Balloon catheter system

Abstract

The invention provides a balloon catheter system which comprises a balloon catheter with a balloon and a restraining support, the outer surface of the balloon is provided with a concave part, the restraining support is arranged outside the balloon and comprises a restraining part, and when the interior of the balloon reaches preset pressure and is in an expansion state, the restraining part is used for restraining the balloon. The restraining part makes contact with the outer surface of the balloon and limits radial expansion of the balloon in the contact area of the restraining part and the outer surface of the balloon, the concave part and the restraining part are matched to form a plurality of protruding parts on the surface of the balloon, the protruding parts can extrude the narrow section of the blood vessel, atheromatous substances, arterial plaques and the like of the narrow section are extruded to deform and attached to the inner wall of the blood vessel, and therefore the blood vessel is protected. And a good blood vessel expansion effect is achieved. Meanwhile, the concave areas are formed among the convex parts, extruded atheromatous substances, artery plaques and the like can move towards the concave areas among the convex parts nearby, part of extruded force is released, and the situation that the blood vessels are damaged due to the fact that smooth muscles of the blood vessel walls are torn too much is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of interventional medical devices, and particularly to a balloon catheter system. Background Art

[0002] From the 1970s to today, the technology of vascular interventional therapy has developed vigorously and rapidly. Balloon angioplasty, as one of the basic operations for endovascular treatment of lower extremity arteriosclerosis obliterans. Common balloons include scored balloons, plain old balloon angioplasty (POBA), drug-coated balloon (DCB), etc.

[0003] The principle of balloon angioplasty is as follows: When the artery is stenosed, information such as the stenosed position, diameter, and length is confirmed through angiography, and then a balloon catheter of the corresponding specification is selected. Then, a sheath is first inserted to establish a channel, and a guide wire is inserted to establish a track. Then, the balloon dilation catheter advances along this channel and track from outside the body until the distal end of the catheter passes through the stenosed segment (aligning the balloon with the stenosed segment). An additional pressure dilation device is used to apply pressure to the balloon catheter to expand the balloon. The balloon expansion squeezes the stenosed segment, and its internal pressure is converted into a dilation force, causing the atherosclerotic substances, arterial plaques, etc. in the stenosed segment to be squeezed and deformed and adhere to the blood vessel inner wall. The balloon is further expanded to appropriately tear the smooth muscle of the blood vessel wall, and the blood vessel and its lumen are further enlarged. After maintaining for a period of time (about dozens of seconds to several minutes), the balloon pressure is removed and it is withdrawn along the guide wire and the channel. Finally, the lumen of the stenosed segment of the blood vessel is enlarged, and a good blood circulation function is restored.

[0004] Currently, when the balloon catheters on the market expand the severely calcified occluded segment of blood vessels, it is easy to cause tearing of the blood vessel intima, forming a flow-limiting dissection, and the flow-limiting dissection is a main cause of restenosis in the short term after surgery. The consequences it causes are not only restenosis, but also acute occlusion or even acute thrombosis. Summary of the Invention

[0005] The present invention provides a balloon catheter system that can reduce the risk of blood vessel intima tearing.

[0006] The present invention provides a balloon catheter system, characterized in that it includes:

[0007] A balloon catheter, including a balloon, the balloon having an inflated state and a contracted state, and the outer surface of the balloon having a recessed portion;

[0008] A constraint stent, provided outside the balloon, the constraint stent including a constraint portion. When the balloon reaches a preset pressure and is in an inflated state, the constraint portion contacts the outer surface of the balloon and restricts the radial expansion of the balloon in the contact area with the outer surface of the balloon. The recessed portion and the constraint portion cooperate to form a plurality of convex portions on the surface of the balloon, and the convex portions protrude away from the inner cavity of the balloon relative to the constraint portion and the recessed portion.

[0009] In one embodiment, the balloon includes at least two balloon bodies arranged in sequence along the axial direction of the balloon catheter. The recessed portion includes a circumferential recessed unit located between two adjacent balloon bodies. The circumferential recessed unit extends in the circumferential direction of the balloon. When the balloon expands to the nominal diameter, the diameter of the circumferential recessed unit is smaller than the nominal diameter of the balloon. The restraining portion includes an axial strut extending along the axial direction of the balloon. When the interior of the balloon reaches a preset pressure and is in an inflated state, the axial strut restricts the radial expansion of the balloon. The axial strut and the circumferential recessed unit cooperate to form a plurality of protruding portions on the surface of the balloon.

[0010] In one embodiment, the restraining stent is fixedly connected to the balloon through an axial end. The restraining portion can move relative to the surface of the balloon. When the interior of the balloon reaches a preset pressure and is in an inflated state, part or all of the restraining portion is located within the recessed portion.

[0011] In one embodiment, the balloon catheter system further includes a traction portion. The traction portion is respectively connected to the restraining portion and the recessed portion, and is used to traction the restraining portion during the inflation process of the balloon, so that part or all of the restraining portion is located within the recessed portion when the interior of the balloon reaches a preset pressure and is in an inflated state.

[0012] In one embodiment, the traction portion includes one or more of a flexible traction unit and an adhesion unit.

[0013] In one embodiment, the balloon catheter system further includes at least one limiting portion. The limiting portion is provided on one axial side of the restraining portion and is used to limit the circumferential deflection of the restraining portion relative to the balloon during the inflation process of the balloon.

[0014] In one embodiment, the balloon includes a proximal segment, a distal segment, and a middle segment located between the proximal segment and the distal segment in the axial direction. The restraining portion is provided on the middle segment. The proximal segment and the distal segment are located outside the restraining portion. Limiting portions are provided on both the proximal segment and / or the distal segment. The limiting portion includes a limiting groove provided on the balloon and a limiting member paired with the limiting groove. The limiting member is provided at the axial end of the restraining portion and is connected to the restraining portion. During the inflation process of the balloon, the limiting member is located within the limiting groove to limit the circumferential deflection of the restraining portion relative to the balloon.

[0015] In one embodiment, the balloon catheter system further includes a connecting portion and an additional portion provided at at least one axial end of the restraining portion. The additional portion is provided between the connecting portion and the restraining portion. The two axial ends of the additional portion are respectively connected to the connecting portion and the restraining portion. The connecting portion is connected to the balloon. When the balloon expands, the additional portion can radially expand following the balloon prior to the restraining portion.

[0016] In one embodiment, the compliance of the convex portion is greater than the compliance of the concave portion.

[0017] In one embodiment, a drug layer is provided on the outer surface of the concave portion.

[0018] The balloon catheter system of the present invention includes a balloon catheter having a balloon and a restraining stent. The outer surface of the balloon has concave portions. The restraining stent is provided outside the balloon. The restraining stent includes a restraining portion. When the interior of the balloon reaches a preset pressure and is in an inflated state, the restraining portion contacts the outer surface of the balloon and restricts the radial expansion of the balloon in the contact area with the outer surface of the balloon. The concave portions and the restraining portion cooperate to form a plurality of convex portions on the balloon surface. The convex portions protrude away from the inner cavity of the balloon relative to the restraining portion and the concave portions. These convex portions can squeeze the stenotic segment of the blood vessel, causing atherosclerotic substances, arterial plaques, etc. in the stenotic segment to be squeezed and deformed and adhere to the inner wall of the blood vessel, achieving a good blood vessel dilation effect. At the same time, since a concave area is formed between the plurality of convex portions, the squeezed atherosclerotic substances, arterial plaques, etc. can move to the concave area between the convex portions nearby, releasing part of the squeezed force and avoiding excessive tearing of the smooth muscle of the blood vessel wall and damaging the blood vessel. Description of the Drawings

[0019] Figure 1 is a schematic structural diagram of the balloon catheter system in an embodiment of the present invention;

[0020] Figure 2 is a partial structural schematic diagram of the balloon catheter in an embodiment of the present invention;

[0021] Figure 3 is a partial structural schematic diagram of the balloon catheter system when the balloon is in an inflated state in an embodiment of the present invention;

[0022] Figure 4 is a schematic plan view of the unfolded restraining stent in an embodiment of the present invention;

[0023] Figures 5a - 5e is a schematic structural diagram of the end connection unit in an embodiment of the present invention;

[0024] Figure 6 is a schematic plan view of the unfolded restraining stent in an embodiment of the present invention;

[0025] Figure 7Schematic diagram of the planar expansion of the restraint bracket in another embodiment of the present invention;

[0026] Figure 8 Folding schematic diagram of the balloon in an embodiment of the present invention;

[0027] Figure 9 Schematic diagram of the planar expansion of the restraint bracket in an embodiment of the present invention (the black-filled part is only used to identify the first mesh hole and the second mesh hole);

[0028] Figure 10 is Figure 9 Enlarged schematic diagram of area A in (the black-filled part is only used to identify the first mesh hole and the second mesh hole);

[0029] Figure 11 Schematic diagram of the planar expansion of the restraint bracket after the restraint bracket follows the balloon to expand in an embodiment of the present invention;

[0030] Figure 12 is Figure 9 Enlarged schematic diagram of area A in;

[0031] Figure 13 Partial structure schematic diagram of the restraint bracket in an embodiment of the present invention;

[0032] Figure 14 Schematic diagram of the planar expansion of the restraint bracket in an embodiment of the present invention;

[0033] Figure 15 is Figure 14 Enlarged schematic diagram of area B in;

[0034] Figure 16 Schematic diagram of the planar expansion of the restraint bracket in another embodiment of the present invention;

[0035] Figure 17 Schematic diagram of the planar expansion of the restraint bracket in yet another embodiment of the present invention;

[0036] Figure 18 Structure schematic diagram of the additional part in an embodiment of the present invention;

[0037] Figure 19 Structure schematic diagram of the balloon catheter system in an embodiment of the present invention;

[0038] Figure 20 Schematic diagram of the planar expansion of the restraint bracket in an embodiment of the present invention;

[0039] Figure 21 Partial structure schematic diagram of the balloon catheter system when the balloon is in an inflated state in an embodiment of the present invention;

[0040] Figure 22Schematic structural diagram of the balloon in the inflated state in an embodiment of the present invention;

[0041] Figure 23 Schematic plan view of the restraining stent in an embodiment of the present invention;

[0042] Figure 24 Schematic partial structural diagram of the balloon catheter system when the balloon is in the inflated state in an embodiment of the present invention;

[0043] Figure 25 Schematic structural diagram of the traction part in an embodiment of the present invention;

[0044] Figure 26 Schematic structural diagram of the limiting part in an embodiment of the present invention. Detailed implementation manners

[0045] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0046] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0048] In the field of interventional medical devices, generally, the end of the medical device implanted into the human body or animal body that is closer to the operator is called the "proximal end", and the end that is farther from the operator is called the "distal end", and the "proximal end" and "distal end" of any component of the medical device are defined based on this principle.

[0049] Embodiment 1

[0050] Refer to Figure 1 and Figure 2, this embodiment provides a balloon catheter system 100, which includes a balloon catheter 10 and a restraining stent 20. The balloon catheter 10 may include a balloon 11 and a tubular assembly 12. Among them, a restraining stent 20 is sleeved outside the balloon 11 for restricting the expansion of the balloon 11.

[0051] The balloon 11 can be radially expanded and radially contracted under the control of an operator. The balloon 11 has an inner cavity. By injecting a medium (such as liquid or gas) into the inner cavity of the balloon 11 and extracting the medium, the radial expansion and radial contraction of the balloon 11 can be controlled respectively. When the balloon 11 is in the expanded state, the balloon 11 includes a proximal section 111, a distal section 113, and a middle section 112 with both ends connected to the proximal section 111 and the distal section 113 respectively. Among them, the middle section 112 of the balloon 11 is the action area (also called the effective area) where the balloon 11 plays a therapeutic effect. In this embodiment, the cross-sectional shape of the balloon 11 is generally circular. In other embodiments, the cross-section of the balloon 11 can also be other suitable shapes such as oval, crescent, semi-circular, etc. The proximal section 111 and the distal section 113 are generally conical, the middle section 112 is generally cylindrical, the cross-sectional area of the proximal end of the proximal section 111 is smaller than the cross-sectional area of the distal end of the proximal section 111, the cross-sectional areas of the middle section 112 are approximately equal, and the cross-sectional area of the proximal end of the distal section 113 is larger than the cross-sectional area of the distal end of the distal section 113. In other embodiments, the shapes of the proximal section 111, the distal section 113, and the middle section 112 of the balloon 11 can be any suitable shapes. The balloon 11 can be a semi-compliant balloon or a compliant balloon. For example, one or several of the materials such as nylon, Pebax, polyurethane, latex, polyethylene terephthalate, and polyethylene can be selected for production.

[0052] The tubular assembly 12 includes at least one tubular member. For example, the tubular assembly 12 includes two tubular members, namely an inner tube 121 and an outer tube 122. Among them, the inner tube 121 is inserted into the outer tube 122 and axially penetrates the inner cavity of the balloon 11 and is fixedly connected to the distal end of the balloon 11, and the distal end of the outer tube 122 is fixedly connected to the proximal end of the balloon 11. A delivery channel is formed between the inner tube 121 and the outer tube 122, and this delivery channel is communicated with the inner cavity of the balloon 11. Through this delivery channel, a medium can be injected into the inner cavity of the balloon 11 or the medium can be extracted from the inner cavity of the balloon 11. A guide wire channel is also provided in the inner tube 121, and the guide wire can axially penetrate the inner tube 121.

[0053] The restraining stent 20 is sleeved outside the balloon 11, and it can restrict the expansion shape of the balloon 11. Refer to Figure 2 , Figure 3 , Figure 4, the constraint bracket 20 includes a constraint portion 21 and a connecting portion 27. In this embodiment, the constraint portion 21 is only provided on the middle section 112 of the balloon 11, that is, the constraint portion 21 does not extend to the proximal section 111 and the distal section 113 of the balloon 11. A plurality of constraint holes (or gaps) are provided on the constraint portion 21. When the pressure inside the balloon 11 reaches a preset pressure (for example, the inside of the balloon 11 reaches a nominal pressure) and is in an expanded state, since the constraint portion 21 contacts part of the outer surface of the balloon 11 and limits the radial expansion of the balloon 11 in the contact area with the outer surface of the balloon 11, the area of ​​the balloon 11 not restricted by the constraint portion 21 protrudes outward through the plurality of constraint holes on the constraint portion 21 to form a plurality of protrusions 115, and the protrusions 115 protrude relative to the constraint portion 21 in a direction away from the inner cavity of the balloon 11. The multiple protrusions 115 can squeeze the narrowed section of the blood vessel, so that the atheromatous substances, arterial plaques, etc. in the narrowed section are squeezed and deformed, and adhere to the inner wall of the blood vessel, which has a good effect of vascular expansion. At the same time, due to the formation of a concave area between the multiple protrusions 115, the squeezed atheromatous substances, arterial plaques, etc. can move to the concave area between the protrusions 115 nearby, releasing part of the squeezed force, and avoiding excessive tearing of the smooth muscle of the blood vessel wall and damaging the blood vessel.

[0054] Reference Figure 1 and Figure 4 The connecting portion 27 is used to connect the constraint portion 21 to other components. For example, the connecting portion 27 fixes the constraint portion 21 to the tubular component 12 so that the constraint bracket 20 is fixed on the balloon catheter 10.

[0055] Exemplarily, the connecting portion 27 is disposed at the axial end of the constraining portion 21 and is connected to the constraining portion 21. In this embodiment, connecting portions 27 are provided at both ends of the constraining portion 21. Among them, the connecting portion 27 located on the distal side of the constraining portion 21 is fixedly connected to the inner tube 121, and the connecting portion 27 located on the proximal side of the constraining portion 21 is fixedly connected to the outer tube 122, and there is no direct connection between the constraining portion 21 and the balloon 11. In other embodiments, the constraining portion 21 may be provided with a connecting portion 27 only at one end. The connecting portion 27 includes a first axial end and a second axial end. The first axial end is farther from the constraining portion 21 than the second axial end. The second axial end is connected to the constraining portion 21. The first axial end of at least one connecting portion 27 is a circumferentially non-closed structure. The so-called circumferentially non-closed structure means that the contour of this structure in the circumferential direction is a non-closed shape, and there is a circumferential interval (or circumferential gap, circumferential notch). Since the first axial end is non-closed in the circumferential direction, before being connected to the tubular member, the first axial end can be deformed in the radial direction, so that its radial dimension changes. By providing a circumferentially non-closed structure at the first axial end of the connecting portion 27, the radial dimension of the first axial end of the connecting portion 27 can be enlarged and / or reduced as needed, so that the risk of the first axial end rubbing against the outer surface of the balloon 11 during the manufacturing process of the balloon catheter system 100 can be reduced, and the first axial end can well match the size of the tubular member of the balloon catheter 10, which is beneficial to improving the propulsion performance and safety performance of the balloon catheter system 100. Exemplarily, in some embodiments, the first axial end has an end opening, and in the natural state (i.e., the state without artificial external force), its radial dimension matches the outer diameter of the tubular member to be sleeved. Therefore, the probability of forming a large step after the first axial end is connected to the tubular member can be reduced. In addition, during the sleeving process with the balloon 11, the first axial end can be deformed radially, so that its end opening is enlarged, and then the balloon 11 can enter the constraining bracket 20 from the end opening, thereby reducing the risk of the first axial end rubbing against the surface of the balloon 11. In some embodiments, the radial dimension of the first axial end in the natural state is large enough (for example, its end opening is larger than the maximum radial dimension of the constraining bracket 20). During the sleeving process with the balloon 11, the risk of the first axial end rubbing against the surface of the balloon 11 can be reduced. During the connection process with the tubular member, the radial dimension of the first axial end can be reduced, for example, its end opening can be reduced to match the outer diameter of the tubular member. Therefore, the probability of forming a large step after the first axial end is connected to the tubular member can be reduced. In some embodiments, in the natural state, the radial dimension of the first axial end can be any other suitable dimension. During the assembly process of the balloon catheter 10, by enlarging and reducing its radial dimension, the probability of forming a large step after the first axial end is connected to the tubular member can also be reduced, and the risk of the first axial end rubbing against the surface of the balloon 11 can be reduced.

[0056] In this embodiment, the first axial ends of the connecting portions 27 connected to both axial ends of the restraining portion 21 are both circumferentially non-closed structures, which enables both axial ends of the restraining bracket 20 to well adapt to tubular members of different pipe diameters (in this embodiment, the outer diameter of the inner pipe 121 is smaller than the inner diameter of the outer pipe 122), and when the balloon 11 is inserted into the inner cavity of the restraining bracket 20, it can be inserted from either end. In other embodiments, only the first axial end of the connecting portion 27 at one axial end of the restraining portion 21 may be a circumferentially non-closed structure, which can also solve the technical problems of the present invention.

[0057] In this embodiment, the circumferentially non-closed structure includes one or more end connecting units 271 and circumferential intervals 273 provided on both circumferential sides of the end connecting unit 271, and the end connecting unit 271 can be connected to the tubular member. When there are multiple end connecting units 271, the multiple end connecting units 271 are arranged along the circumference of the tubular member, and at least two of the end connecting units 271 form an interval in the circumferential direction of the restraining bracket 20. Before the end connecting unit 271 is connected to the tubular member, the end connecting unit 271 can at least move relative to the restraining portion 21 in the radial direction of the restraining bracket 20. Before connecting to the tubular member, pushing any one of the end connecting units 271 can change the radial dimension of the end opening of the first axial end, with simple operation and high efficiency. It can reduce the risk of the first axial end rubbing against the outer surface of the balloon 11 during the manufacturing process of the balloon catheter system 100, and the first axial end can well match the size of the tubular member of the balloon catheter 10. Also, due to the existence of the circumferential interval 273, the end connecting unit 271 can move more easily relative to the restraining portion 21 and has a larger movement space. Therefore, the circumferentially non-closed structure can more conveniently and flexibly undergo radial deformation, so that the change space of its radial dimension is large enough to meet a wider range of requirements during the assembly process.

[0058] Exemplarily, the circumferentially non-closed structure includes at least two end connecting units 271 that are evenly spaced in the circumferential direction of the restraining bracket 20, and the two end connecting units 271 are oppositely arranged in the radial direction of the restraining bracket 20. Such an arrangement is beneficial for the end connecting units 271 to be evenly stressed, beneficial for improving the connection firmness between the connecting portion 27 and the tubular member, and will not overly increase the radial dimension at the connection between the end connecting unit 271 and the tubular member. In other embodiments, the number of end connecting units 271 can be one or more than two.

[0059] Referring to Figure 4 and Figures 5a - 5e , in this embodiment, the shape of the end connecting unit 271 includes a circle (referring to Figure 5b ), an ellipse (referring to Figure 4 271b in Figure 4271a), triangle (refer to Figure 5a , Figure 5c ), T-shaped (refer to Figure 5d ), fork-shaped (refer to Figure 5e ) or one or more of them. In other embodiments, the end connection unit 271 can be selected in any other suitable shape. Exemplarily, the end connection unit 271 can include a closed or non-closed annular connecting member 2711 and a connection hole 2712 provided in the annular connecting member 2711. When it is necessary to connect the end connection unit 271 to the tubular member, the end connection unit 271 can be first fully fitted to the outer surface of the tubular member, and then a heat shrinkable tube is sleeved outside it. Through heat treatment, the heat shrinkable tube can be reduced in diameter and the end connection unit 271 and the tubular member can be firmly wrapped and fixed together. The setting of the annular connecting member and the connection hole 2712 can make the end connection unit 271 better fit the surface of the tubular member, make the surface after their connection smoother, further reduce the probability of forming a large step, and is beneficial to improving the propulsion performance and safety performance of the balloon catheter system 100. In addition, during the heat treatment process, the polymer materials on the heat shrinkable tube and / or the tubular member can enter the connection hole 2712 and be melted together, which is beneficial to improving the connection strength between the end connection unit 271 and the tubular member. Especially when the annular connecting member 2711 is a closed annular structure, the connection strength between the end connection unit 271 and the tubular member can be further improved.

[0060] In this embodiment, the restraint bracket 20 includes two connecting parts 27, namely a first connecting part 27a and a second connecting part 27b. The first connecting part 27a is connected to the proximal end of the restraint part 21, and the second connecting part 27b is connected to the distal end of the restraint part 21. The first axial ends of the two connecting parts 27 both include end connecting units 271 that can move relative to the restraint part 21 in the radial direction of the restraint bracket 20. Exemplarily, the end connecting unit 271 of the first connecting part 27a is denoted as the first end connecting unit 271a, and the end connecting unit 271 of the second connecting part 27b is denoted as the second end connecting unit 271b. The shape of the first end connecting unit 271a may be different from the shape of the second end connecting unit 271b, which is beneficial for the operator to better distinguish the proximal end and the distal end of the restraint bracket 20, and the end connecting unit 271 with a suitable shape can also be selected according to actual needs as the proximal end or the distal end of the restraint bracket 20 to connect with other components. For example, the first end connecting unit 271a is generally in a water droplet shape, and the second end connecting unit 271b is generally in an oval shape. Both can better fit the outer surface of the tubular part, and have a larger contact area with the tubular part, so as to be beneficial for a stable connection with the tubular part, and the surface after connection is relatively flat. The first end connecting unit 271a is connected to the outer tube 122, and the second end connecting unit 271b is connected to the inner tube 121. Since the outer diameter of the outer tube 122 is larger than the outer diameter of the inner tube 121, the requirement for the connection stability between it and the end connecting unit 271 is higher. The water droplet shape of the first end connecting unit 271a can better fit the surface of the tubular part compared with other shapes. Therefore, the water droplet shape of the first end connecting unit 271a is beneficial for improving the connection stability between it and the outer tube 122. Further, the surface area of the first end connecting unit 271a is larger than the surface area of the second end connecting unit 271b, which is beneficial for increasing the contact area between the first end connecting unit 271a and the outer tube 122, so as to further improve the connection stability between the first end connecting unit 271a and the outer tube 122. The tip of the water droplet shape is connected to other components and points to the restraint part 21, which is beneficial for improving the flexibility of its relative movement with other components and for reducing the occurrence of stress concentration at the connection between the tip of the water droplet shape and other components.

[0061] Further, the connecting portion 27 may further include an intermediate connecting unit 272 disposed between the restraining portion 21 and the end connecting unit 271, and the end connecting unit 271 is connected to the restraining portion 21 through the corresponding intermediate connecting unit 272. Along the circumferential direction of the restraining bracket 20, circumferential intervals 273 are provided on both sides of the intermediate connecting unit 272. With such a setting, the intermediate connecting unit 272 can move relative to the restraining portion 21 at least in the radial direction of the restraining bracket 20, which is beneficial to further increase the movable space of the end connecting unit 271 connected thereto relative to the restraining portion 21, thereby further increasing the change space of the radial dimension of the circumferentially non-closed structure, and can meet a wider range of requirements during the assembly process. In this embodiment, each end connecting unit 271 is connected to the restraining portion 21 through the corresponding intermediate connecting unit 272. In other embodiments, some or all of the end connecting units 271 may also be directly connected to the restraining portion 21.

[0062] The above-mentioned intermediate connecting unit 272 may not be directly connected to the balloon 11, so that the intermediate connecting unit 272 can move relative to the balloon 11, which is not only beneficial to better sheathing during the sheath retraction process, but also when the length of the restraining portion 21 changes due to the expansion and contraction process, the intermediate connecting unit 272 can follow its movement to a certain extent without over-pulling the balloon 11 to cause damage to the balloon 11.

[0063] Exemplarily, the intermediate connecting unit 272 includes a connecting rod 2721, one end of the connecting rod 2721 is connected to the restraining portion 21, and the other end is connected to the corresponding end connecting unit 271. The shape of the connecting rod 2721 includes one or more of a straight line shape, a curved line shape, and a broken line shape. Among them, the curved line shape includes one or more of an arc shape, a wave shape, and a zigzag shape. Refer to Figure 4 And Figure 6 , in this embodiment, the shape of the connecting rod 2721 is a straight line shape. Refer to Figure 7 , in another embodiment, the shape of the connecting rod 2721 may be a wave shape. When the length of the restraining portion 21 changes, the curved line-shaped or broken line-shaped connecting rod 2721 can also change its length to a certain extent, thereby providing a change space for the length change of the restraining portion 21, which is beneficial to reducing the risk of breaking the intermediate connecting unit 272 when the restraining portion 21 expands and contracts.

[0064] Refer to Figure 4 , in this embodiment, the two axial ends of the connecting rod 2721 and the central axis of the restraining bracket 20 may be located in the same axial plane. Refer to Figure 6 And Figure 7, in other embodiments, one axial end of the connecting rod 2721 and the central axis of the restraint bracket 20 are located in a first axial plane, and the other axial end of the connecting rod 2721 and the central axis of the restraint bracket 20 are located in a second axial plane, and the first axial plane and the second axial plane intersect. Such a setting enables the connecting rod 2721 (even if it is straight) to change its length to a certain extent when the length of the restraint portion 21 changes, thereby providing a change space for the length change of the restraint portion 21, which is beneficial to reducing the risk of breaking the intermediate connection unit 272 when the restraint portion 21 expands and contracts. For a curved or folded connecting rod 2721, arranging the axial ends of the connecting rod 2721 in different axial planes can further reduce the risk of breaking the intermediate connection unit 272 when the restraint portion 21 expands and contracts.

[0065] Referring to Figure 8 , when the balloon 11 is in the initial contracted state (i.e., the initial contracted state before being used for treatment), the balloon 11 is folded to form a plurality of flaps 114, and the plurality of flaps 114 are folded circumferentially in a predetermined folding direction (for example, clockwise or counterclockwise). Further, referring to Figure 6 and Figure 7 , in other embodiments, one end of the intermediate connection unit 272 directly connected to the restraint portion 21 is defined as the first end 2722, and one end of the intermediate connection unit 272 directly connected to the end connection unit 271 is defined as the second end 2723. The deflection direction of the second end 2723 of the intermediate connection unit 272 relative to the first end 2722 in the circumferential direction of the restraint bracket 20 is opposite to the folding direction of the balloon 11. When the balloon 11 starts to expand, the balloon 11 will generate a force opposite to its folding direction on the restraint portion 21 due to expansion. When the deflection direction of the intermediate connection unit 272 in the circumferential direction is opposite to the folding direction of the balloon 11, it can well buffer the circumferential deflection force received by the restraint portion 21, thereby reducing the degree of deflection of the restraint portion 21, and further reducing the risk of damage and fracture at both ends of the intermediate connection unit 272 caused by the deflection of the restraint portion 21.

[0066] The structure of the restraint portion 21 in this embodiment can be various, which will be illustrated by examples with reference to the accompanying drawings below.

[0067] Referring to Figure 9 and Figure 10, in this embodiment, the restraining portion 21 includes a mesh structure 21a. The mesh structure 21a includes one or more rows of mesh holes 22. Each row of mesh holes 22 includes a plurality of mesh holes 22 arranged circumferentially along the restraining portion 21. The plurality of mesh holes 22 includes one or more first mesh holes 22a and one or more second mesh holes 22b. The first mesh holes 22a and the second mesh holes 22b are alternately arranged circumferentially along the restraining portion 21. For example, in this embodiment, each row of mesh holes 22 is formed by alternately arranging the first mesh holes 22a and the second mesh holes 22b. When the restraining portion 21 is in the first state, the area of the first mesh holes 22a is larger than the area of the second mesh holes 22b. Among them, the first state may be the initial natural radial contraction state of the restraining portion 21, that is, the state when the balloon 11 inside the restraining portion 21 is in the contracted state and the restraining portion 21 is not subjected to artificial external force. By arranging the first mesh holes 22a and the second mesh holes 22b circumferentially along the restraining portion 21, on the one hand, it is beneficial to improve the flexibility of the restraining portion 21, so that the area where the restraining portion 21 is located can better adapt to the curved blood vessel morphology. On the other hand, it is beneficial to improve the hugging performance of the restraining portion 21 (that is, the ability of the restraining portion 21 to return to the initial contraction state after the balloon 11 contracts), so that the balloon catheter system 100 can be repeatedly expanded and contracted in the body many times while still maintaining a good treatment effect. Therefore, multiple stenotic blood vessel segments in the living body can be treated without repeatedly sheathing and releasing the same balloon catheter 10 for different treatment areas, or replacing the balloon catheter 10 many times for different treatment areas. Exemplarily, when the restraining portion 21 is in the first state, the ratio R of the area of the first mesh holes 22a to the area of the second mesh holes 22b ranges from 1.5 to 2.5. When R is greater than 2.5, the difficulty of radial expansion of the restraining portion 21 increases. When R is less than 1.5, the hugging performance of the restraining stent 20 is poor. Therefore, by setting R within the above range, the restraining portion 21 is not only easy to radially expand but also has excellent hugging performance.

[0068] Further, the mesh structure 21a includes one or more columns of mesh holes 22. Each column of mesh holes 22 includes a plurality of mesh holes 22 arranged circumferentially along the restraining portion 21. The plurality of mesh holes 22 includes one or more of the above-mentioned first mesh holes 22a and one or more of the above-mentioned second mesh holes 22b. The first mesh holes 22a and the second mesh holes 22b are alternately arranged axially along the restraining portion 21. For example, in this embodiment, each column of mesh holes 22 is formed by alternately arranging the above-mentioned first mesh holes 22a and the second mesh holes 22b.

[0069] Refer to Figure 11, in this embodiment, when the constraint part 21 is in the second state, the area of the first mesh hole 22a and the area of the second mesh hole 22b are substantially equal. For example, when the constraint part 21 is in the second state, the areas of all the mesh holes 22 are substantially equal, forming a shape similar to a quadrilateral. The above-mentioned second state refers to the radial expansion state of the constraint part 21 when the pressure in the balloon 11 reaches a preset pressure (for example, the inside of the balloon 11 reaches the nominal pressure). Since the constraint part 21 has uniform mesh holes 22 when in the second state, the sizes of the protrusion parts 115 (refer to Figure 3 ) protruding from the multiple mesh holes 22 can be relatively uniform, so that the multiple protrusion parts 115 can all fit well with the stenotic segment of the blood vessel, achieving a good blood vessel dilation effect. At the same time, the multiple uniform protrusion parts 115 can apply a relatively uniform extrusion force to the inner wall of the blood vessel, avoiding excessive tearing of the smooth muscle of the blood vessel wall and damaging the blood vessel.

[0070] Refer to Figure 9 , Figure 10 and Figure 12 , exemplarily, the constraint part 21 includes a plurality of circumferential constraint rings 23 arranged at intervals along the axial direction of the constraint part 21 and a plurality of axial struts 26 arranged at intervals along the circumferential direction of the constraint part 21. The axial struts 26 divide the space between two adjacent circumferential constraint rings 23 into a plurality of first mesh holes 22a and second mesh holes 22b. When the constraint part 21 is in the second state, the above-mentioned axial struts 26 can be substantially parallel to the central axis of the constraint part 21 (that is, the included angle between the line connecting the two axial ends of the axial strut 26 and the central axis of the constraint part 21 does not exceed 15°). In this embodiment, the above-mentioned circumferential constraint ring 23 is a circumferentially closed ring structure (or a circumferentially closed-loop structure). In other embodiments, the circumferential constraint ring 23 can be a circumferentially non-closed structure (or a circumferentially open-loop structure).

[0071] The circumferential constraint ring 23 includes a plurality of vertices 24 arranged at intervals along the circumferential direction of the circumferential constraint ring 23. The plurality of vertices 24 include a first vertex 24a (or called a wave crest) and a second vertex 24b (or called a wave trough), and the first vertex 24a and the second vertex 24b are alternately arranged at intervals along the circumferential direction of the circumferential constraint ring 23. Exemplarily, the first vertex 24a is closer to the distal end of the constraint part 21 than the second vertex 24b. In other embodiments, the vertex 24 closer to the proximal end of the constraint part 21 can also be used as the first vertex 24a.

[0072] The first vertex 24a and the second vertex 24b adjacent in the circumferential direction are connected by a wave rod 25, thereby forming a plurality of waves arranged continuously in sequence in the circumferential direction. Each vertex 24 is connected to two wave rods 25, and the two wave rods 25 are disposed on both sides of the vertex 24 in the circumferential direction of the constraint portion 21. The wave rod 25 can be stretched and contracted relative to the vertex 24 through deformation. When the constraint portion 21 is in the first state, the wave rods 25 on both sides of the vertex 24 approach each other. When the constraint portion 21 is in the second state, the wave rods 25 on both sides of the vertex 24 flip in the direction away from each other, extend in the circumferential direction of the constraint portion 21, and are generally located in the same radial plane (cross-section) of the constraint portion 21 as the wave rods 25 they are connected to.

[0073] Referring to Figure 13 , the wave rod 25 includes an end bending section 251 connected to the vertex 24. For example, when the constraint portion 21 is in the first state, the wave rod 25 includes a first end bending section 251a connected to the first vertex 24a and a second end bending section 251b connected to the second vertex 24b. By providing the end bending section 251 connected to the vertex 24, the stress at the connection between the end of the wave rod 25 and the vertex 24 during the deformation of the wave rod 25 can be reduced, thereby reducing the risk of fracture at the connection between the wave rod 25 and the vertex 24.

[0074] To further reduce the stress at the connection between the wave rod 25 and the vertex 24 during the deformation of the wave rod 25, when the constraint portion 21 is in the first state, the end bending section 251 may include an end transition sub-section 2511 and an end bending sub-section 2512, and the end transition sub-section 2511 is closer to the vertex 24 than the end bending sub-section 2512. As Figure 13 shown, in one embodiment, the end transition sub-section 2511 may be a straight line segment. As Figure 14 , Figure 15 shown, the end transition sub-section 2511 may also be an arc segment, and the radian of the arc segment is smaller than the radian of the end bending sub-section 2512 to achieve a better transition connection effect. It can be understood that in other embodiments, the end transition sub-section 2511 may be omitted, and the end bending section 251 can still reduce the risk of stress concentration at the connection between the wave rod 25 and the vertex 24 to a certain extent.

[0075] Referring to Figure 13, in this embodiment, when the constraint part 21 is in the first state, the wave rod 25 may further include an intermediate section 252 with two ends respectively connected to the first end bent section 251a and the second end bent section 251b. The proximal end point of the intermediate section 252 is farther from the generatrix 21b of the constraint part 21 where the first vertex 24a is located than the distal end point of the intermediate section 252. That is to say, the distal end point of the intermediate section 252 is farther from the generatrix 21b of the constraint part 21 where the second vertex 24b is located than the proximal end point of the intermediate section 252. With such a setting, during the process of the constraint part 21 transitioning from the first state to the second state, the overall flipping amplitude required for the wave rod 25 to flip towards the connected vertex 24 side becomes smaller, thereby further reducing the probability of stress concentration inside the end bent section 251 and at the connection between the end bent section 251 and the vertex 24, which is beneficial to further reducing the risk of fracture of the end bent section 251 itself or fracture at the connection between the end bent section 251 and the vertex 24.

[0076] Exemplarily, referring to Figure 13 and Figure 16 , in this embodiment, when the constraint part 21 is in the first state, the intermediate section 252 includes a straight rod section 2521. The included angle range between the straight rod sections 2521 of two adjacent wave rods 25 is 8° to 35°. For example, the included angle between the straight rod sections 2521 of two adjacent wave rods 25 can be 8°, 10°, 15°, 20°, 25°, 30°, 25°, etc.

[0077] Referring to Figure 14 , in another embodiment, when the constraint part 21 is in the first state, the intermediate section 252 includes a middle bent sub-section 2522. The middle bent sub-section 2522 can be in a curved shape, and the curved shape includes an arc shape, a wavy shape, etc. The middle bent sub-section 2522 includes at least one bending point 2523 (or called a bending vertex), and the middle bent sub-section 2522 can bulge (or called rise) and bend towards one circumferential direction of the constraint part 21 or bend and bulge towards the other circumferential direction of the constraint part 21 at its bending point 2523. The setting of the middle bent sub-section 2522 is beneficial to further improving the hugging performance of the constraint part 21.

[0078] The above-mentioned bent sub-section may include an even number of bending points 2523, and the bending directions at two adjacent bending points 2523 are opposite. The purpose of such a setting is to make the wave shapes at the first vertex 24a and the second vertex 24b more consistent, the force on the wave rod 25 more uniform, and the hugging performance of the constraint part 21 better.

[0079] Exemplarily, Figure 15The middle bending sub-segment 2522 therein includes two bending points 2523. Denote the bending point 2523 closer to the first vertex 24a as the first bending point 2523a, and the bending point 2523 closer to the second vertex 24b as the second bending point 2523b. Among them, the middle bending sub-segment 2522 bulges and bends towards the direction away from the generatrix 21b of the constraint part 21 where the first vertex 24a is located at the first bending point 2523a (that is, bulges and bends towards the outer side direction of the wave where the first vertex 24a is located), and the middle bending sub-segment 2522 bulges and bends towards the direction away from the generatrix 21b of the constraint part 21 where the second vertex 24b is located at the second bending point 2523b (that is, bulges and bends towards the outer side direction of the wave where the second vertex 24b is located). Such a setting is beneficial to reducing the risk of stress concentration in the area where the end bending segment 251 is located. In other embodiments, the middle bending sub-segment 2522 may include an even number of bending points 2523 more than two. As long as the middle bending sub-segment 2522 bulges and bends towards the direction away from the generatrix 21b of the constraint part 21 where the first vertex 24a is located at the bending point 2523 closest to the first vertex 24a, and the middle bending sub-segment 2522 bulges and bends towards the direction away from the generatrix 21b of the constraint part 21 where the second vertex 24b is located at the bending point 2523 closest to the second vertex 24b, the risk of stress concentration in the area where the end bending segment 251 is located can be reduced to a certain extent.

[0080] Furthermore, the middle segment 252 may further include straight rod sub-segments 2521 respectively arranged at both ends of the middle bending sub-segment 2522. Such a setting enables a smooth transition between the middle bending sub-segment 2522 and the end bending segment 251, which is beneficial to improving the freedom of movement of the middle bending sub-segment 2522 relative to the end bending segment 251, and enables the constraint part 21 to be easily radially expanded. In other embodiments, the straight rod sub-segments 2521 connecting the middle bending sub-segment 2522 may be omitted.

[0081] Referring to Figure 9 、 Figure 12 and Figure 15 In this embodiment, each vertex 24 is fixedly connected to the corresponding axial strut 26. The axial strut 26 intersects with the circumferential constraint ring 23 at the vertex 24 it connects, so that each wave rod 25 is connected between two axially adjacent axial struts 26. The axial struts 26 and the wave rods 25 enclose a mesh hole 22. The axially arranged axial struts 26 enclose a circle, and the circumferentially arranged circumferential constraint rings 23 are fixedly connected to each axial strut 26, constraining the axially enclosed axial struts 26 in the circumferential direction and forming the mesh hole 22 at the same time. In other embodiments, it is not necessary that each vertex 24 is connected to the axial strut 26.

[0082] In this embodiment, the axial strut 26 extends from the proximal end of the restraining portion 21 to the distal end of the restraining portion 21. The axial strut 26 includes a plurality of axially uniformly arranged axially bent segments 261, and the axially bent segments 261 can be stretched and contracted through deformation to buffer the axial tensile force during the deployment of the axial restraint ring. Exemplarily, the axially bent segment 261 includes two or more bending points 2523, and the bending directions at two adjacent bending points 2523 are opposite to form a wavy shape. Further, the axial strut 26 may further include a straight reinforcing segment 262 connecting two adjacent axially bent segments 261, and the straight reinforcing segment is disposed at the vertex 24 of the circumferential restraint ring 23 to enhance the connection strength at the connection between the axial strut 26 and the circumferential restraint ring 23. In other embodiments, the above-mentioned straight reinforcing segment 262 may be omitted.

[0083] In this embodiment, when in the second state, the perimeter of the circumferential restraint ring 23 and the nominal diameter of the balloon 11 may satisfy the following expression:

[0084] L1 ∈ [π(D - 1), π(D - 0.2)]

[0085] wherein, L1 represents the perimeter of the circumferential restraint ring 23, in mm, and D represents the nominal diameter of the balloon 11, in mm. Such a setting makes the protrusion height of the protrusion 115 formed from the mesh hole 22 (refer to Figure 3 ) (i.e., the height relative to the protrusion of the restraining portion 21) appropriate. The protrusion 115 can effectively dilate blood vessels, is not likely to cause blood vessel damage, and can also avoid excessive binding force of the restraining portion 21 on the surface of the balloon 11 and damage to the balloon 11. In other embodiments, the perimeter of the circumferential restraint ring 23 and the nominal diameter of the balloon 11 do not necessarily satisfy the above expression, and appropriate parameters can be selected according to actual needs.

[0086] Further, referring to Figure 3 , in this embodiment, the balloon 11 includes two imaging portions 123 arranged at intervals in the axial direction (for example, the imaging portions 123 are arranged at intervals on the inner tube 121). When the restraining portion 21 is in the second state, the restraining portion 21 completely covers the interval region between the two imaging portions 123 in the axial direction. Such a setting includes that the restraining portion 21 can effectively cover the entire effective region of the balloon 11, so that the balloon catheter system 100 can more comprehensively and effectively expand the entire stenotic region, and avoid the situation that the restraining portion 21 cannot cover the entire effective region range of the balloon 11 due to shortening during the transition from the first state to the second state.

[0087] Further, referring to Figure 17, in this embodiment, an additional part 28 is provided at at least one axial end of the constraint part 21. The additional part 28 is arranged between the connection part 27 and the constraint part 21. The two axial ends of the additional part 28 are respectively connected to the connection part 27 and the constraint part 21. When the balloon 11 expands, the additional part 28 can radially expand following the balloon 11 prior to the constraint part 21. The provision of the additional part 28 is beneficial for sharing a part of the force for the connection part 27 during the expansion process of the balloon 11. On the other hand, since it radially expands following the balloon 11 prior to the constraint part 21, after expansion, a circumferential relative constraint is formed between the surface of the expanded balloon 11 and the additional part 28, thereby reducing the risk that the constraint part 21 drives the connection part 27 to deflect relative to the balloon 11 during the expansion process, and further reducing the risk of breakage of the connection part 27.

[0088] Exemplarily, the additional part 28 includes one or more additional circumferential rings 281 and additional axial columns 282. The radial supporting force of the additional circumferential ring 281 is less than that of the circumferential constraint ring 23, which enables the additional part 28 to expand prior to the constraint part 21 faster. The additional circumferential ring 281 and the additional axial columns 282 enclose to form at least one row of additional mesh holes 283. Each row of additional mesh holes 283 includes at least one first additional mesh hole 283a and at least one second additional mesh hole 283b. The first additional mesh hole 283a and the second additional mesh hole 283b are alternately arranged in the circumferential direction of the additional part 28. For example, in this embodiment, each row of additional mesh holes 283 is formed by alternately arranging the first additional mesh hole 283a and the second additional mesh hole 283b. When the additional part 28 is in the first state (i.e., the initial natural radially contracted state), the ratio of the area of the first additional mesh hole 283a to the area of the second additional mesh hole 283b is less than the ratio of the area of the first mesh hole 22a to the area of the second mesh hole 22b. For example, the ratio of the area of the first additional mesh hole 283a to the area of the second additional mesh hole 283b can be in the range of 1.0 to 1.4. Such a setting can also enable the additional part 28 to expand prior to the constraint part 21 faster. Refer to Figure 18 , further, the additional part 28 as a whole can be in a frustum-shaped structure. For example, the cross-sectional area of the axial end farther from the constraint part 21 is smaller than that of the axial end closer to the constraint part 21, so as to better match the shape of the end of the balloon 11, and thus can better respond to the expansion of the end of the balloon 11 and expand accordingly. For example, the additional part 28 located at the distal end of the constraint part 21 and / or the additional part 28 located at the proximal end of the constraint part 21 as a whole is approximately in a frustum-shaped structure, and the cross-sectional area of the axial end farther from the constraint part 21 is smaller than that of the axial end closer to the constraint part 21.

[0089] Refer to Figure 1, in this embodiment, a catheter seat 13 may also be provided at the proximal end of the tubular component 12 for communicating the tubular component 12 with the outside. Interfaces 131 corresponding to and communicating with the delivery channel and the guide wire channel of the tubular component 12 may be respectively provided on the catheter seat 13. It should be noted that the above structures of the catheter seat 13 and the tubular component 12 are only exemplary descriptions. In other embodiments, the structures of the tubular component 12 and the catheter seat 13 may be different from those in this embodiment. In other embodiments, the above catheter seat 13 may be omitted.

[0090] The above constraint stent 20 may be cut or woven from one or more materials such as elastic materials like nitinol, stainless steel, and polymer materials. Each component of the constraint stent 20 may be an integral structure or may be made separately and then spliced together.

[0091] It can be understood that the structures of the connecting portion 27, the constraining portion 21, and the additional portion 28 exemplified in this embodiment can be implemented independently, and can also play their respective beneficial effects. They can also be combined and implemented together to play their respective beneficial effects.

[0092] Embodiment Two

[0093] Referring to Figure 19 , Figure 20 , this embodiment provides a balloon catheter system 100, which includes a balloon catheter 10 and a constraint stent 20. The balloon catheter 10 may include a balloon 11 and a tubular component 12. Among them, a constraint stent 20 for restricting the expansion of the balloon 11 is sleeved outside the balloon 11.

[0094] Referring to Figure 21, the balloon 11 can be radially expanded and radially contracted under the control of an operator. The balloon 11 has an inner cavity. By injecting a medium (such as a liquid or a gas) into the inner cavity of the balloon 11 and extracting the medium, the radial expansion and radial contraction of the balloon 11 can be controlled respectively. When the balloon 11 is in the expanded state, the balloon 11 includes a proximal section 111, a distal section 113, and a middle section 112 with both ends connected to the proximal section 111 and the distal section 113 respectively. Among them, the middle section 112 of the balloon 11 is the action area (also called the effective area) where the balloon 11 exerts a therapeutic effect. In this embodiment, the cross-sectional shape of the balloon 11 is approximately circular. In other embodiments, the cross-section of the balloon 11 can also be other any suitable shapes such as an ellipse, a crescent, a semi-circle, etc. The proximal section 111 and the distal section 113 are approximately conical, and the middle section 112 is approximately cylindrical. The cross-sectional area of the proximal end of the proximal section 111 is smaller than the cross-sectional area of the distal end of the proximal section 111, and the cross-sectional area of the proximal end of the distal section 113 is larger than the cross-sectional area of the distal end of the distal section 113. In other embodiments, the shapes of the proximal section 111, the distal section 113, and the middle section 112 of the balloon 11 can be any suitable shapes. The balloon 11 can be a semi-compliant balloon 11 or a compliant balloon 11, and can be made of one or a mixture of several materials such as nylon, Pebax, polyurethane, latex, polyethylene terephthalate, and polyethylene. The specific structure of the tubular component 12 can refer to the description of Embodiment 1 and will not be elaborated here.

[0095] Refer to Figure 20 and Figure 21, the outer surface of the balloon 11 has a recessed portion 116. The restraining stent 20 is disposed outside the balloon 11 and can limit the expansion shape of the balloon 11. The restraining stent 20 includes a restraining portion 21. The axial two ends of the restraining portion 21 can be directly connected to the axial two ends of the balloon 11, or connected to the axial two ends of the balloon 11 through a connecting portion 27 (the specific structure of the connecting portion 27 can refer to that described in Embodiment 1 and will not be elaborated here). In other embodiments, only one end of the restraining portion 21 can be fixed to the axial end of the balloon 11, and the restraining stent 20 as a whole may not be connected to the balloon 11, but only sleeved outside the balloon 11. When the inside of the balloon 11 reaches a preset pressure (for example, the inside of the balloon 11 reaches the nominal pressure) and is in an expanded state, the restraining portion 21 contacts the outer surface of the balloon 11 and restricts the radial expansion of the balloon 11 in the contact area with the outer surface of the balloon 11. The recessed portion 116 and the restraining portion 21 cooperate to form a plurality of raised portions 115 on the surface of the balloon 11. The raised portions 115 protrude away from the inner cavity of the balloon 11 relative to the restraining portion 21 and the recessed portion 116. The raised portions 115 protrude away from the inner cavity of the balloon 11 relative to the restraining portion 21. The plurality of raised portions 115 can squeeze the stenotic segment of the blood vessel, so that atherosclerotic substances, arterial plaques, etc. in the stenotic segment are squeezed and deformed and attached to the inner wall of the blood vessel, achieving a good blood vessel dilation effect. At the same time, since a recessed area is formed between the plurality of raised portions 115, the squeezed atherosclerotic substances, arterial plaques, etc. can move to the recessed area between the raised portions 115 nearby, releasing part of the squeezed force and avoiding excessive tearing of the smooth muscle of the blood vessel wall and damaging the blood vessel. In addition, compared with the solution of simply forming a plurality of raised portions 115 on the surface of the balloon 11 by the restraining portion 21, the solution of this embodiment can reduce the coverage rate of the restraining portion 21 on the surface of the balloon 11, which is beneficial to improving the flexibility of the area where the balloon 11 is located, so that the balloon catheter 10 can better conform to the bending shape of the blood vessel. Compared with the solution of simply providing the recessed portion 116 on the surface of the balloon 11, the restraining portion 21 of this embodiment can restrain and support the formed raised portions 115 to a certain extent, and can avoid large deformation of the raised portions 115 due to the extrusion of the stenotic segment of the blood vessel, which is beneficial to stabilizing the protruding shape of the raised portions 115, thereby ensuring that the raised portions 115 can achieve the desired blood vessel dilation effect.

[0096] Exemplarily, the balloon 11 includes at least two balloon bodies 112a arranged in sequence along the axial direction of the balloon catheter 10. For example, the middle section 112 of the balloon 11 includes two balloon bodies 112a arranged in sequence along the axial direction of the balloon catheter 10. The recessed portion 116 includes a circumferential recessed unit 116a located between two adjacent balloon bodies 112a. The circumferential recessed unit 116a extends in the circumferential direction of the balloon 11. When the balloon 11 expands to the nominal diameter, the diameter of the circumferential recessed unit 116a is smaller than the nominal diameter of the balloon 11. In this embodiment, circumferential recessed units 116a are provided at both axial ends of each balloon body 112a. The restraining portion 21 includes an axial strut 26 extending in the axial direction of the balloon 11. The number of axial struts 26 may be one or more. When there are multiple axial struts 26, the multiple axial struts 26 may be evenly spaced along the circumferential direction of the balloon 11. When the inside of the balloon 11 reaches the preset pressure and is in the inflated state, the axial strut 26 restricts the radial expansion of the balloon 11. The axial strut 26 and the circumferential recessed unit 116a cooperate to form multiple protrusions 115 on the surface of the balloon 11. The axial ends of the axial strut 26 may be directly connected to the axial ends of the balloon 11, or connected to the axial ends of the balloon 11 through a connecting portion 27 (the specific structure of the connecting portion 27 may refer to that described in Embodiment 1 and will not be elaborated here). Through the cooperation of the circumferential recessed unit 116a and the axial strut 26, when the balloon 11 reaches the preset pressure, multiple protrusions 115 can be evenly formed. The multiple protrusions 115 can all fit well with the vascular stenosis segment, achieving a good vascular dilation effect. At the same time, the multiple uniform protrusions 115 can apply a relatively uniform extrusion force to the inner wall of the blood vessel, avoiding excessive tearing of the smooth muscle of the blood vessel wall and damaging the blood vessel. In addition, the axial strut 26 can easily follow the inflation of the balloon 11 and can effectively restrain it when the inside of the balloon 11 reaches the preset pressure.

[0097] Further, please also refer to Figure 22 , the recessed portion 116 of this embodiment may further include an axial recessed unit 116b. The axial recessed unit 116b extends in the axial direction of the balloon 11 and intersects with the circumferential recessed unit 116a. When the balloon 11 expands to the nominal diameter, the axial recessed unit 116b is recessed towards the inner cavity of the balloon 11. The axial recessed unit 116b and the circumferential recessed unit 116a cooperate to form an array of protrusions 115 on the surface of the balloon 11. For example, a grid-like array of protrusions 115 formed by vertical and horizontal intersections is formed. Please also refer to Figure 23 and Figure 24, the restraining part 21 may further include a circumferential restraining ring 23 extending in the circumferential direction of the balloon 11. The number of the circumferential restraining rings 23 may be one or more. When there are multiple circumferential restraining rings 23, the multiple circumferential restraining rings 23 may be arranged at equal intervals along the axial direction of the balloon 11. The specific structure of the restraining part 21 may refer to the description of the first embodiment. Such a setting makes it easier to form the raised part 115. When a relatively small preset pressure is reached inside the balloon 11, the raised part 115 with a predetermined height can be formed, which is beneficial to reducing the binding force of the restraining part 21 on the surface of the balloon 11, thereby reducing the risk of damage to the surface of the balloon 11 by the restraining part 21; adding the circumferential restraining ring 23 is also beneficial to better maintaining the shape of the raised part 115 and improving the blood vessel dilation effect. For the balloon catheter system 100 with a drug layer (such as a drug coating) provided on the surface of the balloon 11, when the balloon catheter system 100 is in the delivery state, the restraining part 21 can well protect the drug layer and reduce the risk of drug shedding caused by rubbing against the delivery sheath. In addition, the setting of the recessed part 116 can further increase the outer surface area of the balloon 11, increase the drug loading amount on the surface of the balloon 11, and is beneficial to improving the drug treatment effect.

[0098] It can be understood that in other embodiments, the recessed part 116 may only include the circumferential recessed unit 116a, and the restraining part 21 may only include the axial strut 26; or, in other embodiments, the recessed part 116 may only include the axial recessed unit 116b, and the restraining part 21 may only include the circumferential restraining ring 23; of course, in other embodiments, it may include recessed units and restraining parts 21 with other shapes or structures.

[0099] In this embodiment, the restraining stent 20 is fixedly connected to the balloon 11 through the axial ends. For example, the axial ends of the restraining stent 20 are respectively fixedly connected to the axial ends of the balloon 11, and the restraining part 21 may be relatively movable with respect to the surface of the balloon 11. When the pressure inside the balloon 11 reaches the preset pressure and is in the inflated state, part or all of the restraining part 21 is located in the recessed part 116. Such a setting is beneficial to better cooperate with the recessed part 116 to form a regular raised part 115, and can increase the contact area between the surface of the balloon 11 and the inner wall of the blood vessel, which is beneficial to improving the blood vessel dilation effect. For the balloon 11 with a drug layer provided on the surface, it is beneficial to improve the drug application effect, and when the outer surface of the recessed part 116 is provided with a drug layer, the restraining part 21 can promote the fragmentation and release of the drug layer after entering the recessed part 116.

[0100] Further, referring to Figure 25, the balloon catheter system 100 of this embodiment may further include a traction part 117, which is respectively connected to the restraint part 21 and the recess part 116, and is used to traction the restraint part 21 during the inflation process of the balloon 11, so that when the restraint part 21 reaches a preset pressure inside the balloon 11 and is in an inflated state, it is located within the recess part 116. By providing the traction part 117, the probability that the restraint part 21 enters the recess part 116 after the balloon 11 is inflated can be increased. Exemplarily, the traction part 117 includes one or more of a flexible traction unit and an adhesion unit. Among them, the flexible traction unit includes a traction rope, a traction wire, a traction filament, etc. with one end connected to the recess part 116 and the other end connected to the restraint part 21. The flexible traction unit may or may not have elasticity. During the inflation process of the balloon 11, the flexible traction unit can traction the connection part of the restraint part 21 into the area of the recess part 116 connected thereto. The adhesion unit may include adhesion points. By adhering the restraint part 21 and the recess part 116 at a certain adhesion point, for example, adhering the axial end of the restraint part 21 and the corresponding area of the recess part 116 at an adhesion point, so that during the inflation process of the balloon 11, the relative position of the restraint part 21 and the recess part 116 at the adhesion point remains unchanged, thereby promoting other non-adhered parts of the restraint part 21 to also enter the corresponding recess part 116 area. In other embodiments, different structures of the traction part 117 may also be adopted to increase the probability that the restraint part 21 enters the recess part 116 after the balloon 11 is inflated. In other embodiments, the traction part 117 may be omitted.

[0101] In other embodiments, referring to Figure 26 , the balloon catheter system 100 may include at least one limiting part 118, and the limiting part 118 is arranged on one axial side of the restraint part 21 (referring to Figure 25 ), and is used to limit the circumferential deflection of the restraint part 21 relative to the balloon 11 during the inflation process of the balloon 11, thereby increasing the probability that the restraint part 21 enters the recess part 116 after the balloon 11 is inflated.

[0102] Exemplarily, referring to Figure 25 , Figure 26 , the restraint part 21 is arranged on the middle section 112, the proximal section 111 and the distal section 113 are located outside the restraint part 21, and the limiting part 118 can be arranged on the proximal section 111 and / or the distal section 113. The limiting part 118 includes a limiting groove 1181 arranged on the balloon 11 and a limiting member 1182 arranged in a paired manner with the limiting groove 1181. The limiting member 1182 is arranged at the axial end of the restraint part 21 and is connected to the restraint part 21. During the inflation process of the balloon 11, the limiting member 1182 is located within the limiting groove 1181 to limit the circumferential deflection of the restraint part 21 relative to the balloon 11.

[0103] In other embodiments, referring to Figure 17, the balloon catheter system 100 may also be provided with the additional part 28 as described in the first embodiment. For the specific structure, refer to the description of the first embodiment and details will not be repeated here. The provision of the additional part 28 is beneficial to sharing a part of the force for the connecting part 27 during the inflation process of the balloon 11. On the other hand, since it follows the radial inflation of the balloon 11 prior to the restraining part 21, after inflation, a circumferential relative restraint is formed between the surface of the inflated balloon 11 and the additional part 28. Thus, the risk that the restraining part 21 drives the connecting part 27 to deflect relative to the balloon 11 during the inflation process can be reduced, which can further increase the probability that the restraining part 21 enters the recessed part 116 after the balloon 11 is inflated. At the same time, it is also beneficial to reduce the risk of the connecting part 27 breaking. It can be understood that the above-mentioned additional part 28 can be omitted.

[0104] In this embodiment, referring to Figure 22 , the compliance of the convex part 115 can be set to be greater than that of the recessed part 116, so that when the recessed part 116 reaches a predetermined pressure inside the balloon 11, its recessed shape can be better maintained. Exemplarily, when the convex part 115 and the recessed part 116 are made of the same material, the compliance of the recessed part 116 can be reduced by making the side wall thickness of the recessed part 116 greater than that of the convex part 115. Alternatively, a low elastic modulus layer can be provided inside the recessed part 116, and the elastic modulus of the material used for the low elastic modulus layer is less than that of the material used for the convex part 115 to reduce the compliance of the recessed part 116.

[0105] The above-mentioned restraining stent 20 can be cut or woven from one or more materials such as elastic materials like nitinol, stainless steel, and polymer materials. Each component of the restraining stent 20 can be of an integral structure or can be made separately and then spliced together.

[0106] In this embodiment, referring to Figure 1 , a catheter seat 13 can also be provided at the proximal end of the tubular component 12. For the specific structure of the catheter seat 13 and the connection manner with the tubular component 12, refer to the description in the first embodiment and details will not be repeated here. In other embodiments, the above-mentioned catheter seat 13 can be omitted.

[0107] It can be understood that the structures of the connecting part 27, the restraining part 21, the traction part 117, and the additional part 28 exemplified in this embodiment can be implemented separately, and each can also play its respective beneficial effects. They can also be combined and implemented together to jointly play their respective beneficial effects.

[0108] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

Claims

1. A balloon catheter system, characterized in that, Comprising: A balloon catheter, including a balloon which has an inflated state and a deflated state, and the outer surface of the balloon has a recessed portion; A constraint stent disposed outside the balloon. The constraint stent includes a constraint portion. When the internal pressure of the balloon reaches a preset pressure and is in the inflated state, the constraint portion contacts the outer surface of the balloon and restricts the radial expansion of the balloon in the contact area with the outer surface of the balloon. The recessed portion and the constraint portion cooperate to form a plurality of protruding portions on the surface of the balloon, and the protruding portions protrude away from the inner cavity of the balloon relative to the constraint portion and the recessed portion.

2. The balloon catheter system according to claim 1, characterized in that, The balloon includes at least two balloon bodies arranged in sequence along the axial direction of the balloon catheter. The recessed portion includes a circumferential recessed unit located between adjacent two balloon bodies, and the circumferential recessed unit extends in the circumferential direction of the balloon. When the balloon expands to the nominal diameter, the diameter of the circumferential recessed unit is smaller than the nominal diameter of the balloon; the constraint portion includes an axial strut extending along the axial direction of the balloon. When the internal pressure of the balloon reaches a preset pressure and is in the inflated state, the axial strut restricts the radial expansion of the balloon, and the axial strut and the circumferential recessed unit cooperate to form a plurality of protruding portions on the surface of the balloon.

3. The balloon catheter system according to claim 1, characterized in that, The constraint stent is fixedly connected to the balloon through an axial end, and the constraint portion can move relative to the surface of the balloon. When the internal pressure of the balloon reaches a preset pressure and is in the inflated state, part or all of the constraint portion is located in the recessed portion.

4. The balloon catheter system according to claim 3, characterized in that, The balloon catheter system further includes a traction portion, and the traction portion is respectively connected to the constraint portion and the recessed portion, and is used to traction the constraint portion during the inflation process of the balloon, so that part or all of the constraint portion is located in the recessed portion when the internal pressure of the balloon reaches a preset pressure and is in the inflated state.

5. The balloon catheter system according to claim 4, wherein The traction portion includes one or more of a flexible traction unit and an adhesion unit.

6. The balloon catheter system according to claim 3, characterized in that, It further includes at least one limiting portion, and the limiting portion is disposed on one axial side of the constraint portion, and is used to limit the circumferential deflection of the constraint portion relative to the balloon during the inflation process of the balloon.

7. The balloon catheter system according to claim 6, wherein, The balloon includes a proximal section, a distal section and a middle section located between the proximal section and the distal section in the axial direction. The constraint portion is disposed on the middle section, and the proximal section and the distal section are located outside the constraint portion. A limiting portion is provided on the proximal section and / or the distal section. The limiting portion includes a limiting groove provided on the balloon and a limiting member paired with the limiting groove. The limiting member is disposed at the axial end of the constraint portion and is connected to the constraint portion. During the inflation process of the balloon, the limiting member is located in the limiting groove to limit the circumferential deflection of the constraint portion relative to the balloon.

8. The balloon catheter system according to claim 1, characterized in that, It further includes: A connecting portion and an additional portion disposed at at least one axial end of the constraint portion. The additional portion is disposed between the connecting portion and the constraint portion. The two axial ends of the additional portion are respectively connected to the connecting portion and the constraint portion. The connecting portion is connected to the balloon. When the balloon expands, the additional portion can follow the radial expansion of the balloon prior to the constraint portion.

9. The balloon catheter system according to claim 1, characterized in that, The compliance of the protruding portion is greater than the compliance of the recessed portion.

10. The balloon catheter system according to any one of claims 1 to 9, characterized in that, A medicine layer is provided on the outer surface of the recessed portion.

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