Stent for implants inside the tubal

Abstract

The present invention relates to a stent, in particular a stent assembly for insertion into a vessel of the human or animal body. The present invention also relates to a catheter stent insertion device for inserting a stent assembly according to the invention into a vessel of the human or animal body. The present invention also relates to a method for inserting a stent assembly according to the invention into a vessel of the human or animal body using a catheter stent insertion device according to the invention.

Description

Technical Field

[0001] The present invention relates to stents, and more particularly to stents for insertion into the ducts of the human or animal body.

[0002] The present invention also relates to a catheter stent insertion device for inserting the stent according to the present invention into the duct of the human or animal body.

[0003] The present invention also relates to a method for inserting the stent according to the present invention into the duct of the human or animal body using the catheter stent insertion device according to the present invention.

Background Art

[0004] Stents are widely used in medicine to keep open the lumen passage of anatomical ducts or conduits. A wide variety of stents are used for different purposes, from expandable coronary, vascular and bile stents to simple plastic stents used to enable the flow of urine between the kidneys and bladder.

[0005] In particular, vascular stents are generally placed in arteries and veins as part of an angioplasty to support the walls of diseased and weakened arteries or veins. The commonly used treatment procedure uses a catheter to insert and guide an expandable stent towards the affected part of the weakened vessel wall. A catheter containing a collapsed peripheral stent is inserted into the artery or vein and guided towards the deployment position using an appropriate imaging technique such as fluoroscopy. Once the catheter is properly positioned, the collapsed stent is deployed and expanded against the inner wall of the artery or duct.

[0006] Due to external compression and mechanical forces acting at these positions, a flexible stent material such as nitinol is used in most peripheral stent placements.

Summary of the Invention

Problems to be Solved by the Invention

[0007] Segmented stents with high radial strength and flexibility, composed of at least two interconnected independent stent segments, can be used in tubules. A problem with such stents assembled from multiple stent segments is that when the nearest stent segment is deployed from the catheter stent insertion device at the desired or intended deployment position in the tubule, the deployed stent segment immediately expands to its expanded configuration and comes into contact with the inner wall of the tubule.

[0008] Generally, when considering stent placement in an affected vein, pre-treatment ultrasound and CT imaging techniques cannot accurately measure the required length for the venous stent. Only during the stenting procedure can the precise length of the stent be determined using venography and intravascular ultrasound (IVUS) techniques. Stent patency primarily depends on good inflow and outflow, improvement of the patient's symptoms, and accurate stent placement to ensure stent patency.

[0009] It is no longer possible to retract a deployed and expanded stent segment into the catheter stent insertion device for repositioning within the tubule, for example, due to deployment (and expansion) at an inaccurate or undesirable location within the tubule. Since the position of the first stent segment, which has already deployed and expanded within the tubule, cannot be corrected, the remainder of the stent assembly still housed in the catheter stent insertion device must also be fully deployed within the tubule. As a result, the deployed and expanded stent may not be able to fully support the affected tubule wall over the intended length, potentially leading to the failure of the stent placement procedure.

[0010] The present invention aims to provide a solution for the problems identified above, which allows for easy modification of the final longitudinal deployment position of the stent assembly within the tube, while ensuring adequate support along the entire length of the affected tube wall by the deployed and expanded stent. [Means for solving the problem]

[0011] A stent assembly for insertion into a tube in the body of a human or animal is proposed according to the present invention. The stent assembly comprises at least two stent segments having a proximal end, a distal end, and a stent long axis, and segment interconnecting means for interconnecting the two stent segments. The segment interconnecting means is configured to adjust the distance between the two stent segments in the tube between a first configuration in which the tube distance is smallest and a second configuration in which the tube distance is largeest, depending on the translational displacement of one of the two stent segments along the stent long axis in the tube relative to the other of the two stent segments.

[0012] Through the relative translational displacement of stent segments along the stent's long axis, the length of the stent assembly can be adjusted to its intended in-pipe deployment position more directly, versatility, and with greater precision than existing stent designs. Such a stent assembly design, which can be deployed and extended through the translational displacement of individual stent segments, ensures proper support of the affected pipe wall along the entire length of the stent.

[0013] Accordingly, the length-adjustable stent assembly according to the present invention can cover the entire iliofemoral canal in a human or animal with the application / insertion of a single stent assembly. This has a significant advantage over known stent placement procedures that require two separate stents, resulting in undesirable duplication. Thus, since the length of the stent assembly according to the present invention can be adjusted relative to the desired intravascular deployment position, in-situ adjustment and placement in the length-adjustable stent assembly can be performed more accurately using venography and IVUS information collected during the procedure. In an example of the stent assembly according to the present invention, to interconnect at least two stent segments, the segment interconnecting means comprises at least one elongated filament rod having two rod ends, a first rod end connected to a first stent segment and a second rod end connected to a second stent segment. Here, the distance between the first and second rod ends is smaller in the first configuration than in the second configuration.

[0014] In this way, the stent segments are always properly interconnected, maintaining the consistency or integrity of the entire stent assembly. Because the internal tube distance between the first and second rod ends is smaller in the first configuration than in the second configuration, the relative translational displacement of the stent segments interconnected by the filament rods allows the filament rods to adjust the length of the stent within the tube.

[0015] In the first example, in the first and second configurations, the first and second rod ends are radially offset from each other. In other examples of the stent assembly according to the present invention, in the first and second configurations, the first and second rod ends are aligned along the longitudinal axis of the stent when viewed in the longitudinal axis direction. In both examples, reliable interconnection between adjacent stent segments is ensured, maintaining the overall consistency of the segmented stent and enabling versatile translational extension of the stent.

[0016] Preferably, at least one long filament rod is configured to extend in length to ensure relative translational displacement of the stent segments and, consequently, translational elongation of the entire stent assembly during deployment within the tube.

[0017] In particular, at least one long filament rod is configured to elongate in a way that is irreversible. This ensures that the translational elongation of the stent assembly after deployment in the tube is permanent, and that the stent, once extended in the tube, does not revert to a contracted or reduced length configuration. The segmented stent, with its irreversible lengthening aspect of the long filament rod, contacts the tube wall after the deployment and expansion of several stent segments, thus avoiding damage to the inner tube wall that could occur when the deployed and expanded stent assembly contracts in the tube along the stent's longitudinal axis.

[0018] In a favorable example, at least one elongated filament rod is manufactured from an extensible material such as a flexible material. In yet another example, which enables versatile translational displacement of adjacent stent segments, at least one elongated filament rod has an expandable structure, a zigzag structure, or a coil structure.

[0019] In yet another example of a stent assembly according to the present invention, which allows for support or stent placement over a greater length of the affected tubular wall and may be implanted in a curved tubular section, the stent comprises a proximal stent segment, a distal stent segment, and one or more intermediate stent segments positioned between the proximal and distal stent segments, where segment interconnecting means interconnect each of the stent segments.

[0020] In this example, further, in a longitudinal view of the stent, the proximal stent segment has a first length, the distal stent segment has a second length, and the intermediate stent segment has a third length. Here, the third length is smaller than the first and second lengths. In particular, the third length is 5-15 mm. Thus, the stent assembly has proximal and distal stent portions that are longer than the individual intermediate stent segments. The larger stent lengths at the proximal and distal ends provide adequate support for the affected vascular wall at the beginning and end of the stent expanded within the vascular. This ensures proper and secure placement of the stent within the vascular.

[0021] In this simplified example, the first and second lengths are the same. In other examples, the first length is longer than the second length, specifically, the first length is 30-50 mm and the second length is 10-30 mm.

[0022] In yet another example, the maximum distance between stent segments is 1-20 mm.

[0023] Depending on the stent placement procedure performed on the affected tubule in the patient, the number of intermediate stent segments ranges from 1 to 30.

[0024] An example of a catheter stent insertion device is proposed for inserting a stent assembly, comprising at least two stent segments according to the present invention, into a tubule in the body of a human or animal. This catheter stent insertion device allows the length of the stent assembly to be adjusted relative to a desired tubular deployment position so that the affected tubular wall is always properly supported along its entire length by the stent after deployment and expansion within the tubule.

[0025] Here, the catheter stent insertion device according to the present invention is provided for accommodating a stent assembly in a contracted configuration, and includes a hollow stent accommodating tube having a proximal tube end and a distal tube end, and elongation means provided to adjust, within the hollow stent accommodating tube, the distance between a stent segment that has already been deployed and a stent segment to be interconnected next, between a first configuration in which the distance is minimized and a second configuration in which the distance is maximized, by translating the stent segment to be interconnected next along the stent major axis with respect to the already deployed stent segment.

[0026] This enables translational adjustment of the length of the stent with respect to the intended in-tube deployment position so that the diseased tube wall is always properly supported over the entire length by the stent adjusted after deployment and expansion within the tube.

[0027] In an example of the catheter stent insertion device, the elongation means includes a translational spindle that extends through the stent assembly in the contracted configuration. The translational spindle includes an expanded distal stent acting end having an outer dimension larger than the outer dimension of the stent segment in the contracted configuration.

[0028] Therefore, the distance between the undeployed and the contracted stent segments can be set by pulling the undeployed stent segment in the distal translational direction. Since the expanded distal stent acting end has an outer dimension smaller than the inner dimension of the stent segment in the expanded deployment configuration, simple and repetitive elongation steps are possible for the next undeployed and contracted stent segments.

[0029] Preferably, guiding means are provided for guiding the proximal tube end of the hollow stent accommodating tube towards the deployment position within the tube.

[0030] The present invention also relates to a method for inserting a stent according to the present invention into a deployment position within a tube in a human or animal body using the catheter stent insertion device according to the present invention.

[0031] This delicious, A: A catheter stent insertion device, which houses a stent composed of at least two stent segments within a hollow stent housing tube in a retracted configuration, is inserted with the proximal tube open end inside the tube. B: A step of guiding the catheter stent insertion device toward the deployment position inside the tube, C: The step of withdrawing the hollow stent housing tube until at least two proximal stent segments are deployed through the proximal tube opening in the tube, D: A step of adjusting the distance between at least two stent segments between a first configuration in which the distance is smallest and a second configuration in which the distance is largeest, by withdrawing one of at least two stent segments along the long axis of the stent relative to the other already deployed stent segment. E: The steps include withdrawing the hollow stent housing tube and deploying at least one of the two stent segments through the proximal tube opening in the tube, It is equipped with.

[0032] In particular, the method is further characterized by the following steps. D1: Repeat step D for each subsequent stent segment after the stent.

[0033] In yet another example of the method, steps D and D1 are performed within the hollow stent housing tube for each individual stent segment prior to step C. [Brief explanation of the drawing]

[0034] The present invention will be described in more detail with reference to the following accompanying drawings.

[0035] Figures 1a-1d show a schematic first example of a stent assembly according to the present invention in several translational expansion states.

[0036] Figures 2a-2d show a schematic second example of the stent assembly according to the present invention in several translational expansion states.

[0037] Figures 3a-3d show other schematic examples of stent assemblies according to the present invention.

[0038] Figures 4a-4b-4c are detailed diagrams of the stent assembly shown in Figures 1-3 in several expanded states.

[0039] Figures 5a-5e show schematic examples of catheter stent insertion devices according to the present invention. [Modes for carrying out the invention]

[0040] For a better understanding of the present invention, similar parts in the drawings are indicated with the same reference numerals.

[0041] In the following detailed descriptions and claims, various parts are indicated with the “proximal” and “distal” classifications. These classifications are interpreted in relation to the location of the human or animal heart in which the stent is implanted. Specifically, the classification “proximal” is understood to mean “closest to the heart” or “direction toward the heart.” Similarly, “distal” is understood to mean “farthest from the heart” or “direction away from the heart.”

[0042] Generally, when considering stent placement in an affected vein, pre-treatment ultrasound and CT imaging techniques cannot accurately measure the required length for the venous stent. Only during the stenting procedure can the precise length of the stent be determined using venography and intravascular ultrasound (IVUS) techniques. Stent patency primarily depends on good inflow and outflow, improvement of the patient's symptoms, and accurate stent placement to ensure stent patency.

[0043] To address the stent length adjustment problems described above, Figures 1(1a-1d), 2(2a-2d), 3(3a-3d), and 4 show several different examples of the stent assembly according to the present invention in several expansion states in the translational direction. In these figures, the stent assembly is shown together with reference numeral 10.

[0044] The stent assembly 10 includes a proximal stent segment 11 having a proximal segment surface 11a that corresponds to the proximal stent end 10a of the entire stent assembly 10. The proximal stent segment 11 also has a distal segment surface 11b. The stent assembly 10 also includes a distal stent segment 12, which is similarly provided with a proximal segment surface 12a and a distal segment surface 12b. The distal segment surface 12b forms the distal stent end 10b of the stent assembly 10.

[0045] Several intermediate stent segments 13, 13', and 13'' are accommodated between the proximal stent segment 11 and the distal stent segment 12. The number of intermediate stent segments can be arbitrarily selected. In addition to embodiments such as those shown in Figures 1a-1d and 2a-2d, which show three intermediate stent segments 13-13'-13'', any number of intermediate stent segments 13 (1, 2, 3, 4, ..., up to 30, or more) can be selected depending on the stent implant application being performed.

[0046] In this example, the intermediate stent segments 13-13'-13'', etc., are identical in shape and dimensions. However, this identical configuration is not essential for the function of the stent 10 according to the present invention.

[0047] In the first embodiment of the stent assembly 10 shown in Figures 1a-1d and the second embodiment shown in Figures 2a-2d, the individual retracted stent segments 12-13''-13'-13-11 (when viewed from the distal stent end 10b toward the proximal stent end 10a of the stent 10) are housed in the catheter stent insertion device in a retracted configuration, with a minimum distance D1 (theoretically 0 mm, but in practice approximately 0.1-1.0 mm) from each other. The proximal stent end 10a forms the front of the stent assembly 10 when viewed with respect to the direction of the heart in a human or animal body.

[0048] When the catheter stent insertion device is inserted into the tubule together with the stent assembly 10 housed in a retracted configuration, the proximal stent segment 11, as the first segment, is inserted and deployed at a desired position within the tubule of a human or animal body. The initial length X1 of the proximal stent segment 11 needs to be sufficiently long to allow for partial and incomplete insertion and deployment of the proximal stent segment 11 within the tubule, and to allow for confirmation of its precise intravascular position using appropriate known imaging techniques such as fluoroscopy, and subsequently, if an incorrect position is observed, to allow for the partial deployment of the proximal stent segment 11 to be withdrawn into the catheter stent insertion device.

[0049] Preferably, the length X1 is such that partial deployment over the insertion / deployment length, corresponding to approximately 50% of X1 of the first / proximal stent segment 11 within the tubule, still allows the partially deployed proximal stent segment 11 to be pulled back into the catheter stent insertion device, and allows for repositioning of the catheter stent insertion device (the proximal end) within the tubule for subsequent deployment of the updated and modified proximal stent segment 11.

[0050] In this example, both the individual stent length X1 (length of proximal stent segment 11) and X2 (length of distal stent segment 12) are greater than the individual stent length X3 of the intermediate stent segment (one of 13-13'-13''). In Figures 1a-1d and 2a-2d, X1 is shown to be greater than X2, but for example, X1 and X2 are the same length. Typical dimensions of X1, X2, and X3 are X1 is 30-50 mm, X2 is 10-30 mm, and X3 is 5-15 mm. The typical diameter of all stent segments and thus the entire stent assembly 10 is 8-35 mm.

[0051] The stent assembly 10 shown in Figures 1a and 2a is shown in its initial configuration, such as the shortest configuration within the catheter stent insertion device (meaning the stent assembly 10 has the minimum length when measured from the proximal stent end 10a to the distal stent end 10b). The minimum length is indicated with reference numeral Z. The initial total length Z of the stent assembly 10 as shown in Figures 1a and 2a is comprised of the individual stent lengths X1 (length of the proximal stent segment 11), X2 (length of the distal stent segment 12), three times the individual stent lengths X3 of the three intermediate stent segments 13-13'-13'', and four times (the sum of) the minimum distance D1 between each adjacent stent segment.

[0052] In Figures 1a-1d and 2a-2d, there is an interconnection means 30 that interconnects the proximal stent segment 11 to the first intermediate stent segment 13, the first intermediate stent segment 13 to the second intermediate stent segment 13'', the second intermediate stent segment 13'' to the third intermediate stent segment 13''', and finally, in this case, interconnects the third intermediate stent segment 13''' to the distal stent segment 11.

[0053] In both embodiments shown in Figures 1a-1d and 2a-2d (and Figures 4a-4c), the interconnecting means 30 is comprised of several extension rod elements 31-32, each having a first / proximal rod end 31a (32a) and a second / distal rod end 31b (32b) that interconnect adjacent stent segments. The several extension rod elements 31-32, (31'-32'), (31''-32''), (31'''-32''') are configured to elongate in length. Preferably, these extension rod elements 31-32, (31'-32'), (31''-32''), (31'''-32''') are configured to elongate in an irreversible manner by plastic deformation or the like. Therefore, the translational distance between adjacent stent segments can be modified and set to a desired permanent intermediate distance X1, X2, or X3, depending on the desired total length of the stent assembly 10 within the pipe.

[0054] Preferably, the long filament rod elements 31-32, (31'-32'), (31''-32''), (31'''-32'') are made from an extensible material such as a flexible material. Alternatively, in other examples, the long filament rod elements have an expandable structure that allows for extension in the longitudinal direction.

[0055] In the embodiments of the stent assembly 10 in both Figures 1a-1d and 2a-2d, the long filament rod elements 31-32, (31'-32'), (31''-32''), (31'''-32'') have a zigzag structure, and in the embodiment of the stent assembly 10 in Figure 3a-3d, the long filament rod elements 31-32, (31'-32'), (31''-32''), (31'''-32'') have a flexible winding or coil structure. The zigzag, winding, and coil embodiments allow for versatile extension along the long filament rod elements 31-32, (31'-32'), (31''-32''), (31''''-32'') in the longitudinal direction, and set the translational distance between adjacent stent segments interconnected by these zigzag or coiled long filament rod elements 31-32, (31'-32'), (31''''-32''), (31''''-32'''') at the desired deployment position within the tube.

[0056] In the embodiments of the stent assembly 10 shown in Figures 1a-1d (zigzag type) and 3a (winding type) and 3c (coil type), both the first rod ends (31a-32a) and the second rod ends (31b-32b) of the long filament rod elements 31-32, (31'-32'), (31''-32''), (31''''-32'''') are radially offset from each other in view along the stent's long axis 10c in both the first / initial length configuration and the second / extended length configuration.

[0057] In the embodiments of the stent assembly 10 in Figures 2a-2d (zigzag type) and Figures 3b (flexible winding type) and 3d (coil type), both the first rod ends (31a-32a) and the second rod ends (31b-32b) of the length-extendable elongated filament rod elements 31-32, (31'-32'), (31''-32''), (31'''-32''') are aligned with each other in the longitudinal direction when viewed in the direction of the stent's long axis 10c, in both the first / initial length configuration and the second / extended length configuration.

[0058] In Figures 1b and 2b, the initial minimum distance D1 between the proximal stent segment 11 and the first intermediate stent segment 13, as shown in Figures 1a and 2a, is adjusted to the maximum distance indicated with reference numeral D3. The adjustment of the distance D1 between the proximal stent segment 11 and the first intermediate stent segment 13 from the initial minimum distance D1 to the maximum distance D3 is established by the simultaneous translation of the three intermediate stent segments 13-13'-13'' and the distal stent segment 12 over the maximum distance in the direction of the stent long axis 10c (or along the stent long axis 10c) relative to the proximal first stent segment 11 (which is stationary and not displaced).

[0059] The simultaneous translation of these three intermediate stent segments 13-13'-13'' and the distal stent segment 12 in the direction of the stent's long axis 10c (or along the stent's long axis 10c) is indicated by the dashed bidirectional arrows surrounding the three intermediate stent segments 13-13'-13'' and the distal stent segment 12. The total length Z' of the intermediate stent corresponds to the sum of the initial stent lengths X1, X2, X3 (three times), three times the minimum distance D1, and the maximum distance D3. The long filament rod elements 31'-32' that interconnect the proximal stent segment 11 to the first intermediate stent segment 13 are extended in the tube to their full extension length, facilitating translational extension at the maximum distance D3 between the first stent segment 11 and the rest of the stent assembly 10.

[0060] Here, it should be noted that in one example of the deployment technique, the first / proximal stent 11 is already inserted and deployed in the canal, while the remaining stents 13-13'-13''-12 are still housed in a deflated state within the catheter stent insertion device, awaiting further length adjustment as described later with respect to Figures 1c and 2c. Thus, the length-adjustable stent assembly 10 according to the present invention can cover the entire iliofemoral canal in a human or animal with the application / insertion of only one stent assembly. This has a significant advantage over known stent placement procedures that require two separate stents, resulting in undesirable duplication. Thus, since the length of the stent assembly 10 according to the present invention can be adjusted relative to the desired in-canal deployment position, in-situ adjustment and placement in the length-adjustable stent assembly can be performed more accurately using venography and IVUS information collected during the procedure.

[0061] Figures 1c and 2c show the stent assembly 10 further extended by adjusting the initial minimum distance D1 between the intermediate stent segment 13 and the intermediate stent segment 13' (see Figures 1c-2c) from the starting position shown in Figures 1b and 2b to the intermediate distance shown in Figures 1c and 2c with reference numeral D2. The adjustment of the distance between the first intermediate stent segment 13 and the second intermediate stent segment 13' is achieved by the simultaneous translation of the second and third intermediate stent segments 13' and 13'' and the distal stent segment 12 along the stent long axis 10c relative to the proximal stent segment 11 and the first intermediate stent segment 13 (which is stationary and not displaced). The elongated filament rod elements 31''-32'' that interconnect the first intermediate segment 13 to the next intermediate stent segment 13' are extended to the intermediate extension length, facilitating translational extension at the intermediate distance D2 between the first intermediate stent segment 13 and the rest of the stent assembly 10.

[0062] The resulting stent length Z'' is comprised of three times the individual stent lengths X1, X2, and X3, two minimum distances D1, one maximum distance D3 (as set in the stent configurations shown in Figures 1b and 2b), and an intermediate distance D2.

[0063] Similarly, the next / proximal stent 13 has already been inserted and deployed within the tubule, while the remaining stents 13'-13''-12 are still housed in a deflated state within the catheter stent insertion device, awaiting further length adjustment as described later with respect to Figures 1d and 2d.

[0064] Figures 1d and 2d show yet another configuration of the stent assembly 10 having a total stent length of Z''''. The new stent length Z'''' is generated by a further elongation step in which the third intermediate stent segment 13'' and the distal stent segment 12 are translated over the maximum translational distance in the direction of the stent axis 10c (along the stent axis 10c) relative to the proximal stent segment 11 and the first and second intermediate stent segments 13-13' (which are stationary and not displaced). The elongated filament rod elements 31''-32'''' that interconnect the second intermediate segment 13' to the following third and final intermediate stent segments 13'' are elongated to their maximum elongation length, facilitating translational elongation over the maximum distance D3 between the second intermediate stent segment 13' and the rest of the stent assembly 10.

[0065] Thus, the resulting stent length Z'' is comprised of three times the individual stent lengths X1, X2, and X3, one minimum distance D1 (between the distal stent segment 12 and the third intermediate stent segment 13''), an intermediate distance D2 set in Figures 1c and 2c, and twice the maximum distance D3 set in Figures 1b-2b and 1d-2d.

[0066] It should be noted that the second / next proximal stent 13' has already been inserted and deployed within the tubule, while the remaining stents 13''-12 are still housed in a deflated state within the catheter stent insertion device.

[0067] It is clear that the distance between adjacent stent segments can be adjusted to any desired intermediate distance between the minimum length D1 and the maximum length D3 (corresponding to the maximum extension of the flexible and elongated filament rods 31-32) by subsequent translational displacement of a portion of the stent assembly 10, which is the translation of an arbitrary desired translational distance between the minimum distance D1 and the maximum distance adjustment D3 in the longitudinal direction of the stent longitudinal axis 10c (along the longitudinal direction of the stent longitudinal axis 10c) relative to all or some of the stationary and immobile already deployed stent segments.

[0068] The amount of adjustment of the individual distances between several adjacent stent segments can be arbitrarily selected by the physician depending on the placement of the stent assembly 10 within the vascular space (e.g., localized constriction within the vascular space). Thus, the individual positions of several stent segments (in particular the intermediate stent segments 13-13'-13'') within the total length of the stent can be based on MR or CT imaging techniques and real-time fluoroscopy or intravascular ultrasound imaging, which are commonly used during stent placement.

[0069] Figures 4a, 4b, and 4c illustrate the principle of length adjustment according to the present invention in more detail. Figures 4a, 4b, and 4c are enlarged views of the stent assembly 10 of Figure 1-3 (in particular, the interconnection between two adjacent stent segments). The two adjacent stent segments are indicated with reference numerals 11 and 12, which indicate the proximal stent segment 11 and the distal stent segment 12.

[0070] Both adjacent stent segments 11 and 12 are interconnected using segment interconnecting means or segment interconnecting elements, as indicated by reference numeral 30. In one example, the segment interconnecting means or element 30 comprises a first long filament rod 31 and a second long filament rod 32. However, for proper operation of the present invention, one long filament rod 31 is sufficient. In other embodiments, as many as three long filament rods may be provided as part of the segment interconnecting means 30.

[0071] As described above, the long filament rod elements 31-32 are two rod elements whose length can be extended. The two rod ends (31a-31b) and (31b-32b) of the long filament rod elements 31-32 are aligned with each other in the longitudinal direction when viewed in the direction of the stent's long axis 10c, in both the first / initial length configuration and the second / extended length configuration.

[0072] However, the interconnection principle shown in Figures 1a-1d, 3a, and 3c can be realized even if both the first rod ends (31a-32a) and the second rod ends (31b-32b) of the long filament rod elements 31-32 are radially offset from each other in view along the stent's long axis 10c, in both the first / initial length configuration and the second / extended length configuration.

[0073] Similar to the stent assembly configurations in Figures 1a-1d and 2a-2d, additional intermediate stent segments 13-13'-13''-13'', etc., may be positioned between the proximal stent segment 11 and the distal stent segment 12.

[0074] As mentioned above, both the first and second long filament rods 31 (32) are manufactured from an extensible material such as a flexible material, or the long filament rod elements have an expandable structure that allows for extension in the longitudinal direction, in other examples. In the example in Figures 4a-4c, the long filament rod elements 31-32 have a zigzag structure. However, as mentioned above, flexible winding or coil structures are also possible as embodiments. These can be made from the same mesh material from which the intermediate stent segments 13-13'-13'', proximal stent segment 11, and distal stent segment 12 are made. In one example, the material for the intermediate stent segments 13-13'-13'', proximal stent segment 11, distal stent segment 12, and segment interconnecting means 30 (long filament rods) is nitinol. Nitinol is a biocompatible metal memory material used as a standard flexible stent material for external compression and mechanical forces acting on stents implanted in tubes.

[0075] Each length-extendable elongated filament rod 31(32) of the segment interconnecting means or element 30 has a distal rod end 31b(32b) which is fixedly connected at connection point 12a1(12a2) on the periphery of the proximal segment end 12a of the stent segment 12. Similarly, each length-extendable elongated filament rod 31(32) has a proximal rod end 31a(32a) which is similarly fixedly connected at the opposite end of the rod at a fixed position indicated as connection point 11b1(11b2) on the periphery of the distal segment surface 11b of the proximal stent segment 11.

[0076] In this example, connection points 11b2 and 12a2 (and 11b1 and 12a1) are aligned with each other in the longitudinal direction when viewed in the direction of the stent's longitudinal axis 10c.

[0077] As seen in Figure 4a, both the length-extendable long filament rods 31 and 32 exhibit the same minimum length dimensions as in Figures 1a and 2a due to their unextended zigzag structure. In the initial configuration, the distance D1 between adjacent stent segments 11 and 12 is minimal (theoretically 0 mm, but in practice 0.1–1.0 mm). The total length of the initial stent assembly 10 in Figure 4a is shown with L1, which corresponds to the sum of the two lengths of stent segments 11 and 12 plus the initial minimum intermediate distance D1.

[0078] According to the present invention, the stent assembly 10 can be extended along the long axis 10c during deployment in the tubular cavity by translating one of the stent segments (in this case, stent segment 12) in the direction of the stent long axis 10c (or in the direction along the stent long axis 10c) relative to the other of two stent segments (in this case, proximal stent segment 11), whose position is maintained by some means (not shown) of a catheter stent insertion device.

[0079] The translational principle within this pipe is shown in Figures 4b and 4c by the white arrows next to the stent segment 12. The translational displacement of the stent segment 12 relative to the other stent segments 11 increases the length dimensions of both the length-extendable elongated filament rods 31 and 32.

[0080] Figure 4b shows an intermediate configuration of the stent assembly 10 as seen from the initial configuration shown in Figure 4a, similar to, for example, Figure 2b. This shows an intermediate configuration of two adjacent stent segments 11 and 12, where the distance between stent segments 11 and 12 (larger than the initial minimum distance shown with reference numeral D1 in Figure 4a) is indicated with D2. The total length of the stent assembly 10 in Figure 4b is indicated with L2, which corresponds to the two lengths of stent segments 11 and 12 plus the intermediate distance D2 which is increased by the extension of both the length-extendable long filament rods 31 and 32.

[0081] Further translation of the distal stent segment 12 along the stent's long axis 10c relative to the proximal stent segment 11 results in a further increase in the distance between the intermediate stent segments 13 and 13' due to further elongation of the length-extendable elongated filament rods 31 and 32. This translational elongation continues until the elongated filament rods 31 and 32 reach their maximum elongation, reaching the maximum distance between both intermediate stent segments. In the configuration shown in Figure 4c, the elongated filament rods 31 and 32 are fully elongated within the tube, and the distance between stent segments 11 and 12 reaches its maximum length, indicated with reference numeral D3. The total length of the stent assembly 10 in Figure 4c is L3, which corresponds to the two lengths of stent segments 11 and 12 plus the maximum intermediate distance D3 due to the maximum elongation of both length-extendable elongated filament rods 31 and 32.

[0082] It is clear that the maximum distance D3 between stent segments 11 and 12 depends on the maximum extended length of the length-extendable flexible elong filament rods 31 and 32 that interconnect the stent segments 11 and 12. These maximum extended lengths partially depend on the flexible elong filament rods 31 and 32 and the flexible material selected for the zigzag, multiple winding, or coil structure. In Figure 4c, which shows the maximum extension, both the elong filament rods 31 and 32 show the maximum extension in the direction parallel to the stent's long axis 10c.

[0083] It should be noted that the stent extension principle in a tube, as shown in Figure 1-4 with five stent segments, is an example and should not be interpreted as the only possibility for extending the stent assembly according to the present invention. The distance between any adjacent stent segments can be varied and extended to any distance between a minimum (D1) and a maximum (D3) by translational extension using a length-extendable elongated filament rod, which can be stretched by a suitable flexible material and / or geometric structure not limited to zigzag, multiple windings, coils, or expansion structures.

[0084] Theoretically, the distance D1 is equal to 0 mm, but in reality, the minimum value of D1 is approximately 0.5–1.0 mm. Similarly, one or more distances between adjacent stent segments may remain unchanged (staying at the minimum length D1). In fact, they may be skipped or certain distances may be altered, depending on the physician's decision to determine the final stent extension based on local conditions within the tubule near the intended deployment position of the stent assembly 10.

[0085] The stent extension mechanism described in this patent application allows the physician to easily adjust the stent length during stent deployment within the tubule. In particular, the physician can position specific intermediate stent segments within the entire stent assembly so that each intermediate stent segment contacts and supports several desired locations on the tubule wall after insertion and deployment.

[0086] As described above, in one example of the deployment technique, each of the following proximal stents has already been inserted and deployed within the tubule, while the remaining stent is still retracted and housed within the catheter stent insertion device, set aside for further length adjustment. Once the physician determines that the entire stent assembly 10 has the correct length and the correct initial proximal position within the tubule, the decision is made to insert and deploy the remaining stent segments within the tubule under simultaneous distal withdrawal of the catheter stent insertion device. In this way, the entire stent assembly 10, with its correctly adjusted length, is deployed within the tubule to cover the correct desired length.

[0087] Figures 5a-5e disclose a catheter stent insertion device 40 according to the present invention in a sequence of operational stages of deployment of a stent assembly 10 within a tube 100 according to the present invention. The catheter stent insertion device 40 is schematically shown and consists of a hollow stent housing tube 41 for housing a stent (also referred to as a stent assembly) 10 in a retracted configuration. The hollow stent housing tube 41 has an open proximal tube end 41a (shown on the right side of the page in Figure 5) and a distal tube end 41b (shown on the left side of the page in Figures 5a-5e). The distal tube end 41b is connected to a guide means (not shown) located outside the human body.

[0088] Reference numeral 42 indicates a guidewire positioned within the tube 100 to guide the catheter stent insertion device 40 during several stent deployment stages. In this example of stent deployment, the stent assembly 10 consists of a proximal stent segment 11, three intermediate stent segments 13-13'-13'', and a distal stent segment 12. Several stent segments 11-13-13'-13''-12 are interconnected by interconnecting means 30, which consists of several extendable rod elements 31-32 that are zigzag in shape and aligned with each other in the longitudinal direction when viewed in the direction of the stent's long axis 10c, in both the first / initial length configuration and the second / extended length configuration as shown in the embodiments in Figures 2a-2d and 4a-4c.

[0089] Furthermore, flexible windings or coil structures are equally suitable for setting the translational distance between adjacent stent segments interconnected by these zigzag, flexible windings, or coiled elongated filament rod elements 31-32. Similarly, as shown in Figures 1a-1d, the implementation of elongated filament rod elements 31-32 that are radially offset from each other in view along the stent's long axis 10c is also possible as a stent assembly 10 for use in the catheter stent insertion device 40 according to the present invention.

[0090] The catheter stent insertion device 40 is inserted toward the desired deployment position with the proximal tube end 41a inside the tube 100. At this position, the stent (assembly) 10 is deployed, and after deployment within the tube, other stent segments 11-13-13'-13''-12 expand and come into contact with the inner tube wall.

[0091] The catheter stent insertion device 40, shown together with reference numeral 50, also includes a translational extension means, which in this example is configured as a spindle 50. The translational spindle 50 is essentially made from a rigid rod-shaped element, such as a rigid plastic material. The translational spindle 50 is housed inside the hollow stent housing tube 41 and also inside the retracted stent assembly 10, which is configured as a hollow cylindrical shape.

[0092] In Figures 5a-5e, the catheter stent insertion device 40 is enlarged, and the dimensions of several parts are clarified so that the stent assembly 10 in the retracted configuration is positioned in close proximity around the translational spindle 50 and enclosed within the hollow stent housing tube 41. Such a micro-configuration allows for insertion into the tubules of a human or animal body.

[0093] The proximal end of the translational spindle 50 is provided with an expansion stent working end 50a. Since the translational spindle 50 is housed inside the hollow stent housing tube 41, the expansion stent working end 50a has an outer dimension smaller than the inner dimension of the hollow stent housing tube 41, allowing for translational displacement of the entire translational spindle 50 within the hollow stent housing tube 41 along the longitudinal axis (longitudinal axis shown with reference numeral 10c) of the hollow stent housing tube 41 along the guide wire 42 and the stent assembly 10 and tube 100. However, in order to perform the translational extension of the stent assembly 10 as described above in Figures 1a-1d, 2a-2d and 4a-4c, the outer dimension of the expansion stent working end 50a is larger (preferably slightly larger) than the outer dimensions of the individual stent segments 11-13-13'-13''-12 in the contracted, unexpanded configuration of the stent assembly 10. Furthermore, the external dimensions of the extended stent working end 50a are smaller than the internal dimensions of the individual stent segments 11-13-13'-13''-12 in the extended deployment configuration of the stent assembly 10.

[0094] Figure 5a shows the initial stage of the catheter stent insertion device 40, where the retracted stent assembly 10 is housed around the translation spindle 50, and both are fully housed within the hollow stent housing tube 41. The expanded stent working end 50a is aligned with or positioned in close proximity to the proximal tube end 41a. The expanded stent working end 50a is in contact with the proximal end 10a of the retracted stent assembly 10, in particular, with the proximal segment surface 11a of the retracted first / proximal stent segment 11. The catheter stent insertion device 40 advances through the tube 100 using the guidewire 42 until the proximal device end 41a of the hollow stent housing tube 41 reaches the position of deployment of the proximal end 10a of the stent assembly 10.

[0095] As shown in Figure 5a with a black arrow pointing to the right (proximal direction) next to the proximal device end 41a, the manipulation and advancement of the catheter stent insertion device 40 toward the desired or intended deployment position within the tube 100 may be performed by a guide means positioned outside the patient or by the physician. In either method (automatic or manual), the position of the catheter stent insertion device 40 (the proximal device end 41a) prior to the deployment of the stent 10 may be confirmed by fluoroscopy or any other known imaging technique used in stent placement.

[0096] The deployment of the first / proximal stent segment 11, shown in Figure 5b, occurs by distal translational withdrawal of the hollow stent housing tube 41 along its longitudinal axis 10c, as indicated by the leftward-pointing black arrow next to the distal device tube end 41b. During the translational withdrawal of the hollow stent housing tube 41, the stent assembly 10 and the translational spindle 50 remain in their initial deployment positions. Once the hollow stent housing tube 41 has been withdrawn over a translational distance equal to at least the length of the proximal stent segment 11 (indicated with X1 in Figures 1a-1d and 2a-2d), the first / proximal stent segment 11 is released through the proximal tube open end 41a within the tube 100 at the desired or intended deployment position. The stent segment 11 then deploys and expands, making contact with the inner tube wall of the tube 100. This deployment configuration of the stent segment 11 is shown in Figure 5b with reference numeral 11^.

[0097] Referring to Figure 5c, the external dimensions of the working end 50a of the expanded stent are smaller than the internal dimensions of the individual stent segments 11-13-13'-13''-12 in the expanded deployment configuration of the stent assembly 10. In a further deployment step, the translational spindle 50 is withdrawn distally through the expanded stent segments 11^ within the hollow stent housing tube 41 until the working end 50a of the expanded stent is again aligned with the proximal tube end 41a, which was withdrawn distally earlier (Figure 5b), or positioned in close proximity to the proximal tube end 41a. Now, the working end 50a of the expanded stent is in contact with the proximal segment surface 13a of the next contracted stent segment 13.

[0098] In Figure 5c, the first and second long filament rods 31-32 are still at their initial length dimensions.

[0099] In Figure 5d, which shows the stent extension step, the translational spindle 50 is further withdrawn distally (see the black arrow pointing left (distally) next to the distal spindle end 50b). Because the outer dimensions of the expanded stent working end 50a are greater than the outer dimensions of the individual stent segments 11-13-13'-13''-12 in the contracted configuration of the stent assembly 10, the translational spindle 50 similarly pulls or displaces the rest of the stent assembly. Here, the stent segments 12-13''-13'-13 move distally away from the first stent segment 11, which is already deployed and implanted against the inner wall of the tube 100.

[0100] The larger expanding stent working end 50a contacts the smaller proximal segment surface 13a of the contracted stent segment 13, pulling the remaining contracted stent assembly (here, the contracted stent segments 12-13''-13'-13) distally into the hollow stent housing tube 41 (which remains in a fixed position within the tube), resulting in translational extension of the first and second long filament rods 31-32 as previously described with respect to Figures 1a-1d, 2a-2d, and 4a-4c.

[0101] In Figure 5d, the translational spindle 50 and the retracted stent segments 12-13-13'-13'' are displaced distally in the translational direction over a distance that results in maximum extension from the minimum distance (D1 in Figures 1a-1d, 2a-2d, and 4a-4c) to the maximum distance D3 of the first and second elongated filament rods 31-32. However, the distal displacement of the translational spindle 50 and the "extraction" of the assembly of retracted stent segments still present in the subsequent hollow stent housing tube 41 may be interrupted for the use of appropriate imaging techniques in order to perform the desired translational extension of the first and second elongated filament rods 31-32 that interconnect the already deployed and extended stent segments with the undeployed and retracted stent segments within the hollow stent housing tube 41. This allows the extension of the elongated filament rods 31-32 to be set to any length between the minimum distance D1 and the maximum distance D3.

[0102] With the intermediate distance between the already deployed and expanded proximal stent segment 11 and the undeployed and retracted stent segment 13 set to the maximum distance D3 in Figure 5d, the retracted stent segment 13 is deployed as shown in Figure 5e.

[0103] Deployment occurs by distal translational withdrawal of the hollow stent housing tube 41 along its long axis 10c, as shown with a left-pointing black arrow next to the distal device tube end 41b, similar to Figure 5b. During the translational withdrawal of the hollow stent housing tube 41, the retracted stent segments 12-13''-13'-13, the translational spindle 50, and the already deployed stent segment 11 remain in their respective positions.

[0104] When the hollow stent-containing tube 41 is withdrawn over a translational distance equal to at least the length of the stent segment 13 (shown with X3 in Figures 1a-1d and 2a-2d), the intermediate stent segment 13 is released through the proximal tube open end 41a within the tube 100 at a desired or expected deployment position (at a distance D3 from the adjacent stent segment 11 that has already been deployed). Similarly, after deployment, the intermediate stent segment 13 expands and comes into contact with the inner tube wall of the tube 100 (shown with 13^ in Figure 5e).

[0105] As previously described with reference to Figures 5c and 5d, the step of setting the distance between the deployed intermediate stent segment 13 and the next intermediate stent segment 13' is repeated.

[0106] According to the catheter stent insertion device 40 in Figures 5a-5e, each subsequent stent segment can be positioned at a desired distance from an already deployed stent segment. By translating the distal translational spindle 50 toward the distal device end 41b, intermediate distances are set and stent segments are deployed one by one within the tube, thereby enabling the stent assembly 10 according to the present invention to be effectively deployed within the tube. After one stent segment has been deployed, the remainder of the stent, which is housed in a retracted state within the hollow stent housing tube 41 of the catheter stent insertion device 40, can be subjected to subsequent distal translation of the translational spindle 50 over a desired length of the associated interconnecting elongated filament rods 31-32, for the next length adjustment relative to the next deployed stent segment. [Explanation of symbols]

[0107] 10 stents 10a Proximal stent end of stent 10 10b Distal end of stent 10 10c Stent 10 Long axis 11. First / Proximal Stent Segment 11^ First / proximal stent segment in extended configuration 11a Proximal end of the proximal stent segment 11b Distal end of the proximal stent segment 11b1 First connection between the distal end 11b of stent segment 11 and the proximal rod end 31a of the first long filament rod 31 11b2 Second connection between the distal end 11b of stent segment 11 and the proximal rod end 32a of the second long filament rod 32 12. Second / Distal Stent Segment 12a Proximal end of distal stent segment 12a1 First connection between the proximal end 12a of stent segment 12 and the distal rod end 31b of the first long filament rod 31 12a2 Second connection between the proximal end 12a of stent segment 12 and the distal rod end 32b of the second long filament rod 32 12b Distal end of distal stent segment 13. First intermediate stent segment 13^ First intermediate stent segment in the extended configuration 13a Proximal end of the intermediate stent segment 13b Distal end of the intermediate stent segment 13' Second intermediate stent segment 13'' Third intermediate stent segment 30 Segment interconnection means 31. First Long Filament Rod 31a Proximal rod end of the first long filament rod 31b Distal rod end of the first long filament rod 32. Second long filament rod 32a Proximal rod end of the second long filament rod 32b Distal rod end of the second long filament rod D1 Initial minimum distance between two intermediate stent segments D2: Intermediate distance between two intermediate stent segments D3 Maximum distance between two intermediate stent segments X1 First length of proximal stent segment 11 X2 Length of the second / distal stent segment 12 X3 Intermediate stent segment 13-13'-13'' length Z Initial length of the stent in Figure 1 Z' is the midpoint length of the stent in Figure 2. Z'' Further intermediate length of the stent in Figure 3 Z''' Further intermediate length of the stent in Figure 4 40 Catheter stent insertion devices 41 Hollow stent housing tube 41a Proximal tube opening 41b Distal tube end 42 Guidewire 50 Extension means or translational spindle 50a Translational spindle 50's extended stent working end 50b Distal spindle end 100 tubes

Claims

1. It has a proximal end, a distal end, and a stent long axis, It comprises at least two stent segments and segment interconnection means for interconnecting the two stent segments, The segment interconnecting means is configured such that, when inserted into a pipe, the distance between the two stent segments is adjusted between a first configuration in which the distance is smallest and a second configuration in which the distance is largeest by the remaining, non-rotating translational displacement of the at least two stent segments along the long axis of the stent relative to the stationary, immobile, and already deployed stent segments of the at least two stent segments. To interconnect the at least two stent segments, the segment interconnecting means comprises at least one elongated filament rod that is extendable along the long axis of the stent, having two rod ends: a first rod end connected to the first stent segment and a second rod end connected to the second stent segment. The distance between the first rod end and the second rod end is smaller in the first configuration than in the second configuration. A stent for insertion into a tube in the body of a person or animal.

2. The stent for insertion into a tube in the body of a person or animal according to claim 1, wherein in the first and second configurations, the first rod end and the second rod end are radially offset from each other.

3. The stent for insertion into a tube in the body of a person or animal according to claim 1, wherein in the first and second configurations, the first rod end and the second rod end are aligned with each other in the longitudinal direction when viewed in the longitudinal direction of the stent.

4. The stent for insertion into a tube in the body of a person or animal according to any one of claims 1 to 3, wherein the at least one elongated filament rod is configured to extend in length.

5. The stent for insertion into a tube in the body of a person or animal according to claim 4, wherein the at least one elongated filament rod is configured to extend in length in a way that is either non-reversible or reversible, and each is configured to extend the stent permanently or non-permanently.

6. The stent for insertion into a tube in the body of a person or animal according to claim 4 or 5, wherein the at least one long filament rod is made from an extensible material such as a flexible material.

7. The stent for insertion into a tube in the body of a person or animal according to claim 4 or 5, wherein the at least one long filament rod has a telescopic structure.

8. The stent for insertion into a tube in the body of a person or animal according to claim 4 or 5, wherein the at least one long filament rod has a zigzag structure.

9. The stent for insertion into a tube in the body of a person or animal according to claim 4 or 5, wherein the at least one elongated filament rod has a coil structure.

10. It comprises a proximal stent segment, a distal stent segment, and one or more intermediate stent segments positioned between the proximal stent segment and the distal stent segment, The segment interconnection means interconnects each of the stent segments. A stent for insertion into a tube in the body of a person or animal, according to any one of claims 1 to 9.

11. In a longitudinal view of the stent, the proximal stent segment has a first length, the distal stent segment has a second length, and the intermediate stent segment has a third length. The third length is smaller than the first length and the second length. A stent for insertion into a tube in the body of a person or animal, as described in claim 10.

12. The stent for insertion into a tube in the body of a person or animal according to claim 11, wherein the third length is 5-15 mm.

13. A stent for insertion into a tube in the body of a person or animal according to claim 11 or 12, wherein the first length and the second length are the same.

14. A stent for insertion into a tube in the body of a person or animal according to claim 11 or 12, wherein the first length is longer than the second length, the first length is 30-50 mm, and the second length is 10-30 mm.

15. A stent for insertion into a tube in the body of a person or animal, according to any one of claims 1 to 14, wherein the maximum distance between the stent segments is 1-20 mm.

16. A stent for insertion into a tube in the body of a person or animal according to any one of claims 10 to 15, wherein the number of intermediate stent segments is 1 to 30.

17. A catheter stent insertion device for inserting a stent assembly comprising at least two stent segments as described in any one of claims 1 to 16 into a tube in the body of a human or animal, A hollow stent housing tube is provided to accommodate the stent assembly in a retractable configuration, and has a proximal tube open end and a distal tube end. Extension means provided to adjust the distance between an already deployed stent segment and a subsequently interconnected stent segment within the hollow stent housing tube, between a first configuration in which the distance is smallest and a second configuration in which the distance is largest, by translating the subsequently interconnected stent segment along the long axis of the stent relative to the already deployed stent segment; A catheter stent insertion device equipped with [a specific feature].

18. The extension means comprises a translational spindle extending through the stent assembly in the contraction configuration, The translational spindle is equipped with an expanded distal stent working end having an outer dimension larger than the outer dimension of the stent segment in the contracted configuration. A catheter stent insertion device according to claim 17.

19. The catheter stent insertion device according to claim 18, wherein the expanded distal stent operating end has an outer dimension smaller than the inner dimension of the stent segment in the expanded deployment configuration.

20. The catheter stent insertion device according to claim 17 or 18, further comprising a guiding means for guiding the proximal tube end of the hollow stent housing tube toward the deployment position within the tube.

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