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, a plurality of supporting rods and at least one tightening ring; the multiple supporting rods extend in the direction parallel to the longitudinal central axis of the suction catheter and are arranged on the outer side of the first supporting ring at intervals in the circumferential direction. The tightening ring is located on the near end side of the first supporting ring and arranged outside the multiple supporting rods in a sleeving mode. In a natural state, the tightening ring tends to contract inwards in the radial direction. When the far end of the suction catheter is blocked by thrombus, the part, sleeved with the tightening ring, of the supporting rod bends and deforms inwards under the action of the tightening ring and negative pressure. The supporting rod rotates with the first supporting ring as a fulcrum, so that the far-end section of the supporting rod tilts outwards, the far-end end of the supporting pipe expands, and thrombus abutting against the far-end end of the suction catheter can smoothly enter the suction catheter.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular, 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. The larger 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 sucking a larger volume of thrombus in the prior art. Summary of the Invention

[0005] Based on this, it is necessary to provide a suction catheter that can suck 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, a plurality of support rods, and at least one tightening ring; the plurality of support rods extend in a direction parallel to the longitudinal central axis of the suction catheter and are circumferentially spaced apart outside the first support ring; 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 tightening ring is sleeved outside the plurality of support rods at the intermediate section;

[0008] In the natural state, the tightening ring includes a plurality of V-shaped structures arranged circumferentially; or the tightening ring has two open ends, and the two open ends can move relative to each other.

[0009] In one embodiment, the support tube further includes at least one expansion ring, the expansion ring is located on the distal side of the first support ring, and the distal sections of the plurality of support rods are located outside the expansion ring;

[0010] In one embodiment, the support tube further includes at least one second expansion ring, the second expansion ring is located on the distal side of the first expansion ring, and the distal sections of the plurality of support rods are located outside the second expansion ring;

[0011] In a natural state, the second expansion ring has a tendency to expand radially outward, and the diameter of the second expansion ring is greater than that of the first expansion ring when no external force is applied.

[0012] In a natural state, the expansion ring has a tendency to expand radially outward.

[0013] In one embodiment, the expansion ring includes a plurality of V-shaped structures arranged circumferentially; or the expansion ring has two open ends that can move relative to each other.

[0014] In one embodiment, the support tube further includes a second support ring coaxially arranged with the first support ring; the proximal section is located on the proximal side of the second support ring, and the intermediate section is located on the distal side of the second support ring.

[0015] In one embodiment, in a natural state, the distal section is parallel to the central axis of the aspiration catheter.

[0016] In one embodiment, in a natural state, the distal section gradually approaches the central axis of the aspiration catheter in the proximal-to-distal direction.

[0017] In one embodiment, the polymer tube includes an expansion section located on the distal side of the first support ring;

[0018] The expansion section has an unfolded state and a folded state, and when the distal end of the support rod expands outward, the expansion section changes from the folded state to the unfolded state.

[0019] 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 region and a bonding region other than the separation region; in the axial 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 adhered to fix the support rod.

[0020] The aspiration catheter of the present invention is connected to a negative pressure generating device to aspirate thrombus in blood vessels. When the aspiration catheter is in a natural state (without distal blockage), the tightening ring has a tendency to radially contract inward, and the support rod does not deform due to its own strength; when the distal end of the aspiration catheter is blocked by thrombus, the pressure difference inside and outside the aspiration catheter further increases, and the middle section of the support rod bends inward under the action of the tightening ring and negative pressure. Since the first support ring does not deform, the support rod rotates with the first support ring as the fulcrum, so that the distal section of the support rod tilts outward, and thus the distal end of the support tube expands. The thrombus originally against the distal end of the aspiration catheter can enter the aspiration catheter and be smoothly aspirated away. 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

[0021] Figure 1 It is the front view of the aspiration catheter according to the embodiment of the present invention (the polymer tube is made transparent);

[0022] Figure 2 It is the partial front view of the support tube according to the embodiment of the present invention (in the natural state);

[0023] Figure 3 It is the front view of the aspiration catheter section located at the tightening ring according to the embodiment of the present invention (the polymer tube is made transparent);

[0024] Figure 4 It is the partial front view of the support tube according to the embodiment of the present invention (in the distal blockage state);

[0025] Figure 5 It is the three-dimensional view of the tightening ring according to the embodiment of the present invention;

[0026] Figure 6 It is the partial three-dimensional view of the support tube according to other embodiments of the present invention (the tightening ring is an open ring);

[0027] Figure 7 It is the three-dimensional view of the tightening ring according to other embodiments of the present invention;

[0028] Figure 8 It is the front view of the aspiration catheter section located at the first expansion ring according to the embodiment of the present invention (the polymer tube is made transparent);

[0029] Figure 9 It is the partial front view of the tightening ring according to other embodiments of the present invention (without an expansion ring);

[0030] Figure 10Partial front view of the tightening ring according to other embodiments of the present invention (the distal segment moves closer inward);

[0031] Figure 11 Partial perspective view of the aspiration catheter according to other embodiments of the present invention;

[0032] Figure 12 Partial perspective view of the aspiration catheter according to an embodiment of the present invention (a part of the outer tube is hidden);

[0033] Figure 13 Partial cross-sectional view of the aspiration catheter according to an embodiment of the present invention;

[0034] Figure 14 is Figure 11 The enlarged view of part A in Detailed implementation manners

[0035] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying 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.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0037] In order to more clearly describe the structure of the present application, the terms "proximal end" and "distal end" are defined herein as 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 cardiac end" and "distal cardiac end" are defined herein as commonly used terms in the field of interventional medicine. Specifically, the "proximal cardiac end" refers to the end closer to the heart after the medical device is implanted into the human body, and the "distal cardiac end" refers to the end farther from the heart after the medical device is implanted into the human body. The "axial direction" represents its length direction, and the "radial direction" represents the direction perpendicular to the "axial direction".

[0038] Embodiment 1

[0039] As Figure 1 shown, this embodiment provides an aspiration catheter 100, which includes: a polymer tube 110 and a support tube 120 provided in the wall of the polymer tube 110;

[0040] As Figure 2As shown, the support tube 120 includes a first support ring 122, a plurality of support rods 121 and at least one tightening ring 123; the plurality of support rods 121 extend in a direction parallel to the longitudinal center axis of the suction catheter 100 and are circumferentially spaced and arranged outside the first support ring 122; the support rod 121 includes a proximal section 1211, an intermediate section 1212 and a distal section 1213 connected in sequence, the proximal section 1211 and the intermediate section 1212 are located on the proximal side of the first support ring 122, the distal section 1213 is located on the distal side of the first support ring 122, and the tightening ring 123 is at the intermediate section 1212 and sleeved outside the plurality of support rods 121;

[0041] In a natural state, the tightening ring 123 has a tendency to shrink radially inwards.

[0042] In this embodiment, the polymer tube 110 is made of a highly elastic material such as thermoplastic polyurethane (TPU), polyurethane (PU), nylon, etc., and the polymer tube 110 deforms as the support tube 120 deforms. The tightening ring 123 is made of a memory metal material and is heat-treated to obtain an original diameter d1, that is, the tightening ring 123 has an original diameter d1 when not subjected to external force. The cross-section of the support rod 121 can be circular, elliptical, rectangular or other shapes, and the present invention does not limit the cross-sectional shape of the support rod 121.

[0043] 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 2 As shown, when the suction catheter 100 is in a natural state (no distal blockage occurs), the support rods 121 do not deform due to their own strength. At the same time, the tightening rings 123 sleeved outside the plurality of support rods 121 are stretched to have an expanded diameter D1, and D1 is greater than d1. Therefore, when the suction catheter 100 is in a natural state, due to the contraction force of the tightening ring 123 itself, the tightening ring 123 has a tendency to tighten from diameter D1 to diameter d1. Figure 1 As shown, the tightening ring 123 is cut off along the straight line P to obtain Figure 3 The suction catheter segment shown, Figure 3 The tightening ring 123 of the suction catheter section loses the supporting force of the support rod 121 and is tightened to a diameter of d1 under its own contraction force.

[0044] When the distal end of the suction catheter 100 is blocked by a thrombus, Figure 4As shown, 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 bent and deformed inwardly under the tightening force and negative pressure of the tightening ring 123. Since the first support ring 122 does not deform, 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 thus be smoothly sucked away.

[0045] When the diameter of the tightening ring 123 is tightened to the original diameter d1, the tightening ring 123 needs to overcome its own elastic force and the supporting force of the support rod 121 to continue tightening, so that the middle section 1212 of the support rod 121 can be prevented from further collapsing inward, thereby preventing the suction catheter 100 from completely collapsing and clogging. 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.

[0046] like Figure 4 and Figure 5 As shown, in this embodiment, the tightening ring 123 includes a plurality of circumferentially arranged V-shaped structures 1231. The plurality of circumferentially connected V-shaped structures 1231 can enable the tightening ring 123 to expand or contract under the action of an external force.

[0047] In other embodiments, Figure 5 The support tube 120a shown in the figure, the tightening ring 123a adopts another structure. Figure 6 As shown, the tightening ring 123a has two open ends 1231a, and the two open ends 1231a can move relative to each other. When the tightening ring 123a is stretched open, the two open ends 1231a move away from each other.

[0048] In other embodiments, the tightening ring is made of elastic material, such as rubber, silicone, etc. When the distal end of the suction catheter is blocked by a thrombus, the sum of the elastic force of the tightening ring itself and the pressure from outside the suction catheter is greater than the supporting force of the support rod, and the tightening ring is tightened under the action of its own elastic force, thereby bending the middle section of the support rod.

[0049] In this embodiment, review Figure 2, the support tube 120 further includes at least one first expansion ring 124, the first expansion ring 124 is located at the distal side of the first support ring 122 and the distal end section 1213 of the plurality of support rods 121 is located outside the first expansion ring 124; in a natural state, the first expansion ring 124 has a tendency to expand radially outward. The first expansion ring 124 is made of a memory metal material and is heat-treated to obtain an original diameter d2, that is, the first expansion ring 124 has an original diameter d2 when not subjected to external force. The suction catheter 100 of the present invention is connected to a negative pressure generating device to absorb thrombus in a blood vessel. When the suction catheter 100 is in a natural state (no distal blockage occurs), the support rod 121 does not deform due to its own strength, and the distal end section 1213 of the support rod 121 does not rise. At the same time, the first expansion ring 124 surrounded by the plurality of support rods 121 is tightened under the extrusion of the plurality of support rods 121 and has a compressed diameter D2, and D2 is smaller than d2. Therefore, when the suction catheter 100 is in a natural state, due to the expansion force of the first expansion ring 124 itself, the first expansion ring 124 has a tendency to expand from the diameter D2 to the diameter d2. Figure 1 As shown, the tightening ring and the first expansion ring 124 are cut off along the straight line Q to obtain Figure 8 The suction catheter segment shown, Figure 8 The first expansion ring 124 of the suction catheter section loses the restraining force of the support rod 121 and expands to a diameter of d2 under its own expansion force.

[0050] When the distal end of the suction catheter 100 is blocked by a thrombus, Figure 4 As shown, 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 bent inwardly under the contraction force and negative pressure of the tightening ring 123. Since the first support ring 122 does not deform, the support rod 121 rotates with the first support ring 122 as a fulcrum, and the expansion force of the first expansion ring 124 assists the distal section 1213 of the support rod 121 to tilt outward.

[0051] In this embodiment, the first expansion ring 124 includes a plurality of V-shaped structures arranged along the circumferential direction. The plurality of circumferentially connected V-shaped structures can enable the first expansion ring 124 to expand or contract under the action of an external force.

[0052] In other embodiments, review Figure 6 The first expansion ring 124 has two open ends, and the two open ends can move relative to each other. When the first expansion ring 124 is expanded, the two open ends move away from each other.

[0053] Replay Figure 2, in this embodiment, the support tube 120 further includes at least one second expansion ring 125, the second expansion ring 125 is located on the distal side of the first expansion ring 124 and the distal segments 1213 of the plurality of support rods 121 are located outside the second expansion ring 125; in the natural state, the second expansion ring 125 has a tendency to expand radially outward, and the diameter of the second expansion ring 125 is greater than the diameter of the first expansion ring 124 when no external force is applied. Therefore, when the distal end of the aspiration catheter 100 expands, the diameter of the second expansion ring 125 is larger than that of the first expansion ring 124, and the distal end of the aspiration catheter 100 is in the shape of a horn with a far larger diameter at the distal end and a smaller diameter at the proximal end, which is beneficial for thrombus to enter the aspiration catheter 100.

[0054] In other embodiments, such as Figure 9 shown, the support tube 120b only has the tightening ring 123b and does not have the first expansion ring or the second expansion ring.

[0055] Looking back Figure 2 , the support tube 120 further includes a second support ring 126, the second support ring 126 is coaxially arranged with the first support ring 122; the proximal segment 1211 is located on the proximal side of the second support ring 126, and the middle segment 1212 is located on the distal side of the second support ring 126. Due to the presence of the second support ring 126, when the middle segment 1212 undergoes elastic deformation, the second support ring 126 functions to prevent the proximal segment 1211 from sinking inwardly with the middle segment 1212, so that the aspiration catheter 100 maintains its original pipe diameter at the position of the proximal segment 1211, and thus the aspirated thrombus can smoothly reach the proximal end of the aspiration catheter 100. And the support rod 121 is simultaneously placed outside the first support ring 122 and the second support ring 126 to prevent the middle segment 1212 located between the first support ring 122 and the second support ring 126 from collapsing when the aspiration catheter 100 is in the natural state. The proximal segment 1211 and the second support ring 126 can be fixedly connected by welding, bonding, etc., or can be fixed by wrapping the proximal segment 1211 and the second support ring 126 with the polymer tube 110.

[0056] In this embodiment, in the natural state, the distal segment 1213 is parallel to the central axis of the aspiration catheter 100.

[0057] In other embodiments, such as Figure 10The shown support tube 120c, in its natural state, the distal segment 1213c gradually approaches the central axis of the support tube 120c in the proximal-to-distal direction. Therefore, in its natural state, the distal opening of the distal segment 1213c converges inwards. 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.

[0058] As Figure 11 shown, in other embodiments, the polymer tube of the aspiration catheter 100d includes a body segment 111d, a contraction segment 112d, and an expansion segment 113d; the body segment 111d corresponds to the proximal segment, the contraction segment 112d corresponds to the intermediate segment, and the expansion segment 113d corresponds to the distal segment. That is, the expansion segment 113d is located on the distal side of the first support ring 122d, the contraction segment 112d is located between the first support ring 122d and the second support ring 126d, and the body segment 111d is located on the proximal side of the second support ring 126d. (For ease of understanding, the first support ring 122d and the second support ring 126d are shown in the attached Figure 9 figure in dashed lines to show the positional relationship of the body segment, the contraction segment, and the expansion segment; the support rod, the tightening ring, the first expansion ring, and the second expansion ring are not shown in the attached Figure 9 figure.)

[0059] The expansion segment 113d has an unfolded state and a folded state. When the distal end of the support rod expands outwards, the expansion segment 113d changes from the folded state to the unfolded state. Since the distal end of the support rod does not expand outwards, the expansion segment 113d is in the folded state, that is, the expansion segment 113d has a certain margin for circumferential expansion to avoid generating resistance to the support rod when the distal end of the support rod expands outwards.

[0060] As Figure 12 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 13 and Figure 14 shown, the polymer tube 110 has a separation region 116 and a bonding region 117 other than the separation region; in the axial direction of the aspiration catheter 100, the width of the separation region 117 is greater than the width of the first support ring 122, and the separation region 116 covers the first support ring 122; in the separation region 117, the inner layer tube 114 and the outer layer tube 115 are separated, and in the bonding region 116, the inner layer tube 114 and the outer layer tube 115 are bonded together to fix the support rod 121.

[0061] Within the separation region, the inner tube 114 and the outer 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.

[0062] Within the bonding region 117, the inner tube 114 and the outer tube 115 are bonded (for example, the inner tube 114 and the outer tube 115 are bonded by means of high-temperature pressing). The positions of the plurality of support rods 121 are relatively fixed to prevent the support rods 121 from sliding circumferentially along the first support ring 122 during deformation.

[0063] In this embodiment, the width of the separation region 116 is 1.5 times 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.

[0064] 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 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.

[0065] The above-described embodiments merely represent several implementation manners of the present invention. The description 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 modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should 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, a plurality of support rods, and at least one tightening ring; the plurality of support rods extend in a direction parallel to the longitudinal central axis of the aspiration catheter and are circumferentially spaced apart outside the first support ring; 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 tightening ring is at the intermediate section and sleeved outside the plurality of support rods; In the natural state, the tightening ring has a tendency to radially contract inward.

2. The aspiration catheter according to claim 1, wherein The tightening ring includes a plurality of V-shaped structures arranged circumferentially; or the tightening ring has two open ends that can move relative to each other.

3. The aspiration catheter according to claim 1, wherein The support tube further includes at least one first expansion ring, the first expansion ring is located on the distal side of the first support ring and the distal sections of the plurality of support rods are located outside the first expansion ring; In the natural state, the first expansion ring has a tendency to radially expand outward.

4. The aspiration catheter according to claim 3, wherein The support tube further includes at least one second expansion ring, the second expansion ring is located on the distal side of the first expansion ring and the distal sections of the plurality of support rods are located outside the second expansion ring; In the natural state, the second expansion ring has a tendency to radially expand outward, and the diameter of the second expansion ring is greater than the diameter of the first expansion ring when no external force is applied.

5. The aspiration catheter according to claim 3, wherein The expansion ring includes a plurality of V-shaped structures arranged circumferentially; or the expansion ring has two open ends that can move relative to each other.

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

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

8. The aspiration catheter according to claim 1, wherein In the natural state, the distal section gradually approaches the 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 section, the expansion section is located on the distal side of the first support ring; The expansion section has an unfolded state and a folded state, and when the distal end of the support rod expands outward, the expansion section 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 axial 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 attached to fix the support rod.

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