Arteriovenous access valve system and process

Abstract

An arteriovenous graft system is described. The arteriovenous graft system includes an arteriovenous graft that is well suited for use during hemodialysis. In order to minimize or prevent arterial steal, at least one valve device is positioned at the arterial end of the arteriovenous graft. In one embodiment, for instance, the arteriovenous graft system includes a first valve device positioned at the arterial end and a second valve device positioned at the venous end. In one embodiment, the valve devices may include an inflatable balloon that, when inflated, constricts and closes off the arteriovenous graft. If desired, a single actuator can be used to open and close both valve devices.

Description

BACKGROUND[0001]The function of kidneys, which are glandular organs located in the upper abdominal cavity of vertebrates, is to filter blood and remove waste products. Specifically, kidneys separate water and waste products of metabolism from blood and excrete them as urine through the bladder. Chronic renal failure is a disease of the kidney in which the kidney function breaks down and is no longer able to filter blood and remove waste substances. Should certain toxic waste substances not be removed from the blood, the toxic substances may increase to lethal concentrations within the body.[0002]Hemodialysis is a life-sustaining treatment for patients who have renal failure. Hemodialysis is a process whereby the patient's blood is filtered and toxins are removed using an extracorporeal dialysis machine. For hemodialysis to be effective, large volumes of blood must be removed rapidly from the patient's body, passed through the dialysis machine, and returned to the patient. A number o...

AI Technical Summary

Benefits of technology

[0009]In general, the present invention is directed to subcutaneous arteriovenous graft systems and to processes for using the arteriovenous graft systems in a manner that eliminates or at least reduces arterial steal and graft thrombosis. In one embodiment, for instance, the system includes an arteriovenous graft having an arterial end and an opposite venous end. The arterial end is configured to be connected to an artery to form an arterial anastomosis, while the venous end is configured to be connected to a vein to form a venous anastomosis.

[0023]In an alternative embodiment, the check valve may comprise a pair of opposing and overlapping flaps positioned within the arteriovenous graft. The flaps can be integral with the graft or can be attached to the arteriovenous graft on opposing sides. For instance, the flaps can be attached to the graft using sutures or through a welding process. In order to prevent leakage, the check valve can further include edge seals that are positioned on opposing sides of each flap. The edge seals can create a seal with the radial wall of the arteriovenous graft.

[0024]The arteriovenous graft of the present invention is used for hemodialysis. During hemodialysis, two hypodermic needles are inserted into the arteriovenous graft. Blood is removed from the graft using one needle, circulated through a dialysis machine, and returned to the arteriovenous graft through the second needle. When hemodialysis is not being conducted, however, the valve devices of the present invention may be activated in order to minimize arterial steal and prevent thrombosis of the graft.

[0026]In another embodiment, after hemodialysis, the valve device is partially closed to a first position thereby constricting the arteriovenous graft and reducing blood flow through the graft. The patient is then monitored over a period of time, such as days or weeks, and the valve device may be selectively opened or closed from the first position until arterial steal is minimized. In this embodiment, the valve device is closed an amount sufficient to reduce blood flow through the graft without slowing the blood flow to a point where blood clots may form.

Problems solved by technology

Should certain toxic waste substances not be removed from the blood, the toxic substances may increase to lethal concentrations within the body.

Various problems, however, have been experienced with the use of an arteriovenous graft.

Various other complications can also occur.

This collision between the flow of blood and the vein may cause the development of myointimal hyperplasia which leads to the thickening of the vein walls and a narrowing of the vessel.

As the vein narrows, flow through the arteriovenous graft decreases and blood within the graft may ultimately clot.

Graft thrombosis, however, continues to remain a reoccurring complication associated with the use of arteriovenous grafts.

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