Renal Denervation (RDN)

Renal denervation (RDN) is a minimally invasive procedure aiming to reduce high blood pressure by targeting the nerves in the renal arteries (large blood vessels that carry blood from the heart to the kidneys). These nerves play an important role in the body’s regulation of blood pressure through the sympathetic nervous system. In patients with resistant hypertension, these nerves are often overactive, leading to persistently high blood pressure (usually above 130/80 mmHg) despite medication and lifestyle interventions.

Renal denervation (RDN) has been extensively studied in clinical trials, which have demonstrated its effectiveness in lowering blood pressure in patients with resistant hypertension.

At Capital Heart Centre, our experienced Interventional Cardiologist, Dr Joshua Loh will conduct detailed assessments to determine whether you will benefit from renal denervation.

Patients who may benefit from renal denervation usually have the following conditions:

• Diagnosed with Resistant Hypertension: The primary candidates for renal denervation are individuals whose high blood pressure condition cannot be controlled despite:
  • Concurrently taking three different blood pressure medications at their maximally tolerated doses.
  • One of the blood pressure medications being a diuretic (gets rid of fluid and salt from the body).
• Suffering From Adverse Reactions to Medications: Some patients may experience significant side effects from blood pressure medications.
• Seeking a Long-term Solution: Unlike antihypertensive medications, renal denervation provides a more permanent solution by addressing the underlying cause of high blood pressure—the overactivity of the renal sympathetic nerves.
• Diagnosed with Comorbid Conditions: Patients with hypertension suffering from multiple concurrent conditions such as chronic kidney disease, heart failure, or diabetes may benefit from renal denervation.

It is important to note that this procedure is usually considered only when medication and lifestyle modifications have failed to achieve adequate blood pressure control.

Before the procedure, you will undergo several tests to evaluate your overall physical health and the condition of your renal arteries. You may undergo blood tests, imaging studies (like CT or ultrasound scans), and a review of your medical history. This thorough assessment will help to determine whether renal denervation is suitable for you.

Patients undergoing renal denervation will be instructed to fast for a few hours before the procedure and may need to stop taking certain medications temporarily.

1. Application of Anesthesia and Sedation:
   • Renal denervation is usually performed under local anaesthesia, which numbs the area where the catheter will be placed (typically the groin area). Sedation or general anaesthesia may also be administered to help you relax during the procedure.
2. Catheter Insertion:
   • The interventional cardiologist will make a small incision in the groin area Afterwards, an ablation catheter is inserted through the femoral artery and carefully guided through the blood vessels to reach the renal arteries.
3. Nerve Ablation:
   • Once the catheter is in position within the renal arteries, radiofrequency energy or ultrasound waves are delivered through the catheter to ablate (destroy) the sympathetic nerves surrounding the arteries. 
   • After identifying the renal arteries’ location, the catheter equipped with the radiofrequency system will be placed within the renal artery. The treatment is administered in two-minute intervals, repeated four to six times for each artery. Once both renal arteries (left and right) have been treated, the equipment will be removed.
4. Closing of the Incision:
   • After the nerve ablation is complete, the catheter is removed, and pressure is applied to the insertion site to prevent bleeding. The small incision is then closed, and a bandage is applied.

After renal denervation, you will be monitored for a few hours in the recovery area to ensure that there are no immediate complications. Most patients are able to return home the following day, depending on their condition.

In the days following the procedure, you may experience mild soreness or bruising at the catheter insertion site, but this is usually temporary. You will be recommended to avoid rigorous activities and heavy lifting for a few days to allow the insertion site to heal.

Your cardiologist will schedule follow-up appointments to monitor your blood pressure and determine the effectiveness of the procedure. It may take several weeks to a few months for the full benefits of renal denervation to become apparent, as the body gradually adjusts to the reduced activity of the renal sympathetic nerves.

In most cases, patients experience a significant reduction in blood pressure following renal denervation. However, it is important to continue taking any prescribed medications and following lifestyle recommendations as directed by your doctor.

Renal denervation is minimally invasive, meaning it does not require large incisions or major surgery. In general, the procedure is well-tolerated by patients, and discomfort is usually minimal.

Since the procedure is performed under local anaesthesia and sedation, you should not feel pain during the catheter insertion or nerve ablation. However, some patients may experience mild discomfort or a sensation of pressure in the groin area where the catheter is inserted. Moreover, sedation is often provided to help you relax during the procedure, which can further minimise any discomfort. After the procedure, you may experience soreness or bruising at the catheter insertion site. Nonetheless, these side effects are typically mild and resolve within a few days.

As with any medical procedure, renal denervation carries some risks. However, it is generally considered safe, and serious complications are rare. The common risks associated with renal denervation, such as minor bleeding or infection, are generally mild and often resolve on their own. Rare risks involve bradycardia (slow heart rate), pseudoaneurysm (leaking in the artery), retroperitoneal bleeding, and arterial occlusion (artery blockage) from thermal injury.