Dilatation balloon and balloon dilatation catheter

Abstract

The present invention provides a dilatation balloon and a balloon dilatation catheter, wherein the dilatation balloon comprises an outer balloon and an inner balloon; the outer balloon is sleeved outside the inner balloon, and the inner balloon expands when filled with a filling fluid, and drives the outer balloon to expand, wherein the inner balloon has a first predetermined shape during the expansion process; after the inner balloon expands to the first predetermined shape, when it reaches a critical state, the filling fluid inside the inner balloon flows out into the outer balloon and fills the outer balloon. In this way, the inner balloon limits the expansion shape of the dilatation balloon through the first predetermined shape before expanding to the critical state, thereby solving the problem of easy movement of the balloon; further, when the inner balloon reaches a critical state, the filling fluid inside the inner balloon flows out into the outer balloon and fills the outer balloon, so that the restriction on the expansion shape of the dilatation balloon is released, so that the dilatation balloon can expand following the shape of the outer balloon, thereby reducing the formation of paravalvular leakage.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a dilatation balloon and a balloon dilatation catheter. Background Art

[0002] Aortic stenosis (AS) is one of the most common valvular heart diseases and seriously endangers human health. For patients with severe aortic stenosis, surgical aortic valve replacement was once the only treatment that could prolong their lives, but elderly patients are often contraindicated for surgery due to advanced age, weak constitution, severe lesions, or other combined diseases. More and more clinical results have confirmed that interventional therapy is an effective treatment for these high-risk patients or patients for whom traditional open-chest surgery is too risky. Existing interventional treatments include balloon aortic valvuloplasty (BAV) and transcatheter aortic valve implantation (TAVI). In both balloon aortic valvuloplasty (BAV) and transcatheter aortic valve implantation (TAVI), a balloon dilatation catheter is required. In balloon aortic valvuloplasty (BAV), a balloon is used to directly dilate the diseased native aortic valve. During transcatheter aortic valve implantation (TAVI), on the one hand, a balloon is used for pre-dilation to expand the calcified valve leaflets and create good access conditions for the implantation of the artificial valve; on the other hand, post-catheter dilation of the valve balloon after aortic valve implantation can make the artificial valve unfold well and improve its wall adhesion, thereby improving the treatment effect.

[0003] The aortic valve balloon dilatation catheter consists of an expandable valve balloon, a double-lumen tube and two connectors. The valve balloon needs to have the properties of low compliance, dimensional stability, rapid expansion and retraction, puncture resistance, explosion resistance, no movement, synchronous expansion, etc. The inner lumen size of the double-lumen tube is compatible with the guidewire of corresponding specifications, and the outer lumen needs to be unobstructed to ensure that the filling and withdrawal time is as short as possible.

[0004] At present, most valve balloon structures adopt a straight-cylinder design or an 8-shaped design, and the inner tube is usually a circular hollow tube. The straight-cylinder structure is conducive to the uniform expansion of the balloon at the lesion site, avoiding excessive expansion and tearing of the valve leaflets. However, when the straight-cylinder balloon is expanded, it is easy to move when squeezed by severely calcified valve leaflets, causing the balloon to deviate from the lesion site and fail to achieve the effect of expanding the lesion leaflets. The 8-shaped balloon structure can lock the lesion site through the middle waist section (waist), reducing the probability of movement to a certain extent, but because the waist section of the 8-shaped structure is shorter, the expansion of severe calcified lesions is limited, and when the balloon is fully expanded, there is a significant diameter difference between the middle waist section and the two ends, which is easy to cause complications such as paravalvular leakage. Summary of the invention

[0005] The object of the present invention is to provide a dilatation balloon and a balloon dilatation catheter to solve the problems of easy movement and paravalvular leakage in the existing balloon dilatation catheter.

[0006] In order to solve the above technical problems, the present invention provides a dilatation balloon, which comprises: an outer balloon and an inner balloon;

[0007] The outer balloon is sleeved outside the inner balloon, and the inner balloon expands when filled with filling fluid, and drives the outer balloon to expand, wherein the inner balloon has a first predetermined shaping state during the expansion process; after the inner balloon expands to the first predetermined shaping state, when it reaches a critical state, the filling fluid inside the inner balloon flows out into the outer balloon and fills the outer balloon.

[0008] Optionally, in the expansion balloon, the inner balloon continues to expand after expanding to the first predetermined shaping state until it bursts when reaching the critical state, so that the filling fluid inside the inner balloon flows out into the outer balloon and fills the outer balloon.

[0009] Optionally, in the dilatation balloon, the inner balloon includes a first shoulder segment, a waist segment and a second shoulder segment connected in sequence along the axial direction, and the wall thickness of at least the first shoulder segment or the second shoulder segment is not greater than 0.02 mm; or, the inner balloon has a weak area.

[0010] Optionally, in the expansion balloon, the weak area is linear.

[0011] Optionally, in the expansion balloon, a critical pressure when the inner balloon expands to the critical state is less than a preset pressure of the outer balloon's rated expansion.

[0012] Optionally, in the expansion balloon, the inner balloon has a liquid through hole, and the expansion balloon also includes a closing portion, which closes the liquid through hole after the inner balloon expands to the first predetermined forming state and before reaching the critical state, and releases the closure of the liquid through hole when the inner balloon reaches the critical state, so that the filling fluid inside the inner balloon flows out into the outer balloon and fills the outer balloon.

[0013] Optionally, in the dilatation balloon, the sealing portion includes a plug, a sealing patch or a water-soluble filling patch.

[0014] Optionally, in the dilatation balloon, the sealing portion further includes an anchor, and the plug is connected to the outer balloon or the inner balloon via the anchor.

[0015] Optionally, in the expansion balloon, the sealing portion also includes a traction line, the sealing patch is attached to the inner wall of the inner balloon and covers the liquid hole; one end of the traction line is connected to the sealing patch, and the other end of the traction line extends to the proximal end for the operator to pull the sealing patch to remove the cover of the liquid hole.

[0016] Optionally, in the expansion balloon, the inner balloon is a non-compliant balloon, and the inner balloon in the first pre-forming state is in the shape of a dumbbell with bulged ends and a concave middle; the outer balloon is a non-compliant balloon, and the outer balloon expands to the second pre-forming state after the inner balloon reaches a critical state, and the outer balloon in the second pre-forming state is in the shape of a straight cylinder.

[0017] In order to solve the above technical problems, the present invention also provides an expansion balloon, which includes: an outer balloon and an inner balloon; the outer balloon is arranged outside the inner balloon, and when the inner balloon is filled with filling fluid, it drives the outer balloon to expand; wherein the inner balloon has a first predetermined shape during the expansion process; the material of the outer balloon is selected from at least one of PE, PET, PA or Pebax; the material of the inner balloon is selected from at least one of PE, PET, PA or Pebax.

[0018] In order to solve the above technical problems, the present invention also provides an expansion balloon, which includes an outer balloon and an inner balloon; the outer balloon is arranged outside the inner balloon; the inner balloon is configured to have a critical state during the process of filling with filling fluid, so that the filling fluid inside it flows into the outer balloon when it reaches the critical state.

[0019] Optionally, in the expansion balloon, the outer balloon is configured to have a first shape before the inner balloon is in the critical state, and to have a second shape after the inner balloon is in the critical state, the first shape being defined by the inner balloon and different from the second shape.

[0020] To solve the above technical problems, the present invention also provides a balloon dilatation catheter, which comprises: the dilatation balloon as described above and a catheter, wherein the catheter is connected to the proximal end of the inner balloon, and the catheter is used to transmit filling fluid to drive the expansion or contraction of the dilatation balloon.

[0021] To summarize, in the expansion balloon and balloon expansion catheter provided by the present invention, the expansion balloon includes an outer balloon and an inner balloon; the outer balloon is sleeved outside the inner balloon, and the inner balloon expands when filled with filling fluid, and drives the outer balloon to expand, wherein the inner balloon has a first pre-formed state during the expansion process; after the inner balloon expands to the first pre-formed state, when it reaches a critical state, the filling fluid inside the inner balloon flows out into the outer balloon and fills the outer balloon.

[0022] With such configuration, the inner balloon limits the expansion shape of the expansion balloon through the first predetermined state before expanding to the critical state, thereby solving the problem of easy movement of the balloon; further, when the inner balloon reaches the critical state, the filling fluid inside the inner balloon flows out to the outer balloon and fills the outer balloon, so that the restriction of the inner balloon on the expansion shape of the expansion balloon is released, so that the expansion balloon can expand following the shape of the outer balloon, reducing the formation of paravalvular leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0024] Figure 1 is a schematic diagram of a balloon dilatation catheter according to an embodiment of the present invention;

[0025] Figure 2 is a schematic diagram of an expansion balloon according to an embodiment of the present invention when the inner balloon is in a predetermined state;

[0026] Figure 3 is a schematic diagram of an axial cross-section of a dilatation balloon according to an embodiment of the present invention when the inner balloon is in a predetermined state;

[0027] Figure 4 is a schematic diagram of an expansion balloon according to an embodiment of the present invention, in which the outer balloon is in an expanded state;

[0028] Figure 5 Schematic diagram of a sealing sticker and a traction line according to an embodiment of the present invention.

[0029] In the attached figure:

[0030] 1- dilatation balloon; 4- guidewire cavity; 5- connector; 6- developing ring; 7- catheter; 71- inner tube; 72- outer tube; 8- sheath; 9- fluid passage cavity;

[0031] 10-external balloon; 11-first cone section; 12-straight section; 13-second cone section;

[0032] 20-inner balloon; 21-third cone section; 22-main body section; 221-first shoulder section; 222-first transition section; 223-waist section; 224-second transition section; 225-second shoulder section; 23-fourth cone section; 24-liquid hole; 25-closing part; 251-sealing patch; 252-traction line. DETAILED DESCRIPTION

[0033] In order to make the purpose, advantages and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0034] As used in the present invention, the singular forms "one", "an" and "the" include plural objects, the term "or" is generally used to include the meaning of "and / or", the term "several" is generally used to include the meaning of "at least one", and the term "at least two" is generally used to include the meaning of "two or more". In addition, the terms "first", "second" and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" and "third" may explicitly or implicitly include one or at least two of the features, the term "proximal end" is generally the end close to the operator, the term "distal end" is generally the end close to the patient, that is, the end close to the lesion, "one end" and "the other end" as well as "proximal end" and "distal end" generally refer to two corresponding parts, which include not only the endpoints, and the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. In addition, as used in the present invention, an element disposed on another element generally only indicates that there is a connection, coupling, cooperation or transmission relationship between the two elements, and the connection, coupling, cooperation or transmission between the two elements may be direct or indirect through an intermediate element, and cannot be understood as indicating or implying the spatial position relationship between the two elements, that is, one element may be in any orientation such as inside, outside, above, below or on one side of another element, unless otherwise clearly indicated in the content. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] The core idea of ​​the present invention is to provide a dilatation balloon and a balloon dilatation catheter to solve the problem that the existing figure-8-shaped balloon dilatation catheter cannot adapt to multiple deformations.

[0036] The following description is given with reference to the accompanying drawings.

[0037] Please refer to Figures 1 to 5 ,in, Figure 1 is a schematic diagram of a balloon dilatation catheter according to an embodiment of the present invention; Figure 2 is a schematic diagram of an expansion balloon according to an embodiment of the present invention when the inner balloon is in a predetermined state; Figure 3 is a schematic diagram of an axial cross-section of a dilatation balloon according to an embodiment of the present invention when the inner balloon is in a predetermined state; Figure 4 is a schematic diagram of an expansion balloon according to an embodiment of the present invention, in which the outer balloon is in an expanded state; Figure 5 Schematic diagram of a sealing sticker and a traction line according to an embodiment of the present invention.

[0038] like Figure 1 As shown, the first embodiment of the present invention provides a balloon dilatation catheter, which includes: a dilatation balloon 1 and a catheter 7. The dilatation balloon 1 includes: an outer balloon 10 and an inner balloon 20; the catheter 7 is connected to the proximal end of the inner balloon 20, and the catheter 7 is used to transmit a filling fluid to drive the dilatation balloon 1 to expand or contract. The outer balloon 10 is sleeved outside the inner balloon 20, and the inner balloon 20 expands when filled with a filling fluid, and drives the outer balloon 10 to expand. The inner balloon 20 is configured to have a critical state during the process of filling with a filling fluid, so that the filling fluid inside it flows into the outer balloon 10 when it reaches the critical state. The inner balloon 20 has a first pre-shaped state during the dilatation process; after the inner balloon 20 expands to the first pre-shaped state, when it reaches the critical state, the filling fluid inside the inner balloon 20 flows out to the outer balloon 10 and fills the outer balloon 10. It should be noted that the outer balloon 10 is sleeved outside the inner balloon 20, which means that, on the same radial cross section of the expansion balloon 1, the distance between the outer balloon 10 and the axis of the expansion balloon 1 is greater than the distance between the inner balloon 20 and the axis of the expansion balloon 1. Relatively speaking, it can be understood that when one component is located inside another component, the distance between the inner component and the axis is less than the distance between the outer component and the axis.

[0039] Preferably, the outer balloon 10 and the inner balloon 20 are both non-compliant balloons. It should be noted that for a single balloon (such as the outer balloon 10 or the inner balloon 20), when a filling fluid (such as a filling liquid) of a nominal pressure (i.e., rated pressure) is filled into it, the balloon will expand to a certain size. Generally, the cross-section of the balloon is roughly circular at this time, and its diameter (referring to the outer diameter) is the nominal diameter of the balloon. When the filling fluid is continuously poured into a balloon at the nominal diameter to further expand it, the balloon will eventually be burst by the filling fluid, and when the balloon is burst, the pressure inside it is the rated bursting pressure. In this embodiment, a compliant balloon means that the diameter of the balloon at the rated bursting pressure is greater than 30% of the nominal diameter, while a non-compliant balloon means that the diameter of the balloon at the rated bursting pressure is not greater than 15% of the nominal diameter.

[0040] The inner balloon 20 can be pre-set according to the structural morphology of the predetermined expansion site (i.e., the lesion site). Figure 2 and Figure 3 In one example, when the expansion balloon 1 is used in the field of treating heart valve diseases, such as in aortic valve replacement surgery, the inner balloon 20 in the first predetermined state is in the shape of a dumbbell with expanded ends and a concave middle, and includes a main body section 22, wherein the main body section 22 includes a first shoulder section 221, a waist section 223, and a second shoulder section 225 in the axial direction. When the inner balloon 20 is in the first predetermined state, the radial dimension of the first shoulder section 221 is greater than the radial dimension of the waist section 223, and the radial dimension of the second shoulder section 225 is greater than the radial dimension of the waist section 223. The radial dimension here refers to the distance between the outer side walls of the inner balloon 20 passing through the axis of the inner balloon 20. Optionally, the cross section of the inner balloon 20 is circular, and the radial dimension of each segment refers to its diameter. The first shoulder segment 221, the waist segment 223, and the second shoulder segment 225 are all cylindrical straight tubes; preferably, the diameter of the first shoulder segment 221 is the same as the diameter of the second shoulder segment 225. When the inner balloon 20 is filled, due to the pre-shaped design of the inner balloon 20, the inner balloon 20 is formed as follows: Figure 2 and Figure 3 In the dumbbell-shaped state shown, the waist section 223 can be engaged with the heart valve ring to prevent the expansion balloon 1 from moving away from the lesion.

[0041] Optionally, the outer balloon 10 is also a non-compliant balloon, which is used to directly contact human tissue during use. It needs to have a high puncture resistance and a certain compressive strength to avoid being punctured by some human tissues such as calcified valve rings. Preferably, the outer balloon 10 is configured to have a first shape before the inner balloon 20 is in a critical state, and a second shape after the inner balloon 20 is in a critical state. The first shape is defined by the inner balloon 20 and is different from the second shape. Further, after the inner balloon 20 reaches the critical state, the outer balloon 10 continues to expand until it reaches the second pre-formed state. The outer balloon 10 in the second pre-formed state is straight (i.e., the second shape), which includes a straight straight section 12. In a preferred embodiment, the outer balloon 10 also includes a first cone section 11 and a second cone section 13, and the first cone section 11, the straight section 12 and the second cone section 13 are sequentially connected along the axial direction of the outer balloon 10. When the outer balloon 10 is expanded to the second predetermined state (meaning fully expanded, the internal filling pressure reaches the nominal pressure), the first cone section 11 and the second cone section 13 are roughly conical, and the straight section 12 is roughly cylindrical. The shape of the outer balloon 10 is the most common mainstream balloon shape currently. Those skilled in the art can understand its shape based on the prior art. Please refer to Figure 4 , when the outer balloon 10 is in the second pre-forming state, the radial dimension of the straight section 12 is uniform and unchanged. It should be understood that the straight section 12 is not always in a uniform radial dimension during the expansion process of the expansion balloon 1. During the expansion of the inner balloon 20 to the first pre-forming state, the outer balloon 10 and the inner balloon 20 can maintain a roughly similar shape, and the shape of the straight section 12 is also similar to the first pre-forming state of the inner balloon 20, for example, it can be similar to a dumbbell shape (i.e., the first shape). Furthermore, when the inner balloon 20 reaches a critical state, the filling fluid inside the inner balloon 20 flows out into the outer balloon 10 and fills the outer balloon 10. When the outer balloon 10 continues to expand, its straight section 12 gradually transitions to a cylindrical straight barrel shape until the radial dimension of the straight section 12 is uniform. With such a design, after the inner balloon 20 reaches the critical state, the expansion state of the entire expansion balloon 1 is similar to that of a traditional straight-tube balloon. In the pre-expansion of BAV surgery or TAVI surgery, it is easier for the surgeon to select the most suitable balloon specification for treatment according to the size of the diseased native leaflets and / or annuli, and expand the diseased area faster and more evenly; after the aortic valve is implanted in the TAVI surgery, the artificial biological valve can be fully expanded to avoid complications such as paravalvular leakage, thereby improving the quality of TAVI surgery. Optionally, the critical pressure when the inner balloon 20 reaches the critical state can be set in combination with the usage conditions, such as being set within the range of 0.5atm to 1atm. According to the usage requirements, the rated bursting pressure that the outer balloon 10 can withstand is at least 3atm or more.

[0042] Correspondingly, the two ends of the inner balloon 20 include a third cone section 21 and a fourth cone section 23 that are adapted to the shapes of the first cone section 11 and the second cone section 13. After the inner balloon 20 is expanded (such as in the first pre-formed state or when it is about to expand to the first pre-formed state), the third cone section 21 and the fourth cone section 23 are roughly conical and adapted to the shapes of the first cone section 11 and the second cone section 13. The distal end of the first shoulder section 221 is connected to the proximal end of the third cone section 21, and the proximal end of the second shoulder section 225 is connected to the distal end of the fourth cone section 23. Preferably, the main body section 22 also includes two transition sections, namely a first transition section 222 and a second transition section 224. The first transition section 222 is respectively connected to the first shoulder section 221 and the waist section 223, and the second transition section 224 is respectively connected to the waist section 223 and the second shoulder section 225. The setting of the two transition sections can form a transition connection between the shoulder section and the waist section 223. When the radial dimensions of the shoulder section and the waist section 223 are different, the transition section is preferably conical, with the smaller end of the cone connected to the waist section 223 and the larger end connected to the shoulder section.

[0043] Combine the following Figure 1 , Figure 3 and Figure 4 , an exemplary balloon dilatation catheter provided in this embodiment is described, and it should be understood that, Figure 1 The balloon dilatation catheter shown does not represent the actual state of the balloon dilatation catheter when in use, but only illustrates the structural composition of the balloon dilatation catheter.

[0044] Optionally, the catheter 7 is a double-layer structure, which includes an inner tube 71 and an outer tube 72, the outer tube 72 is sleeved outside the inner tube 71, and there is a gap between the inner tube 71 and the outer tube 72, and the gap is used for filling fluid transmission. The inner tube 71 passes through the distal end of the outer tube 72 and extends into the interior of the inner balloon 20, the distal end of the inner balloon 20 is fixedly sealed and connected to the inner tube 71, and the distal end of the outer balloon 10 is fixedly sealed and connected to the distal end of the inner balloon 20; the proximal end of the inner balloon 20 is fixedly sealed and connected to the outer tube 72, and the proximal end of the outer balloon 10 is fixedly sealed and connected to the proximal end of the inner balloon 20. The inner tube 71 is mainly used for the guide wire to pass through, and optionally, a developing ring 6 is also provided on the inner tube 71. When the filling fluid is delivered to the inner balloon 20 through the catheter 7 (referring to the gap between the inner tube 71 and the outer tube 72), the inner balloon 20 and the outer balloon 10 expand, and vice versa, when the filling fluid is extracted from the inner balloon 20 through the catheter 7, the inner balloon 20 and the outer balloon 10 contract. Preferably, the outer balloon 10 and the inner balloon 20 are pre-evacuated, the outer balloon 10 and the inner balloon 20 are close to each other, and the outer balloon 10 and the inner balloon 20 are closely fitted, so that during the expansion and contraction process of the expansion balloon 1, the outer balloon 10 and the inner balloon 20 expand and contract synchronously, which is conducive to better control of the shape of the expansion balloon 1. It should be noted that the "pre-vacuuming" here does not refer to an absolute vacuum in a narrow sense, but should be broadly understood as a negative pressure relative to atmospheric pressure. Due to process limitations, the "vacuum" here can be understood as a rough vacuum (10Torr~760Torr) or a moderate vacuum (1Torr~10Torr).

[0045] Furthermore, the balloon dilatation catheter also includes accessories such as a sheath 8, a liquid passage cavity 9, a guidewire cavity 4, and a connector 5. The interior of the sheath 8 includes a three-way component, and the liquid passage cavity 9, the guidewire cavity 4, and the catheter 7 are respectively connected to the three-way component. Optionally, the guidewire cavity 4 and the inner tube 71 of the catheter 7 are located on the main branch of the three-way component and are interconnected, which is a straight-through configuration; the liquid passage cavity 9 is located on the side branch of the three-way component, and the liquid passage cavity 9 is interconnected with the outer tube 72 of the catheter 7. The proximal ends of the liquid passage cavity 9 and the guidewire cavity 4 are respectively connected to a connector 5, which are respectively used to connect with external compatible components. Those skilled in the art can select and configure the various components of the balloon dilatation catheter according to the prior art.

[0046] The following describes, in conjunction with several exemplary embodiments, an implementation method in which, when the inner balloon 20 reaches a critical state, the filling fluid inside the inner balloon 20 flows out into the outer balloon 10 and fills the outer balloon 10 .

[0047] In one embodiment, after the inner balloon 20 is expanded to the first predetermined state, it continues to be filled with filling fluid and continues to expand until it reaches a critical state and bursts, so that the filling fluid inside the inner balloon 20 flows out into the outer balloon 10 and fills the outer balloon 10. According to the bursting form of the inner balloon 20, it is specifically divided into two categories: overall bursting and partial rupture.

[0048] In the example of the overall explosion of the inner balloon 20, the material of the inner balloon 20 is uniform and has poor pressure resistance, or the local pressure resistance is poor, so that when the inner balloon 20 is filled to the critical pressure, the overall explosion of the inner balloon 20 is triggered. Preferably, the explosion mode of the inner balloon 20 is a fragment-free, axial explosion. Preferably, the critical pressure when the inner balloon 20 expands to the critical state is less than the preset pressure of the rated expansion of the outer balloon 10 (i.e., the nominal pressure of the outer balloon 10 when it is fully expanded). When the inner balloon 20 expands to the critical state and explodes, the outer balloon 10 has not yet expanded to its preset pressure of rated expansion. This avoids the danger caused by the explosion of the outer balloon 10 when the inner balloon 20 explodes, thereby improving the safety of the expansion balloon. Of course, in some other embodiments, the critical pressure of the inner balloon 20 may not be limited to be less than the preset pressure of the rated expansion of the outer balloon 10. Since there is a volume difference between the inner and outer balloons when the inner balloon 20 explodes, the pressure in the outer balloon 10 will drop instantly according to the incompressible property of the liquid. Therefore, if the critical pressure of the inner balloon is set higher than the preset pressure of the rated expansion of the outer balloon 10, the effect of safe use can also be achieved. And if so set, the expansion process of the outer balloon 10 from the dumbbell shape to the straight cylinder shape can also be made more controllable.

[0049] In an exemplary embodiment, the inner balloon 20 reduces the pressure resistance of the inner balloon 20 by reducing the wall thickness. Optionally, the material of the inner balloon 20 can be the same as that of the outer balloon 10. However, the overall wall thickness of the inner balloon 20 is smaller than that of the outer balloon 10, for example, the single-layer wall thickness of the inner balloon 20 is not greater than 0.02 mm, so as to achieve the effect of overall explosion after reaching the critical state.

[0050] In another exemplary embodiment, unlike the previous exemplary embodiment, the overall wall thickness of the inner balloon 20 is not limited to no more than 0.02 mm, and the wall thickness of at least the first shoulder segment 221 or the second shoulder segment 225 of the inner balloon 20 is set to no more than 0.02 mm. Specifically, since the molding process of the inner balloon 20 is usually blow-molded with a thermoplastic polymer, the wall thickness is usually the thinnest at the part with the largest outer diameter of the inner balloon 20, that is, the first shoulder segment 221 and the second shoulder segment 225, and due to the limitation of the force mode, the shoulder segment with the largest outer diameter will break first. Therefore, the wall thickness at the first shoulder segment 221 or the second shoulder segment 225 can be limited to no more than 0.02 mm, so as to achieve the effect of the overall explosion of the inner balloon 20 after reaching the critical state. Of course, in practice, the wall thickness of other parts of the inner balloon 20 can also be set to no more than 0.02 mm, and the explosion effect is similar.

[0051] In some other embodiments, the inner balloon 20 has a weak area. A weak area refers to an area whose mechanical properties are weaker than the rest of the area. When expanding, the weak area may rupture first. The weak area may be formed by reducing the wall thickness on the surface of the inner balloon 20. Since the pressure inside the inner balloon 20 is basically equal everywhere when filled, the existence of any weak area can achieve the effect of overall explosion after the inner balloon 20 reaches a critical state. Optionally, the weak area may be distributed in a point-like manner on the inner balloon 20, and preferably, the weak area is linear. More preferably, the inner balloon 20 has a plurality of linear weak areas, and the plurality of weak areas are uniformly arranged around the inner balloon 20 circumferentially, so that after the inner balloon 20 reaches a critical state, the inner balloon 20 evenly explodes, and the explosion position is controllable, so as to ensure that the filling fluid is evenly in contact with the outer balloon 10 when the inner balloon 20 explodes, so that the outer balloon 10 can be evenly expanded.

[0052] In the example of partial rupture of the inner balloon 20, the inner balloon 20 has a liquid hole 24, and the expansion balloon also includes a sealing portion 25, which seals the liquid hole 24 after the inner balloon 20 expands to the first predetermined state and before reaching the critical state, and releases the sealing of the liquid hole 24 when the inner balloon 20 reaches the critical state, so that the filling fluid inside the inner balloon 20 flows out into the outer balloon 10 and fills the outer balloon 10. Specifically, before the inner balloon 20 expands to the critical state, the liquid hole 24 is covered by the sealing portion 25, until the inner balloon 20 reaches the critical state, the liquid hole 24 is opened, and the inner balloon 20 can release the filling fluid to the outside through the liquid hole 24. According to the form of partial rupture of the inner balloon 20, the sealing portion 25 includes a plug, a sealing patch 251 or a water-soluble filling patch.

[0053] In an exemplary embodiment, the sealing portion 25 includes a plug, which may be a silicone or latex plug with a certain flexibility, and is fixed to the inner balloon 20 by being embedded in the liquid hole 24; after the inner balloon 20 expands to the first predetermined forming state, it continues to be filled with filling fluid and continues to expand. The pressure inside the inner balloon 20 gradually increases and reaches a critical pressure. When it reaches a critical state, the plug is squeezed out of the liquid hole 24 to the area between the inner and outer balloons, and then the filling fluid flows out of the inner balloon 20 from the liquid hole 24, directly contacts the outer balloon 10, fills the outer balloon 10, and as the filling fluid continues to be filled, the outer balloon 10 continues to expand.

[0054] Further, the closure part 25 also includes an anchor, and the plug is connected to the outer balloon 10 or the inner balloon 20 through the anchor. When the plug is used to block the liquid-passing hole 24 in an embedded manner, an additional anchor can be further used to limit the plug from falling off. The anchor can be a line glued to the inside of the outer balloon 10 or the outside of the inner balloon 20. The presence of the anchor can prevent the plug from falling off into the human body when the outer balloon 10 also ruptures. Preferably, the inner balloon 20 has only one liquid-passing hole 24, and the closure part 25 includes only one plug. Since the pressure inside and outside the inner balloon 20 will quickly reach equilibrium when a plug fails at a certain place, only one liquid-passing hole 24 can take effect, and more plugs cannot be squeezed out from the corresponding liquid-passing hole 24. In order to simplify the structure, only one liquid-passing hole 24 can be set on the inner balloon 20, and the closure part 25 also includes only one plug.

[0055] In another exemplary embodiment, different from the previous exemplary embodiment, the closure portion 25 includes a sealing sticker 251, which is preferably pasted to the liquid-through hole 24 in a bonding manner to form a closure of the liquid-through hole 24. The adhesive is mainly for the purpose of satisfying sealing, and the adhesive needs to be insoluble in water or filled with fluid (such as iopromide), and the sealing edge of the sealing sticker 251 needs to be neatly and tightly bonded. But in order to facilitate the separation of the sealing sticker 251, the bonding strength of the adhesive needs to be relatively low, for example, the strength is lower than the adhesive peel strength of 500Pa. In some embodiments, the sealing sticker 251 can be attached to the outside of the inner balloon 20, and when the filling pressure in the inner balloon 20 reaches the critical pressure, the sealing sticker 251 can be directly pushed open.

[0056] Optionally, the closing portion 25 also includes a traction line 252, and the sealing patch 251 is attached to the inner wall of the inner balloon 20 and covers the liquid hole 24; one end of the traction line 252 is connected to the sealing patch 251, and the other end of the traction line 252 extends to the proximal end for the operator to pull the sealing patch 251 to release the covering of the liquid hole 24.

[0057] Preferably, the inner balloon 20 has a plurality of (such as 10) liquid holes 24, and the diameter of each liquid hole 24 is between 0.5 mm and 5 mm. It should be noted that the diameter here is an equivalent diameter. That is, the shape of the liquid hole 24 is not limited to a circle, it can be a polygon or other shapes. If a liquid hole 24 of other shapes is used, the diameter of a circle of equal area corresponding to its hole area is the equivalent diameter of the hole. In order to prevent the sealing patch 251 from escaping from the liquid hole 24 and entering the middle area between the inner balloon 20 and the outer balloon 10, on the one hand, the outer contour shape of the sealing patch 251 needs to be larger than the contour shape of the liquid hole 24 to completely cover the liquid hole 24; on the other hand, the sealing patch 251 needs to be not easily deformed to avoid passing through the liquid hole 24 due to deformation. The optional materials of the sealing patch 251 include metal foil, polymer film or ceramic sheet. More preferably, a plurality of dense liquid holes 24 can be formed into a liquid hole group. The contour shape and number of the liquid hole groups are not limited, and a circle or other polygonal shape may be selected. Each liquid hole group is attached with at least one sealing sticker 251 so that all the liquid hole groups can be covered by the sealing sticker 251 .

[0058] Correspondingly, the sealing portion 25 includes a plurality of traction lines 252, and the back side of each sealing patch 251 (i.e., the side away from the side attached to the liquid through hole 24) is connected to a traction line 252, and then the traction lines 252 converge into a total traction line; the total traction line is led out from the independent outlet (the independent outlet is preferably provided with a hemostatic valve) at the connector 5 of the liquid through cavity 9 of the balloon dilatation catheter. In use, when the inner balloon 20 is filled to a critical state, the operator can pull the total traction line at the proximal end to disengage the sealing patch 251 and release the cover of the liquid through hole 24. The setting of the traction line 252 is convenient for the operator to drive on the one hand, and the operator can actively perform the traction operation under a certain filling pressure to release the sealing of the liquid through hole 24, so that the critical pressure can be a controllable and selectable precise value. On the other hand, when the outer balloon 10 ruptures, the setting of the traction line 252 can prevent the sealing patch 251 from falling into the human body.

[0059] In some other embodiments, the sealing portion 25 includes a water-soluble filling patch. After the inner balloon 20 is expanded to the first predetermined state, the filling fluid may no longer be continuously filled, but a predetermined time may be waited for the water-soluble filling patch to be gradually dissolved until a critical state is reached. The material of the water-soluble filling patch is selected from one of polyacrylamide, chitosan or polyvinyl pyrrolidone (PVP). The water-soluble filling patch is filled in the liquid hole 24. After a period of contact with the filling fluid (such as the filling liquid), the water-soluble filling patch may be dissolved or partially dissolved, resulting in a decrease in mechanical properties, thereby releasing the closure of the liquid hole 24.

[0060] Optionally, the inner balloon 20 is in a folded state when not filled, and the outer balloon 10 is also shrunk and folded accordingly, so that the entire expansion balloon 1 can be shrunk to a smaller outer diameter, which is convenient for the expansion balloon 1 to pass through the blood vessel. When the inner balloon 20 in the folded state is filled with filling fluid, the inner balloon 20 gradually expands toward the critical state, while driving the outer balloon 10 wrapped on the outer side of the inner balloon 20 to expand. On the contrary, when the filling fluid is extracted from the inner balloon 20 before the critical state, the inner balloon 20 gradually shrinks toward the folded state, and the outer balloon 10 also shrinks accordingly.

[0061] Further, the inner balloon 20 in the first pre-shaped state continues to be filled with filling fluid or waits for a certain period of time until a critical state is reached, the inner balloon 20 will burst or rupture, and the filling fluid will flow out of the inner balloon 20 and fill the inside of the outer balloon 10, so that the outer balloon 10 continues to expand as a whole until the outer balloon 10 expands to the second pre-shaped state and reaches its nominal diameter. It can be understood that during this process, when the filling fluid is extracted from the inner balloon 20, the outer balloon 10 may also shrink, but the inner balloon 20 cannot return to the shape before the critical state and will continue to maintain the ruptured shape.

[0062] Optionally, when the inner balloon 20 is in the folded state, the ratio of the axial length of the inner balloon 20 to the axial length of the outer balloon 10 is between 0.9 and 1.0, and more preferably 0.98. The axial lengths of the outer balloon 10 and the inner balloon 20 are roughly the same, and usually the outer balloon 10 is slightly longer than the initial length of the inner balloon 20 (i.e., the axial length of the inner balloon 20 when it is in the folded state); this is because the compliance of the outer balloon 10 and the inner balloon 20 may be different. During the filling process, the two balloons not only have different expansion capabilities in the radial direction, but also in the axial direction. Such a design can ensure that the lengths of the two in the filling state (including the inner balloon 20 in the critical state and before the critical state) are more matched. It should be noted that the initial length of the inner balloon 20 here refers to its initial length before being assembled with the outer balloon 10. Specifically, during the assembly process, the inner balloon 20 in the folded state and the proximal and distal ends of the outer balloon 10 will be aligned, and the inner balloon 20 will be stretched, resulting in the inner balloon 20 being in a stretched state in the axial direction after assembly. Optionally, the initial outer diameter of the straight section 12 of the outer balloon 10 (i.e., the outer diameter of the outer balloon 10 when the inner balloon 20 is in the folded state) is greater than or equal to the initial outer diameter of the shoulder section of the inner balloon 20.

[0063] Preferably, the ratio of the axial length of the waist segment 223 to the sum of the axial lengths of the first shoulder segment 221, the waist segment 223 and the second shoulder segment 225 is between 0 and 0.7; more preferably, the ratio of the axial length of the waist segment 223 to the sum of the axial lengths of the first shoulder segment 221, the waist segment 223, the two transition segments and the second shoulder segment 225 is between 0 and 0.7. When the ratio of the waist segment 223 is close to 0, the inner balloon 20 (referring to when it is in the first predetermined forming state) changes from a dumbbell-like shape to an 8-like shape. Preferably, the ratio of the axial length of the waist segment 223 to the sum of the axial lengths of the first shoulder segment 221, the waist segment 223, the two transition segments and the second shoulder segment 225 is 0.35. Optionally, when the inner balloon 20 is in the first pre-formed state, the ratio of the outer diameter of the waist segment 223 to the nominal diameter of the outer balloon 10 is between 0.3 and 0.75, preferably 0.55; and / or the ratio of the outer diameter of the first shoulder segment 221 and the second shoulder segment 225 to the nominal diameter of the outer balloon 10 is between 0.6 and 1.0, preferably 0.8.

[0064] A specific embodiment of the expansion balloon 1 is disclosed below. It should be understood that the data disclosed below is only a preferred example of the expansion balloon 1 and is not intended to limit the expansion balloon 1.

[0065] The axial length of the straight section 12 of the outer balloon 10 (referring to the size of the outer balloon 10 in the second pre-formed state) is between 20 and 55 mm, preferably 36 mm; the axial length of the first cone section 11 and the second cone section 13 varies with the specification diameter of the outer balloon 10, usually between 8 and 60 mm; the cone end angle of the first cone section 11 and the second cone section 13 (that is, the angle between the cone surfaces of the first cone section 11 and the second cone section 13 and the axis of the outer balloon 10) is between 25° and 100°, preferably 45°.

[0066] The specifications of the outer balloon 10 correspond to the calibration specifications of the required balloon (generally, balloons are calibrated to different calibration specifications based on their own materials, sizes and expansion performance, and the specifications of existing commonly used expansion balloons are generally between 8mm and 34mm): between 14mm and 26mm. The inventors have found that the outer balloon 10 with this calibration specification can achieve a better anti-channeling effect when combined with the inner balloon 20.

[0067] The elastic modulus of the outer balloon 10 is greater than 400Mpa, preferably greater than 1500Mpa. The material of the outer balloon 10 is selected from a combination of one or more polymers such as PE, PET, PA and Pebax, which meets good non-compliance, high puncture resistance and certain compressive strength. The material of the inner balloon 20 can also be selected from a combination of one or more polymers such as PE, PET, PA and Pebax. The present invention does not limit the material, color, layered or woven structure of the outer balloon 10 and the inner balloon 20. Those skilled in the art can select suitable materials to prepare the outer balloon 10 and the inner balloon 20 according to the prior art.

[0068] In summary, in the dilatation balloon and balloon dilatation catheter provided by the present invention, the dilatation balloon includes an outer balloon and an inner balloon; the outer balloon is sleeved outside the inner balloon, the inner balloon is a predetermined non-compliant balloon, the inner balloon expands when filled with filling fluid, and drives the outer balloon to expand; when the inner balloon expands to a critical state, the filling fluid inside the inner balloon flows out into the outer balloon and fills the outer balloon. With such a configuration, the inner balloon is a predetermined non-compliant balloon, which limits the expansion shape of the dilatation balloon before expanding to a critical state, solving the problem of easy movement of the balloon; and then when the inner balloon continues to expand, the filling fluid inside the inner balloon flows out into the outer balloon and fills the outer balloon, so that the restriction of the inner balloon on the expansion shape of the dilatation balloon is released, so that the dilatation balloon can expand following the shape of the outer balloon, reducing the formation of paravalvular leakage.

[0069] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referred to each other. In addition, the different parts between the various embodiments can also be used in combination with each other, and the present invention does not limit this. The above description is only a description of the preferred embodiments of the present invention, and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure are within the scope of protection of the claims.

Claims

1. A dilatation balloon, characterized in that: include: The outer balloon and the inner balloon; The inner balloon is a non-compliant balloon, the outer balloon is a non-compliant balloon, the outer balloon is sleeved outside the inner balloon, the inner balloon expands when filled with filling fluid, and drives the outer balloon to expand, wherein the inner balloon has a first predetermined shape during the expansion process; after the inner balloon expands to the first predetermined shape, when it reaches a critical state, the filling fluid inside the inner balloon flows out into the outer balloon and fills the outer balloon; The inner balloon has a liquid hole, and the expansion balloon also includes a closing portion, which closes the liquid hole after the inner balloon expands to the first predetermined forming state and before reaching the critical state, and releases the closure of the liquid hole when the inner balloon reaches the critical state, so that the filling fluid inside the inner balloon flows out to the outer balloon and fills the outer balloon.

2. The dilatation balloon according to claim 1, characterized in that: After expanding to the first predetermined state, the inner balloon continues to expand until it bursts when reaching the critical state, so that the filling fluid inside the inner balloon flows out into the outer balloon and fills the outer balloon.

3. The dilatation balloon according to claim 2, characterized in that: The inner balloon includes a first shoulder segment, a waist segment and a second shoulder segment connected in sequence along the axial direction, and the wall thickness of at least the first shoulder segment or the second shoulder segment is not greater than 0.02 mm; or, the inner balloon has a weak area.

4. The dilatation balloon according to claim 3, characterized in that: The weak area is linear.

5. The dilatation balloon according to claim 2, characterized in that: The critical pressure when the inner balloon expands to the critical state is less than the preset pressure of the rated expansion of the outer balloon.

6. The dilatation balloon according to claim 1, characterized in that: The sealing portion includes a plug, a sealing patch or a water-soluble filling patch.

7. The dilatation balloon according to claim 6, characterized in that: The sealing portion further includes an anchor, and the plug is connected to the outer balloon or the inner balloon via the anchor.

8. The dilatation balloon according to claim 6, characterized in that: The closing portion also includes a traction line, the sealing patch is attached to the inner wall of the inner balloon and covers the liquid hole; one end of the traction line is connected to the sealing patch, and the other end of the traction line extends to the proximal end for the operator to pull the sealing patch to release the covering of the liquid hole.

9. The dilatation balloon according to claim 1, characterized in that: The inner balloon in the first pre-forming state is in the shape of a dumbbell with expanded ends and a concave middle. After the inner balloon reaches a critical state, the outer balloon expands to the second pre-forming state. The outer balloon in the second pre-forming state is in the shape of a straight cylinder.

10. The dilatation balloon according to claim 1, characterized in that: The material of the outer balloon is selected from at least one of PE, PET, PA or Pebax; the material of the inner balloon is selected from at least one of PE, PET, PA or Pebax.

11. The dilatation balloon according to claim 1, characterized in that: The inner balloon is configured to have a critical state during the process of being filled with filling fluid, so that the filling fluid therein flows into the outer balloon when the inner balloon reaches the critical state.

12. The dilatation balloon according to claim 11, characterized in that: The outer balloon is configured to have a first shape before the inner balloon is in the critical state, and to have a second shape after the inner balloon is in the critical state, the first shape being defined by the inner balloon and being different from the second shape.

13. A balloon dilatation catheter, characterized in that: It comprises the expansion balloon according to any one of claims 1 to 12 and a catheter, wherein the catheter is connected to the proximal end of the inner balloon, and the catheter is used to transmit filling fluid to drive the expansion or contraction of the expansion balloon.

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