A stent suitable for placement in the prostate

Abstract

The present invention provides a stent suitable for being implanted in the prostate, the stent comprising a stent body, a stent base and a pull rope, the stent body being a three-dimensional frame structure, the stent body comprising a main support section, a transition section and a contraction section in sequence from the distal end toward the proximal end, the main support section and the transition section radially expand outwardly compared with the contraction section; the main support section comprises a plurality of main support edges and a distal support frame, the distal support frame being formed at the distal ends of the plurality of main support edges; the transition section comprises a proximal support frame, the proximal support frame having a proximal end and a distal end, the proximal support frame being formed at the proximal ends of the plurality of main support edges; the contraction section comprises a plurality of proximal support edges, the plurality of proximal support edges being arranged circumferentially at intervals, the proximal support edges being formed at the proximal end of the proximal support frame so that the contraction section and the transition section form a closed grid structure.

Description

Technical Field

[0001] The invention belongs to the field of medical devices, and in particular relates to a stent suitable for being placed in a prostate. Background Art

[0002] The prostate is a gland in the male reproductive system, connected to the bladder and urethra, with a sphincter below. The normal size of the prostate is about 20 ml, the size of a walnut. However, under the influence of various factors, the prostate will hypertrophy, exert pressure on the urethra, causing urination difficulties, and then damage the bladder function, which will cause urination difficulties, frequent urination, urinary interruption or weak urine flow. As the disease worsens, urethral stones, bladder tension, urethral infection, and even kidney damage may occur.

[0003] At present, the main treatment methods are often drug therapy or surgical treatment. Drug therapy is often not effective, while surgical treatment is very prone to complications, which may cause the patient to lose sexual function in severe cases. To solve these problems, prostate stents came into being. Prostate stents are made of memory alloy materials. The stents are assembled in vitro and expanded and restored to shape by the patient's body temperature after being transported to the patient's affected area, thereby propping up the patient's affected tissue to achieve a therapeutic effect. The expansion force of the frame structure causes the urethral tissue to degenerate during a few days of treatment. This degeneration of the tissue occurs due to ischemic compression of the supporting edges on the tissue cells, which leads to a decrease in blood flow or a complete lack of blood flow. The lack of blood flow leads to a lack of oxygen in the cells and ultimately to cell death. Within a few days, the proliferating tissue can be reduced to the point where urine flow almost returns to normal. After completing the treatment, the implant can be retrieved from the urethra through a catheter.

[0004] However, most traditional prostate stents are laser-cut stents made of nickel-titanium tubes. The cost of cutting stents is high, the supporting force is weak, the stents are easily displaced after long-term placement, and the stents are difficult to remove. The cutting implants used in the urethral prostate on the market include three supporting edges, the proximal ends of which converge together and the distal ends merge to form a hexagonal grid. The existing literature also discloses a prostate stent, which is formed by four nickel-titanium memory alloys twisted together to form four supporting edges, and the proximal ends converge to form a hexagonal grid. The three supporting edges and the proximal ends of the four supporting edges disclosed above are directly bent and then merged, which is prone to the following technical problems: First, the proximal side is the support vertex, and due to the limited expansion of the bend, it cannot play a good expansion role on the hyperplastic tissue. Second, no closed frame is formed between the proximal supporting edges, and the hyperplastic tissue is very easy to slip and shift from the mesh, and the stent is easy to shift. Complications such as local inflammation and tissue fibrosis are prone to occur after the stent is shifted. Summary of the invention

[0005] In view of the above-mentioned technical problems, the present invention provides a stent suitable for being implanted in the prostate, the stent comprising a stent body, a stent base and a pull rope, the stent body being a three-dimensional frame structure, the stent body comprising a main support section, a transition section and a contraction section in sequence from the distal end to the proximal end, the main support section and the transition section radially expand outward compared to the contraction section; the main support section comprises a plurality of main support edges and a distal support frame, the plurality of main support edges having a proximal end and a distal end, the plurality of main support edges being circumferentially spaced and extending from the proximal end toward the distal end, the distal end The side support frame is formed at the distal ends of multiple main support edges; the transition section includes a proximal support frame, the proximal support frame has a proximal end and a distal end, and the proximal support frame is formed at the proximal ends of multiple main support edges; the contraction section includes a plurality of proximal support edges, the proximal support edges have a proximal end and a distal end, the plurality of proximal support edges are circumferentially spaced and extend from the proximal end toward the distal end, and the proximal ends of the proximal support edges converge on the bracket base, and the proximal support edges are formed at the proximal end of the proximal support frame so that the contraction section and the transition section form a closed grid structure.

[0006] In some embodiments, the stent body includes multiple groups of elastic wires, the multiple groups of elastic wires include at least two elastic wires, the elastic wires have a first braided segment, a first forked segment, a second braided segment and a second forked segment from the proximal end to the distal end, the first braided segments of each group of elastic wires are intertwined to form a proximal support ridge, the first forked segments of each group of elastic wires are separated from each other, and the distal ends of the first forked segments of the multiple groups of elastic wires are intertwined to form a proximal support frame; the second braided segments of the multiple groups of elastic wires are intertwined to form a main support ridge, the second forked segments of the multiple groups of elastic wires are separated from each other, and the second forked segments of the multiple groups of elastic wires are intertwined to form a distal support frame.

[0007] In some embodiments, the proximal end and the distal end of adjacent main supporting edges respectively have two first bifurcated segments and two second bifurcated segments, and the adjacent main supporting edges, the two first bifurcated segments and the two second bifurcated segments form a planar annular frame.

[0008] In some embodiments, the annular frame is a polygonal frame or a circular frame.

[0009] In some embodiments, the radial cross-section of the main body support segment is wide at the bottom and narrow at the top.

[0010] In some embodiments, the radial cross-section of the main body support segment is trapezoidal or triangular.

[0011] In some embodiments, the cross-sectional area of ​​the main body support segment gradually increases in a direction from the distal end to the proximal end.

[0012] In some embodiments, the junction of the two second bifurcated segments of the annular frame forms an arc-shaped protrusion.

[0013] In some embodiments, an arc-shaped pressing tongue is disposed in the bracket body, the proximal end of the arc-shaped pressing tongue is connected to the bracket base, and the other end extends out from the annular frame.

[0014] In some embodiments, the arc-shaped pressure tongue includes a base section, a braided section, and a pressing section, the base section is connected to the bracket base, the braided section is braided and entangled with two main supporting edges, and the pressing section extends from the annular frame.

[0015] In some embodiments, a partial area of ​​the main supporting edge defines an annular ring.

[0016] In some embodiments, a partial section of at least one annular frame is a widened section.

[0017] In some embodiments, the stent body includes multiple groups of elastic wires, each group of elastic wires includes two elastic wires, the first braided segments of the two elastic wires in each group of elastic wires are intertwined to form a proximal support ridge, the first forked segments of the two elastic wires in each group of elastic wires are forked in a Y shape, and the fork angle of one group of elastic wires is greater than the fork angle of the elastic wires in the opposite group, and the distal ends of two adjacent first forked segments of adjacent groups of elastic wires are intertwined and merged to form multiple support sites, and two second braided segments extending distally from each support site are intertwined to form a main support ridge, the distal ends of two adjacent second forked segments of adjacent groups of elastic wires are forked in a Y shape from the main support ridge, and the distal ends of the two second forked segments of each group of elastic wires are intertwined and merged to form a distal support frame.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The stent provided by the present invention adds a transition section between the contraction section and the main support section of the existing stent, so that a closed support grid is formed between the contraction section and the main support section. Compared with the original point support, the support grid can better expand the proliferative tissue; in addition, the closed support grid effectively solves the risk of proliferative tissue easily slipping and shifting from the non-closed stent mesh of the existing stent.

[0020] The present invention forms a planar annular frame with the help of the bifurcated structure of the transition section. Compared with the twisted non-planar frame structure, the planar frame is easier to locate the proliferative tissue and is not easy to slip, thereby ensuring the positioning stability of the stent in the body and reducing the probability of postoperative complications.

[0021] Taking into account the adaptability of the stent to the asymmetric prostate cavity, the stent provided by the present invention does not adopt a completely centrally symmetrical structure, which is more friendly to the prostate and bladder tissues. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the structure of the bracket provided in Example 1;

[0023] Figure 2 A top view of the bracket provided in Example 1;

[0024] Figure 3 A schematic diagram of the implantation process of the stent provided in Example 1;

[0025] Figure 4 A schematic diagram of the structure of the bracket provided in Example 2;

[0026] Figure 5 A schematic diagram of the structure of the bracket provided in Example 3;

[0027] Figure 6 A schematic diagram of the structure of the bracket provided in Example 4;

[0028] Figure 7 A schematic diagram of the structure of the bracket provided in Example 5;

[0029] Figure 8 A schematic diagram of the structure of the bracket provided in Example 6;

[0030] Among them, 1-bracket body, 2-bracket base, 3-pull rope, 11-main support section, 12-transition section, 13-contraction section, 111, 112, 113, 114-main support edge, 115-distal support frame, 120-proximal support frame, 131, 132, 133, 134-proximal support edge, 1311, 1312-first braided section, 1201, 1202-first bifurcated section, 1111, 1121-second braided section, 1151, 1152-second bifurcated section, 100, 101, 102, 103-annular frame, 14-arc-shaped pressure tongue, 40-base section, 41, 42-braided section, 43-pressing section, 1110, 1120-widened section, 116-annular ring. DETAILED DESCRIPTION

[0031] The present invention or the technical solution of the invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings;

[0032] In the description of the present invention, it should be understood that the terms "front", "rear", "upper", "lower" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation of the present invention. In the present application, the proximal end should be interpreted as the part close to the operator (doctor), and the distal end should be understood as the part away from the doctor.

[0033] In the description of the present invention, it should be noted that, unless otherwise specified and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection of two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. Example 1

[0034] See also Figure 1 and Figure 2 An embodiment of the present invention provides a stent suitable for implantation in the prostate, the stent comprising a stent body 1, a stent base 2 and a pull rope 3. Exemplarily, the stent body 1 provided in this embodiment is composed of a plurality of elastic wires intertwined to form a three-dimensional frame structure, the stent body 1 can expand the tissue channel and support the tissue wall, the stent base 2 and the pull rope 3 facilitate the removal of the stent as a whole from the proximal end when removing the stent.

[0035] In the present invention, the distal end and the proximal end are relative to the operator, the end closer to the operator is the proximal end, and the end farther from the operator, that is, the end closer to the surgical site is the distal end. Figure 1 From the perspective of FIG. 1 , for the stent, the distal end is the right end and the proximal end is the left end.

[0036] The structure of the prostate stent is described in detail below in conjunction with various drawings and specific embodiments. It should be understood that the structures of various embodiments are only examples and are not intended to limit the scope of protection of the present invention.

[0037] Please refer again Figure 1The stent body 1 includes a main support section 11, a transition section 12 and a contraction section 13 from the distal end to the proximal end. The main support section 11 and the transition section 12 expand radially outward compared to the contraction section 13 to support and expand the inner wall of the tissue. The main support section 11 includes a plurality of main support edges and a distal support frame 115, wherein the plurality includes more than three support edges. Taking this embodiment as an example, it includes four main supporting edges 111, 112, 113, and 114, and the four main supporting edges 111, 112, 113, and 114 have a proximal end and a distal end. The four supporting edges 111, 112, 113, and 114 are arranged circumferentially and spaced apart and extend from the proximal end to the distal end. The distal support frame 115 is formed at the distal ends of the four main supporting edges 111, 112, 113, and 114. The transition section 12 includes a proximal support frame 120, and the proximal support frame 120 has a proximal end and a distal end. The proximal support frame 120 is formed at the four main supporting edges 111, 1 12, 113, 114 proximal ends; the contraction section 13 includes a plurality of proximal supporting ridges, taking the present embodiment as an example, including four proximal supporting ridges 131, 132, 133, 134, which have a proximal end and a distal end, the four proximal supporting ridges 131, 132, 133, 134 are arranged circumferentially at intervals and extend from the proximal end toward the distal end, and the proximal ends of the four proximal supporting ridges 131, 132, 133, 134 converge on the bracket base 2, the four proximal supporting ridges 131, 132, 133, 134 are formed at the proximal end of the proximal support frame so that the contraction section and the transition section constitute a closed grid structure.

[0038] This embodiment connects the existing contraction and convergence section with the main support section through a transition section, thus forming a closed grid structure between the contraction section and the main support section, thereby effectively solving the risk of proliferative tissue easily slipping out of the existing non-closed stent mesh and displacing the proliferative tissue, and solving the technical problem that the traditional stent design may cause the proliferative tissue to slip out of the stent mesh due to the incomplete closure of the mesh structure.

[0039] In addition, existing stents rely on point support and open grid structures to resist tissue pressure. This structure is often difficult to evenly distribute stress during expansion, and is prone to local stress concentration, resulting in poor support effects. The present invention designs a closed three-dimensional grid structure so that the stent forms a continuous support surface when expanded. This closed grid structure evenly distributes the radial pressure of the stent, thereby providing greater support force and playing a more effective expansion role on proliferating tissue. Finally, the design of the transition section provides a buffer area between the contraction section and the main support section of the stent, so that the stent will not suddenly change from a contracted state to a fully expanded state during expansion. Through this gradual expansion method, the expansion process of the stent is smoother and can better fit the shape of the prostate cavity, thereby providing greater support force during expansion.

[0040] In one embodiment of the present invention, the stent body 1 is woven from existing elastic wires such as metal wire raw materials. Specifically, the stent body includes multiple groups of elastic wires, and the multiple groups of elastic wires include at least two elastic wires. The elastic wires have a first braided segment, a first forked segment, a second braided segment and a second forked segment from the proximal end to the distal end. The first braided segments of each group of elastic wires are intertwined to form a proximal support ridge, and the multiple first forked segments of each group of elastic wires are separated from each other, and the distal ends of the first forked segments of the multiple groups of elastic wires are intertwined to form a proximal support frame, and the second braided segments of the multiple groups of elastic wires are intertwined to form a main support ridge, and the second forked segments of the multiple groups of elastic wires are separated from each other, and the second forked segments of the multiple groups of elastic wires are intertwined and merged to form a distal support frame. Please refer to Figure 1 Taking a group of elastic wires in this embodiment as an example, the weaving principle of the elastic wires is explained. The group of elastic wires includes first weaving segments 1311, 1312, first bifurcated segments 1201, 1202, second weaving segments 1111, 1121 and second weaving segments 1151, 1152, wherein the first weaving segments 1311, 1312 are intertwined with each other to form a proximal support ridge 131, and the two first bifurcated segments 1201, 1202 of the group of elastic wires are separated from each other, and the distal ends of the two first bifurcated segments 1201, 1202 are respectively intertwined with the distal ends of adjacent second bifurcated segments of adjacent groups of elastic wires, and the two second weaving segments 1111, 1121 of the group of elastic wires are respectively intertwined with the adjacent second weaving segments of adjacent groups of elastic wires to form main support ridges 111, 112, and the second bifurcated segments 1151, 1152 of the group of elastic wires are intertwined and merged with each other. Thus, the first bifurcated section 1201 and the second bifurcated section 1202 of the elastic wire are interwoven to form a closed support frame structure, and this closed grid structure effectively prevents the proliferative tissue from slipping out of the stent mesh, reducing the risk of tissue displacement. At the same time, the closed grid also helps to maintain the stable positioning of the stent in the prostate, avoiding secondary surgery or other complications caused by stent displacement.

[0041] In some embodiments of the present invention, see Figure 1 The proximal and distal ends of the adjacent main supporting edges have two first bifurcated segments and two second bifurcated segments, respectively. Figure 2, the adjacent main supporting edges, the two first bifurcated segments and the two second bifurcated segments constitute a planar annular frame 100, 101, 102, 103. In some specific embodiments, the annular frame is a polygonal frame or a circular frame. Exemplarily, taking the adjacent main supporting edges 111, 112 as an example, the proximal end thereof has two first bifurcated segments 1201, 1202, the distal end thereof has two second bifurcated segments 1151, 1152, the adjacent main supporting edges 111, 112, the two first bifurcated segments 1201, 1202 and the two second bifurcated segments 1151, 1152 constitute a planar hexagonal frame 100, which constitutes four hexagonal borders 100, 101, 102, 103 as a whole. In this way, the present invention bifurcates and interweaves on different planes with the help of the first bifurcated section and the second bifurcated section of the transition section 12, so that the originally twisted wire can be kept on a plane when expanding, and finally the stent body forms a ring frame structure of multiple planes. Compared with the non-planar twisted frame structure, the planar ring frame can provide a uniform support surface during expansion, ensuring that the stent is uniformly applied in all directions in the prostate cavity, and preventing the stent displacement or tissue slippage caused by uneven local force. The design of the planar ring frame enables the support point of the stent to fit the surface of the prostate hyperplasia tissue more closely, reducing the gap between the stent and the tissue. In this way, the hyperplastic prostate tissue is difficult to slide or break away from the support area of ​​the stent, thereby improving the fixing effect of the stent. The planar ring frame forms a flat support surface when the stent is expanded, which can be accurately positioned around the hyperplastic tissue. Compared with the non-planar frame structure, this flat structure can fit the tissue surface more accurately, reduce the possibility of tissue sliding, especially when the patient moves in the body or performs daily activities, the position of the stent is easier to maintain stability. The design of the planar structure also has a stronger anti-displacement property. Because the ring frame is unfolded in a plane, it provides more uniform support and is less likely to be twisted or deformed by external forces, thereby greatly reducing the risk of stent displacement in the body. Slippage of proliferative tissue or stent displacement may lead to complications such as tissue damage, pain, or further surgical intervention. The stability design of the planar ring frame reduces the presence of these unstable factors, reduces the incidence of postoperative complications, and improves the quality of postoperative recovery for patients.

[0042] The prostate is similar to an inverted triangle or a herringbone (i.e., an inverted "V" shape). Specifically, the prostate is wider at the bottom and narrower at the top. Because of its wide bottom and narrow top characteristics, the shape of the prostate is similar to a "herringbone". In some embodiments of the present invention, please refer to Figure 2, the radial cross-section of the main support section is wide at the bottom and narrow at the top to fit the prostate cavity; preferably a trapezoid or a triangle, so that the wider annular frame of the stent body 1 is supported at the wider bottom of the prostate, which fits the wider bottom structure of the prostate, ensuring that the stent can be stably positioned in the prostate cavity, reducing the risk of stent slippage, and supporting its narrower opposite side at the top of the prostate, so as to avoid excessive expansion of the prostate tissue caused by the excessively large top of the stent body, causing tissue damage. Through reasonable width distribution, the stent can minimize the pressure and stimulation on the prostate and bladder tissue while ensuring the support effect. This makes the stent more friendly in long-term use and reduces the probability of postoperative complications. Specifically, the width of the annular frame is significantly larger than the width of the annular frame.

[0043] In a further embodiment of the present invention, see Figure 1 and Figure 3 , the cross-sectional area of ​​the main support section 11 gradually increases in the direction from the distal end to the proximal end, so that the distal end of the main support section can contact the bladder wall with a smaller cross-sectional area when entering the bladder, ensuring that the stent can be stably positioned at the junction of the prostate C and the bladder A. Due to the smaller cross-sectional area at the distal end, no excessive pressure is applied to the bladder wall in the bladder A, thereby reducing the mechanical stimulation of the bladder A and reducing the risk of bladder spasm or discomfort. Due to the gradual change in the cross-sectional area, the pressure distribution of the stent on the tissue at different locations is more uniform, reducing the risk of excessive compression of local tissues and further improving the biocompatibility of the stent.

[0044] In this embodiment, the stent body 1 includes 4 groups of elastic wires, the 4 groups of elastic wires include two elastic wires, the first braided segments 1311 and 1312 of the two elastic wires of each group of elastic wires are intertwined to form a proximal support edge, the first bifurcated segments 1201 and 1202 of the two elastic wires of each group of elastic wires are Y-shaped, and the bifurcation angle of the first bifurcated segments 1201 and 1202 of one group of elastic wires is greater than the bifurcation angle of the first bifurcated segments 1201 and 1202 of the opposite group of elastic wires, so that, The different settings of the bifurcation angles of the first bifurcation segments 1201 and 1202 form a main support segment with a radial cross-section that is wide at the bottom and narrow at the top, the distal ends of two adjacent first bifurcation segments of adjacent groups of elastic wires are intertwined and merged to form a plurality of support sites, and two second braided segments extending distally from each support site are wound to form a main support edge, and the distal ends of two adjacent second bifurcation segments of adjacent groups of elastic wires are Y-shaped bifurcated from the main support edge, and the distal ends of the two second bifurcation segments 1151 and 1152 of each group of elastic wires are intertwined and merged.

[0045] In some embodiments, the confluence of the two second bifurcated segments 1151 and 1152 of the annular frame forms an arc-shaped protrusion 1150, which can better grasp the surrounding tissues and prevent the stent from slipping due to pressure changes or changes in body position, thereby further ensuring the stability of the stent in the body. In addition, the local thickness and rigidity of the annular frame are increased, thereby enhancing the expansion force of the stent in the prostate cavity.

[0046] Exemplarily, an arc-shaped pressure tongue 14 is provided in the bracket body, the proximal end of which is connected to the bracket base 2, and the other end extends from the annular frame, thereby providing additional expansion support for the bottom edge and preventing the bracket from slipping and falling off.

[0047] See also Figure 3 The method for prostate stent placement and recovery provided in this embodiment is as follows:

[0048] The size of the patient's prostate C is measured using ultrasound or other examination equipment, and the stent specifications are selected based on its size.

[0049] The stent is loaded into the delivery device, which is inserted from the patient's urethral opening B. The delivery position of the delivery device is observed with ultrasonic and other detection equipment. When the delivery device passes through the prostate C and reaches the patient's bladder opening A, the delivery device is fixed and immobilized, and the stent is released as a whole into the patient's bladder A, and then the delivery device is withdrawn backwards. After the delivery device is withdrawn, the stent will expand to its original expansion state by itself. If the stent is not fully expanded, an appropriate amount of 40°C saline can be injected through the delivery device to assist expansion. The delivery device is then pulled out of the patient's urethra, observed with ultrasonic and other detection equipment, and the delivery device is pulled back to push the stent from the bladder to the patient's prostate. When the arc-shaped tongue 14 of the stent body presses against the outer wall of the patient's bladder opening, the distal support frame is still inside the bladder and has not reached the sphincter, the stent is installed. At this time, the transition section 12 and the main support section 11 both support and contact the inner wall of the tissue, and the annular frame with a larger width is placed below the prostate, and the delivery device is taken out of the patient's urethra. Example 2

[0050] See also Figure 4 The structure of this embodiment is basically the same as that of embodiment 1, except that the bracket provided in this embodiment abandons the arc-shaped pressure tongue, and the bracket still has a good supporting effect. For the technical effect, please refer to the description of embodiment 1 and will not be repeated. Example 3

[0051] See also Figure 5The structure of this embodiment is basically the same as that of the embodiment 2, except that the arc-shaped pressing tongue 14 provided in this embodiment includes a base section 40, braided sections 41, 42 and a pressing section 43, wherein the base section 40 is connected to the bracket base, the braided sections 41, 42 are braided and intertwined with the two main supporting edges 113, 114, and the pressing section 43 extends from the annular frame. In this way, the braided sections 41, 42 are braided and intertwined with the two main supporting edges 113, 114, which not only enhances the overall strength and stability of the bracket body, but also reduces the deviation of the bracket body during the positioning process. Example 4

[0052] See also Figure 6 This embodiment is basically the same as the second embodiment, except that the two supporting edges 111 and 112 of one of the annular frames are widened to form widened sections 1110 and 1120, so that they can cover a larger area of ​​the tissue surface, thereby providing a more stable supporting effect. This design enhances the positioning ability of the stent body and prevents the stent from slipping or shifting in the tissue. Example 5

[0053] See also Figure 7 The structure of this embodiment is basically the same as that of embodiment 1. The stent body includes a main support section 11, a transition section 12 and a contraction section 13 from the distal end to the proximal end. The main support section 11 and the transition section 12 expand radially outward compared to the contraction section 13 to support and expand the inner wall of the tissue. The difference is that embodiment 1 includes four main support edges and four proximal support edges, while the main support section provided in this embodiment includes three main support edges and a distal support frame, the transition section includes a proximal support frame, the proximal support frame has a proximal end and a distal end, and the proximal support frame is formed at the proximal ends of the three main support edges; the contraction section includes three proximal support edges, and the function of the transition section refers to the description of embodiment 1, which will not be repeated here. Example 6

[0054] See also Figure 8 The structure of this embodiment is basically the same as that of Embodiment 5, the main difference being that a partial area of ​​one of the main supporting edges defines an annular ring 116, so that the annular ring 116 significantly increases the force-bearing area of ​​the bracket body compared to the main supporting edge to prevent slipping.

[0055] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0056] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A stent suitable for placement in the prostate, the stent comprising a stent body, a stent base and a drawstring, the stent body being a three-dimensional frame structure, characterized in that: The bracket body includes a main support section, a transition section and a contraction section in sequence from the distal end to the proximal end, and the main support section and the transition section expand radially outward compared with the contraction section; the main support section includes a plurality of main support edges and a distal support frame, the plurality of main support edges have a proximal end and a distal end, the plurality of main support edges are arranged circumferentially at intervals and extend from the proximal end to the distal end, and the distal support frame is formed at the distal ends of the plurality of main support edges; the transition section includes a proximal support frame, the proximal support frame has a proximal end and a distal end, and the proximal support frame is formed at the proximal ends of the plurality of main support edges; the contraction section includes a plurality of proximal support edges, the proximal support edges have a proximal end and a distal end, the plurality of proximal support edges are arranged circumferentially at intervals and extend from the proximal end to the distal end, and the proximal ends of the proximal support edges converge on the bracket base, and the proximal support edges are formed at the proximal end of the proximal support frame so that the contraction section and the transition section form a closed grid structure.

2. The bracket according to claim 1, characterized in that: The stent body comprises a plurality of groups of elastic wires, wherein the plurality of groups of elastic wires comprise at least two elastic wires, wherein the elastic wires have a first braided segment, a first forked segment, a second braided segment and a second forked segment from the proximal end to the distal end, wherein the first braided segments of each group of elastic wires are intertwined to form a proximal support ridge, the first forked segments of each group of elastic wires are separated from each other, and the distal ends of the first forked segments of the plurality of groups of elastic wires are intertwined to form a proximal support frame; the second braided segments of the plurality of groups of elastic wires are intertwined to form a main support ridge, the second forked segments of the plurality of groups of elastic wires are separated from each other, and the second forked segments of the plurality of groups of elastic wires are intertwined to form a distal support frame.

3. The bracket according to claim 2, characterized in that: The proximal end and the distal end of the adjacent main supporting edges respectively have two first bifurcated segments and two second bifurcated segments, and the adjacent main supporting edges, the two first bifurcated segments and the two second bifurcated segments form a planar annular frame.

4. The bracket according to claim 3, characterized in that: The annular frame is a polygonal frame or a circular frame.

5. The bracket according to any one of claims 1 to 4, characterized in that: The radial cross section of the main body support section is wide at the bottom and narrow at the top.

6. The bracket according to claim 5, characterized in that: The radial cross section of the main body support section is trapezoidal or triangular.

7. The bracket according to any one of claims 1 to 4, characterized in that: The cross-sectional area of ​​the main body support section gradually increases in a direction from the distal end to the proximal end.

8. The bracket according to claim 3, characterized in that: The confluence of the two second bifurcated sections of the annular frame forms an arc-shaped protrusion.

9. The bracket according to claim 3, characterized in that: An arc-shaped pressing tongue is arranged in the support body, the proximal end of the arc-shaped pressing tongue is connected in the support base, and the other end extends out from the annular frame.

10. The bracket according to claim 9, characterized in that: The arc-shaped pressing tongue comprises a base section, a braiding section, and a pressing section. The base section is connected to the support base, the braiding section is braided and entangled with two main supporting edges, and the pressing section extends from the annular frame.

11. The bracket according to claim 1, characterized in that: A partial area of ​​the main supporting edge defines an annular ring.

12. The bracket according to claim 3, characterized in that: A partial section of at least one annular frame is a widened section.

13. The bracket according to claim 2, characterized in that: The stent body comprises a plurality of groups of elastic wires, each group of elastic wires comprises two elastic wires, the first braided segments of the two elastic wires of each group of elastic wires are intertwined to form a proximal supporting edge, the first bifurcated segments of the two elastic wires of each group of elastic wires are bifurcated in a Y shape, and the bifurcated angle of one group of elastic wires is greater than the bifurcated angle of the elastic wires of the opposite group, and the distal ends of two adjacent first bifurcated segments of adjacent groups of elastic wires are intertwined and merged to form a plurality of supporting sites, and two second braided segments extending distally from each supporting site are intertwined to form a main supporting edge, the distal ends of two adjacent second bifurcated segments of adjacent groups of elastic wires are bifurcated in a Y shape from the main supporting edge, and the distal ends of the two second bifurcated segments of each group of elastic wires are intertwined and merged to form a distal supporting frame.

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