CN120203696A - A balloon guide catheter - Google Patents

Abstract

The invention discloses a balloon guide catheter, which belongs to the field of medical devices. The catheter adopts an eccentric parallel double-lumen structure design, including an eccentric large cavity as an instrument and a thrombus channel and an eccentric small cavity as a balloon filling cavity. Through the coordinated optimization of the inner and outer double braided layers, the outer braided layer of the catheter adopts a composite braiding method of 2 round wires + 1 flat wire, and the inner braided layer is set with a braiding density of 8-12PPI increasing every 20mm in the Pebax section, which significantly improves the anti-bending performance, is conducive to passing through large-angle curved blood vessels such as the aortic arch and establishing an effective passage, and at the same time, the double-layer braided structure effectively maintains the spatial stability of the small cavity, avoids the closure of the small cavity caused by the bending of the catheter, and realizes rapid filling. By utilizing the difference in melting points between polyimide and Pebax materials, the core shaft cavity making process is replaced by pre-extrusion of a polyimide tube, which solves the problem of the inability to generate a small cavity due to the difficulty in removing the core due to being too small in the traditional manufacturing process, and significantly reduces the difficulty of the production process and the manufacturing cost.

Description

Balloon guiding catheter

Technical Field

The invention belongs to the technical field of medical instruments, and particularly relates to a balloon guiding catheter, in particular to a balloon guiding catheter with a thin wall, a large cavity, rapid filling and bending resistance.

Background

Compared with the traditional proposal, the treatment method for mechanical thrombus extraction by using a balloon guiding catheter to convey interventional thrombus extraction instruments or using the balloon guiding catheter to complete thrombus extraction in the blood vessel, namely, the venous thrombolysis treatment method of cerebral arterial thrombosis has higher blood circulation reconstruction rate and wider treatment time window. In addition, the method for treating the endovascular embolism based on the balloon guiding catheter has the advantages of less bleeding, less wound, less complications, safety, reliability, quick postoperative recovery and the like, and becomes one of the main treatment modes of treating the acute ischemic cerebral apoplexy.

When the balloon guiding catheter is used, the arterial sheath is required to be placed through percutaneous puncture under the monitoring of DSA imaging equipment, a channel is established to enable the auxiliary thrombus taking instrument to reach the proximal end of thrombus in a blood vessel, the thrombus is tightly attached to the wall of the blood vessel through balloon inflation to form partial blocking, the thrombus is adsorbed into the inner cavity of the catheter under the action of external negative pressure so as to be taken out of the body, and then the balloon pressure is released to enable the thrombus to be contracted, so that the balloon guiding catheter is withdrawn, and the aim of reconstructing blood flow is achieved. The key point of using the saccule to guide the catheter to complete the thrombus suction or auxiliary interventional instrument to complete the mechanical thrombus extraction is that the guide catheter itself has good folding resistance, flexibility, torque synchronism and trafficability, can cope with thrombus lesions of complex tortuous vessels, can realize rapid filling and decompression in complex tortuous environments so as to further shorten the operation time, and can provide a larger inner cavity with the same outer diameter to assist other instruments to take out thrombus through the catheter.

Based on the background, the balloon guiding catheter in the prior art has the technical difficulties of catheter torque synchronism, fracture resistance, rapid filling and pressure relief of the thin-wall large cavity and the balloon. In order to solve the problems, the Chinese patent CN102488955B balloon guiding catheter and the preparation method thereof disclose a balloon plugging catheter with a coaxial double-cavity structure, and balloon filling cavities are formed by utilizing gaps between an inner tube and an outer tube, so that the balloon plugging catheter is expected to easily generate asynchronous movement phenomena between the inner tube and the outer tube when passing through a complicated tortuous blood vessel, and further the problems of small filling cavities, low filling speed, outer tube folds and the like are generated. The Chinese patent CN211096928U discloses a balloon guiding catheter which realizes filling cavity channels by a method of establishing capillary channels between the inner tube wall and the outer tube wall, effectively enlarges the inner cavity of the catheter, but it is expected that the thin wall establishes a plurality of capillary channels, which can improve filling speed but also reduce strength of the catheter, increase processing and manufacturing difficulty, are not beneficial to large-scale production, and the torque synchronism of the inner tube and the outer tube cannot be effectively improved. Therefore, there is a need for a balloon guiding catheter with a thin wall, large cavity, rapid filling, folding resistance and good torque synchronism, in particular to a balloon guiding catheter which can rapidly fill under the condition of extremely tortuous vascular access so as to realize effective vascular occlusion and provide a large cavity, can be used for temporarily blocking vascular blood flow, and can be used for removing intravascular thrombus by means of negative pressure or assisting various interventional instruments to complete vascular mechanical thrombus removal or establishing a channel and support for various interventional instruments to enter a target lesion area.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, provides a balloon guiding catheter with thin wall, large cavity, rapid filling and folding resistance, firstly the balloon guiding catheter can solve the folding resistance problem of the intravascular catheter with complex tortuosity, and the problems of rapid filling and pressure relief of the balloon can be solved, and finally, the balloon guiding catheter can realize a larger inner cavity and improve the torque synchronism of the catheter under the condition of the same outer diameter.

In order to achieve the above purpose, the invention provides a balloon guiding catheter, in particular a balloon guiding catheter with a thin wall large cavity, rapid filling and bending resistance, which comprises a catheter, wherein the catheter is provided with an eccentric large cavity and one or more eccentric small cavities, the eccentric large cavity is used as a cavity channel for auxiliary instruments such as a thrombus taking bracket and the like to pass through and thrombus, and the eccentric small cavity is used as a cavity channel for filling the balloon; the catheter is radially sectioned by taking a large cavity and a small cavity which can be symmetrically sectioned, the structure of the catheter is sequentially provided with the large cavity, a PTFE layer, an inner braiding layer, a first high polymer layer, the small cavity, a first high polymer layer, an outer braiding layer and a first high polymer layer from inside to outside, the inner braiding layer surrounds the large cavity and is positioned between the large cavity and the small cavity, the outer braiding layer surrounds the large cavity and the small cavity by taking the center of the section of the catheter as the center, a small cavity channel is positioned between the outer braiding layer and the inner braiding layer, and the large cavity channel is positioned in the PTFE layer;

In another embodiment, the balloon guiding catheter is sectioned in the radial direction of the symmetrical sectioning of the large cavity and the small cavity, and the structure of the balloon guiding catheter sequentially comprises the large cavity, the PTFE layer, the inner braiding layer, the first polymer layer, the small cavity, the outer braiding layer and the first polymer layer from inside to outside;

In another embodiment, the balloon guiding catheter is cut in a radial direction in which both the large cavity and the small cavity can be symmetrically cut, the structure of the balloon guiding catheter is sequentially provided with the large cavity, the PTFE layer, the first polymer layer, the second polymer layer, the small cavity, the second polymer layer, the first polymer layer, the braiding layer and the first polymer layer from inside to outside, the braiding layer takes the center of the section of the catheter as the center, the large cavity and the small cavity are surrounded by the PTFE layer and are positioned in the PTFE layer, the small cavity is surrounded by the second polymer layer, the melting point of the second polymer layer is higher than that of the first polymer layer, and the periphery of the second polymer layer is surrounded by the first polymer layer;

the balloon has compliance, two ends of the balloon are connected with the catheter in a gluing or melting way, and the outer diameter of the connected balloon area is less than or equal to the outer diameter of the catheter;

The developing ring is made of platinum iridium alloy or stainless steel, and is 2-5mm away from the far end of the catheter;

The catheter seat is arranged at the proximal end of the balloon guiding catheter and is provided with two cavities which are respectively communicated with the large cavity and the small cavity of the catheter;

And the stress release tube is arranged at the joint of the catheter seat and the proximal end of the catheter so as to prevent the bending of the catheter body at the joint.

Further, the proximal end of the catheter is ground by taking the large cavity as the center by 10-20mm, so that the outlet of the small cavity channel and the outlet of the large cavity channel are not on a radial section, the large cavity of the grinding section in the catheter seat is communicated with the main cavity channel of the catheter seat, and the small cavity channel after grinding is communicated with the side cavity of the catheter seat.

Further, the far end of the catheter is provided with a section of the area with the length of 25-30mm as a reducing section, the surface of the reducing section of the catheter is provided with a through hole, the through hole is communicated with the small cavity, and the distance from the through hole to the far end of the catheter is 10-15mm. The balloon is welded or adhered to the outer surface of the variable-diameter section of the catheter by taking the through hole as the center, and the small cavity is communicated with the balloon cavity through the through hole.

Further, the cross-section of the small cavity should be square, round, or crescent, and its cross-sectional area is greater than or equal to 0.8 mm2. The cross section of the large cavity is circular or elliptical, the diameter or the short axis length of the large cavity is more than or equal to 2.19mm, the outer diameter of the distal end of the balloon guiding catheter is not more than 2.65mm, and the outer diameter of the proximal end of the balloon guiding catheter is not more than 2.8mm.

Further, the through holes may be elliptical, square or circular, and the specific through hole area is 0.3mm2 or more.

Further, the first polymer layer of the catheter is of a segmented structure, the proximal end to the distal end of the catheter are PA12, pebax7233, pebax6333, pebax5533 and Pebax4033 respectively, the second polymer layer is ‌ Polyimide (PI) material, the specific length of the first polymer layer is Pebax4033 (40-60 mm), pebax5533 (20-40 mm), pebax6333 (15-35 mm), pebax7233 (150-180 mm) and PA12 (rest), and the weaving layer is made of stainless steel or tungsten metal.

Further, the outer braiding layer is formed by braiding round wires and flat wires, and particularly, the round wires are formed by compounding and braiding 2 merged wires and 1 flat wire, wherein the diameter of the 2 merged round wires is in the range of 1/3-1/2 of the width of the flat wire. The thickness of the flat wires of the outer braiding layer is between 0.01 and 0.03mm, the wire width is between 0.06 and 0.09mm, the inner braiding layer is formed by braiding the flat wires, the thickness of the flat wires of the inner braiding layer is between 0.01 and 0.02mm, the wire width is between 0.06 and 0.09mm, and the braiding strand numbers of the outer braiding layer and the inner braiding layer are 16 strands.

Further, the mesh density (PPI) of the inner braid is set in the range of 40-60 at the PA12 segment of the first polymer layer, and the PPI at the Pebax7233, pebax6333, pebax5533, pebax4033 segments of the first polymer layer is set to be 8-12 in increments of 20 mm. The PPI of the outer braid is set in the range of 70-90 in the PA12 section of the first polymer layer, and the PPI of the PPI sections of the first polymer layers Pebax7233, pebax6333, pebax5533 and Pebax4033 are set to be increased by 4-8 every 20 mm.

Further, the material of the balloon is silica gel or polyurethane, and particularly when the material of the balloon is polyurethane, the connection mode of the balloon and the first polymer layer is welding, and a linear low density polyethylene layer (LLDPE) is arranged between the balloon and the first polymer layer as a welding lining layer.

Further, the second polymer layer forms a small cavity of the catheter, and by utilizing the characteristic that the melting point of Polyimide (PI) is higher than that of Pebax, a cavity channel formed by a pre-extruded Polyimide (PI) pipe does not generate solubility collapse during the rheological compounding of Pebax, so that the problem that the small cavity channel is difficult to withdraw and core-pull during the rheological compounding is solved.

Further, the PTFE layer has a wall thickness of 0.0127mm or less.

Compared with the prior art, the technical scheme has the advantages that (1) the catheter adopts an eccentric parallel double-cavity structure design, the defects of pipe body fold, torque transmission delay and poor torsion control performance caused by asynchronous bending of an inner pipe and an outer pipe of a traditional coaxial double-cavity structure are overcome, the inner cavity space is increased under the same outer diameter condition, a larger diameter instrument can conveniently pass through to improve the clinical treatment effect, (2) the outer weaving layer adopts a composite weaving structure of 2 round wires and 1 flat wires through cooperative optimization of the inner weaving layer and the outer weaving layer, the inner weaving layer adopts a gradient design of increasing 8-12PPI per 20mm in the Pebax section, the bending resistance of the catheter is remarkably enhanced, the small cavity is effectively and innovated by the double-layer weaving structure, the small cavity is prevented from being closed due to bending of the catheter, the rapid filling is realized, the polyimide cavity structure is adopted, the melting point of polyimide and Pebax material is utilized, the core pulling is replaced by the polyimide pipe pre-extrusion to manufacture a cavity manufacturing process, the problem that the small cavity is difficult to remove due to excessively small core pulling in the traditional manufacturing process is solved, the manufacturing process cannot be remarkably reduced, and the effective channel is created.

Drawings

The features of the present invention and its advantages will be apparent from the following detailed description of the embodiments of the invention with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of the operation of a balloon guide catheter of the present invention;

FIG. 2 is a schematic view of the overall structure of the balloon guiding catheter of the present invention;

FIG. 3 is a catheter cross-sectional view of the balloon guide catheter of the present invention;

FIG. 4 is a cross-sectional view of a catheter hub and catheter connection of the present invention;

FIG. 5 is a proximal A-A cross-sectional view of a balloon-guided catheter of the present invention;

FIG. 6 is a schematic view of the distal structure of a balloon guiding catheter of the present invention;

FIG. 7 is a schematic view of the balloon welding of the present invention;

FIG. 8 is a proximal B-B cross-sectional view of a balloon-guided catheter of the present invention;

FIG. 9 is a cross-sectional view in the distal C-C direction of the balloon-guided catheter of the present invention;

FIG. 10 is a second cross-sectional view in the distal C-C direction of the balloon-guided catheter of the present invention;

FIG. 11 is a third cross-sectional view in the distal C-C direction of the balloon-guided catheter of the present invention;

FIG. 12 is a view I of the distal through hole D of the balloon guiding catheter of the present invention;

FIG. 13 is a second view of the distal through hole D of the balloon guiding catheter of the present invention;

FIG. 14 is a third view of the distal through hole D of the balloon guiding catheter of the present invention;

FIG. 15 is a cross-sectional view of a balloon guiding catheter in accordance with yet another embodiment of the present invention;

FIG. 16 is a cross-sectional view of a balloon guiding catheter in another embodiment of the invention;

Fig. 17 is a schematic view of the outer braid structure of the balloon catheter of the present invention.

Detailed Description

In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to the appended drawings. In describing embodiments of the present invention in detail, the schematic drawings are not to scale in order to facilitate explanation, but rather should be taken as limiting the invention.

The term "proximal" as used herein refers to the end closer to the operator of the balloon guiding catheter, and the term "distal" refers to the end farther from the operator of the balloon guiding catheter.

As shown in figure 1, the working principle of the balloon guiding catheter is that after femoral artery puncture, the balloon guiding catheter enters the common carotid artery through the abdominal aorta and the aortic arch under the guidance of the guide wire and then reaches the internal carotid artery, then the auxiliary instrument enters the M1 section of the middle cerebral artery through the eccentric large cavity of the balloon guiding catheter, at the moment, the balloon is inflated to be tightly attached to the vessel wall and then blocks the blood flow, the auxiliary instrument takes out or sucks the thrombus of the M1 section to the outside through the eccentric large cavity of the balloon guiding catheter, and after the thrombus taking is completed, the balloon pressure is relieved, and the balloon guiding catheter is withdrawn to the outside.

As shown in fig. 2 to 5, the balloon guiding catheter is composed of a catheter 100, a developing ring 200, a balloon 300, a stress diffusion tube 400, and a catheter holder 500. The distal end of the catheter has a through bore 120 and the catheter 100 is provided with a large lumen 160 or a plurality of small lumens 140. At the proximal end of the catheter is provided a proximal outlet 141 of the small lumen, the distal outlet of the small lumen being the through hole 120. A developing ring 200 is disposed within a range of 2-10mm at the distal end of the catheter 100. The proximal end of the catheter is provided with a grinding section 150 which is ground during the grinding operation centered on the large lumen of the catheter 100 to expose the small lumen outlet 141. Balloon 300 is adhered or welded to the distal end region of catheter 100 centered on through-hole 120 of catheter 100. Catheter hub 500 is provided with a catheter hub side lumen 510 and a catheter hub main lumen 520. The ground section 150 of the catheter 100 and the proximal end of the catheter are connected to a catheter hub 500. Catheter hub side lumen 510 communicates with lumen 140 via proximal outlet 141 of the catheter lumen, lumen 140 communicates with balloon lumen 330 of balloon 300 via through-hole 120 of the catheter, and catheter hub main lumen 520 communicates with lumen 160 of catheter 100.

As shown in fig. 6-7, the distal end of the catheter is provided with a variable diameter stretch 130, where the outer diameter of the catheter 100 is less than or equal to 2.65mm, and the length of the variable diameter stretch 130 is 20-30mm from the distal end to the end point. The material of balloon 300 is preferably silica gel or polyurethane. When the balloon 300 is made of polyurethane, the welding lining layer 600 is arranged at the connection position between the proximal end 310 and the distal end 320 of the balloon and the catheter 100, and a heat shrinkage tube made of Polyolefin (PO) is used for heating the contact position between the welding lining layer 600 and the balloon 300 until the welding lining layer 600 and the balloon 300 are melted in the temperature range of 160-180 ℃ to finish the connection between the balloon 300 and the catheter 100. In particular, the wall thickness of balloon 300 is 0.075mm or less and the length of the balloon is in the range of 10-20mm, and the outer diameter of the balloon 300 is 2.80mm or less after the welding or bonding of balloon 300 is completed.

As shown in fig. 8 to 14, the catheter 100 of the balloon catheter in the first embodiment has a double-woven structure, and the double-woven structure effectively improves the folding resistance of the catheter. The catheter is provided with a large cavity 160, a PTFE layer 131, an inner braid 132, a first polymer layer 133, a small cavity 140, a first polymer layer 133, an outer braid 134 and a first polymer layer 133 in sequence from inside to outside. The inner braid 132 surrounds the large lumen 160 between the large lumen 160 and the small lumen 140, the outer braid 134 surrounds the large lumen 160 and the small lumen 140 inwardly with the center of the catheter cross section, the small lumen 140 is between the outer braid 134 and the inner braid 132, and the large lumen 160 is within the PTFE layer 131. The cross section of the small cavity 140 can be square, elliptic or crescent, the cross section of the small cavity 140 is not less than 0.8mm2, and particularly when the small cavity adopts crescent, the cross section can be larger under the condition of the same wall thickness, so that the flow rate of the filling channel is effectively improved. When the number of the small cavities 140 is a plurality, the large cavities 160 and the central connecting lines of the cross sections of the small cavities 140 are arranged as symmetrical lines, and the number of the small cavities is preferably not more than 3. The shape of the through hole 120 may be circular, elliptical or square, and the cross-sectional area of the through hole is not less than 0.3mm2. The first polymer layer 133 of the catheter 100 has a segmented structure, and specifically PA12, pebax7233, pebax6333, pebax5533, and Pebax4033 are respectively located from the proximal end to the distal end of the catheter. The specific length is Pebax4033 (40-60 mm), pebax5533 (20-40 mm), pebax6333 (15-35 mm), pebax7233 (150-180 mm), and PA12 (rest).

As shown in FIG. 15, in yet another embodiment, the catheter 100 differs from the first embodiment in that the catheter 100 comprises, from inside to outside, a large lumen 160, a PTFE layer 131, an inner braid 132, a first polymer layer 133, an outer braid 134, a small lumen 140, an outer braid 134, and a first polymer layer 133, wherein the inner braid 132 surrounds the large lumen 160 and is disposed between the large lumen 160 and the small lumen 140, the outer braid 134 surrounds the small lumen 140, the small lumen 140 is disposed within the outer braid 134, and the large lumen is disposed within the PTFE layer 131.

As shown in fig. 16, in another embodiment, the catheter 100 is different from the first embodiment in that the catheter 100 includes a large lumen 160, a PTFE layer 131, a first polymer layer 133, a second polymer layer 135, a small lumen 140, a second polymer layer 135, a first polymer layer 133, an outer braid 134, and a first polymer layer 133 from inside to outside. Outer braid 134 centers around the center of the cross-section of catheter 110, surrounding both large lumen 160 and small lumen 140. The large cavity 160 is surrounded by and within the PTFE layer 131. The small cavity 140 is surrounded by the second polymer layer 135, the second polymer layer 135 has a higher melting point than the first polymer layer 131, and the periphery of the second polymer layer 135 is surrounded by the first polymer layer 133. The second polymer layer material is Polyimide (PI), and the characteristic that the melting point of PI is higher than that of Pebax is utilized, so that the cavity formed by the pre-extruded PI pipe does not generate solubility collapse during the rheological compounding of Pebax, and the problem that the small cavity is difficult to withdraw and loose core during the rheological compounding is solved.

As shown in fig. 17, the braid structure of outer braid 134 is a round wire 181+ flat wire 182 structure. In particular, the round wires 181 are combined with 2 and then are compositely woven with 1 flat wire 182, wherein the wire diameter of the 2 round wires 181 is in the range of 1/3-1/2 of the wire width of the flat wire 182. Compared with the common flat wire single-layer braiding and circular wire surrounding braiding, the double-strand circular wire 181 and flat wire 182 mixed braiding mode further improves the folding resistance of the catheter and does not influence the flexibility of the catheter. The thickness of the flat wires 182 of the outer braid is between 0.01 and 0.03 and the wire width is between 0.06 and 0.09 mm. The structure of the inner braid 132 is flat filament braiding, wherein the thickness of the flat filaments of the inner braid 132 is between 0.01 and 0.02mm and the filament width is between 0.06 and 0.09 mm. The number of braided strands of the outer braid 134 and the inner braid 132 is 16, the PPI of the inner braid 132 is set to be in the range of 40 to 60 at PA12 section of the first polymer layer 133, and 8 to 12 per 20mm at Pebax7233, pebax6333, pebax5533, pebax4033 sections. The PPI of the outer braid 134 is set in the range of 70-90 at PA12 section of the first polymer layer 133 and 4-8 per 20mm at Pebax7233, pebax6333, pebax5533, pebax4033 sections.

The above examples are given for clarity of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the invention.

Claims (9)

1. A balloon guide catheter, comprising a catheter (100), a balloon (300), a developing ring (200) and a catheter seat (500), characterized in that: the catheter (100) has an eccentrically arranged large cavity (160) and at least one eccentrically arranged small cavity (140); the cross-sectional structure of the catheter (100) cut along the radial direction is, from inside to outside, the large cavity (160), the PTFE layer (131), the inner braided layer (132), the first polymer layer (133), the small cavity (140), the first polymer layer (134), the inner braided layer (132), the inner braided layer (133), the inner braided layer (132 ... layer (133), an outer braided layer (134), and a first polymer layer (133); the inner braided layer (132) surrounds the outside of the large cavity (160) and is located between the large cavity (160) and the small cavity (140); the outer braided layer (134) surrounds the large cavity (160) and the small cavity (140) with the center of the cross section of the catheter (100) as the center, and the small cavity (140) is located between the outer braided layer (134) and the inner braided layer (132); the large cavity (160) is located inside the PTFE layer (131). 2. The balloon guide catheter according to claim 1 is characterized in that: the first polymer layer (133) is composed of a PA12 segment, a Pebax7233 segment, a Pebax6333 segment, a Pebax5533 segment and a Pebax4033 segment from the proximal end to the distal end, wherein the length of the Pebax4033 segment is 40-60 mm, the Pebax5533 segment is 20-40 mm, the Pebax6333 segment is 15-35 mm, and the Pebax7233 segment is 150-180 mm. 3. The balloon guide catheter according to claim 1 is characterized in that: the PPI of the inner braided layer (132) is set at 40-60 in the PA12 segment of the first polymer layer (133), and the PPI in the Pebax segment is set to increase by 8-12 every 20 mm; the PPI of the outer braided layer (134) is set at 70-90 in the PA12 segment of the first polymer layer (133), and the PPI in the Pebax segment is set to increase by 4-8 every 20 mm. 4. The balloon guide catheter according to claim 1 is characterized in that: the outer braided layer (134) is formed by merging two round wires (181) and woven together with one flat wire (182), wherein the wire diameter of the two round wires (181) after merging is 1/3-1/2 of the width of the flat wire; the thickness of the flat wire of the outer braided layer (134) is 0.01-0.03mm, and the wire width is 0.06-0.09mm. 5. The balloon guide catheter according to claim 1 is characterized in that: the inner braided layer (132) is woven from flat wires, the thickness of the flat wires of the inner braided layer (132) is 0.01-0.02 mm, and the wire width is 0.06-0.09 mm; the number of braided strands of the outer braided layer (134) and the inner braided layer (132) is 16 strands. 6. The balloon guide catheter according to claim 1 is characterized in that: a reducing section (130) is provided at the distal end of the catheter (100), and the length of the reducing section (130) is 25-30 mm; a through hole (120) is provided on the surface of the reducing section (130) of the catheter (100); the through hole (120) is connected to the small cavity (140); the distance from the through hole (120) to the farthest end of the catheter (100) is 10-15 mm; the balloon (300) is welded or bonded to the outside of the reducing section (130) with the through hole (120) as the center. 7. The balloon guide catheter according to claim 1 is characterized in that: the cross-section of the small cavity (140) is square, circular, or crescent-shaped, and its cross-sectional area is greater than or equal to 0.8 mm²; the cross-section of the large cavity (160) is circular or elliptical, and its diameter or short axis length is greater than or equal to 2.19 mm; the distal outer diameter of the catheter (100) is not greater than 2.65 mm; the proximal outer diameter of the catheter (100) is not greater than 2.8 mm. 8. The balloon guide catheter according to claim 1 is characterized in that: a grinding section (150) is provided at 10-20 mm from the proximal end of the catheter, so that the proximal outlet (141) of the small cavity (140) is radially misaligned with the outlet of the large cavity (160), and a shunt structure cooperating with the grinding section (150) is provided in the catheter seat (500), so that the large cavity (160) is connected to the main cavity (520) of the catheter seat, and the small cavity (140) is connected to the side cavity (510) of the catheter seat. 9. A balloon guide catheter, comprising a catheter (100), a balloon (300), a developing ring (200) and a catheter seat (500), characterized in that: the catheter (100) has an eccentrically arranged large cavity (160) and at least one eccentrically arranged small cavity (140); the cross-sectional structure of the catheter (100) cut along the radial direction is, from inside to outside, the large cavity (160), the PTFE layer (131), the first polymer layer (133), the second polymer layer (135), the small cavity (140), the second polymer layer (135) , a first polymer layer (133), an outer braided layer (134), and a first polymer layer (133); the outer braided layer (134) is centered on the center of the cross section of the catheter (100) and surrounds the large cavity (160) and the small cavity (140); the large cavity (160) is surrounded by and located inside the PTFE layer (131); the small cavity (140) is surrounded by the second polymer layer (135); the melting point of the second polymer layer (135) is higher than that of the first polymer layer (131); and the outer periphery of the second polymer layer (135) is surrounded by the first polymer layer (133).