Suspension-type adaptive prostatic stent

Abstract

A suspension-type adaptive prostatic stent, which belongs to the technical field of medical devices. The prostatic stent can be divided into an upper portion, a middle portion and a lower portion according to the functional structure. The upper portion is a suspension structure (1), which is generally spiral-shaped or inverted cone-shaped; a force-bearing ring that is hollow or solid is provided at the upper opening, and is provided with reinforcing ribs (4) in the ring body; and reinforcing ribs (4) can be provided on the side wall of the upper portion, and several hollow holes can be provided in the junction of the upper edge of the side wall and the force-bearing ring. The lower portion is a prostatic stent main body (3), which is generally tubular or is a spindle-shaped sac having an expanded middle portion, is provided with several transverse bulges on the outer side, and is provided with compression-resistant reinforcing ribs (4) in the wall. The middle portion is a transition connecting structure (2) between the suspension structure (1) and the stent main body (3), and is an ultra-thin soft tubular body provided with several reinforcing ribs on the surface. The whole stent is made of a polymer material or made of a polymer material and a metal material. The stent can be used to relieve dysuria, urinary hesitancy, etc., due to urethral obstruction or stricture caused by prostatic diseases, and can also be used as a carrier of a transurethral transdermal drug delivery system for prostatic diseases.

Description

A suspended adaptive prostate stent Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular, relates to a prostate stent for alleviating pain caused by benign prostatic hyperplasia. Background Art

[0002] Benign prostatic hyperplasia (BPH) is a common disease among middle-aged and elderly men. The incidence rate is 50% to 60% in men over 50 years old, rising by approximately 10% for every decade of age over 60, reaching as high as 90% in those over 80 years old. A direct consequence of BPH is urethral stricture, characterized by frequent urination, urgency, and dysuria, which are extremely painful. Approximately 25% of patients undergo surgical treatment. Besides the trauma, pain, and high medical costs, surgical treatment is also plagued by widespread and daunting side effects. Post-prostatectomy complications include impotence (85% to 90%), complete urinary incontinence (1% to 5%), stress urinary incontinence (5% to 20%), rectal injury (1% to 7%), vesicourethral anastomotic stenosis (2% to 23%), wound infection (2% to 20%), and even death (1% to 5%). Furthermore, as those skilled in the art know, no surgery is perfect. In particular, erectile dysfunction after prostatectomy can worsen the already limited sexual function of middle-aged and elderly patients. Therefore, the use of prostate stents has been considered as a simple, effective, non-invasive, inexpensive, minimally painful, removable, and repeatable solution.

[0003] A prostate stent is a physical device placed in the urethra at the prostate to relieve lower urinary tract symptoms caused by benign prostatic hyperplasia (BPH) and other prostate diseases. It is an alternative to urinary catheterization and is classified as a non-drug, non-surgical treatment for BPH.

[0004] There are two types of prostate stents: temporary and permanent. Temporary stents, also known as non-epithelialized stents, remain outside the urothelial tissue and do not embed into it. Permanent stents, also known as intraprostatic stents, allow the urothelium to grow over the stent, covering its surface and eventually embedding into the prostate tissue. This is what we commonly refer to as "growing into the flesh."

[0005] In 1980, Fabian first introduced the use of metal spiral stents placed in the prostatic urethra to treat lower urinary tract obstruction. After the 1990s, related technologies have emerged in China. In existing public information, prostate stents are mostly metal mesh stents or coated metal mesh stents. However, in any case, they rely on the strong elasticity of the metal material itself to expand, swell, and support the inner wall of the urethra for initial anchoring and positioning. This anchoring method can cause persistent pain, discomfort, or foreign body sensation to patients. In addition, the prostate stent cannot be replaced at will. If it is to be removed, the urethral epithelial tissue must be surgically cut, and a new stent cannot be placed immediately. Covered stents also have many problems such as displacement or even slippage after implantation.

[0006] Prior art Chinese patent application No. 200780019099.8 discloses an anchoring structure using threaded concave-convex patterns on the surface of a stent. However, the reliability of this anchoring structure is seriously questionable, and there is a high risk of slippage and displacement.

[0007] Prior art application No. 200610153278.8 utilizes a fixation frame, but it struggles to maintain balance while in the body and is prone to becoming skewed and stuck at the bladder neck. Furthermore, the fixation frame is connected to the urethral stent by a single thin wire, the lower end of which is connected to one side of the upper opening of the urethral stent. When the bladder sphincter is contracted, this wire cannot remain straight, inevitably exerting persistent pressure, pinching, strangulation, and cutting stress on the bladder sphincter. Over time, the wire can even become embedded in the bladder neck muscle, undoubtedly causing persistent pain, discomfort, or a foreign body sensation to the patient.

[0008] The existing Chinese patent application No. 92239852.6 does not take into account the role of the bladder sphincter. When the stent physically stretches the prostatic urethra, it also stretches the bladder sphincter, leaving only the urethral sphincter to control urine flow, which can easily cause urine leakage or stress urinary incontinence in patients.

[0009] It is precisely because of these problems in the existing technology that a truly commercial product that can be widely used in clinical practice has not yet been developed. Therefore, those skilled in the art deeply need a new prostate stent that can provide a simple, effective, non-invasive, inexpensive, minimally painful, removable, and repeatable method to effectively address the symptoms and pain caused by benign prostatic hyperplasia.

[0010] Summary of the Invention

[0011] The present invention addresses various problems of prostate stents in the prior art and is designed in combination with the safety, convenience, and effectiveness of clinical applications and the feasibility and stability of industrial production, as well as the approval at the medical ethics and national regulatory levels.

[0012] Biosafety is a primary consideration for medical products. The present invention utilizes organic polymer materials with excellent biocompatibility and high safety, or a combination of these materials and metal alloys, resulting in an organic composite. This multi-material design, combining rigidity and flexibility, complements each other perfectly, achieving the desired stent design effect.

[0013] The present invention abandons the need for anchoring structures or elastic expansion support positioning of general stents, and rejects the idea of ​​permanent in-body embedding inside tissues, so as to reduce the patient's pain, discomfort or foreign body sensation.

[0014] Therefore, the overall idea of ​​the present invention is to follow the anatomical characteristics of the urethra, conform to the natural space of the cavity, adopt a suspension structure for positioning, and adapt to the physiological process of bladder sphincter contraction and relaxation without affecting autonomous urination and urine locking functions, and a small-scale stent body to reduce patient discomfort and foreign body sensation. The invention concept makes the product more fit to the tissue, adapt to physiological functions, reduce the patient's postoperative pain, and enhance the patient's compliance and comfort in the body during clinical applications.

[0015] Based on the above ideas, the present invention is divided into three parts according to the functions of the stent: upper, middle and lower. The upper part is the suspension structure, the lower part is the prostate stent body, and the middle part is the transition connection structure between the suspension structure and the stent body.

[0016] The function of the suspension structure is to suspend and position the stent body. When in the body, it is located in the bladder cavity above the internal urethral opening and bears and evenly distributes the weight of the lower stent body itself and the downward flushing force of urine on the stent body during urination, thereby ensuring that the stent body does not shift downward or slip.

[0017] The suspension structure is designed into a spiral or inverted cone shape and is made of flexible materials so that it can be face-to-face embedded with the internal urethral opening and surrounding bladder tissue to reduce local irritation of the bladder neck.

[0018] A load-bearing ring is provided at the upper opening of the suspension structure, and has a certain elasticity. The elasticity of the load-bearing ring allows the suspension structure to fully stretch inside the bladder, and the side wall structure allows the gravity of the lower bracket body and the flushing force of urine during urination to be evenly distributed on the load-bearing ring. The combination of rigidity and flexibility can ensure that the suspension structure is stable when in the body. On the other hand, the load-bearing ring also has a certain degree of flexibility and deformability, which is sufficient to facilitate its insertion into or removal from the body through the external urethra with the help of instruments. The concept of positioning the suspension structure is the key innovative technology of the present invention.

[0019] To ensure the physical properties of the load-bearing ring, reinforcing ribs or elastic members made of other heterogeneous materials can be added. The load-bearing ring can also be hollow or thin-walled tubular. The latter can be injected with liquid or gas before use, creating elasticity and flexibility due to internal pressure.

[0020] The side walls of the spiral or conical body of the suspension structure are soft and weak, with limited physical strength and easy to tear. Reinforcements of other heterogeneous materials can be added therein, or strip or mesh structures can be attached to the surface to enhance its tear resistance.

[0021] To facilitate instrument manipulation during stent placement or removal during clinical use, one or more perforations are provided at the junction of the upper edge of the volute or cone sidewall of the suspension structure and the load-bearing ring. These serve as gripping points for urethral interventional instruments, preventing mechanical forces from tearing or damaging the suspension sidewall. To enhance the tear resistance of the perforations, the edges can be thickened and reinforced, and the overall shape of the perforations can be made as smooth as possible.

[0022] The stent body is the main structure that performs its basic functions such as dilating the urethra and unblocking urine flow. In terms of physical structure, a channel space is indispensable, so the tubular structure is the preferred physical form. Combined with the anatomical characteristics of the intraprostatic urethra, a spindle-shaped sac shape with a large bulge in the middle can also be selected.

[0023] The presence of a suspension structure eliminates the need for anchoring devices within the stent body, significantly simplifying its physical structure. Furthermore, to minimize irritation during implantation and the patient's foreign body sensation after implantation, the stent's physical dimensions need to be minimized while maintaining its functional effectiveness. This represents a game-changing improvement over previous stents that relied on expansion for positioning.

[0024] The outer surface of the stent body can be provided with transverse annular protrusions, distributed axially along the outer surface, either equally or unevenly, giving it an overall bamboo-like appearance. These protrusions prevent the stent body from sliding slightly within the urethra and contribute to anchoring the stent in place, but they are not decisive. The cross-section of these transverse annular protrusions is a smooth, triangular or arcuate shape.

[0025] The supporting force of the stent body wall is the basis for maintaining the patency of the pipeline lumen. In order to enhance the basic supporting function of the stent, while appropriately increasing the wall thickness, reinforcing ribs with appropriate rigidity and elasticity can be added to ensure that the stent body has sufficient and appropriate rigid supporting force.

[0026] The reinforcing ribs in the main tube wall of the stent can be made of organic polymer materials with higher hardness, or metal alloy materials. The reinforcing ribs can be designed as spiral spring tubes with equal or uneven pitch; or they can be a combination of two or more unconnected single rings, axially distributed in the tube wall, with equal or uneven spacing. The spiral spring tube or the single ring combination can be of equal or unequal diameter. The reinforcing ribs can also be designed as mesh tubular bodies with various patterns and plane shapes, and the mesh size and shape can vary with the material and manufacturing process. The reinforcing body can be made of metal or non-metallic materials, but should have a certain degree of softness and moderate rigidity. The design of the reinforcing body itself and the appropriate related parameters are well known in the field of human body stents.

[0027] The transition connection between the suspension structure and the stent body is another key innovative technology of the present invention. It is a structure that connects the suspension structure and the stent body into a whole, with its upper end connected to the lower opening of the suspension structure, and the lower end connected to the upper opening of the stent body. When the stent is placed in the human body, the connection structure is located in the urethra at the bladder sphincter (one of the three narrow parts of the male urethra). Functionally, it can neither interfere with the contraction of the bladder sphincter nor interfere with the relaxation of the bladder sphincter. The contraction and relaxation of the bladder sphincter correspond to the bladder's urine locking function and urination function, respectively. Any factors that may affect the contraction and relaxation of the bladder sphincter may lead to abnormalities in the bladder's urine locking function and urination function.

[0028] In response to this key technology, the present invention adopts the following measures to meet this technical demand. First, ultra-soft materials are selected, and secondly, ultra-thin structures are adopted, and then combined with the physical design of the tubular body, multiple measures are taken to achieve the goal of not affecting the contraction function of the bladder sphincter, nor affecting the relaxation function of the bladder sphincter. Ultimately, the abnormality of the bladder's normal urine locking and autonomous urination functions due to the influence of the stent is avoided. In clinical applications, the risk of urine leakage and urinary incontinence, especially stress urinary incontinence, after the patient uses the stent can be greatly reduced, and this tubular connection can reduce its local stimulation to the bladder sphincter and eliminate the patient's postoperative discomfort.

[0029] Ultra-thin structures based on transitional connections can be reinforced with ribs of homogeneous material on the surface or heterogeneous material in the wall to increase their physical strength without significantly affecting their functionality. The ribs can be in the form of strips, distributed longitudinally, or in a mesh pattern.

[0030] This suspended, adaptive prostate stent, as an integrated whole, combines both rigidity and flexibility. The upper suspension structure conforms tightly to the internal urethral opening and the surrounding bladder wall, significantly reducing pressure and irritation on the internal bladder opening while in the body. The middle structure features an ultra-thin, soft wall with excellent flexibility. In the body, it is located within the narrow urethra sphincter. When the bladder sphincter relaxes spontaneously, the middle structure naturally expands under internal urine pressure, forming a tubular structure. Urine flows through the tube under the pressure of bladder contraction, thus not affecting voluntary urination. After urination, the bladder sphincter contracts, and the tubular structure closes. This effectively addresses the problem of existing technologies that forcefully stretch the prostate urethra while also stretching the bladder sphincter, preventing it from closing and causing urine leakage or even incontinence, particularly stress incontinence. Compared to existing technologies, the lower stent body has a smaller diameter and does not require expansion support and anchoring against the urethral wall, thus avoiding persistent pain, discomfort, and foreign body sensation experienced by the patient while the stent is in the body. Combined with the soft and flexible nature of the stent body, it strives to achieve minimal or no sensation in the body, thereby maximizing patient compliance and comfort.

[0031] Alternatively, the novel stent of the present invention can be further used as a convenient drug carrier. The prostatic urethra's mucosal epithelial cells lack a stratum corneum, allowing for rapid and easy drug transdermal delivery with high penetration rates, making it the closest target for transdermal drug delivery of prostate disease. The prostatic urethra runs through the prostate, allowing drugs to immediately reach the prostate tissue and directly target the lesion after permeating the mucosal epithelial cells, making it one of the most promising topics for transdermal drug delivery in the treatment of prostate disease.

[0032] In summary, the main technical features of the present invention are summarized as follows: (1) the use of a suspension structure to position the stent body, and its upper load-bearing ring and spiral or inverted cone shape are important details for achieving the special effect of the suspension structure; (2) the ultra-thin connection structure in the middle will not affect the normal physiological function of the bladder sphincter; (3) the stent body abandons its anchoring structure and functions in the body at the smallest scale, which can avoid many application sequelae; and (4) as a drug carrier, it provides an effective method for transurethral transdermal drug delivery treatment of prostate diseases. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG1 is a perspective schematic diagram of an embodiment.

[0034] FIG2 is a schematic diagram of a usage state of an embodiment.

[0035] FIG3 is a front view of an embodiment.

[0036] FIG4 is a cross-sectional view along direction D in one embodiment, where axis D is the central axis of the entire prostate stent.

[0037] in:

[0038] 1: Suspension structure; 2: Transition connection structure; 3: Bracket body; 4: Reinforcement ribs. DETAILED DESCRIPTION

[0039] The present invention's suspended adaptive prostate stent is entirely made of a composite of organic polymer materials and metal alloy materials. The organic polymer material is preferably silicone material, and the metal alloy material is preferably titanium alloy or medical stainless steel.

[0040] As shown in Figures 1-4, the described suspended adaptive prostate stent can be divided into three parts according to its structure: the upper part is the suspension structure 1, the lower part is the prostate stent body 3, and the middle part is the transition connection structure 2 between the suspension structure and the stent body.

[0041] The upper suspension structure is generally in a spiral or inverted cone shape, with a spiral shape being preferred; its upper opening diameter is 3-50 mm, optimized to be 5-30 mm; its lower opening diameter is 1-15 mm, optimized to be 3-10 mm; its height is 3-50 mm, optimized to be 8-30 mm; its wall thickness is 0.01-3 mm, optimized to be 0.05-2 mm.

[0042] The upper open edge of the suspension structure has a load-bearing ring with a subcircular, rectangular, or semicircular cross-section, preferably subcircular, and a diameter of 0.5 to 8 mm, preferably 1 to 4 mm. The load-bearing ring can be hollow or solid, preferably solid. The ring may or may not contain reinforcing ribs, which can be made of one or more strands of metal alloy or other materials. Preferably, no reinforcing ribs are present.

[0043] The suspension structure 1 may have reinforcing ribs made of homogeneous or heterogeneous materials on or within the sidewalls of its volute or cone. Preferably, the ribs are provided on the surface and manufactured from the same material. The reinforcing ribs 4 may be strip-shaped or grid-shaped, preferably strip-shaped, with one or more ribs arranged longitudinally on the inner surface of the suspension structure. The upper ends of the ribs connect to the lower edge of the load-bearing ring, and the lower ends of the ribs connect to the lower opening of the suspension structure.

[0044] Furthermore, the cross section of the reinforcing rib is triangular, with a width and height of 0.1 to 0.8 mm, preferably 0.2 to 0.5 mm.

[0045] The suspension structure 1 has one or more equally or unevenly spaced perforations at the junction of the load-bearing ring and the sidewall of the vortex or cone, i.e., on the sidewall of the vortex or cone at the lower edge of the load-bearing ring. The perforations are preferably 1 to 4, symmetrically distributed. The perforations are semicircular or inverted triangular in shape, with a width and height of 0.5 to 5 mm, preferably an inverted triangular shape, with a width and height of 2 to 4 mm. The edges of the perforations may be appropriately thickened.

[0046] The suspended adaptive prostate stent has a cylindrical tubular lower portion or a fusiform sac-like structure with a swollen middle portion, preferably a cylindrical tubular structure. The tubular body is open at both ends. The inner diameter of the tubular body is 2 to 15 mm, preferably 3 to 8 mm; the wall thickness is 0.1 to 4 mm, preferably 0.2 to 2 mm; and the length is 10 to 100 mm, preferably 2 to 80 mm.

[0047] Furthermore, the outer surface of the lower support body 3 has a plurality of transverse annular protrusions, each of which has an arcuate cross section, a width of 1 to 5 mm, preferably 2 to 3 mm, and a height of 0.1 to 2 mm, preferably 0.2 to 1 mm.

[0048] Furthermore, the tube wall of the lower stent body 3 includes reinforcing ribs. These ribs are in the form of a helical spring tube, various patterns and mesh shapes, or a combination of two or more unconnected single rings. Preferably, they are in the form of a helical spring tube, with equal or uneven pitch, preferably equal pitch, ranging from 0.1 to 4 mm, preferably 0.2 to 3 mm, and distributed axially within the tube wall. The presence of the reinforcing ribs helps to overcome external pressure and maintain a patency of the stent body's lumen. The design and parameters of these ribs can be routinely adjusted by those skilled in the art based on the requirements and specific embodiments of the present invention.

[0049] The transition connection structure 2 of the described suspended adaptive prostate stent is a transition connection between the suspension structure and the stent body, and is tubular; the upper end is connected to the lower end of the suspension structure 1, and the lower end is connected to the upper end of the stent body 3; the length is 2 to 30 mm, optimized to be 5 to 20 mm; the wall thickness is 0.02 to 2 mm, optimized to be 0.05 to 1 mm. The design and parameters of the middle transition connection structure 2 can be routinely adjusted by those skilled in the art according to the requirements and specific embodiments of the present invention. The general principle is that its structure should be easily affected by the bladder sphincter and placed in an occluded state. At the same time, when the bladder sphincter is released, it is easy for the internal liquid pressure and its own elasticity to make the internal cavity present a dilated state.

[0050] Furthermore, the connection structure between the suspension structure 1 and the support body 3 may be provided with strip-shaped or grid-shaped reinforcement ribs. Preferably, the strip-shaped reinforcement ribs are one or more, arranged longitudinally, and located on the inner surface of the tubular body of the transition connection structure 2. The upper end of the reinforcement ribs seamlessly connects with the inner surface of the side wall of the suspension structure 1, and the lower end is connected to the upper end of the support body 3.

[0051] Example 1

[0052] design

[0053] The suspended adaptive prostate stent of this embodiment is entirely made of a composite of organic polymer material and metal alloy material, wherein the organic polymer material is silicone material and the metal alloy material is medical stainless steel.

[0054] The suspended adaptive prostate stent of this embodiment has an upper suspension structure 1 in a spiral shape, with an upper opening outer diameter of 25 mm, a lower opening inner diameter of 5 mm, a height of 13 mm, and a wall thickness of 0.3 mm.

[0055] Furthermore, a bearing ring is installed at the upper edge of the upper suspension structure. The cross-section of the bearing ring is circular, with a diameter of 2.5mm. Three reinforcing ribs are installed on the sidewalls of the spiral body. They are arranged equidistantly in the longitudinal direction and located on the inner surface of the suspension structure. The upper end connects to the lower edge of the bearing ring, and the lower end directly reaches the upper edge of the bracket body, terminating in the middle of the first transverse annular protrusion on the outer surface of the corresponding bracket body. The cross-section of the reinforcing rib is triangular, with a height of 0.2mm and a base width of 0.4mm.

[0056] The suspended adaptive prostate stent of this embodiment has a lower stent body 3 that is a cylindrical tubular structure with open ends; the tube body is 46.5 mm long, 5 mm in inner diameter, and 0.5 mm in wall thickness.

[0057] Furthermore, five transverse annular protrusions are provided on the outer surface of the lower support body 3. The protrusions have an arched cross-section, with a chord width of 3mm and a chord height of 0.5mm. Reinforcement ribs are provided in the wall of the support body 3, resembling a spiral spring tube.

[0058] In this embodiment of the suspended adaptive prostate stent, the central structure 2 serves as a transitional connection between the upper suspension structure and the lower stent body. It is tubular, with its upper end connected to the lower opening of the suspension structure and its lower end to the upper opening of the stent body. It is 12 mm long, has an inner diameter of 5 mm, and a wall thickness of 0.2 mm. Its inner surface is longitudinally penetrated by reinforcing ribs 4 originating from the suspension structure.

[0059] Production process

[0060] Equipment and Materials

[0061] Mould: Made of aluminum alloy material and commissioned by a specialized CNC company for precision processing.

[0062] Silicone rubber: Momentive-Silopren LSR 2003 liquid silicone rubber is used, and its quality meets the requirements of ISO 10993 and USP Class VI.

[0063] Stainless steel coil spring tube: 42.5mm long, 5.2mm inner diameter. Made of SUS316LVM stainless steel wire, 0.2286mm diameter. 0.75mm pitch. Manufactured by a specialized industrial spring manufacturer.

[0064] White Vaseline: complies with the provisions of the "Chinese Pharmacopoeia" (2020 edition).

[0065] Medical syringes: comply with relevant laws and regulations.

[0066] Process

[0067] The suspended adaptive prostate stent of this embodiment is manufactured by an injection molding process and a one-step integral molding method in a mold.

[0068] The stainless steel coil spring tube was cleaned with household kitchen detergent, rinsed with tap water until there was no foam, finally rinsed with deionized water, and dried at 150°C for 30 min.

[0069] Open the mold, clean the inner surface, and wipe it with white vaseline as a release agent, insert the spiral spring tube, buckle the mold, and clamp it for use.

[0070] Weigh equal amounts of liquid silicone rubber A and B in a 1:1 ratio, stir thoroughly, and vacuum degas. Use a syringe to draw an appropriate amount, eliminating any bubbles, and slowly inject into the mold until a small amount of silicone flows out of the overflow port. Cure at 180°C for 3 minutes. Demold and finish.

[0071] Example 2

[0072] This second embodiment of the invention is a suspended adaptive prostate stent, similar to the first embodiment. Its upper suspension structure 1 has an outer diameter of 28 mm at its upper opening and an inner diameter of 5.5 mm at its lower opening. The cross-sectional diameter of the load-bearing ring is 3 mm. The suspension structure 1 is provided with four perforations, each with four corresponding reinforcing ribs 4.

[0073] The lower bracket body of the second embodiment is 55mm long and 5.5mm in inner diameter, with 6 transverse annular protrusions on the outer surface. The inner wall spiral spring tube is 51mm long and 5.7mm in inner diameter;

[0074] In the suspended adaptive prostate stent of this embodiment, the tubular body of the middle transition connection structure 2 is 14 mm long and has an inner diameter of 5.5 mm.

[0075] Clinical use

[0076] The suspended adaptive prostate stent is pressed into a special catheter, which is then delivered to the internal opening of the bladder through the external urethra. The catheter is withdrawn and the stent is released into the prostate at the same time. The position and posture of the stent are checked under cystoendoscopy for appropriateness, and can be adjusted to a suitable position with foreign body forceps.

[0077] The stent can also be removed from the body using a cystoscope and special foreign body forceps. During the operation, the cystoscope is inserted into the urethra and passed through the inner cavity of the stent body to enter the bladder opening. Operate the cystoscope and special foreign body forceps, clamp the support ring of the suspension structure with the forceps mouth, and slowly pull the support ring so that one side of the suspension structure 1 is pulled toward the bladder opening. Since the entire suspension structure 1 is soft, the support ring and the entire suspension structure are folded at this time. Slowly withdraw the cystoscope, and the folded and deformed support ring and the entire suspension structure can enter the urethra through the bladder opening under the traction of the foreign body forceps. When reaching the upper end of the stent body, since the spatial size of the folded support ring is larger than the inner cavity of the stent body, the folded support ring cannot enter the inner cavity of the stent body; as the cystoscope is withdrawn, the pulling force of the foreign body forceps on the support ring will drive the stent body to slide down along the urethra. Until the cystoscope is completely withdrawn, the entire prostate stent is removed.

[0078] Beneficial effects:

[0079] 1. About the suspension structure

[0080] In the existing public information, prostate stents mostly rely on their own strong radial elastic expansion and expansion support to the inner wall of the urethra for initial anchoring and positioning. This anchoring method can cause bleeding, persistent pain, irritation, discomfort or foreign body sensation to patients. In addition, metal stents cannot be replaced at will due to the growth and embedding of epithelial cells. If they are to be removed, the urethral epithelial tissue must be surgically incised, and a new stent cannot be placed immediately. Covered stents may be displaced or even slipped after implantation. Long-term compression of the stent may also cause ischemia and necrosis of tissue around the urethra or even part of the prostate.

[0081] To overcome these issues, the present invention abandons the concept of elastic expansion support positioning. Based on the anatomical characteristics of the male urethra and the natural space of the cavity, a suspension structure is adopted for positioning. This significantly reduces the physical dimensions of the stent body, thereby reducing or eliminating the pain, discomfort, or foreign body sensation after stent placement. The suspension structure 1 is embedded in the internal urethral opening and the bladder cavity above it, absorbing and evenly distributing the weight of the lower stent body 3 and the downward flushing force of urine during urination, thereby ensuring that the stent body does not shift downward or slip.

[0082] Suspension structure 1 is shaped like a spiral or inverted triangle and is made of flexible material, allowing it to interlock face-to-face with the internal urethral opening and surrounding bladder tissue to reduce local irritation at the bladder neck. The elastic support ring of suspension structure 1 allows it to fully expand within the bladder. This combination of rigidity and flexibility ensures the stability of suspension structure 1 while in the body. Furthermore, the elastic support ring also possesses a certain degree of flexibility, making it easy to insert and remove it through the external urethra using instruments.

[0083] 2. About the Adaptive Structure of the Bladder Sphincter

[0084] The voluntary urination process in normal men is controlled by two barriers: the upper sphincter, the bladder sphincter, and the lower sphincter, the urethral sphincter. Under normal physiological conditions, both the upper and lower sphincters are contracted, completely locking urine in the bladder. Only during urination do the upper and lower sphincters relax simultaneously under conscious control, fully opening both gates of the urethra. Simultaneously, the detrusor muscle contracts, allowing urine to pass through the urethra and out of the body under the pressure of the contraction of the detrusor muscle. After urination, the detrusor muscle relaxes, and the upper and lower urethral sphincters simultaneously resume their contraction. Therefore, under normal circumstances, urine in the bladder does not involuntarily flow out of the body through the urethra. However, when the urethral sphincter or one of its sphincters is incompletely contracted due to external forces such as medical devices, surgical injury such as prostatectomy, or certain diseases, urinary incontinence, leakage, or stress urinary incontinence can occur.

[0085] The bladder sphincter is the first barrier of the human body to lock bladder urine. When a patient is implanted with a stent or device that does not have an adaptive bladder sphincter, the bladder sphincter and its internal urethral opening are mechanically stretched open by the physical action of the stent or device, so that the "gate" between the bladder and the prostatic urethra, namely the internal urethral opening, is forcibly opened. The basic physiological function of the bladder sphincter is released, and the first barrier to lock urine is also lost. Therefore, the "burden" of the human body to control urine falls entirely on the urethral sphincter. Due to the loss of a "gate", the human body's autonomous urine locking function will be greatly reduced, so clinically it may manifest as postoperative pathological symptoms such as urinary incontinence, urinary incontinence, and especially stress urinary incontinence.

[0086] The present invention provides a thin-walled, soft and elastic tubular connecting structure between the prostate stent main body and the accessory device at the position corresponding to the bladder sphincter, so that it can adapt to the relaxation and contraction function of the bladder sphincter and open and close accordingly with the opening and closing of the internal urethral opening. This is undoubtedly the most effective measure to preserve the patient's normal physiological urine locking function and avoid adverse reactions such as urine leakage or urinary incontinence after the use of an inappropriate stent.

[0087] The present invention is consistent with the anatomical characteristics of the human body cavity, and can fully avoid affecting the patient's bladder sphincter function, thereby avoiding adverse consequences caused by stent implantation.

[0088] 3. About the bracket body 3

[0089] The suspension structure enables the small-scale construction of the stent body. However, while this design eliminates the support pain associated with a large stent, its small size can cause the stent body to slide slightly longitudinally within the prostate under the influence of minor external forces, such as levator anus movements. To eliminate this potential risk, the present invention incorporates a raised transverse annular structure on the outer surface of the stent body. This prevents the stent body from sliding slightly longitudinally within the prostate while also providing a synergistic effect on its overall anchoring and positioning.

[0090] 4. As a drug carrier

[0091] Topical transdermal drug delivery has many advantages, such as no first-pass effect, small dosage, high drug concentration in the tissue at the administration site, no systemic effect, small toxic and side effects, high clinical efficacy, and good patient compliance.

[0092] 5. Clinical trial results

[0093] The trial was conducted on 4 patients, and the results were as follows:

[0094] The above theoretical explanations and embodiments describe and point out the fundamental novel features of the application of the present invention, but it should be understood that those skilled in the art may make various omissions, substitutions, and changes to the form and details of the illustrated embodiments without departing from the spirit of the present invention. The present invention is not bound by the above theoretical explanations, nor is it limited to the above-mentioned embodiments which are merely examples, but can be modified in various ways within the scope of protection defined by the attached patent claims. It should also be understood that the present invention can be practiced even without reference to the specific embodiments shown, because the essence of the present invention lies not in the technical difficulty or complexity, but in the novel concept itself. Once the concept described in the claims is known, its practice falls within the ordinary skill of the art.

Claims

1. A suspended adaptive prostate stent, characterized in that: The overall shape of the tubular body is an inverted trumpet, with openings at both ends and an unobstructed lumen, and includes three parts: upper, middle and lower. The upper part is a suspension structure, which has an upper opening and a lower opening, and the diameter of the upper opening is at least twice the diameter of the lower opening. The lower part is a prostate stent body, which has an upper opening and a lower opening. The middle part is a transition connection structure connecting the suspension structure and the stent body, which has an upper opening and a lower opening. The upper opening of the transition connection structure is connected to the lower opening of the suspension structure, and the lower opening of the transition connection structure is connected to the upper opening of the stent body.

2. The prostate stent according to claim 1, characterized in that: The suspension structure is in a spiral or inverted cone shape, with an upper opening diameter of 3 to 50 mm, a lower opening diameter of 1 to 15 mm, and a height of 3 to 50 mm.

3. The prostate stent according to claim 1, characterized in that: The upper opening edge of the suspension structure is provided with a load-bearing ring, the cross section of which is quasi-circular, quasi-rectangular, elliptical or semicircular, and can be solid or hollow, and the outer diameter of the load-bearing ring is 0.5-8 mm.

4. The prostate stent according to claim 3, characterized in that: The load-bearing ring is provided with reinforcing ribs, which can be made of metal or other materials, and whose physical properties can be soft or have certain elastic properties.

5. The prostate stent according to claim 2, characterized in that: The wall thickness of the suspension structure is 0.05-3 mm, and reinforcing ribs made of homogeneous or heterogeneous materials can be arranged on the surface or in the wall.

6. The prostate stent according to claim 5, characterized in that: A plurality of holes are arranged at the junction between the upper edge of the wall of the suspension structure and the load-bearing ring. The holes are triangular or semicircular in shape, with a width, height or diameter of 0.5 to 5 mm respectively. The edges of the holes can be thickened and strengthened.

7. The prostate stent according to claim 1, characterized in that: The stent body is tubular or spindle-shaped with a swollen middle part and open at both ends; the inner diameter of the tube or the cavity is 2-15mm; the wall thickness is 0.1-4mm, and the length is 10-100mm.

8. The prostate stent according to claim 1, characterized in that: The outer surface of the support body is provided with a plurality of transverse annular protrusions distributed axially.

9. The prostate stent according to claim 7, characterized in that: Wherein, compression-resistant reinforcing ribs are arranged inside the tube wall or the capsule wall of the stent body.

10. The prostate stent according to claim 9, characterized in that: The compressive reinforcement ribs may be spiral spring-like tubular bodies with equal or uneven pitches; or may be a combination of two or more unconnected single rings, axially distributed in the tube wall or bladder wall with equal or unequal diameters and uniform or unequal distances; the compressive reinforcement ribs may also be mesh tubular bodies; the compressive reinforcement ribs may be made of metal materials or non-metal materials.

11. The prostate stent according to claim 1, characterized in that: The transition connection structure is tubular, with a length of 2 to 30 mm and a wall thickness of 0.02 to 2 mm.

12. The prostate stent according to claim 1, characterized in that: Reinforcing ribs made of homogeneous or heterogeneous materials may be arranged on the surface or wall of the transition connection structure.

13. The prostate stent according to claim 1 is made of organic polymer material, or a composite of organic polymer material and metal material.

14. Use of the prostate stent according to claim 1 for urinary catheterization of patients with prostate diseases.

15. Use of the prostate stent according to claim 1 as a carrier in a transurethral transdermal drug delivery system for prostate diseases.

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