WO2021121307A1 - Infant pulmonary artery stent - Google Patents

Abstract

Disclosed is an infant pulmonary artery stent (10), wherein the stent (10) is of a balloon dilatation type, the stent (10) comprises a plurality of mesh-tube-shaped unit sections (11, 12) and connecting rods (16), each of the unit sections (11, 12) comprises a plurality of section rods (13) connected end to end, the unit sections (11, 12) define an annular shape, the connecting rods (16) are connected to the adjacent unit sections (11, 12), the number of section rods (13) in each of the unit sections (11, 12) is 12 to 30, the joint between two section rods (13) is a circular arc transition part (14), the connecting rods (16) are evenly distributed in the circumferential direction of the unit sections (11, 12), the joint of one connecting rod (16) is arranged in a spaced manner by at least one circular arc transition part (14), and the joints between adjacent unit sections (11,12) are connected by means of the connecting rods (16). Good flexibility is achieved, and the requirement for interventional treatment of an infant patient can be met.

Description

Toddler Pulmonary Stent Technical field

This application relates to the technical field of vascular intervention, in particular to a pulmonary artery stent for infants.

Background technique

The causes of pulmonary artery stenosis include congenital and acquired stenosis. Among them, congenital stenosis is mostly caused by congenital heart disease with pulmonary circulatory dysplasia, such as tetralogy of Fallot, pulmonary atresia, etc., while acquired stenosis is mostly caused by surgery, such as postoperative anastomotic stenosis.

The physiological characteristics of the pulmonary artery are: low pressure, thin blood vessel wall, large size, large shrinkage and large diameter, and venous blood inside. The tissue structure at the onset of stenosis is mostly caused by postoperative scars or hyperplasia, which is more difficult to expand than normal vascular tissue. At the same time, the diameter of the pulmonary artery will be relatively large, and there may be a large difference between the proximal and distal diameters. After the stent is expanded, it needs to be cylindrical or tapered to ensure that the stent adheres to the wall to conform to the anatomical structure of the pulmonary artery without irritating the blood vessel wall excessively. However, there are currently no specialized pulmonary artery stents in clinical practice at home and abroad, and alternative stents are used, such as CP stents for aortic stenosis or biliary tract stents for biliary tract stenosis, etc. CP stents are too flexible due to the poor flexibility of the stent and the shortening rate is too high. Factors such as high fracture rate, incomplete coverage and other factors cannot meet the requirements of pulmonary artery stenosis; the latter is unable to adapt to the narrowed pulmonary artery with variable anatomical structure due to the small diameter range, small supporting force, and large shrinkage of the stent. Therefore, there is an urgent need for a new type of stent. A pulmonary artery stent that expands according to the anatomy of the pulmonary artery.

In particular, when the stent is applied to infants, the pulmonary artery end of the infant’s pulmonary artery is small and tortuous, and it is relatively difficult for the stent to be pushed to the target location. In addition, the growth and development of the infant’s body changes greatly, and the blood vessels themselves will continue to grow and grow after treatment. Passive stenosis at the stent places higher requirements on the design of the pulmonary artery stent.

Summary of the invention

In order to solve the above technical problems, the main purpose of the present application is to provide an infant pulmonary artery stent suitable for infants and young children, which has good flexibility and can meet the interventional treatment needs of infants and young children.

Another objective of the present application is to provide an infant pulmonary artery stent suitable for infants and young children, which has good flexibility and a small outer diameter after being pressed.

The present application provides a pulmonary artery stent for infants. The stent is a balloon-expandable type. The stent includes a plurality of mesh-shaped unit sections and a connecting rod. The unit section includes a plurality of end-to-end joint rods. The joints are encircled in a ring shape; the connecting rods are connected to adjacent unit sections, the number of joints in each unit section is 12 to 30, the connection between the two joints is a circular arc transition, and the connecting rods are along the unit The joints are evenly distributed in the circumferential direction, at least one connecting part of the connecting rod is arranged at least one of the arc transitions, and the connecting part of the adjacent unit node is connected to the connecting rod correspondingly.

According to an embodiment of the present application, the bracket includes two connecting rods with different circumferential inclination directions.

According to an embodiment of the present application, the stent includes two connecting rods with different circumferential inclination directions, and the connecting rods of the two directions are staggered along the axial direction of the stent.

According to an embodiment of the present application, the connecting rod is an S-shaped, Z-shaped or Ω-shaped connecting rod.

According to an embodiment of the present application, the number of joint rods in each unit section is 18-24.

According to an embodiment of the present application, the two ends of the bracket are end unit sections, and the middle unit section is between the two end unit sections. The radius of the arc transition of the end unit nodes at both ends of the bracket is greater than or equal to the radius of the arc transition of the middle unit node.

According to an embodiment of the present application, the connecting rods between the two end unit sections and the middle unit section have different circumferential inclination directions.

According to an embodiment of the present application, the length of a single link in the middle unit section is 2-5 mm, and the length of a single link in the end unit section is equal to or less than the length of a single link in the middle unit section.

According to an embodiment of the present application, the rod width of each of the middle unit sections is greater than or equal to the rod width of each of the end unit sections.

According to an embodiment of the present application, each of the joints is set at the starting point of the arc transition, or each of the joints is set at the middle of the arc transition.

Compared with the prior art, the above-mentioned technical solutions provided by the embodiments of the present application have the following advantages:

The embodiment of the present application proposes to control the number of joint rods in each unit section of the bracket between 12 and 30, while reducing the number of connecting rods, and configure the bracket to be arranged with at least 2 joint rods. The bracket is designed as an open-loop structure. The open-loop structure is to provide a connecting rod with at least one arc transition between two adjacent unit sections. In this way, the stent in the holding state will have better flexibility.

At the same time, because the open-loop structure can be used to achieve post-expansion, the S connection structure between every two layers can be forward or reverse "S" connection, reverse "S", one positive and one reverse "S" connection makes the stent in the axial direction The two spacing units will not be twisted or shifted in the axial direction due to the same force direction, making some positions too large.

At the same time, the stent is made of thin-walled tubing, which has a smaller outer diameter after being crimped, making it easier to pass through small and tortuous blood vessels.

Description of the drawings

The drawings here are incorporated into the specification and constitute a part of the specification, show embodiments consistent with the present invention, and together with the specification are used to explain the principle of the present invention.

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, In other words, other drawings can be obtained based on these drawings without creative labor.

FIG. 1 is a schematic diagram of the structure of an infant pulmonary artery stent after the first expansion according to an embodiment of the application.

Fig. 2 is a schematic diagram of an enlarged structure at A in Fig. 1.

Fig. 3 is a schematic structural diagram of a pulmonary artery stent for infants provided by an embodiment of the application after the second expansion.

Fig. 4 is a schematic diagram of an enlarged structure at B in Fig. 1.

FIG. 5 is a partial structural schematic diagram 1 of an infant pulmonary artery stent deployed state according to an embodiment of the application.

Fig. 6 is a second partial structural schematic diagram of an infant pulmonary artery stent in a deployed state according to an embodiment of the application.

FIG. 7 is a third partial structural schematic diagram of an infant pulmonary artery stent in a deployed state according to an embodiment of the present application.

Description of reference signs:

10. Stent; 11. End unit section; 12. Middle unit section; 13. Section rod; 14. Arc transition; 16. Connecting rod; 2. Balloon.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments These are a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of this application.

In order to solve the aforementioned problems of the balloon-expandable pulmonary artery stent in the prior art, the embodiments of this application propose to control the number of rods in each unit section of the stent to 12 to 30 under the premise that the diameter of the raw material does not need to be changed. At the same time, the connecting rod is configured to have at least one arc transition for setting. The stent is designed as an open-loop structure. At the same time, because the open-loop structure can be used to achieve post-expansion, the S-connecting structure between every two layers can be forward or reverse. Connect to “S”, reverse to “S”, or there are two types of connecting rods with different inclination directions between the two layers, that is, one positive and negative “S” connecting rod, so that the bracket is on the axis The two spacing units in the direction will not be twisted or shifted in the axial direction due to the same force direction, which makes the occupancy ratio of some positions too large.

At the same time, the stent is made of thin-walled tubing. In a specific embodiment of the application, the thickness of the thin-walled tubing is selected to be between 0.2 and 0.4mm. The stent prepared according to this has a smaller outer diameter after pressing, which is more convenient Through small tortuous blood vessels.

It is understandable that, based on the above-mentioned technical ideas of this application, those skilled in the art can propose various technical solutions based on the above-mentioned technical ideas, which should be regarded as belonging to the scope of the basic technical ideas of this application, which also belong to the scope of this application. Within the claimed scope of protection.

As follows, an exemplary implementation of this application will be introduced in conjunction with the accompanying drawings as follows:

Fig. 1 is a schematic structural diagram of an infant pulmonary artery stent provided by an embodiment of the application after the first expansion, Fig. 2 is an enlarged schematic diagram of the structure at A in Fig. 1, and Fig. 3 is a infant pulmonary artery stent provided by an embodiment of the application The schematic diagram of the structure after the second expansion, and FIG. 4 is the schematic diagram of the enlarged structure at B in FIG. 1.

As shown in the figure, this embodiment of the present application provides an infant pulmonary artery stent. The stent 10 mainly includes a plurality of mesh-shaped unit sections and connecting rods 16. The two ends of the stent 10 can be end unit sections 11, and the two ends Between the unit sections 11 are a plurality of middle unit sections 12. Each unit section includes a plurality of joint rods 13 that are connected end to end, and the plurality of joint rods 13 are connected to each other and form a ring around the axis of the bracket 10. The connecting rod 16 is connected between the adjacent unit sections. The number of the joint rods 16 in each unit section is selected to control from 12 to 30, and the connection between the two joint rods 13 is a circular arc transition 14, and the connecting rod 16 runs along the unit section. It is evenly distributed in the circumferential direction. In this embodiment, it is set that at least one arc transition 14 is arranged at a connection point of a connecting rod 16, and the connecting points on adjacent unit sections are correspondingly connected by the connecting rod 16.

In the specific example shown in FIG. 1, there are a total of 16 section rods 13 in each unit section, and a connecting rod 16 is provided at intervals of two arc transitions 14. As shown in Figures 3 and 4, as the patient grows, the stent in this embodiment can also be expanded twice. For example, the expansion angle between the two rods 13 in Figures 1 and 2 (the angle α in Figure 2) is 30 degrees. The left and right expand twice to the expansion angle of about 90 degrees as shown in Figs. 3 and 4 (the angle α in Fig. 4). The diameter of the stent can be expanded multiple times, which also meets the growth needs of infants and young children after the stent is implanted.

In the embodiment, the material of the stent 10 can be selected from one of stainless steel, cobalt-based alloy, platinum-iridium alloy, nickel-titanium alloy, or magnesium-based alloy.

It should be understood that, according to the embodiment of the present application, the connecting rod 16 can be selected in an applicable connecting rod form such as S-type, Z-type, or Ω-type. On the basis of maintaining the proper flexibility of the stent, the rod width can be selected to increase the support strength of the stent, which is suitable for older infants and young children.

In a further embodiment of the present application, the number of bands of the joint rod 13 in the end unit section 11 and the middle unit section 12 can be selected from 12 to 30 knots, preferably 18 knots or 24 knots, and the number of bands of the joint rod 13 can be increased. The diameter of the stent 10 after expansion is increased. The connecting rods 16 are selected to be uniformly distributed along a circle of the unit section, and the number can be 2-15. The less the number of connecting rods 16 is, the better the flexibility of the bracket 10 is.

When the number of bands of the unit section rod 13 is preferably 24, the connecting rods 16 can be selected as 6, and a connecting rod 16 is arranged at a pair of bands 13 at intervals along the unit section. This design is suitable for maintaining the bracket. Based on the flexibility, the stent can obtain higher support strength, which is suitable for older infants and young children.

When the number of bands of the unit section rod 13 is preferably 18, the number of connecting rods 16 is preferably 3, and one connecting rod 16 is arranged at two pairs of bands 13 along the unit section at intervals. This design makes the bracket 10 better The flexibility, while maintaining the appropriate radial support strength, makes the stent suitable for younger infants and young children.

In the embodiment of the present application, the outer radius of the middle joint rod 13 of the end unit section 11 is selected to be 0.2 to 0.5 mm, and the rod width of the middle joint rod 13 of the end unit section is selected to be 0.1 to 0.3 mm. The outer radius of the middle section rod 13 of the middle unit section 12 is selected to be 0.2 to 0.4 mm, and the rod width range of the middle section rod 13 of the middle section 12 may be selected to be 0.1 to 0.4 mm.

In the embodiment of the present application, the angle, outer radius, and rod width of the rod 13 of the end unit section 11 may be the same as or different from those of the rod 13 of the middle unit section 12. When they are the same, when the stent 10 is expanded, every two apexes of the rods can obtain a uniform expansion angle, and the stent 10 can obtain a uniform supporting force, which is more suitable for pulmonary arteries with equal diameters at the distal and proximal ends of the stenosis. When they are not the same, it is preferable that the angle of the joint rod 13 of the end unit section 11 is smaller than that of the joint rod 13 of the middle unit section 12, and the outer radius of the joint rod 13 of the end unit section 11 is greater than or equal to that of the middle unit section 12. The joint rod 13, the rod width of the joint rod 13 of the end unit section 11 is smaller than the joint rod 13 of the middle unit section 12, and the supporting force of the end part is smaller than the supporting force of the middle part during expansion. This type of stent is suitable for pulmonary arteries whose distal and proximal diameters are not equal.

In a specific embodiment, the rod width of each section rod 13 in the bracket 10 is selected to be 0.2-0.3 mm, preferably 0.25 mm. The wider the rod 13 of the stent 10 is, the greater the radial support force of the stent 10 is. The wall thickness of the stent can be selected from 0.2 to 0.4 mm, preferably 0.3 mm. The stent 10 can have a smaller outer diameter after being crimped, and the outer diameter after crimping ranges from 2.4 mm to 4.1 mm, and the smallest outer diameter after crimping is 2.4 mm, to facilitate the delivery of the stent in the human body, and at the same time, it is easy to make the surface of the stent 10 more quickly endothelialized, which is more conducive to the implantation of the stent. This is especially true during the stent delivery process, which can provide an effect beyond expectation, and the delivery speed of the stent can be greatly improved compared to the existing stent.

In a specific embodiment, the length of the joint rod 13 of the middle unit section 12 can be selected to be 2-5 mm. The length of the joint rod 13 of the end unit section 11 may be the same as that of the joint rod 13 of the middle unit section 12, or may be smaller than the joint rod 13 of the middle unit section 12.

When the length of the joint rod 13 of the end unit section 11 is the same as that of the joint rod 13 of the middle unit section 12, uniform radial support strength can be obtained after the stent is expanded.

When the length of the joint rod 13 of the end unit section 11 is less than the length of the joint rod 13 of the middle unit section 12, after the stent is expanded, the radial support force provided by the end of the stent is greater than the joint rod 13 of the middle unit section 12. At the same time, when the end When the length of the joint rod 13 of the lower unit section 11 is smaller than that of the joint rod 13 of the middle unit section 12, the stent can have a smaller contour effect (flare effect), which makes the stent suitable for delivery in infants and young children.

Fig. 5 is a partial structural schematic diagram 1 of the expanded state of the infant pulmonary artery stent provided by an embodiment of the application, showing that the left connection point of the connecting rod 16 is in the middle of the arc transition 14, and the right connection point of the connecting rod 16 is in the circle Arc transition 14 in the middle. Fig. 6 is a partial structural diagram 2 of the expanded state of the infant pulmonary artery stent provided by an embodiment of the application, showing that the left connection point of the connecting rod 16 is at the upper starting point of the arc transition 14, and the right connection point of the connecting rod 16 Start at the lower side of the arc transition 14. Fig. 7 is a partial structural schematic diagram 3 of the expanded state of a pulmonary artery stent for infants provided by the embodiment of the present application, showing that the left connection point of the connecting rod 16 is at the lower starting point of the arc transition 14, and the right connection point of the connecting rod 16 is at The upper starting point of the arc transition 14.

Wherein, the starting point of the connecting rod 16 may be located on the arc transition 14 of the joint rod 13 at an angle of -80 to 80° with respect to the X axis (parallel to the central axis of the bracket 10), and the preferred starting point of the connecting rod 16 may be located at On a joint rod with an arc angle of 54° to the X axis, in other words, the angle formed by the line between the center of the arc of the joint rod and the starting point of the connecting rod 16 and the X axis is in the range of -80 to 80° , Preferably in the range of -54° to 54°. The distance between the center of the S-shaped connecting rod 16 and the center of the pitch rod along the X axis is 0.3 to 0.6 mm, preferably 0.5 mm, and the distance along the Y axis may be 0.3 to 0.6 mm, preferably 0.5 mm. The connecting rod 16 may start on the arc transition 14 of the joint rod 13 at an arc angle of 0° to the X axis, as shown in Fig. 5; the connecting rod may also be located on the joint rod at an arc angle of 54° or -54° to the X axis. On the circular arc, as shown in Figs. 6 and 7, the connecting rods 16 in the above multiple configurations can be staggered along the axial direction of the stent 10, so that the stent can be deformed uniformly during expansion or crimping.

It should be noted that in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply these There is any such actual relationship or sequence between entities or operations. Moreover, the terms "include", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes those that are not explicitly listed Other elements of, or also include elements inherent to this process, method, article or equipment. If there are no more restrictions, the element defined by the sentence "including a..." does not exclude the existence of other identical elements in the process, method, article, or equipment that includes the element.

The above are only specific embodiments of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown in this document, but should conform to the widest scope consistent with the principles and novel features applied in this document.

Claims (12)

A pulmonary artery stent for infants, the stent is a balloon-expandable type, the stent includes a plurality of mesh-shaped unit sections and a connecting rod, the unit section includes a plurality of end-to-end joint rods, and the unit sections are enclosed in a ring状; The connecting rod is connected between adjacent unit sections, wherein, The number of joint rods in each of the unit sections is 12 to 30, and the connection between the two joint rods is a circular arc transition, and the connecting rods are evenly distributed along the circumferential direction of the unit section, and at least one connecting rod is arranged at least one of the circular arc transitions. The connection point of the adjacent unit section is connected to the connecting rod correspondingly. The infant pulmonary artery stent according to claim 1, wherein the stent includes two connecting rods with different circumferential inclination directions. The infant pulmonary artery stent according to claim 1 or 2, wherein the stent comprises two connecting rods with different circumferential inclination directions, and the connecting rods of the two directions are arranged in each pair of the stent along the axial direction of the stent. Alternate arrangement between adjacent unit nodes. The infant pulmonary artery stent according to any one of claims 1 to 3, wherein the connecting rod is an S-shaped, Z-shaped or Ω-shaped connecting rod. The infant pulmonary artery stent according to any one of claims 1 to 4, wherein the number of rods in each unit section is 18-24. The infant pulmonary artery stent according to any one of claims 1 to 5, wherein the plurality of unit segments include end unit segments located at both ends of the stent and a middle unit segment located between the end unit segments, wherein, The radius of the arc transition of the end unit node is greater than or equal to the radius of the arc transition of the middle unit node. 7. The infant pulmonary artery stent according to claim 6, wherein the connecting rods between the two end unit sections and the middle unit section have different circumferential inclination directions. The infant pulmonary artery stent according to claim 6 or 7, wherein the length of a single rod in the middle unit section is 2 to 5 mm, and the length of a single rod in the end unit section is equal to or less than that of the middle unit section. The length of a single section. The infant pulmonary artery stent according to any one of claims 6 to 8, wherein the rod width of each rod in the middle unit section is greater than or equal to the rod width of each rod in the end unit section. The infant pulmonary artery stent according to any one of claims 1 to 9, wherein each of the connection points is set at the starting point of the arc transition, or, Each of the connection points is arranged in the middle of the arc transition. The infant pulmonary artery stent according to any one of claims 1 to 10, wherein the angle between the connecting point and the center of the arc transition and the axial direction of the stent is between -80 degrees and 80 degrees. Within the range of degrees. The infant pulmonary artery stent according to claim 11, wherein the included angle is in the range of -54 degrees to 54 degrees.

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