JP4686711B2 - Biological duct dilator and catheter - Google Patents

Description

  The present invention relates to a biological duct dilator for expanding a narrowed biological duct and a catheter provided in the biological duct dilator.

  As a method of expanding a stenotic blood vessel or other biological duct as it is, a method of inserting the stent 41 into a stenotic site is employed. For example, as shown in FIG. 14, the stent 41 having a reduced tube diameter is inserted into a living body duct while being held by silicon tubes 42 at both ends of the contracted stent 41 as shown in FIG. Then, the stent 41 is expanded by expanding the balloon 43, and the stent 41 is expanded and fixed to the cylinder diameter at the time of setting. Then, the balloon 43 is contracted and removed from the silicon tube 42 (Patent Document 1).

  Further, as shown in FIG. 15, the stent 41 is attached to the catheter 44 and held by the cover tube 45, the cover tube 45 is pulled backward at the stenosis site to expose the stent 41, and then the balloon 43 is expanded. Thereafter, the stent 41 is expanded by performing the operation as described above. In addition, although the stent 41 is a cylindrical shape normally, a cross section may be shapes, such as an ellipse. (Patent Document 1).

  Since these stents 41 are folded and contracted by being inserted into a tube having an appropriate inner diameter, they are contracted in the length direction due to large contraction in the radial direction, unlike simply extending in the long axis direction. In addition, when the balloon 43 is expanded at the stenosis, it can be easily re-expanded to a preset diameter.

The stent 41 is made of a metal or resin and is formed in a mesh-like cylindrical body in order to realize the contraction in the radial direction at the time of insertion and the expansion in the radial direction at the time of expansion. There is a problem that the force becomes weak and the structure becomes complicated in order to give elasticity and plastic deformation characteristics.
JP-A-5-103830

The present invention has been made in view of the conventional drawbacks, and an object of the present invention is to have a flexibility, to reduce the stress applied to a biological duct, and to be able to be folded into a coil shape into an arbitrary shape. It is an object of the present invention to provide a duct dilator that can be reliably and smoothly expanded at a desired constriction, and that can reliably maintain an expanded state.
It is another object of the present invention to provide a small catheter including a duct expander that can be folded with a reduced diameter and expand a stent.

According to a first aspect of the present invention, a plurality of flexible and elastic belt-like rings are connected and integrated at intervals, and each ring is twisted by one rotation around the circumferential direction. By forming a spiral coil shape, the ring is folded and twisted with a small diameter (approximately 1/3 of the original ring diameter), and by releasing the twist deformation in use, Each of the rings is a duct dilator made of a stent characterized in that each ring has a structure capable of recovering the original ring diameter from a state of being folded in a coil shape.
According to a second aspect of the present invention, in the duct dilator according to the first aspect, the stent according to the first aspect is attached to a hollow tube provided at the distal end of the catheter in a coiled state, and the catheter further includes a stent. A conduit dilator comprising a shell for extruding and detaching from the hollow tube.

In the duct expander of the present invention, a plurality of flexible and elastic belt-like rings are connected and integrated at intervals, and each ring is wound three times by being twisted once around the circumferential direction. The ring is folded with a small diameter and is twisted and deformed, and the diameter of the stent can be reduced, so that the diameter can be reduced including the catheter portion, and the stent can be expanded reliably. In addition, since the stent is flexible and elastic, the stress applied to the biological duct can be reduced.

Hereinafter, a pipe expander according to the present invention will be described in detail with reference to FIGS.
The coiled stent 16 accommodated in the hollow tube constituting the duct dilator is shown in FIGS. 1 and 4.
FIG. 1 shows a schematic view of a stent 16 formed by integrally forming a flexible belt-like ring 10 in a coil shape. The belt-like ring 10 is made of a resin made of a flexible elastic body having a width of several mm to several tens of mm and a diameter of several mm to several tens of mm.

A method of forming the stent 16 attached to the hollow tube constituting the duct dilator is shown in FIGS. FIG. 2 is a diagram illustrating one ring 10 in a catheter in which a plurality of flexible belt-shaped rings made of an elastic material are connected and integrated. Here, a torsion of one rotation is applied around the X direction of the belt-like ring 10 around the circumferential direction . Thus, it is difficult to deform in the circumferential direction and is given torsional deformation, and three ring shapes are obtained as shown in FIG. By aligning these ring diameters, a three-turn coil shape is formed as shown in FIG. That is, FIG. 3, a process of adding a twist of one turn around the X point of the belt-shaped wheels 10 shows, 4, torsion is applied to the strip ring 10 is a result of aligning the three wheel diameter, The belt-like ring 10 is shown in a folded state with a small diameter that is approximately one third of the diameter of the original ring. Thus, the stent 16 has a shape in which a plurality of rings 10 each having a three-turn coil shape are connected and integrated.

  FIG. 5 is a cross-sectional view showing a duct dilator comprising a hollow tubular body in which a stent folded in the inner cylinder 12 is fitted and the stent 16 is pushed out by the first extruding member 14. The duct dilator stores the stent 16 at the tip of the inner tube 12 of the hollow tube. The stent 16 is discharged from the distal end to the outside of the hollow tube body by the movement of the first extruding member 14 slidably inserted in the inner cylinder 12 in the longitudinal direction. That is, the stent 16 is released from the hollow tube body into the living body duct. At this time, the stent 16 is released from the state in which the torsional deformation is released and folded in a coil shape, and is expanded into the inside of the biological duct, and as a result, the wall of the biological duct is expanded.

  FIG. 6 is a cross-sectional view showing a duct expander including a hollow tubular body including an inner cylinder 12 and a second extruding member 18 slidably inserted in the longitudinal direction on the outer side of the inner cylinder. . The stent 16 is folded and attached to the outside of the inner tube 12 of the hollow tube body and is stored in the distal end portion. The stent 16 is released out of the hollow tube body by the movement of the second extruding member 18 slidably inserted in the longitudinal direction. At this time, the stent 16 is released from the state in which the torsional deformation is released and folded in a coil shape, and is expanded into the inside of the biological duct, and as a result, the wall of the biological duct is expanded.

  FIG. 7 is a cross-sectional view showing a duct expander in which the second extruding member 18 of FIG. 6 is formed of a hollow tubular body mounted between the inner cylinder 12 and the outer cylinder 20. The stent 16 is housed by being folded at the distal end portion between the inner cylinder 12 and the outer cylinder 20, and is released to the outside of the hollow tube body by an extruding member 18 slidably fitted in the longitudinal direction. The At this time, the stent 16 is released from the state in which the torsional deformation is released and folded into a coil shape, and is expanded into the living body duct, and as a result, the wall of the living body duct is expanded.

  FIG. 8 is a cross-sectional view showing a duct dilator comprising a hollow tube body in which a stent is inserted between the inner cylinder 12 and the outer cylinder 20 and the stent 16 is pushed out by the third extruding member 22. In the duct dilator, the stent 16 is attached to the distal end between the inner cylinder 12 and the outer cylinder 20 of the hollow tube body. The stent 16 is discharged from the distal end of the hollow tube body by the movement of the ring-shaped extruded piece 22 slidably fitted between the inner tube 12 and the outer tube 20 of the hollow tube body. Reference numeral 23 denotes a stop member for the extruded piece 22. In this case, the extruded piece 22 is provided with a thread 24 inserted into the coiled ring, and the extruded piece 22 is moved by pulling the thread 24 to release the stent 16 from the distal end to the outside of the hollow tube body. The stent 16 needs to be surely expanded in a state where the stent 16 is disposed at a predetermined site in the biological duct. As a method of expanding the stent 16, there are a first method; a method of expanding the stent itself; a second method; a method of expanding the stent using an air bag.

A method for expanding the first stent itself is shown in FIGS. In FIG. 9, a belt-like ring 10 folded with a small diameter is formed on the stent 16, and one rod 26 is inserted into at least one ring, and this rod is opened in the direction in which the coiled ring 10 is opened. The coiled ring 10 is unwound and expanded.
Further, as shown in FIGS. 10 and 11, a developing auxiliary thread 30 with a thread ring 28 is prepared corresponding to each coiled ring, and the thread ring is inserted into the coiled ring. By pulling the thread ring, the coiled ring is expanded and the thread ring is detached from the coiled ring. In this case, it is necessary that a part of the coiled ring is contained in the thread ring 28.

  As shown in FIG. 12, the second method of expanding the stent 16 is to insert an air bag inflated by air through a part of the coiled stent, and to expand the air bag by expanding it. is there. This figure is a cross-sectional view showing a duct dilator comprising a hollow tubular body in which a stent 16 mounted by folding an air bag 32 in the inner cylinder 12 is inserted and the stent 16 is pushed out by a fourth pushing member 34. is there. In the duct dilator, the stent 16 is attached to the distal end in the inner tube 12 of the hollow tube body. The stent 16 has an air bag, and is released from the distal end to the outside of the hollow tube body by the movement of the pushing member 34 slidably inserted into the inner tube 12 of the hollow tube body. And the stent 16 with the air bag 32 is taken to the site | part which should be expanded. Thereafter, the air bag 32 is inflated by air pressure. Thus, the stent 16 is expanded from the contracted diameter to the expanded diameter by the inflated bladder 32.

  FIG. 13 is a schematic diagram illustrating inflation of the stent 16 using an air bladder 32. That is, the air bag 32 is inserted into at least a part of the belt-like ring 10 constituting the coiled stent 16. Then, air is supplied to the air bag 32 to expand the air bag.

  Thus, after the stent 16 has been expanded to its final expanded diameter, the bladder 32 is deflated and the pusher member 34 is withdrawn, leaving the stent 16 in place. The catheter has elasticity, is difficult to deform in the circumferential direction, and is connected to a duct dilator including a stent 16 that is folded into a coiled ring and attached to a hollow tube body by imparting torsional deformation. Become.

  The present invention is used for a biological duct dilator that expands a narrowed biological duct, a catheter equipped with a biological duct dilator, and a stent for a biological duct dilator.

It is the schematic which shows the stent which forms a flexible strip | belt-shaped body integrally in a ring-shaped ring | wheel. It is the schematic which shows the state which added the twist of 1 rotation centering | focusing on the X point of the strip | belt-shaped ring | wheel of FIG. FIG. 3 is a schematic diagram showing a process of applying a twist of one rotation around the X point of the belt-like ring of FIG. 2. FIG. 3 is a schematic view showing a ring-shaped stent in which the band-shaped ring is folded with a small diameter as a result of twisting the band-shaped ring of FIG. 2. It is the schematic which shows the biological duct dilator which concerns on this invention. It is the schematic which shows the other biological duct dilator which concerns on this invention. It is the schematic which shows the further another biological duct dilator which concerns on this invention. It is the schematic which shows the further another biological duct dilator which concerns on this invention. It is the schematic which shows a stent expansion means. It is the schematic which shows another stent expansion means. It is the schematic which shows the state which attached the stent expansion means shown in FIG. It is the schematic which shows the further another biological duct dilator which concerns on this invention. It is the schematic which shows the stent expansion means using an air bag. It is the schematic which shows the conventional biological duct dilator. It is the schematic which shows the other conventional biological duct dilator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Flexible strip | ring-shaped ring | wheel 12 which comprises a stent Inner cylinder 14 The 1st extrusion member 16 Stent 18 The 2nd extrusion member 20 The outer cylinder 22 The 3rd extrusion member 24 The thread | yarn 26 connected to the ring-shaped ring | round | yen 26 Stent expansion means 28 Yarn ring 30 Auxiliary Thread for Deployment 32 Air Bag 34 Fourth Extrusion Member 41 Stent 42 Silicon Tube 43 Balloon 44 Catheter 45 Cover Tube

Claims (2)

A plurality of flexible and elastic belt-like rings are connected and integrated at intervals, and each ring is twisted one turn around the circumferential direction to form a three-turn coil shape. Folded with a small diameter and is in a state of torsional deformation. By releasing the torsional deformation in use, each wheel can be restored to its original diameter from the state of being folded into a coil. A duct dilator comprising a stent characterized by . The stent according to claim 1, wherein the stent is attached to a hollow tube provided at a distal end portion of a catheter in a state of being folded in a coil shape, and the catheter further extrudes the stent from the hollow tube. A pipe expander characterized by having a shell.

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