A catheter having a releasable tip

Abstract

The application discloses a catheter with a releasable head end, comprising a releasable head end, a catheter and a pushing structure, the catheter has a tube cavity arranged along its axial direction; the releasable head end is axially slidably arranged in the distal end of the tube cavity, the releasable head end comprises a release head proximal end always arranged in the tube cavity and a release head distal end which can extend out of the distal end of the tube cavity, the pushing structure is axially slidably arranged in the catheter, the distal end of the pushing structure is in abutting engagement with the release head proximal end of the releasable head end, and the proximal end of the pushing structure extends out of the proximal end of the tube cavity, the release head distal end is a resilient structure and has a radial expansion performance, and the outer diameter of the release head distal end after radial expansion is greater than the diameter of the catheter. The application has small use limitation, can have a larger catheter caliber while occupying less catheter cavity, and can realize a larger embolus suction efficiency.

Description

[0001] The present application is a divisional application of the patent application with application number 202211000461.X and titled "Catheter with releasable head end" and with a filing date of August 19, 2022. TECHNICAL FIELD

[0002] The present application relates to the technical field of medical devices, in particular to the technical field of catheters with releasable head ends. BACKGROUND

[0003] Current common mechanical thrombectomy auxiliary devices include thrombectomy stents and suction catheters. Common suction catheters cooperate with suction pumps and connecting tubes for reperfusion after stent thrombectomy or drug thrombolysis, or use the ADAPT (Aspiration and Direct Antegrade Percutaneous Thrombectomy) technology to directly apply mechanical suction to the reperfusion catheter for thrombectomy. In order to achieve complete thrombus retrieval as much as possible, the blood vessel is completely interrupted, and the catheter has a large caliber and lumen, which can obtain high suction efficiency.

[0004] The invention patent with the authorized announcement number CN107205751B discloses a blood thrombus removal device, which includes a delivery catheter, a self-expandable funnel, and a suction funnel catheter. The device can use a larger port to suction the blood thrombus from a position very close to the blood thrombus, can occlude the artery and stop the flow, and can suction the entire blood thrombus without breaking the blood thrombus; however, the double-catheter structure sacrifices the inner diameter of the suction catheter to a certain extent, resulting in a loss of suction efficiency.

[0005] The invention patent with the application publication number CN111867495A discloses a clot removal device, which includes an expandable treatment member and a delivery wire, and can also be applied to capture thrombi in ischemic treatment, but does not have a safe release / retrieval method to ensure that it is released at the correct position in the blood vessel. SUMMARY

[0006] The purpose of the present application is to solve the problems in the prior art and to provide a catheter with a releasable head end, which can achieve high thrombus suction efficiency.

[0007] To achieve the above-mentioned purpose, the present application provides a catheter with a releasable head end, which includes a releasable head end, a catheter, and a pushing structure. The catheter has an inner lumen arranged along the axial direction. The releasable head end is axially slidably arranged in the distal end of the inner lumen. The releasable head end includes a release head proximal end that is always arranged in the inner lumen and a release head distal end that can be extended out of the distal end of the inner lumen. The pushing structure is axially slidably arranged in the catheter, and the distal end of the pushing structure is in abutting cooperation with the release head proximal end of the releasable head end, and the proximal end of the pushing structure is extended out of the proximal end of the inner lumen. The release head distal end is a flexible structure and has a radial expansion performance. The outer diameter of the release head distal end after radial expansion is greater than the diameter of the catheter.

[0008] As a preferred, the distal end of the catheter is provided with a stepped hole section with a diameter larger than the inner lumen of the catheter, the proximal end of the release head is slidably connected with the stepped hole section, and the length of the stepped hole section is greater than or equal to the length of the release head in the delivery state.

[0009] As a preferred, the distal end of the catheter and the distal end and / or proximal end of the release head are provided with a visualizing element.

[0010] As a preferred, the outer wall of the proximal end of the release head is provided with at least three convex points in contact with the inner lumen of the catheter or the outer wall of the proximal end of the release head is provided with a convex ring outwardly protruding.

[0011] As a preferred, the distal end of the inner lumen is provided with a constricted portion with a diameter smaller than the outer diameter of the convex ring to prevent the proximal end of the release head from being separated from the distal end of the inner lumen.

[0012] As a preferred, the inner wall of the distal end of the inner lumen is provided with a plurality of sliding grooves in sliding cooperation with the convex points, and the sliding grooves are closed at both ends.

[0013] As a preferred, the outer surface of the proximal end of the release head is provided with a first friction surface, and the opening of the distal end of the inner lumen is provided with a second friction surface for cooperating with the first friction surface to prevent the proximal end of the release head from being separated from the inner lumen.

[0014] As a preferred, the proximal end of the release head has a tendency to gradually expand outwardly from the distal end to the proximal end, and the maximum outer diameter of the proximal end of the release head in the free state is greater than the inner diameter of the distal end port of the inner lumen to prevent the proximal end of the release head from being separated from the catheter.

[0015] As a preferred, the pushing structure includes a pushing rod slidably arranged in the catheter and a stopper fixedly arranged at the distal end of the pushing rod, and the stopper is in abutting cooperation with the release head.

[0016] As a preferred, the pushing structure further includes a traction wire arranged in the catheter, the distal end of the traction wire is fixedly connected with the proximal end of the release head, and the proximal end of the traction wire extends to the outside of the proximal end of the catheter.

[0017] As a preferred, the pushing structure is slidably arranged in the inner lumen of the catheter or the inner wall of the catheter is provided with a pushing rod sliding hole matched with the pushing structure.

[0018] As a preferred, the distal end of the release head is a braided structure, and the distal end of the release head is in the shape of a claw, a cylinder, a funnel or a bell after radial expansion.

[0019] As a preferred, the distal end port of the catheter is provided with an elastic structure in interference cooperation with the distal end of the release head during suction.

[0020] The catheter with the releasable head end has the beneficial effects that: the releasable head end is slidably arranged at the distal end of the inner cavity of the tube, the releasable head end is not required to be delivered through an additional pipe, the use is more convenient, the delivery and release and recovery of the releasable head end can be realized by using a single catheter, the use is less limited, the catheter cavity is less occupied while having a larger diameter, and a larger embolus suction efficiency can be realized.

[0021] The features and advantages of the present application will be described in detail with examples in combination with the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a releasable head end delivery state structure schematic diagram of the catheter with the releasable head end according to the first embodiment of the present application.

[0023] Figure 2 is a releasable head end release state structure schematic diagram of the catheter with the releasable head end according to the first embodiment of the present application.

[0024] Figure 3 is Figure 1 B-B section structure schematic diagram in the middle.

[0025] Figure 4 is a catheter internal structure schematic diagram according to the second embodiment of the present application.

[0026] Figure 5 is a releasable head end release state structure schematic diagram of the catheter with the releasable head end according to the third embodiment of the present application.

[0027] Figure 6 is Figure 1 B-B section structure schematic diagram in the middle.

[0028] Figure 7 is a releasable head end release state structure schematic diagram according to the third embodiment.

[0029] Figure 8 is a catheter structure schematic diagram with a releasable head end according to the fourth embodiment of the present application.

[0030] Figure 9 is a catheter structure schematic diagram with a releasable head end according to the fifth embodiment of the present application.

[0031] Figure 10 is Figure 1 A-A section structure schematic diagram in the middle.

[0032] Figure 11 is a catheter structure schematic diagram with a releasable head end according to the fifth embodiment of the present application.

[0033] In the figure: 1-releasable head end, 2-catheter, 3-push structure, 101-releasing head distal end, 102-releasing head proximal end, 13-bump, 111-rail, 112-slots, 21-step hole section, 211-closing limit, 212-second friction surface, 301-stop block, 302-push rod, 303-pulling wire, 1011-first friction surface. DETAILED DESCRIPTION

[0034] In order to make the objects, technical solutions and advantages of the present application clearer, the following further describes the present application with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the scope of the present application. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present application.

[0035] In the description of the present application, it should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0036] In the description of the present application, it should be noted that the terms "center", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present application is used, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third", and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, "a plurality of" means two or more, unless otherwise explicitly and specifically limited. The meaning of "several" is one or more, unless otherwise explicitly and specifically limited.

[0037] In the description of the present application, it is also necessary to explain that, unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] Embodiment one:

[0039] Referring to Figure 1 , Figure 2 , the present application is a catheter with a releasable head end, comprising a releasable head end 1, a catheter 2 and a pushing structure 3, the catheter 2 has a lumen along its axial direction; the releasable head end 1 is axially slidably arranged in the distal end of the lumen, the releasable head end 1 comprises a release head proximal end 102 always arranged in the lumen and a release head distal end 101 which can be extended out of the distal end of the lumen, the pushing structure 3 is axially slidably arranged in the catheter 2, and the distal end of the pushing structure 3 is in contact with the release head proximal end 102 of the releasable head end 1, the release head distal end 101 is a flexible structure and has radial expansion performance, and the outer diameter of the release head distal end 101 after radial expansion is greater than the diameter of the catheter 2. In this embodiment, the releasable head end 1 is slidably arranged at the distal end of the lumen, without the need for additional pipeline to transport the releasable head end 1, which is more convenient to use, a single catheter 2 can realize the transportation, release and recovery of the releasable head end 1, the use is limited, and the catheter lumen is less occupied while having a larger diameter, which can realize larger thrombus extraction efficiency. In the delivery state, the releasable head end 1 is received in the distal end of the lumen, when delivered to a suitable position, the releasable head end 1 is pushed to the distal end by the pushing structure 3 until the release head distal end 101 is released outside the lumen, and the release head proximal end 102 is limited at the distal end of the lumen, and the release head distal end 101 is radially self-expanded or expanded by traction / balloon and the like. Thus, the thrombus can be directly extracted through the lumen and the releasable head end 1, and various auxiliary thrombectomy devices can be introduced into the lumen, and the release head distal end 101 can prevent thrombus escape.

[0040] Referring to Figure 1 , Figure 2 , the distal end of the lumen is provided with a stepped hole section 21 having a diameter greater than that of the lumen, the release head proximal end 102 is slidably connected with the stepped hole section 21, and the length of the stepped hole section 21 is greater than the length of the releasable head end 1 in the delivery state. The stepped hole section 21 is arranged to facilitate cooperation with the releasable head end 1, and the releasable head end 1 can be completely received in the stepped hole section 21 when it is retracted in the lumen, so as to avoid occupying the space of the lumen and maximize the extraction efficiency.

[0041] Referring to Figure 1, Figure 2 The distal end of the catheter 2 and the distal end and the proximal end of the releasable head 1 are provided with a visualizing element. The relative position of the releasable head 1 and the distal end opening of the catheter 2 can be positioned through the visualizing element, so as to avoid the releasable head 1 from being pushed too far and falling off.

[0042] Embodiment two:

[0043] Referring to Figure 3 , Figure 4 On the basis of the embodiment one, the outer wall of the proximal end 102 of the release head is provided with four convex points 13 which are in close contact with the inner wall of the lumen of the tube. The proximal end 102 of the release head can be in close contact with the inner wall of the lumen of the tube, so as to improve the stability and prevent falling off.

[0044] Referring to Figure 3 , Figure 4 The inner wall of the distal end of the lumen of the tube is provided with a plurality of sliding grooves 112 which are in sliding cooperation with the convex points 13. The sliding grooves 112 are closed at both ends. The convex points 13 and the sliding grooves 112 which are closed at both ends are cooperated to limit the proximal end 102 of the release head, so as to prevent the proximal end 102 of the release head from being separated from the distal end of the lumen of the tube and improve the safety.

[0045] Embodiment three:

[0046] Referring to Figure 5 , Figure 6 and Figure 7 On the basis of the embodiment one, the outer wall of the proximal end 102 of the release head is provided with a convex ring 14 which is outwardly protruding. The distal end of the stepped hole section 21 is provided with a limiting mechanism closing limiting part 211 which has a smaller diameter than the diameter of the proximal end 102 of the release head, so as to prevent the proximal end 102 of the release head from being separated from the stepped hole section 21. The limiting mechanism closing limiting part 211 can be cooperated with the outer ring of the proximal end 102 of the release head, so as to limit the proximal end 102 of the release head in the stepped hole section 21, and avoid the releasable head 1 from being separated from the catheter 2.

[0047] Embodiment four:

[0048] Referring to Figure 8 The outer surface of the proximal end 102 of the release head is provided with a first friction surface 1011 which is formed by coating, hot melting and surface treatment. The distal end opening of the lumen of the tube is provided with a second friction surface 212 which is used for cooperating with the first friction surface 1011 to prevent the proximal end 102 of the release head from being separated from the lumen of the tube. Through the friction cooperation of the first friction surface 1011 and the second friction surface 212, a larger friction force can be generated, so as to limit the proximal end 102 of the release head in the distal end of the lumen of the tube and avoid the proximal end 102 of the release head from being separated.

[0049] Embodiment five:

[0050] Referring to Figure 9The proximal end 102 of the release tip has a tendency to gradually expand outward from the distal end to the proximal end, and the maximum outer diameter of the proximal end 102 of the release tip in the free state is greater than the inner diameter of the distal port of the catheter 2. When the proximal end 102 of the release tip is inside the catheter 2, it can be closely attached to the inner wall of the catheter 2 to prevent the proximal end 102 of the release tip from detaching from the catheter 2.

[0051] Example 6:

[0052] See Figure 10 , Figure 11 The pushing structure 3 includes a pushing rod 302 slidably disposed within the catheter 2 and a stop block 301 fixedly disposed at the distal end of the pushing rod 302. The stop block 301 abuts against the releasable tip 1. The cross-section of the pushing rod 302 is an annular shape coaxial with the catheter 2. The pushing rod 302 drives the stop block 301 to move, thereby engaging with the releasable tip 1 and pushing the releasable tip 1 outside the catheter 2. In this embodiment, the cross-section of the pushing rod 302 is an annular shape coaxial with the catheter 2, meaning the pushing structure 3 is also a hollow tubular structure. This arrangement facilitates the delivery of other instruments through the pushing structure 3 without affecting the normal use of the catheter 2. The pushing structure 3 can be immediately withdrawn after pushing. In another optional embodiment, the cross-section of the pushing structure 3 can be a semi-annular shape coaxial with the catheter 2, and there can be multiple pushing structures 3.

[0053] See Figure 11 The pushing structure 3 also includes a traction wire 303 disposed in the catheter 2. The distal end of the traction wire 303 is fixedly connected to the proximal end 102 of the release head, and the proximal end extends to the outside of the proximal end of the catheter 2. When the release head 1 is in the release state and needs to be retracted, the release head 1 can be pulled back by the traction wire 303 until the release head 1 is retracted into the inner lumen of the catheter, which facilitates the retraction of the release head 1.

[0054] Preferably, the pushing structure 3 is slidably disposed within the inner cavity of the tube. In this embodiment, the pushing structure 3 is directly slidably disposed within the inner cavity of the tube, facilitating its removal and preventing it from interfering with suction. In another optional embodiment, a push rod sliding hole adapted to the pushing structure 3 can be provided on the inner wall of the catheter 2, and the pushing structure 3 can be slidably disposed within the push rod sliding hole. This arrangement separates the push rod sliding hole from the inner cavity of the tube, avoiding mutual interference.

[0055] Preferably, the distal end 101 of the release head has a woven structure, and the distal end 101 of the release head expands radially to take the shape of a claw, a cylinder, a funnel, or a bell.

[0056] Preferably, the releasable head 1 comprises a non-permeable membrane made of a biocompatible elastomer polymer.

[0057] Preferably, the proximal end 102 of the release head is in a converged state with the same structure as the distal end 101 of the release head, or in a other cylindrical structure or in a converged state with other materials.

[0058] Preferably, the distal end port of the catheter 2 is provided with an elastic structure, such as coating the distal end port of the catheter 2 with silicone, in the state of suction, the distal end of the release head 101 is tightly attached to the distal end port of the catheter 2 under the action of blood flow, and the elastic structure makes the distal end of the release head 101 and the distal end port of the catheter 2 have an interference fit, further avoiding leakage during suction.

[0059] The working process of the present application is as follows:

[0060] In the working process of the catheter with a releasable head end of the present application, in the delivery state, the releasable head end 1 is accommodated in the distal end of the lumen, the catheter 2 is delivered along the blood vessel, when delivered to the thrombus position, the releasable head end 1 is pushed to the distal end direction by the pushing structure 3, until the distal end of the release head 101 is released outside the lumen, the proximal end of the release head 102 is limited in the distal end of the lumen, the distal end of the release head 101 is self-expanded radially or expanded by auxiliary support such as traction / balloon, after the release head 101 is expanded, it can be attached to the inner wall of the blood vessel, so that the thrombus suction and thrombus escape prevention can be directly performed through the cooperation of the lumen and the releasable head end 1, and various auxiliary thrombectomy devices can be introduced into the lumen.

[0061] The above embodiments are descriptions of the present application, not limitations of the present application, and any simple transformation of the present application belongs to the protection scope of the present application.

Claims

1. A catheter with a releasable tip, comprising a releasable tip (1), a catheter (2) and a pushing structure (3), characterized in that: The catheter (2) has a tube cavity arranged along its axis; the releasable head end (1) is arranged axially in the distal end of the tube cavity, the releasable head end (1) comprises a release head proximal end (102) always arranged in the tube cavity and a release head distal end (101) which can extend out of the distal end of the tube cavity, the push structure (3) is arranged axially in the catheter (2), the distal end of the push structure (3) is in contact with the release head proximal end (102) of the releasable head end (1), and the proximal end of the push structure (3) extends out of the proximal end of the tube cavity, the release head distal end (101) is a flexible structure and has radial expansion performance, the outer diameter of the release head distal end (101) after radial expansion is greater than the diameter of the catheter (2), the outer surface of the release head proximal end (102) is provided with a first friction surface (1011), and the distal end opening of the tube cavity is provided with a second friction surface (212) for cooperating with the first friction surface (1011) to prevent the release head proximal end (102) from separating from the tube cavity; the distal end of the tube cavity is provided with a stepped hole section (21) with a diameter greater than that of the tube cavity, the release head proximal end (102) is slidably connected with the stepped hole section (21), and the length of the stepped hole section (21) is greater than the length of the releasable head end (1) in the delivery state; the outer wall of the release head proximal end (102) is provided with four convex points (13) which are in contact with the tube cavity, and the inner wall of the distal end of the tube cavity is provided with a plurality of sliding grooves (112) which are in sliding cooperation with the convex points (13), and the sliding grooves (112) are closed at both ends; the outer wall of the release head proximal end (102) is provided with a convex ring (14) which is outwardly convex, and the distal end of the stepped hole section (21) is provided with a closing limiting portion (211) with a diameter smaller than that of the release head proximal end (102) to prevent the release head proximal end (102) from separating from the stepped hole section (21).

2. A catheter having a releasable tip as in claim 1, wherein: The release head end proximal end (102) has a tendency to gradually expand outward from the distal end to the proximal end, and the maximum outer diameter of the release head end proximal end (102) in the free state is greater than the inner diameter of the distal end port of the tube cavity, so as to prevent the release head proximal end (102) from separating from the catheter (2).

3. A catheter having a releasable tip as in claim 1, wherein: The distal end of the catheter (2) and the distal end and / or proximal end of the releasable head end (1) are provided with a developing element.

4. A catheter having a releasable tip as in claim 1, wherein: The push structure (3) comprises a push rod (302) which is slidably arranged in the catheter (2) and a stop block (301) which is fixedly arranged at the distal end of the push rod (302), and the stop block (301) is in contact with the releasable head end (1).

5. A catheter having a releasable tip as in claim 1, wherein: The push structure (3) further comprises a traction wire (303) arranged in the catheter (2), the distal end of the traction wire (303) is fixedly connected with the release head proximal end (102), and the proximal end of the traction wire (303) extends to the outside of the proximal end of the catheter (2).

6. A catheter having a releasable tip as in claim 1, wherein: The distal end port of the catheter (2) is provided with a flexible structure which is in interference fit with the release head distal end (101) during suction.

7. A catheter having a releasable tip as in claim 1, wherein: The release head distal end (101) is a woven structure, and the release head distal end (101) is in the shape of a claw, a cylinder, a funnel or a bell after radial expansion.

8. A catheter having a releasable tip as in claim 1, wherein: The releasable tip (1) comprises a non-permeable membrane made of a biocompatible elastomeric polymer. The releasable tip (1) comprises a non-permeable membrane made of a biocompatible elastomeric polymer.

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