For certain medical procedures it is necessary to insert a fluid line into a patient for removing or introducing a fluid. One example of such fluid lines are catheters. Generally speaking, catheters are either used for a relatively short term (e.g., a few hours or days for surgery, etc.), or for more long-term applications. For example, one long-term usage is for hemodialysis for ultra filtration of the blood for patients with renal failure. Another catheter use is for long-term central venous access for prolong intravenous antibiotics, difficult intravenous access, chemotherapy, peritoneal dialysis, or total parenteral nutritional. These catheters are placed via entry points in the internal jugular vein, subclavian vein, femoral veins, or intraperitoneal. The catheters include stabilizing devices to anchor the catheter to the subcutaneous tissues.
One common anchoring device is a tissue ingrowth cuff. The tissue ingrowth cuff seals the opening from within the body and helps stop bleeding and prevent infection. Such a cuff is typically made of Dacron® or a similar biocompatible material, and is attached by an adhesive layer to the outer surface of a catheter cannula. The cuff is generally located on the catheter such that when a distal portion of the catheter is in position in a location to be catheterized, the cuff is positioned external to the catheterized part of the body, but below the surface of the skin in the subcutaneous tissue.
In some cases, the cuff is positioned on the catheter such that when the distal portion of the catheter is inserted in the body part, the cuff is located in a subcutaneous tunnel. The tunnel is formed by a tunneling tool, such as a trocar, either before or after cannulation of the vessel with the distal portion of the catheter. The proximal portion of the catheter having the cuff is drawn in through the tunnel by the tool while the tool passes through the subcutaneous tissue. The cuff is generally sized such that when the procedure is done, the cuff will fit snugly in the tunnel or other area.
After a period of time, the surrounding tissue grows into the fabric of the cuff such that the catheter is stabilized in the catheterized location. In addition, the catheterized location and the subcutaneous tunnel are sealed off, preventing foreign bodies from entering the wound and blood from exiting or pooling around the catheter near the exit site, thereby preventing patient infection. While such fabric cuffs are effective at stabilizing a catheter, they are also difficult to remove.
In order to remove such a cuff from ingrown subcutaneous tissue, such as a tunnel, a practitioner has to detach the cuff by cutting around the cuff with a scalpel or dissecting scissors. The practitioner has to cut the subcutaneous tissue surrounding all edges of the cuff into which tissue has grown. Tissue growth occurs substantially transverse to the longitudinal axis of the cuff around the outer circumference of the cuff. In addition, tissue growth also occurs at angles oblique to the longitudinal axis of the cuff along both of the cuff's side edges. The practitioner must cut around the circumference of the cuff and both side edges to detach the cuff in a relatively difficult, time-consuming surgical procedure that can increase patient bleeding and infection if the whole cuff is not removed. Such prolong surgery and increased bleeding presents several risks, including increased risk of infection. The procedure may also possibly contribute to an increased chance of scar tissue build-up within the subcutaneous area such that patients requiring multiple catheterization procedures may become increasingly difficult to catheterize.
The fabric cuffs also pose problems in the subcutaneous tunneling procedures. Because the cuffs are sized to provide a snug fit in the subcutaneous area, they are difficult to pull smoothly through the tunnel. As the cuff fits snugly within the subcutaneous tunnel, frictional forces against the tunnel wall affect the tunneling and removal of the catheter.
As such, there has been some effort to develop tools to make removal of catheters with tissue ingrowth cuffs easier. One example is set forth in U.S. Patent Application No. 2006/0129134 A1 to Kerr. Kerr is directed to a dialysis catheter assembly, but this reference also discloses a cuff removal tool that has a generally slit tubular structure with a proximal end and a distal end. The proximal end is configured to define a handle and is roughened or knurled to facilitate manipulation and turning of the tool. The distal end defines an array of sharp cutting teeth. The tool is used by telescoping the proximal end of the tube over the catheter. This mounting of the tool over the catheter can be achieved by transversally moving portions of the catheter through the slit defined in the tube. The tool then is rotated so that the teeth cut the scar tissue and the catheter can be removed.
Despite the existence of such tools, further improvements in catheter/fluid line removal devices may be desirable in various applications.
USPTO Backgrounds
USPTO Backgrounds