WO2017159849A1

WO2017159849A1 - Catheter pump and treatment method

Info

Publication number: WO2017159849A1
Application number: PCT/JP2017/010914
Authority: WO
Inventors: 畑優; 森武寿; 竹村知晃
Original assignee: テルモ株式会社
Priority date: 2016-03-18
Filing date: 2017-03-17
Publication date: 2017-09-21
Also published as: JP2019080594A

Abstract

Provided are a catheter pump and a treatment method that are capable of reducing the impact on cardiac valves, retaining an adequate flow rate, and facilitating flow of blood to coronary veins. This catheter pump (10) is inserted into a heart chamber to assist the flow of blood, and has a deformable cannula (30) which is provided with an inflow port (82) on the distal side thereof and discharge ports (83) on the proximal side thereof, and an impeller (50) disposed inside the cannula (30). The cannula (30) has: a proximal tubular part (32) within which the impeller (50) is disposed; a proximal end (36) which is located on the proximal side of the proximal tubular part (32), and the inner diameter of which decreases toward the proximal side; an intermediate tubular part (33) which is located on the distal side of the proximal tubular part (32), and which has an inner diameter smaller than that of the proximal tubular part (32); and a distal tubular part (31) which is located on the distal side of the intermediate tubular part (33), and at which the inflow port (82) is located, wherein the discharge ports (83) are located in the outer peripheral surface of the proximal tubular part (32) and the proximal end (36).

Description

Catheter pump and treatment method

The present invention relates to a catheter pump and a treatment method for assisting cardiac output.

心 Heart failure with reduced cardiac function is a serious health problem with a high mortality rate. When heart failure occurs, the amount of blood necessary for metabolism in tissues throughout the body cannot be pumped out of the heart. For this reason, in recent years, auxiliary devices for assisting cardiac output have been developed for acute heart failure. For example, Patent Document 1 describes a catheter pump that is used by being percutaneously inserted from the femoral artery and reaching the left ventricle from the aorta. This catheter pump has a tubular cannula extending from the left ventricle to the aorta and an impeller rotating inside the cannula. By rotating the impeller inside the cannula, blood inside the cannula can flow from the left ventricle into the aorta and assist in cardiac output.

U.S. Pat. No. 8,734,331

The catheter pump described in Patent Document 1 has a great influence on the aortic valve because the cannula is in contact with the aortic valve. However, if the cannula is made thin, it becomes difficult to ensure the necessary flow rate.

Also, in heart failure, there is a case where it is desired to promote blood inflow because the inflow of blood into the coronary arteries that nourish the heart decreases as the cardiac output decreases.

The present invention has been made to solve the above-described problems, and can provide a catheter pump and a treatment method capable of reducing the influence on a heart valve, ensuring a sufficient flow rate, and promoting blood to a coronary vein. The purpose is to provide.

A catheter pump that achieves the above object is a catheter pump that is inserted into a heart chamber to assist blood flow, and is provided with an inflow port through which blood flows in on the distal side and out of blood on the proximal side. A tubular body provided with a discharge port, which can be radially contracted and expanded; a long shaft portion to which a proximal portion of the cannula is connected; and a rotatable shaft inside the cannula, An impeller for creating a blood flow from the inlet to the outlet, wherein the cannula has a proximal tubular portion in which the impeller is rotatably disposed, and a proximal side of the proximal tubular portion A proximal end connected to the shaft portion and having a portion with an inner diameter decreasing toward the proximal side and located on the distal side of the proximal tubular portion Communicating with the front An intermediate tubular portion having an inner diameter smaller than that of the proximal tubular portion, a distal tubular portion located on a distal side of the intermediate tubular portion, communicating with the intermediate tubular portion, and having the inflow port located therein, The discharge port is located on at least one of an outer peripheral surface of the proximal tubular portion and an outer peripheral surface inclined with respect to a central axis of the impeller at the proximal end portion.

A treatment method for achieving the above object is a treatment method for assisting blood flow by inserting the catheter pump into the heart chamber, inserting the catheter pump into a blood vessel, and moving the distal tubular portion to the left. Placing in the ventricle, placing the intermediate tubular portion in contact with the aortic valve, placing the proximal tubular portion in the aorta, and rotating the impeller to move blood in the left ventricle from the inlet into the cannula Aspirating and releasing into the aorta from the outlet.

The catheter pump and the treatment method configured as described above can reduce the influence on the heart valve to be inserted because the diameter of the intermediate tubular portion is smaller than the diameter of the proximal tubular portion. Moreover, since the diameter of the proximal tubular portion is larger than the diameter of the intermediate tubular portion and can accommodate an impeller having a high discharge pressure, the pressure loss due to the small inner diameter of the intermediate tubular portion is large, and a sufficient flow rate can be secured. Furthermore, since the discharge port is located on the outer peripheral surface of the proximal tubular portion having a diameter larger than that of the intermediate tubular portion or on the outer peripheral surface inclined with respect to the central axis of the impeller at the proximal end portion, blood is located on the side from the discharge port. Is released. For this reason, the blood discharged | emitted to the aorta can be guide | induced to the coronary artery opening provided in the wall surface of an aorta, and the inflow of the blood to a coronary artery can be accelerated | stimulated.

It is a top view which shows the catheter pump which concerns on embodiment. It is sectional drawing which shows the distal part of a catheter pump. It is sectional drawing which shows the state which inserted the catheter pump accommodated in the outer sheath into the left ventricle. It is sectional drawing which shows the state which inserted the catheter pump into the left ventricle. It is sectional drawing which shows the state which act | operated the catheter pump. It is sectional drawing which shows the state which the catheter pump moved to the proximal side in the biological body. It is sectional drawing which shows the state which the catheter pump moved to the distal side in the living body. It is sectional drawing which shows the state which the catheter pump moved to the distal side in the living body. It is a top view which shows the modification of a catheter pump, (A) shows a 1st modification, (B) shows a 2nd modification, (C) shows a 3rd modification. It is a top view which shows the modification of a catheter pump, (A) shows a 4th modification, (B) shows a 5th modification, (C) shows a 6th modification. It is a top view which shows the modification of a catheter pump, (A) shows a 7th modification, (B) shows an 8th modification. It is a top view which shows the modification of a catheter pump, (A) shows a 9th modification, (B) shows a 10th modification. It is sectional drawing which shows the 11th modification of a catheter pump. It is sectional drawing which shows the 12th modification of a catheter pump. It is sectional drawing which shows the 13th modification of a catheter pump. It is sectional drawing which shows the 14th modification of a catheter pump. It is a top view which shows the modification of a catheter pump, (A) shows a 15th modification, (B) shows a 16th modification. It is sectional drawing which shows the 17th modification of a catheter pump. It is sectional drawing which shows the state at the time of removing. It is sectional drawing which shows the 18th modification of a catheter pump.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

The catheter pump 10 according to the embodiment of the present invention is a device used for the treatment of acute heart failure. The catheter pump 10 is percutaneously inserted into a blood vessel and introduced into the heart to operate and assist in cardiac output. In this specification, the side of the device to be inserted into the blood vessel is referred to as “distal side”, and the proximal side for operation is referred to as “proximal side”.

As shown in FIGS. 1 and 2, the catheter pump 10 includes a long shaft portion 20, a cannula 30 disposed on the distal side of the shaft portion 20, and a drive rotatably disposed inside the shaft portion 20. A shaft 40, an impeller 50 fixed to the distal portion of the drive shaft 40, and an outer sheath 60 through which the shaft portion 20 passes are provided.

The shaft portion 20 includes a shaft body 21 that is a tubular body, and a first hub 22 that houses a proximal portion of the drive shaft 40. The shaft body 21 has a first lumen 23 inside. The drive shaft 40 is rotatably accommodated in the first lumen 23. A bearing 24 that rotatably supports the drive shaft 40 is provided at the distal portion of the first lumen 23. The bearing 24 is, for example, a tube made of a low friction material at least on the inner peripheral surface.

The constituent material of the shaft body 21 is preferably a material having hardness and flexibility. For example, polyolefin such as polyethylene and polypropylene, polyester such as polyamide and polyethylene terephthalate, tetrafluoroethylene / ethylene copolymer ( Fluorine polymers such as ETFE), PEEK (polyetheretherketone), polyimide, polytetrafluoroethylene (PTFE) and the like are preferably used. It is also possible to add a metal blade or coil to the material to increase the rigidity.

Examples of the low friction material constituting the bearing 24 include fluorine resin materials such as PTFE and ETFE. Note that the bearing may not be provided.

The first hub 22 is fixed to the proximal portion of the shaft body 21. Inside the first hub 22, a first connecting portion 41 provided at the proximal portion of the drive shaft 40 is disposed.

The drive shaft 40 is a long tube body for receiving the rotational force from the drive device 90 provided outside the body and rotating the impeller 50 at the distal portion. The drive shaft 40 has a guide wire lumen 42 into which a guide wire or the like can be inserted. The guide wire lumen 42 may not be on the drive shaft 40. The drive shaft 40 only needs to be able to transmit the torque generated by the drive device 90. For example, the drive shaft 40 is composed of a multi-layer coiled tube such as a three-layer coil in which a thin round wire or a flat wire is alternately wound in the right and left and right winding directions. Is done. Or, it can be a tube made of a spring consisting of one or more layers, a blade tube in which a blade is knitted into a resin tube, or a spiral cut pipe that can be bent by adding a spiral cut to a metal pipe. Good. The drive shaft 40 includes a first connection portion 41 that can be connected to the second connection portion 91 provided on the rotation shaft 92 of the external drive device 90 in the first hub 22. The driving device 90 has, for example, a motor 93 in order to rotate the rotating shaft 92. The operation of the driving device 90 is controlled by the control unit 100. The control unit 100 includes a CPU (Central Processing Unit) and a storage circuit, and is connected to interfaces such as a keyboard, a mouse, and a monitor. The control unit 100 is a computer, for example. The cannula 30 may be provided with a sensor for acquiring biological information, and the control unit 100 may be connected with an acquisition information receiving device. A sensor for acquiring biological information is located in the proximal tubular portion 32 of the cannula 30 on the base side from the discharge port 83. Thereby, the impeller 50 can acquire biological information immediately after the discharged fluid. The biological information is blood flow rate, flow velocity, and the like.

The cannula 30 is a flexible deformable tube body having a flow path for circulating blood inside. The cannula 30 can be elastically deformed so as to contract in the radial direction, and can return to its original shape by its own elastic force. The cannula 30 includes a distal tubular portion 31 located at the distal portion, a proximal tubular portion 32 located at the proximal portion, and an intermediate tubular portion 33 located between the distal tubular portion 31 and the proximal tubular portion 32. And have. Further, the cannula 30 is located between the distal tubular portion 31 and the intermediate tubular portion 33, and is located between the proximal tubular portion 32 and the intermediate tubular portion 33. And an intermediate change portion 35 whose outer diameter and inner diameter change, and a proximal end portion 36 which is connected to the shaft body 21 on the proximal side of the proximal tubular portion 32 and changes in outer diameter and inner diameter. . Further, the cannula 30 has a tip tube 70 that is located on the distal side of the distal tubular portion 31 and into which a guide wire can be inserted, and a connecting wire 75 that connects the tip tube 70 and the distal tubular portion 31. ing.

The distal tubular portion 31, the distal change portion 34, the intermediate tubular portion 33, the intermediate change portion 35, the proximal tubular portion 32 and the proximal end portion 36 are a flexible deformable membrane body 80 and a tube body 80. A support body 81 for maintaining the shape is integrally formed. The support 81 has a tube shape in which the wire is braided in a mesh shape, can be elastically deformed so as to contract toward the central axis of the tube, and returns to its original shape by its own elastic force. be able to. The support body 81 is disposed inside the film body 80, but may be disposed outside the film body 80 or embedded inside the film body 80 as long as the film body 80 can be supported.

The distal tubular portion 31 is a portion inserted into the left ventricle H (see FIG. 5). The distal tubular portion 31 has a substantially constant inner diameter and outer diameter along the axial direction. The distal tubular portion 31 includes an inflow port 82 having an internal flow channel opened at a distal end. The inflow port 82 is a part into which blood flows when the pump is operated.

The proximal tubular portion 32 is a part located in the ascending aorta A (see FIG. 5). The proximal tubular portion 32 has a substantially constant inner diameter and outer diameter along the axial direction. The proximal tubular portion 32 includes a plurality of discharge ports 83 that penetrate from the inner peripheral surface to the outer peripheral surface. The discharge port 83 is a part that discharges pressurized blood when the pump is operated. The plurality of discharge ports 83 are provided side by side in the circumferential direction of the proximal tubular portion 32. The discharge port 83 is configured by concentrating a support body 81 as a wire between adjacent discharge ports 83 and cutting out a film body 80 at a position where the support body 81 is not provided. In the present embodiment, the discharge port 83 is provided from the proximal portion of the distal tubular portion 31 to the distal portion of the proximal end portion 36. The shape of the discharge port 83 is not particularly limited. However, since the discharge port 83 is provided at the proximal end portion 36 whose diameter decreases toward the proximal side, a shape in which the circumferential width decreases toward the proximal side is preferable. The edge of the discharge port 83 is preferably configured with a curve so that the pressure loss is small. The proximal side of the edge of the discharge port 83 may be configured such that the radius of the curve is larger and the pressure loss is smaller than the distal side of the edge of the discharge port 83. The discharge port 83 may be provided only in the proximal tubular portion 32 or may be provided only in the proximal end portion 36.

The intermediate tubular portion 33 is a portion that passes through the inside of the aortic valve V and is in contact with the aortic valve V (see FIG. 5). The intermediate tubular portion 33 is located between the distal tubular portion 31 and the proximal tubular portion 32. The intermediate tubular portion 33 has a substantially constant inner diameter and outer diameter along the axial direction. The inner and outer diameters of the intermediate tubular portion 33 are smaller than the inner and outer diameters of the distal tubular portion 31 and the proximal tubular portion 32. The flow path inside the intermediate tubular portion 33 circulates the blood flowing from the distal tubular portion 31 to the proximal tubular portion 32. The minimum total channel area (the cross-sectional area of the inner diameter at the position where the inner diameter is minimum) inside the intermediate tubular portion 33 is smaller than the total channel area of the discharge port 83 (the total area of the plurality of discharge ports 83). Further, the minimum total channel area inside the intermediate tubular portion 33 is smaller than the total channel area of the inlet 82 (the cross-sectional area of the inner diameter of the inlet 82).

The distal change portion 34 has an outer diameter and an inner diameter that are tapered from the distal tubular portion 31 toward the intermediate tubular portion 33, and smoothly connects the distal tubular portion 31 and the intermediate tubular portion 33. Since the inner diameter of the distal change portion 34 decreases in a tapered manner toward the proximal side, the flow rate of blood flowing toward the proximal side can be increased while minimizing the pressure loss. Further, since the outer diameter and the inner diameter of the distal change portion 34 change in a taper shape, the distal change portion 34 can be easily expanded and contracted in the radial direction as compared with a case where the distal change portion 34 changes in a step shape. It is. Note that the outer diameter and the inner diameter of the distal change portion 34 may change stepwise. The outer peripheral surface of the distal change portion 34 can contact the aortic valve V located outside the intermediate tubular portion 33. For this reason, the distal change portion 34 has a structure that hardly moves to the ascending aorta A beyond the aortic valve V. Thus, the distal change 34 serves to hold the cannula 30 in place. Further, as shown in FIG. 6, even when the catheter pump 10 is moved in the proximal direction by the flow of blood, the outer peripheral surface of the distal change portion 34 is on the central axis side of the distal surface of the aortic valve V. Touch along. At this time, since the diameter of the distal change portion 34 is changed, the contact area between the distal change portion 34 and the aortic valve V is large, and the backflow of blood can be restricted.

The intermediate changing portion 35 has an outer diameter and an inner diameter that increase in a tapered shape from the intermediate tubular portion 33 toward the proximal tubular portion 32, and smoothly connects the intermediate tubular portion 33 and the proximal tubular portion 32. Since the inner diameter of the intermediate change portion 35 increases in a tapered shape along the axial direction, the flow rate of blood flowing toward the proximal side can be reduced while minimizing the pressure loss. Further, since the outer diameter and the inner diameter of the intermediate change portion 35 change in a taper shape, the intermediate change portion 35 can be easily expanded and contracted in the radial direction as compared with a case where the intermediate change portion 35 changes in a step shape. . In addition, the outer diameter and inner diameter of the intermediate change portion 35 may change in a step shape. The outer peripheral surface of the intermediate change part 35 can contact the aortic valve V located outside the intermediate tubular part 33. For this reason, the intermediate changing portion 35 has a structure that is difficult to move to the left atrium H beyond the aortic valve V. Accordingly, the intermediate changing portion 35 serves to hold the cannula 30 in an appropriate position. Therefore, it may have a surface marker that can be easily recognized by the ultrasonic probe and a metal marker that can be recognized by the X-ray contrast apparatus so that the intermediate tubular portion 33 is arranged at a more appropriate position. In addition, as shown in FIG. 7, even if the catheter pump 10 moves in the distal direction due to the reaction force received by the impeller 50 discharging blood, the outer peripheral surface of the intermediate change portion 35 is close to the aortic valve V. Since it contacts the central axis side of the distal surface, the radial movement of the aortic valve V can be limited. Further, as shown in FIG. 8, even if the aortic valve V is pushed in the direction (proximal direction) opposite to the opening direction (distal direction) of the aortic valve V, the opening force of the aortic valve V causes the distal direction. The movement of the moving catheter pump 10 can be limited.

The proximal end portion 36 is located closer to the proximal side than the proximal tubular portion 32. The proximal portion of the proximal end portion 36 is fixed to the outer peripheral surface of the distal portion of the shaft body 21. The proximal end portion 36 has an outer diameter and an inner diameter that are tapered from the proximal tubular portion 32 toward the distal portion of the shaft body 21, and smoothly connects the proximal tubular portion 32 and the shaft body 21. Since the outer diameter and inner diameter of the proximal end portion 36 change in a tapered shape, the proximal end portion 36 can be easily expanded and contracted in the radial direction as compared with a case where the proximal end portion 36 changes in a stepped shape. The outer diameter and inner diameter of the proximal end portion 36 may change in a step shape.

The outer diameter of the wire constituting the support 81 is, for example, 0.01 to 1 mm, preferably 0.05 to 0.2 mm. It is desirable that the wire is made of a material having shape memory properties. The constituent material of the support 81 is, for example, a shape memory alloy to which a shape memory effect or superelasticity is imparted by heat treatment, stainless steel, titanium, elastic urethane rubber, fluoro rubber, perprene, silicone or other resin, carbon fiber Etc. are suitable. As the shape memory alloy, Ni—Ti, Cu—Al—Ni, Cu—Zn—Al, rubber metal, or a combination thereof is suitable.

The thickness of the film body 80 is, for example, 0.05 to 1 mm. The constituent material of the film body 80 is preferably a stretchable material such as silicone resin or latex, or a resin material such as polyethylene terephthalate or urethane.

The axial length L1 of the distal tubular portion 31 is a length that can be accommodated in the left ventricle H, and is, for example, 5 to 150 mm, and preferably 20 to 80 mm. The length L2 in the axial direction of the intermediate tubular portion 33 is preferably a length that can pass through the aortic valve V, for example, 0.5 to 30 mm, and more preferably 3 to 15 mm. The axial length L3 of the proximal tubular portion 32 is a length that can be accommodated in the ascending aorta A, and is, for example, 3 to 30 mm, and preferably 5 to 15 mm. The overall length of the cannula 30 in the axial direction is, for example, 15 to 210 mm.

The outer diameter D1 of the distal tubular portion 31 is an outer diameter that can pass through the aortic valve V at least in a contracted state, and is preferably 0.2 to 20 mm when contracted and 5 to 50 mm when expanded, for example. The outer diameter D2 of the intermediate tubular portion 33 is an outer diameter that can pass through the aortic valve V in a contracted state, and is preferably 0.2 to 20 mm when contracted, and 4 to 30 mm when expanded. The outer diameter D3 of the proximal tubular portion 32 is an outer diameter that can be disposed in the ascending aorta A, and is preferably 0.2 to 20 mm when contracted and 5 to 45 mm when expanded, for example.

The tip tube 70 is a tube body into which a guide wire can be inserted into the lumen 43. The proximal portion of the tip tube 70 is straight and connected to the connecting wire 75. The distal portion of the tip tube 70 is curved. The tip tube 70 is located on the distal side of the distal tubular portion 31. The axial center of the proximal portion of the tip tube 70 is located on the extension line of the axial center of the distal tubular portion 31. The axis of the proximal portion of the tip tube 70 may be on an extension line of the edge of the distal tubular portion 31. The tip tube 70 may be disposed on the outer sheath 60 or the wall surface of the distal tubular portion 31. When the guide wire is inserted into the lumen 43, the distal portion of the tip tube 70 can be elastically deformed by the rigidity of the guide wire and can be extended linearly. When the guide wire is pulled out from the tip tube 70, the distal portion of the tip tube 70 returns to the original curved state by its own elastic force. For this reason, the sharp tip part of the tip tube 70 becomes difficult to contact a biological tissue, and safety can be ensured.

The connecting wire 75 is a plurality of wires (four in this embodiment) that connect the distal end of the distal tubular portion 31 and the proximal end of the tip tube 70. The plurality of connecting wires 75 are arranged evenly in the circumferential direction of the distal tubular portion 31. The connecting wire 75 can use the same wire as the wire used for the support 81 described above. The connecting wire 75 may be made of a material different from that of the support 81.

The impeller 50 is located inside the proximal tubular portion 32 of the cannula 30. The impeller 50 can be elastically deformed so as to contract in the radial direction or the axial direction, and can return to its original shape by its own elastic force. The impeller 50 is, for example, a centrifugal impeller fixed to the distal portion of the drive shaft 40. The centrifugal impeller is an impeller 50 used for a centrifugal pump. The centrifugal impeller is arranged between two rotating plates 51 that are arranged apart from each other in the rotation axis direction, and is rotated between the rotating plates 51 so that fluid flows radially outward. And a centrifugal blade 52 (blade) for extruding. A suction port 53, which is an opening for taking in fluid between the two rotation plates 51, is provided on the center side of the distal rotation plate 51, and a discharge port 54 that discharges fluid to the outside in the radial direction of the centrifugal blade 52. Is provided. If the fluid is pushed out toward the discharge port 83, the impeller 50 is not limited to the centrifugal pump, and may be, for example, a mixed flow type pump or an axial flow type pump.

The discharge port 83 provided in the proximal tubular portion 32 and the proximal end portion 36 is located on the radially outer side (discharge direction) of the impeller 50. For this reason, the blood discharged from the impeller 50 is effectively discharged from the discharge port 83 to the outside of the cannula 30. The impeller 50 may not be directly fixed to the drive shaft 40. For example, a cylindrical rotary shaft may be fixed to the center of the impeller 50, and the drive shaft 40 may be fixed to the rotary shaft.

The flow rate of blood discharged from the impeller 50 is, for example, 0.1 to 8 Lpm (L / min) under heartbeat. The rotation speed of the impeller 50 is preferably set so as to obtain a desired flow rate, and is set within a range of 10 to 50000 rpm, for example.

The constituent material of the impeller 50 is not particularly limited as long as it is elastically deformed and has a rigidity sufficient to exhibit the function as the impeller, but the same material as the film body 80 and the support body 81 can be used. Resins such as urethane rubber, fluororubber, and silicone are suitable.

The outer sheath 60 is branched from the outer sheath main body 61, which is a tube having a second lumen 62 therein, a second hub 63 provided on the proximal side of the outer sheath main body 61, and the second hub 63. And a port 64 communicating with the lumen 62. A three-way cock 65 is provided at the port 64. The port 64 may be used for injecting a purge solution for reducing blood inflow into the first lumen 23 and the guide wire lumen 42 and friction between the drive shaft 40 and the outer sheath 60. The outer sheath body 61 can accommodate the shaft portion 20 in the second lumen 62. Further, the second lumen 62 can be accommodated while the cannula 30 and the impeller 50 are deformed. At this time, since the distal change portion 34, the intermediate change portion 35, and the proximal end portion 36 are tapered, when the cannula 30 and the impeller 50 are accommodated in the outer sheath body 61, the cannula 30 has the second lumen 62. It is guided smoothly and can be easily accommodated in the second lumen 62. Further, the outer sheath 60 may not be integrated with the outer sheath body 61 but may be inserted through the lumen of the outer sheath body 61. In that case, a port similar to the port 64 may be installed at the proximal end of the outer sheath 60, and the outer sheath body 61 has a function as an introducer sheath.

It is preferable that the inner diameter of the outer sheath body 61 can accommodate the contracted cannula 30 and the impeller 50, for example, 0.3 to 20.1 mm, and more preferably 1 to 10 mm.

Next, for treatment of ischemic heart diseases such as angina pectoris and myocardial infarction, percutaneous coronary angioplasty (PCI: PCI) while assisting cardiac output using the catheter pump 10 according to the present embodiment. A case of performing (Percutaneous Coronary Intervention) will be described as an example. PCI is a treatment technique for expanding a stenosis or occlusion in a coronary artery so as to be expanded by a balloon catheter to restore blood flow.

First, after removing the catheter pump 10 from the package and performing a test operation in water, the cannula 30 and the impeller 50 are accommodated in the outer sheath body 61, and the cannula 30 and the impeller 50 are contracted.

Next, the patient is given local or general anesthesia and an anticoagulant is administered. Next, the introducer sheath is placed in the femoral artery by puncturing the skin by the Seldinger method or the like. The position where the introducer sheath is installed is not limited as long as the catheter pump 10 can be introduced into the left ventricle H. Subsequently, the guide wire 110 is inserted into the femoral artery via the introducer sheath, and reaches the left ventricle H through the descending aorta, the ascending aorta A, and the aortic valve V.

Next, the proximal end portion of the guide wire 110 is inserted into the lumen 43 of the distal tube 70 or the guide wire lumen 42, and the catheter pump 10 is inserted into the introducer sheath along the guide wire 110. Next, the catheter pump 10 is pushed along the guide wire 110 to reach the left ventricle H through the descending aorta, the ascending aorta A, and the aortic valve V as shown in FIG. Thereafter, the guide wire 110 is removed.

Next, the outer sheath 60 is moved to the proximal side while the position of the first hub 22 is maintained. Thereby, the cannula 30 and the impeller 50 are discharged from the distal opening of the outer sheath body 61 into the blood vessel or the heart. As shown in FIGS. 4 and 5, the cannula 30 and the impeller 50 released into the blood vessel or the heart return to the original shape by their own elastic force. At this time, the intermediate tubular portion 33 having a small outer diameter of the cannula 30 is matched with the position of the aortic valve V using an ultrasonic probe or an X-ray device. Thereby, the distal tubular portion 31 having the inflow port 82 is located in the left ventricle H, and the proximal tubular portion 32 having the discharge port 83 is located in the ascending aorta A. The discharge port 83 is located between the aortic valve V and the coronary artery port O. The discharge port 83 may not be located between the aortic valve V and the coronary artery port O. Then, the 1st connection part 41 of the 1st hub 22 is connected with the 2nd connection part 91 of the drive device 90 (refer FIG. 1).

Next, the drive unit 90 is operated by operating the control unit 100. Thereby, the drive shaft 40 rotates and the impeller 50 connected to the drive shaft 40 rotates. As the impeller 50 rotates, a proximal flow occurs within the cannula 30. As a result, blood flows into the cannula 30 from the inlet 82 in the left ventricle H, and blood is discharged into the ascending aorta A from the discharge port 83 in the ascending aorta A. Then, the rotational speed is gradually increased while monitoring the position, flow rate, left intracardiac pressure, aortic pressure, blood pressure, and the like of the cannula 30 and the impeller 50. The positions of the cannula 30 and the impeller 50 can be confirmed by an ultrasonic probe or X-ray contrast. The flow rate of the catheter pump 10 is specified from the number of rotations of the driving device 90 controlled by the control unit 100, the left heart pressure, the aortic pressure, and the like. Left intracardiac pressure, aortic pressure, blood pressure, and the like can be measured by a pulse pressure measuring device, and the pulse pressure measuring device may be provided in the control unit 100. After reaching the desired flow rate or left chamber pressure, the rotational speed is fixed and maintained.

The impeller 50 rotates, and blood sucked from the inlet 82 in the left ventricle H flows into the distal tubular portion 31. Since the inner diameter of the distal tubular portion 31 can be set larger than the inner diameter of the intermediate tubular portion 33 located in the aortic valve V, a large inlet 82 in the left ventricle H can be secured. For this reason, the pressure loss of the blood at the time of inhaling into the inflow port 82 can be reduced as much as possible.

The blood that has entered the distal tubular portion 31 from the inlet 82 flows through the distal changing portion 34 to the intermediate tubular portion 33. The inner tubular portion 33 has an inner diameter that is smaller than the inner diameter of the distal tubular portion 31. For this reason, when blood reaches the intermediate tubular portion 33 from the distal tubular portion 31, the flow velocity increases. At this time, since the inner diameter of the distal change portion 34 is tapered toward the proximal side, the blood flow velocity can be changed while minimizing the pressure loss.

The blood that has entered the intermediate tubular portion 33 flows through the intermediate changing portion 35 to the proximal tubular portion 32. The inner diameter of the proximal tubular portion 32 is larger than the inner diameter of the intermediate tubular portion 33. For this reason, when the blood reaches the proximal tubular portion 32 from the intermediate tubular portion 33, the flow velocity decreases. At this time, since the inner diameter of the intermediate change portion 35 increases in a tapered shape toward the proximal side, the blood flow velocity can be changed while minimizing the pressure loss.

The blood that has entered the proximal tubular portion 32 is sucked into the rotating impeller 50 and discharged in a radially outward direction or a direction inclined more proximally than the radially outer side. When the distal portion of the impeller 50 is located in the intermediate tubular portion 33 or the intermediate change portion 35, blood can be sucked into the impeller 50 before reaching the proximal tubular portion 32.

The blood discharged from the impeller 50 is discharged to the ascending aorta A through the discharge port 83. At this time, since the edge part of the discharge port 83 is configured by a curve, the pressure loss can be minimized.

The blood discharged from the discharge port 83 is oriented in a radially outward direction or a direction inclined more proximally than the radially outer side. For this reason, blood easily reaches the coronary artery opening O located on the radially outer side of the discharge port 83 or on the proximal side of the discharge port 83. For this reason, being oriented in a radially outward direction or a direction inclined more proximally than the radially outward direction can increase the blood inflow pressure to the coronary artery C and promote inflow.

Next, for percutaneous coronary angioplasty (PCI), a PCI guide wire 111 is inserted into the femoral artery or the radial artery or the like and guided to the ascending aorta A. Next, the guide wire 111 that has reached the ascending aorta A is inserted into the coronary ostium O. At this time, the discharge port 83 of the cannula 30 is provided on the outer peripheral surface inclined with respect to the outer peripheral surface of the proximal tubular portion 32 and the axial center of the proximal end portion 36. That is, the opening direction of the discharge port 83 is inclined with respect to the axial center direction of the cannula 30. For this reason, it can suppress that the guide wire 111 for PCI is accidentally inserted in the discharge port 83, and safety is high.

Next, the balloon catheter 112 is inserted into the coronary artery C along the PCI guide wire 111, the balloon is expanded, and the stenosis part or the obstruction part is pushed and expanded. Thereafter, the balloon is deflated, the balloon catheter 112 is removed, and the PCI guide wire 111 is removed. Thereafter, the operation of the catheter pump 10 is continued as needed to continue assisting cardiac output. The operating time of the catheter pump 10 is, for example, several minutes to several hours.

When stopping the operation of the catheter pump 10, the controller 100 is controlled by the control unit 100, and the rotation of the impeller 50 is gradually stopped. Next, after the catheter pump 10 is moved to the descending aorta, the outer sheath 60 is moved relatively to the distal side with respect to the cannula 30 and the impeller 50. Thereby, the cannula 30 and the impeller 50 are accommodated in the second lumen 62 of the outer sheath body 61 while contracting in the radial direction. Next, the catheter pump 10 is extracted from the blood vessel through the introducer sheath. Thereafter, the introducer sheath is removed from the blood vessel, and the puncture site of the femoral artery is stopped to complete the procedure. In addition, when operating the catheter pump 10 for a long time, by using a peel sheath as the introducer sheath, the sheath can be removed during continuous driving, and infection from the puncture portion can be prevented.

As described above, the catheter pump 10 according to the present embodiment is a pump that is inserted into the heart chamber and assists the flow of blood, and is provided with an inflow port 82 through which blood flows into the distal side and is proximal. A tube body provided with a discharge port 83 through which blood flows out, a cannula 30 that can be contracted and expanded in a radial direction, a long shaft portion 20 to which a proximal portion of the cannula 30 is connected, An impeller 50 that is rotatably disposed therein and generates a blood flow from the inlet 82 to the discharge port 83, and the cannula 30 includes a proximal tubular portion in which the impeller 50 is rotatably disposed. 32, a proximal end portion 36 which is located on the proximal side of the proximal tubular portion 32 and has a portion whose inner diameter decreases toward the proximal side and which is connected to the shaft portion 20, and the proximal tubular portion 32 Distal of The intermediate tubular portion 33 having an inner diameter smaller than that of the proximal tubular portion 32, and the intermediate tubular portion 33 located on the distal side of the intermediate tubular portion 33. A distal tubular portion 31 in which the inlet 82 is located, and the outlet 83 is at least of an outer peripheral surface inclined relative to the outer peripheral surface of the proximal tubular portion 32 and the central axis of the impeller 50 of the proximal end portion 36. Located on one side.

Since the diameter of the intermediate tubular portion 33 is smaller than the diameter of the proximal tubular portion 32, the catheter pump 10 configured as described above can reduce the influence on the heart valve to be inserted. Further, since the inner diameter of the proximal tubular portion 32 is larger than the inner diameter of the intermediate tubular portion 33 and can accommodate the impeller 50 having a high discharge pressure, a sufficient flow rate can be secured even if the inner tubular portion 33 has a small inner diameter. Further, since the discharge port 83 is located on the outer peripheral surface of the proximal tubular portion 32 having a diameter larger than that of the intermediate tubular portion 33 or on the outer peripheral surface inclined with respect to the central axis of the impeller 50 of the proximal end portion 36, blood Is discharged laterally from the discharge port 83. For this reason, the blood discharged to the ascending aorta A can be guided to the coronary artery opening O located on the wall surface of the ascending aorta A, and the inflow of blood into the coronary artery C can be promoted.

The impeller 50 is a centrifugal impeller (or mixed flow impeller). Thereby, compared with the case of an axial-flow type impeller, the high flow volume and high pressure of a fluid can be obtained simultaneously. For this reason, even if a flow path is provided in the intermediate tubular portion 33 whose inner diameter is smaller than that of the proximal tubular portion 32 and it is difficult to secure the flow rate, a desirable flow rate can be secured. Further, the centrifugal impeller (or the mixed flow impeller) can be reasonably disposed without difficulty in correspondence with the shape in which the inner diameter increases from the intermediate tubular portion 33 toward the proximal tubular portion 32. For this reason, it is structurally advantageous as a catheter in which it is desirable to reduce the diameter as much as possible for insertion into a thin blood vessel.

Also, the discharge port 83 is located in the discharge direction of the impeller 50. Thereby, the pressure loss of the blood pressurized by the impeller 50 becomes small, and a high flow rate and a high head can be secured.

Also, the total channel area of the discharge port 83 is larger than the minimum total channel area in the intermediate tubular portion 33. Thereby, the blood that has passed through the intermediate tubular portion 33 having a small total channel area can be discharged as much as possible without loss. Therefore, the flow rate at the discharge port 83 can be ensured as large as possible.

Further, the distal tubular portion 31 has an inner diameter larger than that of the intermediate tubular portion 33. The total channel area of the inflow port 82 is larger than the minimum total channel area in the intermediate tubular portion 33. As a result, the pressure loss can be reduced, a sufficient amount of blood can be supplied to the intermediate tubular portion 33 having a small total channel area, and the flow rate can be secured as high as possible.

The present invention also includes a treatment method (therapeutic method) for assisting blood flow by inserting the catheter pump 10 into the heart chamber. In this treatment method, the catheter pump 10 is inserted into the blood vessel, the distal tubular portion 31 is disposed in the left ventricle H, the intermediate tubular portion 33 is disposed at a position in contact with the aortic valve V, and the proximal tubular portion 32 is ascending. And a step of rotating the impeller 50 to suck blood in the left ventricle H from the inflow port 82 into the cannula 30 and discharge from the discharge port 83 into the ascending aorta A.

The treatment method configured as described above can reduce the influence on the aortic valve V because the diameter of the intermediate tubular portion 33 in contact with the aortic valve V is smaller than the diameter of the proximal tubular portion 32. Moreover, since the inner diameter of the proximal tubular portion 32 arranged in the ascending aorta A is larger than the inner diameter of the intermediate tubular portion 33 and can accommodate the impeller 50 having a high discharge pressure, it is sufficient even if the inner tubular portion 33 has a small inner diameter. Secures a high flow rate.

Further, in the step of rotating the impeller 50 to discharge blood into the ascending aorta A from the discharge port 83, the treatment method is less than 90 degrees from the discharge port 83 in the radial direction of the impeller 50 or from the radial direction to the proximal side. Releases blood in a direction inclined at an angle. Thereby, the inflow of blood into the coronary artery C can be promoted via the coronary artery O located on the wall surface of the ascending aorta A.

The treatment method further includes a step of inserting the guide wire 111 (long body) into the coronary artery C while rotating the impeller 50 to discharge blood from the discharge port 83 into the ascending aorta A. The discharge port 83 of the catheter pump 10 is located on the outer peripheral surface of the proximal tubular portion 32 or the outer peripheral surface inclined with respect to the central axis of the impeller 50 of the proximal end portion 36. Therefore, it becomes difficult for the guide wire 111 to erroneously enter the cannula 30 from the discharge port 83, and safety is improved.

Note that the present invention is not limited to the above-described embodiment, and various modifications can be made by those skilled in the art within the technical idea of the present invention. For example, the form of the discharge port is not particularly limited as long as blood can be discharged. For example, as in the first modification shown in FIG. 9A, the discharge port 121 may be a triangle having a corner on the proximal side. In the following, parts having the same functions as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted. Further, as in the second modification shown in FIG. 9B, the discharge ports 122 may be provided in a plurality of rows (two rows in the figure) in the axial direction. Moreover, the discharge port 123 may be provided only in the proximal end portion 36 without being provided in the proximal tubular portion 32 as in the third modified example illustrated in FIG.

Further, the shape of the distal tubular portion and the inlet is not particularly limited. For example, as in the first modification shown in FIG. 9A, in addition to the inflow port 82, the inflow ports 124 penetrating from the inner peripheral surface to the outer peripheral surface are arranged in the circumferential direction on the side surface of the distal tubular portion 31. May be provided. The inflow port 124 has a quadrangular shape, but the shape is not particularly limited. 9B, in addition to the inflow port 82, the side surface of the distal tubular portion 31 is provided with an inflow port 125 penetrating from the inner peripheral surface to the outer peripheral surface. Also good. The inflow ports 125 may be arranged in a circumferential direction and provided in a plurality of rows in the axial direction. Further, as in the third modification shown in FIG. 9C, the distal tubular portion 126 is not provided with an inflow port at the distal end, and penetrates from the inner peripheral surface to the outer peripheral surface on the side surface. An inflow port 127 may be provided.

Further, as in the fourth modification shown in FIG. 10A, the inner diameter and the outer diameter of the cannula 130 may be tapered from the distal tubular portion 132 toward the intermediate tubular portion 131. 10B, the inner diameter and the outer diameter of the distal tubular portion 141 of the cannula 140 may be tapered toward the proximal side. 10C, the length of the intermediate tubular portion 151 of the cannula 150 in the axial direction may be as short as the operating range of the aortic valve V. In the sixth modification shown in FIG. This makes it difficult for the cannula 150 to move in the axial direction within the blood vessel, so that an appropriate position can be more maintained.

Further, as in the seventh modification shown in FIG. 11A, the discharge port 163 of the proximal tubular portion 161 is configured by only the support 81 by removing the film body 162 of the proximal tubular portion 161. May be. Further, as in the eighth modification shown in FIG. 11B, the discharge port 173 of the proximal tubular portion 171 is configured by cutting out the membrane body 172 and the support body 174 of the proximal tubular portion 171 together. May be.

Further, as in the ninth modification shown in FIG. 12A, the support 181 may be a helical wire. Further, as in the tenth modification shown in FIG. 12B, the support body 191 may be configured by arranging a plurality of ring bodies 192 that are folded back in a wave shape in the axial direction. Adjacent ring bodies 192 may be connected or not connected.

Further, as in the eleventh modification shown in FIG. 13, the impeller 200 may be a mixed flow type impeller. The proximal end 202 of the blade 201 of the impeller 200 is located distal to the proximal end 206 of the discharge port 205. Further, the distal end 203 of the blade 201 of the impeller 200 is located on the distal side of the distal end 207 of the discharge port 205. For this reason, the blood discharged from the impeller 200 while being inclined can be efficiently discharged from the discharge port 205.

Further, as in the twelfth modification shown in FIG. 14, the proximal end 202 of the blade 201 of the mixed flow type impeller 200 may be located more distally than the distal end 211 of the discharge port 210. . Even with such a configuration, blood discharged from the impeller 200 at an inclination can be efficiently discharged from the discharge port 215.

Further, as in the thirteenth modification shown in FIG. 15, the discharge port 220 is not provided in the proximal tubular portion 32, but is inclined to the proximal end portion 36 located on the proximal side of the proximal tubular portion 32. It may be provided only in. Further, the impeller 200 is a mixed flow type. Thereby, the blood discharged from the impeller 200 while being inclined is efficiently discharged from the discharge port 220 of the proximal end portion 36 substantially perpendicular to the discharge direction. In addition, since the space on the proximal side of the discharge port 220 inside the cannula 30 becomes smaller, it becomes difficult to generate vortices, and the pressure loss can be further reduced.

Further, as in the fourteenth modification shown in FIG. 16, the discharge port 230 may be provided in the proximal tubular portion 32 and the proximal end portion 36. Further, the impeller 200 is a mixed flow type. Thereby, blood discharged from the impeller 200 while being inclined is efficiently discharged from the discharge port 230 provided in both the proximal tubular portion 32 and the proximal end portion 36. Further, since the space closer to the discharge port 230 inside the cannula 30 becomes smaller, vortices are less likely to be generated, and pressure loss can be further reduced.

Further, as in the fifteenth modification shown in FIG. 17A, a plurality of impellers 240 may be provided in the axial direction. In this case, a control plate 241 for controlling the blood flow may be provided between the two impellers 240. As the constituent material of the control plate 241, the same material as that of the film body 80 can be used. Further, as in the sixteenth modification shown in FIG. 17B, the impeller 250 may be an axial flow type impeller.

Further, as in the seventeenth modification shown in FIG. 18, the impeller 50 may be rotationally driven by a motor 260 disposed inside the shaft body 21. In this case, a drive shaft for transmitting a driving force from the outside is not provided, and a cable 261 for transmitting power to the motor 260 is installed inside the shaft body 21.

Further, as in the eighteenth modification shown in FIG. 19, an adjustment plate 270 for adjusting the direction of blood flow may be provided around the discharge port 83 outside or inside the proximal tubular portion 32. . By providing the adjustment plate 270, the direction of blood flow is adjusted, and pressure loss is reduced. The adjustment plate 270 is fixed to the film body 80 or the support body 81. As the constituent material of the adjustment plate 270, the same material as that of the film body 80, the support body 81, or the impeller 50 can be used.

Further, the catheter pump 10 may have a marker made of an X-ray contrast material at any position.

Furthermore, this application is based on Japanese Patent Application No. 2016-55196 filed on Mar. 18, 2016, the disclosures of which are referenced and incorporated as a whole.

10 catheter pump,
20 shaft part,
21 Shaft body,
30, 130, 140, 150 cannula,
31, 126, 132, 141 distal tubular section,
32, 161, 171 proximal tubular section,
33, 131, 151 Intermediate tubular part,
34 Distal change,
35 Intermediate change part,
36 proximal end,
40 drive shaft,
42 Guidewire lumen,
50, 200, 240, 250 impeller,
52 Centrifugal blade (blade),
60 outer sheath,
61 outer sheath body,
80, 162, 172 film body,
81, 174, 181, 191 support,
82, 124, 125, 127 inlet,
83, 121, 122, 123, 163, 173, 205, 210, 220, 230 outlet,
90 drive device,
93, 260 motor,
111 guide wire (long body),
112 balloon catheter,
201 feathers,
202 proximal end of the wing,
203 distal end of the vane,
206 proximal end of the outlet,
207, 211 The distal end of the outlet,
270 adjustment plate,
D1 the outer diameter of the distal tubular section,
D2 outer diameter of the intermediate tubular part,
D3 the outer diameter of the proximal tubular section,
A Ascending aorta,
C coronary artery,
H Left ventricle,
O coronary artery orifice,
V Aortic valve.

Claims

A catheter pump that is inserted into the heart chamber to assist the flow of blood,
A cannula that is provided with an inflow port through which blood flows in on the distal side and a discharge port through which blood flows out on the proximal side and can be contracted and expanded in a radial direction;
An elongated shaft portion to which the proximal portion of the cannula is coupled;
An impeller rotatably disposed within the cannula and creating a flow of blood from the inlet toward the outlet;
The cannula includes a proximal tubular portion having an impeller rotatably disposed therein;
A proximal end portion that is located on the proximal side of the proximal tubular portion and has a portion that decreases in inner diameter toward the proximal side and is connected to the shaft portion;
An intermediate tubular portion located on the distal side of the proximal tubular portion, communicating with the proximal tubular portion, having a smaller inner diameter than the proximal tubular portion;
A distal tubular portion located distal to the intermediate tubular portion, communicating with the intermediate tubular portion, and wherein the inflow port is located;
The discharge port is a catheter pump located on at least one of an outer peripheral surface of the proximal tubular portion and an outer peripheral surface inclined with respect to a central axis of the impeller at the proximal end portion.
The catheter pump according to claim 1, wherein the impeller is a centrifugal impeller or a mixed flow impeller.
The catheter pump according to claim 1 or 2, wherein the discharge port is located in a discharge direction of the impeller.
The proximal end of the impeller blade is located distal to the proximal end of the outlet;
The catheter pump according to any one of claims 1 to 3, wherein a distal end of the impeller blade is located on a more distal side than a distal end of the discharge port.
The catheter pump according to any one of claims 1 to 4, wherein the impeller is a mixed flow type impeller, and the discharge port is located closer to the proximal side than the proximal tubular portion.
The catheter pump according to any one of claims 1 to 5, further comprising a control plate for controlling a discharge direction of the impeller.
A treatment method for assisting blood flow by inserting the catheter pump according to claim 1 into a heart chamber,
Inserting the catheter pump into a blood vessel, placing the distal tubular portion in the left ventricle, placing the intermediate tubular portion in contact with the aortic valve, and placing the proximal tubular portion in the ascending aorta;
And rotating the impeller to suck blood from the left ventricle into the cannula from the inlet and release it from the outlet into the ascending aorta.
In the step of rotating the impeller to discharge blood from the discharge port into the ascending aorta, the blood is discharged from the discharge port in the radial direction of the impeller or in a direction inclined at an angle of less than 90 degrees from the radial direction to the proximal side. The treatment method according to claim 7, which is released.
The treatment method according to claim 7 or 8, further comprising a step of inserting a long body into the coronary artery while rotating the impeller to discharge blood from the discharge port into the ascending aorta.