GUIDEWIRES & VASCULAR CATHETERS Flashcards
What is the function of the guidewires?
allow the safe introduction of the catheter into the vessel and selective positioning of catheters within the vascular system
What is the construction of the guidewire?
flexible tip & rigid tail
What part of the guidewire is introduced first into the blood vessel
flexible tip
What are the advantages of using a solid stainless steel guidewire?
it reduces:
1. Tip Flaring
2. Blood clotting
3. Abrasion
4. Danger or raveling
what are the disadvantages of using a solid stainless steel guidewire?
lack of versatility
What are the advantages and disadvantages of using a wrapped guidewire?
a - more versatile
d - can damage the vessel/catheter
To reduce the possibility of injury, most wrapped guidewires are improved by using the ____________ coated or _________ coated wrappings
heparin/ teflon
Made of stainless steel or NITINOL
central core
What is the purpose of using stainless steel or nitinol in the central core of the guidewire?
provides turn-for-turn
torque control without compromising flexibility
What is the distal flexible spring coil made of?
platinum or tungsten
What is the purpose of using the platinum/tungsten in the DISTAL FLEXIBLE SPRING COIL
for enhanced fluoroscopic visualization
Usually made up of PTFE or teflon materials with Hydrophilic Coating
Outer coating
2 types of central core
fixed & movable
Refers to the response of the guidewire or catheter to twisting and turning
Torque
Another term for the torque device
torque vise/ deflector handle
what is the torque device for?
Used to direct the guidewire towards the
desired arterial branch
2 kinds of tip configuration
straight tip & j-shaped tip
what is the difference between the straight tip & j-shaped tip?
S - measured in length
- fixed - core straight - 3cm
- movable - core straight - 10-15cm
J - measured in radius
- about 3mm to 3cm
what are the 3 guidewire lengths?
Short guidewires (30-50cm)
Average Length guidewires (100-150cm)
Long Guidewires (260 cm)
Guidewire that is usually used for percutaneous or direct vascular punctures
Short guidewires
Guidewire that is used for adults undergoing selective angiography
Average length guidewires
Long guidewires are used for what?
Used when interchanging vascular catheters
The diameters of guidewires are
measured in __________
fractions of an inch or mm
range sizes of diameters of guidewires
0.014” (0.35 mm) to 0.052” (1.32 mm)
What is the most common diameter used for adults?
0.035” (0.89 mm) and 0.038” (0.97 mm)
Factors to Consider in Selecting the Diameter of Guidewires
Needle gauge
Vessel size
Size of the lumen of vascular catheter
If the guidewire does not advance smoothly, it may be because of
- Tortous vessel
- Position of needle
Precautions when using guidewires
- The bevel of the needle should be positioned facing upward
- Avoid cleaning the guidewire too often during
the examination - Discard guidewire after each use
A long hollow, thin tube with one to several holes at its distal end
vascular catheters
purpose of vascular catheters
serves as a pipeline through which contrast medium can be injected
Materials used for a vascular catheter?
teflon
polyethylene
polyurethane
dacron
Characteristics of teflon
- Has the lowest coefficient of friction
- Has an excellent memory
- can withstand high temperature
characteristics of polyethylene
- Has a medium coefficient of friction
- softer than Teflon
- can be sterilized with cold or hot gas
Contains the same memory, softness, and sterilization requirements
polyurethane
Used in pulmonary and cardiac angiography
and in obtaining cardiac pressures
dacron
readily visualized under fluoroscopy, which facilitates catheter placement. Most angiographic studies use _______ catheter material.
radiopaque
_________ catheters are used for visualization
of air bubbles
radiolucent
The outer diameter of the catheter is most commonly expressed in what scale?
french scale
The French scale has an increment of approximately
0.33 mm or 1/3mm
What is the rule fo the french scale
The smaller the scale, the smaller the millimeter
what are the french sizes for the children when using vascular catheters?
3-6
What are the french sizes of vascular catheters used for adults?
4-7
Catheter shapes can be categorized into four basic shapes:
Straight tip, single curve, double/multiple curve, pigtail
This ______ holed catheters are used for larger
vessels
multiple
Smaller vessels may require a catheter with only _____ end hole
1
Advantages of the combination of end holes and side holes
- Reduces trauma to the vessel
- Enhances the mixing of contrast media with the blood.
- It also reduces any recoil caused by jet-effect of a high-pressure injector
Disadvantage of using the combination of end holes & side holes in catheters
There is an increase potential of blood clotting using multiple holed catheter
What are the other types of catheter?
Guiding catheter, microcatheter, special catheres
Catheter that is used for a variety of angiographic and interventional procedures are also available such as brockenbrough catheter, balloon catheter, and atherocath
special catheters
A catheter that is placed through standard angiographic catheters to allow entry into small or tortuous arteries guided by small steerable
guidewires.
Microcatheter
A catheter that is used to allow safer or more secure passage of devices into the vessel
guiding catheter
