CN111317601A - Tracheal stent - Google Patents

Abstract

The present invention provides a tracheal stent, comprising a hollow tubular support unit, at least part of the support unit is provided with a membrane, the tracheal stent further includes an anchor unit disposed at the distal end of the support unit, the anchor A coating film is provided on the anchoring unit; the anchoring unit includes at least one anchoring part, the anchoring part is set at the distal end of the supporting unit, and the proximal end section connecting the anchoring part and the supporting unit is a straight line type. In the tracheal stent of the present invention, the tracheal stent is configured to include at least a partially covered support unit and an anchoring unit for fixing, and the anchoring unit is provided with a coating, which solves the problem that the bare stent in the prior art is easy to stimulate tissue proliferation. It is difficult to remove the stent from the trachea, and the stent graft in the prior art is prone to displacement. The tracheal stent provided by the invention has little stimulation to the inner wall of the trachea, stable position after implantation, less displacement and easy recovery.

Description

Tracheal stent

technical field

The invention relates to a medical stent, in particular to a tracheal stent.

Background technique

The trachea is a tube connecting the larynx and the lungs, and is composed of cartilage, muscle, connective tissue and mucosa; the cartilage is a "C"-shaped cartilage ring with the gap backward, and the cartilage rings are connected by ligaments. Connected by smooth muscle and dense connective tissue, it maintains a continuous open state. Congenital dysplasia or acquired disease may lead to tracheal stenosis, resulting in poor breathing and even life-threatening. In recent years, the clinical use of built-in tracheal stents in the treatment of tracheal stenosis has achieved remarkable results. Tracheal stents generally cannot be permanently implanted. Clinically, technical requirements for recovery of tracheal stents after a period of implantation are proposed.

Tracheal stents can be divided into silicone stents and metal stents according to their materials. The metal stents are divided into bare stents and covered stents according to whether they are covered or not. The metal materials are generally nickel-titanium memory alloy or stainless steel. Each stent has its own advantages and disadvantages. Bare stents are easy to place and difficult to displace after placement, but it is easy to stimulate the proliferation of granulation tissue, resulting in restenosis of the tracheal passage and the stent is not easy to remove. Although covered stents are easy to remove, they are easy to cause secretion retention. , and the stent is prone to displacement, and the stent compliance becomes poor and cannot adapt to the airway contraction.

In view of the existing bare tracheal stents prone to complications such as granulation tissue hyperplasia leading to airway restenosis, and the defects of easy displacement of covered stents, it is necessary to provide a tracheal stent that is convenient for recovery and less prone to displacement after implantation.

SUMMARY OF THE INVENTION

The present invention provides a tracheal stent, comprising a hollow tubular support unit, at least part of the support unit is provided with a coating, the tracheal stent further includes an anchor unit disposed at the distal end of the support unit, the anchor A coating film is arranged on the anchoring unit; the anchoring unit includes at least one anchoring part, the anchoring part is set at the distal end of the supporting unit, and the proximal end section of the anchoring part connected with the supporting unit is Straight.

In one embodiment, the distal end section of the anchoring portion is a bent section extending toward the central axis of the support unit.

In one embodiment, a bifurcated segment is further included between the proximal end segment and the distal end segment of the anchor portion, and the distal end of the bifurcated segment is connected to the proximal end of at least one of the distal end segments.

In one embodiment, the anchoring portion further includes a bifurcated segment, and the bifurcated segment is disposed at the distal end of the proximal end segment of the anchoring portion.

In one embodiment, the bifurcated segment comprises a multi-stage bifurcation.

In one embodiment, the supporting unit is woven from braided wires, and the anchoring unit is formed by winding the braided wires.

In one embodiment, the anchoring unit is formed by cutting.

In one embodiment, the coating material is titanium nitride, tantalum nitride, zirconium nitride or diamond-like carbon.

In one embodiment, the tracheal stent further includes a recovery unit disposed at the proximal end of the support unit, the recovery unit is a closed annular structure, and the recovery unit is passed through the proximal end of the support unit.

In one embodiment, a coating film is provided on the uncoated portion of the support unit.

In the tracheal stent of the present invention, the tracheal stent is configured to include at least a partially covered support unit and an anchoring unit for fixing, and the anchoring unit is provided with a coating, which solves the problem that the bare stent in the prior art is easy to stimulate tissue proliferation. It is difficult to remove the stent from the trachea, and the stent graft in the prior art is prone to displacement. The tracheal stent provided by the invention has little stimulation to the inner wall of the trachea, stable position after implantation, less displacement and easy recovery.

Description of drawings

1 is a schematic diagram of the overall structure of the tracheal stent according to Embodiment 1 of the present invention;

Fig. 2 is the enlarged structural schematic diagram of the proximal end of the tracheal stent shown in Fig. 1;

Fig. 3 is a schematic diagram when the tracheal stent shown in Fig. 1 is recovered after being implanted in the airway for a certain period of time;

4 is a schematic diagram of the overall structure of the tracheal stent according to Embodiment 2 of the present invention;

Fig. 5 is the enlarged structural schematic diagram of the distal end of the tracheal stent shown in Fig. 4;

6 is a schematic diagram of a distal end structure of a tracheal stent according to another embodiment of the present invention;

7 is a schematic diagram of the overall structure of the tracheal stent according to Embodiment 3 of the present invention;

FIG. 8 is a schematic view of the enlarged structure of the distal end of the tracheal stent shown in FIG. 7;

Fig. 9 is a schematic diagram when the tracheal stent shown in Fig. 1 is recovered after being implanted in the airway for a certain period of time;

Fig. 10 is a schematic diagram of the tracheal stent shown in Fig. 7 when it is recovered after being implanted in the airway for a certain period of time;

11 is a schematic diagram of the overall structure of the tracheal stent according to Embodiment 4 of the present invention;

FIG. 12 is an enlarged schematic view of the distal end of the tracheal stent shown in FIG. 11 .

Detailed ways

In order to better understand the technical solutions and beneficial effects of the present invention, the tracheal stent of the present invention is illustrated below with reference to the accompanying drawings.

For the convenience of description, the position of the tracheal stent relative to the larynx after implantation is defined as follows: the end of the tracheal stent close to the larynx is the "proximal end", and the end of the tracheal stent away from the larynx is the "distal end".

The tracheal stent of the present invention is an improvement made on the metal stent in the prior art. Under normal circumstances, the diameter of the tracheal stent in its natural state is slightly larger than the inner diameter of the physiological trachea. In this way, when the tracheal stent is implanted into the trachea, it can support the trachea with a certain supporting force and relieve the dyspnea caused by airway stenosis.

Example 1

As shown in FIG. 1 , the tracheal stent 10 of the present embodiment is a metal stent, including a support unit 11 having a hollow tubular structure, an anchor unit 12 disposed at the distal end of the support unit 11 , and a recovery unit disposed at the proximal end of the support unit 11 13. Wherein, the support unit 11 may be formed by cross-braiding the braided wires 111 . In addition, a coating film 112 is also provided outside the support unit 11 .

The anchoring unit 12 includes a plurality of anchoring portions 120 circumferentially disposed along the distal end of the supporting unit 11 . The proximal end section 121 of the anchoring portion 120 is linear, and the proximal end of the proximal end section 121 is connected with the distal end of the support unit 11 . In this embodiment, the anchoring portion 120 is formed by winding two ends of the braided wire 111 of the braided support unit 11 . In other embodiments, the anchoring portion 120 can also be a straight rod formed by cutting or other separate straight structures.

The film 112 on the supporting unit 11 in this embodiment does not extend to the anchoring unit 12, and the anchoring unit 12 is a bare metal material. In order to avoid the direct contact between the metal material and the tracheal inner wall tissue to stimulate the tissue to proliferate in large quantities and generate granulation, the anchoring unit 12 in this embodiment is also provided with a coating film. The coating can be formed by electroplating to form a dense film on the surface of the metal material, which can seal the pitting pits caused by dry heat, ethylene oxide and other sterilization methods of the metal stent, and greatly reduce the roughness of the stent surface. , thereby reducing the stimulation of the tracheal wall cells by the anchoring unit 12 and avoiding excessive tissue proliferation. In addition, setting the coating film on the anchoring unit can also reduce the contact angle of the surface of the metal material and improve the hydrophilicity, thereby enhancing the adsorption capacity of the anchoring unit 12 to the tracheal mucosa, with good biocompatibility. At the same time, the coating process can also improve the hardness of the anchoring unit 12, so that the anchoring unit 12 is more flexible when it maintains rebound, is more suitable for the anatomical shape of the trachea, reduces the compression on the tracheal mucosa, and avoids causing local edema. In addition, the coating also has good antibacterial function, thereby reducing the risk of granulation hyperplasia due to cellular inflammation in the tracheal mucosa. The coating material can be selected from materials with good biocompatibility, such as titanium nitride, tantalum nitride, zirconium nitride or diamond-like carbon.

FIG. 2 shows the structure of the retrieval unit 13 at the proximal end of the tracheal stent 10 . As can be seen from FIG. 2 , the recovery unit 13 is provided at the proximal end of the support unit 11 , and is specifically a closed annular structure penetrated in the woven mesh of the support unit 11 , and between the recovery unit 13 and the woven mesh of the support unit 11 . Active. It should be understood that although the film 112 is provided at the proximal end of the support unit 11 in this embodiment, the recovery unit can pass through the film 112, and at this time, the position of the recovery unit 13 can still be regarded as a braid that passes through the support unit 11. inside the mesh. Since the recovery unit 13 is a closed ring structure and is movably connected with the support unit 11 , when the recovery unit 13 is pulled toward the proximal end, the portion passing through the woven mesh of the support unit 11 will also pull the support unit 11 . The proximal end is radially contracted, so that the entire tracheal stent can be easily received into the recovery catheter to realize the recovery of the tracheal stent. It can be understood that, in other embodiments, the recovery unit can also be an open linear structure. For example, one end of the linear structure is fixed on the support unit. When recovering the tracheal stent, the recovery can be achieved by simply pulling the other end. Further, in other embodiments, the recovery unit may also be a recovery structure that facilitates the fixation of the recovery instrument, and the recovery unit may be separately formed and then fixed to the proximal end of the support unit by welding or the like.

The braiding method of the support unit 11 can be a cross braiding of a plurality of braided wires 111, or a single braided wire 111 is wound up and down, that is, a braided wire is spirally wound up around the cylindrical structure to a predetermined height, and then folded back and wound downward. repeatedly. After weaving, the shape of the weaving mesh is rhombus. Since the braided wire is continuously braided on the support unit 11, when the tracheal stent is radially compressed, other parts of the same braided wire adjacent to the compression point will be deformed accordingly. Therefore, the braided tubular body near the compression point (ie, the uncompressed portion of the support unit) will undergo a subsequent radial contraction pre-deformation, and the support unit is tapered from the compression point. In this way, the assembly difficulty of the tracheal stent can be greatly reduced, and the follow-up pre-deformation can reduce the jamming between the tracheal stent structure and the head end of the delivery sheath during assembly. In addition, when the tracheal stent is partially released, the released part can be recovered through the operation of the extracorporeal delivery device, and the delivery device can also be operated to repeatedly release and recover the tracheal stent to achieve optimal positioning. It can be understood that, in other embodiments, the support unit may be formed by laser cutting the tube body.

The cover film 112 is covered on the outside of the support unit 11, and is made of a material with good biocompatibility, such as polytetrafluoroethylene or polyester. The membrane 112 can prevent the proliferating tissue of the tracheal inner wall from growing into the braided mesh of the support unit 11 to cause airway restenosis, and at the same time isolate the braided mesh of the support unit from the tracheal wall tissue, so that the tracheal stent can be easily recovered. It can be understood that, in other embodiments, the coating film may also be provided on the inner side of the support unit, or the coating film may be provided on both the inner side and the outer side of the supporting unit.

It can be understood that, in other embodiments, the coating on the supporting unit may be discontinuously arranged, that is, no coating is provided on part of the supporting unit. In this case, in order to avoid the growth of hyperplastic tissue into the supporting unit, the supporting unit The uncoated part of the coating is subjected to a coating treatment similar to the anchoring unit. Furthermore, the support unit of the coating part can also be coated.

Referring to FIG. 3 , after the tracheal stent 10 of the present embodiment is implanted into the trachea 01, the support unit 11 can ensure that the tracheal stent does not shift in the early stage of implantation through its own supporting force, and after a period of time, the trachea 01 in contact with the anchoring portion 120 There is a small amount of tissue proliferation on the inner wall, so that the anchoring unit 12 further fixes the position of the tracheal stent 10 and ensures the stability of the position of the tracheal stent in the later stage of implantation. At this time, even if there is a lot of secretions in the trachea, the tracheal stent 10 is not easily displaced. After a period of time, when the tracheal stent 10 of this embodiment needs to be recovered, the recovery unit 13 can be connected to the recovery unit 13 through a recovery device (not shown in the figure), and part of the support unit 11 can be received into the recovery catheter 02. At this time, the unrecovered The support unit 11 is partially in the shape of a cone with an opening toward the distal end. Although there is a small amount of hyperplastic tissue 03 near the anchoring unit 12, since the anchoring portion 121 on the anchoring unit 12 is a linear structure extending toward the distal end, when the anchoring portion 121 is pulled out from the hyperplastic tissue 03 toward the proximal end, the Does not scratch tissue. Therefore, no damage will be caused to the inner wall of the trachea due to the proliferative tissue.

To sum up, the film 112 covered by the support unit 11 of the tracheal stent 10 of the present embodiment has good biocompatibility, and the film 112 is in direct contact with the inner wall of the trachea to avoid the braided wire of the support unit 11 and the inner wall of the trachea. Direct contact, thereby reducing the irritation of the metal to the tissue and avoiding excessive tissue proliferation. In addition, the membrane 112 can isolate the proliferating tissue in the trachea, prevent the tissue from growing into the tracheal stent, and ensure the recyclability of the tracheal stent. The anchoring unit 12 located at the distal end of the supporting unit 11 is provided with a coating film, and the anchoring unit 12 can maintain the positioning of the tracheal stent in the trachea, so that the tracheal stent 10 does not shift with changes in the shape of the trachea. The dense coating on the surface of the anchoring unit 12 can reduce the roughness of the surface of the metal material, so as to ensure that the exposed metal wire will not cause excessive stimulation to the inner wall of the trachea and reduce tissue proliferation. During recovery, due to the linear structure of the anchoring portion, when the anchoring unit 12 moves toward the proximal end, it will not cause damage to a small amount of proliferating tissue inside the trachea.

Embodiment 2

FIG. 4 is a schematic diagram of the overall structure of the tracheal stent 20 according to the second embodiment of the present invention. The structure of the tracheal stent 20 of this embodiment is basically the same as that of the tracheal stent 10 of the first embodiment, and the only difference is the anchoring unit 22 at the distal end. As shown in FIG. 5 , the anchoring portion 220 of the anchoring unit 22 in this embodiment includes a proximal end segment 221 extending toward the distal end and a bifurcated segment 222 disposed at the distal end of the proximal end segment 221 . The bifurcated section 222 has two bifurcations that are spaced apart from each other. In this embodiment, the proximal section 221 of the anchoring portion 220 is formed by winding four braided wires, and the two bifurcations of the bifurcated section 222 are formed by winding two braided wires in the proximal section 221 respectively. It can be understood that, in other embodiments, the number of braided wires on the straight section may be other, as long as there are no less than two; similarly, the two bifurcations on the bifurcated section may also be composed of different numbers The braided wire is formed by winding, as shown in FIG. 6 , one of the bifurcations on the bifurcated section 222a may be formed by winding three braided wires in the proximal section 221a, and the other bifurcation has only one braided wire. Further, in other embodiments, the bifurcation segment may include multi-level bifurcations, that is, at least two bifurcations may be further divided under one bifurcation, for example, the bifurcation segment 222a shown in FIG. 6 has three branches The bifurcation of braided filaments can be further divided into a bifurcation with two braided fibers and a bifurcation with only one braided filament. Therefore, as long as the bifurcation of the bifurcated segment includes at least two braided filaments, it is possible to continue to branch out the lower bifurcation. Still further, the same level of bifurcations in the bifurcated segment may include multiple bifurcations, as long as it is ensured that each bifurcation contains at least one braided wire.

The anchoring portion 220 of the tracheal stent 10 in this embodiment includes a proximal end section 221 and a bifurcated section 222. After the tracheal stent 20 is implanted into the trachea, the anchoring unit 22 in this embodiment increases the anchoring area and improves the The overall anchoring performance of the tracheal stent 20 is improved, and the pressure of the anchoring unit 22 on the inner wall of the trachea is also reduced, thereby avoiding ischemic damage to the tracheal mucosa, followed by local edema and mucosal ulcers stimulated by bacteria, which subsequently cause excessive tissue. Proliferation and repair, resulting in a large number of granulation. In addition, when the tracheal stent 20 is recovered, since the bifurcation direction of the bifurcated segment 222 is opposite to the retraction direction of the stent, the bifurcation of the bifurcated segment can still be easily extracted from a small amount of proliferating tissue without It will destroy the overall recovery performance of the stent.

Embodiment 3

FIG. 7 is a schematic diagram of the overall structure of the tracheal stent 30 according to the third embodiment of the present invention. The structure of the tracheal stent 30 of this embodiment is basically the same as that of the tracheal stent 10 of the first embodiment, and the only difference is the anchoring unit 32 at the distal end. As shown in FIG. 8 , the anchoring portion 320 of the tracheal stent 30 in this embodiment includes a proximal end segment 321 extending toward the distal end and a distal end segment 323 connected with the proximal end segment 321 , and the distal end segment 323 is directed toward the support unit Bend segment where the central axis extends. In addition, the connection between the distal end segment 323 and the proximal end segment 321 has a smooth transition without sharp corners.

As shown in FIG. 10 , when the tracheal stent 30 of this embodiment is recovered, due to the smooth transition between the distal end section 323 and the proximal end section 321 , there is no sharp corner, even if the proximal end section 321 diverges outward and is in contact with the inner wall of the trachea The joint will not stab or scratch the inner wall of the trachea, and the safety is higher during recovery.

Embodiment 4

FIG. 11 is a schematic diagram of the overall structure of the tracheal stent 40 of the present embodiment. The structure of the tracheal stent 40 of this embodiment is basically the same as that of the tracheal stent 20 of the second embodiment, and the difference is only in the anchoring unit 42 at the distal end. As shown in FIG. 12 , the anchoring portion 420 of the tracheal stent 40 in this embodiment includes a proximal end segment 421 , a bifurcated segment 422 and a distal end segment 423 . The proximal end section 421 is a straight line, the distal end section 423 is a bending section, and a distal end section 423 is provided at the bifurcated distal end of each bifurcated section 422 . The distal segment 423 extends towards the central axis of the support unit. In addition, the connection between the distal end segment 423 and the bifurcated segment 422 has a smooth transition without sharp corners. It can be understood that, in other embodiments, bending segments may also be selectively provided at the distal ends of some of the bifurcations, and it is not necessary to provide bending segments at the distal ends of each bifurcation.

The tracheal stent 40 of this embodiment will not stab or scratch the inner wall of the trachea when it is recovered, and the safety is high during recovery, and the pressure of the anchoring unit 42 of the tracheal stent 40 of this embodiment on the inner wall of the trachea is small, which greatly reduces tissue proliferation. To the extent that recycling is faster and safer.

It should be understood that the tracheal stent of the present invention will not stimulate massive proliferation of the tracheal inner wall tissue. Even if the tissue proliferates a lot, due to the unique design of the anchoring unit, when the tracheal stent is recovered, it will still not cause damage to the tissue or the tracheal inner wall. At the same time, it should be noted that the physiological environment of trachea is different from that of blood vessels, and different tissues may have different physiological responses to implants of the same design. Therefore, the design of vascular stents cannot be directly used for tracheal stents.

It can be understood that the above-mentioned specific embodiments are only some preferred embodiments, and are not intended to limit the present invention. Those skilled in the art can simply replace part of the structure according to actual needs, and make other changes without departing from the concept of the present invention. Substantial changes are all within the protection scope of the present invention, and the protection scope of the present invention is subject to the claims.

Claims (10)

1. A tracheal stent comprises a hollow tubular supporting unit, and is characterized in that at least part of the supporting unit is provided with a coating film, the tracheal stent also comprises an anchoring unit arranged at the far end of the supporting unit, and the anchoring unit is provided with a coating film; the anchoring unit comprises at least one anchoring part, the anchoring part is arranged at the far end of the supporting unit, and the proximal section of the anchoring part connected with the supporting unit is linear.

2. The tracheal stent of claim 1, wherein the distal section of the anchor is a bent section extending toward the support unit central axis.

3. The tracheal stent of claim 2, further comprising a bifurcated segment between the proximal segment of the anchor and the distal segment, a distal end of the bifurcated segment being connected to a proximal end of at least one of the distal segments.

4. The tracheal stent of claim 1, wherein the anchoring portion further comprises a bifurcated segment disposed at a distal end of a proximal segment of the anchoring portion.

5. The tracheal stent of claim 4, wherein the bifurcated segment comprises a multi-stage bifurcation.

6. A tracheal stent as in any one of claims 1 to 5, wherein the support unit is woven from braided wire and the anchoring unit is formed by winding of the braided wire.

7. A tracheal stent as in any one of claims 1 to 5, wherein the anchoring unit is formed by cutting.

8. A tracheal stent as in any one of claims 1 to 5, wherein the material of the coating is titanium nitride, tantalum nitride, zirconium nitride or diamond-like carbon.

9. The tracheal stent of any one of claims 1 to 5, further comprising a recovery unit disposed at the proximal end of the support unit, wherein the recovery unit is a closed loop structure and is disposed through the proximal end of the support unit.

10. A tracheal stent as in any one of claims 1 to 5, wherein the uncoated portion of the support unit is coated with a coating.

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