Many people suffer from high blood pressure. The causes of an increase in blood pressure are usually overactive renal nerves, which in most cases can be controlled with medication, lifestyle changes and regular measurements. But in about half of people with high blood pressure, the medicines do not work sufficiently and the stimuli that cause high blood pressure are maintained, also known as resistant hypertension. For people with resistant hypertension, renal denervation is used instead of medication. With this technique, a cardiologist partially closes the hyperactive renal nerve with an electric current, allowing the upper pressure to drop from 150 to 120. The effect of the procedure is only noticeable after six to twelve months.

High blood pressure causes and overactive renal nerves

The various causes act on the renal nerves, which react overactively

Causes of high blood pressure

The causes of high blood pressure are different: including hereditary factors, kidney disease and prosperity factors such as obesity, smoking, alcohol and sugar. Numerous articles have been written about these problems and therefore do not require additional attention here. In many cases, medication, lifestyle changes and regular blood pressure measurements are sufficient to keep the disease under control.

High blood pressure and hyperactive renal nerves

The causes of an increase in blood pressure are usually overactive renal nerves. These nerves are responsible for hormone production that regulates blood pressure. If the hyperactivity cannot be reduced through medication and changes in lifestyle, the stimuli that cause high blood pressure are maintained. Then there is resistant hypertension.

Treating overactive renal nerve with renal denervation

About 50% of people with high blood pressure have resistant hypertension. Until recently, little treatment was available for this group, but the renal denervation technique has been developed for these patients.

What is Renal Denervation

Renal denervation literally means: interrupting the function of the nerve pathways to and from the kidneys.It reduces the activity of the renal nerve, which reduces hormone production that regulates blood pressure./ Source: FotoshopTofs, PixabayCausing a hyperactive renal nerve with an electric current. The patients who undergo the operation are first extensively screened by the Nephrology/Internal Medicine department. After that, the procedure may or may not take place. The technique used is comparable to an angioplasty treatment and is also performed by cardiologists. No coincidence of course, because high blood pressure is one of the biggest causes of cardiovascular disease. The cardiologist guides a rod via the artery in the femur to the kidney, with which he uses an electric current to cauterize the hyperactive renal nerve at certain points in the renal artery. This reduces the hormone production that regulates blood pressure, because the stimuli become less strong or even disappear completely. This technique can reduce blood pressure. An upper pressure of 150 can drop to 120. It takes 6 to 12 months for the body to adapt to the new situation, after which the final result can be fully measurable.

Possible risks of renal denervation

The most important risks can be compared with the risks of other procedures in which a catheter is inserted into an artery in the body.

Short-term risks may include:

• Bleeding. A bruise may develop at the puncture site.
• Remaining pain after the procedure at the site where the injection was administered
• Blood vessel complications:
  • Damage to the inside of the blood vessels
  • Breaking loose a piece of cholesterol that gets stuck somewhere else in the body and causes damage there. (cholesterol emboli). In very serious and exceptional cases, surgery may be necessary.
• An allergic reaction to contrast agent.

Long-term effects:

• The long-term effects of this treatment are unknown.
• It is expected that the blood pressure will persist for a long time (2 years).
• Possible beneficial effect on renal function.
• Effects of the treatment on the blood vessel wall itself are unknown. At UMC Utrecht, examination of the renal arteries was performed in 20 patients shortly after renal denervation . No stenosis or other abnormalities of the renal arteries were found.
• Adverse effects in the longer term cannot therefore be ruled out. Experiences to date indicate that adverse effects are not to be expected.

High blood pressure treatments in Dutch hospitals

Since 2010, the treatment of renal denervation has been used in some Dutch hospitals

• The UMC Utrecht is the first hospital in the Netherlands where patients are treated with renal denervation. The first patient was treated in July 2010.
• Haga hospital The Hague
• TweeStedenziekenhuis Tilburg
• Canisius Wilhelmina Hospital (CWZ) in Nijmegen

Long-term renal denervation

At the moment, this procedure is reserved for a specific group of patients, but in the near future renal denervation can be applied on a larger scale, also in patients who do respond to blood pressure lowering agents .And in the distant future to all people with high blood pressure.