High blood pressure is to be treated with a new surround sound system which sends ultrasound waves to the kidneys.

The technique being trialled at Southampton General Hospital, called renal denervation, uses novel technology known as the Surround Sound Hypertension Therapy System to provide an alternative treatment for patients who have been unable to control the condition using conventional medication.

Around 500,000 people in the UK suffer from resistant hypertension, a type of high blood pressure which remains uncontrolled despite the use of three or more drugs.

The condition causes the body to pump blood too forcefully through the arteries and heart and, if left untreated or poorly managed, can lead to heart attacks, stroke or kidney disease.

James Wilkinson, a consultant cardiologist, said: "The development of surround sound therapy for renal denervation represents another potential major advancement in treatment for patients with uncontrolled blood pressure as it can be delivered non-invasively from outside of the body.

"If successful, this technique will offer people who cannot control their blood pressure with medication an option to limit their risk of stroke or heart disease without the need for incisions, lasers or a hospital stay."

Using the surround sound system, clinicians can deliver a focused ultrasound beam from outside the body to disrupt overactive nerves leading to or in the kidneys, which increases blood flow to the organs and reduces levels of a hormone linked to high blood pressure.

The procedure lasts for around an hour and patients return home the same day.

Other forms of renal denervation require an incision and catheter to be passed through the groin and into the body to send high frequency signals to the nerves.

In early-stage trials, three-quarters of treated patients experienced a reduction in blood pressure.

Roland Schmieder, a specialist in hypertension based at University Hospital Erlangen in Germany and the study's principal investigator, said: "With its novel approach, external ultrasound offers potential benefits over existing catheter-based renal denervation techniques.

"If proven successful, non-invasive renal denervation could greatly reduce costs of treatment and increase access for the millions of people worldwide whose blood pressure is not adequately controlled today."