Renal denervation

Renal denervation is a technique that lowers blood pressure in patients with resistant hypertension who are unable to control their blood pressure despite taking more than three drugs to reduce this risk factor.

Different studies have shown that radiofrequency ablation of the arteries of the renal sympathetic nerve gives good long-term (36 months) results. The patients who participated in the study reduced their blood pressure and, in most cases, the number of drugs that they were taking prior to the intervention.

The Instituto Cardiovascular Teknon renal ablation unit is staffed by a multidisciplinary team of specialists including nephrologists, interventional vascular radiologists and interventional cardiologists.

What is hypertension? And what is resistant hypertension?

Hypertension occurs when there is too much pressure in the arterial blood flow. Hypertension is a chronic condition that is not always associated to symptoms (headache, nervousness, nasal haemorrhage), but which increases the patient's cardiovascular risk and can affect his or her quality of life. In most cases, the causes are unknown. According to the Spanish Cardiology Society, around 10 million people suffer from hypertension in Spain. Approximately 10% of these have resistant hypertension.

Resistant hypertension occurs when blood pressure is not controlled despite taking more than three hypertension drugs and making lifestyle changes (physical exercise, control of cholesterol, no smoking or drinking, etc.).

What is a normal blood pressure level?

In general, a person's blood pressure is normal when it is 140/90 mmHg, but this can vary from one patient to another.

If in doubt, it is important to see a specialist to determine whether you are at risk for hypertension.

What causes are related to resistant hypertension?

Resistant hypertension is usually related to factors such as age, obesity, diabetes or chronic kidney disease, among others.

What is renal denervation?

In patients with resistant hypertension despite medication, the specialist, after ruling out a secondary cause, might suggest undergoing renal ablation to control or lower blood pressure.

Renal ablation uses radiofrequency to disrupt the renal sympathetic nerve in order to reduce its activity, which in turn reduces blood pressure.

What does it involve?

Renal ablation is a minimally invasive technique using a catheter with four electrodes, which is inserted into the femoral artery until it reaches the renal arteries. The catheter is then brought to a temperature of 40-50ºC and ablates some small nerves in the renal artery, causing the kidney to produce less pressure-raising hormones. The procedure has to be applied to both kidneys.

The procedure is done under sedation. The patient is hospitalised for one day.

Why is the renal sympathetic system disabled?

Different studies have shown that increased sympathetic activity in the kidney raises blood pressure. When this activity is disabled, blood pressure falls.

Does it have any side effects?

The studies conducted to date have not detected any serious side effects.

What is the outcome?

Renal ablation has a progressive outcome. After the procedure, the specialist gradually reduces the patient's intake of drugs, depending on the results.

Different studies have found that it is an effective technique that lowers blood pressure by at least 15-20 mmHg and up to 30 mmHg. This improves the patient's quality of life and reduces the risk of cardiovascular accidents related to high blood pressure, such as embolism or heart disease.

The studies also show that the patient's blood pressure decreases after the procedure. Patients can subsequently discontinue 2 to 3 of their hypertension drugs, depending on each individual.

Instituto Cardiovascular Teknon Renal Ablation Unit - the Team

• Dr Jorge Moisés, Nephrologist
• Dr Jordi Muchart, specialist in Interventional Vascular Radiology
• Dr Antoni Serra Peñaranda, specialist in Interventional Cardiology