Extending catheter and catheter system

Abstract

The utility model belongs to the technical field of medical instruments, and particularly relates to an extension catheter and a catheter system. The extension catheter comprises a catheter base, a pushing rod and a catheter body which are sequentially connected from the near end to the far end, the hardness of the catheter body is sequentially reduced from the near end to the far end of the catheter body, the catheter body is of a composite structure composed of an inner layer, a middle reinforcing layer and an outer layer, and the middle reinforcing layer is divided into a soft area, a transition area and a pushing area. Compared with the prior art, the composite structural design of the inner layer, the middle reinforcing layer and the outer layer is adopted in the catheter body, high supporting performance, pressure resistance and fracture resistance can be provided, the catheter has good performance in the aspects of functions, safety and the like, and the effect and safety of medical operation can be improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of medical devices, and particularly relates to an extension catheter and a catheter system. Background Art

[0002] Percutaneous transluminal coronary intervention (PCI) refers to a technique that uses percutaneous puncture technology to insert an anchoring balloon catheter or other related instruments to relieve coronary artery stenosis or obstruction and reconstruct coronary artery blood flow. With the continuous development of medicine, medical interventional surgery has also been greatly developed. In the related art, when the extension catheter is placed in the lumen of the guiding catheter, due to the existing gap in the fit, not only does the extension catheter slip, but even slips off, and it is impossible to perform super-selective angiography in the coronary artery branch vessels. For dealing with complex PCI surgeries, the catheter needs to be frequently replaced, which not only prolongs the operation time, but also causes greater harm to the patient.

[0003] The current technical solutions for coronary artery intervention mainly include extension catheters, thrombus aspiration catheters, delivery catheters, etc. These catheters often adopt the mother-daughter catheter method. Although the mother-daughter catheter can better solve the problem of deep catheter insertion in complex lesions, for example, using an extension catheter as an extension of the guiding catheter can provide better stent delivery ability, there are still some limitations:

[0004] 1) There is a gap between the guiding extension catheter and the guiding catheter, which will reduce the negative pressure effect of aspirating thrombus and plaque, resulting in poor aspiration effect and unable to well solve the problem of microcirculation damage caused by the shedding of thrombus and plaque.

[0005] 2) The existing extension catheters adopt the design of a stainless steel braided mesh layer or a spring layer, which has the disadvantages of poor compliance, complex manufacturing process and high cost.

[0006] Based on this, in the present utility model, a novel extension catheter and a catheter system are provided to overcome the above defects. Content of the Utility Model

[0007] The first object of the present utility model is to provide an extension catheter. The catheter body adopts a composite structure design of an inner layer, an intermediate reinforcing layer and an outer layer, which can provide strong support, pressure resistance and anti-flexibility, so that the catheter has good performance in terms of function, safety, etc., and helps to improve the effect and safety of medical operations.

[0008] The utility model adopts the following technical solutions: An extension catheter, which comprises a catheter seat, a push rod and a catheter body connected in sequence from the proximal end to the distal end. A delivery channel for delivering medical devices is arranged in the catheter body. A guide inlet communicating with the delivery channel is arranged at the proximal end of the catheter body, and an anchoring balloon is sleeved on the outer wall of the proximal end of the catheter body.

[0009] The hardness of the catheter body decreases sequentially from the proximal end to the distal end of the catheter body. The catheter body is a composite structure composed of an inner layer, an intermediate reinforcing layer and an outer layer. Among them, the intermediate reinforcing layer is divided into a compliant zone, a transition zone and a pushing zone.

[0010] Further, the intermediate reinforcing layer is a spiral cutting tube layer.

[0011] Further, the compliant zone, the transition zone and the pushing zone satisfy at least one of the following characteristics;

[0012] The slit length of the spiral cutting tube layer in the compliant zone > the slit length of the spiral cutting tube layer in the transition zone > the slit length of the spiral cutting tube layer in the pushing zone;

[0013] Or, the cutting pitch of the spiral cutting tube layer in the compliant zone < the cutting pitch of the spiral cutting tube layer in the transition zone < the cutting pitch of the spiral cutting tube layer in the pushing zone;

[0014] Or, the slit angle of the spiral cutting tube layer in the compliant zone < the slit angle of the spiral cutting tube layer in the transition zone < the slit angle of the spiral cutting tube layer in the pushing zone;

[0015] Or, the pitch of the spiral cutting tube layer in the compliant zone < the pitch of the spiral cutting tube layer in the transition zone < the pitch of the spiral cutting tube layer in the pushing zone.

[0016] Further, a metal connecting piece is arranged at the proximal end of the intermediate reinforcing layer of the catheter body. One end of the metal connecting piece is arranged side by side with the intermediate reinforcing layer of the catheter body, and the other end is connected with the distal end of the push rod.

[0017] Further, the push rod is a Hypotube;

[0018] The metal connecting piece is a metal ring. The metal ring has a spiral structure, and welding areas are respectively arranged at both ends of the connection between the metal ring and the Hypotube to form a welded connection between the metal ring and the Hypotube.

[0019] Further, at the welded connection of the Hypotube and the metal ring, the diameter of the Hypotube decreases.

[0020] Further, a second imaging element is arranged at the distal end of the Hypotube.

[0021] Further, the developing material of the second developing element is one or more of gold wire, tungsten wire, platinum gold wire, and platinum iridium alloy wire.

[0022] Further, a scale or a marking strip is provided on the surface of the hypo tube.

[0023] Further, the push rod is a channeled tubular structure forming a fluid channel, and a through hole is provided at the distal end of the push rod, and the through hole is provided at the middle position of the anchoring balloon to realize communication with the inner cavity of the anchoring balloon;

[0024] The catheter seat has a through channel, and the through channel communicates with the fluid channel of the push rod.

[0025] Further, a heparin cap or a one-way valve is provided at the open end of the catheter seat.

[0026] Further, the extension catheter further includes a guide wire tube, the guide wire tube extends along the length direction of the catheter body and is connected in parallel with the catheter body; the guide wire tube has a guide wire cavity for the guide wire to pass through, the proximal end of the guide wire tube is located outside the distal end of the anchoring balloon, and the distal end of the guide wire tube extends to the distal end of the catheter body.

[0027] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0028] 1) In the present utility model, for the extension catheter, the catheter body adopts a composite structure design of an inner layer, an intermediate reinforcing layer and an outer layer, which can provide strong support, pressure resistance and anti-flexibility, so that the catheter has good performance in terms of function, safety, etc., and helps to improve the effect and safety of medical operations.

[0029] At the same time, the intermediate reinforcing layer is divided into a compliant zone, a transition zone and a pushing zone. The reasonable setting of the characteristics of different zones enables the catheter body to have good compliant adaptability and effective pushing ability as a whole, meets the operation requirements at different stages, improves the success rate and safety of the operation, and reduces the pain of the patient during the operation.

[0030] 2) The intermediate reinforcing layer is a spiral cutting tube layer. Compared with the prior art where the intermediate reinforcing layer adopts a stainless steel braided mesh layer or a spring layer design, the use of a spiral cutting tube layer can have better flexibility while ensuring a certain strength, can better adapt to complex vascular paths, reduce irritation and damage to blood vessels; and can also provide a relatively uniform support force distribution, avoid local stress concentration, and help to improve the stability of the catheter in the blood vessel.

[0031] In addition, the design of spiral cutting tube layers makes its outer diameter smaller and the structure more compact, thereby reducing the outer diameter of the entire extension catheter, reducing the difficulty of insertion and the impact on blood vessels; and the lighter weight helps to reduce the foreign body sensation in the patient's body.

[0032] The second purpose of the utility model is to provide a catheter system, which includes a guiding catheter and the above-mentioned extension catheter, wherein the guiding catheter is provided with a guiding channel, and when the anchoring balloon is not filled, the extension catheter is guided to slide in the guiding channel; when the anchoring balloon is filled, the anchoring balloon expands and abuts against the inner wall of the guiding channel, and the delivery channel of the extension catheter is connected to the guiding channel.

[0033] Furthermore, when the anchoring balloon is subjected to a filling pressure of 0.8 bar to 1.5 bar, the anchoring balloon abuts against an inner wall of the guiding channel, and the anchoring balloon can slide in the guiding channel by moving the pushing rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 This is a schematic diagram of the structure of an extension catheter in one embodiment of the utility model;

[0036] Figure 2 This is a schematic structural diagram of an extension catheter in another embodiment of the utility model;

[0037] Figure 3 This is a schematic diagram of the structure of the anchoring balloon in the extended catheter after being filled in another embodiment of the utility model;

[0038] Figure 4 for Figure 2 A partial structural cross-sectional view;

[0039] Figure 5 This is a diagram showing the welding area between the hypotube and the metal ring in the extended catheter of one embodiment of the utility model;

[0040] Figure 6 This is a schematic diagram of the structure of a hypotube in an extension catheter according to an embodiment of the utility model;

[0041] Figure 7 This is a schematic diagram of the structure of the spirally cut tube layer in the extension catheter of one embodiment of the utility model;

[0042] Figure 8 Schematic diagram of the catheter system structure in an embodiment of the present utility model;

[0043] Figure 9 is Figure 8 partial cross-sectional view of;

[0044] Wherein: catheter seat 1, push rod 2, through hole 20, second imaging element 21, catheter body 3, inner layer 30, intermediate reinforcing layer 31, compliant region 311, transition region 312, push region 313, outer layer 32, delivery channel 33, guide inlet 34, first imaging element 35, metal connector 4, anchoring balloon 5, guide wire tube 6, guiding catheter 7, first interface 70a, second interface 70b, guiding channel 71a, thrombus 8, guide wire 9. Detailed implementation manners

[0045] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0046] Next, in conjunction with attached Figure 1 to attached Figure 9 and specific embodiments, the present utility model will be elaborated in detail:

[0047] It should be noted that in the above description and the following description, "proximal end" generally refers to the end of the medical device that is close to the operator during normal operation, and "distal end" generally refers to the end of the medical device that first enters the patient's body during normal operation.

[0048] As Figure 1-7 shown, the present utility model provides an extended catheter, which can be applied to aspirate thrombus or plaque. The extended catheter includes a catheter seat 1, a push rod 2 and a catheter body 3 connected in sequence from the proximal end to the distal end.

[0049] A delivery channel 33 for delivering medical devices is provided in the catheter body 3. A guide inlet 34 communicating with the delivery channel 33 is provided at the proximal end of the catheter body 3. This guide inlet 34 is an instrument guide inlet and has an inclined structure, which can make the extended catheter have better pushability transmission; and an anchoring balloon 5 is connected to the outer wall of the proximal end of the catheter body 3.

[0050] The softness and hardness of the catheter body 3 gradually decrease from the proximal end to the distal end of the catheter body 3, making the catheter body 3 less obtrusive and better meeting the requirements for pushing the catheter body 3 within the human blood vessels. This can enable doctors to operate more precisely and conveniently, while reducing the pain of patients during the operation. The catheter body 3 is a composite structure composed of an inner layer 30, an intermediate reinforcing layer 31, and an outer layer 32. Among them, the material of the inner layer 30 of the catheter body 3 is one of polytetrafluoroethylene and high-density polyethylene, providing a lower friction for other instruments passing through the delivery channel located within the inner layer 30. The intermediate reinforcing layer 31 is divided into a compliant zone 311, a transition zone 312, and a pushing zone 313. The material of the outer layer 32 is one or a mixture of polyether front polyamide, nylon, and polyurethane elastomer, and the outer surface has a smoother appearance and feel, fully protecting the blood vessels and not easily generating thrombus, dissection, etc.

[0051] In this utility model, for the extension catheter, the catheter body 3 adopts a composite structure design of an inner layer 30, an intermediate reinforcing layer 31, and an outer layer 32, which can provide strong support, pressure resistance, and anti-flexibility, enabling the catheter to perform well in terms of function, safety, etc., and contributing to improving the effect and safety of medical operations.

[0052] At the same time, the intermediate reinforcing layer 31 is divided into a compliant zone 311, a transition zone 312, and a pushing zone 313. The reasonable setting of the characteristics of different regions enables the catheter body 3 to have both good compliant adaptability and effective pushing ability as a whole, meeting the operation requirements at different stages, improving the success rate and safety of the operation, and reducing the pain of patients during the operation.

[0053] Specifically, the intermediate reinforcing layer 31 is a helically cut tube layer, that is, formed by cutting a helical tube using tools such as knives, lasers, and plasmas. The intermediate reinforcing layer 31 being a helically cut tube layer, compared with the design of the intermediate reinforcing layer 31 using a stainless steel braided mesh layer or a spring layer in the prior art, the helically cut tube layer can have more excellent flexibility while ensuring a certain strength, better adapt to complex blood vessel paths, and reduce the irritation and damage to blood vessels; it can also provide a relatively uniform support force distribution, avoiding local stress concentration, and contributing to improving the stability of the catheter within the blood vessel. At the same time, the design of using a helically cut tube layer makes its outer diameter smaller and the structure more compact, thereby reducing the outer diameter of the entire extension catheter, lowering the implantation difficulty and the impact on blood vessels; and it is lighter in weight, helping to reduce the foreign body sensation in the patient's body.

[0054] Specifically, the anchoring balloon 5 is vacuum-flattened and adhered to the outer layer 32 of the catheter body 3. The distal end of the anchoring balloon 5 is tightly welded to the outer layer 32 of the catheter body 3 to form a sealed end; the proximal end of the anchoring balloon 5 is tightly welded to the outer layer 32 of the catheter body 3 and the distal end of the push rod 2, so that the welded joints at both ends of the entire anchoring balloon 4 have a smooth transition, without obvious concave or convex feel, and it is smoother and has lower resistance when entering other channel instruments. A radiopaque marker ring or radiopaque coating may also be provided inside the anchoring balloon 5. During the angiography operation, the radiopaque marker ring or radiopaque coating can display a black shadow to provide position information for the operator. In addition, in this embodiment, the material of the anchoring balloon 5 is one of nylon, silicone rubber, polyurethane elastomer, and thermoplastic elastomer.

[0055] Specifically, in this embodiment, a first radiopaque element 35 may also be provided at the distal end of the catheter body 3. During the angiography operation, the first radiopaque element 35 can display a black shadow to provide position information for the operator. The first radiopaque element 35 can be made of a radiopaque material that is opaque to X-rays, and the radiopaque material is one or more of gold, tungsten, platinum, and platinum-iridium alloy. The first radiopaque element 35 can be a radiopaque ring, a cylindrical helical radiopaque coil, or a radiopaque coating applied to the side wall of the catheter body 3. Specifically, the first radiopaque element 35 is preferably a radiopaque ring, which can help the operator quickly capture the position of the catheter body 3.

[0056] Furthermore, along the direction from the distal end to the proximal end of the catheter body 3, the spiral cutting tube layer is divided into a compliant zone 311, a transition zone 312, and a push zone 313 arranged in sequence, and the compliant zone 311, the transition zone 312, and the push zone 313 satisfy at least one of the following characteristics:

[0057] The slit length L of the spiral cutting tube layer in the compliant zone 311 > the slit length L of the spiral cutting tube layer in the transition zone 312 > the slit length L of the spiral cutting tube layer in the push zone 313;

[0058] Or, the cutting pitch d of the spiral cutting tube layer in the compliant zone 311 < the cutting pitch d of the spiral cutting tube layer in the transition zone 312 < the cutting pitch d of the spiral cutting tube layer in the push zone 313;

[0059] Or, the slit angle θ of the spiral cutting tube layer in the compliant zone 311 < the slit angle θ of the spiral cutting tube layer in the transition zone 312 < the slit angle θ of the spiral cutting tube layer in the push zone 313;

[0060] Or, the pitch p of the spiral cutting tube layer in the compliant zone 311 < the pitch p of the spiral cutting tube layer in the transition zone 312 < the pitch p of the spiral cutting tube layer in the push zone 313.

[0061] It should be noted that for the four parameters of the slit length, cutting spacing, slit angle, and pitch in the three regions of the compliant region 311, transition region 312, and pushing region 313 of the spiral cutting tube layer, one or more of the four parameters can be designed according to the above variation rules, or all can be designed according to the above variation rules.

[0062] It should also be noted that in this application, the slit angle θ is the angle between the slit and the central axis of the catheter.

[0063] By controlling the slit length L, cutting spacing d, slit angle θ, and pitch p of the spiral cutting tube layer, the flexibility of the catheter body 3 can be changed, and it can be divided into a compliant region 311, a transition region 312, and a pushing region 313. As is well known, the longer the slit length L, the smaller the cutting spacing d, the smaller the slit angle θ, or the smaller the pitch p, the more compliant the tube body is and the stronger its passing ability.

[0064] Correspondingly, the compliant region 311 of the spiral cutting tube layer has a longer slit, a smaller cutting spacing, a smaller slit angle, and a smaller pitch, making this region compliant and better able to adapt to complex blood vessel paths, improving the passing ability of the catheter body 3 within the blood vessels. The transition region 312 achieves a smooth transition between the compliant region 311 and the pushing region 313, maintaining a certain degree of compliance to adapt to changes while gradually increasing the convenience of pushing. The pushing region 313 uses a shorter slit, a larger cutting spacing, a larger slit angle, and a larger pitch, making this region more powerful during pushing and facilitating the accurate pushing of the catheter to the target position.

[0065] In summary, through the reasonable setting of the characteristics of different regions, the catheter body 3 as a whole has both good compliant adaptation ability and effective pushing ability, meeting the operation requirements at different stages and improving the success rate and safety of the operation.

[0066] Specifically, in this embodiment, the slit length of the spiral cutting tube layer in the compliant region 311 is 0.6 mm, the cutting spacing is 0.1 mm, the slit angle is 95°, the pitch is 0.09 mm, and the slit width is 0.02 mm.

[0067] The slit length of the spiral cutting tube layer in the transition region 312 is 0.4 mm, the cutting spacing is 0.3 mm, the slit angle is 105°, the pitch is 0.12 mm, and the slit width is 0.02 mm.

[0068] The slit length of the threaded cutting tube layer in the pushing region 313 is 0.1 mm, the cutting spacing is 0.6 mm, the slit angle is 115°, the pitch is 0.30 mm, and the slit width is 0.02 mm.

[0069] Further, a metal connector 4 is provided at the proximal end of the intermediate reinforcing layer 31 of the catheter body 3. One end of the metal connector 4 is arranged in parallel with the intermediate reinforcing layer 31 of the catheter body 3, and the other end is connected to the distal end of the push rod 2. One end of the metal connector 4 can be connected to or non-connected to the intermediate reinforcing layer 31, as long as the two are arranged in parallel.

[0070] Specifically, the push rod 2 is a hypotube. The hypotube has good strength and rigidity, which is convenient for pushing the catheter body 3 to the target position. At the same time, it has good anti-twisting property and is not prone to excessive twisting deformation during the pushing process, ensuring the smoothness of the operation.

[0071] The metal connector 4 is a metal ring. The metal ring has a spiral structure, and welding areas are respectively arranged at both ends of the connection between the metal ring and the hypotube to form a welded connection between the metal ring and the hypotube. The setting of the metal connector 4, especially using a metal ring and through welded connection, can ensure the stability of the connection between the catheter body 3 and the push rod 2 and guarantee the mechanical transmission during the operation. At the same time, the metal ring has a spiral structure, which can well buffer the stress concentration at the connection between the hypotube and the catheter body 3; it can also provide effective bending resistance for the catheter body 3. When the anchoring balloon is inflated, the lumen can also be kept intact. In addition, the spiral structure of the metal ring can provide a certain degree of elasticity and adaptability, making it more adaptable to different situations during the connection and force transmission process.

[0072] In this embodiment, at the welded connection between the hypotube and the metal ring, the diameter of the hypotube is reduced, so that the overall outer diameter will not increase, which is beneficial to the passability in the blood vessel and reduces the damage to the blood vessel.

[0073] At the same time, a second imaging element 21 is provided at the distal end of the hypotube. The second imaging element 21 is plugged at the distal end of the hypotube and is used for imaging and displaying the position of the balloon. Under X-ray, it can be accurately positioned in the patient's body, reducing the operation difficulty. The setting of the second imaging element 21 is convenient for accurately displaying the position of the balloon through imaging during the operation, which helps to improve the accuracy and safety of the operation. The second imaging element 21 can be made of a filamentous material of an X-ray-impermeable imaging material, and the imaging material is one or more of gold wire, tungsten wire, platinum wire, and platinum-iridium alloy wire.

[0074] Further, in order to facilitate medical staff to know the depth of insertion of the catheter body 3 and the anchoring balloon 5 into the human body, scales or marking bands are provided on the surface of the hypotube.

[0075] Further, the push rod 2 is a tubular structure with a channel, forming a fluid channel. A through hole is provided at the distal end of the push rod 2, and the through hole is located at the middle position of the anchoring balloon 5 to achieve communication with the inner cavity of the anchoring balloon 5. In this embodiment, the radial cross-sectional structure of the push rod 2 can be one of an oval shape, a circular shape, and a semi-circular shape; the number of through holes can be 1 to 50, which can be designed and selected by those skilled in the art according to the actual situation. The length of the push rod 2 at the position where the through hole is provided is about 1 mm to 5 mm. Specifically, the through hole is located on the side wall of the distal end of the push rod 2, and the opening of the through hole faces away from the catheter body 3.

[0076] The catheter seat 1 has a through channel, and the through channel is communicated with the fluid channel of the push rod 2; finally, the mutual communication among the catheter seat 1, the push rod 2, and the anchoring balloon 5 is realized to form a single-chamber channel. During operation, a doctor can connect a medium such as an injection fluid at the catheter seat 1, and fill the anchoring balloon 5 through the fluid channel in the push rod 2, so that the anchoring balloon 5 can be quickly anchored in the inner cavity of the guiding catheter 7 and blocked. The distal end of the catheter seat 1 is connected to the proximal end of the push rod 2. In this embodiment, the connection between the two is a welded connection. Preferably, the catheter seat 1 is flatly arranged for easy finger grasping and rotation. A heparin cap or a one-way valve can also be provided at the opening end of the catheter seat 1 to prevent the filled medium from flowing out of the catheter seat 1.

[0077] Further, the extension catheter further includes a guide wire tube 6. The guide wire tube 6 extends along the length direction of the catheter body 3 and is connected to the catheter body 3 in parallel. The guide wire tube 6 has a guide wire cavity for the guide wire to pass through. The proximal end of the guide wire tube 6 is located outside the distal end of the anchoring balloon 5 and does not reach the anchoring balloon 5, and the distal end of the guide wire tube 6 extends to the distal end of the catheter body 3.

[0078] The guide wire tube 6 is arranged in parallel with the catheter body 3, so that the guide wire 9 can pass through the guide wire cavity of the guide wire tube 6 without occupying the area of the conveying channel of the catheter body 3. When suction is performed through the conveying channel of the catheter body 3, the suction path is smooth, the effective suction area is relatively large, the influence of the guide wire 9 on the effective suction area of the lumen can be avoided, and the suction effect can be improved. At the same time, the guide wire 9 passing through the guide wire cavity can also guide and anchor the catheter body 3 to ensure that the extension catheter can be accurately conveyed to the target area. In addition, by squeezing the guide wire 9 with the anchoring balloon 5, it is ensured that the guide wire 9 can stably reach the target position, reducing the risk of displacement or instability of the guide wire 9 during the process. Specifically, the guide wire tube 6 is arranged on the outer wall surface of the catheter body 3.

[0079] Based on the above-mentioned extension catheter, the present invention further provides a catheter system, such as Figure 8 、 9As shown, it can be used for aspirating thrombus or plaque, and includes a guiding catheter 7 and the above-mentioned extension catheter, wherein the guiding catheter 7 is provided with a guiding channel 71a. When the anchoring balloon 5 is not filled, the extension catheter is guided to slide in the guiding channel 71a, and correspondingly, the guide wire 9 is movably passed through the guiding channel 71a and the guide wire cavity; when the anchoring balloon 5 is filled, the anchoring balloon 5 is expanded and abuts against the inner wall of the guiding channel 71a, and presses against the guide wire 9, and the delivery channel 11 of the extension catheter is connected to the guiding channel 71a. The proximal end of the guiding catheter 7 is connected to a Y-type connection valve, i.e., a Y valve.

[0080] Furthermore, a hydrophilic coating is provided on the surface of the anchoring balloon 5. When the anchoring balloon 5 is subjected to a filling pressure of 0.8 bar to 1.5 bar, the anchoring balloon 5 abuts against the inner wall of the guiding channel 71a, and the anchoring balloon 5 can slide in the guiding channel by moving the sea wave tube (i.e., the push rod 2).

[0081] Combined with the figure, taking entering a small blood vessel to aspirate thrombus as an example, the specific working principle of the catheter system of the utility model is as follows:

[0082] Entering the target area: When the thrombus 8 is in a small blood vessel, the guiding catheter 7 is transported to a larger blood vessel near the small blood vessel, and the guide wire 9 is transported to the thrombus 8 in the small blood vessel along the first interface 70a of the Y valve at the proximal end of the guiding catheter 7. The guide wire tube 6 is transported to the extension catheter along the guide wire 9, and the extension catheter extends into the guiding catheter 7 from the first interface 70a of the Y valve at the proximal end of the guiding catheter 7. The distal end of the catheter body 3 of the extension catheter is exposed from the distal end of the guiding catheter 7, the proximal end of the catheter body 3 is located in the guiding channel 71a, one end of the push rod 2 is located in the guiding channel 71a, the other end of the push rod 2 is exposed from the first interface 70a of the Y valve, and the catheter seat 1 is located outside the Y valve. Under the guidance of the guide wire 9, the catheter body 3 enters the designated position. Since the catheter body 3 contains the push rod 2, the push rod 2 can be used to apply force, so that the guiding catheter 7 can easily enter the branch blood vessels and narrow blood vessels.

[0083] Establishing a transmission channel: filling the anchoring balloon 5 through the inner cavity of the catheter seat 1 and the fluid channel in the push rod 2, and anchoring the anchoring balloon 5 in the guiding channel 71a after expansion, the anchoring balloon 5 blocks the gap between the guiding catheter 7 and the catheter body 3, and the guiding channel 71a is connected to the catheter cavity.

[0084] Delivery of contrast agent / drug: The first interface 70a of the push rod 2 extending from the Y-valve of the guiding catheter 7 is blocked, and the contrast agent / drug is delivered at the second interface 70b of the Y-valve. The contrast agent / drug flows along the guiding channel 71a into the delivery channel of the catheter body 3, and then flows out at the distal end of the catheter body 3. The contrast agent / drug flows to the distal end of the small blood vessels, thereby performing super-selective angiography / targeted drug administration.

[0085] An external suction device is used to suck out the thrombus 8 and plaque: the first interface 70a of the push rod 2 extending from the Y valve of the guiding catheter 7 is blocked, and the suction device is connected to the second interface 70b of the Y valve to suck out the thrombus 8 and plaque at the distal end of the catheter body 3. Under the action of negative pressure, the thrombus 8 or calcified plaque flows back to the guiding channel 71a along the delivery channel 33 of the catheter body 3 until it is sucked out of the body.

[0086] Withdrawal of the guide wire 9 (or extension catheter): Use a pressure pump to withdraw the medium in the anchoring balloon 5 under negative pressure. Under X-ray fluoroscopy, confirm that the anchoring balloon 5 is deflated and no medium remains, and withdraw the guide wire 9 (or extension catheter) as a whole until it is out of the body.

[0087] In summary, the catheter system of the utility model has an extended catheter, which is connected to a guide wire tube 6 in parallel in the catheter direction of the catheter body 3, so that the guide wire 9 can pass through the guide wire cavity 51 of the guide wire tube 6 without occupying the area of ​​the delivery channel of the catheter body 3, so that the suction path for suction through the guide channel 71a and the delivery channel is smooth, and the effective suction area is relatively large, which can avoid the influence of the guide wire 9 on the effective suction area of ​​the lumen, and improve the suction effect. At the same time, the guide wire 9 passing through the guide wire cavity can also guide and anchor the catheter body 3, ensuring that the extended catheter can be accurately delivered to the target area. In addition, since the guide wire 9 does not occupy the area of ​​the delivery channel of the catheter body 3, the effective suction area is relatively large, and the suction ability for large thrombi 8 is better, reducing complications. In addition, the extended catheter of the utility model can be used as a guide instrument to be deeply inserted into a farther position of the blood vessel, and can also realize the function of suctioning thrombi 8 and plaques, reduce thrombotic events caused by suctioning thrombi 8, reduce exchanges between instruments, and improve surgical efficiency.

[0088] The utility model is further described above with the help of specific embodiments, but it should be understood that the specific description here should not be construed as limiting the essence and scope of the utility model. Various modifications made to the above embodiments by ordinary technicians in this field after reading this specification are all within the scope of protection of the utility model.

Claims

1. An extension catheter, comprising a catheter seat, a push rod and a catheter body connected in sequence from the proximal end to the distal end, characterized in that: The catheter body is provided with a delivery channel for delivering medical devices, the proximal end of the catheter body is provided with an introduction port connected to the delivery channel, and an anchoring balloon is sleeved on the outer wall of the proximal end of the catheter body; The hardness of the catheter body decreases from the proximal end to the distal end of the catheter body. The catheter body is a composite structure consisting of an inner layer, an intermediate reinforcement layer and an outer layer, wherein the intermediate reinforcement layer is divided into a compliant zone, a transition zone and a push zone.

2. The extension catheter according to claim 1, characterized in that: The middle reinforcement layer is a spirally cut tube layer.

3. The extension catheter according to claim 1, characterized in that: The compliant zone, the transition zone and the push zone satisfy at least one of the following characteristics; The slit length of the spiral cutting tube layer in the compliant zone is greater than the slit length of the spiral cutting tube layer in the transition zone and greater than the slit length of the spiral cutting tube layer in the push zone; Or, the cutting pitch of the spiral cutting tube layer in the compliant zone is less than the cutting pitch of the spiral cutting tube layer in the transition zone and less than the cutting pitch of the spiral cutting tube layer in the pushing zone; Or, the slit angle of the spirally cut tube layer in the compliant zone is less than the slit angle of the spirally cut tube layer in the transition zone and less than the slit angle of the spirally cut tube layer in the push zone; Or, the pitch of the spirally cut tube layer in the compliant zone is less than the pitch of the spirally cut tube layer in the transition zone and less than the pitch of the spirally cut tube layer in the pushing zone.

4. The extension catheter according to claim 1, characterized in that: A metal connector is provided at the proximal end of the middle reinforcement layer of the catheter body, one end of the metal connector is arranged in parallel with the middle reinforcement layer of the catheter body, and the other end is connected to the distal end of the push rod.

5. The extension catheter according to claim 4, characterized in that: The push rod is a hypotube; The metal connecting piece is a metal ring having a spiral structure, and welding areas are respectively arranged at both ends of the connection between the metal ring and the hypotube to form a welding connection between the metal ring and the hypotube.

6. The extension catheter according to claim 5, characterized in that: The diameter of the hypotube is reduced at the welding connection between the hypotube and the metal ring.

7. The extension catheter according to claim 5, characterized in that: A second developing element is provided at the distal end of the hypotube.

8. The extension catheter according to claim 7, characterized in that: The developing material of the second developing element is one or more of gold wire, tungsten wire, platinum wire, and platinum-iridium alloy wire.

9. The extension catheter according to claim 5, characterized in that: The surface of the hypotube is provided with scales or marking bands.

10. The extension catheter according to claim 1, characterized in that: The push rod is a tubular structure with a channel to form a fluid channel, and a through hole is provided at the distal end of the push rod, and the through hole is provided at the middle position of the anchoring balloon to achieve communication with the inner cavity of the anchoring balloon; The catheter seat has a through passage, and the through passage is communicated with the fluid passage of the pushing rod.

11. The extension catheter according to claim 10, characterized in that: A heparin cap or a one-way valve is arranged at the open end of the catheter seat.

12. The extension catheter according to any one of claims 1 to 11, characterized in that: The extension catheter also includes a guide wire tube, which extends along the length direction of the catheter body and is connected in parallel with the catheter body; the guide wire tube has a guide wire cavity for the guide wire to pass through, the proximal end of the guide wire tube is located outside the distal end of the anchoring balloon, and the distal end of the guide wire tube extends to the distal end of the catheter body.

13. A catheter system, characterized in that: It includes a guiding catheter and an extension catheter as described in any one of claims 1 to 12, wherein a guiding channel is provided in the guiding catheter, and when the anchoring balloon is not filled, the extension catheter is guided to slide in the guiding channel; when the anchoring balloon is filled, the anchoring balloon abuts against the inner wall of the guiding channel after expansion, and the delivery channel of the extension catheter is connected to the guiding channel.

14. The catheter system according to claim 13, characterized in that When the anchoring balloon is subjected to a filling pressure of 0.8 bar to 1.5 bar, the anchoring balloon abuts against the inner wall of the guiding channel, and the anchoring balloon can slide in the guiding channel by moving the pushing rod.

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