DE102011121964A1 - Controllable catheter i.e. electrophysiology catheter, for e.g. endovascular interventions in vasculatures for treatment of vascular aneurysm, has distal region that is deformable by applying force on distal extremity of flexible element - Google Patents

Abstract

The catheter (1) has a flexible element (12) arranged in a distal region (6) of the catheter. The distal region is deformable, bendable or contractible by applying force on a distal extremity of the flexible element by using a traction unit or tube elements (2, 3). Another flexible element is arranged in the distal region and connected with the former flexible element. The tube elements are arranged coaxial to each other. The traction unit is partially connected with the distal extremity of the former flexible element and a distal extremity of the latter flexible element. The traction unit is designed as a rope, a flat band, a hose or a pipe. The flexible elements are designed as spring elements i.e. pressure springs, grid elements, braided fabric elements or fabric elements.

Description

The invention relates to a catheter with a controllable catheter tip for diagnostic and therapeutic purposes, primarily for use in vascular systems, as used for example in endovascular interventions.

For the treatment of vascular diseases or treatments of diseases in the vicinity of blood vessels, catheters are advanced via the vascular system to the site of the disease. These vascular diseases can z. As Gefäßaussackungen, so-called aneurysms. In this case, the structure of the vascular system can be very complex.

Catheters are currently placed in alternate advancement by a combination with a guidewire. In this case, both catheter and guidewire can be preformed. By advancing a stiff guidewire bent catheter tips can straighten up again.

For larger calibers, there are also control mechanisms, eg. B. electrophysiology catheters that allow bending of the tip. The catheters with control mechanism are very large in diameter and not suitable for use in small arteries z. B. suitable in the head. Only large bending radii are achieved.

Against this background, the object of the present invention is to provide a catheter with a small diameter, which facilitates the control of the catheter tip by simple means.

This object is achieved by a catheter according to claim 1 and the further advantageous embodiments according to the subclaims.

Proposed is a steerable catheter which is suitable for diagnostic and therapeutic purposes, primarily for use in vascular systems.

• – ein erstes Rohrelement mit einem ersten distalen Ende und einem ersten proximalen Ende,
• – einen distalen Bereich (6) mit einer distalen Öffnung, einen Zwischenbereich und
• – einen proximalen Bereich,
• – zumindest ein flexibles Element, mit einem distalen Ende und einem lateralen Ende, wobei das flexible Element im distalen Bereich des Katheters angeordnet ist und

wobei der distale Bereich durch Aufbringen einer Kraft F auf das distale Ende des flexiblen Elementes verformbar ist. Hierbei erstreckt sich der distale Bereich von einer ersten fiktiven Ebene zu einer zweiten fiktiven Ebene.This includes at least

• A first tubular element having a first distal end and a first proximal end,
• A distal region ( 6 ) with a distal opening, an intermediate area and
• A proximal region,
• At least one flexible element having a distal end and a lateral end, wherein the flexible element is arranged in the distal region of the catheter and

wherein the distal portion is deformable by applying a force F to the distal end of the flexible member. In this case, the distal region extends from a first notional plane to a second notional plane.

Preferably, a traction means for applying a force F is provided on the distal end of the flexible element, whereby the distal region is deformable.

By applying the force F to the traction means, the distal region of the catheter is preferably bendable. This can be achieved, on the one hand, by virtue of the fact that the flexible tip has regions with different rigidity, and / or in that the traction means is fastened only to parts of the catheter tip and thus an off-center force is exerted on the tip.

By deforming the tip of a lighter bending of the catheter, and this in particular the catheter tip is made possible in a vessel branch.

If the force F, preferably the tensile force F, acts evenly on the catheter tip, a shortening of the distal region or the catheter tip is achieved by a compression or contraction of the first flexible element. As a result, a targeted stiffening of the catheter tip is possible.

A further embodiment of the invention provides that a second flexible element is arranged in the distal region of the catheter and the second flexible element is connected to the first flexible element. This second spring element is bent by the application of a tensile force.

Shortened now when applying the maximum tensile force, the first flexible element, the catheter tube member is pushed beyond the curved second flexible element. In this way, the catheter tip can also be advanced beyond the curved catheter piece into a branching vessel.

The bending and simultaneous advancement of the catheter over the bend allows a faster and easier placement of the catheter in vessel branches. In addition, by advancing the catheter beyond the curved catheter tip, the catheter is secured in the branching vessel and slipping of the catheter out of the vessel is prevented.

As flexible elements spring elements, grid elements, braid elements, fabric elements or a combination of material properties z. B. softer and harder materials and / or different material geometries but also combinations of these are used. For example, by varying the wall thickness of the flexible element harder and softer areas can be set.

The traction means for applying the tensile force F at the distal end of the catheter tip may be a wire, a rope, a ribbon, a tube or a tube or combinations thereof. Preferably, the traction means is at least partially in communication with the distal end of the flexible member.

The traction means which is provided for applying the tensile force F can be arranged in the first lumen, but can also be guided in a second lumen, which is additionally arranged in the tubular element. This arrangement of the traction means in a separate lumen has the advantage that the first lumen can be used to perform therapies.

A tube or hose could z. B. are guided coaxially to the first pipe element. As a result, the tube or hose could be used as a traction means per se or form an intermediate lumen or auxiliary lumen for delimiting the traction means from the working lumen.

In the first lumen, two flexible elements, preferably two spring elements, are preferably arranged in the region of the catheter tip. These may be movably arranged opposite the inner wall of the first tubular element of the catheter. The spring elements have a distal and a lateral end, wherein the lateral end of the first spring element is attached to the catheter inner wall, preferably the inner wall of the first tube member of the catheter.

At the distal end of the spring elements is an element for transmitting a tensile force to the lateral end of the catheter, which communicates with the traction means, for example.

By applying a tensile force Fzug 1 by means of the traction device on this element, there is a deformation of the tip of the catheter in such a way that the distal spring element bends by the tensile force F and then compresses the lateral spring element by a maximum tensile force F _max . As a result, both a bend and an advancement of the catheter or the catheter tip is achieved via this bend.

The spring elements can be realized both by additionally integrated components, as well as by the use of different materials or material geometries and arrangements.

In one embodiment of the invention it is provided that the first lumen is designed as a working lumen for at least one guide wire or a contrast agent. The latter allows, for example, a contrast agent injection.

The invention is not limited to a catheter having a tubular element in which one or more flexible elements are arranged to deform, in particular bend, shorten or lengthen, the catheter tip. In addition, embodiments are preferred in which the catheter is designed according to a so-called "tube-in-tube principle".

In this case, the catheter comprises at least a first and a second tubular element, wherein the first tubular element and the second tubular element are arranged coaxially with one another. Preferably, the pipe elements are axially displaceable relative to each other.

In these embodiments of the invention, the first tube element forms an outer tube element and the second tube element forms an inner tube element in which a first lumen is formed, which serves for example for receiving one or more flexible elements, preferably spring elements.

In addition, this lumen can also serve as a working lumen for receiving a guidewire for diagnostic and therapeutic treatments.

In addition, in the first lumen, a traction means may be provided, which is in connection with at least one flexible element and can cause a deformation, preferably bending, shortening or extension of the catheter tip by applying a force and transmission of this on at least one flexible element.

The flexible element can be designed as a spring element, in particular as a compression spring, braid or a grid element and is preferably arranged in the front region of the catheter, that is to say in its tip, which forms the distal region.

The spring is stretched, for example in the initial state, so that the windings do not lie on one another; by exerting a train on the spring, for example by means of the traction means, which is connected to a distal end of the spring, this spring is compressed and thus compressed, so that the spring elements lie on one another. This provides, depending on how the shape of the spring is designed, that the shape of the spring is transferred to the catheter.

One or more spring elements may be arranged between the two tubular elements. In the initial state, that is, before applying a force to the spring elements, these spring elements are far apart, whereby the spring can be very welch. Upon application of a force and the compression of the spring are now the turns of the spring to each other and the spring is thereby stiffened.

Depending on the shape of the spring in the initial state, which may be a biased state, for example, the spring can be changed in shape, for example, by compression in traction by means of a traction device. For example, a curved or bent spring in the prestressed state by pulling action on the traction means can be converted back into a straight shape. This allows the catheter tip to be controlled.

A catheter having a shaped, preferably curved tip can be re-erected by applying pressure until the coils of the spring are superimposed and the catheter tip is stiff and straight. Thus, according to the invention, the deformation or bending or shortening of the catheter tip can be generated by pulling or pushing on at least the first flexible element, preferably the spring, either by the tube-in-tube principle or by the traction means.

In the tube-in-tube principle, for example, the spring may rest within the catheter in the distal region on the inner tube member and be secured to the outer tube member at a distal end at at least one discrete location. If you pull on the outer tube, the spring is curved, for example, on one side, d. H. it is bent about the plane in which it is seated in the inner tube, for example around the second plane through which the distal region of the catheter is bounded.

The first pipe element and / or the second pipe element and / or the reinforcing layer can be formed in one or more layers. Here, one or more fabrics, knitted fabrics, braids, meshes, nets, nonwovens, fiber strand formations can be used. Also may be provided a spring, a continuous or perforated foil or a continuous or perforated tube and the like, as well as combinations thereof.

In particular, by material combinations in which a stiffer and a more flexible material are related to each other, excellent properties for the catheter, especially in the distal area and this particular with regard to its specific deformability, such as bendability and steerability, whereby unwanted injuries in the range of vessel walls can be avoided can be.

• – Kunststoffe, beispielsweise TPU, Silikon, Kautschuk, PE, PP, PA, vorzugsweise Nylon oder Darcon, Biopolymere, sowie deren Mischungen und Copolymere und Kombinationen daraus, vorzugsweise Füllstoffe beinhaltend, besonders bevorzugt Calciumcarbonat oder anorganische Faserstoffe beinhaltend,
• – Metall, beispielsweise Titan, Edelstahl oder sonstige körperverträgliche Metalllegierungen,
• – keramische Materialien,
• – natürliche Faserstoffe, beispielsweise Hanf, Baumwolle und dergleichen.

It is provided that the first tubular element and / or the second tubular element and / or the reinforcing layer comprise at least one material which belongs to the following group:

• Plastics, for example TPU, silicone, rubber, PE, PP, PA, preferably nylon or darcon, biopolymers, and mixtures thereof and copolymers and combinations thereof, preferably containing fillers, particularly preferably calcium carbonate or inorganic fibrous materials,
• Metal, for example titanium, stainless steel or other body-compatible metal alloys,
• - ceramic materials,
• - Natural fibers, such as hemp, cotton and the like.

By such a wide-ranging combination of materials, the catheter can be adjusted functionally in defined sub-areas to the particular application.

The outer tube member may comprise a different material than the inner tube member. As a result, catheters with variable properties can be produced.

It has proved to be advantageous if at least the first tube element comprises a different material than the second tube element. As a result, catheters with variable properties can be produced.

• – Metall, vorzugsweise auf Basis von Titan, Edelstahl, Edelmetall und dergleichen,
• – Kunststoffe, vorzugsweise verstärkte und/oder gefüllte Kunststoffe, besonders bevorzugt faserverstärkte Kunststoffe auf Basis von Polyolefinen, Polyamid, Polyester und dergleichen,
• – kunststoffummantelte Drähte.

For the tension or pressure means for applying the force F and / or the flexible element, the following materials may be used alone or in combination:

• Metal, preferably based on titanium, stainless steel, precious metal and the like,
• Plastics, preferably reinforced and / or filled plastics, particularly preferably fiber-reinforced plastics based on polyolefins, polyamide, polyester and the like,
• - plastic coated wires.

Due to its construction, the catheter according to the invention can have very different dimensions. For example, for the inner tube member and / or the outer tube member and / or the reinforcing layer outer diameter between 0.2 mm to 20 mm, preferably between 0.4 mm to 10 mm. The wall thickness ranges can be provided between 0.001 mm to 2 mm.

For applications in the area of an aorta or large vein, catheters with a Outside diameter up to 8 mm are used. For very small vessels, microcatheters with outer diameters of about 0.4 mm may be provided.

The entire catheter or parts thereof which are subsequently assembled like the inner tube element and / or the outer tube element and / or the reinforcing layer can be produced, for example, by extrusion, coextrusion or injection molding.

It is further contemplated that the inner tube member with the outer tube member and / or the reinforcing layer with the inner tube member and / or the outer tube member during the manufacturing process, such as extrusion, coextrusion or injection molding or a subsequent joining process, for example by gluing, welding, lasers and the like in combination to be brought.

• 1. Therapie von Gefäßerkrankungen
• 2. Interventionelle Radiologie.

Uses for the catheter according to the invention are seen in particular for the following areas:

• 1. Therapy of vascular diseases
• 2. Interventional Radiology.

By way of example, embodiments of the invention are illustrated in the following figures and described in more detail.

1a FIG. 2 schematically shows the structure of an axially cut catheter with a first and a second tube element and a flexible element lying in the initial position, FIG.

1b : schematically the catheter 1a in the shortened state,

1c : schematically the catheter tip off 1a in the bent state,

2a FIG. 2 schematically shows a catheter having a first and a second lumen, FIG.

2 B : the schematic structure of the catheter 2a in a sectional view,

3a FIG. 2 shows the schematic structure of a catheter with a first and a second flexible element in the initial position in a sectional representation, FIG.

3b : schematically the catheter 3a in the bent state by an off-center traction,

3c : schematically the catheter 3a bent and pushed over the bend state by increased traction,

4a FIG. 2 schematically shows a catheter with a mesh element in the catheter tip in the initial state and FIG

4b : schematically the catheter 4a in the loaded or stiffened state.

The invention is not limited to the indicated uses and materials and combinations thereof, but may also be used for other applications, for example for the inspection of cavities, hoses and pipes of all kinds are used.

1a shows schematically the structure of a catheter 1 with a first pipe element 2 and second pipe element 3 according to a tube-in-tube principle in a plan view and as a sectional view AA. The catheter is in the initial position, ie no force is exerted on the catheter, in particular around its tip or in its distal region 6 to deform, preferably to bend or shorten or extend.

A flexible element in the form of a spring element 12 is in a gap 5 arranged, by the mutually coaxial arrangement of the first tubular element 2 and the second tubular element 3 arises.

The distal area 6 with a distal opening 6 ' extends from a first fictitious level 6a to a second fictitious level 6b and forms a lumen 4 , The spring element 12 is in the space 5 in discrete places with the pipe element 2 in conjunction and, for example, in addition to the pipe element 2 or the pipe element 3 rest, which is not shown in this figure.

By relative movement of the tubular elements 3 and 2 to each other along an axis x, for example by means of a Luer connector, not shown, for example, to the tubular element 3 a traction Fzug be exercised, as in the sectional view AA according to 1b shown. As a result, the catheter tip is shortened and by the simultaneous compression of the spring element 12 , whose turns now lie on each other, stiffens. The force Fzug can likewise on the pipe element 2 be exercised, which is not in 1b is shown.

In 1c is a catheter 1 shown in section AA, which is essentially the Structure of the catheter 1a having. It is also in the distal area 6 , preferably near the distal opening 6 ' a means 11 , For example, as a pull wire or an only partially fixed inner tube provided on the one with respect to the axis x unilaterally acting force F _train on the spring element 12 is applied, whereby a bend of the catheter tip is made possible.

In 2a becomes schematically a catheter 1 in a plan view and in 2 B shown in a sectional view. The catheter comprises a tube element 2 in which a first lumen 4 and a second lumen 14 are formed. In the second lumen 14 is a wire 11 arranged. This wire 11 stands over a connecting element 11a with a distal end 12a a first flexible element 12 at least partially connected to in this area of the tubular element 2 a force F _pull on the tube element 2 to be able to raise. Alternatively and not in the 2 B represented, the wire can 11 directly with the distal end 12a of the flexible element 12 keep in touch.

By applying this tensile force to the wire 11 can the spring element 12 together with the pipe element 2 be compressed in this area on one side, whereby a bend of the catheter tip is caused, which in the 2a and 2 B not shown.

In 3a is schematically the structure of a catheter 1 shown, which is in a starting position.

The catheter 1 at least comprises a first tubular element 2 with a first distal end 2 ' and a first proximal end 2 '' , a distal area 6 with a distal opening 6 ' , where the distal area 6 from a first fictional level 6a to a second fictitious level 6b extends. In the area of the second level 6b has the pipe element 2 an abrupt reduction in the diameter of the lumen 4 , relative to an axis x, whereby on the inner wall of the tubular element 2 a circumferential step 2a is formed.

In addition, the catheter includes 1 an intermediate area 7 and a proximal area 8th in which a connection piece, which is not shown in the figure, for example a Luer connector, can be provided, which is provided with a wire 11 is in communication and is suitable for applying the force F.

Furthermore, a first flexible element is provided 12 , with a distal end 12a and a proximal end 12b , wherein the first flexible element 12 in the distal area 6 of the catheter 1 on the stage 2a is arranged.

There is also a second flexible element 13 comprising a distal end 13a and a proximal end 13b , in the distal area 6 of the catheter 1 arranged, which is the first flexible element 12 at its distal end 12a downstream, wherein the second flexible element 13 with the first flexible element 12 at its distal end 12a connected is. The wire 11 is with the distal end 13a of the second flexible element 13 connected.

By applying a force to the wire 11 is the distal area 6 of the catheter bendable or shortened.

3b schematically shows the structure of the catheter 3a in the deformed, ie bent about its axis x state. On the pull wire 11 which is in the lumen 4 is arranged, a tensile force F _{zug1 has been} applied, which leads by the eccentric arrangement of the pull wire with respect to the axis x to a bending of the spring.

In 3c will schematically the catheter 1 out 3a shown in bent state about the axis x, wherein the tubular element 2 by an increased tensile force F _zugmax on the bent spring element 13 can be advanced, for example, in a branching vessel, as not shown in the figure.

4a is schematically a catheter 1 with a flexible element, in the form of a mesh element 12 in the catheter tip 6 shown in the initial state. The mesh element 12 is in discrete areas 6d in conjunction with the distal end 2 ' of the tubular element 2 , In this unloaded state, the mesh element is formed as a relatively soft and flexible element.

By applying a force F to at least one traction means, preferably a wire 11 , the Indian 4a is not shown, the catheter tip is contracted together with the mesh element and thereby shortened and stiffened at the same time, as in 4b shown schematically.

Likewise and not shown in the 4a and 4b the flexible element can be designed in several parts and be a spring element and / or a mesh element and / or a mesh element and / or a fabric element. Thus, a combination of material properties and / or material geometries can be generated.

The invention is not limited to the previously indicated uses and materials and combinations of these, but can also be used for the investigation of other body organs and technical equipment, for example, inspection of cavities hoses and pipes of all kinds are used.

Claims (11)

Controllable catheter ( 1 ) for diagnostic and therapeutic purposes, primarily for use in vascular systems, comprising at least - a first tube element ( 2 ) having a first distal end ( 2 ' ) and a first proximal end ( 2 '' ), - a distal area ( 6 ) with a distal opening ( 6 ' ), - an intermediate area ( 7 ) and - a proximal region ( 8th ), - at least one flexible element, with a distal end and a lateral end, wherein the flexible element in the distal region ( 6 ) of the catheter ( 1 ) and wherein the distal region ( 6 ) is deformable by applying a force (F) to the distal end of the flexible element. A catheter according to claim 1, characterized in that the distal region is bendable by applying the force (F) to the distal end of the flexible element. Catheter according to claim 1, characterized in that the distal region ( 6 ) can be shortened by applying a force (F) to the distal end of the flexible element. Catheter according to one of the preceding claims, characterized in that a second flexible element in the distal region ( 6 ) of the catheter ( 1 ) and the second flexible member is connected to the first flexible member. Catheter according to one of the preceding claims, in which a second tube element ( 3 ), wherein the first tubular element ( 2 ) and the second tubular element ( 3 ) are arranged coaxially with each other. Catheter according to one of the preceding claims, characterized in that the force (F) by means of a traction means ( 11 ), preferably a rope, a flat band, a hose or a tube, preferably by means of the tubular element ( 2 . 3 ) or a combination thereof. Catheter according to one of the preceding claims, characterized in that the traction means ( 11 ) with a distal end ( 12a ) of a first flexible element ( 12 ) is at least partially related. Catheter according to one of the preceding claims, characterized in that the traction means ( 11 ) with a distal end ( 13a ) of a second flexible element ( 13 ) is at least partially related. Catheter according to one of the preceding claims, characterized in that the tube element upon application of a maximum force (F _zugmax ) on the traction means ( 11 ) via the second flexible element ( 13 ) is pushed out. Catheter according to one of the preceding claims, characterized in that the first or second flexible element ( 12 . 13 ) is a spring element, a mesh element, a mesh element, a fabric element or a combination thereof. Catheter according to one of the preceding claims, characterized in that a second lumen ( 14 ) for receiving the traction means ( 11 ) is provided, which in the first tubular element ( 2 ) is arranged.

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