Selective partially-covered metal stent for biliary drainage in ERCP operation

Abstract

The invention provides a selective partially-covered metal stent for biliary drainage in an ERCP (endoscopic retrograde cholangiopancreatography) operation. The selective partially-covered metal stent is characterized by comprising a sheathing canal, a covered stent and a bare stent, wherein the sheathing canal is a double-channel sheathing canal and comprises a sheathing canal inner tube and a sheathing canal outer tube which are arranged in a nested manner; the covered stent is pre-mounted in an annular channel between the sheathing canal inner tube and the sheathing canal outer tube; the bare stent has elasticity and is pre-installed on the inner side of the sheath tube inner tube. Due to the gain effect of the selective partially-covered metal stent design, a new method is provided when the ERCP is used for drainage of benign and malignant stenosis through the design, the stability of stent displacement resistance is considered, and longer smooth time is guaranteed.

Description

Technical Field

[0001] The present invention relates to medical devices, and in particular, to a selective partially covered metal stent for biliary drainage during ERCP. Background Art

[0002] ERCP is the first-line treatment for biliary drainage of benign and malignant strictures. Drainage with bare metal stents and covered metal stents is an important option for ERCP treatment of patients with various benign and malignant strictures.

[0003] Currently, the metal stents mainly applied clinically are divided into bare metal stents and fully covered metal stents. The bare metal stents have the risk of early tumor invasion into the stent and re-blockage, and the patency time is not satisfactory. Although the fully covered stents have a low risk of tumor invasion due to the presence of the covering membrane and can obtain a better patency time, the risk of early displacement is relatively high. Some designs of selective partially covered metal stents aim to balance anti-displacement and extended patency time, but the complexity of biliary strictures results in a lack of application scenarios.

[0004] Therefore, it is an urgent need to achieve a balance between the stability of the stent against displacement and ensuring a longer patency time. Summary of the Invention

[0005] The present invention aims to overcome the above defects and provides a special stent with a selective covering membrane that can be implanted into the biliary tract simply and quickly. Through this design, the stability of the stent against displacement and a longer patency time can be balanced.

[0006] The selective partially covered metal stent for biliary drainage during ERCP provided by the present invention is characterized in that it includes a sheath, a covered stent, and a bare stent;

[0007] Wherein, the sheath is a double-channel sheath, including an inner sheath tube and an outer sheath tube arranged in a nested manner;

[0008] The above-mentioned covered stent is pre-installed in the annular channel between the inner sheath tube and the outer sheath tube;

[0009] The above-mentioned bare stent has elasticity and is pre-installed inside the inner sheath tube.

[0010] Furthermore, the selective partially covered metal stent for biliary drainage during ERCP provided by the present invention is further characterized in that:

[0011] In the annular channel between the inner sheath tube and the outer sheath tube, at the outlet and / or inlet position of the covered stent, a limiting member is provided.

[0012] Furthermore, the selective partially covered metal stent for biliary drainage during ERCP provided by the present invention is further characterized in that:

[0013] The above-mentioned limiting member has the characteristic of deforming under pressure.

[0014] Furthermore, the selective partial membrane-covered metal stent for biliary tract drainage during ERCP provided by the present invention is further characterized in that:

[0015] The head end of the above-mentioned sheath tube has an arc-shaped transition shape that gradually becomes smaller.

[0016] Furthermore, the selective partial membrane-covered metal stent for biliary tract drainage during ERCP provided by the present invention is further characterized in that:

[0017] The above-mentioned membrane-covered stent has elasticity.

[0018] Furthermore, the selective partial membrane-covered metal stent for biliary tract drainage during ERCP provided by the present invention is further characterized in that:

[0019] The above-mentioned membrane-covered stent does not have elasticity.

[0020] Furthermore, the selective partial membrane-covered metal stent for biliary tract drainage during ERCP provided by the present invention is further characterized in that:

[0021] It also includes a matching annular push rod and a linear push rod;

[0022] The shape of the above-mentioned annular push rod matches the annular channel;

[0023] The shape of the above-mentioned linear push rod matches the inner tube of the sheath tube.

[0024] In addition, the present invention also provides another selective partial membrane-covered metal stent for biliary tract drainage during ERCP, which is characterized in that it includes a sheath tube, a membrane-covered stent and a bare stent;

[0025] Among them, the above-mentioned sheath tube is a single-channel sheath tube;

[0026] The above-mentioned membrane-covered stent and bare stent both have elasticity and are pre-installed in the sheath tube in sequence.

[0027] Furthermore, the selective partial membrane-covered metal stent for biliary tract drainage during ERCP provided by the present invention is further characterized in that the above-mentioned membrane-covered stent includes a support barrel formed by annular support metal wires and longitudinal support metal wires, and a membrane;

[0028] The above-mentioned membrane is wrapped around the outer surface of the support barrel.

[0029] Furthermore, the selective partial membrane-covered metal stent for biliary tract drainage during ERCP provided by the present invention is further characterized in that:

[0030] It also includes a matching linear push rod;

[0031] The shape of the above linear push rod matches the inner tube of the sheath tube.

[0032] Functions and effects of the present invention:

[0033] The gain effect of the selective partial membrane-covered metal stent design provides a new method for drainage of benign and malignant strictures during ERCP, and realizes both the stability of the stent against displacement and the guarantee of a longer patency time. Description of the drawings

[0034] Figure 1 , A schematic structural diagram of a selective partial membrane-covered metal stent for biliary drainage during ERCP provided in this embodiment;

[0035] Figure 2 , A schematic cross-sectional structural diagram of a selective partial membrane-covered metal stent for biliary drainage during ERCP provided in this embodiment;

[0036] Figure 3 , A schematic structural diagram of the annular push rod of a selective partial membrane-covered metal stent for biliary drainage during ERCP provided in this embodiment;

[0037] Figure 4 , An effect diagram after implantation of another selective partial membrane-covered metal stent for biliary drainage during ERCP provided in this embodiment; wherein, A is the biliary lesion stenosis site;

[0038] Figure 5 , A schematic structural diagram of another selective partial membrane-covered metal stent for biliary drainage during ERCP provided in this embodiment;

[0039] Figure 6 , A schematic structural diagram of the membrane-covered stent of another selective partial membrane-covered metal stent for biliary drainage during ERCP provided in this embodiment; Detailed implementation manners

[0040] The present invention can be implemented with various changes and can have various embodiments. Therefore, specific embodiments are illustrated in the drawings and described herein. However, this is not to limit the present invention to the specific implementation manners, but should be understood to include all changes, equivalents and alternatives falling within the spirit and technical scope of the present invention.

[0041] As Figure 1 and 2 shown, this embodiment provides a selective partial membrane-covered metal stent for biliary drainage during ERCP, which includes a sheath tube 100, a membrane-covered stent 200 and a bare stent 300;

[0042] The sheath tube 100 is a double-channel sheath tube made of a soft sheath tube, and comprises a sheath inner tube 120 and a sheath outer tube 110 which are nested; the sheath inner tube and the sheath outer tube can move relative to each other.

[0043] The coated stent 200 is pre-installed in the annular channel 130 between the sheath inner tube 120 and the sheath outer tube 110; clinically, the coated stent 200 can be designed with multiple specifications of various lengths, and can be a split design (that is, coated stents of different specifications can be introduced as needed during use); it can also be pre-installed in the annular channel at the factory, and different stents can be selected according to the condition of the patient's lesions.

[0044] The coated stent 200 may be elastic (i.e., it directly forms an open cylindrical structure after being released). When it is elastic, it forms a supporting structure upon release to open the bile duct. When the bare stent inside is released, it can achieve a double pressure effect on the lesion location.

[0045] The stent graft 200 may also be an inelastic structure. When it is an inelastic structure, in order to prevent the stent graft from slipping out of the annular channel during transportation, use or other moving environments, a limiting member 141 is provided at the exit of the stent graft in the annular channel between the inner tube of the sheath and the outer tube of the sheath. Considering the problem that the stent graft may slip out from the other end, a limiting member 142 may also be provided at its inlet.

[0046] The limiting components 141 and 142 may have the property of being deformed under pressure, for example, they may be made of medical soft rubber material or silicone material.

[0047] Considering the guiding property and the effect of further limiting the coated stent 200 / inner tube, the head end 150 of the sheath tube is an arc-shaped transition shape from large to small, such as a bullet head shape, and its head is not closed, and has a through hole or a crack. In addition, the head end 150 of the sheath tube is generally made of elastic or retractable materials, that is, the effect of opening when subjected to internal force.

[0048] The bare stent is an elastic metal stent (i.e., a traditional bare stent structure) that is pre-installed on the inner side of the sheath inner tube.

[0049] During use, the outer tube of the sheath is pulled relative to the inner tube to cause it to move outward relative to the inner tube, thereby exposing the covered stent to the location of the bile duct lesion. The inner tube is then pulled in the same way. While the inner tube is gradually moved outward, the bare stent is pushed out with the aid of a push rod, and the bare stent is fixed at the location of the lesion while the covered stent pops open.

[0050] In addition, in order to realize another use mode of the above-mentioned bracket, a matching annular push rod (such asFigure 3 as shown) and a linear pusher (i.e., a traditional stent pusher, T-shaped or nail-head type);

[0051] The shape of the annular pusher matches the annular channel, so that the covered stent 200 can be withdrawn quickly. Of course, the covered stent 200 can also be pushed out by using a traditional pusher;

[0052] The shape of the linear pusher matches the inner tube of the sheath, and is used to push out the bare stent 300.

[0053] During use, after determining the position of the stent, the covered membrane is carried to the target position by the sheath and then pushed out. After the covered membrane is completely released, the internal bare metal stent is further released, and the sheath is withdrawn while releasing, so that during the release process, the bare metal stent will support or strengthen the opening of the outer covered membrane at the same time or, and finally the selectively partially covered metal stent is completely released (such as Figure 4 ), thereby using the support of the selectively partially covered membrane and the bare metal stent itself to achieve the purpose of balancing the stability of the stent against displacement and ensuring a longer patency time.

[0054] Such as Figure 5 As shown, this embodiment also provides another selectively partially covered metal stent for biliary drainage during ERCP, which includes a sheath 100, a covered stent 200, and a bare stent 300;

[0055] The sheath 100 is a traditional single-channel sheath, and its material is a flexible sheath;

[0056] The covered stent 200 is a membrane barrel type. Specifically, the membrane is covered on, as Figure 6 shown, a support barrel formed by an a annular support wire and a b longitudinal support wire. Since both the a and b support wires have the characteristics of elastic deformation, it becomes an elastic membrane barrel with a certain self-expanding property and support property. The covered stent 200 in this membrane barrel is arranged sequentially with the bare stent 300.

[0057] In the actual operation process, the slow release process is as follows: after the front membrane barrel reaches the target position, it is released first. After the membrane barrel is released, it will expand and open the stenotic biliary lesion position to a certain extent based on the support and self-expanding properties of the metal support wire. At this time, the sheath is passed through the inside of the membrane barrel, and a bare metal stent is continuously implanted at the front end of the membrane barrel, that is, above (in front of) the stenosis and then the bare metal stent is released. When the bare metal stent is released, the implantation operation of the selectively partially covered metal stent is completed, and the result is the same as that of Figure 4 consistent.

[0058] Although the above has been described centering around the embodiments, this is merely illustrative and does not limit the present invention. Those of ordinary skill in the art will understand that various modifications and applications not illustrated above can be made without departing from the essential characteristics of this embodiment. For example, each of the constituent elements specifically shown in the embodiments can be implemented with modifications. Moreover, various differences related to such modifications and applications should be construed as being included within the scope of the present invention defined in the appended claims.

Claims

1. A selective partially covered metal stent for biliary drainage during ERCP, characterized by: Includes sheaths, covered stents and bare stents; Wherein, the sheath tube is a double-channel sheath tube, comprising a sheath tube inner tube and a sheath tube outer tube which are nested; The coated stent is pre-installed in the annular channel between the inner tube of the sheath and the outer tube of the sheath; The bare stent is elastic and is pre-installed on the inner side of the inner tube of the sheath.

2. The selective partially covered metal stent for biliary drainage during ERCP according to claim 1, characterized in that: A limiting component is provided in the annular channel between the sheath inner tube and the sheath outer tube, at the exit and / or the entrance of the stent graft.

3. The selective partially covered metal stent for biliary drainage during ERCP according to claim 1, characterized in that: The coated stent is elastic.

4. The selective partially covered metal stent for biliary drainage during ERCP according to claim 1, characterized in that: The stent graft has no elasticity.

5. The selective partially covered metal stent for biliary drainage during ERCP according to claim 2, characterized in that: The limiting component has the characteristic of being deformed when subjected to pressure.

6. The selective partially covered metal stent for biliary drainage during ERCP according to claim 1, characterized in that: The head end of the sheath tube is in an arc-shaped transition shape that changes from large to small.

7. The selective partially covered metal stent for biliary drainage during ERCP according to any one of claims 1 to 6, characterized in that: Also included are matching ring actuators and linear actuators; The shape of the annular push rod matches the annular channel; The shape of the linear push rod matches the inner tube of the sheath tube.

8. A selective partially covered metal stent for biliary drainage during ERCP, characterized in that: Includes sheaths, covered stents and bare stents; Wherein, the sheath is a single-channel sheath; The coated stent and the bare stent are both elastic and are pre-installed in the sheath tube in sequence.

9. The selective partially covered metal stent for biliary drainage during ERCP according to claim 8, characterized in that: The stent graft comprises a support barrel formed by an annular support metal wire and a longitudinal support metal wire, and a coating; The coating is wrapped around the outer surface of the supporting barrel.

10. The selective partially covered metal stent for biliary drainage during ERCP according to any one of claims 8 to 9, characterized in that: A matching linear actuator is also included; The shape of the linear push rod matches the inner tube of the sheath tube.

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