High-pressure long balloon dilatation catheter and preparation method thereof

Abstract

The invention provides a high-pressure long balloon dilatation catheter and a preparation method thereof.The preparation method comprises the steps that a balloon, an inner tube, an outer tube and a connecting base are prepared and combined and connected, and the high-pressure long balloon dilatation catheter is obtained; the forming method of the balloon comprises the steps of first-time stretching, second-time stretching and inflation stretching forming which are conducted in sequence. Aiming at the compression strength of the high-pressure long balloon dilatation catheter during high-pressure dilatation, according to the preparation method, on the basis of a traditional balloon forming method, first-time stretching is added, and the first-time stretching is set to be water bath stretching, so that the stretching size of a balloon material tube is more uniform, and the tensile strength of the balloon material tube is improved. And the orientation of a molecular chain can be enhanced by stretching twice in sequence, so that the mechanical property of the saccule material tube is enhanced, and finally, the pressure resistance of the saccule is increased when the saccule is expanded.

Description

Technical Field

[0001] The invention relates to the technical field of medical interventional instruments, and in particular to a high-pressure long balloon dilatation catheter and a preparation method thereof. Background Art

[0002] At present, balloon dilatation catheters have become a commonly used medical device for treating intravascular stenosis. Balloon dilatation catheters generally include a balloon, an inner tube and an outer tube nested in each other, and a connecting seat; one end of the outer tube is connected to the proximal end of the balloon, and the other end of the outer tube is connected to the connecting seat; the connecting seat has two cavities, one of which connects the cavity between the inner tube and the outer tube, which is used to fill the medium and expand the balloon, and the other cavity, that is, the straight cavity, connects to the internal lumen of the inner tube, which is used to run the guide wire; the developing ring is installed on the inner tube to indicate the position of the balloon in the lesion; one end of the inner tube is connected to the distal end of the balloon, and the other end is connected to the straight cavity; in actual use, with the guidance of X-rays or ultrasound, the unexpanded balloon is sent to the diseased blood vessel area, and the balloon is expanded, thereby expanding the diseased blood vessel without damaging the blood vessel.

[0003] The high-pressure long balloon for peripheral use is generally larger in diameter and longer in length than conventional coronary balloons, and is suitable for percutaneous transluminal angioplasty (PTA) treatment of peripheral artery obstructive diseases, including in-stent restenosis and obstructive lesions of natural or arteriovenous dialysis fistulas. The problems of traditional high-pressure long balloon catheters for peripheral diseases are as follows: 1) For high-pressure balloons generally used in peripheral arteries, the size of the balloon material tube must be designed to be very thick, and the wall thickness of the balloon is adjusted during balloon molding to increase the pressure resistance of the balloon. However, the above method easily leads to an increase in the outer diameter value of the balloon catheter, that is, the profile value becomes larger, which affects the ability of the balloon catheter to pass through stenotic lesions; if the conventional balloon molding method is continued, it is difficult to achieve high pressure; 2) For long balloons, especially those with a diameter of 3-8mm and a length of more than 60mm, the greater the pressure, the more severe the balloon bending. Excessive bending of the balloon will affect the contact area between the balloon and the lesion tissue and the treatment effect. Especially for drug balloons, excessive bending will affect the drug delivery ability of the balloon.

[0004] Therefore, it is necessary to develop a new type of high-pressure long balloon dilatation catheter and a preparation method thereof, so that the high-pressure long balloon dilatation catheter not only has a higher pressure resistance during expansion, but also avoids the bending phenomenon of the balloon under high pressure. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a high-pressure long balloon dilatation catheter and a preparation method thereof, wherein the preparation method comprises: preparing a balloon, an inner tube, an outer tube and a connecting seat respectively, and combining and connecting them to obtain a high-pressure long balloon dilatation catheter; wherein the balloon molding method comprises a first stretching, a second stretching and an inflation stretching molding performed in sequence. In view of the compressive strength of the high-pressure long balloon dilatation catheter during high-pressure expansion, the preparation method of the present invention adds a first stretching on the basis of the traditional balloon molding method, and sets the first stretching as a water bath stretching, so that the stretching size of the balloon material tube is more uniform, and the two stretchings performed successively can enhance the orientation of the molecular chain, thereby enhancing the mechanical properties of the balloon material tube, and finally increasing the pressure resistance during balloon expansion.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] One of the purposes of the present invention is to provide a method for preparing a high-pressure long balloon dilatation catheter, the method comprising the following contents:

[0008] The balloon, the inner tube, the outer tube and the connecting seat are prepared respectively, and they are assembled and connected to obtain a high-pressure long balloon dilatation catheter;

[0009] The balloon forming method comprises: performing a first stretching on a balloon material tube, wherein the first stretching is water bath stretching, to obtain a stretched balloon material tube; performing a second stretching on the stretched balloon material tube to obtain a balloon material embryo; and performing inflation stretching forming on the balloon material embryo.

[0010] The preparation method of the present invention focuses on improving the balloon molding method, wherein the balloon material tube is subjected to a first stretching and then a second stretching, and then the balloon is molded, so that the balloon has a higher pressure resistance than the traditional balloon molding method; the additional first stretching is water bath stretching, and the balloon material tube is first stretched in a water bath, which can improve the mechanical properties and thus increase the pressure resistance of the balloon.

[0011] As a preferred technical solution of the present invention, the method for preparing the inner tube includes: preparing an inner tube material tube, and setting a groove fold section at one end close to the connecting seat.

[0012] The preparation method of the present invention further performs a groove crease treatment on one end of the inner tube close to the connecting seat, and sets a groove crease section, so that the inner tube will elongate under the action of axial force under high pressure, and the groove crease section will gradually elongate and become smooth, offsetting the axial elongation of the balloon, and can effectively improve the bending phenomenon of the balloon under high pressure.

[0013] It should be noted that the purpose of designing the groove crease section is to improve the bending of the balloon. The elongation of the groove crease can cover the elongation of the balloon under filling pressure. Generally speaking, the length of the groove crease section is 2%-5% of the balloon length. The depth of the groove crease depends on the guide wire used clinically. Generally, the guide wire used clinically is 0.014 / 0.018 / 0.035 inches, that is, the depth of the depression should not cause the guide wire used to feel blocked.

[0014] As a preferred technical solution of the present invention, the balloon tube is made of polymer materials, including nylon (PA12) or block polyether polyamide (Pebax).

[0015] As a preferred technical solution of the present invention, the water bath stretching ratio of the first stretching is 1:1.10-1:1.40, for example, 1:1.10, 1:1.05, 1:1.10, 1:1.15, 1:1.20, 1:1.25, 1:1.30, 1:1.35 or 1:1.40, etc.

[0016] As a preferred technical solution of the present invention, the water bath stretching ratio is 1:1.15-1:1.25, for example, 1:1.15, 1:1.16, 1:1.17, 1:1.18, 1:1.19, 1:1.20, 1:1.21, 1:1.22, 1:1.23, 1:1.24 or 1:1.25, etc.

[0017] It should be noted that the waterbath stretching ratio of the waterbath stretching of the present invention is 1:1.10-1:1.40. When the waterbath stretching ratio is too small, it will not help much for the orientation of the molecular chains of the polymer. When the waterbath stretching ratio is too large, it will cause the molecular chains of the polymer to break due to excessive orientation, which will reduce the mechanical properties of the material. Preferably, it is 1:1.15-1:1.25.

[0018] As a preferred technical solution of the present invention, the water bath temperature for the first stretching is 60-80°C, such as 60°C, 65°C, 70°C, 75°C or 80°C.

[0019] It should be noted that the water bath temperature for the water bath stretching of the present invention is 60-80° C. When the temperature is too low, it is difficult to soften the polymer, and when the temperature is too high, the microstructure of the polymer will be destroyed.

[0020] As a preferred technical solution of the present invention, the second stretching includes: dividing the stretched balloon tube obtained by the first stretching into a heated section and a non-heated section, and controlling the stretching temperature of the heated section to 100-140°C, for example, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C or 140°C, etc.

[0021] It should be noted that the purpose of the secondary stretching is to pull the stretched balloon tube obtained by the first stretching into a balloon blank, specifically including: dividing the stretched balloon tube obtained by the first stretching into a heated section and a non-heated section, the heated section is stretched thin by the action of temperature and stretching displacement, and the non-heated section, i.e., the non-stretched section, forms a balloon blank. The stretching temperature of the heated section is between 100-140°C, and the specific polyamide material is between 120-140°C; the block polyether polyamide material is between 100-130°C. The stretching displacement is determined according to the balloon mold for inflation stretching, and the heated section is required to be able to penetrate into the mold used for balloon molding after stretching; the non-stretched section, i.e., the balloon blank, is determined according to the length of the balloon, and the specific blank length is 50-80% of the balloon length, and preferably in the range of 60-70%, so that the formed balloon has a more uniform wall thickness.

[0022] As a preferred technical solution of the present invention, the inflation stretch molding includes inflation molding and shaping performed sequentially; the temperature of the inflation molding is controlled to be 80-120°C, for example, 80°C, 90°C, 100°C, 110°C or 120°C, etc., the inflation air pressure is 26-35bar, for example, 26bar, 28bar, 30bar, 31bar, 33bar or 35bar, etc., and the temperature of the shaping is controlled to be 120-150°C, for example, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C or 150°C, etc.

[0023] It should be noted that the inflation stretch molding described in the present invention is to place the balloon blank in a mold of required specifications and blow out the required balloon through the effects of temperature, air pressure, etc., including inflation molding and shaping performed in sequence.

[0024] The second object of the present invention is to provide a high-pressure long balloon dilatation catheter, which is prepared by the preparation method described in the first object.

[0025] As a preferred technical solution of the present invention, the diameter of the balloon is 3-8mm, for example, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm or 8mm, and the length is 60-300mm, for example, 60mm, 80mm, 100mm, 130mm, 150mm, 180mm, 200mm, 220mm, 250mm, 280mm or 300mm, etc.

[0026] Compared with the prior art solutions, the present invention has at least the following beneficial effects:

[0027] (1) The preparation method of the present invention focuses on improving the balloon molding method, wherein the balloon material tube is subjected to a first stretching and then a second stretching before the balloon is formed, so that the balloon has a higher pressure resistance than the traditional balloon molding method; the first stretching is added as a water bath stretching, and the balloon material tube is first subjected to a water bath stretching, which can improve the mechanical properties, thereby increasing the pressure resistance of the balloon;

[0028] (2) The preparation method of the present invention further performs a groove crease treatment on one end of the inner tube close to the connecting seat, and sets a groove crease section, so that the inner tube has greater elasticity. When the balloon is filled with medium, the internal pressure of the balloon gradually increases, and the balloon is stretched due to the axial force. The inner tube is indirectly stretched due to the force, thereby avoiding the phenomenon of the balloon bending under high pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic flow chart of the balloon forming method in the preparation method of the present invention;

[0030] Figure 2 Schematic diagram of the structure of a high-pressure long balloon dilatation catheter obtained by the preparation method described in Example 1 of the present invention;

[0031] Figure 3 for Figure 1 Schematic diagram of the state where the inner tube is not subjected to axial force;

[0032] Figure 4 for Figure 1 Schematic diagram of the state where the inner tube is subjected to axial force;

[0033] In the figure: 1-balloon; 2-inner tube; 3-outer tube; 4-groove crease section; 5-connecting seat; 6-developing ring. DETAILED DESCRIPTION

[0034] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0035] The present invention provides a method for preparing a high-pressure long balloon dilatation catheter, the method comprising the following contents:

[0036] The balloon, the inner tube, the outer tube and the connecting seat are prepared respectively, and they are assembled and connected to obtain a high-pressure long balloon dilatation catheter;

[0037] Among them, Figure 1As shown, the balloon forming method comprises: performing a first stretching on a balloon material tube, wherein the first stretching is water bath stretching, wherein the water bath stretching ratio of the first stretching is 1:1.10-1:1.40, preferably 1:1.15-1:1.25, and the water bath temperature of the first stretching is 60-80°C, to obtain a stretched balloon material tube; performing a second stretching on the stretched balloon material tube to obtain a balloon material embryo; the second stretching comprises: dividing the stretched balloon material tube obtained by the first stretching into a heated section and a non-heated section, and the heated section is subjected to The non-heated section, i.e. the non-stretched section, forms a balloon material embryo, and the stretching temperature of the heated section is controlled to be 100-140°C; the balloon material embryo is subjected to inflation and stretching molding, and the inflation and stretching molding is to place the balloon material embryo in a mold of required specifications and blow out the required balloon through the effects of temperature, air pressure, etc., including inflation molding and shaping in sequence, and the inflation molding temperature is controlled to be 80-120°C, the inflation air pressure is controlled to be 26-35bar, and the shaping temperature is controlled to be 120-150°C.

[0038] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0039] Example 1

[0040] This embodiment provides a method for preparing a high-pressure long balloon dilatation catheter. The target parameters of the balloon include: the material is PA12, the nominal pressure is 8 atm, the nominal diameter is 8.0 mm, the length is 150 mm, and the rated burst pressure RBP=22 atm. The preparation method includes the following contents:

[0041] The balloon, the inner tube, the outer tube and the connecting seat are prepared respectively, and they are assembled and connected to obtain a high-pressure long balloon dilatation catheter;

[0042] The balloon forming method includes: preparing a balloon material tube with an inner diameter × outer diameter = 0.0465*0.0950 inch and a length of 300 mm, placing the balloon material tube on a stretching machine with a water bath heating function and biaxial stretching, setting the water bath stretching ratio to 1:1.15 and the water bath temperature to 80°C, performing the first stretching, and obtaining a stretched balloon material tube with an inner diameter × outer diameter = 0.0455*0.0900 inch and a length of 345 mm; dividing the stretched balloon material tube into a heated section and a non-heated section, the heated section is stretched thin by the action of temperature and stretching displacement, the temperature of the heated section is controlled to be 130°C, the stretching displacement is determined according to the balloon mold for inflation stretching, and the heated section is required to be stretched After stretching, the material can be inserted into the mold used for balloon molding, and the non-heated section, i.e., the non-stretched section, forms a balloon embryo. The length of the embryo is 60% of the length of the balloon, and the molded balloon has a more uniform wall thickness; the balloon embryo is subjected to inflation and stretching molding, and the inflation and stretching molding is to place the balloon embryo in a mold of required specifications and blow out the required balloon through the effects of temperature, air pressure, etc., including inflation molding and shaping in sequence, and the inflation molding temperature is controlled to be 100°C, the inflation air pressure is controlled to be 30bar, and the shaping temperature is controlled to be 130°C; the molded balloon is measured at a nominal pressure of 8atm, and the diameter is measured to be between 7.98-8.05mm and the length is 152mm, which meets the size requirements of the target balloon;

[0043] The preparation method of the inner tube comprises: preparing an inner tube material tube, and setting a groove fold section at one end close to the connecting seat; setting the length of the groove fold section to 3% of the length of the balloon;

[0044] Figure 2 The schematic diagram of the structure of the high-pressure long balloon dilatation catheter obtained by the preparation method described in this embodiment is shown, and it can be seen that the high-pressure long balloon dilatation catheter comprises a balloon 1, an inner tube 2, an outer tube 3 and a connecting seat 5; the inner tube 2 is arranged in the cavity of the outer tube 3, one end of the outer tube 3 is connected to the end of the balloon 1 close to the connecting seat, and the other end of the outer tube 3 is connected to the connecting seat 5; the connecting seat 5 has two cavities, one cavity connects the cavity between the inner tube 2 and the outer tube 3, which is used to fill the medium and expand the balloon 1, and the other cavity, that is, the straight cavity, connects the internal cavity of the inner tube 2 for guiding the guide wire; the developing ring 6 is installed on the outer wall of the inner tube 2 and corresponds to the position of the two ends of the balloon 1, which is used to indicate the position of the balloon 1 in the lesion; one end of the inner tube 2 is connected to the end of the balloon 1 away from the connecting seat, and the other end is connected to the straight cavity of the connecting seat 5; the inner tube 2 is provided with a groove crease section 4 at the end close to the connecting seat 5, especially at the end located inside the connecting seat 5. Figure 3 and Figure 4It can be seen that the inner tube 2 will stretch under high pressure due to the axial force, and the groove crease segment 4 will gradually stretch and become smooth. Generally, the bending of a long balloon under high pressure is mainly due to the difference between the axial elongation of the balloon and the axial elongation of the inner tube under high pressure. Specifically, the axial elongation of the balloon is greater than the elongation of the inner tube, resulting in the bending of the balloon under high pressure, which is generally above 8atm. As the pressure increases, the bending phenomenon will worsen. The balloon generally refers to a long balloon with a length of 60-300mm. The longer the length, the more serious the bending of the balloon. The present invention performs a groove crease treatment on one end of the inner tube close to the connecting seat, and sets a groove crease segment, so that the inner tube has greater elasticity. When the balloon is filled with a medium, the internal pressure of the balloon gradually increases, and the balloon is stretched by the axial force, and the inner tube is indirectly stretched by the force, thereby avoiding the phenomenon of the balloon bending under high pressure.

[0045] Example 2

[0046] This embodiment provides a method for preparing a high-pressure long balloon dilatation catheter. Compared with Embodiment 1, the only difference is that the water bath temperature for the first stretching is set to 50°C.

[0047] Example 3

[0048] This embodiment provides a method for preparing a high-pressure long balloon dilatation catheter. Compared with Embodiment 1, the only difference is that the water bath temperature for the first stretching is set to 90°C.

[0049] Example 4

[0050] This embodiment provides a method for preparing a high-pressure long balloon dilatation catheter. Compared with Embodiment 1, the only difference is that the water bath temperature for the first stretching is set to 100°C.

[0051] Comparative Example 1

[0052] This comparative example provides a method for preparing a high-pressure long balloon dilatation catheter. Compared with Example 1, the only difference is that: the first stretching in the balloon molding method is completely omitted, that is, a balloon material tube with an inner diameter × outer diameter = 0.0465*0.0950 inch and a length of 300 mm is prepared, and the second stretching described in Example 1 is directly performed to obtain a balloon blank; the balloon blank is inflated and stretched to obtain a molded balloon.

[0053] Comparative Example 2

[0054] This comparative example provides a method for preparing a high-pressure long balloon dilatation catheter. Compared with Example 1, the only difference is that: the first stretching in the balloon molding method is completely omitted, and a balloon material tube with an inner diameter × outer diameter = 0.0455*0.0900 inch and a length of 300 mm is directly prepared, and the second stretching described in Example 1 is directly performed to obtain a balloon blank; the balloon blank is inflated and stretched to obtain a molded balloon.

[0055] Comparative Example 3

[0056] This comparative example provides a method for preparing a high-pressure long balloon dilatation catheter. Compared with Example 1, the only difference is that the first stretching is not water bath stretching. Specifically, the balloon material tube is placed on a stretching machine with bidirectional stretching, and the balloon material tube is heated to 80°C by ordinary heating method.

[0057] The high-pressure long balloon dilatation catheters prepared in the above examples and comparative examples were subjected to a bursting pressure test, the method of the bursting pressure test comprising: filling the balloon at a pressure increase rate of 2.5 atm / s until the balloon ruptures, and recording the pressure at the time of balloon rupture as the bursting pressure. The specific test results are shown in Table 1.

[0058] Table 1

[0059]

[0060]

[0061] From Table 1, we can see the following points:

[0062] (1) Comparing Example 1 with Examples 2-4, in the balloon molding method of the present invention, the water bath temperature for the first stretching is controlled to be 60-80°C. If the water bath temperature exceeds this range, the bursting pressure will decrease, especially when the water bath temperature is too high, reaching 100°C, the bursting pressure directly drops to 21.88atm.

[0063] (2) Comparing Example 1 with Comparative Examples 1 and 2, the preparation method of the present invention focuses on improving the balloon molding method. The balloon tube is stretched for the first time and then stretched for the second time before being balloon molded. This makes the balloon have a higher pressure resistance than the traditional balloon molding method. Even if Comparative Example 1 uses a balloon tube of the same size as Example 1, the bursting pressure is only 21.98 atm due to the lack of the first stretching. Compared with Comparative Example 2, the bursting pressure does not increase significantly.

[0064] (3) Comparing Example 1 with Comparative Example 3, even though Comparative Example 3 adds a first stretching, the first stretching is not a water bath stretching, and the stretched size of the balloon tube cannot be made more uniform, resulting in a bursting pressure of only 22.07 atm.

[0065] The present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0066] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0067] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0068] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for preparing a high-pressure long balloon dilatation catheter, characterized in that: The preparation method comprises the following contents: The balloon, the inner tube, the outer tube and the connecting seat are prepared respectively, and they are assembled and connected to obtain a high-pressure long balloon dilatation catheter; The balloon forming method comprises: performing a first stretching on a balloon material tube, wherein the first stretching is water bath stretching, to obtain a stretched balloon material tube; performing a second stretching on the stretched balloon material tube to obtain a balloon material embryo; and performing inflation stretching forming on the balloon material embryo.

2. The preparation method according to claim 1, characterized in that: The method for preparing the inner tube comprises: preparing an inner tube material tube, and setting a groove fold section at one end close to the connecting seat.

3. The preparation method according to claim 1 or 2, characterized in that: The balloon tube is made of polymer material, including nylon or block polyether polyamide.

4. The preparation method according to claim 1 or 2, characterized in that: The water bath stretching ratio of the first stretching is 1:1.10-1:1.

40.

5. The preparation method according to claim 4, characterized in that: The waterbath stretching ratio is 1:1.15-1:1.

25.

6. The preparation method according to claim 1 or 2, characterized in that: The water bath temperature for the first stretching is 60-80°C.

7. The preparation method according to claim 1 or 2, characterized in that: The second stretching comprises: dividing the stretched balloon tube obtained by the first stretching into a heated section and a non-heated section, and controlling the stretching temperature of the heated section to be 100-140°C.

8. The preparation method according to claim 1 or 2, characterized in that: The inflation stretch molding includes inflation molding and shaping performed sequentially; the inflation molding temperature is controlled to be 80-120° C., and the inflation air pressure is controlled to be 26-35 bar; and the shaping temperature is controlled to be 120-150° C.

9. A high-pressure long balloon dilatation catheter, characterized in that: The preparation method is described in any one of claims 1 to 8.

10. The high-pressure long balloon dilatation catheter according to claim 9, characterized in that: The balloon has a diameter of 3-8 mm and a length of 60-300 mm.

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