JPH10201854A - Stent preparing method and stent molding table to be used for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To freely provide an endless cylindrical stent, which can be easily fixed and has the arbitrary number of vents by supplying a wire to a user in the form of semiproduct without bonding the fore end and rear end of zigzag- folded wire. SOLUTION: A zigzag-shaped wire 11 for stent preparation is formed while using a stainless steel wire having the diameter of about 0.6mm. When preparing the stent of 8 vents while using a stent molding table 11, for example, a 1st bent part 3 is inserted into the 1st hole of lock holes 13 on a pedestal 12 on one side. Next, a 2nd bent part 3 is inserted into the 1st hole on a pedestal 12 on the other side. The bent part 3 is inserted in the order of 3rd, 5th, 9th, 11th, 13rd and 15th holes. Thus, the zigzag-shaped wire 1 of 8 vents is molded cyrindical and round. After the final bent part 3 is inserted into the 15th hole, a connector 4 mounted on one end is moved in the direction of arrow A and connected to another end 2'. Thus, the endless cylindrical stent having arbitrary number of vents can be easily formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for producing a stent and a stent molding table used for the method. Specifically, when a pathological stenosis of a luminal organ such as trachea, esophagus, bile duct, urethra, blood vessel, etc. is expanded with a wire stent, the expansion force of the stent can be freely selected according to the stenosis situation of the affected part. is there.

[0002]

2. Description of the Related Art Japanese Utility Model Laid-Open Publication No. 4-92207 and Japanese Utility Model Publication No. 7-17314 disclose a stent formed by bending a wire made of stainless steel or the like into a zigzag shape to form a cylindrical shape. In other words, a zigzag wire in which a straight portion and a bent portion are formed alternately and continuously is rounded and formed into a cylindrical shape, and then a technique such as welding the straight portion at the front end of the wire and the straight portion at the rear end is used. Joined and endless. These conventional endless cylindrical stents can mechanically expand a pathological stenosis of a luminal organ by utilizing the elastic force of a bent portion formed in a substantially arc shape.

[0003]

However, since the conventional endless cylindrical stent has a constant expansion force, the strength of the expansion force cannot be adjusted according to the condition of the affected part. For example, for the treatment of tracheal stenosis frequently occurring in small dogs, a 6-vent stent in which a wire is bent six times by 2 cm to form 6 to 12 bends is usually used. However, the degree of stenosis of the trachea was different for each dog, and the severely stenotic trachea could not be sufficiently expanded with a 6-vent stent. In rare cases, it is necessary to treat tracheal stenosis in a large dog, but a 6-vent stent was too small to be useful. for that reason,
Only 8 vents, 10 vents, 12 vents, 16 vents for a very limited purpose of dog tracheal stenosis
It was very inconvenient to prepare various products such as vents. In addition, these various kinds of products manufactured in small quantities are extremely expensive, and have a considerable burden on animal hospitals.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned drawbacks of the conventional endless cylindrical stent, the method of preparing a stent according to the present invention does not join the front end and the rear end of a zigzag bent wire. It is provided to doctors and veterinarians in the form of semi-finished products. Since the bundle of zigzag wires can be cut at any position, the user selects the optimum number of vents to expand the affected area according to the degree of stenosis of the affected area which has been examined in advance, and selects the zigzag wire. May be cut off. Thereafter, the cut zigzag wire is rounded into a cylindrical shape, the front and rear straight ends are brought close to each other, and a connecting tool such as a pipe is attached to both ends to connect both ends of the wire. The attached pipe can be easily fixed by staking it with pliers. In this way, the user can freely obtain an endless cylindrical stent having an arbitrary number of vents. Therefore, the trouble of preparing various products having different expansion forces, such as the conventional 6 vent, 8 vent, and 10 vent, is eliminated. Also, since the cost of manufacturing the stent is significantly reduced,
The burden on animal hospitals can be significantly reduced.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the method for producing a stent of the present invention,
The procedure for processing a zigzag wire for forming a stent in which a straight portion and a bent portion are alternately and continuously formed by being bent in a zigzag shape is configured as follows. That is, a step of selecting the number of vents necessary for expansion of the affected part of the stenosis and separating the zigzag wire at a straight portion, a step of rolling the separated zigzag wire into a cylindrical shape and bringing the front end and the rear end of the wire close to each other, Attaching and fixing a connector to the front end and the rear end of the wire.

[0006] The connecting tool is preferably a pipe having an inside diameter into which a straight portion of a zigzag wire can be inserted. The material of the pipe is preferably a biocompatible material such as stainless steel, a tantalum titanium alloy, and a nickel titanium alloy. When using a pair of pliers, etc., to caulk the fittings attached to both ends of the wire, if the ends of the wire straight section inserted into the fittings are in contact, the caulking method will be insufficient and the fixation will be incomplete. It is. Therefore, it is preferable that the ends of the straight portions at both ends of the wire do not come into contact with each other, but are slightly spaced from each other, and that the gaps be caulked. As a means for spacing the stumps, a “constricted pipe” or a “partitioned pipe” can be used. Alternatively, it is troublesome to fine-tune the length of the straight portions at both ends of the wire before the connection, so a “twin pipe” can be used. In the case of a twin-type pipe, it can be easily and reliably fixed by caulking the single pipe portion regardless of the length of the straight section stump.

[0007] A stent forming table for carrying out the method for producing a stent of the present invention is formed by selecting the number of vents necessary for expanding a diseased part of a stenosis, rolling a zigzag-shaped wire cut out into a cylindrical shape, and then forming a round at the front and rear ends of the wire. A pair of left and right pedestals with a plurality of stop holes for inserting the bent part of the zigzag wire on the bottom circumferential line, facing the bottom, for attaching and connecting the connecting tool And a supporting column for detachably supporting both pedestals.

[0008] The bottom surface of the pedestal of the above-mentioned stent forming table is arbitrary, such as circular, square or polygonal. The shape of the stop hole formed in the circumferential line on the bottom surface is not particularly limited as long as the shape is such that a substantially arc-shaped bent portion of the zigzag wire can be inserted. Near each stop hole,
It is convenient to mark the hole numbers in order from the first.

Further, it is preferable that the column supporting the two pedestals whose bottom surfaces face each other has a cylindrical shape. When the outer periphery of the support is in contact with each stop hole, the zigzag wire is easily rolled into a cylindrical shape. However, when the whole is cylindrical, there is no gap when attaching the connecting tool to both ends of the wire or when the connecting tool is <sewn> with pliers, which is inconvenient. Therefore, it is preferable that the outer diameter of the intermediate portion of the support be smaller than the outer diameters of the both ends so that the linear portion of the wire is separated from the support.

The support and the pedestal are detachable. When the completed stent is removed from the molding platform with the connectors secured to both ends of the wire, one or both pedestals must be disengaged from the struts, or the struts must be split into two. Which one to adopt is a matter of product design. A storage cavity for the coupling device may be provided in the column.

Further, if the support pillar is made to be able to expand and contract, it is possible to cope with the fact that the angle of the linear portion changes little by little as the number of vents increases and becomes longer. In addition, stents of various sizes having different lengths of the linear portion can be manufactured on the same molding table. The support means is preferably a screw or a step, but is not particularly limited.

When using the stent forming table constructed as described above, the bent portions of the separated zigzag wires are inserted alternately from the ends into the stopping holes of the left and right pedestals. At the time of insertion, if the straight portion is slightly bent with a finger, the bent portion can easily fit into the stop hole, so that the zigzag wire can be easily formed into a cylindrical shape. Moreover, as shown in FIG. 1, the straight portion at the front end of the wire and the straight portion at the rear end naturally come close to each other. For this reason, a connecting tool such as a pipe can be easily mounted on both ends of the wire, and the mounted connecting tool can be easily fixed. Therefore, an endless cylindrical stent in which both ends of the wire are connected can be easily produced.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. However, the examples described below exemplify the stent manufacturing method of the present invention and the stent forming table used therein, and the stent manufacturing method and the stent forming table according to the present invention are not specified as follows. In addition, the drawings are merely for explanation, and do not limit the scope of the present invention.

In FIG. 1, a zigzag wire 1 for making a stent is a stainless steel wire having a diameter of 0.6 mm, and a length of a straight portion 2 is 2 cm to 6 cm.
The substantially arc-shaped bent portion 3 is inserted into a stop hole 13 formed in the bottom surface of a pair of left and right pedestals 12 of the stent forming table 11.

Although the stent forming table 11 illustrated in FIG. 1 is made of wood, it may be made of a hard synthetic resin. On the bottom surfaces of a pair of left and right disk-shaped pedestals 12, 16 stop holes 13 are respectively formed at equal intervals. A pair of pedestals 12, 12 whose bottom faces face each other, are detachably and elastically supported by a female column 14 and a male column 15, each of which has a two-stage cylindrical shape with a T-shaped vertical section. In the illustrated example, the support and the pedestal are integrally formed. However, the support and the pedestal may be separated from each other, and the pedestal may be separated from the support. Although a screw thread is shown as the expansion and contraction means 16 of the male and female columns 14, 15, any well-known technique such as a sliding step can be arbitrarily adopted. The expansion / contraction means 16 also serves as an attaching / detaching means, and can separate the two columns 14 and 15 after the stent is formed. Since the column is a two-stage cylindrical shape, the connecting portion between the columns 14 and 15 is narrowed, and a space is formed between the wire straight portion 2 and the column being formed. Although not shown, a connector housing may be provided so as to penetrate the center of the male support 15 and the base 12 in contact with the male support 15.

When an eight-vented stent is prepared using the stent molding table 11 of the above embodiment, one of the pedestals 12 is used.
The first bent portion 3 is inserted into the first hole of the stop hole 13, and then the second bent portion is inserted into the first hole of the other pedestal 12.
Subsequently, by inserting the bent portions 3 in the order of the third, fifth, seventh, ninth, eleventh, thirteenth, and fifteenth holes, the zigzag wire 1 having eight vents can be easily formed into a cylindrical shape.

When the last bent portion 3 is inserted into the fifteenth hole, the straight-line stump 2 'at the rear end of the wire comes close to the straight-line stump 2' at the front end of the wire extending from the first hole. I have. For this reason, the connecting tool 4 attached to one of the stumps
Can be easily attached to another stump 2 '. Since a space is formed between the attached connecting tool 4 and the column of the stent forming table 11,
By inserting a pressing tool such as pliers into this space, the connecting tool 4 can be reliably <caulked>. When both ends of the wire have been connected, the female strut 14 and the male strut 15 are pulled apart to obtain a completed endless cylindrical stent.

FIG. 2 shows a "constricted pipe" of the connecting member 4a.
FIG. By pressing the constricted portion 5 with pliers or the like and <caulking>, both ends 2 ′, 2 ′ of the front and rear ends of the wire can be simultaneously and reliably connected by a single press.

FIG. 3 is a longitudinal sectional view showing the "partition type pipe" of the connecting member 4b. By compressing (caulking) the partition 6 with pliers or the like, the same effect as that of the constricted pipe is exhibited. In addition, strength reduction at the constricted portion 5, which is a drawback of the constricted pipe, is eliminated.

FIG. 4 is a longitudinal sectional view showing the "twin pipe" of the connecting member 4c. By pressing the single pipe part 7, 7 with pliers, etc., and crimping, the wire ends 2 ', 2'
Can be reliably connected. In addition, since it is not necessary to adjust the length of the straight portions at both ends of the wire, the connecting operation can be further simplified.

When the endless cylindrical stent prepared as described above is inserted into a tracheal stenosis of a dog, a tracheostomy surgical operation is performed. That is, a pad is applied to the neck of a dog anesthetized and laid on his back to maintain the operative area of the larynx.
Next, the skin is incised from the posterior part of the larynx toward the sternum, and the muscles are separated and pulled left and right to expose the trachea. Next, the trachea slightly anterior to the stenosis is vertically opened, and a rod-shaped compressed stent is inserted into the stenosis with tweezers or the like. Withdrawing the tweezers expands the stent and dilates the tracheal stenosis. Thus, an arbitrary portion of the expanded stent is sewn to the trachea with a nylon suture. The stent fixed to the trachea with a suture does not fall off from a predetermined position in the stenosis. Finally, the tracheotomy and skin incision are sutured and terminated.

At a veterinary hospital run by the inventor of the present invention, 16 dogs with tracheal stenosis were experimented with stenting surgery. As a result, the operation was successful in all cases, and chronic cough and dyspnea caused by tracheal stenosis were observed. The symptoms were completely resolved. In addition, no adverse effects due to the intratracheal indwelling of the stent have been recognized at present, after the longest indwelling period of 2 years and 4 months has elapsed.

The longest case of the above-mentioned in-tracheal stent is as follows. First consultation on July 31, 1993, dog breed Yorkie, 2 years old, weighing 1.6 kg, coughing, and visited the hospital. Although radiographic examination shows mild tracheal stenosis, medical treatment with steroid hormones and sedatives is attempted for the time being. As a result of continuing medical treatment, the symptoms of cough improved, but gradually healed and his weight decreased to 1.4 kg.
Suddenly, she was hospitalized for anorexia and dyspnea on September 17, 2010. While the tracheal tube having an outer diameter of 4 mm is inserted immediately to start oxygen inhalation, the position and degree of stenosis are examined by radiography. Then, an 8-vent stent (2 cm in length of a straight portion) was immediately prepared, sterilized and sterilized by an autoclave, and then tracheostomy-opened to be mounted on a stenosis. After the operation, the patient recovered steadily without any signs of coughing or dyspnea, and when discharged from the hospital after 5 days, had a strong appetite. At the time of thread removal 10 days later, the body weight had increased to 1.5 kg. His weight continued to increase, reaching 1.75 kg on December 25, three months after the operation, and settled to the 1.7 kg range thereafter. Since then, no abnormal findings have occurred until January 1997, two years and four months after the operation. The same applies to the other 15 examples.

[0024]

The present invention is embodied in the form described above and has the following effects.

[0025] By providing the user with the front and rear ends of the zigzag wire for forming a stent not joined,
The user can create a stent having an optimum number of vents for expanding the affected area according to the condition of the affected area. For this reason, it is not necessary to purchase and always keep various stents having different numbers of vents. For animal hospitals that do not have a health insurance system, it has become a considerable burden to keep a variety of stents available when they cannot be used. The fact that this problem can be solved by the present invention is a great gospel of animal hospitals.

By using the stent forming table, it is extremely easy to form a zigzag wire which is cut by selecting the number of vents necessary for expanding the stenosis affected part, and anyone can easily roll it into a cylindrical shape. By rounding the zigzag wire into a cylindrical shape, the straight-line stump at the front end of the wire and the straight-line stump at the rear end approach each other. Since it is easy to attach and fix the connecting tool to both adjacent stumps, an endless cylindrical stent can be easily produced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a stent forming table.

FIG. 2 is a longitudinal sectional view showing an embodiment of the coupler.

FIG. 3 is a longitudinal sectional view showing an embodiment of the coupler.

FIG. 4 is a longitudinal sectional view showing an embodiment of the connector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Zigzag wire for stent production 2 Straight part 2 'Stump 3 Bent part 4, 4a, 4b, 4c Connector 5 Constriction part 6 Partition part 7 Single tube part 11 Stent forming base 12 Pedestal 13 Stop hole 14 Female post 15 Male post 16 Telescopic means

Claims (2)

[Claims] 1. A zigzag wire forming procedure for forming a stent in which a straight portion and a bent portion are alternately and continuously formed by bending in a zigzag shape, wherein the number of vents necessary for expanding a diseased part of the stenosis is selected. A step of separating the wire at a straight line portion, a step of rolling the separated zigzag wire into a cylindrical shape and bringing the wire front end and the rear end close to each other, and attaching and fixing a coupling tool to the approached wire front end and the rear end And a method for producing a stent. 2. A forming table for rolling a zigzag wire for forming a stent into a cylindrical shape and connecting the front and rear ends of the wire, and a stopper for inserting a bent portion of the zigzag wire on a circumferential line on a bottom surface. Consisting of a pair of pedestals with a plurality of holes perforated, and a column that detachably supports both pedestals,
Stent molding table.