Note: Descriptions are shown in the official language in which they were submitted.
PATENT APPLICATION
PC 8375
DEVICE FOR TMPLANTING AN ENDOPROSTHESTS
~ckaround of the Tnventio_n
The present invention relates to a devic8 for
implanting an endoprosthesis in a channel-shaped
vessel in the human or animal body with an elongated
tubular sleeve element having a distal and a proximal
end, said distal end being designed to receive an
endoprosthesis inserted thereinto in a radially
compressed state, and with an elongated core element.
This element is displaceable in the outer sleeve
element relative thereto and located coaxially
thereto, as a stationary plunger, said core element
having a distal and a proximal end, with a shoulder
designed to abut an inserted endoprosthesis being
located in the vicinity of the distal end in such
fashion that an endoprosthesis inserted into the
sleeve element is ejectable by movement of the sleeve
element relative to the core element, whereupon the
endoprosthesis expands automatically and abuts the
wall of the vessel, said sleeve element and said core
element each having an actuating handle at the
proximal end, with the actuating handle of the sleeve
element having at~least one projection designed as a
support for a unilaterally applied human finger that
does not surround the handle.
Implanted endoprostheses can generally be used
for constricted lumina, for example constrictions of
blood vessels. These endoprostheses, also called
stents, are often tubes of woven wire which are
30' composed of elastic filaments such that the woven
wire tube is inserted in a radially compressed state
to the point in the vessel to be treated that is to
be expanded, by means of an implanting device,
whereupon the implanting device releases the
endoprosthesis so that the latter expands, abuts the
walls of the vessel, and dilates the constriction.
XX/AMS/dp 45 850 a
28.9.1993
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Such implantable endoprostheses and
corresponding devices for implanting them are
disclosed in U.S. patents -A-4,655,771, U.S.-A-4-
954,126, and U.S.-A-5,026,377. Another disclosure
can be found in the book ~~Katheter-interventionen in
der Angiologie~~ Catheter Intervention in Angiology]
by Felix Mahler, Georg Thieme Verlag, Stuttgart/New
York, pages 31-35 (General Methodology and
Instruments). Reference is made to this citation
expressly for purposes of disclosure.
The woven wire tube or a correspondingly
structured endoprosthesis is then gripped in the
radially compressed state in an outer sleeve element.
Inside the sleeve element is a core element provided
with a shoulder and designed as a plunger permanently
held in place. The core element is ejectable axially
relative to the outer sleeve and can abut the
endoprosthesis with its shoulder. A relative
movement of the sleeve element with respect to the
sore element is performed to release the
endoprosthesis. When the implanting device is used
correctly, the core element is kept stationary for
this relative movement and the sleeve element is
retraoted.
If the implanting device is operated incorrectly
and it is not the core element but the sleeve element
that is held stationary to perform the relative
movement, even if the endoprosthesis emerges properly
from the distal end of the sleeve element and the
endoprosthesis is released, the endoprosthesis in
this procedure is pushed forward in the vessel,
injuring said vessel. If the physician does not have
an opportunity to monitor this optically in real-time
images, the free ends of the endoprosthesis penetrate
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the wall of the vessel. At the same time, the
elements of the endoprosthesis that are not designed
for this load, in other words the above-mentioned
elastic filaments, for example, are permanently
deformed and thus render the endoprosthesis
ineffective. Although implanting devices have been
proposed that permit the endoprosthesis to be folded
back into the outer sleeve element, when the elements
of the endoprosthesis are permanently deformed by
this improper operation, even this solution is no
longer reliable. The bent and therefore ineffective
endoprosthesis may therefore have to be left in the
vessel. Ths location of the now ineffective
endoprosthesis can no longer be changed either.
Provided it is only partially unfolded, it can at
best be pulled within narrow limits toward the
operating side. In the least favorable case,
therefare, an endoprosthesis that has become useless
must be left precisely at the point in the vessel at
which an intact endoprosthesis was indicated, in
other words the point at which the vessel has been
altered by disease.
Hence, possible improper operation of the
implanting devices used for these endaprostheses can
lead to situations that have far-reaching
consequences. Tmproper operation with these devices
can easily occur in any event because the outer
sleeve which has to be retracted during proper
operation is located in the vessel for nearly its
entire length and is held there with a certain amount
of adhesive friction. Hence, the outer sleeve
element opposes the movement required for proper
operation with a certain amount of resistance.
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In the known devices, although the operating end
is designed so that the relative movement between the
core element and the outer sleeve element is executed
easily and reliably in a shearing motion, the known
devices suffer from the disadvantage that the
operating handles are so designed that both types of
movement, the correct type of movement with a
stationary core element and the improper type of
movement with a stationary sleeve element, are
completely identical as far as the ease with which
either can be performed. The known handle
arrangements offer no preferred operation as far as
correct or incorrect operation is concerned. The
shearing motion suggested by the known handles
incorporates a single correct as well as many
incorrect forms of movement. The choice between
correct and incorrect operation of the known handles
is solely a matter of judgement on the part of the
physician and the sequence of movements that are
actually performed during operation depend upon the
ability of the physician to reliably convert into
practice the results of previous selection. In
addition, the handle arrangement of the known devices
can be associated by some operators with the
operation of a conventional hypodermic syringe. In
conventional hypodermic syringes, the plunger is
normally advanced relative to the external barrel.
In this case, however, this motion is precisely the
wrong one.
It has also developed that in many applications
the known handles are incomplete as far as placing
the implanting device with the necessary reliability
and safety in the correct starting position before
releasing the endoprosthesis is concerned.
CA 02103389 2001-08-14
66152-123
Sununary of the Invention
The invention is designed to provide a remedy in
this regard.
According to the invention there is provided a
5 device for implanting an endoprosthesis in a human or animal
body, comprising: an elongated core member having a distal
end and a proximal end, with a shoulder adjacent to the
distal end adapted to prevent movement of an endoprosthesis
toward the proximal enct of the elongated core member and a
first handle in the form of a pistol grip affixed adjacent
to the proximal end; an elongated tubular sleeve adapted to
receive an endoprosthe~:is therein coaxially surrounding and
movable with respect to the elongated core member, the
elongate tubular sleeve; having a distal end and a proximal
end with a second handle in the form of two projections
affixed to the proximal. end extending radially from the
elongated tubular sleeve; a means for locking the elongated
tubular sleeve to the elongated core member to prevent
relative longitudinal rr~ovement therebetween; a third handle
in the form of a projecaion extending radially outward from
the elongated core member opposite the first handle; the two
projections of the second handle being located diametrically
opposite to one another and lying in the same plane as the
first handle and third handle.
The invention. achieves the goal of providing a
device for implanting an endoprosthesis in a channel-shaped
vessel in the human or animal body, which is easy to
manufacture, whose placement in the starting position prior
to the release of the endoprosthesis is facilitated, which
66152-123
CA 02103389 2001-08-14
5a
poses limited demands on the skill of the operator, and in
which correct operation of the device is facilitated while
improper operation is made more difficult.
The invention makes it possible for the implanting
device to be placed with the necessary reliability and
safety in the correct ~;tarting position prior to the release
of the endoprosthesis. The outer sleeve element is secured
relative to the core element by the locking device. It is
no longer necessary to manipulate the outer sleeve element
to set the implanting device, but the inner core element,
projecting further at the proximal end of the device, can be
used to manipulate the entire device. A projecting handle
in the shape of a pistol butt, designed to be gripped by the
thumb and first joint of the index finger, is provided on
this internal core element. The projecting pistol butt
shape, which can be grasped in the manner described serves
both to control and advance the implanting device using the
operator's wrist. The resulting forces provide safe,
reliable, and accurate control that requires less dexterity
on the part of the physician.
On the other hand, there is no pistol butt on the
outer sleeve element, but rather a handle like
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those provided on known devices. This other type of
handle merely serves as a support for a finger that
abuts it on one side but does not surround the
handle. Because of the fact that the pistol butt is
mounted on the inner core element and the fact that a
very different handle is provided on the other part,
the inner core element is always positioned relative
to the wrist, which must be held stationary easily.
The inner core element is not associated with the
fingers or a finger.
When a shearing motion is performed between the
thumb and index finger as in the prior art, it may
require little dexterity and ability to hold the:
thumb stationary arid move the index finger toward the
thumb. However, it requires considerable dexterity
to hold the index finger stationary during this
motion in the prior art and to move the thumb toward
the index finger. On the other hand, the i.rvention
takes a completely different approach to operating
the device. Either a finger or fingers is/are moved
toward tha wrist when the handle on the outer sleeve
is within range of the fingers from the pistol butt,
or the other hand is used for the shearing motion.
In the first case, a movement of the handle is
involved and hence the simplest possible operating
movement is feasible. It requires the minimum amount
of dexterity, accuracy, and attention. In the second
case, when the handle on the outer sleeve is beyond
the reach of the fingers from the pistol butt, the
second hand performs the shearing motion alone
without regard to holding it stationary. The wrist
with which the pistol butt is associated in both
cases can be held stationary, in this operation,
however, because its position is controlled by a
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completely different set of muscles than the fingers.
The combination of features in the invention
therefore facilitates correct operation and no longer
requires any particular skill on the part of the
physician. The resistance to motion of the outer
sleeve element in the vessel can thus be overcome
more easily without simultaneously exerting an
opposing pushing force on the core element.
The handles of the outer sleeve and the inner
core are made to be very different according to the
invention, each for a different type of grip.
Improper operation of the device is thus made
considerably more difficult because the handles would
have to be gripped in a manner for which they are not
designed. This means, however, that the choice
between correct and incorrect operation is not left
merely to the judgement of the physician. In the
device, according to the invention, before the
incorrect step can in fact be taken, the improper
choice would also require overcoming some definite
hurdles in manipulation. Inadvertent improper
operation is therefore practically impossible.
The pistol butt provided, in the combination of
features according to the invention, is known from
many areas of life and is used in the invention
precisely because of the type of operation for which
it is known in the other areas. Therefore, the
combination of features of the.invention suggests to
the impartial observer the mode of operation, and the
design of the invention in particular cannot evoke
any improper associations that could result in
improper operation.
Another advantage is the fact that by locking
the outer sleeve element to both the core element and
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the pistol butt, an implanting device is obtained
which can be rotated in a particularly skillful
manner as the device is inserted into the vessel.
With a beveled end at the tip, which is known in and
of itself, this device can then be placed without a
dilator. In other words, it can be used without a
separate unit which is conical for example, and
expands the vessel first before the device is
advanced. The beveled cut at the tip of the device
can be guided by carefully rotating the device with
the pistol butt through any constrictions of the
vessel. In the trachea, such narrow points include
the vocal cords, for example.
If another handle is provided on the core
Z5 element in addition to the pistol-butt-shaped handle,
serving as a support for a finger applied
unilaterally but not wrapped around the handle, and
located opposite the handle of the sleeve element,
the devise can then be operated more easily with two
hands. It only takes one hand, then, to produce the
relative movement~between the sleeve element and the
core element, while the other hand must only hold the
device steady. In this case, the entire span of one
hand can be used to produce the relative movement,
and as result a particularly long endoprosthesis can
be released directly without any leverage. The
pistol butt can then be gripped especially
effectively not just with the thumb and the first
joint of the index finger, but in this case by
surrounding it with the entire hand. It is also
conceivable to have a device with this combination of
features that cannot be operated with only one hand
once the pistol butt is gripped by the operator. To
achieve this, it is only necessary to locate the
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handle attached to the outer sleeve element far
enough away from the pistol butt. In any case, due
to the separation of the °'hold stationary°' and
'°release" functions, operation with two hands is a
more reliable method during long release movements.
Especially delicate positioning of the device in
the starting position for releasing the
endoprosthesis, and especially reliable retention in
the stationary position, are made possible when the
pistol-shaped handle on the core element is designed
so that it can be surrounded by the middle, ring, and
little fingers.
When the actuating handle of the sleeve element
has two projections located diametrically opposite
one another, the other handle of the core element is
located diametrically opposite the pistol-butt-shaped
handle, and the two projections of the sleeve element
are in a plane that coincides with the plane defined
by the pistol butt-shaped handle and the other
handle, a grip for the operator is offered that
matches human anatomy very closely. No severe
bending of the wrists is required, and the lower arms
of the operator during the operation of the device
are at an angle of 90 degrees to one another.
Because extreme positions of the operator's limbs are
avoided, a considerable degree of safety and
reliability during operation is guaranteed.
Brief Description of the Drawincts
The invention will now be described in greater
detail with reference to the drawings that show only
one embodiment.
Figure 1 is a side view of an implanting device
designed according to the invention.
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Figure 2 is a top view of the device shown in
Figure 1.
Figure 3 is a side view of the core element of
the device, and
Figure 4 is a side view of the sleeve element of
the device.
Detailed Description of the Invention
The implanting device is basically composed of
two parts, an outer sleeve element 1 and an inner
core element 4. These two elements are displaceable
relative to one another. Distal end 2 of sleeve
element 1 is made divergent and then beveled. The
endoprosthesis, cut to the desired length, is
inserted in an elastically compressed state into this
distal end 2 and held there. Two projections 10 and
11 are provided on the proximal end 3 of sleeve
element 1 and it is evident that a retracting motion
of sleeve element 1 relative to core element 4, to be
described below, is permitted exclusively by fingers
surrounding these projections 10, 11, for example the
index finger and middle finger of the human hand.
A shoulder 7 is provided at distal end 5 of core
element 4. Hence, core element 4 is designed as a
plunger held in the stationary position which can act
on one end of an endoprosthesis. Core element 4 has
a pistol butt-shaped handle 8 at the proximal end 6.
Another handle 9 acting as a support is provided
diametrically opposite the latter. It is evident
that pistol butt-shaped handle 8, the other handle 9,
projection 10, and projection 11 all lie in the same
plane.
Two guide rods 12, 13 project from the vicinity
of pistol butt-shaped handle 8 of core element 4 in
the direction of the distal end of core element 4.
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These guide rods 12, 13 are inserted into tubular
sections 14, 15 of sleeve element 1 so that relative
rotary motion between sleeve element 1 and core
element ~ is rendered impossible in such a manner
that the above-mentioned handles and projections
always retain their preset positions relative to one
another. The interior of core element 4 is connected
by a connection 16 with the environment. This
connection makes it possible, for example, to insert
a medium into the vessel to be treated or if
necessary to perform suction.
Core element 4 which is made in the form of a
hollow cylinder because of the nature of the internal
space can also receive other medical instruments in
its interior. For examples an endoscope can be
placed in core element 4. This allows visual
monitoring of the placement of the endoprosthesis.
The connection from the outside would also pass
through connection 16.
Sleeve element 1 also has a locking screw 17 at
proximal end 3 by~means of which sleeve element 1 can
be locked to core element 4.
The device is operated as follows. In a first
step, sleeve element 1 is moved leftward in the
figures on core element 4 so that shoulder 7 of core
element 4 comes to rest inside sleeve element 1.
Then sleeve element 1 is locked to core element 4 by
tightening locking screw 17. Then the endoprosthesis
is inserted at distal end 2 into sleeve element 1 in
an elastically compressed state, so that one of its
ends lies opposite shaulder 7 of core element 4.
Contact is not absolutely necessary since the
endoprosthesis, because of its elastic pretensioning
force, abuts the inside wall of sleeve element 1 and
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is thus protected from inadvertent displacement. To
insert the endoprosthesis into the vessel to be
treated, after all of the previous medical measures
have been taken according to generally known
procedures, the physician grips pistol butt-shaped
handle 8 at least with the thumb and first joint of
the index finger. The implanting device with the
endoprosthesis is then inserted into the vessel until
the endoprosthesis is located exactly at the desired
point in the vessel. The procedures for monitoring
and checking the positions of such endoprostheses are
generally known. It is clear that, because of the
pistol butt-shaped handle, extremely reliable
manipulation of the device and rotation if necessary
are made possible.
To release the endoprosthesis, locking screw 17
is first loosened by the other hand and then by
pressing two fingers of the other hand on projections
10 and 11 and by applying the thumb of this hand to
projection 9, which acts as a support, sleeve element
1 can be retracted slowly in the direction toward
pistol butt-shaped handle 8. Since handle 8 is
basically still surrounded by the fist, the force
acting on projections 10, 11 and hence on sleeve
element 1 is less than the force acting on core
element 4, which must now be held so that it will not
slide back, so that undesired ejection of the
endoprosthesis during this manipulation is rendered
impossible. By pressing on shoulder 7 of core
element ~, the retraction of sleeve element 1 causes
the endoprpsthesis to emerge from the interior of
sleeve element 1 and it can then relax and expand,
abutting the inside wall of the vessel to be treated
and performing its expanding function therein.
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at is therefore clear that the human application
of force to that part of the device which is not
meant to be moved during manipulation to release the
endoprosthesis is much greater than that to the
device to be displaced, thus permitting reliable
placement of the endoprosthesis without the
possibility of improper operation.
In closing, it should be mentioned that
implantation in accordance with this invention also
incorporates a temporary placement of an
endoprosthesis in a vessel.
