Renal denervation (RDN) is a catheter-based therapy for hypertension that targets the sympathetic nerves running in the wall of the renal arteries. Overactivity of these nerves — the kidney-to-brain and brain-to-kidney signalling that raises sodium retention, renin release, and vascular tone — is a recognized driver of blood pressure that stays high despite multiple medications. By delivering energy from inside the renal artery to interrupt the surrounding nerve fibers, RDN turns down this feedback loop. After a turbulent evidence history, rigorous sham-controlled trials re-established the therapy, and renal denervation has since entered contemporary hypertension practice as an adjunct for selected patients.
The Rationale: Why the Kidney's Nerves?
The renal sympathetic nerves travel in the adventitia of the renal arteries, making them reachable from within the lumen. Efferent fibers promote sodium and water retention and renin release; afferent fibers signal the central nervous system to raise systemic sympathetic tone. In resistant hypertension this axis is often overactive, so interrupting it addresses a mechanism that drugs only partly reach — and, unlike medication, it does not depend on daily adherence, which is itself a major reason blood pressure stays uncontrolled.
The Evidence Arc
RDN's history is instructive. Early unblinded studies were dramatically positive; the first sham-controlled trial then failed to meet its endpoint, and enthusiasm collapsed. Rather than abandon the idea, the field redesigned it — better catheters, fuller circumferential ablation, cleaner patient selection, and blinded, sham-controlled methodology. The second generation of trials showed consistent, if modest, blood-pressure reductions versus sham across both medicated and unmedicated cohorts. That disciplined recovery is why RDN now appears in guideline discussions as an option for shared decision-making, not a cure-all.
The Procedure
RDN is performed like other endovascular interventions: femoral or radial access, a guiding catheter to each renal artery, and an ablation catheter advanced into the vessel. Energy — radiofrequency in most systems — is applied in a circumferential, longitudinally distributed pattern along the main artery and, where appropriate, its branches, to interrupt the periarterial nerves while sparing the vessel wall. The procedure typically takes about an hour; there is no implant, and patients usually go home within a day. Because there is no lasting hardware and no chronic drug exposure, the safety focus is procedural: access-site care and preservation of renal artery integrity.
Patient Selection
The strongest candidates are patients with confirmed resistant hypertension — elevated pressure despite three or more agents including a diuretic, verified by ambulatory monitoring — and those who cannot tolerate or will not adhere to medication. Suitable renal artery anatomy is a prerequisite (adequate diameter and length, no critical stenosis or prior stenting). Secondary causes of hypertension must be excluded first. Selection is a specialist decision that weighs anatomy, comorbidity, and the patient's own priorities about lifelong pharmacotherapy versus a procedure.
Device Considerations and the INVAMED Delta System
Contemporary RDN catheters aim for reliable circumferential nerve interruption with predictable, wall-sparing energy delivery. INVAMED's Delta Renal Denervation System is INVAMED's entry in this category, part of the broader coronary and cardiac intervention portfolio. As with all of these technologies, availability and approved indications vary by country, and the treating physician selects the system and technique per the Instructions for Use.
Frequently Asked Questions
Does renal denervation cure hypertension?
No — it lowers blood pressure by a meaningful but modest amount and is used alongside, not instead of, lifestyle measures and (usually) medication. Its appeal is an always-on effect independent of daily adherence.
Is renal denervation permanent?
The nerve interruption is intended to be durable; there is no implant. Long-term follow-up studies continue to characterize the durability of the blood-pressure effect.
Who should consider renal denervation?
Patients with true resistant hypertension confirmed on ambulatory monitoring, or those unable to tolerate or adhere to medications, with suitable renal artery anatomy and secondary causes excluded.
Is the procedure safe?
Modern sham-controlled trials found safety comparable to control, with the main considerations being access-site events and preserving renal artery integrity. There is no chronic drug exposure and no retained device.
Related on INVAMED
Portfolio: coronary artery disease & cardiac interventions. Patient hub: coronary artery disease.
Device availability and regulatory status vary by country. Please contact INVAMED or your authorized local distributor for current regulatory information applicable to your region.