U.S. patent application number 14/146678 was filed with the patent office on 2014-07-10 for device and method for crimping an implant.
This patent application is currently assigned to BIOTRONIK AG. The applicant listed for this patent is BIOTRONIK AG. Invention is credited to Amir Fargahi.
Application Number | 20140190587 14/146678 |
Document ID | / |
Family ID | 49911156 |
Filed Date | 2014-07-10 |
United States Patent
Application |
20140190587 |
Kind Code |
A1 |
Fargahi; Amir |
July 10, 2014 |
Device and Method for Crimping an Implant
Abstract
A device (10, 10') and method for crimping an implant (20),
which can assume either a compressed state or an expanded state, at
least over a portion of the length thereof. An crimping device is
attained according to the invention in that a hollow-cylindrical
and/or hollow-conical, preferably braided wire netting is provided,
in the inner volume (14, 14') of which the implant (20) in the
expanded state can be placed, at least via a section thereof,
wherein, upon application of a tensile force on at least one end in
the longitudinal direction, and/or upon application of a
compressive force in the radial direction, the wire netting
simultaneous undergoes extension and a reduction of the inner
diameter (d, d') such that the implant (20) can be transformed, at
least along a section thereof, from the expanded state into the
compressed state.
Inventors: |
Fargahi; Amir; (Buelach,
CH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BIOTRONIK AG |
Buelach |
|
CH |
|
|
Assignee: |
BIOTRONIK AG
Buelach
CH
|
Family ID: |
49911156 |
Appl. No.: |
14/146678 |
Filed: |
January 2, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61750361 |
Jan 9, 2013 |
|
|
|
Current U.S.
Class: |
140/106 ;
140/105 |
Current CPC
Class: |
A61F 2/9522 20200501;
B21F 1/002 20130101; A61F 2/95 20130101; A61F 2/966 20130101 |
Class at
Publication: |
140/106 ;
140/105 |
International
Class: |
B21F 1/00 20060101
B21F001/00 |
Claims
1. A device for crimping an implant, in particular an intraluminal
endoprosthesis, which can assume either a compressed state or an
expanded state at least over a portion of the length thereof,
characterized by a hollow-cylindrical and/or hollow-conical,
optionally braided wire netting, in an inner volume of which the
implant in the expanded state can be placed, at least via a section
thereof, wherein, upon application of a tensile force on at least
one end in the longitudinal direction, and/or upon application of a
compressive force in the radial direction, the wire netting
simultaneously undergoes extension and a reduction of the inner
diameter such that the implant can be transformed, at least along a
section thereof, from the expanded state into the compressed
state.
2. The device according to claim 1, characterized in that the wire
netting comprises a polymer or a metal alloy, optionally a
stainless steel or cobalt-based alloy, the metal alloy optionally
containing at least one element selected from the group consisting
of Fe, Co, Cr and Ni.
3. The device according to claim 1, characterized in that the wire
netting comprises a ring on at least one end in the direction of
the longitudinal axis, the ring being displaceable relative to the
other end of the wire netting in the longitudinal direction,
optionally along a rail.
4. The device according to claim 1, characterized in that the
device can be placed into a coolant.
5. A method for crimping an implant, in particular an intraluminal
endoprosthesis, which can assume either a compressed state or an
expanded state at least over a portion of the length thereof,
optionally via the use of a device for crimping according to claim
1, the method having the following steps: inserting at least a
section of the implant, which is initially in the expanded state,
into the inner volume of a hollow-cylindrical and/or
hollow-conical, optionally braided wire netting; and reducing the
inner diameter via application of a tensile force on at least one
end of the wire netting in the longitudinal direction, and/or a
compressive force onto the wire netting in the radial direction
such that the inserted implant is transformed from the expanded
state into the compressed state, at least along a section.
6. The method according to claim 5, characterized in that the
implant and, optionally the device for crimping, are cooled in a
coolant to below a transition temperature before the implant is
transformed into the compressed state.
7. The method according to claim 5, characterized in that, in order
to apply a tensile force, a ring mounted at a first end of the wire
netting in the longitudinal direction is displaced optionally on a
rail relative to the stationary, opposing second end of the wire
netting.
8. The method according to claim 5, characterized in that, after
the transformation into the compressed state, the compressed
section of the implant is inserted into a tubular outer shaft of a
catheter.
9. The method according to claim 8, characterized in that the
implant is also transformed into the compressed state in a second
section, which was initially not inserted into the outer shaft, and
is then inserted into the outer shaft.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. provisional patent
application Ser. No. 61/750,361, filed Jan. 9, 2013.
TECHNICAL FIELD
[0002] The present invention relates to a device for crimping an
implant, in particular an intraluminal endoprosthesis, and an
associated method.
BACKGROUND
[0003] A wide variety of medical implants, in particular
intraluminal endoprostheses, for highly diverse applications are
known from the prior art. Implants according to the present
invention are endovascular prostheses or other endoprostheses, such
as stents (vascular stents (including stents for use in the region
of the heart, and heart valve stents, e.g. mitral valve stent,
pulmonary valve stent) and bile duct stents), endoprostheses for
closing a patent foramen ovale (PFO), stent grafts for treating
aneurysms, endoprostheses for closing an ASD (atrial septal
defect), and prostheses in the region of hard and soft tissue. Such
an implant is often introduced into the organ or vessel to be
treated by way of a catheter.
[0004] In many cases, stents and other implants have a filigree,
hollow-cylindrical (tubular) and/or hollow-conical main structure
that is open at both longitudinal ends, wherein the main structure
is often composed of a plurality of struts. Valve cusps, for
example three valve cusps, can be disposed on the inner side of
such a main structure, for example in the case of a heart valve
stent, wherein the valve cusps can form the heart valve and
comprise a plastic or a biological material, for example porcine
pericardium. In this case, the stent carries the heart valve and
anchors this in the heart.
[0005] Stents and other implants typically assume two states,
namely a compressed state having a small diameter and an expanded
state having a larger diameter. Using a catheter, the implant in
the compressed state can be introduced through narrow vessels into
the vessel or organ to be treated and can be positioned at the
point to be treated. To this end, the implant is crimped and
thereby transformed at least over a portion of the length thereof
from the expanded state having a larger diameter into the
compressed state having a smaller diameter. The implant is then
dilated at the treatment site, for example using the balloon of the
catheter, and returns to the expanded state, in which the implant
remains in the vessel or organ, being fixed there, after the
catheter has been removed from the body of the treated patient.
Alternatively, in the case in which the main structure of the
implant is made of a self-expanding metal (e.g. Nitinol), the
implant assumes the compressed state via compression below the
transition temperature and assumes the expanded state above the
transition temperature.
[0006] Document U.S. Pat. No. 8,029,564 B2 discloses a heart valve
prosthesis and a deflection device. The system also includes a
line, which is guided through the free ends of the stent posts,
which carry the heart valve. By way of this line, the stent posts
can be deflected inwardly in order to attain a closed state.
However, this system is not suitable for being transferred
non-invasively using a catheter to the point to be treated since
this system is too voluminous in the base region.
[0007] US 2011/0056064 A1 discloses a crimping tool that is very
cost-intensive to manufacture since it has a complex design having
a large number of precisely manufactured parts that must move in a
synchronous manner. The crimping tool has a plurality of bars in
particular, which are disposed next to one another around a
circumference and can rotate about an axis extending transversely
to the particular bar. The implant to be crimped can be placed into
the opening formed between the ends of the bars. A lever is moved
in order to displace guide pins--each guide pin being disposed at a
front end of a bar--in a slot such that the radius of the opening
formed between the bars is decreased or increased. In order to
crimp a heart valve stent, the pins are displaced such that the
radius of the opening is reduced. In this tool, the stent is
completely covered by the tool during the crimping procedure since
the bars and the pins are located between two plates, and the tool
therefore has a large expansion in the longitudinal direction of
the stent and has a relatively great weight. For this reason, the
implant cannot be visually monitored during crimping. Furthermore,
it cannot be ruled out that the bars will overlap when the opening
radius is reduced, and therefore the risk of damage to the implant
and the tissue parts disposed on the implant is high. Furthermore,
due to the large mass of the tool, a great deal of effort is
required to bring the tool below the transition temperature, which
is necessary when the implant is made of a self-expanding
material.
[0008] EP 2 229 921 A1 discloses a device for crimping that has a
plurality of wires stretched between two interspaced rings along a
cylinder jacket line. If one of these rings is rotated relative to
the second ring about an axis parallel to these jacket lines, the
wires are twisted to the common axis and thereby form an
hourglass-type geometric surface similar to a hyperboloid of
rotation. The opening defined by the section having the smallest
diameter, which is formed between these wires, is made smaller or
larger as the rings are twisted further. An implant can be disposed
in this opening and can be crimped by reducing the size of the
opening. This known device also has a relatively complex design and
is therefore difficult to assemble. The implant is covered by the
wires of the device during crimping, thereby preventing visual
monitoring of this known device as well during the crimping
process. A further disadvantage is that the tension in the wires is
greater at the two ends, at which the wires are attached to the
opposing rings, than in the central region thereof. This results in
non-uniform distribution of the compressive force on the implant.
Due to the large number of wires and the required large rings at
the ends thereof, the known device is relatively large and
heavy.
SUMMARY
[0009] The problem to be addressed is therefore that of creating a
device for crimping such an implant that has a less complicated
design and is smaller and easier to handle. A method for crimping
that is reliable and easy to carry out shall also be provided.
[0010] The aforementioned problem is solved by a device as provided
herein.
[0011] In particular, a device according to the invention has a
hollow-cylindrical and/or hollow-conical, braided wire netting,
into the inner volume of which the implant, in the expanded state,
can be placed at least via a section thereof or in entirety,
wherein, upon application of a tensile force on at least one end in
the direction of the longitudinal axis, and/or upon application of
a compressive force in the radial direction, the wire netting
simultaneously undergoes extension and a reduction of the inner
diameter such that the implant placed in the inner volume of the
wire netting can be transformed from the expanded state into the
compressed state, at least along a section (i.e. along a portion of
the length thereof) or along the entire length thereof due to the
reduction of the inner diameter of the wire netting. The wire
netting is also referred to in the following as a braid. The device
according to the invention makes it possible, for example, to
reduce the inner diameter at most to 1/4 of the inner diameter in
the expanded state, preferably at most to 1/5 of the inner diameter
in the expanded state.
[0012] The aforementioned device has a relatively compact design.
In the starting state, in which the implant in the expanded state
can be placed into the inner volume, the inner diameter of the wire
netting is only slightly larger than the outer diameter of the
implant. The length of the wire netting in the longitudinal
direction is also preferably slightly greater than the length of
the implant or the length of the section of the implant to be
crimped.
[0013] The design of the device according to the invention in the
form of a wire netting (braid) results in a simple and lightweight
design of the device according to the invention. For example, the
wire netting comprises a polymer or a metal alloy, wherein the
metal alloy preferably contains at least one of the elements of the
group iron (Fe), cobalt (Co), chromium (Cr), nickel (Ni).
Particularly preferably, the wire netting comprises stainless steel
or a cobalt-based superalloy. The braid can be deformed
elastically, homogeneously and uniformly, thereby enabling the
braid to expand and bend in all directions. Particularly
preferably, the braid has self-expanding properties, in particular
the braid can comprise a Phynox (Elgiloy) alloy. Phynox (Elgiloy)
is an austenitic, hardenable, superalloy based on cobalt (40% by
weight Co, 20% by weight Cr, 16% by weight Ni and 7% by weight Mo).
The mechanical strength thereof can exceed 2,600 N/mm2. The maximum
tensile strength is highly dependent on the cold working carried
out in advance. The alloy is non-magnetic, highly
corrosion-resistant (more corrosion-resistant than any other
stainless steel) and temperature-resistant. Furthermore, the alloy
has a high modulus of elasticity (220 kN/mm2) combined with a yield
strength of 1,800 N/mm2, and so the alloy is extremely well-suited
for the braid according to the invention. The alloy is available
from the company Lamineries MATTHEY SA (La Neuveville,
Switzerland).
[0014] As mentioned above, pulling the braid longitudinally results
in a reduction of the inner diameter. In the opposite case,
expanding the wire netting such that the inner and outer diameter
are increased shortens the wire netting. The metal alloys that can
be used for the o braid are preferably not alloys having a memory
effect, thereby ensuring that phase conversion does not occur in
the temperature range of 0.degree. C. to 40.degree. C. in
particular. It is therefore possible for continuous elongation of
the wire netting with diameter reduction, or shortening with an
increase in diameter to take place in a reversible manner in this
temperature range without phase-conversion influences.
[0015] In a further exemplary embodiment, the wire netting
comprises a first hollow-cylindrical section and a second
hollow-conical section. In this exemplary embodiment, the implant
is inserted in the hollow-cylindrical section and is advantageously
crimped or compressed in the hollow-conical section. This shape is
favorable for crimping.
[0016] In order to reduce diameter in a particularly simple manner,
a ring is provided on at least one first end in the longitudinal
direction (direction of the longitudinal axis) of the wire netting,
the ring being displaceable relative to the second end of the wire
netting in the direction of the longitudinal axis, preferably along
a rail. The second end of the wire netting is held stationary. The
displacement of the ring results in application of a tensile force
onto the wire netting. To this end, the ring is fastened to the
particular end of the wire netting. In a preferred exemplary
embodiment, the braid comprises a ring on both ends in the
longitudinal direction. The rail preferably extends parallel to the
longitudinal axis of the hollow-cylindrical or hollow-conical wire
netting.
[0017] Since the device is compact and lightweight, as described
above, the device can be easily placed into a coolant, thereby
enabling the implant and the wire netting to be cooled to a
temperature below the transition temperature. Cold water at
0.degree. C., for example, can be used as such a coolant.
[0018] The aforementioned problem is further solved by a simple
method for crimping an implant
[0019] According thereto, the following steps in particular are
carried out. In a first step, the implant, which is initially
present in the expanded state, is placed at least via a section
thereof or in entirety into the inner volume of a
hollow-cylindrical or hollow-conical, preferably braided wire
netting. Next, a tensile force is applied on at least one end of
the wire netting in the direction of the longitudinal axis thereof,
and/or a compressive force is applied to the wire netting in the
radial direction, thereby reducing the inner diameter of the wire
netting such that the inserted implant is transformed from the
expanded state into the compressed state at least along a section.
This method is very simple and can be carried out cost-effectively.
It can be implemented manually or in an automated process.
[0020] In a further exemplary embodiment, the implant and,
preferably, the device are cooled in a coolant to below the
transition temperature before the implant is transformed into the
compressed state.
[0021] In a simple manner, a tensile force can be applied to the
wire netting in the longitudinal direction of the wire netting in
that a ring mounted at a first end of the wire netting in the
longitudinal direction is preferably displaced on a rail relative
to the stationary, opposing second end of the wire netting, wherein
the rail preferably extends parallel to the longitudinal direction.
In the present description of the invention, the direction that
extends parallel to the longitudinal axis of the wire netting or
the implant is referred to as the longitudinal direction of the
wire netting or the implant.
[0022] In a further exemplary embodiment, after the transition to
the compressed state, the associated section of the implant can be
inserted into a tubular outer shaft of a catheter in order to
optionally also fix the compressed state above the transition
temperature or to introduce the implant into the body to be
treated.
[0023] In a development of the invention, a second section of the
implant, which was initially not inserted into the outer shaft, is
then also transformed into the compressed state, preferably by way
of the above-described device according to the invention or the
above-described method according to the invention, and is then also
inserted into the outer shaft.
[0024] Further objectives, features, advantages, and possible
applications of the invention will become apparent from the
following description of exemplary embodiments of the invention,
with reference to the figures. All the features that are described
and/or graphically depicted are the subject of the present
invention, either alone or in any combination, independently of
their wording in the claims or their dependency reference.
DESCRIPTION OF THE DRAWINGS
[0025] The drawings show, schematically:
[0026] FIG. 1A a first exemplary embodiment of a device according
to the invention in a view from the side in the starting state,
[0027] FIG. 1B an intersection point of a device according to the
invention in a view from the side in the expanded state,
[0028] FIG. 1C a mesh of a device according to the invention in a
view from the side,
[0029] FIG. 1D the mesh shown in FIG. 1C in a view from the side in
the expanded state and in the compressed state,
[0030] FIG. 2 the implant to be crimped in a view from the
side,
[0031] FIG. 3 a container containing coolant, in which the implant
to be crimped is cooled, in a perspective view from the side,
[0032] FIG. 4 a section of the device according to the invention as
shown in FIG. 1, in a view from the side, comprising an implant in
the expanded state disposed therein,
[0033] FIG. 5 the section according to FIG. 4 in a first
intermediate step of the crimping process in a view from the
side,
[0034] FIG. 6 the section according to FIG. 4 in a second
intermediate step of the crimping process in a view from the
side,
[0035] FIG. 7 the implant after crimping, in the compressed state
in a view from the side, wherein the wire netting was reshaped back
into the starting state,
[0036] FIG. 8 the insertion of the crimped implant into an outer
shaft of a catheter in a view from the side,
[0037] FIGS. 9 and 10 the implant, which has been partially
inserted into the outer shaft of a catheter, disposed in the device
according to the invention as shown in FIG. 1, wherein in FIG. 10
the implant after crimping is disposed entirely, i.e. along the
entire length thereof, in the outer shaft, in a view from the
side,
[0038] FIG. 11 the implant, which is disposed in entirety in the
outer shaft of a catheter, after conclusion of the crimping
process, in a view from the side,
[0039] FIG. 12 a second exemplary embodiment of a device according
to the invention in a perspective view from the side in the
starting state and
[0040] FIG. 13 the exemplary embodiment according to FIG. 12 in a
perspective view from the side in the final state after conclusion
of the crimping process.
DETAILED DESCRIPTION
[0041] The figures show two exemplary embodiments of a device
according to the invention in a schematic and simplified manner
and, in particular, show the details that are important in order to
understand the invention. Some of the details that are
insignificant for the invention were omitted. Furthermore, the
expression "distal end" in the context of the present invention
refers to the end of the implant that points away from the treating
physician while the implant is being introduced into the body, and
the "proximal end" points toward the person who is operating a
catheter, for example.
[0042] The exemplary embodiment of a device 10 for crimping an
implant 20 (e.g. a heart valve stent), which is shown in FIGS. 1 to
7 and 9 to 10, comprises a hollow-cylindrical, braided wire netting
in a first section 11 and a hollow-conical braided wire netting in
a second section 12.
[0043] The wire netting can be formed, for example, of wires 15
having a circular cross section made of a Phynox (Elgiloy) alloy
(Co--Cr--Ni alloy, see above), which have a wire diameter of 0.2
mm. The angle between the wires at the intersection points is
.alpha.=175.degree., for example, in the expanded state. The mesh
length L of the mesh 15a spanned by the wires 15 is 5 mm, and the
mesh width b is 0.9 mm in the expanded state. There are fifteen
intersection points 19 disposed around the entire circumference of
the wire netting. One intersection point 19 of such a wire netting
is shown in FIG. 1B. A mesh 15a spanned by wires 15 is shown in the
expanded state in FIGS. 1C and 1D. The wire netting is stretched in
order to transform the mesh into the state 15a' shown in FIG. 1D.
The forces acting on the mesh 15a during compression are
illustrated by the outer arrows in FIG. 1D. The exemplary
embodiment of a device according to the invention, which is shown
in FIGS. 1A to 1D, comprises round wire, as described above,
although this can also comprise flat wire or a combination of the
two wire types.
[0044] In the starting state before crimping, which is shown in
FIG. 1A, the implant 20 can be inserted in the expanded state into
the inner volume 14 of the wire netting, as shown in FIG. 4. The
inner volume 14 is formed by the hollow space enclosed by the
hollow cone or hollow cylinder. The direction indicated by the
arrow 25 in FIG. 4 extends parallel to the longitudinal axis 13 of
the wire netting in the sections 11 and 12. The implant 20 is
preferably inserted from the side on which the wire grating forms
the hollow cylinder 11.
[0045] In a preferred exemplary embodiment, the implant 20 was
cooled in a coolant 40 to a temperature below the transition
temperature, for example to 0.degree. C., before being placed into
the crimping device 10, as shown in FIG. 3. An ice block 41 floats
in the water bath in order to hold the coolant 40, which is
preferably water, at the temperature of 0.degree. C. In a further
exemplary embodiment, the entire crimping process can be carried
out in the coolant 40.
[0046] After the implant 20 has been placed into the wire netting
of the crimping device 10, the next step--after the implant was
slid into the hollow-conical section 12 of the crimping device
10--is to stretch the crimping device in the longitudinal direction
(see the arrow 25) or to apply pressure from the outside in the
radial direction, which extends transversely to the longitudinal
direction, as indicated by the arrow 26 in FIG. 5, thereby reducing
the inner diameter d of the inner volume 14 and crimping the
implant 20. For example, the inner diameter d is reduced by the
external pressure to 1/5 of the value in the expanded state.
[0047] In Table 1 that follows, the aforementioned example is
explained once more, using numbers.
TABLE-US-00001 TABLE 1 Material of the crimping device 10 e.g.
Phynox (Elgiloy) (Co Cr Ni alloy) Diameter d of the wire of the
wire 0.2 mm netting Angle .alpha. between the wires in the inter-
175.degree. section point in the expanded state Mesh length L (see
FIG. 1C) 5 mm Mesh width b (see FIG. 1C) 0.9 mm Number of
intersection points around 15 the circumference of the wire netting
Circumference of the wire netting in 15 .times. 0.9 mm = 13.5 mm
the compressed state Circumference of the wire netting in 15
.times. 5 mm = 75 mm the expanded state Compression ratio:
circumference 455% (circumference in the expanded state (75 mm
=> 13.5 mm) to the circumference in the compressed state) Change
in the inner diameter upon tran- 21.2 mm sition from the expanded
state to the (23 mm - 0.8 mm) => compressed state 3.4 mm (4.2 mm
- 0.8 mm)
[0048] FIG. 6 shows the implant 20 in the compressed state, wherein
the crimping device 10 is shown in this illustration in the state
thereof having the smallest inner diameter dmin. The crimping tool
10 can now be shortened once more in the longitudinal direction or
stretched in the radial direction (arrow 26), whereupon the inner
diameter d increases. This is illustrated in FIG. 7. In this state,
the implant 20 can be removed from the crimping tool 10.
[0049] Next, the implant 20 is inserted by way of the crimped
section thereof, into an outer shaft 30, which is formed by a
polymer tube, for example (cf. FIG. 8).
[0050] In a next step, which is shown in FIG. 9, the implant 20 is
now inserted together with the outer shaft 30 thereof into the
crimping device 10 once more in order to crimp the section of the
implant 20 that still protrudes from the outer shaft 30. In this
step as well, in analogy to the crimping step explained by
reference to FIGS. 5 and 6, the inner diameter of the crimping
device 10 is reduced via the application of a tensile force along
the longitudinal direction of the crimping device, and/or a
compressive force in the radial direction. Next, as shown in FIG.
10, the outer shaft 20 is slid entirely over the implant until the
outer shaft reaches the catheter tip 33 (cf. FIG. 11).
[0051] FIGS. 12 and 13 show how the inner diameter can be easily
reduced, via reference to a further exemplary embodiment of a
crimping device.
[0052] As shown in the first exemplary embodiment, which is
depicted in FIG. 1, the second exemplary embodiment of a device 10'
according to the invention also comprises a wire netting, which is
hollow-cylindrical in this case. A ring 16, 17 is provided at both
ends of the wire netting in the longitudinal direction, wherein the
ring (proximal ring) 16 disposed on the left side in the
illustration is stationary, while the (distal) ring 17 disposed on
the right side in the illustration is disposed such that it is
displaceble on a rail 18. If the distal ring 17 is now displaced
parallel to the longitudinal direction of the wire netting along
the rail 18 (arrow 25), the inner diameter d' of the inner volume
14' is reduced, in particular in the center section of the wire
netting, until a minimal inner diameter dmin' is reached there when
the distal ring 17 has the greatest distance from the proximal ring
16 in the direction of the rail 18. An implant (which is not shown
in FIGS. 12 and 13) disposed in this region of the wire netting is
reliably crimped by way of this diameter reduction.
[0053] It will be apparent to those skilled in the art that
numerous modifications and variations of the described examples and
embodiments are possible in light of the above teaching. The
disclosed examples and embodiments are presented for purposes of
illustration only. Other alternate embodiments may include some or
all of the features disclosed herein. Therefore, it is the intent
to cover all such modifications and alternate embodiments as may
come within the true scope of this invention.
LIST OF REFERENCE SIGNS
[0054] 10, 10' crimping device [0055] 11 hollow-cylindrical section
[0056] 12 hollow-conical section [0057] 13 longitudinal axis of the
crimping device 10 [0058] 14, 14' inner volume [0059] 15 wire
[0060] 15a mesh spanned by wires 15 in the starting state [0061]
15a' mesh 15a after reduction of the inner diameter [0062] 16
proximal ring [0063] 17 distal ring [0064] 18 rail [0065] 19
intersection point [0066] 20 implant [0067] 25, 26 arrow [0068] 30
outer shaft [0069] 33 catheter tip [0070] 40 coolant [0071] 41 ice
block [0072] b mesh width [0073] d wire diameter [0074] d, d' inner
diameter [0075] dmin, dmin' smallest inner diameter of the wire
netting of the implant 10, 10' [0076] L mesh length [0077] .alpha.
angle at the intersection point of the wires 15
* * * * *