JPH0675413U - Aneurysm treatment tool - Google Patents

Abstract

(57) [Summary] [Construction] The present invention relates to a metal knitted structure in which a stainless wire (2) is bent in a zigzag shape and both ends of the wire are joined, and the cross section is a polygonal tubular body as a whole. The present invention relates to a device (1) for treating a dissecting aneurysm, the side surface of which is covered with a knitted fabric (4). [Effect] According to the therapeutic device of the present invention, as a surgical procedure, only the introduction of the introducer into the blood vessel can reduce the burden on the patient and safely cure the dissecting aortic aneurysm. it can. By appropriately using a covered stent alone or in combination with a bare stent, appropriate treatment can be performed according to the onset time and range of an aortic aneurysm. Further, by positively utilizing the tissue protrusion suppressing function of the cloth, it is also useful as a lumen holder when the lumen is narrowed due to a malignant or benign disease such as trachea, esophagus, and biliary tract.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a therapeutic device suitable for treating an aneurysm, particularly a dissecting aortic aneurysm.

[0002]

[Prior art]

 An aneurysm, especially a dissecting aortic aneurysm, means that the intima of the aorta causes an ulcer, the intima is partially ruptured, and blood then flows into the aortic wall, causing the aortic wall to dissociate into two layers. 2 (the state of (A) in FIG. 2. Here, the blood passage formed between the outer membrane: a and the inner membrane: b is a “false cavity”, the inner membrane that is the original blood passage. The internal space is called the "true lumen". If this state is left unattended, the outer wall of the aorta will eventually rupture, leading to death.

As a treatment method for dissecting aortic aneurysm, the intimal rupture part (hereinafter referred to as “entry”, which has been surgically operated as an urgent treatment, is referred to as an “outlet part of blood in a“ false cavity ”. Reentry) is closed by suture or the dissociated blood vessel is excised and the excised portion is replaced with an artificial blood vessel.

However, in the above-mentioned suture closure surgery, suture closure itself is extremely difficult because the tissue around the entry is fragile, and even if suture closure is successful and the immediate danger can be overcome, 5 years after the operation. There are many cases of death within. On the other hand, the artificial vascular replacement method is a major operation because it is a major operation, and when the “pseudo-lumen” is long, the artificial blood vessel replacement blocks the bifurcation of the blood vessel branching from the aorta. Therefore, it cannot be applied.

Recently, as a method that does not rely on surgery, for arteriosclerosis obliterans (including stenosis / occlusion) in the iliac artery region, a metal braided structure of a stainless wire (hereinafter referred to as a stent) Insert into the stenosis / occlusion part or intimal detachment part, and use the expansion force of the stent to reopen the blood vessel (in the case of stenosis / occlusion). It has been reported that it causes the blood to flow into the “true lumen”, but there is obstruction due to protrusion of atheromatous plaque from the space of the stent, and in the case of intimal detachment. However, there is still room for consideration for clinical applications such as the inability to block the blood flow from the entry to the “false cavity”.

[0006]

[Problems to be Solved by the Invention]

 The present invention aims to provide an improved stent for healing an aneurysm, particularly a dissecting aortic aneurysm, without surgery and at an early stage.

[0007]

[Means for Solving the Problems]

 That is, the treatment device of the present invention is a treatment device for a dissecting aneurysm, in which a stainless steel wire is bent in a zigzag manner and both ends of the wire are joined together, and the stent has a polygonal cross section and is a tubular body as a whole. It is characterized in that the side surface of is covered with a knitted fabric.

Here, a stainless wire is bent in a zigzag manner, and both ends of the wire are joined. The cross section of the polygonal shape as a whole is a tubular body, which means that the tubular body shrinks and expands in the radial direction. This is because the force is used for inserting and fixing the stent into the intravascular lesion (this stent (1) has a catheter-like introducer (as shown in FIG. 3) to be inserted into a blood vessel. 5) The inner space of the distal end portion of 5) is radially reduced and filled, and after introducing the introducer to the vicinity of the intravascular lesion, the pusher (6) is fixed to gradually introduce the introducer. Upon withdrawal, the stent is sequentially released into the blood vessel from the tip and expands in conformity with the intravascular lesion, and the expansion force fixes the stent to the blood vessel wall.

The reason why stainless steel is used as a constituent material of the stent of the present invention is that it has been applied in many cases as a surgical material to be placed in a living body, so long as it has little influence on the living body. For example, it does not exclude other materials. In addition to biocompatibility, nickel-titanium-based shape memory alloys have the ability to restore their shape, so that lesions have complicated shapes such as carotid bifurcations. It is one of the preferable materials when it is a part.

On the other hand, the above-mentioned fabric plays a role of inducing coagulation in the vicinity of the lesion, closing the entry early, and blocking blood flow to the “false cavity”. Of course, since the stitch structure of the stent results in a denser stitch structure in the fabric, as a side effect, the protrusion and entry of the atheromatous plaque from the gap, which is a problem of conventional stents, is a side effect. (The active use of this function makes the therapeutic device of the present invention not only a therapeutic device for dissecting aneurysms, but also for malignant and benign diseases such as the trachea, esophagus, and biliary tract). It is also useful as a lumen holder used to hold and treat these lumens when they become narrowed). The reason why the cloth is knitted by knitting is that the main purpose of the cloth is as described above, so that the structure of the cloth has elasticity so that the expansion force of the stent is not limited. This is to make it happen.

Here, the yarn material constituting the above-mentioned cloth is preferably made of nylon or polyethylene terephthalate. This is because it has been used for many years as a biomaterial such as a suture thread.

Further, it is more preferable that the above-mentioned fabric has a cationic functional group introduced on its surface. This is because the entry is blocked more quickly due to the formation of a blood clot.

As a method of introducing the cationic functional group, there are methods such as coating and physical adsorption, which can be easily carried out. However, in order to enhance the binding stability of the cationic functional group, a cationic monomer is used in the fabric constitution. Graft polymerization is preferably carried out on the surface of the material.

Examples of the above-mentioned cationic monomer include N, N-dimethylaminopropyl acrylic amide (hereinafter referred to as DMPAA) and N, N-dimethylaminoethyl methacrylate (hereinafter referred to as DMAEMA).

The specific introduction of the cationic functional group is carried out as follows. First, the surface of the fabric is roughened with ozone or plasma. Then, the fabric is immersed in an aqueous solution of DMPAA or DMAEMA (about 7.5% by weight), and photopolymerized by a high pressure mercury lamp (about 400 watts) in the presence of a trace amount of sodium periodate.

[0015]

【Example】

 Dissociated aortic aneurysms were prepared in each of 5 adult dogs (aorta inner diameter: 13 to 18 mm) weighing 17 to 20 kg.

The stent of the present invention (the basic structure is that a stainless wire (2) having a diameter of 0.38 mm is bent in a zigzag shape and the both ends of the wire are joined to the lesioned part of each dog. The diameter and the length of the body are 20 mm, respectively, and hereinafter referred to as a basic stent. The one shown in Fig. 1 is formed by connecting two basic stents with a connecting wire (3) at the top and bottom. Hereinafter, the two stents are referred to as “two stents” and the “three stents”, respectively, according to the number of connected basic stents. Therefore, the one shown in FIG. 1 is called “two stents”. Here, reference numeral 4 is a knitted fabric that covers the side surface of the stent and is knitted as such, although it hardly regulates the expansion force of the stent. In addition, this fabric is In this section, it is tied to the wire with a fine count thread. Below, we will refer to the stent covered with this fabric as "covered stent" and the stent not covered with fabric as "bare stent". , Inserted and arranged according to the above procedure.

The number and types of used stents used in the experiment are as follows. The first day: Triple covered stents (fabric yarn material is Dacron-30d, shuttle diameter: 19 mm), Next day: Two triple bare stents were additionally inserted downstream. Only one double-covered stent (the fabric thread material is nylon-12d, pot diameter: 13 mm) (2 examples). Two covered stents (the fabric thread material is nylon-12d, pot diameter: 13 mm) and three triple bare stents were used together (two examples).

On the next day, angiographic observation confirmed that the entry was closed (). Since backflow of blood from the reentry was observed, two triple bare stents were additionally inserted in the wake. One week later, by angiography, the pseudolumen was completely closed (). After 3 months, the condition was observed (one case: dissection), and it was confirmed that the false lumen continued to be closed and that the stent was covered with neointima. It was confirmed by observation of the condition (angiography) after a long period of time that not only the entry was closed but also the false lumen was completely closed (). As a result of applying the cationic functional group introduced to the surface of the fabric in the same manner thereafter, it was observed that the closure of the entry tended to be earlier than that of the case where the cationic functional group was not introduced.

[0019]

【effect】

 As described above, according to the therapeutic device of the present invention, as a surgical procedure, only the introduction of the introducer into the blood vessel is performed, so that the burden on the patient is small and the dissecting aortic aneurysm can be safely cured. be able to. Incidentally, by appropriately using a covered stent alone or in combination with a bare stent, or by appropriately using the presence or absence of surface treatment of the fabric, an appropriate treatment can be performed according to the onset time and range of the aortic aneurysm. Further, by positively utilizing the tissue protrusion suppressing function of the cloth, it is also useful as a lumen holding tool when the lumen is narrowed due to a malignant or benign disease such as the trachea, esophagus, and biliary tract.

[Brief description of drawings]

FIG. 1 is a development view illustrating an embodiment of the therapeutic device of the present invention.

FIG. 2 is a diagram schematically showing a process of treating a dissecting aneurysm with the treatment device of the present invention (where (A) is a state in which a dissecting aneurysm is formed, and (B) is , (C) shows a state in which the intima rupture portion is loaded with the therapeutic device of the present invention, and (C) shows a state in which the intimal rupture portion is closed. There is one covered stent and one triple triple stent).

FIG. 3 is a diagram schematically showing a process of mounting / releasing a treatment tool of the present invention to / from an instrument for loading an affected part.

[Explanation of symbols]

 1 ... Treatment device (stent) 2 ... Basic wire (wire) 3 ... Connection wire 4 ... Cloth 5 ... Introducer 6 ... Pusher a ... outer membrane b ... inner membrane

 ─────────────────────────────────────────────────── ───Continued from the front page (72) Creator Mizumoto Ryo 1-1 Yahata-cho, Tsu-shi, Mie Condominium Yamani 3-D

Claims (4)

[Scope of utility model registration request] 1. A knitted fabric is coated on the side surface of a metal knitted structure in which a stainless steel wire is bent in a zigzag shape and both ends of the wire are joined, and the cross section of which is a polygonal tubular body as a whole. A device for treating dissecting aneurysms. 2. The therapeutic device according to claim 1, wherein a shape memory alloy is used instead of the stainless steel. 3. The fabric is knitted from nylon or polyethylene terephthalate yarn.
Or the treatment tool according to any one of 2. 4. The therapeutic device according to claim 3, wherein the fabric has a cationic functional group introduced on its surface.