EP0821598A1

EP0821598A1 - Device for temporarily closing a canal in a body, in particular for assisting the function of the heart by application of counter-pressure

Info

Publication number: EP0821598A1
Application number: EP96915067A
Authority: EP
Inventors: Georges Boussignac; Pierre Hilaire
Original assignee: Laboratoire Nycomed SA; Laboratoires Nycomed SA
Current assignee: Laboratoire Nycomed SA; Laboratoires Nycomed SA
Priority date: 1995-04-21
Filing date: 1996-04-22
Publication date: 1998-02-04
Also published as: WO1996032971A1; CA2215235A1; NO974839L; US5861010A; FR2733143A1; JPH11503641A; NO974839D0; FR2733143B1

Abstract

The present invention concerns a device for temporarily closing a canal in a body, in particular for assisting the function of the heart by application of counter-pressure. The device is characterized in that it comprises a first inflatable structure (1) which, in the inflated state, defines a sleeve shaped to match the internal surface of the canal, providing a central conduit (4). The device further comprises a second inflatable structure which expands radially, preferably from the exterior to the interior, is held by the first structure (1) and shaped such that, in the inflated state, it permits substantially complete closure of the central conduit (4) formed after inflation of the first structure. The device finally comprises means allowing each of these first and second inflatable structures to be in fluid communication with a fluid delivery source.

Description

Device for temporarily closing a body canal, in particular useful for cardiac assistance by back pressure.

The present invention generally relates to a device suitable for being inserted inside a body channel to allow its temporary closure, preferably in a controlled manner.

The invention mainly finds application in the field of cardiac assistance by counter-pulse where this device is introduced into the aorta, and will be described below for reasons of clarity, in the context of this application. It is obvious, however, that the invention must be considered to have a much broader scope which extends to any use requiring a possibly controlled obturation of any body canal such as the esophagus, the trachea, the digestive tract. or urinary tract.

It is known that cardiac assistance by counterpulse is mainly used in interventional cardiology to ensure cerebral irrigation during the treatment of coronary affections.

This assistance is generally carried out using an elastic balloon catheter placed in the aorta of the patient obstructing this artery in the inflated state in a controlled manner in synchronism with the cardiac pulsations. This has the effect of blocking the blood going towards the lower parts of the body so as to favor, during systole, only the upper food in particular of the heart and the brain.

The catheters currently used for the implementation of this technique generally consist of a tube comprising a first channel allowing the passage of a guide intended to facilitate the positioning of the balloon and a second channel intended to allow the inflation and deflation of the ball.

Synchronism with heartbeats is obtained by means of a slave pump.

At each pulse, the balloon at the end of inflation presses against the internal wall of the artery.

The repetition of these contacts between the balloon and the internal wall of the artery can be the cause of undesirable trauma.

In addition, the ball also carries in its movement the various devices necessary for the intervention and thus tackles them with each pulse. against the aortic wall, the aforementioned risks of trauma are further increased.

Under these conditions, the main object of the present invention is to solve the technical problem consisting in the supply of a temporary closure device of a new design which can in particular be implemented easily and without trauma for the body canal. .

The solution according to the present invention, to solve this technical problem consists of a device for temporarily closing a body channel in which a fluid circulates, in particular useful for cardiac assistance by back pressure, characterized in that it includes:

- A first inflatable structure defining, in the inflated state, a sleeve shaped to conform to the internal surface of said channel by providing a central conduit for the passage of said body fluid;

- A second inflatable and deflatable structure independently of the first with radial expansion, maintained by said first structure and shaped to allow the inflated state to close substantially completely said central duct formed after inflation of said first structure;

- Means allowing the fluid communication of each of said first and second inflatable structures with a fluid supply source, for the inflation and deflation of these structures.

Thus, the originality of the device according to the present invention lies mainly in the fact that the obturation of the body channel is carried out practically without any impact against the internal wall of the body channel.

Advantageously, the inflation of the aforementioned second structure causing the closure of said channel is carried out radially from the outside to the inside, unlike the devices of the prior art using a balloon with radial expansion from the inside. outwards.

This particular conformation of the second inflatable structure guarantees the total absence of shock against the internal wall of the body canal. As indicated previously, the balloon catheters used until now only have the effect of blocking the blood going towards the lower parts. from the body. The assistance thus provided can be defined as "passive".

On the basis of this observation, the inventors formulated and sought to solve the new technical problem consisting in the supply of a device capable of providing "active" assistance resulting, in the context of cardiac assistance by counter-pulse, by a possibility of increasing the volume of blood expelled to the brain by means of the obturation device.

Thus, according to a particularly advantageous characteristic of the device according to the present invention, the aforementioned second structure is shaped in such a way that its inflation causes a displacement of the fluid contained in the aforementioned central duct in the axial direction of the body channel.

As can be understood, such a conformation leads, in the context of the application illustrated by way of example, to a pumping system of the peristaltic type expelling, each time the aorta is closed, a volume of blood to the corresponding brain. substantially at the volume of the second structure in the inflated state.

The assistance thus carried out can be qualified as activated.

Of course, the peristalsis sought in this application can be easily reversed in the context of other applications.

Thus, in the context of assistance of the peristaltic type, the obturation of the central duct during inflation is first carried out at a point close to the proximal end of said duct and then propagates in an axial direction towards the distal end of said drove. On the other hand, in the case where the peristalsis is reversed (assistance of the "anti-peristaltic" type), the propagation takes place in the opposite direction, that is to say from the distal end towards the proximal end of the conduit central.

According to a currently preferred embodiment, the aforementioned first inflatable structure comprises a spirally wound tube whose turns can be contiguous or preferably non-contiguous.

As a variant, this first structure can also be produced in the form of a double-walled tube as for example described in American patent No. 5,108,370 incorporated here by reference.

The first inflatable structure of the device according to the present invention fulfills a double function.

First of all, by coming into direct or indirect contact with the body canal, it protects the internal wall. Furthermore, it makes it possible to maintain the second inflatable structure by allowing during inflation that the expansion occurs radially from the outside to the inside.

According to a currently preferred embodiment, the aforementioned second inflatable structure consists of a double-walled tube.

As will be understood, it is the external wall of this tube which is held by the first inflatable structure, while the internal wall is deformed during inflation until the above-mentioned central duct is substantially closed. According to a particularly advantageous characteristic, the spirally wound tube forming the aforementioned first inflatable structure is disposed between the two walls of the tube constituting the aforementioned second inflatable structure.

As a variant, the double-walled tube constituting the aforementioned second inflatable structure can be disposed internally to the first inflatable structure by being fixed thereon either directly, for example by gluing, or indirectly by means of any suitable connection means.

Advantageously, the obturation device according to the present invention further comprises a catheter intended to allow its positioning inside the body channel. Preferably, this catheter will be arranged radially and externally relative to the aforementioned first inflatable structure.

The present application also aims to cover the use of a device for closing a body channel as defined above for the manufacture of a device for assisting cardiac assistance by back pressure. Other characteristics and advantages of the invention will appear from the following description made with reference to the accompanying drawings given solely by way of non-limiting example, and in which:

- Figure 1 is a schematic end view showing a temporary closure device of a body canal according to the invention shown before its implantation;

- Figure 2 is a sectional view along line II - II of Figure 1;

- Figure 2A is a sectional view along line A-A of Figure 2;

- Figure 2B is a sectional view along line BB of Figure 2; - Figure 3 is an end view similar to Figure 1 of a temporary closure device according to the present invention shown in a position of use where only the first structure is in the inflated state;

- Figure 4 is a sectional view along line IV-IV of Figure 3; - Figure 4A is a sectional view along line A-A of Figure 4;

- Figure 4B is a sectional view along line B-B of Figure 4;

- Figure 5 is an end view similar to Figure 3 of a temporary closure device according to the present invention shown in the position of use during inflation of the second structure; - Figure 6 is a sectional view along line VI-VI of Figure 5;

- Figure 6A is a sectional view along line A-A of Figure 6;

- Figure 6B is a sectional view along line B-B of Figure 6;

- Figure 7 is an end view similar to Figures 3 and 5 of a temporary closure device according to the present invention shown in the position of use after inflation of the first and second inflatable structures mentioned above;

- Figure 8 is a sectional view along line VIII-VIII of Figure 7;

FIG. 8A is a sectional view along line A-A of FIG. 8 and

- Figure 8B is a sectional view along line BB of Figure 8. In Figures 1 to 8B, there is therefore shown illustrated a currently preferred embodiment of a temporary closure device of a body channel in its different positions: - prior to its installation (Figures 1 to 2B);

- in the implanted position where only the first structure is in the inflated state, thus allowing the circulation of the bodily fluid (FIGS. 3 to 4B);

in the position of use, during inflation of the second structure, in order to illustrate its operation in "peristaltic" mode (FIGS. 5 to 6B); and

- In the use position, at the end of inflation of the second inflatable structure, the latter substantially completely closing the central duct of the first structure (FIGS. 7 to 8B). In general, a device for temporarily closing a coφoral canal according to the present invention comprises two independently inflatable structures.

The first inflatable structure, in the inflated state, defines a sleeve shaped to conform to the internal surface of the coφorel channel by providing a central duct 4.

This sleeve can be substantially cylindrical, as in the example shown, but can by construction have other shapes, such as for example conical or diabolo, to adapt to the anatomy of the implantation site. This first structure is constituted, in the example shown, by a tube 1 wound in a spiral, and whose turns are not contiguous.

The tube 1 can be produced for example from a material such as a semi-rigid thermoplastic, such as in particular a polyamide, a polyurethane or a copolymer of the PEBAX® type sold by the company ATOCHEM. The second inflatable structure is constituted in the example represented by a double-walled tube, namely an external wall or membrane 2 and an elastic internal wall or membrane 3.

The external membrane 2 is preferably arranged outside the spirally wound tube 1 while being held pressed by the latter (in the inflated state) against the internal wall of the coφorel channel not shown.

The elastic internal membrane 3 will preferably be made of a thermoplastic material which may be a polyamide, a polyurethane, a copolymer of the PEBAX® type or else a silicone.

It is the same for the outer membrane 2 which will preferably be made of the same material as the inner membrane 3.

Advantageously, the double-track tube constituting the second inflatable structure has a length substantially equal to the length of the sleeve formed by the tube 1 in the inflated state.

As will be understood, the swelling of the above-mentioned double-walled tube is accompanied by a radial expansion towards the inside of its internal membrane 3 which will gradually cause the central duct 4 to be closed.

To allow operation comparable to peristaltic pumping, it is necessary that when the second structure is inflated, the central duct 4 is closed, as shown in FIG. 6, at a point relatively close to the proximal end of said duct and then propagates in an axial direction towards the distal end of said duct to reach the position shown in FIG. 8.

To achieve this objective, the thickness of the internal wall 3 of the double-track tube forming the second inflatable structure will gradually vary from one end to the other of the duct, being smaller on the side of the proximal end in the case an operation of the peristaltic type, greater on the side of the proximal end in the case of an operation of the anti-peristaltic type.

The obturation device according to the present invention further comprises a catheter generally designated by the reference numeral 5 intended to allow its implantation inside the coφorel canal.

This catheter is constituted, in a manner known per se, by an elongated flexible tube comprising a proximal part not shown and a distal part at the level of which are the first and second inflatable structures mentioned above.

The catheter 5 has a first lumen 6 extending over its entire length and allowing the passage of a guide wire, not shown.

The catheter 5 further comprises means allowing the fluid communication of each of said first and second inflatable structures with a source of fluid supply.

To this end, the catheter 5 comprises a second lumen 8 and a third lumen 7 extending substantially parallel to each other over a major part of its length and communicating respectively with the inflation chambers of the first and of the second inflatable structure, namely by means of a radial hole made in the wall of the catheter, or preferably by means of a flexible connector.

These second and third lumens are connected at the proximal end of the catheter 5 to a source of fluid supply allowing the inflation and deflation of the first and second inflatable structures. In a manner known per se, the catheter 5 will be equipped for this purpose partly proximally with a three-way connector of the LUER LOCK type.

The fluid used for inflation will for example be a gas or a pressurized liquid. R

In the drawings, the reference numeral 9 represents a flexible connector connecting the third lumen 7 to the inflation chamber of the second inflatable structure.

In the presently preferred embodiment, the catheter 5 is disposed radially and externally relative to the spirally wound tube 1 constituting the first inflatable structure along a generatrix of the sleeve formed by the latter in the inflated state.

More specifically, the catheter 5 is arranged between the external membrane 2 of the second structure and the external surface formed by the tube 1. As a variant, the catheter 5 can be placed inside the spirally wound tube 1, by being connected directly or indirectly to it.

The operation of the temporary closure device which has just been described is easily deduced from its structure.

Thus, the catheter 5 carrying at its distal part the first and second inflatable structures is introduced using a metal guide, in a conventional manner, up to the level of the chosen implantation site.

During this operation, the aforementioned first and second inflatable structures were folded, for example in a spiral as shown in FIGS. 1 to

2B so that the dimensions of the catheter carrying these structures are smaller than the internal dimensions of the coφorel canal into which the device is introduced.

The first inflatable structure is then inflated by forming a sleeve coming to marry the internal surface of the channel while providing an open central duct allowing the circulation of the coφorel fluid in the direction indicated by the arrow F in FIG. 4.

The second inflatable structure is then inflated in synchronism with the heartbeat by means of a conventional pump.

The thickness of the internal wall 3 being smaller on the proximal side than on the distal side, the obturation of the central duct resulting from the inflation of the second structure is first carried out at a point close to the proximal end of the central duct 4 defined by the spirally wound tube 1, as shown in Figure 6.

When the inflation continues, the obturation thus produced in the proximal part propagates in an axial direction towards the distal end of the central duct 4 to reach the position shown in FIG. 8. The coφorel fluid contained in the free space of the central duct 4 is thus discharged in the direction of the arrow F shown in FIG. 6, allowing operation of the peristaltic type.

The coφoreal fluid expelled at each closure of the channel makes the assistance thus practiced "active".

It should be noted that one can provide on the device which has just been described means allowing an easy exit of this device after intervention.

For this purpose, it is possible, for example, to provide an elastic cylindrical sheath or an elastic wire wound in a spiral and arranged around the first and second inflatable structures to allow the folding of the latter and an easy extraction of the catheter carrying these structures, from the coφorel channel in which it was introduced.

The temporary closure device which has just been described is therefore particularly advantageous in comparison with the devices known from the state of the art, insofar as it makes it possible to implement active and non-traumatic assistance for the coeloreal canal. .

Claims

CLAIMS 1. Device for temporarily closing a coφoreal channel in which a fluid circulates, in particular useful for cardiac assistance by back pressure, characterized in that it comprises: - a first inflatable structure defining in the inflated state , a sleeve shaped to conform to the internal surface of said channel by providing a central conduit (4) for the passage of said coφoreal fluid;

- A second inflatable and deflatable structure independently of the first with radial expansion maintained by said first structure and shaped to allow the inflated state to close substantially completely said central duct formed after inflation of said first structure;

2. Device according to claim 1, characterized in that the aforesaid second inflatable structure is radially expanding from the outside to the inside.

3. Device according to claim 1 or 2, characterized in that the aforesaid second inflatable structure is shaped such that its inflation causes a displacement of the fluid contained in the aforementioned central duct (4) in the axial direction of the coφorel channel.

4. Device according to claim 1 or 2, characterized in that the aforesaid first inflatable structure comprises a spirally wound tube (1).

5. Device according to claim 4, characterized in that the turns of the tube (1) above are not contiguous.

6. Device according to one of claims 1 to 5, characterized in that the aforesaid second inflatable structure consists of a double-walled tube.

7. Device according to claim 6, characterized in that the aforementioned spirally wound tube (1) is disposed between the two walls (2, 3) of the tube constituting the aforementioned second inflatable structure.

8. Device according to one of claims 1 to 7, characterized in that it further comprises, a catheter (5) intended to allow its positioning inside the coφorel channel.

9. Device according to claim 8, characterized in that the aforementioned catheter (5) comprises a first lumen (6) extending over its entire length and allowing the passage of a guide wire.

10. Device according to one of claims 8 or 9, characterized in that the aforementioned catheter (5) is arranged radially and externally relative to the aforementioned first inflatable structure.

11. Device according to one of claims 8 to 10, characterized in that the aforementioned catheter (5) comprises a second lumen (8) extending over a major part of its length and communicating with the inflation chamber of the first inflatable structure, either via a radial hole in the wall of said catheter, or via a flexible connector; said lumen being connected at the proximal end of the catheter to a source of fluid supply allowing the inflation of said first structure.

12. Device according to one of claims 8 to 11, characterized in that the aforementioned catheter (5) comprises a third lumen (7) extending over most of its length and communicating with the inflation chamber of the second inflatable structure, either via a radial hole made in the wall of said catheter, or via a flexible connector (9); said lumen being connected at the proximal end of the catheter to a source of fluid supply allowing the inflation of said second structure.

13. Use of a device for closing a coφoreal channel according to one of claims 1 to 12, for the manufacture of a device for assisting cardiac assistance by back pressure.