CN117414231A - Controllable self-expanding tectorial membrane support - Google Patents

Abstract

The invention discloses a controllable self-expanding stent, which comprises a stent framework and a coating; the bracket framework is composed of wave ring units which are axially arranged; the coating film is wrapped on the bracket framework corresponding to the coating film part; the waveform rods of the distal end part and the proximal end part, which are vertically adjacent, are connected through a transverse continuous connecting rod, and form a diamond-shaped closed grid with the connecting rod; the upper and lower adjacent wave-shaped rods of the film covering part are connected through a transverse discontinuous connecting rod. The invention has enough supporting force and flexibility, can easily pass through and be placed in a tortuous blood vessel, and avoids damage to the blood vessel in the tortuous section: the wall attaching effect of the bracket is good, and the internal leakage is reduced or eliminated; the invention has good controllability when released, and can be adjusted after recovery until the stent is placed satisfactorily after the stent is fully unfolded, so as to ensure the treatment effect and enhance the confidence of operators.

Description

Controllable self-expanding tectorial membrane support

Technical Field

The invention relates to the technical field of vascular stents, in particular to a controllable self-expandable stent.

Background

The small vessel wall damage (defect) of the bending section refers to the damage disease of the cerebral vessel wall (the small vessel diameter of the cerebral vessel and the tortuosity of the cerebral vessel are the characteristics of the cerebral vessel), and comprises cerebral aneurysms (saccular aneurysms, pseudo-aneurysms, traumatic aneurysms, interlayer aneurysms, spindle aneurysms and the like), carotid sponges Dou Lou (CCF) and the damage of the arterial wall caused by various reasons. Cerebral aneurysms are common diseases, the occurrence rate of which reaches 5-7%, are common in middle-aged and elderly people, and are common in women. The annual incidence of cerebral aneurysm rupture is 0-1%, and once rupture occurs, the direct mortality rate of the cerebral aneurysm rupture reaches more than 20%. Other vascular wall damages (including CCF) often invade blood vessels from direct trauma or secondary to other lesions, with mild ocular hyperemia and vision loss, and severe massive bleeding without rescuing from death. Current treatments for cerebral aneurysms include traditional surgical exposure and clamping operations and intravascular treatment techniques, and because surgical exposure and clamping operations are traumatic and have high incidence of complications, the current treatments for cerebral aneurysms are mainly intravascular treatments in the industry. The intravascular treatment technology comprises an aneurysm cavity spring ring embolism technology, a covered stent treatment technology, a tumor orifice turbulence device technology, an intratumoral turbulence device technology and the like.

The cerebral aneurysm endoluminal spring coil embolization technology has been used clinically for over 20 years, but is still the main technology of cerebral aneurysm endovascular treatment. In recent years, the spoiler technology for treating cerebral aneurysms has been increasingly accepted clinically, and clinical bulk cases are reported more and more. Accordingly, research into turbulators (including tumor orifice turbulators and intra-tumor cavity turbulators) for treating cerebral aneurysms is active. The stent graft technique has few clinical applications, and is only applied to a few complicated cerebrovascular diseases. The mechanism of the cerebral aneurysm cavity spring coil embolization technology is to apply a spring coil to fill the aneurysm cavity to prevent or stop the rupture of the aneurysm, and the aim of the pursued treatment is to completely and densely fill, but the rate of the aim is about 70%, although various auxiliary embolization technologies are adopted. In addition, cerebral aneurysm cavity coil embolization techniques have the undesirable consequence of intraoperative microcatheter, microcatheter wire, coil-related aneurysm rupture, tumor body occupancy effects following coil embolization pressing against surrounding brain tissue; the turbulent flow device in the tumor cavity is characterized in that a material with a special structure is arranged in the tumor cavity, so that the thrombus is formed due to the change of blood flow in the tumor cavity, and the arterial aneurysm is applicable to the cerebral vascular bifurcation part which is refractory to other methods. The method has the defects that the individuation of the aneurysm has high demand on materials, the possibility of thrombus escape exists, the treatment behavior has the risk of rupture in the aneurysm cavity, and the method is not suitable for the treatment of ruptured cerebral aneurysm; the device for turbulent flow at the tumor mouth is characterized in that a bracket with small net gap is placed in a tumor-carrying artery at the tumor mouth, so that the blood flow entering a tumor cavity is reduced, the flow direction is changed, and a thrombus is slowly formed to block the aneurysm, and the device has the defects that the aneurysm cannot be blocked immediately, the cerebral aneurysm cannot be used for rupture, partial aneurysm cannot be blocked completely, and the operation requirement is high.

In addition, there is also a covered stent which can repair damaged lesions of the vessel wall immediately. However, the existing covered stent is balloon-expanded, has poor controllability, is difficult to run in a curved cerebral blood vessel, is easy to cause internal leakage after being released and poor in adherence, can not achieve a treatment effect, and the expanded balloon is easy to damage the blood vessel, so that serious complications or even death caused by cerebral hemorrhage are caused. For example, the only Willis covered stent for cerebrovascular diseases is balloon expansion Zhang Jietuo, the balloon pressure is higher when the balloon is expanded, the stent is hard and straight, the vascular is easily damaged in the content of the tortuous cerebral vessels, the flexibility is poor, the stent is difficult to cross the tortuous vessels and the inner leakage is easily caused by poor adhesion of the stent in the tortuous vessels, and the treatment effect is influenced. Therefore, it is necessary to improve the existing cerebral vascular stent graft, and a stent graft which has enough supporting force and good flexibility, can avoid the damage to the blood vessel at the tortuosity section, and can meet the requirement of immediate repair of the wall defect lesion of the tortuosity blood vessel (cerebral blood vessel) to the maximum extent is provided.

Disclosure of Invention

Therefore, based on the background, the invention provides the controllable self-expanding stent, and the diamond open-loop unit and the waveform thereof are arranged on the stent covering part, so that the stent has enough tension on the circumference, is wrapped with the thin film with reasonable size, can not only keep the supporting force of the stent on a tortuosity section blood vessel, but also has enough flexibility, and can avoid damage to the tortuosity section blood vessel; when in operation, after the tectorial membrane part is fully unfolded, the proximal bare stent part and the distal end of the pushing tube are still connected in the delivery catheter, and the stent position can be properly retracted and adjusted according to the requirement so as to ensure the treatment effect.

The technical scheme provided by the invention is as follows:

it also comprises a coating film;

the bracket framework is composed of wave ring units which are axially arranged, and each wave ring unit comprises 2 wave rods with wave troughs and wave crests which are opposite to each other;

the bracket framework is sequentially provided with a distal end part, a film covering part and a proximal end part from top to bottom;

the coating film is wrapped on the bracket framework corresponding to the coating film part;

the waveform rods of the distal end part and the proximal end part, which are vertically adjacent, are connected through a transverse continuous connecting rod, and form a diamond-shaped closed grid with the connecting rod;

the upper and lower adjacent wavy rods of the film covering part are connected through a transverse discontinuous connecting rod;

the wavy rod of which the distal end part is closest to the film covering part is connected with the wavy rod of which the film covering part is closest to the distal end part through a transversely discontinuous connecting rod;

the wavy bar closest to the film covering part and the wavy bar closest to the film covering part are connected through a transverse discontinuous connecting rod.

One implementation is as follows: the connecting rod is wavy.

One implementation is as follows: the connecting rod is S-shaped.

One implementation is as follows: the distal portion has a first flared opening and the proximal portion has a second flared opening.

One implementation is as follows: the port of the distal end part and the port of the proximal end part are respectively circumferentially provided with a first metal mark and a second metal mark which are matched with the conveying guide wire.

One implementation is as follows: third metal marks are embedded in the circumference of the upper end and the lower end of the film coating part respectively.

One implementation is as follows: the coating film is covered outside the corresponding bracket framework of the coating film part through hot pressing.

One implementation is as follows: the longitudinal length of the distal end portion is 2-3mm, the longitudinal length of the proximal end portion is 5mm, and the longitudinal length of the covering film portion is 7-25mm.

One implementation is as follows: the coating film is made of one of an expanded tetrafluoroethylene film, a polylactic acid polymer film or a nano film, and the thickness of the coating film is 15-20um.

One implementation is as follows: the wave-shaped rod is made of nickel-titanium alloy.

One implementation is as follows: the first metal mark, the second metal mark and the third metal mark are all made of platinum.

One implementation way is that the bracket framework is woven by metal rods or is made by metal laser cutting.

By adopting the technical scheme, the beneficial effects are as follows:

(1) the invention has enough supporting force and flexibility, can be easily placed through and on the curved blood vessel, and avoids damage to the blood vessel at the curved section:

the open loop unit and the waveform thereof of the covered part are combined with the superelastic performance of the metal rod material of the nickel-titanium alloy, so that the covered part can keep enough tension in the axial direction, the outer diameter and the length of the covered film on the covered stent framework are slightly larger than those of the corresponding stent framework, so that the covered film section stent is suitable for complete expansion, can be tightly attached to a tortuous vascular intima, can keep the flexibility of the tortuous vascular, avoid the damage to the blood vessel of the tortuous vascular, and ensure the operation success rate and the treatment effect;

(2) the bracket has good wall attaching effect, and reduces or eliminates internal leakage: the stent framework is in a horn mouth-shaped structure at the proximal end part and the distal end part, plays a role in anchoring the stent in a blood vessel, enables two ends of the tectorial membrane to be correspondingly horn mouth-shaped, strengthens the adherence of the membranes at the two ends and prevents internal leakage.

(3) The invention relates to a self-expanding stent, which can avoid the damage of a high-pressure balloon of the balloon-expanding stent to cerebral vessels, in particular to curved blood vessels.

(4) The invention has good controllability when released, and can be adjusted after being properly retracted until being placed satisfactorily after the stent of the covered part is fully unfolded, so as to ensure the treatment effect and enhance the confidence of operators: the proximal end part is designed as a bare stent section with a certain length, is a controllable part during stent placement, and can ensure that the distal ends of the bare stent and the pushing tube at the proximal end part are still connected in the conveying catheter when the stent at the covered part is completely unfolded, so that the covered stent is allowed to be properly retracted and adjusted.

(5) The port of the far end part of the stent, the port of the near end part and the near and far ends of the tectorial membrane part are all provided with the metal marks made of platinum materials in the circumference, and the metal marks are light-tight and easy to identify under X-ray perspective and are used for accurately positioning the tectorial membrane stent during placement.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic structural view of a stent framework according to the present invention;

fig. 3 is a schematic structural view of the stent graft of the present invention in a state in which the stent graft is virtually spread;

fig. 4 is a schematic structural view of the stent framework of the present invention in a state in which the stent framework is virtually laid out;

FIG. 5 is a schematic view of the structure of the film according to the present invention;

FIG. 6 is a reference diagram of a usage status of the present invention;

FIG. 7 is a second reference diagram of the usage status of the present invention;

fig. 8 is a reference diagram of a use state of the present invention.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "vertical", "circumferential", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.

In the description of the invention, a "first feature" or "second feature" may include one or more of such features. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature.

The invention is further described below with reference to the accompanying drawings.

Example 1: the controllable self-expanding stent graft shown in figures 1 to 8 comprises a stent framework 1, wherein the stent framework 1 is a hollow tubular body; it also comprises a coating 2; the coating film 2 is coated on a bracket framework corresponding to the coating film part 11;

the bracket framework 1 is formed by directly weaving a wave-shaped rod or cutting metal by laser; in specific implementation, the wavy rod is made of nickel-titanium alloy, has shape memory and superelasticity, and ensures that the bracket framework has enough tension. The bracket framework 1 is composed of wave ring units 15 which are axially arranged, and the wave ring units 15 comprise 2 wave rods (shown in figure 3) with wave troughs and wave crests which are respectively opposite; the bracket framework 1 sequentially comprises a distal end part 13 (L1), a film covering part 11 (L2) and a proximal end part 12 (L3) from top to bottom; the lower proximal end is the end that is closer to the delivery catheter 7 when the stent graft is delivered into a blood vessel, whereas the distal end is the end that is farther from the delivery catheter 7.

The waveform rods 14 of the distal end part 13 and the proximal end part 12 which are adjacent up and down are connected through a connecting rod 16 which is continuous in the transverse direction, and the waveform rods 14 of the distal end part 13 and the proximal end part 12 and the connecting rod 16 form a diamond-shaped closed grid 17;

the wave bars 14 adjacent to each other up and down of the film coating part 11 are connected by a connecting bar 16 discontinuous in the transverse direction; the wavy bar 14 of the distal end portion 13 closest to the film covering portion 11 and the wavy bar 14 of the film covering portion 11 closest to the distal end portion 13 are connected by a laterally discontinuous connecting bar 16; that is, the connecting rods 14 of the film covering part are arranged at intervals of a plurality of peaks or troughs transversely, the number of peaks or troughs spaced between adjacent connecting rods is random, for example, the number of peaks or troughs spaced can be 3 or 4 or 5 randomly. The adjacent wavy bars of the tectorial membrane part and the connecting bars arranged at intervals form an open-loop grid structure, so that the transverse supporting force and the longitudinal flexibility of the bracket can be facilitated, and the full expanding and the wall attaching effect of the bracket can be facilitated.

The wavy bar 14 of the proximal portion 12 closest to the covering film portion 11 and the wavy bar 14 of the covering film portion 11 closest to the proximal portion 12 are connected by a laterally discontinuous connecting bar 16, which is arranged in the same manner as the connecting bar of the covering film portion.

The connecting rod 16 is wave-shaped. As shown in fig. 1 to 4, the connecting rod may have an S-wave shape, the implementation of which is not limited to the S-wave shape, and may have a wave shape consisting of 2 or 3S-shapes, for example. The connecting rod is wavy and can play a certain role in buffering and deforming, so that the full expanding and adherence of the bracket are further improved.

The distal end portion 13 has a first flared opening 131 and the proximal end portion 12 has a second flared opening 121. Not only plays a role in anchoring the stent in the blood vessel, but also ensures that the two ends of the tectorial membrane are correspondingly horn-shaped, especially at the near end, so as to increase the adherence and prevent internal leakage.

The port circumference of the proximal part 12 is provided with a first metal mark 3 matched with the delivery guide wire, and the port circumference of the distal part 13 is provided with a second metal mark 4. The upper and lower ends of the film coating portion 11 are respectively circumferentially embedded with a third metal mark 5. When the first metal mark 3, the second metal mark 4 and the third metal mark 5 are all made of platinum, as shown in fig. 7, the first metal mark 3 is matched with the conveying guide wire 6 in the conveying guide tube 7 and is matched with the conveying guide wire 6, so that the unexpanded stent framework is ensured to be connected with the far end of the conveying guide wire before the stent framework is out of the conveying guide tube, and free pushing and withdrawing are kept; and can also be used as an X-ray opaque mark which is easy to identify during operation and used for accurately positioning the covered stent during placement. .

In the specific implementation, the number of the first metal marks 3, the second metal marks 4 and the third metal marks 5 can be 3-4 respectively, and all the first metal marks, the second metal marks and the third metal marks are equidistantly distributed along the circumference of the bracket framework.

The coating film 2 is covered outside the corresponding bracket framework of the coating film part through hot pressing. As shown in fig. 5, the covering film 2 may be fixed on the stent framework by hot-pressing points 21 distributed circumferentially at equal intervals. In practice, the area of the fixing point is about 1mm ² The size, the number of fixed points is not less than 3.

In the specific implementation, the coating can be made of one of an expansion tetrafluoroethylene film, a polylactic acid polymer film or a nano film, the film thickness is ultra-thin and is 15-20um, the length and the tubular diameter of the coating are slightly larger than those of a bracket framework with the same specification, and the coating is coated on the bracket framework by hot pressing;

the method comprises the following steps:

the other parts of the covered film are in a free state except the hot-pressing points so as to conform to the flexibility of the stent framework, and the horn mouth-shaped design of the distal end part and the proximal end part of the stent framework is considered, so that the diameter and the length of the tubular covered film are larger than those of the stent framework corresponding to the covered film part, and the flexibility and the adherence of the stent in a blood vessel can be ensured to the greatest extent. In particular embodiments, the diameter and length of the tube of the stent graft is about 10% greater than the maximum diameter and length of the stent scaffold, respectively.

In a specific implementation, the longitudinal length L1 of the distal end portion 13 is 2-3mm, the longitudinal length L2 of the proximal end portion 12 is 5mm, and the longitudinal length L3 of the film covering portion 11 is 7-25mm. The proximal end of the stent framework is a bare stent section with a certain length, and can be connected with the distal end of the conveying guide wire 6 in the conveying catheter 7 after the stent of the covered stent section is fully unfolded, and the position of the stent can be retracted and adjusted until the stent is satisfactory before judging whether the treatment effect of the covered stent is satisfactory or not.

In specific implementation, the length of the bracket framework corresponding to the film covering part can be divided into 6 stages, namely, the length of each stage is 7, 10, 13, 16, 20 and 25mm; the pipe diameter of the bracket framework corresponding to the film coating part is 3.0-5.5mm, and the step difference is 0.25mm in grading, namely, the pipe diameter of each specific step is 3.0, 3.25, 3.5, 3.75, 4.0, 4.25, 4.5, 4.75, 5.0, 5.25 and 5.5mm, so that an operator can select the film coating bracket more conveniently when aiming at different lesion sizes.

In the specific application of the present invention, as shown in fig. 6, the stent is in a state of being bent, and fig. 7 (wherein the structure of the connecting rod is not shown in fig. 7) is that the stent covering portion of the stent covering device is fully opened, the controllable portion (proximal portion) is in an unreleased state, so that the treatment purpose is not achieved, and the stent system can be recovered and adjusted (as described above) and then released; fig. 8 shows the controllable portion (proximal portion) having been released and the stent graft device completely disengaged, at which point the stent system has not been retrieved and deployed.

The self-expanding stent can ensure transportation in a microcatheter, walking and placement in a tortuous vessel; the flexibility and the transverse supporting force of the bracket can be ensured by selecting the bracket framework material and matching the diamond open-loop units with the waveforms; the covering film can ensure the blocking effect and endothelialization; the stent framework is reasonably matched with the tectorial membrane, so that the stretching degree of the tectorial membrane stent device in tortuous vessels is ensured.

The controllable self-expanding stent can meet the purpose of immediate repair and treatment of the wall defect lesion of the curved blood vessel (cerebral blood vessel) to the greatest extent, overcomes the defects that the closest to the controllable self-expanding stent, such as the dense net stent, can not immediately cure the lesion and the flexibility of the traditional balloon-expandable stent is insufficient in the aspects of difficult travel of the curved blood vessel, poor adherence and vascular injury, and can greatly expand the treatment indication and the effectiveness of the device in the wall damage lesion of the cerebral blood vessel (except the functional branch of the blood vessel of the treatment section).

The invention and its embodiments have been described above with no limitation, and the actual construction is not limited to the embodiments of the invention as shown in the drawings. In summary, if one of ordinary skill in the art is informed by this disclosure, a structural manner and an embodiment similar to the technical solution should not be creatively devised without departing from the gist of the present invention.

Claims (10)

1. A controllable self-expanding stent for repairing damage of a small vessel wall at a bending section comprises a stent framework 1, wherein the stent framework 1 is a hollow cylindrical body;

it is characterized in that the method comprises the steps of,

it also comprises a coating film;

the bracket framework is sequentially provided with a distal end part, a film covering part and a proximal end part from top to bottom;

the coating film is wrapped on the bracket framework corresponding to the coating film part;

the bracket framework is composed of wave ring units which are axially arranged, and each wave ring unit comprises 2 wave rods with wave troughs and wave crests which are opposite to each other;

the waveform rods of the distal end part and the proximal end part, which are vertically adjacent, are connected through a transverse continuous connecting rod, and form a diamond-shaped closed grid with the connecting rod;

the upper and lower adjacent wavy rods of the film covering part are connected through a transverse discontinuous connecting rod;

the wavy rod of which the distal end part is closest to the film covering part is connected with the wavy rod of which the film covering part is closest to the distal end part through a transversely discontinuous connecting rod;

the wavy bar closest to the film covering part and the wavy bar closest to the film covering part are connected through a transverse discontinuous connecting rod.

2. A controllable self-expanding stent graft for repairing a vessel wall defect at a curved segment as defined in claim 1, wherein said connecting rod is wavy.

3. A controllable self-expanding stent graft for repairing a vessel wall failure at a curved segment as defined in claim 2, wherein said connecting rod is S-wave shaped.

4. A controllable self-expanding stent as claimed in claim 1, wherein said distal portion has a first flared opening and said proximal portion has a second flared opening.

5. The controllable self-expanding stent graft for repairing a damaged vessel wall of a curved segment of claim 1, wherein the distal end port and the proximal end port are circumferentially provided with a first metallic marker and a second metallic marker, respectively, which are engaged with a delivery guidewire.

6. The controllable self-expanding stent graft for repairing a damaged wall of a vessel at a curved section of claim 1, wherein third metal marks are respectively embedded in the upper and lower ends of the stent graft circumferentially.

7. The controllable self-expanding stent graft for repairing a damaged wall of a vessel at a curved section according to claim 1, wherein the stent is covered outside the stent framework corresponding to the stent part by hot pressing.

8. A controllable self-expanding stent as claimed in claim 1, wherein the longitudinal length of the distal portion is 2-3mm, the longitudinal length of the proximal portion is 5mm, and the longitudinal length of the stent is 7-25mm.

9. The controllable self-expanding stent for repairing the damage of the wall of a blood vessel at a bending section according to claim 1, wherein the coating is made of one of an expanded tetrafluoroethylene film, a polylactic acid polymer film or a nano film, and the thickness of the coating is 15-20um.

10. The controllable self-expanding stent graft for repairing a vessel wall defect at a curved segment of claim 1, wherein said undulating rod is comprised of nitinol.