U.S. patent application number 15/040915 was filed with the patent office on 2016-06-09 for twisted stent.
The applicant listed for this patent is C.R. Bard, Inc.. Invention is credited to Andrzej J. Chanduszko.
Application Number | 20160158042 15/040915 |
Document ID | / |
Family ID | 40073157 |
Filed Date | 2016-06-09 |
United States Patent
Application |
20160158042 |
Kind Code |
A1 |
Chanduszko; Andrzej J. |
June 9, 2016 |
TWISTED STENT
Abstract
A stent is disclosed and can include a stent body having a
longitudinal axis. The stent body can also have a network of struts
that can define a plurality of cells defined between interconnected
struts. Each of the plurality of cells includes a major axis that
is angled with respect to the longitudinal axis to form a cell
angle, b.
Inventors: |
Chanduszko; Andrzej J.;
(Chandler, AZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
C.R. Bard, Inc. |
Murray Hill |
NJ |
US |
|
|
Family ID: |
40073157 |
Appl. No.: |
15/040915 |
Filed: |
February 10, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11753909 |
May 25, 2007 |
9265636 |
|
|
15040915 |
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Current U.S.
Class: |
623/1.11 |
Current CPC
Class: |
A61F 2002/91558
20130101; A61F 2/9517 20200501; A61F 2/88 20130101; A61F 2/91
20130101; A61F 2/95 20130101; A61F 2/9522 20200501; A61F 2/915
20130101 |
International
Class: |
A61F 2/95 20060101
A61F002/95 |
Claims
1. A stent delivery tool comprising: an inner carrier catheter
wherein the inner carrier catheter includes a stent engagement area
configured to engage a twisted stent, with a stent enantiomorphous
form, and configured to prevent the twisted stent from rotating
relative to the inner carrier catheter.
2. The stent delivery tool of claim 1 wherein the stent engagement
area includes a delivery helical structure extending at least
partially along the stent engagement area and having a delivery
structure enantiomorphous form.
3. The stent delivery tool of claim 2 wherein the delivery helical
structure comprises a helical groove.
4. The stent delivery tool of claim 3 wherein an engagement angle
equals the angle between the helical groove and a longitudinal axis
of the inner carrier catheter.
5. The stent delivery tool of claim 4 wherein the engagement angle
is greater than zero degrees and less than ninety degrees.
6. The stent delivery tool of claim 5 wherein the engagement angle
is greater than one degree and less than sixty degrees.
7. The stent delivery tool of claim 6 wherein the engagement angle
is greater than two degrees and less than forty-five degrees.
8. The stent delivery tool of claim 7 wherein the engagement angle
is greater than five degrees and less than thirty degrees.
9. The stent delivery tool of claim 8 wherein the stent
enantiomorphous form is left- or right-handed and the delivery
structure enantiomorphous form is opposite that of the stent
enantiomorphous form.
10. The stent delivery tool of claim 2 wherein the delivery helical
structure comprises a raised helical rib.
11. The stent delivery tool of claim 10 wherein an engagement angle
equals the angle between the helical groove and a longitudinal axis
of the inner carrier catheter.
12. The stent delivery tool of claim 11 wherein the engagement
angle is greater than zero degrees and less than ninety
degrees.
13. The stent delivery tool of claim 12 wherein the engagement
angle is greater than one degree and less than sixty degrees.
14. The stent delivery tool of claim 13 wherein the engagement
angle is greater than two degrees and less than forty-five
degrees.
15. The stent delivery tool of claim 14 wherein the engagement
angle is greater than five degrees and less than thirty
degrees.
16. The stent delivery tool of claim 15 wherein the stent
enantiomorphous form is left- or right-handed and the delivery
structure enantiomorphous form is opposite that of the stent
enantiomorphous form.
17. A stent delivery tool comprising: an inner carrier catheter
wherein the inner carrier catheter includes a stent engagement area
configured to engage a twisted stent, with a stent enantiomorphous
form, and configured to prevent the twisted stent from rotating
relative to the inner carrier catheter, wherein the stent
engagement area includes a delivery helical structure extending at
least partially along the stent engagement area, having a delivery
structure enantiomorphous form, and comprising a helical groove, an
engagement angle equals the angle between the helical groove and a
longitudinal axis of the inner carrier catheter, and the engagement
angle is greater than zero degrees and less than ninety
degrees.
18. A stent delivery tool comprising: an inner carrier catheter
wherein the inner carrier catheter includes a stent engagement area
configured to engage a twisted stent, with a stent enantiomorphous
form, and configured to prevent the twisted stent from rotating
relative to the inner carrier catheter, wherein the stent
engagement area includes a delivery helical structure extending at
least partially along the stent engagement area, having a delivery
structure enantiomorphous form, and comprising a raised helical
rib, an engagement angle equals the angle between the helical
groove and a longitudinal axis of the inner carrier catheter, and
the engagement angle is greater than zero degrees and less than
ninety degrees.
Description
PRIORITY
[0001] This application is a division of U.S. application Ser. No.
11/753,909, now U.S. Pat. No. 9,265,636, filed May 25, 2007, which
is incorporated by reference in its entirety into this
application.
FIELD OF THE DISCLOSURE
[0002] The present disclosure relates generally to surgical
devices. More specifically, the present disclosure relates to
stents and stent delivery devices.
BACKGROUND
[0003] Vascular stenosis is an abnormal narrowing in a blood
vessel. Vascular stenosis can include peripheral artery stenosis,
coronary artery stenosis, carotid artery stenosis, and renal artery
stenosis. There exist several ways to detect vascular stenosis. For
example, a vascular stenosis can be detected using a stethoscope to
amplify bruit, i.e., noise, within the blood vessel due to
turbulent blood flow through the narrowed blood vessel.
Alternatively, one or more imaging methods can be used to detect
and locate a vascular stenosis. For example, ultrasound, magnetic
resonance imaging, and computed tomography can be used to detect
and locate a vascular stenosis.
[0004] A common cause of vascular stenosis is atherosclerosis.
Atherosclerosis, aka, hardening of the arteries, is a disease that
affects the arterial blood vessel. Atherosclerosis is caused by the
formation of multiple plaques within the arteries. As plaque builds
up within an artery, the diameter of the artery is reduced and
results in a stenosis.
[0005] Vascular stenosis can be treated using a stent. A stent can
be from a shape memory material or a non-shape memory material. A
stent made from a non-shape memory material can be installed on a
balloon catheter and then, threaded through a patient's
cardiovascular system to the stenosis. Once the stent is in place
within the stenosis, the balloon catheter can be inflated in order
to deform the stent and move the stent to an expanded
configuration. Thereafter, the balloon catheter can be deflated and
withdrawn from the patient.
[0006] A stent made from a shape memory material can be installed
on a catheter and a sleeve can be placed over the stent. The
catheter and sleeve can be threaded through a patient's
cardiovascular system to the stenosis. Once the stent is in place
within the stenosis, the sleeve can be removed from the stent. When
exposed to the patient's body temperature, the stent automatically
can move to an expanded configuration that corresponds to a shape
memory configuration.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a plan view of a stent delivery device;
[0008] FIG. 2 is a detailed view of a stent delivery device;
[0009] FIG. 3 is a plan view of a handle for a stent delivery
device;
[0010] FIG. 4 is a cross-section view of the handle;
[0011] FIG. 5 is a plan view of the stent delivery device engaged
with the handle;
[0012] FIG. 6 is a plan view of a stent in a collapsed
configuration;
[0013] FIG. 7 is a plan view of a stent in an expanded
configuration;
[0014] FIG. 8 is a plan view of a stent installed on a stent
delivery device; and
[0015] FIG. 9 is a flow chart illustrating one method of installing
and deploying a stent.
DETAILED DESCRIPTION OF THE DRAWINGS
[0016] A stent is disclosed and can include a stent body having a
longitudinal axis. The stent body can also have a network of struts
that can define a plurality of cells defined between interconnected
struts. Each of the plurality of cells includes a major axis that
is angled with respect to the longitudinal axis to form a cell
angle, b.
[0017] In another embodiment, a stent is disclosed and can include
a stent body having a proximal end and distal end. The stent body
can also have a longitudinal axis. The stent is configured to
collapse radially about the longitudinal axis as the proximal end
is rotated with respect to the distal end.
[0018] In yet another embodiment, a method of preparing a stent for
deployment is disclosed. The stent can have a proximal end and a
distal end. The method can include grasping the proximal end of the
stent, grasping the distal end of the stent, and rotating the
proximal end and the distal end with respect to each other in order
to move the stent to a collapsed configuration.
[0019] In still another embodiment, a stent delivery tool is
disclosed and can include an inner carrier catheter. The inner
carrier catheter can include a stent engagement area that can be
configured to engage a twisted stent and prevent the twisted stent
from rotating relative to the inner carrier catheter.
Description of a Stent Delivery Device
[0020] Referring to FIG. 1, a stent delivery device is shown and is
generally designated 100. As shown, the stent delivery device 100
includes a body 102 having a proximal end 104 and a distal end 106.
A first syringe attachment 108 can be formed in the body 102
between the proximal end 104 and the distal end 106. In a
particular embodiment, the first syringe attachment 108 can be a
Luer syringe attachment. The first syringe attachment 108 can
provide fluid communication to a lumen formed within an outer
sheath 110, described below.
[0021] FIG. 1 indicates that the stent delivery device 100 can
include an outer sheath 110. The outer sheath 110 can include a
proximal end 112 and a distal end 114. Further, the outer sheath
110 can extend from the distal end 106 of the body 102 of the stent
delivery device 100. In particular, the proximal end 112 of the
outer sheath 110 can be attached to the distal end 106 of the body
102 of the stent delivery device 100. The distal end 114 of the
outer sheath 110 can be relatively soft and rounded. The outer
sheath 110 can include a lumen 116 formed therein. Further, the
distal end 114 of the outer sheath 110 can include a radiopaque
band 118.
[0022] As illustrated in FIG. 1, the stent delivery device 100 can
further include an inner carrier catheter 120. The inner carrier
catheter 120 can extend through the body 102 of the stent delivery
device 100 and into the lumen 116 formed in the outer sheath 110.
The inner carrier catheter 120 can be coaxial with the outer sheath
110. Further, the inner carrier catheter 120 can include a proximal
end 122 and a distal end 124. The inner carrier catheter 120 can be
formed with a lumen (not shown) that can be sized to fit over a
guide wire. In particular, the lumen of the inner carrier catheter
120 can fit over a 0.035 inch guide wire.
[0023] As shown in FIG. 1, a stent 126 can be compressed between
the inner catheter 120, e.g., the distal end of the inner catheter
120, and the outer sheath 110. A handle 128 can be attached to, or
otherwise extend from, the proximal end 122 of the inner carrier
catheter 120. The handle 128 can include a proximal end 130 and a
distal end 132. The proximal end 130 of the handle 128 can include
a second syringe attachment 134. In a particular embodiment, the
second syringe attachment 134 can be a Luer syringe attachment. The
second syringe attachment 134 can provide fluid communication with
the lumen formed within the inner carrier catheter 120.
[0024] The stent delivery device 100 can also include a safety clip
140 installed between the body 102 of the stent delivery device 100
and the handle 128 of the inner carrier catheter 120. The safety
clip 140 can include a proximal end 142 and a distal end 144.
Further, the safety clip 140 can include a butterfly handle 146
between the proximal end 142 of the safety clip 140 and the distal
end 144 of the safety clip 140. In a particular embodiment, the
stent deliver device 100 can be installed between the body 102 of
the stent delivery device 100 and the handle 128 of the inner
carrier catheter 120 such that the proximal end 142 of the safety
clip 140 abuts the distal end 132 of the handle 128 and the distal
end 144 of the safety clip 140 abuts the proximal end 104 of the
body 102.
[0025] The safety clip 140 can fit over the inner carrier catheter
120. Further, the safety clip 140 can prevent the body 102 of the
stent delivery device 100 from moving relative to the handle 128 of
the inner carrier catheter 120. Further, the safety clip 140 can
prevent the outer sheath 110 from sliding relative to the inner
carrier catheter 120. During use, the stent delivery device 100 can
be threaded into a cardiovascular system of a patient to a target
area. The radio opaque band 118 formed on the outer sheath 110 can
be used to guide the stent delivery device into the cardiovascular
system of a patient, e.g., with the aid of fluoroscopy. Further, a
pair of radiopaque bands on the stent 126 can aid in positioning
the stent 126 within the patient. Once the stent 126 is properly
positioned, the butterfly handle 146 can be squeezed in order to
remove the safety clip 140 from the inner carrier catheter 120 and
the stent delivery device 100. Thereafter, the body 102 of the
stent delivery device 100 can be moved toward the handle of the
inner carrier catheter 120 in order to slide the outer sheath 110
off of the stent 126 and expose the stent 126 inside the
patient.
[0026] Once the stent 126 is exposed within the patient, the stent
126 can be deployed within the patient by exposing the patient to a
laser having a wavelength of approximately seven hundred and eighty
nanometers (780 nm). The energy can melt a polymer on the stent 126
and allow the stent 126 to move to a shape memory configuration,
e.g., an expanded configuration, within the patient, and be
deployed within the patient. After the stent 126 is deployed, the
inner carrier catheter 120 can be withdrawn from the patient.
[0027] FIG. 2 is a detailed view of the inner carrier catheter 120.
As shown, the inner carrier catheter 120 can include a stent
engagement area 200 near the distal end 124 of the inner carrier
catheter 120. As shown, the stent engagement area 200 can include a
helical structure 202 extending along the length of the stent
engagement area 200. The helical structure 202 can include a
helical groove formed in the inner carrier catheter 120.
Alternatively, the helical structure 202 can include a raised
helical rib, or thread, formed on the inner carrier catheter 120.
In a particular embodiment, the helical structure 202 is angled
with respect to a longitudinal axis 204 of the inner carrier
catheter 120 to form a stent engagement angle 206, a.
[0028] In a particular embodiment, a can be greater than zero
degrees and less than ninety degrees (0<a<90). In another
embodiment, a can be greater than one degree and less than sixty
degrees (1<a<60). In yet another embodiment, a can be greater
than two degrees and less than forty-five degrees (2<a<45).
In still another embodiment, a can be greater than five degrees and
less than thirty degrees (5<a<30).
[0029] As shown in FIG. 2, the inner carrier catheter 120 can
include a tip 208 and the stent engagement area 200 can be formed
on the tip of the inner carrier catheter 120. The tip 208 of the
inner carrier catheter 120 can be disposed on a post 210 formed on
the inner carrier catheter 120. Further, the tip 208 of the inner
carrier catheter 120 can rotate on the post 210. Accordingly, when
a stent is deployed and the inner carrier catheter 120 is withdrawn
from the deployed stent, the tip 208 of the inner carrier catheter
120 can rotate within the deployed stent. The deployed stent can
remain stationary within an artery in which the stent is
deployed.
[0030] FIG. 3 and FIG. 4 illustrate a handle assembly, generally
designated 300 that can be used in conjunction with the stent
delivery system 100, described above. As shown in FIG. 3 and FIG.
4, the handle assembly 300 can include a housing 302. The housing
302 can be hollow and can include a proximal end 304 and a distal
end 306.
[0031] As depicted in FIG. 4, a rail support structure 308 can be
disposed within the housing 302 near the proximal end 304 of the
housing 302. A pair of rails 310 can extend between the distal end
306 of the housing 302 and the rail support structure 308. The
handle assembly 300 can also include a carrier 312 that can be
slidably disposed on the rails 310. In a particular embodiment, the
carrier 312 can be configured to receive the body of a stent
delivery system, e.g., the stent delivery system 100, described
above.
[0032] A shaft 314 can extend from the housing 302 near the rail
support structure 308, e.g., between the rail support structure 308
and the distal end 306 of the housing 302. In a particular
embodiment, the shaft 314 is substantially perpendicular to the
rails 310. A ratchet wheel 316 can be rotatably disposed on the
shaft 314. The ratchet wheel 316 can be formed with a plurality of
teeth 318 around the outer periphery of the ratchet wheel 316. The
handle assembly 300 can also include a pawl 320 extending from the
rail support structure 308. The pawl 320 can be configured to
engage the ratchet wheel 316, e.g., the teeth 318 of the ratchet
wheel 316, and permit rotation of the ratchet wheel 316 in a single
direction, e.g., clockwise.
[0033] FIG. 4 further shows that the handle assembly 300 can
include a cable 322. The cable 322 can include a proximal end 324
and a distal end 326. The cable 322 can extend within the housing
along the length of the rails 310. Further, the proximal end 324 of
the cable 322 can be wrapped, or otherwise disposed, around the
ratchet wheel 316. The distal end 326 of the cable 322 can be
attached, or otherwise affixed, to the carrier 312. As the ratchet
wheel 316 is rotated, the cable 322 can be rolled onto the ratchet
wheel 316 and the carrier 312 can slide along the rails 310 toward
the proximal end 304 of the housing 302.
[0034] As illustrated in FIG. 4, the handle assembly 300 can also
include a trigger 328 extending from the housing 302. The trigger
328 can include a proximal end 330 and a distal end 332. The
proximal end 330 of the trigger 328 can be rotatably engaged with
the housing 302 and the distal end 332 of the trigger 328 can be
free. As such, the trigger 328 can rotate around the proximal end
330 of the trigger 328.
[0035] FIG. 4 further indicates that an arm 334 can extend from the
trigger 328. The arm 334 can include a plurality of teeth 336 that
can engage the teeth 318 formed on the ratchet wheel 316. The
handle assembly 300 can also include a spring 338 installed around
a post 340 within the housing 302. The spring 338 can bias the
trigger 328 outward relative to the housing 302. In a particular
embodiment, when the trigger 328 is squeezed inward relative to the
housing 302, the arm 334 can rotate the ratchet wheel 316 and cause
the carrier 312 to slide within the housing 302 toward the proximal
end 304 of the housing 302.
[0036] In a particular embodiment, the stent delivery device 100
can be engaged with the handle assembly 300 as shown in FIG. 5.
Specifically, the body 102 of the stent delivery device 100 can be
inserted within the carrier 312. Further, the inner carrier
catheter 120 can be installed within the housing 302 of the handle
assembly 300 so that the handle 128 of the inner carrier catheter
120 extends through the proximal end 304 of the housing 302. The
handle 128 of the inner carrier catheter 120 can be engaged with
the housing 302 so that the handle 128 does not move relative to
the housing during operation of the handle assembly 300.
[0037] Accordingly, the safety clip 140 can be removed from the
stent delivery device 100 and the trigger 328 can be squeezed to
move the carrier 312 within the handle assembly 300 toward the
proximal end 304 of the housing 302. As the carrier 312 moves, the
body 102 of the stent delivery device 100 can be moved toward the
handle 128 of the inner carrier catheter 120. As the body 102 of
the stent delivery device 100 moves toward the handle of the inner
carrier catheter 120, the outer sheath 110 can slide off of the
stent 126 and expose the stent 126 inside a patient.
Description of a Twisted Stent
[0038] Referring to FIG. 6 and FIG. 7, a stent is shown and is
generally designated 600. As shown, the stent 600 can include a
stent body 602. The stent body 602 can be hollow and generally
cylindrical. Further, the stent body 602 can include a proximal end
604 and a distal end 606. The proximal end 604 can include a
radiopaque band 608. The distal end 606 can also include a
radiopaque band 610.
[0039] As indicated in FIG. 6 and FIG. 7, the stent body 602 can
include a plurality of struts 612. Further, the struts 612 can
establish a plurality of cells 614 within the stent body 602. The
struts 612 can be in the form of an interconnected network or
matrix that is generally continuous. The struts 612 can form a
repeating pattern that can define an array of cells 614. The cells
614, as shown, can be closed. However, it is noted that the stent
600 may have localized areas in which other struts 612 do not form
closed cells. In other words, the stent 600 can be a closed-cell
stent in which each cell is separate from adjacent cells.
Alternatively, the stent 600 can be an open-cell stent in which one
or more struts between two or more adjacent cells is removed from
the construction of the stent 600.
[0040] In a particular embodiment, as shown, each cell 614 can be
hexagonally shaped. Alternatively, each cell 614 can be generally
diamond shaped, generally elliptical, or another shape that can
allow the stent 600 to be collapsed as described herein.
[0041] The stent 600 is movable between a collapsed configuration,
shown in FIG. 6, and an expanded configuration, shown in FIG. 7.
FIG. 6 and FIG. 7 show that the stent 600 can have a diameter 616.
The diameter 616 of the stent 600, in the collapsed configuration,
is relatively smaller than the diameter 616 of the stent 600 in the
expanded configuration. In the collapsed configuration, the cells
614 within the stent body 602 can be collapsed. Further, in the
expanded configuration the cells 614 within the stent body 602 can
be expanded.
[0042] Referring to FIG. 7, the stent 600 can include a
longitudinal axis 622. Further, each cell 614 can include a minor
axis 618 and a major axis 620. Each cell 614 can include a minor
length along the minor axis 618 and a major length along the major
axis 620. Moreover, each cell 614 can have an aspect ratio defined
by the ratio of the minor length to the major length, when the
stent 600 is expanded as shown in FIG. 7. In a particular
embodiment, the aspect ratio of each cell 614 can be less than or
equal to one (1). In another embodiment, the aspect ratio of each
cell 614 can be approximately three-quarters (0.75). In yet another
embodiment, the aspect ratio of each cell 614 can be approximately
one-half (0.5). In still another embodiment, the aspect ratio of
each cell 614 can be approximately one-quarter (0.25).
[0043] The major axis 620 of each cell 614 can be angled with
respect to the longitudinal axis 622 to establish a cell angle 624,
b. In a particular embodiment, b can be greater than zero degrees
and less than ninety degrees (0<b<90). In another embodiment,
b can be greater than one degree and less than sixty degrees
(1<b<60). In yet another embodiment, b can be greater than
two degrees and less than forty-five degrees (2<b<45). In
still another embodiment, b can be greater than five degrees and
less than thirty degrees (5<b<30).
[0044] The orientation of the cells 614 can allow the cells to form
a helical pattern around the stent body 602 and can allow the stent
600 to be collapsed by grasping the ends of the stent 600 and
rotating the ends with respect to each other. This means relative
rotation with respect to both ends. For example, the proximal end
604 can be fixed and the distal end 606 can be rotated around the
longitudinal axis 622. Further, the distal end 606 can be fixed and
the proximal end 604 can be rotated around the longitudinal axis
622. Also, both ends can be rotated in opposite directions relative
to each other around the longitudinal axis 622. As the ends of the
stent 600 are rotated relative to each other, the cells 614 can
collapse. As the cells 614 collapse, the stent 600 can collapse.
Further, as the stent 600 collapses, the diameter 616 of the stent
600 can decrease substantially uniformly from an expanded diameter,
D.sub.E, to a collapsed diameter, D.sub.C. In a particular
embodiment, a ratio of D.sub.C to D.sub.E is approximately one-half
(D.sub.C/D.sub.E=0.5). In another embodiment, a ratio of D.sub.C to
D.sub.E is approximately one-quarter (D.sub.C/D.sub.E=0.25). In yet
another embodiment, a ratio of D.sub.C to D.sub.E is approximately
one-eighth (D.sub.C/D.sub.E=0.125).
[0045] In a particular embodiment, the stent 600 can be made from a
shape memory material. The shape memory material can include a
shape memory polymer, a shape memory metal, or a combination
thereof. Further, the shape memory metal can include a metal alloy.
The metal alloy can include a nickel titanium alloy, e.g., nitinol.
The stent 600 can particularly be made principally from, or even
consist essentially of, nitinol.
[0046] In an alternative embodiment, the stent 600 can be made from
a non-shape memory metal, e.g., stainless steel, titanium, a
cobalt-chrome alloy, or a combination thereof. In such a case, the
stent 600 can be balloon deployable. In other words, the stent can
be installed over a balloon catheter. When the stent is in an
appropriate location within a patient, a balloon on the balloon
catheter can be inflated in order to expand the stent within the
patient.
[0047] FIG. 8 illustrates a stent, e.g., the stent 600 described
herein, installed on the inner carrier catheter, e.g., the inner
carrier catheter 120 described herein. FIG. 8 shows the stent 600
installed over the stent engagement area 200 of the inner carrier
catheter 120. As shown, the helical pattern established by the
stent cells 614 is arranged so that it is opposite the helical
structure 202 within the stent engagement area 200. Accordingly,
the helical structure 202 can engage the stent 600 and
substantially prevent the stent 600 from rotating on the inner
carrier catheter 120 during installation and deployment of the
stent.
Description of a Method of Forming a Stent
[0048] Referring to FIG. 9, a method of forming a stent is shown
and commences at block 900. At block 900, the proximal end of the
stent can be grasped. At block 902, the distal end of the stent can
be grasped. In a particular embodiment, the ends of the stent can
be grasped by a mechanical gripping device. Alternatively, a user
can grasp the ends of the stent with his or her fingers.
[0049] Moving to block 904, the proximal end of the stent can be
rotated relative to the distal end of the stent in order to move
the stent to a collapsed configuration. In a particular embodiment,
the proximal end of the stent can be rotated in a first direction
relative to a longitudinal axis, e.g., clockwise, and the distal
end of the stent can be rotated in a second direction relative to
the longitudinal axis opposite the first direction, e.g.,
counterclockwise. In a particular embodiment, the stent can be
formed with a plurality of helically arranged cells, as described
herein. As the ends of the stent are rotated, the cells can
collapse and the stent can collapse.
[0050] Continuing to block 906, after the stent is moved to a
collapsed configuration, the stent can be installed over a carrier
catheter while in the collapsed configuration. Thereafter, at block
908, an outer sheath can be installed over the carrier catheter and
the stent. The method can then end at block 910.
[0051] In a particular embodiment, a chilling agent, e.g., liquid
nitrogen, can be applied to the stent before it is collapsed.
Cooling the stent before, or as, the stent is collapsed can aid in
collapsing the stent and can substantially prevent the stent from
springing outward and expanding when a collapsing force is removed
from the stent.
CONCLUSION
[0052] With the configuration of embodiments described above, the
twisted stent as disclosed herein provides a device that can be
used to treat a stenosis. According to an embodiment, the twisted
stent includes a stent body having a plurality of cells arranged in
a helical pattern around the stent body. The twisted stent can be
relatively easily collapsed by grasping the ends of the twisted
stent and rotating the ends in opposite directions. As the ends of
the stent are rotated, the helical arrangement of the cells allows
the cells to collapse. As the cells collapse, the stent collapses.
Embodiments not only provide stent configurations that have
superior deployment characteristics, but also have reduced
profiles.
[0053] Accordingly, embodiments can be moved from a collapsed
configuration to an expanded configuration and then, returned to a
collapsed configuration. For example, a stent can be moved from a
collapsed configuration to an expanded configuration that
corresponds to a shape memory configuration. Thereafter, the stent
can be returned to the collapsed configuration as described
herein.
[0054] The above-disclosed subject matter is to be considered
illustrative, and not restrictive, and the appended claims are
intended to cover all such modifications, enhancements, and other
embodiments that fall within the true spirit and scope of the
present invention. Thus, to the maximum extent allowed by law, the
scope of the present invention is to be determined by the broadest
permissible interpretation of the following claims and their
equivalents, and shall not be restricted or limited by the
foregoing detailed description.
* * * * *