DE19607451B4 - Occlusion implant for occluding arteriovenous shorting connections - Google Patents

Abstract

Occlusive implant (1) for occluding arteriovenous shorting connections in the human or animal body, comprising a wire (2) made of metal or plastic with shape memory properties, bent in the form of a double cone helix and threadedly wound with a secondary wire (6), characterized in that Windings (10) of the double helix are formed so that the turns (10) of a cone (3) are pressed against each other by axially acting flow forces and are each pressed by an adjacent turn (10) with a smaller diameter radially outward against the vessel wall of the short-circuit connection.

Description

The The present invention relates to a occlusion implant for occluding arteriovenous shorting connections in the human or animal body, which makes a wire out Has metal or plastic with shape memory properties, bent in the form of a double helix and wound thread-shaped with a secondary wire is.

at arteriovenous Short-circuit connections is it is mostly congenital malformations of the human or animal body, the long-term serious damage to the affected body organs to lead. One common in humans occurring form of the arteriovenous shorting connection is a vascular connection between the pulmonary artery (pulmonary artery) and the main artery (Aorta), the so-called ductus arteriosus Botalli. This vascular connection is present in all unborn children and is usually after birth through active contraction of the muscles in the wall of the duct and later coalescence the innermost vascular layers anatomically closed. Some children, however, lack one sufficient contractility of the musculature in the duct, so that the Vascular connection not or not sufficiently closed. This has the consequence that on the one hand the blood supply of the body diminished and on the other hand, the lung flow is increased. This leads to heart failure (heart failure). Over the years, there is an increase in pressure in the pulmonary circulation changes pulmonary capillaries (pulmonary hypertension, Eisenmenger reaction), which lead to the death of the patient can.

To the prior art, it is possible to Ductus arteriosus Botalli by surgical procedures, drug therapy or with the help of catheter techniques to close, where an implant is placed in the duct. As implants are For example, applied to a metal frame graft Polyvinyl alcohol (Ivalon) or a Doppelschirmchen known that folded into the inside of the body is introduced and released in the duct. These implants have the disadvantage that they only with relatively large caliber introduction cutlery with a diameter of 9 mm (28 French) inside the body introduced can be. They are not for the use in new or premature babies suitable in which due to the large-caliber introducers a vascular lesion unavoidable would.

Furthermore In the prior art occlusion implants are known which a metal or plastic wire with shape memory properties have, which is bent in the form of a double cone helix. Such Occlusion implants are stretched in the introducer introduced and introduced together with this into the body. in the Ductus arteriosus Botalli becomes the occlusion implant from the catheter released and resumes its predetermined helical shape. The diameter of the turns of such occlusion implants will a bit bigger than the diameter of the duct is chosen so that Occlusion implant is somewhat narrowed radially and elastic restoring forces of Turns against the vessel wall of the duct and anchor the implant there. By the possibility of the diameter of the occlusion implant for insertion into the interior of the body to shrink by being in the stretched state in the insertion kit can be introduced introduction Cutlery with relatively small widths of 1.5 mm (4-5 French) are used. these can also for Newborns or infants used without vascular lesions too cause.

The thin wire material but has only a small surface, with the result that the individual turns due to the elastic restoring forces in the vessel wall of the duct and there to damage the intima lead can. Furthermore, the blood flow in the ductus arteriosus affects Botalli relatively large axial Flow forces on the occlusion implant, so that there is a risk that the individual Windings are pushed axially into each other. In this case will the entire occlusion implant into an irregular ball with unpredictable structure, its secure anchoring to the vessel wall of the duct is uncertain and that can lead to embolism or other complications.

According to the state of the art, it is also known to wind the double-cone-shaped shape memory wire of an occlusion implant in a thread-like manner. An occlusion implant of such a wound shape memory wire has substantially larger surfaces and can accordingly be supported with larger support surfaces on the vessel wall of the ductus arteriosus Botalli. Furthermore, the thread-shaped winding of the shape memory wire gives the turns of the double cone coil a greater spatial fullness, which causes the occlusion implant to be anchored in the duct, in addition to the elastic restoring forces, by a self-festering effect. Namely, the flow forces acting axially on the occlusion implant due to blood flow in the duct are deflected by the supporting coils of the cone into radially outwardly directed support forces. More specifically, the individual turns are pressed together by the flow forces, each turn being from an adjacent turn with a smaller diameter is pushed radially outward against the wall of the duct. However, a prerequisite for this selbst bekneifenden effect is that the individual turns of the cone have such a large spatial abundance that the successive turns can support each other.

The known, in itself thread-shaped However, wound double cone coils have the disadvantage that the individual Windings have only a low dimensional stability. Already small, radial from the outside forces acting on the windings bring the turns out of their original circular shape. The low dimensional stability is more than 2.5 especially for larger diameter occlusion implants mm disadvantageous because the desired self-festering effect is no longer readily available. The individual pressed against each other, namely, unstable turns do not become of the axial flow force only radially outward pressed but they also dodge inward, so that again explained above, unwanted ball formation results.

Another vaso-occlusive device for occluding a site in the vasculature is known from US Pat WO 94/09705 A1 known. The implant has helical windings, which may extend through the implant a wire wound in various possible configurations, which may be made of a suitable material having shape memory alloys. The implant can be in the form of a double cone.

The However, the implant described here is primarily intended to to be placed in aneurysms. The structure of the implant is therefore not altogether in such a way that a secure anchoring in one Vessel with high Blood flow as the ductus arteriosus Botalli through the top described effect of the individual turns is brought each other.

A vaso-occlusive implant having a plurality of coils is also the WO 93/11719 A1 refer to. However, this implant is intended primarily for placement in aneurysms and is not designed so that a secure anchoring in the vessel is achieved by the effect of the individual turns on each other.

It It is therefore an object of the invention to provide an occlusion implant of the beginning to create said type, which avoids the disadvantages mentioned, in particular a secure closure also relatively more arteriovenous Shunts allowed and with a for Newborn and infants suitable introducer set is insertable.

object The invention is an occlusion implant for occluding arteriovenous shorting connections in the human or animal body, which makes a wire out Has metal or plastic with shape memory properties, bent in the form of a double helix and wound thread-shaped with a secondary wire is, wherein the turns of the double cone helix are formed, that the turns of a cone by axially acting flow forces against each other depressed and each of an adjacent smaller diameter coil radially outward against the vessel wall the short-circuit connection pressed become.

At the Occlusion implant according to the invention has the shape memory wire primarily the function of giving the double cone coil the required dimensional stability. The thread-like around the shape memory wire wound secondary wire has in contrast the function, the windings of the double cone a larger spatial Abundance so that they can better support themselves on the walls of the duct. By the opposite the prior art greater dimensional rigidity one hand, and the big one spatial Fullness of Windings, on the other hand, also occur with occlusion implants of large diameter with big ones Security of the desired, self grazing effect. With all this, the occlusion implant is according to the invention nevertheless with an introduction set very small caliber, z. B. 1 mm (2-3 French) insertable and therefore for newborns and infants suitable.

With the occlusion implant according to the invention can be very wide arteriovenous short-circuit connections secure anatomical closure. Also the closing a ductus arteriosus botalli with a typically very high Blood flow and without significant restrictions is thus easily possible. The means that just patients, where a duct closure urgently needed is because of the blood flow through the ductus is very high and thus a significant damage to the involved body organs is caused, now for the first time with a double-conical occlusion implant can be treated.

In order to accelerate thrombus formation after insertion of the occlusion implant into the duct, the invention proposes that the secondary wire consists of a thrombogenic material. For example, implants provided with thrombogenic fibers are known from US Pat WO 95/25480 A1 known. The formation of thrombi quickly causes the occlusion implant to grow into the intima of the duct and to finally close its anatomical closure. A quick thrombus picture It is important to release the patient from his symptoms as quickly as possible and to avoid further damage to the affected body organs. For example, platinum or gold alloys are used as thrombogenic materials. The shape memory wire of the occlusion implant bent in the form of a double cone coil still consists of a material with shape memory properties of metal or plastic and gives the individual turns of the occlusion implant the high dimensional stability. Due to the structure of the occlusion implant of two different wires, the wire materials can be chosen so that they are optimally matched to the particular task of the wire, dimensional stability or thrombogenicity.

Around a representation of the occlusion implant by means of one with x-rays To enable working imaging method, proposes the invention before that secondary wire from a radiopaque Material exists. This can be the entire insertion process of the occlusion implant and its exposure inside the body in the area of the arteriovenous shorting connection via a on X-rays follow a based imaging procedure. This ensures a precise positioning of the occlusion implant to a desired Place inside the body. In a follow-up of the duct closure can be again through a X-rays based imaging procedure to check the efficacy of the inserted occlusion implant. When X-ray opaque materials especially platinum and gold alloys have proven themselves.

A preferred embodiment the invention provides that to the distal end of the occlusion implant the shape memory wire and the secondary wire unsolvable connected to each other. This will cause a shifting of the shape memory wire and the secondary wire prevented relative to each other. The occlusion implant retains during the insertion process and also in the duct its structure. This is for a proper function of the occlusion implant is indispensable. The distal end of the occlusion implant leaves during the insertion process First, the introductory cutlery and is also first pushed into the duct. It must be guaranteed be that the Shape memory wire and the secondary wire at the distal end is not in the introducer or in the vessel wall snag. This would a proper positioning of the occlusion implant and cause damage to the duct. By the compound of the invention of the shape memory wire with the secondary wire at the distal end of the occlusion implant becomes its smooth Move out of the introductory cutlery and insertion ensured in the duct.

A particularly advantageous embodiment the invention provides that to the proximal end of the occlusion implant a particular spherical fastener is arranged. For insertion of the occlusion implant in the inside of the body it is stretched Condition pulled into a catheter. For this purpose, a grasps at the distal end a sliding mechanism arranged in the catheter gripping mechanism the spherical one Fastener and pulls the occlusion implant lengthwise in the catheter. Then the catheter will be together with the catheter Occlusion implant in the body introduced and to the arteriovenous Short-circuit connection emotional. There, the sliding gate together with the occlusion implant driven out of the catheter. Due to the pseudoelastic properties of the wire material takes it inside the body again the previously imposed form of a double cone helix at. The occlusion implant is after pushing out out of the catheter in an optimal position, it will open by opening the Gripping mechanism mechanically from the sliding gate of the catheter solved. However, if the position of the occlusion implant is in need of improvement, so It can be wholly or partially pulled back into the catheter and new be positioned. this makes possible optimal positioning and secure anchoring of the occlusion implant in the duct and a rapid, trouble-free closing of the duct. Of course the fastening element can have any three-dimensional shape, in practice, however, has the ball-shaped fastener Especially proven due to its symmetry properties.

A another embodiment the invention provides that in the middle part of the occlusion implant, in which the two cones meet on the front side, radially outwardly extending threads of surgical Nylon material brush-like are arranged. additionally to the thrombogenic material properties of the secondary wire promote the threads the Thrombosis in the area of the occlusion implant after its Insertion in the duct. There is a rapid anatomical closure of the duct, the patient is relieved of his symptoms and another damage the affected body organs is avoided.

One embodiment The invention will be explained in more detail below with reference to the drawings. It demonstrate:

1 an occlusion implant according to the invention in side view;

2 the section II of the inventive exclude occlusion implant 1 ;

3 the section along the line III-III in the direction of the arrows of the occlusion implant according to the invention 1 ,

In The following description of the drawings will be for the same Components matching Reference numeral used.

In 1 is an occlusion implant according to the invention as a whole with the reference numeral 1 characterized. The external shape of the occlusion implant 1 is formed by a shape memory wire bent in the form of a double cone coil 2 characterized. The shape of the double cone helix is determined by a first cone 3 and a second cone 4 passing through a middle section 5 are connected to each other at the front. The two cones 3 . 4 and the middle part 5 be in one piece from the shape memory wire 2 bent. The shape memory wire 2 consists of a biocompatible, pseudoelastic nickel-titanium wire. It is over its entire length with a thrombogenic, radiopaque secondary wire 6 wound from a platinum alloy thread-shaped. After the insertion of the occlusion implant 1 In an arteriovenous short-circuit connection in the human body to accelerate thrombus formation, are at the middle part 5 of the occlusion implant 1 radially outward threads 7 made of surgical nylon material arranged like a brush. At the distal end 1a of the occlusion implant 1 is the shape memory wire 2 with the secondary wire 6 undetachably connected to a shifting of the two wires 2 . 6 to prevent each other and at insertion of the occlusion implant 1 a hooking of the shape memory wire 2 or the secondary wire 6 in the catheter or in the vessel wall to prevent the ductus.

In 2 is the section II off 1 shown enlarged. It can be clearly seen that the shape memory wire 2 from the secondary wire 6 wound in a thread-shaped manner. At the proximal end 1b of the occlusion implant 1 is a spherical fastener 8th on the shape memory wire 2 appropriate. For insertion of the occlusion implant 1 in the body, it is pulled in the extended state in a catheter, not shown. The catheter has inside a sliding gate with a gripping mechanism at its distal end. The gripping mechanism engages around the spherical fastener 8th and the sliding gate comes with the occlusion implant 1 withdrawn into the catheter. Subsequently, the catheter with the Okklusionsimpiantat therein 1 introduced into the body and positioned in the area of the arteriovenous shorting connection. There, the sliding gate together with the occlusion implant 1 driven out of the catheter. Immediately after exiting the catheter, the occlusion implant picks up 1 due to the pseudoelastic properties of the wire material again to him imposed form of a double helix. Is the occlusion implant 1 after pushing out of the catheter in an optimal position, it is mechanically released from the sliding gate by the gripping mechanism, the spherical fastener 8th releases. In case of insufficient positioning of the occlusion implant 1 in the arteriovenous shorting connection, the occlusion implant can 1 retracted back into the catheter at any time and repositioned.

3 shows the occlusion implant according to the invention 1 in section along the line III-III 1 in the direction of the arrows. It is the central middle part 5 to recognize, by the turns 10 of the shape memory wire 2 in the area of the first conus 3 is surrounded. For clarity, the threads are 7 in 3 not shown. After exposure of the occlusion implant 1 in the arteriovenous short-circuit connection, it endeavors to regain the form of a double cone coil originally imposed on it. The maximum diameter of the turns 10 of the occlusion implant 1 is chosen slightly larger than the diameter of the short-circuit connection, so that the turns 10 of the shape memory wire 2 Press against the innermost vascular layers of the shorting connection. Only through the use of the supporting shape memory wire 2 these elastic restoring forces acting radially outwards are so great that a secure fixation of the occlusion implant 1 is ensured in the arteriovenous shorting connection. An additional anchoring of the occlusion implant 1 occurs through the self-festering effect. In this case, axial flow forces in the direction of the blood flow in the arteriovenous short-circuit connection 9 on the occlusion implant 1 exercised. The individual turns 10 of the first conus 3 are thereby pressed against each other and each of an adjacent turn 10 with a smaller diameter pressed radially outward against the vessel wall of the short-circuit connection. The greater the blood flow and thus the axial flow forces, the stronger the occlusion implant becomes 1 anchored by the radial support forces in the short-circuit connection. For the deflection of the axial flow forces in radially outward support force requires on the one hand sufficient stability and on the other hand sufficient spatial abundance of the individual turns 10 of the occlusion implant 1 , This stability is provided by the shape memory wire 2 guaranteed; the spatial abundance results from the secondary wire 6 , Through the interaction of the wires 2 and 6 a uniform, controlled and predictable deployment of the radially outward support forces is possible.

Claims (6)

Occlusion implant ( 1 ) for closing arteriovenous short-circuit connections in the human or animal body, which wire ( 2 ) made of metal or plastic with shape memory properties bent in the form of a double helix and with a secondary wire ( 6 ) is wound in a thread-shaped manner, characterized in that the turns ( 10 ) of the double helix are designed such that the turns ( 10 ) of a conus ( 3 ) by axially acting flow forces against each other and each of an adjacent turn ( 10 ) are pressed with a smaller diameter radially outward against the vessel wall of the short-circuit connection. Occlusion implant ( 1 ) according to claim 1, characterized in that the secondary wire ( 6 ) consists of a thrombogenic material. Occlusion implant ( 1 ) according to claim 1 or 2, characterized in that the secondary wire ( 6 ) consists of a radiopaque material. Occlusion implant ( 1 ) according to one or more of claims 1 to 3, characterized in that at its distal end ( 1a ) the shape memory wire ( 2 ) and the secondary wire ( 6 ) are inextricably linked. Occlusion implant ( 1 ) according to one or more of claims 1 to 4, characterized in that at its proximal end ( 1b ) a particular spherical fastener ( 8th ) is arranged. Occlusion implant ( 1 ) according to one or more of claims 1 to 5, characterized in that in the middle part ( 5 ) of the occlusion implant ( 1 ), in which the two cones ( 3 . 4 ) meet on the front side, radially outwardly extending threads ( 7 ) are arranged brush-like from surgical nylon material.