CA2103389C

CA2103389C - Device for implanting an endoprosthesis

Info

Publication number: CA2103389C
Application number: CA2103389A
Authority: CA
Inventors: Marc Gianotti; Susanne Hank; Rolf Baldinger
Original assignee: Schneider Europe GmbH
Current assignee: Schneider Europe GmbH
Priority date: 1992-12-20
Filing date: 1993-11-18
Publication date: 2002-07-16
Anticipated expiration: 2013-11-18
Also published as: EP0603423A1; ES2108075T3; JP2648283B2; JPH07534A; ATE157857T1; AU669581B2; CA2103389A1; DE59208901D1; EP0603423B1; AU5215893A

Abstract

Sleeve element (1) is mounted in a lengthwise displaceable fashion on a core element (4). Core element (4) has a pistol butt-shaped handle (8). Sleeve element (1) has two projections (10, 11) which can only be surrounded by fingers in order to retract sleeve element (1) onto core element (4) to eject an endoprosthesis. Because of its pistol butt-shaped handle (8), greater human force can be used to hold core element (4) than it is possible to use to retract sleeve element (1) by applying fingers to its projections (10, 11). This ensures that when the endoprosthesis is positioned and released by retracting sleeve element (1), there will be no change in the position of core element (4), which would cause an undesired change in the position of the endoprosthesis to be implanted.

Description

PATENT APPLICATION

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 ~i(f~~8~

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 z:~~~3g 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.

~lUJ~~

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.

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 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 1J~
_g_ 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 ~~~338~
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 ~~.~~38 _8_ 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 ~:~~~~3~
_g_ 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.

2~u~38~

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.

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 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.

~, 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.

Claims

CLAIMS:

1. ~A 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 end 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 endoprosthesis 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 movement therebetween;
a third handle in the form of a projection 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.

2. ~The device of Claim 1 wherein the elongated core member has at least one guide rod extending parallel thereto from adjacent the proximal end toward the distal end and the elongated tubular sleeve has at least one guide tube extending parallel thereto from the proximal end to the distal end whereby relative rotary motion between the elongated core member and the elongated tubular sleeve is prevented when the guide rod is inserted in the guide tube.

3. ~The device according to Claim 1, wherein the elongated core member is a hollow cylinder adapted to receive other medical instruments.