JP2007319272A - Device for percutaneous blood clot removal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device to capture scattering blood clots or foreign matters like the balloons of scattered foreign objects, and when new blood clots are produced, to prevent their scattering in the proximity of the part to be treated in intervention medical treatments such as a percutaneous angioplasty, etc. <P>SOLUTION: The device 1 for percutaneous blood clot removal is provided with a sheath provided with the proximal and distal ends for insertion into the body cavity as well as a developable removal member 4. The percutaneous blood clot removal device 1 is characterized in that an inside sheath 31 is provided within the above sheath, i.e., an outside sheath 21, in that the developable removal member 4 is provided at the tip of the inside sheath 31, in that the removal member 4 is of a self-developing type that does not interrupt blood flow, and in that the removal member 4 can be stored inside the outside sheath 21 together with the inside sheath 31. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a device for removing a thrombus for use in a treatment for removing a thrombus in a blood vessel.

Conventionally, as a thrombus removal method, a method has been used in which a small incision is made in an exposed blood vessel, a balloon catheter or the like is inserted from the incision through the thrombus, and the thrombus is removed while the catheter is pulled back. ing.

Further, as a percutaneous approach, there are a method of sucking a thrombus from a thrombus aspiration catheter or injecting a thrombolytic agent from a thrombolysis catheter. The thrombus suction catheter is, for example, a tubular body having a cut surface with an inclined tip opening, the tip opening is formed in a concave shape in the inclined direction, and the tip side of the cut surface is flat and flexible. A thrombus suction catheter with a small pressure loss has been proposed (Patent Document 1).
Further, as the thrombolysis catheter, there has been proposed a method in which a large number of side holes are formed in the catheter and a thrombolytic agent is sprayed into the thrombus and dissolved (Patent Document 2).

JP2004-222946 US Pat. No. 6,524,300

  However, the thrombus removal method that incises blood vessels has the advantage of exposing a patient's blood vessels and reliably removing a large amount of thrombus, but because it treats by incising not only the skin but also the blood vessel wall, it has an aggressive nature. It has the disadvantage of being large.

  On the other hand, a method using a thrombus aspiration catheter, which is a method for removing a percutaneous thrombus, has an advantage that it can be treated with low attack compared to a thrombus removal method for incising a blood vessel. However, since thrombus removal is performed by suction from the lumen of the catheter, it is difficult to remove a large amount of thrombus at a time. Moreover, since the thrombus removal method using the thrombus aspiration catheter uses a catheter having a small diameter with respect to the blood vessel, the sputum-like thrombus cannot be easily removed in some cases. In particular, it is impossible to remove old thrombus.

  Also, the method using a thrombolysis catheter has the advantage that it can be treated with less invasiveness than the method of incising blood vessels. However, it is difficult to dissolve an old thrombus and it may cause side effects such as bleeding due to the dissolving agent.

  A conventional catheter including an introducer cannot prevent thrombus scattering during operation.

  Furthermore, it has been difficult for a conventional introducer to collect a metal stent or the like placed in a blood vessel that is thicker than the lumen of the introducer.

  That is, an object of the present invention is to provide a thrombus removal device that can remove a large amount of thrombus with low attack and can reliably remove the thrombus.

  Therefore, in order to solve the above problems, the present inventors have provided a percutaneous thrombectomy device comprising a sheath having a proximal end and a distal end inserted into a body cavity, and a deployable removal member. An inner sheath is provided inside the sheath, which is an outer sheath, and a deployable removal member is fixed to the distal end of the inner sheath, and the removal member is a self-expanding removal member that does not block blood flow. And the removal member has been found to solve the above problems by using a percutaneous thrombectomy device characterized in that it can be housed together with the inner sheath inside the outer sheath, leading to the present invention. It was.

  By using the percutaneous thrombectomy device of the present invention, thrombus such as thrombus from the treatment part which is a distal part is removed in interventional treatment such as percutaneous angioplasty using a balloon catheter. be able to.

  Hereinafter, the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments.

  FIG. 1 is a side view of an exemplary embodiment of a thrombus removal device of the present invention. FIG. 1A is a side view of a state in which a removal member provided at the distal end of the inner sheath is housed inside the outer sheath. FIG. 1B is a diagram showing a state in which the removal member is deployed with the distal end of the inner sheath positioned before the distal end of the outer sheath.

  In FIG. 1, a percutaneous thrombus removal device 1 includes an insertion tool 2 and a removal tool 3. The insertion tool 2 includes an outer sheath 21 and an outer sheath base body 22 on the proximal end side of the outer sheath 21. The removal tool 3 includes an inner sheath 31, and an inner sheath base body 32 on the rear end side of the inner sheath 31. The percutaneous thrombus removing device 1 is in a state in which an inner sheath 31 is provided inside an outer sheath 21. A deployable removal member 4 is provided at the distal end of the inner sheath 31.

  As shown in FIG. 1A, the removing member 4 can be housed inside the outer sheath 21 together with the inner sheath 31, and as shown in FIG. It is also possible that the diameter of the tip of the removal member 4 is expanded beyond the inner diameter of the outer sheath at a position ahead of the distal end. As shown in FIGS. 1B and 3, the diameter of the capture port 41 increases as the distal end 23 of the outer sheath moves beyond the distal end 23. The diameter of the distal end of the removal member 4 is larger than the inner diameter of the outer sheath, and the diameter of the capture port 41 is expanded, whereby the bowl-shaped thrombus in front of the removal member 4 can be easily captured. The rear end 42 of the removing member 4 is attached to the distal end of the inner sheath 31 and is open. As a method of attaching the rear end 42 to the distal end of the inner sheath, the catheter and / or guide wire passes through the inner sheath 31 with the rear end 42 opened, and the distal end of the catheter moves to the tip of the removal member. It is preferable that it is attached so as to be able to. The attachment method is not particularly limited, and a method in which the rear end 42 is bonded to the inner side or the outer side in the vicinity of the inner sheath front end with an adhesive or the like to be substantially integrated can be used. In order to facilitate the insertion / extraction of the inner sheath 31 into the outer sheath 21, it is possible to use a method in which the rear end 42 is adhered to the inside of the vicinity of the inner sheath distal end. It is preferable because it does not get caught at the end.

  Since the removal member 4 is a self-expanding type, it is not necessary to apply an action force for enlargement by any means, and the capture port 41 is expanded by moving the removal member 4. The removal member is not particularly limited as long as it is made of a material that can be self-expanded. However, even if the removal member is stored in the outer sheath for a long time and contracted, the removal member is planned to be expanded. It is preferable to include a shape memory alloy as a material because it is easy to restore the expanded shape. The shape memory alloy is not particularly limited, but for example, so-called nitinol can be used. Further, when the removal member is a basket-shaped removal member made of a shape memory alloy, it can be easily slid within the outer sheath. Therefore, the removal member is coated with a material having low surface tension and good slipperiness. It is preferable that the surface is coated with a silicon material such as a silicon resin.

  The size of the removal member 4 can be adjusted by adjusting the position of the distal end of the inner sheath relative to the outer sheath. As shown in FIG. 3, the diameter of the capture port 41 is such that the tip of the removal member is along the wall of the body cavity so that the thrombus in the body cavity can be collected and captured. It is preferable. The diameter of the capture port 4 is desirably thick enough to contact the blood vessel wall according to the blood vessel diameter. In the fully expanded state, it is desirable that the diameter of the aorta is 17 to 23 mm, particularly 20 mm, and the peripheral blood vessel is 2.7 to 3.3 mm, particularly 3 mm. In addition, by adjusting the length of insertion of the inner sheath with respect to the outer sheath, the diameter (opening diameter) of the capture port 41 can be easily adjusted to be restricted by the distal end of the outer sheath. Moreover, in order to make it easier to adjust the diameter of the capture port 4, an opening adjustment display such as a scale may be provided on the outer surface of the inner sheath 31.

  Further, the removing member 4 has a structure that allows a body fluid, particularly blood, to pass therethrough without blocking the blood flow. In the drawing, the removing member 4 has a basket shape having holes. The removal member 4 may have a shape in which a support member made of a shape memory alloy supports a resin-made net-like body in a conical shape other than the basket shape as in the embodiment in FIGS. 1 (a) and 1 (b). good. Since the removal member 4 has a basket shape formed of a shape memory alloy wire, the removal member 4 has a good strength and / or durability when capturing a thrombus and has a mesh shape such as a basket shape. It is preferable because a thrombus can be easily removed. Since the basket-shaped removal member does not damage a body cavity such as a blood vessel wall during the capture of a thrombus, it is preferable that the tip portion is not sharp, and a shape in which the wire is curved as shown in FIG. It is preferable to be provided in the part. Further, in order to more smoothly open and close the removal member, the basket is configured such that the ends of the plurality of wire members constituting the basket-like removal member are positioned at the connection portion with the inner sheath, It is preferable that there is no joint.

  In the embodiment of FIG. 1 (a), the hole for allowing the body fluid to pass through the removal member 4 is an aperture that allows body fluid to pass therethrough and captures a thrombus that is generated when the constriction is expanded. If it is good. Specifically, the diameter of the capture port 4 is preferably 100 μm or more because it is possible to capture a larger thrombus than a component contained in a body fluid component such as leukocytes in a state where the capture port 4 is expanded to the maximum. . The microthrombus does not pose a problem even if it enters the circulation, and it is sufficient that only a certain amount of thrombus can be captured, so that it is more preferably 100 to 1000 μm, and particularly preferably 150 to 300 μm.

  FIG. 2 is a longitudinal sectional view of the insertion tool 2 in the embodiment shown in FIG. The insertion tool 2 includes an outer sheath 21. The proximal end 212 of the outer sheath 21 is fitted into the recess 221 of the outer sheath base body 22. The cover body 23, which is an elastic body, has the engagement convex portion 231 engaged with the wall surface of the small-diameter portion 222 of the outer sheath 22 and is fixed to the outer sheath base body 22, and grips the outer sheath 22 by its elasticity. Thus, the fitted state between the outer sheath 21 and the outer sheath base body 22 is maintained. The outer sheath base body 22 includes a through-hole portion 223 and an internal space 224, and further includes a connection portion 225 having a branch channel 226. In addition, the insertion tool 2 includes a valve body 24 sandwiched between a step portion 227 and a lid body 25 at the opening of the outer sheath base body 22. By making the inner sheath penetrate the valve body 6 and further penetrate the inner space 224, the through hole portion 223, and the outer sheath 21, the inner sheath is provided inside the outer sheath as shown in FIG. be able to. The valve body 24 preferably has a cross-shaped cut so that it can be used as a check valve.

  The connecting portion 225 of the insertion tool 2 can be connected to a tube, and a cock or the like can be attached to the other end of the connecting end portion of the tube. In this way, when a percutaneous thrombus removal device is inserted into a body cavity, a blood clot capturing operation can be performed without leakage of body fluid such as blood existing between the insertion tool 2 and the outer surface of the inner sheath 31. Can do. In the illustrated embodiment, an outer sheath base body is provided, and a valve body is provided on the outer sheath base body to prevent leakage of body fluid, but it is not always necessary to provide an outer sheath base body. It is also possible to provide a valve body directly on the sheath to prevent body fluid leakage. However, since the contrast agent can be introduced into the body cavity via the tube connected to the connection portion 226, the outer sheath is preferably connected to the sheath base body in which the connection portion 226 is formed.

  The removal tool 3 includes an inner sheath 31, an inner sheath base body 32, a cover body 33, and a removal member 4. The removal tool 3 in the illustrated embodiment has the same structure as the insertion tool 2 except that the removal member 4 is provided, and the outer diameter of the inner sheath is smaller than the inner diameter of the outer sheath. The removal tool 3 includes a valve body, and is provided at the rear end of the inner sheath so as to be sandwiched between an outer sheath base body 32 and a lid body 35 as a check valve into which a guide wire and / or a balloon catheter can be inserted and removed. It is preferable. The inner sheath base body 32 of the removal tool 3 includes a connection portion, like the outer sheath base body 22 of the insertion portion 2. However, as in the case of the insertion tool 2, the outer sheath base body is not necessarily an essential component, but since a contrast agent or the like can be easily introduced into the body cavity, a connection portion connected to the tube is provided. Preferably it is.

  The inner diameter of the inner sheath and the outer sheath is not particularly limited as long as the inner sheath can be inserted into a body cavity such as a blood vessel and the inner sheath can be accommodated inside the outer sheath, but a thrombus such as a thrombus is captured. When used for this purpose, it is preferable that the inner diameter of the outer sheath is 6 to 12 French and the inner diameter of the inner sheath is 4 to 10 French because it can be inserted without damaging the inside of the blood vessel. In addition, a French is converted by 1 mm = 3 French.

  The material of the inner sheath and the outer sheath in the present invention is not particularly limited, but it is preferable to use various elastomers including fluorine resin, nylon resin, polyurethane resin, polyethylene, polypropylene, and nylon elastomer, and vice versa. It is more preferable to use nylon resin or nylon elastomer from the viewpoint of ease of processing such as welding or adhesion for arranging a stop valve or the like.

  In the percutaneous thrombectomy device of the present invention, the inner and outer sheaths, the sheath base body, and the cover body can be made of a known material and are particularly limited as long as they can be used for the sheath introducer. It is not a thing.

  In the percutaneous thrombectomy device of the present invention, as shown in FIG. 4, the distal end of the catheter 5 passes through the valve body of the removal tool 3, passes through the inside of the inner sheath 31, and further passes through the inside of the removal member 4. The stenosis part 6 of the blood vessel can be expanded by moving forward through the removal member and inflating the balloon 51 provided at the distal end of the catheter 5. Due to the expansion of the balloon, the thrombus 61 is captured from the stenosis 6 by the removal member 4 by the blood flow. In FIG. 4, tubes 71 and 72 are attached to the insertion tool 2 and the removal tool 3, respectively, and a contrast medium can be introduced into the blood vessel from the tube 71. Further, it is possible to suck the captured thrombus from the tube 72. In the embodiment shown in FIG. 4, since the outer sheath is provided with a tube 72 that communicates with the gap between the outer sheath and the inner sheath on the inner side of the tube, the thrombus adhered when the capturing body is accommodated in the outer sheath. It is possible to prevent the scattered foreign matter such as from being scattered again into the body cavity even when the amount of the scattered foreign matter is large. The same applies when a stent is used instead of the balloon 51. The percutaneous thrombectomy device, like the catheter 5, easily inserts a thrombectomy catheter or lysis catheter and / or forceps for intravascular operation represented by removal of an intravascular metal stent. It is possible. When the catheter or the like is inserted into the blood vessel through the percutaneous thrombus removing device and an intravascular operation is performed, the thrombus is scattered, but the percutaneous thrombus removing device of the present invention is To prevent the thrombus from spreading further because the removal member can receive a thrombus scattered during the operation of the inserted thrombectomy catheter, dissolution catheter or forceps in the blood vessel or a newly formed thrombus. And the function of preventing the scattering of a new thrombus can be prevented, so that the spreading of the thrombus generated in the intravascular operation can be prevented from further expanding.

  Thus, the transcutaneous thrombus removing device of the present invention can also capture foreign matters such as thrombi that scatter and balloons that become scattered foreign matter on the proximal side from the treatment target site. It can be suitably used for interventional treatment such as plastic surgery.

(A) The side view of the state in which the removal member with which the front-end | tip of the inner sheath in one embodiment of the percutaneous thrombus removal device of this invention was equipped was accommodated inside the outer sheath. (B) The side view of the state which developed the removal member by positioning the front-end | tip of the inner sheath in the percutaneous thrombus removal device of FIG.1 (b) ahead of the distal end of an outer sheath. The longitudinal cross-sectional view of the insertion tool of the percutaneous thrombus removal device in the example of embodiment of FIG. The longitudinal cross-sectional view of the percutaneous thrombus removal device in the example of embodiment of FIG. Explanatory drawing at the time of using the percutaneous thrombus removal device in the embodiment example of FIG. 1 for percutaneous angioplasty.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Percutaneous thrombus removal device 2 Insertion tool 3 Removal tool 4 Removal member 5 Catheter 6 Stenosis part 71, 72 Tube 8 Blood vessel 9 Skin 21 Outer sheath 22 Outer sheath base body 23, 33 Cover body 24 Valve body 25, 35 Lid 31 Inner sheath 32 Inner sheath base body

Claims (7)

A transcutaneous thrombectomy device comprising a sheath with a proximal end and a distal end inserted into a body cavity and a deployable removal member,
An inner sheath inside the sheath which is an outer sheath;
A deployable removal member is provided at the tip of the inner sheath,
The removal member is a self-expanding removal member that does not block blood flow,
The percutaneous thrombectomy device, wherein the removal member is housed inside the outer sheath together with the inner sheath. The removal member is in a basket shape using a shape memory alloy having a self-expanding ability,
The removal member may be repeatedly performed such that the removal member is housed inside the outer sheath and the removal member is deployed at a position ahead of the distal end of the outer sheath. The transcutaneous thrombectomy device according to claim 1, which is possible. The removal member is
The percutaneous thrombus according to claim 1 or 2, wherein an opening diameter of the removal member after deployment can be adjusted by adjusting a length of insertion of the inner sheath with respect to the outer sheath. Removal device.   The percutaneous thrombectomy device according to any one of claims 1 to 3, further comprising a check valve capable of inserting and removing a guide wire and / or a balloon catheter at a proximal end of the inner sheath. A transcutaneous thrombectomy device comprising an insertion tool and a removal tool,
The insertion tool includes an outer sheath and an outer sheath base body on a proximal end side of the outer sheath,
The removal tool includes an inner sheath, an inner sheath base body on the proximal end side of the inner sheath, and a basket-shaped removal member at a distal end portion of the inner sheath,
The removal member can be housed inside the outer sheath together with the inner sheath;
The transcutaneous thrombectomy device, wherein the outer sheath base body and the inner sheath base body are provided with a valve body to prevent blood leakage. The insertion of a thrombectomy catheter or lysis catheter and / or insertion of forceps for intravascular operation represented by removal of an intravascular metal stent is possible inside the inner sheath. The transcutaneous thrombus removal device according to any one of -5. The removal member is a removal member for receiving the thrombus scattered during the operation and the newly formed thrombus by the removal member to prevent the spread of the thrombus from expanding,
The transcutaneous thrombectomy device is a device having a function capable of preventing the scattering of a new thrombus,
The percutaneous thrombus removal device according to any one of claims 1 to 6.

Images