A simple implant the size of a paper clip can dramatically lower high blood pressure in patients not responding to drugs, research has shown.
The device, called a "coupler", is inserted between an artery and vein in the upper thigh during a 40-minute procedure under local anaesthetic.
It creates a passage way between the two vessels that acts like a safety valve, reducing pressure in the arterial system by allowing some blood to flow into the veins.
The effectiveness of the device was studied in a group of 83 patients with uncontrolled hypertension, or high blood pressure.
Forty four were fitted with the coupler while the rest acted as a "control group" and received conventional drug treatment.
Those given the implant experienced a "significant and durable" reduction in blood pressure compared with the control group, said the scientists. They also had fewer complications and hospital admissions linked to high blood pressure.
The device also worked well in patients who had failed to respond to renal denervation, a procedure that involves the removal of nerves.
Story continues below...
Lead researcher Dr Melvin Lobo, from Queen Mary, University of London, said: "This is an entirely new and highly promising concept in high blood pressure treatment. Existing drugs focus on hormonal or neurological regulation of blood pressure, and newer treatments such as renal denervation are uniquely centred on the renal nervous system.
"The coupler effectively targets the mechanical aspects of how blood circulation works - so it's a totally new approach to controlling blood pressure. 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."
Patients with the coupler had their average systolic, or "pumping", blood pressure reduced by 26.9 millimetres of mercury compared with 3.7 mm Hg for the control group.
The implant is made by the US company Rox Medical, which funded the study published online in The Lancet medical journal.