U.S. patent application number 13/579918 was filed with the patent office on 2013-04-18 for expandable medical implant.
This patent application is currently assigned to TRANSCAATHETER TECHNOLOGIES GMBH. The applicant listed for this patent is Wolfgang Goetz, Hou-Sen Lim. Invention is credited to Wolfgang Goetz, Hou-Sen Lim.
Application Number | 20130091688 13/579918 |
Document ID | / |
Family ID | 44317286 |
Filed Date | 2013-04-18 |
United States Patent
Application |
20130091688 |
Kind Code |
A1 |
Goetz; Wolfgang ; et
al. |
April 18, 2013 |
EXPANDABLE MEDICAL IMPLANT
Abstract
A method for crimping a medical implant includes at least one
foldable and/or unfoldable structure on or around or over a portion
or outer surface of a catheter or of a catheter tip. No pressure
beyond a predetermined pressure is exerted on the structure during
and/or after crimping of the implant.
Inventors: |
Goetz; Wolfgang;
(Regensburg, DE) ; Lim; Hou-Sen; (Singapore,
SG) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Goetz; Wolfgang
Lim; Hou-Sen |
Regensburg
Singapore |
|
DE
SG |
|
|
Assignee: |
TRANSCAATHETER TECHNOLOGIES
GMBH
REGENSBURG
DE
|
Family ID: |
44317286 |
Appl. No.: |
13/579918 |
Filed: |
February 16, 2011 |
PCT Filed: |
February 16, 2011 |
PCT NO: |
PCT/EP11/00738 |
371 Date: |
December 27, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61306564 |
Feb 22, 2010 |
|
|
|
Current U.S.
Class: |
29/505 ;
29/243.5 |
Current CPC
Class: |
A61F 2/2418 20130101;
A61F 2/2412 20130101; A61F 2002/9511 20130101; A61F 2/2439
20130101; A61F 2250/0073 20130101; Y10T 29/49908 20150115; Y10T
29/53709 20150115; A61F 2/95 20130101; A61F 2/9522 20200501; B23P
11/005 20130101 |
Class at
Publication: |
29/505 ;
29/243.5 |
International
Class: |
B23P 11/00 20060101
B23P011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 17, 2010 |
DE |
102010008382.8 |
Claims
1. A method for crimping a medical implant comprising at least one
foldable and unfoldable structure on or around or over a portion or
outer surface of a catheter or of a catheter tip or another
delivery device or part thereof, wherein no pressure beyond a
predetermined pressure is exerted on the structure during and/or
after crimping of the implant.
2. A method according to claim 1, wherein the foldable and
unfoldable structure is one or more heart valve leaflets or
replacements or substitutes thereof or comprises those.
3. A method according to claim 1, wherein the implant comprises one
or more interconnecting elements, and wherein the pressure exerted
on the structure is determined between the interconnecting elements
and the outer surface or the portion of the catheter.
4. A method according to claim 1, where the predetermined pressure
is 0 N per square millimetre (0 N/mm.sup.2).
5. A method according to claim 1, where the predetermined pressure
is 5 N per square millimetre (5 N/mm.sup.2).
6. An implant crimped according to a method according to claim
1.
7. Delivery device comprising an implant according to claim 6.
8. Crimping device for crimping of an implant comprising at least
one foldable and/or unfoldable structure on or around or over a
portion or outer surface of a catheter or of a catheter tip with a
predetermined pressure exerted on the structure.
9. Crimping device for crimping of an implant comprising at least
one foldable and/or unfoldable structure on or around or over a
portion or outer surface of a catheter or of a catheter tip, the
crimping device comprising a pressure limiting arrangement for
limiting the pressure that is exerted or exertable on the implant
or on the structure during and/or after crimping of the
implant.
10. Crimping device according to claim 8, comprising a pressure or
force sensor measuring the pressure exerted on the structure upon
crimping.
Description
[0001] The present invention relates to a method for crimping of a
medical implant onto a delivery implement such as a catheter
according to claim 1. The invention further relates to an implant
according to claim 6, and also to a delivery device according to
claim 7 and a crimping device according to claims 8 and 9.
[0002] In a number of patients, certain body functions have to be
carried out or supported by means of technical devices temporarily
or permanently disposed to that end ("implanted") in the patient's
body.
[0003] Quite frequently, implants are delivered to the implantation
site within the body by means of a catheter. This is particularly
true for implants that are implanted within the body vessel system
including the heart itself.
[0004] In such cases, the implant is being crimped onto the
catheter and released from the latter at the implantation site.
[0005] Obviously, since upon crimping remarkable mechanical forces
are applied on the implant and also on certain structures implanted
together with and fixed to the implant, the crimping process has
some influence on the integrity of the crimped implant.
[0006] Therefore, it is one object of the present invention to
provide an additional crimping method. According to another aspect
of the present invention, an implant and a delivery implement are
to be provided.
[0007] The object of the invention is solved by means of a method
according to claim 1.
[0008] Accordingly, a method for crimping a medical implant
comprising at least one foldable or collapsible or crimpable and
unfoldable or expandable structure (therefore also referred to as
structures) on or around or over a portion or outer surface of a
catheter or of a catheter tip or of any other delivery implement or
device or part thereof is proposed. The method comprises the
feature that no pressure is exerted on the structure during and/or
after crimping of the implant beyond a predetermined pressure.
[0009] The implant according to the invention is defined by claim
6. The implant according to the invention is crimped onto the
catheter using the method according to the invention.
[0010] The delivery device according to the invention is defined by
claim 7. It comprises at least one implant according to the
invention.
[0011] The crimping device according to the invention is defined by
claim 8. Accordingly, the crimping device for crimping of an
implant comprising at least one foldable and unfoldable structure
on or around or over a portion or outer surface of a catheter or of
a catheter tip with a predetermined pressure exerted on the
structure.
[0012] Embodiments can include one or more of the following
features.
[0013] In some embodiments according to the method according to the
invention, in the context of the present invention the term
"crimping a medical implant" may mean the crimping result achieved
after termination of the entire crimping process of the medical
implant.
[0014] In the context of the present invention the term "crimping a
medical implant" may mean that the implant crimped by using the
method according to the invention is to be understood as prepared
on the catheter or delivery implement or device to be inserted or
implanted
[0015] In certain embodiments according to the method according to
the invention, in the context of the present invention the term
"crimping a medical implant" may mean that additional or further
crimping it not necessary or not contemplated or not required
before implanting of the implant.
[0016] In some embodiments according to the method according to the
invention, in the context of the present invention the term
"predetermined pressure" may refer to a pressure value that has
been determined and/or considered and/or selected by the person
responsible for the crimping process or carrying out the same
before or during the crimping process takes place.
[0017] In certain embodiments of the method according to the
invention, in the context of the present invention the term
"predetermined pressure" may refer to a pressure value adjusted at
a crimping device. The value can preferably be adjusted as a
maximum pressure value exerted on certain structures of the
implant, for example, heart valve replacement leaflets or
commissures thereof.
[0018] In some embodiments of the method according to the
invention, in the context of the present invention the term
pressure exerted "during and/or after crimping of the implant" may
refer to pressure exerted by means of the crimping itself.
[0019] In particular embodiments of the method according to the
invention, the method comprises the step of measuring the pressure
acting on or in the structure, or between the structure and other
parts of the implant, or between the structure and the delivery
device (in particular, the circumferential surface or a section
thereof of the delivery device), and the step of terminating the
crimping procedure once the pressure measured has reached the
predetermined pressure or exceeds the predetermined pressure. In
some of these embodiments, the methods comprises placing a pressure
or force sensor in direct contact with the structure.
[0020] In certain embodiments of the method according to the
invention, in the context of the present invention the term
"predetermined pressure" may refer to a pressure that exclusively
results from the crimping steps as such. In those embodiments,
pressure exerted on the structures at issue stemming or originating
from other pressure sources than by the crimping steps is not
referred to as the predetermined pressure. Such other pressure
comprises the atmospheric pressure, water or fluid pressure, and
the like. In certain embodiments, such additional pressure does not
contribute to the determined pressure or the level thereof.
[0021] In some embodiments of the method according to the present
invention a predetermined pressure may be understood as a
predetermined force, strain, stress and the like as well. Hence, in
those embodiments, the terms pressure, force, strain, stress and
the like may be understood as interchangeable.
[0022] In certain embodiments according to the invention, the
predetermined pressure is to be understood as a maximally allowable
pressure that is measured or may be measured between the structure
of the implant and a circumferential surface or an envelope of the
delivery device, or equals the such measured pressure.
[0023] In some embodiments, the foldable and unfoldable structure
is one or more heart valve leaflets or commissures or replacements
or substitutes thereof or comprises those.
[0024] In certain embodiments, the structure is not the proximal or
the distal ring of the implant.
[0025] In some embodiments, the structure on the implant is not
intended to contribute to the temporary fixation of the implant on
the delivery implement/device.
[0026] In certain embodiments, the implant comprises one or more
interconnecting elements, and the pressure exerted or applying on
the structure is determined between the interconnecting elements
and the outer surface or the portion of the catheter.
[0027] The interconnecting elements may be embodied as posts
interconnecting a proximal and a distal ring or support
structure.
[0028] The interconnecting elements may be embodied as radially (as
regards a longitudinal axis of the implant or of the delivery
device) expandable or shiftable structures, of the implant, wherein
they are expanded or shifted or moved away from the upon expansion
of implant.
[0029] The interconnecting elements may be embodied as one or more
posts.
[0030] The interconnecting elements may be embodied as structures
provided for maintaining a distance between a distal ring and a
proximal ring of the implant
[0031] In some embodiments, the predetermined pressure is 0 N per
square millimetre (0 N/mm.sup.2) or 1 N/mm.sup.2 or 2 N/mm.sup.2 or
3 N/mm.sup.2 or 5 N/mm.sup.2. If the predetermined pressure is 0
N/mm.sup.2 or about 0 N/mm.sup.2, the method according to the
invention may be called a "zero pressure crimping" method.
[0032] In certain embodiments, the predetermined pressure is 5 N
per square millimetre (5 N/mm.sup.2) or 8 N/mm.sup.2 or 10
N/mm.sup.2 or 15 N/mm.sup.2 or 20 N/mm.sup.2 or 25 N/mm.sup.2 or 30
N/mm.sup.2 or any value in between. In some embodiments, the method
according to the invention is carried out manually by the aid of
non-electric tools.
[0033] In certain embodiments, the method according to the
invention is carried out by the aid of automatic tools. Such tools
can be electric, pneumatic, hydraulic tools and the like.
[0034] In some embodiments, the crimping device for crimping of an
implant comprising at least one foldable and unfoldable structure
on or around or over a portion or outer surface of a catheter or of
a catheter tip, comprises a pressure limiting means for limiting
the pressure that is exerted or exertable on the implant and/or on
the structure during and/or after crimping of the implant.
[0035] In certain embodiments, the pressure (or force) exerted or
exertable on the structure may be known once the pressure (or
force) exerted on the implant comprising the structure is known.
For example, it might be known--e.g. from known relationships
between a first and a second pressure as defined in the
following--that zero pressure (being one example of a first
pressure) is applied on the structure if less than a certain
pressure (second pressure) is exerted on the implant during
crimping. In those embodiments, it may be sufficient to limit the
(second) pressure applied to the implant. As may be known in that
case from earlier experiments or from a look-up-table, the (first)
pressure applied to the structures or acting on the structures in
question will then not be higher than a predetermined pressure or a
pressure considered to be a maximum pressure that is allowed to
apply to the structure.
[0036] In some embodiments, the crimping device comprises a
pressure sensor (or is functionally linked with it) that reflects
the pressure or force exerted on the structure at issue (e.g., the
leaflets comprised by the implant) during crimping. Preferably, the
pressure sensor is placed, for example, between the structure at
issue (such as the leaflets of the implant) and a neighbouring
structure (such as an outer surface or other part of the catheter
used). In certain embodiments, such a pressure sensor or any other
suitable sensor is provided with the catheter. In some embodiments,
the pressure sensor or any other suitable sensor is located within
a lumen of the catheter or on an outer surface thereof.
[0037] In certain embodiments, the crimping device is intended
and/or configured for crimping by means of a predetermined pressure
exerted on the structure during and/or after crimping of the
implant.
[0038] In some embodiments, the crimping device comprises a
controller for limiting or controlling the pressure exerted on the
structure of the implant.
[0039] In certain embodiments, the crimping device comprises an
adjusting means for adjusting the pressure exerted upon crimping.
The adjusting means may be connected to the controller.
[0040] In some embodiments, the crimping device is intended and/or
configured for crimping medical implants, in particular for
crimping only medical implants.
[0041] In certain embodiments, the crimping device comprises one or
more pressure sensors that output a signal indicating the pressure
applied on the structures at issue during crimping.
[0042] The implant according to the invention may be of an
expandable and again foldable or collapsible, respectively, type.
Such implants may, for example, be changed in its diameter by means
of strings guided around certain portions of the implant that can
be tightened or released. The features required to be amendable in
diameter are not in the main focus of the present invention. Since
they are further explained in great detail in WO 2008/029296 A2
("Minimally invasive heart valve replacement", filed on Feb. 15,
2007) to the inventors of the present invention, and also in WO
2009/109348 A1 ("Stent, welcher vom expandierten Zustand
kontrolliert erneut im Durchmesser verringerbar ist", filed on Mar.
2, 2009) also to the inventors of the present invention, for the
sake of avoiding repetition it is referred to those documents as
regards those features. The respective disclosure is herewith
incorporated into the present application by way of reference. The
same applies to any material mentioned in either of both
applications.
[0043] Whenever reference is made within the present specification
to a catheter, it is to be noted that the term "catheter" is used
by way of example for a delivery implement or device for delivering
the implant to the implantation site. Hence, the present invention
is not to be understood to relate only to catheters - rather, any
suitable device for advancing an implant to its implantation site
is also contemplated by the inventors.
[0044] Along with advantages that are obvious to the skilled one,
the embodiments may provide one or more of the following
advantages.
[0045] Although crimping of implants, in particular stents, is
well-known in the art and probably the most often used method for
temporarily fixing an implant on a catheter, according to the
findings of the inventors the implant or structures comprised by
the implant are frequently adversely compressed and sometimes even
damaged. Those damages have hitherto not been realized neither by
the skilled ones nor by the public. The present inventors, however,
realized a problem resulting from applying undue pressure on, e.g.,
the leaflets of a heart valve replacement such as the one described
in above mentioned WO 2008/029296 A2. It appears that the damages
observed resulted from a pressure applied on the leaflet and the
commissures upon crimping between the interconnecting elements or
posts and the sleeve, respectively, on the one side, and the
crimping surface (outer surface) of the catheter on the other
side.
[0046] In some embodiments, it is proposed to carry out the method
according to the present invention by advantageously making use of
a new implant design providing for space (the first gap) between
the interconnecting elements and the catheter to allow, e.g., the
commissures of above implant of the figures or other structures to
be located between the interconnecting elements and the catheter
surface without being pressed or even damaged.
[0047] Further, in certain embodiments, it is proposed to carry out
the method according to the present invention by advantageously
making use of another new design of the implant that provides for
sufficient space (second gap) for structures such as the leaflets
of the implant of WO 2008/029296 A2 between a sleeve (if provided)
or the vessel wall during delivery of the implant, and the surface
of the relatively hard and inelastic catheter.
[0048] In some embodiments, crushing of leaflets of a valve
replacement comprised by the implant may be advantageously
avoided.
[0049] In certain embodiments, a disruption of collagen fibres
found by the inventors of the present invention within leaflets of
a valve replacement of natural origin (bovine, for example) after
having been crimped can advantageously be prevented.
[0050] Other aspects, features, and advantages will be apparent
from the description, figures and claims.
[0051] In the following, the invention is further explained by
means of the figures of the drawing. However, the invention must
not be limited to the examples explained by means of the figures.
It is noted that within the attached drawing identical reference
numeral denote identical or similar structures.
[0052] FIG. 1 shows a schematic illustration of an implant
according to the invention in a first embodiment;
[0053] FIG. 2 shows a schematic illustration of an implant
according to the invention in a second embodiment;
[0054] FIG. 3 shows a schematic illustration of a crimping device
according to a first embodiment of the invention; and
[0055] FIG. 4 shows a schematic illustration of a crimping device
according to a second embodiment of the invention.
[0056] FIG. 1 shows a schematic illustration of an implant 1
according to the invention in a first embodiment. The implant 1 is
crimped onto the outer surface 23 of the tip 3 of a catheter 5. The
catheter 5 has a proximal ring 7, a distal ring 9 and posts 12 with
proximal and distal ends 12a, 12b. Strings 15a, 15b are guided by
means of the distal ring 9 and the proximal ring 7, respectively.
The strings 15a, 15b may be used for folding and unfolding of the
implant 1 in a controlled manner.
[0057] The implant 1 may be a heart valve replacement as is
described in WO 2008/029296 A2 or in WO 2009/109348 A1 as referred
to above.
[0058] As can be seen from FIG. 1, the implant 1 is tightly crimped
onto the catheter 5 such that ring-shaped portions 25 and 27 are in
contact with the outer surface 23 of the catheter 5. As can also be
seen, at least a first gap dl between the post 12 and the outer
surface 23 of the implant 1 is created and/or maintained during
crimping. In certain embodiments according to the invention, the
first gap dl has the shape of a tube. In the embodiment of FIG. 1
it is due to the first gap dl that structures comprised by the
implant such as heart leaflets or commissures (both not shown in
the figures) may be left unstressed, unpressed unforced and the
like upon and after crimping of the entire implant 1 or the implant
as such, respectively.
[0059] FIG. 2 shows a schematic illustration of an implant 1
according to the invention in a second embodiment.
[0060] In the second embodiment, in contrast to the crimping state
shown in FIG. 1 in which the implant 1 is in contact or form fit
with the outer surface 23 of the catheter 5 along ring- shaped
portions 25 and 27, the implant 1 does not have contact with the
outer surface 23 at all. Rather, after completion of the crimping
process of implant 1, a second gap d2 remained between the implant
1 (e.g., its post 12 or its ring-shaped portions 25 and 27 of the
distal and proximal rings 9, 7) and the outer surface 23 of the
catheter. A interconnection between the catheter 5 and the implant
1 needed for delivery of the implant 1 to its implantation site may
be achieved by means of the strings 15a, 15b, which are connected
to the catheter 5 (interconnection is not shown in FIG. 1 or 2; it
can, however be seen in all detail in WO 2008/029296 A2 or in WO
2009/109348 A1 as referred to above). A connection may also be
achieved by means of a sleeve (not shown) covering the implant
during delivery.
[0061] The interconnection between implant 1 and catheter 5 is a
more loose one when compared to that achieved by the crimping the
result of which is shown in FIG. 1.
[0062] As is obvious to the skilled person, structures of the
implant 1 such as (not shown) heart valve leaflets may be comprised
and housed by the implant 1 during and after crimping of the
implant 1 without being stressed, crushed, forced, pushed and/or
the like. Gaps d1, d2 and d3 provide sufficient space for such
structures such that the implant can be crimped without any adverse
effect happening to said structures.
[0063] As can be seen from FIG. 2, in contrast to the implant shown
in FIG. 1 , at least one (or all) of the posts 12 of the implant 1
are arranged such that it is level with the distal and proximal
rings 7, 9. Hence, as can be derived from FIG. 2, the method
according to the present invention can be carried out with any type
of implant. The benefit of the method according to the invention
does not depend on the concrete or specific design or embodiment of
the implant.
[0064] FIG. 3 shows a schematic illustration of a hand-held and
hand-operated crimping device 31 according to a first embodiment of
the invention.
[0065] The crimping device 31 comprises actuators 33a, 33b
comprising brackets 35a, 35b for receiving the (not shown) implant
for crimping same. The actuators 33a, 33b are connected to each
other by means of an articulation or a joint 37. They are further
connected to each other by means of a pressure limiting means 39.
The pressure limiting means 39 may be adjustable. It limits the
pressure exerted to the structure at issue of the implant to the
predetermined pressure.
[0066] FIG. 4 shows a schematic illustration of a crimping device
according to a second embodiment of the invention.
[0067] Like the crimping device of FIG. 3, the crimping device 31
comprises actuators 33a, 33b comprising brackets 35a, 35b for
receiving the (not shown) implant for crimping the same.
[0068] In contrast to the first embodiment, in the second
embodiment the crimping device comprises pressure limiting means
embodied as controller 41. The controller 41 may be interconnected
to an adjusting means 43 for adjusting the maximum pressure exerted
to the structure in question of the implant in correspondence to
the predetermined pressure.
[0069] It is noted that the crimping device according to the
invention may have in any embodiment thereof (that is, irrespective
of any further features of the crimping devices 31 shown in FIG. 3
or 4) a sensor for measuring the pressure or force exerted on the
structure during crimping.
* * * * *