Medicinal balloon catheter for benign prostatic hyperplasia

Abstract

The application relates to the technical field of balloon catheters, and discloses a drug balloon catheter for treating benign prostatic hyperplasia, which comprises an external catheter rod, a guide wire and a drug balloon base arranged outside the guide wire. A concave assembly is arranged on the outer wall of the drug balloon base. The concave assembly comprises a plurality of accommodation cavities arranged on the surface of the drug balloon base. Each accommodation cavity is recessed towards the inner side of the drug balloon base. A contact protruding component is fixedly connected to the inner wall of each accommodation cavity. The concave assembly is arranged on the outer wall of the drug balloon base. The height matching structure of the accommodation cavities and the contact protruding components realizes the protection effect of hiding the components in the deflated state, helps to completely avoid the disadvantages of traditional drug balloon coating exposure delivery, effectively improves the problems of drug coating rubbing and scratching the urethral mucosa and early shedding and loss during the catheter intervention delivery process, and greatly improves the drug effective retention rate and the drug stability.

Description

Technical Field

[0001] This invention relates to the field of balloon catheter technology, specifically to a drug-eluting balloon catheter for the treatment of benign prostatic hyperplasia. Background Technology

[0002] This invention relates to the field of medical device technology, specifically to a drug-eluting balloon catheter for the treatment of benign prostatic hyperplasia (BPH). BPH is the most common degenerative urinary system disease in middle-aged and elderly men. Its incidence increases with age, easily leading to lower urinary tract symptoms such as urethral stricture, difficulty urinating, urinary frequency, and urgency, severely impacting patients' quality of life.

[0003] Traditional clinical treatment methods are mainly divided into two categories: long-term oral medication conservative treatment and surgical resection treatment. Among them, drug conservative treatment has a long cycle, obvious side effects, and is prone to recurrence after discontinuation of medication; while traditional surgical procedures such as electrocautery and laser enucleation are highly invasive, have a long postoperative recovery period, and carry the risk of complications such as bleeding, urethral injury, and sexual dysfunction.

[0004] In recent years, drug-coated balloon interventional therapy has gradually become the mainstream minimally invasive treatment for benign prostatic hyperplasia due to its advantages such as being minimally invasive, having a fast recovery time, being repeatable, and not requiring the implantation of foreign bodies. This technique involves the drug coating on the surface of the balloon contacting the hyperplastic lesion tissue to achieve local drug delivery to inhibit glandular hyperplasia and relieve tissue edema. It can improve urethral obstruction symptoms while preserving the patient's normal physiological functions. It has high clinical applicability and safety and has broad application prospects.

[0005] However, existing drug-eluting balloon catheters for the treatment of benign prostatic hyperplasia still have many significant drawbacks in actual clinical applications, which greatly limit the treatment effect and applicable scenarios.

[0006] First, in traditional drug-eluting balloons, the drug coating is directly exposed on the surface of the balloon base. During the catheter's delivery through the urethral cavity, the exposed drug coating will continuously rub and scratch against the urethral mucosa and cavity folds, causing a large amount of drug to fall off and be lost prematurely. The effective drug retention rate is low, which ultimately leads to insufficient drug dosage at the lesion site and poor long-term treatment effect.

[0007] Secondly, traditional drug-eluting balloons rely solely on overall balloon expansion for passive drug delivery. This limited balloon expansion and deformation results in poor fit to uneven or severely bulging benign prostatic hyperplasia lesions, failing to create effective compression contact with the hyperplastic areas. Consequently, drug adhesion is uneven, penetration depth is insufficient, and targeted therapy efficacy is poor. More critically, existing drug-eluting balloons employ a single solid-coating passive drug release mode. During balloon expansion and application, the drug is easily scraped away by the hyperplastic tissue, leading to significant drug attenuation in the core contact area of ​​the lesion. This makes it difficult to achieve high-concentration, precise drug delivery. Furthermore, this single-mode delivery cannot simultaneously achieve both uniform basic drug delivery and enhanced local therapy, significantly limiting its effectiveness in treating severe bulging benign prostatic hyperplasia.

[0008] In addition, conventional balloon structures have poor controllability of deformation, limited expansion range, and insufficient flexible fit, making them prone to drug delivery blind spots. Overall, they have low drug utilization and poor treatment stability, making it difficult to meet the current clinical treatment needs for refinement, differentiation, and high efficacy.

[0009] Therefore, this invention proposes a drug-eluting balloon catheter for the treatment of benign prostatic hyperplasia. Summary of the Invention

[0010] The purpose of this invention is to provide a drug-eluting balloon catheter for the treatment of benign prostatic hyperplasia, in order to solve the problems mentioned in the background art.

[0011] To achieve the above objectives, the present invention provides the following technical solution: a drug-eluting balloon catheter for the treatment of benign prostatic hyperplasia, comprising an external catheter rod, a guide wire, and a drug-eluting balloon base sleeved on the outside of the guide wire. The outer wall of the drug-eluting balloon base is provided with a recessed assembly, which includes a plurality of receiving cavities formed on the surface of the drug-eluting balloon base. Each receiving cavity is recessed towards the inner side of the drug-eluting balloon base. A contact protrusion is fixedly connected to the inner wall of each receiving cavity, and the protrusion height of the contact protrusion is less than that of the receiving cavity. The drug-eluting balloon base has a depth of indentation. The outer surface of the balloon base, the wall surface of the cavity, and the outer surface of the contact protrusion are all coated with a drug for treating benign prostatic hyperplasia. The balloon base can be pressurized to allow an expansion medium to be introduced. When the balloon base is deflated, the contact protrusion is housed within the cavity. When the balloon base is inflated, the cavity deforms with the balloon base, causing the contact protrusion to extend outward and contact the prostatic hyperplasia lesion tissue.

[0012] Preferably, the receiving cavity is an elongated groove extending along the axial direction of the drug capsule base, and the contact protrusion is a strip-shaped protrusion adapted to the elongated groove.

[0013] Preferably, after the drug-eluting balloon substrate is pressurized and expanded, the elongated groove is stretched and flattened to be flush with the outer surface of the drug-eluting balloon substrate, and the strip-shaped contact protrusion protrudes from the substrate surface.

[0014] Preferably, the receiving cavity is a V-shaped groove structure. During the inflation and expansion of the drug capsule matrix, the V-shaped receiving cavity can be rotated and deformed outward as a whole, so that the receiving cavity together with the internal contact protrusions protrudes outward.

[0015] Preferably, the V-shaped groove includes symmetrically arranged V-shaped receiving sidewalls, and a stress-reducing crease area is provided at the junction of the two V-shaped receiving sidewalls. The stress-reducing crease area adopts a locally thinned rounded corner structure to form a deformation inflection point, so that the V-shaped receiving sidewall can smoothly bend outward along the stress-reducing crease area, realizing the overall outward bulging action of the groove.

[0016] Preferably, the receiving cavity is a spherical cavity, and the contact protrusion is a spherical protrusion that is adapted to the spherical cavity.

[0017] Preferably, a pressure-rupture-type drug-storage microcapsule is fixedly connected to the side of the contact protrusion away from the receiving cavity. The pressure-rupture-type drug-storage microcapsule is made of a pressure-ruptureable polymer film material and contains a liquid drug for treating benign prostatic hyperplasia. When the contact protrusion is subjected to the compressive load of the lesion tissue, the pressure-rupture-type drug-storage microcapsule ruptures under pressure, releasing the internal liquid drug.

[0018] Preferably, a plurality of drug-guiding protrusions are fixedly connected to the outer surface of the contact protrusion member. When the pressure-induced rupture drug storage microcapsule ruptures and releases liquid drug, the drug-guiding protrusions guide and disperse the liquid drug, so that the drug is applied to the surface of the prostate lesion tissue.

[0019] Preferably, the receiving cavity and the drug balloon base are integrally formed, and the plurality of the recess assemblies are evenly spaced along the circumference of the drug balloon base. The outer contour of the contact protrusion member is higher than the outer circular surface of the drug balloon base after expansion, and the top of the contact protrusion member is provided with an arc transition surface.

[0020] Preferably, the contact protrusion is fixed to the inner wall of the receiving cavity by adhesive bonding or thermal fusion.

[0021] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention, by setting a recessed assembly on the outer wall of the drug-eluting balloon base, utilizes the highly coordinated structure of the receiving cavity and the contact protrusion to achieve a protective effect of the entire component being concealed within the balloon in the collapsed state. This helps to completely avoid the drawbacks of traditional drug-eluting balloons with exposed coatings during delivery, effectively improving the problems of friction and scratching between the drug coating and the urethral mucosa and premature shedding and loss during catheter-assisted delivery. It significantly improves the effective drug retention rate and drug delivery stability. Traditional drug-eluting balloons have the drug-loaded coating exposed throughout the entire process, resulting in significant loss during urethral passage and insufficient effective drug quantity reaching the lesion, affecting the treatment effect. This invention, relying on the concave receiving structure, effectively shields and protects the entire drug coating during the balloon's collapsed delivery stage, reducing drug loss from the structural source, ensuring sufficient basic drug quantity for lesion delivery, and stably achieving uniform drug delivery throughout the lesion, significantly improving drug utilization efficiency, and effectively solving the defects of uncontrollable drug delivery and excessive early loss in existing technologies.

[0022] 2. This invention, by setting a deformable elongated cavity structure, achieves a layered deformation effect where the groove flattens and the protrusions are exposed individually after balloon expansion. This helps to retain the basic drug delivery function of traditional balloons while adding a targeted protrusion adhesion structure, effectively improving the problems of traditional balloons that rely solely on overall expansion, have weak adhesion, and insufficient contact. It improves the tightness of drug adhesion and the depth of drug penetration on the surface of hyperplastic tissue. Conventional drug balloons have a flat surface after expansion, which is poorly adapted to uneven benign prostatic hyperplasia lesions and easily forms drug delivery blind spots, making it impossible to achieve targeted pressure drug delivery. After balloon expansion, this structure restores the flatness of the base area to achieve basic drug delivery, and the protruding components precisely abut against the hyperplastic protrusions. Through flexible micro-compression, the local drug adhesion effect is enhanced, taking into account both uniform drug delivery throughout the entire area and local targeted enhanced drug delivery, which greatly improves the overall treatment uniformity and treatment precision of ordinary hyperplastic lesions.

[0023] 3. This invention utilizes a V-shaped convex cavity with a stress-reducing crease area to achieve an active outward deformation function of the contact protrusion. Compared to a passive flattening structure, it has a larger protrusion stroke and deformation range, which helps to enhance the compression contact ability for lesions with uneven and irregular shapes. It effectively improves the problems of limited protrusion range, insufficient adhesion pressure, and low local drug dosage of traditional balloons, and increases the drug deposition and adhesion coverage in areas of severe hyperplasia. The V-shaped flipping structure relies on the thinned rounded corner crease to form a stable deformation inflection point, which can achieve smooth outward flipping. Compared to a single stretching and flattening structure, it can actively form a flexible pressure against the hyperplastic protrusion tissue, further compressing the tissue gap and promoting drug penetration. It significantly improves the adaptability of complex lesion shapes, effectively makes up for the technical shortcomings of poor adaptability and shallow drug delivery of straight structures, and significantly broadens the clinical application scope of the device.

[0024] 4. This invention utilizes a closed-loop active drug release structure with a spherical receiving cavity and pressure-triggered drug-releasing microcapsules to achieve pressure-triggered, targeted drug release. This helps to completely overcome the drawbacks of traditional passive coating-based drug release methods, such as easy wear and tear, easy detachment, and rapid drug decay. It effectively improves the problems of insufficient drug dosage and weak efficacy in the core contact area of ​​the lesion, increasing the local drug concentration and targeted therapeutic effect in severe protruding benign prostatic hyperplasia. During delivery and expansion, the liquid drug is stored in a completely sealed manner, preventing premature leakage and frictional loss. Drug release only occurs when the protruding component presses against the lesion to reach the preset pressure, achieving precise drug release based on pressure. Combined with the uniform dispersion effect of the drug-guiding protrusions, the liquid drug can quickly and evenly infiltrate the hyperplastic tissue, forming an instantaneous high-concentration drug delivery effect, significantly improving local drug penetration and lesion ablation.

[0025] 5. This invention achieves optimized combination of structural stability, drug delivery uniformity, and multiple drug delivery modes through an integrally molded matrix structure, a circumferentially uniformly arranged concave assembly, and a solid-liquid dual-layer drug delivery system. This helps to balance minimally invasive safety, structural stability, and stepwise treatment effects, effectively improving the problems of unstable deformation, single drug delivery mode, and poor adaptability of traditional drug balloon structures. It enhances the overall safety, stability, and clinical efficacy of treatment. The integrally molded receiving cavity has good synchronous deformation, and the contact protrusions fixed by adhesion or thermal fusion ensure that it does not fall off or fail under repeated deformation. The circumferentially uniformly arranged multiple sets of concave assemblies ensure uniform drug delivery to circumferential hyperplastic tissue of the urethra, eliminating treatment dead zones. The dual-layer system of long-acting solid coating drug delivery combined with instantaneous enhanced liquid drug delivery can adapt to different hyperplasia symptoms of mild, moderate, and severe hyperplasia. The flexible arc protrusion structure can avoid mucosal damage, improving the safety of intervention and withdrawal while ensuring treatment efficacy, significantly improving overall clinical applicability. Attached Figure Description

[0026] Figure 1 This is a partial three-dimensional schematic diagram of the drug capsule matrix in a contracted state in Embodiment 1 of the present invention; Figure 2 This is a partial three-dimensional schematic diagram of the drug-eluting balloon matrix in an expanded state in Embodiment 1 of the present invention; Figure 3 This is a partial three-dimensional schematic diagram of the drug capsule matrix in a contracted state in Embodiment 2 of the present invention; Figure 4 This is a partial three-dimensional schematic diagram of the V-shaped receiving sidewall and stress-weakening crease area in Embodiment 2 of the present invention; Figure 5 This is a partial three-dimensional schematic diagram of the drug-eluting balloon matrix in an expanded state in Embodiment 2 of the present invention; Figure 6 This is a partial three-dimensional schematic diagram of the drug-eluting balloon matrix in a contracted state in Embodiment 3 of the present invention; Figure 7 For the present invention Figure 6 Enlarged 3D structural diagram at point A; Figure 8 This is a partial three-dimensional schematic diagram of the drug capsule matrix in an expanded state in Embodiment 3 of the present invention.

[0027] In the picture: 1. Guide wire; 2. Drug capsule matrix; 3. Recess assembly; 31. Receiving cavity; 311. V-shaped receiving sidewall; 312. Stress-weakening crease area; 32. Contact protrusion component; 321. Pressure-induced rupture drug storage microcapsule; 322. Drug delivery protrusion. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0029] It should be noted that the external catheter rod, guide wire 1, drug-eluting balloon base 2, drug coating on the component surface, pressure-fracturing drug-eluting microcapsule 321, and the internally encapsulated liquid therapeutic agent used in this patent are all mature existing structures and commonly used medical materials in the field of interventional drug-eluting balloons. The catheter rod is used for the delivery and positioning support of the overall catheter; the guide wire 1 is used for minimally invasive guidance and establishing instrument access; the drug-eluting balloon base 2 serves as a pressurizable and deformable carrier substrate; the surface drug coating is a commonly used solid drug-loaded structure for benign prostatic hyperplasia treatment; and the pressure-fracturing drug-eluting microcapsule... The capsule 321 is an existing biodegradable, pressure-bearing, ruptured capsule for drug storage. The liquid therapeutic agent is a standardized drug solution routinely used in clinical practice for the treatment of benign prostatic hyperplasia. The specific materials, manufacturing processes, basic working principles, and pharmacological effects of the above-mentioned components are all existing known technologies. This application has not made any improvements to them. The innovation of this application lies only in the cooperative structure of the recessed assembly 3, the receiving cavity 31, and the contact protrusion member 32, as well as the combination structure of deformation-protected drug and targeted extrusion drug release. Therefore, the conventional structure, materials, and principles of the above-mentioned existing components will not be repeated hereafter.

[0030] Please see Figures 1 to 2 The present invention provides an embodiment: A drug-eluting balloon catheter for treating benign prostatic hyperplasia includes an external catheter rod, a guide wire 1, and a drug-eluting balloon base 2 sleeved on the outside of the guide wire 1. The outer wall of the drug-eluting balloon base 2 has a recess assembly 3, which includes several receiving cavities 31 formed on the surface of the drug-eluting balloon base 2. Each receiving cavity 31 is recessed towards the inside of the drug-eluting balloon base 2. A contact protrusion member 32 is fixedly connected to the inner wall of each receiving cavity 31. The protrusion height of the contact protrusion member 32 is less than the recess depth of the receiving cavity 31. The outer surface of the base 2, the cavity wall surface of the receiving cavity 31, and the outer surface of the contact protrusion 32 are all coated with a drug coating for treating benign prostatic hyperplasia. The inside of the drug balloon base 2 can be supplied with an expansion medium by a pressure pump. When the drug balloon base 2 is in a deflated state, the contact protrusion 32 is housed in the cavity of the receiving cavity 31. When the drug balloon base 2 is inflated, the receiving cavity 31 deforms with the drug balloon base 2, causing the contact protrusion 32 to extend outward, so that the contact protrusion 32 contacts the prostatic hyperplasia lesion tissue.

[0031] Please see Figures 1 to 2 The receiving cavity 31 is an elongated groove extending along the axial direction of the drug capsule base 2, and the contact protrusion 32 is a strip-shaped protrusion adapted to the elongated groove. After the drug capsule base 2 is pressurized and expanded, the elongated groove is stretched and flattened to be flush with the outer surface of the drug capsule base 2, and the strip-shaped contact protrusion 32 protrudes from the surface of the base.

[0032] It should be noted that the receiving cavity 31 and the drug balloon base 2 are integrally formed structures. Multiple recess assemblies 3 are evenly spaced along the circumference of the drug balloon base 2. The outer contour of the contact protrusion member 32 is higher than the outer circular surface of the drug balloon base 2 after expansion. The top of the contact protrusion member 32 is provided with an arc transition surface. The contact protrusion member 32 is fixed to the inner wall of the receiving cavity 31 by bonding or thermal fusion.

[0033] It should be added that, in this embodiment, the therapeutic drug loaded on the drug coating can be a commonly used therapeutic drug for benign prostatic hyperplasia, such as tamsulosin, finasteride, or a combination of both, or anti-inflammatory drugs can be added according to clinical needs; the contact protrusion 32 is made of a biocompatible elastic polymer material, such as silicone or polyurethane elastomer, and has good elastic deformation capability, and is not a rigid component. When the balloon is inflated and expands to contact the lesion, the contact protrusion 32 can undergo moderate elastic compression deformation, which can both slightly abut and adhere to the hyperplastic lesion tissue, increasing the contact area between the drug coating and the lesion, and avoid rigid compression that could cause scratches or contusions to the urethral tissue.

[0034] As a specific working principle of the above embodiment one: In the clinical interventional treatment process, the device completes the minimally invasive delivery intervention through the external catheter rod and the guide wire 1.

[0035] Traditional drug-eluting balloons expose the drug coating directly on the outer surface of the balloon. During the delivery of the drug through the urethral cavity, the exposed coating is prone to continuous friction and abrasion with the urethral mucosa, causing a large amount of drug to fall off and be lost prematurely. This significantly reduces the actual dosage delivered to the lesion and affects the final treatment effect.

[0036] In this embodiment, a recessed assembly 3 is added to the outer wall of the drug balloon base 2. By utilizing the concave structure of the receiving cavity 31 and the size design of the protrusion height of the contact protrusion member 32 being less than the recess depth of the receiving cavity 31, the contact protrusion member 32 can be completely stored and hidden inside the receiving cavity 31 when the drug balloon base 2 is in a collapsed delivery state.

[0037] At this time, the full-area drug coating on the outer surface of the drug balloon substrate 2, the cavity wall of the receiving cavity 31, and the surface of the contact protrusion 32 can be effectively protected, completely avoiding frictional contact between the coating and the urethral mucosa during interventional delivery, minimizing premature drug loss, effectively ensuring the effective drug payload, and solving the defects of traditional drug balloons such as large drug loss and insufficient drug delivery.

[0038] After the catheter is delivered to the location of the prostatic hyperplasia lesion, an expansion medium is introduced into the drug balloon base 2 through a pressure pump, causing the drug balloon base 2 to be gradually pressurized and expanded. The originally concave elongated receiving cavity 31 is gradually stretched and flattened with the deformation of the drug balloon base 2, and finally becomes flush with the outer surface of the drug balloon base 2.

[0039] At this point, the drug coating that was originally hidden in the cavity wall of the receiving cavity 31 is completely exposed, forming a full-area drug delivery surface together with the coating on the outer surface of the drug balloon substrate 2. Its drug delivery mode is consistent with the traditional drug balloon surface drug delivery method, which can achieve basic uniform drug delivery in the lesion area and ensure basic treatment effect.

[0040] At the same time, only the strip-shaped contact protrusion 32 protrudes from the substrate surface, forming an additional enhancement structure that traditional balloons do not have.

[0041] The protruding elastic contact protrusion 32 can fit and slightly press against the prostatic hyperplasia lesion tissue. Relying on its own elastic deformation to adapt to the surface contour of the lesion, it achieves flexible contact. It will not damage the normal urethral mucosa tissue, and can make the drug coating on the surface of the contact protrusion 32 deeply fit the hyperplastic lesion. The drug penetration effect is improved by targeted compression and fitting.

[0042] Based on the traditional basic drug delivery mode, this structure uses a raised structure to target and compress the proliferative lesions for drug delivery, which greatly increases the amount of drug deposited at the proliferative lesion site and the accuracy of drug delivery. It takes into account both basic uniform drug delivery and targeted synergistic therapy, and significantly improves the local treatment effect of benign prostatic hyperplasia.

[0043] Based on Example 1, Example 2: Compared with Example 1, this example changes the structural form of the receiving cavity 31. In Example 1, the elongated receiving cavity 31 is flattened by stretching the drug balloon base 2, and the contact protrusion member 32 is passively protruded by the overall expansion of the drug balloon base 2. The protrusion range is limited, and the compression and adhesion force to the uneven proliferative lesions is insufficient. In this example, a flip-out V-shaped receiving cavity 31 structure is adopted. By using the flip deformation of the receiving cavity 31 itself, the contact protrusion member 32 is actively pushed outward, which can obtain a larger protrusion stroke, enhance the compression and contact effect on the uneven prostatic hyperplasia lesions, and improve the drug adhesion and penetration ability at the lesion site.

[0044] Please see Figures 3 to 5 The receiving cavity 31 has a V-shaped groove structure. During the inflation and expansion of the drug capsule base 2, the V-shaped receiving cavity 31 can be rotated and deformed outward as a whole, so that the receiving cavity 31 together with the internal contact protrusion member 32 protrudes outward. The V-shaped groove includes symmetrically arranged V-shaped receiving sidewalls 311. The stress weakening fold area 312 is set at the connection position of the two V-shaped receiving sidewalls 311. The stress weakening fold area 312 adopts a locally thinned rounded corner structure, which forms a deformation inflection point, so that the V-shaped receiving sidewall 311 can be smoothly rotated and bent outward along the stress weakening fold area 312, realizing the overall outward rotation and protrusion of the groove.

[0045] It should be noted that the stress-weakening crease area 312 is locally thinned and rounded. The material wall thickness at this location is less than the wall thickness of the two V-shaped receiving sidewalls 311, which is a mechanically weak point in the entire V-shaped groove. After the drug capsule base 2 is filled with pressure, the wall of the drug capsule base 2 will be subjected to outward expansion tension. When the tension is transmitted to the V-shaped receiving cavity 31, the stress will preferentially concentrate in the stress-weakening crease area 312 with a smaller wall thickness. The rounded transition can avoid the appearance of stress at the corner of the crease. The material tears, allowing the two V-shaped receiving sidewalls 311 to use the stress-weakening crease area 312 as a pivot point for rotation. The two V-shaped receiving sidewalls 311, which were originally concave inward, open outward around this pivot point. The V-shaped configuration, which was originally concave inward with the opening facing inward, is reversed as the two sidewalls flip outward and open, transforming into an outward convex V-shape with the opening facing outward. This pushes the contact protrusion member 32 installed inside the groove outward together, completing the transformation from a concave V-shape to an outward convex V-shape.

[0046] As for the specific working principle of the above embodiment 2: The operation of the intervention delivery stage in this embodiment is consistent with that in embodiment 1. The device is inserted into the urethra through the external catheter rod and the guide wire 1. When the drug balloon base 2 is in a deflated state, the contact protrusion 32 is housed inside the concave V-shaped receiving cavity 31. The concave cavity shields and protects the drug coating, reducing the drug from being rubbed and detached by the urethral mucosa during delivery, and ensuring the drug load.

[0047] Once the catheter is positioned at the location of the benign prostatic hyperplasia lesion, the pressure pump introduces an expansion medium into the drug balloon base 2, causing the balloon wall to expand outwards.

[0048] Unlike Embodiment 1, which relies on stretching the base material to flatten the groove and passively protrude the contact protrusion 32, this embodiment utilizes the fulcrum effect of the stress-weakened crease area 312 to drive the V-shaped receiving sidewall 311 to flip outward, so that the entire receiving cavity 31 changes from an inward concave shape to an outward convex V-shape, thereby driving the contact protrusion 32 to actively push outward and obtain a larger protrusion stroke.

[0049] After the V-shaped receiving cavity 31 is everted, the drug coating on the cavity wall is exposed outward, realizing basic drug delivery to the lesion area; at the same time, the contact protrusion 32 has a larger extension range, which can form a stronger flexible compression fit to the undulating surface of the prostatic hyperplasia lesion. The elastic contact protrusion 32 adapts to the surface contour of the lesion, so that the drug coating on the surface of the component is fully pressed onto the surface of the hyperplastic tissue, increasing the amount of local drug deposition.

[0050] After depressurization, the V-shaped receiving cavity 31 returns to its original inwardly concave shape as the balloon deflates, and the contact protrusion 32 retracts back into the cavity, reducing the risk of rubbing against the urethral tissue during the retraction process and completing one targeted drug delivery treatment.

[0051] Based on Example 2, Example 3 further optimizes the drug release method compared to Example 2, specifically addressing the issues of easy drug detachment and insufficient drug contact with the lesion present in Example 2. In Example 2, the V-shaped receiving cavity 31 undergoes a gradual deformation process from concave to convex, prematurely exposing the drug coating on the contact protrusion component 32. During the process of balloon adhesion and compression of proliferative tissue, the surface drug coating is easily scraped off by friction from the proliferative tissue, leading to drug attenuation and insufficient drug concentration in the core contact area of ​​the lesion, thus affecting the targeted therapy effect. This example abandons the passive drug delivery method relying solely on the surface solid coating and adopts a pressure-triggered active drug release structure. During the overall delivery and expansion deformation of the balloon, the liquid drug remains sealed under pressure. Inside the rupture-prone drug-storing microcapsule 321, there is no premature exposure or frictional loss of drug. When the drug-storing capsule base 2 expands to the desired extent, the spherical contact protrusion 32 precisely presses against the protruding lesion of benign prostatic hyperplasia. Relying on the reaction force of the lesion to form a compressive load, the pressure-prone drug-storing microcapsule 321 automatically ruptures after reaching the preset pressure, releasing a high concentration of liquid drug at a specific point. In conjunction with the drug-guiding protrusions 322 on the surface of the contact protrusion 32, the liquid drug is evenly distributed and spread, allowing the liquid drug to fully wet and penetrate the hyperplastic tissue. At the same time, combined with the original solid drug coating on the surface of the component, a solid-liquid dual drug delivery system is formed, which completely solves the defects of insufficient drug dosage and large drug loss in traditional passive drug delivery, and significantly improves the drug delivery accuracy and treatment effect of severe protruding hyperplasia lesions.

[0052] Please see Figures 6 to 8 The receiving cavity 31 is a spherical cavity, and the contact protrusion 32 is a spherical protrusion that is adapted to the spherical cavity. A pressure-rupture drug storage microcapsule 321 is fixedly connected to the side of the contact protrusion 32 away from the receiving cavity 31. The pressure-rupture drug storage microcapsule 321 is made of a pressure-ruptureable polymer film material. The pressure-rupture drug storage microcapsule 321 contains a liquid drug for treating benign prostatic hyperplasia. When the contact protrusion 32 is subjected to the pressure load of the lesion tissue, the pressure-rupture drug storage microcapsule 321 ruptures under pressure and releases the internal liquid drug. Several drug guiding protrusions 322 are fixedly connected to the outer surface of the contact protrusion 32. When the pressure-rupture drug storage microcapsule 321 ruptures and the liquid drug flows out, the drug guiding protrusions 322 guide and disperse the liquid drug, so that the drug is applied to the surface of the prostate lesion tissue.

[0053] It should be added that the pressure-fracturing drug-reservoir microcapsule 321 uses a biocompatible, brittle polymer film, such as polylactic-co-glycolic acid copolymer (PLGA) or modified polyvinyl alcohol film, with the film thickness controlled at the micrometer level. This allows it to rupture under pressure without producing sharp fragments. After rupture, the capsule material is gradually degraded and absorbed by the body, leaving no foreign matter. The liquid medication encapsulated inside the microcapsule is a liquid preparation for treating benign prostatic hyperplasia (BPH). The medication can be a liquid compound of tamsulosin and finasteride, or anti-inflammatory and anti-swelling adjuvant drugs can be added. This can relax the urethra, inhibit glandular hyperplasia, and reduce local edema and inflammation in the prostatic hyperplasia tissue. When intact, the pressure-fracturing drug-reservoir microcapsule 321 can isolate the internal liquid medication. Throughout the entire balloon delivery process, the liquid medication is sealed inside the microcapsule and will not leak out prematurely. The medication will only rupture and be released when it comes into contact with the protruding component 32, which presses against the lesion and generates a compressive load.

[0054] As for the specific working principle of the above embodiment three: Based on the above structure, this embodiment achieves precise, low-loss, and high-concentration targeted drug delivery through a closed pressure-triggered drug release structure, which completely makes up for the technical shortcomings of passive exposed coating drug delivery in embodiments one and two, such as easy drug detachment and insufficient effective drug amount.

[0055] During the clinical minimally invasive interventional delivery process, the drug balloon base 2 is in a collapsed state. The contact protrusion 32 and the pressure-induced rupture drug storage microcapsule 321 installed on its outside are completely housed and hidden inside the spherical receiving cavity 31, and are not exposed. Relying on the shielding and protective function of the spherical receiving cavity 31, the solid drug coating on the surface of the component and the liquid drug inside the microcapsule can be protected at the same time. This effectively avoids the problem of drug shedding and drug loss caused by the friction between the catheter and the mucosa during the passage of the catheter through the urethra, ensuring zero drug leakage and zero premature loss throughout the process.

[0056] Once the device is delivered and positioned at the location of the benign prostatic hyperplasia lesion, an expansion medium is introduced into the drug-eluting balloon base 2 via a pressure pump. The drug-eluting balloon base 2 undergoes overall expansion and deformation. The spherical receiving cavity 31 protrudes outward synchronously with the deformation of the base, gradually expanding from its original concave shape to an outward protrusion. This, in turn, causes the contact protrusion component 32 housed inside and the pressure-induced rupture drug storage microcapsule 321 to protrude outward synchronously, enabling the microcapsule structure to precisely align with the protruding lesion of benign prostatic hyperplasia.

[0057] Unlike the previous two embodiments, which suffer from the defects of premature contact and friction leading to exposed coatings, this embodiment ensures that the drug is completely sealed by the microcapsule during the balloon expansion and bonding stage. Only when the contact protrusion 32 forms an effective compressive load with the protruding tissue and reaches the preset pressure threshold will the pressure-induced rupture drug storage microcapsule 321 rupture under pressure, releasing the high-concentration liquid therapeutic agent inside at a specific point.

[0058] The overflowing liquid drug spreads evenly and infiltrates the proliferating tissue under the diversion and guidance of the drug guiding protrusion 322, and together with the solid drug coating on the surface of the contact protrusion 32, forms a solid-liquid combined two-layer drug delivery system.

[0059] This structure first achieves full-process drug protection through concave cavity storage, then precisely positions the drug through balloon expansion, and finally relies on pressure to trigger targeted drug release, which greatly improves drug utilization and local drug concentration at the lesion. It is specifically adapted for severe protruding benign prostatic hyperplasia, and significantly improves the accuracy and effectiveness of treatment.

[0060] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0061] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A drug-eluting balloon catheter for treating benign prostatic hyperplasia, comprising an external catheter rod, a guide wire (1), and a drug-eluting balloon base (2) sleeved on the outside of the guide wire (1), characterized in that: The outer wall of the drug-eluting balloon base (2) is provided with a recess assembly (3). The recess assembly (3) includes a plurality of receiving cavities (31) formed on the surface of the drug-eluting balloon base (2). Each receiving cavity (31) is recessed toward the inner side of the drug-eluting balloon base (2). A contact protrusion member (32) is fixedly connected to the inner wall of each receiving cavity (31). The protrusion height of the contact protrusion member (32) is less than the recess depth of the receiving cavity (31). The outer surface of the drug-eluting balloon base (2), the cavity wall surface of the receiving cavity (31), and the contact protrusion member (32) are all connected together. The outer surface of the protruding member (32) is provided with a drug coating for treating benign prostatic hyperplasia. The drug balloon base (2) can be filled with an expansion medium by a pressure pump. When the drug balloon base (2) is in a deflated state, the contact protruding member (32) is housed in the cavity of the receiving cavity (31). When the drug balloon base (2) is pressurized and expanded, the receiving cavity (31) deforms with the drug balloon base (2), causing the contact protruding member (32) to extend outward, so that the contact protruding member (32) contacts the prostatic hyperplasia lesion tissue.

2. The drug-eluting balloon catheter for treating benign prostatic hyperplasia according to claim 1, characterized in that: The receiving cavity (31) is an elongated groove extending along the axial direction of the drug capsule base (2), and the contact protrusion (32) is a strip-shaped protrusion adapted to the elongated groove.

3. The drug-eluting balloon catheter for treating benign prostatic hyperplasia according to claim 2, characterized in that: After the drug balloon substrate (2) is pressurized and expanded, the elongated groove is stretched and flattened to be flush with the outer surface of the drug balloon substrate (2), and the strip-shaped contact protrusion (32) protrudes from the substrate surface.

4. The drug-eluting balloon catheter for treating benign prostatic hyperplasia according to claim 1, characterized in that: The receiving cavity (31) is a V-shaped groove structure. During the inflation and expansion of the drug balloon matrix (2), the receiving cavity (31) of the V-shaped structure can be rotated and deformed outward as a whole, so that the receiving cavity (31) together with the internal contact protrusion member (32) protrudes outward.

5. The drug-eluting balloon catheter for treating benign prostatic hyperplasia according to claim 4, characterized in that: The V-shaped groove includes symmetrically arranged V-shaped receiving sidewalls (311). Stress-weakening fold area (312) is provided at the connection position of the two V-shaped receiving sidewalls (311). The stress-weakening fold area (312) adopts a locally thinned rounded corner structure to form a deformation inflection point, so that the V-shaped receiving sidewall (311) can smoothly bend outward along the stress-weakening fold area (312) to realize the overall outward bulging action of the groove.

6. The drug-eluting balloon catheter for treating benign prostatic hyperplasia according to claim 1, characterized in that: The receiving cavity (31) is a spherical cavity, and the contact protrusion (32) is a spherical protrusion that is adapted to the spherical cavity.

7. The drug-eluting balloon catheter for treating benign prostatic hyperplasia according to claim 6, characterized in that: The contact protrusion (32) is fixedly connected to a pressure-rupture drug storage microcapsule (321) on the side away from the receiving cavity (31). The pressure-rupture drug storage microcapsule (321) is made of a pressure-ruptureable polymer film material. The pressure-rupture drug storage microcapsule (321) is encapsulated with a liquid drug for treating benign prostatic hyperplasia. When the contact protrusion (32) is subjected to the compressive load of the lesion tissue, the pressure-rupture drug storage microcapsule (321) ruptures under pressure and releases the internal liquid drug.

8. The drug-eluting balloon catheter for treating benign prostatic hyperplasia according to claim 7, characterized in that: The outer surface of the contact protrusion member (32) is fixedly connected with a number of drug guiding protrusions (322). When the pressure-induced rupture drug storage microcapsule (321) ruptures and the liquid drug flows out, the drug guiding protrusions (322) guide and disperse the liquid drug so that the drug is applied to the surface of the prostate lesion tissue.

9. A drug-eluting balloon catheter for treating benign prostatic hyperplasia according to any one of claims 1-8, characterized in that: The receiving cavity (31) and the drug balloon base (2) are integrally formed. Multiple recess assemblies (3) are evenly spaced along the circumference of the drug balloon base (2). The outer contour of the contact protrusion member (32) is higher than the outer circular surface of the drug balloon base (2) after expansion. The top of the contact protrusion member (32) is provided with an arc transition surface.

10. A drug-eluting balloon catheter for treating benign prostatic hyperplasia according to claim 9, characterized in that: The contact protrusion (32) is fixed to the inner wall of the receiving cavity (31) by adhesive bonding or thermal fusion.

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