Catheter-based renal sympathetic denervation: limitations to and gaps in the evidence.

PURPOSE OF REVIEW: Renal sympathetic nerves play a significant role in the development and maintenance of hypertension. Percutaneous catheter-based radioablation of the sympathetic nerves around the renal arteries is a true innovation in follow up to prior animal studies. In this opinion article, we will review the role of the renal sympathetic network in hypertension, and the evidence (or the lack of it) for renal sympathetic denervation as a treatment modality for human hypertension.

RECENT FINDINGS: Over the last 5 years, path-breaking research has raised the promise of a dramatically effective therapy for treatment of resistant hypertension in the form of renal sympathetic denervation. Unfortunately, on the basis of limited proof-of-concept and prospective observational studies, this method was widely perceived as a proven therapy for resistant hypertension. As we have learnt from history, only properly designed prospective randomized controlled trials can tell whether that is indeed the truth.

SUMMARY: Catheter-based renal sympathetic denervation, despite the recent setbacks, remains a novel and innovative therapeutic intervention, which may still have a role to play in the treatment of carefully selected patients with truly resistant hypertension. Mechanistic studies designed to address the cause of the blood pressure response (or lack thereof) to renal denervation are the next logical step. However, the long-term implications of renal denervation, especially safety issues with respect to the lack of renal sympathetic response in times of physiological need, are not well understood.