Functional properties and performance of new and reprocessed coronary angioplasty balloon catheters

Functional Properties and Performance of New and Reprocessed

Coronary Angioplasty Balloon Catheters

Mariangela Fedel1, Francesco Tessarolo1, Paolo Ferrari2, Christian Lösche3,

Nikou Ghassemieh3, Giovanni Maria Guarrera4 and Giandomenico Nollo2,5

1 Department of Materials Engineering and Industrial Technologies, University of Trento, Trento, Italy

2 Department of Physics, University of Trento, Trento, Italy

3 Department of Research and Development, Vanguard AG, Berlin, Germany

4 Department of Care and Rehabilitation, Azienda Provinciale per i Servizi Sanitari, Trento, Italy

5 ITC-irst, Trento, Italy

Correspondence to:

Mariangela Fedel

Department of Materials Engineering and Industrial Technologies, University of Trento

Via Mesiano, 77

38050 Trento, Italy

Tel +39 0461 881594; Fax +39 0461 883952

[email protected]

Abstract

The need of health costs control has prompted the reuse of devices originally

manufactured for single use only. To assess reprocessing feasibility of disposable

medical devices, hygienic, technical, and functional aspects must be taken into account,

besides economical, ethical, and legal implications. This study aims to characterize

percutaneous transluminal coronary angioplasty catheters and to evaluate performance

changes induced by reprocessing. Multiple testing, including crossing profile,

slipperiness, compliance and burst pressure tests, were performed at different steps of

the protocol on 21 catheters, reprocessed up to two times.

The study highlighted that both clinical use and reprocessing procedures can affect

angioplasty catheters characteristics. Mechanical stress induced on balloon materials by

inflation during clinical practice, and thermal and chemical stresses undergone by

polymers during cleaning and sterilization procedures caused modifications of materials

response, inducing an overall shrinking effect. However, compliance tests showed the

conformity of reprocessed balloons with manufacturers original specifications within

the 10% limit of acceptance. The measured burst pressure of reprocessed devices was

80% higher than the rated burst pressure recommended by manufacturers, thus

removing any concern of breakage during reuse. A strict dependence on device model in

catheters behaviour was found, specifically for balloons crossing profile and

slipperiness. Main changes occurred after the first reprocessing cycle, while a second

cleaning and sterilization did not introduce further alterations. On the whole, the

magnitude of modifications introduced up to two reprocessing cycles did not

compromise in-vitro catheters performance.

Keywords: single use medical devices; PTCA catheters; reuse; reprocessing;

functionality tests.

INTRODUCTION

The rapid development of minimally invasive procedure for diagnosis and

therapy had led to a considerable increase in the cost of medical equipment. Many

medical devices, and in particular devices for interventional cardiology, are nowadays

placed on the market as Single Use Devices (SUDs). However, reuse of SUDs is

common practice in USA and Canada under specific regulatory frameworks by the

Food and Drug Administration (FDA)1,2 and by the Conseil d’Évaluation des

Technologies de la Santé du Quebec (CETS)3 respectively. On the other side, there is a

paucity of European studies on the practicability of reprocessing procedures4 and the

European juridical approach is still quite heterogeneous.

Percutaneous transluminal coronary angioplasty (PTCA) catheters, with more

than one million coronary interventions performed annually worldwide, are an example

of medical devices labelled by manufacturers as SUDs, with significant financial burden

on health services.5,6 Such devices are used to reopen coronary vessels clogged by

atherosclerosis, in order to restore a proper blood flow to the cardiac muscle. Balloon-

tipped catheters are threaded through the skin into the artery to reach the vascular

stenosis and inflated to expand the diameter of the occluded vessel. Although safeness

and efficiency of reused angioplasty catheters is debated, the practice of their

reprocessing is actually of large extent in western countries.7-13

In order to assure the safety of restored devices, the conformity to the intended

use and the equivalence of performance between new and reprocessed devices, both

hygienic and technical requirements must be satisfied.14-17 Possible modifications of

catheter materials and functional properties, that might occur during decontamination

and cleaning procedures with chemical aggressive agents or during EtO sterilization,

must be carefully evaluated.18 In the case of balloon coronary catheters, crossing profile,

balloon compliance, crossability and burst pressure are the most critical parameters that

describe devices functional behaviour.19-21 The assessment of such parameters is

therefore mandatory to certify a qualified reprocessing protocol for angioplasty

catheters.

This work aims to evaluate the functional properties of PTCA restored catheters

and to compare them respect to new devices specifications. With this purpose a

multifaced analysis of performances was carried out on new and reprocessed devices by

using specifically developed instrumentation and testing set-up.

MATERIALS AND METHODS

PTCA catheters

Modern rapid-exchange angioplasty catheters consist of a proximal stainless steel

hypotube and a polymeric (Polyamide/Polyethylene) double-lumen distal portion,

usually covered with an hydrophilic coating,22 ending with a dilating balloon.

Compliant and semi-compliant polymers are employed to produce catheters with

different specifications, such as balloon size (length and nominal diameter), compliance

(diameter vs inflation pressure) and operative pressure. Polymeric guiding catheters and

radio-opaque guide-wires are employed during clinical use to support the advancement

of balloons up to the lesion.

In this study 21 rapid exchange PTCA catheters from different manufacturers,

with variable balloon size (2.0–3.5 mm) and balloon length (10-30 mm), have been

tested. Nine catheters (hereafter referred as “new”) were taken from the shelf in sterile

original packages and twelve devices were collected from the catheterization laboratory

of the Department of Cardiology at S.Chiara Hospital, Trento, after clinical use on

patient (hereafter referred as “used”). As reported in Table I, new and used devices were

grouped according to manufacturer and size features. Seven catheters were reprocessed

once before destructive bursting test, while 14 were reprocessed twice. On the whole, a

total amount of 56 complete testing cycles was carried out.

Reprocessing Protocol

The reprocessing protocol consisted basically of two main steps: preconditioning

(decontamination and cleaning) and sterilization. Catheters were decontaminated by

immersion in Perfektan Endo (3% in water, 15 min), and Instru Plus (5% in water, 15

min). The cleaning was achieved with a special machine that repeatedly injected

detergent and disinfectant solutions at 55°C on catheter lumens and external surface.

Specific chemical agents for thermosensitive instruments, effective against bacteria,

fungi and virus (including HBV and HIV) were employed. Devices were then rinsed

with purified water and, finally, with sterile water. When completely dry, catheters

external surface was cleaned with a gauze soaked in disinfectant solution. Balloons

were then folded with a three-blade folding-machine, covered with a cap of suitable

dimensions, and double-wrapped in standard sterilization packaging. Due to the

complex design of the products, to the presence of long narrow lumens, and to the

thermal sensitivity of polymeric materials, Ethylene Oxide (EtO) was adopted as

elective technique for the sterilization (180 min at 6% EtO concentration, 94% CO2,

42°C, 1.7 bar).

Functional Tests

Crossing Profile. Crossing profile, defined as the diameter of the smallest

aperture that a folded catheter can cross, was measured by means of a laser scan

micrometer (ODAC® 32xy, Zumbach Electronics). The distal portion of the catheter

was positioned on a straight, rigid guide-wire while two perpendicular laser beams

scanned the balloon for the whole length without direct touching. As originary crossing

profile of used balloons could not be assayed, this test was performed only on new

devices (groups A-C) before and after reprocessing. Every device was tested three

times, and the crossing profile was calculated as the mean of the maximum values

registered during each single measurement.

Slipperiness. The sliding behaviour of the catheter during clinical intervention is

influenced by the interaction of the catheter with coronary vessels, guiding catheter and

guide-wire. The quantification of the friction forces exerted by balloon catheters was

accomplished by means of a special coronary vessel model23. This model, realized in

accordance with anatomic considerations, simulated the structure of an healthy right

coronary vessel with a properly shaped polyethylene sleeve (1.5 mm internal diameter).

The coronary model, and associated models of aorta and arteria femoralis, were

constantly maintained in water at body temperature (T=37°C) in order to reproduce

physiologic conditions.

Rapid exchange catheters were mounted on a guide-wire (0.014”, BBraun,

Melsungen AG) fixed at the and of the artificial vessel, and inserted in a guiding

catheter (7FR JR4 100cm, Vista Brite tip®, Cordis) acting as support track. PTCA

catheters were then clamped at their proximal end, advanced for 65mm into the

coronary vessel model by a stepper motor at a speed of 8 mm/sec, and withdrawn at the

same speed. Every catheter was tested three times, with a rotation of 120° over the

guide-wire at every advancement. Force transducers based on strain-gauge technology

were positioned in four critical points of the coronary vessel model (Figure 1) to

evaluate respectively insertion forces, support forces on the tip of the guiding catheter,

wall reaction forces and friction forces exerted on the guide-wire. As for the crossing

profile, slipperiness was measured only on new catheters (groups A-C), comparing data

before and after reprocessing.

Compliance. The compliance curve (balloon diameter vs inflating pressure),

was measured by a laser scan micrometer (ODAC® 32xy, Zumbach Electronics), as

used in crossing profile evaluation. Catheters were filled with water by means of an

automatic inflator at a rate of 0.7 atm/sec up to the nominal pressure and maintained at

this pressure for 15 sec. Balloon material underwent a gradual dilatation, reaching

saturation after some seconds. According to this behaviou,r and considering the mean

clinical inflation time, the experimental working diameter was collected 7 seconds after

the achievement of nominal pressure (Figure 2). As consecutive inflation cycles up to

the nominal pressure induced creeping and plastic deformation of balloon polymers, the

limit-diameter reached at the third inflation was assumed as representative of the

nominal diameter.

Burst Pressure. Manufacturers provide as pressure operative limit value the

rated burst pressure (RBP), defined as the maximum statistically guaranteed pressure

withstood by 99.9% of an inflated balloon with a 95% confidence level. To verify the

absence of leakages and the resistance to high pressure, catheters were inflated ten times

up to the RBP. Balloons were then finally brought to rupture and the burst pressure (BP)

value was registered as the maximum inflating pressure reached before bursting.

Statistical Analysis. To compare products with different features, in particular

with different balloon size and RBP, data collected after one and two reprocessing

cycles were normalized to theoretical nominal values when reported on the packaging,

and to measured reference values otherwise. Thus, per cent values were obtained,

assessing the increase or decrease of the physical quantities respect to the values for

new devices.

Continuous data were presented as the mean ± standard deviation. Continuous

variables were analysed using Kruskal-Wallis and Mann-Whitney U-test. P values

<0.05 were considered statistically significant.

RESULTS

Crossing Profile. After one reprocessing cycle, catheters showed a mean

increase in crossing profile of 29±18%. Partial deterioration of balloon folding after

reconditioning was assessed, in particular for larger balloons (Table II), but the degree

of changes was different for the various groups of devices tested. After the second

complete cycle of cleaning and sterilization, the crossing profile did not increase

significantly further on (33±18%).

Slipperiness. Figure 3 reports the typical behaviour of the force intensities

registered by the four different sensors during advancement and withdrawal of the

catheter into the coronary vessel model. Insertion force (Figure 3a) represents the most

important sliding feature, as it characterizes the friction actually felt by the clinician

during catheter positioning and could be related to intervention duration and efficacy.8,13

Each device presents a typical slipperiness curve that carries information about tip

conformation, friction exerted by radio-opaque markers, and materials stiffness and

flexibility.

The maximum force intensities registered during catheter advancement into the

bending artery-model were extrapolated and selected as meaningful parameter. Figure 4

summarizes the results and compares data relative to the different device classes (A, B1,

B2 and C). The maximum intensity of insertion force required to advance the catheter

was generally smaller than 1N, but distinct catheters classes presented different

characteristic values. Changes induced on catheters slipperiness by reprocessing

procedures were also strictly model related. The most significant variations between

new and restored devices occurred after the first reprocessing cycle, with an appreciable

decrease of 21±4% for the group A, and a variable increase up to about 22% for the

other groups. After the second reprocessing cycle, there were no further significant

modifications in the maximum strain applied during catheter insertion.

Support forces exerted on the tip of the guiding catheter, wall reaction forces,

and friction forces exerted on the guide-wire presented a similar trend (Figure 3b-d),

with variable dependence on the class of products tested. Withdrawal forces generally

showed the same behaviour as the relative forces registered during catheters

advancement and are not reported here for sake of brevity.

Compliance. New devices always presented smaller diameters when compared

to nominal values (Figure 5), ranging from –2.3±1.6% to –5.2±1.0%. Used catheters

tested before reprocessing exhibited a greater compliance than the new ones

(+1.5±2.8% ÷ -1.3±2.3% ), probably due to repeated inflation cycles over the nominal

pressure, as commonly performed in clinical practice. Apart from this offset, the

nominal diameter of new and used catheters followed the same trend during

reconditioning. After cleaning procedure balloons diameter experienced a first decrease.

Catheters underwent a further appreciable shrink at the end of the first complete

reprocessing cycle, but they did never exceed original specification limits. Neither new,

nor used balloons changed significantly their diameter at nominal pressure after a

second reprocessing cycle.

Burst Pressure. Three out of 21 catheters underwent fractures in the Luer-Lock,

and couldn’t therefore be tested for burst pressure. The tightness of these products was

compromised either by cracks or leakages in the Luer-Lock.

All the other catheters tolerated repeated inflations up to the RBP without

pressure leakages. The mean pressure required to reach bursting for regenerated

balloons was always largely above the RBP limits recommended by the manufacturers.

On the average, the burst pressure after one and two reprocessing cycles was

respectively 81±21% and 77±32% higher compared to the RBP reference values (Figure

6). No significant differences in burst pressure values between new and used catheters

were registered. PTCA catheters always burst causing long longitudinal fractures on

balloon walls, as previously documented,19,20 but no pinhole ruptures were detected.

DISCUSSION

This study aimed at testing recent models of PTCA catheters currently in use in

clinical practice. Devices from many manufacturers and with different nominal

specification have been selected, thus to consider a wide spectrum of the current market,

even though the number of new catheters tested was limited by the cost of the devices.

Due to the shortage of information from manufacturers about technical characteristics of

original products, and about the exact composition of materials employed, a first

analysis of new catheters was necessary to get a reference baseline for subsequent

comparisons with used and reprocessed devices.

By testing the most crucial functional parameters of PTCA catheters at different

steps of the reprocessing protocol, we evidenced that both use and regeneration process

can affect catheters behaviour and introduce functional changes at different degree. On

the whole, devices functionality up to the second reprocessing cycle was however

preserved.

Balloons refolding represented one of the most critical parameters for quality

control of reconditioned devices. Once deflated, balloons were unlikely to regain the

original crossing profile. The attempt to lower crossing profile by covering the balloon

with a plastic cap of proper diameter during sterilization did not always succeed and

sometimes originated wrinkles in balloon wings. Anyway, higher crossing profile does

not necessarily mean lower catheter crossability or increased difficulty in catheter

positioning. As highlighted by the slipperiness measurements performed in the

coronary-vessel model, no direct correlation seem to exist between the friction forces

registered during catheters advancement/withdrawal and the diameter of folded

balloons. On the contrary, catheter sliding features proved to be model related, as

recently evidenced by Brown et al.19 In our study, force profiles seemed to be affected

by constructive characteristics, as flexibility of catheter shaft, tip conformation and

lubricious polymer properties, rather than by reprocessing procedures.

Inflation tests proved that semi-compliant polymers used for balloons

manufacturing, slowly adapted to pressure increase and a creeping effect of balloon

materials was registered. The compliance of used catheters showed to depend on the

total strain applied, that is to say, on the number and duration of inflations and on the

maximum pressure sustained during intervention. The need to dilate hard-calcified

atherosclerotic plaques during clinical use may lead to exceede the nominal pressure,

thus causing an overstretching of the balloon, with consequent loss of elasticity of the

polymeric material.

Cleaning and resterilization procedures could, on the other side, introduce

thermal and chemical stresses on materials,24 affecting balloons diameter. Compliance

tests documented an appreciable shrinking of balloons at the first reprocessing, that did

not increase significantly after a second cleaning and sterilization.

Several studies reported the effects of EtO on polymeric biomaterials.25

According to some authors, EtO could generate structural modifications by oxidizing

the polymeric chains.26 Despite this hypotheses, other studies found that repeated

exposure of polyethylene catheters to EtO had no significant effect on their mechanical

strength.27,28 Balloon materials shrinking reported in this work could be caused by

exceeding the glass transition temperature of balloon polymers during automatic

cleaning, or by chemical action of the agents employed in decontamination and

cleaning. Nevertheless, it is noteworthy to report that diameter variations induced by

reprocessing did never exceed the limit of variability given by manufacturers for new

products, (usually certified as 10% of the nominal values). On the average, a maximum

diameter decrease of 5.2±1.0% was reached after reprocessing. By these considerations

we want to underline that compliance tests, if performed regularly on each device, can

provide more precise information about the functionality of the single product, whether

new or reprocessed.

Bursting of both new and used balloons after one or two reprocessing cycles was

achieved at pressure values approximately 80% higher than the RBP certified by

manufacturers. The wide gap between experimental and nominal bursting pressure

seems to assure a large safety margin. Moreover, bursting pressure is a device specific

feature and seems not to be affected by multiple reprocessing. The presence of hard

calcified coronary plaques represents however a possible cause of damages on balloon

surface, that could not be tested in-vitro.

The leakages in the Luer-Lock that affected three devices, underlined the

weakness of this part of the catheter, and could be related to materials quality (intended

for single use only) or to the reprocessing technique.

A first inspection by means of conventional microscopy is fundamental to detect

leaks, kinks or lumen obstructions and to reject macroscopically damaged catheters

before starting reprocessing procedure.

Further clinical trials are required to relate in-vitro and in-vivo performance of

reprocessed catheters and to evaluate the possibility of clinical complications to take

place. The present study for the assessment of PTCA catheters performance was, in fact,

completely conducted in-vitro, thus providing a potential limitation. As reported in

some recent clinical study, there is however little evidence of increased risks related to

balloon catheters reprocessing. According to some authors, reuse strategy is in fact not

associated with increased procedure time or worsening of other procedural

variables.8,9,12,13

CONCLUSIONS

This study aimed to assess PTCA catheters performance before and after

reconditioning. Testing performed during this trial on angioplasty catheters succeeded

in characterizing both new and reprocessed devices. Crossing profile, slipperiness,

compliance and burst pressure proved to be relevant parameters to describe functional

properties of balloon catheters.

Devices response to reprocessing showed to be highly related to the model of

catheter tested. This result supports the statement that, for safe reusing, each product

should undergo individual evaluations to establish the conformity of restored devices

with nominal performance. A reprocessing facility, whether represented by hospital or

third-party reprocessor, should thus hold suitable laboratories to validate regeneration

procedures and to perform methodically adequate and up-to-date testing and quality

controls.

Nevertheless, further clinical trials need to be carried out in order to assess the

degree of importance of the functional changes induced by use and reprocessing, and to

establish whether catheter modifications could negatively affect clinical practice in

terms of procedure time or adverse clinical events.

Acknoledgments

This work was supported by SICC-SIX Project financed by Fondo Unico per la Ricerca

2001, Provincia Autonoma di Trento.

The authors would like to acknowledge the staff of the Hemodynamics Laboratory at

the S. Chiara Hospital, Trento, for catheters retreival.

Running Heads: Functional properties of reprocessed PTCA catheters

REFERENCES

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single-use devices. Updated November 1, 1999. Available at

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13. Browne KF, Maldonaldo R, Telatnik M, Vlietstra RE, Brenner AS. Initial

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coronary angioplasty equipement: technical and clinical issues. Editorial. Am

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Medical Products. Hygienic requirements for processing of medical devices.

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FIGURE CAPTIONS

Figure 1.

Simplified schematic representation of the coronary-vessel set-up for the quantification

of catheters slipperiness. The geometrical structure of the coronary-vessel model

simulated the anatomy of an healthy right coronary branch. The four sensors positioned

along the path of the PTCA catheter measured, respectively, the force exerted during

catheter advancement/withdrawal (A), the support force on the tip of the guiding

catheter (B), the reaction force of the coronary-model wall (C), and the friction force on

the guide-wire (D).

Figure 2.

Balloon inflation protocol (lower panel) and typical compliance curve (upper panel).

Catheters were inflated at 0.7 atm/sec up to the nominal pressure and maintained at this

pressure for 15 sec. Subseqent inflating cycles showed shift in compliance curve;

according to this behaviour, experimental diameter values were collected at the third

inflation cycle, 7 sec after the achievement of nominal pressure.

Figure 3.

Forces exerted during advancement (0-65 mm) and withdrawal (65-130 mm) of the

PTCA catheter in the coronary vessel model. As depicted in Figure 1: (a) insertion

forces, (b) support forces on the tip of the guiding catheter, (c) wall reaction forces and

(d) friction forces exerted on the guide-wire. Arrows indicate the maximum values

registered by each sensor, that are summarized in Figure 4.

Figure 4.

Comparison among maximum forces intensity of new and reprocessed catheters for

groups A, B1, B2 and C (Tab 1). Data were measured during catheter advancement in

the coronary-vessel model: (a) insertion force, (b) support force on the tip of the guiding

catheter, (c) wall reaction force, (d) friction force exerted on the guide-wire.

Reprocessing did not seem to critically affect catheters sliding behaviour, but

slipperiness properties show to be highly dependent on device classes.

Figure 5.

Effects of cleaning and reprocessing on balloon working diameter. Experimental

diameters were normalized to the nominal specifications. Data refer to new devices (a),

and to products used once on patients (b). Both new and used catheters underwent a

progressive shrinking, but working diameter changes were always below the 10% error

bar certified by manufacturers.

Figure 6.

Mean burst pressure (BP) of balloon catheters subjected respectively to one and two

reprocessing cycles. Data are normalized to the rated burst pressure (RBP) values

provided by manufacturers. Reprocessing seems not to affect bursting pressure, as the

breaking point value did not change significantly from first to second cycle and was

always markedly higher than the nominal value.

Figure 1.

Figure 2.

2,5

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Figure 3.

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-1,0

-0,5

0,0

0,5

1,0


F (N

)

-0,8

-0,4

0,0

0,4

0,8


F (N

)

-0,3

-0,2

-0,1

0,0

0,1

0,2


F (N

)

-0,4

-0,2

0,0

0,2

0,4


F (N

)

Figure 4.

(a) (b)

(c) (d)

0,0

0,2

0,4

0,6

0,8

1,0

New 1 Reprocessing 2 Reprocessings

|F| (

N)

0,0

0,2

0,4

0,6

0,8


|F| (

N)

0,0

0,1

0,2

0,3


|F| (

N)

0,0

0,1

0,2

0,3

0,4


|F| (

N)

A B1 B2 C

(a) (b)

(c) (d)

0,0

0,2

0,4

0,6

0,8

1,0


|F| (

N)

0,0

0,2

0,4

0,6

0,8


|F| (

N)

0,0

0,1

0,2

0,3


|F| (

N)

0,0

0,1

0,2

0,3

0,4


|F| (

N)

A B1 B2 C

(a)

(b)

D = experimental working diameter

ND = nominal diameter

Figure 5.

-8

-6

-4

-2

0

New 1 Cleaning 1 Reprocessing 2 Reprocessings

(D-N

D)/N

D %

-4

-2

0

2

4

6

First use 1 Cleaning 1 Reprocessing 2 Reprocessings

(D-N

D)/N

D %

BP = Burst Pressure

RBP = Rated Burst Pressure

Figure 6.

76,6 %81,5 %

0

20

40

60

80

100

120

1 Reprocessing 2 Reprocessings

((BP-

RB

P)/R

BP)

%

TABLE I. Catheter Models and Nominal Specifications.

n = number of products tested.

ND = Nominal Diameter

L = Balloon Length

NP = Nominal Pressure

RBP = Rated Burst Pressure.

Catheters were divided in two main groups, including new products taken from the shelf

and products used once on patient. The devices were sub-grouped according to

manufacturer (A-F) and ballon size (1-3).

New catheters

Group (n) Article Manufacturer ND (mm)

L (mm)

NP (atm)

RBP (atm)

A (n=4) Amadeus® EuroCOR GmbH 3.5 20 6 16

B1 (n=2) Adanté™ Boston Scientific 3.0 30 6 14

B2 (n=2) Adanté™ Boston Scientific 2.5 20 6 14

C (n=1) U-Pass™ Cordis J&J 2.75 10 6 14

Used catheters

Group (n) Article Manufacturer ND (mm)

L (mm)

NP (atm)

RBP (atm)

D1 (n=3) Maverick2TM Boston Scientific 2.0 20 6 12

D2 (n=2) Maverick2TM Boston Scientific 2.5 20 6 14

E1 (n=2) AquaT3TM Cordis J&J 2.0 20 8 14



F1 (n=1) Avion Invatec 2.0 20 7(bar) 15(bar)

F2 (n=1) Avion Invatec 2.5 20 7(bar) 17(bar)

TABLE II. Crossing Profile of New and Reprocessed Devices.

Group New (mm)

1 Reprocessing (mm)

2 Reprocessings (mm)

A 1.02±0.05 1.50±0.02* 1.57±0.10*

B1 0.99±0.05 1.02±0.01 1.16±0.05

B2 1.07±0.01 1.44±0.12 1.37±0.01*

C 0.94±0.01 1.24±0.02* 1.25±0.01*

* P<0.05 vs new balloon (U-test)

Crossing profile of PTCA catheters reprocessed once and twice, compared to new

devices. P values <0.05 were considered statistically significant.

Running Heads:

Functional properties of new and reprocessed PTCA catheters.

Functional properties and performance of new and reprocessed coronary angioplasty balloon catheters

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