Suction catheter

Abstract

The invention provides a suction catheter. The suction catheter comprises a macromolecule tube and a supporting tube arranged in the wall of the macromolecule tube. The supporting pipe comprises a first supporting ring and a plurality of supporting rods, and the supporting rods extend in the direction parallel to the longitudinal center axis of the suction catheter and are arranged on the outer side of the first supporting ring at intervals in the circumferential direction. The supporting rod comprises a near-end section, a middle section and a far-end section which are sequentially connected, the near-end section and the middle section are located on the near-end side of the first supporting ring, the far-end section is located on the far-end side of the first supporting ring, and the rigidity of the far-end section or the near-end section is larger than that of the middle section. When the far end of the aspiration catheter is blocked by thrombus, the middle section of the supporting rod is bent inwards, the far end section of the supporting rod tilts outwards, and therefore the far end of the supporting rod expands, and the thrombus originally blocked at the far end of the aspiration catheter can smoothly enter the aspiration catheter.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a suction catheter. Background Art

[0002] Acute ischemic stroke is the most common type of stroke, which is caused by cerebral thrombosis or blockage of cerebral blood vessels by thrombus resulting in hypoxia of brain tissue. Cerebral thrombosis is characterized by high incidence, high disability rate, high mortality rate, and high recurrence rate. The main treatment methods are mainly divided into two categories: drug thrombolysis and mechanical thrombectomy.

[0003] Mechanical thrombectomy mainly includes methods such as thrombectomy, laser thrombectomy, thrombus capture net thrombectomy, and aspiration thrombectomy. Its main problem is that when the thrombus is large, simple aspiration of the thrombus may not be able to retrieve the thrombus, and the large thrombus may block the distal end of the suction catheter, and even increasing the suction pressure cannot suck the blood vessel into the suction catheter.

[0004] Therefore, there is an urgent need to provide a suction device to solve the problem that the distal end of the suction catheter is blocked by thrombus when the existing suction catheter aspirates a thrombus with a larger volume. Summary of the Invention

[0005] Based on this, it is necessary to provide a suction catheter capable of sucking large-volume thrombus.

[0006] The present invention provides a suction catheter, including: a polymer tube and a support tube disposed in the wall of the polymer tube;

[0007] The support tube includes a first support ring and a plurality of support rods, and the plurality of support rods extend in a direction parallel to the longitudinal central axis of the suction catheter and are arranged at intervals in the circumferential direction outside the first support ring;

[0008] The support rod includes a proximal section, an intermediate section, and a distal section connected in sequence. The proximal section and the intermediate section are located on the proximal side of the first support ring, the distal section is located on the distal side of the first support ring, and the stiffness of the distal section or the proximal section is greater than that of the intermediate section.

[0009] In one embodiment, the intermediate section has a deformed section, and the outer diameter of the proximal section or the outer diameter of the distal section is greater than the outer diameter of the deformed section.

[0010] In one embodiment, the intermediate section further has a first connection section, the first connection section connects the deformed section and the distal section, and the outer diameter of the first connection section is equal to the outer diameter of the distal section.

[0011] In one embodiment, the support tube further includes a second support ring, which is coaxially arranged with the first support ring; the proximal section is located on the proximal side of the second support ring, and the middle section is located on the distal side of the second support ring.

[0012] In one embodiment, the middle section further includes a second connecting section, which connects the deformed section and the proximal section, and the outer diameter of the second connecting section is equal to the outer diameter of the proximal section.

[0013] In one embodiment, at least two limiting rods are connected between the first support ring and the second support ring, and the stiffness of the limiting rods is greater than that of the middle section.

[0014] In one embodiment, in the natural state, the distal section is parallel to the longitudinal central axis of the aspiration catheter.

[0015] In one embodiment, in the natural state, the distal section gradually approaches the longitudinal central axis of the aspiration catheter in the proximal-to-distal direction.

[0016] In one embodiment, the polymer tube includes an expansion section, which is located on the distal side of the first support ring;

[0017] The expansion section has an unfolded state and a folded state. When the distal end of the support rod expands outward, the expansion section changes from the folded state to the unfolded state.

[0018] In one embodiment, the polymer tube includes an inner layer tube and an outer layer tube, and the support tube is arranged between the inner layer tube and the outer layer tube; the polymer tube has a separation area and a bonding area other than the separation area; in the longitudinal central axis direction of the aspiration catheter, the width of the separation area is greater than the width of the first support ring, and the separation area covers the first support ring; in the separation area, the inner layer tube and the outer layer tube are separated, and in the bonding area, the inner layer tube and the outer layer tube are attached to fix the support rod.

[0019] The aspiration catheter of the present invention is connected to a negative pressure generating device to aspirate thrombus in blood vessels. When the distal end of the aspiration catheter is blocked by a thrombus, the pressure difference between the inside and outside of the aspiration catheter further increases. Since the middle section of the support rod has a relatively small stiffness, it first bends inward under the action of the pressure difference between the inside and outside of the aspiration catheter. At this time, since the first support ring has not deformed, the support rod rotates with the first support ring as the fulcrum, so that the distal section of the support rod tilts outward. As a result, the distal end of the support tube expands, and the thrombus originally blocking the distal end of the aspiration catheter can smoothly enter the aspiration catheter. Compared with the aspiration catheters in the prior art, the aspiration catheter of the present invention can automatically expand the distal end when it is blocked, enabling the thrombus to smoothly enter the aspiration catheter without manually operating the distal end of the aspiration catheter to expand. Description of the Drawings

[0020] Figure 1 is the front view of the aspiration catheter according to an embodiment of the present invention (the polymer tube is made transparent);

[0021] Figure 2 is the partial front view of the support tube according to an embodiment of the present invention (in the natural state);

[0022] Figure 3 is the partial front view of the support tube according to an embodiment of the present invention (in the aspiration state);

[0023] Figure 4 is the partial perspective view of the support tube according to an embodiment of the present invention (in the aspiration state);

[0024] Figure 5 is the partial front view of the support tube according to other embodiments of the present invention (in the natural state);

[0025] Figure 6 is the partial perspective view of the aspiration catheter according to other embodiments of the present invention;

[0026] Figure 7 is the partial perspective view of the aspiration catheter according to an embodiment of the present invention (a part of the outer tube is hidden);

[0027] Figure 8 is the partial cross-sectional view of the aspiration catheter according to an embodiment of the present invention;

[0028] Figure 9 is Figure 8 the enlarged view of part A in Detailed Embodiments

[0029] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the description of the present invention herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the related listed items.

[0031] For a clearer description of the structure of the present application, the terms "proximal end" and "distal end" are defined herein as the commonly used terms in the field of interventional medicine. Specifically, the "distal end" refers to the end far from the operator during the surgical operation, and the "proximal end" refers to the end close to the operator during the surgical operation. The terms "proximal side" and "distal side" are defined herein as the commonly used terms in the field of interventional medicine. Specifically, the "proximal side" refers to the end closer to the heart after the medical device is implanted into the human body, and the "distal side" refers to the end farther from the heart after the medical device is implanted into the human body. "Axial direction" refers to its length direction, and "radial direction" refers to the direction perpendicular to the "axial direction".

[0032] Embodiment 1

[0033] As Figure 1 shown, this embodiment provides a suction catheter 100, which includes: a polymer tube 110 and a support tube 120 disposed in the wall of the polymer tube 110;

[0034] As Figure 2 shown, the support tube 120 includes a first support ring 122 and a plurality of support rods 121, and the plurality of support rods 121 extend in a direction parallel to the longitudinal central axis of the suction catheter 100 and are circumferentially spaced apart on the outer side of the first support ring 122;

[0035] The support rod 121 includes a proximal segment 1211, an intermediate segment 1212, and a distal segment 1213 connected in sequence. The proximal segment 1211 and the intermediate segment 1212 are located on the proximal side of the first support ring 122, the distal segment 1213 is located on the distal side of the first support ring 122, and the stiffness of the distal segment 1213 or the proximal segment 1211 is greater than that of the intermediate segment 1212.

[0036] The polymer tube 110 is made of a highly elastic material such as thermoplastic polyurethane (TPU), polyurethane (PU), nylon, etc., and the polymer tube deforms as the support tube deforms. The support rod 121 is made of a metal material, such as nickel-titanium alloy, stainless steel, etc., wherein the stiffness is the ability of the material to resist elastic deformation when subjected to force. That is, when subjected to the same pressure, the smaller the stiffness of the material, the greater the degree of elastic deformation; or the smaller the stiffness of the material, the smaller the force it is subjected to when elastic deformation begins. In this embodiment, the forces to which the proximal segment 1211 and the distal segment 1213 are subjected when they begin to deform are greater than the force to which the middle segment 1212 is subjected when it begins to deform.

[0037] The suction catheter 100 of the present invention is connected to a negative pressure generating device to absorb blood clots in the blood vessels. Figure 3 As shown, when the distal end of the suction catheter 100 is blocked by a thrombus, the pressure difference between the inside and outside of the suction catheter 100 is further increased, and the middle section 1212 of the support rod 121 is first bent inwardly under the action of the pressure difference between the inside and outside of the suction catheter 100 due to its low rigidity. Since the first support ring 122 is not deformed at this time, the support rod 121 rotates with the first support ring 122 as a fulcrum, so that the distal section 1213 of the support rod 121 is tilted outward, thereby the distal end of the support tube 120 is expanded, and the thrombus originally against the distal end of the suction catheter 100 can enter the suction catheter 100 and then be smoothly sucked away. Compared with the suction catheter 100 in the prior art, the suction catheter 100 of the present invention can automatically expand the distal end when the distal end is blocked, so that the thrombus can smoothly enter the suction catheter 100, without manually operating the distal end of the suction catheter 100 to expand.

[0038] In this embodiment, review Figure 2 , the middle section 1212 has a deformation section 12121, and the outer diameter of the proximal section 1211 or the outer diameter of the distal section 1213 is larger than the outer diameter of the deformation section 12121. The support rod 121 is made of the same material, and since the outer diameter of the deformation section 12121 is smaller, the rigidity at the deformation section 12121 is smaller, and when subjected to the same pressure, the deformation section 12121 is the first to bend. In other embodiments, the deformation section 12121 is made of other materials, and the rigidity of the material used to make the deformation section 12121 is smaller than the rigidity of the material used to make the other parts of the middle section 1212, and when subjected to the same pressure, the deformation section 12121 is the first to bend.

[0039] The middle section 1212 further has a first connection section 12122. The first connection section 12122 connects the deformation section 12121 and the distal section 1213, and the outer diameter of the first connection section 12122 is equal to the outer diameter of the distal section 1213. In this embodiment, the support rod 121 is made of the same material, and the outer diameter of the first connection section 12122 is equal to the outer diameter of the distal section 1213, that is, the stiffness of the connection section is equal to the stiffness of the distal section 1213. When the deformation section 12121 undergoes elastic deformation, neither the first connection section 12122 nor the distal section 1213 undergoes deformation, preventing the first connection section 12122 from bending at the first support ring 122, so that the support rod 121 can rotate with the first support ring 122 as the fulcrum.

[0040] The support tube 120 further includes a second support ring 123. The second support ring 123 is coaxially arranged with the first support ring 122; the proximal section 1211 is located on the proximal side of the second support ring 123, and the middle section 1212 is located on the distal side of the second support ring 123. Due to the presence of the second support ring 123, when the middle section 1212 undergoes elastic deformation, the second support ring 123 functions to prevent the proximal section 1211 from being recessed inwardly with the middle section 1212, maintaining the original pipe diameter of the aspiration catheter 100 at the position of the proximal section 1211, enabling the aspirated thrombus to smoothly reach the proximal end of the aspiration catheter 100. The proximal section 1211 and the second support ring 123 can be fixedly connected by welding, bonding, etc., or the two can be fixed by wrapping the proximal section 1211 and the second support ring 123 with the polymer tube 110.

[0041] The middle section 1212 further has a second connection section 12123. The second connection section 12123 connects the deformation section 12121 and the proximal section 1211, and the outer diameter of the second connection section 12123 is equal to the outer diameter of the proximal section 1211. In this embodiment, the support rod 121 is made of the same material, and the outer diameter of the second connection section 12123 is equal to the outer diameter of the proximal section 1211, that is, the stiffness of the connection section is equal to the stiffness of the proximal section 1211. When the deformation section 12121 undergoes elastic deformation, neither the second connection section 12123 nor the proximal section 1211 in contact with the second support ring 123 undergoes deformation, preventing the support rod 121 from undergoing plastic deformation due to multiple bends at the second support ring 123.

[0042] At least two limiting rods 124 are connected between the first support ring 122 and the second support ring 123. The stiffness of the limiting rods 124 is greater than that of the middle section 1212. Since the stiffness of the limiting rods 124 is greater than the stiffness of the middle section 1212, such asFigure 4 As shown, when the middle section 1212 undergoes elastic deformation, the limiting rod does not deform, thus supporting the polymer tube 110 that is recessed inward as the middle section 1212 deforms, and preventing the polymer tube 110 from completely collapsing. In other embodiments, three or more limiting rods are connected between the first support ring 122 and the second support ring 123, and the limiting rods are arranged at intervals in the circumferential direction of the aspiration catheter 100.

[0043] In this embodiment, in the natural state, as Figure 2 shown, the distal section 1213 is parallel to the longitudinal central axis of the aspiration catheter 100.

[0044] In other embodiments, as Figure 5 shown, in the natural state, the distal section 1213a gradually approaches the longitudinal central axis of the aspiration catheter in the proximal-to-distal direction. Therefore, in the natural state, the distal openings of the support rods 121a converge inward. When no thrombus is aspirated, the aspiration catheter with a smaller distal opening can reduce the amount of blood withdrawn and reduce the blood loss of the patient.

[0045] As Figure 6 shown, in other embodiments, the polymer tube of the aspiration catheter 100b includes a body section 111b, a contraction section 112b, and an expansion section 113b; the body section 111b corresponds to the proximal section, the contraction section 112b corresponds to the middle section, and the expansion section 113b corresponds to the distal section. That is, the expansion section 113b is located on the distal side of the first support ring 122b, the contraction section 112b is located between the first support ring 122b and the second support ring 123b, and the body section 111b is located on the proximal side of the second support ring 123b. (For ease of understanding, the first support ring 122b and the second support ring 123b are shown in the appendix Figure 6 in dashed lines to show the positional relationship of the body section, the contraction section, and the expansion section; the support rods and the limiting rods are not shown in the appendix Figure 6 .)

[0046] The expansion section 113b has an unfolded state and a folded state. When the distal end of the support rod expands outward, the expansion section 113b changes from the folded state to the unfolded state. Since the expansion section 113b is in the folded state when the distal end of the support rod does not expand outward, that is, the expansion section 113b has a certain margin for circumferential expansion, preventing the expansion section from generating resistance to the support rod when the distal end of the support rod expands outward.

[0047] As Figure 7As shown, the polymer tube 110 includes an inner layer tube 114 and an outer layer tube 115, and the support tube 120 is disposed between the inner layer tube 114 and the outer layer tube 115; as Figure 8 and Figure 9 shown, the polymer tube 110 has a separation region 116 and a bonding region 117 other than the separation region 116; in the longitudinal central axis direction of the suction catheter 100, the width of the separation region 116 is greater than the width of the first support ring 122, and the separation region 116 covers the first support ring 122; within the separation region 116, the inner layer tube 114 and the outer layer tube 115 are separated, and within the bonding region 117, the inner layer tube 114 and the outer layer tube 115 are adhered to fix the support rod 121.

[0048] Within the separation region 116, the inner layer tube 114 and the outer layer tube 115 are separated. Therefore, within the separation region 116, the support rod 121 and the first support ring 122 can move relative to each other to a certain extent, so that the support rod 121 can rotate around the first support ring 122.

[0049] Within the bonding region 117, the inner layer tube 114 and the outer layer tube 115 are adhered (for example, the inner layer tube 114 and the outer layer tube 115 are adhered by means of high temperature and pressure), and the positions of the plurality of support rods 121 are relatively fixed, so as to prevent the support rods 121 from sliding circumferentially along the first support ring 122 when deformed.

[0050] In this embodiment, the width of the separation region 116 is twice that of the first support ring 122, which can not only enable the support rod 121 and the first support ring 122 to move relative to each other to a certain extent, but also prevent the first support ring 122 from moving in the circumferential direction of the suction catheter 100.

[0051] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0052] The above-described embodiments only represent several implementation manners of the present invention, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A suction catheter, characterized in that, Comprising: A polymer tube and a support tube disposed in the wall of the polymer tube; The support tube includes a first support ring and a plurality of support rods, and the plurality of support rods extend in a direction parallel to the longitudinal central axis of the aspiration catheter and are arranged at intervals in the circumferential direction outside the first support ring; The support rod includes a proximal segment, an intermediate segment, and a distal segment connected in sequence. The proximal segment and the intermediate segment are located on the proximal side of the first support ring, the distal segment is located on the distal side of the first support ring, and the stiffness of the distal segment or the proximal segment is greater than that of the intermediate segment.

2. The aspiration catheter according to claim 1, wherein The intermediate segment has a deformation segment, and the outer diameter of the proximal segment or the outer diameter of the distal segment is greater than the outer diameter of the deformation segment.

3. The aspiration catheter according to claim 2, wherein The intermediate segment further has a first connection segment, the first connection segment connects the deformation segment and the distal segment, and the outer diameter of the first connection segment is equal to the outer diameter of the distal segment.

4. The aspiration catheter according to claim 1, wherein The support tube further includes a second support ring, and the second support ring is coaxially arranged with the first support ring; the proximal segment is located on the proximal side of the second support ring, and the intermediate segment is located on the distal side of the second support ring.

5. The aspiration catheter according to claim 4, wherein The intermediate segment further includes a second connection segment, the second connection segment connects the deformation segment and the proximal segment, and the outer diameter of the second connection segment is equal to the outer diameter of the proximal segment.

6. The aspiration catheter according to claim 4, wherein At least two limiting rods are connected between the first support ring and the second support ring, and the stiffness of the limiting rods is greater than that of the intermediate segment.

7. The aspiration catheter according to claim 1, wherein In the natural state, the distal segment is parallel to the longitudinal central axis of the aspiration catheter.

8. The aspiration catheter according to claim 1, wherein In the natural state, the distal segment gradually approaches the longitudinal central axis of the aspiration catheter in the proximal-to-distal direction.

9. The aspiration catheter according to claim 1, wherein The polymer tube includes an expansion segment, and the expansion segment is located on the distal side of the first support ring; The expansion segment has an unfolded state and a folded state, and when the distal end of the support rod expands outward, the expansion segment changes from the folded state to the unfolded state.

10. The aspiration catheter according to claim 1, wherein The polymer tube includes an inner layer tube and an outer layer tube, and the support tube is disposed between the inner layer tube and the outer layer tube; the polymer tube has a separation region and a bonding region other than the separation region; in the longitudinal central axis direction of the aspiration catheter, the width of the separation region is greater than the width of the first support ring, and the separation region covers the first support ring; In the separation region, the inner layer tube and the outer layer tube are separated, and in the bonding region, the inner layer tube and the outer layer tube are bonded to fix the support rod.

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