Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Reexamination Certificate
2001-01-26
2003-07-08
Gartenberg, Ehud (Department: 3754)
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
C604S523000, C604S525000, C604S526000, C604S164130, C600S585000, C600S434000
Reexamination Certificate
active
06589227
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority of the following European applications:
Serial No. 00610012.7 filed Jan. 28, 2000
Serial No. 00610013.5 filed Jan. 28, 2000
Serial No. 00610014.3 filed Jan. 28, 2000
Serial No. 00610015.0 filed Jan. 28, 2000
TECHNICAL FIELD
The present invention relates to the field of medical devices and more particularly to vascular devices such as catheters and delivery systems for implantable devices.
BACKGROUND OF THE INVENTION
Catheters for medical diagnostic or therapeutic use are well known. A catheter has a distal end and a proximal end, with a body extending therebetween and a lumen extending therethrough from end to end. A wide variety of catheters exists for percutaneous insertion by the Seldinger technique into the vascular system to accomplish diagnostic or therapeutic objectives. The vessels of the peripheral vasculature have a relatively large diameter and low tortuosity, the coronary vasculature is somewhat smaller and more tortuous, and the vasculature in the soft tissue of the brain and liver is of small lumen and is very tortuous.
In order to be able to access the various parts of the vasculature, the catheter needs to be flexible and to maintain its column strength when it follows a tortuous path. The contradictory requirements for flexibility and column strength are particularly pronounced in catheters for intracranial catheterizations used in a variety of diagnostic and interventional neurological techniques including delivery of contrast fluids, drugs or a vasoocclusive agent, treatment of tumors, aneurysms, AVS (arteriovenous shunts) and so forth.
When a central member is to be moved within a catheter or sheath to perform an activity at or beyond the distal end of the catheter, after the catheter has been positioned, the central member is to be pushed through the catheter lumen. The more tortuous the path and the smaller the catheter the more difficult it is to advance the central member through the catheter lumen. This difficulty is in particular pronounced in coaxial systems for intracranial use. Where the central member is a delivery device for an embolization coil and must be rotated to disconnect from the coil upon release at the treatment site, the central member must be capable of transmitting torque to its distal end for assured coil disconnection; one such prior art coil delivery system is disclosed in U.S. Pat. No. 5,122,136; but it is a common problem that such prior art coil delivery members have relatively high rigidity which is problematic in small or tortuous vessels with aneurysms. Where the device is a pusher to push a device such as a stent from the distal end of the catheter, the pusher must have substantial column strength as well as great flexibility.
Where a catheter is to be used for delivery of an endovascular prosthesis to a treatment site, such as a stent, a stent graft, a valve member, or a filter, where the prosthesis is compressed to pass through the catheter and then selfexpand upon release therefrom within a body lumen, the prosthesis must be constrained while within the catheter and imposes significant forces against the surrounding catheter body.
It is an objective of the present invention to provide a medical device that includes a distal area that is very flexible and yet easily pushable and capable of transferring torque in an assured, controllable manner.
It is another objective to provide a catheter system that makes it easier to advance the central member through the catheter also in cases where the catheter exhibits sharp turns.
It is further an objective to provide a catheter that resists the substantial radially outward forces of a compressed endovascular prosthesis contained within the distal end thereof, and yet be very flexible and capable of transferring torque.
It is yet another objective to provide a central member for movement within a catheter lumen that is very flexible, has substantial column strength and/or is capable of transferring torque.
SUMMARY OF THE INVENTION
The foregoing and other problems are solved and a technical advance is achieved in an illustrative medical device for passage along the vasculature of a patient, having a body portion comprising primarily a plurality of coils or turns of a plurality of wound filaments or wires. The medical device may be a catheter or may be one or more components of a delivery system for endovascular devices, such as a central member within a catheter, for example, a pusher or delivery device for an embolization coil. Two to twelve filaments such as wires, and preferably from four to eight wires, are preferably helically wound adjacent to each other as a group or row with a pitch corresponding generally to the aggregate width of the adjacent wires in the row.
The wound wires transfer torque and also force components directed in the axial direction of the medical device to the distal end thereof, and this construction is found to give a very high resistance to kinking of the medical device. When a catheter according to the present invention is heavily bent, the cross-section of the catheter maintains a circular shape. This provides a distinct advantage over prior art catheters which are deformed into an oval shape in cross-section when bent leading to kinking. The catheter surprisingly maintains its capabilities for transferring torque and push when it follows a tortuous path involving two or more loops, probably because of the excellent kinking resistance. These qualities facilitate placement of the catheter at the desired position in the vascular system, and by making the catheter system so that the inner surface of the catheter is mainly undeformable by a central member moving axially therewithin, it is virtually impossible for the central member to get stuck in the catheter wall, even in situations where the catheter is heavily curved. This is in contrast to prior art coaxial systems where the catheter is made of a soft material such as a resin, the inner surface of which is readily deformable in a local area, causing the formation of a small bead in front of the tip of the central member bearing against the wall of the curved catheter. It is an advantage of the catheter according to the present invention that the wall is primarily made of wires that provide a hard and relatively slippery inner surface resulting in low resistance to advancing the central member through the lumen of the catheter.
The inventive catheter maintains three valuable characteristics of very high flexibility, pushability and torqueability even when set in a very tortuous pattern involving two or more tight loops, and the catheter can thus be of use in very small and distant vessels such as deep brain sites accessed by intracranial catheterization. Preferably, a thin sealing coating of elastic, low-friction material, or adhesive material may be provided over the outwardly directed surfaces of the coiled wires or along the inner surfaces that define a lumen, or at least in recesses between abutting wires or in interstices between nonabutting turns between the groups of wires, thus sealing the interstices between the wires so that the catheter wall is leakproof especially where the device is a catheter or sheath.
Further, wires may have the same diameter in the group and extend the entire length of the device, or the device may have portions with wires of different diameters, lessening toward the distal end and thereby decreasing gradually in outer diameter; the device may also have a noncoiled part in the proximal region such as a supplementary cannula or tubing.
In the present context, the term “catheter” is to be understood in the sense that it can be an ordinary catheter, but also a sheath, which is a short catheter, and in the latter case the central member can be a catheter, e.g., a catheter according to the present invention. The sheath can have a check-flow valve or a fitting at the proximal end in order to stop bleeding out of the puncture site. In one aspect, the catheter may be utilized without a guidewire. When i
Gartenberg Ehud
Nicolas Frederick C.
William Cook Europe APS
LandOfFree
Endovascular medical device with plurality of wires does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Endovascular medical device with plurality of wires, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Endovascular medical device with plurality of wires will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3104620