Reverse release stent delivery system

Abstract

The invention relates to a reverse release stent delivery system, which comprises an outer sheath tube, one end of the envelope recovery assembly is sleeved with a stent, the end, close to the heart, of the stent is a stent near end, the other end of the stent is a stent far end, the stent is wrapped with a flexible envelope, and the flexible envelope is connected with the envelope recovery assembly; the guide wire is used for tying the flexible envelope into a cylindrical shape; the locking assembly is used for locking the other end, away from the handle, of the guide wire, and the locking assembly is used for locking one end of the guide wire; and the bracket is connected with the rear release assembly. According to the reverse release stent conveying system, the release sequence from far to near is that the far end of the stent is accurately positioned, and unexpected branch blood vessel covering is avoided; as the far end is released firstly, the non-horn mouth faces forwards, and stent backward movement caused by blood flow impact is reduced; the bending performance is better, more surgical sites can be reached, the tying holes are arranged at various intervals, and the unfolding speed when each section of the stent is released can be controlled according to the surgical requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a reverse-release stent delivery system. Background Art

[0002] With the aging of the population, the incidence of cardiovascular diseases has increased year by year, and medical treatment methods have also shifted from traditional surgical operations with high trauma, high surgical difficulty and high complication rates to interventional treatment operations with low trauma and low surgical difficulty. Aortic stent implantation is generally performed by puncturing the femoral artery to insert the stent into the human body along the sheath, and then reach the lesion site through the aortic channel, release the stent, cover the lesion blood vessel, establish a new vascular pathway or repair the lesion blood vessel.

[0003] The principle of stent treatment for aortic dissection is to cover the rupture of aortic dissection with the polymer material of the stent-covered stent, block the blood flow into the false lumen to prevent further expansion or even rupture of the dissection. The rupture is often located at the branch vessel. During the antegrade release process from the proximal end to the distal end, the distal positioning of the existing vascular stent is often inaccurate due to the backward movement of blood flow impact or the forward jump of the stent, resulting in unexpected shielding of the branch vessel or incomplete closure of the rupture, which leads to organ ischemia or endoleak and other consequences that harm the patient.

[0004] Most of the existing vascular stents are released by proximal positioning. The proximal end of the stent is fixed by a post-release device, and the diameter of the stent section is shrunk into the inner cavity of the outer sheath. When releasing, the outer sheath is withdrawn, and the proximal end of the stent first expands into a cone-shaped opening, and is released in a forward direction from the proximal end to the distal end.

[0005] In the existing form of retracting the outer sheath, the proximal end of the stent first expands into a cone-shaped opening, and the area subjected to the impact of blood flow is large, which is prone to backward movement; the existing device method of compressing into the outer sheath may cause the developing ring at the rear end of the stent to shift forward, causing the operator to misjudge the position of the rear end of the stent before release. Summary of the invention

[0006] To this end, the technical problem to be solved by the present invention is to overcome the problem in the prior art that the forward release method is difficult to accurately position the distal end of the stent due to displacement caused by blood flow impact after release, shortening of the distal ends of each section of the stent to the proximal end, and changes in the length of the stent (manufacturing tolerance, offset when the development point is compressed), which can easily cause unexpected shielding of branch vessels or incomplete coverage of diseased vessels.

[0007] In order to solve the above technical problems, the present invention provides a stent delivery system for reverse release, comprising an outer sheath tube, one end of which is connected to a handle, and the interior of the outer sheath tube is configured as a hollow cavity; a capsule recovery component, one end of which is arranged in the hollow cavity, and the other end of the capsule recovery component extends out of the hollow cavity, an end of which is close to the heart, and a stent is sleeved on the end of the capsule recovery component extending out of the hollow cavity, the end of the stent close to the heart is the stent proximal end, and the end of the stent away from the heart is the stent distal end, and the outer end of the stent is arranged in the hollow cavity. The upper part is wrapped with a flexible coating, and the flexible coating is connected to the coating recovery component; a guide wire, one end of which is connected to the handle connected to the outer sheath, and the guide wire is used to tie the flexible coating to be cylindrical; a locking component, which is connected to the coating recovery component, and the locking component is used to lock the other end of the guide wire away from the handle, and the locking component is used to lock one end of the guide wire; a rear release component, one end of which passes through the coating recovery component and extends into the outer sheath, and the other end of the rear release component extends out of the stent proximal end of the stent, and the stent is connected to the rear release component. The reverse release stent delivery system of the present invention has a release sequence from far to near: accurate positioning of the distal end of the stent to avoid unexpected covering of branch vessels; because the distal end is released first, the non-flared mouth faces forward, reducing the stent backward movement caused by blood flow impact; better bending performance, more surgical sites can be reached, and the spacing of the tie holes can be arranged in a variety of ways: the deployment speed of each section of the stent when released can be controlled according to surgical requirements.

[0008] In one embodiment of the present invention, the stent includes a stent body and a bare crown, the stent body is sleeved on the outside of one end of the membrane recovery component extending out of the hollow cavity, the end of the stent body close to the heart is the stent proximal end, and the end of the stent body away from the heart is the stent distal end, and the bare crown is connected to the proximal end of the stent.

[0009] In one embodiment of the present invention, the capsule recovery component includes a guide wire guide body and a guide head, the guide wire guide body is a cylinder, and the axial direction of the guide wire guide body is set as hollow cavity two, one end of the guide wire guide body is set in hollow cavity one, and the other end of the guide wire guide body extends out of hollow cavity one, the guide head is fixedly connected to the end of the guide wire guide body extending out of hollow cavity one close to the proximal end of the stent, and the guide head is used for the guide wire to pass through.

[0010] In one embodiment of the present invention, the outer wall of the guide head is conically arranged, and the diameter of the guide head gradually decreases from the proximal end of the stent to the distal end of the stent. An annular groove is provided on the outer circumference of the guide head, and one or more circular through holes 1 are provided in the axial direction of the guide head. The circular through hole 1 is connected to the hollow cavity 2, and the guide wire can pass through the circular through hole 1.

[0011] In one embodiment of the present invention, the flexible membrane includes a membrane body one, a membrane body two and an intermediate connecting part, the membrane body one and the membrane body two have the same structure, and the membrane body one and the membrane body two are both rectangular thin sheets, the intermediate connecting part is arranged between the membrane body one and the membrane body two, and the intermediate connecting part is a rectangular strip, an assembly avoidance hole is provided at the middle position of the intermediate connecting part, and wire passing holes are provided on both sides of the assembly avoidance hole, the wire passing hole is connected to the circular through hole one, and the guide wire can pass through the wire passing hole.

[0012] In one embodiment of the present invention, the long sides of the capsule body one and the capsule body two along the axis direction of the stent are respectively provided with a distal tie hole, a middle tie hole and a proximal tie hole, and the guide wire is folded back and passed through the distal tie hole, the middle tie hole and the proximal tie hole on the capsule body one and the capsule body two to sew the capsule body one and the capsule body two together.

[0013] In one embodiment of the present invention, the locking assembly includes a locking inner ring and a locking outer ring, the locking inner ring is sleeved on the rear release assembly, the locking outer ring is sleeved outside the locking inner ring, the locking inner ring and the locking outer ring are both set to be annular, the inner wall of the locking outer ring is provided with two release notches, the two release notches are on the same diameter, the outer wall of the locking inner ring is provided with two guide wire limiting grooves, the two guide wire limiting grooves are on the same diameter, one end of the guide wire is provided in the guide wire limiting groove, when the guide wire limiting groove and the release notch are relatively misaligned, the guide wire is locked between the inner wall of the locking outer ring and the guide wire limiting groove. 1. The locking assembly mainly serves the function of locking and insurance, that is, to prevent the envelope from being released during transportation or being released prematurely due to the operator's misoperation. 2. After the locking assembly is released, the flexible envelope is released by pulling out the release guide wire through the button / knob / slider of the delivery handle.

[0014] In one embodiment of the present invention, the release recess is arranged in an arch shape along the radial cross section of the locking outer ring, the guide wire limiting groove is a semicircular groove, and the guide wire limiting groove is provided with an arc-shaped protrusion along the axial direction of the locking inner ring.

[0015] In one embodiment of the present invention, the rear release assembly includes a rear release rod, a TIP head, a rear release claw and a connecting rod, the TIP head is fixedly connected to one end of the rear release rod, the rear release claw is connected to one end of the connecting rod, the other end of the rear release rod passes through the rear release claw and extends into the connecting rod, and the connecting rod is arranged inside the guide wire guide body.

[0016] In one embodiment of the present invention, a guidewire channel is formed between the inner wall of the guidewire guide body and the outer wall of the connecting rod, and one end of the guidewire away from the locking assembly passes through the guidewire channel.

[0017] The above technical solution of the present invention has the following beneficial effects compared with the prior art: The reverse-release stent delivery system described in the present invention fixes the proximal end of the stent in the rear release device to prevent the stent from moving forward, and opens the flexible diameter-reducing device that fixes the stent by withdrawing the control guide wire, so that the stent is gradually released from the distal end to the proximal end. It can reduce the effect of blood flow impact on the stent and overcome the backward movement caused by blood flow impact; in the case of branch blood vessels, the distal end of the stent can be accurately positioned to avoid the risk of blocking the branch blood vessels and reduce the risk of surgery; in addition, the stent is loaded in a flexible diameter-reducing device with low friction and good flexibility, and can enter a more tortuous vascular pathway. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein Figure 1 It is a schematic structural diagram of a stent delivery system for reverse release during stent compression in a preferred embodiment of the present invention; Figure 2 It is a schematic diagram of the structure of the bracket in the preferred embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the stent and the flexible envelope in a preferred embodiment of the present invention; Figure 4 It is a schematic structural diagram of a stent delivery system for reverse release in a preferred embodiment of the present invention when the stent is not compressed; Figure 5 This is a schematic diagram of the structure of the flexible envelope in a preferred embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of a flexible coating wrapped stent in a preferred embodiment of the present invention; Figure 7 This is a schematic diagram of the outlet of the release guide wire in a preferred embodiment of the present invention; Figure 8 It is a cross-sectional view of the guide wire release and envelope recovery assembly in the preferred embodiment of the present invention; Fig. 9 This is a schematic diagram of the structure of the stent released from the distal end in a preferred embodiment of the present invention; Fig.10 It is a structural schematic diagram of a locking assembly in a preferred embodiment of the present invention; Fig.11 It is a structural schematic diagram of the locking state of the locking assembly in the preferred embodiment of the present invention; Fig.12 It is a structural schematic diagram of the locking assembly in the released state in the preferred embodiment of the present invention; Fig.13 This is a schematic diagram of the structure of the locking inner ring in a preferred embodiment of the present invention; Fig.14 A schematic diagram of the process of introducing the reverse-release stent delivery system into the human body in a preferred embodiment of the present invention; Fig.15 A schematic diagram of a stent delivery system for reverse release reaching a predetermined position in a preferred embodiment of the present invention; Fig.16 It is a schematic diagram of the retraction of the outer sheath of the stent delivery system for reverse release in a preferred embodiment of the present invention; Fig.17 A schematic diagram of the process of releasing the stent from the distal end to the proximal end in a preferred embodiment of the present invention; Fig.18 It is a schematic diagram of the complete release of the stent of the stent delivery system of the reverse release in the preferred embodiment of the present invention; Fig.19 This is a schematic diagram of the withdrawal of the reverse-release stent delivery system from the human body in a preferred embodiment of the present invention.

[0019] Description of the accompanying drawings: outer sheath 1, envelope recovery component 2, guide wire guide body 21, guide head 22, annular groove 221, circular through hole 1 222, guide head body 1 223, guide head body 2 24, connecting column 225, flexible envelope 3, envelope body 1 31, distal tie hole 311, middle tie hole 312, proximal tie hole 313, envelope body 2 32, intermediate connecting part 33, assembly avoidance hole 331, wire hole 332, recovery fixing hole 333, guide wire 4, locking component 5, Locking inner ring 51, guidewire limiting groove 511, locking outer ring 52, release notch 521, rear release assembly 6, rear release rod 61, TIP head 62, rear release claw 63, connecting rod 64, guidewire channel 65, stent 100, stent proximal end 101, stent distal end 102, stent body 103, bare crown 104, release guidewire distal end A, release guidewire proximal end B, guidewire exit direction C, flexible envelope detachment direction D, guidewire withdrawal direction E, femoral artery F, renal artery G, aortic aneurysm H, thoracic aorta I. DETAILED DESCRIPTION

[0020] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0021] Reference Figure 1As shown, the reverse release stent delivery system of the present invention comprises: an outer sheath tube 1, one end of which is connected to a handle, and the interior of the outer sheath tube 1 is set as a hollow cavity; a capsule recovery component 2, one end of which is set in the hollow cavity, and the other end of the capsule recovery component 2 extends out of the hollow cavity, close to the heart, and the end of the capsule recovery component 2 extending out of the hollow cavity is sleeved with a stent 100, the end of the stent 100 close to the heart is the stent proximal end 101, and the end of the stent 100 away from the heart is the stent distal end 102, and the outside of the stent 100 is wrapped with a flexible capsule 3, the flexible envelope 3 is connected to the envelope recovery component 2; a guide wire 4, one end of which is connected to the handle connected to the outer sheath 1, and the guide wire 4 is used to tie the flexible envelope 3 into a cylindrical shape; a locking component 5, which is connected to the envelope recovery component 2, and the locking component 5 is used to lock the other end of the guide wire 4 away from the handle, and the locking component 5 is used to lock one end of the guide wire 4; a rear release component 6, one end of which passes through the envelope recovery component 2 and extends into the outer sheath 1, and the other end of the rear release component 6 extends out of the proximal end 101 of the stent 100, and the stent 100 is connected to the rear release component 6.

[0022] The flexible coating 3 is not fixedly connected to the coating recovery component 2, and the part close to the proximal end 101 of the stent is independently sutured and fixed to the metal frame of the proximal end 101 of the stent. In procedures that do not require docking with other branch stents, the operation of recovering the flexible coating 3 can be omitted, thereby reducing the operation time and the surgical risk.

[0023] Reference Figure 2 , 3 As shown, the stent 100 includes a stent body 103 and a bare crown 104. The stent body 103 is sleeved on the outside of one end of the membrane recovery component 2 extending out of the hollow cavity. The end of the stent body 103 close to the heart is the stent proximal end 101, and the end of the stent body 103 away from the heart is the stent distal end 102. The bare crown 104 is connected to the stent proximal end 101, and the bare crown 104 is periodically arranged with peaks and troughs intermittently alternating.

[0024] The stent 100 can be divided into a bare stent and a covered stent. Since the skeleton material of the stent 100 is a hollow elastic structure made of stainless steel or nickel-titanium memory metal, the stent body 103 can achieve restraint compression and release expansion. The proximal and distal ends of the stent 100 are both provided with developing Mark points, which are made of platinum-iridium alloy in this example, so that the position of the stent can be dynamically monitored by the operator's radiographic development equipment.

[0025] 1: Bare stents are usually tubular structures made of stainless steel or nickel-titanium memory metal materials. Some bare stents are woven into a grid cylinder shape with metal wires.

[0026] 2: A coated stent is a bare stent that is covered or sewn with a layer of polymer material, which can be PET\PTFE\nylon\polypropylene, etc. (the polymer material can be fully covered or partially covered).

[0027] Bare crown 104: The metal skeleton of the stent has at least one corrugated ring that is not covered by the sub-material, which can be composed of a corrugated shape laser-cut from a metal tube or a metal wire bent into a hook shape.

[0028] Reference Figure 6 As shown, the capsule recovery component 2 includes a guide wire guide body 21 and a guide head 22, the guide wire guide body 21 is a cylinder, and the axial direction of the guide wire guide body 21 is set as a hollow cavity two, one end of the guide wire guide body 21 is set in the hollow cavity one, and the other end of the guide wire guide body 21 extends out of the hollow cavity one, the guide head 22 is fixedly connected to the end of the guide wire guide body 21 extending out of the hollow cavity one near the proximal end 101 of the stent, and the guide head 22 is used for the guide wire 4 to pass through.

[0029] Reference Figure 6-9 As shown, the outer wall of the guide head 22 is conically arranged, and the diameter of the guide head 22 gradually decreases from the proximal end 101 of the stent to the distal end 102 of the stent. An annular groove 221 is arranged on the outer circumference of the guide head 22, and one or more circular through holes 222 are arranged in the axial direction of the guide head 22. The circular through hole 222 is connected to the hollow cavity 2, and the guide wire 4 can pass through the circular through hole 222. The guide head 22 is composed of two parts, including a guide head body 223 and a guide head body 224, the one or more circular through holes 222 are arranged on the guide head body 224, the outer walls of the guide head body 223 and the guide head body 224 are both conically arranged, the guide head body 224 is connected to the guide wire guide body 21, and two symmetrically arranged connecting columns 225 are arranged on the end faces opposite to the guide head body 223 and the guide head body 224, one end of the connecting column 225 is fixedly connected to the guide head body 223, and two circular grooves are arranged on the guide head body 224, the two circular grooves and the two symmetrically arranged connecting columns 225 are symmetrically arranged one by one, and one end of the connecting column 225 extending out of the guide head body 223 is inserted into the circular groove.

[0030] In the process of releasing the stent 100, the locking assembly 5 is released, the release guide wire 4 is retracted, and the distal end 102 of the release guide wire is separated from the flexible envelope 3 along the tie hole on the flexible envelope 3. The distal end 102 of the stent expands rapidly due to its self-expansion and adheres to the blood vessel wall; the section of the release guide wire that has not been separated remains compressed, the section that has not been separated is limited by the flexible envelope 3, and the bare crown 104 is fixed by the rear release device, the stent 100 can still remain stable in the axial direction, effectively avoiding the problem of forward jumping and shortening of the stent 100.

[0031] Reference Figure 4 , 5 As shown, the flexible envelope 3 includes an envelope body 1 31, an envelope body 2 32 and an intermediate connection part 33. The envelope body 1 31 and the envelope body 2 32 have the same structure, and the envelope body 1 31 and the envelope body 2 32 are both rectangular thin sheets. The intermediate connection part 33 is arranged between the envelope body 1 31 and the envelope body 2 32, and the intermediate connection part 33 is in the shape of a rectangular strip. An assembly avoidance hole 331 is arranged in the middle position of the intermediate connection part 33, and both sides of the assembly avoidance hole 331 are provided with wire holes 332, the wire holes 332 are connected to the circular through hole 1 222, and the guide wire 4 can pass through the wire holes 332. The width of the intermediate connection part 33 is relatively small and it is arranged between the envelope body 1 31 and the envelope body 2 32 for its connection function. The assembly avoidance hole 331 is provided with a recovery fixing hole 333 on both sides close to the envelope body 1 31 and the envelope body 2 32. The two recovery fixing holes 333, the two circular grooves and the two symmetrically arranged connecting cylinders 225 are symmetrically arranged one by one. First, after removing the guide head body 1 223 from the guide head body 2 24, the middle connecting part 33 is placed in contact with the guide head body 2 24, and the recovery fixing hole 333 and the circular groove are overlapped. Then the guide head body 1 223 is installed on the guide head body 2 24, so that the connecting cylinder 225 passes through the recovery fixing hole 333 and is inserted into the circular groove. Glue can be applied to the connecting cylinder 225 in advance, so as to ensure the stable connection between the guide head body 1 223 and the guide head body 2 224. The lower end surface of the guide head body 1 223 and the upper end surface of the guide head body 2 224 clamp the middle connecting part 33 of the flexible envelope axially. Because the connecting column 225 on the guide head 223 extends to the recovery fixing hole 333 of the flexible envelope, the flexible envelope is circumferentially limited, so that the flexible envelope 3 is limited on the guide head 22, and the two pieces of the envelope body 1 31 and the envelope body 2 32 are bent to cover the stent 100. After the two sides of the openings of the envelope body 1 31 and the envelope body 2 32 are bound together by the guide wire 4, the envelope body 1 31 and the envelope body 2 32 form a cylindrical shape and wrap around the outer wall of the stent 100.

[0032] The stent 100 is axially inserted into one end of the flexible envelope 3, and after pre-compression (pre-compression is optional) (pre-shrinking is performed using a detachable binding line during pre-compression), the two flexible envelopes (encapsulation body 1 31 and envelope body 2 32) are closed, so that the envelope body 1 31 and the envelope body 2 32 cover the entire stent 100; the flexible envelope 3 can be a single-piece or multi-piece open-loop high-connection-strength and high-biocompatibility polymer material film (e-PTFE, PET, etc.), and the connection section between the flexible envelope 3 and the guide head 22 has a recovery fixing hole 333 (two connecting columns 225 are connected to the guide head 22 and inserted into the recovery fixing holes 333 of the envelope and fixed to the end face of the envelope recovery component 2, which can ensure that the flexible envelope 3 is not loosened or detached during the retraction process), a wire hole 332 (avoiding the release guide wire channel) and an assembly avoidance hole 331 (the flexible envelope 3 can be directly inserted along the head end of the rear release component 6 without pre-installation).

[0033] Reference Figure 5 As shown, the envelope body 1 31 and the envelope body 2 32 are respectively provided with a distal tie hole 311, a middle tie hole 312 and a proximal tie hole 313 on the long side along the axis direction of the stent 100, and the guide wire 4 is turned back through the distal tie hole 311, the middle tie hole 312 and the proximal tie hole 313 on the envelope body 1 31 and the envelope body 2 32 to sew the envelope body 1 31 and the envelope body 2 32 together. The distal tie hole 311, the middle tie hole 312 and the proximal tie hole 313 are located on the same straight line, the hole spacing between the distal tie hole 311 and the proximal tie hole 313 is small, and the hole spacing between the middle tie holes 312 is large. In this way, one end of the guide wire 4 is fixed on the locking assembly 5, and the movable end of the guide wire 4 is unidirectionally folded back and penetrated into the tie holes of the envelope body 1 31 and the envelope body 2 32, and the open loop edges of the two envelope bodies 1 31 and the envelope body 2 32 are sewed together to form a closed loop cylinder that wraps the outside of the stent 100. The movable end of the guide wire 4 passes through the distal tie hole 311, the middle tie hole 312 and the proximal tie hole 313, passes through the wire hole 332 and the circular through hole 1 222 and is connected to the handle connected to the outer sheath 1. The flexible envelope 3 has tie holes arranged continuously on both sides, and the arrangement of each section of the tie holes can be adjusted according to requirements to control the withdrawal time of the release guide wire 4, thereby regulating the speed of the stent 100 when it is released in the body.

[0034] The hole spacing between the distal tie hole 311 and the proximal tie hole 313 is small (slow release speed, gentler release process, more accurate positioning), and the hole spacing between the middle tie hole 312 is large (fast release speed, reduced operation time).

[0035] Reference Figure 10-13As shown, the locking assembly 5 includes a locking inner ring 51 and a locking outer ring 52, the locking inner ring 51 is sleeved on the rear release assembly 6, and the locking outer ring 52 is sleeved on the outside of the locking inner ring 51, the locking inner ring 51 and the locking outer ring 52 are both arranged in a circular ring shape, and two release recesses 521 are arranged on the inner wall of the locking outer ring 52, and the two release recesses 521 are on the same diameter, and two guide wire limiting grooves 511 are arranged on the outer wall of the locking inner ring 51, and the two guide wire limiting grooves 511 are on the same diameter, and one end of the guide wire 4 is arranged in the guide wire limiting groove 511, and when the guide wire limiting groove 511 and the release recess 521 are relatively misaligned, the guide wire 4 is locked between the inner wall of the locking outer ring 52 and the guide wire limiting groove 511. The principle of the locking assembly 5 is that the two release notches 521 correspond to the two guide wire limiting grooves 511 one by one. When the two release notches 521 and the two guide wire limiting grooves 511 are in the same straight line, the release notches 521 and the guide wire limiting grooves 511 are arranged opposite to each other. At this time, due to the existence of the release notches 521, the locking outer ring 52 does not compress the guide wire 4 in the guide wire limiting groove 511, so that the guide wire 4 can be released. The release notches 521 are arranged in an arched shape along the radial cross section of the locking outer ring 52, the guide wire limiting groove 511 is a semicircular groove, and the guide wire limiting groove 511 is provided with an arc-shaped convex portion 512 along the axial direction of the locking inner ring 51.

[0036] The release guide wire distal end A is locked and unlocked by the locking assembly 5. The locking inner ring 51 of the locking assembly 5 is axially limited on the pull rod of the rear release assembly 6, and the locking outer ring 52 is sleeved on the locking inner ring 51 and fixed to the rotating pipe of the handle. By rotating the rotating handle on the handle, the locking outer ring 52 can be made to rotate circumferentially around the locking inner ring 51. The release guide wire distal end A is inserted into the guide wire limiting groove 511 and limited to the outer peripheral surface of the locking inner ring 51 (with a raised arc-shaped protrusion 512, which can better prevent the release guide wire distal end A from axial movement when the locking outer ring 52 is pressed tightly). The locking outer ring 52 has one or more release notches 521. In the released state, the release guide wire can move freely axially in the cavity of the release notch 521 and the guide wire limiting groove 511; the locking outer ring 52 is rotated to make the line connecting the release notches 521 perpendicular to the line connecting the guide wire limiting groove 511, and the inner wall surface of the locking outer ring 52 squeezes the release guide wire, causing the guide wire 4 to be slightly deformed and closely attached to the limiting groove, thereby increasing the friction force and completely locking the distal end A of the release guide wire.

[0037] Reference Figure 4As shown, the rear release assembly 6 includes a rear release rod 61, a TIP head 62, a rear release claw 63 and a connecting rod 64, wherein the TIP head 62 is fixedly connected to one end of the rear release rod 61, the rear release claw 63 is connected to one end of the connecting rod 64, and the other end of the rear release rod 61 passes through the rear release claw 63 and extends into the connecting rod 64, and the connecting rod 64 is arranged inside the guide wire guide body 21. A guide wire channel 65 is formed between the inner wall of the guide wire guide body 21 and the outer wall of the connecting rod 64, and one end of the guide wire 4 away from the locking assembly 5 passes through the guide wire channel 65.

[0038] When the stent 100 is not released, the bare crown 104 of the proximal end 101 of the stent is pressed against the crest of the bare crown 104 by the rear release claw 63 to lock the stent 100. The entire stent 100 in the axial direction is enveloped by the flexible envelope 3 and the compression and release of the stent 100 are controlled by the pull-down and withdrawal of the rear release component 6 (the stent 100 has a memory metal skeleton, which quickly expands radially to a fixed outer diameter after release). The outer sheath 1 has a hollow cavity extending from the axial direction, which can accommodate the stent 100 compressed by the flexible envelope 3, and can move axially under the control of the handle to expose or converge the flexible envelope 3.

[0039] The working principle of the reverse release stent delivery system of the present invention is: The rear release component 6 runs through the entire system axially along the guide wire channel 65, is led out at the outlet at the end of the guide head 22, and points to the direction of the conveyor handle. After the flexible envelope 3 covers the entire stent 100, the corresponding tie holes (distal tie holes 311, middle tie holes 312 and proximal tie holes 313) are arranged in order, and the tie holes (distal tie holes 311, middle tie holes 312 and proximal tie holes 313) on the upper and lower sides (symmetrical or asymmetrical) of the flexible envelope 3 are unidirectionally alternately connected in series, and the two envelopes (envelope body 1 31 and envelope body 2 32) are brought together and bound into a cylindrical shape from the proximal end 101 of the stent to the distal end 102 of the stent. At this time, the pre-compressed lumen or restraining line on the stent 100 is evacuated, and the stent 100 is slightly expanded outward and closely attached to the flexible coating 3; the coating recovery component 2 is retracted, so that the guide head 22 carries the connecting section of the flexible coating 3 to wrap around the proximal end of the stent 100, and the connecting section of the flexible coating 3 is embedded in the trough position between the bare crowns 104, exposing the flexible coating 3 outside the bare crowns 104, and the flexible coating 3 is tightened at the distal end of the release guide wire 4 and snapped into the locking component 5. After this step, the release component 6 has completed the compression of the stent. Compared with the existing loading method of compressing the stent and pushing it into the outer sheath, this stent loading method has no axial compression in the sheath, and the flexible coating 3 makes the stent 100 evenly stressed, compressing the stent 100 as a whole in the radial direction. The developing point installed at the tail end can be kept flush with the tail end of the stent, and the positioning of the tail end of the stent under imaging is more accurate.

[0040] Reference Figure 14-19As shown, the stent delivery system of the reverse release corresponds to the following six processes: introduction into the human body, reaching the predetermined position, withdrawing the outer sheath to expose the flexible diameter reduction device, releasing the stent, completing the stent release, and withdrawing the device from the human body. (The release of the thoracic aorta stent is only a demonstration, and the position of the stent release is not specified, which can be applied to various needs).

[0041] See Fig.14 During the operation, the femoral artery F was punctured on one side, and a guide wire was inserted and an angiography catheter was introduced along the guide wire to complete angiography of the thoracic aorta I to determine the diameter and length of the aortic aneurysm H and the location of the branch vessels. The angiography catheter was exchanged with the guide wire, the angiography catheter was removed, and the guide wire was retained.

[0042] like Fig.15 A subcutaneous incision and a femoral artery incision are made at the puncture site, and the stent delivery system is introduced along the guide wire. The position of the TIP head 62 is observed under imaging until it reaches the predetermined position.

[0043] like Fig.16 Keep the main body of the delivery system stable, withdraw the outer sheath 1, and expose the flexible diameter-reducing device loaded with the stent. According to the developing point of the tail end of the stent under the image, the main body of the delivery system can be moved axially to adjust the flexible diameter-reducing device to the release point. In addition, because the flexible diameter-reducing device is composed of a flexible coating 3 with high connection strength and good compliance, in some surgical sites that the outer sheath 1 cannot reach (the blood vessel angle is too small, the blood vessel pathway is too tortuous, causing the outer sheath 1 to easily collapse radially), the outer sheath 1 can be withdrawn to expose and push the flexible diameter-reducing device to the surgical site. The flexible structure can also better conform to the curvature of the blood vessel pathway during surgery and adapt to more complex approaches.

[0044] See Fig.17 After the flexible diameter reduction device is positioned, the locking outer ring 52 is rotated to release the distal end of the guide wire, and the proximal end of the release guide wire is withdrawn, and the two flexible coating bodies 1 31 and 32 are separated, and the stent 100 begins to expand from the distal end 102 of the stent to the proximal end 101 of the stent, and is tightly attached to the inner wall of the blood vessel.

[0045] See Fig.18 After withdrawing the rear release component 6, the bare crown of the proximal end 101 of the stent is disengaged from the hook of the rear release device, and the bare crown 104 completely releases the proximal end 101 of the stent to fully unfold and anchor to the inner wall of the blood vessel to complete the fixation of the stent 100 on the blood vessel.

[0046] See Fig.19 The delivery system handle is moved backwards to completely remove the guide wire, release wire and post-release device from the human body. The optional flexible envelope 3 can be withdrawn from the human body along the fully expanded stent lumen along with the envelope recovery component 2, or can be sutured and fixed to the stent proximal end 101 to remain in the body.

[0047] The stent is wrapped and compressed by releasing the guide wire in series with the bundle hole of the diameter shrinking device, and the distal end of the release guide wire is pulled down and withdrawn to compress and release the stent; the release guide wire is pulled away from the distal end to the proximal end to separate the flexible envelope, so as to release the stent from the distal end to the proximal end. The spacing arrangement of the bundle holes controls the speed of stent release.

[0048] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A stent delivery system for reverse release, characterized in that: include, An outer sheath tube, one end of which is connected to a handle, and the interior of the outer sheath tube is configured as a hollow cavity 1; A capsule recovery component, one end of which is arranged in the hollow cavity one, and the other end of the capsule recovery component extends out of the hollow cavity one, close to the heart, the end of the capsule recovery component extending out of the hollow cavity one is sleeved with a stent, the end of the stent close to the heart is the stent proximal end, and the end of the stent away from the heart is the stent distal end, the outside of the stent is wrapped with a flexible capsule, and the flexible capsule is connected to the capsule recovery component; A guide wire, one end of which is connected to the handle connected to the outer sheath, and the guide wire is used to tie the flexible envelope into a cylindrical shape; A locking assembly connected to the capsule recovery assembly and used to lock the other end of the guide wire away from the handle, and the locking assembly is used to lock one end of the guide wire; A rear release component has one end that penetrates the capsule recovery component and extends into the outer sheath, and the other end of the rear release component extends out of the proximal end of the stent, and the stent is connected to the rear release component.

2. The retrograde stent delivery system according to claim 1, characterized in that: The stent includes a stent body and a bare crown. The stent body is sleeved on the outside of one end of the membrane recovery component extending out of the hollow cavity. The end of the stent body close to the heart is the stent proximal end, and the end of the stent body away from the heart is the stent distal end. The bare crown is connected to the proximal end of the stent.

3. The retrograde stent delivery system according to claim 1, characterized in that: The capsule recovery component includes a guide wire guide body and a guide head. The guide wire guide body is a cylinder, and the axial direction of the guide wire guide body is set as a hollow cavity two. One end of the guide wire guide body is set in the hollow cavity one, and the other end of the guide wire guide body extends out of the hollow cavity one. The guide head is fixedly connected to the end of the guide wire guide body extending out of the hollow cavity one near the proximal end of the stent, and the guide head is used for the guide wire to pass through.

4. The retrograde stent delivery system according to claim 3, characterized in that: The outer wall of the guide head is conically arranged, and the diameter of the guide head gradually decreases from the proximal end to the distal end of the stent. An annular groove is arranged on the outer circumference of the guide head, and one or more circular through holes 1 are arranged in the axial direction of the guide head. The circular through hole 1 is connected with the hollow cavity 2, and the guide wire can pass through the circular through hole 1.

5. The retrograde stent delivery system according to claim 4, characterized in that: The flexible membrane includes a membrane body one, a membrane body two and an intermediate connecting part. The membrane body one and the membrane body two have the same structure, and the membrane body one and the membrane body two are both rectangular thin sheets. The intermediate connecting part is arranged between the membrane body one and the membrane body two, and the intermediate connecting part is in the shape of a rectangular strip. An assembly avoidance hole is provided at the middle position of the intermediate connecting part, and wire passing holes are provided on both sides of the assembly avoidance hole. The wire passing hole is connected to the circular through hole one, and the guide wire can pass through the wire passing hole.

6. The retrograde stent delivery system according to claim 5, characterized in that: The long sides of the envelope body 1 and the envelope body 2 along the axis direction of the stent are respectively provided with a distal tie hole, a middle tie hole and a proximal tie hole. The guide wire is folded back and passed through the distal tie hole, the middle tie hole and the proximal tie hole on the envelope body 1 and the envelope body 2 to sew the envelope body 1 and the envelope body 2 together.

7. The retrograde stent delivery system according to claim 1, characterized in that: The locking assembly includes a locking inner ring and a locking outer ring, the locking inner ring is sleeved on the rear release assembly, the locking outer ring is sleeved on the outside of the locking inner ring, the locking inner ring and the locking outer ring are both arranged in an annular shape, the inner wall of the locking outer ring is provided with two release notches, the two release notches are on the same diameter, the outer wall of the locking inner ring is provided with two guide wire limiting grooves, the two guide wire limiting grooves are on the same diameter, one end of a guide wire is arranged in the guide wire limiting groove, and when the guide wire limiting groove and the release notch are relatively misaligned, the guide wire is locked between the inner wall of the locking outer ring and the guide wire limiting groove.

8. The retrograde stent delivery system according to claim 7, characterized in that: The release notch is arranged in an arch shape along the radial cross section of the locking outer ring, the guide wire limiting groove is a semicircular groove, and the guide wire limiting groove is provided with an arc-shaped convex portion along the axial direction of the locking inner ring.

9. The retrograde stent delivery system according to claim 3, characterized in that: The rear release assembly includes a rear release rod, a TIP head, a rear release claw and a connecting rod, wherein the TIP head is fixedly connected to one end of the rear release rod, the rear release claw is connected to one end of the connecting rod, the other end of the rear release rod passes through the rear release claw and extends into the connecting rod, and the connecting rod is arranged inside the guide wire guide body.

10. The retrograde stent delivery system according to claim 9, characterized in that: A guide wire channel is formed between the inner wall of the guide wire guide body and the outer wall of the connecting rod, and one end of the guide wire away from the locking assembly passes through the guide wire channel.

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