Prosthesis (i.e. – artificial body members) – parts thereof – or ai – Arterial prosthesis – Stent combined with surgical delivery system
Reexamination Certificate
2001-07-31
2004-06-29
Bui, Vy Q. (Department: 3731)
Prosthesis (i.e., artificial body members), parts thereof, or ai
Arterial prosthesis
Stent combined with surgical delivery system
Reexamination Certificate
active
06755854
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to vascular catheters and devices, and more specifically to a control device for deploying self-expanding medical devices. Vascular catheters and devices are currently employed in a variety of medical procedures. These procedures often require manipulation (or actuation) of the vascular device by a mechanism located outside the patient's body. The present invention is specifically useful in deploying self-expanding medical devices, such as a self-expanding stent or graft, within a patient's vasculature.
Catheters have long been used in intraluminal procedures for various medical needs. They generally are made from elongated tubes which may be placed within various body lumens. A common use for catheters is the treatment of vascular diseases. Such procedures usually involve the percutaneous introduction of an interventional device into the lumen of the artery, usually through the catheter. One widely known and medically accepted procedure is balloon angioplasty in which an inflatable balloon is introduced within the stenosed region of the blood vessel to dilate the occluded vessel. The uninflated balloon catheter is initially inserted into the patient's arterial system and is advanced and manipulated into the area of stenosis in the artery. The balloon is inflated to compress the plaque and press the vessel wall radially outward to increase the diameter of the vessel, resulting in increased blood flow. The balloon is then deflated to a small profile so that the dilatation catheter can be withdrawn from the patient's vasculature. Enhanced blood flow should now resume in the dilated artery. As should be appreciated by those skilled in the art, while the above-described procedure is typical, it is not the only method used in angioplasty.
In the procedure of the kind referenced above, abrupt reclosure may occur or restenosis of the artery may develop over time, which may require another angioplasty procedure, a surgical bypass operation, or some other method of repairing or strengthening the injured area. To reduce the likelihood of the occurrence of abrupt reclosure and to strengthen the area, a physician can implant an intravascular prosthesis for maintaining vascular patency, commonly known as a stent, inside the artery across the lesion. The stent can be crimped onto the balloon portion of the catheter and transported in its delivery diameter through the patient's vasculature. At the deployment site, the stent is expanded to a larger diameter, often by inflating the balloon portion of the catheter.
A variety of stent designs have been developed and include self-expanding stents insertable and deliverable through the patient's vasculature in a compressed state for deployment in a body. Unlike balloon expandable stents which rely on an external radial force to expand the stent at the area of treatment, self-expanding stents are made from materials which are self-expanding in order to move between a compressed or collapsed position to an expanded, implanted position. Stent delivery catheters used for implanting self-expanding stents usually include an inner member upon which the compressed or collapsed stent is mounted and an outer restraining sheath placed over the stent to maintain it in its compressed state prior to deployment. When the stent is to be deployed in the body vessel, the outer restraining sheath is retracted in relation to the inner member to uncover the compressed stent, allowing the stent to immediately move into its expanded condition for implantation in the patient.
Vascular grafts also can be implanted within a body vessel utilizing a delivery catheter which is percutaneously introduced into the patient's vasculature system. These types of grafts may include a number of self-expanding rings, or small stents, placed along a flexible tubular member that forms a conduit once implanted in a body vessel. Vascular grafts are utilized to bypass diseased and weakened body vessels, such as when an artery experiences an aneurysm which weakens and abnormally expands the artery. In this manner, the vascular graft will act as a conduit for blood to flow freely there through, bypassing the diseased portion of the arterial wall caused by the aneurysm. As a result, the chances that the artery could possibly rupture due to pressure build-up in the artery is greatly reduced. Self-expanding vascular grafts also can be mounted onto a delivery catheter which includes a restraining sheath placed over the entire vascular graft, including the self-expanding rings, in order to maintain the graft in a collapsed position. Once the physician is able to manipulate the vascular graft into the desired location in the patient's vasculature, the simple retraction of the restraining sheath from the vascular graft will cause the self-expanding rings or stents to expand and contact the wall of the body lumen in which the graft is implanted.
These various treatments at the intraluminal site typically require the manipulation of the catheter system, a portion of which remains external to the patient's body. The physician must actuate the catheter system to retract the restraining sheath in order to properly deploy the stent or vascular graft in the body vessel. Actuator mechanisms which can be located at the proximal end of the catherter system may be as simple as a control handle attached to the restraining sheath that can be manipulated by the physician to retract the restraining sheath from the self-expanding medical device. During the placement of a stent or graft, it is important that the retraction of the restraining sheath be performed while the main catheter, on which the stent or graft is mounted, remains stationery in the body lumen. Some control mechanisms for retracting the restraining sheath requires that some force be applied by the physician in the longitudinal direction of the delivery catheter (i.e., in an axial direction). This force, in turn, can be transmitted to the main catheter assembly which can cause the stent or graft to move from the desired location within the body lumen. As the physician retracts the sheath, if the main catheter holding the stent or graft moves proximally with the sheath out of the target area, precision placement of the medical device will not be accomplished. Therefore, when a physician uses this type of device, the mere act of retracting the restraining sheath can sometimes result in inaccurate placement of the medical device within the body vessel.
Another problem exists when self-expanding stents or grafts which have an appreciable length (for example, 60 mm and longer) are to be deployed. These larger devices usually are more difficult to deploy accurately using existing catheter systems because a long retraction stroke is needed to retract the distal end of the restraining sheath from the medical device. In such cases, the physician may experience some difficulties in moving the proximal control device the required length to fully expose the self-expanding medical device. Moreover, the deployment of longer stents and grafts may require higher forces to retract the restraining sheath due to frictional forces which can be generated between the stent or graft and the restraining sheath as the sheath is being retracted. Therefore, the physician may have to apply more force to adequately retract the restraining sheath when a long stent or graft is being implanted. Thus, when a long stent or graft is being implanted, a physician may find it difficult to manipulate the proximalcontrol device while maintaining the remainder of the catheter system stationary to prevent the stent or graft from moving from the desired area of implantation.
Thus, what has been needed is a control mechanism which helps to provide a more precise deployment of a self-expanding medical device within the body vessel to reduce the chances that the physician may inadvertently move the medical device from the intended area of treatment. An improved control device is also needed w
Gillick Matthew J.
Stalker Kent C. B.
Advanced Cardiovascular Systems Inc.
Bui Vy Q.
Fulwider Patton Lee & Utecht LLP
LandOfFree
Control device and mechanism for deploying a self-expanding... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Control device and mechanism for deploying a self-expanding..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Control device and mechanism for deploying a self-expanding... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3341954