Surgery – Radioactive substance applied to body for therapy – Radioactive substance placed within body
Reexamination Certificate
1997-05-20
2001-04-03
Jastrzab, Jeffrey R. (Department: 3762)
Surgery
Radioactive substance applied to body for therapy
Radioactive substance placed within body
C600S008000
Reexamination Certificate
active
06210312
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus and method for reducing the likelihood of development of restenosis after arterial intervention, and more particularly to a hollow guide wire for delivery of a radioactive source to the site of the lesion following, or during, an intravascular procedure such as percutaneous transluminal coronary angioplasty (PTCA).
2. Description of the Prior Art
In PTCA procedures, a guiding catheter having a preshaped distal tip is percutaneously introduced into the cardiovascular system of a patient and advanced therein until the preshaped distal tip thereof is disposed within the aorta adjacent to the ostium of the desired coronary artery. The guiding catheter is twisted or torqued from the proximal end to turn the distal tip of the guiding catheter so that it can be guided into the coronary ostium. In an over-the-wire dilatation catheter system, a dilatation catheter having a balloon on its distal end and a guide wire slidably disposed within an inner lumen of the dilatation catheter are introduced into and advanced through the guiding catheter to its distal tip. The distal tip of the guide wire is usually manually shaped (i.e., curved) before the guide wire is introduced into the guiding catheter along with the dilatation catheter. The guide wire is usually first advanced out the distal tip of the guiding catheter, into the patient's coronary artery, and torque is applied to the proximal end of the guide wire, which extends out of the patient, to guide the curved or otherwise shaped distal end of the guide wire as the guide wire is advanced within the coronary anatomy until the distal end of the guide wire enters the desired artery. The advancement of the guide wire within the selected artery continues until its distal end crosses the lesion to be dilated. The dilatation catheter is then advanced out the distal tip of the guiding catheter, over the previously advanced guide wire, until the balloon on the distal extremity of the dilatation catheter is properly positioned across the lesion. Once properly positioned, the dilatation balloon is inflated to a predetermined size (preferably the same as the normal inner diameter of the artery at that particular location) with radiopaque liquid at relatively high pressures (e.g., 4-12 atmospheres) to dilate the stenosed region of the diseased artery. The balloon is then deflated so that the dilatation catheter can be removed from the dilated stenosis and blood flow can resume through the dilated artery.
A rapid exchange catheter has a relatively short guide wire-receiving sleeve or inner lumen (sometimes referred to as the “rail”) extending a short distance through the distal portion of the catheter body. This inner lumen preferably extends approximately 10 cm, and typically about 30 to 40 cm, from a first guide wire port at the distal end of the catheter to a second side guide wire port located on the catheter body. In some catheters the rail can be much smaller than 10 cm, especially when the side guide wire port is located distal to the inflation balloon. The catheter can be advanced within the patient's vascular system in much the same fashion as described above as the short, guide wire lumen of the catheter slides along the length of the guide wire. Alternatively, the guide wire may be first advanced within the patient's vasculature until the distal end of the guide wire extends distally to the stenosis with the catheter then being mounted onto the proximal end of the in-place guide wire and advanced over the guide wire until the balloon portion is positioned across the stenosis. This particular structure allows for the rapid exchange of the catheter usually without the need for an exchange wire or adding a guide wire extension to the proximal end of the guide wire. Other over-the-wire or rapid exchange catheters can also be designed to utilize therapeutic or diagnostic means in place of the balloon in the description above.
Several notable improvements have recently been made in balloon angioplasty catheters. One such improvement is described in U.S. Pat. No. 4,748,982 (Horzewski et al.) wherein a short sleeve or inner lumen at least about 10 cm in length is provided within the distal section of the catheter body which extends from a first port proximal to the balloon to a second port in the distal end of the guide wire and which is adapted to slidably receive a guide wire. The proximal port is not less than about 10 cm and not more than about 40 cm from the distal end of the catheter. Preferably, a slit is provided in the catheter body extending from the proximal port to a location proximal to the proximal end of the balloon to facilitate the rapid removal of the catheter from the proximal end of the guide wire which extends out of the patient.
Another improvement, which was introduced into the market place by the assignee of the present application (Advanced Cardiovascular Systems, Inc.), has been perfusion-type dilatation catheters which allow for long term dilatations to repair arterial dissections and other arterial damage. These perfusion catheters have a plurality of perfusion ports in the wall forming at least part of the catheter body proximal to the balloon which are in fluid communication with an inner lumen extending to the distal end of the catheter body. A plurality of perfusion ports are preferably provided in the catheter body distal to the balloon which also are in fluid communication with the inner lumen extending to the distal end of the catheter body. When the balloon on the distal extremity of the dilatation catheter is inflated to dilate a stenosis, oxygenated blood in the artery or other vessel, depending upon the location of the dilatation catheter within the coronary anatomy, passes through the proximal perfusion ports, through the inner lumen of the catheter body and out the distal perfusion ports. This provides oxygenated blood downstream from the inflated balloon to thereby prevent or minimize ischemic conditions in tissue distal to the catheter to thereby facilitate long term dilatations. As is appreciated by those skilled in the art, tissue distal to a stenosis is frequently already in jeopardy due to ischemic conditions which may exist. As a result, care should be exercised in sizing the perfusion ports and the inner lumen to ensure that there is adequate flow of oxygenated blood to tissue distal to the catheter to eliminate or minimize ischemic conditions. Unfortunately, commercially available perfusion catheters have relatively large profiles due to the size of the inner tubular member which extends through the interior of the balloon and which prevents their use in many distal coronary locations.
A major and continual thrust of development work in the field of intravascular catheters, particularly coronary angioplasty catheters, has been to reduce the profile, i.e. transverse dimensions, of such catheters and to improve the flexibility thereof without detrimentally affecting their “pushability,” particularly in the distal portion of such catheters. A reduction in profile with little or no loss in pushability allows a dilatation catheter to be advanced much further into a patient's coronary vasculature and to cross much tighter lesions.
The guide wires employed in coronary angioplasty are of relatively small diameter because of the relatively small size of the blood vessels and the luminal openings of the dilatation catheters which pass over the guide wires. To facilitate steering or placement within the cardiovascular system, a guide wire should be both relatively flexible toward its distal end and relatively rigid from a torsional standpoint over its entire length (i.e. it should possess “pushability” and “torqueability”). These two desirable properties are somewhat inconsistent and difficult to achieve in practice.
While guide wires designed for coronary angioplasty can, at least in theory, also be employed in the peripheral organs such as the arms and the legs, they may not have suffic
Advanced Cardiovascular Systems Inc.
Blakely & Sokoloff, Taylor & Zafman
Jastrzab Jeffrey R.
LandOfFree
Catheter and guide wire assembly for delivery of a radiation... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Catheter and guide wire assembly for delivery of a radiation..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Catheter and guide wire assembly for delivery of a radiation... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2529186