What is renal denervation?
The kidneys are connected to the nervous system by fine nerves that run in the wall of the kidney arteries. When these nerves are overactive they keep blood pressure high by holding salt and water in the body and tightening the blood vessels. Renal denervation is a procedure in which a catheter is passed into each kidney artery and gentle energy is applied to the artery wall to quieten these nerves. Nothing is left behind in the body.
Why is it done?
It is offered to patients whose blood pressure remains too high despite taking several medications correctly, or who cannot tolerate their tablets. Lowering blood pressure reduces the long-term risk of stroke, heart attack, heart failure and kidney damage. Renal denervation is not a replacement for medication or for lifestyle measures such as reducing salt, losing weight and exercising; it is an addition that in most patients produces a modest but lasting further drop in blood pressure. Before the procedure we confirm that the readings are genuinely high, usually with a twenty-four hour blood pressure monitor, check that no other treatable cause is present, and image the kidney arteries.
What happens on the day?
You come in fasting for a day case or single overnight stay. In the catheterisation laboratory a drip is placed, the groin or wrist is numbed with local anaesthetic and you are given sedation and pain medication to keep you comfortable. A catheter is guided from the groin or wrist artery into each kidney artery, contrast dye is used to map the vessel and the treatment catheter then delivers a series of short energy applications at several points around the artery.
What to expect afterwards
Most patients go home the same day or the next morning. Very importantly, all your blood pressure medication is continued exactly as before, and only reduced later, by your doctor, if the readings allow.
Possible complications
The procedure has a good safety record but risks exist. Common: bruising, tenderness or bleeding at the groin or wrist puncture, and back or abdominal ache for a day or two. Uncommon: injury to the kidney artery wall, including a tear, spasm or a reaction to the contrast dye.
This information does not replace a consultation. Please discuss your own risks and options with your cardiologist.