JPH0751375A - Baloon catheter for angioplasty - Google Patents

Abstract

PURPOSE: To easily observe the anatomic status of coronary arteries with the X-ray fluoroscopy by providing a means having a medium radiation non- transmission level extended along the corresponding part of a catheter thereon at a position nearer to the base end of a means having a high radiation non- transmission level. CONSTITUTION: A helical coil 50 and a marker band 72 are formed out of a material having a high radiopacity such as platinum or an alloy containing a large amount of platinum for uses as a slender radiopacity element extended along almost all or the whole of the tip of a catheter. In addition, a radiopacity image formed along the length of the forward end of the catheter is made dark enough, but not at such a level as obstructing the detailed observation of the anatomic status of the coronary arteries via the injection of a radiopacity contrast fluid. Also, the radiation non-transmission level of the forward end of the catheter is kept so that a gray image is generated, compared with an extremely dark image formed on the forward end and the marker band 72 due to the radiopacity coil 50.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is a divisional application of the patent application No. 729,541 filed on May 2, 1985, January 1989.
It is based on the partial continuation application of the patent application No. 303,908 filed on the 30th.

[0002] The present invention relates to improvements in catheters for performing balloon angioplasty on stenosed vessels.

[0003]

Balloon angioplasty has been used extensively in recent years in the treatment of occluded arteries such as coronary arteries and has shown good results. The method involves advancing a catheter with a special balloon at its tip to the site of the stenosis. The balloon portion of the catheter is positioned in its deflated state at the stenosis and then expanded at high pressure to radially outwardly compress biological material, such as the porridge forming the stenosis. This type of balloon inflation system is described in US Pat. Nos. 4,195,637 and 4,323,071. In these situations where balloon angioplasty is applied, good use of the catheter can avoid the great risk of complicated and costly bypass surgery. However, not all arterial stenosis is treatable with balloon angioplasty. A type of arterial occlusion that cannot be treated with angioplasty is one in which the passage through the stenosis is so narrow that it cannot be inserted into the stenosis even when the balloon is in its deflated and deflated state. There is.
If the stenotic opening is sufficient to pass the guidewire but not the deflated angioplasty balloon, this method is impractical. Flat dilatation catheters have been developed to allow balloon angioplasty to be performed on such narrow stenotic arteries.
Flattened dilatation catheters typically have relatively small cross-sectional dimensions, especially in the balloon region, so that the balloon can be inserted in a deflated state into a narrow stenosis. Typically, such flat dilatation catheters include a guidewire secured as an integral part of the catheter. The guidewire may form part of or extend through the catheter to facilitate manipulation of the catheter and advance through the branch vessel of the catheter. A significant improvement of such a flat catheter was 1989 1
It is disclosed in U.S. Patent Application No. 303,908, filed March 30, The plow-shaped catheter described in Japanese Patent Application No. 303,908 has a very small diameter, and has a small-diameter, thin-walled balloon at the tip thereof. The catheter is constructed and arranged so that it can be advanced through the diameter of the patient's blood vessel, controlled and manipulated from its proximal end, and selectively steerable at the bifurcation of the vasculature. . The body portion of the catheter comprises a flexible elongated hollow body adapted to transfer torque from the proximal end of the catheter to the distal end. A small diameter balloon support wire is attached to and extends from the tip of the flexible hollow shaft. A helical spring is attached to the tip of the support wire. The dilatation balloon is attached to the tip end portion of the main body shaft at its base end, and the tip end of the balloon is attached to the base end of the helical spring. An expansion / contraction port is formed on the hollow main shaft near the distal end of the proximal connection portion of the balloon and communicates with the inside of the balloon to expand and contract the balloon. The tip portion of the catheter extending beyond the balloon comprises a helical spring and a portion of the support wire. The support wire tapers within the helical spring, providing progressive flexibility in the distal direction. The tip of the tip section is bent into a curved condition such that rotation of the catheter from its proximal end allows selective steering and steering. The balloon is extremely thin. The deflated and collapsed balloon portion of the catheter has a very small diameter, creating a very small profile.

[0004]

In order for the catheter to be steerable, the tip of the catheter is made of a highly radiopaque material, and thus X
It can be easily observed by fluoroscopy. Typically,
Such catheters include a radiopaque element in the distal portion of the catheter, beyond the balloon and toward the tip. In addition, small radiopaque markers can be placed at other locations along the catheter so that the location of other portions of the catheter, such as the proximal end of the balloon, can be determined fluoroscopically. . Patent Application No. 303,908 mentioned above
In the catheter described in U.S. Pat. No. 5,967,961, the helical spring at the tip of the catheter is made of a very radiopaque alloy and appears very dark on the fluoroscopic screen. Providing a highly radiopaque portion of the catheter in the distal direction of the balloon is important in positioning the catheter, but this portion is relatively short, and the shape and morphology of the artery in which the catheter is to be positioned is determined. Little can be shown. The anatomy of the patient's coronary arteries is important to the physician. Typically, during the angioplasty procedure, the physician will inject the radiopaque contrast fluid into the artery being treated so that the contours and anatomy of the artery are visible for only a short period of time. The doctor also uses a camera to record the anatomy of the coronary arteries in a permanently reproducible form. The injection of radiopaque contrast fluid allows the physician to observe and determine the location and nature of the stricture site to be treated. It is desirable for the doctor to continuously grasp the anatomy of the coronary artery by fluoroscopy, but for this purpose, a radiopaque contrast medium must be continuously injected, which is a problem. It is impossible. The amount of radiopaque contrast fluid that can be injected into the patient's body is limited. Therefore, there is a need for a means by which the anatomy of the coronary arteries can be continuously observed without the continuous use of radiopaque contrast media. It is an object of the present invention to provide a balloon dilatation catheter that facilitates fluoroscopic observation of the anatomy of the coronary artery in which the majority of the catheter is located.

[0005]

SUMMARY OF THE INVENTION In accordance with the present invention, a highly radiopaque distal portion proximal catheter extends along a majority of the catheter distal length near the proximal end of the balloon. Modified to have medium radiopacity. Thus, the moderately radiopaque portion following the highly radiopaque portion is visible as a light but discernible gray shaded area, allowing the physician to view the anatomy of the coronary artery where the balloon is located. The contours and paths of the morphology can be observed. In addition, by providing moderate radiopacity, the physician can also inject radiopaque contrast fluid to view the anatomy of the coronary arteries in greater detail. By providing only a moderately radiopaque portion, it does not interfere with the physician's viewing of such details.

More specifically, in the present invention, the support wire of the balloon is light gray, but has sufficient radioactivity such as gold to form a discernible image on the fluoroscope. Coated with a thin membrane of permeable material. In a variation of the invention, the portion of the support wire that extends through the balloon is not radiopaque, so when the physician injects the radiopaque liquid into the area of the stenosis where the balloon is positioned, The balloon support wire does not render it radiolucent. In such a form, all radiopacity is the result of radiopaque contrast fluid, which allows the physician to obtain the most detailed and non-interfering images.

Thus, the general object of the present invention is to provide radiopaque images of different shades of shadow over most of the anatomy of the vessel both proximally and distally of the dilatation balloon. A balloon dilatation catheter adapted to be provided.

Yet another object of the present invention is to provide a catheter of the above type wherein different portions of the catheter exhibit different radiopacity when viewed under fluoroscopy.

[0009]

The above and other objects and advantages of the present invention will be better understood with reference to the more detailed description below in conjunction with the accompanying drawings.

FIG. 1 illustrates a flattened balloon dilatation catheter 12 adapted for use in the coronary arteries. The dilatation catheter 12 has an extremely thin structure having a cross section substantially equal to the cross section of a small diameter guide wire. The dilatation catheter 12 has a balloon 26 that defines a small cross-sectional shape that allows it to pass through a narrow stenosis when deflated.
have. The balloon 26 and other portions of the catheter 12, in its deflated configuration, define an outer diameter equal to the outer diameter of the small diameter guidewire. However, it should be understood that the present invention is applicable to catheters of other sizes as well.

The catheter 12 shown in FIG. 1 is approximately 150 cm when applied to the coronary arteries by the subcutaneous femoral artery technique.
It is about the size.

Catheter 12 has a relatively long proximal portion 28 formed from a thin solid wall tube, such as a hypodermic tube. In the illustrated embodiment, the proximal portion 28
Can be as long as 120 cm. The proximal portion 28 has torsional rigidity, and the rotational motion imparted to the proximal portion can be almost completely transmitted to the distal end. As will be described below, the tip of the catheter can be bent to have a predetermined curved state. The rotational force applied to the catheter can be controlled to selectively guide and steer the curved tip of the catheter as it is advanced. The proximal portion 28 can also be flexible and can be bent longitudinally to conform to the curved state of the patient's vasculature. The proximal portion 28 of the catheter 12 is sufficiently flexible, for adults, 2.
It can be flexed to follow the curvature of the coronary ostium of patients with radii on the order of 5 to 3.5 inches. Alternatively, the length of the proximal portion 28 is preferably selected so that it does not have to pass through the ostium of the coronary artery.

In the preferred embodiment of the present invention, as shown more clearly in the enlarged view of FIG.
8 is 0.022 inch outer diameter, about 0.003 inch wall thickness and 0.0
It has a 16 inch inner diameter passage. Conventional connection 32
Is secured to the proximal end of tubular portion 28 and is a syringe (not shown)
For easy connection to expansion / contraction devices such as.

The catheter 12 includes a tip portion 34 extending from the tip of the proximal portion 28 to the tip of the catheter 12. The distal portion 34 includes a small diameter elongated support wire 44 connected to the proximal portion 28 and extending distally from the proximal portion 28. The support wire 44 is
A short transition tube 36 connects to the proximal tube 28. The transition tube 36 is about 3 inches long and is formed of an elongated flexible hypodermic tube having a smaller diameter than the proximal tube 28. In the exemplary embodiment, transition tube 36 has an outer diameter of 0.015 inches and a wall thickness of 0.003.
It is formed with a hypodermic injection tube of 5 inches and an inner diameter of 0.008 inches. The proximal end of tube 36 is received within the distal end of inner passage 30 of proximal portion 28 and is secured thereto by soldering or brazing. The solid support wire 44 is the transition tube 3
It is attached to the tip of 6. In the illustrated embodiment, the very thin support wire 44 is 0.008 inches in diameter and is preferably received within the tip of the tube 36 and secured by soldering or brazing. Support wire 44 is tube 36
Close the tip of. To allow the balloon 26 to expand and contract, the transition tube 36 is formed with holes 46 on either side of the wall of the tube to communicate with the internal passages 38, 30 of the catheter. The hole 46 is approximately in the wall of the transition tube 36.
It can be defined by forming a pair of 0.005 x 0.020 inch elliptical ports. A support wire 44 supports the balloon 26 and extends distally beyond the balloon 26 to form the core of the tip portion 48. The tip portion comprises a helically wound radiopaque coil spring 50 attached to the tip of the core wire in the manner described below. The coil spring 50 can be formed of a platinum alloy having a high platinum content.

The balloon 26 is molded and formed of a high strength polymeric material in a manner that provides a thin balloon wall, which preferably has a wall thickness of about 0.005 inches rather than about 0.001 inches or more. The balloon can be manufactured as described in U.S. Pat. No. 4,490,421 issued Dec. 25, 1984, which is referenced for further details regarding the manufacture of the balloon.

As shown in an enlarged view in FIG. 3, the balloon includes a cylindrical body portion 52. In the illustrated embodiment, the balloon 26 preferably has an outer diameter of 2.0 to 4.0 mm. As mentioned above, the balloon is formed of a high strength material that does not stretch when expanded. The length of the balloon 26 can be about 15 mm. The balloon is formed with tapered portions 54 and 56 at the proximal and distal ends, respectively. The tapered portion 56 at the tip meets a narrow neck portion 58 that fits snugly around and is pressed against the proximal end of the coil spring 50. The neck portion 58 at the tip of the balloon 26 is attached to the coil spring 50 with an adhesive. As will be described in more detail below, the proximal end of the coil spring 50 is the distal neck portion 5 of the balloon 26.
It is firmly soldered to the coil wire in the area where 8 is connected. The proximal tapered portion 54 meets the narrow proximal neck portion 60.

An extension sleeve 62 is adhesively attached to the proximal neck 60 to communicate the interior of the balloon 26 with the inflation / deflation passages 30, 38 of the tube. The extension sleeve 62 extends proximally beyond the support wire 44.
The proximal end of the extension sleeve 62 is formed of the same material as the balloon 26, and the balloon is connected to the body tube 28.
It is firmly adhered to the outer surface of 6. The elongate sleeve 62 defines an annular passage 64 around the support wire 44. The annular passage 64 communicates the hole 46 with the interior of the balloon 26 to inflate and deflate the balloon.

As shown in FIG. 3, the distally extending tip portion 48 of the balloon 26 has a relatively soft potential for increased distal flexibility and reduced risk of vessel injury or damage. Provide a tip. In the illustrated embodiment, the tip portion is about 3 cm long. Coil spring 5
0 is the support wire 4 at its proximal end as indicated by reference numeral 66.
Soldered to 4. The tip of the support wire 44 is also soldered to the coil spring 50, as shown at 68. The soldered joint 68 and tip 69 of the support wire 44 have an end in front of the tip of the coil spring 50.
The tip 70 of the coil spring 50 has a soldered joint 68.
Extends about 5 cm beyond and defines a very flexible cushioning tip. The rounded weld bead 67 is the coil spring 5.
It is formed at the tip of 0. The tip portion 48 is more flexible in the tip direction. The support wire 44 can be tapered and polished, for example, smoothly polished to a 0.002 inch diameter at its tip 69.

The tip 70 of the coil spring 50 is provided with a flexible and bendable stainless steel shaping ribbon 71 having one end fixed to the support wire tip 69 and the other end fixed to the tip welding lead 67. There is. The shaping ribbon 71
Is an elongated rectangular cross section of about 0.001 inch × 0.002 inch. The shaping ribbon 71 is adapted to retain the curved state when it is bent and relaxed into a desired curved state. With the preset bending state, the catheter 12 can be steered by rotating the catheter 12 from its proximal end. The catheter can be rotated to guide the pre-bent tip 70 in a desired selected direction within the patient's blood vessel.

The catheter is also provided with a radiopaque marker band 72, which is preferably formed of platinum. The radiopaque marker band 72 is positioned near the proximal end of the body portion of the balloon 26. In the illustrated embodiment, the marker band 72 is rigidly attached to the support wire 44. The marker band 72 provides a means by which the physician can locate the balloon 26 by fluoroscopy.

In order to allow the catheter to pass through the lumen of the catheter that may guide the balloon catheter into the coronary arteries, the balloon 26 should also be retractable into a shape and size that allows it to pass through the lumen of the guide catheter. I have to The present invention accomplishes these objectives by using an elongated small diameter support wire 44 extending through the balloon and a balloon having a very thin but high strength wall. When the catheter 12 is inserted through the guide catheter, the balloon 26 is contracted by applying a suction force by the connecting portion 32 with a syringe. Balloon 26 and elongate sleeve 62 tend to deflate, forming radially extending wings as illustrated in FIGS. 3A-1 and 3B-1, respectively. These wings 62
W, 26W wrap around the support wire 44 as the catheter is advanced through the main lumen of the guide catheter. The wing portion 26W has an S-shape as shown in FIGS. 3A-2I,
Alternatively, the core wire 44 can be wrapped in any of the C-shaped configurations shown in FIGS. 3A-3. In either form, the overall diameter of the deflated and deflated balloon portion of catheter 12 is 6 in addition to the diameter of support wire 44.
Includes layers of balloon material. The balloon is formed of a high strength, thin material with a wall thickness that is preferably no greater than about 0.001 inches. Thus, the dimension of the six balloon layers plus the diameter of the support wire is approximately 0.014 inch. In this way, the balloon is about
It can be contracted to a diameter of 4, which allows it to easily pass through the main lumen of the guide catheter.

In use, a large-diameter guide catheter, which the dilatation catheter 12 can pass through first, is usually inserted into the patient's blood vessel through the femoral artery and advanced through the aorta, and the tip of the guide catheter reaches the coronary artery. Position in the ostium of the coronary artery or in the coronary artery to be treated. After positioning the larger guide catheter, the catheter 12 is advanced through the larger catheter with its balloon 26 deflated. The diameter of the catheter 12 is substantially the same as that of the conventional guide wire in the illustrated embodiment. Thus, the dilatation catheter 12 can be advanced out of the distal opening of the guide catheter in its deflated configuration of the balloon 26, and by advancing the catheter through the artery of the patient and rotatably manipulating it into the stenosis site. And can be inserted through the stricture site. The dilatation balloon 26 is then expanded by pressure to force the balloon 26 to expand to its maximum diameter, thereby expanding the passageway through the stenosis.

When the balloon 26 is expanded and the opening through the stricture is enlarged, the balloon 26 is deflated by deflating the balloon. The catheter can then be withdrawn from the patient.

As mentioned above, the catheter 12 is extremely flexible at its distal end portion 34. The proximal portion 28 is sufficiently flexible that it can be relatively easily bent through the aorta. However, the proximal portion 28 and the distal portion 3
It is desirable to dimension the catheter so that the four connections are located closer to the proximal end of the aorta. The bends from the aorta through the coronary ostium and then through the coronary arteries should be steeper and have a shorter radius. The length of the more flexible tip portion 34 is as follows. That is, the more rigid proximal tube 28 does not pass through a relatively sharp bend such as a bend reaching the coronary ostium from the guide catheter,
The balloon should be long enough to reach deep into the coronary branch. The tip portion 34, which is comprised of a substantially thin flexible support wire 44, can be easily bent relatively sharply. Thus, only the portion of the catheter 12 that actually enters the coronary artery is provided with the elongated support wire 44. This support wire is extremely flexible and bends easily, allowing it to pass through the bends of the shorter radii found in the coronary branch.

The catheter is very easy to steer due to the solid wall of the tube of the elongated proximal portion 28. The tube is substantially torsionally stiff and tends to transfer any rotational force applied to the proximal end to the distal end. Thin 0.008
The middle portion of a catheter having an inch diameter wire is undersized for effective torque transmission over a relatively long distance, but the tip portion 34 is relatively short, preferably about 25 cm to 32 cm and therefore the transmission of torque from the proximal end of the catheter to the distal end is not significantly adversely affected. The distal portion is preferably no more than about 25 cm to 32 cm in length as compared to a solid wall tubular proximal portion having a length of about 143 cm to 150 cm. In this way, by forming a bent portion at the tip of the tip portion, the direction of the catheter 12 can be controlled by rotating the catheter from the proximal end.

The helical coil 50 and the marker band 72
Are formed of highly radiopaque materials such as platinum or platinum-rich alloys. Thus, the helical coil 50 and marker band 72 are useful for fluoroscopically indicating the position of the distal end portion 48 and the proximal end of the balloon. When performing an angioplasty procedure, it is important for the physician to know the morphology and shape of the patient's coronary arteries. Typically, this involves injecting a radiopaque contrast fluid into a patient's artery and allowing the patient to be fluoroscopy by fluoroscopy for a short period of time, usually a few seconds while the radiopaque contrast fluid is present in the artery. This is done by observing the arteries of. Therefore, the physician cannot obtain continuous information about the shape of the artery through which the catheter passes. It is desirable for doctors to have such information. As such, to provide a means for the physician to continuously observe the orientation of the catheter and the shape of the coronary artery advancing the catheter, the present invention provides an elongated strip extending along most or all of the catheter's distal end portion 34. A radiopaque element is provided. In the illustrated embodiment, under fluoroscopy, the tip portion 34
The radiopaque means is accomplished by plating the support wire 44 with a radiopaque material, such as gold, which is shown schematically at 45 in FIG. The support wire 44 can be coated along the entire length in the distal direction from the connecting portion with the tube 36 through the balloon. Apart from this, a support wire 44 extending through the balloon 26.
The region (1) can be made unplated so that it cannot be observed by X-ray fluoroscopy. In this way, when the catheter is placed in the patient's artery, the substantial length of the catheter near the proximal end of the balloon can be observed by fluoroscopy, and the doctor does not have to inject the radiopaque contrast liquid. Coronary contours and passages can be displayed for.

The radiopaque image provided along the length of the tip of the catheter is sufficiently dark and observable by fluoroscopy that a doctor may inject a radiopaque contrast solution. It is desirable that it not be so dark as to prevent a closer look at specific parts of the coronary anatomy. For this reason, it is desirable that the means for rendering the tip portion 34 radiopaque be brighter than the darkest feasible fluoroscopic image formed by the means. Radiopacity refers to the radiopaque coil 50
It is desirable that the degree is such that a "gray" image is produced as compared with an extremely dark image formed on the tip portion and the marker band 72 by. By providing a "gray" statue,
The clinician can use the catheter 34 without interfering with the fluoroscopic image provided when the radiopaque contrast fluid is injected into the artery.
It is possible to observe the path and direction of the tip portion of the. As an example, the support wire 44 is 0.0002 inches to 0.000.
Desirably, it is in the form of an inner core 44A plated with a layer of gold 48 that is about 7 inches thick. Helical coil 5
0 is formed by winding a platinum alloy wire having a diameter of about 0.003 inch. The marker band 72 can be formed of a platinum alloy ring. Thus, in the illustrated embodiment, the catheter has a relatively short tip portion 48, and the marker band 72 at the proximal end of the balloon 26 appears very dark, while
Support wire 44 appears as a lighter gray image X
Provide a fluoroscopic image. Avoiding the provision of radiopaque means along the length of the balloon itself, the arterial region in which the balloon is positioned, i.e. the critical region of the stenosis, does not interfere with the fluoroscopy even slightly, without radiopacity. It is desirable to be completely observable with a transparent contrast medium. This can be achieved simply by omitting gold plating on the portion of the support wire 44 that extends through the balloon.

As an alternative to plating the support wire 44 with a highly radiopaque material such as gold, the moderately radiopaque "grey" tip portion 34 allows the wire 44 itself to be moderately radiopaque. It can be realized by forming it with a radiopaque alloy. For example, platinum alloys, gold and ruthenium can be used that are selected to maintain sufficient torsional rigidity for the catheter tip section 34. Yet another way of providing a medium radiopacity is to form the support wire 44 of composite wire, as shown in the enlarged and exaggerated cross-sectional view of FIG. As shown in FIG. 6, the composite support wire 44 comprises an inner core 44 having a tubular composite or jacket 74 of radiopaque material mechanically contracted thereabout.
It has B. Composite wire structure has inner core 44B
It is desirable if one seeks to provide a thicker layer of radiopaque material around the. On the contrary, the conventional electroplating method is a relatively time-consuming method, and the maximum thickness that can form the gold plating is about 0.0005 inch. Much thicker layers can be achieved with composite wires. The composite wire is obtained by providing a core wire 44B and a thin walled tube of metal forming the jacket 74. As an example, to form a 0.008 inch diameter support wire, the core wire 44B can be formed of 0.003 inch diameter stainless steel. It has a wall thickness of about 0.003 inch and an inner diameter of about 0.0035 inch, which is slightly larger than the inner diameter of the inner core 44B.
A gold hypodermic tube is provided. The hypodermic gold tube slides over inner core 44B and squeezes them together through a 0.008 inch outer diameter die. The die deflates and squeezes the hypodermic tubing to a smaller diameter and squeezes tightly around the core wire 44B to mechanically secure them together in the composite wire. Similar composite wire is available from Sigmund Corn Company of Mount Vernon, New York.
Marketed by numerous vendors such as the Cohn Company). Of course, other materials and dimensions can be selected for core wire 44B and jacket 74 depending on the desired properties of the wire. As another example,
The core wire 44B may be 0.006 inches in diameter with the composite 74 having a final thickness on the order of 0.001 inches.

One advantage of using a composite wire for the support wire 44 is to polish and remove the radiopaque composite portion, if desired, to provide support wire 4
The radiopacity along the length of 4 can be varied as desired. For example, if it is desirable to form a catheter in which the distal portion of the balloon proximal to the balloon has a moderate “grey” radiopacity while the portion below the balloon forms a non-radiopaque catheter, A portion of the composite material 74 is polished and removed in the region of the support wire located at. In such an embodiment, it would be desirable to provide a highly radiopaque marker band on the support wire 44 or at the proximal and distal regions of the balloon, with both ends of the balloon highlighted by fluoroscopy.

FIG. 7 illustrates yet another embodiment having a support wire in the form of a stepped taper in its tip region and having a composite material configuration for the support wire. As shown in FIG. 7, the support wire 44 is
Most of its length has a proximal end portion 45 which is a continuous diameter portion of the order of 0.008 inches. The tip of the support wire, which is about 8.5 cm in length, has a taper in a stepped shape and is gradually tapered so that the flexibility is increased in the tip direction. For example, a 0.008 inch diameter cylindrical support wire may be about 3 cm long and may include a tapered conical section 76 tapering down to about 0.006 inch. The part 76 has a constant diameter (0.00
6 inch) cylindrical barrel portion 78. The barrel portion 78 can be as long as 2.5 cm. The tip 80 is tapered downwards and is about 0.00
A second conical tapered portion having a diameter of 2 inches can be formed. In this embodiment, the proximal end of the coil spring may be attached to the distal end portion 80 such that the proximal edge of the spring is about 1.8 cm from the tip of the portion 80. The tip of the balloon, which can be about 2.5 cm long, is attached to the spring base with an adhesive.
The proximal end of the balloon is attached to the extension 60 in the area of the barrel portion 78. Such core wires can be formed from radiolucent wires, or wires or composite wires plated with radiopaque metals. In the plated form, the wire can be formed with plated portions and unplated portions using selected conventional plating techniques for plating techniques.
If it is desired to use a composite wire, provide one such composite wire, which is centerlessly polished on the tip,
It is possible to provide the desired tapered configuration for the catheter. Depending on the final dimensions, some or all of the composite can be ground away in the tip region of the wire. For example, in the embodiment shown in FIG. 7, if the composite wire is about 0.001 inch thick, the barrel portions 78, 80 will not be composited as the composite material is ground and removed during the centerless polishing process. Does not exist. The medium radiopaque portion may have a leading edge approximately 35 cm from the tip of wire 44, as indicated by phantom line 82 in FIG. The support wire 44 is shown with an exaggerated diameter for convenience of drawing.

In light of the above, the present invention provides a means for continuously fluoroscopically demonstrating the fluoroscopic morphology of a coronary artery as the catheter travels a substantial distance along the proximal portion of the catheter. It will be appreciated that it relates to improvements in catheters, and particularly catheters used in coronary angioplasty. Furthermore, it is an object of the invention that, if a radiopaque contrast liquid is to be injected, such an injection is possible without unduly disturbing the fluoroscopic view of the coronary anatomy.

However, the above description of the present invention is merely an example of the present invention, and other modifications, embodiments and equivalents of the present invention will be apparent to those skilled in the art without departing from the spirit thereof. You should understand.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a dilatation catheter.

FIG. 2 is an enlarged longitudinal cross-sectional view of a portion of a dilatation catheter that includes a transition region from a proximal portion to a distal portion. Figure 2
2A is a cross-sectional view during the transition along line 2A-2A in FIG.

FIG. 3 is an enlarged vertical sectional view showing a balloon portion and a distal end portion of the dilatation catheter. 3A is a cross-sectional view of the catheter balloon taken along line 3A-3A in FIG. 3A-1 is a view of the catheter balloon of FIG. 3A in a deflated and deflated state. FIGS. 3A-2 are views of a deflated dilatation catheter balloon having wings wrapped in S and C, respectively, around a support wire.
3A-3 are views of a deflated dilatation catheter balloon having wings wrapped in S and C, respectively, around a support wire. FIG. 3B is a cross-sectional view showing the sleeve extension of the catheter when it is in an expanded condition from the catheter. FIG. 3B-1 is a view of the sleeve of FIG. 3B in a deflated, deflated state.

FIG. 4 is an enlarged cross-sectional view of a connection portion between a balloon and a balloon extension sleeve.

FIG. 5 is an enlarged cross-sectional view of the catheter core wire as a whole showing its radiopaque coating in exaggerated thickness.

FIG. 6 is an exaggerated cross-sectional view of details of a support wire composited with a radiopaque material.

FIG. 7 is an exaggerated cross-sectional view of details of the tip of a balloon catheter with a support wire having a tapered tip portion and a composite portion of a radiopaque material portion.

[Explanation of symbols]

 12 dilatation catheter 26 balloon 30 inner passageway 32 connection portion 34 tip portion 36 transition tube 38 inner passageway 44 support wire 44B core wire 46 hole 48 tip portion 50 coil spring 52 body portion 54 tapered portion 56 tapered portion 58 neck portion 60 bases End neck portion 62 Extension sleeve 64 Annular passage 67 Weld bead portion 68 Joint 69 Tip 70 Tip 71 Shaped ribbon 72 Marker band 74 Jacket 76 Conical portion 78 Barrel portion 80 Cutting edge portion

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Brian Jay White Thorndike Road, Rowell, 01852, Massachusetts, USA 28

Claims (12)

[Claims] 1. An angioplasty balloon catheter comprising an elongate flexible shaft having a proximal end and a distal end, and a balloon attached to the catheter in the distal region thereof, the shaft expanding and contracting the balloon. And a very radiopaque means carried by the catheter near the distal end of the balloon, and mounted on the catheter near the proximal end of the very radiopaque means. A medium radiopaque means extending along a substantial portion of the catheter, the highly radiopaque means capable of forming a dark fluoroscopic image, the medium radiopacity being provided. An angioplasty balloon catheter, characterized in that the transmissive means is capable of producing a fluoroscopic image which is brighter than the image of the very radiopaque means. 2. The catheter of claim 1, wherein the moderately radiopaque means extends through the balloon and over a substantial distance near the proximal end of the balloon. 3. The catheter of claim 1, wherein the moderately radiopaque means extends from the proximal end of the balloon toward the proximal end of the shaft and along a substantial portion of the catheter and is substantially in the balloon region. A catheter characterized by the absence of a radiopaque means. 4. The catheter of claim 1, further comprising an elongated flexible member extending over at least a distal portion of the catheter, the distal portion being located substantially proximate to the balloon. Catheter extending proximally from the distal end of the catheter towards, and wherein the moderate radiopaque means is carried by the elongated flexible member. 5. The catheter of claim 4, wherein the medium radiopaque means comprises a plated portion of radiopaque material on the elongated flexible element. 6. The catheter of claim 4, wherein the medium radiopaque means comprises a composite of radiopaque material on the elongated flexible element. 7. The balloon catheter of claim 5, further comprising a short highly radiopaque element carried by the catheter adjacent the proximal end of the balloon. 8. The balloon catheter of claim 6 further comprising a short highly radiopaque element carried by the catheter adjacent the proximal end of the balloon. 9. The catheter of claim 4, wherein the tip portion has a length of about 25 cm to 35 cm. 10. The catheter of claim 1 or 2, comprising an elongate flexible member extending over at least a distal portion of the catheter, the distal portion of the catheter oriented substantially toward the proximal end of the balloon. A catheter extending proximally from the distal end, wherein the medium radiopaque means is defined by the elongated flexible member formed of a medium radiopaque material. 11. The catheter according to claim 1 or 2,
A catheter characterized in that the catheter is sized and adapted to be inserted into a coronary artery. 12. An angioplasty balloon catheter, comprising an elongated longitudinally flexible tubular proximal portion having a proximal end and a distal end, and an elongated distal portion extending beyond the distal end of the proximal portion and into the distal portion. The distal end portion is shorter and more flexible than the proximal end portion, and further, the balloon carried by the distal end portion and the proximal end of the catheter communicate with the inside of the balloon to enable expansion and contraction of the balloon. A tubular proximal portion defining an inner lumen, a distal portion including a short support wire having a diameter smaller than the outer diameter of the distal end of the proximal portion, and a balloon supported on the support wire extending through the balloon. And a means for communicating the lumen of the proximal tubular portion with the interior of the balloon, the proximal portion and the support wire having sufficient torsional rigidity, and the catheter adapted to the shape of the human coronary ostium. A shape, when the tip portion is in the coronary arteries, catheter,
A catheter characterized in that the rotational force applied to the proximal end is controllably transferable from the proximal end to the distal end.