A balloon dilatation catheter

Abstract

The present invention relates to a balloon dilatation catheter, comprising a push tube, an inner tube and a balloon, wherein the inner tube is arranged at the distal end of the push tube, and the balloon is sleeved on the outer surface of the inner tube; wherein the push tube is formed by extrusion of polylaurolactam and polyether block polyamide. The push tube of the balloon dilatation catheter has both reliable support and good flexibility, and can pass through tortuous blood vessels, calcified blood vessels and long-section occluded blood vessels, thereby improving the use performance.

Description

Technical Field

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

[0002] Since the success of the first percutaneous transluminal coronary angioplasty (PTCA) in 1977, interventional therapy has been rapidly developed in the past four decades, especially in the last decade, from the initial coronary artery to almost all blood vessels in the body. Interventional therapy has the advantages of less bleeding, less trauma, fewer complications, faster postoperative recovery, safety and reliability, which greatly reduces the pain suffered by patients. Balloon dilatation is a common interventional treatment method, which can be used to dilate narrowed blood vessels.

[0003] In recent years, with the aging of the population in China, the number of elderly patients suffering from lower limb ischemia due to lower limb arteriosclerosis and occlusion has increased. The lesions of lower limb ischemia are characterized by calcification and elongation of the lesion site. When using balloon dilatation for treatment, due to the poor pushing performance and low pressure resistance of the existing balloon dilatation catheter, it is difficult for the balloon dilatation catheter to pass through the calcified lesions and long-segment occluded blood vessels, and thus the relevant surgical treatment cannot be completed. Summary of the invention

[0004] The object of the present invention is to provide a balloon dilatation catheter, which has good pushing performance and can smoothly pass through calcified lesions and long-section occluded blood vessels.

[0005] To achieve the above-mentioned purpose, the present invention provides a balloon dilatation catheter, comprising a push tube, an inner tube and a balloon, wherein the inner tube is arranged at the distal end of the push tube, and the balloon is sleeved on the outer surface of the inner tube; wherein the push tube is formed by extrusion of a blend of polylaurolactam and polyether block polyamide.

[0006] Optionally, the mass ratio of the polylaurolactam to the polyether block polyamide is (1.5-9):1.

[0007] Optionally, the balloon is a high-pressure balloon.

[0008] Optionally, it also includes a hydrophilic coating, which covers the outer surface of the balloon and the distal outer surface of the push tube; and / or the balloon dilatation catheter also includes a conical tip, which is arranged at the distal end of the inner tube and extends from the distal end of the balloon; the hydrophilic coating covers the outer surface of the conical tip, the outer surface of the balloon and the distal outer surface of the push tube.

[0009] Optionally, in the axial direction of the balloon dilatation catheter, the length of the hydrophilic coating is 300 mm-500 mm.

[0010] Optionally, the push tube includes a filling cavity and a guidewire cavity which are arranged in parallel along its axial direction and isolated from each other; the cross-section of the filling cavity is crescent-shaped, and the distal end of the filling cavity is connected to the balloon; the cross-section of the guidewire cavity is circular, and the distal end of the guidewire cavity is connected to the inner tube.

[0011] Optionally, the distal cavity wall of the guidewire cavity and the proximal tube wall of the inner tube are formed into one piece by heat pressing.

[0012] Optionally, a connecting piece is further included, which is arranged at the proximal end of the pushing tube and includes a first connector and a second connector; the first connector is connected to the filling cavity, and the second connector is connected to the guide wire cavity.

[0013] Optionally, the distance from the proximal end point of the filling chamber to the proximal end point of the balloon is smaller than the distance from the proximal end point of the guidewire chamber to the proximal end point of the balloon; an infusion hole is provided on the proximal cavity wall of the filling chamber, the infusion hole is connected to the first connector, and the proximal end of the filling chamber is a closed end.

[0014] Optionally, the proximal end of the push tube extends into the interior of the connector; the balloon dilatation catheter also includes a first connecting tube, which is arranged at the proximal end of the push tube by heat pressing and closes the proximal end of the filling cavity; the inner wall of the connector is sealed and connected to the first connecting tube.

[0015] Optionally, it further includes a second connecting tube, which is sleeved on the pushing tube by heat pressing; at least part of the second connecting tube is arranged inside the connecting piece and is sealed and connected to the inner wall of the connecting piece.

[0016] Optionally, a stress diffusion tube is further included, which is sleeved on the outer surface of the proximal end of the pushing tube and is arranged adjacent to the distal end of the connecting piece.

[0017] Optionally, the inner tube is further provided with a developing element, and the number of the developing elements is two, which are respectively arranged corresponding to the proximal end and the distal end of the balloon.

[0018] Compared with the prior art, the balloon dilatation catheter of the present invention has the following advantages:

[0019] First, the balloon dilatation catheter includes a push tube, an inner tube and a balloon, wherein the inner tube is arranged at the distal end of the push tube, and the balloon is sleeved on the outer surface of the inner tube; wherein the push tube is formed by extrusion of polylaurolactam and polyether block polyamide. The push tube made of the mixture of polylaurolactam and block polyether amide has good flexibility and support, so that it can smoothly pass through calcified lesions and long-section occluded blood vessels.

[0020] Second, the balloon is a high-pressure balloon, which improves the pressure resistance of the entire balloon dilation catheter and improves the dilation effect.

[0021] Third, the balloon dilatation catheter also includes a hydrophilic coating, which at least covers the outer surface of the balloon and the outer surface of the proximal end of the push tube, so that the balloon dilatation catheter has less friction when traveling in the blood vessel, which is convenient for pushing, and the hydrophilic coating is not provided on the middle and proximal outer surfaces of the push tube, so that the push tube has good controllability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to better understand the present invention and do not constitute an improper limitation of the present invention.

[0023] Figure 1 is a schematic structural diagram of a balloon dilatation catheter provided according to an embodiment of the present invention;

[0024] Figure 2 yes Figure 1 AA cross-sectional view of the balloon dilatation catheter shown;

[0025] Figure 3 yes Figure 1 BB section view of the balloon dilatation catheter shown;

[0026] Figure 4 It is a schematic diagram of a case where the inner tube of a balloon dilatation catheter provided by an embodiment of the present invention is connected to a push tube, and the distal end of the original tube of the push tube is cut;

[0027] Figure 5 It is a schematic diagram of the inner tube of the balloon dilatation catheter provided by one embodiment of the present invention being connected to the push tube;

[0028] Figure 6 It is a schematic diagram of a proximal end of an original tube of a balloon dilatation catheter provided by an embodiment of the present invention being cut when the proximal end of the original tube of the propelling tube is connected to a connecting piece;

[0029] Figure 7 It is a schematic diagram of a case where a first connecting tube and a second connecting tube are arranged on a push tube of a balloon dilatation catheter provided according to an embodiment of the present invention.

[0030] [Description of reference numerals is as follows]:

[0031] 100-push pipe, 100'-original pipe;

[0032] 110-filling lumen, 120-guidewire lumen;

[0033] 200-inner tube;

[0034] 300-Balloon;

[0035] 400 - tapered tip;

[0036] 500-connector;

[0037] 510-first connector, 520-second connector;

[0038] 600-stress diffusion tube;

[0039] 710-first connecting pipe, 720-second connecting pipe;

[0040] 800-developing element;

[0041] 900-Heat shrink tubing. DETAILED DESCRIPTION

[0042] The following is an explanation of the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the present embodiment only illustrate the basic concept of the present invention in a schematic manner, and only the components related to the present invention are shown in the figure instead of being drawn according to the number, shape and size of the components in the actual implementation. The type, quantity and proportion of each component in the actual implementation can be a random change, and the component layout type may also be more complicated.

[0043] In addition, each embodiment of the following description has one or more technical features, but this does not mean that the user of the present invention must implement all the technical features in any embodiment at the same time, or can only implement part or all of the technical features in different embodiments separately. In other words, under the premise that implementation is possible, those skilled in the art can selectively implement part or all of the technical features in any embodiment according to the disclosure of the present invention and according to the design specifications or implementation requirements, or selectively implement a combination of part or all of the technical features in multiple embodiments, thereby increasing the flexibility of the implementation of the present invention.

[0044] As used in this specification, the singular forms "a", "an", and "the" include plural objects, unless the content clearly indicates otherwise. As used in this specification, the term "or" is generally used in a sense that includes "and / or", unless the content clearly indicates otherwise, 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 connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium, and it can be a connection between the internal parts of two elements or an interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0045] In order to make the purpose, advantages and features of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings. It should be noted that the drawings are all in very simplified form and in non-precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. The same or similar reference numerals in the drawings represent the same or similar components.

[0046] In this article, the terms "proximal" and "distal" refer to the relative orientation, relative position, and direction of components or actions relative to each other from the perspective of a doctor using the medical device. Although "proximal" and "distal" are not restrictive, "proximal" usually refers to the end of the medical device that is close to the doctor during normal operation, and "distal" usually refers to the end that first enters the patient's body.

[0047] Figure 1 The structure diagram of the balloon dilatation catheter provided by the embodiment of the present invention is shown. Figure 2 Shows Figure 1 A-axis sectional view. Please refer to Figure 1 and Figure 2 The balloon dilatation catheter comprises a push tube 100, an inner tube 200 and a balloon 300, wherein the inner tube 200 is arranged at the distal end of the push tube 100, and the balloon 300 is sleeved on the outer surface of the inner tube 200. The push tube 100 is formed by extrusion of polylaurolactam (PA12) and polyether block polyamide (Pebax), and the specific extrusion process is set according to the actual situation, as long as the polylaurolactam and polyether block polyamide can be melted, mixed evenly and extruded to obtain the original tube of the push tube of a predetermined shape. The push tube 100 of the balloon dilatation catheter provided in this embodiment has both flexibility and support, so that the balloon dilatation catheter has good bending ability and excellent pushing performance, ensuring that it passes through tortuous blood vessels, calcified lesions and long-segment occluded blood vessels, and improves the use performance.

[0048] Preferably, the mass ratio of polylaurolactam to polyether block polyamide is (1.5-9): 1. In a specific embodiment, the mass ratio of polylaurolactam to polyether block polyamide is 8:2. According to GB / T232-2010, the toughness of the push tube 100 made of the mixed material with this ratio is tested using a conventional three-point bending test device. When the sample is pressed down 4mm, the force applied by the pressure head to the sample is 1.5N-3.5N, indicating that the push tube 100 has good flexibility. In this embodiment, the grade of polylaurolactam is PA12: Grilamid L25, and the grade of polyether block polyamide is Pebax7233 SA01 MED.

[0049] The total length of the balloon dilatation catheter is 40cm-150cm. When the balloon dilatation catheter is used for balloon dilatation, the push tube 100 is used to transmit the push force applied by the operator so that the balloon 300 reaches the predetermined position. During the movement of the balloon 300, in order to facilitate the guidance, the distal end of the inner tube 200 is also provided with a conical tip 400, and the conical tip 400 extends from the distal end of the balloon 300. The conical tip 400 is made of polyether block polyamide and titanium dioxide (TiO 2 ) mixture. Further, the balloon dilatation catheter also includes a hydrophilic coating (not shown in the figure), which covers the outer surface of the tapered tip 400, the outer surface of the balloon 300 and the outer surface of the distal end of the push tube 100. The hydrophilic coating is used to reduce the friction between the distal end of the balloon dilatation catheter and the blood vessel during the push process, which is easy to transport and reduces damage to the blood vessel wall. In an alternative embodiment, the hydrophilic coating can also cover the outer surface of the balloon 300 and the outer surface of the distal end of the push tube 100, but not the outer surface of the tapered tip 400. The hydrophilic coating is not provided on the middle and proximal end of the push tube 100 to ensure that the push tube 100 has good controllability. In this embodiment, according to the length of the balloon 300, the length of the hydrophilic coating in the axial direction of the balloon dilatation catheter is 300mm-500mm. The main component of the hydrophilic coating can be polyvinyl pyrrolidone, or it can be formed by curing any existing hydrophilic coating composition, which will not be repeated in this embodiment.

[0050] Preferably, the balloon 300 is a high-pressure balloon, which can effectively expand in calcified blood vessels, fully open the diseased blood vessels, and enhance the treatment effect. The inner layer of the balloon 300 described in this embodiment (the part where the balloon is connected to the inner tube 200) is a low-compliance high-pressure balloon made of polylaurolactam, with a diameter of 3.0mm-14.0mm and a length of 20mm-220mm, which can withstand a pressure of 16atm-3atm. Specifically, the balloon 300 includes an inner layer and an outer layer, and the inner layer and the outer layer together enclose an inner cavity for accommodating a filling agent, and the inner layer is extruded by polylaurolactam, and the outer layer is extruded by polyether block polyamide.

[0051] The method of using the balloon dilatation catheter is as follows: first, a guide wire is implanted in the patient's body, and then the balloon dilatation catheter is passed over the guide wire. Then, the operator applies a pushing force to the proximal end of the push tube 100 to push the distal end of the balloon dilatation catheter along the guide wire into the blood vessel and reach the lesion location, and then the filling agent is infused into the balloon 300 through the push tube 100 to expand the balloon 300 and open the narrowed blood vessel.

[0052] To achieve the above purpose, Figure 3 As shown, the push tube 100 includes a filling chamber 110 and a guide wire chamber 120 which are arranged in parallel and isolated from each other along its axial direction, the distal end of the filling chamber 110 is communicated with the balloon 300, and the distal end of the guide wire chamber 120 is communicated with the inner tube 200. The cross section of the filling chamber 110 is crescent-shaped, and the cross section of the guide wire chamber 120 is circular. The push tube 100 of this structure makes maximum use of its cross section to construct the filling chamber 110, shortening the filling and withdrawal time of the filling agent.

[0053] Further, the balloon dilatation catheter further comprises a connector 500, which is disposed at the proximal end of the push tube 100 and comprises a first connector 510 and a second connector 520, wherein the first connector 510 is in communication with the filling cavity 110, and the second connector 520 is in communication with the guidewire cavity 120. Thus, in actual use, the guidewire passes through the tapered tip 400, the guidewire cavity 120 and the second connector 520. The first connector 510 is connected to a filling agent syringe, and the filling agent syringe injects a filling agent into the balloon 300 via the first connector 510 and the filling cavity 110, and the filling agent may be a contrast agent or the like.

[0054] Optionally, the proximal end of the push tube 100 extends into the interior of the connector 500 and is connected to the connector 500, and the distance from the proximal end of the filling chamber 110 to the proximal end of the balloon 300 is smaller than the distance from the proximal end of the guidewire chamber 120 to the proximal end of the balloon 300. The proximal end of the filling chamber 110 is a closed end, and a perfusion hole (not shown) is provided on the proximal wall of the filling chamber 110, and the first connector 510 is connected to the filling chamber 110 through the perfusion hole.

[0055] During the process of pushing the balloon dilatation catheter, the operator applies a pushing force to the connector 500, and transmits the pushing force to the push tube 100 via the connector 500. In order to prevent the proximal end of the push tube 100 (specifically, the position of the push tube 100 corresponding to the distal end of the connector 500) from being stressed and being bent, the balloon dilatation catheter preferably includes a stress diffusion tube 600 (such as Figure 1 As shown in FIG. 1 , the stress diffusion tube 600 is sleeved on the outer surface of the proximal end of the push tube 100 and is disposed adjacent to the distal end of the connector 500. The stress diffusion tube 600 is made of a flexible material such as silicone and plays a role in diffusing stress.

[0056] Furthermore, the balloon dilatation catheter further comprises a first connecting tube 710 (such as Figure 5 As shown in the figure, the first connecting tube 710 is fixedly sleeved on the proximal end of the push tube 100. The first connecting tube 500 and the push tube 100 are connected by hot pressing, and in the process of connecting the two, the first connecting tube 710 also closes the proximal end of the filling cavity 110 (the specific method will be described below). The inner wall of the connecting piece 500 is sealed and connected to the first connecting tube 710 by a dispensing or injection molding process. The balloon dilatation catheter also includes a second connecting tube 720, which is fixedly sleeved on the position corresponding to the distal end of the push tube 100 and the connecting piece 500 by hot pressing, so that at least part of the second connecting tube 720 is arranged inside the connecting piece 500, and is sealed and connected to the inner wall of the connecting piece 500 by a dispensing or injection molding process. The connection between the push tube 100 and the connecting piece 500 is achieved by the first connecting tube 710 and the second connecting tube 720, which improves the sealing and avoids leakage.

[0057] In this embodiment, the inner tube 200 is made of polylaurolactam. The distance from the distal end of the guidewire cavity 120 to the connector 500 is smaller than the distance from the distal end of the filling cavity 110 to the connector 500. The cavity wall of the guidewire cavity 120 and the proximal wall of the inner tube 200 are formed into one piece by hot pressing, thereby improving the connection strength between the push tube 100 and the inner tube 200. The specific connection method of the two will be described in detail below.

[0058] Furthermore, at least one developing element 800 is provided at the distal end of the balloon dilatation catheter to display the position of the balloon 300 during the pushing process. The developing element 800 can be made of a developing metal such as a platinum-iridium alloy, and is preferably provided on the inner tube 200, which is safe and reliable. In this embodiment, the number of the developing elements 800 is two, and the two developing elements 800 are provided corresponding to the proximal end and the distal end of the balloon 300, respectively.

[0059] Next, this article will combine Figure 4 and Figure 6 The present invention introduces the assembly method of the inner tube 200 of the balloon dilatation catheter and the push tube 100, and the push tube 100 and the connector ( Figures 4 to 7 The assembly method of FIG. 1 is not shown.

[0060] The process of assembling the push tube 100 and the inner tube 200 is as follows:

[0061] An original tube 100 ′ and an inner tube 200 of a push tube 100 are provided, and the filling cavity 110 and the guide wire cavity 120 are flush at the proximal end and the distal end of the original tube.

[0062] The wall of the guidewire cavity 120 is cut at the distal end of the original tube 100' so that the distance between the distal end of the guidewire cavity 120 and the distal end of the filling cavity 110 is 4mm-6mm. Care should be taken not to damage the wall of the filling cavity 110 during cutting. Figure 4 And inserting an inner liner (not shown in the figure) into the inner tube 200 and the filling cavity 110 to support the tube wall of the inner tube 200 and the cavity wall of the filling cavity 110 respectively, so as to avoid deformation of the inner tube 200 and the filling cavity 110 during subsequent processing.

[0063] The proximal end of the inner tube 200 is inserted into the distal end of the guidewire cavity 120 (the outer diameter of the inner tube 200 is slightly smaller than the inner diameter of the guidewire cavity 120 to facilitate insertion and docking), and the lining in the inner tube 200 is also inserted into the guidewire cavity 120.

[0064] A heat shrink tube 900 is mounted on the connection between the inner tube 200 and the push tube 100 (eg Figure 5 shown).

[0065] The heat shrink tube 900 is heated by rotation, the heating temperature is 420°F-450°F, and the heating time is about 55s-65s.

[0066] After the heat shrink tube 900 is cooled, the heat shrink tube 900 is peeled off.

[0067] The above method was used to make samples, of which ten samples were heated at 420℉, 430℉, 440℉ and 450℉, and the heating time of each sample was 60s. By observing the appearance of the connection between the inner tube and the push tube, it was found that when the heating temperature was 420℉, the appearance of the connection point met the requirements, while when the heating temperature was 450℉, the material was severely deformed and the appearance of the connection point was defective. The samples were subjected to a tensile test, and the results are shown in Table 1. It can be seen from Table 1 that when the heating temperature was 420℉, the tensile strength of the connection point was low and could not meet the use requirements. In summary, when connecting the inner tube and the push tube, the heating temperature is preferably 430℉-440℉.

[0068] Table 1 Tensile strength of the connection point between the push tube and the inner tube

[0069]

[0070] The process of assembling the push tube 100 and the connecting piece is as follows:

[0071] Liners are inserted into the filling cavity 110 of the original tube 100 ′ of the push tube 100 and the guidewire cavity 120 .

[0072] The wall of the filling cavity 110 is cut at the proximal end of the original tube 100' of the push tube 100, so that the distance between the proximal end of the filling cavity 110 and the proximal end of the guide wire cavity 120 is 4mm-6mm. When cutting, be careful not to damage the wall of the guide wire cavity 120. The shape of the proximal end of the original tube 100' of the push tube 100 after cutting is as follows: Figure 6 shown.

[0073] An infusion hole is provided on the wall of the filling cavity 110 away from the guidewire cavity 120 , and in the axial direction of the pushing tube 100 , the distance from the infusion hole to the proximal end point of the guidewire cavity 120 is 24 mm-28 mm.

[0074] A connection area is determined on the push tube 100. In the axial direction of the push tube 100, the distance from the connection area to the proximal end point of the guidewire cavity 120 is 48 mm to 52 mm. A second connection tube 720 is sleeved on the second connection area of ​​the push tube 100. The second connection tube 720 is made of polyether block polyamide and has an axial length of about 28 mm.

[0075] A heat shrink tube 900 is mounted on the push tube 100 and covers the second connecting tube 720 (such as Figure 7 shown).

[0076] The heat shrink tube 900 is heated to fix the second connecting tube 720 and the pushing tube 100 together.

[0077] The inner lining of the filling cavity 110 of the push tube 100 is removed, and a first connecting tube 710 is sleeved on the proximal end of the push tube 100 without covering the perfusion hole. The first connecting tube 710 is made of polyether block polyamide and is about 15 mm long.

[0078] Another heat shrink tube 900 is mounted on the proximal end of the push tube 100 and covers the first connecting tube 710 (such as Figure 7 shown).

[0079] The heat shrink tube 900 is heated at 190°C for 50 seconds to fix the first connecting tube 710 to the pushing tube 100. Since there is no lining in the filling cavity 110, when the heat shrink tube 900 shrinks, the proximal wall of the filling cavity 110 melts and closes the proximal end of the filling cavity 110.

[0080] After cooling, the two heat shrink tubes 900 are peeled off.

[0081] Finally, the proximal end of the push tube 100 is inserted into the connector to connect the first connector 510 with the injection hole, and the second connector 720 is disposed at the distal end of the connector, and at least a portion of the second connector 720 is located in the connector. The first connector 710 is sealed and connected to the inner wall of the connector, and the second connector 720 is sealed and connected to the inner wall of the connector by a dispensing or injection molding process.

[0082] Those skilled in the art can understand that in the above process, the position of the connection area, the position of the perfusion hole, the length of the first connecting tube and the length of the second connecting tube are all reasonably set according to the size of the balloon dilatation catheter.

[0083] The technical solution provided in the embodiment of the present invention has both reliable support and good flexibility because the push tube is extruded by polylaurolactam and polyether block polyamide, and can pass through tortuous blood vessels to reach the designated lesion site, and can fully dilate calcified or long-segment occluded blood vessels. It can be understood by those skilled in the art that the balloon dilatation catheter provided in the embodiment of the present invention can also be used for the dilation of arteriovenous fistulas and post-dilatation of stents.

[0084] Although the present invention is disclosed as above, it is not limited thereto. Those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A balloon dilatation catheter, characterized in that: The invention comprises a push tube, an inner tube and a balloon, wherein the inner tube is arranged at the distal end of the push tube, and the balloon is a high-pressure balloon and is sleeved on the outer surface of the inner tube; wherein the push tube is formed by extrusion of polylaurolactam and polyether block polyamide, and the mass ratio of polylaurolactam to polyether block polyamide is (1.5-9):1; the push tube comprises a filling cavity and a guide wire cavity which are arranged in parallel along its axial direction and isolated from each other; the cross section of the filling cavity is crescent-shaped, and the distal end of the filling cavity is connected to the balloon; the cross section of the guide wire cavity is circular, and the distal end of the guide wire cavity is connected to the inner tube; The balloon dilatation catheter also includes a hydrophilic coating, which covers the outer surface of the balloon and the outer surface of the distal end of the push tube, and the length of the hydrophilic coating in the axial direction of the balloon dilatation catheter is 300mm-500mm; the balloon dilatation catheter also includes a conical tip, which is arranged at the distal end of the inner tube and extends from the distal end of the balloon; the hydrophilic coating covers the outer surface of the conical tip, the outer surface of the balloon and the outer surface of the distal end of the push tube.

2. The balloon dilatation catheter according to claim 1, characterized in that: The distal lumen wall of the guidewire lumen and the proximal tube wall of the inner tube are formed into one piece by heat pressing.

3. The balloon dilatation catheter according to claim 1, characterized in that: It also includes a connecting piece, which is arranged at the proximal end of the pushing tube and includes a first connector and a second connector; the first connector is connected to the filling cavity, and the second connector is connected to the guide wire cavity.

4. The balloon dilatation catheter according to claim 3, characterized in that: The distance from the proximal end point of the filling cavity to the proximal end point of the balloon is smaller than the distance from the proximal end point of the guidewire cavity to the proximal end point of the balloon; a perfusion hole is provided on the proximal cavity wall of the filling cavity, the perfusion hole is connected to the first connector, and the proximal end of the filling cavity is a closed end.

5. The balloon dilatation catheter according to claim 4, characterized in that: The proximal end of the push tube extends into the interior of the connector; the balloon dilatation catheter also includes a first connecting tube, which is arranged at the proximal end of the push tube by heat pressing and closes the proximal end of the filling cavity; the inner wall of the connector is sealed and connected to the first connecting tube.

6. The balloon dilatation catheter according to claim 4, characterized in that: It also includes a second connecting tube, which is sleeved on the pushing tube by heat pressing; at least part of the second connecting tube is arranged inside the connecting piece and is sealed and connected to the inner wall of the connecting piece.

7. The balloon dilatation catheter according to claim 3, characterized in that: It also includes a stress diffusion tube, which is sleeved on the outer surface of the proximal end of the pushing tube and is arranged adjacent to the distal end of the connecting piece.

8. The balloon dilatation catheter according to claim 1, characterized in that: The inner tube is also provided with a developing element, and the number of the developing elements is two, which are respectively arranged corresponding to the proximal end and the distal end of the balloon.

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