Implant could cut dialysis risks

JOHNS HOPKINS U. (US) — A new device designed to be implanted under the skin could reduce the risk of infection, clotting, and narrowing of the blood vessels in patients who need dialysis because of kidney failure.

The prototype, which has yet to be used in human patients, would allow easy access to the patient’s bloodstream and could be opened and closed at the beginning and end of a dialysis procedure.

Each year kidney failure requires 1.5 million people globally and 350,000 in the United States alone to undergo regular hemodialysis to prevent a fatal buildup of toxins in the bloodstream. The three most common ways to connect the machine to a patient’s bloodstream work only for a limited time because of problems with infection, blood clots, and narrowing of the blood vessels.

Researchers say current dialysis access options are “grossly inadequate,” contributing to increased healthcare expenses and, in some cases, patient deaths.

The device, which was developed by a team of engineering graduate students at Johns Hopkins University working with Thomas Reifsnyder, assistant professor of surgery; and Kelvin Hong and Clifford R. Weiss, assistant professors of radiology, won first prize at the 2011 ASME Innovation Showcase.

Two valves on the Hemova Port can be opened by a dialysis technician with a syringe from outside the skin. The technician can also close the valves when the procedure is over, an approach that helps avoid infection and clotting. The device also includes a simple cleaning system.

Currently, most dialysis access sites are in the arm or the heart. The new device is designed to be sutured to the leg’s femoral vein, avoiding the unnaturally high blood flows that cause vessel narrowing when dialysis machines are connected to veins and arteries in the arm.

The leg connection should also allow the site to remain in use for a significantly longer period of time, the student researchers say.

Clinical trials involving human patients could being as soon as 2013.

More news from Johns Hopkins University: