Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Reexamination Certificate
1999-04-15
2001-05-15
Yasko, John D. (Department: 3763)
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
C606S192000
Reexamination Certificate
active
06231543
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to intravascular catheters, and more particularly to balloon dilation catheters suitable for angioplasty procedures.
2. Description of the Related Art
Balloon dilation catheters can be used in a variety of medical procedures and are most widely associated with percutaneous transluminal coronary angioplasty (PTCA). This procedure typically involves introducing a balloon dilation catheter into a patient's vascular system and advancing the catheter to a stenosis or other blockage site within a coronary artery. The balloon is then inflated by supplying fluid under pressure to the balloon. The inflation of the balloon stretches the artery, thereby dilating the stenosed region and restoring the diameter of the artery for increased blood flow.
One or multiple dilations may be necessary to effectively dilate the artery. In many instances, multiple dilations using multiple “over-the-wire” catheters having balloons with increasingly larger diameters may be required. An over-the-wire catheter is one where a separate guidewire lumen is provided so that the catheter can be guided to the stenosis site by running the catheter along the guidewire. In a typical procedure, a physician will first insert and advance a guidewire to the stenosis site. An initial over-the-wire balloon dilation catheter having a fairly small diameter balloon is then passed over the guidewire to the site and the balloon is inflated to partially dilate the vessel, then deflated and the catheter withdrawn. Progressively larger balloon catheters are then advanced to the stenosis along the guidewire, inflated, deflated, and then withdrawn in succession to sufficiently enlarge the opening.
In order to treat stenoses in small arteries, or to treat stenoses having small diameter openings, there have been continuing efforts to reduce the profile of balloon dilation catheters. One disadvantage of over-the-wire balloon dilation catheters is that the overall profile of these catheters is limited due to the provision of both a guidewire lumen and an inflation lumen for inflating the balloon catheter. So-called “fixed wire” catheters have been developed that provide for a lower profile. These catheters are generally fixed to a guidewire or guiding member for advancement to a site of stenosis advance and therefore a guidewire lumen for relative movement between the guidewire and catheter is not required, allowing for a reduced profile relative to an over-the-wire catheter. The lower profile allows these catheters to cross tighter lesions and to generally be advanced deeper into coronary vasculature. The disadvantage of such catheters is that the physician is unable to maintain position at the stenosis site when withdrawing the catheter and replacing it with one having a different balloon diameter. Instead, the path to the stenosis must be continually reestablished.
Therefore, a need exists for reduced profile dilation catheters that can be advanced over a guidewire positioned at a stenosis site. A further need exists for such catheters that are easily manufactured, durable and easy to use.
SUMMARY OF THE INVENTION
The present invention meets the above needs and is directed to a dilation catheter having a catheter shaft with an inner lumen for receiving a guidewire, and an inflatable balloon member located at the distal portion of the shaft and in fluid communication with the inner lumen. A seal is disposed within the inner lumen of the shaft that allows for movement of the guidewire relative to the inner lumen, while also providing for a fluid tight seal around the guidewire independent of fluid pressure within the lumen. A valve is located along the catheter shaft and is adapted to engage the guidewire and provide for a fluid tight seal around the guidewire when fluid under pressure is applied to the interior of the balloon member. The seal is preferably located at the distal portion of the shaft, and in one embodiment of the invention, can be located at the distal tip of the shaft itself. In a preferred embodiment of the invention, the valve is located proximal to the seal.
In another preferred embodiment of the invention, the valve includes a tubular member formed of elastomeric material. As fluid pressure builds in the balloon, the tubular member deflects and compresses against the guidewire to form a fluid tight seal around the guidewire.
In yet another preferred embodiment of the invention, a perforated rigid sleeve surrounds the tubular member and is connected to the shaft. The rigidity of the sleeve provides structural support for the shaft in the region of the tubular member. The perforations provide for fluid communication between the interior of the balloon and the tubular element, thereby allowing the tubular member to deflect and compress against the guidewire when fluid under pressure is introduced into interior of the balloon. In a modification of this embodiment, a radiopaque marker can be incorporated directly into the sleeve to aid in visualization of the catheter tip during use.
In operation, the catheter of the present invention is advanced over a guidewire positioned at a stenosis site. The seal maintains a fluid tight seal around the guidewire while allowing movement of the catheter over the wire. By maintaining a fluid tight seal around the guidewire, the seal operates to keep the patient's bodily fluids, i.e., blood, from entering the catheter lumen. The introduction of blood into the lumen can greatly reduce the effectiveness and lifespan of a catheter. Once blood is introduced into the lumen, it often will tend to coagulate and foul the inner lumen, thereby impeding the passage of the catheter over the guidewire. In addition, such fouling limits the potential reusability of the catheter. By restricting entry of blood into the inner lumen, the seal allows for ease of use and longevity of the catheter of the present invention.
By providing a fluid tight seal around the guidewire, the seal also prevents air or other media within the lumen from entering a patient's blood stream, a potentially harmful occurrence, as the catheter is advanced over the guidewire to the site of dilation. Once the catheter is positioned at the stenosis site, the seal operates in concert with the valve to prevent inflation media from entering the patient's bloodstream upon inflation of the balloon. As the balloon is inflated, fluid pressure in the balloon interior builds and deflects the valve into sealing engagement with the guidewire, thus strengthening the overall fluid tight seal around the guidewire as fluid pressure in the lumen increases.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description, appended claims and accompanying drawings.
REFERENCES:
patent: 4932959 (1990-06-01), Horzewski et al.
patent: 5032113 (1991-07-01), Burns
patent: 5085636 (1992-02-01), Burns
patent: 5217434 (1993-06-01), Arney
patent: 5324259 (1994-06-01), Taylor et al.
patent: 5437632 (1995-08-01), Engelson
patent: 5454788 (1995-10-01), Walker et al.
patent: 5476477 (1995-12-01), Burns
patent: 5484408 (1996-01-01), Burns
patent: 5531689 (1996-07-01), Burns et al.
patent: 5569201 (1996-10-01), Burns
patent: 5676654 (1997-10-01), Ellis et al.
patent: 5749849 (1998-05-01), Engelson
patent: 0371486 A1 (1989-11-01), None
patent: 0462482 A1 (1991-06-01), None
Errazo Arlene L.
Hegde Anant V.
Intella Interventional Systems, Inc.
Limbach & Limbach LLP
Yasko John D.
LandOfFree
Single lumen 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 Single lumen balloon catheter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Single lumen balloon catheter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2522631