Dimitriadis Dimokritos MD

interventional cardiologist

THESSALONIKI

Five steps for

success

A thorough knowledge of the basic angioplasty equipment is required for coronary intervention.

✓The correct choice of equipment can make a complex intervention appear effortless,

✓whereas the less appropriate equipment choices can make a straightforward intervention, laborious and challenging.

Can we have the right tool to do the job ?

First step: the puncture

•Trans femoral access

•Transradial access

•Left distal transradial access in

the anatomical snuffbox

55 years male with

nstemi!

Second step: the guiding catheter

✓Guiding catheters

✓Wires

✓Balloons

✓Stents

PCI material Selecting the right material for the procedure

Guide Catheters

The single most important choice (afterpatient selection) for the performance of a

successful intervention is the selection of the appropriate guide catheter (Safety, ease of the

case, case duration)

Role of Guiding Catheter

✓Atraumatic tip

✓Preformed curves and configurations

✓Torque control

✓Kink resistance

✓Radiopacity

✓Support

✓Device Compatility

Important Features of a Guide Catheter

✓Hub – “handle” configuration.

✓Shaft – polyurethane or polyethylene with wire/nylon braiding to provide

support and torque transmission. Catheter gradually softens from proximal to distal tip.

✓Tip – soft and atraumatic; of varying shape and length; radiopaque marker.

Components of a catheter

Diameter Side holes LengthCurve

style/length

Guide Catheter Selection

French size influence

7-8 Fr Guides6 Fr Guides

✓Increased support✓Improved visualization✓Better torque transmission

✓Larger puncture site✓Pressure damping✓Increased contrast usage

✓Small arterial puncture✓Brachial/radial access✓Less contrast✓Less back bleeding✓Deeper engagement

✓Decrease support✓Decreased visualization✓Decreased torque✓Smaller internal lumen✓Device limiting

PR

OS

CO

NS

Side holes allow perfusion but don't prevent guide catheter injury to the ostium

Guide catheter side holes

To improve antegrade perfusion when a large catheter engages a small coronary ostium, catheters with side holes are helpful.

They are also useful in PCI of a lesion located very proximally to or at the ostium

Types of Guiding Catheters Curves

Standard➢Standard guides provide coaxial alignment for the majority of patients with relatively straight forward aortas and vessel orientation. These guides often ride above the sinuses or rarely reach into the sinus

Support➢Support guide catheters derive their support primarily from the sinus of Valsalva

Extra Support and specialty Curves➢Gather their support from the opposite wall of the aorta

Types of Guiding Catheters Curves

Judkins left catheter showing the contact point (+) with aorta providing back-up support

Extra back-up curve catheter with large area of contact (+) between catheter and contralateral aortic wall, providing greater support

How to chose the right guiding catheter?

Why so many sizes and shapes?

The third step: guide wire

✓Guiding catheters

✓Wires

✓Balloons

✓Stents

PCI material Selecting the right material for the procedure

Wires

The choice of guide wire is second only to choice of guide catheter for

the performance of successful intervention

Common terms used to describe guide wire main characteristics

To steer through the vessel in order to access and cross the

lesion

To support and facilitate delivery of any interventional

devices

✓Steerability✓Torque ✓Flexibility ✓Visibilty✓Crossability✓Trackability

ROLE-IMPORTANT FEATURES OF GUIDE WIRE

✓Support

Core

Tip

Outer covering

Wire Coating

The core material will affect wire performance: Flexibility, support, steering and tracking

Guide wires: Central Core

Stainless Steel: Excellent support, transmission of push

and torque, Steerable

Nitinol (Nickel and Titanium): Excellent flexibility, kink resistance

High Tensile Strength Stainless Steel: Shape retention,

Excellent steering, tracking

A more practical classification of guide wires

Workhorse guide wires strike a nice balance between tip flexibility, shaft support and steerability

Secondary curve matches vessel size

Primary curve matches most angulated vessel bend

Forth step: the balloon

✓Guiding catheters

✓Wires

✓Balloons

✓Stents

PCI material Selecting the right material for the procedure

balloons

✓Dilating force

✓Pushability

✓Trackability

✓Crossability

✓Confromability

✓Inflation/deflation times

✓Withdrawal

✓Wire movement

Requirements of PTCA Balloons

Guidewire exits balloon catheter several cm proximal to the distal tip

Guidewire travels separately from the balloon catheter180 through 195 cm steerable is typically used

(+) Single operator

Allows for quick exchange of balloons

(-) Can’t reshape or exchange guidewire

without losing positionPushability may be compromised due tothe short wire lumen

Consists of a balloon catheter with a movable guide wire passing through the

entire length of its lumen 300 cm steerable guide wire is typically used

Rapid Exchange-Rx

(+) Ability to change guidewire without

losing positionSuperior pushability

(-) Typically needs 2 operators

Slightly larger profiles and shaftsCan take more time requiring more fluoroscopy

Over the wire-OTW

Longer taper reduce profiles and enhance crossability

Steep transition deliver focal dilatation and minimize edge dissections

Catheter Tip examples and Balloon Transition angles

Trackability refers to the balloon’s ability to track the wire up to the target lesion while

pushability refers to the ability to cross the lesion with the balloon. These are not easily

measured in vitro but are perhaps more important than catheter profile in today’s practice of interventional cardiology

Compliant: Diameter increases in

ratio with the increase in inflation force (size of balloon may grow beyond the ceiling of clinical safety)

Non-compliant: reach and

maintain specified size regardless of inflation pressure (little to no flexibility in vessel sizing)

Semi-compliant: Wide working

pressure with controlled flexibility in balloon sizing

Balloon Compliance

Dogboning

Do not re-wrap very well and, thus, can be difficult to re-use after initial inflations.

Circumferential Rupture

Balloon separates in two halves

Longitudinal (Axial) Tear

Balloon ruptures in a clean tear along the length of the balloon

Pinhole Puncture

High pressure jet of contrast forced through pinhole and directed at vessel wall

Balloon Burst Patterns

Fifth step: the stent

✓Guiding catheters

✓Wires

✓Balloons

✓Stents

PCI material Selecting the right material for the procedure

Stents

The Value of Thin Stent Struts

✓Reduced acute injury

✓Reduced inflammation

✓Rapid incorporation of struts

within neointima

✓Rapid re-endothelialization

Pre-Clinical Models have demonstrated

Stent Platform Evolution From Stainless Steel to Platinum Chromium

Future of Stents

• Thinner Struts

•Abluminal drug delivery

•Biodegradeable polymer

• Polymerless stents

•Biodegradeable stents

An important factor of uncertainty about the efficacy of drug-eluting stents is the use of polymers.

✓Time and rate of degradation

✓Suboptimal Scaffolding and radial force over time

✓Recoil early and late

✓Radiopacity of the stents

✓In vivo elution of drug

✓Complex implantation technique-difficult deliverability

✓Maintenance of stent integrity before, at and post deployment

✓Remaining polymer (inflamation, giant cells, fibrin, prothrombogenic effects)

✓Biodegradable products

THANK YOU!