A covered stent system and methods of using the same

Abstract

The application discloses a covered stent system, which comprises a mandrel, a function tube, a self-expanding covered stent, and an outer sleeve tube; the mandrel is arranged in the function tube, and the mandrel comprises a mandrel body, a first developing ring and a first stent hook ring, wherein the first developing ring and the first stent hook ring are sequentially arranged at the front end of the mandrel body; the function tube comprises a tube body and a second stent hook ring, a second developing ring, a balloon developing ring, a dilating balloon and a function tube seat which are sequentially arranged on the tube body; the function tube seat is provided with a liquid injection port; one end of the self-expanding covered stent is connected with the first stent hook ring, and the other end is connected with the second stent hook ring; and the outer sleeve tube is arranged outside the self-expanding covered stent and the function tube. The application further provides a use method of the covered stent system. The application can be adapted to different diameter blood vessels, can avoid tearing the blood vessels, and does not need secondary dilating operation.

Description

Technical Field

[0001] This invention belongs to the field of medical devices, specifically relating to a covered stent system and its usage method. Background Technology

[0002] Intracranial aneurysms are abnormal bulges formed when local damage to the vessel wall of an intracranial artery, caused by congenital developmental abnormalities or acquired injury, leads to gradual dilation under hemodynamic load and other factors. Currently, surgical treatment for intracranial aneurysms mainly includes two methods: open craniotomy clipping and endovascular interventional therapy.

[0003] The principle of covered stent treatment for intracranial aneurysms is to implant a bio-physical barrier stent into the parent artery. While maintaining the patency of the parent artery, it isolates the aneurysm and causes internal thrombus formation, thereby achieving the goal of curing the lesion. It has significant advantages in treating wide-necked, giant, dissecting, or pseudoaneurysms without adjacent major branch vessels. The only currently available Willis covered stent is a balloon-expandable laser-engraved stent with an external suture membrane, composed of a cobalt-based alloy stent and a polytetrafluoroethylene membrane. This stent has the following problems: it cannot be adjusted and is not suitable for various blood vessels; incomplete stent deployment and inability to adjust can cause vascular tearing. This is because when the stent is placed in a significantly tortuous segment of the vessel, the balloon expansion straightens the tortuous vessel, causing tearing of the vessel wall or tearing and damage to the branch arteries in the area, leading to fatal bleeding; poor apposition requires a second dilation surgery. Summary of the Invention

[0004] The purpose of this invention is to provide a covered stent system and its method of use, which can be adapted to blood vessels of different diameters, avoids tearing of blood vessels, and eliminates the need for secondary dilation surgery.

[0005] The technical solution adopted in this invention is:

[0006] A covered stent system includes a mandrel, a functional tube, a self-expanding covered stent, and an outer tube;

[0007] The mandrel is placed inside the functional tube and extends out of the functional tube; the mandrel and the functional tube can move relative to each other along the axis; the mandrel includes a mandrel body, a first developing ring, and a first support hook, with the first developing ring and the first support hook sequentially located at the front end of the mandrel body;

[0008] The functional tube includes a tube body, a second support hook, a second imaging ring, a balloon imaging ring, a dilation balloon, and a functional tube seat; the second support hook is placed at the front end of the tube body, the functional tube seat is placed at the rear end of the tube body, the second imaging ring, the balloon imaging ring, and the dilation balloon are placed between the second support hook and the functional tube seat, and the functional tube seat is provided with an injection port.

[0009] One end of the self-expanding film-coated bracket is connected to the first bracket hook, and the other end is connected to the second bracket hook.

[0010] The outer sleeve is placed outside the self-expanding film-coated support and the functional tube, and can move along the functional tube.

[0011] According to the above scheme, there are two balloon imaging rings, which are placed on both sides of the dilating balloon.

[0012] According to the above scheme, the tail end of the outer tube is provided with an outer tube seat.

[0013] According to the above scheme, the first bracket hook and the second bracket hook respectively hook the braided loops at both ends of the self-expanding film-coated bracket.

[0014] According to the above scheme, both the first bracket hook and the second bracket hook include a hook body, a hook stop and teeth. The hook stop is placed at one end of the hook body and the tooth ring is located at the other end of the hook body.

[0015] According to the above scheme, the tail end of the mandrel body is provided with a mandrel seat.

[0016] The present invention also discloses a method for using the above-described covered stent system, which includes the following steps:

[0017] 1) Under the guidance of the first imaging ring, reach the target point and move the outer sleeve backward so that the self-expanding coated stent is only constrained by the first stent hook and the second stent hook.

[0018] 2) Slowly and steadily pull back the mandrel seat. The mandrel seat drives the mandrel body to move backward. The first bracket hook moves backward with the mandrel body, and the self-expanding film-coating bracket gradually expands.

[0019] 3) When the self-expanding covered stent expands to a certain extent, the first stent hook and the second stent hook disengage, and the self-expanding covered stent is placed at the affected area; the mandrel retracts to the limit position (when the first stent hook and the second stent hook are in contact); at this time, the self-expanding covered stent is completely released.

[0020] 4) Remove the mandrel, functional tube, and outer tube from the body.

[0021] According to the above scheme, in step 3), if the self-expanding covered stent does not expand to the required position, continue to move the outer tube backward until the dilation balloon is exposed, in preparation for assisted dilation.

[0022] Under the guidance of the balloon imaging ring, the dilation balloon is manipulated to the incompletely inflated self-expanding covered stent. Dilation fluid is injected into the infusion port to inflate the balloon, thereby assisting the self-expanding covered stent to fully expand and fit tightly against the blood vessel. The dilation fluid is then withdrawn to return the balloon to its initial state.

[0023] According to the above scheme, the self-expanding membrane-coated stent is formed by attaching polymer materials.

[0024] In this invention, the teeth on the stent hooks hook the braided loops at both ends of the radially contractible self-expanding covered stent, which can fix the self-expanding covered stent between the mandrel and the functional tube. By changing the relative position of the mandrel and the functional tube, the self-expanding covered stent can be adjusted and released, and the operating physician can adjust the stent to the optimal release position.

[0025] The release principle of self-expanding covered stents: When the stent core is relatively close to the stent hooks on the functional tube, the self-expanding covered stent can expand by 60% to 80%. The middle section of the self-expanding covered stent first contacts and adheres to the vessel wall. At this time, the self-expanding covered stent has not fallen off the stent hooks. The operator can choose the operation method according to the situation: ① When the position is reasonable, since the middle section of the self-expanding covered stent has already adhered to the vessel wall, the stent core is pulled backward. At this time, the two stent hooks are relatively close, the two sides of the self-expanding covered stent expand, and the stent hooks can no longer hook the braided loops at both ends of the self-expanding covered stent, and the self-expanding covered stent is completely released; ② When the position is unreasonable, the stent core is pushed forward. The relative position of the stent core and the stent hooks on the functional tube becomes farther. The self-expanding covered stent is tightened and forms radial contraction, losing contact with the vessel wall. At this time, the operator can move the self-expanding covered stent to the ideal position.

[0026] In this invention, the first imaging ring is exposed and used to display the position of the self-expanding covered stent tip in the three-dimensional imaging system, guiding the operator's interventional procedure. The first stent hook is used to adjust the length of the self-expanding covered stent, correspondingly adjusting the expansion size of the self-expanding covered stent. Working together with the second stent hook, the operator can adjust the placement position of the self-expanding covered stent using both, avoiding the risk of misplacement during a single placement. The mandrel seat can serve as an operating handle for convenient operation. The outer sheath primarily restrains the self-expanding covered stent and the dilation balloon, keeping them in a contracted state.

[0027] In this invention, the second imaging ring is used to visualize the tail end of the self-expanding covered stent in a three-dimensional imaging system. The balloon imaging ring is used to visualize the position of the dilation balloon. In cases where the self-expanding covered stent is not fully expanded, the dilation balloon is used to promptly correct the issue, assisting the self-expanding covered stent in expanding into the correct position and adhering tightly to the blood vessel. The infusion port is used to inject balloon inflation fluid.

[0028] The beneficial effects of this invention are as follows:

[0029] It replaces the traditional sandwich structure, reduces the intravascular diameter ratio, strengthens the structure, and has a seamless joint, thus avoiding the risk of blood undercurrent.

[0030] The self-expanding covered stent utilizes simple physical principles to achieve controllable expansion, without impacting blood vessels, and provides operators with adjustment space, reducing the risk of failure.

[0031] Using an expansion balloon can quickly and promptly remedy situations where self-expanding covered stents fail to expand adequately, avoiding the need for a second surgery;

[0032] Self-expanding covered stents avoid the problem of balloon dilation not being able to adapt to blood vessels of different diameters. Their stable release greatly improves the problems of inaccurate delivery and inability to adjust of previous products, and solves the risk of operation during a single release. Attached Figure Description

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0034] Figure 1 This is a schematic diagram of the structure of the covered stent system;

[0035] Figure 2 This is an exploded view of the covered scaffold system;

[0036] Figure 3 This is a schematic diagram of the bracket hook structure;

[0037] Figure 4 This is a structural diagram of a stent hook and a self-expanding film-coated stent;

[0038] Figure 5 This is a structural diagram of a self-expanding covered stent with hooks and expansion mechanism.

[0039] Figure 6 This is a schematic diagram of step 2);

[0040] Figure 7 This is a schematic diagram of the expansion of the self-expanding membrane-covered stent in step 2);

[0041] Figure 8 This is a schematic diagram of step 3);

[0042] Figure 9 This is a diagram illustrating the remedial measures.

[0043] In the diagram: 1. Mandrel, 1.1. Mandrel body, 1.2. First imaging ring, 1.3. First support hook, 1.4. Mandrel seat, 2. Functional tube, 2.1. Tube body, 2.2. Second support hook, 2.3. Second imaging ring, 2.4. First balloon imaging ring, 2.5. Dilation balloon, 2.6. Second balloon imaging ring, 2.7. Functional tube seat, 2.8. Injection port, 3. Self-expanding membrane support, 4. Outer tube, 5. Outer tube seat, 6. Hook body, 7. Hook stop, 8. Tooth. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the 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 merely illustrative and not intended to limit the invention.

[0045] like Figures 1-5 As shown, a film-coated support system includes a mandrel 1, a functional tube 2, a self-expanding film-coated support 3, and an outer tube 4. The mandrel 1 is placed inside and extends out of the functional tube 2; the mandrel 1 and the functional tube 2 are movable relative to each other along an axis. The mandrel 1 includes a mandrel body 1.1, a first developing ring 1.2, a first support hook 1.3, and a mandrel seat 1.4. The first developing ring 1.2 and the first support hook 1.3 are sequentially arranged at the front end of the mandrel body 1.1, and the mandrel seat 1.4 is located at the rear end of the mandrel body 1.1. The functional tube 2 includes a tube body 2.1, a second support hook 2.2, a second imaging ring 2.3, a first balloon imaging ring 2.4, a dilation balloon 2.5, a first balloon imaging ring 2.6, and a functional tube seat 2.7. The second support hook 2.2 is located at the front end of the tube body 2.1, and the functional tube seat 2.7 is located at the rear end of the tube body 2.1. The second imaging ring 2.3, the first balloon imaging ring 2.4, the dilation balloon 2.5, and the first balloon imaging ring 2.6 are sequentially arranged between the second support hook 2.2 and the functional tube seat 2.7. An injection port 2.8 is provided on the functional tube seat 2.7. In a preferred embodiment, the first support hook 1.3 and the second support hook 2.2 include a hook body 6, a hook stop 7, and teeth 8. The hook stop 7 is located at one end of the hook body 6, and the teeth 8 are arranged around the other end of the hook body 7. One end of the self-expanding film-coated stent 3 is connected to the first stent hook 1.3 by a braided loop wire, and the other end is connected to the second stent hook 2.2 by a braided loop wire. The outer tube 4 is placed outside the self-expanding film-coated stent 3 and the functional tube 2, and can move along the functional tube 2. An outer tube seat 5 is provided at the tail end of the outer tube 4.

[0046] The above-mentioned covered stent system is used as follows:

[0047] 1) Under the guidance of the first imaging ring, reach the target point and move the outer sleeve backward so that the self-expanding coated stent is only constrained by the first stent hook and the second stent hook.

[0048] 2) Slowly and steadily pull back the mandrel seat. The mandrel seat drives the mandrel body to move backward. The first bracket hook moves backward with the mandrel body, and the self-expanding film-coating bracket gradually expands.

[0049] 3) When the self-expanding covered stent expands to a certain extent, the first stent hook and the second stent hook disengage, and the self-expanding covered stent is placed at the affected area; the mandrel retracts to the limit position (when the first stent hook and the second stent hook are in contact); at this time, the self-expanding covered stent is completely released.

[0050] If the self-expanding covered stent does not fully inflate, continue to move the outer cannula backward until the dilation balloon is exposed, preparing for assisted dilation; under the guidance of the balloon imaging ring, manipulate the dilation balloon to the incompletely inflated self-expanding covered stent, and inflate the balloon by injecting dilation fluid into the infusion port, thereby assisting the self-expanding covered stent to fully inflate and fit tightly against the blood vessel; withdraw the dilation fluid to return the dilation balloon to its initial state;

[0051] 4) Remove the mandrel, functional tube, and outer tube from the body.

[0052] In this invention, the self-expanding membrane-coated scaffold is formed by attaching a polymer material.

[0053] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A covered stent system, characterized by: The core shaft, the function tube, the self-expanding covered stent and the outer sleeve tube are arranged in sequence. The core shaft is arranged in the function tube and extends out of the function tube. The function tube comprises a tube body, a second stent hook ring, a second developing ring, a balloon developing ring, a dilating balloon and a function tube seat. The second stent hook ring is arranged at the front end of the tube body, and the function tube seat is arranged at the tail end of the tube body. The second developing ring, the balloon developing ring and the dilating balloon are arranged between the second stent hook ring and the function tube seat. The function tube seat is provided with a liquid injection port.

2. The covered stent system of claim 1, wherein: The first stent hook ring and the second stent hook ring each comprise a hook ring body, a hook ring stopper and a tooth.

3. The covered stent system of claim 1, wherein: The hook ring stopper is arranged at one end of the hook ring body, and the tooth is arranged at the other end of the hook ring body. The tooth of the first stent hook ring and the tooth of the second stent hook ring respectively hook the braided ring wires at the two ends of the self-expanding covered stent. The outer sleeve tube is arranged outside the self-expanding covered stent and the function tube and can move along the function tube. When the first developing ring reaches the target point, the outer sleeve tube is moved backward, so that the self-expanding covered stent is only constrained by the first stent hook ring and the second stent hook ring. The core shaft seat drives the core shaft body to move backward, the first stent hook ring moves backward with the core shaft body, and the self-expanding covered stent gradually expands. When the self-expanding covered stent expands to a certain extent, the first stent hook ring and the second stent hook ring are released, and the self-expanding covered stent is arranged at the lesion. If the self-expanding covered stent is not expanded to the position, the dilating balloon is expanded to assist the self-expanding covered stent to expand completely and tightly adhere to the blood vessel. The tail end of the outer sleeve tube is provided with an outer sleeve tube seat. The tail end of the core shaft body is provided with a core shaft seat. The tail end of the core shaft body is provided with a core shaft seat.

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