Implanted Fistula Device Lowers Blood Pressure

An innovative vascular coupling device tackles resistant high blood pressure (BP) by joining an artery and a vein together in the groin.

Researchers at Queen Mary, University of London (QMUL; United Kingdom), the Wales Heart Research Institute (Cardiff, United Kingdom), and other institutions conducted a randomized, blinded endpoint clinical trial of the efficacy of the Rox coupler, a paper-clip sized implant which is inserted between the artery and vein in the upper thigh, creating a partial anastomosis. The study involved 83 patients from 16 European centers, all of whom had resistant high blood pressure and had not responded to at least three types of drug treatment.


The results showed that the 44 patients who received the Coupler experienced a significant (26.9%) and durable reduction in blood pressure, as well as a reduced number of hypertensive complications and hospital admissions for high blood pressure crises. The Coupler also worked well among patients who had failed to respond to renal denervation, suggesting that it targets different mechanisms of BP control. An unwanted side effect, however, was leg swelling, with 29% of patients who received the Coupler requiring a stent. The study was published on January 22, 2015, in the Lancet.

“This is an entirely new and highly promising concept in high blood pressure treatment. The Coupler effectively targets the mechanical aspects of how blood circulation works, so it's a totally new approach to controlling blood pressure,” said lead author Melvin Lobo, MD, of QMUL. “The Coupler also highlights the importance of arterial stiffness as a major cause of resistant high blood pressure and it targets this issue both safely and successfully. Once the Coupler is placed, the results are also immediate, which again is unique to this treatment.”

The Rox coupler is a small metal stent made of nickel-titanium (nitinol) which forms an anastomosis between venous and arterial iliac vessels, allowing blood to flow between the high pressure artery and the low pressure vein. The device is inserted and positioned via a laparoscopic procedure at the groin under local anesthesia, and is fully reversible by placing a covered stent over the arterial side of the anastomosis. The Rox coupler is a product of Rox Medical (San Clemente, CA, USA).

Related Links:
Queen Mary, University of London
Wales Heart Research Institute
Rox Medical