CN113952597B

CN113952597B - Balloon catheter assembly with constraint structure

Info

Publication number: CN113952597B
Application number: CN202111363690.3A
Authority: CN
Inventors: 王秀伟; 林琳; 刘继勇; 秦泗海; 李文松
Original assignee: Kossel Medtech Suzhou Co ltd
Current assignee: Kossel Medtech Suzhou Co ltd
Priority date: 2021-11-17
Filing date: 2021-11-17
Publication date: 2023-04-14
Anticipated expiration: 2041-11-17
Also published as: CN116212206A; CN113952597A

Abstract

The embodiment of the specification discloses a balloon catheter assembly with a constraint structure, which comprises a catheter seat, a balloon and a catheter connected between the catheter seat and the balloon; the balloon is wrapped by a constraint structure, the constraint structure comprises a connection near end, a connection far end and an action section connected between the connection near end and the connection far end, and the width of at least one connecting rod connected with the near end and/or the connection far end is larger than that of at least one connecting rod of the action section.

Description

Balloon catheter assembly with constraint structure

Technical Field

The present description relates to the field of medical devices, and in particular, to a balloon catheter assembly.

Background

The invasive use of percutaneous transluminal angioplasty is a significant advance in the treatment of vascular disease. Over the years of development, balloon angioplasty has been a well-established technique that is well recognized in the medical community. Balloon angioplasty is mainly aimed at revascularization of stenotic and occluded blood vessels by inserting a catheter with an inflatable balloon into the vascular system, then inflating the balloon within the stenotic and occluded area in the blood vessel under an externally applied pressure, and further applying a radial pressure to the inner wall of the blood vessel to widen the stenotic and occluded area and make the blood flow more unobstructed.

The expansion saccule can be restrained by a restraining structure sleeved outside the expansion saccule in the expansion process, so that the expansion saccule has certain expansion size and expansion shape. However, in practical applications, it is found that, when the balloon is inflated, the constraining structure may be broken due to problems such as too low toughness or too concentrated stress, and further damage the balloon, or even cause serious injury to the patient. Therefore, there is a need for a more reliable balloon catheter assembly and constraining structure for those skilled in the art.

Disclosure of Invention

Embodiments of the present description provide a balloon catheter assembly comprising a catheter hub, a balloon, and a catheter connected between the catheter hub and the balloon; the balloon is wrapped by a constraint structure, the constraint structure comprises a connection near end, a connection far end and an action section connected between the connection near end and the connection far end, and the width of at least one connecting rod connected with the near end and/or the connection far end is larger than that of at least one connecting rod of the action section.

In some embodiments, the width of the at least one connecting rod connecting the proximal end and/or the distal end is 2 to 4 times the width of the at least one connecting rod of the active segment.

In some embodiments, the catheter comprises an inner tube, an outer tube sleeved outside the inner tube, and a connecting tube disposed between the outer tube and the balloon; the far end of the outer tube is connected with the connecting tube, and the outer surface of the connecting tube is connected with the near end of the balloon through an adhesive layer.

In some embodiments, the connecting tube is made of nylon or polyether block polyamide and the adhesive layer is made of polyether block amide.

In some embodiments, the length of the connecting tube is 8mm to 15mm.

In some embodiments, the bonding layer is L-shaped in cross-section.

In some embodiments, the constraining structure is a memory alloy stent integrally cut and formed, and at least one circular arc buffer section is formed at least one connecting intersection point of each metal wire in the memory alloy stent.

In some embodiments, the balloon is a single layer balloon entirely of nylon, nylon copolymer and/or parylene, or a double layer balloon with a parylene inner layer and a nylon outer layer.

In some embodiments, the proximal attachment end of the constraining structure is fixedly attached to the proximal end of the adhesive layer.

In some embodiments, each of the wires in the constraining structure is circular, trapezoidal, and/or triangular in cross-section.

Drawings

The embodiments of the present specification will be further explained by way of exemplary embodiments, which will be described in detail by way of the accompanying drawings. These embodiments are not intended to be limiting, and in these embodiments like numerals refer to like structures, wherein:

fig. 1 is a schematic structural view of a balloon catheter assembly according to some embodiments of the present disclosure.

Fig. 2 is a schematic view of a connecting rod of a balloon catheter assembly of some embodiments of the present description.

Fig. 3 is a partially enlarged schematic view of a balloon catheter assembly according to some embodiments of the present description.

Fig. 4 is a schematic view of the attachment of the adhesive layer of the balloon catheter assembly according to some embodiments of the present disclosure.

Fig. 5 is a schematic view of a wire connection of a constraining structure of a balloon catheter assembly according to some embodiments of the present description.

Fig. 6 is a schematic cross-sectional view of a wire of a constraining structure of a balloon catheter assembly of some embodiments of the present description.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present specification, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only examples or embodiments of the present description, and that for a person skilled in the art, the present description can also be applied to other similar scenarios on the basis of these drawings without inventive effort. It is to be understood that these exemplary embodiments are given solely to enable those skilled in the relevant art to better understand and implement the present description, and are not intended to limit the scope of the present description in any way. Unless otherwise apparent from the context, or otherwise indicated, like reference numbers in the figures refer to the same structure or operation.

As used in this specification and the appended claims, the terms "a," "an," "the," and/or "the" are not to be taken in a singular sense, but rather are to be construed to include a plural sense unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" are intended to cover only the explicitly identified steps or elements as not constituting an exclusive list and that the method or apparatus may comprise further steps or elements. The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment".

In the description of the present specification, it is to be understood that the terms "distal", "proximal", "inner", "outer", "distal", "near", "end", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are used only for convenience in describing and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present specification.

In this specification, unless explicitly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and include, for example, "connected" can be a fixed connection, a removable connection, or an integral part; can be directly connected or indirectly connected through an intermediate medium; communication between the interior of two elements may be possible, as well as the fact that two elements have an interactive relationship. Unless otherwise specifically defined, the specific meanings of the above terms in the present specification can be understood as specific cases by those skilled in the art.

In the process of reconstructing the blood transportation of a narrow and occluded blood vessel by using balloon angioplasty, the balloon catheter can be restrained by a restraining structure sleeved outside the balloon catheter, so that the balloon catheter has certain expansion size and expansion shape, and the stress of the blood vessel is more accurate. However, in some practical applications, it is found that when the balloon is inflated, the constraining structure may be broken due to problems such as too low toughness or too concentrated stress, and further damage the balloon, or even cause serious injury to the patient.

In view of the above problems, some embodiments of the present disclosure provide a balloon catheter assembly, which avoids the connecting rods located at the proximal and/or distal connecting ends of the constraining structure from being too low in toughness due to excessive loss during the electropolishing process by increasing the width of the connecting rods located at the proximal and/or distal connecting ends of the constraining structure before electropolishing, so that the width of at least one connecting rod located at the proximal and/or distal connecting end is greater than the width of at least one connecting rod located at the active segment of the constraining structure.

In other embodiments of the present description, the stress distribution may also be altered by changing the shape of constraining structures in the balloon catheter assembly. For example, at least one rounded buffer section may be formed at the connection intersection of the constraining structure to avoid fracture during expansion or contraction due to excessive stress concentration at the connection intersection.

The following provides a detailed description of a balloon catheter assembly according to an embodiment of the present disclosure with reference to the drawings.

Referring to fig. 1, in some embodiments, a balloon catheter assembly 100 may include a catheter hub 110, a balloon 120, and a catheter 130 coupled between the catheter hub 110 and the balloon 120, wherein the balloon 120 is externally wrapped with a constraining structure 140 for limiting the balloon's inflated size and shape.

In some embodiments, the balloon catheter assembly 100 may include one or more balloons 120, and the one or more balloons 120 may be expanded or contracted under the control of an operator (e.g., a physician or nurse). When the balloon 120 is expanded, it can act on the inner wall of the blood vessel, so as to expand the narrow and occluded area in the blood vessel, and further widen the narrow and occluded area in the blood vessel, so that the blood flow is smoother.

In some embodiments, when the balloon catheter assembly 100 includes a plurality of (e.g., two or more) balloons 120, the plurality of balloons 120 may be arranged in an order, equidistantly or non-equidistantly.

In some embodiments, the plurality of balloons 120 may be divided into distal balloons and proximal balloons according to their distance relationship to catheter hub 110. Wherein, distal balloon may refer to one or more of the plurality of balloons that are distal from catheter hub 110, and similarly, proximal balloon may refer to one or more of the plurality of balloons that are proximal to catheter hub 110.

In some embodiments, the material of the balloon 120 may be one or more of nylon, nylon copolymer, or poly-terephthalic plastic (e.g., PET (Polyethylene terephthalate)).

Catheter hub 110 may be used to connect or secure catheter 130. In some embodiments, the catheter 130 may include a plurality of internal cavities (e.g., a guidewire lumen, a distal balloon inflation lumen, a proximal balloon inflation lumen, a drug-loaded lumen, etc.), and the catheter hub 110 may be provided with respective ports corresponding to the respective internal cavities of the catheter 130.

For example, in some possible embodiments, the catheter hub 110 may include a first port, a second port, a third port, and a fourth port thereon, and the first port may be connected to a guidewire lumen of the catheter 130 for intraoperative guidance through a guidewire or for sensing pressure within the lumen; the second interface can be communicated with the far balloon expansion cavity of the catheter 130, the third interface can be communicated with the near balloon expansion cavity of the catheter 130, and the second interface and the third interface can be used for injecting liquid or gas into the far balloon and the near balloon respectively during operation so as to control the balloon bodies to expand sequentially or simultaneously and enable the balloon bodies at the two ends to expand to temporarily block blood flow, thereby forming a closed blood vessel cavity; the fourth port may be in communication with the drug-loaded lumen of catheter 130 for an initial withdrawal and subsequent infusion by the insufflator through the fourth port during a procedure, such that blood within the enclosed vascular cavity dissolves the drug-loaded lumen and then returns to the enclosed vascular cavity.

It should be noted that the above structures of catheter hub 110 and catheter 130 are merely exemplary. In some other embodiments, catheter 130 may include more or fewer internal lumens and, accordingly, more or fewer ports on catheter hub 110.

The constraining structure 140 may be wrapped around the outside of the balloon 120, limiting its expanded size and shape. Referring to fig. 2, in some embodiments, the constraining structure 140 may include a connecting proximal end 141, a connecting distal end 142, and an acting segment 143 connected between the connecting proximal end 141 and the connecting distal end 142 and acting on the balloon 120 to limit its inflated size and inflated shape. Where coupling proximal end 141 may refer to the end proximal to catheter hub 110 and coupling distal end 142 may refer to the end distal to catheter hub 110.

In some embodiments, the active segment 143, the proximal connecting end 141, and/or the distal connecting end 142 of the constraint structure 140 can each include at least one connecting rod. The connecting rod connecting the proximal end 141 and/or the distal end 1 may be connected to other components of the balloon catheter assembly 100 to secure the constraining structure 140. The connecting rods of the acting section 143 may be connected to each other and form a net-shaped ring structure capable of generating corresponding deformation with the balloon inflation or deflation to wrap the balloon 120, so as to limit the inflation size and inflation shape of the balloon 120.

In some embodiments, the biocompatibility of the constraint structure 140 is related to both the host response induced by the material and the degradation of the material in the human environment. For example, in the case of a constraining structure made of nitinol, the dissolution of nickel ions can cause problems of allergy, inflammation, etc., and the release rate of nickel ions is closely related to the surface quality of the constraining structure (specifically, the higher the corrosion resistance of the constraining structure, the slower the release rate of nickel ions, and the corrosion resistance of the constraining structure depends on its specific structure and surface morphology).

The surface morphology, in particular, the surface roughness, can be improved by electropolishing. However, when the constraint structure 140 is machined by electropolishing, since the number of connecting rods at the active section 143 is greater than the number of connecting rods at the connection proximal end 141 and/or the connection distal end 142, the current passing through the connecting rods at the connection proximal end 141 and/or the connection distal end 142 is greater than the current passing through the connecting rods at the active section 143, which results in excessive loss of the width of the connecting rods at the connection proximal end 141 and/or the connection distal end 142 after polishing, and thus causes a certain safety hazard to the constraint structure 140.

Therefore, in order to avoid excessive loss of the width of the connecting rod after polishing at the connecting proximal end 141 and/or the connecting distal end 142, in some embodiments, the width of the connecting rod at the connecting proximal end 141 and/or the connecting distal end 142 can be increased before electropolishing, thereby compensating for the loss of the width of the connecting rod during electrochemical polishing.

Based on this, in some embodiments, the width of at least one connecting rod at the connecting proximal end 141 and/or the connecting distal end 142 may be greater than the width of at least one connecting rod at the active section 143, thereby ensuring that the connecting rods at the connecting proximal end 141 and/or the connecting distal end 142 and the connecting rods at the active section 143 have a width satisfying a predetermined requirement after electropolishing. It should be noted that the "width" of the connecting rod described in the present specification may refer to a dimension perpendicular to the length extension direction of the connecting rod.

Referring to fig. 2, in some embodiments, the connecting rod 1411 at the proximal end 141 and the connecting rod 1421 at the distal end 142 may be in a substantially parallel configuration, and the connecting rod 1431 at the active segment 143 may be connected to a plurality of S-shaped wires to form a mesh structure wrapped around the balloon 120. Wherein, the connecting bar 1411 at the connecting proximal end 141 and the connecting bar 1421 at the connecting distal end 142 are substantially parallel to each other, the angle therebetween can be less than or equal to 15 °.

Referring to fig. 2, in some embodiments, the number of connecting bars 1431 located at the action section 143 may be twice the number of connecting bars 1411 located at the connection proximal end 141 or the number of connecting bars 1421 located at the connection distal end 142, in other words, the current flowing through the connecting bars 1411 and the connecting bars 1421 may be twice the current flowing through the connecting bars 1431.

Based on this, in some embodiments, in order to ensure that the connection bars 1411 and/or 1421 at the connection proximal end 141 and/or the connection distal end 142 and the connection bars 1431 at the action section 143 have widths satisfying a predetermined requirement after being electropolished, the widths of the connection bars 1411 and/or 1421 at the connection proximal end 141 and/or the connection distal end 142 before being electropolished may be set to be 1.5 to 4 times the width of the connection bars 1431 of the action section 143.

Optionally, in some embodiments, the width of the connecting bar 1411 and/or 1421 can also be 2 to 4 times the width of the connecting bar 1431; in some embodiments, the width of the connecting bar 1411 and/or 1421 can also be 1.5 to 3.5 times the width of the connecting bar 1431; in some embodiments, the width of the connecting bar 1411 and/or 1421 can also be 1.5 to 3 times the width of the connecting bar 1431; in some embodiments, the width of the connecting bar 1411 and/or 1421 can also be 2 to 3 times the width of the connecting bar 1431.

In some embodiments, the width W1 of the tie bars 1411 and/or 1421 at the connecting proximal end 141 and/or the connecting distal end 142 prior to electropolishing can be between 0.2mm and 0.3mm, and the width W2 of the tie bars 1431 at the active segment 143 prior to electropolishing can be between 0.08mm and 0.15 mm.

It should be noted that the above relation of the number between the connecting rod 1431 and the connecting rods 1411 and/or 1421 is only an exemplary one. In some embodiments, the ratio of the number of connecting bars 1431 to the number of connecting

bars

1411 or 1421 may be less than or greater than 2, and correspondingly, the ratio of the width of the connecting bars 1411 and/or 1421 to the width of the connecting bar 1431 may be less than 2 or greater than 4.

Fig. 3 is a schematic structural view of a balloon catheter assembly according to further embodiments of the present disclosure.

As shown in fig. 3, in some embodiments, the catheter 130 may include a stress diffusion tube 131, an inner tube 132, an outer tube 133 disposed over the inner tube 132, and a connecting tube 134 disposed between the outer tube and the balloon proximal end 1201. Wherein one end of stress diffusion tube 131 is connected to catheter hub 110 and the other end is connected to the proximal end of outer tube 133. The distal end of outer tube 133 is attached to the proximal end of connecting tube 134, and the distal end of connecting tube 134 is attached to the proximal end 1201 of balloon 120 by adhesive 135.

In some embodiments, the inner tube 132 may be a tubular element, such as a round tube, a square tube, or other regular/irregular shaped element. In some embodiments, inner tube 132 may include a plurality of internal lumens, such as a guidewire lumen, a distal balloon inflation lumen, a proximal balloon inflation lumen, a drug loading lumen, for receiving a guidewire, a distal inflation gas or liquid, a proximal inflation gas or liquid, an active drug, and the like, respectively.

In some embodiments, inner tube 132 may be fabricated from a metal or polymeric material, such as stainless steel, polyamide, polyether block amide, polyurethane, and the like. In some embodiments, the inner and/or outer walls of inner tube 132 may include a lubricious coating, such as a polytetrafluoroethylene coating or the like, to reduce frictional resistance thereof.

In some embodiments, outer tube 133 may be braided using wire. Also, to provide for better orientation of the outer tube 133 as it enters the vascular system, in some embodiments, the wire used may be a flat wire (i.e., a wire having a flattened shape).

In some embodiments, to reduce the size of the outer tube 133, the metal wires may be stainless steel wires or nickel titanium wires, preferably flat stainless steel or nickel titanium wires with a thickness of less than 0.2mm, such as 0.1mm, 0.08mm, 0.15mm, etc., which are braided so that the inner diameter of the entire outer tube 133 is controlled to be 0.6mm to 1.2mm, and the outer diameter is correspondingly controlled to be 0.8mm to 1.4mm.

In some embodiments, the outer tube 133 may include an outer layer and an inner layer, and the material of the outer layer and/or the inner layer may be polyimide, polyether block amide, polytetrafluoroethylene, or the like. In some embodiments, to control the thickness of the outer and/or inner layer to be less than 0.2mm, the wire may be directly wound on the inner layer of the outer tube 133 or the wire may be co-extruded with the outer and/or inner layer.

In some embodiments, the outer tube 133 may be bonded to the stress diffusion tube 131 by an adhesive, for example, the stress diffusion tube 131 and the outer tube 133 may be positioned, and then an adhesive may be added, and the adhesive may be applied to cause capillary action through a narrow space between the two, thereby sufficiently bonding the two. Exemplary adhesives may include polyimide adhesives, polytetrafluoroethylene adhesives, and the like.

In some embodiments, to enhance pushability and twistability of balloon 120, the connection of the distal end of outer tube 133 to the proximal end of balloon 120 may be via connecting tube 134 and adhesive layer 135.

In some embodiments, the distal end of the outer tube 133 may be coupled to the proximal end of the connecting tube 134, and the distal end of the connecting tube 134 may be coupled to the proximal end 1201 of the balloon 120 by the adhesive layer 135. In some embodiments, to reduce the outer diameter of the catheter 130 as much as possible, an adhesive layer 135 may be attached to the outer surface of the connecting tube 134 and/or the inner surface of the proximal end 1201 of the balloon 120.

In some embodiments, to achieve sufficient adhesion, the adhesive layer 135 may be simultaneously adhered to the inner surface of the proximal end 1201 of the balloon 120, the outer surface of the distal end of the connecting tube 134, and the cross-section of the distal end of the connecting tube 134.

In some embodiments, the outer tube 133 and the balloon 120 may have different radial dimensions, and the connecting tube 134 may have a variable diameter structure to ensure that the two ends of the connecting tube 134 can be reliably connected to the proximal end 1201 of the balloon 120 and the distal end of the outer tube 133, respectively. Specifically, the dimensions of the two ends of the connecting tube 134 may be different, wherein the dimension of the end near the outer tube 133 may be the same as or close to the dimension of the outer tube 133, and the dimension of the end near the balloon proximal end 1201 may be the same as or close to the dimension of the balloon proximal end 1201.

In some embodiments, to provide for better torqueability of the balloon segments, a softer connecting tube 134 may be used to connect the outer tube 133 to the proximal end 1201 of the balloon 120. In some embodiments, the connection tube 134 and the adhesive layer 135 may be made of different soft materials.

In some embodiments, to facilitate adhesion, the adhesive layer 135 may be a material with a relatively low melting point. In some embodiments, the bonding layer 135 may be formed of a material having a melting point lower than that of the connection tube 134.

In some embodiments, the connection tube 134 may be made of nylon or polyether block Polyamide (PEBAX) material, and the adhesive layer 135 may be made of polyether block amide (PEBA) material.

In some embodiments, considering that the soft material may increase the torsion performance, but also may cause the pushing performance to be deteriorated, by providing the adhesive layer 135 at the connection tube 134, on one hand, the connection tube 134 made of the soft material may be slightly thickened to increase the toughness, and on the other hand, due to the low melting point of the material used for the adhesive layer 135, the material may be rapidly melted when heated, so as to firmly connect the distal end of the outer tube 133 and the proximal end 1201 of the balloon.

Fig. 4 is a schematic view of an adhesive layer of a balloon catheter assembly of some embodiments of the present description.

Referring to fig. 4, in some embodiments, in order to achieve sufficient adhesion of the adhesive layer 135 to the connecting tube 134 and the proximal end 1201 of the balloon, the adhesive layer 135 may be provided in an L-shaped cross-section configuration. Specifically, the adhesive layer 135 may include a first connection portion 135-1 and a second connection portion 135-2, wherein the first connection portion 135-1 has a thickness greater than that of the second connection portion 135-2, the first connection portion 135-1 may be connected to both a section of the distal end of the connection tube 134 and the inner surface of the proximal end 1201 of the balloon, and the second connection portion 135-2 may be connected to the outer surface of the connection tube 134. It should be noted that, the bonding layer 135 with the L-shaped cross section connects the proximal end 1201 of the catheter 134 and the proximal end 1201 of the balloon, so that the connecting area between the two is increased, and the connection between the two is more reliable.

In some embodiments, the adhesive layer 135 may be thermally welded by using a laser, heat radiating metal jaws, RF energy, or other methods. In some embodiments, the thermal welding temperature may be controlled in a plurality of ramp-up phases: in the first stage, the welding temperature is raised to 100-110 ℃ for 20-30 s, so that the bonding layer 135 is softened; and in the second stage, the welding temperature is raised to 150-160 ℃ for 80-100 seconds, and the bonding layer 135 is fully welded.

In some embodiments, it has been found through experiments that when the length of the connection tube 134 is too long (e.g., greater than 15 mm), the pushing force cannot be transmitted, thereby resulting in poor pushing performance, and when the length of the connection tube 134 is too short (e.g., less than 8 mm), the twisting performance is poor due to the close distance of the plurality of welding points.

Based on the above test results, in some embodiments, in order to ensure the combination of the torsion performance and the pushing performance of the balloon segment, the length of the connecting tube 134 may be controlled between 8mm and 15mm. Alternatively, in some embodiments, the length of the connection tube 134 may be 8mm to 10mm; in some embodiments, the length of the connection tube 134 may be 10mm to 15mm; in some embodiments, the length of the connection tube 134 may be 9mm to 12mm.

In some embodiments, it is contemplated that the torsional and pushing properties of the balloon segment are also related to the thickness of the connecting tube 134, whether the adhesive layer 135 is added, and the thickness of the adhesive layer 135. In order to ensure the comprehensive torsion performance and pushing performance of the balloon segment, in some embodiments, an adhesive layer 135 may be disposed at the joint of the connecting tube 134 and the proximal end 1201 of the balloon, and the thickness of the adhesive layer 135 may be controlled to be between 0.1mm and 0.2mm, and the thickness of the connecting tube 134 may be controlled to be between 0.1mm and 0.2mm.

In order to verify the above feasibility regarding the thickness of the adhesive layer 135 and the thickness of the connection pipe 134, the applicant carried out corresponding tests. Exemplary test results are shown in the following table:

as can be seen from the above table, when the adhesive layer 135 is disposed at the joint between the connection tube 134 and the proximal end 1201 of the balloon, the thickness of the adhesive layer 135 is controlled to be 0.1mm to 0.2mm, and the thickness of the connection tube 134 is controlled to be 0.1mm to 0.2mm, the balloon catheter assembly 100 has a larger maximum pushing force and a better over-bending capability (i.e., has better torsion performance and pushing performance). Illustratively, in some embodiments, the thickness of the connection tube 134 may be set to 0.1mm, and the thickness of the adhesive layer 135 may be set to 0.2mm; in some embodiments, the thickness of the connection tube 134 may be set to 0.2mm, and the thickness of the adhesive layer 135 may be set to 0.1mm.

In some embodiments, to accommodate peripheral requirements, the balloon 120 may be 20mm to 40mm in length and 5mm to 16mm in diameter. Alternatively, in some embodiments, balloon 120 may be 20mm to 30mm in length and 5mm to 10mm in diameter; in some embodiments, balloon 120 may have a length of 25mm to 35mm and a diameter of 8mm to 12mm.

In some embodiments, balloon 120 may be a single layer balloon made of nylon or nylon copolymer, or poly-p-phenylene terephtalate plastic, or may be a double layer balloon with an inner layer made of poly-p-phenylene terephtalate plastic and an outer layer made of nylon. It should be noted that in some embodiments, by providing balloon 120 as a double-layer balloon with an inner layer made of a plastic such as parylene and an outer layer made of nylon, the balloon can be prevented from being damaged by excessive force applied to the constraining structure 140 when balloon 120 is inflated.

In some embodiments, the constraining structure 140 may be a memory alloy stent formed by integral cutting (e.g., laser integral cutting), exemplary memory alloys may include nickel-titanium alloys, copper-nickel alloys, and the like. Referring to fig. 2 and 5, in some embodiments, the memory metal stent may include a plurality of wires that may be divided into a connection bar 1411 at the connection proximal end 141, a connection bar 1421 at the connection distal end 142, a connection bar 1431 at the action section 143, and an S-shaped structure criss-cross connected with the connection bar 1411 at the connection proximal end/the connection bar 1421 at the connection distal end/the connection bar 1431 at the action section according to positions or shapes.

In some embodiments, the plurality of S-shaped structures may be arranged in an array along the arrangement direction of the balloon 120. Wherein each column constitutes a wave-shaped confinement ring, and each confinement ring can be connected with at least one of the connection rod 1411 at the connection proximal end, the connection rod 1421 at the connection distal end, and the connection rod 1431 at the action section. In some embodiments, to allow the constraining structure 140 to have substantially the same constraining force on the balloon 120 at different locations, the plurality of constraining rings may have the same spacing between them.

The S-shaped structure can be expanded or contracted with the balloon 120, so as to limit the size and shape of the balloon 120, in other words, the S-shaped structure can cooperate with the longitudinal and radial expansion of the balloon 120 during the expansion process, and can keep the balloon 120 at a desired position during the expansion process.

In some embodiments, the overall length of the constraining loop formed by the S-shaped structure after inflation with the balloon 120 may be greater than the maximum circumference of the balloon 120 after inflation. In some embodiments, to provide for substantially the same constraining effect of the constraining rings on balloon 120, different constraining rings may be configured to have substantially the same contraction performance and circumference.

In some embodiments, at least one rounded bumper segment can be formed in the memory metal stent at least one junction 1432 of each wire. Specifically, the connecting intersection point of any two metal wires in the memory metal stent forms a round angle or a circular arc-shaped structure during cutting, so that the fracture of the stent caused by the over-concentration of stress at the connecting intersection point 1432 of each metal wire in the expansion or contraction process is avoided, and further serious injury is caused to a patient. In addition, by setting the connection intersection point 1432 to be a rounded corner or a circular arc, the balloon 120 can be prevented from being damaged due to an excessively sharp force applied to the balloon 120, compared with a sharp corner structure such as an acute angle or a right angle.

Referring to fig. 5, in some embodiments, the rounded or radiused shape formed by the wire at the point of juncture when cut may be an arc of a circle having a radius R1, which may be concave or convex relative to the point of juncture. In some embodiments, the radius R1 of the rounded corner or circular arc structure may be between 0.5mm and 1mm, wherein the radius R1 and the arc length of the rounded corner or circular arc structure at each connecting intersection may be the same or different.

In some embodiments, the proximal connection end 141 of the constraining structure 140 may be connected at the proximal end of the adhesive layer 135 (e.g., the second connection portion 135-2) or the proximal end 1201 of the balloon. In some embodiments, by attaching the proximal attachment end 141 of the constraining structure 140 to the proximal end (e.g., the second attachment portion 135-2) of the adhesive layer 135, the proximal attachment end 141 of the constraining structure 140 can be prevented from expanding with the balloon as compared to the proximal end 1201 of the balloon, thereby achieving a better stop effect, and the overall outer diameter of the catheter 130 can be reduced to some extent as compared to the proximal attachment end 1201 of the balloon.

The coupling distal end 142 of constraining structure 140 may be coupled to the distal end of balloon 120, where the distal end of balloon 120 may refer to the location of balloon 120 that is farthest from catheter hub 110. In some embodiments, the distal attachment end 142 of the constraining structure 140 can be fixedly attached to the distal end of the balloon 120 by bonding or snapping, and similarly, the proximal attachment end 141 of the constraining structure 140 can be fixedly attached to the proximal end of the bonding layer 135 or the proximal end 1201 of the balloon by bonding or snapping.

Referring to fig. 6, in some embodiments, the cross-section of the wire in the constraining structure 140, which may refer to a section perpendicular to the direction of extension of the length of the wire, may be one or more of trapezoidal (as shown in fig. 6A), triangular (as shown in fig. 6B), or circular (as shown in fig. 6C). In some embodiments, the radial dimension of the wires in the constraining structure 140 may be between 0.1mm and 0.2mm. It should be noted that the shape of the cross section of the wire is merely an exemplary illustration, and in the embodiment of the present specification, the shape of the cross section of the wire may be, but is not limited to, the trapezoid, the triangle, and the circle. For example, in some embodiments, the cross-sectional shape of the wire may also be rectangular.

In some embodiments, the outer surface of balloon 120 and the outer surface of constraining structure 140 may be used to apply a drug. In some embodiments, the drug may be applied to the outer surface of the balloon 120 and/or the outer surface of the constraining structure 140 in a single application. In other embodiments, an opening communicating with the drug-loading cavity inside the catheter 130 may be formed between two adjacent balloons 120, and the drug may also be delivered through the drug-loading cavity formed in the catheter 130, and delivered to the outer surface of the balloon 120 and/or the outer surface of the constraint structure 140 through the opening formed between two adjacent balloons, or directly dissolved in the blood vessel cavity, where the outer surface of the constraint structure 140 may refer to a surface thereof facing away from the balloon 120. In some embodiments, the balloon catheter assembly 100 may further include a visualization assembly, and the drug may be accurately administered to the target location to be treated at a fixed point according to the image of the inside of the blood vessel obtained by the visualization assembly, so as to improve the therapeutic effect of the drug on the inner wall of the blood vessel to some extent.

In some embodiments, to increase the area of the outer surface of the constraining structure 140 that is coated with the drug, a wire with a trapezoidal cross-section may be selected to form the constraining structure 140 with the lower base surface 610 of the wire having a trapezoidal cross-section facing outward (i.e., away from the balloon 120), or a wire with a triangular cross-section with the longest of the three sides (e.g., 621) facing outward (i.e., away from the balloon 120). Considering that when the cross-sectional shape of the wire is a triangle, the force applied to the balloon 120 by the side of the wire facing the balloon 120 may be relatively sharp (i.e., the force per unit area is relatively large), and therefore, in order to avoid the balloon being damaged by the too sharp force applied by the wire during the inflation process, in some embodiments, the area of the side of the wire facing the balloon 120 and contacting the balloon 120 may be increased, for example, the angle of one corner of the triangle facing the balloon 120 may be increased to form an obtuse angle larger than 120 °, so that not only the contact area of the wire with the balloon 120 during the inflation process may be increased, and the force applied to the balloon per unit area may be reduced, but also the area of the side 620 facing away from the balloon 120 may be increased, thereby increasing the area available for coating the drug. In some embodiments, the outer surface of the constraining structure may be provided with a drug coating. In some embodiments, the drug coating may be disposed only on the outer surface of the balloon and not on the outer surface of the constraining structure, since the balloon, when disposed on the outer surface of the constraining structure, may cause the wire portion of the constraining structure to form a depression with respect to the balloon during expansion, and may not contact the inner wall of the blood vessel, thereby preventing drug release.

In some embodiments, the drug coating on the outer surface of the constraining structure 140 may comprise at least one other active drug other than a macrolide, for example at least one selected from the group consisting of paclitaxel and its derivatives, rapamycin and its derivatives, phosphodiesterase inhibitors, thrombin inhibitors, thymidine kinase inhibitors, antibiotics, adenosine. It should be noted that the above drugs are only exemplary, and in the embodiment of the present disclosure, the drug coating on the outer surface of the constraining structure 140 may be, but not limited to, the aforementioned exemplary drugs.

Having thus described the basic concept, it will be apparent to those skilled in the art that the foregoing detailed disclosure is to be regarded as illustrative only and not as limiting the present specification. Various modifications, improvements and adaptations to the present description may occur to those skilled in the art, although not explicitly described herein. Such alterations, modifications, and improvements are intended to be suggested in this specification, and are intended to be within the spirit and scope of the exemplary embodiments of this specification.

Also, the description uses specific words to describe embodiments of the description. Reference throughout this specification to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the specification is included. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the specification may be combined as appropriate.

Similarly, it should be noted that in the preceding description of embodiments of the present specification, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to imply that more features than are expressly recited in a claim. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.

Numerals describing the number of components, attributes, etc. are used in some embodiments, it being understood that such numerals used in the description of the embodiments are modified in some instances by the use of the modifier "about", "approximately" or "substantially". Unless otherwise indicated, "about", "approximately" or "substantially" indicates that the number allows a variation of ± 20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximations that may vary depending upon the desired properties of the individual embodiments. In some embodiments, the numerical parameter should take into account the specified significant digits and employ a general digit preserving approach. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the range in some embodiments of the specification are approximations, in specific embodiments, such numerical values are set forth as precisely as possible within the practical range.

For each patent, patent application publication, and other material, such as articles, books, specifications, publications, documents, etc., cited in this specification, the entire contents of each are hereby incorporated by reference into this specification. Except where the application history document does not conform to or conflict with the contents of the present specification, it is to be understood that the application history document, as used herein in the present specification or appended claims, is intended to define the broadest scope of the present specification (whether presently or later in the specification) rather than the broadest scope of the present specification. It is to be understood that the descriptions, definitions and/or uses of terms in the accompanying materials of this specification shall control if they are inconsistent or contrary to the descriptions and/or uses of terms in this specification.

Finally, it should be understood that the embodiments described herein are merely illustrative of the principles of the embodiments described herein. Other variations are also possible within the scope of the present description. Thus, by way of example, and not limitation, alternative configurations of the embodiments of the specification can be considered consistent with the teachings of the specification. Accordingly, the embodiments of the present description are not limited to only those embodiments explicitly described and depicted herein.

Claims

1. A balloon catheter assembly with a constraining structure comprising a catheter hub, a balloon, and a catheter connected between the catheter hub and the balloon; the balloon is externally wrapped with a constraint structure, and the constraint structure comprises a connection near end, a connection far end and an action section connected between the connection near end and the connection far end, and is a memory alloy stent formed by integral cutting; the number of the connecting rods of the action section is larger than that of the connecting rods connected with the near end and/or the far end; processing the constraint structure by electrolytic polishing; the width of the at least one connecting rod connected with the near end and/or the far end is 1.5-4 times of the width of the at least one connecting rod of the action section, so that the phenomenon that the width of the connecting rod positioned at the near end and/or the far end is excessively lost after polishing is avoided, and the loss of the rod width in the electrochemical polishing process is compensated.

2. The assembly according to claim 1, wherein the width of the at least one connecting rod connecting the proximal end and/or the distal end is between 2 and 4 times the width of the at least one connecting rod of the active section.

3. The assembly of claim 1, wherein the catheter comprises an inner tube, an outer tube disposed over the inner tube, and a connecting tube disposed between the outer tube and the balloon; the far end of the outer tube is connected with the connecting tube, and the outer surface of the connecting tube is connected with the near end of the balloon through an adhesive layer.

4. The assembly of claim 3, wherein the connecting tube is made of nylon or polyether block polyamide and the adhesive layer is made of polyether block amide.

5. An assembly according to claim 3 or 4, characterised in that the length of the connecting tube is 8-15 mm.

6. The assembly of claim 3, wherein the bond layer is L-shaped in cross-section.

7. The assembly of claim 1, wherein at least one of the connecting intersections of each of the wires in the memory alloy stent forms at least one rounded buffer segment.

8. The assembly of claim 1 or 7, wherein the balloon is a single layer balloon entirely of nylon, nylon copolymer and/or parylene, or a double layer balloon with an inner layer of parylene and an outer layer of nylon.

9. The assembly of claim 3, wherein the proximal attachment end of the constraining structure is fixedly attached to the proximal end of the adhesive layer.

10. The assembly of claim 7, wherein each of said wires in said constraint structure is circular, trapezoidal and/or triangular in cross-section.