WO2021135351A1

WO2021135351A1 - Implant body delivery system and inner tube thereof

Info

Publication number: WO2021135351A1
Application number: PCT/CN2020/113616
Authority: WO
Inventors: 朱清; 刘梦钦; 姬庆茹; 袁振宇
Original assignee: 上海鸿脉医疗科技有限公司
Priority date: 2019-12-31
Filing date: 2020-09-04
Publication date: 2021-07-08
Also published as: AR120645A1; CN113116618A

Abstract

Provided are an implant body delivery system and inner tube (3) thereof; the inner tube (3) comprises an inner-tube main body (31), and a friction body (34) arranged on the outer surface of the inner-tube main body (31), the friction body (34) comprising a first friction layer (341) and a second friction layer (342) having different coefficients of friction; the friction body (34) has a first state and a second state; when the friction body (34) is in the first state, the first friction layer (341) is exposed on the outer surface of the inner-tube main body (31); when the friction body (34) is in the second state, the first friction layer (341) is covered and the second friction layer (342) is exposed on the outer surface of the inner-tube main body (31). The provided implant-body delivery system is such that the implant body (4) is released and positioned accurately and stably, axial shortening does not occur, and the safe withdrawal of the delivery system is ensured.

Description

Implant delivery system and its inner tube

Technical field

The invention relates to the technical field of medical devices, in particular to an implant delivery system and its inner tube.

Background technique

With the development of endoluminal technology, the use of stents has been widely recognized by radiologists, cardiologists and surgeons. Stents and stent grafts are used to support various tubular passages in the body, including arteries, veins, and air. Tract, gastrointestinal tract and bile duct. The preferred method of stent placement is to use a professional delivery system to accurately place and deploy the stent at the desired treatment site through the body's own channel. With the help of the smaller outer diameter of the delivery system, the doctor can minimize the surgical incision to achieve minimally invasive operations.

Stents can generally be plastically deformed (e.g., "balloon expandable" stents) or elastically deformed (e.g., "self-expanding" stents) in order to recover from a compressed state to a diameter in an expanded state. Firstly, the stent is installed on the delivery system by radial compression and delivered into the human body, and then the release of the stent is controlled by the manipulating mechanism of the external part of the conveyor to restore the stent to its functional diameter. The current general technology is to place the stent radially compressed in the annular space between two concentric catheters. The inner tube is used for the guide wire to pass. When the stent needs to be released, the outer tube is pulled back relative to the inner tube and passes through the inner tube. , The relative axial displacement of the outer tube releases the stent, and the stent elastically returns to a predetermined diameter at this time.

In a specific implementation, it is also necessary to add a coaxial intermediate tube between the inner tube and the outer tube, which is located at the proximal end of the stent and is in axial contact with the stent. When the outer tube is pulled back, the middle tube remains motionless, so that the stent is restricted from withdrawing with the outer tube, so that the stent can be released smoothly. Due to the existence of this limit, the stent is bound to be subjected to the axial compression force applied to it by the outer tube and the middle tube during the release process, which usually causes the stent to shorten and lead to inaccurate positioning of the stent. At the same time, this release method also requires the stent to have strong axial rigidity in the compressed state. Otherwise, the stent will be severely shortened during the release process, and may even cause serious damage to the stent. As a result, the design of the stent is greatly restricted, and it is usually necessary to add axial connecting rods between the stent segments to solve the problem of axial rigidity of the stent. However, the axial connecting rod will adversely affect the axial fatigue and bending performance of the stent, and greatly reduce the overall performance of the stent.

One of the methods to solve the above problems is to optimize or change the force state of the stent when it is released, to change the stent from an axially compressed state to a tensioned state, or to minimize the axial compressive force received during the stent release. For example, the stent delivery system described in Comparative Document 1 (Publication No. CN102499801A) and the stent delivery system described in Comparative Document 2 (Publication No. CN104706449A) both restrict the axial displacement of the stent through a rear release mechanism at the distal end of the delivery system. Therefore, the stent is always stretched during the release process without shortening. However, this method is generally only suitable for systems with a larger outer tube diameter due to the larger volume of the rear release mechanism. In addition, since the inner tube bears a large axial compression force during the release process, it is easy to bend instably during the release process.

Moreover, the above delivery system requires multiple parts to be operated to release the stent, and after the stent is released, an operating mechanism is also required to release the post-release constraint of the distal end, which has the disadvantage of complicated and difficult release.

Summary of the invention

The purpose of the present invention is to provide an implant delivery system and its inner tube, which can enable accurate and stable release and positioning of the implant without causing axial shortening, and at the same time can ensure the safe withdrawal of the delivery system.

In order to solve the above technical problems, the present invention provides an inner tube for transporting an implant, including an inner tube main body, and a friction body arranged on the outer surface of the inner tube main body, and the friction body includes different friction coefficients. A first friction layer and a second friction layer; the friction body has a first state and a second state, when the friction body is in the first state, the first friction layer is exposed on the outer surface of the inner tube body, When the friction body is in the second state, the first friction layer is covered and the second friction layer is exposed on the outer surface of the inner tube main body.

Preferably, the friction coefficient of the first friction layer is greater than the friction coefficient of the second friction layer.

Preferably, the first friction layer and the second friction layer are distributed along the axial or radial direction of the inner tube main body.

Preferably, the inner tube includes a plurality of the friction bodies, and the plurality of friction bodies are distributed along the axial and/or circumferential direction of the inner tube main body.

Preferably, the first friction layer and the second friction layer are distributed along the axial direction of the inner tube body; when the friction body is in the first state, the second friction layer is on the inner tube body Fold up in the axial direction; when the friction body is in the second state, the second friction layer is unfolded in the axial direction of the inner tube main body and covers the first friction layer.

Preferably, when the friction body is in the first state, in the radial direction of the inner tube, the thickness of the first friction layer is greater than or equal to the thickness of the second friction layer.

Preferably, the first friction layer and the second friction layer are distributed along the radial direction of the inner tube body, and the first friction layer is located between the inner tube body and the second friction layer; When the friction body is in the first state, the friction body is folded in the axial direction of the inner tube body, and the first friction layer is exposed on the outer surface of the inner tube body; the friction body is in the second state. In the state, the friction body expands in the axial direction of the inner tube main body, and the second friction layer is exposed on the outer surface of the inner tube main body.

Preferably, the friction portion extends along the circumferential direction of the inner tube main body, and the second friction layer is divided into at least two pieces in the circumferential direction.

Preferably, the length of the first friction layer and/or the second friction layer in the axial direction is 1mm-5mm; the thickness of the first friction layer and/or the second friction layer in the radial direction is 0.1mm-0.5mm.

Preferably, the material of the first friction layer is silica gel or polyurethane, and/or the material of the second friction layer is polytetrafluoroethylene or ethylene trifluoroethylene copolymer.

In order to solve the above technical problems, the present invention also provides an implant delivery system, including a handle, an outer tube, and the above inner tube. The outer tube has an axially penetrating inner cavity, and the inner tube is located in the inner cavity and Extending along the axial direction of the inner cavity, a gap for accommodating the implant is formed between the outer tube and the inner tube, and both the outer tube and the inner tube are connected with the handle, so The handle controls the movement of the outer tube and the inner tube in the axial direction.

Preferably, it further comprises an implant body which is accommodated in the gap formed between the outer tube and the inner tube and covers the friction body of the inner tube.

Compared with the prior art, the present invention has the following beneficial effects: the implant delivery system and its inner tube provided by the present invention provide a first friction layer and a second friction layer with different friction coefficients on the surface of the inner tube body, and are in different states. , The first friction layer and the second friction layer are respectively in contact with the inner surface of the implant, thereby changing the friction and lubricating properties of the contact surface between the inner tube and the implant; when the outer tube is withdrawn, the outer tube and the stent The frictional force is small, the friction layer with the larger friction coefficient on the inner tube is in contact with the implant body and the static friction force is large, so that the implant body is released and positioned accurately and stably without axial shortening; when the inner tube is withdrawn, the inner tube The friction layer on the tube with a small friction coefficient is in contact with the implant and has a small static friction, which can effectively prevent the problem of affecting the positioning of the released implant during the withdrawal process, making the operation safer; in addition, the present invention improves the ease of product Realization and practicability, the scope of application of the implant can include all arterial or venous branch and peripheral small stents, and other applicable implants.

Description of the drawings

Figure 1 is a schematic diagram of the overall structure of a stent delivery system in an embodiment of the present invention;

Fig. 2 is a schematic diagram of the inner tube structure at A in Fig. 1;

Fig. 3 is an enlarged schematic diagram of a partial cross-section of Fig. 2 B in a folded state;

4 is an enlarged schematic diagram of a partial cross-section of B in FIG. 2 in an unfolded state;

Figure 5 is a schematic diagram of the circumferential distribution of the inner tube;

6 is an enlarged schematic view of a partial cross-section of an inner tube in a folded state according to another embodiment of the present invention;

Fig. 7 is an enlarged schematic diagram of a partial cross-section of an inner tube in an unfolded state according to another embodiment of the present invention.

In the picture:

1 Handle 2 Outer tube 3 Inner tube 4 Bracket

11 Rotary release mechanism 12 Control turntable 13 Turntable seat 14 One-way valve

15 Infusion pipe 31 Inner pipe body 32 End connector 33 Steel pipe

34 Friction body 341 First friction layer 342 Second friction layer

343 First side 344 Second side 3431 First side 3432 Second side

Detailed ways

The present invention will be further described below in conjunction with the drawings and embodiments.

In order to describe the structural features of the present invention more clearly, the present invention uses "proximal", "distal", and "axial" as orientation words, where "proximal" means the end close to the operator during the operation; "distal" "End" refers to the end far away from the operator, and the axial direction refers to the direction of the axis of the inner tube. The terms "inner", "outer", "upper", "lower", "left", "right" and similar expressions used in the present invention are for illustrative purposes only, and do not mean that they are the only embodiments. The term "or" is usually used in the meaning including "and/or" unless the content clearly indicates otherwise.

The present invention provides an inner tube and a delivery system that solves the problem of shortening of the stent release process. The first friction layer and the second friction layer with different friction coefficients are arranged on the surface of the inner tube main body, and in different states, the first friction layer and the second friction layer are provided. The first friction layer and the second friction layer are in contact with the inner surface of the implant respectively, thereby changing the friction and lubricating properties of the contact surface between the inner tube and the implant; when the outer tube is withdrawn, the friction between the outer tube and the stent is small, The friction layer on the inner tube with a larger friction coefficient is in contact with the implant body and the static friction force is large, so that the implant body is released and positioned accurately and stably without axial shortening; when the inner tube is withdrawn, the friction coefficient on the inner tube is relatively high. The small friction layer is in contact with the implant and the static friction is small, which can effectively prevent the problem of affecting the positioning of the released implant during the withdrawal process, making the operation safer.

The implant in this embodiment is described by taking a blood vessel stent as an example. The blood vessel stent is made of a cylindrical polyester sheet or other polymer materials and a plurality of self-expanding alloy stent segments sutured or heat-melted, or only contains alloy Bracket part. In the implant delivery system and its inner tube provided by the present invention, friction layers with different friction coefficients are arranged on the inner tube. During the release of the vascular stent, the stent contacts the friction layer with the high friction coefficient on the inner tube, and the stent is in contact with the friction layer on the inner tube. The friction between the inner tube is large, and the withdrawal of the outer tube will not change the axial length of the stent or make the stent move backward as a whole. When the stent is released and the inner tube is withdrawn, the stent and the friction layer with a low friction coefficient on the inner tube are in contact, and the friction between the inner tube and the positioned stent is small, and it can be withdrawn safely.

1 and 2, the implant delivery system provided in this embodiment includes a handle 1, an outer tube 2 and an inner tube 3. The outer tube 2 has an axially penetrating inner cavity, and the inner tube 3 is located in the inner cavity And extending along the axial direction of the inner cavity, a gap for accommodating the stent 4 is formed between the outer tube 2 and the inner tube 3. The handle 1 is provided with a rotation release mechanism 11 and a rotatable control dial 12 to control the outer tube 2 Move in the axial direction to control the release of the stent 4; the control turntable 12 is fixed on the turntable seat 13, and the distal end of the handle 1 is provided with an infusion tube 15 and a one-way valve 14. Before the operation, a syringe filled with physiological saline Connect with the one-way valve 14, pass the physiological saline in the syringe through the one-way valve 14, the infusion tube 15, the gap between the inner tube 3 and the outer tube 2, and the stent 4, and finally flow out from the distal end of the outer tube 2 to deliver The air inside the system is completely exhausted to avoid the formation of air clots. The proximal end of the handle is provided with a steel tube 33 and an inner tube tail end connecting piece 32. The bracket 4 is compressed and installed between the inner tube 3 and the outer tube 2. When released, the outer tube 2 is retracted by rotating the release mechanism 11 to complete the release of the stent 4. After the release is completed, the entire delivery system is withdrawn from the body through the entire retracement of the delivery system.

The present invention does not particularly limit the structure of the handle 1 and its components, and the handle 1 can be a handle of various structures. The inner tube 3 includes an inner tube body 31. The inner tube body 31 is provided with a friction body 34 on the outer surface where the support 4 is placed. The friction body 34 is composed of a first friction layer 341 and a second friction layer 342 with different friction coefficients. The body 34 has a first state and a second state. When the friction body 34 is in the first state, the first friction layer 341 is exposed on the outer surface of the inner tube body 31. When the friction body 34 is in the second state, the first friction layer 341 is The second friction layer 342 covers and is exposed on the outer surface of the inner tube main body 31. Preferably, the first friction layer 341 has a first friction coefficient, and the second friction layer 342 has a second friction coefficient, and the first friction coefficient is greater than the second friction coefficient. Further, the first friction layer 341 or/and the second friction layer 342 constitute a plurality of friction bodies 34, the plurality of friction bodies 34 are alternately distributed along the axial and/or circumferential direction of the inner tube main body 31, and the friction bodies 34 is in contact with the inner surface of the bracket 4 to generate friction. The friction body extends along the circumferential direction of the inner tube main body 31, and the second friction layer 342 is divided into at least two pieces in the circumferential direction. When the stent 4 is in the compressed state, the friction body 34 is in the first state, and the first friction layer 341 is in contact with the inner surface of the stent 4; when the stent 4 is in the expanded state and the inner tube 3 is retracted, the friction layer 34 is in the first state. In the second state, the second friction layer 342 is in contact with the inner surface of the bracket 4. The first state of this embodiment is the folded state, and the second state is the unfolded state. In other embodiments, it may not be limited to these two states.

Example 1

In this embodiment, the plurality of friction bodies 34 are distributed along the axial direction of the inner tube main body 31, and the first friction layer 341 and the second friction layer 342 are alternately distributed along the axial direction of the inner tube main body 31.

Fig. 2 is a schematic diagram of the structure of the inner tube at A in Fig. 1. 2, the inner tube 3 includes an inner tube main body 31. The outer surface of the distal end of the inner tube main body 31 is alternately provided with a first friction layer 341 and a second friction layer 342 in the axial direction. The first friction layer 341 has a first friction layer. The second friction layer 342 is composed of a material with a coefficient of friction, and the second friction layer 342 is composed of a material with a second coefficient of friction. The material with the first friction coefficient is a high friction coefficient material, preferably silicone or polyurethane; the material with the second friction coefficient is a low friction coefficient material, preferably polytetrafluoroethylene (PTFE) or ethylene trifluoroethylene copolymer. The present invention does not particularly limit the material with the first coefficient of friction and the material with the second coefficient of friction, and is not limited to the two materials mentioned in this embodiment, as long as the material can meet the friction requirement. In one embodiment, the first friction layer 341 and the second friction layer 342 may be fixedly connected to the outer surface of the inner tube main body 31 by means of glue bonding, and the present invention does not specifically limit the specific connection method. 3, when the stent 4 is in the compressed state, before the inner tube 3 is retracted, the second friction layer 342 is in a folded state, and the first friction layer 341 is not covered, so that the inner tube 3 is in a high friction state as a whole. The inner surface is in contact with the first friction layer 341, and the friction portion formed by the first friction layer 341 provides the friction force required for the support 4 to release. During the release of the stent 4, the friction between the stent 4 and the inner tube 3 is large, and the withdrawal of the outer tube 2 will not change the axial length of the stent 4 or cause the stent 4 to move in the proximal direction as a whole. Please refer to Figure 4, when the stent 4 is released and the inner tube 3 retracts (rightward movement in the figure), the second friction layer is touched due to the slight backward movement of the inner tube 3 (rightward movement in the figure) 342 is automatically expanded. The expanded second friction layer 342 covers the outer surface of the first friction layer 341, so that the inner tube 3 is in a low friction state. The inner surface of the stent 4 is in contact with the second friction layer 342. At this time, The frictional force between the friction part formed by the second friction layer 342 and the stent 4 is very small. Therefore, when the conveying system is retracted, the friction between the inner tube 3 and the positioned stent 4 is small, and it can be retracted safely.

Please continue to refer to FIG. 3, in a preferred embodiment, in the folded state, the lengths of the first friction layer 341 and the second friction layer 342 in the axial direction are equal, and the length range is preferably 1mm-5mm, and the second friction layer After 342 is unfolded, it can completely cover the surface of the first friction layer 341; in the folded state, in the radial direction of the inner tube 3, the thickness of the first friction layer 341 should be equal to or greater than the thickness of the second friction layer 342 to ensure the In this state, the first friction layer 341 can be in contact with the bracket 4, and the thickness is preferably in the range of 0.1 mm-0.5 mm, and preferably may be smaller than the minimum inner diameter of the bracket 4 in the expanded state.

5, in order to make the second friction layer 342 easier to expand and cover the surface of the first friction layer 341 when the inner tube 3 is retracted, it can be designed as a split structure, and the second friction layer 342 is around the circumference. It can be equally divided into 2-8 slices upwards, preferably 4 slices, as shown in Figure 5. In specific implementation, the number of split lobes can be adjusted according to specific conditions.

Example 2

It is different from the alternating distribution of the first friction layer 341 and the second friction layer 342 in Embodiment 1. The friction body 34 of this embodiment includes the first friction layer 341 and the second friction layer 342 distributed along the radial direction of the inner tube body, and the first friction layer 341 is located on the inner tube body 31 And the second friction layer 342. Referring to FIG. 6, the friction layer 34 provided on the outer surface of the inner tube main body 31 where the bracket 4 is placed has a first side 343 and a second side 344; the first side 343 has a first friction layer 341, and the second side 344 has a first side. Two friction layer 342. When the friction body 34 is in the first state, the friction body 34 is folded in the axial direction of the inner tube main body 31, the first side 343 has a first surface 3431 and a second surface 3432, and at least the second surface 3432 of the first side 343 has For the first coefficient of friction, the first surface 3431 of the first side 343 is fixedly connected to the outer surface of the inner tube main body 31, and the second surface 3432 of the first side 343 is exposed on the outer surface of the inner tube main body 31. Referring to FIG. 7, when the friction body 34 is in the second state, the friction body 34 is expanded in the axial direction of the inner tube body 31, the second surface 3432 of the first side 343 is in contact with the outer surface of the inner tube body 31, and the second side 344 is exposed on the outer surface of the inner tube main body 31. When the stent 4 is released, the friction body 34 is in a folded state, as shown in FIG. 6; at this time, the overall friction coefficient of the inner tube 3 is relatively large, and the second surface 3432 with a high friction coefficient is in contact with the inner surface of the stent 4. The friction force between 4 and the inner tube 3 is large, so that the position of the stent 4 and the inner tube 3 is relatively immobile, and the stent 4 will not shrink. When the stent 4 is opened, the inner tube 3 is retracted, and when the inner tube 3 moves back slightly, the friction body 34 is automatically expanded and is in the second state, and the second side 344 with a low friction coefficient is exposed, as shown in Fig. 7 Show. At this time, the overall friction coefficient of the inner tube 3 becomes smaller, and the second side 344 formed by the second friction layer 342 contacts the inner surface of the stent 4 after unfolding, and the inner tube 3 can be withdrawn smoothly without causing the stent 4 to shift. .

Similarly, in order to make the friction body 34 easier to unfold, the split structure design in FIG. 5 can be adopted, and the friction body 34 can be equally divided into 2-8 pieces in the circumferential direction, preferably 4 pieces. In specific implementation, the number of split lobes can be adjusted according to specific conditions. In the folded state, the length of the friction body 34 in the axial direction is preferably 1mm-5mm; the thickness in the radial direction is preferably 0.1mm-0.5mm, which may preferably be smaller than the minimum inner diameter of the stent 4 in the expanded state.

In summary, the implant delivery system and its inner tube provided in this embodiment have at least the following advantages:

1) Specialized and refined treatment of the inner tube structure, applying high-friction and low-friction materials to the inner tube to change the friction and lubrication properties of the outer surface of the inner tube;

2) When the outer tube is withdrawn, the friction between the outer tube and the stent is small, the inner tube is in contact with the stent and the static friction is large, so that the stent is released and positioned accurately and stably without axial shrinkage;

3) This structure can effectively prevent the problem of affecting the positioning of the released stent during the withdrawal process, reduce the friction between the inner tube and the stent, and make the operation safer;

4) The present invention improves the ease of realization and practicability of the product. The use range of this type of stent can include all arterial or venous branch and peripheral small stents, and other applicable implants.

Although the present invention has been disclosed as above in preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be as defined in the claims.

Claims

An inner tube for transporting an implant, which is characterized in that it comprises an inner tube body, and a friction body arranged on the outer surface of the inner tube body. The friction body includes a first friction layer with different friction coefficients and The second friction layer; the friction body has a first state and a second state, when the friction body is in the first state, the first friction layer is exposed on the outer surface of the inner tube body, and the friction body is in In the second state, the first friction layer is covered and the second friction layer is exposed on the outer surface of the inner tube main body.
The inner tube according to claim 1, wherein the friction coefficient of the first friction layer is greater than the friction coefficient of the second friction layer.
The inner tube according to claim 1 or 2, wherein the first friction layer and the second friction layer are distributed along the axial or radial direction of the inner tube main body.
The inner tube according to claim 1 or 2, wherein the inner tube comprises a plurality of the friction bodies, and the plurality of friction bodies are distributed along the axial and/or circumferential direction of the inner tube main body.
The inner tube according to claim 1 or 2, wherein the first friction layer and the second friction layer are distributed along the axial direction of the inner tube main body; when the friction body is in the first state, The second friction layer is folded in the axial direction of the inner tube body; when the friction body is in the second state, the second friction layer is expanded in the axial direction of the inner tube body and covers the first A friction layer.
The inner tube of claim 5, wherein when the friction body is in the first state, in the radial direction of the inner tube, the thickness of the first friction layer is greater than or equal to the thickness of the second friction layer thickness of.
The inner tube according to claim 1 or 2, wherein the first friction layer and the second friction layer are distributed along the radial direction of the inner tube main body, and the first friction layer is located on the Between the inner tube body and the second friction layer; when the friction body is in the first state, the friction body is folded in the axial direction of the inner tube body, and the first friction layer is exposed on the inner tube The outer surface of the tube body; when the friction body is in the second state, the friction body is expanded in the axial direction of the inner tube body, and the second friction layer is exposed on the outer surface of the inner tube body.
The inner tube according to claim 3, wherein the friction body extends in the circumferential direction of the inner tube main body, and the second friction layer is divided into at least two pieces in the circumferential direction.
The inner tube according to claim 1 or 2, wherein the length of the first friction layer and/or the second friction layer in the axial direction is 1mm-5mm; the first friction layer and/or Or the thickness of the second friction layer in the radial direction is 0.1mm-0.5mm.
The inner tube according to claim 2, wherein the material of the first friction layer is silicone or polyurethane, and/or the material of the second friction layer is polytetrafluoroethylene or ethylene trifluoroethylene copolymer Things.
An implant delivery system, comprising a handle, an outer tube, and the inner tube according to any one of claims 1-10, the outer tube has an axially penetrating inner cavity, and the inner tube is located in the In the inner cavity and extending along the axial direction of the inner cavity, a gap for accommodating the implant is formed between the outer tube and the inner tube, and both the outer tube and the inner tube are connected to the The handle is connected, and the handle controls the movement of the outer tube and the inner tube in the axial direction.
The implant delivery system of claim 11, further comprising an implant, the implant being accommodated in the gap formed between the outer tube and the inner tube, and covering The friction body of the inner tube.