Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Reexamination Certificate
1999-10-08
2001-11-27
Mendez, Manuel (Department: 3763)
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
Reexamination Certificate
active
06322534
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to vascular balloon catheters which may be used for percutaneous transluminal angioplasty procedures, or alternatively may be used to position and expand a reinforcing stent within a blood vessel. In particular, the invention is especially adapted to treatment of small diameter blood vessels within the brain and may, for example, be used to temporarily occlude a blood vessel to evaluate the results of the occlusion prior to placing a permanent occlusion device within the vessel.
2. Description of the Prior Art
Medical catheters exist for a wide variety of purposes, including diagnostic procedures and interventional therapy including drug delivery, drainage, and perfusion. Catheters for each of these purposes may be introduced to numerous target sites within a patient's body by guiding the catheter through the vascular system. A wide variety of specific catheter designs have been proposed for such different uses.
Of particular interest to the present invention, small diameter tubular access catheters are presently being used for diagnostic and interventional therapy techniques for vessels within the brain, such as the imaging and treatment of aneurysms, tumors, arteriovenous malformations and fistulas. Such techniques place a number of requirements on catheters which are to be employed. The primary requirement is size. The blood vessels in the brain are frequently as small as several millimeters, or less, requiring that catheters have an outside diameter as small as one French (0.33 millimeters). In addition to small size, the brain vasculature is highly tortuous, requiring that catheters for use in vessels of the brain be very flexible, particularly at their distal ends, to pass through the regions of tortuosity. Difficulties in catheter positioning, however, make it desirable to impart high tensile and column strength over at least the proximal portion of the catheter. Additionally, the blood vessels of the brain are relatively fragile, so it is desirable that the catheters have a soft, non-traumatic exterior to prevent injury.
It would therefore be desirable to provide improved small diameter, flexible balloon catheters suitable for introduction to very small blood vessels, particularly to the vasculature of the brain. Such balloon catheters should provide sufficient flexibility to permit access to the tortuous regions of this vasculature, while retaining sufficient tensile, column, and hoop strengths to enhance resistance to kinking and collapse. The improved catheters should also have enhanced positioning characteristics, including pushability and torqueability. Additionally, it would be desirable to have an improved wall strength over a portion or all of the catheter wall to resist bursting and failure when introducing high pressure fluids.
U.S. Pat. No. 4,739,768, describes a catheter consisting of an inner layer and an outer layer, where the inner layer terminates proximally of the outer layer to form a relatively more flexible distal end. World Patent No. 91/17782 describes a catheter having a braid-reinforced distal end with a low friction surface. World Patent No. 93/02733 describes a catheter having four regions of different stiffness. Braid and otherwise reinforced catheter structures are described in U.S. Pat. Nos. 3,416,531; 3,924,632; 4,425,919; 4,586,923; 4,764,324; 4,817,613; 4,899,787; 5,045,072; 5,057,092; 5,061,257; and European Patent No. 555088. U.S. Pat. No. 4.921,478 to Solano et al. shows a cerebral balloon catheter having an open central lumen and a specially shaped balloon.
U.S. Pat. No. 4,976,690 describes a variable stiffness angioplastic catheter in which the stiffness of the catheter is generally controlled by utilizing various catheter wall thicknesses and catheter diameters in order to provide a balloon catheter with a relatively stiff proximal portion and a more flexible distal portion.
U.S. Pat. No. 5,728,065 discloses a balloon catheter in which a flat helical coil is embedded along the length of the inner tubular body of the catheter for providing a relatively stiff proximal portion and in which the turns of the helical coil are spaced apart at the distal portion of the catheter in order to provide for a more flexible distal portion.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a balloon catheter which includes an inner catheter body comprised of an inner tubular member, a braided reinforcing layer disposed over the inner tubular member and extending from the proximal end of the inner tubular member and terminating at its distal end at a distance in a range of between about 10 and 70 centimeters from the distal tip of the inner tubular member. A coil reinforcing layer comprised of single metallic wire is formed in a helical configuration and is disposed over the remainder of the inner tubular member, i.e. extending from the distal end of the braided layer to about the distal end of the inner tubular member. An outer layer of a soft polymer material is formed over the braided reinforcing layer and coil reinforcing layer and generally extends from the proximal end to the distal end of the inner tubular member. The balloon catheter also includes an outer tubular member extending coaxially over the inner tubular member to form an inflation lumen between the outer and inner tubular members. The outer tubular member extends from the proximal end of the inner tubular member and terminates short of the distal end of the inner tubular member. An inflatable balloon having proximal and distal portions extending from the body portion of the balloon extends coaxially over the inner tubular member at the distal end of this member and the proximal portion of the balloon is sealed in fluid-tight relationship to the distal end of the outer tubular member. The distal portion of the inflatable balloon is sealed in fluid-tight relationship with the distal end of the inner tubular member. In addition, a coupling member, such as a Y-connector, having a lumen extending therethrough is mounted on the proximal end of the outer tubular member and the lumen of the coupling member is in fluid communication with the lumen between the outer tubular member and the inner tubular member in order that fluid may be injected into the lumen of the coupling to thereby inflate the balloon.
In accordance with another aspect of the present invention, the braided reinforcing layer is comprised of braided wrapped onto the outer surface of the inner tubular member. Preferably, the braided strands are formed of stainless steel wires.
In accordance with still another aspect of the present invention, the coil reinforcing layer is comprised of a single wire of circular cross section which is helically wrapped around the outer surface of the inner tubular member. Preferably, the wire is formed from platinum.
In accordance with still another aspect of the present invention, the outer tubular member has a proximal portion and a distal portion in which the distal portion has an outer diameter less than the outer diameter of the proximal portion of the outer tubular member. Preferably, the distal portion of the outer tubular member also has an inner diameter which is less than the inner diameter of the proximal portion of the outer tubular member.
Accordingly, with this construction of the catheter portion of the balloon catheter, the proximal portion of the catheter body remains relatively stiff so that the catheter may be pushed into and through the vasculature of the human body and the distal portion of the catheter body is constructed in a manner to be very flexible in order to track through the very tortuous vascular of the human body.
REFERENCES:
patent: 3416531 (1968-12-01), Edwards
patent: 3640282 (1972-02-01), Kamen et al.
patent: 3924632 (1975-12-01), Cook
patent: 4020829 (1977-05-01), Wilson et al.
patent: 4425919 (1984-01-01), Alston, Jr. et al.
patent: 4516972 (1985-05-01), Samson
patent: 4545390 (1985-10-01), Leary
patent: 4579127 (1986-04-01), Haacke
pate
Collins Henry W.
Cordis Corporation
Mendez Manuel
LandOfFree
Variable stiffness balloon catheter does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Variable stiffness balloon catheter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Variable stiffness balloon catheter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2574843