Interventional sheath tube with far-end girdling function

Abstract

The invention relates to an intervention sheath tube with a far-end ring cutting function, which belongs to the field of medical equipment and comprises a ring cutting head, a tube body and a transfusion assembly. The girdling head is arranged on one side of the pipe body, and the pipe body comprises an outer pipe and an inner pipe which are coaxially connected in a sleeved mode. A liquid conveying assembly is arranged between the outer pipe and the inner pipe, a first liquid conveying hole communicated with the liquid conveying assembly is formed in the area, away from the girdling head, of the outer side of the outer pipe, a liquid conveying pipe communicated with the first liquid conveying hole is arranged outside the pipe body, and the tail end of the liquid conveying pipe is connected with a stop valve. A second infusion hole communicated with the infusion assembly is formed in the area, close to the girdling head, of the inner side of the inner pipe. The infusion assembly is integrated in the tube body, the infusion assembly effectively exhausts gas through the expanded inlet end liquid collecting cavity and the expanded outlet end liquid collecting cavity at the two ends, and the potential safety hazard that the gas is input into the blood vessel is eliminated.

Description

Technical Field

[0001] This invention belongs to the field of medical devices, specifically relating to an interventional sheath with distal circumferential resection function. Background Technology

[0002] In interventional vascular surgery, the interventional sheath, as one of the core instruments, primarily functions to establish a channel between the blood vessel and external instruments, providing guidance and support for the advancement and manipulation of interventional devices such as catheters and guidewires. It also ensures the smooth execution of procedures such as intravenous infusion and drug administration, significantly impacting the safety and effectiveness of the surgery. With the continuous development of interventional vascular treatment technologies, clinicians have placed higher demands on the adaptability, connection reliability, operational safety, and flexibility of interventional sheaths.

[0003] Currently, the connection between the circumferential tip and the body of interventional sheaths is mostly achieved through simple sleeve or adhesive bonding, without a dedicated reinforcing structure. This results in insufficient connection strength, making them prone to loosening or even detachment during surgical instrument advancement and traction. Furthermore, the junction between the circumferential tip and the body often exhibits a significant abrupt change in diameter, forming a step-like structure. This structure generates considerable resistance during instrument advancement, increasing the difficulty of the procedure and easily scraping or damaging the vessel wall, leading to complications such as vasospasm and bleeding.

[0004] Meanwhile, existing interventional sheaths typically have a hemostatic valve at the end furthest from the circumferential infusion head, connected to the infusion tubing via a hemostatic valve connector. A three-way stop valve at the end of the tubing connects to external medications and irrigation solutions. Due to the length of the infusion tubing and the lack of targeted venting optimization in the infusion channel, air cannot be completely expelled from the tubing and infusion channel during pre-infusion filling or intraoperative opening of the stop valve and hemostatic valve. This air can easily enter the patient's blood vessels with the medication, causing serious and potentially fatal complications such as air embolism, severely threatening the patient's life. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide an interventional sheath with distal circumferential cutting function. The present invention integrates an infusion assembly inside the tube body. The infusion assembly effectively discharges gas through the inlet collection chamber and the outlet collection chamber that are expanded at both ends, thus eliminating the safety hazard of gas entering the blood vessel.

[0006] The technical solution adopted by this invention to solve its existing problems is: An interventional sheath with distal circumferential cutting function includes a circumferential cutting head, a tube body, and an infusion assembly; A circumferential cutting head is disposed on one side of the tube body, which includes an outer tube and an inner tube coaxially sleeved together. An infusion assembly is provided between the outer tube and the inner tube. A first infusion hole, which is connected to the infusion assembly, is provided on the outer side of the outer tube away from the circumcision head. An infusion tube, which is connected to the first infusion hole, is provided on the outer side of the tube body. A shut-off valve is connected to the end of the infusion tube. A second infusion hole, which is connected to the infusion assembly, is provided on the inner side of the inner tube near the circumcision head.

[0007] Furthermore, the infusion assembly includes an annular inlet collection chamber and an outlet collection chamber, with the inlet collection chamber and the outlet collection chamber connected by several infusion pipes. The inlet end collection chamber has an inlet through hole that is connected to the first inlet hole on its side wall, and the outlet end collection chamber has a outlet through hole that is connected to the second inlet hole.

[0008] Furthermore, plugs are inserted inside the second infusion port and the drainage through-hole. A pull rope is connected to the area where the plug leaks into the inner tube, and the end of the pull rope passes through the tube body away from the circumferential cutting head.

[0009] Furthermore, a connecting assembly is provided at the end of the tube body away from the circumferential cutting head. The connecting assembly includes an upper cover, a coaxially sleeved outer sleeve and an inner sleeve, a spring cavity, and an outer connecting pipe. The end of the tube is inserted between the outer sleeve and the inner sleeve. The ends of the outer sleeve and the inner sleeve are fixedly connected to the top cover. The spring cavity is coaxially connected to the top cover. The spring cavity is coaxially provided with a sliding plate and a spring. The spring is located on the side of the sliding plate facing away from the ring cut head. The sliding plate is fixed with a pull rod. The end of the pull rod passes through to the outside of the connecting component. The end of the pull rope passes through the inside of the spring cavity and is connected to the slide plate; The outer tube is connected to the first infusion port on the outer tube.

[0010] Furthermore, a connecting pipe is provided between the outer tube and the infusion tube. A retaining ring is protruding in the middle of the outer wall of the connecting pipe. The connecting pipes on both sides of the retaining ring are respectively inserted into the outer tube and the infusion tube. The end of the connecting pipe connected to the outer tube is inserted into the inlet end collection chamber through the inlet through hole. The connecting pipe located inside the inlet end collection chamber is provided with several side through holes arranged radially.

[0011] Furthermore, at least one plug is provided on the inner wall of the inner tube, two of which are symmetrically arranged around their axis and fixedly connected to the inner tube. The end of the pull rope connected to the plug passes through the slide plate and the connecting assembly, is placed outside the connecting assembly, and is fixedly connected to the first pull ring.

[0012] Furthermore, the circumferential cutting head includes a circumferential cutting portion and an insertion portion that are coaxially connected; The end of the circumferential cutting section opposite to the insertion section is provided with a ring-shaped cutting edge; The inner diameter of the insertion part is larger than the inner diameter of the circumferential cutting part, and the outer diameter is smaller than the outer diameter of the circumferential cutting part. The insertion part is provided with several adhesive through holes arranged radially thereon.

[0013] Furthermore, the insertion part of the circumferential cutting head is inserted between the outer tube and the inner tube, with the outer diameter of the circumferential cutting part being the same as the outer diameter of the outer tube, and the inner diameter of the circumferential cutting part being the same as the inner diameter of the inner tube.

[0014] Furthermore, the cutting edge of the circumferential cut is either flat or beveled.

[0015] Furthermore, a stainless steel wire braided layer is provided between the outer tube and the inner tube.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) In the infusion assembly between the outer tube and the inner tube, in conjunction with the pre-filling drug solution process, the infusion channel can be completely filled with drug solution, and the internal air can be completely expelled, thus avoiding the risk of gas in the infusion tube entering the blood vessels with the infusion in the existing technology.

[0017] (2) During infusion, the medicine can be discharged simply by pulling the lever to remove the blockage, which is convenient to operate; the discharge end collection chamber has a large volume and is connected to multiple delivery tubes, ensuring that air can be squeezed into the inlet end collection chamber during infusion, thus ensuring the pre-filling and venting effect; the side through hole design at the end of the connecting tube effectively avoids the outlet channel from being blocked, ensuring smooth infusion; the retaining ring structure can accurately determine the insertion position of the connecting tube, ensuring the reliability of the infusion assembly connection.

[0018] (3) At least three plugs are set on the inner wall of the inner tube. Two of the plugs are symmetrically fixed and are equipped with a pull rope and a first pull ring structure. By pulling the first pull ring, the direction of the circumferential cutting head can be changed, which meets the adjustment needs of the circumferential cutting head orientation during surgery and improves the flexibility and precision of operation.

[0019] (4) The circumferential cutting head is connected to the tube body via a combination of insertion and heat fusion processes, achieving an embedded semi-enclosed connection. During heat fusion, the tube body material fills the adhesive through-hole to form a snap-fit ​​unit, while directly bonding the outer and inner tubes, significantly enhancing the connection strength between the circumferential cutting head and the tube body. There is no abrupt change in diameter at the junction of the circumferential cutting head and the tube body, forming a smooth and continuous outer surface transition, which ensures the cutting function and avoids resistance caused by steps or additional damage to the vessel wall during instrument pushing.

[0020] (5) The circumferential cutting head is made of stainless steel or nickel-titanium alloy rigid ring. The circumferential cutting head supports two forms: flat and oblique. The flat cut forms a complete circular incision, which is suitable for rotary cutting and propulsion scenarios. The oblique cut increases the puncture force and the ability to wedge into stenotic lesions, which can meet the needs of different application scenarios. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] Figure 1 This is a diagram of the interventional sheath structure. Figure 2 This is a first structural diagram of an interventional sheath with distal circumferential cutting function according to the present invention. Figure 3 for Figure 2 sectional view, Figure 4 for Figure 3 Enlarged view of a portion of point A in the middle. Figure 5 for Figure 3 Enlarged view of a section at point B in the middle. Figure 6 This is a cross-sectional view of the connection between the interventional sheath body and the circumcision head, which has a distal circumcision function according to the present invention. Figure 7 This is a cross-sectional view of the connection between the interventional sheath body with distal circumferential cutting function and the discharge end collection chamber according to the present invention. Figure 8 This is a first structural diagram of the ring cutter in this invention. Figure 9 This is a second structural diagram of the ring cutter in this invention. Figure 10 This is a structural diagram of an infusion assembly with distal circumferential cutting function in an interventional sheath according to the present invention. Figure 11 This is a structural diagram of an interventional sheath control assembly with distal circumferential cutting function according to the present invention. Figure 12 This is a structural diagram of a connecting tube in an interventional sheath with distal circumferential cutting function according to the present invention. Figure 13 This is a second structural diagram of an interventional sheath with distal circumferential cutting function according to the present invention. Figure 14 for Figure 13 sectional view, Figure 15 for Figure 14 Enlarged view of a section at point C. Figure 16 This is a third structural diagram of an interventional sheath with distal circumferential cutting function according to the present invention.

[0023] In the diagram: 1-ring cut, 101-insertion part, 102-adhesive through hole, 2-tube body, 201-outer tube, 202-inner tube, 3-infusion assembly, 301-inlet end collection chamber, 302-infusion tube, 303-outlet end collection chamber, 304-inlet through hole, 305-outlet through hole, 4-block, 5-pull rope, 501-first pull ring, 6-slide plate, 7-pull rod, 701-second pull ring, 8-connecting assembly, 801-top cover, 802-outer sleeve, 803-inner sleeve, 804-spring cavity, 805-outer tube, 806-connecting rod, 807-guide plate, 808-accessory connecting tube, 9-spring, 10-connecting tube, 1001-stop ring, 1002-side through hole, 11-infusion tube, 12-stop valve. Detailed Implementation

[0024] The attached figure shows a preferred embodiment of an interventional sheath with distal circumferential cutting function. The invention will be further described in detail below with reference to the attached figure.

[0025] Depend on Figures 1 to 16 As shown, an interventional sheath with distal circumcision function includes a circumcision head and a sheath body 2.

[0026] The circumferential cutting head is constructed entirely of a rigid ring made of stainless steel or nickel-titanium alloy, comprising a coaxially connected circumferential cutting section 1 and an insertion section 101. The end of the circumferential cutting section 1 facing away from the insertion section 101 has an annular cutting edge. To suit different application scenarios, the cutting edge of the circumferential cutting section 1 can be flat or beveled. A flat edge means the end face of the cutting edge is perpendicular to the axis, forming a complete circular incision, suitable for rotary cutting and advancement; a beveled edge means the end face of the cutting edge is at an angle, inclined to the axis, increasing puncture force and the ability to wed into stenotic lesions.

[0027] The inner diameter of the insertion part 101 is larger than the inner diameter of the circumferential cutting part 1, and the outer diameter is smaller than the outer diameter of the circumferential cutting part 1. The insertion part 101 is provided with a plurality of adhesive through holes 102 arranged radially thereon.

[0028] With the insertion part 101, the circumferential cutting head is connected to the tube body 2 through a semi-enclosed and embedded manner. The insertion part 101 is inserted between the outer tube 201 and the inner tube 202 of the tube body 2, and then the tube body 2 and the insertion part 101 are tightly bonded through a heat fusion process. The adhesive through hole 102 can be blocked by the material flow during the heat fusion process of the tube body 2, thus forming a snap-fit ​​unit and directly bonding the outer tube 201 and the inner tube 202, increasing the connection strength between the tube body 2 and the insertion part 101.

[0029] The tube body 2 includes an outer tube 201 and an inner tube 202 that are coaxially sleeved together. Both the outer tube 201 and the inner tube 202 are made of transparent plastic, such as polytetrafluoroethylene, and a 304 stainless steel wire braided layer is provided between the outer tube 201 and the inner tube 202.

[0030] The insertion portion 101 of the circumferential cutting head is inserted between the outer tube 201 and the inner tube 202. The outer diameter of the circumferential cutting portion 1 is the same as the outer diameter of the outer tube 201, and the inner diameter of the circumferential cutting portion 1 is the same as the inner diameter of the inner tube 202. At the junction of the circumferential cutting portion 1 and the tube body 2, there is no obvious abrupt change in diameter, forming a smooth and continuous outer surface transition. This almost integrated design ensures the cutting function while avoiding resistance caused by steps or additional damage to the blood vessel wall during instrument advancement.

[0031] Existing interventional sheaths used in vascular interventional procedures have a hemostatic valve at the end furthest from the circumferential cutting head. The connector of the hemostatic valve is connected to an infusion tubing 11, and a three-way shut-off valve 12 is located at the end of the infusion tubing 11. The shut-off valve 12 connects to external medications and flushing solutions, allowing medications or flushing solutions to be injected into the tubing body 2 through the infusion tubing 11 and the hemostatic valve. Because the infusion tubing 11 is of a certain length, when the shut-off valve 12 and the hemostatic valve are opened, gas inside the infusion tubing 11 can easily enter the blood vessel through the interventional sheath.

[0032] To address this issue, in this embodiment, an infusion assembly 3 is provided between the outer tube 201 and the inner tube 202. A first infusion hole, which is connected to the infusion assembly 3, is provided on the outer side of the outer tube 201 away from the circumcision head. An infusion tube 11, which is connected to the first infusion hole, is provided on the outside of the tube body 2. A shut-off valve 12 is connected to the end of the infusion tube 11. A second infusion hole, which is connected to the infusion assembly 3, is provided on the inner side of the inner tube 202 near the circumcision head.

[0033] The infusion assembly 3 includes an annular inlet collection chamber 301 and an outlet collection chamber 303, which are connected by several infusion pipes 302. The inlet end collection chamber 301 has an inlet through hole 304 that is connected to the first inlet hole on its side wall, and the outlet end collection chamber 303 has a outlet through hole 305 that is connected to the second inlet hole.

[0034] The second infusion port and the drainage through-hole 305 are fitted with a plug 4. The area where the plug 4 leaks into the inner tube 202 is connected to a pull rope 5. The end of the pull rope 5 passes through the end of the tube body 2 away from the annular cutting head.

[0035] The tube body 2 is provided with a connecting component 8 at the end away from the circumferential cutting head. The connecting component 8 includes an upper cover 801, a coaxially sleeved outer tube 802 and an inner tube 803, a spring cavity 804 and an outer tube 805.

[0036] The end of the tube 2 is inserted between the outer sleeve 802 and the inner sleeve 803. The ends of the outer sleeve 802 and the inner sleeve 803 are fixedly connected to the upper cover 801. The spring cavity 804 is coaxially connected to the upper cover 801. The spring cavity 804 is coaxially provided with a slide plate 6 and a spring 9. The spring 9 is located on the side of the slide plate 6 facing away from the ring cutter. The slide plate 6 is fixed with a pull rod 7. The end of the pull rod 7 passes through to the outside of the connecting assembly 8 and is fixedly connected with a second pull ring 701.

[0037] The upper cover 801 seals one end of the outer sleeve 802 and the inner sleeve 803. An accessory connecting tube 808, which communicates with the interior of the tube body 2, is provided on the upper cover 801. The axis of the accessory connecting tube 808 is arranged parallel to or inclined to the axis of the tube body 2. The end of the accessory connecting tube 808 has a threaded opening, covered with a cap that is threadedly connected to it. Opening the cap allows connection of other surgical instruments via the accessory connecting tube.

[0038] The end of the pull rope 5 passes through the inside of the spring cavity 804 and is connected to the slide plate 6. To guide the pull rope 5, a guide plate 807 is coaxially fixed to the inside of the upper cover 801 via a connecting rod 806. The guide plate 807 has the same number of through holes as the pull rope 5, arranged in a circular array around its axis. The pull rope 5 passes through the through holes, and the entrance of the through holes is chamfered. The pull rope 5 passing through the through holes is arranged parallel to the axis of the spring cavity 804.

[0039] Driven by the spring 9, the slide plate 6 is located on the side of the spring cavity 804 near the blockage 4, and the pull rope 5 is in a slack state, effectively avoiding accidental operation or scratches that could prematurely open the blockage 4.

[0040] The outer tube 805 is connected to the first infusion port on the outer tube 201. A connecting tube 10 is provided between the outer tube 805 and the infusion tube 11. A retaining ring 1001 protrudes from the middle of the outer wall of the connecting tube 10. The connecting tubes 10 on both sides of the retaining ring 1001 are respectively inserted into the outer tube 805 and the infusion tube 11. The end of the connecting tube 10 connected to the outer tube 805 is inserted into the inlet end collection chamber 301 through the inlet through hole 304. The connecting tube 10 located inside the inlet end collection chamber 301 is provided with a plurality of side through holes 1002 arranged radially thereon.

[0041] The retaining ring 1001 determines whether the connecting pipe 10 inserted into the inlet end collection chamber 301 is in the correct position. When the retaining ring 1001 abuts against the outer pipe 805, the end of the connecting pipe 10 is inserted into the inlet end collection chamber 301, and the side through hole 1002 is located in the inlet end collection chamber 301. Liquid exits through the side through hole 1002, effectively preventing the connecting pipe 10 from being blocked and ensuring a smooth liquid outlet channel.

[0042] Before use, open the shut-off valve 12 and inject the medicine into the inlet end collection chamber 301 through the infusion tube 11 and the connecting tube 10. Then, the medicine is delivered to the outlet end collection chamber 303 through the delivery tube 302. Since the outlet end collection chamber 303 has a large volume and is connected to multiple delivery tubes 302, the air inside the outlet end collection chamber 303 will be squeezed into the inlet end collection chamber 301 through the delivery tubes 302 during the liquid injection process. The medicine fills the outlet end collection chamber 303, the delivery tubes 302 and the inlet end collection chamber 301 in sequence. When the infusion tube 11 is also filled, close the shut-off valve 12.

[0043] When intravenous infusion is required during surgery, simply pull out the lever 7, and the blockage 4 will be removed via the slide plate 6 and the pull rope 5, allowing the medication to be discharged and achieving the purpose of infusion.

[0044] Currently, most interventional sheaths have a fixed connection between the circumferential cutting tip and the sheath body, meaning the direction of the cutting tip cannot be adjusted according to surgical needs. In surgeries involving complex vascular lesions, such as tortuous or branching vessels, surgeons struggle to precisely adjust the orientation of the cutting tip to match the location and angle of the lesion. They can only achieve this by adjusting the overall direction of the interventional sheath's movement, which is difficult and inaccurate. This not only increases surgical time but can also lead to damage to the vessel wall due to excessive adjustment, reducing the safety and effectiveness of the procedure.

[0045] To allow adjustment of the direction of the circumferential cutting head, at least three plugs 4 are provided on the inner wall of the inner tube 202. Two of the plugs 4, which are symmetrically arranged around their axis, are fixedly connected to the inner tube 202 and cannot be detached. The end of the pull rope 5 connected to the plug 4 passes through the slide plate 6 and the connecting assembly 8 and is placed outside the connecting assembly 8. A first pull ring 501 is fixedly connected to it. By pulling the first pull ring 501, the direction of the circumferential cutting head is changed.

[0046] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. An interventional sheath with distal circumferential cutting function, characterized in that: It includes a circumferential cutting head, a tubing body (2), and an infusion assembly (3); A ring-cutting head is disposed on one side of the tube body (2), the tube body (2) including an outer tube (201) and an inner tube (202) coaxially sleeved together; An infusion assembly (3) is provided between the outer tube (201) and the inner tube (202). A first infusion hole is provided on the outer side of the outer tube (201) away from the circumcision head and is connected to the infusion assembly (3). An infusion tube (11) is provided on the outside of the tube body (2) and is connected to the first infusion hole. A shut-off valve (12) is connected to the end of the infusion tube (11). A second infusion hole is provided on the inner side of the inner tube (202) near the circumcision head and is connected to the infusion assembly (3).

2. The interventional sheath with distal circumferential cutting function according to claim 1, characterized in that: The infusion assembly (3) includes an annular inlet collection chamber (301) and an outlet collection chamber (303), and the inlet collection chamber (301) and the outlet collection chamber (303) are connected through several infusion pipes (302). The inlet end collection chamber (301) has an inlet through hole (304) that is connected to the first inlet hole on its side wall, and the outlet end collection chamber (303) has a outlet through hole (305) that is connected to the second inlet hole.

3. An interventional sheath with distal circumferential cutting function according to claim 2, characterized in that: The second infusion hole and the drain hole (305) are fitted with a plug (4). The area where the plug (4) leaks into the inner tube (202) is connected to a pull rope (5). The end of the pull rope (5) passes through the tube body (2) away from the ring cut head.

4. An interventional sheath with distal circumferential cutting function according to claim 3, characterized in that: The tube body (2) is provided with a connecting assembly (8) at one end away from the circumferential cutting head. The connecting assembly (8) includes an upper cover (801), a coaxially sleeved outer tube (802), an inner tube (803), a spring cavity (804), and an outer tube (805). The end of the tube body (2) is inserted between the outer sleeve (802) and the inner sleeve (803). The ends of the outer sleeve (802) and the inner sleeve (803) are fixedly connected to the top cover (801). The spring cavity (804) is coaxially connected to the top cover (801). The spring cavity (804) is coaxially provided with a slide plate (6) and a spring (9). The spring (9) is located on the side of the slide plate (6) facing away from the ring cut head. The slide plate (6) is fixed with a pull rod (7). The end of the pull rod (7) passes through to the outside of the connecting assembly (8). The end of the pull rope (5) passes through the inside of the spring cavity (804) and is connected to the slide plate (6); The outer tube (805) is connected to the first infusion hole on the outer tube (201).

5. An interventional sheath with distal circumferential cutting function according to claim 4, characterized in that: A connecting pipe (10) is provided between the outer tube (805) and the infusion tube (11). A retaining ring (1001) is protruding in the middle of the outer wall of the connecting pipe (10). The connecting pipes (10) on both sides of the retaining ring (1001) are respectively inserted into the outer tube (805) and the infusion tube (11). The end of the connecting pipe (10) connected to the outer tube (805) is inserted into the inlet end collection chamber (301) through the inlet through hole (304). The connecting pipe (10) located inside the inlet end collection chamber (301) is provided with a number of side through holes (1002) arranged radially therein.

6. An interventional sheath with distal circumferential cutting function according to claim 4, characterized in that: The inner wall of the inner tube (202) is provided with at least 3 plugs (4), two of which are symmetrically arranged around their axis and are fixedly connected to the inner tube (202). The end of the pull rope (5) connected to the plug (4) passes through the slide plate (6) and the connecting assembly (8) is placed outside the connecting assembly (8) and is fixedly connected to the first pull ring (501).

7. An interventional sheath with distal circumferential cutting function according to any one of claims 1 to 6, characterized in that: The circumferential cutting head includes a circumferential cutting part (1) and an insertion part (101) connected coaxially. The annular cutting part (1) has an annular cutting edge at one end away from the insertion part (101); The inner diameter of the insertion part (101) is larger than the inner diameter of the circumferential cutting part (1), and the outer diameter is smaller than the outer diameter of the circumferential cutting part (1). The insertion part (101) is provided with a plurality of adhesive through holes (102) arranged radially thereon.

8. An interventional sheath with distal circumferential cutting function according to claim 7, characterized in that: The insertion part (101) of the ring cutter is inserted between the outer tube (201) and the inner tube (202). The outer diameter of the ring cutter (1) is the same as the outer diameter of the outer tube (201), and the inner diameter of the ring cutter (1) is the same as the inner diameter of the inner tube (202).

9. An interventional sheath with distal circumferential cutting function according to claim 7, characterized in that: The cutting edge of the circumferential cutting part (1) is flat or oblique.

10. An interventional sheath with distal circumferential cutting function according to claim 8 or 9, characterized in that: A 304 stainless steel wire braided layer is provided between the outer tube (201) and the inner tube (202).

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