Balloon stent system

Abstract

The invention discloses a balloon stent system which comprises a balloon body, and the balloon body has a radial expansion state and a radial contraction state. The catheter piece is arranged on one side of the balloon body and used for switching the radial expansion state and the radial contraction state of the balloon body; the stent is arranged on the outer side wall of the balloon body and used for supporting a blood vessel; the cutting assembly is arranged on the outer side wall of the balloon body, and the cutting assembly comprises a plurality of sets of nicking pieces which are arranged in the direction parallel to the axial direction of the balloon body. In the initial stage, the nicking piece is still in the first state, and after the nicking piece reaches a lesion area, the balloon body expands and the nicking piece cuts plaques, the driving piece drives the nicking piece to be switched from the first state to the second state, so that the first cutting piece and the second cutting piece are separated, the cavity is opened, and the stent is allowed to be separated from the cavity; therefore, accurate deployment of the stent in a blood vessel or other lumen is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of balloon, and specifically relates to a balloon stent system. Background Art

[0002] For many years, vascular occlusion in the human body has become a major medical problem. This is because vascular occlusion leads to a reduction in blood flow through the blood vessels, resulting in various serious complications. It is mainly caused by some yellowish-white, porridge-like plaques embedded in the inner layer of the blood vessel wall.

[0003] Among them, vascular intervention therapy is an important treatment method for the above conditions. In vascular intervention therapy, a balloon catheter is usually used as a treatment instrument for vascular intervention. However, it is difficult to dilate blood vessel stenosis with a long segment, accompanied by calcification or fibrosis. The reason is that the surface of the balloon of the traditional balloon catheter is smooth, which may cause disordered tearing of the plaque and the inner wall of the blood vessel after dilation, accompanied by the risk of causing vascular dissection. In the face of the above situation, some medical device companies have developed special balloon categories such as cutting and scoring.

[0004] Specifically, parts that can focus the dilation stress are added to the surface of the ordinary balloon to open a firm or extremely tough stenosis lesion. After the balloon is dilated, it may be necessary to implant a vascular stent to prevent the risk of restenosis caused by elastic recoil or proliferation of vascular smooth muscle cells in the stenosis site.

[0005] When implanting a vascular stent, in order to prevent restenosis caused by the proliferation of vascular smooth muscle cells in the stenosis site, some balloon stents will choose to coat drugs that inhibit the proliferation of vascular smooth muscle cells in the middle layer. However, due to the blockage of vascular plaques, a large amount of the drugs on the surface of the stent may fall off due to friction during the process of delivering the device to the lesion site. After the stent is dilated, too little drug on its surface may not be able to fully penetrate and act on the inner wall of the blood vessel in the severely stenotic area, resulting in limited drug effects. Summary of the Invention

[0006] In order to solve at least one technical problem mentioned in the background art, the purpose of the present invention is to provide a balloon stent system, which reduces excessive shedding of the drugs on the surface of the stent during the process of delivering the stent to the lesion.

[0007] To achieve the above purpose, the present invention provides the following technical solution: A balloon stent system, including a balloon body, the balloon body having a radially expanded state and a radially contracted state; a catheter member, arranged on one side of the balloon body, for switching the radially expanded state and the radially contracted state of the balloon body; a stent, arranged on the outer side wall of the balloon body, for supporting the blood vessel; The cutting assembly is disposed on the outer sidewall of the balloon body. The cutting assembly includes multiple groups of scoring members arranged parallel to the axial direction of the balloon body; Each group of the scoring members includes a first cutting member and a second cutting member arranged circumferentially around the balloon body. Both the first cutting member and the second cutting member have a first state and a second state. When in the first state, the side of the first cutting member away from the balloon body contacts the side of the second cutting member away from the balloon body, and a cavity for placing a part of the stent is formed between the first cutting member and the second cutting member. When in the second state, the first cutting member and the second cutting member do not contact, and the cavity formed between the first cutting member and the second cutting member is opened; The driving assembly is disposed on the balloon body and is used to drive the first cutting member and the second cutting member to switch between the first state and the second state.

[0008] The driving assembly includes a bladder strip disposed on the balloon body. The chamber of the bladder strip is communicated with the chamber of the balloon body. The cutting assembly is fixedly installed on the bladder strip. When the bladder strip is inflated, the first cutting member and the second cutting member do not contact. When the bladder strip is deflated, the first cutting member and the second cutting member contact.

[0009] Further, a liquid semi-permeable membrane is disposed on the bladder strip, and the liquid semi-permeable membrane separates the chamber of the bladder strip from the chamber of the balloon body.

[0010] Further, the cross-section of the scoring member along the radial direction of the balloon body is triangular. The first cutting member and the second cutting member are arranged in mirror symmetry, and the sides of the first cutting member and the second cutting member away from the balloon body are sharp corners.

[0011] Further, a plurality of cutting grooves are formed on the opposite sides of the first cutting member and the second cutting member, and the plurality of cutting grooves are distributed along the axial direction of the balloon body.

[0012] Further, there are multiple cutting members, and the multiple cutting members are distributed circumferentially around the balloon body.

[0013] Further, the stent is made of shape memory metal.

[0014] Further, the stent is a nitinol stent.

[0015] Further, a drug for inhibiting the proliferation of vascular medial smooth muscle cells is coated on the stent.

[0016] Further, the catheter member includes an inner tube and an outer tube. The inner tube is disposed through the inner cavity of the outer tube. The balloon body is disposed around the outer tube, and the chamber of the balloon body is communicated with the inner cavity of the outer tube.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: In the initial stage, the first cutting member and the second cutting member on the scoring member are still in the first state. When reaching the lesion area, the balloon body expands. After the scoring member cuts the plaque, the driving member drives the first cutting member and the second cutting member to switch from the first state to the second state, separating the first cutting member and the second cutting member, opening the cavity, and allowing the stent to detach from the cavity, thereby realizing the precise deployment of the stent in a blood vessel or other lumen. After the operation, the balloon shrinks to release the stent, completing the treatment process. Throughout the process, the design of the cutting assembly ensures that the stent can be precisely positioned and released according to requirements, while reducing the friction between the stent and the blood vessel wall or plaque, and preserving the drug on the stent that inhibits the proliferation of vascular smooth muscle cells in the middle layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a first schematic diagram of the overall structure change of the present invention; Figure 2 is a second schematic diagram of the overall structure change of the present invention; Figure 3 In the present invention Figure 1 is a partially enlarged schematic diagram of the structure at A; Figure 4 In the present invention Figure 2 is a partially enlarged schematic diagram of the structure at B; Figure 5 In the present invention Figure 1 is a partially enlarged schematic diagram of the structure at C; Figure 6 is a schematic diagram of the structure of the scoring member of the present invention; Figure 7 is a schematic diagram of the structure of the driving assembly of the present invention; Figure 8 is a first schematic diagram of the stent overlap of the present invention; Figure 9 is a second schematic diagram of the stent overlap of the present invention; Figure 10 is a third schematic diagram of the stent overlap of the present invention; Figure 11 is a schematic diagram of the structure of the catheter member of the present invention.

[0019] In the figure: 1. Balloon body; 2. Catheter member; 21. Inner tube; 22. Outer tube; 3. Cutting assembly; 31. Scoring member; 311. First cutting member; 312. Second cutting member; 313. Cutting groove; 314. Cavity; 32. Driving assembly; 321. Balloon strip; 322. Liquid semi-permeable membrane; 4. Tail seat; 5. Stent. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the protection scope of the present invention.

[0021] There may be vascular plaques in human blood vessels due to various reasons, namely atherosclerotic plaques, which are some yellowish-white, porridge-like masses embedded in the inner layer of the arterial vessel wall. Factors such as aging, lack of exercise, smoking, drinking, high blood lipid, high blood pressure, diabetes, obesity, etc. can all lead to the formation of vascular plaques.

[0022] If the plaque is allowed to develop, the shedding or fragmentation of the plaque may lead to blood vessels in the brain, causing ischemic stroke, or lead to coronary artery blockage, causing angina or even myocardial infarction, or block the blood vessels in the lower extremities, resulting in lower extremity vascular embolism and ischemic necrosis of the affected limb. Carotid artery plaques will cause stenosis of the blood vessel lumen, reduce cerebral blood supply, and cause symptoms such as dizziness, tinnitus, insomnia, memory decline, etc.

[0023] Generally speaking, once an arterial plaque is detected, active treatment should be carried out. For example, drugs are used to control blood lipid and cholesterol to inhibit the growth of the plaque; when the blood vessel stenosis is severe enough to affect the normal blood supply, it is necessary to decide whether to perform surgery after evaluation. There are two common surgical methods: endarterectomy and angioplasty. For plaques in some blood vessels such as cerebral blood vessels, they cannot be removed, and the operator may dilate the stenotic blood vessel through a balloon or a stent to keep the diseased blood vessel unobstructed.

[0024] In the usual interventional treatment of vascular stenosis, doctors will use a balloon to dilate the stenotic part, or use a balloon stent to implant a metal stent while dilating the stenotic part to obtain a more stable blood vessel lumen.

[0025] Please refer to Figure 1 , in which the structure of the instrument used includes a tailstock 4, a catheter member 2, and a balloon body 1. As Figure 11 shown, the catheter member 2 includes an inner tube 21 and an outer tube 22. The inner tube 21 is disposed through the inner cavity of the outer tube 22. The balloon body 1 is disposed around the outer tube 22, and the balloon body 1 is communicated with the inner cavity of the outer tube 22. The inner tube 21 is used for threading a guide wire. When the balloon body 1 will reach the diseased position along the guide wire, by introducing gas or liquid into the inner cavity of the outer tube 22, as Figure 1 to Figure 2 shown, the balloon body 1 is inflated to dilate the stenotic part.

[0026] However, it is difficult to expand a long segment of vascular stenosis with calcification or fibrosis, and because the balloon surface is smooth, it may cause disordered tearing of plaques and the inner wall of the blood vessel after expansion, accompanied by the risk of vascular dissection. In the face of the above situation, the surgeon may use a pressure-focused balloon to treat the lesion, that is, special balloons such as cutting and scoring. The main purpose is to cut off the continuity of the lesion position by cutting the calcification, and avoid disordered tearing of plaques and the inner wall of the blood vessel after expansion.

[0027] like Figure 1 As shown, its main structure is a cutting assembly 3 arranged on the outer side wall of the balloon body 1. Generally, there are multiple cutting assemblies 3, which are distributed circumferentially around the balloon body 1. During the expansion process of the balloon body 1, the cutting assembly 3 first contacts the plaque and cuts off the continuity of the plaque. Then, the balloon body 1 squeezes the cut plaque to reduce the migration of the plaque and irregular tearing.

[0028] It should be noted that due to the excessive proliferation of vascular endothelium and smooth muscle, or the patient has chronic diseases such as hypertension and diabetes and other comprehensive factors, the lesion site of some patients will be restenoticed after surgery. Therefore, a stent will be implanted at the lesion site to alleviate the above situation. Mainly, the stent 5 is placed on the outer wall of the balloon body 1, and arrives at the lesion site together with the balloon body 1. When the balloon body 1 expands, the stent 5 also expands to support the stenotic site of the blood vessel to prevent the risk of restenosis caused by elastic retraction of the stenotic site or proliferation of smooth muscle cells in the middle layer of the blood vessel.

[0029] The stent 5 is mainly composed of a ring structure and straight ribs, and its entire body is a tube shape similar to a blood vessel.

[0030] When implanting the vascular stent 5, in order to further prevent restenosis caused by proliferation of vascular smooth muscle cells at the stenotic site, some balloon stents 5 are coated with drugs that inhibit the proliferation of smooth muscle cells in the middle layer of the blood vessels (mainly rapamycin or paclitaxel, etc.). However, due to the obstruction of vascular plaques, a large amount of drugs on the surface of the stent 5 may fall off due to friction during the process of the device being delivered to the lesion site. After the stent 5 is expanded, there is too little drug on its surface and it may not be able to fully penetrate and act on the inner wall of the blood vessel at the severely narrowed site, resulting in limited drug effect.

[0031] To solve the above technical problems, this embodiment mainly improves the cutting assembly 3, and reduces the drug shedding on the stent 5 through the cutting assembly 3. The specific design is as follows: Figure 3As shown, the cutting assembly 3 includes multiple groups of scoring members 31 arranged parallel to the axial direction of the balloon body 1; each group of scoring members 31 includes a first cutting member 311 and a second cutting member 312 arranged along the circumferential direction of the balloon body 1. Both the first cutting member 311 and the second cutting member 312 have a first state and a second state. When in the first state, the side of the first cutting member 311 away from the balloon body 1 contacts the side of the second cutting member 312 away from the balloon body 1, as Figure 5 shown, a cavity 314 for placing a part of the stent 5 is formed between the first cutting member 311 and the second cutting member 312, as Figure 4 shown, when in the second state, the first cutting member 311 and the second cutting member 312 do not contact each other, and the cavity 314 formed between the first cutting member 311 and the second cutting member 312 is opened; a driving assembly 32 is arranged on the balloon body 1 and is used to drive the first cutting member 311 and the second cutting member 312 to switch between the first state and the second state.

[0032] As Figure 1 、 Figure 5 、 Figure 6 and Figure 8 shown, in the initial stage, the first cutting member 311 and the second cutting member on the scoring member 31 are in the first state, and a cavity 314 is formed between the first cutting member 311 and the second cutting member 312. The cavities 314 of each group of scoring members 31 of a single cutting assembly 3 are connected. The straight ribs of the stent 5 are located in the cavity 314, that is, the stent 5 is restricted by the scoring member 31 to prevent the stent 5 from detaching from the balloon body 1. At the same time, the cavity 314 of the scoring member 31 can accommodate a certain length of the stent 5, reducing the friction between the stent 5 and the blood vessel wall or plaque during the transportation process, and thus reducing the large amount of shedding of the drug on the stent 5; as Figure 9 shown, when reaching the lesion area, the balloon body 1 expands. After the scoring member cuts the plaque, the driving assembly 32 drives the first cutting member 311 and the second cutting member 312 to switch from the first state to the second state, separating the first cutting member 311 and the second cutting member 312, and opening the cavity 314, allowing the stent 5 to detach from the cavity 314, thereby realizing the precise deployment of the stent 5 in the blood vessel or other lumens, as Figure 10 shown, after the operation, the balloon shrinks to release the stent 5, completing the treatment process. During the whole process, the design of the cutting assembly 3 ensures that the stent 5 can be accurately positioned and released according to requirements, while reducing the friction between the stent 5 and the blood vessel wall or plaque, and preserving the drug on the stent 5 that inhibits the proliferation of vascular smooth muscle cells.

[0033] As Figure 5 and Figure 6As shown, the scoring member 31 is triangular along the radial section of the balloon body 1 , the first cutting member 311 and the second cutting member 312 are arranged in mirror symmetry, and the first cutting member 311 and the second cutting member 312 are sharp corners on the side away from the balloon body 1 .

[0034] The triangular structure formed by the mirror-symmetrical scoring piece 31 can maintain its shape more stably. In the process of treating arterial stenosis, after the device reaches the lesion, when the balloon body 1 expands, the triangular structure formed by the scoring piece 31 will squeeze the hard plaque in the blood vessel, and the circumferentially arranged cutting component 3 can cut the stenotic plaque in all directions. At the same time, the scoring piece 31 is made of metal. The metal scoring piece 31 has a higher hardness and is more efficient in cutting plaques than some polymer scoring pieces 31.

[0035] like Figure 5 and Figure 6 As shown, in order to facilitate the smooth movement of the balloon body 1 in the blood vessel, a plurality of grooves 313 are provided on the opposite sides of the first cutting piece 311 and the second cutting piece 312, and the plurality of grooves 313 are distributed along the axial direction of the balloon body 1. The single cutting assembly 3 formed by the plurality of groups of notched pieces 31 is in the shape of a long strip, and the grooves 313 are provided on the first cutting piece 311 and the second cutting piece 312, which to a certain extent improves the overall bendability of the device and the compliance of the device, while maintaining the plaque cutting performance, improves the device to have better bending performance when passing through curved blood vessels and treating curved segment lesions, and reduces the risks of straightening blood vessels, dissection, etc. during treatment.

[0036] like Figure 5 and Figure 7 As shown, the driving component 32 specifically includes a capsule strip 321 arranged on the balloon body 1, the capsule strip 321 is connected to the balloon body 1, and the cutting component 3 is fixedly installed on the capsule strip 321. When the capsule strip 321 is filled, the first cutting member 311 is not in contact with the second cutting member 312. When the capsule strip 321 is deflated, the first cutting member 311 is in contact with the second cutting member 312.

[0037] The design of the driving component 32 cleverly combines the functions of the capsule strip 321 and the cutting component 3. The specific working principle is that when the capsule strip 321 changes its shape by filling and shrinking, it can trigger the contact and separation of the first cutting piece 311 and the second cutting piece 312. When the balloon body 1 is not expanded, the capsule strip 321 is in a deflated state, and the first cutting piece 311 and the second cutting piece 312 are in contact to constrain the stent 5; when the balloon body 1 reaches the lesion area, the balloon body 1 is filled and expanded, and the capsule strip 321 is connected to the balloon body 1, so that the capsule strip 321 expands and maintains tension. At this time, the first cutting piece 311 and the second cutting piece 312 will gradually separate as the surface area of ​​the capsule strip 321 increases, thereby opening the cavity 314, and the stent 5 can be separated from the cavity 314.

[0038] It should be noted that when the balloon body 1 contracts, since the strip 321 is communicated with the inner cavity of the balloon body 1, the strip 321 will also contract. At this time, the first cutting member 311 and the second cutting member 312 will gradually approach each other. If the contraction is relatively fast, the first cutting member 311 and the second cutting member 312 may hook the stent 5 again.

[0039] As Figure 7 shown, in order to better release the stent 5. A liquid semi-permeable membrane 322 is provided on the strip 321. The liquid semi-permeable membrane 322 separates the cavity of the strip 321 from the cavity of the balloon body 1. When the liquid passes through both sides of the liquid semi-permeable membrane 322, it needs to exceed the rated pressure before it can pass through the liquid semi-permeable membrane 322. When it is less than the rated pressure, it is difficult for the liquid to pass through the liquid semi-permeable membrane 322.

[0040] Specifically, during the process of introducing the liquid into the balloon body 1, before the filling pressure reaches the rated pressure of the balloon body 1, the liquid is temporarily difficult to pass through the liquid semi-permeable membrane 322. At this time, only the balloon body 1 fills and expands. When the filling pressure exceeds the rated pressure (that is, when the balloon body 1 expands to nearly the maximum), the liquid will enter the strip 321 through the semi-permeable membrane and fill the strip 321, so that the first cutting member 311 and the second cutting member 312 are separated, facilitating the detachment of the stent 5. When the liquid in the balloon body 1 is withdrawn and contracts, due to the function of the liquid semi-permeable membrane 322, the liquid in the strip 321 will not flow out quickly, and the strip 321 will not contract sharply. Therefore, the first cutting member 311 and the second cutting member 312 remain separated, that is, the cavity 314 remains open, avoiding the first cutting member 311 and the second cutting member 312 from hooking the stent 5 again.

[0041] In the existing marketed medical device products, most of the stents 5 use stainless steel or cobalt-chromium alloy as the stent 5 material. Therefore, the stent 5 can be attached to the balloon body 1, and its shape implanted in the blood vessel depends on the expanded diameter of the balloon body 1. It does not have the shape memory characteristic and the supporting performance for the blood vessel lumen. Therefore, if the stenosis occurs in the peripheral artery or carotid artery of the lower limb and other parts where activities may occur, the activities of the human body after implanting the stent 5 may cause extrusion to the blood vessel and the stent 5 in the blood vessel, changing its shape in the human body, resulting in the stent 5 being unable to adhere to the inner wall of the blood vessel, causing consequences such as restenosis of the blood vessel or detachment of the stent 5.

[0042] To alleviate the above technical problems, the stent 5 is made of shape memory metal. Specifically, it is a nickel-titanium stent 5 with shape memory function, belonging to a self-expanding stent. After the balloon body 1 is withdrawn from the body, since it tends to deform towards the natural open state under the action of human body temperature, it can continuously apply radial support force to the inner wall of the blood vessel at the lesion site, reduce the elastic recoil of the blood vessel after the operation, and the stent 5 has better wall adhesion, is closer to the inner wall of the blood vessel, and it is easier for vascular endothelial cells to grow onto the stent 5. The endothelialization speed of the stent 5 is faster, and thus there is a lower risk of thrombus formation within the stent 5, reducing the burden on the patient of taking anticoagulant drugs and improving the treatment prognosis.

[0043] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

Claims

1. A balloon stent system, characterized in that, it includes a balloon body which has a radially expanded state and a radially contracted state; a catheter member provided on one side of the balloon body for switching the radially expanded state and the radially contracted state of the balloon body; a stent provided on the outer wall of the balloon body for supporting blood vessels; a cutting assembly provided on the outer wall of the balloon body, and the cutting assembly includes multiple groups of scoring members arranged parallel to the axial direction of the balloon body; each group of the scoring members includes a first cutting member and a second cutting member arranged circumferentially on the balloon body. Both the first cutting member and the second cutting member have a first state and a second state. When in the first state, the side of the first cutting member away from the balloon body contacts the side of the second cutting member away from the balloon body, and a cavity for placing a part of the stent is formed between the first cutting member and the second cutting member. When in the second state, the first cutting member and the second cutting member do not contact, and the cavity formed between the first cutting member and the second cutting member is opened; a driving assembly provided on the balloon body for switching the first state and the second state of the first cutting member and the second cutting member.

2. The balloon stent system according to claim 1, wherein The driving assembly includes a strip provided on the balloon body. The chamber of the strip is communicated with the chamber of the balloon body. The cutting assembly is fixedly installed on the strip. When the strip is filled, the first cutting member and the second cutting member do not contact. When the strip is deflated, the first cutting member and the second cutting member contact.

3. The balloon stent system according to claim 2, wherein A liquid semi-permeable membrane is provided on the strip, and the liquid semi-permeable membrane separates the chamber of the strip from the chamber of the balloon body.

4. The balloon stent system according to claim 1, characterized in that, The scoring member is triangular in the radial section of the balloon body. The first cutting member and the second cutting member are arranged in mirror symmetry, and the sides of the first cutting member and the second cutting member away from the balloon body are sharp corners.

5. The balloon stent system according to claim 1, wherein Multiple cutting grooves are provided on the sides of the first cutting member and the second cutting member facing away from each other, and the multiple cutting grooves are distributed along the axial direction of the balloon body.

6. The balloon stent system according to claim 1, wherein, There are multiple cutting members, and the multiple cutting members are distributed circumferentially on the balloon body.

7. The balloon stent system according to claim 1, wherein, The stent is made of shape memory metal.

8. The balloon stent system according to claim 7, characterized in that, The stent is a nitinol stent.

9. The balloon stent system according to claim 1, characterized in that, The stent is coated with a drug that inhibits the proliferation of vascular smooth muscle cells in the middle layer.

10. The balloon stent system according to claim 1, wherein The catheter member includes an inner tube and an outer tube. The inner tube is inserted into the inner cavity of the outer tube. The balloon body is disposed around the outer tube, and the chamber of the balloon body is communicated with the inner cavity of the outer tube.

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