U.S. patent application number 12/136994 was filed with the patent office on 2008-10-02 for system and method for establishing vascular access.
Invention is credited to John E. Carlson, Scott L. Harris, Michael J. Orth, Craig K. Tsuji.
Application Number | 20080243169 12/136994 |
Document ID | / |
Family ID | 24955125 |
Filed Date | 2008-10-02 |
United States Patent
Application |
20080243169 |
Kind Code |
A1 |
Carlson; John E. ; et
al. |
October 2, 2008 |
SYSTEM AND METHOD FOR ESTABLISHING VASCULAR ACCESS
Abstract
Systems, kits, and methods for establishing vascular access are
described. A system typically includes a radially expandable
sleeve, a dilator, and a guidewire. The methods comprise
positioning the guidewire through an initial tissue tract, passing
the radially expandable sleeve over the guidewire through the
tissue tract to a target blood vessel, and thereafter passing the
dilator over the guidewire and through the radially expandable
sleeve to effect radial expansion of the sleeve. Use of the sleeve
reduces the risk of injuring tissue surrounding the tissue tract by
lessening the axial forces imparted to the tissue. Kits comprise at
least the radially expandable sleeve together with instructions for
use.
Inventors: |
Carlson; John E.; (San Jose,
CA) ; Tsuji; Craig K.; (Santa Clara, CA) ;
Harris; Scott L.; (Los Gatos, CA) ; Orth; Michael
J.; (Morgan Hill, CA) |
Correspondence
Address: |
Tyco Healthcare Group LP
60 MIDDLETOWN AVENUE
NORTH HAVEN
CT
06473
US
|
Family ID: |
24955125 |
Appl. No.: |
12/136994 |
Filed: |
June 11, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10704073 |
Nov 5, 2003 |
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12136994 |
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09735282 |
Dec 11, 2000 |
6692462 |
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10704073 |
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09314878 |
May 19, 1999 |
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09735282 |
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Current U.S.
Class: |
606/198 |
Current CPC
Class: |
A61M 25/0662 20130101;
A61B 17/3439 20130101; A61B 17/3421 20130101; A61B 17/3431
20130101; A61B 17/3415 20130101 |
Class at
Publication: |
606/198 |
International
Class: |
A61M 29/00 20060101
A61M029/00 |
Claims
1. A method for establishing vascular access comprising the steps
of: introducing a distal end of a guidewire into a target vessel;
introducing a radially expandable sleeve over the guidewire such
that a distal end of the sleeve lies within the target vessel; and
introducing a dilator over a proximal end of the guidewire and into
a proximal end of the sleeve, and advancing the dilator distally
along the guidewire and into the sleeve to effectuate radial
expansion of the sleeve.
2. The method of claim 1, further comprising the step of providing
a dilator including an outer sheath at least partially surrounding
a removable inner member, and removing the inner member of the
introduced dilator, whereby the outer sheath of the dilator is left
in place within the sleeve.
3. The method of claim 1, further comprising the step of providing
a dilator defining a longitudinal lumen therethrough having an
internal dimension between approximately 0.46 mm and approximately
1.0 mm.
4. The method of claim 3, wherein the step of providing a dilator
includes providing a dilator having an outer dimension between
approximately 1.0 mm and approximately 3.3 mm.
5. The method of claim 4, wherein the step of providing a dilator
includes providing a dilator having an outer dimension between
approximately 1.3 mm and approximately 2.5 mm.
6. The method of claim 1, further comprising the step of providing
a radially expandable sleeve including a tubular braid formed of a
mesh of non-elastic filaments which shorten axially as they are
expanded radially.
7. A method for establishing access to a vascular lumen, the method
comprising the steps of: positioning a guidewire through tissue
such that a distal end thereof is disposed within the vascular
lumen; providing an access assembly including a sleeve introducer
positioned within a radially expandable sleeve; introducing the
access assembly over the guidewire such that a distal end of the
sleeve lies within a target vessel; and introducing a dilator over
the sleeve introducer such that the dilator is disposed between the
sleeve introducer and the radially expandable sleeve, wherein the
dilator has a diameter that is larger than an initial diameter of
the radially expandable sleeve, whereby the dilator radially
enlarges a tissue tract formed in the tissue and facilitates access
to the vascular lumen.
8. The method of claim 7, further including the step of removing
the sleeve introducer and the guidewire from the vascular lumen,
thereby leaving the dilator in place within the sleeve.
9. The method of claim 7, wherein the step of positioning a sleeve
introducer within a radially expandable sleeve includes positioning
a sleeve introducer having a tapered distal member with a shaft
extending proximally therefrom within the radially expandable
sleeve, the distal member being configured and dimensioned to
facilitate passage of the access assembly through a tissue tract
formed in the tissue to the vascular lumen.
10. The method of claim 9, wherein the step of positioning a sleeve
introducer within a radially expandable sleeve includes positioning
a sleeve introducer including a shaft defining a lumen therethrough
that is configured to receive the guidewire.
11. The method of claim 10, wherein the step of positioning a
sleeve introducer within a radially expandable sleeve includes
positioning a sleeve introducer in which the tapered distal member
of the sleeve introducer has a proximal end defining a radial
dimension substantially equal to an outer radial dimension defined
by the distal end of the radially expandable sleeve.
12. The method of claim 9, wherein the step of introducing a
dilator includes introducing a dilator defining a longitudinal
lumen therethrough configured to receive the shaft of the sleeve
introducer.
13. The method of claim 12, wherein the step of introducing a
dilator includes introducing a dilator defining a longitudinal
lumen therethrough with an internal dimension between approximately
0.46 mm and approximately 1.0 mm.
14. The method of claim 12, wherein the step of introducing a
dilator includes introducing a dilator having an outer radial
dimension along its entire length that is larger than an inner
radial dimension of the sleeve such that insertion of the dilator
into the sleeve effectuates radial expansion of the sleeve.
15. The method of claim 14, wherein the step of positioning a
sleeve introducer within a radially expandable sleeve includes
positioning a sleeve introducer within a radially expandable sleeve
having a tubular braid formed of a mesh of non-elastic filaments
which shorten axially as they are expanded radially.
16. The method of claim 14, wherein the step of introducing a
dilator includes introducing a dilator having an outer dimension
between approximately 1.0 mm and approximately 3.3 mm.
17. An improved method of establishing percutaneous access to a
target vessel over a guidewire positioned within a tissue tract and
having a distal end positioned within the target vessel, wherein
the improved method comprises the steps of: positioning a sleeve
introducer within a radially expandable sleeve to form an access
assembly; introducing and advancing the access assembly over the
guidewire such that a distal end of the radially expandable sleeve
lies within the target vessel; and introducing a dilator over the
sleeve introducer and into the radially expandable sleeve to
thereby enlarge the tissue tract and facilitate expanded access to
the target vessel.
18. The improved method of claim 17, wherein the step of
positioning a sleeve introducer within a radially expandable sleeve
includes positioning a sleeve introducer having a tapered distal
member with a shaft extending proximally therefrom, the tapered
distal member being configured and dimensioned to facilitate
passage of the access assembly through the tissue tract to the
target vessel.
19. The improved method of claim 18, wherein the step of
positioning a sleeve introducer within a radially expandable sleeve
includes positioning a sleeve introducer wherein the shaft defines
a lumen therethrough that is configured to receive the
guidewire.
20. The method of claim 19, wherein the step of positioning a
sleeve introducer within a radially expandable sleeve includes
positioning a sleeve introducer wherein the distal member of the
sleeve introducer has a proximal end defining a radial dimension
substantially equal to an outer radial dimension defined by the
distal end of the sleeve, wherein the distal member tapers distally
from the proximal end thereof.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a Divisional Application which claims
the benefit of and priority to U.S. application Ser. No.
10/704,073, filed on Nov. 5, 2003, which is a Divisional
Application which claims the benefit of and priority to U.S.
application Ser. No. 09/735,282, filed on Dec. 11, 2000, now U.S.
Pat. No. 6,692,462, which is a Continuation-in-Part Application
which claims the benefit of and priority to U.S. application Ser.
No. 09/314,878, filed on May 19, 1999, the full disclosures of each
of which being incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to medical devices
and medical methods. In particular, the present invention relates
to systems, kits, and techniques for establishing percutaneous
vascular access.
[0004] Access to patient blood vessels is necessary for a wide
variety of diagnostic and therapeutic purposes. For example,
intravascular catheters are introduced to both the arterial
vasculature and the venous vasculature, typically using either
surgical cut down techniques or percutaneous introduction
techniques. Of particular interest to the present invention, the
most common percutaneous introduction technique is referred to as
the Seldinger technique. While a wide variety of variations exist,
the basic Seldinger technique relies on initially accessing a
target blood vessel with a needle. A guidewire is then passed
through the needle into the blood vessel, and the needle withdrawn
over the guidewire. A dilator is then passed over a guidewire to
enlarge the diameter of the tissue tract so that it can accommodate
a larger introducer sheath. Once the introducer sheath is in place,
access to the blood vessel can be reliably obtained through a lumen
of the sheath.
[0005] With the introduction of a greater number and variety of
intravascular techniques, including angioplasty, atherectomy,
endovascular aneurysm repair, minimally invasive cardiac surgery,
and the like, a need has arisen to provide relatively large
diameter access to the vasculature. Thus, access sheaths having a
diameter of 24 French (8 mm) or greater are now commonly introduced
using the Seldinger or other percutaneous techniques. As the number
and size of procedures increase, so does the risk of complications
which place individual patients at risk and which are costly to the
healthcare system.
[0006] As larger and larger access diameters are sought, the need
to dilate the tissue tract becomes greater. The use of conventional
dilators, however, can significantly traumatize the skin. In
particular, advancement of a conventional dilator through a tissue
tract exerts significant axial forces on the tissue, potentially
causing injury and delamination of adjacent tissue layers.
[0007] For these reasons, it would be desirable to provide improved
systems, kits, and methods for establishing percutaneous vascular
access for catheterization and other vascular procedures. In
particular, it would be desirable to provide vascular access
techniques which could dilate a percutaneous tissue tract with
minimum trauma to tissue surrounding the tract. Such techniques
should be suitable for forming large (as well as small) diameter
access channels, typically having diameters as large as 6 mm,
preferably as large as 8 mm, or larger. It would be still further
desirable if the improved systems, kits, and methods would require
little modification of existing techniques and systems for
establishing vascular access. At least some of these objectives
will be met by the inventions described hereinafter.
[0008] 2. Description of the Background Art
[0009] The use of radially expanding dilators for accessing
non-vascular body locations is described in U.S. Pat. Nos.
5,814,058; 5,431,676, 5,183,464, and copending application Ser. No.
08/424,696, all of which are commonly assigned with the present
application and the full disclosures of which are incorporated
herein by reference. U.S. Pat. No. 5,230,705, describes use of a
needle disposed within a dilation structure for use in intravenous
catheterization. See also U.S. Pat. Nos. 5,312,417; 5,246,424;
5,201,756, 5,139,511, and 4,899,729.
SUMMARY OF THE INVENTION
[0010] The present invention provides improved systems, kits, and
methods for establishing percutaneous access to a patient's
vasculature. Access can be established to a variety of particular
blood vessels, including both arteries and veins, such as the
femoral artery, radial artery, and the like. The purpose for
accessing the vasculature can be diagnostic, such as angiography,
intravascular ultrasound, cardiac mapping, or the like, or can be
therapeutic, such as angioplasty, atherectomy, minimally invasive
cardiac surgeries, endovascular aneurysm repair, cardiac ablation,
or the like.
[0011] The methods of the present invention comprise particular
improvements over the Seldinger technique, as described above,
employing a sheath dilator for expanding an initial needle
penetration to a target blood vessel. As set forth in the
Background section, use of a dilatorlsheath assembly directly
within a tissue tract can subject the tissue to significant axial
forces which can delaminate or otherwise damage the tissue
surrounding the tissue tract.
[0012] The present invention reduces the risk of injuring the
tissue by introducing a radially expandable sleeve over a guidewire
which has been placed through the tissue tract using otherwise
conventional techniques. The radially expandable sleeve will be
immobilized (typically being manually held) relative to the tissue
tract so that axial advancement of a sheath/dilator or other
dilating member through the radially expandable sleeve will impart
little or no axial force to the underlying tissue. Instead, only
radially expansive forces will be transmitted outwardly through the
sleeve.
[0013] Systems according to the present invention for establishing
vascular access over a guidewire comprise a dilator and a radially
expandable sleeve. The dilator has a lumen sized to be introduced
over the guidewire. The guidewire will have a pre-selected diameter
which is generally constant over its entire length. The diameter
will be relatively small, typically being either 0.36 mm (0.014
in.) or 0.89 mm (0.035 in.), which are conventional sizes for
guidewires used for vascular access. The lumen of the dilator will
be sized slightly greater than the outside diameter of the
guidewire with which it is to be used, typically being 0.46 mm
(0.018 in.) or 1 mm (0.4 in.) for each of the guidewire sizes
mentioned above. The dilator will have an outside diameter selected
to provide for a desired degree of radial expansion of the tissue
tract. Typically, the outside diameter of the dilator will be in
the range from 1 mm to 2.5 mm for the smaller guidewire size and
1.3 mm to 3.3 mm for the larger guidewire size.
[0014] The radially expandable sleeve will have a lumen
therethrough and an unexpanded diameter which is only slightly
greater than the diameter of the associated guidewire, e.g., 0.41
mm (0.016 in.) for the 0.36 mm (0.014 in.) guidewire and 0.96 mm
(0.038 in.) for the 0.89 mm (0.035 in.) guidewire. Typically, the
sleeve will have an outside diameter which is no more than 300% of
the guidewire diameter, preferably being no more than 200% of the
guidewire diameter. The sleeve, however, will have an expandable
outer wall which permits the dilator to be introduced over the
guidewire and through the sleeve to cause expansion. In a first
embodiment, the outer wall of the radially expandable sleeve can be
compliant or elastic so that its cross-section collapses after
expansion if the dilator used for expansion is withdrawn.
Typically, the compliant or elastic structure will be reinforced
with a tubular braid, e.g., a braid formed as a mesh of non-elastic
filaments where radial expansion will cause axial shortening of the
braid. The braid may be embedded in the elastic or compliant layer
or may be covered by the elastic or compliant layer.
[0015] Alternatively, the radially expandable sleeve may have a
plastically deformable body or may comprise a locking structure so
that it retains its expanded diameter after dilation. Typically,
the plastically deformable radially expandable sleeves will also be
reinforced with the braid. For example, the braid may be covered or
impregnated with a suitable plastically deformable material, such
as expanded PTFE, irradiated polyesters, and the like. As an
alternative or an addition to use of the plastically deformable
sleeve matrix, the braid reinforcement may be configured so that
the braid filaments interlock upon radial expansion. Thus, the
filaments in themselves will resist radial collapse after the
sleeve has been expanded.
[0016] When the system employs an elastic or compliant radially
expandable sleeve, it will be necessary to provide further system
component(s) to retain the sleeve in its expanded configuration
after the dilator has effected dilation. Conveniently, this can be
accomplished using a conventional sheath/dilator assembly as the
dilator. After the sleeve has been expanded (thus expanding the
tissue tract), an inner portion of the assembly, usually referred
to as the dilator, can be withdrawn from the sheath, leaving the
sheath in place to maintain the expanded diameter of the tissue
tract. While this is an effective approach and utilizes a device
with which the treating physician is quite familiar, it has the
disadvantage that the radially expandable sleeve adds a very small
thickness to the diameter to which the tissue tract is expanded.
Use of the plastically deformable or locking sleeve will, in
contrast, allow use of a simple dilator, i.e., one without an
associated sheath. Thus, there will be no additional structure and
no need to dilate the tissue tract any more than would be required
with a conventional sheath dilator.
[0017] Optionally, the system may further comprise a sleeve
introducer adapted to facilitate introduction of the sleeve over a
guidewire through the tissue tract. In some patients, conventional
Seldinger and other access techniques can be difficult due to the
presence of scar tissue or other complicating factors. In such
cases, significant pushing force may be required to advance the
sleeve over the guidewire. While the small profile of the
introducer sleeve reduces the force necessary for introduction over
the guidewire, in some cases it will be desirable to still further
reduce the introduction force. Such a reduction in introduction
force can be accomplished by providing a tapered distal tip on the
sleeve. While this could be done by modifying the design of the
sleeve itself, it is more easily accomplished using a separate
introducer sleeve having a tapered distal end a lumen therethrough.
The sleeve is configured to receive a guidewire through its lumen
and to be received within the lumen of the radially expandable
sleeve. By then placing the radially expandable sleeve over the
sleeve introducer, the temporary assembly of the sleeve and sleeve
introducer can be introduced over the guidewire so that the tapered
end of the sleeve introducer first advances through and dilates the
tissue tract to reduce the necessary introduction force. After the
distal end of the assembly reaches the blood vessel, the dilator
may then be introduced over the assembly, i.e., the lumen of the
dilator will pass over the exterior of the sleeve introducer. After
dilation of the radially expansible sleeve is accomplished, the
sleeve introducer and guidewire can then be removed from the
expanded access channel defined by the dilator.
[0018] Methods according to the present invention for establishing
vascular access comprise forming a percutaneous tissue tract to a
target blood vessel. Typically the tissue tract is initially formed
using a needle and guidewire according to conventional techniques,
such as the first steps in a Seldinger access protocol. A guidewire
is positioned in the tissue tract, and a radially expandable sleeve
positioned over the guidewire and through the tissue tract so that
a distal end of the sleeve lies in the blood vessel. A proximal end
of the sleeve will remain outside the tissue tract, and the sleeve
may then be expanded from a narrow diameter configuration to a
larger diameter configuration to provide an access lumen to the
blood vessel. In a first embodiment, the sleeve will be plastically
deformable or otherwise capable of maintaining its larger diameter
configuration, and expansion can be effected using a simple dilator
without an associated sheath. In an alternative embodiment, the
radially expandable sleeve will be elastic or compliant and
expansion can be effected using a sheath dilator where the dilator
is removed after expansion and the sheath left in place to maintain
the desired access lumen. Usually, the radially expandable sleeve
which is advanced over the guidewire will have an outer diameter
which is no more than 300% larger than the guidewire diameter,
preferably no more than 200% larger.
[0019] The present invention still further provides kits for
performing any of the methods described herein. The kits will
comprise at least a radially expandable sleeve together with
instructions setting forth a method according to the present
invention. Usually, the kits will further comprise a dilator and
optionally still further comprise a guide dilator may be a simple
dilator with no associated access sheath when the radially sleeve
is plastically deformable or otherwise capable of maintaining its
expanded diameter configuration. Alternatively, the dilator can be
a conventional sheath/dilator combination when the radially
expandable sleeve is elastic or compliant.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 illustrates a system comprising a radially expandable
sleeve, a dilator, and a guidewire, according to the present
invention.
[0021] FIGS. 2A-2E illustrate use of the system of FIG. 1 for
establishing vascular access to a target blood vessel according to
a method of the present invention.
[0022] FIG. 3 illustrates a sleeve introducer which may combined in
an assembly with a radially expandable sleeve and optionally a
guidewire according to the systems and methods of the present
invention.
[0023] FIGS. 4A-4C illustrate use of the sleeve introducer assembly
of FIG. 3 in the methods of the present invention.
[0024] FIG. 5 illustrates a system comprising a radially expandable
sleeve, a needle and a dilator, according to the present
invention.
[0025] FIG. 6A-6D illustrate use of the system of FIG. 5 for
establishing vascular access to a target blood vessel, according to
the present invention.
[0026] FIG. 7 illustrates a kit constructed in accordance with the
principles of the present invention.
DESCRIPTION OF THE SPECIFIC EMBODIMENTS
[0027] Referring to FIG. 1, a system 10 for establishing vascular
access according to the principles of the present invention
comprises a radially expandable sleeve 12, a dilator 14, and a
guidewire 16. The radially expandable sleeve comprises a radially
expandable tubular body having a proximal end, a distal end, and an
axial lumen extending from the proximal end to the distal end.
Usually, a handle 20 is provided at the proximal end of the body so
that the sleeve can be manually held during use, e.g., tension can
be applied on the handle as the dilator 14 is passed through the
body of the sleeve as described in more detail below. The radially
expandable sleeve 12 may have a compliant or elastic structure
which permits expansion from an initial small diameter (radially
collapsed) configuration to a larger diameter configuration which
is caused by introduction of the dilator therethrough. Use of the
compliant or elastic sleeve will require a separate component for
maintaining the expanded diameter of the tissue tract, as described
in more detail below. Alternatively, the radially expandable sleeve
can have a plastic or other locking structure so that, once
expanded, it will retain its large diameter configuration without
the need for using other supports, devices, or the like.
[0028] An exemplary radially expandable sleeve comprises an
expandable tubular braid which is initially an elongated,
narrow-diameter configuration. The braid may be open, but will
usually be laminated or covered with a coating or layer of elastic
or plastically deformable material, such as silicone rubber, latex,
polyethylene, urethane, C-flex, or the like. The braid is
preferably formed as a mesh of individual non-elastic filaments,
such as polyamide fibers, polyester, stainless steel, or the like.
The specific structures for forming such radially expandable
sleeves are described in U.S. Pat. No. 5,814,058, a full disclosure
of which has previously been incorporated herein by reference.
[0029] Exemplary sleeve diameters have been set forth above.
Usually, the sleeve will have a length in the range from 3 cm to 30
cm, more usually from 10 cm to 25 cm. The exact dimensions of the
sleeve will depend on the desired use and location of the target
blood vessel to be accessed.
[0030] A dilator 14 may be a simple dilator having a tapered distal
end and smooth transition to a uniform body diameter. The dilator
will have a guidewire lumen to permit introduction over the
guidewire and through the radially expandable sleeve, as described
in more detail below. As illustrated, dilator 14 is in the form of
a conventional sheath/dilator assembly of the type which is
commercially available from vendors, such as Bard Cardiology,
Billerica, Mass., under the trade name Input.TM.. The
dilator/sheath assembly includes an outer sheath 30 with an inner
tapered dilator 32 which is removable from the sheath. The sheath
has a hemostatic valve 36 at its distal end and a side access tube
37 which permits perfusion or aspiration through the lumen of the
sheath. The dilator 32 has a handle 38 at its proximal end and an
internal lumen which permits introduction over the guidewire 16.
The guidewire 16 may be a conventional vascular access guidewire,
typically having a diameter of either 0.36 mm (0.014 in.) or 0.89
mm (0.035 in.), and a length in the range from 35 cm to 100 cm.
[0031] Referring now to FIGS. 2A-2E, use of the system 10 for
accessing a blood vessel BV will be described. First, an initial
tissue tract is formed using a needle N and syringe S assembly as
shown in FIG. 2A. After access of the needle into the blood vessel
BV is confirmed, typically by noting the flow of blood into the
syringe S, the syringe may be removed and a guidewire GW placed
through the needle into the blood vessel BV. The needle N may then
be withdrawn over the proximal end of the guidewire GW, leaving the
guidewire in place through a tissue tract TT, as illustrated in
FIG. 2B. The radially expandable sleeve 12 is then introduced over
the guidewire GW so that its distal end 13 lies within the blood
vessel BV, as shown in FIG. 2C. The dilator 14 is then introduced
over the guidewire GW so that the distal end of the dilator 14
causes radial expansion of the sleeve 12, as shown in FIG. 2D.
After the dilator has been fully inserted through the sleeve 12 an
inner dilator portion 32 may be withdrawn from the sheath 30,
leaving the sheath in place through the radially expandable sleeve
12, both being over the guidewire GW, as shown in FIG. 2E. Vascular
access has now been established for performing any one of a wide
variety of diagnostic or therapeutic procedures as well described
in the medical and patent literature.
[0032] Referring now to FIG. 3, a sleeve introducer 50 may be
combined with a radially expandable sleeve 52 and optionally a
guidewire 54 to form an expansible sleeve assembly intended for
introduction through difficult tissue tracts, i.e., tissue tracts
which might otherwise require excessive pushing force to introduce
a sleeve according to the methods of the present invention. The
sleeve introducer 50 comprises a tapered distal end 60, typically a
conical element having a smaller diameter at its distal end and a
larger diameter at its proximal end. The introducer 50 further
comprises a shaft 62 extending proximally from the tapered distal
end 60. The shaft will be a small tube, and the distal end 60 and
shaft 62 together define a lumen which may be introduced over the
guidewire 54. The outer diameter of the shaft 62 is selected so
that it fits within the inner diameter of radially expandable
sleeve 52. Preferably, the proximal end of the tapered distal end
60 will have a diameter which is the same as the outer diameter of
the distal end 66 of the radially expandable sleeve 52. In this
way, the sleeve introducer 50 may be placed within the lumen of the
radially expandable sleeve 52 to form an assembly having a tapered
distal end which facilitates introduction over the guidewire
54.
[0033] Referring now to FIGS. 4A-4C use of the assembly of FIG. 3
for dilating the tissue tract to a blood vessel BV will be
described. The guidewire 54 is first placed into the blood vessel
BV, typically using a needle as described above in connection in
FIG. 3A. Usually, the guidewire 54 used for more difficult
introductions will have a slightly smaller diameter than would
otherwise be necessary, such as a diameter of about 0.6 mm (0.025
in.). The assembly of the sleeve introducer 50 and radially
expandable sleeve 52 is then introduced over the guidewire, with
the guidewire passing directly through the lumen of the introducer
50. The tapered distal end 60 of the introducer 50 thus leads the
way through the tissue over the guidewire 54, so that the taper
facilitates passage of the assembly through the tissue. After the
assembly is in place, as shown in FIG. 4B, a dilator 30 having an
inner portion 32 may be introduced directly over the exterior of
the sleeve introducer 50, as shown in FIG. 4C. After the tissue
tract has been completely dilated, the combination of the sleeve
introducer 50 and guidewire 54 may be withdrawn, leaving the inner
diameter of the inner dilator portion 32 available for expanded
access to the blood vessel BV.
[0034] Alternatively, as shown in FIG. 5, a system 110 for
establishing vascular access according to the principles of the
present invention comprises a needle N, a radially expandable
sleeve 112, and a dilator 114. The dilator 114 may be similar or
identical to the dilator 14 previously described. However, in this
case the dilator need not have a guidewire lumen. As previously
illustrated, dilator 114 may be in the form of a conventional
sheath/dilator assembly of the type which is commercially available
from vendors, such as Bard Cardiology, Billerica, Mass., under the
trade name Input.TM.. The dilator/sheath assembly includes an outer
sheath 130 with an inner tapered dilator 132 which is removable
from the sheath. The sheath has a hemostatic valve 136 at its
distal end and a side access tube 137 which permits perfusion or
aspiration through the lumen of the sheath. The dilator 132 has a
handle 138 at its proximal end. The dilator 114 shown in FIG. 5 is
a conventional dilator, having a tapered distal end and a generally
cylindrical body proximal to the distal end, without an associated
access sheath. Such a dilator is suitable for use with or without
an associated sheath.
[0035] The radially expandable sleeve 112 may be similar or
identical to the sleeve 12 previously described and comprises a
radially expandable tubular body having a proximal end, a distal
end, and an axial lumen extending from the proximal end to the
distal end. The expandable sleeve 112 may have a compliant or
elastic structure which permits expansion from an initial small
diameter (radially collapsed) configuration to a larger diameter
configuration which is caused by introduction of the dilator 114
therethrough. Use of the compliant or elastic sleeve may require a
separate component for maintaining the expanded diameter of the
tissue tract. Such a component may be an access sheath associated
with the dilator. In this case, the sleeve may contain a seal to
prevent blood loss when the sheath is in place. As previously
mentioned, the sheath itself may contain a hemostasis valve 136
preventing pressurized flow of blood within the blood vessel to
escape through the sheath.
[0036] Alternatively, the radially expandable sleeve can have a
plastic or other locking structure so that, once expanded, it will
retain its large diameter configuration without the need for using
other supports, devices, or the like, such as an access sheath. In
this case, the sleeve itself would include a hemostasis valve
within its axial lumen. Such a valve will maintain a closed
position when the dilator or other devices are removed from the
sleeve, thus preventing the pressurized flow of blood within the
blood vessel to escape through the sleeve. The valve will maintain
an open position when activated, such as by the insertion of a
catheter or other device through the valve. For example, a duckbill
or miter valve would be particularly suitable.
[0037] Referring now to FIGS. 6A-6C, use of the system 110 for
access vessel BV will be described. First, an initial tissue tract
is formed using the expandable sleeve 112 mounted on an assembly
comprising the needle N and a syringe S, as shown in FIG. 6A. After
access of the needle into the blood vessel BV is confirmed,
typically by noting the flow of blood into the syringe S, the
needle/syringe assembly is withdrawn leaving the sleeve 112 in
place though a tissue tract TT to the blood vessel BV, as
illustrated in FIG. 6B. The sheath 130 dilator 132 assembly is then
introduced through the sleeve 112 causing radial expansion of the
sleeve 112, as shown in FIG. 6C. After the assembly has been fully
inserted through the sleeve 112, the inner dilator portion 132 may
be withdrawn from the sheath 130, leaving the sheath in place
through the radially expandable sleeve 112, as shown in FIG. 6D.
Vascular access has now been established for performing any one of
a wide variety of diagnostic or therapeutic procedures as well
described in the medical and patent literature.
[0038] Referring now to FIG. 7, kits according to the present
invention will comprise at least a radially expandable sleeve 12 or
112 together with instructions for use IFU setting forth any of the
methods according to the principles of the present invention.
Usually, a dilator 14 or 114 will also be included in the kit. The
dilator 14 or 114 is shown as a simple dilator without an
associated access sheath. Such a dilator is suitable for use with
or without a sheath. The kits may optionally further comprise a
guidewire GW, a sheath, a sleeve introducer 50, and/or a needle N
and all kit components will typically be packaged in a box, tray,
tube, pouch, or other conventional medical device package P. The
kit components which are employed in the medical procedure will
typically be maintained within sterile packaging, with individual
components being packaged either together or separately in
different sterile containers. Usually, even when packaged in
separate sterile containers, all components of the kit will be
placed together within a common package. The instructions for use
may be provided on a separate printed sheet, such as a conventional
package insert, or may be printed in whole or in part on other
portions of the packaging or the device itself.
[0039] While the above is a complete description of the preferred
embodiments of the invention, various alternatives, modifications,
and equivalents may be used. Therefore, the above description
should not be taken as limiting the scope of the invention which is
defined by the appended claims.
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