Dilatation balloon and balloon dilatation catheter

Abstract

The present invention provides an expansion balloon and a balloon expansion catheter, wherein the expansion balloon comprises an outer balloon and an inner balloon; the outer balloon is sleeved outside the inner balloon, the inner balloon switches between a folded state, a pre-formed state and a first expansion state, and the outer balloon has a second expansion state; when the inner balloon in the folded state to the pre-formed state is filled with filling fluid, the inner balloon expands from the folded state to the pre-formed state, and the outer balloon expands with the expansion of the inner balloon; when the inner balloon in the pre-formed state continues to be filled with filling fluid, the inner balloon continues to expand and drives the outer balloon to expand, until the outer balloon expands to the second expansion state, the inner balloon is in the first expansion state. With such configuration, the pre-formed state of the inner balloon can meet the requirements of anchoring different lesion positions, locally expanding lesion positions and setting of special balloon external structure; the outer balloon limits the final expansion form of the expansion balloon, avoiding complications caused by excessive expansion.

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 ring and create good access conditions for the implantation of the artificial valve; on the other hand, post-dilation of the valve by balloon catheter 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, valve balloon structures mostly adopt straight-cylinder design or figure-8 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 it is 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 figure-8 balloon structure can lock the lesion site through the middle waist segment (waist), reducing the probability of movement to a certain extent. The existing figure-8 balloons can be mainly divided into two categories:

[0005] One type is to prevent movement. The concave waist section will not disappear even after the balloon is fully expanded. When the balloon is fully expanded, there is a significant diameter difference between the middle waist section and the two ends. Although this type of balloon has better anti-movement performance, it has a weaker expansion effect on the lesion. During the use of artificial valves, if the expansion is not sufficient, complications such as paravalvular leakage are likely to occur.

[0006] Another type of lumbar segment is fully propped up after the balloon is fully expanded. The balloon is in the shape of a figure 8 during the gradual filling process. When fully filled, it changes to a straight cylindrical shape, thus avoiding the disadvantage of insufficient expansion. However, the existing balloons that can be deformed from a figure 8 type to a straight shape can only be used once. In current BAV or TAVI surgeries, the balloon needs to be filled multiple times to ensure the quality of the operation. After a single expansion and deformation, if the balloon cannot form an 8-shaped shape again, it is also easy to move during subsequent operations. Summary of the invention

[0007] The purpose of the present invention is to provide a dilatation balloon and a balloon dilatation catheter to solve the problem that the existing 8-shaped balloon dilatation catheter cannot adapt to multiple deformations.

[0008] In order to solve the above technical problems, the present invention provides a dilatation balloon, which comprises: an outer balloon and an inner balloon;

[0009] The outer balloon is sleeved outside the inner balloon, the inner balloon switches between a folded state, a predetermined shape state adapted to a predetermined expansion position, and a first expansion state, and the outer balloon has a second expansion state;

[0010] When the inner balloon in the folded state to the predetermined state is filled with filling fluid, the inner balloon expands from the folded state to the predetermined state, and the outer balloon expands along with the expansion of the inner balloon; when the inner balloon in the predetermined state continues to be filled with filling fluid, the inner balloon continues to expand and drives the outer balloon to expand, until the outer balloon expands to the second expanded state, and the inner balloon is in the first expanded state;

[0011] Optionally, when the inner balloon is filled with fluid, the inner balloon contracts from the first expanded state to the folded state, and the outer balloon contracts along with the contraction of the inner balloon.

[0012] Optionally, the outer balloon is a non-compliant balloon, and the inner balloon is a compliant balloon.

[0013] Optionally, in the expansion balloon, the inner balloon includes a first shoulder segment, a waist segment and a second shoulder segment in sequence along the axial direction. When the inner balloon is in the predetermined forming state, the radial dimension of the first shoulder segment is larger than the radial dimension of the waist segment, and the radial dimension of the second shoulder segment is larger than the radial dimension of the waist segment.

[0014] Optionally, in the dilatation balloon, the inner balloon further includes two transition segments, one of the transition segments respectively connecting the first shoulder segment and the waist segment, and the other of the transition segments respectively connecting the waist segment and the second shoulder segment.

[0015] Optionally, in the dilation balloon, the outer balloon includes a straight section, and the ratio of the sum of the axial lengths of the first shoulder section, the waist section, the two transition sections and the second shoulder section to the axial length of the straight section is between 0.95 and 1.2.

[0016] Optionally, in the dilatation balloon, a ratio of an axial length of the waist segment to a sum of axial lengths of the first shoulder segment, the waist segment and the second shoulder segment is between 0 and 0.7.

[0017] Optionally, in the expansion balloon, when the inner balloon is in the pre-formed state, the ratio of the outer diameter of the waist segment to the nominal diameter of the outer balloon is between 0.3 and 0.75; and / or the ratio of the outer diameter of the first shoulder segment or the second shoulder segment to the nominal diameter of the outer balloon is between 0.6 and 1.0.

[0018] Optionally, in the expansion balloon, the outer balloon includes a straight section, and when the outer balloon is in the second expansion state, the radial size of the straight section is uniform and unchanged.

[0019] Optionally, in the expansion balloon, a vacuum is pre-drawn between the outer balloon and the inner balloon, and the outer balloon and the inner balloon are in contact with each other.

[0020] Optionally, in the expansion balloon, when the inner balloon is in the folded state, a ratio of an axial length of the inner balloon to an axial length of the outer balloon is between 0.9 and 1.0.

[0021] 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 elastic modulus of the outer balloon is greater than 400Mpa, and the elastic modulus of the inner balloon is less than 200Mpa; when the inner balloon is filled with filling fluid, it drives the outer balloon to expand; wherein the inner balloon has a predetermined shape during the expansion process.

[0022] Optionally, in the expansion balloon, the main balloon material is selected from at least one of PE, PET, PA or Pebax; the inner balloon material is selected from at least one of TPEE, TPU or silicone.

[0023] 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, wherein the outer balloon is sleeved 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 predetermined shape during the expansion process, and the predetermined shape is a dumbbell shape with bulged two ends and a concave middle.

[0024] 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, wherein the outer balloon is sleeved 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 predetermined shape during the expansion process, and in the predetermined shape, the filling pressure of the inner balloon is between 0.1atm and 2atm.

[0025] 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.

[0026] 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 switches between a folded state, a predetermined shape state matched with a predetermined expansion position, and a first expansion state, and the outer balloon has a second expansion state; when the inner balloon in the folded state to the predetermined shape state is filled with filling fluid, the inner balloon expands from the folded state to the predetermined shape state, and the outer balloon expands with the expansion of the inner balloon; when the inner balloon in the predetermined shape state continues to be filled with filling fluid, the inner balloon continues to expand and drives the outer balloon to expand, until the outer balloon expands to the second expansion state, and the inner balloon is in the first expansion state.

[0027] With such configuration, the pre-formed state of the inner balloon can meet the requirements of anchoring different lesion locations, local expansion of lesion locations, and special balloon external structure settings; the outer balloon limits the final expansion shape of the expansion balloon, avoiding complications caused by over-expansion. By combining two balloons with different performances, the inner balloon satisfies the requirements that the expansion balloon can still return to its original shape after multiple expansions, and form similar morphological changes during the expansion process (i.e., the pre-formed state), and the final expansion shape can be limited by the outer balloon (i.e., the outer balloon is in the first expansion state), significantly reducing complications. Furthermore, the inner and outer balloons each have their own unique mechanical properties. The outer balloon can provide higher puncture resistance, pressure resistance, and the appearance of limiting the final expansion shape of the expansion balloon, while the inner balloon can provide the ability to control the deformation process adapted to the predetermined expansion site. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] 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.

[0029] Figure 1 is a schematic diagram of a balloon dilatation catheter according to an embodiment of the present invention;

[0030] 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;

[0031] 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;

[0032] Figure 4 is a schematic diagram of an expansion balloon according to an embodiment of the present invention, with the outer balloon being in a first expansion state;

[0033] Figure 5 yes Figure 4 A schematic diagram of a transverse cross-section of a dilated balloon is shown;

[0034] Figure 6 yes Figure 4 A schematic diagram of an axial section of a dilation balloon is shown;

[0035] Figure 7 is a schematic diagram of a dilatation balloon according to an embodiment of the present invention when the inner balloon is in a folded state;

[0036] Figure 8 yes Figure 7 Schematic diagram of a transverse cross-section of a dilation balloon is shown.

[0037] In the attached figure:

[0038] 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;

[0039] 10-external balloon; 11-first cone section; 12-straight section; 13-second cone section;

[0040] 20-inner balloon; 21-third cone section; 22-first shoulder section; 23-first transition section; 24-waist section; 25-second transition section; 26-second shoulder section; 27-fourth cone section. DETAILED DESCRIPTION

[0041] 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.

[0042] 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 technical features indicated. 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 body; 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.

[0043] 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.

[0044] The following description is given with reference to the accompanying drawings.

[0045] Please refer to Figures 1 to 8 ,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, with the outer balloon being in a first expansion state; Figure 5 yes Figure 4 A schematic diagram of a transverse cross-section of a dilated balloon is shown; Figure 6 yes Figure 4A schematic diagram of an axial section of a dilation balloon is shown; Figure 7 is a schematic diagram of a dilatation balloon according to an embodiment of the present invention when the inner balloon is in a folded state; Figure 8 yes Figure 7 Schematic diagram of a transverse cross-section of a dilation balloon is shown.

[0046] like Figure 1 and Figure 2 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 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 switches between a folded state, a predetermined state adapted to a predetermined expansion position, and a first expansion state, and the outer balloon 10 has a second expansion state; when the inner balloon 20 in the folded state to the predetermined state is filled with a filling fluid, the inner balloon 20 expands from the folded state to the predetermined state, and the outer balloon 10 expands with the expansion of the inner balloon 20; when the inner balloon 20 in the predetermined state continues to be filled with a filling fluid, the inner balloon 20 continues to expand and drives the outer balloon 10 to expand, until the outer balloon 10 expands to the second expansion state, the inner balloon 20 is in the first expansion state. It should be noted that the outer balloon 10 is sleeved outside the inner balloon 20 here 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 of the inner component relative to the axis is smaller than the distance of the outer component relative to the axis.

[0047] Furthermore, when the inner balloon 20 is filled with fluid, the inner balloon 20 shrinks from the first expanded state to the folded state, and the outer balloon 10 shrinks along with the shrinkage of the inner balloon 20. When the inner balloon 20 is filled with fluid, its shrinkage process is opposite to the expansion process when the filling fluid is filled. In particular, when the extraction speed is fast, the inner balloon 20 can shrink from the first expanded state to the folded state very quickly, and does not necessarily form a predetermined state. The expansion balloon 1 can repeatedly fill and extract the inner balloon 20, so that the expansion balloon 1 can achieve repeated expansion and contraction.

[0048] Preferably, the outer balloon 10 is a non-compliant balloon, and the inner balloon 20 is a compliant balloon. 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. The filling fluid is continuously poured into a balloon at a nominal diameter to further expand it, and eventually the balloon will 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, and 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.

[0049] The outer balloon 10 is 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 annuli. The inner balloon 20 is a compliant balloon, which is arranged inside the outer balloon 10. It needs to have good elastic deformation ability. As the filling pressure increases, the inner balloon 20 can produce obvious expansion accordingly. Further, the inner balloon 20 can be pre-set according to the structural morphology of the predetermined expansion site (i.e., the lesion site). For example, when the expansion balloon 1 is used in the field of heart valve disease treatment, such as aortic valve surgery, the predetermined shape of the inner balloon 20 can be set to a dumbbell shape, i.e., a shape with bulging at both ends and a concave shape in the middle, so as to achieve effects similar to being engaged in the lesion site (anchoring) and locally expanding the lesion site. The compressive strength and material mechanical properties (elastic modulus or material hardness) of the outer balloon 10 are significantly higher than those of the inner balloon 20.

[0050] The inventors found that when a compliant balloon encounters resistance in a blood vessel, the shape of the balloon may change and expand toward a place with less resistance, which may lead to two outcomes: one is that the squeezing force applied to the surrounding lesions is significantly reduced; the other is that the continuous increase in filling pressure will cause the shoulders at both ends of the balloon to over-expand, thereby causing damage to the normal blood vessel wall and causing dissection. Expansion of stenotic lesions is prone to cause dissection, so compliant balloons are generally not used in angioplasty. In valvuloplasty, if the balloon is over-expanded, it is also likely to cause tearing of the native valve ring and cause serious complications. Therefore, compliant balloons are generally not used in valvuloplasty. When the outer balloon 10 and the inner balloon 20 are used in combination, the non-compliant outer balloon 10 limits the final expansion shape of the expansion balloon 1, avoiding the complications caused by over-expansion when using a compliant balloon alone, and the compliant inner balloon 20 meets the requirement that the expansion balloon 1 can still return to its original shape after multiple expansions.

[0051] Combine the following Figure 1 , Figure 3 and Figure 5 , 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.

[0052] 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).

[0053] 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.

[0054] In a preferred embodiment, the outer balloon 10 includes a first cone section 11, a straight section 12, and a second cone section 13 connected in sequence along its own axial direction. After the outer balloon 10 is expanded, 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 existing technology. Please refer to Figures 4 to 6 When the outer balloon 10 is in the second expansion state, the radial dimension of the straight section 12 remains constant. It should be understood that the straight section 12 is not always in a state of uniform radial dimension during the expansion process of the expansion balloon 1. During the expansion process of the inner balloon 20 from the folded state to the predetermined shape, the outer balloon 10 and the inner balloon 20 remain roughly similar in shape, and the shape of the straight section 12 is also similar to the predetermined shape of the inner balloon 20, for example, it may be similar to a dumbbell shape.

[0055] Correspondingly, the two ends of the inner balloon 20 include a third cone segment 21 and a fourth cone segment 27 that are adapted to the shapes of the first cone segment 11 and the second cone segment 13. After the inner balloon 20 is expanded (such as in a predetermined state or a second expanded state), the third cone segment 21 and the fourth cone segment 27 are roughly conical and adapted to the shapes of the first cone segment 11 and the second cone segment 13.

[0056] For further information, please refer to Figure 2 and Figure 3 Taking a dilatation balloon 1 applied to the field of heart valve disease as an example, the inner balloon 20 includes a first shoulder segment 22, a waist segment 24 and a second shoulder segment 26 in the axial direction. When the inner balloon 20 is in the predetermined state, the radial dimension of the first shoulder segment 22 is greater than the radial dimension of the waist segment 24, and the radial dimension of the second shoulder segment 26 is greater than the radial dimension of the waist segment 24. The distal end of the first shoulder segment 22 is connected to the proximal end of the third cone segment 21, and the proximal end of the second shoulder segment 26 is connected to the distal end of the fourth cone segment 27. 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 22, the waist segment 24 and the second shoulder segment 26 are all cylindrical straight tubes; preferably, the diameter of the first shoulder segment 22 is the same as the diameter of the second shoulder segment 26. When the inner balloon 20 is partially filled, due to the pre-shaped design of the inner balloon 20, a Figure 2 In the dumbbell-shaped state shown, the waist section 24 can be engaged with the heart valve annulus to prevent the expansion balloon 1 from moving away from the lesion.

[0057] Please refer to Figure 7 and Figure 8When the inner balloon 20 is in a folded state, the outer balloon 10 also shrinks and folds accordingly, and 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. Preferably, the inner balloon 20 has a thinner wall thickness, such as the wall thickness of the inner balloon 20 can be between 0.005 and 0.1 mm, and more preferably 0.01 mm; the smaller wall thickness of the inner balloon 20 can meet the overall smaller outer diameter of the expansion balloon 1. When the inner balloon 20 in the folded state is filled with filling fluid, the inner balloon 20 gradually expands to a predetermined state, while driving the outer balloon 10 coated on the outside of the inner balloon 20 to expand. On the contrary, when the filling fluid is extracted from the inner balloon 20 in the predetermined state, the inner balloon 20 gradually shrinks to a folded state, and the outer balloon 10 also shrinks accordingly.

[0058] Furthermore, the inner balloon 20 in the predetermined state continues to be filled with filling fluid, and the inner balloon 20 will continue to expand. However, due to the restriction of the outer balloon 10, the expansion rate of the inner balloon 20 in the waist section 24 is greater than the expansion rate of the first shoulder section 22 and the second shoulder section 26 at this stage, until the outer diameter of the waist section 24 is the same as the outer diameter of the first shoulder section 22 and the second shoulder section 26, and under the restriction of the straight section 12 of the outer balloon 10, the expansion rates of the three sections are consistent, that is, the first shoulder section 22, the waist section 24 and the second shoulder section 26 are roughly cylindrical. In some embodiments, when the outer diameter of the waist section 24 is the same as the outer diameter of the first shoulder section 22 and the second shoulder section 26, it is considered that the inner balloon 20 is in the first expansion state, the outer balloon 10 is in the second expansion state, and the entire expansion balloon 1 reaches its nominal diameter. In other embodiments, when the outer diameter of the waist segment 24 is the same as the outer diameter of the first shoulder segment 22 and the second shoulder segment 26, the inner balloon 20 may continue to be filled with filling fluid to allow the expansion balloon 1 to continue to expand as a whole until the expansion balloon 1 reaches its nominal diameter, at which time the inner balloon 20 is in the first expansion state and the outer balloon 10 is in the second expansion state. It can be understood that when the filling fluid is extracted from the inner balloon 20, the contraction process of the expansion balloon 1 is opposite to the above expansion process, and those skilled in the art can refer to the above description for understanding, which will not be repeated here. When the outer diameter of the waist segment 24 is the same as the outer diameter of the first shoulder segment 22 and the second shoulder segment 26, 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 valve leaflets and / or valve rings, and to 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 the TAVI surgery.

[0059] Optionally, the inner balloon 20 further includes two transition sections, namely a first transition section 23 and a second transition section 25, wherein one of the transition sections (i.e., the first transition section 23) is respectively connected to the first shoulder section 22 and the waist section 24, and the other transition section (i.e., the second transition section 25) is respectively connected to the waist section 24 and the second shoulder section 26. The setting of the transition section can form a transition connection between the shoulder section and the waist section 24. When the radial dimensions of the shoulder section and the waist section 24 are different, the transition section is preferably conical, wherein the smaller end of the cone is connected to the waist section 24, and the larger end is connected to the shoulder section.

[0060] Optionally, the sum of the axial lengths of the first shoulder segment 22, the waist segment 24, the two transition segments and the second shoulder segment 26, and the axial length of the straight segment 12 is between 0.95 and 1.2, preferably 1.0. Considering the difference between the compliance of the inner balloon 20 and the non-compliance of the outer balloon 10, the ratio in the above range can make the inner and outer balloons fit better during expansion and contraction, and avoid problems such as warping and peeling. Optionally, the axial length of the first shoulder segment 22, the waist segment 24, the two transition segments, the second shoulder segment 26, and the straight segment 12 is the length of the inner balloon 20 in a folded state. It should be noted that the length of the inner balloon 20 in a folded state here refers to its initial length before being assembled with the outer balloon 10. Specifically, during the assembly process, the proximal and distal ends of the inner balloon 20 in the folded state and the outer balloon 10 will be aligned, and the inner balloon 20 will be stretched, thereby causing the inner balloon 20 to be in a stretched state in the axial direction after assembly. Further, 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 the outer balloon 10 is usually 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 is 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 filling states (including the inner balloon 20 in the predetermined state and the first expansion state, and in the state between the two) are more matched. 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.

[0061] Preferably, the ratio of the axial length of the waist segment 24 to the sum of the axial lengths of the first shoulder segment 22, the waist segment 24 and the second shoulder segment 26 is between 0 and 0.7; more preferably, the ratio of the axial length of the waist segment 24 to the sum of the axial lengths of the first shoulder segment 22, the waist segment 24, the two transition segments and the second shoulder segment 26 is between 0 and 0.7. When the ratio of the waist segment 24 is close to 0, the inner balloon 20 (referring to its predetermined shape) changes from a dumbbell-like shape to an 8-like shape. Preferably, the ratio of the axial length of the waist segment 24 to the sum of the axial lengths of the first shoulder segment 22, the waist segment 24, the two transition segments and the second shoulder segment 26 is 0.35. Optionally, when the inner balloon 20 is in a predetermined shape, the ratio of the outer diameter of the waist segment 24 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 22 and the second shoulder segment 26 to the nominal diameter of the outer balloon 10 is between 0.6 and 1.0, preferably 0.8.

[0062] Furthermore, the filling pressure of the inner balloon 20 in the pre-shaped state can be selected and set as needed. The inventors found that in the pre-shaped state, the filling pressure of the inner balloon 20 is related to the difference in initial diameters of the inner and outer balloons, the difference in diameters between the waist section 24 and the shoulder section of the inner balloon 20 when the inner balloon 20 is in the pre-shaped state, and the elastic modulus of the material of the inner and outer balloons. Preferably, in combination with the appropriate values ​​of the above-mentioned related factors, the filling pressure of the inner balloon 20 can be selected in the range of 0.1atm to 2atm.

[0063] 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.

[0064] The axial length of the straight section 12 of the outer balloon 10 (referring to the size of the outer balloon 10 under nominal pressure) 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°.

[0065] 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.

[0066] 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 one or more combinations of high molecular polymers such as PE, PET, PA and Pebax, which meet good non-compliance, high puncture resistance and certain compressive strength. The present invention does not limit the material, color, layered or woven structure of the outer balloon 10. Those skilled in the art can select suitable materials to prepare the outer balloon 10 according to the prior art.

[0067] The material of the inner balloon 20 is selected from at least one of thermoplastic elastomers such as TPEE or TPU and silicone (mainly elastomeric silicone with a breaking elongation greater than 400%); the elastic modulus of the inner balloon 20 is less than 200Mpa, preferably less than 50Mpa.

[0068] 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 switches between a folded state, a predetermined shape state matched with a predetermined expansion position, and a first expansion state, and the outer balloon has a second expansion state; when the inner balloon in the folded state to the predetermined shape state is filled with filling fluid, the inner balloon expands from the folded state to the predetermined shape state, and the outer balloon expands with the expansion of the inner balloon; when the inner balloon in the predetermined shape state continues to be filled with filling fluid, the inner balloon continues to expand and drives the outer balloon to expand, until the outer balloon expands to the second expansion state, and the inner balloon is in the first expansion state.

[0069] With such configuration, the pre-formed state of the inner balloon can meet the requirements of anchoring different lesion locations, local expansion of lesion locations, and special balloon external structure settings; the outer balloon limits the final expansion shape of the expansion balloon, avoiding complications caused by over-expansion. By combining two balloons with different performances, the inner balloon satisfies the requirements that the expansion balloon can still return to its original shape after multiple expansions, and form similar morphological changes during the expansion process (i.e., the pre-formed state), and the final expansion shape can be limited by the outer balloon (i.e., the outer balloon is in the first expansion state), significantly reducing complications. Furthermore, the inner and outer balloons each have their own unique mechanical properties. The outer balloon can provide higher puncture resistance, pressure resistance, and the appearance of limiting the final expansion shape of the expansion balloon, while the inner balloon can provide the ability to control the deformation process adapted to the predetermined expansion site.

[0070] 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 outer balloon is sheathed outside the inner balloon, the inner balloon switches between a folded state, a pre-shaped state and a first expanded state, and the outer balloon has a second expanded state; When the inner balloon in the folded state to the predetermined shape state is filled with filling fluid, the inner balloon expands from the folded state to the predetermined shape state, and the outer balloon expands along with the expansion of the inner balloon; wherein the inner balloon has a predetermined shape state during the expansion process, and the predetermined shape state is a dumbbell shape with bulged ends and a concave middle; when the inner balloon in the predetermined shape state continues to be filled with filling fluid, the inner balloon continues to expand and drives the outer balloon to expand, until the outer balloon expands to the second expanded state, and the inner balloon is in the first expanded state; The inner balloon includes a first shoulder segment, a waist segment and a second shoulder segment in sequence along the axial direction. When the inner balloon is in the predetermined forming state, the radial dimension of the first shoulder segment is larger than the radial dimension of the waist segment, and the radial dimension of the second shoulder segment is larger than the radial dimension of the waist segment. When the inner balloon is filled with fluid, the inner balloon contracts from the first expanded state to the folded state, and the outer balloon contracts along with the contraction of the inner balloon; The inner balloon is allowed to be repeatedly inflated and deflated, so that the expansion balloon can be repeatedly expanded and deflated.

2. The dilatation balloon according to claim 1, characterized in that: The outer balloon is a non-compliant balloon, and the inner balloon is a compliant balloon.

3. The dilatation balloon according to claim 1, characterized in that: The inner balloon further comprises two transition sections, one of which is respectively connected to the first shoulder section and the waist section, and the other of which is respectively connected to the waist section and the second shoulder section.

4. The dilatation balloon according to claim 3, characterized in that: The outer balloon comprises a straight section, and the ratio of the sum of the axial lengths of the first shoulder section, the waist section, the two transition sections and the second shoulder section to the axial length of the straight section is between 0.95 and 1.

2.

5. The dilatation balloon according to claim 3, characterized in that: The ratio of the axial length of the waist segment to the sum of the axial lengths of the first shoulder segment, the waist segment and the second shoulder segment is between 0 and 0.

7.

6. The dilatation balloon according to claim 3, characterized in that: When the inner balloon is in the pre-formed state, the ratio of the outer diameter of the waist segment to the nominal diameter of the outer balloon is between 0.3 and 0.75; and / or the ratio of the outer diameter of the first shoulder segment or the second shoulder segment to the nominal diameter of the outer balloon is between 0.6 and 1.

0.

7. The dilatation balloon according to claim 1, characterized in that: The outer balloon comprises a straight section, and when the outer balloon is in the second expansion state, the radial dimension of the straight section is uniform and unchanged.

8. The dilatation balloon according to claim 1, characterized in that: The outer balloon and the inner balloon are pre-evacuated, and the outer balloon and the inner balloon are in contact with each other.

9. The dilatation balloon according to claim 1, characterized in that: When the inner balloon is in the folded state, the ratio of the axial length of the inner balloon to the axial length of the outer balloon is between 0.9 and 1.

0.

10. The dilatation balloon according to claim 1, characterized in that: The elastic modulus of the outer balloon is greater than 400 MPa, and the elastic modulus of the inner balloon is less than 200 MPa.

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

12. The dilatation balloon according to claim 1, characterized in that: In the predetermined state, the filling pressure of the inner balloon is between 0.1 atm and 2 atm.

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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