U.S. patent application number 09/915135 was filed with the patent office on 2002-01-24 for catheter with an expandable end portion.
Invention is credited to Conlon, Dominic, Mulholland, Patrick, O'Carroll, Gerard.
Application Number | 20020010476 09/915135 |
Document ID | / |
Family ID | 11041989 |
Filed Date | 2002-01-24 |
United States Patent
Application |
20020010476 |
Kind Code |
A1 |
Mulholland, Patrick ; et
al. |
January 24, 2002 |
Catheter with an expandable end portion
Abstract
A catheter (2) is used in medical applications, for example for
the retrieval of a sample from a patient or the insertion or
retrieval of medical devices such as filters, stents (3) to and
from the patient. The catheter (2) includes an expandable tip (6)
at a leading portion of a catheter tube portion (5). This
expandable tip (6) can retrieve or deliver samples, medical
devices, etc. (3), which are slightly larger than the dimensions of
a main catheter tube (5) inserted into the patient. The expandable
tip (6) can also include extension members (10) which provide axial
support to the expandable tip (6) but which still allow expansion
in the radial direction.
Inventors: |
Mulholland, Patrick; (County
Westmeath, IE) ; O'Carroll, Gerard; (County Sligo,
IE) ; Conlon, Dominic; (County Sligo, IE) |
Correspondence
Address: |
JACOBSON, PRICE, HOLMAN & STERN
PROFESSIONAL LIMITED LIABILITY COMPANY
400 SEVENTH STREET N.W.
WASHINGTON
DC
20004
US
|
Family ID: |
11041989 |
Appl. No.: |
09/915135 |
Filed: |
July 26, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09915135 |
Jul 26, 2001 |
|
|
|
PCT/IE00/00011 |
Jan 28, 2000 |
|
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Current U.S.
Class: |
606/108 |
Current CPC
Class: |
A61F 2/011 20200501;
A61F 2002/9528 20130101; A61M 2025/0081 20130101; A61M 25/0068
20130101; A61B 17/22031 20130101; A61M 25/0074 20130101; Y10T
403/32032 20150115; A61M 25/008 20130101; A61F 2/95 20130101 |
Class at
Publication: |
606/108 |
International
Class: |
A61B 017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 28, 1999 |
IE |
990058 |
Claims
1. A catheter comprising a catheter tube portion and a tip
extending axially from the catheter tube portion, the tip being
flexible relative to the catheter tube portion, characterised in
that the catheter includes reinforcement means to enhance the axial
strength of the tip while facilitating radial expansion of the tip
to accommodate an article in the tip.
2. A catheter as claimed in claim 1 wherein the tip is a soft tip
of flexible material.
3. A catheter as claimed in claim 1 or 2 wherein the reinforcement
means comprises an extension means extending from the catheter tube
portion.
4. A catheter as claimed in claim 3 wherein the tip includes a free
distal end and the extension means terminates at a position that is
axially spaced back from the free end of the tip.
5. A catheter as claimed in claim 3 or 4 wherein the extension
means comprises at least one extension member extending from said
catheter tube portion into said expandable tip.
6. A catheter as claimed in any of claims 3 to 5 wherein the
extension means comprises a plurality of extension members
extending from said catheter tube portion into said expandable
tip.
7. A catheter as claimed in claim 6 wherein said at least one
extension member is tapered toward a leading portion of said
expandable tip.
8. A catheter as claimed in claim 6 or 7 wherein said plurality of
extension members are equi-spaced in the direction of said
expandable tip.
9. A catheter as claimed in any of claims 6 to 8 wherein said
plurality of extension members are tapered toward a leading portion
of said expandable tip.
10. A catheter as claimed in any of claims 6 to 9 wherein the
number of said plurality of extension members is four.
11. A catheter as claimed in any of claims 6 to 10 wherein said at
least one extension member includes a radiused tip.
12. A catheter as claimed in claim 9 wherein said plurality of
extension members each include a radiused tip.
13. A catheter as claimed in any preceding claim wherein the tip
has a free end which is rounded for ease of passage of an
article.
14. A catheter as claimed in any preceding claim wherein the tip
has a free end which is rounded for ease of passage of the tip
through the vasculature.
15. A catheter as claimed in any preceding claim wherein the tip
comprises a tubular sleeve of flexible material.
16. A catheter as claimed in claim 15 wherein the sleeve is
attached to the catheter tube portion by heating.
17. A catheter as claimed in any preceding claim wherein the tip
has an outer diameter which is approximately the same dimension as
the outer diameter of the catheter tube portion.
18. A retrieval catheter for retrieving an article comprising a
catheter tube portion and a tip extending axially from the catheter
tube portion, the tip being flexible relative to the catheter tube
portion, characterised in that the catheter includes reinforcement
means to enhance the axial strength of the tip while facilitating
radial expansion of the tip to accommodate an article in the
tip.
19. A retrieval catheter as claimed in claim 18 wherein the article
to be retrieved has a larger dimension then that of the normal
internal dimension of the tip.
20. A catheter as claimed in any preceding claim wherein the tip is
movable from a delivery configuration in which the outer diameter
of the tip is approximately of the same dimension as the outer
diameter of the catheter portion to which it is attached, to an
expandable position as an article is received in the tip.
21. A catheter as claimed in any preceding claim wherein the tip is
progressively movable to an expanded position in response to
receiving an article in the tip.
22. A catheter tube portion having a tip extending axially from the
catheter tube portion, characterised in that the catheter tube
portion includes reinforcement means to enhance the axial strength
of the tip while facilitating radial expansion of the tip to
accommodate an article in the tip.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is directed to a catheter, for example
a retrieval or delivery catheter used in medical applications,
which has an expandable end portion.
[0003] 2. Discussion of the Background
[0004] Catheters are well known medical devices used to facilitate
various medical procedures, such as diagnostic or delivery
procedures. Catheter tubes are inserted into a body of a patient
for various medical procedures. For example, a catheter may be used
in performing diagnostic procedures such as removing a sample from
a body site of a patient. The catheter tube is used in this
situation as the delivery vehicle for the medical instrument which
removes the sample. Further, sophisticated medical implant devices,
such as filters and stents, can be delivered and retrieved into and
from the body site of the patient using a catheter.
[0005] Generally, a catheter has a tube portion which is relatively
stiff in both axial and radial directions to allow proper placement
of the catheter in the patient's body, but which may be fitted with
a distal soft tip which first contacts tissues in the patient. The
soft tip is provided to minimise discomfort for the patient when
the catheter is inserted into the patient. For example,
WO-A-9808562 A describes a catheter with an insert molded catheter
tip. However, there are constraints on the use of such catheters in
that such catheters can only be relatively small sized, and thus
can only be used to retrieve and deliver relatively small samples
and medical devices.
SUMMARY OF THE INVENTION
[0006] Accordingly, one object of the present invention is to
provide a novel catheter which can be used to retrieve larger
objects and deliver and retrieve larger medical devices than in the
background art.
[0007] A further object of the present invention is to provide a
novel catheter which can accommodate an article with a slightly
larger dimension than that of a main catheter tube itself.
[0008] The novel catheter of the present invention achieves these
and other objects by including a portion near a distal tip end
which is expandable in size in a radial direction to accommodate
larger size samples or medical devices. The catheter includes
reinforcement means to enhance the axial strength of the tip while
facilitating radial expansion of the tip to accommodate an
article.
[0009] As a further feature, the novel catheter of the present
invention can further include reinforcing portions in the
expandable portion to enhance strength in the axial direction,
while still allowing expansion in the radial direction.
[0010] Most preferably the tip is a soft tip of flexible
material.
[0011] In a preferred embodiment the reinforcement means comprises
an extension means extending from the catheter tube portion.
Preferably the tip includes a free distal end and the extension
means terminates at a position that is axially spaced back from the
free end of the tip.
[0012] In one embodiment of the invention the extension means
comprises at least one extension member extending from said
catheter tube portion into said expandable tip.
[0013] Preferably the extension means comprises a plurality of
extension members extending from said catheter tube portion into
said expandable tip. To provide a gradual change in the axial
reinforcement preferably said at least one extension member is
tapered toward a leading portion of said expandable tip.
[0014] Axial reinforcement and radial expansion is facilitated
particularly when said plurality of extension members are
equi-spaced in the direction of said expandable member.
[0015] Preferably said plurality of extension members are tapered
toward a leading portion of said expandable member.
[0016] For ease of manufacture while providing the desired
reinforcement characteristics preferably the number of said
plurality of extension members is four.
[0017] To provide atraumatic transition to the soft tip preferably
said at least one extension member includes a radiused tip.
Ideally, said plurality of extension members each include a
radiused tip.
[0018] In addition, for ease of passage of an article into or out
of the tip preferably the tip has a free end which is rounded.
[0019] In a preferred embodiment the tip has a free end which is
rounded for ease of passage of the tip through a body passageway
such as the vasculature.
[0020] Preferably the tip comprises a tubular sleeve of flexible
material. For ease of manufacture and to provide a smooth
transition preferably the sleeve is attached to the catheter tube
portion by heating.
[0021] Ideally to provide a smooth transition the tip has an outer
diameter which is approximately the same dimension as the outer
diameter of the catheter tube portion.
[0022] In one aspect the invention provides a retrieval catheter
for retrieving an article such as a filter comprising a catheter
tube portion and a tip extending axially from the catheter tube
portion, the tip being flexible relative to the catheter tube
portion, characterised in that the catheter includes reinforcement
means to enhance the axial strength of the tip while facilitating
radial expansion of the tip to accommodate an article in the tip.
Usually the article to be retrieved has a larger dimension then
that of the normal internal dimension of the tip.
[0023] In one embodiment of the invention the tip is movable from a
delivery configuration in which the outer diameter of the tip is
approximately of the same dimension as the outer diameter of the
catheter portion to which it is attached, to an expandable position
as an article is received in the tip.
[0024] For ease of use, preferably the tip is progressively movable
to the expanded position in response to receiving an article in the
tip.
[0025] The invention also provides a catheter tube portion having a
tip extending axially from the catheter tube portion, in which the
catheter tube portion includes reinforcement means to enhance the
axial strength of the tip while facilitating radial expansion of
the tip to accommodate an article in the tip.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The invention will be more clearly understood by reference
to the following detailed description when considered in
conjunction with the accompanying drawings, wherein:
[0027] FIG. 1 is an overall view of the novel catheter of the
present invention used with an introducer;
[0028] FIG. 2 shows a more detailed view of a tip portion of the
catheter of FIG. 1;
[0029] FIGS. 3(a) and 3(b) are cross sectional views of the tip
portion of the catheter on the lines IIIa-IIIa and IIIb-IIIb
respectively of FIG. 2;
[0030] FIG. 4(a) is an exploded view of the tip portion of the
catheter of the present invention;
[0031] FIG. 4(b) is a cross sectional view on an enlarged scale of
a distal end of the tip portion of the catheter;
[0032] FIGS. 5(a) to 5(d) are diagrammatic views showing one
operation of the catheter; and
[0033] FIG. 6 is a scale drawing, as an example, of an actual
implementation of the novel catheter of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] Referring to the drawings, wherein like reference numerals
designate identical or corresponding parts throughout the several
views, and more particularly to FIG. 1 thereof, the overall device
1 is an introducer, e.g. a percutaneous introducer, with a catheter
portion 2. FIG. 1 illustrates the catheter portion 2 according to
the present invention, for example a retrieval catheter, which is
attached to an introducer having a hub portion 20 and a side lead
tube 21 which leads into the hub portion 20. A medical instrument
to be inserted into a patient is placed through the hub portion 20.
This medical instrument placed through the hub portion 20 may be,
as examples, a retrieval element to retrieve a sample, a clot or
previously inserted medical device such as a stent or filter from a
patient's body, or a delivery element to deliver a medical device
to a patient's body.
[0035] The catheter 2 may also be used to deliver or retrieve
another catheter. The catheter portion 2 of FIG. 1 includes a
catheter tube portion 5 which is relatively rigid in both the axial
and radial directions to facilitate delivery of the catheter tube
portion 5 through a lumen. That is, the catheter tube portion 5 is
a portion actually inserted into the patient.
[0036] The catheter portion 2 of the present invention further
includes an expandable soft tip portion 6 with a distal tip area
6a. The expandable tip 6 is in the form of a sleeve which has an
outer diameter which is nominally the same as the outer diameter of
the catheter tube portion 5. The distal soft tip area 6a initially
contacts tissues of the patient as the catheter tube portion 5 is
inserted into the patient, and minimises discomfort in the patient
by virtue of its softness. The expandable soft tip portion 6 is
flexible in both the axial and radial directions, and particularly
is expandable in the radial direction. This expandable tip portion
6 may be made of a radiopaque or non-radiopaque material. Examples
of materials for the expandable tip portion 6 include PEBA
(polyether block polyamide), nylon, polyurethane or
polyethylene.
[0037] FIGS. 2, 3 and 4 provide further details of the catheter
portion 2 including the expandable soft portion 6. The catheter
portion 2 includes extension legs 10 formed inside of the
expandable portion 6. That is, the catheter tube portion 5 is
processed to form extension legs 10 at the leading edge of the
catheter tube portion 5. The extension legs 10 can be formed in the
catheter tube portion 5 by, for example, cutting catheter tube
portion 5 using a punch and die set with a profile to achieve a
desired taper in the extension legs 10. The extension legs 10
provide a reinforcement in the axial direction of the expandable
portion 6 over their length to enhance the strength of expandable
portion 6 in the axial direction, while still providing expansion
in the radial direction. In the embodiment shown in FIGS. 2-4 four
extension legs 10 are equi-spaced around the expandable portion 6
to provide support in the axial direction and uniform flexibility
in the radial direction. These extension legs 10 are tapered
towards the free end of the expandable portion 6 to provide a
gradually increasing controlled axial flexibility to allow the
catheter tube portion 5 to be comfortably guided into the
patient.
[0038] The expandable portion 6, which as noted above can be formed
of a radiopaque or non-radiopaque material such as PEBA, nylon,
polyurethane or polyethylene, can be secured to the main catheter
tube portion 5 by heating such as by RF (radio frequency) welding
the expandable portion 6 to the main catheter tube portion 5. On
heating, the extension legs 10 merge into the expandable portion
6.
[0039] It will be noted that the expandable soft portion 6 extends
distally beyond the axial extent of the extension legs 10 to
provide the distal soft tip 6a which is not axially reinforced. The
soft tip 6a has a free end that is rounded internally at 23 for
ease of passage of an article 3, and is also rounded externally at
24 for ease of atraumatic passage of the tip through a body
passageway such as the vasculature.
[0040] FIG. 6 shows an actual implementation of the catheter
portion 2 in the present invention. Element 12 shows distal tips of
the extension legs 10, and element 13 shows proximal tips of the
extension legs 10, which tips 12, 13 can be radiused. That is, the
tips 12, 13 of the extension legs 10 can be rounded to prevent
creating a sharp edge, and thereby generating a weak point in the
soft tip area 6a or the expandable portion 6. Generating a weak
point in the expandable portion 6 could result in a tear in the
soft tip, and if the tips 12, 13 of the extension legs 10 are
radiused such a weak point and resulting tear may be prevented.
Typical dimensions in millimeters are as follows:
1 1.sub.1 18.00 .+-. 1.50 1.sub.2 15.00 .+-. 0.25 1.sub.3 0.70
[0041] FIGS. 5(a) to 5(d) show the catheter 2 of the present
invention in use as a retrieval catheter as an example of one use
of catheter 2. As shown in FIG. 5(a), an article 3 for retrieval,
for example a sample or clot within a patient or a medical device
such as a stent or filter previously inserted in the patient, is
approached by the catheter tube portion 5. A retrieval device may
be inserted in the introducer 1 and through the hub 20, through the
catheter tube portion 5, and then through the expandable portion 6,
to contact the sample 3. Alternatively the article 3, especially
when in the form of a medical device such as a filter, may be
attached, on introduction, to a guide wire 11 as shown in FIG.
5(a). Th retrieval device then retrieves the article 3 into the
expandable portion 6 of the catheter portion 2 as shown in FIGS.
5(b) to 5(d). The article 3 is first pulled back by pulling the
guide wire and engages the distal tip 6a which is not reinforced
and expands radially to receive the proximal end of the article 3.
As the article 3 is drawn further back into the expandable portion
6 the expandable portion 6 expands radially outwardly. However the
expandable portion 6 is gradually axially reinforced by the
extension legs 10 to smooth the capture of the article 3. This
expandable portion 6 extending axially from the catheter tube
portion 5 is flexible relative to the catheter tube portion 5. The
catheter portion includes reinforcement means to enhance the axial
strength of the expandable portion 6 while facilitating radial
expansion of the tip to accommodate an article 3 in the expandable
portion 6. The tip expands to accommodate the article 3. As noted
above, the extension legs 10 provide some support in the axial
direction, but still allow expansion in the radial direction, to
thereby allow expandable portion 6 to expand to allow the article 3
to be drawn into the expandable portion 6. The catheter tube
portion 5 can then be removed from the patient with the article 3
housed therein.
[0042] In this way, this operation in the present invention allows
a sample or device 3 which may be larger than the catheter
tube-portion 5 to be retrieved from a patient. A medical device
which may be larger than the catheter tube portion 5 can also be
delivered to a patient in a similar manner.
[0043] Obviously, numerous modifications and variations of the
present invention are possible in light of the above teachings. It
is therefore to be understood that within the scope of the appended
claims the present invention may be practised otherwise than as
specifically disclosed therein.
* * * * *