Note: Descriptions are shown in the official language in which they were submitted.
1 15772~
This is a division of our co-pending Canadian Patent Applica-
tion No. 326,236 filed April 24, 1979.
This application relates to a combination of a guiding catheter
assembly and a dilating catheter assembly.
As disclosed in the following three references:
1. Gruntzig, A.: Die perkutane transluminale
Rekanalisation chronischer
Arterienverschlusse mit
einer neuen Dilationstechnik;
p. 50. Baden-Baden, 1977.
2. Gruntzig, A., H.H. Riedhammer, M. Turina,
~utishauer W. Verh. Dtsch.
Ges. Kreislaufforschg. 1976,
42 282.
3. Gruntzig, A., R. Myler, E. Hanna, Turina
M. Abstracts Circulation.
1977 56 84.
a technique has been developed for percutaneous transluminal coronary
angioplasty. This technique consists of a catheter system introduced
via the femoral artery under local anesthesia. A preshaped guiding
catheter is positioned into the orifice of the coronary artery and
through this catheter a second dilation catheter is advanced into the
branches of the coronary artery. The dilation catheter has an elliptical-
shaped distensible balloon portion near the tip which can be inflated and
deflated. After traYersing the stenotic lesion of the coronary artery,
the distensible portion is inflated with fluid which compresses the
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._i
~ 15772~
atherosclerotic material in a direction generally perpendicular to
the wall of the vessel thereby dilating the lumen of the vessel.
Peripheral arterial lesions treated by this technique have
demonstrated by morphological studies that the atheroma can be
compressed leaving a smooth luminal surface noted at the time of
restudy. The patency rate two years following dilation of iliac
and femoropopliteal atherosclerotic lesions was greater than 70~.
The continued success of this techni~ue could greatly widen the
horizons for coronary angiography and provide another treatment
for patients with angina pectoris.
The guiding and dilating catheters utilized by Gruntzig
in his work have been more or less hand made. They have been
difficult and expensive to fabricate and for that reason it has
been very difficult to obtain an adequate supply of the same.
There is therefore a need for a new and improved guiding and
dilation catheters and methods for making the same.
Summary of the Invention
To perform coronary percutaneous transluminal angioplasty,
vascular guiding and dilating catheters must be provided. The
present invention is directed to a combination of a guiding
catheter assembly and dilating catheter assembly.
The in~ention pro~ides in a combination of a guiding
catheter as~embly and a dilating catheter assembly, the guiding
catheter assembly comprising a first flexible tubular member formed
of a material which has a low coefficient of friction, a second
flexible tu~ular member encasing said first tubular member so that
the first tubular mem~er fits tightly in the second tubular member,
said combined first and second tubular members having proximal and
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1 157728
distal ends and a fitting mounted on the proximal end, the dilating
catheter assembly comprising a flexible tubular member, said
tubular member of said dilating catheter assembly having proximal
and distal ends and an inflatable annular portion formed integral
with the tubular member of ~aid dilating catheter assembly near the
distal end thereof, a fitting mounted on the proximal end of the
tubular member of the dilating catheter assembly, said dilating
catheter assembly being disposed within said guiding catheter
assembly and means for inflating and deflating said inflatable
annular portion.
The guiding catheter assembly has a very low coefficient
of friction so that the dilating catheter assembly can be readily
inserted into the same, and should have sufficient rigidity so that
it can be readily manoeuvered.
The dilating catheter assembly is preferably such that
the balloon can be readily and reliably formed.
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The dilating catheter assembly may be formed of an irradiated modified
polyolefin tubing, and may have inner and outer coaxial tubular members in which
a distal pressure seal is formed between the inner and outer t~bular members
solely by heating the outer tubular member.
Additional features of the invention will appear from the following
description in which the preferred embodiments are set forth in detail in con-
junction with the accompanying drawings.
Brief Description of the Drawings
Figure 1 is a perspective view of a dilator, a guiding catheter
assembly, a dilating catheter assembly and a balloon flushing tube and showing
the manner in which they are used with respect to each other and incorporated
into assemblies for performing coronary percutaneous transluminal angioplasty.
Figure 2 is a cross-sectional view taken along the line 2-2 of the
guiding catheter assembly.
Figure 3 is a cross-sectional view taken along the line 3-3 of the
dilating catheter assembly.
Figure 4 is a cross-sectional view taken along the line 4-4 of the
dilating catheter assembly.
Figure 5 is a cross-sectional view taken along the line 5-5 of Figure
4-
Figures 6A and 6B are taken along the line 6-6 of Figure 5 and show
the balloon in inflated and deflated conditions respectively.
Figures 7A, 7B, 7~ and 7D illustrate the steps utilized in one method
for forming the balloon from the irradiated modified polyolefin tubing utilized
for the dilating catheter assembly.
Figures 8A and 8B illustrate the steps in another method utilized for
forming the balloon on the outer catheter of the dilating catheter assembly.
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~ ~57728
Figures 9~ and 9B show the seeps utilized in the
method for forming the inner catheter of the dilating catheter
assembly.
Figures l~A and 10~ show the steps in the method of
inserting the inner tubular member into the outer tubular
member having a balloon formed therein and shrinking the
distal end of the outer tubular member onto the distal end of
the inner tubular member to provide an air-tight adhesi~e-free
seal and providing a flow passage through which fluid can be
introduced into the balloon for inflating the same and
withdrawing it from the balloon for deflating the same.
Description of the Preferred Em~odiments
The guiding catheter assembly 21 shown in Figure 1
consists of first and second coaxial tubular members 22 and
23. The first tubular member is formed of a material which has
an extremely low coefficient of friction as for example TFE
Teflon ITM) ~a tetrafluoroethylene polymer) having a
coefficient of friction of spproximately .02. For the
material for the first tubular member, the coefficient of
friction can range from a8 low a value as possible to .05. ~t
iS al50 desirable that the material utilized for the first
tubular member have a certain amount of flexibility. The
first tubular member has a guiding passageway 24 having ~n
internal diameter of approximately .094 of an inch. It also
can have a ~uitable wall thickness preferably in the vicinity
of .OOB of an inch. ~owever, these dimensions can vary within
the range of approximately +15~ and still be satisfactory.
- Although TFE Teflon (~M~ ~tilized for the first
tubular member was very desirable because it had a very low
coefficient of friction, it was found, however, that it was
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~ 1S7728
too flexible ~o ~erve ag a guldinq catheter because it could
not be properly manipulated in the body of the patient. It ~8
for this reason that the second ~u~ular member 23 i8 provided.
This second tubul~r ~ember is formed of a heat-shrinkable
ir,r~diated modified polyolefin such as RNF-100 type 2 supplied
by Raychem Corporation of Menlo Par~, California. The heat
~hrinkable tubing selected hsd an internal diameter of .120 of
an inch which was of a sufficient size so that the first
tubular member could be readlly inserted into the same. The
secona tubular member of, the assembled first and second
tubular members 22 and 23 was then progressively heated along
its length in a suitable manner such as by a hot air tool to a
suitable temperature as for example 120C to cause the second
or outer tubular member 23 to shrink in 8 manner well known to
those skilled in the art so that it forms a skin-ti~ht fit with
respect to the first tubular member 22. Alternatively this
can be accomplished by passinq the assembled f$rst and second
tubu}ar members throu~h a cylindrical heating unit to cause
progressive heating of the second tubular member.
The assembly i8 provided with proximal and distal
ends 25 and 26. The distal end i8 provided with bends to form
a shape identical to the standard coronary catheter. A left
coronary guiding catheter is formed by providing two bends 27
and 28 of approximately 12S-l~Ob (proximal) and 60-90
(distal1 each in the same direction to provide the bends which
are shown in Pigure 1 for a left coronary artery. As soon as
the bends 27 and 28 have been formed, the distal end can be cut
off to the desired length and tbereafter, the distal end can
be sanded or smoothed in a suitable manner. An annular recess
30 is formed on the extreme distal end of the tubular member
1 1$7728
23. For a right coronary guiding catheter a single bend 29 as
shown ~y the broken lines in ~igure 1 can be provided.
An a~tachment or fitting 31 ls secured to the
proximal end of the first and second tubular member in a
suitable manner. The attachment or fitting 31 i8 in the form
of a female Luer fitting or attachment having a metal
cylindrical extension 32 on which there is crimped a metal
band 33. The first or inner tubular member 22 is inserted into
the cylindrical extension 32 and the second or outer tubular
mem~er 23 is slipped over the cylindrical extension 32 and the
band 33. A sleeve 34 also formed of a similar heat-shrinkable
tubing is thereafter slid over the outer or second tubutar
member 23 and the ~itting 31. The sleeve 34 is then heated to
a suitable temperature as for example 120~C to cause it to
1~ shrink over the fitting 31 and also over the proximal end of
the first and second tubular members 22 and 23 to form an
excellent leakproof adhesive-free connection between the
parts.
The material which is utilized for the second
tubular member 23 has a substantially higher coefficient of
friction than the material utilized for the first tubular
member 22. ~owever, this is not objectionable since the
second tubular member will be inserted into the blood vessel
over a wire in a s~andasd percutaneous technique and thus will
be lubricated by the blood in the vessel. The use of the
guiding catheter assem~ly will be described in conjunction
with the dilating catheter assem~ly hereinafter described.
The guiding catheter assembly 21 has a suitable
length which is tailored to the purpose for which it is used.
3D As for example, when utilizing the same for doing coronary
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~ ~57728
percutaneous transluminal anqioplasty on adults, a length of
95-110 cm. is utilized.
The dilating catheter assembly 36 as shown in Figure
1, consists of first and second tubular members 37 and 38. The
first and second tubular members 3~ and 38 are formed of heat-
shrinkable tubing of the type hereinbefore described
manufactured by ~aychem Corporation of Menlo Park, California.
The first tubular member 37 is provided with a flow passage 39
extending the length of the same. The first tubular member 37
~s coaxially disposed within the second tubular member in such
a manner so that the second tubular member surrounds the first
tubular member. The combined first and second tubular members
37 and 38 have a proximal end 41 and a distal end 42. The
second tubular member 38 has formed therein a balloon-like
lS portion near the distal end 42 of the first and second tubular
members 37 and 3B. An annular flow passage 44 is formed
between the second tubular member 38 and extends from the
proximal end into the balloon-like portion 4~ ~o permit the
introduction of fluid into the balloon-like portion 43 for
inflating the ~alloon-like portion and for withdrawing fluid
from the same for deflating the balloon-like portion.
The method by which the assembly consisting of the
first and second tubular members 37 and 38 with the balloon-
like portion 43 and the passages 39 and 44 formed therein can
be seen by reference to Fi~ures 7A through 7D. The second
tubular member 38 has an initial inside diameter of 0.065
inches and an initial outside diameter of 0.085 inches. As is
well known to those skilled in the art, the manufacture of
heat-shrinkable tubing is accomplished by extruding a modified
polyolefin to a predetermined size and utilizing high energy
1 157728
ionizing radiation to cause cross-linking of the polymer
cha~ns to occur. Thereafter, the tub~ng ~g expanded to a
suitable ratio such as 2:1. A mandrel 46 in the form of a
Teflon tube is inserted into the tubular member 38 as shown in
S Figure 7A. The member 38 is then progressively heated as
~hown in Figure 7B to shrink the member 38 down onto the
mandrel 46 so that it has an inside diameter of approximately
.0~8 inches and an outside diameter of .072 inches with a wall
thickness of .0~7 inches. The steps shown in ~igures 7A and 7B
are only carried out to provide a tubular member 38 of the
desired size. Alternatively this can be accomplished by
producin~ initially a heat-shrinkable tubing of the desired
size. The mandrel 46 is withdrawn to the position shown in
Figure 7C and another mandrel 47 in the form of a Teflon tube
having an outside diameter of .054 inches is placed in the
distal end 42. The mandrel 46 extends substantially the
entire length of the second tubular member 38 which can have a
suitable length ranging from lOS to 120 cm. The mandrel 47 is
spaced from mandrel 46 to provide a space 49 through which the
ballon-like portion 43 is to be formed. The other mandrel 47
serves as a support for supporting the distal end of the
second tubular member 38. ~he second tubular member 3B is
then heated to a suitable temperature as for example 120~.
in the vicinity of the ends of the mandrels 46 and 47 facing
2~ the space 49 to shrink those portions of the second tubular
member 33 onto the mandrels 46 and 47 to form air-tight seals.
The portion of the mem~er 38 encircling the space 49 is then
heated until the material reaches a temperature beyond its
crystalline melting point. With the mandrel 46 clamped shut
at its proximal end, fluid under pressure is introduced by
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1 157728
æuita~le means such as a syring~ (no~ shown) through the
passage 51 into the space 49 in the tubular member 38 to cause
the tubular member to expand to form the ballcon-like portion
43 as shown in Figure 7D. By way of example, air under
S pressure of 4 to 5 p.s.i. was utilized to form the balloon-
like portion 43. Other fluids can be utilized if desired.
The balloon-like portion 43 is formed by expanding
that portion of the tubing 38 surrounding the space 49 to its
elastic limit which generally corresponds to a ratio of 4 or 5
to 1 from the original extruded irradiated tubing size prior
to the initial expansion.
The balloon-like portion 43 thus formed preferably
has dimensions ranging in length from approximately 1 to 2
centimeters and an outside diameter ranging from .120 to .140
inches and a wall thickness ranging from .002 to .004 inches.
Alternatively the ~alloon-like portion 43 can be
formed as shown in Figures 8A and 8~. As shown therein, the
mandrel 46 can be removed and amother mandrel S3 having holes
54 inserted into the distal end. Heat is then applied to the
tubular member on opposite ends of ~he holes 54 to shrink the
tu~ular member 38 so that it forms air-tight seals with the
mandrel 38. The proximal end of the member 38 is clamped and
air is introduced into the distal end after the member 38 has
been heated in the vicinity of the holes to a temperature
beyond the crysta71~ne metting point and a balloon-like
portion 43 is formed in the manner hereinbefore desrribed.
Thereafter, the mandrel 53 can be removed.
The balloon-like portion is permitted to cool to
room temperat~re while the pressure is maintained in the
balloon so that the temperature of the material falls below
g
1 157728
its crystal~ine melting point to thereby retain a sem~-
permanent balloon-like port~on 43 within the second tubular
member adjacent the di~tal end thereof. After the balloon-
like portion has been suff~c~ently cooled, the Teflon (~M)
mandrel~ 46 and 47 are removed to provide a aecond or outer
shèath.
The first or inner tubular member 37 ~s formed by
taking a tube of heat-~hrinkable tubing of the type
hereinbefore described having an outside diameter of 0.~5 and
1~ having an inside diameter .~30 having a su~tab~e length as for
example approximately 110 cm. and placing within the same a
Teflon (TM) coated ~uide wire ~or ~ Teflon lTMl mandrel) 56
having ~n outside diameter of 0.021 inches as shown in Figure
9A. The fir~t tubular member 37 with the guide wire 56 therein
lS which serves as a mandrel i~ heated to a suitable temperature
as for example 125C. and Qtretched to cause the first tubular
memb~er 37 to ~hr~nk down onto the guide w~re 56 as ~hown in
Figure SB.
The assembly which is shown in Figure 9B is then
taken and inserted into the outer sheath or tubular member 38
which is shown in Figure lOA. It extends beyond both ends of
the outer ~heath and passes through the balloon portion 43.
The balloon-like portion 43 ~s tben c~vered with a cover ~9 of
a suitable type ~uch as aluminum foi} for protecting the
balloon~ e portion 43 from heat. Thereafter, the portion of
the second tubular member 38 from the ba~loon-like portion 43
to the distal end i~ heated to a ~uitable temperature as for
example 12~C. to cause the outer tubular member 38 to chrink
tightly onto the first tubular member 37 wlth the Teflon (TN)
guide wire or mandrel ~6 therein to provide a fluid tight
adhesive-free seal between the first and second tubular
~ember~ 37 and 3B. After the material has cooled, the mandrel
5~ is removed
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157728
to provide the construction bereinbefore described that is, a
first tubu~ar member 37 with a flow passage 39 tberein and a
second tubular member 38 coaxial with tubular member 37 with
an annular flow passage 44 there$n extending from the proximal
S end into the balloon portion 43.
The proximal ends of the first and second tubular
members 37 and 38 as shown in Figure 3 are inserted into an
adapter body 66. The body 66 is formed of a suitable material
such as metal and is provided with a cen~ral~y disposed bore
67 which opens through a female Luer type fitting 68. The
adapter body 66 is also provided with a threaded cylindrical
projection 69 and a ~enerally conical portion 72 which
pro~ects beyond the threaded projection 69. The adapter body
66 is provided with a side arm 76 which is provided with a
cylindrical bore 77 that extends into the bore 67 at a
suitable angle as for example an angle of approximately 30.
A well 78 is formed in the side arm 76 and is provided with an
internally threaded portion 79 and a conical-shaped recess 81.
As shown particularly in Figure 3, the first or inner tubular
2~ member 37 is placed in contact with a fitting 86. ~he fitting
86 is provided with a cylindrical bore 87. As can be seen, the
fitting 86 is in the form of a conventional female-type Luer
fitting. The fittin~ 86 is provided with a threaded project-
ion ~8 which engages the internal threads 79. It is also
2~ provided with a conical projection 89 which is adapted to seat
against the conical recess 81.
In the construction shown in Figure 3, the inner
tubular member 37 is brouyht into en~agement with the inner
end of a conical bore 91 provided in the threaded portion 88
3~ and the conical portion 8g of the fitting 86 and is thus in
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1 157728
communication with the cylindrical bore 87. Suitable means is
provided for maintaining the flow passage 39 in tbe first
tubular member 3~ in communlcstion with the conical bore 91
and consists of a heat-shrinkable tubular member 92 which is
secured to the proximal end of the first tubular member 37.
Member 92 is provided for the purpose of reinforcing the
proximal end of the tubular member 37. ~nother heat-
shrinkab~e tubular member 93 which has a flared outer end is
shrunk onto the tubular member 92 snd is fitted onto the
conical projection 89 and is firmly held in place by threading
of the fitting B6 into the side arm 76.
A heat shrinkable tubular member 96 having a flared
outer end is secured to the proximal end of the second tubular
member 38. The flared outer end of the tubular member 96 is
1~ then positioned over the conical portion 72 of the adapter
body 66 and is held in place by a collar 97 which is provided
with a well 98 havitng an internally threaded portion 99 and a
conical recess 101 against which the conical projection 72 is
adapted to seat to firmly grip the flared portion of the
tubular member 96.
First and second syringes 106 and 107 are adapted to
be placed in the fittings 8~ and 68 as shown particularly in
~igure 1. The syringes 1~6 and 107 are of a conventional type
and therefore will not be descri~ed in detai~.
2S After the fittings hereinbefore described have been
provided on the proximal end of the first and second tubular
members 37 and 38, the distal end can be cut to the proper
length and then ground to provide a smooth tapered distal end.
The balloon flushing tube 111 which is also shown in
3~ Figure 1 consists of 8 long tubular member 112 formed of a
~ 157728
suitable mater$al such as ~tainlesssteel ln lenqth 36 to ~0
inches. By way of an e~ample, it can have an outside diameter
of .020 inch and an internal diameter of 0.10 ~nch. The tubing
112 has ~ts proximal end connected to a conventional female
Luer-type fitting 113 formed of a suitable ~aterial such as
aluminum. The tubular member 112 can be secured to the
fitting 113 by soldering or by a crimp fit.
A dilator 116 which ig ~hown in Figure 1 is of a
conventional type and conQists of a flexible tube 117 formed
of plastic and having a tapered distal end 118 having an
out~ide diameter of .030 inches and an inside d~ameter of .04~
inches. A female Luer-type fitting 119 iB secured to the
proximal end o~ the tube 117. A flexible Teflon (TM) coated
1~ guide wire 121 of a conventional type with an outside diameter
of .038 inche5 i8 adapted to ~e inserted through the dilator
116 as shown.
Use of the guiding catheter 21, the dilating
catheter 36 and the balloon flushing tube 111 can now be
briefly described as follows. Let ~t be assumed that it i8
desired to utilize these devices with a middle-aged patient
who has been identified as having a significant narrowing in
one of the coronary arteries as for example the left anterior
descend~ng coronary artery, i.e. the proximal portion of that
vessel for wh~ch a coronary transluminsl dilation is
considered advicable.
The patient iB brought into a ster~le environment
8na i5 prepared by steriliz~ng one of the groins. In
preparation for operating ~pon the patient, the dilating
catheter assembly 36 is checked. Normally, the d~lating
catheter assembly 36 would be suppl~ed with the balloon
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~ lS7728
flushing tube 111 in place. However if this i~ not the ca~e,
the balloon flushing tube 111 can be inserted through the
passage 44 until it enters into the balloon 43. A syringe (not
shown) filled with a radiographic contragt liquid inserted into
the fitting 113 and the fluid i~ introduced into the balloon 43
to fili the balloon at the same time to flush out any ~ir
bubbleY which may exist $n the balloon or in the passage or
lumen 44 leading to and from the t~lloon. The balloon flushing
tube 111 can then be removed and as ~oon ~s it is removed, a
syringe 107 is placed in the fitting 68 and is filled with a
radiographic con~tra~t liguid. The operations thus far
described have taken place outside the body of the patient.
Before inserting the dilating catheter a~sembly 36 into the
body, ~he inflation and deflation of the balloon 43 can be
readily checked merely ~y operating the syringe 107. A
conventional pressure gauge and pressure regulator 115 are
provided sssociated with the syringe 107 so that one can
ascertain and limit the pres~ure being applied to the b~lloon
43 to approximately 45 to ~0 psi.
When this has been ac~omplished the gulding catheter
21 can be inserted into the p~tient in a standard percutaneous
technigue. The guiding catheter 21 h~s been designed ~o that
$t can enter into one of either the right or left femoral
arterie~. In such a technique, a needle is inserted into the
femoral artery and the Teflon ~TM) covered guide wire ~21 i~
inserted through the needle and through the femoral artery into
the aorta. The m~vement of the guide wire and positioning
thereof is observed with conventional fluoro~copic technigues.
~t is posit~oned 80 thst its tip i~ generally at the level of
the diaphragm of the patient whiCh
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~ 157728
is essentially half way up the aorta. The dilator 116 i8
positioned in the guiding catheter assembly 21 BO that the
flexible tapered tip 118 projects fr the distal end of the
; quiding catheter assembly 21.
The distal end of the guiding catheter as~embly 21
.
is then straightened out and the dilator ~nd the guiding
catheter 21 are passed over the guide wire which is already in
place and is then introduced into the femoral artery. The
guiding catheter is then passed up along the g~ide wire using
the guide wire as a guide to the descending aorta or arch of
the aorta. During the time that the guiding catheter assembly
is being inserted, the operatlon is under continuous
fluoroscopic control. ~he dilator carriea by the end of the
guiding catheter assembly is radiopaque and therefore can be
easily visualized radiographically. ~he guiding catheter is
inserted until the distal end of the catheter is at the
desired point which will generally be in the ascending portion
of the sorta several centimeters from the coronary artery
ostium. As soon as the guiding catheter assembly has reached
this position, the guide wire and the dilator can be removed
from the guiding catheter and the guidin~ catheter will be
aspirated to remove any debr~s then flushed with radiopaque
contrast medium. ~hereafter, the catheter can be flushed with
a saline solution or contrast medium.
As soon as entry ~nto the blood vessel has been
accomplished as hereinbefore aescribed with the guiding
catheter assembly 21, the patient can ~e glven intravenous
heparin in a stan~ard ~ose to act as sn anticoagulant and to
prevent any abnormal thrombosis or blood clot formation on the
catheter or ~n the areas of catheter entry. ~he yuidiny
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1 157728
catheter assembly 21 can then be filled with a radiographic
contrast material such as ~enoqraphin 76 and the catheter c~n
be advanced until it engages into the left main coronary
ostium which is the artery to be utilized. The positioning of
the guiding catheter can be confirmed by one ~r more
injections of the contrast$ng liquid into the coronary vessel
in which fluoroscopic observations are taking place.
As soon as ~t has been ascertained that the guiding
catheter assembly 21 has been properly positioned in the
1~ coronary ostium, the dilating catheter assembly 36 can be
inserted. To insert the dilating catheter, the balloon 43 is
completely deflated as shown in Figure 6B. When it is
deflated, it may assume the position shown by broken lines in
Figure 6B so that the dilating catheter assembly 36 can be
readily inserted into the guiding catheter assembly 21. As
hereinbefore explained, since the guiding catheter assembly 21
is formed of a first tubular member which is formed of a
material having a low coefficient of friction, it is possible
to push the dilating catheter assembly 36 through the entire
length of the guiding catheter assembly 21 so that it will
protrude out of the distal tip of the guiding catheter
assembly by suitable distance such as S or 6 cm. and protrude
into the left main coronary orifice.
Initia1ly the balloon 43 is positioned in one of the
closest portions of the vessel the aorta and then gradually
under fluoroscopic control i6 advanced to the point where the
narrowing has been previously documented to exist. The
balloon is then appropriately positioned in the narrowed
portion.
Atthough it should be possible in al} cases to be
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~ 1~7728
able to insert the dilat~ng catheter 36 into the guiding
catheter assembly without the help of a guide wire, a small
guide wire can be utilized if deslred. If such is the case, a
small guide wire can be inserted through the sidearm 76 and
through the first tubular member 37 so it extends ~ust to the
distal portion of the dilating catheter assemb}y 36 or
slightly beyond it. If such guide wire is utilized, after the
dilating catheter assembly 36 is ~n position, the small guide
wire can be removed and the syringe 106 having a radiographic
}~ contrast li~uid therein can be mounted on the side arm 76 and
small injections of the contrasting liguid can be introduced
into the first inner tubular member 37 through the passage 39
to document the position of the distal end of the dilating
catheter assembly 36. lf desired, the guide wire can be
reinserted at any time to be used as an aid in guiding the
dilating catheter into the vessel that has previously
demonstrated that it is subject to a stenosis or narrowing.
As soon as it has been established that the balloon 43 has been
positioned within the stenosis, pressure can be applied ~y the
use of the hand syringe 107 to inflate the balloon to a
suitable pressure as for example from 3 to 5 atmospheres. The
inflation of the balloon can be visualized radiographically
~ecause the balloon is filled with a radiographic contrast
liquid. By way of example, the balloon would be inflated for a
period ranging from 2 to S seconds and then deflated rapidly
and removed from the stenosis at which time a second coronary
contrast injection can be made either through the guiding
catheter itself or through the passage 39 of the inner
catheter 37.
3~ As far as can be ascertained, the inflation of the
~ lS7728
balloon causes dilation of ~he materia~ deposited in the wall
of the vessel by càusing elonqation of the mater~al along the
wall and compressing of the material against the wall so that
the end result ls an lncreased blood vessel lumen ~ize with
S increased blood flow to provide an improved o~ygen delivery to
the jeopardized portion of the heart muscle or ~yocardium.
The procedure can be repeated as many times as
deemed necessary either on the same site or at a stenosis or
narrowing in a ~econd vessel. As soon as the necessary
dilations have been completed, the dilating catheter assembly
36 can be removed. Thereafter, the guidinq catheter assembly
21 can be removed merely by pulling it out of the femoral
artery. As soon as the quiding catheter has been removed, the
groin ~s held firmly to prevent any bleeding until clotting
has been accomplished. The patient csn then be returned to
his room and instructed to remain at bed rest with the legs
straight and flat for approximately ~ix hours after which
normal routine activ~ty can be undertaken by the patient.
~t should be appreciated that if desired, a dilating
2~ catheter assembly 36 can be provided which only utilizes a
single tubular member w~th a balloon near its distal end.
When this is the case, the f$rst tubular member 37 can be
omitted, and the tubular member which is utilized can be
shrunk down to the final desired size onto mandrels prior to
formation of the ballcon portion.
It is apparent from the foregoing that there has
been provided a vascular dilating catheter and an assembly
thereof and method for making the same which-ma~es it poss~ble
to fabricate the same utilizing quantity production
techniques. The construction of the guiding catheter assembly
- 18 -
1 1~772~
and the dilating catheter assembly ~s suc~ ehat the methods
utilized take advantage of heat-shrin~able tubing. The
guiding catheter assembly has an interior surface which has a
very low coefficient of friction so that the dilating catheter
assembly can be readily inserted therethrough. In addition,
the guiding catheter assembly has sufficient rigidity so that
it can be readily manuevered. The dilating catheter assembly
is provided with a balloon which is formed integral therewith
which can be readily inflated and deflated through an annular
1~ passage independently from fluid infusion or pressure
measurements through the inner catheter.
~9
