ASDIN 9th Annual Scientific Meeting

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Fundamentals of

Arterial and Venous Angioplasty

Thomas M. Vesely, MD

Saint Louis, Missouri

Disclosure

Consultant for:

W.L. Gore & Associates

Transonic, Inc.

Phase One Medical

R4 Vascular, Inc.

Three layers of

blood vessel wall

intima

media

adventia

Artery Vein

Atherosclerosis Neointimal hyperplasiaAngioplasty = controlled vascular injury

Disruption or dissection of the medial layer is

the primary mechanism for endoluminal expansion

tear in medial layer

ASDIN 9th Annual Scientific Meeting

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Pre-angioplasty

Post-angioplasty Pre-angioplasty Post-angioplasty

Luminal enlargement due to disruption of blood vessel wall

The length of the angioplasty balloon should

extend ~ 5mm beyond the end of the stenosis

3cm

Use 4cm length balloon

Minimize the length of balloon within normal vein

Angioplasty damages the venous endothelium

and can incite neointimal hyperplasia

7.8mm

The diameter of the angioplasty balloon should

be ~ 15% - 20% larger than the diameter of the

normal blood vessel adjacent to the stenosis

54mm

Measurement using radiographic ruler

Measurement using

digital software

ASDIN 9th Annual Scientific Meeting

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Know the tools of your trade

Anatomy of an Angioplasty Balloon

• Length

• DiameterPrimary selection criteria :

balloon length

nominal diametertip length

shoulder

balloon diameter

rated burst pressure nominal pressure

Balloon Compliance

Diameter at nominal pressure 6.5mm 6.8mm

Diameter at rated burst pressure 7.2mm 7.0mm

Compliance 9.8% 2.2%

Balloon A Balloon B

Nominal pressure = inflation pressure required to reach specified diameter

Rated Burst Pressure = the pressure at which 99.9% of balloons

will survive with 95% confidence

Change in balloon diameter as a function of inflation pressure

Balloon Compliance

• Angioplasty balloons

are non-compliant

• Maintain fixed shape

and diameter with

increasing pressure

Non-compliant balloon Compliant balloon

- maintains fix diameter

with increasing pressure

- increasing diameter

with increasing pressure

ASDIN 9th Annual Scientific Meeting

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rated burst

pressure

The rated burst pressure decreases

as the diameter of the balloon increases

The larger the balloon radius,

the larger the wall tension exerted

Law of LaPlace

Geometry of Balloon Inflation

Mechanical force of dilation (DF) is greatest

at the waist on the balloon

In order to increase the force of dilatation (DF)

increase the diameter of the balloon or

Increase the inflation pressure (HP)

Trerotola et al. J Vasc Intervent Radiol 2005; 16: 1613 - 1618

Angioplasty Balloon Inflation Pressures

Balloon Inflation Pressure

Mean >15 atm > 20 atm >30 atm

PTFE Graft 15.4 atm 53% 9% 1%

Fistula 15.2 atm 59% 20% 6%

ASDIN 9th Annual Scientific Meeting

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7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

0

2

4

6

8

10

Inflation Pressure

Mean inflation pressure: 17.2 atm

Nu

mb

er

of

Ste

no

ses

Angioplasty Balloon Inflation Pressures

TM Vesely JVIR 2005;17: 623-628

Atherosclerosis Neointimal hyperplasia

4 – 8 atmospheres

inflation pressure

15 – 20 atmospheres

inflation pressure

Angioplasty Balloon

Burst Pressure

Following an angioplasty procedure

the PTA balloon was saved and

tested to determine the burst pressure

• Centurion

• Blue Max

• Workhorse II

• PowerFlex Extreme

• Conquest25 balloons of each type

were inflated until rupture

22 23 24 25 26 27 28 29 300

1

2

3

4

5

6

7

8

9

10

Balloon Burst Pressure (atm)

CenturionWorkhorse II Extreme

Nu

mb

er

of

Ba

llo

on

s

Distribution of Balloon Burst Pressures

RBP = 16 atm RBP = 20 atm RBP = 20 atm

Angioplasty Balloon Burst Pressure

Rated BP Actual BP

Workhorse II 16 atm 26.1 atm

Centurion 20 atm 27.8 atm

Extreme 20 atm 28.7 atm

Blue Max 20 atm >30.0 atm

Conquest 30 atm

7mm and 8mm diameter balloons

>30.0 atm

Summary

Measure stenoses

in order to

Select correct diameter and length of balloon

in order to

Minimize dilatation of normal blood vessel

ASDIN 9th Annual Scientific Meeting

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