JP2006230482A - Blood removing catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blood removing catheter which efficiently removes blood flowing into a coronary sinus from coronary arteries through a coronary vein to the outside of a body and shows the same operationality as catheters used in a conventional percutaneous coronary intervention or PCI. <P>SOLUTION: The blood removing catheter is equipped with a blood removing lumen in the inside and a hub 5 in the rear end part. When an equivalent diameter Dm is defined as (4×Sm)/Lm, where the minimum circumferential cross-sectional area of the blood removing lumen is Sm, and a wetted perimeter is Lm, Dm is at least 1.80 mm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a blood removal catheter used for medical purposes, and more particularly to a blood removal catheter that temporarily removes blood outside the body in order to remove the contrast agent locally administered to the coronary artery from the blood. .

  Conventionally, when a stenosis or occlusion occurs in a blood vessel such as a blood vessel, or a blood vessel is occluded by a thrombus, the blood vessel that improves the blood flow on the peripheral side of the blood vessel by expanding the stenosis or occlusion site with a balloon catheter Plastic surgery (PTA: Percutaneous Transluminal Angioplasty, PTCA: Percutaneous Transluminal Coronary Angioplasty) has many surgical cases in many medical institutions and has become a common treatment for this type of disease.

  With the evolution of devices such as DCA (Directional Coronary Atomology) and rotor vibrators, atherectomy therapy is also performed to excise the atheroma via a catheter. In addition, stents that are indwelled in order to maintain the patency state of the expanded stenosis site or the occlusion site are often used. These PTCA, atherectomy therapy, stenting, and the like are collectively referred to as percutaneous coronary intervention (PCI). In recent years, due to improvements in the skill level of surgeons and device performance, highly difficult cases such as left main coronary artery (LMT) lesions and chronic total occlusion (CTO) lesions have become PCI indications.

A contrast agent is an indispensable agent at the time of coronary angiography (CAG) and PCI, and is widely used. On the other hand, contrast agents are known to have side effects such as renal dysfunction, skin disorders, cardiovascular disorders, respiratory disorders, and urinary disorders. Therefore, attempts have been made to suppress the amount of contrast medium used as much as possible by using an injector or the like.
However, the number of contrast enhancements increases in complicated cases with high difficulty such as LMT lesions and CTO lesions, and the amount of contrast agent used inevitably increases. In addition, a drug eluting stent (DES) that dramatically reduces the occurrence of restenosis after stent placement has been developed in recent years, and has a high therapeutic effect. In the current situation, more contrast agents are used in order to accurately grasp the lesion properties such as the above and to position the DES with respect to the lesion.

  In recent years, it has been reported that patients undergoing PCI often have diabetes mellitus, and renal dysfunction is a problem among side effects caused by contrast agents. In order to suppress such renal dysfunction called contrast-induced nephropathy, especially for patients with renal insufficiency, fluid replacement before and after PCI operation, administration of N-acetylcysteine, etc., and contrast medium by dialysis after PCI operation Removal has been attempted.

  Above all, dialysis was considered to be an effective means for removing contrast medium in blood, but reports have been made to question its effect. As presented in Non-Patent Document 1, in patients with chronic renal failure, the incidence of contrast-induced nephropathy in the group that did dialysis after using the contrast medium (dialysis group) and in the group that did not (non-dialysis group) There is no difference. It is suggested that the time from administration of the contrast medium to dialysis is long, and blood containing the contrast medium continues to circulate in the body during this period, causing renal dysfunction. Against this background, there is a need for a treatment system that reduces the burden on the kidney caused by contrast agents during PCI, and related techniques are disclosed.

  In Patent Document 1, a balloon catheter comprising an expandable balloon, and a catheter body having a catheter lumen extending from the proximal end portion to the distal end portion and a balloon lumen extending from the proximal end portion to the balloon, There is disclosed a balloon catheter characterized in that a plurality of apertures penetrating the catheter lumen are provided from the tip of the balloon of the catheter body.

  A schematic cross-sectional view of the heart is shown in FIG. This catheter was placed at the coronary sinus ostium 012, and the blood flow from the coronary sinus ostium 012 to the right atrium 011 was blocked by expanding the balloon almost simultaneously with the administration of the contrast medium to the coronary artery, and was administered to the coronary artery. The purpose is to collect blood containing a contrast agent from the catheter lumen. However, this catheter has the following problems.

  First, it is difficult to dilate the balloon at the coronary sinus ostium 012 and block the blood flow to the right atrium 011. The coronary artery becomes an arteriole and circulates through the capillaries to the venule. Several venules join together to form a large heart vein, middle heart vein, small heart vein, etc., and together with the remaining venules join together into the coronary sinus and flow into the right atrium. Thus, a very large number of veins flow into the coronary sinus, and the inflow site covers a wide area up to the vicinity of the coronary sinus ostium 012. That is, when the balloon is expanded inside the coronary sinus, the blood flow from the venule that merges near the coronary sinus port 012 flows into the right atrium 011 without being blocked, and is introduced into the catheter lumen. It will be difficult to do.

Also, the wall of the coronary sinus is very thin, and balloon expansion can cause wall damage and perforation. When damage or perforation occurs, blood flows out between the heart and the pericardium, increasing the risk of causing serious illnesses such as cardiac tamponade.
On the other hand, it is extremely difficult to place the balloon accurately at a position that reliably covers the coronary sinus ostium 012 and to fix the balloon in place because of the influence of the heartbeat. Therefore, in the case of the balloon catheter according to the prior art, it is difficult to block the blood flow from the coronary sinus to the right atrium 011 and introduce it into the catheter lumen. As a result, the contrast agent administered to the coronary artery The recovery rate is low.
Coronary Intervention, vol. 2, no. 4,2003,78-83 JP 7-303701 A

  Therefore, in view of the above problems, the present invention intends to solve the problem that blood that flows into the coronary sinus from the coronary artery via the coronary vein can be efficiently removed from the body, and the conventional PCI is used. The present invention is to provide a blood removal catheter whose operability is the same as the catheters used in the above.

  As a result of intensive studies to solve the above-mentioned problems, a blood removal catheter that is disposed in a living body lumen, has a front end and a rear end, and is used for blood removal from the front end. The blood catheter has a blood removal lumen inside and a hub at the rear end, and when the minimum circumferential cross-sectional area of the blood removal lumen is Sm and the immersion side length is Lm, (4 × Sm) / Lm The inventors have invented a blood removal catheter characterized in that Dm is 1.80 mm or more when the equivalent diameter defined by is Dm.

In the present invention, the perimeter of the minimum cross-sectional area in the circumferential direction of the blood removal lumen is defined as the immersion length. For example, when the circumferential minimum cross-sectional area portion of the blood removal lumen is a circle having a diameter a, assuming that the circumference is π, the immersion side length Lm = π × a,
The cross-sectional area Sm = (1/4) × π × a ^ 2, and the equivalent diameter Dm = a.
Further, when the circumferential cross section of the blood removal lumen is a square with one side b,
The immersion side length Lm = 4 × b, the cross-sectional area Sm = b ^ 2, and the equivalent diameter Dm = b.
Furthermore, when the circumferential minimum cross-sectional area portion of the blood removal lumen has a donut shape defined by concentric circles having a diameter c and a diameter d (where d> c),
Immersion length Lm = π × (c + d), cross-sectional area Sm = (1/4) × π × (d ^ 2-c ^ 2),
The equivalent diameter Dm = dc.

  Here, it is preferable that a side hole is provided on the distal end side of the blood removal catheter, the side holes are preferably 2 or more and 10 or less, and the number of side holes existing on the same circumference is one. It is preferable that the side holes are arranged in a spiral shape. Further, when the cross-sectional area of the side hole is Ss and the immersion side length is Ls, Ds is preferably 1.80 mm or more when the equivalent diameter defined by (4 × Ss) / Ls is Ds. .

Here, it is preferable that the blood removal catheter is constituted by a combination of a braided tube in which a metal and a resin are combined, and a resin tube, and the distal end side is preferably constituted by a resin tube.
The resin preferably includes an elastomer having a Shore hardness of 25D or more and 75D or less or a blend of the elastomers, and the elastomer is more preferably a polyamide-based elastomer. In addition, a radiopaque substance may be mixed with the resin, and a hydrophilic coating may be applied to the outer surface of the blood removal catheter.

It is preferable to have a sub-catheter removably attached in the blood removal lumen, the sub-catheter being composed of a flexible tubular member, and preferably having a hub at the rear end. The member is preferably composed of a resin tube.
Here, the resin is either high-density polyethylene or low-density polyethylene, or polytetrafluoroethylene (PTFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer. It is preferably any one of a coalescence (FEP), a tetrafluoroethylene / ethylene copolymer (ETFE), a polyvinylidene fluoride (PVDF), and a polychlorotrifluoroethylene (PCTFE). The resin may be mixed with a radiopaque material, and the tubular member may be provided with a radiopaque marker.

Furthermore, it is preferable that a tip for suppressing damage to the biological lumen is attached to the distal end of the blood removal catheter, and a tip for suppressing damage to the biological lumen is attached to the tip of the sub-catheter. It may be. Here, it is preferable that the chip is made of a resin, and the resin has an shore hardness of 25D or more and 40D or less, or a blend of the elastomer, and the resin is mixed with an X-ray opaque material. It is preferable.
The living body lumen in which the blood removal catheter according to the present invention is placed is particularly preferably a coronary sinus.

  According to the present invention, blood flowing from the coronary artery into the coronary sinus via the coronary vein can be efficiently removed from the body. The contrast agent administered to the coronary artery can be removed by blood purification such as dialysis and adsorption, and the contrast agent that causes contrast-induced nephropathy can be effectively removed. In addition, the feeling of use of the blood removal catheter according to the present invention is not different from the catheters used in the conventional PCI, and therefore it is possible to safely remove blood outside the body without excessively extending the operation time. .

  Hereinafter, various embodiments of a blood removal catheter according to the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, a catheter according to the present invention has a distal end and a rear end, and is a blood removal catheter for removing blood from the distal end to the outside of the body. Equivalent diameter defined as (4 × Sm) / Lm, provided with a blood removal lumen and a hub at the rear end, where Sm is the minimum circumferential cross-sectional area of the blood removal lumen and Lm is the immersion side length When Dm is Dm, Dm is 1.80 mm or more.

The amount of blood removed when blood is removed through a catheter can be predicted hydrodynamically. When a fluid such as blood flows in a tube such as a blood removal catheter, the Reynolds number Re, which is a dimensionless amount representing the flow in the tube, is expressed as in Equation 1. Here, the circumferential cross-sectional area of the blood removal lumen is Sm, the blood flow velocity in the blood removal lumen is U, the immersion side length is Lm, the equivalent diameter is Dm, the blood density is ρ, and the blood viscosity is μ. . Formula 1:
Re = (Dm × U × ρ) / μ = [(4 × Sm) / Lm] × (ρ / μ)
It is known that when the Reynolds number is less than 2,100, it becomes laminar flow, and when it exceeds 4,000, it becomes turbulent flow. Assuming that the circumferential cross-sectional shape of the blood removal lumen is a circle having a diameter of 3 mm, the Reynolds number is generally on the order of several tens. Therefore, the blood flow in the blood removal lumen is considered laminar.

For the laminar flow in the tube, the Hagen-Poiseuille equation shown in Equation 2 holds. Here, the radius of the blood removal lumen is R, the length of the blood removal lumen is L, the absolute value of the pressure difference (hereinafter referred to as blood removal pressure) applied during blood removal is ΔP, and the blood removal amount is Q. The blood removal pressure in the present invention is a pressure difference P1− when the pressure when the blood removal amount is 0 mL / min is P0 mmHg, and the pressure when the blood removal amount is Q1 mL / min (Q1> 0) is P1 mmHg. P0. Formula 2:
Q = (π × R ^ 4 × ΔP) / (8 × μ × L)
When blood containing contrast medium administered to coronary arteries is removed from the coronary sinus and the blood from which contrast medium has been removed by adsorption or other blood purification methods is returned to the body, the removal of contrast medium by blood purification is efficient. In order to carry out, a higher blood removal amount is preferable. The blood removal amount is preferably at least 25 mL / min or more, and more preferably 50 mL / min or more. More preferably, it is 80 mL / min or more. As a method for increasing the blood removal amount, there are a method for increasing blood removal pressure using a means such as a pump or a syringe, or a method for increasing the equivalent diameter of the blood removal lumen. As the blood removal amount increases, the value of P1 decreases, and the blood removal pressure becomes negative pressure. If the blood pressure is less than −200 mmHg, there is a high possibility that the blood vessel will be occluded, which is dangerous. Therefore, the blood pressure is preferably −200 mmHg or more. From the viewpoint of preventing blood vessel flattening, the blood pressure removal is preferably −150 mmHg or more, more preferably −100 mmHg or more.

  In order for the blood removal amount to be 80 mL / min or more under the condition where the blood pressure is -100 mmHg or more, the equivalent diameter Dm is preferably 1.80 mm or more. When Dm is less than 1.80 mm, it is difficult to stably obtain a blood removal amount of 80 mL / min or more under conditions where blood removal pressure is -100 mmHg or more.

  As shown in FIG. 4, it is preferable that a side hole is provided at the distal end side of the blood removal catheter according to the present invention, preferably at a site to be inserted into a living body lumen to be removed. When a blood removal catheter is inserted and placed in a very thin walled area such as the coronary sinus, blood removal blood pressure affects the distal end of the blood removal catheter in close contact with the surrounding wall. There is a case. Such close contact not only does not achieve the necessary blood removal volume, but also increases the risk of damage to surrounding walls and perforation. By setting the equivalent diameter of the tip portion to 1.80 mm or more, the possibility of being in close contact with the surrounding wall is reduced, but by providing a side hole, the possibility is further reduced, which is preferable.

  In order to more effectively prevent close contact with the surrounding wall, it is preferable that there are two or more side holes. It is self-evident that by providing a plurality of side holes, blood removal can be performed safely unless all the side holes are in close contact with the surrounding walls.

  On the other hand, since the intensity | strength of the part with which the side hole was equipped falls by the increase in the number of side holes, it is preferable that there are 10 or less side holes. Further, by providing the side hole, the flexibility of the blood removal catheter at the portion is improved, but the kink resistance is lowered. Therefore, in order to maximize the merit of providing the side hole without causing kinking to the blood removal catheter, the number of side holes existing on the same circumference is preferably one. Increasing the number of side holes present on the same circumference is not preferable because the risk of kinking and further tearing of the blood removal catheter increases.

  The effect of the present invention is not limited unless two or more patterns on which the side holes are arranged exist on the same circumference. That is, a pattern in which a plurality of side holes are arranged in a straight line in the axial direction, a pattern arranged in a spiral shape as shown in FIG. In the case of blood removal from a living body lumen that is relatively close to the outer diameter of the blood removal catheter, it is preferably arranged in a spiral shape from the viewpoint of preventing close contact with the surrounding wall described above. Here, the number of side holes per unit helix, the inclination of the helix, and the like can be designed according to the target biological lumen.

  Moreover, it is preferable that the equivalent diameter Ds of a side hole is 1.80 mm or more. When Ds is smaller than 1.80 mm, it is difficult to secure a blood removal amount of 80 mL / min or more under the condition that the blood pressure is -100 mmHg or more.

  The shape of the side hole does not hinder the effect of the present invention, and the shape of the side hole can be any shape in consideration of the flexibility and strength of the blood removal catheter. That is, the shape may be a circle (FIG. 5), an ellipse (FIGS. 4 and 6), a rectangle, or the like. In the case of an oval shape, the major axis direction may be the axial direction of the blood removal catheter or the circumferential direction. In the case of a rectangle, the long side direction may be the axial direction of the blood removal catheter or the circumferential direction. Furthermore, it is not necessary for all the side hole shapes to be the same shape, and shapes such as a circle, an ellipse, and a rectangle may be combined. Considering the ease of processing and the deformability of the side hole shape when the blood removal catheter is bent, the side hole shape is preferably circular or elliptical.

  The method for providing side holes does not limit the effects of the present invention. Laser processing with a YAG laser, excimer laser, femtosecond laser, etc., cutting with a punch, etc. are preferably used.

The catheter for blood removal according to the present invention is used at the time of PCI and is introduced percutaneously into the body lumen from the thigh, neck, arm, etc., so an effective length of 50 cm or more is preferable, and an effective length of 80 cm or more is preferable. Is more preferable. Thus, in order to introduce a blood removal catheter having a relatively long effective length into a target living body lumen, it is necessary to apply torque and perform operations such as rotation and pushing. Therefore, the blood removal catheter according to the present invention is required to have torque transmission. Moreover, in order to introduce into a flexible and bent biological lumen, flexibility is also required. To achieve a stable blood removal volume, even if a blood removal catheter is placed in a bent biological lumen, the blood removal catheter will not kink and a sufficient blood removal lumen will not be secured. Don't be. Therefore, kink resistance is also required. As mentioned above, it is preferable that the blood removal catheter according to the present invention is constituted by a combination of a braided tube in which a metal and a resin are combined and a resin tube. By using a braided tube, torque transmission, kink resistance, and flexibility are secured at the same time.
In particular, assuming the case of introduction into a venous biological lumen whose wall is thinner and more flexible than the arterial system, the distal side of the blood removal catheter is preferably composed of a resin tube. By using a resin tube on the distal end side, flexibility is improved as compared with the case where the entire blood removal catheter is made of a braided tube, and it can be safely introduced into a living body lumen having a thin wall. The length of the resin tube provided on the distal end side does not limit the effect of the present invention, and can be selected according to the properties of the target biological lumen.

  In order to facilitate introduction into the living body lumen, the distal end side of the blood removal catheter may be processed into an arbitrary shape in advance as shown in FIG. Although FIG. 2 shows an example in which three bent shapes are provided, the number and shape of the bends are not limited. In the example of FIG. 2, the bent shape is given on the same plane, but the bent shape may be shown not only on the same plane but also on a plurality of planes as shown in FIG. 3.

  The bending shape imparting method does not limit the effect of the present invention, and any processing method can be used. As a preferred example, there is a method in which a core material for maintaining the shape of the blood removal lumen is inserted and a desired bent shape is given and the shape is memorized by heat treatment.

The resin constituting the braided tube or the resin constituting the resin tube preferably contains an elastomer having a Shore hardness of 25D or more and 75D or less or a blend of the elastomers. Use of an elastomer makes it easy to achieve both strength and flexibility. In particular, in the case of a braided tube, flexibility can be easily realized by using the elastomer or a blend of the elastomer on the outer surface.
When using only an elastomer having a Shore hardness lower than 25D, it is difficult to maintain the strength, which is not preferable. Moreover, when only an elastomer larger than 75D is used, the flexibility becomes low, which is not preferable. The elastomer may be blended in any ratio to achieve the desired strength and flexibility. The resin used for the braided tube and the resin tube may be the same elastomer or different elastomers, but it is preferable to use different elastomers in order to easily control the physical properties of the blood removal catheter. Further, it is not necessary to use the same resin over the entire length of the braided tube or the resin tube, and a plurality of resins may be used to incline the physical properties in the length direction of the tube. As a preferred example, the resin used for the braided tube has a Shore hardness of 40D or more and 75D or less, and the resin used for the resin tube has a Shore hardness of 25D or more and 63D or less.

  Here, in consideration of processability and the like, the elastomer is preferably a polyamide-based elastomer. The production method of the braided tube and the resin tube does not limit the effect of the present invention. In the case of the braided tube, polytetrafluoroethylene (PTFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), tetrafluoroethylene / ethylene copolymer A metal wire is braided on the outer surface of the tube made of a fluororesin such as coalescence (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), or a polyamide-based elastomer. It can be made by coating an elastomer or a blend of said elastomers. A stainless steel alloy, a cobalt-chromium alloy, a nickel-titanium alloy, or the like can be used as the metal strand, and the cross-sectional shape thereof may be any shape such as a circle, an ellipse, and a rectangle. The resin tube can be produced by an extrusion molding method, a dipping method, a wire coating method, or the like.

  The blood removal catheter is introduced into the living body lumen under fluoroscopy. Therefore, it is preferable that the blood removal catheter has radiopacity. As a method of providing radiopacity, a method of providing a marker made of a material having radiopacity on the outer surface or inner surface of a blood removal catheter, an alloy containing a noble metal in a metal strand constituting the braided tube From the viewpoint of keeping the flexibility of the blood removal catheter as high as possible, and a method of mixing a radiopaque material with the resin constituting the braided tube and / or the resin tube. A method of mixing a tube and / or a resin constituting the resin tube with a radiopaque substance, and a method of providing a marker made of a radiopaque material on the outer surface or inner surface of a blood removal catheter are preferable. . When the marker is provided, the number of markers provided is not limited. One may be provided only at the distal end of the blood removal catheter (FIG. 7), or may be provided around the side hole (FIG. 8).

  As a method of mixing the X-ray opaque material with the resin, a pellet of the resin kneaded with the X-ray opaque material is prepared in advance, the method using the pellet, the braided tube and / or the resin There is a method of mixing a resin and a radiopaque material when producing a tube, and any method may be used.

  The type of the radiopaque material is not particularly limited, and metal compounds such as barium and bismuth, and noble metal compounds such as gold and platinum are preferably used, but barium is used from the viewpoint of adaptability to the manufacturing method described above. Particularly preferred are oxides such as bismuth.

  The content of the radiopaque substance is preferably as high as possible within a range that does not greatly impair the physical properties of the resin and can be molded. When the barium or bismuth oxide described above is used, the amount is preferably 30% by weight or more.

  In order to improve the operability when introducing the blood removal catheter into the living body lumen, and to reduce the risk of damage to the living body lumen accompanying the introduction, a hydrophilic coating is applied to the outer surface of the catheter. Preferably it is. It is possible to reduce the frictional resistance when introduced into the living body lumen by the hydrophilic coating. The kind of coating material is not limited and can be selected according to the physical properties of the braided tube or resin tube to be used. For example, hydrophilic polymers such as poly (2-hydroxyethyl methacrylate), polyacrylamide, and polyvinylpyrrolidone can be used. You may adjust so that frictional resistance may be increased / decreased gradually by adjusting the kind of coating material and coating thickness in the length direction of this catheter.

  The blood removal catheter may be guided over a guide wire for easier introduction into the body lumen. In this case, similarly to the case where the guide catheter is engaged with the coronary artery entrance at the time of PCI, the guide catheter is inserted into the body with the guide wire disposed inside the blood removal catheter. A lumen for inserting a guide wire independent of the blood removal lumen (guide wire lumen) may be provided inside the blood removal catheter, but without changing the equivalent diameter of the blood removal lumen (= while maintaining the blood removal amount) ) Providing a guide wire lumen is not preferable because the outer diameter of the blood removal catheter inevitably increases. Therefore, it is preferable to use a blood removal lumen as a guide wire lumen.

  When a guide wire is inserted from the hub of the blood removal catheter according to the present invention, particularly when the distal end of the guide wire has a J-shaped curve, as shown in FIG. 9, from the side hole provided in the blood removal catheter. The tip of the guide wire pops out, and the guide wire cannot be easily guided. In addition, when a guide wire is inserted into a blood removal catheter once introduced into a living body lumen and the tip of the guide wire jumps out of the side hole as shown in FIG. 9, the guide wire is operated under fluoroscopy. The guide wire tip must be adjusted so that it comes out from the tip of the blood removal catheter. It is very time consuming to perform such adjustment under fluoroscopy, which not only increases the operator's stress but also increases the burden on the patient. Furthermore, if the operation is continued without noticing that the guide wire has jumped out of the side hole under fluoroscopy, there is a possibility that the blood removal catheter may be broken due to breakage of the side hole portion.

  From the above, as shown in FIG. 11, it is preferable to have a sub-catheter detachably attached to the blood removal lumen of the blood removal catheter according to the present invention. By using the lumen of the sub-catheter as a guide wire lumen, it is possible to prevent the guide wire from jumping out from the side hole of the blood removal catheter. Placing the sub-catheter within the blood removal lumen reduces the circumferential cross-sectional area of the blood removal lumen. However, since the sub-catheter is detachably attached, it is removed by removing the sub-catheter during blood removal. Can maintain blood volume. If it is necessary to operate the blood removal catheter together with the guide wire after removing the sub catheter, the guide wire can be inserted after the sub catheter is placed in the blood removal lumen, allowing safe operation. It is.

  The sub-catheter shown in FIG. 10 is composed of a flexible tubular member, and preferably has a hub at the rear end. By comprising a flexible member, even when the blood removal catheter is provided with a bent shape, it can be easily detached. In addition, by providing a hub at the rear end, the inside of the sub-catheter can be flushed with physiological saline containing heparin or the like, and thrombus formation during use can be suppressed and used safely. The method for connecting the sub-catheter and the blood removal catheter is not limited. As an example, as shown in FIGS. 10 and 11, the blood removal is performed by using a male luer at the end of the hub. It is detachably connected to the rear end (female luer) of the hub provided at the rear end of the catheter.

  The tubular member is preferably composed of a resin tube, and the resin is either high-density polyethylene or low-density polyethylene, or polytetrafluoroethylene (PTFE), a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer. (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), tetrafluoroethylene / ethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), or polychlorotrifluoroethylene (PCTFE) Preferably there is. By using any of the above-mentioned materials, it is possible to reduce not only the frictional resistance when attaching / detaching the subcatheter to / from the blood removal catheter, but also the frictional resistance between the subcatheter and the guide wire, and good operability. Is feasible.

  As with the blood removal catheter, the sub-catheter is preferably radiopaque. As a method for providing radiopacity, the subcatheter is made of a material having radiopacity on the outer surface or inner surface of the subcatheter from the viewpoint of maintaining the flexibility of the subcatheter as high as possible and realizing high radiopacity. A method of providing a marker to be used and a method of mixing a radiopaque substance with the resin constituting the sub-catheter are preferable.

  The material which comprises the said marker is not specifically limited, Noble metal compounds, such as metal compounds, such as barium and bismuth, gold | metal | money, platinum, are used suitably.

  As a method of mixing the radiopaque material with the resin, a pellet of the resin kneaded with the radiopaque material is prepared in advance, and the pellet is used. When the resin tube is manufactured There is a method of mixing a resin and a radiopaque material, and any method may be used.

  The kind of the radiopaque material mixed with the resin is not particularly limited, and metal compounds such as barium and bismuth, and noble metal compounds such as gold and platinum are preferably used. From the viewpoint of properties, oxides such as barium and bismuth are particularly preferable. Further, the content is preferably as high as possible within a range that does not greatly impair the physical properties of the resin and can be molded. When the barium or bismuth oxide described above is used, the amount is preferably 30% by weight or more.

  When the sub-catheter is attached to the blood removal catheter, the relative positions of the catheters do not limit the effect of the present invention. That is, the distal end of the sub-catheter may be disposed on the distal end side with respect to the distal end of the blood removal catheter, or may be disposed on the rear end side with respect to the distal end of the blood removal catheter. In any arrangement state, it is preferable that a tip is provided at the foremost part in order to prevent damage to the living body lumen where the blood removal catheter is arranged.

  When the distal end of the sub-catheter is disposed closer to the distal end than the distal end of the blood removal catheter, the tip is preferably provided at the distal end of the sub-catheter. Further, when the distal end of the sub-catheter is disposed on the rear end side with respect to the distal end of the blood removal catheter, it is preferable that the tip is provided at the distal end of the blood removal catheter. In this way, the tip of the tip is provided at the most distal portion with the sub-catheter and the blood removal catheter attached, thereby suppressing damage to the living body lumen.

Since the tip is for suppressing damage to the living body lumen as described above, it is preferable that the tip is flexible. That is, the chip is preferably made of a resin, and the resin has an Shore hardness of 25D or more and 40D or less, or a blend of the elastomers. When using only an elastomer having a Shore hardness lower than 25D, it is difficult to maintain the strength, which is not preferable. Moreover, when only an elastomer larger than 40D is used, flexibility is lowered, which is not preferable. The elastomer may be blended in any ratio to achieve the desired strength and flexibility. It is not necessary to use the same resin over the entire length of the chip, and a plurality of resins may be used to incline physical properties in the length direction of the chip.
Since the tip is the most distal portion with the sub-catheter and the blood removal catheter attached, it is necessary to accurately grasp the position under X-ray fluoroscopy. Therefore, it is preferable that a radiopaque material is mixed in the resin constituting the chip.

  As a method of mixing the radiopaque material with the resin, a pellet of the resin kneaded with the radiopaque material is prepared in advance, and the pellet is used. When the resin tube is manufactured There is a method of mixing a resin and a radiopaque material, and any method may be used.

  The kind of the radiopaque material mixed with the resin is not particularly limited, and metal compounds such as barium and bismuth, and noble metal compounds such as gold and platinum are preferably used. From the viewpoint of properties, oxides such as barium and bismuth are particularly preferable. Further, the content is preferably as high as possible within a range that does not greatly impair the physical properties of the resin and can be molded. When the barium or bismuth oxide described above is used, the amount is preferably 30% by weight or more.

  The method for producing a blood removal catheter and a sub-catheter according to the present invention does not limit the effects of the present invention. The typical structure of the blood removal catheter is shown in FIGS. 1 to 4, and the tip and the resin tube, the resin tube and the braided tube, the braided tube and the hub are connected, and the braided tube and the hub are connected to each other. Is connected with a strain relief for preventing kinks and the like during use of the catheter. The typical structure of the sub-catheter is as shown in FIG. 10, in which a tip and a resin tube, a resin tube and a hub are connected, and a kink or the like when using the catheter is connected to the connection portion of the resin tube and the hub. A strain relief is connected to prevent it.

The connection method in each connection part is not specifically limited, Methods, such as adhesion | attachment using an adhesive agent and heat welding, can be used.
In the case of adhesion, the type of adhesive to be used is not limited, and cyanoacrylate, urethane, silicone, epoxy, and other adhesives can be suitably used. The effect type of the adhesive is not limited, and adhesives such as a two-component mixed type, a water absorption curable type, a heat curable type, and a UV curable type can be suitably used. It is preferable to use an adhesive having a hardness after curing such that the rigidity of the connection part does not change discontinuously before and after the connection part. The adhesive should be used in consideration of the material, dimensions, rigidity, etc. of the material to be bonded. You can choose. In order to reduce the diameter of the connection part, heat treatment, polishing treatment, etc. may be carried out before and after bonding. In the case of difficult-to-adhere materials such as polyolefin, surface treatment such as plasma treatment using oxygen gas or the like is performed. You may carry out.

  The material constituting the hub is not particularly limited, and a general-purpose resin that can be injection-molded is preferably used. Examples include polycarbonate, polyamide, polyurethane, polysulfone, polyarylate, styrene-butadiene copolymer, polyolefin and the like.

Specific examples and comparative examples according to the present invention will be described in detail below, but the present invention is not limited to the following examples.
Example 1
A braided tube with an outer diameter of 2.05 mm, an inner diameter of 1.85 mm, and a length of 900 mm is prepared using a metal braid made of SUS304 alloy and processed by holding a single 0.10 mm x 0.03 mm metal wire with 16 strokes. did. The inner layer is polytetrafluoroethylene (Polyflon F-207, Daikin Industries, Ltd.), and the outer layer is four types of polyamide elastomers (PEBAX7233SA01 (Shore hardness 72D), PEBAX6333SA01 (Shore hardness 63D), PEBAX5533SA01 (Shore hardness 55D), PEBAX4033SA01 (Shore) Hardness 40D) was produced by a switching extrusion method using elf atom (Corporation).

  A polyamide elastomer (PEBAX4033SA01 (Shore hardness 40D) elf atom) was used to produce a tube having an outer diameter of 3.00 mm, an inner diameter of 2.25 mm, and a length of 150 mm by extrusion molding. A pre-shaped SUS304 alloy core material with an outer diameter of 2.20 mm was inserted into the produced tube. A resin tube was obtained by heating for 45 minutes in an oven at 180 ° C. with a polyolefin heat shrinkable tube covered, and performing a shaping process as shown in FIG. In addition, a 5 mm long chip made of polyamide elastomer (PEBAX3533SA01 (Shore hardness 35D) elf atom) was thermally welded to the tip of the resin tube.

After heat-welding the braided tube and resin tube, a two-component mixed urethane adhesive (UR0531, a hub made of strain relief made of polyamide elastomer (PEBAX5533SA01, elf atchem) and polycarbonate (Makloron 2658, Bayer) H. B. Fuller) was used as a blood removal catheter.
Dm in Example 1 is 1.85 mm.
(Example 2)
A braided tube was prepared in the same manner as in Example 1 except that the outer diameter was 2.95 mm and the inner diameter was 2.75 mm.
A resin tube was prepared in the same manner as in Example 1 except that a tube was prepared using a polyamide elastomer (PEBAX3533SA01 (Shore hardness 35D), elfatochem), and two side holes having a diameter of 2.10 mm were provided using an excimer laser. Produced. The phase difference between the side holes was 180 °, and the distance between the side holes in the length direction was 40 mm. A blood removal catheter was prepared in the same manner as in Example 1 using the obtained braided tube and resin tube.

  A resin tube having an outer diameter of 2.20 mm, an inner diameter of 1.90 mm, and a length of 1,050 mm was produced by extrusion molding using low density polyethylene (LF480M, Nippon Polychem Co., Ltd.), and polycarbonate (Makloron 2658, Bayer) at one end. The hub produced in (1) was bonded with a two-component mixed urethane adhesive (UR0531, HB Fuller) to produce a sub-catheter. Prior to bonding, oxygen plasma treatment was performed.

In Example 2, Dm is 2.25 mm and Ds is 2.10 mm.
(Example 3)
A braided tube was prepared in the same manner as in Example 1 except that the outer diameter was 2.40 mm and the inner diameter was 2.20 mm.
A tube made of resin was made in the same manner as in Example 1 except that a tube was made using a polyamide elastomer (PEBAX5533SA01 (Shore hardness 55D), elfatochem) and two side holes having a diameter of 1.85 mm were given using an excimer laser. Produced. The phase difference between the side holes was 180 °, and the distance between the side holes in the length direction was 40 mm. A blood removal catheter was prepared in the same manner as in Example 1 using the obtained braided tube and resin tube.

  A sub-catheter was prepared in the same manner as in Example 2 except that the outer diameter was 1.80 mm and the inner diameter was 1.50 mm.

In Example 3, Dm is 2.20 mm and Ds is 1.85 mm.
Example 4
A blood removal catheter was prepared in the same manner as in Example 3 except that the number of side holes was 10, the phase difference was 90 °, and the distance between the side holes in the length direction was 5 mm.

  The sub-catheter was produced in the same manner as in Example 3.

In Example 4, Dm is 2.20 mm and Ds is 1.85 mm.
(Comparative example)
A braided tube was prepared in the same manner as in Example 1 except that the outer diameter was 1.80 mm and the inner diameter was 1.60 mm. Further, a resin tube was prepared in the same manner as in Example 1 except that the outer diameter was 2.40 mm, the inner diameter was 1.60 mm, and the core material used in shaping was changed to an outer diameter of 1.55 mm. A blood removal catheter was prepared in the same manner as in Example 1 using the obtained braided tube and resin tube.

In the comparative example, Dm is 1.60 mm, and Ds is 1.60 mm.
(Evaluation)
A 10 Fr sheath introducer inserted into the right femoral vein under inhalation anesthesia was inserted into an LWD pig (body weight 58.5 kg). A blood removal catheter was placed in the coronary sinus under fluoroscopy. A 0.035 ″ guide wire was used in combination, and in Examples 2 to 4, the sub-catheter was placed in a blood removal catheter, and the sub-catheter was removed after placement.

Blood removal was performed using a blood collection pump in a state where an extension tube having a length of 1,000 mm was connected to the hub of the blood removal catheter, and blood removal and blood removal were measured.
(result)
Any of Examples 1 to 4 and Comparative Example according to the present invention could be placed in the coronary sinus. In Examples 2 to 4, the guide wire did not jump out of the side hole of the blood removal catheter due to the effect of the sub-catheter, and the operation was possible.

In Example 1, blood removal was possible at a rate of 100 mL / min at −80 mmHg, in Example 2 at −18 mmHg, in Example 3 at −33 mmHg, and in Example 4 at −30 mmHg. The blood removal rate is 80 mL / min or more at a blood removal pressure of −100 mmHg or more, which is a preferable condition for removing blood containing a contrast agent and returning blood from which the contrast agent has been removed by a blood purification method such as adsorption. The condition was met.
On the other hand, in the comparative example, only a blood removal amount of about 60 mL / min was obtained in a blood removal range of −100 mmHg or more, blood containing a contrast medium was removed, and the contrast medium was removed by a blood purification method such as adsorption. Application to a system that returns blood to the body was considered difficult.

It is the schematic which shows an example of the catheter for blood removal. It is the schematic which shows a different example of the catheter for blood removal. It is a side view which shows an example of the catheter for blood removal shown in FIG. It is the schematic which shows an example which has a side hole among the catheters for blood removal. It is the schematic which shows an example of the front end side of the catheter for blood removal. It is the schematic which shows an example from which the front end side of the blood removal catheter differs. It is the schematic which shows an example from which the front end side of the blood removal catheter differs. It is the schematic which shows an example from which the front end side of the blood removal catheter differs. It is the schematic which shows the state which the guide wire protruded from the side hole of the blood removal catheter. It is the schematic of a subcatheter. It is the schematic which shows the state which inserted the guide wire into the blood removal catheter provided with the subcatheter. It is an enlarged view of the front end side of the blood removal catheter shown in FIG. 1 is a cross-sectional view of a typical heart.

Explanation of symbols

001 Tip 002 Plastic tube 003 Braided tube 004 Strain relief 005 Hub 006 Side hole 007 Marker 008 Guide wire 009 Blood removal catheter 010 Inferior vena cava 011 Right atrium 012 Coronary sinus ostium

Claims (24)

  A blood removal catheter disposed in a living body lumen, having a front end and a rear end, for blood removal from the body from the front end, the blood removal catheter having a blood removal lumen therein and a rear A hub is provided at the end, and when the minimum cross-sectional area in the circumferential direction of the blood removal lumen is Sm and the immersion side length is Lm, the equivalent diameter defined by (4 × Sm) / Lm is Dm. Is a blood removal catheter characterized by being 1.80 mm or more.   The blood removal catheter according to claim 1, further comprising a side hole on a distal end side of the blood removal catheter.   The blood removal catheter according to claim 2, wherein the number of side holes is 2 or more and 10 or less.   The blood removal catheter according to claim 3, wherein the number of side holes present on the same circumference is one.   The blood removal catheter according to claim 3 or 4, wherein the side hole is disposed in a spiral shape.   6. The Ds is 1.80 mm or more when the equivalent diameter defined by (4 × Ss) / Ls is Ds where the cross-sectional area of the side hole is Ss and the immersion edge length is Ls. A blood removal catheter according to any one of the above.   The blood removal catheter according to any one of claims 1 to 6, wherein the blood removal catheter is configured by a combination of a braided tube in which a metal and a resin are combined, and a resin tube.   The blood removal catheter according to any one of claims 2 to 7, wherein the distal end side is formed of a resin tube.   The blood removal catheter according to claim 7 or 8, wherein the resin contains an elastomer having a Shore hardness of 25D or more and 75D or less or a blend of the elastomers.   The blood removal catheter according to claim 9, wherein the elastomer is a polyamide-based elastomer.   The blood removal catheter according to claim 9, wherein a radiopaque substance is mixed in the resin.   The blood removal catheter according to any one of claims 1 to 11, wherein a hydrophilic coating is applied to an outer surface of the blood removal catheter.   The blood removal catheter according to any one of claims 2 to 12, further comprising a sub-catheter removably attached to the blood removal lumen.   The blood removal catheter according to claim 13, wherein the sub-catheter is formed of a flexible tubular member and includes a hub at a rear end portion.   The blood removal catheter according to claim 14, wherein the tubular member is formed of a resin tube.   The blood removal catheter according to claim 15, wherein the resin is either high-density polyethylene or low-density polyethylene.   The resin is polytetrafluoroethylene (PTFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), tetrafluoroethylene / ethylene copolymer (ETFE). ), Polyvinylidene fluoride (PVDF), or polychlorotrifluoroethylene (PCTFE).   The blood removal catheter according to claim 15, wherein a radiopaque substance is mixed in the resin.   The blood removal catheter according to any one of claims 14 to 18, wherein the tubular member is provided with a radiopaque marker.   The blood removal catheter according to any one of claims 1 to 19, wherein a tip for suppressing damage to a living body lumen is attached to a distal end of the blood removal catheter.   The blood removal catheter according to any one of claims 14 to 19, wherein a tip for suppressing damage to a living body lumen is attached to a distal end of the sub-catheter.   The blood removal catheter according to claim 20 or 21, wherein the tip is made of a resin, and the resin has an Shore hardness of 25D or more and 40D or less, or a blend of the elastomers.   The blood removal catheter according to claim 22, wherein a radiopaque substance is mixed with the resin.   The blood removal catheter according to any one of claims 1 to 23, wherein the biological lumen is a coronary sinus.

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