravasation • Type II – Containing pericardial or myocardial blushing • Type III - having≥ 1 mm diameter with contrast streaming: and cavity spilling – Management • Reversal of anticoagulations • Prolonged balloon inflation • PTFE covered stent • Coil embolization • Use of gel foams
  27. 27. Pseudolesions/Concertina effect • Stenosis that appears in any artery after the coronary guidewire is placed in the artery • Appears in tortuous vessels that have been straightened out by the guidewire
  28. 28. Diagnosis • Will disappear if the wire is withdrawn • Replacement of a stiff wire with a flexible floppy wire eliminates pseudolesion • Microcatheter or a balloon catheter can be placed distal to the lesion Complications • In some cases cause hemodynamic compromise and ischemia
  29. 29. Guidewire Entrapment Factors • Presence of calcified vessels (Eg:- RCA) • Repeated use of wire for multiple interventions • Repeated attempts at crossing the same lesion multiple times with the same wire • Two wires my become entrapped when the “Buddy wire” technique is used • Crossing fresh stent struts
  30. 30. Management • Advance a small profile balloon or a small caliber catheter (transit catheter) to the attachment site and pull back gently • When a second or “buddy wire” gets trapped between a stent and the vessel wall gentle traction can be used • Surgery
  31. 31. Guidewire fracture and Embolization • Risk factors are calcified lesion, bifurcation stenting and prolonged procedures • Management – Surgery – Snaring the Embolized wire fragment • The Amplatz Gooseneck Microsnare • The EnSnare Triple Loop Device • The X Pro Micro Elite Snare • The Alligator Retrieval Device – Push and paste
  32. 32. Balance Middleweight Universal wire (Abbott Vascular/Guidant, Santa Clara, CA) • Quite steerable - tip is suitable for bending in a “J” configuration for distal advancement into the distal vessel bed with minimal trauma while still maintaining some torque • shape retention relatively poor -any J configuration tends to become magnified over time → consequent loss in steerability • moderately torquable- progression - minimal friction (light hydrophilic coating) - Dye injection may also be helpful to propagate distal advancement • suitable for rapid, uncomplicated interventions • low risk to cause dissections/distal perforations • support - low to moderate
  33. 33. Fielder™ / Fielder FC™ (Asahi Intec Co.) • Special guidewire - distal coil coated with polymer sleeve & further coated with a hydrophilic coating • Provides advanced slip performance & trackability for highly stenosed lesion & tortuous vessels • Very good torque performance • Combines both slide and torque performance • Primary wire used in the retrograde technique of recanalization of CTO
  34. 34. 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
  35. 35. Galeo guide wire
  36. 36. Guidewire Strategies for Approaching CTO • A) Guidewires for Approaching Micro-channels – Crosswire NT – Whisper / Pilot – Rinato – Shinobe / Shinobe Plus – ChoICE PT / ChoICE PT ES – PT Graphix – PT2 • B) Guidewires for Drilling Strategy – Persuader – Miracle Bros – Cross-It • C) Guidewires for Penetrating Strategy – Cross IT – Conquest Pro – Liber 8 • D) Guidewires for Retrograde Technique – Fielder/FielderFC – X -treme – Whisper – ChoICE PT2 – Runthrough / Runthrough Hypercoat
  37. 37. Selection of a Guidewire • Vessel anatomy • Lesion morphology • Devices to be used
  38. 38. Conclusion It is suggested that the operator may use a limited number of wires from the several types available for purchase

×