JP2022096126A - Medical device - Google Patents

Abstract

To efficiently recover stenotic matter even in a peripheral blood vessel region while reducing a risk of complications during surgery.SOLUTION: A medical device 1 for cutting stenotic matter S1 in a living body lumen and recovering it includes a long-sized outside catheter 100 having an internal cavity 111 communicating from the tip to the base end, and a long-sized inside catheter 200 stored in the internal cavity 111 of the outside catheter 100 so as to move back and forth. The inside catheter 200 includes a body part 210, a tip part 220 provided on a tip side of the body part 210, and a convex blade 240 provided in a part of the body part 210 and the tip part 220 for cutting the stenotic matter S1 by an advancing operation of the inside catheter 200. The maximum outer diameter of the tip part 220 is larger than an inner diameter (corresponding to a diameter of the internal cavity 111) of the outside catheter 100.SELECTED DRAWING: Figure 2A

Description

The present invention relates to a medical device.

As a method for treating a stenosis caused by a stenosis such as a thrombosis, plaque, or calcified lesion formed in a blood vessel, a method of dilating the blood vessel with a balloon catheter or a mesh-like or coiled stent as a support for the blood vessel is used in the blood vessel. Examples include the method of detention. However, depending on the nature, size, shape, formation site, etc. of the stenosis, a sufficient therapeutic effect may not be obtained only by treatment using a balloon catheter or a stent.

In such a case, a method of directly collecting the stenosis is known as a treatment method that contributes to the improvement of the stenosis. As a technique for directly recovering a stenosis, the following Patent Document 1 describes suction removal of a stenosis outside the body by applying negative pressure from the base end of a catheter body having a suction lumen that communicates from the tip to the base. The suction catheter to be used is disclosed.

Japanese Unexamined Patent Publication No. 2010-17211

However, since the conventional suction catheter as disclosed in Patent Document 1 is an instrument for collecting a stenosis only by a suction operation, it may not be possible to collect the stenosis depending on the formation location and properties of the stenosis. In particular, since the lesion length is relatively long in the stenotic region in the peripheral blood vessel region, it is difficult to efficiently collect the stenosis.

In addition, if the sucked stenosis becomes clogged in the suction lumen during suction recovery of the stenosis, the operator must insert and remove the suction catheter to remove the stenosis. If the size of the stenosis is large, the suction lumen is particularly prone to clogging, the number of catheter insertions and removals increases, and the procedure may take a long time.

Further, in the conventional suction catheter, since the tip of the catheter is always open, even if the stenosis is pulled into the suction lumen, the stenosis may fall out from the opening during the insertion / removal operation. .. In recent years, in consideration of reducing the burden on patients, the puncture site is increasingly set to the wrist instead of the lower leg. Therefore, the stenosis that has fallen off the catheter is more likely to invade the cerebral blood vessels and the mesenteric artery than when the puncture site is the lower leg, and there is a concern about the risk of complications such as stroke and mesenteric artery occlusion.

As a result of diligent research to solve the above problems with conventional suction catheters, the inventor of the present application efficiently recovers stenosis even if the lesion is in the peripheral vascular region while reducing the risk of intraoperative complications. We have come to develop a new device that can be used.

At least one embodiment of the present invention has been made in view of the above circumstances, and specifically, it is possible to efficiently recover a stenosis even in a peripheral vascular region while suppressing the risk of intraoperative complications. It is to provide medical devices that can be used.

The medical device according to the present embodiment is a medical device that cuts and recovers a stenosis in a biological lumen, and is a long outer catheter having a lumen that communicates from the tip end to the proximal end, and the outer catheter said. A long inner catheter that is retractably housed in the lumen is provided, and the inner catheter includes a main body portion, a tip portion provided on the distal end side of the main body portion, a part of the main body portion, and the said. It has a convex blade provided at the tip and cuts the stenosis by the advance operation of the inner catheter, and the maximum outer diameter of the tip is larger than the inner diameter of the outer catheter.

According to at least one embodiment of the present invention, the stenosis can be efficiently recovered even in the peripheral vascular region while suppressing the risk of intraoperative complications.

It is a block diagram of the medical device which concerns on this embodiment. FIG. 3 is a schematic cross-sectional view taken along the long axis direction when the medial catheter is in the initial position in the medical device according to the present embodiment. In the medical device according to this embodiment, it is a schematic cross-sectional view along the long axis direction in the state where the advanced inner catheter is returned to the initial position. It is a schematic block diagram which looked at the medical device which concerns on this embodiment from the tip side. It is a conceptual diagram which shows the state which the constriction is sandwiched between blades in the medical device which concerns on this embodiment. FIG. 3 is a conceptual diagram showing a state in which a stenotic object is scraped off and aspirated and recovered in the process of accommodating the inner catheter shown in FIG. 4A in the outer cylinder. It is a figure which shows the use example of the medical device which concerns on this embodiment, and is the schematic diagram which shows the state which delivered the guide wire to the vicinity of a constriction part. It is a figure which shows the use example of the medical device which concerns on this Embodiment, and is the schematic diagram which shows the state which delivered this device to the vicinity of a constriction part along a guide wire. It is a figure which shows the use example of the medical device which concerns on this Embodiment, and is the schematic diagram which shows the state which the constriction is cutting by this device. It is a figure which shows the use example of the medical device which concerns on this Embodiment, and is the schematic diagram which shows the state which the stenosis sandwiched in this device is removed. It is a figure which shows the use example of the medical device which concerns on this Embodiment, and is the schematic diagram which shows the state which the stenosis removed from this device is sucked and recovered.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The embodiments shown here are examples for embodying the technical idea of the present invention, and do not limit the present invention. In addition, all other feasible forms, examples, operational techniques, etc. that can be considered by those skilled in the art without departing from the gist of the present invention are included in the scope and gist of the present invention, and are described in the claims. It is included in the scope of the invention and its equality.

Further, the drawings attached to the present specification may be represented schematically by changing the scale, aspect ratio, shape, etc. from the actual product for convenience of illustration and comprehension. However, it does not limit the interpretation of the present invention.

In the present specification, the side to be inserted into the living tissue is referred to as "tip" or "tip side", and the hand side for operating the medical device 1 is referred to as "base end" or "base end side". Further, in the present specification, the "long axis direction" is the direction along the central axis C of the medical device 1, and the "diameter direction" is the axis orthogonal cross section (cross section) with the long axis direction of the medical device 1 as the reference axis. In, the direction is set to be separated or approached from the outer catheter 100 (or the inner catheter 200), and the "circumferential direction" is the rotation direction with respect to the long axis direction of the medical device 1.

In the following description, when the explanations are given with ordinal numbers such as "first" and "second", they are used for convenience and do not specify any order unless otherwise specified.

[Constitution]
First, the configuration of the medical device 1 according to the present embodiment will be described. As shown in FIG. 1, the medical device 1 has an outer catheter 100 and an inner catheter 200.

As shown in FIGS. 5A to 5E, for example, the medical device 1 according to the present embodiment cuts a stenosis S1 such as a thrombus, a plaque, or a calcified lesion formed in a stenosis S of a biological lumen such as a blood vessel B. It is a medical device that can be used for the procedure of collecting the blood vessel. The medical device 1 is inserted into the living lumen from a patient's puncture site (limb or the like) with the inner catheter 200 attached to the outer catheter 100, and the tip portion is delivered to the stenosis portion S for use.

<Outer catheter>
As shown in FIGS. 2A and 2B, the outer catheter 100 includes a long shaft portion 110 having a substantially constant outer diameter in which a lumen 111 into which a medical long body such as the inner catheter 200 can be inserted is formed, and a shaft. It has a hub 120 arranged at the base end portion of the portion 110, and a protrusion 130 provided on the inner wall of the lumen 111.

The shaft portion 110 is made of a flexible tubular member having a substantially constant outer diameter, and has a lumen 111 in which the inner catheter 200 can be accommodated. At the tip of the shaft portion 110, a tip opening 111a communicating with the lumen 111 of the shaft portion 110 is formed.

For the shaft portion 110, for example, a material used for a catheter or the like known in the medical field can be applied. As an example, the constituent material of the shaft portion 110 is a fluororesin such as polytetrafluoroethylene (PTFE), an ethylene / tetrafluoroethylene copolymer (ETFE), a perfluoroalkoxy fluororesin (PFA), and an olefin such as polyethylene and polypropylene. Examples thereof include based resins or mixtures thereof, polyurethanes, polyesters, polyamides, polyether nylon resins, olefin resins and mixtures of ethylene / vinyl acetate copolymers and the like.

The hub 120 of the outer catheter 100 has a connector (Y connector) 121 known in the medical field. The connector 121 has a port 122 through which a contrast medium and a liquid for priming can flow, a valve body 123 arranged inside the hub 120, and an opener 124 for operating the opening and closing of the valve body 123. There is. Further, on the base end side of the hub 120, a base end port (not shown) for putting in and taking out a long medical body and the like into and out of the hub 120 is provided.

Further, the port 122 can be connected to a suction device (not shown) for sucking and collecting the cut narrowed object S1. The suction device can be composed of, for example, a syringe capable of generating a negative pressure, a known fluid suction pump, or the like. Since the lumen 111 becomes negative pressure due to the suction operation of the suction device connected to the port 122, the outer catheter 100 can suck the stenotic object S1 scraped off from the inner catheter 200.

The constituent material of the hub 120 is not particularly limited, and a material used for a hub or the like known in the medical field can be applied. As the constituent material of the hub 120, for example, polyolefins such as polyethylene and polypropylene, and thermoplastic resins such as polycarbonate, polyamide, polysulfone and polyarylate can be preferably used.

The protrusion 130 is provided on the inner surface of the lumen 111 of the outer catheter 100 by a predetermined distance from the tip end of the shaft portion 110 toward the proximal end. The forming range of the protrusion 130 is appropriately set according to the length in the long axis direction in the forming region of the second blade 242.

The protrusion 130 has a shape in which the tip gradually tapers from the base end on the outer surface side of the lumen 111 toward the central axis C so that the protrusion 130 can enter the second groove portion 242a of the second blade 242 described later. There is. In the present embodiment, the protrusion 130 has a configuration in which a plurality of annular bodies having a substantially right-angled triangular cross section whose outer diameter gradually increases from the tip in the long axis direction to the base end are arranged in a row in the long axis direction.

The top of the protrusion 130 is set to have a radial height so as to come into contact with the outer surface of the second blade 242 provided on the main body 210 of the inner catheter 200 and the second groove 242a. As a result, when the inner catheter 200 is pulled into the outer catheter 100, the protrusion 130 comes into contact with the second groove 242a, and the stenosis S1 attached to the second blade 242 and the stenosis S1 sandwiched between the second grooves 242a. Can be scraped off.

The protrusion 130 has a substantially right-angled triangular shape with a tip having a maximum inner diameter and a base end having a minimum inner diameter. Therefore, when the protrusions 130 are arranged adjacent to each other along the long axis direction, for example, as shown in FIG. 2A, the tips of one protrusions 130 adjacent to each other in the long axis direction and the tips of the protrusions 130 are adjacent to each other. A radial step is created between the base and the base of the other matching protrusions 130. This step functions as a so-called "back" that prevents the stenosis S1 scraped off by the protrusion 130 from moving to the tip opening 111a of the outer catheter 100.

The medical device 1 according to the present embodiment has a configuration in which a plurality of the above steps are provided from the distal end side along the long axis direction of the lumen 111 of the outer catheter 100. Therefore, the narrowed object S1 scraped off by the protrusion 130 is hindered from moving toward the tip side by the plurality of steps. Therefore, the stenotic object S1 once collected by the medical device 1 is not released into the living lumen from the tip opening 111a of the outer catheter 100.

In the medical device 1 according to the present embodiment, the protrusion 130 has a substantially right-angled cross section along the long axis direction as shown in FIG. 2A in order to obtain the effect of preventing the release of the narrowed object S1 as described above. It has a triangular shape. However, the main purpose of the protrusion 130 is to come into contact with the second groove 242a of the second blade 242 and scrape off the narrowed object S1. Therefore, the cross-sectional shape of the protrusion 130 is not limited to a substantially right triangle that can form a step that functions as a barb, and at least abuts on the outer surface of the second blade 242 and the second groove 242a to scrape off the narrowed object S1. Any shape that can be used is sufficient.

Further, the protrusion 130 is provided with a plurality of annular bodies along the major axis direction with respect to the lumen 111, but may be one. Even with such a configuration, the operator scrapes off the stenosis S1 attached to the second blade 242 and the stenosis S1 sandwiched between the second groove 242a by repeating the retracting operation of the inner catheter 200 a plurality of times. be able to. Further, the protrusion 130 is not limited to the annular body, and may be composed of a plurality of protrusions provided on the inner surface of the lumen 111 at predetermined intervals along the circumferential direction.

The protrusion 130 can be used, for example, in the medical field so that the stenosis S1 adhering to the outer surface of the second blade 242 and the stenosis S1 sandwiched between the second groove 242a can be scraped off without damaging the second blade 242. It is composed of a material having appropriate hardness and flexibility (synthetic resin material such as silicone rubber).

<Inner catheter>
As shown in FIGS. 2A and 2B, the inner catheter 200 has a main body portion 210 which is a long tubular member, and an outer diameter which is partially larger than the outer diameter of the main body portion 210 and is provided on the distal end side of the main body portion 210. It has a tip portion 220 having a diameter and a grip portion 230 that is gripped by the operator's fingers during a cutting recovery operation or the like. The inner catheter 200 can move back and forth in the lumen 111 of the outer catheter 100 by manipulating the grip portion 230 by the operator.

Further, as shown in FIGS. 2A and 2B, the medial catheter 200 is restricted from moving in the longitudinal direction with respect to the lateral catheter 100 by arranging the distal end 220 outside the lateral catheter 100.

The main body 210 is made of a flexible tubular member having a substantially constant outer diameter, and has a lumen 211 into which a medical device such as a guide wire G can be inserted. At the tip of the main body 210, a tip opening 211a communicating with the lumen 211 of the main body 210 is formed.

The distal end 220 has a lumen 221 whose proximal end expands radially from the outer diameter of the main body 210 and the inner diameter of the inner diameter 111 of the outer catheter 100, and gradually contracts from the proximal end toward the distal end. It has a tapered shape with a diameter. In the present embodiment, the tip portion 220 has a substantially conical trapezoidal shape in cross section along the major axis direction, and the lumen 221 communicates with the lumen 211 of the main body portion 210. With the medial catheter 200 housed in the lateral catheter 100, the tip 220 is located outward of the lateral catheter 100.

A convex blade 240 for cutting the narrowed object S1 is provided on the distal end side of the inner catheter 200.

The blade 240 is composed of a first blade 241 provided on the outer surface of the tip portion 220 and a second blade 242 provided on the outer surface of the main body portion 210 by a predetermined distance from the tip end of the main body portion 210 toward the base end. Has been done. In the medical device 1 of the present embodiment, the portion of the inner catheter 200 provided with the blade 240 functions as a “cutting recovery unit”.

The first blade 241 is provided from the tip end side to the base end side on the outer surface of the tip end portion 220. The second blade 242 is provided by a predetermined distance from the tip end side on the outer surface of the main body portion 210 toward the base end side. The formation region of the second blade 242 with respect to the main body portion 210 can be appropriately set according to the size (total length) of the narrowed object S1.

The first blade 241 and the second blade 242 both have a mountain-shaped cross section as a convex shape, and the tips are sharply formed. Further, in a cross-sectional view along the long axis direction, a groove portion 240a is formed between adjacent blades 240. In the first blade 241 provided at the tip portion 220, the first groove portion 241a is formed between the adjacent first blades 241. Further, in the second blade 242 provided in the main body 210, a second groove portion 242a is formed between the adjacent second blades 242.

Considering the work efficiency of the cutting recovery work of the narrowed object S1, the blade 240 preferably has a spiral shape extending in the circumferential direction of the main body portion 210 and the tip portion 220. By making the blade shape spiral, when the inner catheter 200 is rotated and advanced toward the distal end side, the blade 240 can smoothly enter the inside of the stenosis S1 and cut the stenosis S1. can. Further, in the case of the spirally shaped blade 240, since the groove portion 240a is formed in the inner catheter 200 along the circumferential direction, the narrowed object S1 is sandwiched between the groove portions 240a during cutting, and the recovery efficiency can be improved. ..

As the inner catheter 200, for example, a material used for a catheter known in the medical field can be used. As an example, the constituent material of the inner catheter 200 is a fluororesin such as polytetrafluoroethylene (PTFE), an ethylene / tetrafluoroethylene copolymer (ETFE), a perfluoroalkoxy alkane resin (PFA), and an olefin such as polyethylene and polypropylene. Examples thereof include based resins or mixtures thereof, polyurethanes, polyesters, polyamides, polyether nylon resins, olefin resins and mixtures of ethylene / vinyl acetate copolymers and the like.

The tip 220 and the blade 240 are preferably made of a material harder than the inner catheter 200 so that the narrowed object S1 can be cut. Further, the tip portion 220 and the blade 240 may be made of a material different from that of the inner catheter 200 (for example, a metal that can be used in the medical field with less influence on the human body).

2A or 3 shows the dimensions of the medical device 1 according to this embodiment. In FIG. 2A or FIG. 3, the outer diameter of the outer catheter 100 is "X1". The inner diameter of the lumen 111 of the outer catheter 100 (the inner diameter of the lumen 111 not including the protrusion 130) is "X2". The minimum inner diameter including the protrusion 130 of the outer catheter 100 (ie, the distance between the apexes of the radially opposed protrusions 130 in the outer catheter 100) is "X3". The outer diameter of the inner catheter 200 (the outer diameter of the main body 210 not including the second blade 242) is "Y1". The maximum outer diameter of the medial catheter 200, including the second blade 242, is "Y2". The maximum outer diameter of the tip portion 220 is "Y3".

The outer diameter X1 of the outer catheter 100 is set to be larger than the maximum outer diameter Y3 of the tip 220 of the inner catheter 200 (X1> Y3). Therefore, in the medical device 1 according to the present embodiment, the maximum outer diameter is the outer diameter of the outer catheter 100 when the inner catheter 200 is attached to the outer catheter 100. Thereby, when the medical device 1 is removed from the living lumen, the proximal end side of the tip portion 220 can be smoothly removed without being caught in the living lumen.

Further, the maximum outer diameter Y3 of the tip portion 220 is set to be larger than the inner diameter X2 of the lumen 111 of the outer catheter 100 (X2 <Y3). That is, the tip 220 is not housed in the outer catheter 100. Therefore, in the distal end portion 220, when the inner catheter 200 is retracted, the distal end surface of the distal end portion 220 abuts on the distal end surface of the outer catheter 100, and the lumen 111 of the outer catheter 100 is closed. Lumen. Therefore, the stenotic object S1 collected in the outer catheter is not released from the outer catheter 100 because the tip portion 220 functions as the lid of the outer catheter 100.

Further, the minimum inner diameter X3 of the lumen 111 including the protrusion 130 of the outer catheter 100 is set to be larger than the maximum outer diameter Y2 including the second blade 242 of the inner catheter 200 (X3> Y2). As a result, when the inner catheter 200 is retracted, the second groove portion 242a of the second blade 242 comes into contact with the protrusion 130. As a result, the stenosis S1 attached to the second blade 242 of the inner catheter 200 and the stenosis S1 sandwiched between the second groove 242a are scraped off by the protrusion 130.

The outer diameter Y1 of the main body 210 of the inner catheter 200 is set smaller than the inner diameter X2 of the outer catheter 100 (X2> Y1). Therefore, a gap is formed between the lumen 111 of the outer catheter 100 and the outer surface of the inner catheter 200. The stenotic object S1 is suction-recovered through this gap by creating a negative pressure in the lumen 111 of the outer catheter 100.

Next, with reference to FIG. 4, the behavior of the cut narrowed object S1 at the time of recovery will be described.

In the inner catheter 200, as shown in FIG. 4A, a part of the narrowed object S1 cut at the tip portion 220 adheres to the first groove portion 241a of the first blade 241 and the second groove portion 242a of the second blade 242. When the main body 210 of the inner catheter 200 is pulled into the lumen 111 of the outer catheter 100 by the retracting operation of the operator, the protrusion 130 sequentially enters the second groove 242a as shown in FIG. 4B. As a result, the narrowed object S1 sandwiched between the inner catheter 200 is scraped off from the second groove portion 242a by the protrusion 130. The scraped stenosis S1 is sucked and transported to the outside through the lumen 111 of the outer catheter 100. Further, the narrowed object S1 sandwiched between the first groove portions 241a can be recovered by removing the medical device 1 from the body.

As described above, the medical device 1 according to the present embodiment sucks and recovers the cut stenosis S1, but not only the stenosis S1 cut by the inner catheter 200 but also the stenosis attached to the second blade 242 during cutting. The narrowed object S1 sandwiched between S1 and the second groove portion 242a can also be recovered. If the outer catheter 100 does not have the protrusion 130, the stenosis S1 attached to the second blade 242 and the stenosis S1 sandwiched between the second grooves 242a are living organisms while the cutting operation is repeated. It may fall off in the lumen. However, since the medical device 1 according to the present embodiment includes the protrusion 130 in the lumen 111 of the outer catheter 100, the stenosis S1 attached to the second blade 242 and the stenosis S1 sandwiched between the second groove 242a. Is scraped off in the lumen 111 by the protrusion 130. Therefore, in the medical device 1, the stenosis S1 can be safely cut and recovered without the stenosis S1 falling off in the living lumen at the time of cutting recovery.

In the pulling operation of the inner catheter 200, the main body 210 may be pulled into the outer catheter 100 while rotating in the circumferential direction, or the main body 210 may be pulled in as it is along the long axis direction without rotating. The operations may be combined. In any operation, the narrowed object S1 attached to the second blade 242 and the narrowed object S1 sandwiched between the second groove portions 242a are scraped off by the protrusion 130.

[motion]
Next, an example of using the medical device 1 according to the present embodiment will be described with reference to FIGS. 5A to 5E. It should be noted that the operations described below are presented in an exemplary order and are not limited to the specific order presented. The following usage example is an operation when cutting and sucking and recovering a stenosis S1 formed in a stenosis S in a blood vessel B which is a living lumen.

First, as shown in FIG. 5A, the operator inserts the guide wire G to the target position in order to deliver the medical device 1 to the narrowed portion S.

The surgeon then delivers the medical device 1 to the constriction S along the guidewire G, as shown in FIG. 5B. Subsequently, as shown in FIG. 5C, the operator removes the guide wire G and advances the medial catheter 200. The medial catheter 200 advances from the lateral catheter 100 and moves toward the constriction S in the blood vessel B.

Next, as shown in FIG. 5C, the operator advances the tip 220 to the stenosis S while rotating the medial catheter 200, and cuts the stenosis S1 at the tip 220. As shown in FIG. 5C, the cut narrowed object S1 enters the first groove portion 241a of the first blade 241 and the second groove portion 242a of the second blade 242.

Next, the surgeon performs a pull-in operation to pull the inner catheter 200 advanced in the blood vessel B into the outer catheter 100. During the pulling operation, as shown in FIG. 5D, the protrusion 130 abuts on the outer surface of the second blade 242 and the second groove 242a, and is sandwiched between the narrowed object S1 and the second groove 242a attached to the second blade 242. Scrape off the stenotic object S1.

Then, as shown in FIG. 5E, the scraped stenosis S1 is sucked to the proximal end side through the lumen 111 of the outer catheter 100 and discharged to the outside.

In the cutting recovery work of the stenosis S1, the stenosis S1 is removed from the stenosis portion S by repeating the advance operation and the retracting operation of the inner catheter 200 a plurality of times in the series of flows shown in FIGS. 5B to 5D. be able to.

[Action effect]
As described above, the medical device 1 according to the present embodiment is housed in a long outer catheter 100 having a lumen 111 communicating from the tip end to the proximal end and a lumen 111 of the outer catheter 100 so as to be able to advance and retreat. It is a device provided with a long inner catheter 200 and for the purpose of cutting and recovering a stenotic object S1 in a living lumen. In the medical device 1, the inner catheter 200 is provided in the main body 210, the tip 220 provided on the distal end side of the main body 210, and a part of the main body 210 and the distal end 220 to advance the inner catheter 200. It has a convex blade 240 for cutting the stenosis S1 and the maximum outer diameter of the tip 220 is larger than the inner diameter of the outer catheter 100 (corresponding to the diameter of the lumen 111).

With such a configuration, when the inner catheter 200 is retracted, the distal end surface of the distal end portion 220 abuts on the distal end surface of the outer catheter 100 and closes the distal end opening 111a of the outer catheter 100. .. Therefore, in the medical device 1, the stenosis S1 once collected is not released from the outer catheter 100, and the risk of complications due to the re-release of the stenosis S1 into the living lumen is reduced.

Further, in the medical device 1 according to the present embodiment, the inner surface of the lumen 111 of the outer catheter 100 has a groove portion 240a formed between the outer surface of the blade 240 of the inner catheter 200 and the blades 240 adjacent to each other in the longitudinal direction. It is preferable that the minimum inner diameter X3 including the protrusion 130 of the outer catheter 100 is larger than the maximum outer diameter Y2 including the second blade 242 of the inner catheter 200.

With such a configuration, when the inner catheter 200 is retracted, the second groove portion 242a of the second blade 242 comes into contact with the protrusion 130. Therefore, the stenosis S1 attached to the second blade 242 of the inner catheter 200 and the stenosis S1 sandwiched between the second groove 242a are surely scraped off in the lumen 111 of the outer catheter 100 by the protrusion 130. It is collected by suction.

Further, it is preferable that the protrusion 130 of the medical device 1 according to the present embodiment has a substantially right-angled triangular cross section in which the outer diameter gradually increases from the base end in the long axis direction toward the tip end.

With such a configuration, as shown in FIG. 2A, when the protrusions 130 are arranged adjacent to each other along the long axis direction, the tips of one protrusions 130 adjacent to each other in the long axis direction and the protrusions 130 A radial step is created between the tip and the base end of another protrusion 130 adjacent to the tip. This step functions as a "barb" that prevents the stenosis S1 scraped off by the protrusion 130 from moving to the tip opening 111a of the outer catheter 100. Therefore, the stenotic object S1 scraped off by the protrusion 130 is hindered from moving toward the distal end side due to this step, and is released from the distal end opening 111a of the outer catheter 100 into the living lumen such as the blood vessel B. Be prevented.

Further, in the medical device 1 according to the present embodiment, it is preferable that the distal end portion 220 of the inner catheter 200 has a tapered shape in which the proximal end has a maximum outer diameter and the diameter gradually decreases toward the distal end.

With such a configuration, when cutting the narrowed object S1, the tip portion 220 easily advances into the inside of the narrowed object S1, and the cutting recovery work can be efficiently performed.

Further, in the medical device 1 according to the present embodiment, it is preferable that the blade 240 has a spiral shape extending in the circumferential direction from the tip end to the base end.

With such a configuration, when the inner catheter 200 is rotated and advanced toward the distal end side, the distal end portion 220 can easily enter the inside of the narrowed object S1 and efficiently cut the narrowed object S1. can.

1 medical device,
100 outer catheter,
110 shaft part (111 lumen),
120 hubs,
130 protrusions,
200 inner catheter,
210 Main body (211 lumen),
220 tip (221 lumen),
230 grip,
240 blade (240a groove)
241 1st blade (241a 1st groove),
242 2nd blade (242a 2nd groove),
B blood vessel (living lumen)
S stenosis part S1 stenosis.

Claims (5)

There is a medical device that cuts and recovers stenosis in the lumen of the living body.
A long lateral catheter with a lumen that communicates from the tip to the base,
A long inner catheter, which is retractably housed in the lumen of the outer catheter, is provided.
The inner catheter is provided at the main body, a tip provided on the distal end side of the main body, a part of the main body, and the distal end, and cuts the stenosis by an advance operation of the inner catheter. With a convex blade,
A medical device in which the maximum outer diameter of the tip is larger than the inner diameter of the outer catheter. The inner surface of the lumen of the outer catheter is provided with a protrusion capable of contacting the outer surface of the blade of the inner catheter and a groove formed between the blades adjacent to each other in the longitudinal direction.
The medical device according to claim 1, wherein the minimum inner diameter including the protrusion of the outer catheter is larger than the maximum outer diameter including the blade of the inner catheter. The medical device according to claim 2, wherein the protrusion has a substantially right-angled triangular cross section in which the outer diameter gradually increases from the base end in the long axis direction toward the tip end. The medical device according to any one of claims 1 to 3, wherein the distal end portion of the inner catheter has a tapered shape in which the proximal end has a maximum outer diameter and gradually shrinks toward the distal end. The medical device according to any one of claims 1 to 4, wherein the blade has a spiral shape extending in the circumferential direction from the tip end to the base end.

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