Stents and stent insertion devices

Abstract

A stent and an insertion device thereof are provided. The stent comprises a stent body (1). The stent body (1) includes a first stent section (2) having at least one lumen (4) for drainage and guidewire passage, and a second stent section (3) having a second cross section different from the first cross section of the first stent section (2). The first cross section of the first stent section (2) transitions to a second cross section of the second stent section (3) to form the stent body (1) such that the stent body (1) drains or injects fluids through the lumen (4). The structure of the stent employs a siphon principle for drainage by utilizing a crescent-shaped cross section in the second stent segment (3). The crescent-shaped or flat second stent segment (3) is thinner, more flexible, and lighter than conventional stents. The advantage of the crescent-shaped or flat structure is that it reduces irritation to organs and preserves sphincter function.

Description

[Technical field]

[0001] This application relates generally to medical devices, and more particularly to stents and Incorporating a stent Regarding the insertion device. [Background technology]

[0002] Double J stents, also known as pigtail stents, feature curled ends at both ends. Conventional double J stents provide internal support and drainage functions and are utilized in various scenarios requiring intraluminal implantation to address conditions such as ureteritis. However, in clinical applications, conventional double J stents can cause significant discomfort to patients due to expansion of the tubular portion of the stent resulting in compression of the surrounding tissue. In particular, existing ureteral or biliary stents can cause significant discomfort when implanted, such as pain, frequent urination, and urgency due to bladder irritation. Moreover, known stents typically have two ends, each of which includes a coiled segment. When such a stent is placed in a patient, the length of the stent in the renal pelvis is fixed while the remaining portion of the stent remains in the bladder. While this may not cause irritation in patients with long ureters, in patients with short ureters, the thick and improperly coiled ends can cause significant discomfort.

[0003] CN112107781 discloses a ureteral stent comprising a first body communicating with a second body disposed in the ureter, and a bladder section communicating with the second body and disposed in the bladder. The first body is an elastic tube wound horizontally in an Archimedes spiral shape. The first body of the ureteral stent disposed in the renal pelvis can adjust the overall length of the stent when disposed in the human body by changing the number of wound circles. This design allows a single stent length to accommodate patients with different ureteral lengths. The tape measure-like structure of the first body and the intravesical section greatly reduces the size of the stent in the bladder, thereby minimizing bladder irritation caused by the stent. However, this conventional device has limitations, especially since the wound tube takes up a significant amount of space, which compresses the patient's sphincter, thereby hindering both the drainage and infusion of fluids. Therefore, they have the disadvantage that the integral transition may still irritate the bladder upon placement.

[0004] China Publication No. 111494778 discloses a ureteral stent that can be visualized. The ureteral stent is made of a material that includes a first contrast agent and a second contrast agent that are respectively distributed in different regions of the ureteral stent. This embodiment facilitates clear visualization of the position of the ureteral stent during X-ray or ultrasound examination, thereby improving medical observation. Meanwhile, this embodiment allows flexible selection of examination modalities based on individual patient requirements, eliminating the need for stent exchange during the procedure, thereby reducing patient discomfort and burden. However, while this known device uses contrast agents to observe the position of the stent in the patient's body, it does not address the problem of bladder irritation. Moreover, this known device is designed only for drainage and is ineffective for fluid injection. This forces the known stent to be exchanged for a different ureteral stent whenever fluid injection is required, which requires discomfort and burden for the patient.

[0005] There may be differences between the prior art known to the applicant and the prior art known to the patent examiner, and although this specification refers to many contents and disclosures of documents and patent documents, not all of them are listed comprehensively in the specification, so it should be noted that this application includes the technical features of all these prior arts, and the applicant reserves the right to supplement further relevant prior art and technical features in accordance with the relevant regulations. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the present application a first stent segment having at least one lumen for drainage and / or guidewire passage; a second stent segment having a second cross-section different from the first cross-section of the first stent segment; A stent comprising a stent body including: The first cross section of the first stent segment transitions to the second cross section of the second stent segment to form a stent body that allows for drainage and / or infusion of fluids through the lumen. The stent of the present application is structurally characterized by a crescent-shaped cross section of the second stent segment that facilitates siphon drainage. Compared to conventional stents made of the same material, the crescent-shaped or flat second stent segment disclosed herein is thinner, more flexible, and lighter. The crescent-shaped or flat structure also advantageously reduces irritation to the patient's organs and preserves the function of the patient's sphincter.

[0007] According to a preferred embodiment, the connection between the first and second cross sections reduces the compressive force exerted by the patient's sphincter on the second stent segment, thereby reducing irritation to the patient undergoing drainage, thereby preserving sphincter function.

[0008] According to a preferred embodiment, the first stent segment has a free end that is wound in a first direction to form a deformable first loop, and the second stent segment has a free end that is wound in a second direction to form a deformable second loop. Preferably, the first radial surface, which is the radial radiating surface of the first loop, and the second radial surface, which is the radial radiating surface of the second loop, are spaced apart (shifted) from each other by a first angle within a range of 0° to 180°. By providing the first loop and the second loop, the stent can be better fixed even in patients with different lengths of body cavities.

[0009] According to a preferred embodiment, the second cross section comprises a drainage structure with a crescent-shaped cross section or a flat shape. Preferably, the ratio of the area of ​​the second cross section to the area of ​​the first cross section defines the completeness of the stent body. Based on the selected completeness, the drainage efficiency of the stent body is inversely proportional to the patient comfort.

[0010] According to a preferred embodiment, the connection comprises a first connection end of the first stent segment and a second connection end of the second stent segment, the first connection end of the first stent segment forming a planar beveled end that meets the axis of the first stent segment at a second angle. Preferably, the second angle is in the range of 0°-90°, which results in a smooth profile of the connection between the first and second cross sections. The transition from the first to the second cross section by this beveled surface is free of edges and corners, ensuring patient comfort. A second angle of 90° provides an optimal connection between the first and second stent segments and maximizes the pushing action of the pusher. Preferably, the bevel angle may be 30°, 45° or 60°. At 60°, the pusher achieves a satisfactory pushing efficiency while maintaining acceptable patient comfort. At 45°, the pusher balances acceptable pushing efficiency with sufficient patient comfort. At 30°, the pusher provides acceptable pushing efficiency with satisfactory patient comfort.

[0011] Considering that conventional ureteral or biliary stents may cause obvious discomfort when placed, such as pain due to bladder irritation, frequent urination, and urgency, the present application provides a stent that cannot be fitted with existing positioners designed for conventional ureteral or biliary stents due to the specially designed cross-section of the lower end of the disclosed stent.

[0012] The present application further provides an insertion device for deploying a stent, the insertion device comprising: an inner tube for drainage and / or passage of a guidewire; an outer tube for separating the stent body from the guide wire; At least the following is provided. Preferably, in use, the fastener secures the drainage structure of the second cross section of the second stent segment of the stent body to the outer tube after the inner tube is disposed within the outer tube and inserted into the lumen formed in the first stent segment of the stent body. When assembled with a stent, the insertion device of the present application not only functions as a catheter, but also facilitates injection of contrast agents and injection of fluids.

[0013] According to a preferred embodiment, the inner tube is An inner tube body that serves as a lumen for drainage and guidewire passage; a first Luer connector that serves as a port on the inner tube for connecting to the outer tube; a second Luer connector for removably connecting to an external connector; Equipped with. Preferably, the ends of the inner tube remote from the first and second Luer connectors are inserted into a lumen in the first stent segment of the stent body for drainage and / or guidewire passage. The assembled insertion device and stent of the present application allow for simple and efficient placement of the stent into a patient, and may optionally be used as a ureteral or biliary catheter for injection of contrast agents or other fluids.

[0014] According to a preferred embodiment, the inner tube is a first radiopaque marker located at an end of the inner tube body remote from the first and second luer connectors; a second radiopaque marker positioned between the first radiopaque marker and the first luer connector; It further comprises: Preferably, the first and second radiopaque markers are used to position the stent body during the stent placement procedure.

[0015] According to a preferred embodiment, the outer tube comprises: An outer pipe body that accommodates the inner pipe body; a handle located at an end of the outer tube body and configured to advance or retract the outer tube; a third Luer connector for connecting to the inner tube; Equipped with. Preferably, the third luer connector and the first luer connector are connected such that when the inner tube is inserted into the outer tube and assembled with the outer tube, the inner tube and the outer tube are fixedly positioned relative to each other.

[0016] In a preferred embodiment, the surfaces of the inner and outer tubes are provided with a coating that enhances the comfort and safety of the patient receiving the stent using the insertion device. [Brief description of the drawings]

[0017] [Figure 1] 1 is a schematic diagram of a stent according to one embodiment of the present application.

[0018] [Diagram 2] FIG. 2 is a schematic diagram of a stent according to an embodiment of the present application, in which the stent has a first angle of 90° and a single turn loop.

[0019] [Diagram 3] FIG. 2 is a schematic diagram of a stent according to an embodiment of the present application, in which the stent has a first angle of 90° and double wrapped loops.

[0020] [Figure 4] FIG. 2 is a schematic diagram of a stent according to one embodiment of the present application, in which the stent has a first angle of 90° and a single turn loop with a retention assembly.

[0021] [Diagram 5] FIG. 2 is a schematic diagram of a stent according to an embodiment of the present application, in which the stent has a first angle of 180° and a single turn loop.

[0022] [Figure 6] FIG. 2 is a schematic diagram of a stent according to an embodiment of the present application, in which the stent has a first angle of 180° and double wrapped loops.

[0023] [Figure 7] FIG. 2 is a schematic diagram of a stent according to an embodiment of the present application, in which the stent has a first angle of 180° and a single turn loop with a retention assembly.

[0024] [Figure 8] FIG. 2 is an application diagram of a stent according to one embodiment of the present application.

[0025] [Figure 9] FIG. 2 is an enlarged view of a connection portion of a stent according to an embodiment of the present application.

[0026] [Figure 10] FIG. 2 is a schematic diagram of a stent according to an embodiment of the present application, in which the stent has a flat drainage configuration.

[0027] [Figure 11] FIG. 2 is a schematic diagram of an inner tube of a stent according to one embodiment of the present application.

[0028] [Figure 12] FIG. 2 is a cross-sectional view of an outer tube of a stent according to one embodiment of the present application.

[0029] [Figure 13] FIG. 2 is a schematic diagram of a stent according to an embodiment of the present application, in which a second stent segment and an outer tube are assembled.

[0030] [Figure 14] FIG. 1 is a perspective view showing a stent and an insertion device being assembled according to one embodiment of the present application.

[0031] [Figure 15] FIG. 1 is a side view showing the stent and insertion device being assembled according to one embodiment of the present application.

[0032] [Figure 16] FIG. 1 is a front view showing the stent and insertion device assembled according to one embodiment of the present application.

[0033] [Figure 17] FIG. 2 is a cross-sectional view according to one embodiment of the present application showing the stent and insertion device being assembled. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] The present application will now be described in detail with reference to the accompanying drawings. EMBODIMENT 1

[0035] The present application relates to a stent comprising at least a stent body 1 having a first stent segment 2, which transitions into a second stent segment 3. The first stent segment 2 has at least one lumen 4 for drainage or guidewire passage. The connection 8 between the first stent segment 2 and the second stent segment 3 is arranged such that it transitions from a first cross section of the first stent segment 2 to a second cross section of the second stent segment 3. The second stent segment 3 defines at least one recess on its inside that communicates with and is adapted to the lumen 4. Preferably, the first stent segment 2 is tubular and defines a lumen 4 inside thereof, so as to form a continuous tube. The first stent segment 2 is inserted into a body cavity of a patient to function as a ureteral or biliary catheter. The second stent segment 3 extends from the first stent segment 2, but with a changing cross section. The first stent segment 2 has a cross section that is preferably circular in shape. Since the lumen 4 is present, this cross section can be considered as a ring shape. However, for clarity, this cross section will be referred to herein as a circular cross section. The second stent segment 3 has a non-circular cross section, which is a result of a transition from the circular cross section of the first stent segment 2. Preferably, the cross section of the second stent segment 3 is crescent shaped. The crescent and circular shapes may be any suitable proportions determined by the anatomical characteristics of the patient. For example, for an average patient, the crescent may be a 50% crescent shape, or a semicircular shape, or a semi-ring shape. If the patient's body cavity is relatively narrow, it is preferable that the crescent shape is a crescent shape that is larger than 50% to ensure the entry of the stent body 1. If the patient's body cavity is relatively loose, it is preferable that the crescent shape is a crescent shape that is smaller than 50% to ensure the comfort of the patient. It should be noted that the first cross section may be a circular, elliptical, or oval tubular cross section. For the sake of brevity, all other conceivable shapes of the cross section not listed herein are intended to be within the scope of this application. The second cross section is an incomplete shape of the first cross section.The complete shape may have a circular, elliptical or oval tubular cross section as described above. Specifically, the first cross section may be elliptical and the second cross section may be partially elliptical in shape with a completeness of 50%, less than 50% or more than 50%, respectively. An elliptical cross section is advantageous for patient comfort, since it creates little pressure inside the patient, but disadvantageous for smooth drainage. Therefore, the choice of shape is made according to the anatomical characteristics of the patient. For example, in patients with relatively narrow ureters, a stent with a less complete cross section is preferred. In another example, the first cross section is elliptical, and the second cross section may be in the shape of a partial ellipse with a completeness of 50%, less than 50%, or more than 50%. The elliptical structure has a smooth profile with a narrow upper end and a wide lower end, which contributes to both smooth drainage and satisfactory patient comfort. In particular, the curved contour of the ellipse ensures smooth flow of fluid without hindrance during drainage. Based on the above second cross section, it can be understood that the second cross section has side edges formed with a radius (R) to prevent damage to the patient's body cavity. Specifically, the R angle is formed at the edge of the second cross section where the completeness is broken.

[0036] According to a preferred embodiment, the cross section of the second stent segment 3 may alternatively be rectangular. In this case, the second stent segment 3 serves as a flat drainage piece of the stent for fluid evacuation. The lumen 4 is for the passage of a guide wire. The second stent segment 3 is straight, J-shaped or pigtail-shaped at its end away from the lumen 4 to facilitate fixation of the stent and prevent it from dislocating. The first stent segment 2 allows the fluid to exit the lumen 4 at the center of the stent body 1 or the fluid to exit from the outer circumference of the stent body 1. The second stent segment 3 has a cross section of a different shape. In particular, the second stent segment 3 may be crescent-shaped or a flat drainage piece in cross section for siphon-based drainage. Advantages of such a shape include causing little irritation to the patient's body and maintaining the function of the sphincter. In an embodiment, the second stent segment 3 of the disclosed stent has a crescent-shaped cross-section for siphon-based drainage. The crescent-shaped or flat second stent segment 3 of the present application is thinner, more flexible, and lighter than its conventional counterpart made of the same material. The crescent-shaped or flat structure also advantageously reduces irritation to the patient's organs and preserves the function of the patient's sphincter muscles.

[0037] According to a preferred embodiment, the connection between the first stent segment 2 and the second stent segment 3 may be achieved by splitting or uniting means, or any other suitable means. As the first stent segment 2 enters the patient's body lumen, the second stent segment 3 is retracted into the patient's body lumen. The split connection may be performed using removable medical components such as clips, screws, etc. The uniting connection may be achieved by heat welding, injection molding, or ultrasonic welding.

[0038] According to a preferred embodiment, the free end of the first stent segment 2 is rolled up in a first direction to form a deformable first loop 5, and the free end of the second stent segment 3 is rolled up in a second direction to form a deformable second loop 6. The first radial surface of the first loop 5 and the second radial surface of the second loop 6 are formed to form a first angle between 0 degrees and 180 degrees with each other. In the present application, the first direction refers to a direction extending from the first stent segment 2 to the axis of the second stent segment 3. The second direction refers to a direction opposite to the first direction. The first radial surface and the second radial surface include a plane extending beyond the first loop 5 and the second loop 6. The angle defined by the first radial surface and the second radial surface is the first angle. Preferably, the first radial surface and the second radial surface extend through a straight line on which the stent body 1 is located. In other words, the first radial surface and the second radial surface rotate about the same axis, thereby forming a first angle that varies in a constant plane. Preferably, the first loop 5 and the second loop 6 each have a diameter in the range of 10 mm to 30 mm. The first loop 5 and the second loop 6 are for providing additional extension length to facilitate placement of the stent within the patient's body. Preferably, the first loop 5 and the second loop 6 further facilitate fixation in the patient's bladder and renal calyx. Preferably, the first stent segment 2 has a diameter in the range of 1.0 mm to 30 mm. It has a diameter in the range of ~3.0mm.

[0039] The first angle is the angle between the first loop 5 on the first stent segment 2 and the second loop 6 on the second stent segment 3 when they are projected onto the same plane. Specifically, the plane is a cross section of the first stent segment 2 or the second stent segment 3. For example, as shown in FIG. 5, the cross section of the first stent segment 2 or the second stent segment 3 is a plane that faces inward and is perpendicular to the first stent segment 2 and the second stent segment 3. The first loop 5 and the second loop 6 are On the same planeThe first loop 5 and the second loop 6 of the stent body 1 have opposite projection directions and form a first angle of 180°. As shown in FIG. 1, the angle between the first loop 5 and the second loop 6 of the stent body 1 is zero. In other words, the first angle is zero. As shown in FIG. 2, the first loop 5 and the second loop 6 of the stent body 1 are perpendicular to each other or differ from each other by 90°, so the first angle is 90°. As shown in FIG. 5, the first loop 5 and the second loop 6 of the stent are parallel to each other or differ from each other by 180°, so the first angle is 180°. It is clear that the first angle may be any other value not listed here. Providing loops at the two ends eliminates the difficulty in fixing the stent in patients with different body lumen lengths. The loops at the two ends facilitate the fixing of the stent body 1. Preferably, the first loop 5 and the second loop 6 each generally have a single turn or two turns, although any greater number of turns can be envisaged for the first loop 5 and the second loop 6. In the present application, by selecting the first angle in the first loop 5 and the second loop 6, respectively, it is possible to make the stent suitable for patients with different physiological characteristics and to fix the stent in a set position without the risk of displacement.

[0040] According to a preferred embodiment, the first radial surface of the first loop 5 and the second radial surface of the second loop 6 overlap in one plane. Alternatively, the first radial surface of the first loop 5 and the second radial surface of the second loop 6 are perpendicular to each other. This makes it possible to form a stent in which the first angle between the first loop 5 and the second loop 6 is 0°, 90° or 180°.

[0041] According to a preferred embodiment, the connection portion 8 includes a first connection end of the first stent segment 2 and a second connection end of the second stent segment 3. The first connection end of the first stent segment 2 has an inclined end. The angle at which the contact surface of the inclined end intersects with the axis of the first stent segment 2 forms a second angle. The second connection end of the second stent segment 3 and the first connection end of the first stent segment 2 are connected to make a smooth transition. As shown in FIG. 9, the angle at which two straight lines in the cross section are connected is the second angle. The second angle may be 90°, but is preferably an oblique angle. By inclining the transition, the presence of corners in the connection can be eliminated, improving the comfort of the patient. In contrast, an angle of 90° is preferred from the viewpoint of the connection between the first stent segment 2 and the second stent segment 3, and the pushing efficiency of the pusher is maximized. Preferably, the inclination is 30°, 45°, or 60°. At a tilt angle of 60°, the pusher can have a satisfactory pushing efficiency and acceptable patient comfort. At a tilt angle of 45°, the pusher supports a balance between good pushing efficiency and satisfactory patient comfort. At a tilt angle of 30°, the pusher can have a satisfactory patient comfort and acceptable pushing efficiency.

[0042] According to a preferred embodiment, an opening communicating with the lumen is formed at the end of the first loop 5 of the first stent segment 2. Alternatively, the end of the first loop 5 is formed as a closed end.

[0043] According to a preferred embodiment, the first stent segment 2 is provided with solid walls or pores for draining water, and the second stent segment 3 is provided with solid walls, pores, and / or longitudinal ridges (ridges) for draining water. Preferably, the diameter of the first stent segment 2 can be appropriately selected to better fit the body lumen, such as the ureter or bile duct. The diameter of the second stent segment 3 can be selected according to the selection of the diameter of the first stent segment 2 to better fit the body lumen. The materials used to manufacture the first stent segment 2 and the second stent segment 3 can be flexible or semi-rigid materials, or any combination thereof. The materials can be soluble or insoluble. Usable materials include PVC, latex, silicone, PU, ​​TPE, as well as organic soluble materials, such as polyglycolic acid, porcine small intestine submucosa, and exogenous collagen, but are not limited thereto. The first stent segment 2 and the second stent segment 3 may be made of the same material or may be made of different materials.

[0044] According to a preferred embodiment, the end of the second stent segment 3 remote from the first stent segment 2 is provided with a retention assembly 7 adapted to be left outside the patient's body lumen. The retention assembly 7 is used to remove the stent body 1 from the patient's body lumen.

[0045] According to a preferred embodiment, the stent body 1 has gradient markings arranged along its length.

[0046] According to a preferred embodiment, the stent further comprises a separate pusher of tubular structure, such as the first stent segment 2. The pusher is used to position the stent body 1 in the body cavity of the patient. The pusher has at least one second lumen 4 for the passage of a guidewire or other related device. The pusher and the stent body 1 are detachably connected to each other. The stent body 1 and the pusher are formed as separate components with a detachable connecting portion to facilitate the insertion of the stent body 1 into the body cavity. The detachable connecting portion may be connected in a mechanical or magnetic way. The pusher is Hard (rigid) The pusher may be made of rigid, semi-rigid, or flexible material. The end of the pusher facing away from the user of the device (the distal end) contacts the proximal end of the stent body 1. The distal end of the pusher may be horizontal or angled to better connect the proximal end of the stent body 1 to the user of the device.

[0047] According to a preferred embodiment, each of the first stent segment 2 and the second stent segment 3 is covered with a layer of hydrophilic or antibacterial or anti-calcification coating. The pusher is covered with a layer of hydrophilic or antibacterial coating. The hydrophilic coating serves to reduce the coefficient of friction between the stent body 1 and the contact part of the patient. This reduces the discomfort caused when the stent is inserted into the patient's body and prevents the patient's internal organs and blood vessels from being damaged by excessive friction. The application of the antibacterial or anti-calcification coating also helps to prevent infection, thereby making the stent procedure safer for the patient.

[0048] The working principle and the usage of the stent of the present application will be further explained for clarity.

[0049] The first stent segment 2 of the stent body 1 is generally pushed forward using a guidewire. In the process of the guidewire being inserted into the patient's body lumen, it is important to keep the first loop 5 of the first stent segment 2 vertical so that the second loop 6 of the second stent segment 3 can follow the first stent segment 2 and easily advance into the patient's body lumen. Once the stent body 1 is in the patient's body lumen, the first loop 5 will automatically Once the first stent segment 2 is positioned as per the treatment plan, a pusher is typically used to stabilize the stent body 1, after which the guidewire can be removed. An auxiliary lumen (i.e., lumen 4) in the pusher is for injection of contrast media or insertion of other related devices. The connection between the distal end of the pusher and the proximal end of the stent body 1 can be used as a pressing point between the stent body 1 and the pusher. EMBODIMENT 2

[0050] This embodiment complements the previously described embodiments and figures (specifically the various models of the stent disclosed), and for the sake of brevity, a redundant description will not be repeated here.

[0051] According to a preferred aspect, FIG. 1 depicts a preferred embodiment of the stent of the present application. As shown, a stent with a first angle of 0° and a single turn loop is shown. This represents a basic design example of the present application. FIG. 2, FIG. 3, and FIG. 4 respectively show stents with a first angle of 90° and different numbers of loops and with or without a retention assembly. FIG. 5, FIG. 6, and FIG. 7 respectively show stents with a first angle of 180° and different numbers of loops and with or without a retention assembly as well. These examples represent alternative configurations that may be particularly suitable for practical use. However, there may be other alternative configurations, such as configurations with different configurations of first angle, second angle, and number of loop turns, without being limited thereto. FIG. 8 shows a practical application of the stent of the present application. Preferably, the stent is positioned in the bladder and renal calyx of a patient. FIG. 9 provides a close-up view of the connection of the present application. The angle formed by the two straight lines is the second angle. FIG. 10 shows another preferred embodiment of the stent of the present application. In addition to the single turn structure of each of the first loop 5 and the second loop 6, the present application further proposes a multi-turn structure for forming the first loop 5 and the second loop 6. The required length of the stent varies depending on the anatomical characteristics of the patient who uses the stent. The first loop 5 and the second loop 6 with the multi-turn structure provide additional elongation capability and allow the stent to be adapted to various patients with different anatomical characteristics. In particular, depending on the height and age of the patient, a stent that is too long may cause discomfort, while a stent that is too short may not properly fix itself in the patient's bladder and renal calyx. The additional turns provided by the multi-turn structure allow the stent to better fix itself in the patient's bladder and renal calyx and provide the stent with additional elongation capability. EMBODIMENT 3

[0052] This embodiment is a further improvement of the above-mentioned embodiment, and a description of the overlapping contents will be omitted.

[0053] The present embodiment relates to an insertion device for placing such a stent. Existing ureteral or biliary stents, when placed in the body, can cause significant discomfort, such as pain due to bladder irritation, frequent urination, and urgency. Although the embodiments of the present application provide a stent with increased comfort, the unique cross-sectional design at the lower end of the stent renders the stent incompatible with existing introducers for conventional ureteral or biliary stents. Therefore, the present application further provides an insertion device configured to place the stent disclosed in the present application in the body of a patient. Furthermore, conventional ureteral and biliary stents are intended only for post-operative support and drainage. The insertion device of the present embodiment, when combined with a stent, serves as a catheter to facilitate injection of contrast and fluid.

[0054] According to a preferred embodiment, the insertion device comprises at least an inner tube 9 and an outer tube 10, as shown in Figure 15. Figure 15 shows the inner tube 9 and the outer tube 10 in an assembled state. Preferably, The inner tube 9 and the outer tube 10 are arranged coaxially and can be connected via a luer connector. Appearance 10 The concentric lumen is configured for passage of a guidewire or for injection of fluids. inner tube 9 acts as a pusher tube to facilitate separation of the stent from the guidewire. As shown in FIG. 12, the inner tube 9 preferably includes an outer tube body 17, a handle 18 and a third luer connector 16. As shown in FIG. 11, preferably, outer tube 10 includes a first radiopaque marker 11, a second radiopaque marker 12, an inner tube body 13, a first luer connector 14, and a second luer connector 15. Preferably, Handle 18 The end of the inner tube 9 remote from the stent is tapered for easy insertion into the lumen 4 of the stent, thereby combining the stent and inner tube 9 as an integral unit. At this point, outer tube 10 Second Luer connector 15It can be used to inject contrast media or act as a urinary or biliary catheter for inputting other fluids. When the inner tube 9 and the outer tube 10 are connected to each other via a Luer connector, inner tube 9 By firmly pressing the upper handle 18, the stent can be separated from the inner tube 9 and placed in the patient's body. Preferably, the first radiopaque marker 11 is located at the end of the inner tube body 13 away from the first luer connector 14 and the second luer connector 15. The first radiopaque marker 11 and the second radiopaque marker 12 are for indicating the location of the stent during the stent placement procedure. In this technical method, the first radiopaque marker 11 and the second radiopaque marker 12 on the inner tube body 13 can be embedded metal pieces in the form of rings, wires, or springs, as long as they are visible on radiography. By embedding the first radiopaque marker 11 and the second radiopaque marker 12 at different positions on the inner tube body 13, the medical staff can easily see the location of the stent on the radiograph. outer tube 10 The position of the catheter can be accurately identified. The first radiopaque marker 11 and the second radiopaque marker 12 can realize radiographically accurate insertion. Thus, the present application improves clinical catheter insertion in terms of positioning accuracy and success rate. Preferably, the first radiopaque marker 11 and the second radiopaque marker 12 are fitted onto the inner tube body 13 as metal rings, metal wires, or metal springs. More preferably, the first radiopaque marker 11 and the second radiopaque marker 12 may be made of either nickel-titanium alloy, tungsten, or platinum. Preferably, both the first luer connector 14 and the second luer connector 15 are spaced apart from the first radiopaque marker 11. outer tube 10The first luer connector 14 is located at the end of the inner tube body 13 relative to the second luer connector 15. Preferably, the inner tube 9 and the outer tube 10 are coated to enhance patient comfort and safety. The coating may be a super lubricious coating, the material comprising at least one of polyvinylpyrrolidone (PVP), polyacrylamide (PAM), hydrophilic silver nitrate, or other hydrophilic super lubricious materials. Preferably, the outer surface of the outer tube 10 is also provided with distance markers to facilitate proper insertion by the medical practitioner. Preferably, the handle 18 is flat for easy grip. Preferably, inner tube 9 Stent inner tube 9 The second stent segment 3 further comprises an end through which a fastener 19 passes for fastening to the second stent segment 3, thereby preventing displacement of the end of the stent. Preferably, the fastener 19 may comprise a radiopaque material to facilitate positioning by the medical personnel. Figure 13 shows a schematic representation of the fastener 19 for fastening the second stent segment 3. Preferably, the fastener 19 is formed as a fastening sleeve or clamp. Preferably, the first luer connector 14 and the second luer connector 15 are the male and female parts of a luer connection, respectively. The first luer connector 14 is inner tube 9 for connecting with the third luer connector 16 outer tube 10 The insertion device and stent combination of the present application allow for easy and efficient placement in the patient's body and are suitable for use in the ureter or bile duct. The catheter functions as a catheter for the catheter, thereby conveniently allowing injection of contrast agents and other fluids.

[0055] The working principle and the method of use of the stent of the present application will be further explained for clarity.

[0056] 1. After the safety guidewire is placed in the patient's body, the stent and the insertion device are assembled together. Figure 14 shows the assembled state of the stent, the inner tube 9, and the outer tube 10. Figures 16 and 17 are respectively a front view and a cross-sectional view of the combination of the stent and the insertion device. Preferably, outer tube 10 but inner tube 9 The inner tube 9 is then inserted into the lumen 4 of the first stent segment 2 of the stent, and the tubes are then secured together via the first luer connector 14 and the third luer connector 16. The tape portion at the front end of the inner tube 9 is then inserted into the lumen 4 of the first stent segment 2 of the stent. The crescent-shaped drainage structure or the flat drainage structure or the drainage structure of another shape of the stent is secured to the lumen 4 by the fasteners 19. inner tube 9 is fixed at.

[0057] 2. A guide wire is inserted from the front end of the insertion device. The insertion device is advanced along the guide wire. In this process, the positions of the first radiopaque marker 11 and the second radiopaque marker 12 are radiologically checked, and the distance markers on the outer tube 10 are observed to confirm whether the stent has reached the intended position. If contrast is required for radiographic confirmation, outer tube 10 A contrast agent may be injected through a second Luer connector 15 at the rear end of the stent. The contrast agent then flows along the insertion device and the stent and out of the lumen 4, making the corresponding tissue radiographically visible.

[0058] 3. With the stent positioned in the intended location, placement of the stent within the patient's ureter can be easily accomplished by ensuring that the inner and outer tubes 9, 10 are assembled together and pushing the handle 18 away from the stent. The second stent segment 3 of the stent will automatically detach from the inner tube 9. The integrity of the withdrawn inner and outer tubes 9, 10 are checked and preferably again radiographically confirmed that the stent is properly positioned.

[0059] Throughout this application, features preceded by the term "preferably" are optional but not required, and applicant also reserves the right to withdraw or omit such preferred features at any time.

[0060] It should be noted that the specific embodiments described above are exemplary. Those skilled in the art may take inspiration from this application and come up with various solutions, all of which are within the scope and protected by this application. Furthermore, those skilled in the art will appreciate that the description and accompanying drawings provided in this application are exemplary and do not limit any of the appended claims. The scope of this application is defined by the appended claims and their equivalents. The application provided herein encompasses multiple inventive concepts, denoted by phrases such as "preferably," "according to a preferred embodiment," and "optionally," each of which represents a separate concept disclosed in a respective paragraph. Applicant reserves the right to file one or more divisional applications based on each inventive concept. [Explanation of symbols]

[0061] 1 Stent body 2 First stent segment 3 Second stent segment 4 Lumens 5. First Loop 6 Second Loop 7 Retaining Assembly 8 Connections 9 Inner tube 10 outer tube 11 First radiopaque marker 12 Second radiopaque marker 13 Inner tube body 14 First Luer Connector 15 Second Luer Connector 16 Third Luer Connector 17 Outer tube body 18 Handle 19 Fasteners

Claims

1. A stent comprising a stent body (1), the stent body (1) comprising: a first stent segment (2) having at least one lumen (4) for drainage and / or guidewire passage; a second stent segment (3) having a second cross-section different from the first cross-section of the first stent segment (2); Including, The first cross section of the first stent segment (2) transitions into the second cross section of the second stent segment (3) to form the stent body (1) such that the stent body (1) is adapted to evacuate or inject fluids through the lumen (4). Stent.

2. 2. The stent of claim 1, wherein a connection (8) connecting the first and second cross sections reduces irritation to the patient by reducing the compressive force exerted by the patient's sphincter muscles on the second stent segment (3) during drainage.

3. a free end of the first stent segment (2) bent in a first direction to form a deformable first loop (5), and a free end of the second stent segment (3) bent in a second direction to form a deformable second loop (6); a first radial surface of the first loop (5) and a second radial surface of the second loop (6) are spaced apart from each other by a first angle in the range of 0° to 180°; 3. A stent according to claim 1 or 2.

4. the second cross-section comprises a drainage structure having a crescent-shaped cross-section or a flattened shape; the area ratio between the second cross section and the first cross section defines the integrity of the stent body (1), and based on the selection of the integrity, the efficiency of drainage through the stent body (1) is inversely proportional to the patient comfort. A stent according to any one of claims 1 to 3.

5. the connecting portion (8) comprises a first connecting end of the first stent segment (2) and a second connecting end of the second stent segment (3), the first connecting end of the first stent segment (2) being formed as an oblique end defining a tangent plane that intersects with an axis of the first stent segment (2) to form a second angle; the second angle is in the range of 0° to 90° such that the connection (8) connecting the first cross section and the second cross section has a smooth profile; A stent according to any one of claims 1 to 4.

6. 1. An insertion device for placing a stent, comprising: an inner tube (9) for drainage and for passing a guidewire; an outer tube (10) for separating the stent body (1) of the stent from the guide wire; At least In use, after the inner tube (9) is disposed in the outer tube (10) and inserted into a lumen (4) formed in the first stent segment (2) of the stent body (1), a fastener (19) fixes the drainage structure of the second cross section of the second stent segment (3) of the stent body (1) to the outer tube (10). Insertion device.

7. The inner tube (9) is an inner tube body (13) that serves as a lumen for drainage and guidewire passage; a first luer connector (14) serving as a port of the inner tube (9) for connection to the outer tube (10); A second luer connector (15) for removably connecting to an external connector; Equipped with one end of the inner tube (9) remote from the first luer connector (14) and the second luer connector (15) is inserted into a lumen (4) in the first stent segment (2) of the stent body (1) for drainage or guidewire passage; 7. The insertion device of claim 6.

8. The inner tube (9) is a first radiopaque marker (11) located at one end of the inner tube body (13) remote from the first luer connector (14) and the second luer connector (15); a second radiopaque marker (12) located between the first radiopaque marker (11) and the first luer connector (14); Further comprising: The first radiopaque marker (11) and the second radiopaque marker (12) are used to position the stent body (1) during a stent placement procedure. An insertion device according to claim 6 or 7.

9. The outer tube (10) is an outer pipe body (17) that accommodates the inner pipe body (13); a handle (18) located at an end of the outer tube body (17) and configured to be manipulated to advance or retract the outer tube (10); A third luer connector (16) for connecting the inner tube (9); Equipped with the third luer connector (16) and the first luer connector (14) are connected such that the relative positions of the inner tube (9) and the outer tube (10) are fixed when the inner tube (9) is inserted into the outer tube (10) and assembled with the outer tube (10); An insertion device according to any one of claims 6 to 8.

10. The insertion device according to any one of claims 6 to 9, wherein the surfaces of the inner tube (9) and the outer tube (10) are provided with a coating that improves patient comfort and safety.

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