U.S. patent application number 10/727986 was filed with the patent office on 2004-12-23 for delivery catheter.
This patent application is currently assigned to SALVIAC Limited. Invention is credited to Brady, Eamon, Gilson, Paul, Vale, David.
Application Number | 20040260308 10/727986 |
Document ID | / |
Family ID | 11041754 |
Filed Date | 2004-12-23 |
United States Patent
Application |
20040260308 |
Kind Code |
A1 |
Gilson, Paul ; et
al. |
December 23, 2004 |
Delivery catheter
Abstract
A medical catheter for the transvascular deployment of a
collapsible medical device such as a filter has a tubular body
formed by an inner tubular core surrounded by an outer thin-walled
tube which is fixed to the core. The outer thin-walled tube extends
outwardly beyond a distal end of the core to form a fixed
thin-walled medical device embracing pod. The filter is carried on
a guidewire which is slidably engagable within a central lumen of
the core and the filter can be collapsed against the guidewire for
loading within the pod. With the filter thus loaded within the pod
the distal end of the catheter can be manoeuvred through a
patient's vascular system to a desired deployment site where the
filter is discharged from the pod allowing the filter to expand
within the blood vessel for use filtering blood flowing through the
blood vessel.
Inventors: |
Gilson, Paul; (Moycullen,
IE) ; Vale, David; (Clontarf, IE) ; Brady,
Eamon; (Elphin, IE) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW, GARRETT & DUNNER
LLP
1300 I STREET, NW
WASHINGTON
DC
20005
US
|
Assignee: |
SALVIAC Limited
|
Family ID: |
11041754 |
Appl. No.: |
10/727986 |
Filed: |
December 5, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10727986 |
Dec 5, 2003 |
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09676468 |
Oct 2, 2000 |
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6752819 |
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09676468 |
Oct 2, 2000 |
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PCT/IE99/00021 |
Apr 1, 1999 |
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Current U.S.
Class: |
606/108 ;
606/200 |
Current CPC
Class: |
A61F 2/0108 20200501;
A61F 2/013 20130101; A61F 2230/0006 20130101; A61F 2/0095 20130101;
A61F 2/95 20130101 |
Class at
Publication: |
606/108 ;
606/200 |
International
Class: |
A61F 011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 2, 1998 |
IE |
980242 |
Claims
1. A medical catheter for the transvascular deployment of a medical
device, the catheter comprising an elongate tubular body having a
proximal end and a distal end, a tubular housing being formed at
the distal end of the body for reception of the medical device, a
deployment means for engagement with the medical device, being
movable through the housing to move the medical device between a
stored position within the housing and an in-use position
externally of the housing, characterized in that the housing
comprises a tubular thin-walled medical device embracing pod fixed
at the distal end of the body, the pod extending outwardly from the
distal end of the body and forming an integral extension
thereof.
2-28. (Canceled)
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a medical catheter and more
particularly to a catheter for the transvascular deployment of
expandable medical devices, such as an intravascular embolic filter
device, in a collapsed condition.
BACKGROUND OF THE INVENTION
[0002] The device as described herein relates to a carotid
angioplasty procedure with an, intravascular filter being placed
distally to capture procedural emboli being released. Other medical
procedures warrant the use of distal protection systems.
Angioplasty and stenting of surgically implanted Saphenous Vein
grafts that have stenosed and primary treatment of Renal artery
stenoses are applicable also. Indeed, the insertion of embolic
protection devices to protect patients during any vascular surgery
is envisioned as being applicable to this invention.
[0003] A particularly useful form of embolic protection device in
the form of a filter element for placing in a desired position has
been described in our co-pending Patent Application No.
PCT.backslash.IE98.backslash.000- 93 the contents of which are
incorporated herein by reference. For example, this filter element
is compressed into a housing or pod to advance it to the required
location in a vessel. Once in situ the housing is withdrawn or the
filter element is advanced. This allows the compressed filter
element to expand to the required size and occlude the vessel
except for the path or paths provided through the filter which thus
provides a pathway for blood and has means for capturing and
retaining undesired embolic material released during the surgical
operation or percutaneous interventional procedure.
[0004] There are difficulties with such expandable devices, whether
they be filters or other devices in that firstly they have to be
correctly and efficiently compressed and retained within the pod so
that when released from the pod, they will expand to assume the
correct shape and will not have been distorted by the compression
within the pod. The problems of distortion or incorrect expansion
tend to be exacerbated if the medical device is stored for long
periods within the pod prior to use. Secondly, it is important that
the pod and the catheter tube itself be manipulated to the site of
use without causing damage to, for example, the arteries through
which it is being manipulated. Difficulties may arise if, for
example, the catheter tube, or more particularly the pod as the pod
effectively leads in the insertion, were to damage the artery
sidewall and thus cause for example a break-away of atherosclerotic
plaque from the carotid arteries.
[0005] Essentially this leads to certain requirements. The device
needs to be efficiently compressed. The resulting compressed device
needs to be manipulated in its pod as efficiently as possible.
Further, there is a need for loading such catheters in a way that
will facilitate their use on unloading.
[0006] It is known to mount implantable medical devices at a distal
end of a delivery catheter for transvascular deployment. Upon
reaching a desired location within a patients vasculature the
catheter is withdrawn relative to the medical device thus allowing
the medical device to expand or be expanded within the blood
vessel. In the prior art WO98/07387 and U.S. Pat. No. 5,064,435
show stent delivery systems essentially comprising a catheter with
a stent mounted in a collapsed state at a distal end of the
catheter under a retractable outer sheath. An abutment within the
bore of the catheter spaced proximally from the distal end of the
catheter prevents retraction of the stent as the outer sheath is
withdrawn over the stent. Each of these devices has at least two
main components, namely an inner catheter and an outer sheath which
is slidably retractable on the catheter to expose the stent for
deployment.
[0007] These deployment catheters need to have lateral flexibility
in order to manoeuvre through the vascalature but at the same time
be sufficiently pushable so that they can be steered and
manipulated through the vascalature. The mounting of a medical
device within the distal end of the catheter either greatly limits
the size of the medical device that can be accommodated or
necessitates enlargement of the catheter which restricts access of
the catheter within the vascalature of a patient.
[0008] Catheters of this type tend to be relatively long and the
loading of a medical device within the distal end of the catheter
prior to use can be a somewhat cumbersome operation for the
surgeon. The length of the catheters makes them unwieldy and
difficult to keep sterile. There is also a difficulty in ensuring
air is excluded from the medical device and catheter during
loading.
[0009] The present invention is directed towards overcoming these
problems.
SUMMARY OF THE INVENTION
[0010] According to the invention there is provided a catheter for
the transvascular deployment of a medical device, the catheter
comprising an elongate tubular body having a proximal end and a
distal end, a tubular housing being formed at the distal end of the
body for reception of the medical device, a deployment means for
engagement with the medical device, being movable through the
housing to move the medical device between a stored position within
the housing and an in-use position externally of the housing,
characterised in that the housing comprises a tubular thin-walled
medical device embracing pod fixed at the distal end of the body,
the pod extending outwardly from the distal end of the body and
forming an extension thereof. Conveniently, the pod and the
catheter body form a single integral unit for deployment of the
medical device.
[0011] Preferably the catheter body has an inner tubular core
encased within a concentric thin-walled tubular outer sheath which
is fixed to the core, the sheath being extended outwardly of a
distal end of the core to form the pod.
[0012] The advantage of using the thin-walled tube is that the
maximum volume to retain the medical device for deployment is
achieved. Further the pod is relatively flexible on the catheter
further facilitating its manipulation and passage through
vasculature to the desired site of use.
[0013] Preferably the inner tubular core is formed from a steel
spring, but may alternatively be formed from polymeric material.
Any suitable material may be used as the core is now covered by the
thin-walled tubular outer sheath which is effectively the important
tube, being the vessel contact surface. Alternatively, a thin
walled pod may be achieved by locally thinning a polymeric tube at
the distal end of the tube.
[0014] Preferably the thin-walled tube is manufactured from a low
friction material and ideally is manufactured from
polytetrafluoroethylene (PTFE) often sold under the Registered
Trade Mark TEFLON. The thin walled tube may alternatively be
manufactured from any other suitable thin walled material of low
friction coefficient or employing a friction reducing agent or
component to minimise the friction coefficient. The advantage of
this is that firstly the catheter will not damage arteries, for
example the carotid, knocking off atherosclerotic plaque. Further
this will allow the easy removal of the implant from th
catheter.
[0015] Where the outer thin walled tube is formed of PTFE, it would
typically have a thickness of less than 0.004 inches. The thickness
of thin walled tubes of other materials may vary somewhat depending
on the characteristics of the material being used.
[0016] In another aspect the invention provides a method of loading
such a catheter comprising:
[0017] inserting a loading tube into the pod at a free end of the
outer thin-walled tube; and
[0018] compressing the medical device and delivering the compressed
medical device through the loading tube into the pod.
[0019] The problem is that if one did not insert the loading tube
into the pod the thin-walled tube would collapse in compression
when trying to insert the medical device. The use of the loading
tube prevents such collapse.
[0020] Preferably the loading tube is a further thin-walled tube
which is inserted into the pod for smooth delivery of the medical
device into the pod.
[0021] Ideally the medical device is compressed by delivering the
filter device through a funnel and into the loading tube which is
mounted at an outlet of the funnel.
[0022] In another aspect the invention provides a delivery system
for transvascular deployment of a medical device, the system
comprising a catheter in combination with an associated separate
loading device which is operable to collapse the medical device
from an expanded in-use position to a collapsed position for
reception within the pod.
[0023] Preferably the loading device comprises means for radially
compressing the medical device.
[0024] In a particularly preferred embodiment the loading device
comprises a funnel having an enlarged inlet end and a narrowed
outlet end, the outlet end being engageable within the pod.
[0025] In another embodiment, the loading device comprises a main
support having a funnel-shaped bore formed from a frusto-conical
filter device receiving portion terminating in a cylindrical
portion formed by a thin-walled loading tube projecting from the
main support. This funnel-like arrangement is a very suitable
arrangement of loading a pod on the catheter with a compressible
filter device.
[0026] Ideally the cone angle is between 15.degree. and 65.degree.
and preferably may be between 35.degree. and 45.degree.. This
allows a sufficiently gentle compression of a filter device,
particularly one of a polymeric material.
[0027] In one particularly preferred embodiment of the invention,
the main support, is formed from perspex and the thin-walled
loading tube is formed from PTFE material. The perspex gives a
smooth surface.
[0028] Preferably the loading tube is mounted on the main support
on a metal spigot at an outlet end of the funnel.
[0029] In a still further aspect the invention provides a pack for
an elongate intravascular catheter of the type comprising a tubular
body with a proximal end and a distal end, the distal end adapted
for reception of a medical device, the pack comprising a tray
having means for releasably holding the distal end of the catheter
relative to an associated catheter loading device in a cooperative
juxtaposition on the tray, the loading device being operable to
collapse the medical device from an expanded in-use position to a
collapsed position for reception within the pod. This facilitate
raid and correct loading, of a medical device within the
catheter.
[0030] Preferably the tray has a liquid retaining bath formed by
recess in the tray, the bath having a depth sufficient to
accommodate in a totally submerged state the distal end of the
catheter and a medical device for submerged loading of the medical
device into the catheter.
[0031] In another embodiment the tray has a catheter holding
channel communicating with the bath, the channel defining a pathway
around the tray which supports the catheter in a loading position
on the tray.
[0032] Preferably the means for securing the catheter within the
channel comprises a number of retainers spaced-apart along the
channel, each retainer comprising two or more associated
projections which project inwardly from opposite side walls of the
channel adjacent a mouth of the channel, the projections being
resiliently deformable for snap engagement of the catheter within
the channel behind the projections.
[0033] Conveniently a ramp is provided at an end of the channel
communicating with the bath to direct a distal end of the catheter
towards a bottom of the bath.
[0034] In another embodiment means is provided within the bath for
supporting the distal end of the catheter above the bottom of the
bath. Preferably said supporting means is a step adjacent the
channel.
[0035] In another embodiment means is provided within the bath for
supporting a catheter loading device for engagement with the distal
end of the catheter to guide a medical device into the distal end
of the catheter. Preferably said means comprises a recess in a side
wall of the bath for reception of a funnel with an outlet pipe of
the funnel directed towards the channel for engagement within the
distal end of the catheter.
[0036] Ideally, it will be appreciated that the device for loading
the catheter with a compressible filter device such as described
above may be used in conjunction with this pack. The advantage of
this is that the filter device can be submerged in a saline bath
during loading into the pod which ensures that air is excluded from
the filter device when loading as it would obviously cause medical
complications if air was introduced to the bloodstream during an
angioplasty and stenting procedure.
[0037] The tray system with the catheter distal end submerged,
combined with appropriately designed catheter proximal end and
standard device flushing techniques can ensure a fluid filled
device is introduced to the vasculature.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The invention will be more clearly understood from the
following description of some embodiments thereof, given by way of
example only, with reference to the accompanying drawings, in
which:--
[0039] FIG. 1 is a perspective diagrammatic view of a catheter
assembly according to the invention,
[0040] FIG. 2 is a detail partially sectioned elevational view
showing an expandable filter device loaded into a distal end of the
catheter,
[0041] FIG. 3 is a sectional view showing a distal end portion of
the catheter and a loading device for use with the catheter,
[0042] FIG. 4a is a detail sectional elevational view of the distal
end portion of the catheter,
[0043] FIG. 4b is a view similar to FIG. 4a showing another
catheter construction,
[0044] FIG. 4c is a view similar to 4a showing another catheter
construction,
[0045] FIG. 5 is a detail diagrammatic partially sectioned
perspective view showing the distal end of the catheter about to be
loaded,
[0046] FIG. 6 is a detail sectional elevational view showing the
distal end of the catheter loaded with the loading device still in
position,
[0047] FIG. 7 is a detail sectional elevational view of a filter
device for use with the catheter shown in an expanded in-use
position;
[0048] FIG. 8 is a sectional view of portion of the loading
device,
[0049] FIG. 9 is a plan view of a pack for holding the catheter
assembly according to the invention,
[0050] FIG. 10 are, detail plan views of retaining clip portions of
the pack of FIG. 9,
[0051] FIG. 11 is a perspective view showing a bath portion of the
pack of FIG. 9, and
[0052] FIG. 12 is a sectional view of the bath portion of the pack
illustrated in FIG. 11.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0053] Referring to the drawings and initially to FIGS. 1 and 2
thereof, there is illustrated a catheter, indicated generally by
the reference numeral 1, for mounting a collapsible filter 2 or
other collapsible medical device. The catheter has on it's free
distal end a pod 3 within which the filter 2 is shown compressed in
FIG. 2. A guide wire 6 on which the filter 2 is mounted is also
illustrated in FIG. 2.
[0054] FIG. 7 shows the collapsible filter device 2, of the type
described in our Patent Application No. PCT/IE98/00093, in an
expanded in-use position. The filter device 2 is mounted adjacent a
distal end of the guidewire 6 which terminates at the distal end in
a flexible spring tip 7.
[0055] The filter device can be collapsed inwardly against the
guidewire 6 for reception within the pod 3 as shown in FIG. 2.
[0056] Referring particularly to FIGS. 2, 3 and 4a the catheter 1
comprises an outer thin walled tube 10 of PTFE or other thin walled
polymer tube surrounding an elongate tubular body forming an inner
support core which in this embodiment is formed by a spring 11. The
outer thin wall tube 10 projects beyond a distal free end 12 of the
spring 11 to form the pod 3.
[0057] An alternative catheter construction is shown in FIG. 4b. In
this case the catheter 1 is formed by a polymeric tube body 14
having a thin-walled distal end portion 15 which forms the pod 3.
This thin-walled pod 3 is formed by locally thinning the polymeric
tube body 14 at the distal end 15 of the tube body 14. A still
further construction is shown in FIG. 4c in which in this case the
inner support core is formed from polymeric tubing 16.
[0058] FIG. 3 also illustrates a loading device indicated generally
by the reference numeral 20, which loading device comprises a
support 21 having a funnel-shape bore 22 formed from a
frusto-conical filter device receiving portion 25 terminating in a
cylindrical portion formed by a thin wall stainless steel spigot 23
on which is mounted a loading tube 24, again of a flexible thin
wall material, in this embodiment PTFE. It will be seen from FIG. 3
how the loading device 20 is inserted into the pod 3.
[0059] To use the loading device 20, referring now specifically to
FIGS. 5 and 6, the filter 2 is connected to the guidewire 6 and is
drawn through the loading device 20 where it is compressed and
pulled through the spigot 23 and the loading tube 24 until it rests
within the pod 3 at a proximal end of the pod 3. With the guidewire
6 held fast relative to the catheter, the loading device 20 is
withdrawn leaving behind the filter 2 which is now mounted within
the pod 3 as shown in FIG. 2. It will be appreciated that the
filter device 2 will move smoothly through the loading tube 24 as
the loading tube 24 is in tension during loading.
[0060] The catheter 1 can then be delivered trans-arterially
according to standard clinical practice to a deployment site. As
the catheter 1 is moved through the arteries a leading end of the
pod 3 which is flexible will deflect to assist in guiding the
catheter 1 to the deployment site without damaging the artery wall.
Once in position the filter device 2 is held stationary whilst
catheter body incorporating the pod 3 is retracted. When released
the filter device 2 will expand to fill the vessel.
[0061] Advantageously for use simply as a deployment catheter the
thickness of the pod wall can be minimised, and consequently the
crossing profile of the catheter can be minimised, as the pod does
not need to be able to withstand compressive forces which would
collapse the pod. When retaining the medical device and when
pushing the medical device out of the pod for deployment the pod
wall is in tension and so will not collapse. For loading the
medical device in the pod the loading tube of the loading device
projects into the pod to shield the pod from compressive forces
which would collapse the pod.
[0062] It will be appreciated that instead of having the guidewire
co-axially mounted within the catheter along the full length of the
catheter, the guidewire may only be co-axial with an outer free end
of the catheter. In this case, the guidewire is mounted alongside
the catheter and enters an inlet hole adjacent the outer free end
of the catheter (typically 5-20 cm from the end of the catheter) to
travel coaxially within the outer free end of the catheter. This
configuration is commonly referred to as a RAPID EXCHANGE
system.
[0063] It will be appreciated that the catheter/pod assembly may be
constructed with a single polymeric tubing that has an integral
distal thin walled section describing the pod. This construction
can be achieved by a localised moulding operation. Alternatively, a
pod may be bonded to the proximal tube by way of adhesive or
welding.
[0064] The pod described in any of the constructions may be
fabricated with enough longitudinal stiffness such that it can
withstand compressive loading of a filter element into it. In this
embodiment the delivery catheter may also be used as a retrieval
catheter.
[0065] Referring now specifically to FIGS. 9 to 12, there is
illustrated a pack for retaining a catheter assembly. Such a
catheter assembly could be of conventional construction or may be
as is illustrated, a catheter 1 according to the present
invention.
[0066] Referring to FIGS. 9 and 10 initially, the pack has a
moulded plastics tray 30 which is recessed to support the parts of
a catheter such as, for example, a recess 31 to retain a
conventional Y-connector with an associated hub receiving slot 32
at one end for reception of a hub mounted at a proximal end of a
catheter. A bath 33 is formed by another recess in the tray 30. A
catheter mounting recess or channel 34 extends between the hub
receiving slot 32 and the bath 33. It will be noted that the
channel 34 is shaped to define a desired curve with no sharp bends
and smooth transitions to facilitate loading of a catheter in situ.
The channel 34 is provided with a number of spaced-apart retaining
clips 37 illustrated in FIG. 10. Each retaining clip 37 comprises
three associated projections 42 which project inwardly from
opposite side walls 43 of the channel 34 adjacent an upwardly open
mouth of the channel 34. These projections 42 and/or the side walls
43 of the channel 34 are resiliently deformable for snap engagement
of a tubular catheter body within the channel 34 behind the
projections 42. A downwardly sloping ramp 44 (FIG. 12) is provided
at an end of the channel 34 communicating with the bath 33 to
direct a distal end of a catheter 1 towards a bottom of the bath
33. Further recesses 39 and 40 respectively are provided to retain
an adapter and a syringe for flushing the catheter 1 with saline
solution. Obviously, it will be appreciated that many other forms
of apparatus could be provided.
[0067] The bath 33 has a bottom 45 with an upwardly extending side
wall 46. It will be noted that a step 47 is provided adjacent the
channel 34 for supporting the distal end of the catheter 1 above
the bottom 45 of the bath 33 to facilitate loading of the catheter
1 with a medical device 2.
[0068] A recess 48 is shaped in the step 47 for reception of the
loading device 20 for the catheter 1. When the loading device 20 is
mounted in the recess 48 the loading tube 24 extends into the pod 3
of the catheter 1 in a cooperating loading position. Lugs 49 at
each side of the recess 48 engage and retain the support 21 in the
recess 48. These lugs 49 are resiliently deformable for snap
engagement of the support 21 in the recess 48 and to allow release
of the support 21 from the recess 48.
[0069] A further channel 50 for a balloon tube is also provided on
the tray 30 having a number of spaced-apart retaining projections
52 (FIG. 10) to retain a balloon tube in the channel 50. In use,
the catheter 1 is packaged on the tray 30, being mounted within the
channel 34 so it is held on the tray 30 in a position ready for
loading. Saline solution is injected through the catheter 1 to
exclude air from the catheter 1 and the bath 33 is filled with
saline solution. The guidewire 6 having the filter 2 attached is
then fed through the loading device 20 and through the catheter 1.
Air is excluded from the filter 2 which is submerged in the saline
bath and the filter 2 is then drawn through the loading device 20
into the pod 3 at the distal end of the catheter 1. The loading is
conducted under water to prevent air entrapment in the filter
device 2 whilst loading the filter device 2 in the pod 3 at the
distal end of the catheter 1. It will be noted that the pod 3 at
the distal end of the catheter 1 is submerged and, the catheter 1
is held firmly on the tray in loading engagement with the loading
device 20 while the filter 2 is being loaded into the pod 3.
[0070] The invention is not limited to the embodiments hereinbefore
described which may be varied in both construction and detail
within the scope of the appended claims.
* * * * *