Expansion balloon

Abstract

The dilatation balloon comprises a catheter, a balloon body arranged on the catheter in a sleeving mode and a support arranged on the balloon body in a sleeving mode, and the support comprises a support body arranged outside the balloon body in a sleeving mode and a plurality of anchoring components arranged on the outer surface of the support body. The anchoring components are configured to penetrate into calcification lesion of the inner wall of a blood vessel when the stent body is in an expansion state, the capsule forms an outline with the middle portion obviously protruding relative to the two end portions in a full state, the catheter is provided with a first limiting structure, and the stent body is correspondingly provided with a second limiting structure. The first limiting structure and the second limiting structure can be matched with each other so as to allow the catheter and the stent body to generate certain relative movement in the axial direction, and local pressurization and expansion are conducted on a specific area of the stent body through the middle portion of the bag body. Therefore, not only are the fitness and anchoring effect of the stent in irregular calcification lesions improved, but also the pertinence and safety of treatment are enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to an expandable balloon. Background Art

[0002] Chinese Patent CN113599032A discloses a technical solution for assisting a stent spike to penetrate a calcified lesion and perform deep drug delivery through balloon inflation. The technical solution specifically includes a catheter, a balloon sleeved on the catheter, and a stent sleeved outside the balloon. During use, a filling medium is filled into the balloon through the filling port of the catheter to expand the balloon and push the stent to expand, thereby driving the spikes on the surface of the stent to penetrate into the calcified lesion area in the blood vessel wall to achieve local drug delivery. However, in this technical solution, the balloon and the stent are usually fixedly connected, and the balloon expands uniformly or approximately uniformly in the filled state, lacking the ability to controllably pressurize specific areas. Therefore, in the face of complex situations such as irregularly shaped lesion areas or local severe stenosis, it is difficult to effectively pressurize and expand a local area of the stent, resulting in poor stent adhesion and poor anchoring effect, thereby affecting the treatment effect and the clinical application range. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an expandable balloon aiming to improve the adhesion and anchoring effect in irregular calcified lesions in view of the above-mentioned defects in the prior art.

[0004] According to the present invention, there is provided an expandable balloon, comprising a catheter, a balloon body sleeved on the catheter, and a stent sleeved on the balloon body. The stent includes a stent main body sleeved outside the balloon body and a plurality of anchoring members arranged on the outer surface of the stent main body. The plurality of anchoring members are configured to penetrate into the calcified lesions of the blood vessel inner wall when the stent main body is in an expanded state. The balloon body forms a contour in which the middle part protrudes significantly relative to the two end parts in the filled state. The catheter is provided with a first limiting structure, and the stent main body is correspondingly provided with a second limiting structure. The first limiting structure and the second limiting structure can cooperate with each other to allow a certain relative movement along the axial direction between the catheter and the stent main body, and realize local pressurized expansion of a specific area of the stent main body by using the middle part of the balloon body.

[0005] Further, the first limiting structure includes two limiting protrusions arranged on the outer wall of the catheter, and the second limiting structure includes a limiting ring arranged at the end of the stent main body. The limiting ring is sleeved on the catheter and located between the two limiting protrusions. The distance between the two limiting protrusions along the axial direction of the catheter forms the maximum relative displacement between the catheter and the stent main body.

[0006] Further, the first limiting structure includes a limiting slider disposed on the outer wall of the catheter, and the second limiting structure includes a limiting cylinder disposed at the end of the stent body. The limiting slider is slidably disposed within the limiting cylinder, and the spacing of the limiting cylinder along the axial direction of the catheter forms the maximum relative displacement between the catheter and the stent body.

[0007] Further, the bladder is a double-layer structure and includes an inner bladder and an outer bladder. The inner bladder forms a uniformly expanding contour in the inflated state, and the outer bladder forms a contour with a significantly protruding middle portion relative to the two end portions in the inflated state.

[0008] Further, the inner bladder and the outer bladder are configured to be independently inflated. The inner bladder is inflated first to drive the overall expansion of the stent, and the outer bladder is inflated later to drive the local pressurized expansion of the stent.

[0009] Further, the outer bladder includes a first bladder segment, a second bladder segment, and a third bladder segment connected in sequence. The degree of expansion of the second bladder segment is greater than that of the first bladder segment and the third bladder segment.

[0010] Further, the bladder is a single-layer structure and includes a first bladder segment, a second bladder segment, and a third bladder segment connected in sequence. The degree of expansion of the second bladder segment is greater than that of the first bladder segment and the third bladder segment, and is configured to deflate after a single inflation to drive the overall expansion of the stent, and then move to a local position of the stent for secondary inflation to drive the local pressurized expansion of the stent.

[0011] Further, a drug coating for inhibiting vascular restenosis is coated on the anchoring member.

[0012] Further, a drug-loading groove is provided on the anchoring member, and a drug-loading space is formed inside the drug-loading groove and filled with a drug coating for inhibiting vascular restenosis.

[0013] Further, the anchoring member is formed as a sheet-like spiky member.

[0014] Compared with the prior art, the present invention realizes the controllable relative displacement between the balloon and the stent through the design of the limiting structure, and combines the bladder structure with the characteristic of a significantly protruding middle portion, so that during the expansion process, the middle portion of the bladder can accurately act on a specific area of the stent as the relative movement between the catheter and the stent changes, thereby realizing the local pressurized expansion of the stent. In this way, not only the conformity and anchoring effect of the stent in irregular calcified lesions are improved, but also the pertinence and safety of the treatment are enhanced, thus significantly improving the overall treatment effect and clinical applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] With reference to the accompanying drawings and by referring to the following detailed description, it will be easier to have a more complete understanding of the present invention and easier to understand its accompanying advantages and features.

[0016] Figure 1 It is a schematic diagram of the overall structure of the embodiment of the present invention when the bladder is not filled.

[0017] Figure 2 It is a schematic diagram of the structure of the filled bladder in the embodiment of the present invention.

[0018] Figure 3 It is a schematic diagram of the structure of the expanded stent in the embodiment of the present invention.

[0019] Figure 4 is Figure 3 the enlarged view of part A in

[0020] Figure 5 It is a schematic diagram of the structure of the spike section in the natural state in the embodiment of the present invention.

[0021] In the drawings: 10 is a catheter; 20 is a bladder, 21 is an inner bladder, 22 is an outer bladder; 30 is a stent, 31 is a stent body, 32 is an anchoring member, 321 is a fixed section, 322 is a deformation section, 323 is a spike section, 3231 is a first section, 3232 is a second section, 3233 is a third section; 40 is a limiting protrusion; 50 is a limiting ring; 60 is a drug-carrying groove; 70 is a slotted structure, 71 is a first group of slots, 72 is a second group of slots.

[0022] It should be noted that the drawings are used to illustrate the present invention, rather than limiting the present invention. Note that the drawings showing the structure may not be drawn to scale. And, in the drawings, the same or similar elements are labeled with the same or similar reference numerals. Detailed Embodiments

[0023] In order to make the content of the present invention clearer and easier to understand, the content of the present invention will be described in detail below in conjunction with specific embodiments and drawings.

[0024] As used in the present invention, "proximal" and "distal" should be understood as being observed from the direction of the attending physician. "Proximal" refers to the end closer to the attending physician, that is, corresponding to the "left end" in the reference drawings, and "distal" refers to the end farther from the attending physician, that is, corresponding to the "right end" in the reference drawings. Similarly, "proximal segment" refers to a segment or a specific area closer to the attending physician, and "distal segment" refers to a segment or a specific area farther from the attending physician.

[0025] Such as Figures 1 to 5As shown in the figure, the dilation balloon of this embodiment includes a catheter 10, a balloon body 20 sleeved on the catheter 10, and a stent 30 sleeved outside the balloon body 20. The balloon body 20 is generally located at the distal segment of the catheter 10 and is used to push the stent 30 to expand in the inflated state, so as to effectively support and treat the vascular stenosis site. Specifically, the balloon body 20 forms a contour with the middle part significantly protruding relative to the two end parts in the inflated state, and this special inflation form provides a basic condition for subsequent pressurized dilation of a local area of the stent 30.

[0026] The stent 30 includes a stent body 31 and a plurality of anchoring members 32. The stent body 31 is a hollow tubular structure, usually made of a metal material such as a nitinol tube by laser engraving and processed by a heat treatment process for shape memory setting, so that it has good self-expansion performance and resilience recovery ability. The stent body 31 has two basic forms: a contracted state with radial contraction and a dilated state with radial self-expansion to support blood vessels. In the non-inflated state, the stent 30 is in a compressed state and closely adheres to the surface of the balloon body 20 for easy delivery. When the balloon body 20 is filled with a filling medium, the stent 30 expands accordingly and closely adheres to the blood vessel wall to play a supporting role. The plurality of anchoring members 32 are uniformly distributed along the circumferential direction on the outer surface of the stent body 31 and are configured to penetrate into the calcified lesion tissue of the blood vessel inner wall when the stent body 31 is in the expanded state, so as to enhance the anchoring force between the stent and the blood vessel wall and prevent the stent 30 from slipping or retracting during the expansion process.

[0027] An integrated manufacturing process is adopted between the anchoring member 32 and the stent body 31, such as being made by laser engraving and overall heat setting on the same metal tube, ensuring the consistency, strength and stability of the structure. After the stent is formed, a drug coating for inhibiting vascular restenosis is coated on the outer surface of the entire stent 30. The drug coating can select anti-proliferative drugs commonly used in the prior art, such as rapamycin, paclitaxel, etc. The design of this drug coating not only helps to improve the drug utilization rate, but also can penetrate into the lesion tissue together with the anchoring member 32 during the stent expansion process to achieve deep drug delivery, thereby effectively inhibiting the abnormal proliferation of smooth muscle cells, reducing the incidence of postoperative vascular restenosis, and improving the treatment effect.

[0028] In order to achieve local pressurized dilation of a specific area of the stent 30, a limiting structure system is provided between the catheter 10 and the stent body 31 in this embodiment. Specifically, a first limiting structure is provided on the catheter 10, and a corresponding second limiting structure is provided on the stent body 31. The two cooperate with each other to allow a certain relative movement along the axial direction between the catheter 10 and the stent body 31. This design, combined with the middle convex structure formed after the inflation of the bladder 20, enables the middle part of the bladder 20 to accurately act on a specific area of the stent 30 with the relative displacement between the catheter 10 and the stent body 31 during the dilation process, achieving local pressurized dilation. This locally controllable pressurization mechanism significantly improves the conformity and anchoring effect of the stent in complex lesions (such as irregular calcification or local severe stenosis), enhances the pertinence and safety of the treatment, and thus improves the overall treatment effect and clinical applicability. In this way, through the design of the limiting structure and combined with the bladder structure with local convex characteristics in this embodiment, a technical solution capable of locally pressurizing and dilating a specific area of the stent is jointly constructed.

[0029] In this embodiment, the first limiting structure specifically includes two limiting protrusions 40 provided on the outer wall of the catheter 10. The limiting protrusions 40 can be integrally formed with the catheter 10 and have good structural strength and wear resistance. The corresponding second limiting structure includes a limiting ring 50 provided at the proximal end of the stent body 31. The limiting ring 50 is sleeved on the catheter 10 and located between the two limiting protrusions 40, and its size is not larger than the outer diameter of the limiting protrusions 40, so that the limiting ring 50 can slide freely between the two limiting protrusions 40. The limiting ring 50 can be indirectly fixed to the end of the stent body 31 through a connecting rod to ensure its stability and guiding property during the dilation process. The distance between the two limiting protrusions 40 determines the maximum relative displacement range along the axial direction between the catheter 10 and the stent body 31, thereby controlling the position and length of the local pressurization area. In addition, the limiting protrusions 40 can be made of a polymer material added with barium sulfate, and the limiting ring 50 can be made of a radiopaque metal material, so that the limiting protrusions 40 and the limiting ring 50 have a radiopaque function, which is convenient for intraoperative operation.

[0030] Of course, those skilled in the art can understand that in other possible embodiments, the first limiting structure can also be a limiting slider provided on the outer wall of the catheter 10, and the second limiting structure can be a limiting cylinder provided at the end of the stent body 31. The limiting slider can be slidably embedded inside the limiting cylinder, and the length of the limiting cylinder along the axial direction of the catheter 10 is the maximum allowable relative displacement range. This method can also achieve the same technical effect as this embodiment and belongs to the protection scope of the present invention.

[0031] In this embodiment, the capsule body 20 has a double-layer structure, including an inner capsule body 21 and an outer capsule body 22. Among them, the inner capsule body 21 forms a uniformly expanded contour in the filled state, which is used to drive the overall expansion of the stent 30; while the outer capsule body 22 includes a first capsule body segment, a second capsule body segment, and a third capsule body segment connected in sequence, and the degree of expansion of the second capsule body segment is greater than that of the first capsule body segment and the third capsule body segment, so that a contour with the middle part significantly protruding from both ends is formed after the outer capsule body 22 is filled. The inner capsule body 21 and the outer capsule body 22 are respectively provided with independent filling channels, and these filling channels are integrally arranged inside the catheter 10, allowing independent filling operations. Specifically, there are two non-communicating fluid channels inside the catheter 10, one for connecting and filling the inner capsule body 21, and the other for connecting and filling the outer capsule body 22. The dual-channel independent filling technology belongs to the category of existing technologies, and its specific structure and implementation method will not be elaborated here. During actual use, first, the inner capsule body 21 is filled to expand the stent 30 as a whole and fit it to the blood vessel wall. This stage is called "pre-expansion". After the stent 30 is initially expanded and anchored to the blood vessel by the anchoring member 32, the outer capsule body 22 is then filled, and the protruding middle part is used to locally pressurize and expand a specific area of the stent 30. During this process, the capsule body 20 can also be driven to move relative to the stent 30 by operating the catheter 10 to accurately position the required locally pressurized area. If necessary, the inner capsule body 21 can be appropriately depressurized before the second filling, but the filling state of the inner capsule body 21 needs to be restored before the second filling to ensure the stability of the overall structure.

[0032] Of course, in addition to the above double-layer structure, the capsule body 20 can also adopt a single-layer structure, including a first capsule body segment, a second capsule body segment, and a third capsule body segment connected in sequence, and the degree of expansion of the second capsule body segment is higher than the other two segments, so that a contour with a convex middle part is formed in the filled state. The single-layer capsule body 20 can drive the overall expansion of the stent 30 after one filling, and move to the target position for secondary filling after depressurization to achieve local pressurized expansion of the stent, which can also achieve the expected therapeutic purpose.

[0033] The anchoring member 32 is formed into a sheet-like spiky structure, and when the stent body 31 is in the expanded state, it gradually deviates from the outer surface of the stent body 31 from the proximal end to the distal end. This inclined design is beneficial to reducing the frictional resistance with the blood vessel wall when withdrawing from the human body and improving safety. Each anchoring member 32 has an elastically deformable part and is configured to be able to adaptively deform according to the thickness of the contacted calcified lesion to effectively penetrate the irregular calcified lesion and promote drug release. Even in the calcified lesion area with a large thickness difference, all the anchoring members 32 can still maintain good penetration and structural stability, ensuring that the drug can be evenly distributed in the target lesion area, significantly improving the drug utilization rate and therapeutic effect. Moreover, the anchoring member 32 is provided with a drug-carrying groove 60, specifically asFigure 5 As shown, the drug loading groove 60 is not through-through, and a drug loading space is formed inside the drug loading groove 60 and filled with a drug coating, which further improves the therapeutic effect.

[0034] See also Figure 3 and Figure 4 As shown, each anchoring member 32 includes a fixed section 321, a deformable section 322 and a spike section 323 connected in sequence, and the spike section 323 is a portion of the anchoring member 32 away from the outer surface of the stent body 31. The fixed section 321 is connected to the outer surface of the stent body 31 and is located on the outer circumference of the stent body 31. The deformable section 322 and the spike section 323 are tilted outward relative to the fixed section 321, so that when the stent body 31 is in an expanded state, the deformable section 322 and the spike section 323 can gradually deviate from the stent body 31 from the proximal end to the distal end. The deformable section 322 is connected between the fixed section 321 and the spike section 323 to form a portion of the anchoring member 32 that can be elastically deformed, allowing the spike section 323 to contact calcified lesions of different thicknesses, and then the deformable section 322 can be deformed adaptively, so as to achieve effective penetration of the spike section 323 into irregular calcified lesions and promote drug release.

[0035] In order to enhance the elastic deformation capability of the anchoring member 32, a slotted structure 70 is provided on the deformation section 322 to form a spring-like structure. The slotted structures 70 are located on both sides of the deformation section 322 in the length direction, and the fixing section 321 and the spike section 323 are respectively connected to the two ends of the deformation section 322 in the length direction. Figure 5 As shown, the slotted structure 70 includes a first group of slots 71 and a second group of slots 72. The first group of slots 71 runs through one side of the deformation section 322, and the second group of slots 72 runs through the other side of the deformation section 322. The first group of slots 71 and the second group of slots 72 are arranged alternately, so that the slotted structure 70 forms at least one arched area, thereby simulating the effect of a spring. This design not only improves the elastic response ability of the anchoring member 32, but also enhances its adaptability in lesions of different thicknesses. The design of the slotted structure 70 is similar to a spring mechanism. When encountering a thicker calcified lesion, the slotted structure 70 will be compressed and deformed, and when encountering a thinner lesion, it will be slightly bent or not bent, thereby ensuring that each anchoring member 32 can effectively penetrate the lesion tissue, and each anchoring member 32 is relatively independent and does not affect each other.

[0036] In addition, the inner wall surface of the slotted structure 70 is also coated with a drug coating. That is, in addition to acting as a spring, the first set of slots 71 and the second set of slots 72 also accommodate a drug coating inside. This not only increases the drug loading capacity of the entire anchoring member 32, but also ensures that the drug can be rapidly released when it comes into contact with the diseased tissue, achieving the best treatment effect. The design of this multi-layer drug coating enables the drug to be more evenly distributed throughout the diseased area, significantly improving the drug utilization rate and treatment effect. At the same time, due to the presence of the slotted structure 70, the drug can be released at different positions of the anchoring member 32, further increasing the penetration depth and coverage range of the drug.

[0037] The spike section 323 is a split structure and includes a first section 3231, a second section 3232, and a third section 3233 whose roots are connected together. The roots of the first section 3231, the second section 3232, and the third section 3233 are connected to different positions of the end of the deformation section 322 away from the stent body 31, and are configured to fit together to form a compact structure such as a triangular shape in the natural state, specifically as Figure 5 shown. This design not only keeps the spike section 323 in a compact shape when not under force, which is beneficial to the smooth delivery of the stent, but also enables the three sections to elastically deform and separate relative to the root when subjected to a reverse force from the calcified lesion, thereby increasing the penetration angle and contact area, significantly enhancing the coverage range and penetration depth of the calcified lesion area, reducing the risk of slippage, improving the penetration efficiency, and thus enhancing the effect of inhibiting vascular restenosis and improving the overall treatment performance of the stent.

[0038] Specifically, the first section 3231, the second section 3232, and the third section 3233 are integrally formed on the outer surface of the stent body 31 by a laser cutting process. The first section 3231 and the third section 3233 are symmetrically arranged on both sides of the second section 3232, and can deviate from the second section 3232 in opposite directions respectively when subjected to a reverse force from the calcified lesion. The tip of the second section 3232 protrudes more than the tips of the first section 3231 and the third section 3233, so that when penetrating the calcified lesion, the second section 3232 first contacts and penetrates the calcified lesion to play an anchoring role. In addition, the size of the second section 3232 is larger than that of the first section 3231 and the third section 3233 to strengthen the anchoring effect. Since the size of the second section 3232 is relatively large, a drug-loading groove 60 is provided on the second section 3232. The drug-loading groove 60 is not through, and a drug-loading space is formed inside the drug-loading groove 60 and filled with a drug coating, further improving the treatment effect.

[0039] It should be noted that the spiked section 323 is not limited to the above three-section structure, and may also include only the first and second sections connected at the root, or include more sections according to clinical needs. As long as it is satisfied that the spiked section includes at least the first and second sections connected at the root, and there is a certain gap between the two to allow them to separate along the root when receiving a reverse force from the calcified lesion, so as to achieve a larger angle of penetration into the calcified lesion. This flexible design can be adjusted according to different lesion types and clinical needs to achieve the best treatment effect.

[0040] It can be understood that although the present invention has been disclosed above with preferred embodiments, the above embodiments are not intended to limit the present invention. For any person skilled in the art, without departing from the scope of the technical solution of the present invention, many possible changes and modifications can be made to the technical solution of the present invention by using the technical content disclosed above, or modified into equivalent embodiments with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. An expandable balloon, comprising a catheter, a balloon body sleeved on the catheter, and a stent sleeved on the balloon body. The stent includes a stent main body sleeved outside the balloon body and a plurality of anchoring members arranged on the outer surface of the stent main body. The plurality of anchoring members are configured to penetrate into the calcified lesions of the blood vessel inner wall when the stent main body is in an expanded state, and is characterized in that, The sac forms a contour with the middle part protruding significantly relative to the two end parts in the filled state. A first limiting structure is provided on the catheter, and a second limiting structure is correspondingly provided on the stent body. The first limiting structure and the second limiting structure can cooperate with each other to allow a certain relative movement along the axial direction between the catheter and the stent body, and realize local pressure expansion of a specific area of the stent body by the middle part of the sac.

2. The dilatation balloon according to claim 1, characterized in that, The first limiting structure includes two limiting protrusions provided on the outer wall of the catheter, and the second limiting structure includes a limiting ring provided at the end of the stent body. The limiting ring is sleeved on the catheter and located between the two limiting protrusions. The distance between the two limiting protrusions along the axial direction of the catheter forms the maximum relative displacement between the catheter and the stent body.

3. The dilatation balloon according to claim 1, characterized in that, The first limiting structure includes a limiting slider provided on the outer wall of the catheter, and the second limiting structure includes a limiting cylinder provided at the end of the stent body. The limiting slider is slidably arranged in the limiting cylinder, and the distance between the limiting cylinders along the axial direction of the catheter forms the maximum relative displacement between the catheter and the stent body.

4. The dilatation balloon according to claim 1, wherein The sac is a double-layer structure and includes an inner sac and an outer sac. The inner sac forms a uniformly expanded contour in the filled state, and the outer sac forms a contour with the middle part protruding significantly relative to the two end parts in the filled state.

5. The dilatation balloon according to claim 4, characterized in that, The inner sac and the outer sac are configured to be independently filled. The inner sac is filled first to drive the overall expansion of the stent, and the outer sac is filled later to drive the local pressure expansion of the stent.

6. The dilatation balloon according to claim 4, wherein The outer sac includes a first sac segment, a second sac segment, and a third sac segment connected in sequence. The degree of expansion of the second sac segment is greater than that of the first sac segment and the third sac segment.

7. The dilatation balloon according to claim 1, wherein, The sac is a single-layer structure and includes a first sac segment, a second sac segment, and a third sac segment connected in sequence. The degree of expansion of the second sac segment is greater than that of the first sac segment and the third sac segment, and is configured to relieve pressure after one filling to drive the overall expansion of the stent, and then move to a local position of the stent for secondary filling to drive the local pressure expansion of the stent.

8. The dilatation balloon according to claim 1, wherein, The anchoring member is coated with a drug coating for inhibiting vascular restenosis.

9. The dilatation balloon according to claim 1, characterized in that, The anchoring member is provided with a drug-carrying groove, and a drug-carrying space is formed inside the drug-carrying groove and filled with a drug coating for inhibiting vascular restenosis.

10. The dilatation balloon according to claim 1, characterized in that, The anchoring member is formed as a sheet-like spiky member.

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