Microcatheter and method of use

Abstract

The present invention provides a microcatheter, comprising a catheter body, and at least two balloons, each of which is arranged in sequence from the distal end to the proximal end of the catheter body and can expand and contract independently, and the balloon closest to the proximal end of the catheter body is used to load a stent. A rotary valve is arranged at the proximal end of the catheter body, and is used to control each of the balloons to expand and contract independently. The volume of the balloons after expansion increases successively, so that the microcatheter can achieve the effect of gradient expansion of the occluded part of the lesion, and can load the stent at the same time, reducing the amount of balloons used during the operation, which is conducive to reducing the cost of the operation. Correspondingly, the present invention also provides a method for using a microcatheter.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a microcatheter and a use method thereof. Background Art

[0002] Percutaneous coronary intervention (PCI) for the treatment of coronary atherosclerosis has evolved from 1977 to today and has become increasingly mature. In the process of percutaneous coronary intervention, the guiding catheter is first placed in the coronary artery opening via a guidewire, and the guidewire is inserted through the guiding catheter. After the guidewire passes through the stenotic lesion, the dilatation balloon catheter is inserted through the guidewire to dilate the local lesion, and then the stent is implanted and released to achieve the purpose of treating the lesion. However, for chronic total occlusion (CTO) of the coronary artery, the lesions are often located in the tortuous part of the blood vessel, the lesion occlusion time is long, and the length of the occluded lesion is generally greater than 20mm, which makes it difficult for the guidewire to pass through the occluded lesion. According to statistical data, the applicant found that the inability of the guidewire to pass through the occluded blood vessel segment accounted for 85%-90% of the failures of interventional surgery for CTO lesions.

[0003] Currently, most clinicians use a combination of microcatheters and guidewires to pass through the site of CTO lesions. Microcatheters can enhance the maneuverability, support, and safety of guidewires, and can significantly enhance the ability of guidewires to pass through occluded lesions. However, current microcatheters still have problems when entering occluded lesions forward. The follow-up force of the guidewire and microcatheter is insufficient, and the support force of the microcatheter on the guidewire is insufficient, which causes the microcatheter to be unable to move forward when it is halfway through the occluded lesion, and finally the microcatheter has to be withdrawn. And even if the microcatheter successfully passes through the occluded lesion and penetrates the site of the occluded lesion, it is still necessary to load the stent with a balloon and deliver it to the site of the lesion for expansion. It is conservatively estimated that 2-3 balloons are needed to complete an operation, which imposes a serious economic burden on patients. Summary of the invention

[0004] The purpose of the present invention is to provide a microcatheter that can achieve gradient expansion to completely occlude the lesion site and can simultaneously load a stent, thereby reducing the amount of balloons used during surgery and reducing the cost of surgery.

[0005] In order to achieve the above object, the present invention provides a microcatheter, comprising:

[0006] a catheter body; and,

[0007] At least two balloons are sequentially arranged along the catheter body, each of the balloons can be expanded and contracted independently, and the volume of the balloons after expansion increases sequentially from the distal end to the proximal end of the catheter body, and the balloon closest to the proximal end of the catheter body is used to load the stent;

[0008] The rotary valve is arranged at the proximal end of the catheter body and is used to control each balloon to expand and contract independently.

[0009] Optionally, the lengths of the balloons increase sequentially, wherein the length of the balloon closest to the proximal end of the catheter body is the largest.

[0010] Optionally, a perfusion cavity corresponding to the balloon is provided in the tube wall of the catheter body, the distal end of the perfusion cavity is communicated with the corresponding balloon, and the proximal end is connected to the rotary valve.

[0011] Optionally, the rotary valve comprises a first connecting member, a rotating member and a Luer connector, wherein the distal end and the proximal end of the first connecting member are respectively connected to the proximal end of the catheter body and the Luer connector, and the rotating member is sleeved outside the first connecting member and is rotatably connected to the first connecting member;

[0012] The rotating member is provided with an injection cavity, and the injection cavity is communicated with any of the perfusion cavities by rotating the rotating member.

[0013] Optionally, the rotary valve also includes a second connecting member, the proximal end of the second connecting member is non-fixedly overlapped with the distal end of the rotating member, and the distal end is fixedly overlapped with the proximal end of the catheter body, and the second connecting member is provided with a connecting cavity corresponding one-to-one to the perfusion cavity, and the distal end of the connecting cavity corresponds to the proximal end of the perfusion cavity, and the rotating member is rotated to connect the injection cavity with any of the connecting cavities.

[0014] Optionally, a mark corresponding to each of the perfusion cavities is provided on the outer circumferential surface of the second connecting member for identifying the perfusion cavities.

[0015] Optionally, a ratchet structure is further provided between the first connecting member and the rotating member, the ratchet teeth of the ratchet structure correspond one-to-one to the perfusion chambers, and the inner circumference of the rotating member is provided with grooves corresponding one-to-one to the ratchet teeth.

[0016] Optionally, the first connecting member is made of elastic material.

[0017] Optionally, the number of the balloon and the number of the perfusion cavities are both three, and the perfusion cavities are evenly distributed circumferentially along the axis of the catheter body.

[0018] Optionally, the length of one of the three balloons is 5mm-10mm, the length of another one is 15mm-25mm, and the length of the remaining one is 20mm-30mm.

[0019] In addition, the present invention also provides a method for using the microcatheter, comprising:

[0020] Step S1: Load the stent on the balloon closest to the proximal end of the catheter body, and execute step S2;

[0021] Step S2: moving the catheter body until any balloon is stuck by the lesion occlusion part, when the stuck balloon is the balloon closest to the proximal end, expanding the balloon closest to the proximal end to expand the stent, and executing step S5; when the stuck balloon is not the balloon closest to the proximal end, executing step S3;

[0022] Step S3: expanding the stuck balloon to expand the occluded part of the lesion, and executing step S4;

[0023] Step S4: shrinking the stuck balloon and returning to step S2;

[0024] Step S5: Deflate the balloon at the proximal end and withdraw the microcatheter.

[0025] In the microcatheter provided by the present invention, at least two balloons are arranged in sequence along the catheter body, each of which can expand and contract independently, and the volume of the balloon after expansion increases in sequence from the distal end to the proximal end of the catheter body, and the balloon closest to the proximal end of the catheter body is used to load the stent, and the rotary valve is used to control each balloon to expand and contract independently. The microcatheter can achieve the effect of gradient expansion of the lesion occlusion part, and can load the stent at the same time, reduce the use of balloons during the operation, and help reduce the cost of the operation.

[0026] In addition, an injection cavity is provided on the rotating part of the rotary valve, and can rotate relative to the first connecting part, the catheter body and the Luer connector to connect the injection cavity with any of the perfusion cavities, so that the rotary valve can control the balloons to expand and contract independently.

[0027] In addition, a ratchet structure is provided between the first connecting member and the rotating member, and the ratchet teeth of the ratchet structure are arranged on the outer circumferential surface of the first connecting member and correspond one-to-one to the perfusion chambers. The inner circumferential surface of the rotating member is provided with grooves corresponding one-to-one to the ratchet teeth, so that the first connecting member and the rotating member can be interlocked to prevent the rotary valve from leaking when the balloon is perfused with balloon fluid.

[0028] In addition, markings corresponding to the perfusion cavities are arranged on the outer peripheral surface of the second connecting member, so as to facilitate the operator to identify the balloon to be expanded or contracted.

[0029] In addition, the first connecting member is made of elastic material, which increases the sealing performance of the rotary valve and further avoids leakage of the rotary valve when the balloon is filled with balloon fluid.

[0030] Correspondingly, the present invention also provides a method for using the microcatheter. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram of a microcatheter in an embodiment of the present invention;

[0032] Figure 2 is a cross-sectional view of a microcatheter in an embodiment of the present invention;

[0033] Figure 3 Schematic diagram of the microcatheter in the embodiment of the present invention from the B perspective;

[0034] Figure 4 is a schematic diagram of a microcatheter from a viewing angle A in an embodiment of the present invention;

[0035] Figure 5 is a schematic diagram of a second connecting piece of a microcatheter in an embodiment of the present invention;

[0036] Figure 6 is a first schematic diagram of a rotary valve of a microcatheter in an embodiment of the present invention;

[0037] Figure 7 is a second schematic diagram of a rotary valve of a microcatheter in an embodiment of the present invention;

[0038] Figure 8 is a flow chart of a method for using a microcatheter in an embodiment of the present invention;

[0039] Fig. 9 is a schematic diagram of a first position of a microcatheter and a lesion occlusion site in an embodiment of the present invention;

[0040] Fig.10 is a schematic diagram of a second position of the microcatheter and the lesion occlusion site in an embodiment of the present invention;

[0041] Fig.11 is a schematic diagram of a third position of the microcatheter and the lesion occlusion site in an embodiment of the present invention;

[0042] Fig.12 is a schematic diagram of a fourth position of the microcatheter and the lesion occlusion site in an embodiment of the present invention;

[0043] Fig.13 is a schematic diagram of a fifth position of the microcatheter and the lesion occlusion site in an embodiment of the present invention;

[0044] Fig.14 is a schematic diagram of a sixth position of the microcatheter and the lesion occlusion site in an embodiment of the present invention;

[0045] The reference numerals are as follows:

[0046] 100-catheter body; 110-infusion cavity; 111-infusion port;

[0047] 200-balloon; 210-first balloon; 220-second balloon; 230-third balloon;

[0048] 300-rotary valve; 310-Luer connector; 320-first connecting piece; 321-ratchet teeth; 330-rotating piece; 331-injection port; 332-injection cavity; 333-Y-shaped end; 340-second connecting piece; 341-connecting cavity; 342-label;

[0049] 400-lesion occlusion site;

[0050] 500-Stand. DETAILED DESCRIPTION

[0051] The specific implementation of the present invention will be described in more detail below in conjunction with the schematic diagram. The advantages and features of the present invention will become clearer based on the following description. It should be noted that the drawings are all in a very simplified form and are not in exact proportions, and are only used to facilitate and clearly assist in explaining the purpose of the embodiments of the present invention.

[0052] The definitions of "proximal" and "distal" in this article are: "proximal" generally refers to the end of the medical device that is close to the operator during normal operation, and "distal" generally refers to the end of the medical device that first enters the patient's body during normal operation.

[0053] Figure 1 Schematic diagram of the microcatheter in this embodiment. Figure 1 As shown, the microcatheter includes a catheter body 100 and a balloon 200. The catheter body 100 is a slender hose, and at least two balloons 200 are sequentially arranged from the distal end to the proximal end of the catheter body 100, each of the balloons 200 can expand and contract independently, and the balloon 200 closest to the proximal end of the catheter body 100 is used to load the stent. The number of the balloons 200 can be two, three, four or five, which is not limited here.

[0054] As an exemplary embodiment, there are three balloons 200, namely, a first balloon 210, a second balloon 220 and a third balloon 230. The first balloon 210 is closest to the distal end of the catheter body 100, and the third balloon 230 is closest to the proximal end of the catheter body 100. The third balloon 230 has the function of loading and releasing the stent.

[0055] Optionally, the first balloon 210, the second balloon 220 and the third balloon 230 are of the same size. By controlling the expansion amount of each balloon 200, the expansion degrees of the first balloon 210, the second balloon 220 and the third balloon 230 are increased in sequence, and then the volumes of the expanded first balloon 210, the second balloon 220 and the third balloon 230 are increased in sequence, so as to achieve the effect of gradient expansion of the balloon 200 to occlude the lesion.

[0056] Preferably, the lengths of the first balloon 210, the second balloon 220 and the third balloon 230 are inconsistent, wherein the length of the first balloon 210 is the smallest, and the length of the third balloon 230 is the largest, and the length of the balloon 200 refers to the length in the axial direction. Therefore, the volumes of the first balloon 210, the second balloon 220 and the third balloon 230 after expansion increase in sequence. Optionally, the length of the first balloon 210 in the axial direction is 5mm-10mm, the length of the second balloon 220 in the axial direction is 15mm-25mm, and the length of the third balloon 230 in the axial direction is 20mm-30mm.

[0057] Figure 2 is a cross-sectional view of the microcatheter in this embodiment. Figure 3 FIG. 2 is a schematic diagram of a microcatheter from a B perspective in an embodiment of the present invention. Figure 2 and Figure 3 As shown, the central cavity of the catheter body 100 is used for the passage of the CTO guidewire. A perfusion cavity 110 corresponding to the balloon 200 is provided in the tube wall of the catheter body 100, and the distal end of the perfusion cavity 110 is communicated with the corresponding balloon 200, and the proximal end is connected to the rotary valve 300. A perfusion port 111 is provided at the distal end of the perfusion cavity 110, and the perfusion cavity 110 perfuses the balloon 200 with balloon liquid through the perfusion port 111. As an exemplary embodiment, the number of the balloon 200 is three, and at this time, the first perfusion cavity 110, the second perfusion cavity 110 and the third perfusion cavity 110 corresponding to the first balloon 210, the second balloon 220 and the third balloon 230 are opened in the tube wall of the catheter body 100. The first balloon 210 is infused with balloon liquid through the first infusion chamber 110 to expand the first balloon 210. Similarly, the second balloon 220 is infused with balloon liquid through the second infusion chamber 110 to expand the second balloon 220. The third balloon 230 is infused with balloon liquid through the third infusion chamber 110 to expand the third balloon 230. In this way, the first balloon 210, the second balloon 220 and the third balloon 230 can be expanded and contracted independently.

[0058] Furthermore, the perfusion chambers 110 are evenly distributed along the circumference of the axis of the catheter body 100. That is, the first perfusion chamber 110, the second perfusion chamber 110 and the third perfusion chamber 110

[0059] The plurality of conductive particles are evenly distributed along the circumference of the axis of the catheter body 100 .

[0060] Continue to refer to Figure 1 and Figure 2 The microcatheter further includes a rotary valve 300, which is disposed at the proximal end of the catheter body 100 and is used to control the independent expansion and contraction of each balloon 200. In detail, the proximal ends of the first perfusion chamber 110, the second perfusion chamber 110, and the third perfusion chamber 110 are connected to the rotary valve 300, and the rotary valve 300 can control the balloon fluid to flow to any one of the first perfusion chamber 110, the second perfusion chamber 110, and the third perfusion chamber 110, so that the first balloon 210, the second balloon 220, and the third balloon 230 can expand independently.

[0061] Figure 4 FIG. 4 is a schematic diagram of the microcatheter in this embodiment from the perspective of A. Figure 4 As shown, the rotary valve 300 includes a first connecting member 320, a rotating member 330 and a Luer connector 310. The distal end and the proximal end of the first connecting member 320 are respectively connected to the proximal end of the catheter body 100 and the Luer connector 310. The rotating member 330 is sleeved outside the first connecting member 320 and is rotatably connected to the first connecting member 320. The rotating member 330 is provided with an injection cavity 332, and the injection cavity 332 is connected to any of the perfusion cavities 110 by rotating the rotating member 330.

[0062] The first connecting piece 320 is located in the innermost layer of the rotary valve 300, with the proximal end overlapping the Luer connector 310 and the distal end connected to the catheter body 100, so that the central cavity of the catheter body 100 is a sealed cavity, and no leakage will occur during ultrasound angiography. As a preferred embodiment, the first connecting piece 320 is made of elastic material, which can improve the sealing performance of the first connecting piece 320 and play a better sealing role.

[0063] Figure 5 FIG. 4 is a schematic diagram of the second connecting member of the microcatheter in this embodiment. Figure 5As shown, the rotary valve 300 further includes a second connecting member 340, the proximal end of the second connecting member 340 is non-fixedly overlapped with the distal end of the rotating member 330, and the distal end is fixedly overlapped with the proximal end of the catheter body 100, and the second connecting member 340 is provided with a communication cavity 341 corresponding to the perfusion cavity 110. The distal end of the communication cavity 341 is connected to the proximal end of the corresponding perfusion cavity 110, and the rotating member 330 is rotated to make the injection cavity 332 communicate with any of the communication cavities 341, and the injection cavity 332 will be connected with the perfusion cavity 110.

[0064] It should be known that if the rotating member 330 is directly connected to the catheter body 100, the torque during rotation will cause the catheter body 100 to deform, which will cause the problem of balloon fluid leakage at the connection between the catheter body 100 and the rotary valve 300. It should be known that the proximal end of the second connecting member 340 is not fixedly overlapped with the distal end of the rotating member 330, and the distal end is fixedly overlapped with the proximal end of the catheter body 100. The second connecting member 340 can play a role in reinforcing the catheter body 100 to prevent the catheter body 100 from deforming, thereby preventing balloon fluid leakage.

[0065] Figure 6 FIG. 1 is a first schematic diagram of the rotary valve of the microcatheter in this embodiment. Figure 6 As shown, the outer circumference of the second connecting member 340 is provided with a mark 342 corresponding to the perfusion cavity 110, which is used to mark 342 the perfusion cavity 110. As an exemplary embodiment, the outer circumference of the second connecting member 340 is provided with words 1, 2, and 3, which correspond to the first balloon 210, the second balloon 220, and the third balloon 230, and the first perfusion cavity 110, the second perfusion cavity 110, and the third perfusion cavity 110, respectively. The rotating member 330 is Y-shaped, and the Y-shaped end 333 thereof is provided with an injection port 331. The operator can also use the Y-shaped end 333 to turn the rotating member 330. When the operator needs to expand the first balloon 210 of the microcatheter, the operator moves the Y-shaped end 333 on the rotating member 330, and rotates the injection port 331 of the rotating member 330 to correspond to the mark 342. Then, the injection cavity 332 on the rotating member 330 is connected to the first perfusion cavity 110, and the first balloon 210 is expanded after the balloon fluid is injected through the injection port 331. Similarly, when the operator needs to expand the second balloon 220 of the microcatheter, the operator moves the Y-shaped end 333 on the rotating member 330, and rotates the injection port 331 of the rotating member 330 to a position corresponding to the mark 342. When the operator needs to expand the third balloon 230 of the microcatheter, the operator moves the Y-shaped end 333 on the rotating member 330, and rotates the injection port 331 of the rotating member 330 to a position corresponding to the mark 342.

[0066] It should be understood that the balloon fluid may be a developer, so that the balloon 200 can be more easily identified by the operator, which is beneficial to the operation.

[0067] In an optional embodiment, the words of the logo 342 are Chinese numerals or Roman numerals. It should be understood that the style of the logo 342 can also be changed according to the experience of those skilled in the art, and is not limited here.

[0068] Figure 7 FIG. 2 is a second schematic diagram of a rotary valve of a microcatheter in an embodiment of the present invention. Figure 7 A ratchet structure is further provided between the first connecting member 320 and the rotating member 330 , and the ratchet teeth 321 of the ratchet structure are arranged on the outer circumference of the first connecting member 320 and correspond one-to-one with the perfusion chamber 110 , and the inner circumference of the rotating member 330 is provided with grooves corresponding one-to-one with the ratchet teeth 321 .

[0069] The ratchet mechanism is used for one-way driving and can prevent reversal. The ratchet teeth are usually one-way teeth. When the rotating member 330 rotates, the groove arranged on the inner circumference of the rotating member 330 slides on the ratchet wheel, and the rotating member 330 stops rotating. The ratchet wheel will be stuck in the groove, so that the first connecting member 320 and the rotating member 330 remain locked. The ratchet teeth 321 are arranged on the outer circumference of the first connecting member 320 and correspond to the perfusion chamber 110 one by one. At this time, the perfusion chamber 110 and the injection chamber 332 are in a connected state.

[0070] Correspondingly, the present invention also provides a method for using the microcatheter.

[0071] Figure 8 FIG. 4 is a flow chart of the method for using the microcatheter in this embodiment. Figure 8 As shown, the method for using the microcatheter comprises the following steps:

[0072] Step S1: Load the stent on the balloon closest to the proximal end of the catheter body 100, and execute step S2;

[0073] Step S2: moving the catheter body 100 until any balloon is stuck by the lesion occlusion part, when the stuck balloon is the balloon closest to the proximal end, expanding the balloon closest to the proximal end to expand the stent, and executing step S5; when the stuck balloon is not the balloon closest to the proximal end, executing step S3;

[0074] Step S3: expanding the stuck balloon to expand the occluded part of the lesion, and executing step S4;

[0075] Step S4: shrinking the stuck balloon and returning to step S2;

[0076] Step S5: Deflate the balloon at the proximal end and withdraw the microcatheter.

[0077] The method of using the microcatheter will be further described below in conjunction with the accompanying drawings.

[0078] Fig. 9 Schematic diagram of the first position of the microcatheter and the lesion occlusion site 400 in this embodiment. Fig.10 FIG. 4 is a schematic diagram of the second position of the microcatheter and the lesion occlusion site 400 in this embodiment. Fig. 9 and Fig.10 As shown, three balloons 200 are sequentially arranged from the distal end to the proximal end of the microcatheter, namely, a first balloon 210, a second balloon 220 and a third balloon 230, and the first balloon 210 is shorter in axial direction than the second balloon 220, and the second balloon 220 is shorter in axial direction than the third balloon 230. The stent 500 to be implanted in the lesion occlusion site 400 is loaded in the third balloon 230.

[0079] The movable catheter body 100 and the first balloon 210, the second balloon 220 and the third balloon 230, the volume of the first balloon 210 in the contracted state is larger than the channel of the lesion occlusion part 400, so that the first balloon 200 is stuck by the lesion occlusion part 400, and the first balloon 210 is controlled to expand by the rotary valve 300 to expand the lesion occlusion part 400.

[0080] Fig.11 Schematic diagram of the third position of the microcatheter and the lesion occlusion site 400 in the embodiment of the present invention. Fig.12 FIG. 4 is a schematic diagram of a fourth position of a microcatheter and a lesion occlusion site 400 in an embodiment of the present invention. Fig.11 and Fig.12 As shown, after the lesion occlusion part 400 is expanded by the first balloon 210, the first balloon 210 is contracted. Since the expanded lesion occlusion part 400 will be enlarged, the catheter body 100 is continued to be moved. After contraction, the first balloon 210 can pass through the lesion occlusion part 400. The catheter body 100 is continued to be moved until the second balloon 220 is stuck by the lesion occlusion part 400. At this time, the second balloon 220 is controlled to expand by the rotary valve 300 to expand the lesion occlusion part 400 again.

[0081] Fig.13 Schematic diagram of the fifth position of the microcatheter and the lesion occlusion site 400 in the embodiment of the present invention. Fig.14 FIG. 4 is a sixth position diagram of the microcatheter and the lesion occlusion part 400 in an embodiment of the present invention. Fig.13 and 14As shown, after the lesion occlusion part 400 is expanded by the second balloon 220, the second balloon 220 is contracted. Since the lesion occlusion part 400 expanded again by the second balloon 220 will be further expanded, the catheter body 100 is continued to be moved at this time, and the second balloon 220 can pass through the lesion occlusion part 400 after contraction. The catheter body 100 is continued to be moved until the third balloon 230 moves to the lesion occlusion part 400. The proximal balloon 200 is expanded to expand the stent 500, so that the stent 500 is placed in the lesion occlusion part 400. Finally, the third balloon 230 is contracted and the microcatheter is withdrawn.

[0082] It should be understood that if the first balloon 210 expands the lesion occlusion part 400, and the catheter body 100 continues to move, the second balloon 220 will not be stuck in the lesion occlusion part 400. At this time, the second balloon 220 can also be moved to the middle of the lesion occlusion part 400, and the second balloon 220 can be expanded to expand the lesion occlusion part 400 again, so that the third balloon 230 can enter the lesion occlusion part 400 more conveniently.

[0083] In summary, the microcatheter provided in the embodiment of the present invention includes a catheter body and at least two balloons, which are arranged in sequence from the distal end to the proximal end of the catheter body and the length in the axial direction increases in sequence. Each of the balloons can expand and contract independently, and the balloon closest to the proximal end of the catheter body is used to load the stent. As a result, the microcatheter can achieve the effect of gradient expansion of the occluded part of the lesion, and can load the stent at the same time, reducing the amount of balloons used during the operation, which is conducive to reducing the cost of the operation. In addition, an injection cavity is provided on the rotating part of the rotary valve, and can be rotated relative to the first connecting part, the catheter body and the Luer connector to connect the injection cavity with any of the perfusion cavities, so that the rotary valve can control the balloons to expand and contract independently. In addition, a ratchet structure is provided between the first connecting member and the rotating member, and the ratchet teeth of the ratchet structure are provided on the outer circumference of the first connecting member and correspond one-to-one with the perfusion cavity. The inner circumference of the rotating member is provided with grooves corresponding one-to-one with the ratchet teeth, so that the first connecting member and the rotating member can be interlocked, thereby preventing the rotary valve from leaking when the balloon is perfused with balloon fluid. In addition, a mark corresponding one-to-one with the perfusion cavity is provided on the outer circumference of the second connecting member, thereby facilitating the operator to identify the balloon to be expanded or contracted. In addition, the first connecting member is made of elastic material, which increases the sealing performance of the rotary valve and further prevents the rotary valve from leaking when the balloon is perfused with balloon fluid. Accordingly, the present invention also provides a method for using a microcatheter.

[0084] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any technician in the relevant technical field, without departing from the scope of the technical solution of the present invention, makes any form of equivalent replacement or modification to the technical solution and technical content disclosed in the present invention, which does not depart from the content of the technical solution of the present invention and still falls within the protection scope of the present invention.

Claims

1. A microcatheter, characterized in that: include: Catheter body; as well as, At least two balloons are sequentially arranged along the catheter body, each of the balloons can be expanded and contracted independently, and the volume of the balloons after expansion increases sequentially from the distal end to the proximal end of the catheter body, and the balloon closest to the proximal end of the catheter body is used to load the stent; A rotary valve, disposed at the proximal end of the catheter body, for controlling each balloon to independently expand and contract; A perfusion cavity corresponding to each of the balloons is provided in the wall of the catheter body, the distal end of the perfusion cavity is communicated with the corresponding balloon, and the proximal end is connected with the rotary valve; The rotary valve comprises a first connecting member, a rotating member and a Luer connector, wherein the distal end and the proximal end of the first connecting member are respectively connected to the proximal end of the catheter body and the Luer connector, and the rotating member is sleeved outside the first connecting member and is rotatably connected to the first connecting member; The rotating member is provided with an injection cavity, and the injection cavity is connected with any of the perfusion cavities by rotating the rotating member; The rotary valve further comprises a second connecting member, the proximal end of the second connecting member is non-fixedly overlapped with the distal end of the rotating member, and the distal end is fixedly overlapped with the proximal end of the catheter body, the second connecting member is provided with a communicating cavity corresponding to the perfusion cavity one by one, the distal end of the communicating cavity corresponds to the proximal end of the perfusion cavity, and the rotating member is rotated to make the injection cavity communicate with any of the communicating cavities; A ratchet structure is further provided between the first connecting member and the rotating member, the ratchet teeth of the ratchet structure correspond one-to-one to the perfusion chambers, and the inner circumference of the rotating member is provided with grooves corresponding one-to-one to the ratchet teeth.

2. The microcatheter according to claim 1, characterized in that: The lengths of the balloons increase in sequence, wherein the length of the balloon closest to the proximal end of the catheter body is the largest.

3. The microcatheter according to claim 2, characterized in that: The outer peripheral surface of the second connecting member is provided with a mark corresponding to the perfusion cavity one by one, and is used to mark the perfusion cavity.

4. The microcatheter according to claim 2, characterized in that: The first connecting member is made of elastic material.

5. The microcatheter according to claim 2, characterized in that: The number of the balloons and the number of the perfusion cavities are both three, and the perfusion cavities are evenly distributed along the circumference of the axis of the catheter body.

6. The microcatheter according to claim 5, characterized in that: One of the three balloons has a length of 5mm-10mm, another has a length of 15mm-25mm, and the remaining one has a length of 20mm-30mm.

7. The microcatheter according to claim 1, characterized in that: The rotating member is provided with an injection port communicated with its injection cavity.

8. The microcatheter according to claim 1, characterized in that: The rotating member is Y-shaped.

9. The microcatheter according to claim 3, characterized in that: The logo is Chinese numerals or Roman numerals.

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