JP2016059508A - catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter device which can prevent catch of a stent to a guide wire lumen.SOLUTION: A whole body 310 or part of a hollow body for penetrating a guide wire and disposed on a tip end of a catheter sheath is formed of a biodegradable material, as the result, since start of maneuver, when certain length of time has passed, whole body or part of the hollow body is biodegraded and eliminated, and a factor of catch of the stent is eliminated.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a catheter, and more particularly to a catheter having a relatively short guide wire lumen at the distal end.

  As a catheter used for diagnosis and treatment, there is a catheter having a relatively short guide wire lumen at a distal end portion. This catheter is inserted into the blood vessel with the guide wire inserted through the guide wire lumen, and can be quickly inserted and removed from the guide wire, so-called “rapid exchange type (short monorail type)”. A catheter. As an application of such a catheter, there is an image diagnosis for obtaining an image of a blood vessel lumen. As an apparatus for acquiring an image of a blood vessel lumen, an intravascular ultrasonic diagnostic apparatus (IVUS: Intravascular Ultra Sound), an optical coherence tomography diagnostic apparatus (OCT: Optical Coherence Tomography), and the like are known (Patent Document 1). The purpose of obtaining the image of the blood vessel lumen is to determine the position of the blood vessel on which the stent is to be placed, or to diagnose the progress of the already placed stent.

  A catheter used for an intravascular ultrasonic diagnostic apparatus has an imaging core having an element for transmitting and receiving ultrasonic waves, which is rotatable in the vicinity of the distal end thereof and movable in the axial direction of the rotation axis. Contained. On the other hand, a catheter used in an optical coherence tomography diagnostic apparatus accommodates an imaging core that has an optical element that emits and receives light that is rotatable in the vicinity of its distal end and movable in the axial direction of the rotation axis. doing.

  Although the intravascular ultrasound diagnostic apparatus and optical coherence tomography diagnostic apparatus have the above-described differences in the structure of the imaging core itself, scanning is performed while moving in the axial direction while rotating to obtain an intravascular tomographic image. It also has a common structure in terms. Therefore, recently, there is also a catheter that houses an imaging core having both the above-described ultrasonic element and optical element, and a hybrid type apparatus that simultaneously performs tomographic diagnosis using both ultrasonic waves and optical interference. It has been proposed (Patent Document 2). Hereinafter, these devices are simply referred to as diagnostic imaging devices.

JP 2007-267867 A WO2014 / 073016A1

  In the above image diagnostic apparatus, in order to guide the catheter to the affected area to be diagnosed, a guide wire is usually inserted from the patient's wrist or the blood vessel at the base of the thigh, and the tip of the guide wire is checked while checking with an X-ray image. Work to reach the affected area. Thereafter, an operation of inserting a catheter having a hollow body penetrating the guide wire (also referred to as a guide wire lumen) at the tip is performed. As a result, the catheter is guided by the guide wire and reaches the affected area. In general, the blood vessel has a tortuous shape, and the catheter is inserted along the blood vessel. Therefore, both the catheter body and the hollow body are made of a flexible material (for example, polyethylene).

  Now, in order to confirm the progress of the stent placed in the blood vessel, consider the case where the catheter is inserted as described above. In this case, the distal end portion of the catheter is scanned after being guided to a position passing through the stent. When a series of scanning processes is completed, the guide wire and the catheter are retracted and discharged out of the body. At this time, the opening of the hollow body for allowing the guide wire in the catheter to penetrate may be caught by the stent. Such a situation will be described with reference to FIG.

  In FIG. 2, reference numeral 100 denotes a stent, reference numeral 200 denotes a guide wire, and reference numeral 300 denotes a catheter sheath forming a part of the catheter. A hollow body 310 for penetrating the guide wire 200 is provided at the distal end portion of the catheter sheath 300. The stent 100 has a small diameter until it is placed in the blood vessel, and the diameter of the stent 100 is expanded after placement, and is maintained in the expanded state and fixed in the blood vessel. Therefore, the stent 100 has a network structure as shown in the figure. Inevitably, the end portion of the stent 100 has a concave portion and a convex portion due to a network structure.

  When the scan is completed, the catheter sheath 300 is retracted along the arrow 400 indicating the diagnostic imaging apparatus side in order to discharge the catheter sheath 300 from the body. During the retraction operation, it is desired to prevent the convex portion 100a of the stent 100 from entering the opening which is the end surface of the hollow body 310 on the diagnostic imaging apparatus side. Therefore, in general, the opening of the hollow body 310 has an inclined structure as illustrated. As a result of this inclined structure, even if the convex part 100a of the stent 100 is in contact with the inclined part, the convex part 100a only slides along the inclination, and can be prevented from entering into the opening of the hollow body 310.

  However, the above sliding effect cannot be expected at the portion of the opening that is farthest from the catheter sheath 300. That is, when the convex portion 100a of the stent 100 enters the portion of the opening of the hollow body 310 that is the farthest from the catheter sheath 300, the hollow body 310 is caught by the stent 100. Normally, when such a catching situation occurs, the catheter sheath 300 is pushed once, and in some cases, the catheter sheath 300 is rotated by twisting it by hand and then pulled again to perform catching operation. It has been released. However, if the catheter sheath 300 is further retracted along the arrow 400 without performing this avoiding operation, that is, in a state where the stent 100 is caught in the hollow body 310, the opening of the hollow body 310 is illustrated. As indicated by reference numeral 311 at the bottom, the opening is further expanded and deformed. If it becomes like this, the probability that the hollow body 310 and the stent 100 will be caught will increase further. Therefore, the possibility of falling into a vicious circle due to the repetition of the avoidance operation cannot be denied. In addition, the present inventors are concerned that it will be impossible to release the hooked state at hand, and it will develop into a surgical operation in the worst case.

  The present invention has been made in view of the above problems, and eliminates the possibility of developing to a surgical operation, and provides a technique for easily discharging a catheter out of the body.

In order to solve the above problems, for example, the catheter of the present invention has the following configuration. That is,
A catheter having a hollow body for passing a guide wire through a distal end portion of the catheter sheath,
At least a part of the hollow body is made of a biodegradable material.

  According to the present invention, when a certain amount of time has elapsed from the start of the procedure, the hollow body or a part of the hollow body is biodegraded, and it is possible to eliminate the cause of being caught on the stent. Therefore, the catheter can be easily and reliably discharged from the body.

It is a figure which shows the whole image of the catheter used for the diagnostic imaging apparatus in embodiment. It is a figure for demonstrating the conventional problem. It is a figure which shows the structure and function of the front-end | tip part of the catheter in embodiment. It is a figure which shows the other example of the structure and function of the front-end | tip part of the catheter in embodiment.

  Embodiments according to the present invention will be described below in detail with reference to the accompanying drawings.

  In the embodiment, a catheter for an intravascular ultrasonic diagnostic apparatus (IVUS) will be described as an example. As will be apparent from the description below, the present invention is not characterized by the structure of the imaging core inside the catheter, but by the structure of a hollow body that penetrates the guide wire provided at the distal end of the catheter. . Therefore, it is clear that the present invention can be used for an optical interference diagnostic imaging apparatus using a guide wire, a catheter of a hybrid diagnostic imaging apparatus using both ultrasound and optical interference, and a suction catheter for treatment. It should be noted that the present invention is not limited to the description of the present embodiment.

  FIG. 1 is an overall configuration diagram of a catheter 500 in the embodiment. In FIG. 1, the same components as those in FIG. 2 described above are denoted by the same reference numerals. The catheter 500 includes a long catheter sheath 300 that is inserted into a blood vessel, and a connector portion 501 that is disposed on the user's hand side without being inserted into the blood vessel for operation by the user. At the distal end of the catheter sheath 300, a tube-shaped hollow body 310 is provided for penetrating the guide wire 200 for guiding to the blood vessel position to be diagnosed and holding the tube slidably. The catheter sheath 300 forms a continuous lumen from the connection portion with the hollow body 310 to the connection portion with the connector portion 202.

  An imaging core 600 that is rotatable and movable in the axial direction of the catheter sheath 300 is housed inside the lumen (working lumen) of the catheter sheath 300. The imaging core 600 includes an ultrasonic element that transmits ultrasonic waves in a direction orthogonal to the axial direction of the catheter sheath 300 and receives reflected waves thereof. In addition, the imaging core 600 is fixed with a drive shaft 601 that accommodates a signal line for transmitting the rotational force from the connector unit 501 and electrically connecting with the ultrasonic element. When the drive shaft 601 is rotated and moved in the axial direction, the imaging core 600 is also rotated and moved in the axial direction accordingly. The connector unit 501 is connected to a pullback unit (not shown) (also referred to as a motor drive unit) that constitutes a part of the intravascular ultrasonic diagnostic apparatus, and the intravascular ultrasonic diagnostic apparatus and the semiconductor element described above are electrically connected. Will be connected to.

  Note that the main point of the present invention is the structure of the distal end portion of the catheter 500, and therefore, the details of the processing in the intravascular ultrasonic diagnostic apparatus will not be described.

  The feature of the catheter 500 in the embodiment is the material of the hollow body 310 for penetrating a guide wire provided at the distal end of the catheter 500. The hollow body 310 in the embodiment is a biodegradable material. The biodegradable material is preferably an agglomerated coacervate phase containing a biodegradable polymer, and the biodegradable polymer is a blend of a polycationic polymer and a polyanionic polymer. Is more preferable. A specific material is a blend of atelocollagen and chondroitin sulfate, which is a combination of collagen and polysaccharide, but any other material that decomposes at a sufficient rate when in contact with blood and does not affect the living body. It doesn't matter. For example, polylactic acid, polyglycolic acid, poly (L-lactide), poly (D, L-lactide), polyglycolic acid, poly (L-lactide-co-D, L-lactide), poly (L-lactide- Co-glycolide), poly (D, L-lactide-co-glycolide), poly (glycolide-co-trimethylene carbonate), poly (D, L-lactide-co-caprolactone), poly (glycolide-co-caprolactone) , Polyethylene oxide, polyoxaester, polydioxanone, polypropylene fumarate, poly (ethyl glutamate-co-glutamic acid), poly (tert-butyloxy-carbonylmethyl glutamate), polycaprolactone, polycaprolactone-co-butyl acrylate, polyhydroxybutyrate , Poly (phosphazene), poly (phosphate ester), poly (amino acid), poly Redepsipeptide, maleic anhydride copolymer, polyiminocarbonate, poly [(97.5% dimethyltrimethylene carbonate) -co- (2.5% trimethylene carbonate)], poly (orthoester), tyrosine-derived polyarylate, tyrosine-derived polycarbonate, tyrosine It may be a biodegradable material selected from the group consisting of derivatized polyimino carbonate, tyrosine derivatized polyphosphonate, polyalkylene oxide, hydroxypropylmethylcellulose, polysaccharides, proteins, and any of the above copolymers, terpolymers and blends. However, at the time of diagnosis, it is desirable that the shape of the hollow body 310 is maintained during a period in which the catheter 500 is guided by the guide wire 200 to reach the diagnosis site and a series of scanning processes are performed. In general, it is known that the time required for the IVUS procedure is about 120 minutes. Therefore, it is desired that the shape is maintained until about 100 minutes have elapsed since the start of the procedure. The inventor made the hollow body 310 as a blend of the above-mentioned atelocollagen and chondroitin sulfate, and applied a coating film for protecting the surface of the hollow body 310 for about 100 minutes after contact with blood. As a result, the disassembly from the part coated with the coating film is not started, and the decomposition starts gradually from the part not coated with the coating film, so when the procedure is finished after the catheter 500 is inserted into the patient's blood vessel. The shape of the hollow body 310 can be maintained up to (about 100 minutes in the embodiment) as compared with the case where no coating film is applied. In addition, the coating film may be removed from the surface of the hollow body 310 by separating and collecting the coating film when the procedure is completed, or by designing the coating film so that it does not dissolve and dissolve. . As described above, by applying a coating film, the progress of decomposition can be controlled in accordance with the state of the procedure, but the shape of the hollow body 310 does not necessarily have to be maintained, and the guide wire can be penetrated. As long as the procedure is not hindered. For example, by adjusting the mixing ratio of blends with different degradation rates among the biodegradable polymers used in the biodegradable materials, or by setting the dimensions including the thickness and width of the biodegradable material parts, The degree of decomposition and the degree of change in the shape of the hollow body 310 due to decomposition may be appropriately adjusted.

  FIG. 3A shows a structure in the vicinity of the distal end portion of the catheter 500 in the embodiment. As described above, the difference from the prior art is that the hollow body 310 is a biodegradable material. When the procedure is started, the hollow body 310 is further decomposed after about 100 minutes, and as a result, the hollow body 310 does not exist from the catheter sheath 300 as shown in FIG. Therefore, in this state, there is no longer a situation where the stent is caught, and the catheter 500 can be easily pulled back out of the body.

  In addition, the code | symbol 315 in Fig.3 (a) is a perforation for functioning as a starting point in order to accelerate | stimulate biodegradation. As already described, the portion most likely to be caught with the stent is the position of the opening on the connector portion 501 side (hereinafter simply referred to as the opening) in the hollow body 310 farthest from the catheter sheath 300. Therefore, a perforation 315 is provided at this position. By providing this perforation 315, the following effects can be expected.

  As described above, the time required for the procedure is at most about 120 minutes. However, on the other hand, the procedure is often completed in a shorter time. Suppose that the diagnosis is completed in about 60 minutes and the stent is caught in the opening when the catheter 500 (catheter sheath 300) is to be discharged from the body. Further, it is assumed that even if the avoidance operation described above is performed, the catch cannot be released. In the case of the embodiment, since the hollow body starts to decompose after about 60 minutes, it does not develop into a serious problem. However, it is also true that the shorter the procedure time, the smaller the burden on the patient. That the opening is caught by the stent means that the position indicated by the perforation 315 is caught by the stent. When the stent is caught, a force extending to the site is applied, the coating at the site of the perforation 315 is broken, and biodegradation of the hollow body 310 starts from the position. That is, disassembly can be started without waiting for 100 minutes from the start of the procedure, and it can be expected that the catheter 500 can be quickly discharged out of the body and the procedure can be completed. Moreover, the perforation 315 should just be a biodegradation start part used as the starting point of the biodegradation of the hollow body 310 as mentioned above. For example, the hollow body 310 may have a shape that becomes the weakest part of biodegradation fastest, and even a broken hole or notch may be designed to be partially thin in the hollow body 310. Alternatively, a biodegradable material having a shorter period until biodegraded and disappears (can be eliminated) than the biodegradable material that forms the entire shape of the hollow body 310 may be partially employed.

  As described above, the structure of the catheter in the embodiment is used, and the hollow body 310 is made of a biodegradable material, thereby eliminating the phenomenon that the opening of the hollow body 310 is caught by the stent after an appropriate time has elapsed. Will be able to.

[Second Embodiment]
In the said embodiment, although the raw material of the whole hollow body 310 was made into a biodegradable material, the example which makes that one part a biodegradable material is demonstrated using FIG. 4 (a), (b).

  FIG. 4A shows the structure of the catheter sheath 300 at the distal end of the catheter 500. A feature of the second embodiment is that the cylindrical portion indicated by the hollow body 310 is connected to the openings at both ends, and the linear portion 411 opposite to the side connected to the catheter sheath 300 is a biodegradable material, The other part 412 is the point comprised with the same polyethylene as the past. In addition, a perforation 315 similar to that in the above embodiment is provided in the opening of the portion 411 in the hollow body 310.

  With this configuration, when the biodegradable material in the part 411 is decomposed due to the passage of time or being caught by the stent, as shown in FIG. The notch portion 450 is formed along the axial direction of the hollow body cylinder, and the portion where the stent is caught does not exist. That is, the same effect as the first embodiment is successfully achieved. In addition, according to the second embodiment, the biodegradable material of the part 411 is also merely for maintaining the cylindrical shape of the hollow body 310, so that the manufacturing cost can be reduced.

  In the embodiment, the catheter for the intravascular ultrasonic diagnostic apparatus has been described as an example. However, as is clear from the above description, the structure of the imaging core inside the catheter is not characteristic, but the distal end of the catheter The structure of the hollow body which penetrates the guide wire provided in is characteristic. Therefore, it is apparent that the present invention can be used for an optical interference diagnostic imaging apparatus using a guide wire, a catheter of a hybrid diagnostic imaging apparatus using both ultrasonic waves and optical interference, and a suction catheter for treatment. The present invention is not limited by the description of the present embodiment.

Claims (5)

A catheter having a hollow body for passing a guide wire through a distal end portion of the catheter sheath,
A catheter comprising at least a part of the hollow body made of a biodegradable material.   The catheter according to claim 1, wherein the biodegradable material is obtained by agglomerating and solidifying a coacervate phase containing a biodegradable polymer.   The catheter according to claim 1 or 2, wherein the biodegradable material is provided in a linear portion that connects openings at both ends of the hollow body and is opposite to a side that is connected to the catheter sheath.   The catheter according to any one of claims 1 to 3, wherein the hollow body is coated with a membrane that prevents biodegradation for a preset time.   The catheter according to claim 4, wherein a biodegradation start portion is provided in the biodegradable material farthest from the catheter sheath in an opening portion of the hollow body closer to a rear end side of the catheter sheath. .

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