U.S. patent application number 10/917974 was filed with the patent office on 2006-02-16 for catheter incorporating a guidewire exit ramp.
This patent application is currently assigned to SciMed Life Systems, Inc.. Invention is credited to Michael P. Boutillette.
Application Number | 20060036233 10/917974 |
Document ID | / |
Family ID | 35800952 |
Filed Date | 2006-02-16 |
United States Patent
Application |
20060036233 |
Kind Code |
A1 |
Boutillette; Michael P. |
February 16, 2006 |
Catheter incorporating a guidewire exit ramp
Abstract
Guidewire exit ramp members that may be placed over a tubular
member having a guidewire lumen, which longitudinally extending and
laterally accessible, and methods of use. The guidewire exit ramp
member can be placed to force a guidewire loaded through the lumen
in a first direction to be forced out of the lumen via an opening,
slit or channel. The guidewire exit ramp member, in an illustrative
embodiment, takes the form of a relatively short member having a
proximal portion and a distally extending flap. The flap may be
designed to enter and remain in a longitudinally accessible
guidewire lumen. Combinations of such ramp members and device
shafts having longitudinally extending laterally accessible
guidewire lumens are also disclosed, as are methods for securing
such combinations together. A method of backloading a guidewire
into a catheter while causing lateral exit of the guidewire at a
desired location is also shown.
Inventors: |
Boutillette; Michael P.;
(Waltham, MA) |
Correspondence
Address: |
CROMPTON, SEAGER & TUFTE, LLC
1221 NICOLLET AVENUE
SUITE 800
MINNEAPOLIS
MN
55403-2420
US
|
Assignee: |
SciMed Life Systems, Inc.
|
Family ID: |
35800952 |
Appl. No.: |
10/917974 |
Filed: |
August 12, 2004 |
Current U.S.
Class: |
604/528 ;
600/585; 606/108 |
Current CPC
Class: |
A61M 25/00 20130101;
A61M 2025/0183 20130101; A61M 29/02 20130101; A61M 25/0169
20130101 |
Class at
Publication: |
604/528 ;
600/585; 606/108 |
International
Class: |
A61M 25/01 20060101
A61M025/01 |
Claims
1. A guidewire exit ramp member for use with an elongate medical
device having a longitudinally extending laterally accessible
guidewire lumen, the member having a proximal end and a distal end,
the member comprising: a proximal portion extending distally from
the proximal end, the proximal portion shaped and sized to surround
and receive an axial portion of the elongate medical device; and a
flap extending distally from the proximal portion, the flap sized
for entry into the guidewire lumen.
2. The member of claim 1, further comprising a distal shaft portion
extending distally from the proximal portion, the distal shaft
portion shaped to receive the elongate medical device when the flap
is placed in the guidewire lumen.
3. The member of claim 2, wherein the flap comprises a flat end
portion.
4. The member of claim 2, wherein the flap includes a distal end
shaped to correspond to a portion of the guidewire lumen.
5. The member of claim 2, wherein the flap is flexible such that,
when the flap is disposed within the guidewire lumen, a guidewire
passing from a location proximal of the member within the guidewire
lumen is readily allowed past the flap in the guidewire lumen.
6. The member of claim 5, wherein the flap is shaped such that a
guidewire backloaded into the guidewire lumen will be forced out of
the guidewire lumen by the flap when the flap is placed in the
guidewire lumen.
7. A combination guidewire exit ramp member and an elongate medical
device comprising: a shaft including a longitudinally extending
laterally accessible guidewire lumen; and a ramp member including a
proximal portion extending distally from the proximal end, the
proximal portion shaped and sized to surround and receive an axial
portion of the shaft of the elongate medical device and a flap
extending distally from the proximal portion, the flap sized for
lateral entry into the guidewire lumen of the elongate medical
device.
8. The combination of claim 7, wherein the ramp member further
comprises a distal portion extending distally from the proximal
portion, the distal portion shaped to receive the elongate medical
device when the flap is placed in the guidewire lumen.
9. The combination of claim 8, wherein the flap comprises a flat
end portion.
10. The combination of claim 8, wherein the flap comprises a curved
end portion.
11. The combination of claim 8, wherein the flap includes a distal
end shaped to correspond to a portion of the guidewire lumen.
12. The combination of claim 8, wherein the flap is flexible such
that, when the flap is disposed within the guidewire lumen, a
guidewire passing from a location proximal of the member within the
guidewire lumen is readily allowed past the flap in the guidewire
lumen.
13. The combination of claim 12, wherein the flap is shaped such
that a guidewire backloaded into the guidewire lumen will be forced
out of the guidewire lumen by the flap when the flap is placed in
the guidewire lumen.
14. The combination of claim 7, wherein the elongate medical device
includes an opening cut into the guidewire lumen, the opening sized
for passage of the flap into the guidewire lumen.
15. The combination of claim 14, wherein the member is placed on
the elongate medical device such that the flap extends through the
opening into the guidewire lumen.
16. The combination of claim 15, wherein the member is secured to
the elongate medical device.
17. The combination of claim 7, wherein the elongate medical device
further includes an auxiliary lumen in addition to the guidewire
lumen.
18. The combination of claim 7, wherein the elongate medical device
includes a longitudinally accessible guidewire lumen.
19. The combination of claim 18, wherein the longitudinally
accessible guidewire lumen includes an axially extending channel
for accessing the guidewire lumen.
20. The combination of claim 18, wherein the longitudinally
accessible guidewire lumen includes a weakened wall portion
allowing access to the guidewire lumen along a length thereof.
21. A method of preparing an elongate medical device having
proximal and distal ends for use, wherein the elongate medical
device comprises an elongate shaft including a longitudinally
accessible guidewire lumen therein, the method comprising the steps
of: providing a guidewire exit ramp member having proximal and
distal ends and including: (a) a proximal portion extending
distally from the proximal end, the surrounding portion shaped and
sized to surround and receive a portion of the elongate medical
device; and (b) a flap extending distally from the proximal
portion, the flap sized for entry into the longitudinally
accessible guidewire lumen; sliding the member onto the elongate
medical device; and sliding the flap into the longitudinally
accessible guidewire lumen.
22. The method of claim 21, wherein the elongate medical device
includes an opening extending into the guidewire lumen, wherein the
step of sliding the flap into the longitudinally accessible
guidewire lumen includes sliding the flap through the opening.
23. The method of claim 21, further comprising backloading the
elongate medical device over a guidewire having proximal and distal
ends, wherein during the step of backloading: the proximal end of
the guidewire is passed into the guidewire lumen at the distal end
of the elongate medical device; and relative motion between the
guidewire and elongate medical device advances the proximal end of
the guidewire proximally within the guidewire lumen until the flap
engages the proximal end of the guidewire and forces the proximal
end of the guidewire laterally out of the guidewire lumen.
24. A guidewire ramp member for use with an elongate medical device
having a guidewire lumen, the guidewire ramp member including: a
proximal portion adapted to receive the elongate medical device
therein; and an impinging portion shaped and having sufficient
stiffness to pinch and at least partly collapse a portion of the
guidewire lumen.
25. A combination comprising: an elongate medical device including
a guidewire lumen with a wall having a transverse cut therein; and
a guidewire ramp member as in claim 24; wherein the guidewire ramp
member is placed on the elongate medical device such that the
impinging portion pinches a portion of the guidewire lumen adjacent
the transverse cut.
Description
FIELD
[0001] The present invention is related to the field of medical
devices. More particularly, the present invention is related to
catheters and other elongate medical devices incorporating
guidewire lumens.
BACKGROUND
[0002] The use of catheters for minimally invasive medical
procedures has become widespread. In many such procedures, a
guidewire is used to help place the distal end of a catheter at a
desired location. In practice, the use of a guidewire and an
elongate medical device such as a catheter can create a number of
difficulties.
[0003] If a guidewire or catheter proves unsuitable once inserted
into a patient, it is removed and replaced. With early
technologies, the catheter typically tracked over the guidewire
along its entire length. When a catheter was removed, these early
technologies required allowing the entire length of the catheter
(typically 150 cm or longer) to pass over the guidewire without
releasing the proximal end of the guidewire. This required a
guidewire having a length of at least 300 cm, or a shorter
guidewire used in combination with a guidewire extension. Such long
guidewires required extra hands in the operating arena, increasing
costs and creating a greater risk of loss of sterility, as well as
making procedures last longer.
[0004] Rapid exchange catheters and single operator exchange
catheters have been developed to make it easier and quicker to
substitute one catheter or guidewire for another. An example single
operator exchange catheter is the Autotome.TM. RX sphincterotome,
marketed by Boston Scientific Corporation, Natick, Mass., which
makes use of an elongated guidewire lumen in the form of a C-shaped
channel.
[0005] The C-shaped channel allows lateral movement of a guidewire
out of the guidewire lumen through the opening in the C-shaped
channel over the longitudinal length of the channel. Such an
opening, as well as openings or accesses created by the use of
C-shaped, U-shaped, perforated or slit guidewire lumens, makes the
longitudinally extending guidewire lumen a laterally accessible
guidewire lumen. Lumens having a weakened, thin, or thinned wall
through which a guidewire may tear for removal may also be
considered as including a laterally accessible guidewire lumen.
SUMMARY
[0006] The present invention, in an illustrative embodiment,
includes a guidewire exit ramp member that may be placed over a
tubular member having a longitudinally extending guidewire lumen
that is laterally accessible generally continuously over at least a
portion of the length of the tubular member. The guidewire exit
ramp member can be placed to force a guidewire passing into the
guidewire lumen in a first direction to be forced out of the lumen
via an opening, slit or channel. The guidewire exit ramp member, in
an illustrative embodiment, takes the form of a ramp member having
a proximal portion and a distally extending flap. The flap may be
designed to enter and remain in a longitudinally extending
laterally accessible guidewire lumen.
[0007] Another illustrative embodiment includes a method of
providing a guidewire exit location for an elongate medical device.
A guidewire exit ramp member is placed on an elongate member having
a longitudinally extending guidewire lumen with a slit or opening
therein over a certain length. The elongate member may include a
skive or other opening into the guidewire lumen. The guidewire exit
ramp member is placed near the skived portion or opening and slid
in a direction such that a flap of the guidewire exit ramp member
goes through the skive into the guidewire lumen. In some
embodiments, the guidewire exit ramp member may be secured in place
by heat bonding, adhesive, or the other attachment methods. When
the method is complete, a guidewire passed through the guidewire
lumen in a first direction is forced out of the guidewire lumen by
the flap of the guidewire exit ramp member. In a further
embodiment, the flap is flexible enough such that, when a guidewire
is passed through the guidewire lumen in a second direction, the
guidewire readily passes by the flap with little or no added
resistance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1A is a partial elevational view of a medical device
shaft having a longitudinally extending laterally accessible
guidewire lumen;
[0009] FIG. 1B is a cross-sectional view along line 1B-1B of FIG.
1A;
[0010] FIG. 2 is a plan view of a cannula including a
longitudinally extending laterally accessible guidewire lumen;
[0011] FIG. 3 is a perspective view of a guidewire exit ramp member
for use in conjunction with a medical device shaft having a
longitudinally extending laterally accessible guidewire lumen;
[0012] FIG. 4 is an elevation view of the illustrative guidewire
exit ramp member of FIG. 3 showing the flap;
[0013] FIG. 5 is a side view of the illustrative guidewire exit
ramp member of FIG. 3;
[0014] FIG. 6 is an end view from a distal location of the
illustrative guidewire exit ramp member of FIG. 3;
[0015] FIG. 7 is an elevation view of an alternative example
guidewire exit ramp with a curved flap;
[0016] FIG. 8A is an elevation view of an illustrative guidewire
exit ramp coupled with a medical device shaft having a
longitudinally extending laterally accessible guidewire lumen;
[0017] FIG. 8B is a section view along line 8B-8B of FIG. 8A;
[0018] FIGS. 9A-9C are section views along lines 9A-9A, 9B-9B, and
9C-9C of FIG. 8A;
[0019] FIGS. 10A-10C, 11A-11C, and 12A-12C illustrate placement of
a guidewire exit ramp on another medical device shaft having a
closed longitudinally extending laterally accessible guidewire
lumen;
[0020] FIGS. 13A-13C illustrate in elevation and section views an
alternative embodiment using a relatively stiff plastic guidewire
exit ramp member; and
[0021] FIGS. 14A-14C illustrate placement of the embodiment of
FIGS. 13A-13B on an elongate medical device shaft.
DETAILED DESCRIPTION
[0022] The following detailed description should be read with
reference to the drawings. The drawings, which are not necessarily
to scale, depict illustrative embodiments and are not intended to
limit the scope of the invention.
[0023] FIG. 1A is a partial elevational view of a medical device
shaft having a longitudinally extending laterally accessible
guidewire lumen. The shaft 10 includes a channel 12 for laterally
accessing a guidewire lumen passing therethrough. FIG. 1B is a
cross-sectional view along line 1B-1B of FIG. 1A. As illustrated by
FIG. 1B, the guidewire lumen 14 includes the channel 12. Two
auxiliary lumens 16, 18 are also illustrated. While a triple lumen
shaft 10 is illustrated, any number of lumens, from a single lumen
up to 3, 4, or more lumens, may be provided in a shaft for use with
the present invention.
[0024] The channel 12 is illustrated for providing access to a
generally U-shaped guidewire lumen. Instead of a U-shape, a
C-shaped opening may be provided, the C-shape helping to retain a
guidewire in the lumen 14. Additionally, a slit may be used.
Alternatively, instead of an channel 12 creating an opening, a wall
for the lumen 14 where the channel is shown may be thin or
intentionally thinned to enable a guidewire to be torn
therethrough. Perforations may also be provided to make the
longitudinally extending guidewire lumen 14 laterally accessible.
Laterally accessible, as used herein, refers to a guidewire lumen
that can be accessed along a length thereof, where access can be
had either through an existing opening or by tearing a guidewire
disposed in the guidewire lumen laterally through a slit, thin,
thinned, perforated, or otherwise relatively weak lumen wall
section.
[0025] FIG. 2 is a plan view of a cannula including a
longitudinally extending laterally accessible guidewire lumen. The
cannula 20 may incorporate a shaft 10 as illustrated in FIGS. 1A
and 1B having a distal end 22 and a proximal end 24. A slit 26
extends along a length of the shaft toward the distal end 22; while
not shown, the slit 26 may extend proximally to a guidewire entry
adaptor 28. The example also illustrates marker bands near the
distal end. Proximal of the adaptor 28 is a manifold 30 including
two fluid infusion ports. The cannula in FIG. 2 may have a similar
cross section to that shown in FIG. 1B, except to the extent that a
slit 26 is used instead of a U-shaped opening. The fluid infusion
ports on the manifold 30 may be coupled to the auxiliary lumens of
the cannula shaft for infusing fluids to a location at or near the
distal end 22.
[0026] The adaptor 28 shown functions by having a side-directed
ramp/lumen with an opening allowing for lateral removal of a
guidewire therefrom. The proximal end of the guidewire is
controlled proximal of the adaptor 28 such that there is no need to
force a backloaded guidewire from the guidewire lumen. The
guidewire can be removed through the slit 26 once the exchange
procedure starts. However, the exact location where the guidewire
exits the slit 26 is not controlled. In particular, if a guidewire
is backloaded into such a rapid exchange catheter, the adaptor 28
does not force the guidewire out of the catheter.
[0027] An example and description of such an adaptor 28 is given by
Windheuser et al., in U.S. Pat. No. 6,606,515, the disclosure of
which is incorporated herein by reference. The adaptor 28 has a
relatively large profile in order to achieve ease of guidewire
entry through a funnel-shaped portion, as further discussed by
Windheuser et al., and is designed to prevent passage of the entire
adaptor through a side port in an endoscope. Such sizing would also
typically prevent passage through a guide catheter used in a
vascular procedure.
[0028] During a catheter exchange procedure, with the guidewire
already in place at a desired location in the patient (i.e., a
vascular location, a location in the biliary tract, or any other
cannulated location), the guidewire will extend through the
guidewire lumen from the adaptor 28 to the distal end 22. To
exchange the cannula 20, the guidewire is moved laterally out of
the adaptor 28 and held in place as the cannula 20 is withdrawn. As
the cannula 20 is withdrawn, the guidewire passes through the slit
26, remaining in its internal location in the patient without
requiring a guidewire extension. The slit 26 may extend to the
distal end 22, or may stop proximal of the distal end.
[0029] FIG. 3 is a perspective view of a guidewire exit ramp member
for use in conjunction with a medical device shaft having a
longitudinally extending laterally accessible guidewire lumen. The
illustrative example guidewire exit ramp member includes a proximal
portion 50, a flap 52, and a distal section 54. The proximal
portion 50 surrounds and/or tracks over an elongate medical device
on which the guidewire exit ramp member is used. The shape is shown
as cylindrical but may instead be oval, polygonal, or other shapes
including polygons with one or more curved sides.
[0030] In other illustrative examples, the proximal portion 50 may
only partly surround an elongate medical device, and may instead
take the form of a partial cylinder, or may have one or more gaps.
In several embodiments, the form illustrated in FIG. 3 is used for
its low profile, allowing the guidewire exit ramp member to be
readily placed and used even in situations where low profile is a
concern.
[0031] FIG. 4 is an elevation view of the illustrative guidewire
exit ramp member of FIG. 3 showing the flap 52 more clearly. As can
be seen, the example flap 52 has rather angular distal ends,
extending distally relative to, but shorter than, the distal
section 54. In other embodiments the flap 52 may be longer than the
distal section 54, and, in one embodiment, the distal section 54
may be entirely omitted. For some embodiments, the flap 52 will be
inserted through a transversely cut opening in an elongate medical
device, as further explained below. For such embodiments, the
inclusion of the distal section 54 may help maintain the shape,
pushability, and/or anti-kinking characteristics of the elongate
medical device across the transverse cut since the transverse cut
may weaken the elongate medical device.
[0032] FIG. 5 is a side view of the illustrative guidewire exit
ramp member of FIG. 3. The distal portion 54 has a reduced profile
due to the flap 52. FIG. 6 is an end view of the illustrative
guidewire exit ramp member of FIG. 3. The flap 52 is shown
extending down into the lumen defined by the distal portion 54,
which is in line with the lumen formed in the proximal portion 50.
In an illustrative embodiment, the flap 52 is biased to bend down
as illustrated by FIGS. 3 and 5-6.
[0033] In one embodiment, the guidewire exit ramp member shown in
FIGS. 3-6 is formed by a molding process. In other embodiments, the
guidewire exit ramp member may be formed by cutting a tubular
member. The ramp member may be sized to correspond to a given size
of elongate medical device shaft. For example, given a 6-French
elongate medical device shaft, the inner diameter defined by the
proximal portion of the ramp member may be just large enough to
slide over such a device shaft. The inner surface of the ramp
member may include a lubricious coating to allow easy movement and
placement over the device shaft. Alternatively, the material chosen
for making the ramp member may be chosen for its lubricious
properties.
[0034] The ramp member may be formed of a wide variety of
materials. In some embodiments the ramp member is formed of a nylon
material, which is inexpensive and easy to mold, as well as being a
popular material for medical applications. Polycarbonate may also
be used, as well as any of a wide variety of polymers, copolymers
and metals or alloys known for use in medical devices, catheters,
cannulas, endoscopes, and the like. Any other suitable
biocompatible material may also be used and/or incorporated.
[0035] FIG. 7 is an elevation view of an alternative example
guidewire exit ramp member with a curved flap. As illustrated, the
guidewire exit ramp member includes a proximal portion 60, a flap
62, and a (optional) distal portion 64. As shown at 66, the flap 62
has curved ends, which may allow the flap 62 to extend into and
generally match the contours of a guidewire lumen having curved
interior contours. Rather than a simple curve as shown, the flap 62
may be designed to match a particular guidewire lumen shape/cross
section.
[0036] FIG. 8A is an elevation view of an illustrative guidewire
exit ramp coupled with a medical device shaft having a
longitudinally extending laterally accessible guidewire lumen. A
device shaft 100 is shown with a guidewire exit ramp member 102
placed thereover. The ramp member 102 includes a flap 104 that is
aligned with and enters a channel 106 (shown as a U-shaped channel
for the purposes of illustration). The longitudinal cross section
of FIG. 8B illustrates that the ramp member 102 has a proximal
portion that surrounds the device shaft 100, with the flap 104
extending down into the channel 106.
[0037] The transverse section views of FIGS. 9A-9C illustrate that
the device shaft 100 is shown having the channel 106 as well as
auxiliary lumens 108 and 110. As shown in FIG. 9B, along line 9B-9B
in FIG. 8A, the flap 104 extends partly into the channel 106, with
the optional distal portion of the ramp member 102 extending around
the device shaft 100 at that location. FIG. 9C is taken at a more
distal location along the device shaft 100 and ramp member 102, as
shown by line 9C-9C of FIG. 8A. By this point, the flap 104 extends
down to the base of the channel 106. If a guidewire is backloaded
into the channel 106, the flap 104 will force the guidewire out of
the channel 106. However, if a guidewire is passed distally from a
more proximal location, as can be seen in FIG. 8B, the slant of the
flap 104 will allow the flap 104 to deflect so that the guidewire
may pass with little resistance generated by the flap 104.
[0038] FIGS. 10A-10C, 11A-11C, and 12A-12C illustrate placement of
a guidewire exit ramp on another medical device shaft having a
closed longitudinally extending laterally accessible guidewire
lumen. Referring to FIGS. 10A-10C, a guidewire exit ramp member 200
having a flap 202 is shown placed on a device shaft 204, the device
shaft 204 having an opening shown as skive 206. The ramp member 200
is shown some distance proximal of the skive 206 on the device
shaft 204.
[0039] As highlighted in FIG. 10B, (a section view along line
10B-10B of FIG. 10A) the device shaft 204 includes a guidewire
lumen 208 having a thinned wall 210, as well as an additional
auxiliary lumen 212. The thinned wall 210 enables a guidewire to
laterally exit the guidewire lumen 208 by tearing through the
thinned wall 210. To further weaken the wall, perforations may be
provided. The thinned wall 210 may be provided during extrusion or
by post-extrusion machining. The longitudinal cross section of FIG.
10C illustrates the skive opening into the guidewire lumen 208.
[0040] Turning to FIGS. 11A-11C, FIG. 11A shows that the ramp
member 200 has been advanced such that the flap 202 partly enters
the skive 206 in the device shaft 204. FIG. 11B shows in transverse
cross section that the flap 202 reaches partly down into the
guidewire lumen 208 through the skive 206. As shown by FIG. 11C,
the skive 206 enables easy entry of the flap 202 down into the
guidewire lumen 208 through the thin wall 210. In some embodiments,
the flap 202 may be biased downward such that it readily extends
through the skive 206. It should be noted that the thinned wall 210
would not be necessary to use the guidewire ramp member 200 in the
fashion shown, since the flap 202 simply enters through an opening
into the guidewire lumen 208.
[0041] Referring now to FIGS. 12A-12C, the ramp member 200 is moved
distally along the device shaft 204 until the flap 202 completely
enters the guidewire lumen 208 through the skive 206. Once this
location is reached, the flap 202 may rest against an interior wall
of the guidewire lumen 208. When so located, a guidewire proximal
end passing in a proximal direction through the guidewire lumen 208
may be forced laterally out of the device shaft 204 by the flap
202. Thus backloading of a guidewire into the device shaft 204 can
be performed easily with an assurance that a guidewire will exit
the device shaft 204 at a desired location defined by the skive 206
and the ramp member 200. In various illustrative embodiments, the
ramp member 200 may be moveable with respect to the shaft or
secured (by adhesive or welding, for example) to the device shaft
204 once placed as shown in FIG. 12A.
[0042] FIGS. 13A-13C illustrate in elevation and section views of
an alternative embodiment making use of a pinch or squeeze type of
ramp. As can be seen, the ramp member 300 includes a proximal
portion 302 and a pinching portion 304. The pinching portion 304
may be sized to reduce the internal diameter or cross-sectional
area of the ramp member sufficient to collapse a portion of a
guidewire lumen. In one embodiment, the reduced diameter/area is
sized to prevent pinching of any auxiliary lumens of an associated
medical device, though some compression may be acceptable. It
should be noted that the pinching portion need not be cylindrical
and may take on a variety of shapes adapted for use with various
catheter shafts. As shown in FIG. 13C, the transverse section of
the pinching portion 304 is shaped to receive a catheter shaft
without pinching any auxiliary lumens, instead being shaped to
compress only the guidewire lumen. The dashed lines of FIG. 13C
represent, in phantom, the locations of a guidewire lumen and two
auxiliary lumens for a catheter shaft received and pinched by the
ramp member 300. It can be seen that two of the lumens (the
auxiliary lumens) would not be significantly blocked.
[0043] FIGS. 14A-14C illustrate placement of the embodiment of
FIGS. 13A-13B on an elongate medical device shaft. As shown in FIG.
14A, the elongate medical device shaft 310 is provided with a
transverse cut 312 that may take the form of a skive or slit. If
desired, the shaft 310 may include a guidewire lumen having a
thinned or weakened wall. As shown in FIG. 14B, the ramp member 300
is slid onto the shaft 310 until the ramp member 300 engages the
transverse cut 312. At the location of the transverse cut 312, the
shaft 310 will be inherently weaker due to the transverse cut 312
across a portion of the wall of the guidewire lumen. Turning to
FIG. 14C, it can be seen that the ramp 304 of the ramp member 300
collapses a portion of the wall of the guidewire lumen 314, but the
auxiliary lumen 316 is not significantly affected. The proximal
portion 302 aids in letting the ramp 306 collapse the wall of the
guidewire lumen 314. A guidewire backloaded into the shaft 310 will
now be forced out of the guidewire lumen 314 at the ramp 304. Any
suitable plastics may be used for the shaft 310 and the ramp member
300. For the alternative embodiments of FIGS. 13A-13B and 14A-14C,
the ramp member 300 may be formed of a stiffer material than the
material used to define the guidewire lumen 314. To preserve the
patency of the auxiliary lumen 316, some embodiments may make use
of a reinforcing member to support the auxiliary lumen 316.
[0044] Those skilled in the art will recognize that the present
invention may be manifested in a variety of forms other than the
specific embodiments described and contemplated herein.
Accordingly, departures in form and detail may be made without
departing from the scope and spirit of the present invention as
described in the appended claims.
* * * * *