Ureteral stent

Abstract

The utility model belongs to the technical field of medical instruments, and discloses a ureteral stent. The ureteral stent comprises a metal framework, the metal framework is of a spiral spring structure, an elastic thin film is partially or completely attached to the inner side and / or the outer side of the metal framework, the thin film is formed by covering a film when the spiral spring structure is pulled open to generate a gap, and when the spiral spring structure is released and restored to a natural state, the elastic thin film is attached to the metal framework. The thin film is extruded by the rebounded spiral spring structure, and the thin film and the metal framework are encircled to form an impermeable tube cavity. Due to the fact that the elastic thin film is attached to the inner side and / or the outer side of the metal framework, when the metal framework is stretched or compressed, complete impermeability can be kept, no gap is generated at the bending gap of the ureteral stent, ureteral wall tissue proliferative ingrowth is avoided, restenosis of the ureter is effectively avoided, and the ureteral stent has the advantages of being simple in structure and convenient to use. The clinical experience of the patient is greatly improved, and the pain is relieved.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a ureteral stent. Background Technology

[0002] In today's society, urinary system diseases are prevalent. Besides congenital causes, a significant proportion are due to localized ureteral stricture caused by tumors, surgery, or other lesions. Ureteral stricture makes it difficult for urine to travel from the renal pelvis to the bladder, increasing pressure within the renal pelvis and leading to hydronephrosis, which in turn causes a series of complications and other risks.

[0003] Ureteral strictures can be classified as temporary or permanent (incurable). Currently, the clinical treatment for temporary ureteral strictures typically involves inserting a double-J stent. The hollow, supportive double-J stent ensures unobstructed drainage of urine from the narrowed ureter, alleviating hydronephrosis. Once the stricture is relieved, the double-J stent is removed. For permanent ureteral strictures, aside from some cases where ureteral reconstruction is possible (which has a high recurrence rate), there are no good clinical solutions. The common practice remains the insertion of a double-J stent, requiring frequent replacement to maintain patency of the narrowed ureter. However, with the two ends of the double-J stent located in the renal pelvis and bladder respectively, long-term insertion greatly increases the risk of urinary tract infections. Furthermore, frequent stent changes cause significant physical and psychological distress and financial burden for patients.

[0004] For the reasons mentioned above, medical companies worldwide have actively innovated and developed several ureteral stents that can be implanted long-term (ranging from 1 to 3 years, with a maximum of 8 years), achieving good clinical results, such as Memokath. TM 051 Metallic ureteral stents. However, this structure can bend when the ureter is excessively tortuous or when the patient's position changes. At the bend, the spring structure on one side can stretch and create a gap, disrupting the original dense structure. This can lead to proliferative ingrowth of ureteral wall tissue, causing ureteral restenosis and adverse consequences. Therefore, to avoid new stenosis caused by hyperplasia, covered self-expanding metallic stents are used in clinical practice. However, the adhesion of covered stents is reduced, and ureteral stents are prone to displacement. Utility Model Content

[0005] The purpose of this invention is to provide a ureteral stent that addresses the problem of ureteral restenosis caused by the stretching of existing stents at bends in the ureter when the patient's ureter is excessively tortuous or changes in body position. This stretching creates gaps in the stent structure, disrupting the original dense structure and leading to proliferative ingrowth of ureteral wall tissue. The ureteral stent of this invention prevents proliferative ingrowth of ureteral wall tissue at the bends, effectively avoiding ureteral restenosis.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A ureteral stent, comprising:

[0008] A metal skeleton is configured to have a helical spring structure, with a partially or completely elastic film attached to the inner and / or outer sides of the metal skeleton. The film is formed when the helical spring structure is pulled apart to create a gap. When the helical spring structure is released and returns to its natural state, the film is compressed by the rebounding helical spring structure. The film and the metal skeleton together form an impermeable cavity.

[0009] In some possible implementations, the metal frame is provided with a plurality of anti-displacement parts. Before being activated, the anti-displacement parts are configured as dense tubular structures with the same diameter as the metal frame. After being activated, the anti-displacement parts are configured as trumpet-shaped or dumbbell-shaped structures.

[0010] In some possible implementations, one anti-displacement part is provided, located at one end of the metal frame. Before activation, the anti-displacement part is a dense tubular structure with the same diameter as the metal frame; after activation, it becomes a trumpet-shaped structure with a gradually increasing diameter. Alternatively, two anti-displacement parts are provided, located at both ends of the metal frame. Before activation, they are dense tubular structures with the same diameter as the metal frame; after activation, they become trumpet-shaped structures with a gradually increasing diameter. Alternatively, three anti-displacement parts are provided, with two located at both ends of the metal frame and one located in the middle. Before activation, all anti-displacement parts are dense tubular structures with the same diameter as the metal frame; after activation, the anti-displacement parts at both ends become trumpet-shaped structures with a gradually increasing diameter, and the middle anti-displacement part becomes a dumbbell-shaped structure.

[0011] In some possible implementations, the outer diameter of the anti-displacement part is 1.5mm-10mm before activation; after activation, the maximum outer diameter of the anti-displacement part is 5mm-20mm.

[0012] In some possible implementations, the material of the metal skeleton includes any one of NiTi alloy, NiTiNb alloy, NiTiCu alloy, tantalum, platinum, platinum-iridium alloy, chromium-molybdenum alloy, magnesium, magnesium alloy, iron, or stainless steel.

[0013] In some possible implementations, the material of the anti-displacement part includes any one of NiTi alloy, NiTiNb alloy, or NiTiCu alloy.

[0014] In some possible implementations, the film is made of any one of polycarbonate polyurethane, polytetrafluoroethylene, polyester, silicone, polyester or polyurethane.

[0015] In some possible embodiments, the film is coated with a coating material comprising any one of isobutyltriethoxysilane, 3-ureopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, or fluoropropylsilane.

[0016] In some possible implementations, a plurality of developing blocks are provided at both ends of the metal frame; the developing blocks are made of any one of tantalum, platinum, platinum-iridium alloy, gold, silver or stainless steel.

[0017] In some possible implementations, the film portion located between adjacent spirals of the metal skeleton is provided with a tear-resistant line, the tensile strength of which is lower than the tensile strength of the film.

[0018] In some possible implementations, the spacing between adjacent spirals of the metal skeleton is 0mm-5mm; the length of the impermeable lumen is 30mm-300mm.

[0019] The beneficial effects of this utility model are as follows: The ureteral stent provided by this utility model has an elastic membrane attached to the inner and / or outer side of the metal skeleton. The membrane is formed when the helical spring structure is stretched to create a gap. When the helical spring structure is released and returns to its natural state, the membrane is compressed by the rebounding helical spring structure. The membrane and the metal skeleton together form an impermeable lumen. The impermeability can be maintained when the metal skeleton is stretched or compressed. There is no gap at the bending gap of the ureteral stent, and no proliferative ingrowth of ureteral wall tissue will occur, effectively avoiding ureteral restenosis, greatly improving the clinical experience of patients and relieving pain. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the thin film after it is attached to the metal skeleton according to an embodiment of the present invention;

[0021] Figure 2 This is a cross-sectional view of the metal frame provided in this embodiment of the present invention, with one end having an anti-displacement part and the anti-displacement part not being activated;

[0022] Figure 3 This is a cross-sectional view of the metal frame provided in this embodiment of the present invention, wherein one end is provided with an anti-displacement part and the anti-displacement part is activated;

[0023] Figure 4This is a three-dimensional view of the metal frame provided in this embodiment of the present invention, after one end of the frame has an anti-displacement part and the anti-displacement part has been activated;

[0024] Figure 5 This is a cross-sectional view of the metal frame provided in this embodiment of the present invention, with anti-displacement portions provided at both ends and the anti-displacement portions not being activated;

[0025] Figure 6 This is a cross-sectional view of the metal frame provided in this embodiment of the present invention, with anti-displacement portions provided at both ends and the anti-displacement portions activated.

[0026] Figure 7 This is a three-dimensional view of the metal frame provided in this embodiment of the present invention, with anti-displacement parts provided at both ends and the anti-displacement parts activated.

[0027] Figure 8 This is a cross-sectional view of the metal frame provided in this embodiment of the present invention, with anti-displacement portions provided at both ends and in the middle, and the anti-displacement portions not being activated;

[0028] Figure 9 This is a cross-sectional view of the metal frame provided in this embodiment of the present invention, with anti-displacement portions provided at both ends and in the middle, and the anti-displacement portions being activated.

[0029] Figure 10 This is a three-dimensional view of the metal frame provided in this embodiment of the present invention, which has anti-displacement parts at both ends and in the middle, and the anti-displacement parts are activated.

[0030] In the picture:

[0031] 100. Metal frame; 200. Membrane; 300. Anti-displacement part. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0033] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0034] This embodiment provides a ureteral stent designed to address the problem that existing stents, when the ureter is excessively tortuous or the patient's position changes, cause gaps (e.g., gaps of 0mm-5mm) in the stent structure due to stretching, disrupting the original dense structure and leading to proliferative ingrowth of ureteral wall tissue, resulting in ureteral restenosis. The ureteral stent of this embodiment prevents proliferative ingrowth of ureteral wall tissue at the bends, effectively avoiding ureteral restenosis.

[0035] like Figure 1 As shown, the ureteral stent includes a metal frame 100, which is configured to have a helical spring structure. The inner and / or outer sides of the metal frame 100 are partially or completely covered with an elastic membrane 200. The membrane 200 is formed when the helical spring structure is pulled apart to create a gap. When the helical spring structure (outer diameter of 1.5mm-10mm) is released and returns to its natural state, the membrane 200 is compressed by the rebounding helical spring structure. The membrane 200 and the metal frame 100 together form an impermeable lumen.

[0036] The aforementioned ureteral stent features an elastic membrane 200 attached to the inner and / or outer side of a metal skeleton 100. The membrane 200 is formed when a gap is created by the stretching of a helical spring structure. When the helical spring structure is released and returns to its natural state, the membrane 200 is compressed by the rebounding helical spring structure. When the metal skeleton 100 bends, the membrane 200, previously compressed by the helical spring structure, is pulled out, sealing the gap created by the bend. This obstructs tissue ingrowth, and the membrane 200 and the metal skeleton 100 together form an impermeable lumen. The metal skeleton 100 maintains its impermeability when stretched or compressed. Because the pulled-out membrane 200 exists within the gap of the helical spring structure at the bending gap of the ureteral stent, no proliferative ingrowth of ureteral wall tissue occurs, effectively preventing ureteral restenosis and significantly improving the patient's clinical experience and alleviating pain. Furthermore, similar stent designs can also be applied to the treatment of stenosis in other cavities and tubes of the body, not just ureteral stenosis.

[0037] See Figures 2 to 10As shown, the metal skeleton 100 is provided with several anti-displacement portions 300. Before activation, the anti-displacement portions 300 are dense tubular structures with the same diameter as the metal skeleton 100. After activation, the anti-displacement portions 300 become trumpet-shaped or dumbbell-shaped structures. The anti-displacement portions 300 can be inserted into a kidney and / or bladder and into the ureter located between them. This arrangement increases the force between the ureteral stent and the ureteral wall, thereby fixing the ureteral stent at the ureteral stenosis and preventing ureteral stent displacement. The anti-displacement portions 300 can be located at any part of the metal skeleton 100, or multiple parts of the metal skeleton 100 can be located simultaneously. (See attached image) Figures 2 to 10 The image shows several of the most common positions of the anti-displacement unit 300, but does not cover all the possible positions of the anti-displacement unit 300.

[0038] Optionally, such as Figures 2 to 4 As shown, one anti-displacement part 300 is provided, located at one end of the metal frame 100. Before activation, the anti-displacement part 300 is a dense tubular structure with the same diameter as the metal frame 100. After activation, the anti-displacement part 300 is a funnel-shaped structure with a gradually increasing diameter; or, as shown... Figures 5 to 7 As shown, two anti-displacement parts 300 are provided, respectively located at both ends of the metal frame 100. Before activation, the anti-displacement parts 300 are configured as dense tubular structures with the same diameter as the metal frame 100. After activation, the anti-displacement parts 300 are configured as trumpet-shaped structures with gradually increasing diameters; or, as shown... Figures 8 to 10 As shown, three anti-displacement parts 300 are provided. Two anti-displacement parts 300 are respectively located at both ends of the metal frame 100, and the third anti-displacement part 300 is located in the middle of the metal frame 100. Before activation, all anti-displacement parts 300 are configured as dense tubular structures with the same diameter as the metal frame 100. After activation, the anti-displacement parts 300 at both ends are configured as trumpet-shaped structures with gradually increasing diameters, and the anti-displacement part 300 in the middle is configured as a dumbbell-shaped structure. In other embodiments, the anti-displacement parts 300 can be located at any position of the metal frame 100 according to actual needs, and multiple anti-displacement parts 300 can be located at multiple different positions of the metal frame 100. Preferably, before activation, the outer diameter of the anti-displacement part 300 is 1.5mm-10mm; after activation, the maximum outer diameter of the anti-displacement part 300 is 5mm-20mm.

[0039] Optionally, the anti-displacement part 300 is made of shape memory alloy, including any one of NiTi alloy, NiTiNb alloy or NiTiCu alloy, such that the As point of the anti-displacement part 300 is 38℃-50℃, the Af point is 40℃-60℃, and the Mf point is 0℃-30℃.

[0040] After a ureteral stent is implanted into the ureteral stricture site via a ureteral stent delivery system, hot water above its Af point (the end temperature of the austenitic phase transformation when heated) is injected into the anti-migration section 300. This activates the anti-migration section 300, causing it to expand into a gradually increasing diameter trumpet-shaped or dumbbell-shaped structure, thereby fixing the ureteral stent in the ureteral stricture and preventing stent displacement. When removing the ureteral stent, cold water below its Mf point (the end temperature of the martensitic phase transformation when cooled) is injected into the anti-migration section 300. This reduces the strength of the anti-migration section 300, softens it, and stretches it into an almost straight shape, losing its support to the ureteral wall. Then, tools such as foreign body forceps are used to clamp the proximal end of the ureteral stent to pull it out of the ureter and remove it. For re-delivery, the ureteral stent can be delivered to the patient's ureteral stricture site via the delivery system.

[0041] In this embodiment, the metal skeleton 100 is made of any one of NiTi alloy, NiTiNb alloy, NiTiCu alloy, tantalum, platinum, platinum-iridium alloy, chromium-molybdenum alloy, magnesium, magnesium alloy, iron, or stainless steel. All of the above-mentioned materials have good elasticity, which makes it easy for the ureteral stent to conform to the internal conditions of the ureter after it is inserted into the ureter.

[0042] Optionally, the spacing between adjacent spirals of the metal skeleton 100 is 0mm-5mm; the length of the impenetrable lumen is 30mm-300mm.

[0043] Preferably, both ends of the metal skeleton 100 are surrounded by a plurality of imaging blocks (not shown) along the metal wire of the helical spring structure; the imaging blocks are made of any one of tantalum, platinum, platinum-iridium alloy, gold, silver or stainless steel. By setting imaging blocks, doctors can make a diagnosis.

[0044] Optionally, the portion of the membrane 200 located between adjacent spirals of the metal skeleton 100 is provided with an easy-tear line (not shown), the tensile strength of which is lower than that of the membrane 200. This easy-tear line maintains the integrity of the covered portion during the service life of the ureteral stent, ensuring that the entire impermeable lumen prevents proliferative ingrowth of ureteral wall tissue. During ureteral stent removal, the covered portion can be torn apart along the easy-tear line under the pulling action of tools such as foreign body forceps, thereby stretching the entire metal skeleton 100 into an approximately straight shape. Combined with the anti-displacement portion 300, which is also stretched into an approximately straight shape under the action of cold water, the entire ureteral stent can be easily removed from the ureter.

[0045] In this embodiment, the material of the film 200 includes any one of polycarbonate polyurethane, polytetrafluoroethylene, polyester, silicone, polyester, or polyurethane. Preferably, the film 200 is coated with a coating; the coating may be a hydrophilic coating; the material of the coating includes any one of isobutyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, or fluoropropylsilane.

[0046] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A ureteral stent, characterized in that, include: A metal skeleton (100) is configured to have a helical spring structure. The inner and / or outer sides of the metal skeleton (100) are partially or entirely covered with an elastic film (200). The film (200) is formed when the helical spring structure is pulled apart to create a gap. When the helical spring structure is released and returns to its natural state, the film (200) is squeezed by the rebounding helical spring structure. The film (200) and the metal skeleton (100) together form an impermeable cavity.

2. The ureteral stent according to claim 1, characterized in that, The metal frame (100) is provided with a plurality of anti-displacement parts (300). Before being activated, the anti-displacement parts (300) are configured as a dense tubular structure with the same diameter as the metal frame (100). After being activated, the anti-displacement parts (300) are configured as a trumpet-shaped or dumbbell-shaped structure.

3. The ureteral stent according to claim 2, characterized in that, One anti-displacement part (300) is provided, located at one end of the metal frame (100). Before activation, the anti-displacement part (300) is a dense tubular structure with the same diameter as the metal frame (100). After activation, the anti-displacement part (300) is a trumpet-shaped structure with a gradually increasing diameter. Alternatively, two anti-displacement parts (300) are provided, located at opposite ends of the metal frame (100). Before activation, each anti-displacement part (300) is a dense tubular structure with the same diameter as the metal frame (100). When activated, the anti-displacement part (300) is configured as a trumpet-shaped structure with a gradually increasing diameter; or, three anti-displacement parts (300) are provided, two of which are respectively located at both ends of the metal frame (100), and the other is located in the middle of the metal frame (100). Before activation, all the anti-displacement parts (300) are configured as a dense tubular structure with the same diameter as the metal frame (100). After activation, the anti-displacement parts (300) at both ends are configured as trumpet-shaped structures with a gradually increasing diameter, and the anti-displacement part (300) in the middle is configured as a dumbbell-shaped structure.

4. The ureteral stent according to claim 2, characterized in that, Before activation, the outer diameter of the anti-displacement part (300) is 1.5mm-10mm; after activation, the maximum outer diameter of the anti-displacement part (300) is 5mm-20mm.

5. The ureteral stent according to claim 1, characterized in that, The metal skeleton (100) is made of any one of NiTi alloy, NiTiNb alloy, NiTiCu alloy, tantalum, platinum, platinum-iridium alloy, chromium-molybdenum alloy, magnesium, magnesium alloy, iron or stainless steel.

6. The ureteral stent according to claim 2, characterized in that, The anti-displacement part (300) is made of any one of NiTi alloy, NiTiNb alloy or NiTiCu alloy.

7. The ureteral stent according to claim 1, characterized in that, The material of the film (200) includes any one of polycarbonate polyurethane, polytetrafluoroethylene, polyester, silicone, polyester or polyurethane.

8. The ureteral stent according to claim 1, characterized in that, The film (200) is coated with a coating material, which includes any one of isobutyltriethoxysilane, 3-ureopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane or fluoropropylsilane.

9. The ureteral stent according to claim 1, characterized in that, Both ends of the metal frame (100) are provided with a plurality of developing blocks; the developing blocks are made of any one of tantalum, platinum, platinum-iridium alloy, gold, silver or stainless steel.

10. The ureteral stent according to claim 1, characterized in that, The portion of the film (200) located between adjacent spirals of the metal skeleton (100) is provided with a tear line, the tensile strength of which is lower than the tensile strength of the film (200).

11. The ureteral stent according to claim 1, characterized in that, The spacing between adjacent spirals of the metal skeleton (100) is 0mm-5mm; the length of the impermeable cavity is 30mm-300mm.

Images