JP3597066B2 - Ultrasound catheter - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to an ultrasonic catheter used for displaying a cross-sectional image of a blood vessel, for example, by inserting it into a body cavity of a blood vessel, a blood vessel, a digestive tract, or the like, and particularly using a guide wire in the body cavity. It can be inserted into
[0002]
[Prior art]
As a treatment for a vascular stenosis causing a myocardial infarction or the like, a surgical technique of performing a percutaneous treatment using a catheter has been performed. This surgical technique includes a method of pushing and expanding a stenosis with a dilatation catheter having a balloon at the tip, a method of placing a metal tube called a stent, and a method of rotating a grindstone or a cutter with a device called a rotablator (trademark) to remove the stenosis. There are various methods such as a resection method, and a preferable method is selected according to the properties of the stenosis and the condition of the patient. Ultrasound catheters are mainly used during percutaneous treatment of such vascular stenosis, observing the properties of the stenosis, and used as an aid in making decisions for the selection of treatment means. It is also used for observations. Therefore, the ultrasonic catheter is required to be able to pass through a stenosis part of the blood vessel.
[0003]
Such an ultrasonic catheter is provided with an ultrasonic vibrator or an ultrasonic reflecting mirror rotatably at a distal end of an insertion portion, and after being inserted into a body cavity, through a drive shaft or the like extending from a drive portion on the hand side. Scanning (radial scanning) while rotating is common. In this type of ultrasonic catheter, an ultrasonic transducer or a mirror is provided near the distal end of a tubular main body, and a drive shaft having a distal end connected to the ultrasonic transducer or a mirror and a tubular main body surrounding the drive shaft are close to the hand. To the drive unit or a connector unit connected to the drive unit.
[0004]
In addition, the ultrasound transmission medium is filled around the ultrasound transducer and / or the mirror in the tube body. The ultrasonic transmission medium is for efficiently transmitting the ultrasonic beam, and is sealed in a manufacturing stage or injected by an operator immediately before insertion into a body cavity. Here, those that are sealed at the manufacturing stage are preferable in that there is no need to inject before use, but those that have a small diameter and a thin wall to be inserted into a blood vessel are sterilized by the presence of a liquid inside. The catheter may be broken during the process, which is technically difficult. Therefore, an injection hole for an ultrasonic transmission medium is provided at the base end of the ultrasonic catheter, and physiological saline is injected (primed) as an ultrasonic transmission medium before the operation, and air bubbles adhere to the transducer surface during use. In general, an ultrasonic catheter of a type in which air bubbles are removed by injecting (flushing) physiological saline at a high pressure from a base end is generally used. Such an ultrasonic catheter preferably has a discharge hole for an ultrasonic transmission medium at its tip in order to improve the efficiency of flushing.
[0005]
Meanwhile, in order to insert the ultrasound catheter bile duct, pancreatic duct, a narrow lumen of a blood vessel or the like safely and easily by inserting a guide wire first, there is an ultrasound catheter so as to be inserted therealong. Therefore, a tube (lumen) through which a guidewire is inserted is formed at the distal end of such an ultrasonic catheter. Examples of the ultrasonic probe having the guide wire lumen include those disclosed in JP-A-10-80425 and JP-T-10-500584.
[0006]
Such a known ultrasonic catheter has a guide wire lumen formed only at the distal end of the catheter tube main body. As described above, the catheter provided with the guide wire lumen only at the distal end is used when the ultrasonic catheter is replaced with another catheter such as a therapeutic dilatation catheter while maintaining the guide wire in the blood vessel. Only the catheter can be removed and a new catheter can be inserted along the indwelling guidewire. Such a catheter is generally referred to as an RX (rapid exchange) type catheter.
[0007]
[Problems to be solved by the invention]
Since such an ultrasonic catheter pushes a narrow blood vessel along a fixed guide wire, a large load is generated at the root of the guide wire lumen, that is, at the tip of the main body of the ultrasonic catheter. In addition, since the discharge hole for flushing needs to be provided at the position of the tip end of the ultrasonic vibrator, the hole is provided at the position where the most burden is imposed, and there is a possibility that the hole may be bent.
[0008]
In addition, since the flow of blood tends to stagnate in the guide wire lumen, blood coagulation is likely to occur. When coagulation occurs, the slidability between the guide wire and the inner wall of the guide wire lumen decreases, and the operability of the ultrasonic catheter deteriorates. Further, when the catheter is pushed forward so as to pass through a tightly bent portion in the blood vessel in a state where the sliding property between the inner wall of the guide wire lumen and the guide wire is reduced, the above-described guide wire for the guide wire is used. There is a possibility that the root of the lumen may be bent (kinked).
[0009]
The present invention has been made in view of such problems, and prevents a decrease in strength of an ultrasonic catheter due to a discharge hole for flushing, and enhances the slidability of a guide wire lumen inner wall, It is an object of the present invention to provide an ultrasonic catheter to which a thrombus hardly adheres and which is easy to remove even if it adheres.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a long tubular main body to be inserted into a body cavity or a lumen, an ultrasonic vibrator provided in a lumen of the main body, and a distal end portion of the main body. In an ultrasonic catheter having a provided guide wire conduit, the guide wire conduit has a guide wire port provided at a distal end position of the ultrasonic vibrator and a most distal end position of the ultrasonic catheter. An ultrasonic catheter, further comprising a passage extending so as to have a passage communicating with the inside of the lumen of the main body and the inner wall of the conduit for the guide wire.
[0011]
In addition, it is preferable that a reinforcing member for firmly joining and supporting the guide wire channel is provided at a distal end in the lumen of the main body, and the passage communicates with the inside of the reinforcing member.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0013]
FIG. 1 is a side view showing an ultrasonic catheter according to the present invention.
[0014]
FIG. 2 is a partial cross-sectional view of the distal end portion of the ultrasonic catheter according to the embodiment shown in FIG.
[0015]
FIG. 3 is a schematic configuration diagram for explaining the overall configuration of the ultrasonic catheter system according to the present invention.
[0016]
In FIG. 1, an ultrasonic catheter 1 comprises a catheter sheath 2 which is a tubular main body inserted into a body cavity or a lumen, and a connector 3 for connecting to an external drive source 30 (FIG. 3). Consists of a sheath connector 3a connected to the catheter sheath 2 and a drive shaft connector 3b connected to an ultrasonic transducer via a drive shaft described later. The distal end of the catheter sheath 2 is provided with a guide wire lumen (pipe) 15. The sheath connector 3a is provided with a flushing port 5, which is plugged except when flushing is performed. The drive shaft connector 3b is provided with a confirmation port 6 for confirming the end of priming, which is also usually plugged.
[0017]
The catheter sheath 2 has a multilayer structure of a resin such as polyimide, polyamide, polyester, polyethylene, polyurethane, and the like. A metal sheath is formed between the resin layers at the base end from the position where the ultrasonic transducer exists in the lumen. A reinforcing body such as a braid or a flat coil is provided.
[0018]
In FIG. 2, reference numeral 10 denotes a drive shaft formed of a densely wound coil of a metal wire such as stainless steel. Inside the drive shaft, a signal line (not shown) is connected to the ultrasonic vibrator 13 and extends to the connector 3. A cylindrical housing 11 is fixed to the tip of the drive shaft 10. An opening 12 is provided in a side wall of the housing 11, and an ultrasonic transducer 13 connected to the above-described signal line is fixed inside the opening 12. A coil 14 is further provided at the tip of the housing 11. The coil 14 improves the rotational stability of the drive shaft 10 and the ultrasonic oscillator 13, prevents bending (kinking) at the distal end portion of the catheter sheath 2, and fixes the ultrasonic oscillator 13 with the catheter sheath 2 fixed. When the is moved in the axial direction, the housing can be prevented from contacting the catheter sheath 2. The housing 11, the drive shaft 10 and the coil 14 are fixed with a fixing material 23 such as solder.
[0019]
The housing 11 is made of a ceramic material such as alumina or zirconia, or a metal material such as stainless steel (SUS304), and has an outer diameter substantially equal to that of the drive shaft 10 in order to reduce sliding resistance with the inside of the catheter sheath 2. Consists of a cylindrical pipe. The ultrasonic transducer 13 is formed by forming electrodes on both sides of a rectangular or circular piezoelectric material made of PZT or the like by vapor deposition, printing, or the like. The installation position of the ultrasonic vibrator 13 is such that the center of gravity of the housing 11 in a state where the ultrasonic vibrator 13 and the back material (not shown) are incorporated is near the center in the rotation axis direction so that the drive shaft 10 does not cause uneven rotation. It is installed in such a position.
[0020]
Reference numeral 15 denotes a guide wire lumen provided at the distal end of the catheter sheath 2. The guide wire lumen 15 extends between a guide wire insertion port 16 provided at a more distal position than the ultrasonic transducer 13 and a guide wire outlet 17 at the most distal position of the ultrasonic catheter 1. 2 is made of a resin-made tubular member 18 having a length of about 20 to 30 mm adhered to the distal end.
[0021]
An opening 20 of a passage 19 communicating with the lumen of the catheter sheath is provided on the inner wall of the guide wire lumen 15. The passage 19 is formed so as to pass through the center of the reinforcing member 21 provided at the distal end of the lumen of the catheter sheath 2.
[0022]
Reference numeral 22 denotes an X-ray opaque marker for confirming the position of the distal end of the ultrasound catheter 1 under X-ray fluoroscopy when inserted into a body cavity, and is composed of a metal coil having high X-ray opacity such as Pt, Au, and Ir. Is done.
[0023]
Next, a method of joining the tubular member 18 to the catheter sheath 2 will be described. First, the reinforcing member 21 made of a heat-fusible material is inserted into the inside of the distal end side of the catheter sheath 2, and then the tubular member 18 is inserted from the distal end side of the catheter sheath 2 to penetrate the side wall of the catheter sheath 2. With the distal end side of the reinforcing member 21 in contact with the base of the tubular member 18, hot air is applied from above the catheter sheath 2 using a hot air heater or the like to heat the catheter sheath 2, the tubular member 18, and the reinforcing member 21. We fuse. Here, an opening and a passage are provided in advance in the tubular member 18 and the reinforcing member 21, and when fusion is performed, the tubular member 18 and the reinforcing member 21 pass through the opening 20 from the distal end opening (guide wire outlet 17) and into the catheter sheath 2. Then, a stainless steel wire or a flat plate is inserted into an opening and a passage provided in advance, and after the reinforcing member 21 which is a heat-fusible material is hardened, the stainless wire or the like is pulled out, thereby forming the passage 19. Secure.
[0024]
As described above, since the tubular member 18 is firmly joined to and supported by the catheter sheath 2 by the reinforcing member 21, the bending resistance at the joint (base) of the tubular member 18 is enhanced.
[0025]
Since the passage 19 communicates with the inner wall of the conduit of the guide wire lumen 15 via the reinforcing member 21, the strength of the distal end portion of the catheter sheath 2 does not decrease. The priming operation is performed via the passage 19. When the injection is performed from the distal end of the ultrasonic catheter 1, the fluid pressure near the ultrasonic vibrator 13 installed at the distal end increases, and air bubbles hardly adhere to the surface of the ultrasonic vibrator 13. Specifically, in the priming operation, the ultrasonic catheter 1 is housed in a dedicated holder (not shown) before the operation, and reaches the confirmation port 6 provided at the rear end through the opening 20 from the guide wire outlet 17. An ultrasound transmission medium, such as saline, is injected into the catheter until the injection is completed. Further, during the operation, flushing is performed from the flushing port 5, and physiological saline or the like can be discharged from the inside of the catheter to the inside of the tubular member 18 through the opening 20.
[0026]
The external drive source 30 in FIG. 3 has a built-in motor and drives the ultrasonic vibrator 13 to rotate via the drive shaft 10. The ultrasonic transducer 13 is also electrically connected to a signal line extending inside the drive shaft 10, and transmission / reception signals of ultrasonic waves are transmitted to the ultrasonic diagnostic apparatus 31. The ultrasonic diagnostic apparatus 31 displays a cross-sectional image of the inside of the body cavity on the display unit 32, and adjustment of the image and control of the driving device are performed by the operation panel 33. The obtained image is recorded by the image recording device 34.
[0027]
FIG. 4 is a side sectional view illustrating the structure of the proximal end portion of the ultrasonic catheter 1 according to the present invention. In FIG. 4, the drive shaft connector 3 b is connected to the proximal end side of the drive shaft 10, and can move the ultrasonic transducer 13 toward the hand side relatively to the catheter sheath 2. The drive shaft connector 3b includes a guide tube 40 that can slide inside the sheath connector 3a while covering a predetermined portion of the base end of the drive shaft 10. The guide tube 40 is for preventing the base end portion of the drive shaft 10 from being exposed to the outside when the drive shaft 10 is pulled. The guide tube 40 has an inflatable portion 41 at the tip end thereof, and the guide tube from the sheath connector 3a. 40 is prevented from falling off.
[0028]
The sheath connector 3a is connected to the rear end of the catheter sheath 2 at a connection port 42, and has an O-ring-shaped seal for maintaining airtightness between the sheath connector 3a and a drive shaft connector 3b inserted into the sheath connector 3a. The seal member 43 is provided with a member 43 and a screw portion 44, and the screw member 44 and the screw mechanism provided on the pusher 45 are connected to each other to hold the seal member 43.
[0029]
The base end of the drive shaft connector 3b is detachable from the external drive source 30, and the rotation terminal 46 rotates together with the drive shaft 10 in engagement with the motor drive device. 47 is a signal line.
[0030]
The scanning of the ultrasonic wave in the ultrasonic catheter 1 of the present invention is performed by transmitting the rotational motion of the motor in the external drive source 30 to the drive shaft 10 and rotating the housing 11 fixed to the tip of the drive shaft 10. This is performed by scanning the ultrasonic waves transmitted and received by the ultrasonic transducer 13 provided in the housing 11 in a substantially radial direction. The ultrasound image obtained here is a transverse cross-sectional image inside the blood vessel. Further, by pulling the entire ultrasound catheter 1 or the drive shaft connector 3b toward the hand side and moving the drive shaft 5 in the longitudinal direction, a 360 ° cross-sectional image of the surrounding tissue body spaced apart in the axial direction in the blood vessel is obtained. Can be obtained by scanning to an arbitrary position.
[0031]
Next, the operation of the ultrasonic catheter of the present invention will be described. FIG. 5 is a diagram showing a state in which the ultrasonic catheter 1 of the present invention is inserted into a blood vessel, the distal end portion passes through a blood vessel having a sharp bend, and an ultrasonic scan is performed. Here, the guide wire 50 is fixed, and the ultrasonic catheter 1 in which the guide wire 50 is inserted into the guide wire lumen 15 is pushed forward from outside the body cavity. As described above, when the ultrasonic catheter 1 advances in the bent blood vessel, the stress is most concentrated on the root portion 51 of the tubular member 18 forming the guide wire lumen 15. The attaching portion 51 is a portion where the ultrasonic transducer and the drive shaft do not exist inside, and is a portion where the mechanical strength is weakest in the ultrasonic catheter 1 due to its structure. Since no opening for priming or flushing is provided and a reinforcing member is provided, bending rigidity is improved, and kink (bending) is prevented.
[0032]
Also, when the movement of the ultrasonic catheter 1 is relatively small, for example, when performing a diagnosis in a blood vessel relatively slowly and in detail, the blood flow in the lumen of the guide wire lumen 15 is stagnant, and a partial coagulation of blood occurs. Tends to occur. In such a case, the slidability between the surface of the guidewire 50 and the inner surface of the guidewire lumen 15 decreases, and the operability of the ultrasonic catheter 1 deteriorates. When the ultrasonic catheter 1 is pushed in such a state in which the slidability is reduced, the stress applied to the base portion 51 further increases. In such a case, the priming liquid (saline) flows into the lumen of the tubular member 18 through the passage 19 by performing flushing from the flushing port 5 provided on the connector 3 at the rear end of the ultrasonic catheter 1. Therefore, the sliding property between the tubular member 18 and the guide wire 50 can be improved by the hydrophilic coating on the surface of the guide wire 50.
[0033]
It should be noted that the embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.
[0034]
【The invention's effect】
As described above, according to the ultrasonic catheter of the present invention, a kink occurs at the base of the guide wire lumen of the catheter sheath even when the distal end portion passes through a tightly bent blood vessel during catheter operation. In addition, a path for priming and / or flushing can be formed, and even if the slidability with a guide wire is reduced, the slidability can be improved while being inserted into a blood vessel, and the operator can be improved. Discomfort and fatigue can be reduced.
[Brief description of the drawings]
FIG. 1 is a side view showing an ultrasonic catheter according to the present invention.
FIG. 2 is a partial cross-sectional view of a distal end portion of the ultrasonic catheter according to the present invention.
FIG. 3 is a diagram illustrating an overall system configuration of an ultrasonic catheter according to the present invention.
FIG. 4 is a cross-sectional side view of a proximal portion of the ultrasonic catheter according to the present invention.
FIG. 5 is a view showing a state in which the ultrasonic catheter according to the present invention is inserted into a blood vessel having a sharp bend.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Ultrasonic catheter 2 ... Catheter sheath 3 ... Connector 10 ... Drive shaft 11 ... Housing 12 ... Opening 13 ... Ultrasonic transducer 14 ... Coil 15 ... Guide wire lumen 16 ... Guide wire insertion port 17 ... Guide wire outlet 18 ... Tubular member 19 ... passage 20 ... opening 21 ... reinforcing member 22 ... X-ray opaque marker 30 ... external drive source 31 ... ultrasonic diagnostic device 32 ... display unit 33 ... operation panel 34 ... image recording device 50 ... guide wire

Claims (2)

It has a long tubular main body inserted into a body cavity or a lumen, an ultrasonic vibrator provided in the lumen of the main body, and a guide wire channel provided at a distal end portion of the main body. In the ultrasonic catheter, the conduit for the guide wire extends so as to have a guide wire port provided at a distal end position of the ultrasonic transducer and a distal end position of the ultrasonic catheter, and a tube of the main body. An ultrasonic catheter further comprising a passage communicating the inside of the cavity with the inner wall of the guide wire conduit . 2. The device according to claim 1, further comprising: a reinforcing member for firmly joining and supporting the guide wire conduit at a distal end in the lumen of the main body, wherein the passage communicates with the inside of the reinforcing member. An ultrasonic catheter according to item 1.

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