JP2011036317A - Protecting stent system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent embolic substance wastes which may be generated when expanding an embolized and stenosed affected site in the blood vessel using a balloon and a catheter from scattering into a blood vessel. <P>SOLUTION: A protecting stent 40 placed in the embolized and stenosed affected site 62 in the blood vessel 60 is characterized in that a plurality of thin wires constituted of a shape memory material are made to cross each other and knitted in a longitudinal direction while forming gaps between knitted stitches of a diamond shape to form a hose-shaped body whose both ends are open, knitted length is set longer than the length of the embolized and stenosed affected site, knitted outer diameter is set larger than the inner diameter of the blood vessel after expanding the embolized and stenosed affected site, the knitted diamond-shaped gaps between the knitted stitches is set into a thinness capable of collecting the embolic substance wastes when expanding the embolized and stenosed affected site, and the stent is provided with superelasticity while memorizing the knitted outer diameter and length. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a protective stent system, and more particularly to a protective stent system that can be used to expand an affected area of an embolus stenosis in a blood vessel.

  When a thrombus substance adheres to and accumulates on the inner wall of the blood vessel, the inner diameter of the blood vessel is narrowed, resulting in trouble in blood circulation. As one of the methods for dealing with such an embolus stenosis affected part, forcibly expanding the embolic stenosis affected part is performed. For the expansion, a catheter, a balloon, a stent, or the like is used. During the expansion, the thrombus material is peeled off and becomes fine embolic material waste. If this embolic material debris flows in the blood vessel, a new embolic stenosis may occur on another downstream side. Therefore, a filter device is used to collect these embolic material debris.

  For example, Patent Document 1 discloses a catheter for embolizing an embolus stenosis in a blood vessel, a guide wire with an embolus collection filter used with a stent, a tip, a nose cone for posture stabilization, and embolus collection. A configuration is described that includes a storage sheath in which a filter is folded and stored, and a stainless steel protective wire. Here, the embolus waste collecting filter is a looped wire frame made of a shape memory alloy, a filter cloth for collection made of a permeable porous synthetic resin film having pores of 20 μm to 500 μm by laser light, It is composed of a spinner tube to be stably deployed, and by pulling the storage sheath proximally, it has a trapping net shape having an opening with a diameter of about 0.2 mm to 2 mm and a length of about 2 mm to 10 mm. Is disclosed.

  The embolus waste collecting filter is deployed and arranged at a distance of at least 1.5 cm from the target affected part position to the distal side (downstream side) as the position of the loop-shaped wire frame at the time of deployment, and the expansion at the target affected part position The attached embolus of the affected area is compressed or cut by crushing or removing with a catheter or stent, etc., and the small granular floating embolus inevitably generated when the stenosis is expanded is collected with this embolus collecting filter. Then, it is described that the embolus waste collecting filter containing floating embolus waste is folded and collected in the housing sheath.

  Patent Document 2 states that a filter device is further included in a stent catheter including a catheter body, an inflatable balloon, and a stent. Here, the filter device includes an introduction sheath, a guide wire, and an expandable filter assembly. The expandable filter assembly includes an expansion frame including a plurality of support columns, and a polyurethane having a hole size of 60 μm to 100 μm. Forming a mesh into the desired filter shape and including a filter mesh that is adhered to the struts by ultrasonic welding or adhesive, and when the stenosis region is opened by the stent, the plaque breaks away from the vessel wall and blood It is disclosed that it is carried downstream by the flow and strikes and is captured in the filter mesh, and the expansion frame of the filter assembly is retracted and recovered after the treatment area is opened.

  Patent Document 3 discloses a self-expandable repositionable intravascular device used as a stent, an occlusion body, or a filter as a woven intravascular device. Here, a central sinus filter is disclosed which has a closed structure at both ends and is woven by a braiding machine using six or more shape memory wires having a Nitinol diameter of 0.006 inches to 0.012 inches. Yes.

JP 2002-253679 A JP 2007-222658 A JP 2009-56314 A

  In any of the above-mentioned patent documents, in the prior art, a balloon, a stent, etc. for expanding an embolic stenosis affected part are disposed in a filter device that collects embolic material debris that may be generated when the embolic stenotic affected part is expanded. It is provided on the downstream side of the blood flow from the site of the affected area of the embolus stenosis. In both cases, after the embolic material is collected, it is folded and collected outside the body.

  In these prior arts, in the expanded state of the filter device, the collection opening faces the upstream side of the blood flow, the blood flow passes through the mesh gap of the filter device, and embolic material waste is collected in the mesh gap. Is done. After that, when the filter device is folded for recovery, the opening is closed, so that the blood flow is blocked by the closing port, so that the flow is once reversed, and then the original flow direction is returned to the filter. It will flow along the folded outside of the device. In this way, when the filter device is folded and closed, the blood flow changes direction at the opening of the filter device, so that the embolic material debris collected in the opening of the filter device by the reversal of the blood flow to the outside. Scattering can occur.

  Thus, if embolic material debris is sprinkled from the filter device into the blood vessel when the filter device is folded, the filter device no longer exists downstream from this, which may cause a new thrombus.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a protective stent system that suppresses scattering of embolic material that may occur during the expansion of an embolus stenosis site into a blood vessel under a new idea, instead of a filter device of the prior art. That is.

  A protective stent system according to the present invention is a protective stent used for covering an affected area of an embolus stenosis in a blood vessel from the inside of the blood vessel toward a wall surface and leaving it in the blood vessel as it is, and a plurality of stents made of a shape memory material. Crossing each other, forming a diamond-shaped stitch gap and forming a hose-like body knitted in the longitudinal direction to open both ends, and the knitted length is set longer than the length of the affected area of the embolus stenosis, and the knitted outer diameter Is set to be larger than the inner diameter of the blood vessel after dilation of the embolus stenosis, and the knitted diamond-like stitch gap is set to be fine enough to collect embolic material debris during the embolism stenosis dilation, and is shaped with respect to the knitted outer diameter and length A protective stent that is memorized and provided with superelasticity, and a guide wire portion that has a protective stent holding portion for holding the protective stent on the distal side, Protective stent holding portion by extending the protective stent in the axial direction by moving the guide wire portion relatively to the base end side by using a microcatheter portion having a slide passage that accommodates the inside so that the portion can be slid in the axial direction Can be accommodated inside the microcatheter part in a state of being held in, and the guide wire part is moved relatively to the distal side so that the protective stent is pulled out of the microcatheter part and expanded radially to the original shape, Thereafter, the guide wire portion can be accommodated inside the microcatheter portion while the protective stent is left in place by moving the guide wire portion relatively to the base end side.

  Further, in the protective stent system according to the present invention, the guide wire portion has a distal end stopper and a proximal end stopper arranged along the axial direction at intervals defining the protective stent holding portion, When the guide wire part is passed through the openings at both ends of the hose-like body and housed inside the microcatheter part, it is free from both the terminal side stopper and the base end side stopper, and within the range of the protective stent holding part. When it is elongated and pulled out of the microcatheter part, it is reduced to the original shape in the axial direction and free to the original shape in the radial direction as a free state from both the terminal side stopper and the base end side stopper. Expanded, the guide wire part can move freely in the axial direction from the opening at both ends of the expanded hose-like body, including the end side stopper and the base end side stopper It is preferable.

  In the protective stent system according to the present invention, it is preferable that the diameter of the fine wire and the knitting pitch in the longitudinal direction are set so that the diamond stitch gap in the knitted state is 50 μm to 150 μm.

  With the above configuration, the protective stent system is a protective stent that is used to cover an affected area of an embolus stenosis in a blood vessel from the inside of the blood vessel toward the wall surface and is left in the blood vessel as it is, and a plurality of the stents made of a shape memory material Crossing each other, forming a diamond-shaped stitch gap and forming a hose-like body knitted in the longitudinal direction to open both ends, and the knitted length is set longer than the length of the affected area of the embolus stenosis, and the knitted outer diameter Is set to be larger than the inner diameter of the blood vessel after dilation of the embolus stenosis, and the knitted diamond-like stitch gap is set to be fine enough to collect embolic material debris during the embolism stenosis dilation, and is shaped with respect to the knitted outer diameter and length A protective stent that is memorized and provided with superelasticity, and a guide wire portion that has a protective stent holding portion that holds the protective stent on the distal side.

  Then, by operating the guide wire portion using the microcatheter portion, the protective stent can be accommodated inside the microcatheter portion while being elongated in the axial direction and held in the protective stent holding portion. It can be pulled out of the catheter section and expanded radially to its original shape, leaving the protective stent in place.

  Thereby, the microcatheter part in a state in which the protective stent is housed inside is moved to the affected part of the embolus stenosis in the blood vessel, and the guidewire part is moved relative to the microcatheter part, whereby the protective stent is moved to the guidewire part. The affected area of the embolus stenosis can be covered with a protective stent from the inside of the blood vessel toward the wall surface.

  Therefore, instead of installing a filter device downstream of the affected area of the embolic stenosis as in the prior art, a protective stent knitted with a thin line is placed so as to cover the affected area of the embolic stenosis from the inside of the blood vessel toward the wall surface. it can. Thereby, it is possible to effectively suppress the embolic material debris that may be generated when the affected area of the embolic stenosis is expanded into the blood vessel.

  In the protective stent system, the guide wire portion has a distal end stopper and a proximal end stopper arranged along the axial direction at intervals defining the protective stent holding portion. The protective stent has a guide wire portion passed through the openings at both ends of the hose-like body, and is in a free state from both the terminal side stopper and the base end side stopper. Then, when the protective stent is expanded to the original shape in the radial direction by the operation of the guide wire portion, the guide wire portion including the terminal side stopper and the base end side stopper is opened from the openings at both ends of the expanded hose-like body. Since it can move freely in the axial direction, it becomes easy to place the expanded protective stent as it is.

  In the protective stent system, the diameter of the fine wire and the knitting pitch in the longitudinal direction are set so that the diamond stitch gap in the knitted state is 50 μm to 150 μm. Thereby, it is possible to effectively suppress the scattering of embolic material debris into the blood vessel that may occur when the affected area of the embolus stenosis is expanded by the stitch.

In embodiment which concerns on this invention, it is a figure which shows a mode that the protective stent catheter system containing a protective stent system is used clinically. In embodiment which concerns on this invention, it is a figure explaining the structure and effect | action of a protective stent catheter system. In embodiment which concerns on this invention, it is a figure explaining a procedure when a protection stent catheter system is used clinically. In embodiment which concerns on this invention, it is a figure explaining the embolic stenosis affected part to which a protective stent catheter system is applied clinically. In embodiment which concerns on this invention, it is a figure explaining a mode when a protection stent catheter system is inserted in an embolic stenosis affected part clinically. In embodiment which concerns on this invention, it is a figure explaining a mode when a protection stent catheter system covers and covers an embolic stenosis affected part clinically. In embodiment which concerns on this invention, after a protective stent catheter system is used clinically, it is a figure explaining the procedure when an embolization stenosis affected part is expanded by a balloon catheter system. In embodiment which concerns on this invention, it is a figure explaining the structure and effect | action of a balloon catheter system applied after a protective stent catheter system is used clinically. In embodiment which concerns on this invention, after a protective stent catheter system is used clinically, it is a figure explaining a mode when a balloon catheter system is inserted in an embolic stenosis affected part. In embodiment which concerns on this invention, after a protective stent catheter system is used clinically, it is a figure explaining a mode when the balloon catheter system inserted in the embolic stenosis affected part expands. In embodiment which concerns on this invention, after a protective stent catheter system is used clinically, it is a figure explaining the mode of the embolic stenosis affected part expanded by the balloon catheter system. In embodiment which concerns on this invention, it is a figure explaining the procedure which indwells the self-expanding stent catheter system in the embolic stenosis diseased part where the protective stent catheter system was used clinically and was further expanded by the balloon catheter system. In embodiment which concerns on this invention, it is a figure explaining a structure and an effect | action of the self-expanding stent catheter system applied to the embolic stenosis affected part which the protection stent catheter system was used clinically and was further expanded by the balloon catheter system. In the embodiment according to the present invention, a state in which a protective stent catheter system is used clinically and a self-expanding stent catheter system is inserted into an embolic stenosis affected part expanded by a balloon catheter system will be described. It is a figure to do. In embodiment which concerns on this invention, it is a figure explaining a mode when the self-expanding stent inserted in the embolus stenosis affected part expanded by the balloon catheter system is used by the protective stent catheter system clinically. In embodiment which concerns on this invention, it is a figure explaining a mode that the expanded self-expanding stent is indwelled in the embolic stenosis affected part expanded by the balloon catheter system when the protective stent catheter system is used clinically.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, a stent having a uniform stitch by knitting a fine wire of Ni-Ti alloy will be described as a protective stent, but the material of the fine wire is a shape memory material, and the knitted length is longer than the length of the affected area of the embolic stenosis. The knitted outer diameter is set larger than the inner diameter of the blood vessel after dilation of the embolus stenosis, and the knitted diamond-shaped stitch gap is set to be fine enough to collect the embolic material debris during the embolization stenosis expansion. If there are, the dimensions and the like can be appropriately changed according to clinical use.

  In the following description, the protective stent system includes a protective stent and a guide wire portion, and the protective stent is protected by extending in the axial direction on the protective stent holding portion of the guide wire portion using the protective stent microcatheter portion. It will be described as being stored and held inside the stent microcatheter, or extended to the original shape that has been pulled out of the protective stent microcatheter and memorized in shape. What is necessary is just to be able to accommodate the stent and the guide wire portion inside.

  In addition, materials, shapes, dimensions, and the like described below are exemplifications, and these contents can be changed as appropriate according to the size of the affected area of the embolic stenosis. As an example used clinically, an affected area of an embolus stenosis in a cerebral blood vessel will be described. The size of the affected area of the embolic stenosis is an example for explanation.

  In the following, when the microcatheter part is inserted into the body of the living body, the distal end that is the traveling direction side is referred to as the distal side, and the side that is operated outside the living body and is the proximal side is referred to as the base end side. To. The base end side is generally called the distal side, and the base end side is generally called the proxy side.

  Below, the same code | symbol is attached | subjected to the same element in all the drawings, and the overlapping description is abbreviate | omitted. In the description in the text, the symbols described before are used as necessary.

  Here, differences between the protective stent, the protective stent system, the protective stent catheter system, and the protective stent delivery system will be described.

  As described above, the protective stent system includes a protective stent and a guide wire portion. Here, the protective stent has a shape memory and is superelastic as will be described in detail later. Therefore, the protective stent is elongated by constraining its outer shape, and the original shape memory shape is removed by removing the constraint. Can be extended to Here, the shape of the protective stent cannot be defined only by the protective stent system.

  Therefore, in clinical practice, a protective stent microcatheter part that can accommodate the protective stent system in an axially movable manner is used. That is, when the protective stent system is inserted into the patient's body, the outer shape of the protective stent is regulated by the inner diameter of the protective stent microcatheter portion and is held in the guide wire portion in an elongated shape in the axial direction. Then, the protective stent microcatheter part and the guide wire part are relatively moved in the axial direction at a desired site, the protective stent is pulled out of the protective stent microcatheter part, the outer shape is restrained, and the shape is memorized. Expand to its original shape. In this way, in clinical practice, a protective stent system and a protective catheter microcatheter part are used as a set, and this can be called a protective stent catheter system.

  Thus, in clinical practice, the protective stent microcatheter part and the protective stent system are used in combination, but it is desirable that the protective stent system can be handled independently by transportation or the like until clinical use. For this purpose, a sheath introducer is used to accommodate a portion on which the stent on the terminal side of the guide wire portion in the protective stent system is mounted. The sheath introducer corresponds to the tip portion of the protective catheter microcatheter part and has the same inner diameter as the inner diameter of the microcatheter part. In this way, in the pre-stage used in clinical practice, a protective stent system and a sheath introducer can be combined and handled as an independent part, so this can be called a protective stent delivery system.

  As described above, the protective stent system includes a protective stent and a guide wire portion, and the protective stent catheter system is clinically used in combination with a protective stent system and a protective stent microcatheter portion. The protective stent delivery system is a combination of a protective stent system and a sheath introducer that can be handled as an independent part in a non-clinical setting.

  Here, as long as the outer diameter of the protective stent system is adapted, various kinds of protective catheter microcatheter portions can be used. In other words, a general-purpose protective stent system can be obtained by setting the outer diameter of the protective stent system in accordance with the inner diameter of a standard microcatheter part. Moreover, it becomes possible to use the standard sheath introducer matched with the internal diameter of the standard microcatheter part by doing in this way.

  FIG. 1 is a diagram showing how a protective stent catheter system 10 is used in clinical practice. Here, as described above, the protective stent catheter system 10 includes the protective stent system including the protective stent 40 and the guide wire portion 20 and the micro catheter portion 12 for the protective stent.

  In FIG. 1, when a patient having an embolus stenosis diseased part 62 in a blood vessel 60 of the brain is subjected to a treatment for dilating the embolus stenosis using a balloon catheter system and a self-expanding stent catheter system, the embolus stenosis is performed prior to the treatment. A state where the protective stent 40 is indwelled in the affected part 62 is shown.

  For placement of the protective stent 40, application of the balloon catheter system, and placement of the self-expanding stent, first, the guiding catheter 100 is inserted from the artery such as the thigh of the patient 8 to the vicinity of the carotid artery 6.

  The guiding catheter 100 is also called a parent catheter, and is a protective stent microcatheter portion 12 used for placement of the protective stent 40, a balloon microcatheter portion used for a balloon catheter system, and a self-expanding stent used for placement of a self-expanding stent. A catheter having a larger inner diameter than any of the outer diameters of the stent microcatheter part, which can be inserted into the aorta. A guide wire is used for guiding the guiding catheter 100 in the aorta. As the guide wire for guide, the guide wire portion 20 on which the protective stent 40 is not yet mounted can be used.

  Since the carotid artery 6 generally has a diameter of several millimeters, the insertion of the guiding catheter 100 is stopped before that. The protective stent microcatheter part 12 is inserted into the guiding catheter 100, and only the protective stent microcatheter part 12 is advanced from the carotid artery 6 toward the site of the embolus stenosis affected part 62.

  When the protective stent microcatheter part 12 is advanced to the vicinity of the site of the embolus stenosis affected part 62, the protective stent system is inserted into the protective stent microcatheter part 12 before and after that. Specifically, the guide wire portion 20 holding the protective stent 40 at the end portion is inserted. Here, as described above, a protective stent delivery system including a sheath introducer is provided. The distal end opening of the sheath introducer is directed to the proximal end opening of the protective stent microcatheter section 12, and the guide wire section 20 that holds the protective stent 41 that has already been extended to the distal end is provided. The sheath introducer is inserted into the protective stent microcatheter section 12.

  When the guide wire portion 20 that holds the protective stent 40 on the distal side advances through the protective stent microcatheter portion 12 and reaches the site of the embolized stenosis diseased portion 62, the guide wire portion 20 becomes the protective stent micro catheter portion 12. On the other hand, the operation is performed so as to move relatively toward the end side. As a result, the protective stent that has been elongated in the axial direction inside the protective catheter microcatheter portion 12 is pulled out to the outside of the protective stent microcatheter portion 12 and expanded to the original shape that has been memorized. To do. FIG. 1 shows a state of the protective stent 40 expanded at the site of the embolus stenosis diseased part 62.

  FIG. 2 is a diagram illustrating the configuration and operation of the protective stent catheter system 10. 2A is a cross-sectional view when the elongated and elongated protective stent 41 is housed in the protective stent microcatheter portion 12, and FIG. 2B is a cross-sectional view of the protective stent. FIG. 6C is a cross-sectional view when the expanded protective stent 40 is pulled out to the outside of the catheter portion 12, and the guide wire portion 20 and the protective stent microcatheter portion 12 are left as they are. It is sectional drawing when collect | recovering.

  As shown in FIGS. 2A to 2C, the protective stent catheter system 10 includes a protective stent that is stretched in the axial direction by the relative movement of the protective catheter microcatheter portion 12 and the guide wire portion 20. The protective stent 40 is accommodated inside the microcatheter portion 12 for use, or the protective stent is pulled out of the microcatheter portion 12 for protective stent and expanded to the original shape, and the protective stent 40 is further extended from the guide wire portion 20. Has the effect of separating.

  As described above, the protective stent catheter system 10 is provided on the protective stent microcatheter portion 12, the guide wire portion 20 inserted into the protective stent micro catheter portion 12, and the distal end side of the guide wire portion 20. And a protective stent held by the protective stent holding part 31. Here, the protective stent system is a part including a protective stent and a guide wire portion 20.

  As will be described later, since the length and the outer diameter of the protective stent are changed depending on whether the protective stent is inside or outside the protective stent microcatheter portion 12, FIG. 2 shows the protective stent microcatheter portion. The reference numerals of the protective stent 40 outside the protective stent 40 and the protective stent 41 inside the protective stent microcatheter 12 are changed.

  The protective catheter microcatheter portion 12 is a flexible tube having a slide passage that accommodates the guide wire portion 20 in the axial direction so as to be slidable. The protective stent microcatheter section 12 is selected for medical use, and plastic tubes such as urethane tubes and nylon tubes can be used. In order to secure the strength, it is possible to use a material embedded with a stainless mesh. For example, the outer diameter is 0.90 mm, the inner diameter is 0.52 mm, the tube wall thickness is 0.19 mm, and the total length is about 1600 mm.

  The guide wire portion 20 is a thin flexible wire having a function of guiding when the protective stent catheter system 10 is inserted into a living body tube portion and a function of holding the protective stent 40. The material of the guide wire portion 20 is a metal suitable for medical use such as stainless steel. As an example of dimensions, one having an outer diameter on the base end side of 0.34 mm and a total length of about 1800 mm can be used. The outer diameter can be gradually tapered on the end side.

  The protective stent 40 crosses a plurality of thin wires made of a shape memory material, and forms a hose-like body that is knitted in the longitudinal direction while forming a diamond-shaped stitch gap and is open at both ends. It is set longer than the length of the affected area of the embolus stenosis, the outer diameter knitted is larger than the inner diameter of the blood vessel after dilation of the embolus stenosis, and the knitted diamond-shaped stitch gap is fine enough to collect embolic material debris during embolization stenosis expansion The outer diameter and length knitted are memorized and superelasticity is given.

  In order to knitting the protective stent 40 as a hose-like body, an even number of NiTi alloy thin wires having shape memory and superelastic properties are used, and the even number is divided into two, and every other half is in a left-handed spiral shape. The remaining 72 halves are wound in a right-handed spiral shape on a die having a cylindrical peripheral surface, and a left-handed thin wire and a right-handed thin wire have a cylindrical surface so that the right-handed thin wire intersects with a plain weave. The mold is pulled up at a constant speed in the axial direction. The knitted hose-like body is subjected to aging treatment for imparting superelasticity together with a mold having a cylindrical peripheral surface thereof, and then returned to room temperature, so that the shape at the time of imparting superelasticity, that is, a mold having a cylindrical peripheral surface is provided. The shape knitted on top is stored.

  Therefore, the knitting length along the axial direction of the protective stent 40 can be set by the length from the knitting start to the knitting end on the mold having the cylindrical peripheral surface. Further, the outer diameter of the protective stent 40 can be set by the outer diameter of a mold having a cylindrical peripheral surface and the diameter of a thin wire. Further, among the diamond-shaped stitch gaps knitted by the protective stent 40, the stitch gap along the radial direction or the circumferential direction can be set by the outer peripheral length of the mold having the cylindrical peripheral surface, the number of fine wires, and the diameter of the fine wires. The stitch gap along the axial direction, which is the longitudinal direction, can be set at a knitting pitch determined by the lifting speed of the mold per cycle around which a plurality of fine wires are wound around the mold having a cylindrical peripheral surface.

  As an example, the diameter of the fine wire is 50 μm = 0.05 mm, the outer diameter of the mold having a cylindrical peripheral surface is 5 mm, and the number of fine wires is 100. In this case, the stitch gap along the circumferential direction of the protective stent 40 is {(π × 5 mm) / 50} −0.05 mm = 0.314 mm−0.05 mm = 0.264 mm. If the number of fine wires is 200, the stitch gap is 0.157 mm−0.05 mm = 0.107 mm. Thus, the stitch gap along the circumferential direction of the protective stent 40 can be set by the number of thin lines.

  The stitch gap along the axial direction is preferably substantially the same as the stitch gap along the circumferential direction in order to reduce the bias in collecting embolic material debris. For example, when the stitch gap along the circumferential direction is set to about 100 μm = 0.1 mm, the knitting speed in the axial direction per cycle in which a plurality of thin wires are wound around a mold having a cylindrical circumferential surface. The knitting pitch may be 100 μm + (50 μm which is the diameter of the thin wire) = 150 μm = 0.15 mm. In this way, the stitch gap along the axial direction of the protective stent 40 can be set by the knitting pitch in the axial direction.

  Since the size of the diamond-shaped stitch gap of the protective stent 40 is set to be fine enough to collect embolic material debris during the embolus stenosis expansion, the stitch gap is preferably 50 μm to 150 μm, for example.

  For example, if the length along the axial direction of the blood vessel of the embolic stenosis is about 10 mm, the narrowest inner diameter of the embolic stenosis is about 1.5 mm, and the inner diameter of the blood vessel where the embolic stenosis has not occurred is about 4 mm, the protective stent 40 is Preferably, the total length when knitted is about 15 mm, the outer diameter when knitted is about 5 mm, and the stitch gap when knitted is about 50 μm to 150 μm. That is, the total length when the protective stent 40 is knitted should be long enough to cover the entire affected area of the embolus stenosis, and the outer diameter when knitted should be larger than the inner diameter of the blood vessel in which the embolic stenosis has not occurred. Is good.

  Returning to the description of FIG. 2, when the protective stent 41 is accommodated inside the protective stent microcatheter portion 12, the inner diameter of the protective stent microcatheter portion 12 is as shown in FIG. The outer diameter is constrained, and it is elongated in the axial direction. In the above example, the outer diameter of the protective stent 41 is constrained to 0.52 mm, which is the inner diameter of the protective catheter microcatheter portion 12, and is stretched in the longitudinal direction to an axial length of about 100 mm. .

  The stoppers 30 and 32 in FIG. 2 are annular members that are respectively fixed to the guide wire portion 20 with a predetermined interval along the longitudinal direction of the guide wire portion 20. A portion between the stopper 30 on the base end side and the stopper 32 on the terminal end corresponds to the protective stent holding portion 31 that holds the protective stent 40. Fixing between the stoppers 30 and 32 and the guide wire portion 20 can be performed using an appropriate adhesive. As the stoppers 30 and 32, a stainless pipe having a length of 1.0 mm, an outer diameter of 0.4 mm, and an inner diameter slightly larger than the outer diameter of the guide wire portion 20 can be used.

  Here, the protective stent 40 is held between the stoppers 30 and 32. However, the protective stent 40 is not fixed to any of the stoppers 30 and 32 and is in a free state. That is, the protective stent 40 can freely insert and pull out the guide wire portion 20 from any of the openings at both ends of the hose-like body.

  That is, when the protective stent 40 is housed inside the protective stent microcatheter portion 12, the range of the protective stent holding portion 31 is set free from both the distal end stopper 32 and the proximal end stopper 30. It is elongated in a long way. Further, when the protective stent 40 is pulled out of the protective stent microcatheter portion 12, the protective stent 40 is reduced from the distal end stopper 32 and the proximal end stopper 30 to a free state and reduced to the original shape in the axial direction. Then, the guide wire portion 20 is freely moved in the axial direction including the stopper 32 on the distal end side and the stopper 30 on the proximal end side from the opening at both ends of the expanded hose-like body. Is possible.

  The coil 34 in FIG. 2 is a member that is provided closer to the distal end side of the guide wire portion 20 than the stopper 32 and has a function of protecting the tip of the guide wire portion 20 that is sharp. Further, the coil 34 can have a function as a terminal side marker indicating the position on the terminal side of the guide wire portion 20 by using a radiopaque material such as Pt. The coil 34 is fixed to the stopper 32 and the distal end side of the guide wire portion 20 with an adhesive.

  As the coil 34, for example, a coil formed by winding a thin Pt wire in a spiral shape can be used. As an example of the dimensions of the helical coil, the outer diameter can be about 0.34 mm, the inner diameter can be about 0.20 mm, and the length can be about 32 mm.

  FIG. 2A is a view showing a state in which the protective stent 40 is elongated in the axial direction and is housed in the protective catheter microcatheter portion 12. Here, the guide wire portion 20 is pulled toward the proximal end side with respect to the protective stent microcatheter portion 12 so that at least the protective stent holding portion 31 is located inside the protective stent microcatheter portion 12.

  FIG. 2B is a diagram showing a state in which the protective stent 40 has returned to the outer diameter and length when the protective stent 40 has been knitted and has been restrained by the inner diameter of the protective stent microcatheter portion 12. is there. Here, the guide wire portion 20 protrudes to the distal side with respect to the protective stent microcatheter portion 12 so that at least the protective stent holding portion 31 is positioned outside the protective stent microcatheter portion 12.

  FIG. 2C is a diagram illustrating a state where the protective stent 40 is separated from the position of the protective stent holding portion 31 of the guide wire portion 20 and occupies a single position. In clinical practice, this corresponds to a state in which the guide wire portion 20 is recovered outside the body along the guiding catheter 100 together with the protective stent microcatheter portion 12 while the protective stent 40 remains in place at the affected area of the embolic stenosis. Here, both the guide wire portion 20 and the protective catheter microcatheter portion 12 are drawn closer to the proximal end than the protective stent 40.

  The effect of the protective stent system or the protective stent catheter system 10 having the above-described configuration will be further clarified by explanation of how it is used in clinical practice. In the following, the use of the protective stent catheter system 10 will be described using an example in which the embolic stenosis of the affected part 62 in the cerebral blood vessel 60 is expanded, and then the balloon catheter system and the self-expanding stent catheter system are described. A state of being used will be described.

  FIG. 3 is a flowchart showing a procedure when the protective stent catheter system 10 is used in clinical practice, and FIGS. 4 to 6 are diagrams for explaining how the protective stent catheter system 10 is applied clinically.

  In order to expand the embolic stenosis of the affected part 62 in the cerebral blood vessel 60, first, the guiding catheter 100 is inserted into the body of the patient (S10). Specifically, as described in FIG. 1, the guiding catheter 100 is inserted from the artery such as the thigh of the patient 8 to the vicinity of the carotid artery 6.

  Next, the protective catheter microcatheter portion 12 is inserted along the guiding catheter 100 (S12). Specifically, as described with reference to FIG. 1, the protective stent microcatheter portion 12 is inserted into the guiding catheter 100, and only the protective stent microcatheter portion 12 extends beyond the carotid artery 6. It is advanced aiming at the part of.

FIG. 4 is a view showing a state of an embolus stenosis affected part 62 in a blood vessel 60 of the brain. Vascular 60 is a normal site, but its inside diameter is D _A, the embolic stenosis diseased part 62, the narrowest at its inner diameter D _N1, and the blood flow becomes poor. The embolus stenosis diseased part 62 is caused by accumulation of an atheroma, a mass material called an atheroma 63, which is a thrombus, on the inner wall of a blood vessel. Hereinafter, as an example of the dimensions, the normal inner diameter D _A of the blood vessel 60 is 4 mm, the length L _N of the embolus stenosis affected part 62 is 10 mm, and the narrowest inner diameter D _N1 = 1.5 mm. This dimension is an example for explaining the relationship with the dimension of the protective stent 40, and may be other than this.

  Returning to FIG. 3, the guide wire portion 20 on which the elongated protective stent 41 is mounted on the distal side is inserted into the protective stent microcatheter portion 12 (S14). The guide wire portion 20 on which the protective stent 41 is mounted on the distal side is the protective stent system itself, and a combination of the protective stent system and the protective stent microcatheter portion 12 is the protective stent catheter system 10.

FIG. 5 is a view showing a state in which the protective stent catheter system 10 is inserted into the embolus stenosis diseased part 62. In the above example, since the outer diameter of the protective catheter microcatheter portion 12 is 0.9 mm, it is thinner than the narrowest inner diameter D _N1 = 1.5 mm of the embolic stenosis diseased portion 62. Therefore, in this case, the protective stent microcatheter part 12 can be passed through the embolic stenosis affected part 62, and then the guide wire part 20 for mounting the protective stent on the distal side can be passed through the inner diameter of the protective stent microcatheter part 12. it can.

Incidentally, the narrowest inner diameter D _N1 embolic stenosis diseased part 62, when the diameter is smaller than the outer diameter of the protective stent for microcatheter 12, using a balloon catheter system that will be described later, slightly expand the inner diameter of the embolic stenosis diseased part 62 The outer diameter of the protective stent microcatheter portion 12 can be made larger, and then S12 and S14 can be executed.

  Returning to FIG. 3 again, the protective stent is expanded in the embolic stenosis diseased part 62 (S16). Specifically, in the protective stent catheter system 10, the guide wire portion 20 protrudes to the distal side with respect to the protective stent microcatheter portion 12, and the protective stent holding portion 31 comes outside the protective stent microcatheter portion 12. To. Although this state is the state described with reference to FIG. 2B, the embolic stenosis affected part 62 is located just where it expands, so the protective stent covers the embolic stenosis affected part 62 from the inside of the blood vessel 60 toward the wall surface. Will be expanded as follows. In FIG. 6 which will be described later, the protective stent 42 is shown expanded after following the inner wall surface of the embolus stenosis affected part 62.

In this way, in order to expand the protective stent 42 so as to cover the embolus stenosis affected part 62 from the inside of the blood vessel 60 toward the wall surface, the protective stent 41 in FIG. 5 is positioned while observing the X-ray image of the coil 34. Need to do. The total length L _S of the protective stent 40 is set longer than L _N so that the protective stent 42 can sufficiently cover the length L _N = 10 mm of the embolus stenosis affected part 62 even if the positioning is slightly shifted. In the above, the total length L _{S of the} protective stent is set to 15 mm.

  Then, the protective stent 42 is placed in the embolus stenosis diseased part 62 (S18). Specifically, in the protective stent catheter system 10, the guide wire portion 20 is accommodated in the protective stent microcatheter portion 12 that has already moved to the proximal end side of the protective stent 42. 20 is drawn to the base end side. Then, the protective catheter microcatheter portion 12 is recovered outside the body through the guiding catheter 100 together with the guide wire portion 20 (S20).

  The state is the state described with reference to FIG. 2C, but the protective stent 42 has already expanded so as to cover the embolic stenosis affected part 62 from the inside of the blood vessel 60 toward the wall surface, and the protective stent 42. Is in a free state with respect to the stoppers 30 and 32, the protective stent 42 does not move from that position even if the guide wire portion 20 moves. That is, the protective stent 42 remains attached to the inner wall of the embolus stenosis affected part 62.

This is shown in FIG. FIG. 6 shows an external view of the protective stent 42 with respect to the central axis of the blood vessel 60 and a cross-sectional view of the protective stent 42 on the lower half. As described above, the protective stent 42 is attached by its elasticity so as to cover the embolus stenosis affected part 62 from the inside of the blood vessel 60 toward the wall surface. In other words, since the outer diameter stored in the shape of the protective stent 42 is about 5 mm, the elasticity that can expand sufficiently outside the inner diameter D _A of the normal part of the blood vessel 60 and the narrowest inner diameter D _N1 of the embolic stenosis affected part 62. have.

  In this manner, the protective stent 42 can cover the embolus stenosis affected part 62 so as to firmly press it from the inside of the blood vessel 60 toward the wall surface. Since the diamond-shaped stitch gap knitted of the protective stent 42 is set to 50 μm to 150 μm as described above, the atheroma 63 of the affected area 62 of the embolus stenosis peels off during the subsequent embolus stenosis expansion and the embolus It is possible to prevent material waste from being scattered in the blood vessel 60.

  In other words, the protective stent 42 has a function as a protective wall material that prevents the embolus stenosis diseased part 62 from peeling off, rather than a filter function that collects embolic material debris scattered in the blood vessel 60. The stitch gap is necessary to ensure the elasticity of the protective stent 42 in the radial direction, and also functions to prevent the embolus stenosis affected part 62 from scattering into the blood vessel 60 even if the embolus stenosis affected part 62 is peeled off.

  FIGS. 7 to 16 are views for explaining how the protective stent 42 is indwelled in the embolus stenosis affected part 62 and functions as a protective wall material to expand the embolic stenosis affected part 62. . Here, FIGS. 7 to 11 are views showing a state in which the affected part 62 of the embolus stenosis is expanded using the balloon catheter system 50 so that the next self-expanding stent catheter system 80 can be easily passed. FIGS. 12 to 16 are views showing a state in which the self-expanding stent 90 is placed in an embolic stenosis affected part expanded by the balloon catheter system 50 and the blood flow is improved in a state where the embolic stenosis affected part is sufficiently expanded. In these processes, the protective stent is always attached so as to cover the affected area of the embolic stenosis from the inside of the blood vessel 60 toward the wall surface due to its elasticity.

  FIG. 7 is a diagram for explaining a procedure when the embolic stenosis diseased part 62 is expanded by the balloon catheter system 50 after the protective stent 42 is placed in the embolus stenosis diseased part 62. Here, after the protective stent catheter system 10 is recovered from the body in S20 described with reference to FIG. 3, the balloon catheter system 50 is subsequently inserted. Specifically, the balloon microcatheter portion 52 is inserted, and the guide wire portion 20 is inserted before and after this (S22).

  The state of the balloon catheter system 50 is shown in FIG. FIG. 8A shows a state of the folded balloon 71, and FIG. 8B shows a state where the balloon 70 is expanded by supplying the expansion fluid 58 to the inner space of the folded balloon 71. FIG. FIG. As shown in FIG. 8, the balloon catheter system 50 includes a guide wire portion 20 and a balloon microcatheter portion 52 into which the guide wire portion 20 is inserted. The same guide wire portion 20 as described in FIG. 2 can be used.

  The balloon microcatheter portion 52 is a microcatheter in which a balloon 71 folded in a normal state is provided on the outer periphery on the terminal side. The folded balloon 71 is a plastic film-like bag body and is attached to the outer periphery of the balloon microcatheter portion 52 so that the inside thereof is in a sealed state. As such a plastic film, for example, a nylon elastomer can be used.

  The balloon microcatheter portion 52 is provided with an expansion fluid passage 56 that communicates with the inner space of the folded balloon 71 along the axial direction, in addition to the through-hole for inserting the guide wire portion 20. One end of the expansion fluid passage 56 is connected to a connection port 57 that opens toward the inner space of the folded balloon 71, and the other end is provided on the base end side of the balloon microcatheter portion 52. Connected to the supply port 54. The expansion fluid supply port 54 is exposed outside the body of the patient 8, so that the expansion fluid 58 is folded from the outside of the patient 8 through the expansion fluid supply port 54 and the expansion fluid passage 56. 71 can be supplied to the internal space. As the expansion fluid 58, for example, a mixed fluid of physiological saline and contrast medium can be used.

  The folded balloon 71 is formed by brazing a plastic film in advance, and when the internal space is in a reduced pressure state, the balloon 71 is folded as if the umbrella is indented, and the outer diameter becomes extremely small. This state is shown in FIG. Then, the expansion fluid 58 is supplied to the internal space and pressurized, so that the expanded balloon 70 becomes as if the umbrella is unfolded. This state is shown in FIG. When the expansion fluid 58 is recovered and decompressed from FIG. 8B, the expanded balloon 70 returns to the folded balloon 71 again.

In FIG. 8, the outer diameter of the folded balloon 71 can be about 1 mm to about 1.3 mm, for example. Further, the axial length of the expanded balloon 70 and L _B, when the outer diameter during expansion and D _B, L _B is the same extent as the length L _N of the embolic stenosis diseased part 62, therefore, protected The total length L _{S in} the axial direction of the stent 40 is shorter. D _B is able acceleration by the supply pressure of the expansion fluid 58, as the maximum value, the larger than the inner diameter D _A of the normal portion of the vessel 60 desirably.

  As described above, since the change from the folded balloon 71 to the expanded balloon 70 is adjusted by the supply pressure of the expansion fluid 58, an expansion force corresponding to the supply pressure can be generated. The embolized stenosis affected part 62 can be expanded, or the self-expanding force of the self-expanding stent 90 described in FIG.

  FIG. 9 is a view showing a state in which the balloon catheter system 50 is inserted into the embolus stenosis diseased part 62. In the above example, since the outer diameter of the folded balloon 71 is about 1 mm to about 1.3 mm, it can pass through the affected area 62 of the embolus stenosis. Since the embolus stenosis affected part 62 is already firmly covered with the protective stent 40, even when the folded balloon 71 passes, even if the embolus stenosis affected part 62 comes into contact with the embolus stenosis affected part 62 at the outer periphery or the like, the embolic material debris is scattered in the blood vessel 60. Is prevented.

Returning to FIG. 7 again, next, balloon expansion is performed in the embolus stenosis affected part 62 (S24). Specifically, as illustrated in FIG. 8B, the expansion fluid 58 is supplied to the inner space of the folded balloon 71, thereby forming the expanded balloon 70. This is shown in FIG. Here, the embolus stenosis affected part 62 is expanded by the supply pressure of the expansion fluid 58 (S26), and the embolus stenosis affected part 64 whose narrowest inner diameter is DN ₂ is shown. The expanded inner diameter DN ₂ of the embolus stenosis affected part 64 is such that a self-expanding stent catheter system 80 described in FIG. 12 and subsequent figures can be inserted, and can be, for example, about 3 mm.

  When the expanded embolus stenosis affected part 64 is formed in this way, as shown in FIG. 7, the balloon is deflated (S28). Specifically, the expansion fluid 58 is recovered, and further decompressed, the internal space of the expanded balloon 70 is reduced and returned to the folded balloon 71 state.

  Then, the balloon catheter system 50 is collected. Specifically, the balloon microcatheter portion 52 is collected outside the body of the patient 8 through the guiding catheter 100 together with the guide wire portion 20 (S30).

This is shown in FIG. Although embolic stenosis affected area 64 that is extended to the inner diameter D _N2 is formed as described above, also in this case, protection stent 42 by its elasticity, further extended to follow the embolic stenosis affected area 64 is extended, The expanded embolus stenosis affected part 64 is pressed so as to cover from the inside of the blood vessel 60 toward the wall surface. In FIG. 11, this state is illustrated as a further expanded protective stent 43. In FIG. 11, similarly to FIG. 6, the outer half of the central axis of the blood vessel 60 is shown as an external view of the protective stent 43, and the lower half is a sectional view of the protective stent 43.

  FIG. 12 is a diagram for explaining a procedure when the self-expanding stent 90 is placed in the embolic stenosis diseased part using the self-expanding stent catheter system 80 after the expanded embolic stenosis diseased part 64 is formed. Here, in S30 described with reference to FIG. 7, after the balloon catheter system 50 is recovered from the body, the self-expanding stent catheter system 80 is subsequently inserted. Specifically, the microcatheter portion 82 for the self-expanding stent is inserted, and the guide wire portion 20 is inserted before and after this (S32).

  The appearance of the self-expanding stent catheter system 80 is shown in FIG. 13A is a cross-sectional view when the self-expanding stent 91 in a contracted state is housed in the microcatheter portion 82 for the self-expanding stent, and FIG. 13B is a sectional view when the self-expanding stent is self-expanding. Sectional drawing when it becomes the self-expanding stent 90 which is pulled out to the outside of the microcatheter part 82 for the expansion stent and is expanded, (c) shows the guide wire part 20 and the self-expansion with the expanded self-expanding stent 90 as it is. It is sectional drawing when the microcatheter part 82 for stents is collect | recovered.

  As shown in FIGS. 13 (a) to (c), the self-expanding stent catheter system 80 is disposed inside the outer tube portion 84 and the outer tube portion 84 constituting the microcatheter portion 82 for the self-expanding stent, The self-expanding stent is radially compressed and contracted by the relative movement with the inner cylinder portion 86 that holds the self-expanding stent that has undergone shape memory and superelastic treatment, and is accommodated in the outer cylinder portion 84, or The self-expanding stent is pulled out to the outside of the outer tube portion 84 and expanded to the original shape memorized, and the expanded self-expanding stent 90 is separated from the guide wire portion 20.

  As shown in FIG. 13, the self-expanding stent catheter system 80 includes a self-expanding stent microcatheter portion 82 including an outer tubular portion 84 and an inner tubular portion 86, and a guide wire inserted into the inner tubular portion 86. Portion 20 and a self-expanding stent held by a self-expanding stent holding portion 89 provided on the distal end side of the inner tube portion 86. The same guide wire portion 20 as described in FIG. 2 can be used.

  Since the outer diameter of the self-expanding stent changes between when it is inside the outer cylinder portion 84 and when it is outside, in FIG. 13, the self-expanding stent 90 outside the outer cylinder portion 84 The sign is changed with the self-expanding stent 91 in the cylindrical portion 84.

  The self-expanding stent microcatheter portion 82 is a double-structured tubular portion in which the outer tubular portion 84 and the inner tubular portion 86 are movable in the axial direction. The outer cylindrical portion 84 includes an inner cylindrical portion 86 therein, and is a cylindrical member having a function of defining the outer diameter of the self-expanding stent held by the inner cylindrical portion 86, particularly by the inner diameter dimension thereof. The outer cylinder portion 84 is selected for medical use, and a plastic tube such as a urethane tube or a nylon tube can be used. In order to secure the strength, it is possible to use a material embedded with a stainless mesh. For example, the outer diameter is about 2 mm, the tube wall thickness is about 0.2 mm, and the total length is about 1600 mm.

  The inner cylinder portion 86 has a slide passage that accommodates the guide wire portion 20 in the axial direction so that the guide wire portion 20 can be slid in the axial direction. It is a member. The self-expanding stent holding portion 89 is formed as a portion whose outer diameter is reduced along the axial direction from the arrowhead portion 88 which is the distal end portion of the inner cylindrical portion 86. The inner cylinder portion 86 is selected for medical use, and a plastic tube such as a urethane tube or a nylon tube formed into a predetermined shape can be used.

As an example of the dimensions of the inner cylinder part 86, the inner diameter into which the guide wire part 20 is inserted is 0.52 mm, the outer diameter of the part excluding the self-expanding stent holding part 89 is about 1.6 mm, and the self-expanding stent holding part 89 The self-expanding stent holding part 89 has an outer diameter of 0.90 mm, an axial length L _SES of about 10 mm, and a total length of about 1600 mm.

  The expanded self-expanding stent 90 is made of a material having shape memory and superelasticity such as a Ni-Ti alloy and is contracted and deformed in the radial direction when an external force is applied, but when the external force is removed, It is a stent having a characteristic of returning to the outer diameter stored in the original shape memory. As such a self-expanding stent 90, a cylindrical material made of a Ni—Ti alloy and having a plurality of holes appropriately formed by laser processing or the like and subjected to shape memory / superelasticity treatment can be used. The plurality of holes are provided to facilitate deformation in the radial direction when an external force is applied.

  Therefore, the self-expanding stent 90 in the expanded state is arranged at the position of the self-expanding stent holding portion 89 of the inner cylinder portion 86, and the self-expansion is performed by the inner diameter of the outer cylinder portion 84 at that position using an appropriate arrangement jig. By contracting and deforming in the radial direction so as to regulate the outer diameter of the stent, the self-expanding stent 91 in a contracted state can be accommodated in the outer cylindrical portion 84. The contracted self-expanding stent 91 is expanded by moving the outer tube portion 84 toward the base end side with respect to the inner tube portion 86 so that the self-expanding stent holding portion 89 is outside the outer tube portion 84. The self-expanding stent 90 can be returned to its state.

As the dimensions of such a self-expanding stent, as shown in FIG. 13, when the outer diameter of the expanded self-expanding stent 90 is D _SES and its axial length is L _SES , D _SES is It is preferably larger than the normal inner diameter D _A and L _SES is shorter than the total length L _S of the protective stent 40. For example, in the above example, D _SES can be about 5 mm and L _SES can be about 10 mm.

  FIG. 14 is a view showing a state where the self-expanding stent catheter system 80 is inserted into the expanded embolic stenosis diseased part 64. In the above example, since the outer diameter of the outer tube portion 84 constituting the microcatheter portion 82 for a self-expanding stent is about 2 mm, it can pass through the expanded embolus stenosis affected portion 64. Since the expanded embolic stenosis affected part 64 is already covered firmly with the protective stent 43, even when the self-expanding stent catheter system 80 passes, even if it contacts the embolic stenosis affected part 64 on the outer periphery or the like, the embolic material debris remains in the blood vessel. Scattering into 60 is prevented.

Returning to FIG. 12 again, next, the self-expanding stent is expanded in the embolic stenosis affected area 64 (S34). Specifically, the self-expanding stent in a contracted state is obtained by moving the outer tube portion 84 toward the base end side with respect to the inner tube portion 86 so that the self-expanding stent holding portion 89 is outside the outer tube portion 84. 91 is returned to the expanded self-expanding stent. At this time, since the extension force of the self expanding stent itself is not very big, but expanded embolic stenosis affected area 64 to some extent further expand, often can not be returned completely to normal inner diameter D _A.

  FIG. 15 shows this state. Here, since the outer diameter of the expanded self-expanding stent has not returned to the outer diameter stored in shape memory, the inner wall of the blood vessel 60 is pressed by its elasticity. In FIG. 15, it is shown as a self-expanding stent 93 in intimate contact with the blood vessel 60 in distinction from the expanded self-expanding stent 90 of FIG. 13. At this time, since the protective stent 43 is located between the expanded embolus stenosis diseased part 64 and the self-expanding stent 93, even if the self-expanding stent 93 presses the inner wall of the blood vessel 60 by its elasticity, the embolus is present. The material waste is prevented from scattering into the blood vessel 60.

  When the self-expanding stent 93 is brought into close contact with the blood vessel 60 via the protective stent 43 as described above, the indwelling process of the self-expanding stent 93 is performed next as shown in FIG. 12 (S36). Specifically, the inner cylinder part 86 is drawn into the outer cylinder part 84 together with the guide wire part 20.

  The state is the state described with reference to FIG. 13C, but the self-expanding stent 93 has already been expanded so as to press the affected area 64 of the embolus stenosis from the inside of the blood vessel 60 toward the wall surface. Since the stent 93 is not fixed with respect to the self-expanding stent holding part 89 of the inner cylinder part 86, even if the inner cylinder part 86 and the guide wire part 20 move, the self-expanding stent 93 does not move from that position. That is, the self-expanding stent 93 is in a state where the inner wall of the embolus stenosis affected part 64 is pressed through the protective stent 43.

  In this manner, the self-expanding stent 93 presses the inner wall of the embolus stenosis affected part 64 through the protective stent 43, whereby the embolus stenosis affected part 64 of the blood vessel 60 can be stably expanded and blood flow is improved. be able to.

When it is considered that expansion of the embolus stenosis affected part 64 is insufficient from the viewpoint of blood flow, the self-expanding stent catheter system 80 is temporarily recovered, and the balloon catheter system 50 is used again to further expand the embolic stenosis affected part. Can do. In this case, an outer diameter that is the shape memory of self-expanding stents, larger than the normal inner diameter D _A of the vessel 60, The outer diameter that shape memory protection stent normal inner diameter D of the vessel 60 _Since it is larger than _A , both can follow the shape of the further expanded embolic stenosis, firmly protect the inner wall of the blood vessel 60, and can be pressed down.

  Thus, when the embolus stenosis affected part is expanded to a state where the blood flow is sufficiently improved, and the self-expanding stent presses the inner wall of the expanded embolic stenosis affected part through the protective stent. The self-expanding stent catheter system 80 is retrieved. Specifically, the microcatheter portion 82 for the self-expanding stent is first recovered outside the body of the patient 8 through the guiding catheter 100 (S38), and the guide wire portion 20 passes through the guiding catheter 100 before and after this. It is collected outside the body of the patient 8 (S40).

The state in the middle is shown in FIG. Here, the narrowest inner diameter is shown as _DN3 as a result of the final expansion of the affected area of the embolic stenosis. Here, although both the protective stent and the self-expanding stent follow by their elasticity, the states are shown as the protective stent 45 and the self-expanding stent 95. 16 and FIG. 11, the upper half shows the external view of the self-expanding stent 95 with respect to the central axis of the blood vessel 60, and the lower half shows the cross-sectional views of the protective stent 45 and the self-expanding stent 95. Has been.

  Returning to FIG. 12 again, the guiding catheter 100 is recovered from the body of the patient 8 (S42), whereby the treatment for a series of embolic stenosis in the blood vessel 60 is completed.

  The protective stent system according to the present invention can be used for treatment of an affected area of an embolus stenosis in a blood vessel.

  6 Carotid artery, 8 patients, 10 Protective stent catheter system, 12 Protective stent microcatheter part, 20 Guide wire part, 30, 32 stopper, 31 Protective stent holding part, 34 Coil, 40, 41, 42, 43, 45 Protective stent , 50 Balloon catheter system, 52 Balloon microcatheter section, 54 Expansion fluid supply port, 56 Expansion fluid passage, 57 Connection port, 58 Expansion fluid, 60 Blood vessel, 62 Embolus stenosis diseased part, 63 Atheromas, 64 Embolus stenosis diseased part , 70, 71 balloon, 80 self-expanding stent catheter system, 82 self-expanding stent microcatheter part, 84 outer cylinder part, 86 inner cylinder part, 88 arrowhead part, 89 self-expanding stent holding part, 90, 91, 93, 95 Self-expanding stent, 100 ga Catheter.

Claims (3)

A protective stent used to cover an affected area of an embolus stenosis in a blood vessel from the inside of the blood vessel toward the wall surface, and to be placed in the blood vessel as it is, crossing a plurality of fine lines made of shape memory material, diamond A hose-like body that is knitted in the longitudinal direction while forming a knitted stitch gap and opened at both ends, the knitted length is set longer than the length of the affected area of the embolic stenosis, and the knitted outer diameter is larger than the vascular inner diameter after embolization stenosis expansion Also, the diamond-shaped stitch gap knitted is set to be fine enough to collect embolic material debris during embolus stenosis expansion, and superelasticity is given by memorizing the knitted outer diameter and length A protective stent;
A guide wire portion having a protective stent holding portion for holding the protective stent on the distal side;
With
Using a microcatheter portion having a slide passage that accommodates the guide wire portion in the axial direction so that the guide wire portion can be slid in the axial direction, the protective stent is elongated in the axial direction by moving the guide wire portion relatively to the base end side, thereby protecting the stent. It can be accommodated inside the microcatheter part while being held by the holding part, and the protective stent is pulled out to the outside of the microcatheter part by moving the guide wire part relatively to the distal side and expanded to the original shape in the radial direction And then moving the guide wire portion relatively to the base end side so that the guide wire portion can be accommodated inside the microcatheter portion while the protective stent remains in place. The protective stent system according to claim 1.
The guide wire part
Having a distal end stopper and a proximal end stopper disposed along the axial direction at intervals defining the protective stent holding portion;
Protective stent
Guide wire parts are passed through the openings at both ends of the hose-like body,
When housed inside the microcatheter part, as a free state from both the terminal side stopper and the base end side stopper, it is elongated in the range of the protective stent holding part,
When pulled out of the microcatheter part, it is expanded from the distal side stopper and the base end side stopper in a free state, reduced to the original shape in the axial direction and expanded to the original shape in the radial direction. A protective stent system in which a guide wire portion including a distal end stopper and a base end stopper can be freely moved in an axial direction from openings at both ends of a hose-like body. The protective stent system according to claim 1.
Protective stent
A protective stent system, wherein a diameter of a fine wire and a knitting pitch in a longitudinal direction are set so that a diamond stitch gap in a knitted state is 50 μm to 150 μm.

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