Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Reexamination Certificate
1999-06-15
2001-07-10
Coggins, Wynn Wood (Department: 3763)
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
C604S004010, C604S093010
Reexamination Certificate
active
06258079
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the design and use of medical devices, and more particularly to a method and system for establishing temporary access to a patient's vascular system for hemodialysis and other extracorporeal blood treatments.
Access to a patient's vascular system can be established by a variety of temporary and permanently implanted devices. Most simply, temporary access can be provided by the direct percutaneous introduction of a needle through the patient's skin and into a blood vessel. While such a direct approach is relatively simple and suitable for applications which are limited in time, such as intravenous feeding, intravenous drug delivery, and the like, they are not suitable for hemodialysis and other extracorporeal procedures that must be repeated periodically, often for the lifetime of the patient.
For hemodialysis and other extracorporeal treatment regimens, a variety of transcutaneous catheters and implantable ports have been proposed over the years. Transcutaneous catheters, such as the Tesio catheter available from Med Comp and the Perm-Cath™ available from Quinton, comprise a single catheter tube having a distal end placed in a vein in an in-dwelling manner and a proximal end which extends through the skin and is which available for connection to a hemodialysis or other blood treatment system. Such catheter includes a DACRON® cuff disposed just beneath the skin in order to reduce the risk of infection.
Implantable ports, in contrast, are entirely subcutaneous and connected to a vein or an artery by a subcutaneous cannula. Access to the port is achieved by percutaneous placement of a needle or other connecting tube. Such ports typically comprise a needle-penetrable septum to permit percutaneous penetration of the needle. Recently, several valved-port designs have been proposed, where introduction of a needle or other access tube opens the valve to provide flow to the cannula which connects to the blood vessel.
Both the transcutaneous and implanted port vascular access systems suffer from certain disadvantages and limitations. A particular problem with prior transcutaneous and implanted port vascular access systems has been replacement. It is often necessary to replace a transcutaneous catheter when its distal end becomes dysfunctional due to plugging or other causes. Heretofore, it has usually been necessary to remove the entire catheter, including the subcutaneous cuff which has become ingrown in the tissue. In the case of implanted port systems, either the port or the cannula attached to the blood vessel could become dysfunctional. Heretofore, it has generally been necessary to remove both the port and the implanted cannula when either needs to be replaced.
It would therefore be desirable to provide improved methods, systems, and kits which permit only a portion of an implanted system to be replaced when other portions of the system remain functional. Such improved methods, systems, and kits should both simplify such replacement procedures and reduce trauma to patient's undergoing such procedures. In addition, it would be desirable if the improved methods, systems, and kits were useful with a wide variety of implantable catheters (including at least subcutaneous catheters and transcutaneous catheters used for vascular access), were easy to use, and could reduce costs associated with long term maintenance of such implantable access devices. At least some of these objectives will be met by the different aspects of the present invention described below.
2. Description of the Background Art
U.S. Pat. Nos. 5,562,617 and 5,041,098 are exemplary of implantable systems employing cannulas extending between a port and a blood vessel for providing extracorporeal circulation. U.S. Pat. Nos. 5,417,656 and 5,281,199 show implantable ports which are connected to vascular cannulas via a transition region (FIG. 1A) and to a multiple branch cannula (FIG. 21). U.S. Pat. No. 4,892,518 shows an implanted port with a transition region extending to a cannula. U.S. Pat. Nos. 5,234,406 and 5,215,530 show two-piece catheters having a distal portion which can be placed percutaneously. The '406 patent discloses a large diameter proximal portion to enhance the flow rate of anesthetics to the subarachnoid region of the spine. U.S. Pat. Nos. 5,203,771 and 4,181,132 show implantable connectors which provide for percutaneous access to implanted shunts.
Related co-pending applications, assigned to the assignee of the present application, include Ser. Nos. 08/745,903; 08/724,948; 08/634,634; 08/539,105; and 60/036,124.
The full disclosures of each of the U.S. Patents and co-pending applications listed above are hereby incorporated herein by reference.
SUMMARY OF THE INVENTION
The present invention provides improved methods, systems, and kits for maintaining access to body lumens, particularly blood vessels, but also the peritoneal cavity, and the like. The systems comprise an access cannula, usually comprising a distal portion and a proximal portion, which is implanted from the body lumen to a proximal access site, typically an implanted port or a transcutaneous access location catheter. Distal access to the body lumen is effected by any one of a variety of access devices and techniques, such as in-dwelling cannulas, cross-tubes (T-catheters), end-to-side anastomosis, and the like. The methods and the systems of the present invention facilitate and simplify replacement of all or a portion of the systems implanted should such replacement become necessary.
According to the present invention, an implanted cannula system may be replaced by separately removing either a distal portion or a proximal portion thereof. The methods comprise surgically exposing a portion of the access cannula while leaving at least one of the distal end (attached to a body lumen) and the proximal portion unexposed. The access cannula is disconnected at the site where it has been exposed (typically by removing one end from a remote connector or severing the cannula at a pre-selected site along its length to produce a free end for subsequent reconnection) and thereafter replacing one of the distal portion and the proximal portion while leaving the other in place. The replaced section can then be connected to the previously implanted section in order to reestablish access. Typically, the entire distal end of the cannula will be exposed when it is desired to replace the distal portion. Alternatively, the entire proximal portion of the cannula may be exposed when it is desired to replace the proximal portion. Alternatively, when replacing the proximal portion which is connected at its proximal end to an implanted port, it may only be necessary to surgically expose the port and the distal end of the proximal portion leaving the intermediate portion thereof subcutaneously implanted.
The methods of the present invention for replacing portion(s) of a previously implanted cannula system will be useful where the implanted cannula comprises a proximal section and a separate distal section, typically connected by an intermediate connector, as described in more detail below. The methods will also be useful for replacing portions of an “integral” cannula, e.g., a cannula formed from a continuous tube without discrete connection points within the tube. When employed with two-piece cannulas (or optionally cannulas having three or more pieces), the replacement may be performed at a point of prior attachment, usually the point where the cannula is connected by the immediate connector(s). When employed with integral cannulas, it will be necessary to cut or otherwise sever the cannula at a point to which a new section of the cannula can be reattached. Of course, even when employing multiple-piece cannulas, it will be possible to sever the cannula body at other sites (i.e., where no connectors are present) to perform the replacement methods of the present invention.
Thus, in a first aspect of the method of the present invention, the distal
Beathard Gerald
Brugger James M.
Buffaloe George W.
Burbank Jeffrey H.
Finch Charles D.
Blyveis Deborah
Coggins Wynn Wood
Townsend and Townsend / and Crew LLP
Vasca, Inc.
LandOfFree
Method and systems for establishing vascular access does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and systems for establishing vascular access, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and systems for establishing vascular access will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2439294