JP2010233686A - Catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To confirm the position of an already indwelled polymer stent in indwelling a plurality of polymer stents one by one in order. <P>SOLUTION: This catheter includes: a guide wire 2; a conduit 1 for conducting the guide wire; an outer balloon 3 provided outside the conduit; an outer stent 4 disposed outside the outer balloon; an inner balloon 5 provided inside the conduit; and an inner stent 6 disposed inside the inner balloon and having higher X-ray absorptivity than the outer stent. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a catheter used in image observation using a medical X-ray imaging system, particularly when endovascular treatment is performed using a polymer stent.

  There is a treatment method called intravascular intervention treatment. In this method, when there is a lesion in a blood vessel, a treatment device such as a catheter, a guide wire, or a stent is inserted into the blood vessel from outside the body, and the treatment is performed remotely. Since the work is remotely performed in the body, it is common to use an X-ray image for the observation.

  A doctor determines a stent placement position, a stent expansion diameter, and the like while viewing a real-time X-ray image, and performs an operation. For example, in a long lesion, after the first stent is placed, the second stent is placed side by side with the first stent. For this reason, it is essential for the doctor to know the indwelling position of the first stent.

  In recent years, a stent called a polymer stent has been proposed. In this stent, the stent platform (structure) is made of a polymer rather than a metal as in the present. This stent is characterized in that when it is placed in a living body, it is absorbed by the living body and disappears after several months.

  Since the polymer has a low X-ray absorption rate, the contrast in the X-ray image is extremely small. That is very hard to see. When a doctor places a stent, there is a problem that the polymer stent cannot be seen.

  That is, when placing a plurality of polymer stents one by one in order, the position of the polymer stent that has been placed cannot be confirmed.

JP 2003-102845 A JP 2007-503923 A

  An object of the present invention is to make it possible to confirm the position of a polymer stent that has been placed when a plurality of polymer stents are placed one by one in order.

A first aspect of the present invention is a guide wire, a conduit for conducting the guide wire, an outer balloon provided outside the conduit, an outer stent disposed outside the outer balloon, and an inner side of the conduit. A catheter comprising an inner balloon and an inner stent disposed inside the inner balloon and having a higher x-ray absorption than the outer stent.
According to a second aspect of the present invention, there is provided a guide wire, a conduit for conducting the guide wire, an outer balloon provided outside the conduit, a stent disposed outside the outer balloon, A catheter is provided that includes an inner balloon disposed on the inside for partially deforming the guidewire upon expansion.
According to a third aspect of the present invention, there is provided a guide wire having an interior partitioned into a plurality of hollow chambers by a partition, a conduit for conducting the guide wire, an outer balloon provided outside the conduit, and the outer An outer stent disposed on the outside of the balloon; and a plurality of hollow needles provided on the inner side of the conduit and provided toward the inner side. And an inner balloon for injecting the contrast medium through the hollow needle.
A fourth aspect of the present invention provides a catheter comprising a conduit for conducting a guide wire, an outer balloon provided outside the conduit, and an inner balloon provided inside the conduit.

  According to the present invention, when a plurality of polymer stents are placed one by one in order, the position of the placed polymer stent can be confirmed.

It is a longitudinal cross-sectional view of the catheter and guide wire which concern on 1st Embodiment of this invention. It is a longitudinal cross-sectional view at the time of balloon expansion of the catheter and guide wire of FIG. 1 is a diagram showing a state in which two polymer stents by the catheter are placed in order. It is a figure which shows the some modification relevant to this 1st Embodiment. It is a figure which shows the some modification relevant to this 1st Embodiment. It is a longitudinal cross-sectional view of the catheter and guide wire which concern on 2nd Embodiment of this invention. It is a longitudinal cross-sectional view at the time of balloon expansion of the catheter and guide wire of FIG. It is a perspective perspective view of the catheter and guide wire which concern on 2nd Embodiment of this invention. It is a longitudinal cross-sectional view of the catheter and guide wire which concern on 3rd Embodiment of this invention. FIG. 10 is a longitudinal sectional view of the catheter and guide wire in FIG. 9 when the balloon is expanded. It is a perspective perspective view of the catheter and guide wire which concern on 3rd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
As described above, in intravascular intervention treatment, polymer stents (bioabsorbable stents and outer stents) will soon appear and are expected to become mainstream in an instant. This polymer stent has a very low X-ray absorption rate, and therefore cannot be visualized by an X-ray imaging system. For example, when the second stent is to be placed in the blood vessel, the first stent cannot be seen, so it is difficult to place the second stent in the correct position with respect to the first stent. Therefore, in this embodiment, for example, a metal stent (referred to as an inner stent) as an X-ray opaque substance is provided on the inner side of the catheter. We propose a catheter characterized in that it remains attached to the guide wire and is reflected in X-rays. This stent can be positioned when the second one is inserted, and it can always know the exact position regardless of which direction the arm is swung or the bed is moved, and the procedure is accurate and fast. Become.

  As shown in FIG. 1, the catheter according to this embodiment includes a conduit 1 that conducts a guide wire 2. A balloon (referred to as an outer balloon) 3 is provided outside the vicinity of the distal end of the conduit 1. Typically, a mesh-shaped polymer stent (referred to as an outer stent) 4 is inserted outside the outer balloon 3 in a contracted state. The outer stent 4 is made of a polymer, has a low X-ray absorption rate, and hardly has an X-ray shadow. Actually, the conduit 1 has a double tube structure, and an expansion agent is poured into the outer balloon 3 from the intermediate layer of the double tube, and the outer balloon 3 expands (expands). Due to the expansion of the outer balloon 3, the outer stent 4 expands and is fixed in a state where the blood vessel is expanded.

  Inside the vicinity of the distal end of the conduit 1, a balloon (referred to as an inner balloon) 5 is provided. A mesh-shaped stent (referred to as an inner stent) 6 is typically inserted inside the inner balloon 5 in an expanded state. The inner stent 6 has an X-ray absorption rate higher than that of the outer stent 4, and the X-ray shadow can be confirmed clearly on the X-ray fluoroscopic image. The inner stent 6 is typically made of metal. The inner stent 6 has substantially the same length as the outer stent 4 and is disposed at substantially the same position at the distal end of the conduit 1.

  The inner balloon 5 is connected to the outer balloon 3 by a plurality of holes 7 formed in the conduit 1 and expands with the expansion of the outer balloon 3. Due to the expansion of the inner balloon 5, the inner stent 6 contracts and comes into close contact with the guide wire 2.

  FIG. 3 shows a procedure of a procedure for placing two polymer stents 4-1 and 4-2 in a blood vessel. First, the guide wire 2 is inserted into the blood vessel and inserted to the treatment target position. Then, the first conduit 1-1 is inserted along the guide wire 2 to the treatment target position (before expansion).

  In that position, the expansion agent is poured from the intermediate layer of the conduit 1-1. As a result, the outer balloon 3 and the inner balloon 5 expand (expand). By expanding the outer balloon 3, the first outer stent 4-1 expands and pushes the blood vessel. Due to the expansion of the inner balloon 5, the inner stent 6 contracts and comes into close contact with the guide wire 2.

  Subsequently, the expanding agent is sucked from the intermediate layer of the conduit 1-1. Thereby, the outer balloon 3 and the inner balloon 5 contract (shrink). Due to the contraction of the outer balloon 3, the first outer stent 4-1 is detached from the outer balloon 3 and the conduit 1. Similarly, contraction of the inner balloon 5 causes the inner stent 6 to detach from the inner balloon 5 and the conduit 1.

  With the guide wire 2 as it is, the first conduit 1-1 is pulled out (extracted). As a result, the first outer stent 4-1 is left in place with the blood vessel expanded. Further, the inner stent 6 is maintained in place with the outer stent 4-1 while being in close contact with the guide wire 2. The outer stent 4-1 is made of polymer, and its shadow is hardly seen on the fluoroscopic image. On the other hand, the inner stent 6 is made of metal, and its shadow can be clearly identified on the X-ray fluoroscopic image. As described above, the inner stent 6 is substantially the same length as the outer stent 4 and is disposed at substantially the same position at the distal end of the conduit 1, so that the position of the inner stent 6 is substantially the same as the position of the outer stent 4. It is the same, and the position of the outer stent 4 can be grasped from the shadow of the inner stent 6 reflected on the fluoroscopic image.

  Next, a second conduit 1-2 having a second polymer stent 4-2 is inserted along the guide wire 2. While grasping the indwelling position of the first polymer stent 4-1 through the shadow of the inner stent 6 on the fluoroscopic image, the second polymer stent 4-2 is disposed at the rear end of the first polymer stent 4-1. Insert it to an appropriate position so that the tips of the two overlap slightly. At that position, the balloon of the second conduit 1-2 is expanded to place the second polymer stent 4-2.

  When the placement of the first polymer stent 4-1 and the second polymer stent 4-2 is completed, the guide wire 2 is pulled out from the blood vessel together with the inner stent 6.

  Thus, a special catheter is used in this embodiment. In this catheter, two stents 4 and 6 and two balloons 3 and 5 are integrally formed with respect to one catheter. Of these, the outer balloon 3 and the outer stent 4 have the same structure as usual, but the other inner balloon 5 is located inside the conduit 1, and a new stent 6 is further inside the inner balloon 5. It is installed. The outer stent 4 is made of a polymer material, for example, and the inner stent 6 is made of a radiopaque metallic material. When the balloons 3 and 5 are expanded, the two balloons 3 and 5 are expanded simultaneously. The outer balloon 3 operates in the same manner as a normal balloon. The inner balloon 5 is expanded to contract the inner stent 6. When the balloon 5 is further expanded, the inner stent 6 is completely contracted, and is wound around the guide wire 2 passing through the inside of the conduit 1 and fixed to the guide wire 2. Next, when the outer and inner balloons 3 and 5 are contracted simultaneously, the outer stent 4 and the inner stent 6 are detached from the balloons 3 and 5 and are left in place. That is, the inner stent 6 is placed while being wound around the wire 2. Finally, when the conduit 1 is removed, the two stents 4 and 6 remain in place along the blood vessels in the body. When an X-ray image is acquired in this state, the outer polymer stent 4 is very difficult to see because of its low radiopacity, but the inner metal stent 6 appears to be radiopaque. Specifically, the wire 2 appears to be thick only at that portion. Due to the difference in thickness, the doctor can clearly visualize the position along the blood vessel axis where the polymer stent 4 is placed.

  The doctor then tries to insert a second stent 4. The doctor advances the conduit 1 with the second stent 4 into the blood vessel. The catheter and stent 4 at this time may be conventional. In the X-ray image seen by the doctor, the position of the placement position of the first polymer stent 4 along the blood vessel is known from the shadow of the inner stent 6 in the X-ray image, and the second positioning is performed using this as a mark. For example, the second stent 4-2 and the first stent 4-1 are positioned so as to overlap by 1 mm. The second stent 4-2 is expanded and placed. Remove the second catheter.

  When all treatments are complete, the doctor finally removes the guidewire. As described above, the two polymer stents could be easily positioned.

(Modification)
In the above description, the stent 6 is used inside. At this time, the inner stent 6 is expanded at the time of insertion, and is contracted by being compressed by the balloon 5 from the outside. Therefore, the stent 6 has a structure that can contract when the stent 6 is vertically pressurized from the outside. The stent 6 is typically a network structure, but need not be limited to that network structure. For example, as illustrated in FIG. 4, the inner stent 6 may be a metal mesh structure, a metal cylindrical structure, a metal cylindrical structure having a plurality of slits, or a non-metallic cylindrical structure having a heat-shrinkable structure. Good.

  In the above description, the structure of the double stents 4 and 6 is used. However, the stent 6 that does not transmit X-rays on the inside may be, for example, any one that can mark both ends of the outer stent 4 that are opaque to X-rays. As shown in FIG. 5, for example, the inner stent 6 may be two ring-shaped inner stent portions 8 and 9.

  Moreover, when winding, it is desirable for both ends to be as smooth as possible. This assumes a case where another device (for example, an intravascular ultrasound probe) or the like is further advanced along the wire 2 after the stent 4 is inserted. If the edge is striking, it becomes difficult to advance these additional devices, and as shown in FIG. 5, smoothing the edge facilitates the passage of the device.

(Second Embodiment)
6, 7, and 8 show longitudinal sectional views of the catheter according to the second embodiment. A conventional guide wire is like a wire. The guide wire 10 of the present embodiment has the same outer diameter as a conventional guide wire, but has a hollow structure and is like a tube. Unlike the first embodiment, in the second embodiment, The inner stent 6 is not provided. In the catheter used in the second embodiment, an outer polymer stent 4 and two balloons 3 and 5 are integrally formed with respect to one catheter.

  Of these, one balloon 3 and one stent 4 have the same structure as usual, but the other inner balloon 5 is on the inside of the conduit 1. The outer stent 4 is made of a polymer material, for example. When the balloons 3 and 5 are expanded, the two balloons 3 and 4 are expanded simultaneously. The outer balloon 3 operates in the same manner as a normal balloon. When the inner balloon 5 is expanded, the guide wire 10 of the inner hollow tube structure is compressed. Thereby, the guide wire 10 is partially crushed, the hollow of the portion is eliminated, and the outer diameter is partially thinned (thinned). When an X-ray image is acquired in this state, the outer polymer stent 4 is very difficult to see because of its low radiopacity, but the guide wire 10 appears partially thin at that position. Comparing the axial front and back, the difference in the guide wire fineness enables the doctor to clearly visualize the position along the blood vessel axis where the polymer stent 4 is placed.

(Third embodiment)
9, 10, and 11 show longitudinal sectional views of the catheter according to the third embodiment. A conventional guide wire is like a wire. The guide wire 11 of the present embodiment has the same outer diameter as a conventional guide wire, but has a hollow structure and is divided into hollow chambers (compartments) 12 every about 1 mm. Specific examples include, for example, a structure such as a ship ballast or a structure like bamboo.

  Unlike the first embodiment, in the catheter used in the third embodiment, one stent 4 and two balloons 3 and 5 are integrally formed with respect to one catheter. Of these, one balloon 3 and one stent 4 have the same structure as usual, but the other inner balloon 13 has a plurality of hollow needles 14 on its surface. The inside of the inner balloon 13 and the hollow needle 14 are electrically connected.

  By expanding the inner balloon 13, the needle 14 stands and pierces the guide wire 11. A liquid (in this case, a dark contrast medium) is injected from the needle 14 at a high pressure like an injection needle and injected into each hollow chamber 12 of the guide wire 11. The contrast medium is injected only into the compartment 12 where the balloon 13 is expanded. When an X-ray image is acquired in this state, the outer polymer stent 4 is very difficult to see because of its small X-ray opacity, but the portion of the guide wire 11 is usually thin, but the portion where the contrast agent is injected is It looks dark. Comparing the axial direction before and after, due to the difference in the darkness of the guide wire 11, the doctor can clearly visualize the position along the blood vessel axis where the polymer stent 4 is placed.

(Modification)
In the third embodiment, the wires are separated, but a micro catheter may be used.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  For example, although the polymer stent has been described in the above embodiment, the present invention is not limited to the polymer. In addition to polymers, any platform that has a low X-ray absorption rate can be applied.

  In addition to stents, for example, it can be applied to drugs (with low fluidity). In other words, this method makes it possible to know where the drug is administered (applied). This is useful in cases where drugs are overcoated. For example, in Stem Cell treatment, it can be applied as a marker of where Stem Cell was administered from. For example, it is possible to replace the method currently called “IVUS marking”. The IVUS marking is as follows. An operator who uses an X-ray imaging device moves an object with a high X-ray absorption coefficient (here, intravascular ultrasound: IVUS) to the position where the stent is to be placed, and performs X-ray imaging on the X-ray image. The shadow of the object (IVUS) is clearly depicted. The operator performs the stent placement operation while viewing this image.

  In addition to stents, it can also be applied to treatments where the shape of the lesion is not known, such as laser treatment. In other words, this method makes it possible to clearly understand where the last laser irradiation was performed when additional laser irradiation was performed.

  The present invention is used when confirming the position of a polymer stent that has been placed when a plurality of polymer stents are placed one by one in order.

  DESCRIPTION OF SYMBOLS 1 ... Conduit 12 ... Guide wire, 3 ... Outer balloon, 4 ... Outer stent (polymer stent), 5 ... Inner balloon, 6 ... Inner stent (metal stent)

Claims (7)

A conduit;
An outer balloon provided outside the conduit;
An outer stent disposed outside the outer balloon;
An inner balloon provided inside the conduit;
A catheter comprising an inner stent disposed inside the inner balloon and having a higher X-ray absorption rate than the outer stent. The catheter according to claim 1, wherein the inner stent has a metal mesh structure, a metal cylindrical structure, a metal cylindrical structure having a plurality of slits, or a non-metallic cylindrical structure made of heat shrink. The catheter of claim 1, wherein the inner stent comprises at least two inner stent portions. A conduit for conducting the guide wire;
An outer balloon provided outside the conduit;
A stent disposed outside the outer balloon;
A catheter comprising an inner balloon provided inside the conduit for partially deforming the guide wire upon expansion. The catheter according to claim 4, wherein the guide wire has a hollow structure. A guide wire whose interior is partitioned into a plurality of hollow chambers by partition walls;
A conduit for conducting the guide wire;
An outer balloon provided outside the conduit;
An outer stent disposed outside the outer balloon;
A plurality of hollow needles provided on the inside of the conduit and provided toward the inside are provided, and the contrast agent is injected into the hollow chamber of the guide wire through the plurality of hollow needles by expansion by pouring of the contrast agent. A catheter comprising an inner balloon for performing the operation. A conduit for conducting thin wires;
An outer balloon provided outside the conduit;
A catheter comprising an inner balloon provided inside the conduit.

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