JP2011010866A - Stent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stent which stays in an esophageal tube temporarily for a period necessary for preventing an affected part from occlusion, then is collected easily.SOLUTION: A stent 1 includes an indwelled part 4 which stays in a body cavity and is composed of a wire member of a shape memory alloy. The wire member extends almost linearly at a temperature lower than a body temperature while being formed at the body temperature into a contact coil shape with a larger external diameter than the inner diameter of the body cavity where the stent should be stayed. When the stent is inserted through an oral cavity while being kept at the temperature lower than the body temperature, the indwelled part 4 is easily inserted near the affected part in the body cavity with the almost linearly extended condition. Further, by being inserted near the affected part, the temperature rises up to the body temperature so that the indwelled part 4 in the body cavity is deformed to the contact coil shape for expanding the body cavity, and that the inner diameter is secured for food or the like to be easily passed through.

Description

  The present invention relates to a stent.

  Conventionally, esophageal intubation treatment is performed by using a balloon or a stent when a region cut out extensively by endoscopic mucosal resection for early esophageal cancer becomes narrow. The stent is made of silicone rubber or metal, and is generally placed in the esophagus with the esophagus inner diameter enlarged (see, for example, Patent Document 1 and Patent Document 2). .

JP 2006-296559 A JP-A-8-206227

  However, the esophageal tube facilitates the passage of food by mucus secreted by the mucous membranes and smoothly moves food from the mouth to the stomach by peristaltic movement, which makes the patient feel uncomfortable when the stent is placed, and the patient's QOL There is an inconvenience of lowering. In other words, as an esophageal stent, it is desired to develop a temporary indwelling stent that can be temporarily placed in the esophageal canal for a period necessary to prevent occlusion of the affected area, and then recovered.

  The present invention has been made in view of the circumstances described above, and provides a stent that is temporarily placed in the esophageal canal for a period necessary to prevent occlusion of an affected area, and can be easily recovered thereafter. The purpose is to do.

In order to achieve the above object, the present invention provides the following means.
The present invention is a stent provided with a body cavity indwelling portion that extends in a substantially linear shape at a temperature lower than the body temperature and includes a wire made of a shape memory material that is formed into a close coil shape having an outer diameter larger than the inner diameter of the body cavity to be placed at the body temperature I will provide a.

  According to the present invention, when inserted through the oral cavity while being held at a temperature lower than the body temperature, the wire made of the shape memory material extends substantially linearly, so that the guide wire, the guide sheath, or the inner It can be easily inserted to the vicinity of the affected part in the body cavity using the channel of the endoscope. When the wire is inserted in the vicinity of the affected part, the temperature rises to the body temperature, so that the body cavity indwelling part is deformed into a close-contact coil shape. Since this body cavity indwelling portion has an outer dimension larger than the body cavity inner diameter, the body cavity is pushed outward in the radial direction to expand the body cavity. Therefore, by applying to a site that protrudes inward from the body cavity, such as an affected part, the body cavity can be expanded to ensure an inner diameter, and food or the like can be easily passed.

  Furthermore, according to the present invention, since the body cavity indwelling portion is formed in a close-contact coil shape, the tissue on the body cavity inner wall cannot enter the body cavity indwelling portion. Therefore, the indwelling part in the body cavity is prevented from adhering to the inner wall of the body cavity, and can be easily recovered after a certain period of time without damaging the inner wall of the body cavity.

In the said invention, the surface of the wire of the said body cavity indwelling part may be coat | covered with the biocompatible double network gel.
By doing in this way, when the in-body-cavity indwelling part is formed in a close-contact coil shape, the gap between the wire rods is closed by the double network gel. Thereby, the penetration | invasion of the structure | tissue of the body cavity inner wall from between wire rods can be prevented further reliably. Double network gel is excellent in abrasion resistance, elasticity, breaking strength, and torsional strength, so even if the indwelling part in the body cavity is deformed from a substantially straight state into a close coil shape, it easily follows this deformation. Can continue to coat the wire. The double network gel includes, for example, a non-bioabsorbable gel such as acrylamide or a bioabsorbable gel including gelatin and cellulose.

Moreover, in the said invention, one end may be connected to the said body cavity indwelling part, and the linear fixing | fixed part provided with the fixing tool latched by a tooth | gear or an oral cavity part at the other end may be provided.
By doing in this way, the in-vivo indwelling part can be hold | maintained so that it may not fall downstream by latching the fixing tool provided in the end of the linear fixing | fixed part to a tooth | gear or an oral cavity part. Since it becomes easy to collect | recover by making it adhere | attached coil shape and it becomes difficult to adhere | attach, since fixing force cannot be obtained, it can prevent more reliably by a fixing | fixed part.

Moreover, in the said invention, the said wire may be formed in the tubular shape which can penetrate a guide wire.
By doing in this way, a guide wire can be made to pass through the through-hole inside a wire, and it can introduce | transduce into the desired site | part inside a body cavity easily.

  According to the present invention, there is an effect that it is temporarily left in the esophageal canal for a period necessary to prevent the occlusion of the affected part and can be easily recovered thereafter.

It is a front view which respectively shows the form in the case of (a) body temperature, (b) body temperature or more of the stent which concerns on one Embodiment of this invention. It is a partial perspective view for demonstrating the internal structure of the stent of FIG. It is a figure which shows the state which utilized the stent of FIG. 1 for the lumen | capacitance securing of a patient's esophagus. It is a partial perspective view for demonstrating the modification of the internal structure of the stent of FIG.

A stent according to an embodiment of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the stent 1 according to the present embodiment is configured by a wire made of a flexible material, and includes a locking portion 2 that is fixed to an oral cavity such as a patient's tooth at one end thereof. And a body cavity indwelling part 4 connected to the fixing part 3.

The fixing part 3 is made of a flexible material such as nylon, for example, and can be deformed into an arbitrary form according to the tissue shape in the surrounding body cavity and the tension applied to itself.
The locking portion 2 of the fixing portion 3 is formed in an annular shape so as to be hooked on a patient's tooth, for example, a molar. The form of the latching | locking part 2 is not restricted to this, When the orthodontic appliance is mounted | worn, you may have a form fixed to the orthodontic appliance.

As shown in FIG. 1 (a), the body cavity indwelling portion 4 extends substantially linearly at a temperature lower than the body temperature, and as shown in FIG. As shown in FIG. 2, a wire 4a made of a shape memory material formed in a close-contact coil shape having a larger outer diameter is covered with a coating 4b made of a biocompatible material.
Examples of shape memory materials include metals such as Ni—Ti alloys, Cu—Al—Ni alloys, Cu—Zn—Al alloys, and resins such as high-rigidity plastics.

  Examples of the biocompatible material used for the coating 4b include a non-bioabsorbable gel such as acrylamide or a double network gel including a bioabsorbable gel including gelatin and cellulose.

The operation of the stent 1 according to this embodiment configured as described above will be described below.
In order to secure the lumen and prevent restenosis by inserting the stent 1 according to the present embodiment into the body cavity A such as the esophagus or the trachea, first, a guide wire or guide held at a temperature lower than the body temperature of the patient. A sheath or endoscope is inserted into the body cavity A. Next, the stent 1 is set at a temperature lower than the body temperature of the patient, so that the stent 1 is extended in a substantially linear shape as shown in FIG. The stent 1 is introduced into the body cavity through the forceps channel of the mirror.

  When the stent 1 is released into the body cavity A from the guide wire, the guide sheath, or the distal end of the endoscope, the temperature of the stent 1 is raised to the body temperature. Therefore, as shown in FIG. 4 is deformed into a close-contact coil shape. As shown in FIG. 3, the in-vivo indwelling portion 4 is set to have an outer dimension larger than the inner diameter of the body cavity A, so that the body cavity A is expanded by pressing the inner wall of the body cavity A radially outward. . Therefore, the body cavity indwelling part 4 of the stent 1 according to the present embodiment is applied to a site that protrudes inward in the radial direction of the body cavity A such as an affected part, so that the body cavity A can be expanded to secure the lumen. .

  When the insertion of the body cavity indwelling portion 4 is completed, the guide wire, the guide sheath or the endoscope is removed from the body cavity A, and the locking portion 2 of the fixing portion 3 connected to the body cavity indwelling portion 4 is obtained. Is fixed to, for example, molar B in the patient's mouth. Since the locking portion 2 is formed in a ring shape in advance, it can be easily fixed by being hooked on the molar B.

  According to the stent 1 according to the present embodiment configured as described above, since it is inserted in a substantially linear form at a temperature lower than the body temperature, the insertion operation can be easily performed using a guide wire, a guide sheath, or an endoscope. It can be carried out. Further, since the stent 1 according to the present embodiment is merely released into the body cavity A and the in-vivo indwelling portion 4 is formed in a close-contact coil shape, the stent 1 can be simply placed in the affected area in the body cavity A to open the lumen. Can be secured.

  In this case, according to the stent 1 according to the present embodiment, the double network gel constituting the coating 4b covering the wire 4a of the body cavity indwelling portion 4 made of a shape memory material has wear resistance, elasticity, resistance to resistance. Since it is excellent in breakability and torsional strength, even if the wire 4a constituting the in-vivo indwelling portion 4 that is substantially linear is deformed into a close-contact coil shape in the body cavity A, it flexibly deforms following the deformation. And the state which coat | covered the wire 4a which consists of shape memory materials is maintained.

  The body cavity indwelling portion 4 is inserted into the body cavity A and takes the form of a tightly coiled structure in which the wires are brought into close contact with each other, so that the wires are brought into close contact with each other without a gap. In particular, since the wire 4a made of a shape memory material is covered with the coating 4b made of a double network gel, the coating 4b is brought into close contact with each other when a coherent coil shape is formed, filling a minute gap, The indwelling part 4 is formed in a cylindrical shape without a gap.

Thereby, it is possible to prevent the tissue on the inner wall of the body cavity A from entering the body cavity indwelling portion 4. That is, when the stent 1 is placed in the body cavity A, the tissue on the inner wall of the body cavity A tries to invade so that the stent 1 is taken in. Since no gap is formed, the invasion of tissue can be prevented.
Therefore, the body cavity indwelling part 4 can be prevented from adhering to the inner wall of the body cavity A.

  Further, the body cavity indwelling portion 4 receives a force in the direction of falling downstream due to the peristaltic motion of the body cavity A in a state where the body cavity A is placed in the body cavity A and the body cavity A is expanded. According to the stent 1 according to the present embodiment, since the locking portion 2 of the fixing portion 3 is fixed to the molar B in the patient's oral cavity, even if the body cavity indwelling portion 4 receives a force due to a peristaltic motion or the like. It is possible to prevent the body cavity A from falling off the inner wall.

  Then, after the elapse of a certain period required to prevent restenosis of the body cavity A, the indwelling part 4 in the body cavity is stretched by tension by removing the locking part 2 from the molar B and pulling the fixing part 3. It is. In this case, when a tension acts on the indwelling coil-shaped in-vivo indwelling portion 4, the in-vivo in-vivo indwelling portion 4 is stretched in the direction of releasing the intimate contact state and its diameter is contracted. It is easily removed and collected.

  In this case, since the tissue on the inner wall of the body cavity A is not adhered to the in-vivo indwelling portion 4, even if it is separated from the inner wall of the body cavity A by applying tension, it can be easily recovered without damaging the inner wall of the body cavity A. There is.

  In the stent 1 according to the present embodiment, the double network gel preferably has a moisture content of 70 to 95% and a fracture strain of 50 to 90%. In addition, a drug having an anti-adhesion effect such as hyaluronic acid may be applied to the surfaces of the fixing portion 3 and the body cavity indwelling portion 4.

Moreover, it is preferable that the tensile breaking strength of the wire which comprises the fixing | fixed part 3 and the body cavity indwelling part 4 is 1 N or more. Moreover, it is preferable that the average wire diameter of the in-body-cavity indwelling portion 4 covered with the wire 4 of the fixing portion 3 and the coating 4b made of double network gel is 0.5 to 5 mm.
Moreover, the fixing | fixed part 3 and the body cavity indwelling part 4 may be mutually connected so that attachment or detachment is possible by a hook, caulking, or a button.

  In addition, the wire 4a made of the shape memory material is coated with the coating 4b made of the double network gel. However, as this method, the wire made of the double network gel is made of the shape memory material in addition to the coating method as a whole. Arbitrary methods, such as the method of coat | covering by winding on the surface of the wire 4a which become, can be employ | adopted.

In addition, the indwelling operation in the body cavity A is performed by inserting and placing the stent 1 according to the present embodiment into an inner hole of a catheter (not shown) in a state of a substantially linear shape, so that the stent 1 is like a guide wire. Using the catheter inserted into the body cavity A, the catheter may be discharged from the distal end of the catheter into the body cavity A and formed into a close-contact coil shape.
Further, as shown in FIG. 4, when a hollow wire 4a having an inner hole 4c is used as the wire 4a constituting the stent 1, a thinner guide wire 5 is inserted into the inner hole 4c of the wire 4a. May be inserted into the body cavity A.

A body cavity B molar (tooth)
1 Stent 2 Locking part (fixing tool)
3 Fixed part 4 In-vivo indwelling part 4a Wire 4b Coating (double network gel)

Claims (4)

  A stent provided with a body cavity indwelling portion that includes a wire made of a shape memory material that extends in a substantially linear shape at a temperature lower than body temperature and is formed in a close-contact coil shape having an outer diameter larger than the inner diameter of the body cavity to be placed at body temperature.   The stent according to claim 1, wherein the surface of the wire in the body cavity indwelling portion is covered with a biocompatible double network gel.   The stent according to claim 1 or 2, further comprising a linear fixing portion having one end connected to the in-vivo indwelling portion and the other end provided with a fixing device that is locked to a tooth or an oral cavity.   The stent according to any one of claims 1 to 3, wherein the wire is formed in a tubular shape through which a guide wire can be inserted.

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