Note: Descriptions are shown in the official language in which they were submitted.
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CATHETER HAYING INTEGRAL EXPANDABLElCOLLAPSIBLE
LUMEN
FIELD OF THE INVENTION
The present invention is generally related to medical catheters and
procedures for using the same, and more particularly to catheters having
multiple
lumens adapted to be inserted into body vessels including access vessels
having a
limited diameter with respect to the cannula diameter.
BACKGROUND OF THE XNVENTION
In the medical professifln, the use of catheters to deliver and vent fluids
from body vessels is becoming more pervasive due to the advancement of
minimally invasive procedures. It is oRen desired to insert a eathetex into a
body
vessel such as the aorta, urethra etc. via an access vessel having a
restricted
diameter. The catheter usually has a plurality of lumens, for instance, one
lumen
to infuse a fluid such as a medicant or oxygenated blood, and another lumen
for
inflating a balloon to selectively occlude the body vessel. 'The number of
lumens,
and particularly the aggregate cross sectional area of the lumens,
substantially
determines the overall catheter diameter. It is desired to keep the overall
diameter
2 0 of the catheter as small as possible, especially with respect to the
access vessel
and the vessel for which it is ihtended to be placed to reduce trauma to the
vessel.
With respect to aortic balloon catheters in particular, these catheters may
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be percutaneously inserted into a patient's femoral artery, serving as an
access
vessel, and advanced upwardly into the aorta of the patient. According to one
conventional method, a first catheter is inserted into the femoral artery and
advanced into the ascending aorta. The catheter may include a balloon for
selectively occluding the aorta and have multiple lumens terminating at the
distal
end thereof for delivering cardiopitgia to the aortic root and/or venting
fluid from
the aorta above the aortic root. Other lumens may provide for instrumentation
to
be inserted into the aorta, which may be advanced through the aortic valve
into the
heart. The proximal end of the catheter may be provided with a lumen
terminating
proximate the point of insertion to provide arterial return of oxygenated
blood.
Alternatively, a separate second catheter may be inserted into the patient's
ether
femoral artery to provide arterial return of oxygenated blood. This second
catheter is used to reduce the overall diameter of the frst catheter body
advanced
into the aorta, thus reducing trauma to the aorta Iining_ The distal end of
this
second catheter is also advanced only to proximate the point of insertion
since it is
semi-rigid and has a relatively large diameter to provide the required
arterial
return of oxygenated blood into the aorta. By using a second catheter, a
rather
large diameter first catheter is not necessary to be inserted into the aorta
which
may cage trauma to the lining of the artery. However, returning oxygenated
2 0 blood well below the aorta requires oxygenated blood to flow counter to
typical
arterial blood flow, upwardly into the ascending aorta to the various arteries
branching therefrom.
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The disadvantages of this approach include the fact that returning
oxygenated blood to the aorta upwardly in a direction counter to normal flow
has
been found in some studies to be damaging to the artery lining, and v~rhich
may
create aortic dissection; aneurysms, and in some cases death. In addition,
this
znethad requires a second infusion catheter to be inserted and manipulated
which
can be cumbersome.
A semi-rigid catheter having a large lumen for providing arterial return of
oxygenated blood, as well as having lumens for pressure sensing, cardioplegia
deliverylventing, and balloon inflation, necessitates a relatively large
aortic
1 o balloon catheter having a large overall diameter that is difficult to
femorally insert
and manipulate up into the ascending aorta. If too Large a catheter is used,
the
artery can be damaged or traumatized during insertion. It is desired to
provide an improved cath~ter suited for uae in body vessels having a limited
diameter while being capable of delivering fluids at a high flow rate, two
criteria
that typically limit each other. In particular, the improved catheter would
have
one intended use as a catheter that can be femorally inserted tv provide
arterial
return of oxygenated blood into the ascending aorta.
SUMMARY OF THE INVENTION
2 0 The present invention achieves technical advantages as a single catheter
having a relatively large inflatablelcollapsible lumen suited for insertion
via
smaller access vessels into larger vessels. The larger lumen is collapsed
during
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insertion, and inflated during fluid delivery. The catheter can be inserted
via an
access artery and provide arterial return of oxygenated blood into the
ascending
aorta. This inflatable/collapsible lumen is secured to the main catheter body
distal
end, and surrounds the main catheter body having raultiplc lumens for
facilitating
other functions, such as pressure sensing at the catheter distal end, balloon
inflation, and delivery of cardioplegia/venting at the catheter distal end.
In one embodiment, the catheter of the present invention derives technical
advantages as being adapted to be percutaneously positioned into the aorta via
a
femoral artery with the large lumen in the collapsed position. This large
lumen
to has a very thin wall facilitaring inflationlcollapsing about the main
catheter body,
preferably being comprised of polyethylene. Subsequently, by infusing a fluid,
such as oxygenated blood, into the large lumen, the large lumen self expands
due
to fluid pressure of the fluid flowing therethrough to the lumen distal end.
In
another embodiment, the catheter can be inserted into ether access vessels
such as
a subclavian artery.
The present invention derives technical advantages as a single catheter
having multiple lumens and a reduced overall diameter. The catheter has a
relatively small overall diameter during insertion through access arteries to
the
aorta with the large lumen in the collapsed position during advancement. This
z o small diameter provides good control of the catheter during insertion,
reducing the
risk of damaging yr traumatizing the lining of the artery. The catheter main
body
provides advancement of the large lumen within the vessel, and the catheter is
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sufficiently rigid to avoid kinking during insertion.
The present invention. has other numerous uses and advantages in the
surgical field whereby a large catheter lumen is required for exchanging a
fluid tv
a body vessel, hut the body vessel has a relatively small diameter and is
difficult
to navigate in and is susceph'ble to trauma. For instance, the present
invention is
ideally suited for use as a ureter catheter as well.
EItIEF DESCRIPTION OF THE DRAWYNGS
Figure 1 is a perspective view of the catheter of the present invention
1 o shown fcmorally inserted irito the aorta to provide arterial return of
oxygenated
blood when the catheter is used as an aortic catheter, wherein the large
inflatable
lumen is in the collapsed position during insertion to minimize trauma to the
arteries and then'ated during delivery of oxygetaated blood;
Figure 2 is a longitudinal cross section of the catheter of the present
invention shown in Figure 1 including the large inflatable/collapsible lumen
shown in the collapsed state as carried by the catheter body for advancement
into
a body vessel, such as for the procedure shown in Figure 1;
Figure 3 is a longitudinal cross section of the catheter of Figure 1
illustrating the large lumen in the expanded state when fluid flows
therethmugh
z o into the body vessel;
Figure 4 is a transverse cross-section of the catheter taken along line 4-4 in
Figure 2 with the large lumen in the collapsed state;
5
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Fire 5 is a transverse cross-section of the catheter taken along line S-5 in
Figure 3 with, the large lumtn in the expanded state; and
Figure 6 is a view of the eathcta of the present invention inserted i~ato the
aorta via the left subclavian artery.
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DESCRIPTION OF THE PRE)fERRED EMBOAIMENT
Referring now to Figure 1, there is shown generally at 10 a catheter
according to the preferred embodiment of the present invention used as an
aortic
balloon catheter femorally inserted into a patient and advanced into a~n
ascending
aorta 1 i of a heart 12. Catheter I O is seen to have a balloon member 14
positioned and expanded within the ascending aorta 1 I to occlude the aorta
above
an aortic valve 16. Catheter 10 is further seen to include a cardioplegia
deliverylventing port 1$ and a pressut'e sensing port 20. Both ports 18 and 20
are
defined distal of the balloon 14 far use within the ascending aorta above the
aortic
Z o valve 16. Catheter 10 is further seen to include a large integral
expandablelcollapsible lumen 22 defined between a main catheter body 24 and a
thin-walled sleeve 40 disposed about and carried by the main catheter body 24.
Lumen 22 terminates proximate the distal end of the catheter 10, but proximal
the
balloop member 14. Lumen 22 is ideal for providing arterial return of
oxygenated
2 5 blood to the ascending aorta from an extracorpareal pump (not shown).
The present invention derives technical advantages as a cathettr having a
large lumen 22 that can b~ collapsed when inserted through a smaller access
artery, such as the femoral artery; and into the ascending aorta. The catheter
has a
reduced overall diameter during insertion, thereby reducing trauma to the
artery
2 0 and improving control during insertion. The fluid pressure of the
oxygenated
blood delivered through lumen 22 causes member 40 to self expand from a
collapsed state within the artery, whereby the diameter of the large lumen 22
is
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sufficient to provide oxygenated blood at a suffteient rate and pressure to
perfuse
the human body. As shown, a single catheter 10 is suitable for providing
multiple
functions during aortic porfusion, without requiring a second catheter and
minimizing damage to the lining of the aorta.
Referring now to Figure 2 and Figure 3, there is shown a longitudinal
cross section of catheter 10 according to the preferred embodiment of the
present
invention. Sleeve member 40 is illustrated in the collapsed state in Figure 2,
and
in the expanded state in Figure 3. A transverse cross-section of catheter 10
having
the member 40 in the ovllapsed state taken along line 4-4 in Figure 2 is shown
in
z 0 Figure 4. A transverse cross-section of catheter 10 having the member 40
in the
expanded state taken along line 5-S in Figure 3 is shown in Figure 5. It is
noted
again that the catheter 10 of the prestnt invention is ideally suited as an
aortic
balloon catheter, however, the catheter 10 has other intended uses as well,
such as
a ureter catheter, and limitation for use as an aortic balloon catheter as
described
with reference to Figure l is not to be inferred.
Catheter 10 is seen to have the main catheter body 24 which may be
comprised of a conventional material such as polyvinylchloride (PVC),
polyurethane, and polyethylene, although limitation to these materials is not
to be
inferred as catheter body 24 can be comprised of elastomeric materials as
well,
2 0 such as silicone. Extendixtg within catheter body 24 is a plurality of
lumens
including a first lumen 26 extending to distal port 18, a second lumen 28
extending to distal port 20, and third lumen 30 extending to a balloon
inflation
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port 32 within ballaan 14. Also shown is ballvvn 14 being sealingly disposed
about the distal end of the catheter body 24 to form a cavity 36 therewithin.
When
used as an aortic perfusion catheter, aortic root pressure is sensed via lumen
28
and port 20 above the aortic root 1b to determine if the balloon i4 is
properly
occluding the aorta 1 i . Then, cardioplegia is delivered to the aorta
proximate the
aortic root 16 via the lumen 26 and port 18 while sensing pressure at the
aortic
root to maintain a pressure of about 50-100 mm Hg.
'fhe integral expandablelcollapsible lumen 22 is formed by the thin-walled
flexible lumen member 40 secured about and carried by the main catheter body
l0 24. Lumen member 40 is preferably secured only at the distal end thereof at
41,
but may alternatively be secured along a line to the outer surface of the main
catheter body 24, either mteiEmittcntly or continuously along catheter body 24
if
desired. Securing lumen member 40 to catheter body 24 ensures that the distal
end of member 40 is carried with main body 24 of catheter I O during
insertion.
Lumen member 40 preferably has a plurality of eircumferentially
extending openings 42 disposed at the member distal and 44, whereby lumen 22
terminates at a distal lumen vpenirtg et 46. Lumen opening 46 and sidewall
openings 42 facilitate infusing fluid out the distal end of the large lumen 22
when
expanded by the fluid pressure. Advantageously, lumen member 40 has a very
2 0 thin wall thickness to maintain a low profile when collapsed about
catheter body
24, as shown in Figure 2 and Figure 4. The collapsed lumen member 40 is folded
and wrapped about the catheter body 24 and heated during manufacturing to keep
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the member close to catheter body 24, as shown in Figure 4, untit unfolded
when
inflated. Member 40 has a wall thickness preferably in the range of .002
inches,
and preferably less than 0.41 inches, and is preferably comprised of a strong
and
resilient material such as polyethylene. Thus, the relative thickness of
member 40
is not drawn to scale in Figure 2 and Figure 3. However, other dimensions and
other conventional materials can be utilized as well, and limitation to
polyethylene
is not to be inferred. For instance, PVC> and polyurethane are suitable as
weil.
The material chosen for lumen member 40 could be the same as the catheter body
24 to facilitate a secure atts~ch~ment thereto using conventional mechanical,
1 o chemical or thermal bonding techniques.
In the preferred embodiment of the present invention, the inner diameter of
lumen 22 in the expanded position, as shown in Figure 3 and Figure 5, is
substantially larger than the outer diameter of the main catheter body 24,
such as a
4 to 1 ratio. For example, the inner diameter of expanded lumen 22 may be
about
10.7mm (32 fr.), and the outer diameter of main catheter body 24 may be about
2.7mm (8 fr.), although limitation to these dimensions is not to be inferred.
This
expandable lumen 22 is idoal for delivering a fluid, such as oxygenated blood,
at a
large fluid rate, whereby the smaller lumens 26, Z8 and 30 are rather small
and
suited for their intended use; such as previously discussed. The main catheter
2 0 body 24 is comprised of a suitable material such that it will not kink or
buckle
during insertion into the intended body vessel, such as the aorta or urethra.
If
desired, one of the lumens; such as lumen 26, can be provided with a malleable
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guide wire to selectively provide rigidity to the catheter body 24 and aid
insertion
of catheter 10 into the intended body vessel.
Cessation of fluid flow from the pump (nvt shown) through the lumen 22
will cause the lumen member 40 to collapse about the catheter body 24. Removal
of catheter l 4 from the body.vessel, generally after fluid flow through lumen
22
has ceased, will further constrict lumen member 40 to cause any remaining
fluid
in lumen 22 to be dispensed out the distal opening 46 of the lwmen 22. The
lumen
member 40 having a very flexible and thin wall will collapse about catheter
body
24 as forces from the body vessel compress the lumen member 40 into its
collapsed position, thus facilitating the easy removal of catheter 10 from the
body
vessel. The reduced catheter diameter during withdrawal further reduces trauma
to the body vessel, which is a tuber technical advantage of the present
invention.
Still referring to Figure 2 and Figure 3, the proximal end of catheter 10 is
seen to have versatile features that have additional technical advantages.
Each
patient has different physical attributes and dimensions, and thus, the
catheter of
the present invention can be adapted to have a sufficient length for use
within
each particular patient. 'rhe proximal end of catheter 10 is seen to have a
substantially rigid tubular body member generally shown at 50. The proximal
end
of the thin wall lumen mensber 40 is scan to be disposed about and sealiz~gly
2 o attached about the circumference of the body member 50 distal end shown at
52.
Notably, the proximal end of the lumen member 40 is seen to be bunched
together
in an accordion or serpentine like arrangement. This allows the length of the
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lemon member 40 de:6ned distal of the distal end 52 to be selectively adjusted
along with the ltngth of catheter body 24 slidably extending through body
member 50, thereby allowing the physician to selectively adjust the length of
the
catheter from body member distal end 52 to the catheter distal end 54. As
s indicated by the arrows, the main catheter body 24 is seen to be
longitudinally
slidably adjustable within a flow passageway 56 extending within body 50. Main
catheter body 24 can be selectively adjusted by the physician such that it can
be
extended or retracted thz~ough body member 50 and proximal end 58. To provide
a
sealed, fluid tight, lumen 56, the proximal end 58 of body mennber SO has
z o positioned therein a hemoatasis valve 60 sealingly disposed about the main
catheter body 24. Valve 60 is sealingly engaged against flee inner wall of
passageway 56 to prevent oxygenated blood 66 from back flowing through
proximal end 58, and to provide friction holding catheter body 24 in place at
the
selected position. The main catheter body 24 is Longitudinally and slidably
15 adjustable through valve 60 by the physician.
A flanged connector 62 is seen to form a Y connection in combination
with proximal end 58 and has a passageway 64 extending therethmugh in fluid
communication with~passsgeway 5b. An oxygenated blood source 66 is fluidly
coupled to member 62 and provides oxygenated blood to the catheter I 0 via the
z 0 passageway b4, lumen 56, and ultimately to the expandableJcollapsible
passageway 22 for delivery to the artery via the opening 46 and openings 42.
The
proximal end of catheter 10 is seen to have extending therefrom three separate
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passageways, namely, a passageway 70 in fluidg communication with lumen 30
and coupled to an inflation source 72, a passageway 74 in fluid communication
with lumen 28 and coupled to a presswe sensor device 76, and a passageway 78
in
fluid communication with Lumen 26 and coupled to a fluid delivery source 80.
S Each passageway connects to a respective connector, as Shawn in Figure 1.
The outer diameter of main catheter body 24 is significantly smaller than
the outer diameter of passageway 36 extending through body member 50. This
creates a sufficient passageway 56 about main catheter body 24 for oxygenated
blood to be communicated therethrvugh as sufficient rate and pressure to
perfuse
l0 the human body as shown in Figure 1. It is noted that the outer diameter of
passageway 56 is less than the diameter of passageway 22 formed by the fully
inflated lumen member 40, and thus, the fluid pressure will be higher through
passageway 56 than the fluid pressure within passageway 22 during use.
However, the short catheter portion that the blood is at a higher pressure is
15 relatively short in relation to the overall length of the catheter I0.
'Thus, the
required pressure for the oxygenated blood source 66 is suitable for delivery
of
oxygenated blood to an artery of the body, such as the aorta illustrated in
Figure 1.
As shown in Figure 3, the diatnefer of the lumen member 40 between proximate
body member 50 and a traiasition 82 is reduced with respect to the lumen
member
2 4 44 distal of transition 82 as this portion and the body member distal end
52
typically are positioned in the smaller aeceas artery. The body member 50 has
sufficient strength to facilitate insertion into a smaller access artery.
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Referring now to Figure 6, there is shown an alternative preferred method
of the use of the present invention whereby the catheter 10 is inserted into
the
ascending aorta via the left subclavian artery shown at 90. Like the femoral
artery, the loft subclavian artery can also be used as an access vessel for
S positioning the catheter IO within the ascending aorta, as shown. The Left
subclavian artery, like the femoral artery, has a diameter less than the
larger aortic
artery and thus limits the overall diameter of the catheter that can be
inserted
iherethrough. The prcseat invention is ideal for insertion through small
arteries
for ultimate positioning within a larger artery, such as for the purpose of
delivering fluids into the large artery at suitable flow rates while
minimizing
trauma to the arteries by the catheter.
It is intended that other arteries are suitable as access sites for the
present
invention as well, such as the left cartaid artery 92 and the right cartoid
artery 94
as shown in Figure 4. The desired insertion artery is left to the choice of
the
z 5 surgeon and will depend upon many criteria and will vary from patient to
patient.
In summary, the pressnt invention achieves technical advantages as a
catheter which has the functional characteristics of a catheter having a
predetermined outer diameter, but which during insertion and withdrawal has a
smaller effective overall Eliamtter. The present invention achieves advantages
of a
2 0 single catheter having multiple Iumens, including a large inflatable lumen
22,
which is suitable for insertion into smaller access arteries to reduce trauma
to the
arteries or blood vessels during insertion and withdrawal, while providing
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significant fluid flow thercthmugh to and toward the distal end of the
catheter 10.
The proximal end of the catheter has an adjustable length to allow the
physician
to adjust the length of the catheter during surgery to the particular patieat.
Though the invention has been described with respect to a specific
preferred embodiment, many v»ations and modifications will became apparent
to those skilled in the art upon reading the present application. It is
therefore the
intention that the appended claims be interpreted as broadly as possible in
view of
the prior art to include au such variations and modifications.
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