CN108670501B - Sheath tube convenient for recovering interventional instrument and conveying system - Google Patents

Abstract

The invention discloses a sheath tube convenient for recovering an interventional instrument and a conveying system using the sheath tube. According to the invention, the floating piece is arranged on the sheath tube, so that the interventional instrument can be guided and stored back into the sheath tube when the interventional instrument is positioned poorly and needs to be recovered, and the operation difficulty is reduced.

Description

Sheath tube convenient for recovering interventional instrument and conveying system

Technical Field

The invention relates to the field of medical instruments, in particular to a sheath tube for conveying an interventional instrument and a conveying system adopting the sheath tube.

Background

As shown in fig. 1-3, existing prosthetic heart valve delivery systems can be used to deliver a prosthetic heart valve prosthesis to a diseased annulus. The delivery system mainly comprises a handle 1, wherein the handle 1 is used for controlling the deployment and recovery of a prosthetic heart valve prosthesis at the far end of the system, a sheath core assembly 4 and a sheath tube which is in sliding fit with the periphery of the sheath core assembly are arranged in the handle in a penetrating manner, and a sleeve tube 2 for protecting blood vessels is further arranged outside the sheath tube.

The sheath comprises a thinner proximal sheath and a thicker distal sheath. The distal end of the sheath core assembly 4 is provided with a fixing head and a guiding head, a loading section is arranged between the fixing head and the guiding head and is used for loading the artificial heart valve prosthesis 5 (comprising a bracket and a valve in the bracket), the distal end of the sheath tube is provided with a containing area 31, and the containing area 31 has a diameter larger than that of a proximal end part 32 so as to be used for wrapping the artificial heart valve prosthesis 5 loaded on the loading section; in use, the prosthetic heart valve prosthesis 5 is exposed in the body and released into the blood upon withdrawal of the sheath relative to the sheath-core assembly 4, controlled by the handle; conversely, when there is an inaccurate stent release point of the prosthetic heart valve prosthesis 5, the prosthetic heart valve prosthesis 5 needs to be recovered into the human body by the delivery system, at this time, the sheath tube is advanced relative to the sheath core assembly 4, and the accommodating area 31 at the distal end of the sheath tube wraps the prosthetic heart valve prosthesis 5 into the loading section, and the prosthetic heart valve prosthesis is recovered.

In the existing operation, the accommodating area 31 is made of PTFE, the whole body is soft, and in the recovery process, the accommodating area 31 is soft, so that the stent which is expanded by decompression is easy to be folded, and once the folding and stacking occur, the artificial heart valve stent cannot be compressed again, so that the recovery fails.

In the prior art, in order to increase the rigidity of the accommodating area 31, a skeleton layer 6 is added to the side wall of the accommodating area 31, the portion of the sheath tube in the skeleton layer 6 is an inner film layer 311, and the portion of the outer wall of the skeleton layer 6 is an outer film layer 312.

The skeleton layer 6 can be a spiral or net shape formed by cutting a nickel-titanium alloy tube or weaving or winding nickel-titanium alloy wires; whether cut or woven, compliance and rigidity are considerations. After the addition of the coil or mesh, the stiffness of the receiving area 31 increases, but upon retrieval, a very high force is required to compress the stent, particularly in the initial state, upon retrieval of the stent in its tapered expanded state, such that the receiving area 31 slides over the stent to wrap the stent; because the opening section of the accommodating area 31 is a uniform cylindrical cavity, the accommodating area 31 is difficult to slide outside the bracket in the initial state, and the recovery operation difficulty is high.

Disclosure of Invention

The invention improves the far end side of the holding area of the sheath tube, is beneficial to recovering the interventional instrument, reduces the operation difficulty and improves the safety.

The sheath tube comprises a tube body, wherein a plurality of floating sheets are arranged at the far end side of the tube body, and are sequentially distributed along the circumferential direction of the tube body, and two adjacent floating sheets are connected through a connecting rib.

In the invention, the proximal side of the floating piece is connected with the end part of the side wall of the tube body, and the distal side of the floating piece can swing outwards in a radial direction, so that the guiding sheath tube can slide relatively to the interventional instrument when the interventional instrument is recovered, and the released part of the interventional instrument can be further stored and compressed.

The floating sheets are arranged at intervals along the circumferential direction of the tube body to obtain the degree of freedom of outward expansion, but in order to improve the radial binding force on the interventional instrument, part of the floating sheets are connected with each other or any two adjacent floating sheets are connected with each other through connecting ribs.

Preferably, the tube body is provided with a containing area for containing the interventional instrument, the containing area is of a three-layer structure, the tube body sequentially comprises an outer membrane layer, a framework layer and an inner membrane layer from outside to inside, and the floating piece is connected with the far end side of the framework layer.

The framework layer can be formed by cutting a nickel-titanium alloy tube or weaving nickel-titanium alloy wires, for example, the framework layer is spiral or net-shaped; the framework layer can also be cut by a 304 stainless steel tube; the outer membrane layer and the inner membrane layer are made of polymer materials, such as Elasthane, pe11ethane, pebax or Grilamide with lubricating performance.

Preferably, the floating plate and the framework layer are of an integrated structure.

The integral structure is convenient for processing and forming, and can also improve the axial tensile capacity.

The floating plate is exposed outside the outer film layer and the inner film layer. That is, the floating plate itself is entirely outside the outer membrane layer and the inner membrane layer, and it is further preferable that one or both of the outer membrane layer and the inner membrane layer extend distally and cover at least a part of the floating plate in order to provide smoothness for the sheath tube to pass through the body.

As a further preferred aspect, one or both of the outer membrane layer and the inner membrane layer extends toward the distal end side of the straight floating piece, and covers the floating piece entirely on the respective sides.

The outer film layer and the inner film layer are mutually dip-coated or adhered or hot-melted into a whole at the interval part of the floating piece.

Preferably, the floating plate extends in a straight line in the axial direction of the pipe body.

The floating sheets may be straight strips extending along the axial direction and having a certain width, and the width of each floating sheet in the circumferential direction may be the same or different, for example, a plurality of wider floating sheets are distributed at intervals, and one or more thinner floating sheets are arranged between two adjacent wider floating sheets.

Preferably, the floating plate extends along a curve in the axial direction of the pipe body.

The floating sheets can extend along an irregular path in the axial direction of the pipe body, can extend in equal width in shape, can change in width while extending in the axial direction, and can be complementary in width at different positions so as to avoid interference. When the floating sheets extend along the curve in the axial direction of the pipe body, for example, arc lines, spiral lines or fold lines are adopted.

Preferably, the floating plate extends along the axial direction of the pipe body and also has radial undulation.

The radial undulations may provide clearance for applying a stronger radial tightening force to the interventional instrument, compressing and receiving the interventional instrument, such as the float plate, in a wavy shape.

Preferably, the floating plate extends along the axial direction of the pipe body and also has circumferential undulation.

For example, the floating plate undulates circumferentially.

Preferably, the distal end of the float is rolled outwardly.

The outward rolling refers to the general trend, the trend of each part is not required to be completely consistent in the rolling process, and the rolling angle relative to the axis of the sheath tube is 180-360 degrees from the beginning of rolling to the pointing of the tail end. In particular, the end part of the distal end is preferably provided with an arc surface, so that unnecessary resistance is avoided when the device is advanced in the body, and the risk of puncture can be eliminated.

Preferably, the proximal side of the float plate is wider than the distal side.

The floating piece can extend in the axial direction (at least has a component extending along the axial direction of the sheath tube in the invention), and can extend in the same width or slightly change in width, and the distal end side is slightly narrow so as to facilitate the outward expansion and storage of the interventional instrument. For example, the ratio of the width of the proximal side to the width of the distal side of the floating piece is 1:1.1 to 2, preferably 1:1.2 to 1.5.

Preferably, the float plate is gradually narrowed in width from the proximal side to the distal side.

The tendency to narrow may be gradual or may be a stepwise abrupt change, for example, a stepwise narrowing of the width of the float plate from the proximal side to the distal side.

Preferably, the narrowing trend is related to the angle that the connection line between the proximal end and the distal end of each of the opposite sides of the floating piece is a reference line, and the included angle between the two reference lines is 15 degrees.

Preferably, the thickness of the floating plate is the same as the skeleton layer.

Optionally, the thickness of the floating piece is 0.3-0.4 mm.

Preferably, the floating plate has a length of 3 to 7mm in the axial direction of the pipe body.

The adaptive length is more favorable for guiding and accommodating the interventional instrument, and preferably, the floating plate has the length of 4-6 mm in the axial direction of the tube body.

Preferably, the distal side of the float plate has an arcuate edge.

The curved edges can reduce the pushing resistance and improve the safety.

Preferably, the number of the floating plates is 6 to 10.

As a further preferable aspect, the floating pieces are uniformly arranged in the circumferential direction. The gap between the adjacent floating pieces may be substantially the same as the width of the floating piece, and when the gap between the adjacent floating pieces is the same as the width of the floating piece irrespective of the width change, the sum of the wrap angles of the floating pieces in the circumferential direction is 180 degrees.

Considering the variation of the gap width, the sum of the wrap angles of each floating plate in the circumferential direction is optionally 150 to 300 degrees.

Preferably, through holes are formed in the floating plates, and the outer membrane layer and the inner membrane layer are intersected at the through hole positions.

The through holes are formed in order to enable the floating piece to be better adhered to the outer membrane layer and the inner membrane layer, and the inner membrane or the outer membrane and the floating piece are prevented from being peeled off due to large friction force when the support is recovered.

Preferably, the through holes are arranged in a plurality from the proximal end to the distal end. For example, 3 to 6 through holes are uniformly distributed.

The through holes are circular and elliptical in shape; the shape of each through hole on the same floating piece is the same or different; the shapes of the through holes on different floating plates are the same or different.

In the plurality of floating plates, preferably, connecting ribs are arranged between any two adjacent floating plates, and further preferably, all connecting ribs have the same axial position. For example, in the axial direction of the pipe body, the connecting rib is positioned at the middle part of the floating plate.

Preferably, the connecting ribs extend between two adjacent floating plates with equal width or unequal width.

The connecting ribs are strip-shaped and are placed and connected between two adjacent floating sheets in an integrated structure, and the connecting ribs can be changed in width.

Preferably, the connecting rib is provided with one or more expansion crack areas.

Preferably, the fracture zone has a thinner thickness and/or a narrower width than other adjacent portions of the tie bar.

With a thinner thickness and/or narrower width, a break can occur at the limit of expansion or upon interference with the interventional instrument to ensure that recovery can still continue.

Preferably, the cracking zone is positioned at the middle part of the length direction of the connecting rib. Or the cracking area is adjacent to the connecting part of the connecting rib and the floating piece.

Optionally, the connecting rib is arc-shaped, and the arc top is convex to the proximal side of the floating piece.

And 1-3 connecting ribs are arranged between two adjacent floating plates.

The connecting ribs and the floating sheets are of an integrated structure. Or the connecting ribs and the floating plates are of mutually fixed split structures, and the fixing mode is welding, binding or bonding.

The connecting ribs and the floating plates are made of the same or different materials.

When the connecting ribs and the floating plates are of a mutually fixed split structure, the connecting ribs can optionally pass through or be bound on the floating plates, and the floating plates are provided with positioning holes or positioning grooves for fixing or winding the connecting ribs.

Preferably, one or both of the outer membrane layer and the inner membrane layer extend distally and cover the tie bars.

The strength can be improved by covering the connecting ribs with the outer film layer or the inner film layer, and the connecting ribs can be still coated and bound when broken because the outer film layer or the inner film layer is made of flexible materials and the allowable deformation is large, so that potential safety hazards caused by outward tilting of the connecting ribs are avoided.

The invention also provides a conveying system for conveniently recovering the interventional instrument, which comprises a sheath core and a sheath tube which is in sliding fit with the outer part of the sheath core, wherein the distal end of the sheath core is provided with a guide head positioned at the end part and a fixed head adjacent to the guide head, a loading area for accommodating the interventional instrument is arranged between the guide head and the fixed head, the sheath tube comprises a proximal sheath tube and a distal sheath tube, and the distal sheath tube is the sheath tube.

The distal sheath, i.e. the side with the receiving area, may be of prior art as far as the proximal side is concerned, which is not the subject of improvement.

Preferably, the distal sheath has a pre-release state fully covering the loading zone, a semi-release state exposing a portion of the interventional instrument, and a release state fully disengaged from the interventional instrument;

in the pre-release state, the distal end side of the floating piece is lapped on the outer periphery of the guide head;

the half-release state is divided into a back half-release state in which the sheath moves towards the proximal end and a recovery half-release state in which the sheath moves towards the distal end according to the movement direction of the sheath relative to the sheath core, and the connecting rib has a cracking state or a non-cracking state in the recovery half-release state.

Preferably, the distal sheath has a larger tube diameter than the proximal sheath.

One or both of the outer membrane layer and the inner membrane layer extend towards the distal end side and cover the connecting ribs, and the inner membrane or the outer membrane covering the connecting ribs has a swelling state or a non-swelling state in a recovery half-release state.

The floating piece extends along the axial direction of the pipe body and also has radial undulation; the interventional instrument is provided with a hollowed-out part, and the radially inward undulating structure is positioned at the hollowed-out part of the interventional instrument before release.

The interventional instrument takes an aortic valve stent as an example, the expansion force of the aortic valve stent ranges from 240 mmHg to 320mmHg, and the corresponding expansion force when the corresponding connecting tendon breaks ranges from 240 mmHg to 320mmHg.

According to the invention, the floating piece is arranged on the sheath tube, so that the interventional instrument can be guided and stored back into the sheath tube when the interventional instrument is positioned poorly and needs to be recovered, and the operation difficulty is reduced.

Drawings

FIG. 1 is a schematic diagram of a prior art conveyor system;

FIG. 2 is a cross-sectional view at A in FIG. 1;

FIG. 3 is a cross-sectional view of the receiving area of FIG. 1;

FIG. 4 is a schematic structural view of the framework layer and the attached floating sheets in example 1;

FIG. 5 is a schematic view of a portion of the floating plate of FIG. 4;

FIG. 6 is a schematic view showing the cooperation between the floating plate and the bracket when the bracket is recovered;

FIG. 7 is a schematic structural diagram of the carcass layer and the attached floating sheets in example 2;

fig. 8 is a schematic structural diagram of the framework layer and the attached floating sheets in example 3.

Detailed Description

Example 1

Referring to fig. 4 to 6, in this embodiment, compared with the prior art, the main improvement is that a plurality of floating sheets 7 are arranged at the distal end of the sheath tube, each floating sheet 7 is sequentially arranged along the circumferential direction, and two adjacent floating sheets 7 are connected through a connecting rib 8.

In the drawings of the embodiments of the present invention, only the skeleton layer and the floating sheet at the distal end thereof are illustrated, and the sheath and the rest of the delivery system may be in the prior art, for example, the sheath includes a proximal sheath and a distal sheath, and the distal sheath has a receiving area with a larger diameter to wrap the loaded interventional device, which may be various vascular stents, occluders, etc., and in this embodiment, the aortic valve stent is taken as an example, and includes a stent 9 and a valve disposed inside the stent 9.

The holding area is three-layer structure, from outside to inside includes adventitia layer, skeleton layer and interior rete in proper order, and each floating piece 7 and skeleton layer integrated structure just are located the distal end side of skeleton layer.

The skeleton layer is tubular structure, is formed by nickel titanium alloy pipe cutting or by nickel titanium alloy silk braiding, and proximal end 61 is the taper of binding off, and hole 62 not only can increase flexibility, can also make skeleton layer and interior, the better subsides of adventitia layer cover together. The outer membrane layer and the inner membrane layer can be respectively made of Elasthane, pe11ethane, pebax or Grilamide with lubricating property.

The floating plate 7 and the framework layer 6 are of an integrated structure, so that the floating plate is convenient to machine and form, and the axial tensile capacity can be improved. The floating piece 7 is exposed to the outside of the outer film layer and the inner film layer.

The floating sheet 7 also has radial undulation to take shape while extending along the axial direction of the sheath tube body, and the distal end side of the floating sheet 7 has an outward turning structure 71, and the turning angle is preferably 270-360 degrees relative to the axial direction of the sheath tube. Avoiding unnecessary resistance when advancing in the body and eliminating the risk of puncture. The radial undulations may be wavy or everted structures may be formed by prior art techniques such as thermal processing techniques.

The proximal end 73 of the float sheet 7 is wider than the distal end 72, the width ratio of the distal end to the proximal end is 1:1.1-2, preferably 1:1.2-1.5, and the width of the float sheet 7 gradually narrows from the proximal end side to the distal end side.

The thickness of the floating plate 7 is 0.3-0.4 mm, the length of the floating plate 7 in the axial direction of the pipe body is 3-7 mm, and 8 floating plates 7 are uniformly distributed in the circumferential direction in the embodiment.

Connecting ribs 8 are arranged between any two adjacent floating plates 7, and all connecting ribs 8 have the same axial position.

The connecting ribs 8 can be broken when the floating plate 7 expands to the limit, so that the expansion degree of the floating plate 7 is further increased. To guide the tie bar 8 to fracture at a designated location, the tie bar is provided with one or more expansion zones 81, the expansion zones 81 having a thinner thickness and/or a narrower width relative to other adjacent portions of the tie bar. The use of a thinner thickness and/or narrower width may allow for fracture at the expansion limit or interference with the interventional instrument to ensure that stent retrieval may continue.

The connecting rib 8 and the floating plate 7 are integrally formed, in other embodiments, one or both of the outer film layer and the inner film layer extends towards the distal end side and covers the connecting rib 8, especially the outer film layer, which covers the connecting rib 8, not only can improve the strength, but also can still keep coating and binding the connecting rib 8 when the connecting rib 8 breaks, so that the connecting rib 8 is prevented from tilting outwards to form a potential safety hazard.

The distal sheath, and in particular the receiving zone, has a pre-release state fully covering the stent 9, a semi-release state exposing a portion of the stent 9, and a release state fully disengaged from the stent 9; in the pre-release state, the distal end side of the float 7 is placed on the outer periphery of the guide head in the sheath-core assembly; because the bracket 9 is provided with the hollowed-out part, the part of the floating piece 7 protruding radially inwards can be positioned at the hollowed-out part, so that the influence of the overlarge outer diameter on the in-vivo running is avoided.

The half-release state is classified into a pullback half-release state in which the sheath moves proximally and a retrieval half-release state in which the sheath moves distally, depending on the direction of movement of the sheath relative to the sheath core.

In the pre-release state, the tie-bar breaking strength is greater than the stent expansion force, so that the stent can be restrained to remain in a compressed state.

The retracted and semi-released state, i.e. the normal release of the stent 9 in the body, generally does not cause the fracture of the connecting rib 8, when the stent 9 needs to be recovered, the distal end moves relative to the sheath core Guan Chao, and in combination with fig. 6, at this time, part of the stent 9 has been expanded into a cone shape, the distal end of the floating plate 7 turns outward, and the outward expansion of the floating plate 7 itself forms a flare to facilitate guiding the stent 9 to reenter the sheath, if the resistance is too large or interference occurs with the stent 9, the connecting rib 8 breaks, and each floating plate 7 can further increase the outward expansion degree to continue the recovery process until the stent 9 is completely retracted into the accommodating area.

If the outer membrane layer and the inner membrane layer of the sheath tube extend and cover the connecting rib 8, the inner membrane or the outer membrane covering the connecting rib 8 may not be cracked when the connecting rib 8 breaks due to higher flexibility, and swelling may also occur.

In the invention, the distal end side of the floating piece can swing radially outwards, so that the guiding sheath tube can slide relatively to the interventional instrument when the interventional instrument is recovered, and the released part of the interventional instrument can be further stored and compressed.

Example 2

Referring to fig. 7, example 2 is different from example 1 in that the carcass layer and the floating plate are cut from stainless steel pipe, and the floating plate 7 has a straight path extending in the axial direction and is not bent.

Example 3

Referring to fig. 8, embodiment 3 is different from embodiment 2 in that the floating plate 7 is further provided with a through hole 74, and the outer film layer and the inner film layer can be better adhered together by intersecting each other at the through hole part, so as to prevent peeling phenomenon. The through holes are distributed from the proximal end to the distal end, and the shape of the through holes is round or oval.

The above disclosure is merely a specific embodiment of the present invention, but the present invention is not limited thereto, and those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention. It is apparent that such modifications and variations are intended to be within the scope of the invention as claimed. In addition, although specific terms are used in the present specification, these terms are for convenience of description only and do not constitute any particular limitation on the present invention.

Claims (18)

1. The sheath tube is characterized in that a plurality of floating sheets are arranged at the far end side of the tube body, each floating sheet is sequentially distributed along the circumferential direction of the tube body, and two adjacent floating sheets are connected through a connecting rib;

the connecting rib is provided with one or more expansion crack areas, and the expansion crack areas have thinner thickness and/or narrower width relative to other adjacent parts of the connecting rib.

2. The sheath tube for conveniently recovering the interventional instrument according to claim 1, wherein the tube body is provided with a containing area for containing the interventional instrument, the containing area is of a three-layer structure, the sheath tube sequentially comprises an outer membrane layer, a framework layer and an inner membrane layer from outside to inside, and the floating piece is connected with the distal end side of the framework layer.

3. The sheath for facilitating retrieval of an interventional instrument of claim 2, wherein the float plate is of unitary construction with the carcass layer.

4. The sheath for facilitating retrieval of an interventional instrument of claim 1, wherein the float plate extends in a straight line in the axial direction of the tube body.

5. The sheath for facilitating retrieval of an interventional instrument of claim 1, wherein the float plate extends curvilinearly in the axial direction of the tube body.

6. The sheath for facilitating retrieval of an interventional instrument of claim 5, wherein the float plate has radial undulations while extending axially along the tube body.

7. The sheath for facilitating retrieval of an interventional instrument of claim 5, wherein the distal end of the float blade is rolled outwardly.

8. The sheath for facilitating retrieval of an interventional instrument of claim 1, wherein the proximal side of the float plate is wider than the distal side.

9. The sheath for facilitating retrieval of an interventional instrument of claim 8, wherein the float plate tapers in width from a proximal side to a distal side.

10. The sheath tube for facilitating recovery of interventional instruments according to claim 1, wherein the floating plate has a length of 3-7 mm in the axial direction of the tube body.

11. The sheath for facilitating retrieval of an interventional instrument of claim 1, wherein the distal side of the float plate has an arcuate edge.

12. The sheath tube convenient for recycling interventional instruments according to claim 1, wherein the number of the floating plates is 6-10.

13. The sheath for facilitating retrieval of interventional instruments of claim 2, wherein the floating plate is provided with a through hole, and the adventitia layer and the intima layer meet each other at the through hole.

14. The sheath for facilitating retrieval of an interventional instrument of claim 1, wherein the tie bars extend equally or unequally between two adjacent floating plates.

15. The sheath for facilitating retrieval of an interventional instrument of claim 2, wherein one or both of the adventitia layer and the intima layer extends distally and overlies a tie bar.

16. The utility model provides a be convenient for retrieve interventional instrument conveying system, includes sheath core and sliding fit at the sheath pipe of sheath core outside, is the guide head that is located the tip at the distal end of sheath core and the fixed head that is adjacent the guide head, is the loading zone of holding interventional instrument between guide head and fixed head, its characterized in that, the sheath pipe includes proximal end sheath pipe and distal end sheath pipe, distal end sheath pipe is the sheath pipe of any one of claims 1~ 15.

17. The easy retrieval interventional instrument delivery system of claim 16, wherein the distal sheath has a pre-release state fully covering the loading zone, a semi-release state exposing a portion of the interventional instrument, and a release state fully disengaging the interventional instrument;

in the pre-release state, the distal end side of the floating piece is lapped on the outer periphery of the guide head;

the half-release state is divided into a back half-release state in which the sheath moves towards the proximal end and a recovery half-release state in which the sheath moves towards the distal end according to the movement direction of the sheath relative to the sheath core, and the connecting rib has a cracking state or a non-cracking state in the recovery half-release state.

18. The easy retrieval interventional instrument delivery system of claim 16, wherein the distal sheath has a larger tube diameter than the proximal sheath.