The present invention relates to the field of dialysis catheters for insertion into body vessels for the purpose of dialyzing patients with kidney failure. Typically, dialysis catheters are double lumen catheters having proximal and distal ends with lumens extending between the two ends. The distal end is placed where there is a high flow of blood, typically near the heart. The high blood flow enables a sufficient volume of blood to be processed through the catheter and cleaned by a dialysis machine. The proximal end is typically placed on the chest for easy access to connect blood lines from the dialysis machine.
A typical medical procedure for implanting a catheter when accessing the jugular vein involves a small incision in the skin of the neck over the jugular vein. Subsequently, the vessel is dilated to allow the insertion of an introducer sheath. The sub-cutaneous tissue under the skin, adjacent to the insertion site, is tunneled with a dilator, thus allowing the passage and anchoring of the catheter right above the clavicle. After insertion of the catheter, the sheath is removed by peeling it apart.
Dialysis catheters vary considerably from one manufacturer to another. However, one common requirement for virtually all dialysis catheters is open-ended distal ends for the removal of blood from the blood vessel to the dialysis machine and the return of the processed blood from the dialysis machine to the blood vessel. One known problem is that the open-ended arterial intake port is prone to blockage by thrombosis and fibrin buildup, thus preventing or reducing the flow considerably. When this happens and the blood flow cannot be restored, doctors are forced to remove the catheter and replace it with a new catheter. This process is very costly and induces additional trauma to the patient. More importantly, it also puts the patient at further risks for infection during the catheter exchange procedure.
In one aspect, a dialysis catheter is provided having a first tube with a first tube distal end having an intake port. A second tube extends parallel to and is connected to the first tube, and includes a second tube distal end with a discharge port. A cover is located on the first tube that is movable from a first position, in which it blocks the intake port, to a second position, in which the intake port is unblocked. A longitudinally extending control wire hole is defined through a wall of the first tube. A control wire extends through the hole. The control wire has a first end that is fixed to the cover and a second end. A switch is connected to the second end of the control wire that is movable in order to move the cover between the first and second positions.
Preferably, during use in dialysis procedures, the arterial intake port is closed at all times until the patient is ready for dialysis treatment. By keeping the arterial intake closed by the cover, buildup of fibrin or thrombosis is kept on the outside of the port. When dialyzing the patient, the switch is moved so that the cover is in the second, open position where the intake port is unblocked, which also allows for the clearing of any buildup on the intake port. Once the dialysis treatment is completed, the switch is moved back so that the cover is in the first position, covering the intake port.
Preferably after dialyzing the patient, each of the lumens defined by the first and second tubes is primed with anti-coagulent medication, typically Heparin, to prevent blood from clotting the lumens. In the known prior devices, the Heparin leaks out the open-ended ports, which leads to clotting of the lumens. The closed arterial port provided by the present invention reduces the chances of Heparin leaking out of the intake port, thus acting further to prevent blockage of the arterial lumen. Most blood flow blockage problems are associated with the arterial intake lumens, although a similar cover could also be provided for the venal discharge port from the second tube, if desired.
The foregoing summary as well as the following detailed description will be better understood when read in conjunction with the appended drawings where a preferred embodiment of the invention is shown. In the drawings:
Certain terminology is used in the following detailed description for convenience only and is not considered limiting. The words “upper” and “lower” designate direction in the drawings to which reference is made. Additionally, the terms “proximal” and “distal” refer to the dialysis catheter based upon the portion which would be handled by a doctor or nurse setting the catheter in a patient for dialysis treatment. Additionally, the terms “a” and “one” are defined as including one or more of the referenced items unless specifically noted.
Referring to
In the preferred embodiment, the first and second tubes 19, 21 are formed as a unitary dual tube having a generally circular outer wall 28 and an inner dividing wall 30, as shown in
Preferably, the dual tube 19, 21 is made of a polyurethane or silicone material. However, other suitable medical grade materials may be utilized.
Referring to
The longitudinally extending hole 32 in the outer wall 28 of the first tube in proximity to the top thereof, as shown in
Referring to
As shown in
The second longitudinally extending hole 33, shown in
As a further alternative, when the unitary dual tube shown in
Referring again to
In the preferred embodiment, the hub 14 is formed as a molded part or parts, and is preferably formed in two halves that can be joined together to connect the tubes 19, 21, 50 and 52 to the passages 36 and 38. By forming the hub 14 as two molded halves 34, the tubes can be accurately set in position and can be sealed in place by bonding or adhering the two halves together. The mating plane of one half is shown in
In use, the catheter 10 is inserted into a patient's blood vessel with the cover 25 in the closed position. When dialysis is to be initiated, the switch 44 is utilized to move the cover 25 to the second, open position such that the intake port 24 is unblocked. Blood is withdrawn from the patient via the arterial lumen defined by the first tube 19, first passage 36 and the proximal arterial tube 50 where it is drawn into the dialysis machine and treated. The treated blood is returned via the venal lumen 22 defined by the proximal venal tube 52, the second passage 38 and the second tube 21. At the end of the dialysis treatment, the switch 44 is moved to return the cover 25 to the closed position where the arterial port 24 is blocked. Each lumen is then primed with anti-coagulant medication, preferably Heparin to prevent blood from clotting the lumens. The closed arterial port reduces the chance of Heparin leaking out of the port and therefore prevents blockage of the arterial lumen. As most blood flow blockage problems are associated with the arterial lumen in practice, a cover has only been shown as being provided for the arterial port 24. However, it is also possible within the scope of the present invention to provide a second cover for the discharge port 26 from the second tube 21, if desired.
Referring again to
Those skilled in the art will understand that the cover 25 does not need to entirely close the arterial port 24, but should generally cover a majority of the arterial port opening.
While the preferred embodiment of the invention has been described, the invention is not limited to the specific arrangement provided. Rather, the scope of the invention is defined by the appended claims.
This application claims the benefit of U.S. provisional application No. 61/066,531, field Feb. 21, 2008, which is incorporated by reference as if fully set forth.
Number | Date | Country | |
---|---|---|---|
61066531 | Feb 2008 | US |