Stent

Abstract

The invention relates to a stent (1) having a main body (2) and at least one leg (3, 4) connected to the main body (2), wherein the stent (1) is formed from a wire mesh. A transition region (5, 6) between the main body (2) and the leg (3, 4) comprises an articulated connection (7) and a pivoting region (8) adjacent to the articulated connection (7), such that an angle (α, β) formed between the longitudinal axes (L2, L3, L4) of the main body (2) and the at least one leg (3, 4) is adjustable.

Description

[0001] 14.10.2025 XP / anh

[0002] Our reference: BESS088WO

[0003] Bess Pro GmbH Gustav-Krone-Straße 7, 14167 Berlin, DE

[0004] Stent

[0005] The present invention relates to a stent having the features in the preamble of claim 1.

[0006] Narrowing of the central airways, also called stenosis, often results from tumor growth in or near a patient's trachea and bronchi. To prevent suffocation, vascular supports called stents can be endoscopically implanted into the patient's airways, either temporarily or permanently.

[0007] Stents are typically straight and come in various lengths and diameters. In certain cases, stents are also required to stent a bifurcation, a branching point in the airways, particularly between the trachea and the bronchi. Stents designed for bifurcations have a main body and at least one limb. Corresponding airway stents made of silicone are known in the art. The silicone makes these stents soft and flexible, but they have the disadvantage that they can only be inserted into the airways using rigid endoscopic equipment, and the airway constrictions must be dilated before insertion. For this reason, self-expanding metal stents made of nitinol have been preferred for several years. These are housed in a compressible external catheter and can be guided through narrow passages within the airways using a guidewire.When the external catheter is withdrawn, they unfold, automatically widening the constriction within the airways.

[0008] A disadvantage of nitinol stents known in the prior art is their rigidity. While the force the stent exerts against the pressure acting on the airways, particularly tumor pressure, and thus dilates the stenosis, is desirable, the stent's rigidity can lead to problems at the bifurcation. Crucially, the alignment between the main body and the limb, and thus the angle formed between them, must precisely match the individual anatomy of the patient's airway segment being stented. In practice, however, this is rarely the case, so rigid stents constantly press against the patient's bronchi. In particular, the ends of the stent can bore into and perforate the bronchial wall.

[0009] Starting from this, the invention is based on the objective of demonstrating a stent with a main body and at least one leg connected to the main body, the angle of which formed between the main body and the at least one leg can be passively adapted to the individual anatomy of a lumen to be stented in a patient.

[0010] This problem is solved in a stent with the features of claim 1.

[0011] The dependent claims relate to expedient further developments of the inventions.

[0012] The stent according to the invention comprises a main body and at least one leg connected to the main body. Both the main body and the at least one leg are preferably substantially cylindrical. The stent has a supporting framework made of a deformable wire mesh. The stent is particularly self-expanding. It can be surrounded by a sheath made of a plastic material, which expands together with the supporting wire mesh. The sheath also holds the wire mesh in shape, in that adjacent wires are connected to each other via the flexible sheath. The sheath follows the movement of the supporting wire framework. Preferably, it is a respiratory stent.

[0013] The stent according to the invention is characterized in that a transition area between the main body and the leg has a joint connection and a pivot area adjacent to the joint connection, such that an angle formed between the longitudinal axes of the main body and the at least one leg can be adjusted. The at least one leg can be pivoted relative to the main body by means of the joint connection. This allows the angle formed between the main body and the at least one leg to be adjusted. Only a small force is required to act on the stent for this adjustment. This is not an active adjustment mechanism. Rather, the stent passively adapts to the respective anatomy of the patient's airway segment to be stented.

[0014] The stent thus offers the advantage of automatically adapting to the precise course of the airway, and in particular to bifurcations. No additional intervention is required, and precise stent fitting prior to implantation is unnecessary. Importantly, this flexibility is achieved while maintaining the structural rigidity of conventional stents, which is essential for the stent's function. Using a stent according to the invention effectively prevents damage to the airway channels, especially in the area of ​​a bifurcation.

[0015] The joint connection is formed by the wire mesh of the stent itself. In this case, the wire mesh transitions directly from the main body to the leg at the joint connection. The joint connection thus forms the link between the main body and the leg. The joint connection defines the pivot point or axis around which the leg can pivot.

[0016] The joint connection can also be formed by an additional joint element, which is connected to the wire mesh of the main body and the legs. It is important that a stable connection between the main body and the legs is ensured, particularly due to the force transmission from the main body to at least one leg during the implantation procedure.

[0017] Preferably, the pivot area adjacent to the joint connection is designed without restraints. This means that a space is formed between the wire mesh of the main body and the wire mesh of at least one leg within the pivot area. The stent therefore has no wire mesh in this space. Preferably, the respective end regions of the main body and the leg are braided back within the pivot area. This space allows the leg to pivot relative to the main body by means of the joint connection, as the opposing end regions of the main body and the leg can shift relative to each other within the pivot area.

[0018] The main body and at least one leg each have at least one loop in the pivoting area, wherein the at least one loop of the main body engages in the at least one loop of the at least one leg, and the loops are designed to be slidable relative to each other. The loops or tabs project, in particular, from the adjacent wire mesh. Due to the slidable, interlocking loops, the at least one leg can be pivoted in the direction of the longitudinal axis of the main body by a force acting upon it. Depending on the direction of pivoting, the interlocking loops are pushed together or apart, with the result that the angle formed between the main body and the at least one leg is increased or decreased.

[0019] Preferably, the main body and the at least one leg each have two to fifteen interlocking loops. Particularly preferably, the main body and the at least one leg each have three, five, seven, nine, eleven, or thirteen interlocking loops. The odd number of loops allows for an advantageous symmetrical distribution of the loops along the swivel range.

[0020] The maximum swivel angle can be adjusted by varying the size and shape of the interlocking loops.

[0021] In a particularly advantageous embodiment, the stent is Y-shaped and has two legs. The Y-shape is formed by the main body transitioning into the two legs at its ends. A stent designed accordingly is particularly suitable for use in a bifurcation between the trachea and the bronchi.

[0022] If the stent is Y-shaped, it is further considered advantageous if the transition area between the main body and the respective leg has a hinge connection and a pivoting area. In this advantageous embodiment, both legs connected to the main body are pivotable relative to the main body, so that the angle between the main body and the respective leg can be adjusted. The stent can thus adapt optimally to the anatomy of the patient's lumen.

[0023] According to a further development of the invention, the joint connection is arranged opposite the angle formed between the at least one leg and the main body.

[0024] If the stent is Y-shaped, the joint connections are preferably located in the area of ​​the stent where the legs merge side by side into the main body.

[0025] In the Y-shaped embodiment of the stent, the tip of the main body, i.e., the section of the main body between the legs, is rigid. In particular, the stent is more stable and rigid in this area than in the rest of the joint and at least as stable and rigid as in the other stent sections. Within the scope of the invention, this means that the stent deforms less in this area when a force is applied than in its other sections. During implantation of the Y-shaped stents, they are advanced until the bifurcation of the stent, i.e., the section of the main body between the legs, rests on the carina, the tracheal cartilage between the two main bronchi. Thus, during stent implantation, a force acts on the tip of the main body between the legs. Due to the rigidity of this section, the stent is not compressed or deformed during implantation.Once the stent is implanted, due to the rigid structure of this area, it can effectively displace a tumor in the carina region, thus enabling free passage through the patient's airways.

[0026] The joint connection extends particularly along 1 to 25%, preferably along 2 to 15%, and most preferably along 3 to 10% of the circumference of at least one leg in the transition area. This has proven to be an advantageous compromise between stability and flexibility.

[0027] The pivoting range is preferably arranged in the area of ​​the angle formed between the at least one leg and the main body.

[0028] In an advantageous embodiment of the invention, an angle between 100° and 170° is formed between the main body and the at least one leg. With a corresponding angle, common bifurcations in the airways, and in particular between the trachea and the bronchi, can be effectively splinted.

[0029] Preferably, the angle between the main body and at least one leg is adjustable by up to 5°, preferably by up to 10°, particularly preferably by up to 15°, and especially by up to 20°. Adjustability of the angle within the specified intervals allows the stent to be adapted to different airway anatomies in patients. The swivel angle intervals depend in particular on the size of the interlocking loops and can be regulated by them.

[0030] Preferably, the main body has a diameter that is greater than or equal to the diameter of at least one leg. In an advantageous embodiment of the invention, the stent, and thus the wire mesh of the stent, is formed from a single wire. In this embodiment, the stent is therefore formed from a continuous wire. This is advantageous for the stability of the stent and enables an atraumatic stent design, as there are only a few free wire ends.

[0031] The invention is explained in more detail below with reference to an embodiment schematically illustrated in the drawings. The drawings show:

[0032] Figure 1 shows a braided Y-shaped stent according to the prior art in a front view and a side view,

[0033] Figure 2 shows a stent in a first embodiment in a starting position and a pivoted position,

[0034] Figure 3 shows a stent according to the invention in a second embodiment in a starting position and a pivoted position and

[0035] Figure 4 shows a stent according to the invention in a third embodiment in a starting position and a pivoted position.

[0036] In the figures, the same reference symbols are used for identical or functionally corresponding components or parts, even if a repeated description is omitted for the sake of simplicity.

[0037] Figure 1 shows a Y-shaped, self-expanding stent 1 known from the prior art. Figure 1a) shows the stent 1 in a front view and Figure 1b) in a side view. The stent 1 has a main body 2, a first leg 3, and a second leg 4. Both the main body 2 and the legs 3 and 4 connected to the main body 2 have a substantially cylindrical shape. The diameter D2 of the main body 2 is larger compared to the diameters D3 and D4 of the legs 3 and 4.

[0038] The main body 2 and the legs 3, 4 are formed from a continuous wire mesh. The wire mesh of the main body 2 transitions into the mesh of the two legs 3, 4. The wire mesh is formed from a single wire.

[0039] Figure 1 shows the stent 1 in its expanded state. The legs 3 and 4 are not pivotable relative to the main body 2. Therefore, the angles a and β formed between the legs 3 and 4 and the main body 2 are not variable. This means that the angles a and β between the main body 2 and the legs 3 and 4 are fixed in the implanted state of the stent 1. It is therefore essential that the stent 1 is precisely matched to the anatomy of the patient's airway to prevent damage to the airway walls. Airway perforation can occur, in particular, if the angles a and β formed between the legs 3 and 4 and the main body 2 do not correspond to the anatomy of the patient's airway.

[0040] Figure 2 shows a stent 1 in a first embodiment. The stent 1 is self-expanding and Y-shaped.

[0041] Figure 2a) shows the stent 1 in a starting position. The basic structure of the stent 1 corresponds to that of the prior art variant shown in Figure 1. The stent 1 also has a main body 2 and two legs 3, 4 connected to the main body 2. The stent 1 is formed from a wire mesh. The main body 2 as well as the legs 3, 4 are essentially cylindrical, with the diameter D2 of the main body being larger than the respective diameters D3, D4 of the legs 3, 4.

[0042] Between the main body 2 and the legs 3, 4, a transition region 5, 6 is formed in each case. The transition regions 5, 6 each have a hinge connection 7 and a pivot area 8 adjacent to the hinge connection 7. The pivot area 8 is indicated by the dashed oval. The hinge connection 7 is formed by the wire mesh of the stent 1 itself. In the area of ​​the hinge connection 7, the wire mesh extends from the main body 2 into the respective legs 3, 4 and pivotally connects them. The hinge connection 7 thus also represents the connection between the main body 2 and the respective legs 3, 4.

[0043] The joint connection 7 extends along 1 to 25% of the circumference of the respective leg 3, 4 in the transition area 5, 6. This has proven to be a good compromise between stability and pivotability.

[0044] The joint connections 7 are arranged opposite each other to the angles a, ß formed between the legs 3, 4 and the main body 2.

[0045] The pivoting range 8 according to the invention extends along the circumference of the respective leg 3, 4, which is not formed by the joint connection 7.

[0046] In the first embodiment of the invention, the pivot area 8 is designed to be unconstrained. It is a free space in which the wire mesh between the main body 2 and the legs 3, 4 is not connected. The main body 2 and the legs 3, 4 have end loops 9 in the pivot area 8 that are opposite each other and do not interlock. The connection between the main body 2 and the legs 3, 4 is therefore made exclusively via the joint connections 7.

[0047] Figure 2b) shows the stent 1 in a pivoted position of the first leg 3. The dashed line indicates the original path of the leg 3. The arrow shows that the leg 3 has pivoted away from the other leg 4. The pivot axis is the joint 7. Due to the pivoting movement, the angle α between the longitudinal axis L3 of the leg 3 and the longitudinal axis L4 of the main body 2 is reduced. The end loops 9 are shifted over one another and close the gap. The loops 9 do not interlock.

[0048] Due to the pivotable design of the legs 3, 4 relative to the main body 2, the stent 1 can passively adapt to the course of the lumen to be stented within a patient's body. Precise adjustment of the angles a, β formed between the main body 2 and the legs 3, 4 to the patient's anatomy prior to stent 1 implantation is not required. It is also possible to pivot the legs 3, 4 in the opposite direction. In this case, the space formed between the legs 3, 4 and the main body is increased. This is not shown in the figures.

[0049] The angles a, ß between the main body 2 and the legs 3, 4 are between 170° and 100° in the initial state.

[0050] By shifting the legs 3, 4, the respective angle a, ß between the main body 2 and the leg 3, 4 can be adjusted by up to 20° in both directions.

[0051] Figure 3 shows a second embodiment of a stent 1 according to the invention. The basic structure of the stent 1 corresponds to that of the first embodiment. In the second embodiment, however, two of the opposing loops 9 interlock in the transition regions 5, 6 and form an eye 10 in the initial position according to Figure 3 a). The interlocking loops 9 project beyond the adjacent loops 9. This allows the loops 9 to interlock without the other loops 9 being in contact in the initial position.

[0052] The interlocking loops 9 are designed to be slidable relative to one another. This slidable design of the loops 9 allows the legs 3, 4 to be pivoted relative to the main body 2. This is shown in Figure 3 b). The legs 3, 4 can be pivoted both upwards and downwards in the plane of the image. A pivoting movement out of the plane of the image is also conceivable. This pivoting movement allows the angle α and β formed between the main body 2 and the respective legs 3, 4 to be adjusted. Therefore, it is not necessary for the stent 1 according to the invention to be precisely adapted to the anatomical structure of the patient's airways before implantation.Should slight deviations occur between the orientation of legs 3, 4 relative to the main body 2 and the corresponding course of the patient's airways, the angle α or β formed between the main body 2 and the respective legs 3, 4 can passively and automatically adapt to the structure of the bifurcation. Figure 3b) shows a downward displacement of leg 3 in the direction of the image, thus into a compressed position. Here, the interlocking loops 9 of the main body 2 and leg 3 are moved towards each other, so that the area of ​​the eye 10 formed by the loops 9 is increased compared to the initial position. The downward displacement of leg 3 in the direction of the image reduces the angle α formed between the main body 2 and leg 3. Analogous to the first embodiment, the remaining loops 9 overlap without interlocking.

[0053] The interlocking loops 9 increase the stability of the stent 1 without adversely affecting the adaptability of the stent.

[0054] The shifting of the second leg (4) also works according to this principle.

[0055] The tip of the main body 2, specifically the area of ​​the main body 2 between the legs 3 and 4, is rigid. In particular, the stent 1 is more stable and rigid in this area than in the rest of the joint 7 and at least as stable and rigid as in the other stent sections. During implantation of the Y-shaped stents 1, they are advanced until the bifurcation of the stent 1, i.e., the area of ​​the main body 2 between the legs 3 and 4, rests on the carina, the tracheal cartilage between the two main bronchi of a patient. During implantation of the stent 1, a force F thus acts on the tip of the main body 2 between the legs 3 and 4. Due to the rigidity of this area, the stent 1 is not compressed or deformed during implantation.Once the stent 1 is implanted, it can effectively displace a tumor in the carina due to the smooth structure of this area, thus enabling free passage through the patient's airways.

[0056] Figure 4 shows a third embodiment of the stent 1 according to the invention. In this embodiment, all loops 9 of the main body 2 engage with the respective opposite loops 9 of the legs 3, 4, forming a respective eye 10. Figure 4a) shows the stent 1 in a starting position and Figure 4b) in a deflated state. The operating principle corresponds to the second embodiment, whereby the stability of the stent 1 is increased by the larger number of interlocking loops 9.

[0057] The wire mesh of stent 1 is embedded in a silicone sheath, which provides additional stability to stent 1 and ensures that the wire mesh does not come into direct contact with the patient's tissue. The sheath is not shown in detail in Figures 2 to 4.

[0058] Reference mark:

[0059] 1 - Stent

[0060] 2 - Main body

[0061] 3 - first thigh

[0062] 4 - second thigh

[0063] 5 - Transition area

[0064] 6 - Transition area

[0065] 7 - Joint connection

[0066] 8 - Swivel range

[0067] 9 - Loop

[0068] 10 - eye a - angle ß - angle

[0069] D2 - Diameter of 2

[0070] D3 - Diameter of 3

[0071] D4 - Diameter of 4

[0072] L2 - Longitudinal axis of 2

[0073] L3 - Longitudinal axis of 3

[0074] L4 - Longitudinal axis of 4

[0075] F - Force

Claims

Patent claims 1. Stent (1) with a main body (2) and at least one leg (3, 4) connected to the main body (2), wherein the stent (1) is formed from a wire mesh and a transition region (5, 6) between the main body (2) and the leg (3, 4) has a hinge connection (7) and a pivot region (8) adjacent to the hinge connection (7), such that an angle (a, β) formed between the longitudinal axes (L2, L3, L4) of the main body (2) and the at least one leg (3, 4) is adjustable, characterized in that the main body (2) has at least one loop (9) in the pivot region (8) and the at least one leg (3, 4) has at least one loop (9) in the pivot region (8), wherein the at least one loop (9) of the main body (2) is inserted into the at least one loop (9) of the at least one leg (3, 4) engages and the loops (9) are designed to be movable relative to each other,wherein the joint connection (7) is formed by the wire mesh of the stent (1) itself.

2. Stent (1) according to claim 1, characterized in that the pivoting area (8) is designed without restraints, such that a free space is formed between the wire mesh of the main body (2) and the wire mesh of the at least one leg (3, 4).

3. Stent (1 ) according to one of claims 1 to 2, characterized in that the stent (1) is Y-shaped and has two legs (3, 4).

4. Stent (1 ) according to one of claims 1 to 3, characterized in that the joint connection (7) extends along 1 to 25%, preferably along 2 to 15%, particularly preferably along 3 to 10% of the circumference of the at least one leg (3, 4) in the transition area (5, 6).

5. Stent (1 ) according to one of claims 1 to 4, characterized in that the joint connection (7) is arranged opposite the angle (a, ß) formed between the at least one leg (3, 4) and the main body (2).

6. Stent (1 ) according to one of claims 1 to 5, characterized in that the pivoting area (8) is arranged in the area of ​​the angle (a, ß) formed between the at least one leg (3, 4) and the main body (2).

7. Stent (1 ) according to one of claims 1 to 6, characterized in that the main body (2) and the at least one leg (3, 4) each have 2 to 15 loops (9) that interlock.

8. Stent (1 ) according to one of claims 1 to 7, characterized in that an angle (a, ß) between 170° and 100° is formed between the main body (2) and the at least one leg (3, 4).

9. Stent (1 ) according to one of claims 1 to 8, characterized in that the angle (a, ß) between the main body (2) and the at least one leg (3, 4) is adjustable by up to 5°, preferably up to 10°, particularly preferably up to 15° and particularly up to 20°.

10. Stent (1 ) according to one of claims 1 to 9, characterized in that the main body (2) and the at least one leg (3, 4) are essentially cylindrical.

11. Stent (1) according to claim 10, dadu rc hge ke nn ze ichn et that the main body (2) has a diameter (D2) which is larger than the diameter (D3, D4) of the at least one leg (3, 4) or corresponds to it.

12. Stent (1 ) according to one of claims 1 to 11, dad by rz ge nze chnet that the wire mesh is embedded in a sheath, in particular in a silicone sheath.

13. Stent (1 ) according to one of claims 1 to 12, dad by rg ge kennze chnet that the stent (1) is formed from a single wire.

14. Stent (1 ) according to one of claims 1 to 13, characterized in that the area of ​​the main body (2) between the legs (3, 4) is rigid.

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