2. • P - Percutaneous ( i.e. through the skin)
• T - Transluminal (i.e. within the vessel walls)
• C - Coronary (i.e. vessels of the heart )
• A - Angioplasty (i.e. stretching of the vessel walls)
What is P.T.C.A. ???
5. • Flexible hollow tubes that
are inserted into the vessel to
obtain intravascular access.
• It has a haemostatic valve
that prevents a back flow of
blood from the arterial site.
• The sheath permits repeated
exchange of devices.
• Diagnostic procedures utilize
4 – 7 Fr.
• Interventional procedures
utilize 6 – 8 Fr.
• Sheath lengths vary from 10
– 11 cm. (Short) or 23 – 55
cm (Long).
Introducer Sheaths
6. A table of various French sizes
are shown below:
• 1 French = 0.33 or 1/3 mm
• 3 French = 1 mm
• 6 French = 2 mm
• 7 French = 2 1/3 or 2.33 mm
• 8 French = 2 2/3 or 2.66 mm
• 9 French = 3 mm
• 10 French = 3 1/3 or 3.3
7. Different French Sizes with color
• French size Color
4F Red
5 F Grey
6F Green
7F Orange
8F Blue
9F Black
8. • A guide wire comprises of a central core with a coil wrap on the
outside and a spring tip at the distal end.
• Proximal shaft of the guide wire has to be stiff for torque
transmission.
• Distal tip is smooth, flexible and has a radiopaque tip available in a
variety of tip shapes i.e. straight, angled or J-shaped.
• Guide wire tips vary in flexibility and are typically referred to as
Floppy, Intermediate or Standard.
Guide wires
10. • Floppy – flexibility improves trackability and softer tip reduces risk
of dissection or plaque disruption.
• Intermediate – most commonly used in radiological procedures,
has a firmer tip and good pushability.
• Standard – Firmest tip, better torque control, most commonly used
in chronic total occlusions (C.T.O’s).
Guide wires
11. • Coatings – Guide wires more often
than not have a lubricious coating
which is manufacturer dependent or
proprietary ( e.g. Teflon, PTFE,
Silicone or other hydrophilics) and
reduces friction when traversing
through the guide catheter and
crossing the lesion.
• Performance – Dependent on
design and construction, guide wires
may vary in stiffness, steerability, tip
flexibility, trackability, pushability
,crossability and visibility.
• Sizing – Guide wires vary in a
range of sizes such as
.010”;.012”;.014”;.016”;.018”;.025”;.03
2”; .038”
Lengths vary from 150 cm to 400 cm.
Guide wires
Hydrophilic coating
12. • Balloon dilatation catheters are
used to dilate a lesion by
exerting a radial force on the
inner wall of the vessel.
• B.D.C’s have two lumens – an
inflation port to inflate the
balloon and a guide wire lumen.
• The balloon is fused to the distal
end of the catheter.
• Radiopaque markers at each end
of the balloon facilitate the
precise placement of the balloon
within the lesion.
• Performance of the balloon may
be enhanced by applying a
hydrophilic coating.
Balloon Dilatation
Catheters
13. • Ideally the balloon catheter should be made of material that is puncture and
rupture resistant, collapses to the lowest profile and inflates and deflates
rapidly.
• Balloon catheters should be able to provide good pushability and
trackability.
• The diameter of the BDC should be large enough to exert dilating pressure
against the endoluminal surface of the vessel, but at the same time not too
large enough to cause excessive trauma.
•The inflation pressure required to achieve the inflated balloon diameter is
referred to as ‘Nominal Pressure’. Typical nominal pressures range from 3
atm to 12 atm.
•‘Rated Burst Pressure’ is defined as a 99.9 % chance of the balloon catheter
not rupturing at that pressure.
•‘Mean Burst Pressure’ is defined as a 50 % of the balloon catheter rupturing
at that pressure.
Balloon Dilatation
Catheters
16. • Compliance of a balloon catheter is defined as the rate at which the
size of the balloon increases once it is inflated beyond it’s nominal
pressure.
• Compliance is dependent on the material of the balloon catheter.
• Hence Low Compliance means that once the balloon catheter has
reached its Nominal stated pressure, additional pressure applied to
the catheter will not increase it’s diameter drastically.
Compliance of a balloon Balloon
Dilatation Catheters
17. Other Known Applications of Balloon
1. Delivery and deployment of the stents.
2. Pre-conditioning of the lesion prior to the stent placement.
3. Post dilatation of the deployed stent to ensure its optimal conformability.
4. Enabling entry in a sub-total or totally occluded vessel.
5. Patching up of a dissected flap or temporary leak prevention during
perforation.
6. Delivery of pharmacologically active substances for the prevention of
restenosis(DEB).
7. Approximation of lesion length and vessel diameter in absence of QCA
tools/software.
22. Balloon Expandable Stents
• Balloon expandable stents are pre loaded and compressed or
crimped on to a balloon catheter which is inflated at the site of the
lesion.
• BE stents have a high radial strength but lack longitudinal flexibility
as a result of which they may be difficult to deploy in tortuous
vessels.
• BE stents provide a stable, non-shifting surface that facilitates early
re-endothelialization.
23. • Self-expanding stents use a specialized delivery system and rely on
a spring loaded action to achieve expansion.
• SE stents have a high degree of flexibility, ease of placement and a
delivery system that incorporates a smaller diameter.
Self-expanding Stents
24. • Biocompatibility
Ability of the stent material to resist thrombosis and corrosion.
• Flexibility
Ability of the stent/delivery system to navigate through tortuous and
angulated anatomy.
• Visibility
Characteristic of the stent material to be visualized under
fluoroscopy.
Stent Characteristics
25. • Radial Strength
Ability of the stent material to withstand the pressure exerted on
itself by the artery surrounding it.
• Stent Surface Area
Ability of the stent to cover the entire diseased portion of the lesion.
Higher the stent surface area, higher the rate of restenosis due to
tendency towards thrombus formation. A decreased surface area
may have lower restenosis but could have insufficient radial
strength.
Stent Characteristics
26. Some Important
Mechanical Properties of a
Stent
• After the dilatation process, with the balloon still inflated, the stent
has a certain diameter. On deflation the stent automatically bounces
back due to the elastic forces
• This is the Elastic (Stent) recoil, usually expressed in percent terms.
Elastic (Stent)
Recoil
Diameter with Balloon Inflated
Diameter after Balloon
Deflated
27. • The “Elasticity” of a stent is defined as the ability of the stent to
adapt to the external forces on the stent without collapsing.
• The “Radial Force” of a stent is defined as the maximum external
pressure exerted on a stent before it collapses.
Elasticty of a
stent
Crushed
Stent
External Force < Radial force External Force > Radial
Force
Stent reaction to external forces
e.g. the moving Heart
Some Important
Mechanical Properties of a
Stent
