A stent delivery system with a gradually changing rigidity component

Abstract

The present application relates to a stent delivery system with a rigid gradient component, comprising an outer sheath, an inner tube sleeved within the outer sheath, and a stent gripped at the distal end of the inner tube, wherein a rigid gradient component is provided between the outer sheath and the inner tube, the rigid gradient component being sleeved outside the inner tube, the distal end of the inner tube extending out of the rigid gradient component, the proximal end of the stent overlapping the distal end of the rigid gradient component, and a spiral groove being provided on the rigid gradient component, wherein the spiral groove is a pitch gradient structure. The present application achieves a rigid transition between the stent and the tube body connected thereto in the stent delivery system by applying a rigid gradient component, so that the bending strength of the entire stent delivery system is continuously and evenly gradient, and the delivery system has both pushing properties and flexibility.

Description

Technical Field

[0001] The present application relates to the field of medical devices, and in particular to a stent delivery system having a rigidity gradient component. Background Art

[0002] Stent implantation is an important method for treating vascular stenosis or lesions. The stent system consists of two parts: the stent and the delivery system. The stent is inserted into the blood vessel through a puncture through the delivery system. Under the push of the external handle end, the stent passes through the vascular conduit and reaches the stenosis or lesion site and is released into the blood vessel. The stent supports the stenosis site in the blood vessel through self-expansion or balloon expansion, achieving vascular reconstruction. During the stent implantation procedure, the delivery system is an indispensable part of delivering the stent to the lesion site in the human body during interventional treatment. However, the effectiveness of the delivery system in passing through curved blood vessels is still not very good. The reason is that the existing stent delivery system has the problem that the bending strength between the stent end (distal end) and the tube body disposed in the outer sheath does not change continuously and uniformly, that is, there is a problem of excessively large sudden changes in bending strength. This is because the stent and the tube body in the delivery system are made of different materials, resulting in a large difference in bending strength. This leads to a large sudden change in bending strength at the junction, which makes the bending strength of the entire delivery sheath unable to change continuously and uniformly. When the delivery system passes through a complex and curved blood vessel, the stent and the tube connected / overlapped to it will bend, resulting in an increase in the local friction between the sheath of the delivery system and the blood vessel wall, making it impossible to effectively transmit the pushing force. The pushing force at the handle end is greatly reduced, making it difficult for the delivery system to push, and it is difficult for the stent system to pass through the curved part of the blood vessel to reach the lesion location. The existing stent delivery system solves this problem by increasing the thickness of the outer sheath. Although this method increases the bending strength of the entire delivery system, it greatly reduces the flexibility of the stent delivery system and reduces the passability of the delivery system. Therefore, there is an urgent need for a stent delivery system that has both pushing and flexibility. Summary of the Invention

[0003] In order to overcome the defects in the existing technology, the present invention uses laser cutting to design and implement a stent delivery system with a rigid gradient component to solve the problem of uneven and continuous changes in the bending strength of the delivery sheath in the stent delivery system, and bending when passing through curved blood vessels.

[0004] The object of the present invention is achieved through the following technical solutions:

[0005] A stent delivery system with a rigid gradient component comprises an outer sheath, an inner tube sleeved within the outer sheath, and a stent gripped at the distal end of the inner tube. A rigid gradient component is provided between the outer sheath and the inner tube, the rigid gradient component is sleeved outside the inner tube, the distal end of the inner tube extends out of the rigid gradient component, the proximal end of the stent overlaps with the distal end of the rigid gradient component, and a spiral groove is provided on the rigid gradient component, the spiral groove being a pitch gradient structure.

[0006] The purpose of the present invention can be further achieved by the following technical solutions:

[0007] In one embodiment, the pitch of the spiral groove gradually increases from the distal end to the proximal end, and the bending strength of the rigid gradient component gradually increases from the distal end to the proximal end, so that the bending strength of the proximal part of the stent and the bending strength of the distal part of the rigid gradient component change continuously.

[0008] In one embodiment, the pitch of the spiral groove gradually decreases from the distal end to the proximal end, and the bending strength of the rigidity gradient component gradually decreases from the distal end to the proximal end.

[0009] In one embodiment, the rigid gradient component is formed by laser cutting from a tube.

[0010] In a preferred embodiment, the tube is a stainless steel tube, a nickel-titanium alloy tube, a cobalt-chromium alloy tube or a polymer material tube.

[0011] In one embodiment, the proximal end of the rigid gradual change component is fixedly connected to the inner tube. In a preferred embodiment, the minimum bending radius of the proximal end of the rigid gradual change component is close to the minimum bending radius of the inner tube.

[0012] In one embodiment, the proximal end of the rigid gradient component is fixedly connected to the operating end.

[0013] In one embodiment, a plurality of developing rings are provided at the end of the bracket, and a plurality of slots matching the developing rings are provided at the distal end of the rigid gradient component, and the slots are cooperatively connected with the developing rings.

[0014] In one embodiment, a tapered catheter head is fixedly connected to the distal end of the inner tube.

[0015] In one embodiment, the outer sheath and the inner tube are both fixedly connected to a handle, and the outer sheath is manipulated to move axially relative to the inner tube by a release knob provided on the handle to release the stent.

[0016] In one embodiment, the proximal end of the rigid gradient component is fixedly connected to the operating end via a middle tube. In a preferred embodiment, the minimum bending radius of the proximal end of the rigid gradient component is close to the minimum bending radius of the middle tube.

[0017] In a preferred embodiment, the stent delivery system is further provided with a liner rod, the proximal end of the inner tube is sleeved in the liner rod, the distal end of the liner rod is fixedly connected to the middle tube, or the distal end of the liner rod is connected to the rigid gradient component.

[0018] In a preferred embodiment, a plurality of glue dispensing holes are provided on the liner rod, and the inner tube is connected to the liner rod through the glue dispensing holes.

[0019] In a preferred embodiment, the outer sheath and the inner tube are both fixedly connected to a handle, and the release knob provided on the handle is used to manipulate the outer sheath to move axially relative to the inner tube along the liner rod to release the stent.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. The present invention realizes a rigid transition between the stent and the tube body supporting the stent in the stent delivery system by applying a rigid gradient component, and the rigid gradient component adjusts the pitch so that its bending strength is between the stent and the inner tube or the middle tube; so that the minimum bending radius of the distal part of the rigid gradient component is close to the minimum bending radius of the proximal part of the stent, and the bending strength of the proximal part of the rigid gradient component gradually increases, so that the bending strength of the entire stent delivery system changes continuously and evenly, so that the delivery system has both pushing properties and flexibility.

[0022] 2. The present invention provides a connection between the bracket and the distal end of the rigid gradient component by providing a slot to clamp the developing ring of the bracket, so as to make the bending resistance of the bracket end and the rigid gradient component continuously and gradually change, thereby preventing a sudden change in rigidity at the connection point, which would cause bending problems at the connection point. The connection between the bracket and the distal end of the rigid gradient component can also solve the problem of the bracket jumping forward when released. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 4 is a schematic cross-sectional view of the distal end portion of an embodiment of the stent delivery system of the present invention.

[0024] Figure 2 It is a schematic cross-sectional structural diagram of the proximal portion of an embodiment of the stent delivery system of the present invention.

[0025] Figure 3 It is a schematic structural diagram of the support of the present invention.

[0026] Figure 4a-4d Schematic diagrams of the structures of different embodiments of the rigid gradient component of the present invention.

[0027] Figure 5 It is a structural schematic diagram of an embodiment of the liner rod of the present invention.

[0028] Figure 6 FIG. 4 is a schematic cross-sectional view of the distal end portion of another embodiment of the stent delivery system of the present invention.

[0029] Figure 7 It is a schematic cross-sectional structural diagram of the proximal portion of another embodiment of the stent delivery system of the present invention.

[0030] Figure 8 It is a structural schematic diagram of another embodiment of the liner rod of the present invention.

[0031] Figure 9 It is a schematic diagram of the use effect of the stent delivery system in the prior art.

[0032] Figure 10 It is a schematic diagram of the use effect of the stent delivery system of the present invention. DETAILED DESCRIPTION

[0033] The technical solution of the present invention and the advantages thereof are further described in detail below with reference to the accompanying drawings and specific embodiments. Components in the accompanying drawings are not necessarily drawn to scale, and the focus is on illustrating the concept of the present invention.

[0034] In various specific embodiments of the present invention, well-known structures or materials involved therein are not described in detail. In addition, those skilled in the art should understand that the following various embodiments are only for illustration and are not intended to limit the scope of protection of the present invention.

[0035] Before describing the specific embodiments of the present invention in detail, the terms involved in the present invention are explained as follows:

[0036] “Proximal end” refers to the end closer to the operator, and “distal end” refers to the end farther from the operator.

[0037] Example 1

[0038] like Figure 1As shown, the present invention uses laser cutting to design and implement a stent delivery system with a rigid gradient component, which includes an outer sheath 4, an inner tube 2 sleeved in the outer sheath 4, and a stent 3 gripped at the distal end of the inner tube 2. A rigid gradient component 5 is provided between the outer sheath 4 and the inner tube 2. The rigid gradient component 5 is sleeved outside the inner tube 2, and the distal end of the inner tube 2 extends out of the rigid gradient component 5. The proximal end of the stent 3 overlaps with the distal end of the rigid gradient component 5. A spiral groove is provided on the rigid gradient component 5, and the spiral groove is a pitch gradient structure. The rigid gradient component 5 is formed by laser cutting of a pipe. In one embodiment, the pipe is a stainless steel pipe, a nickel-titanium alloy pipe, a cobalt-chromium alloy pipe, or a polymer material pipe. In one embodiment, the pitch of the spiral groove gradually increases from the distal end to the proximal end, the minimum bending radius of the distal end of the rigid gradient component 5 is close to the minimum bending radius of the stent 3, and the bending strength of the rigid gradient component 5 gradually increases from the distal end to the proximal end, so that the bending strength of the entire stent delivery system changes continuously and evenly, so that the delivery system has both pushability and flexibility. The outer sheath 4 and the inner tube 2 are both fixedly connected to the handle, and the release knob provided on the handle is used to manipulate the outer sheath 4 to move axially relative to the inner tube 2 to achieve the release of the stent 3. A conical catheter head 1 is fixedly connected to the distal end of the inner tube 2. In one embodiment, the distal end of the inner tube 2 is connected to the conical catheter head 1 by gluing. The provision of the conical catheter head 1 can prevent contusion of the blood vessels and increase the lesion-passing ability of the stent delivery system.

[0039] In the existing stent system, if the metal coverage of the implanted stent is high, the bending strength of the stent is high. The bending strength of the stent is much greater than the bending strength of the inner tube of the outer sheath, so the pitch change of the rigid gradient structure set at the proximal end of the stent is different from the embodiment described above. In this case, Figure 4b As shown, the pitch of the spiral groove gradually decreases from the distal end to the proximal end, and the bending strength of the rigid gradient component gradually decreases from the distal end to the proximal end. Of course, those skilled in the art can choose other pitch variation methods according to the application scenario of the product and the curved structure of the blood vessel, for example, Figure 4c As shown, the pitch gradually increases and then gradually decreases, or as Figure 4d As shown, the distance gradually decreases and then gradually increases to adapt to different vascular structures, so that the entire stent delivery system has good pushability and flexibility, and improves the system's ability to pass through lesions.

[0040] like Figure 1 and Figure 2As shown, in one embodiment, the proximal end of the rigid gradient component 5 is fixedly connected to the handle 9 through the middle tube 6, and the minimum bending radius of the proximal end of the rigid gradient component 5 is close to the minimum bending radius of the middle tube 6, so as to achieve a continuous and uniform change in the bending strength of the connection area between the rigid gradient component 5 and the middle tube 6, so that the stent delivery system as a whole has good flexibility. In one embodiment, as Figures 4a-4d As shown, a groove 52 is provided at the proximal end of the rigid gradient component 5 so as to be welded to the middle tube 6 .

[0041] like Figure 9 As shown, the existing stent delivery system has a large difference in bending resistance due to the different materials of the stent and the sheath of the delivery system, which leads to a large rigidity mutation at the connection point, so that the bending strength of the entire delivery sheath cannot be continuously and evenly changed. When the delivery system passes through a complex curved blood vessel, the connection between the stent and the sheath will bend, resulting in an increase in the local friction between the outer sheath of the delivery system and the blood vessel wall, making it impossible to effectively transmit the pushing force. The pushing force at the handle end is greatly reduced, making it difficult to push the delivery system, and it is difficult for the stent system to pass through the curved part of the blood vessel to reach the lesion location. A rigid gradient component 5 is provided in the stent delivery system of the present application, such as Figure 4a As shown, a spiral groove 53 is provided on the rigid gradient component 5, and the spiral groove 53 is a gradient structure with a pitch gradually increasing from the distal end to the proximal end, which can achieve the continuity of the rigid transition between the stent 3 and the sheath in the stent delivery system. Figure 10 As shown, the stent delivery system of the present application will not bend at the junction of the stent and the tube body supporting the stent when passing through a complex and curved blood vessel. The pushing force can be effectively transmitted to the distal end of the catheter, and it has good passing ability. This structure makes the stent delivery system as a whole have both pushing properties and flexibility.

[0042] like Figure 3 As shown, in one embodiment, a plurality of developing rings 31 are provided at the end of the bracket 3, as shown in FIG. Figures 4a-4d As shown, a plurality of retaining grooves 51 matching the developing ring 31 are provided at the distal end of the rigid gradient component 5, and the retaining grooves 51 are cooperatively connected to the developing ring 31. The retaining grooves 51 provided at the distal end of the rigid gradient component 5 of the present invention can retain the developing ring 31 of the bracket 3 to provide a connection between the bracket 3 and the distal end of the rigid gradient component 5, so that the bending strength of the proximal end of the bracket 3 and the rigid gradient component 5 continuously and gradually changes, preventing a sudden change in rigidity at the connection that could cause bending problems at the connection. The connection between the bracket 3 and the distal end of the rigid gradient component 5 can also solve the problem of the bracket 3 jumping forward when released.

[0043] like Figure 2As shown, in one embodiment, the stent delivery system is further provided with a liner rod 7, the proximal end of the inner tube 2 is fixedly connected to the liner rod 7, and in one embodiment, the inner tube 2 is sleeved in the liner rod 7. The distal end of the liner rod 7 is connected to the middle tube 6, and in one embodiment, as shown Figure 5 As shown, a liner rod groove 71 is provided at the distal end of the liner rod 7, and the proximal end of the middle tube 6 is welded to the distal end of the liner rod 7 at the liner rod groove 71. In another embodiment, a plurality of glue holes 72 are provided on the liner rod 7, and glue is injected into the glue holes 72 to achieve a fixed connection between the liner rod 7 and the inner tube 2. The outer sheath tube 4 is fixedly connected to the handle 9, and the release knob provided on the handle 9 is used to manipulate the outer sheath tube 4 to move axially along the liner rod 7 relative to the inner tube 2 to achieve the release of the bracket 3.

[0044] Example 2

[0045] This embodiment differs from the first embodiment in that Figure 6 As shown, no middle tube is provided in the stent delivery system. The stent delivery system with a rigid gradient component in this embodiment includes an outer sheath 4, an inner tube 2 sleeved in the outer sheath 4, and a stent 3 gripped at the distal end of the inner tube 2. A rigid gradient component 5 is provided between the outer sheath 4 and the inner tube 2. The rigid gradient component 5 is sleeved outside the inner tube 2, and the distal end of the inner tube 2 extends out of the rigid gradient component 5. The proximal end of the stent 3 overlaps with the distal end of the rigid gradient component 5. A spiral groove is provided on the rigid gradient component 5, and the spiral groove is a gradient structure in which the pitch gradually increases from the distal end to the proximal end. The rigid gradient component 5 is formed by laser cutting of a pipe. In one embodiment, the pipe is a stainless steel pipe, a nickel-titanium alloy pipe, a cobalt-chromium alloy pipe or a polymer material pipe. In one embodiment, the bending strength of the distal portion of the rigid gradient component 5 is close to that of the stent 3. The bending strength of the rigid gradient component 5 gradually increases from the distal end to the proximal end, resulting in a continuous and uniform change in the bending strength of the entire stent delivery system, making the delivery system both pushable and compliant. A tapered catheter head 1 is fixedly connected to the distal end of the inner tube 2. In one embodiment, the distal end of the inner tube 2 and the tapered catheter head 1 are connected by gluing. The provision of the tapered catheter head 1 can prevent vascular contusion and increase the stent delivery system's ability to pass through lesions.

[0046] like Figure 7 As shown, the stent delivery system is further provided with a liner rod 7, the proximal end of the inner tube 2 is sleeved in the liner rod 7, and the distal end of the liner rod 7 is connected to the proximal end of the rigid gradient component 5. In one embodiment, as shown Figure 8As shown, a step 73 is provided at the distal end of the lining rod 7, and the outer diameter of the step 73 is smaller than the inner diameter of the rigid gradient component 5. The proximal end of the rigid gradient component 5 is sleeved with the distal end of the lining rod 7 through the step 73. In one embodiment, a plurality of glue dispensing holes 72 are provided on the lining rod 7, and glue is injected into the glue dispensing holes 72 to achieve a fixed connection between the lining rod 7 and the inner tube 2. The outer sheath tube 4 is fixedly connected to the handle 9, and the release knob provided on the handle 9 is used to manipulate the outer sheath tube 4 to move axially along the lining rod 7 relative to the inner tube 2 to achieve the release of the bracket 3.

[0047] The bending strength of the distal portion of the rigid gradient component 5 is close to that of the stent 3 . The bending strength of the rigid gradient component 5 gradually increases from the distal end to the proximal end, and its bending strength changes continuously and evenly, so that the stent delivery system as a whole has good bending resistance.

[0048] like Figure 9 As shown, the existing stent delivery system has a large difference in bending resistance due to the different materials of the stent and the sheath of the delivery system, which leads to a large rigidity mutation at the connection point, so that the bending strength of the entire delivery sheath cannot be continuously and evenly changed. When the delivery system passes through a complex curved blood vessel, the connection between the stent and the sheath will bend, resulting in an increase in the local friction between the outer sheath of the delivery system and the blood vessel wall, making it impossible to effectively transmit the pushing force. The pushing force at the handle end is greatly reduced, making it difficult to push the delivery system, and it is difficult for the stent system to pass through the curved part of the blood vessel to reach the lesion location. A rigid gradient component 5 is provided in the stent delivery system of the present application, such as Figure 4b As shown, a spiral groove 53 is provided on the rigid gradient component 5, and the spiral groove 53 is a gradient structure with a pitch gradually decreasing from the distal end to the proximal end, which can achieve the continuity of the rigid transition between the stent 3 and the sheath in the stent delivery system. Figure 10 As shown, the stent delivery system of the present application will not bend at the junction of the proximal end of the stent and the inner tube 2 when passing through a complex and curved blood vessel. The pushing force can be effectively transmitted to the distal end of the catheter, and it has good passing ability. This structure makes the stent delivery system as a whole have both pushing properties and flexibility.

[0049] The above detailed description of the present invention is intended to enable persons familiar with the art to understand the contents of the present invention and implement them. It does not limit the scope of protection of the present invention. Any equivalent changes or modifications made based on the spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A stent delivery system with a rigid gradient component, comprising an outer sheath, an inner tube sleeved within the outer sheath, and a stent gripped at the distal end of the inner tube, characterized in that: A rigid gradient component is provided between the outer sheath and the inner tube, the rigid gradient component is sleeved outside the inner tube, the distal end of the inner tube extends out of the rigid gradient component, the proximal end of the bracket overlaps the distal end of the rigid gradient component, a spiral groove is provided on the rigid gradient component, the spiral groove is a pitch gradient structure, a plurality of developing rings are provided at the end of the bracket, and a plurality of card grooves matching the developing rings are provided at the distal end of the rigid gradient component, the card grooves are matched with the developing rings, so that the bending strength of the proximal end of the bracket and the rigid gradient component continuously changes gradually, and the rigid gradient component is formed by laser cutting of a tube.

2. The stent delivery system according to claim 1, wherein: The pitch of the spiral groove gradually increases from the distal end to the proximal end, and the bending strength of the rigidity gradient component gradually increases from the distal end to the proximal end.

3. The stent delivery system according to claim 1, wherein: The pitch of the spiral groove gradually decreases from the distal end to the proximal end, and the bending strength of the rigidity gradient component gradually decreases from the distal end to the proximal end.

4. The stent delivery system according to claim 1, wherein: The proximal end of the rigid gradual-change component is fixedly connected to the inner tube.

5. The stent delivery system according to claim 1, wherein: The proximal end of the rigid gradual change component is fixedly connected to the operating end.

6. The stent delivery system according to claim 1, wherein: The proximal end of the rigid gradient component is fixedly connected to the operating end through a middle tube.

7. The stent delivery system according to claim 6, wherein: The stent delivery system is also provided with a liner rod, the proximal end of the inner tube is sleeved in the liner rod, the distal end of the liner rod is fixedly connected to the middle tube, or the distal end of the liner rod is connected to the rigid gradient component.

8. The stent delivery system according to claim 7, wherein: The outer sheath tube and the inner tube are both fixedly connected to the handle, and the release knob provided on the handle is used to manipulate the outer sheath tube to move axially relative to the inner tube along the liner rod to release the stent.

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