The Sympathetic Nervous System
Renal sympathetic nerve hyper-activation leads to renin secretion, sodium reabsorption and decreased renal perfusion. Increased sympathetic nerve activity plays a key role in the pathophysiology of essential hypertension.1, 2 The overactive sympathetic nervous system not only plays a role in hypertension, but may also have a role in heart failure, kidney disease, metabolic syndrome and sleep apnea.3
In the past, sympathectomy (surgical cutting of a sympathetic nerve) to interrupt this oversignaling was performed in patients with severe hypertension. The surgery did lead to a reduction in blood pressure, but was a highly invasive procedure.2, 3
Renal Denervation (RDN)
For patients unable to effectively control their blood pressure with lifestyle changes and medication therapy, a new class of interventional products have been under development this past decade as an investigational treatment of hypertension using a procedure called renal denervation. This investigational procedure ablates the sympathetic nerves in order to reduce their overactivity. Most recently, data from three sham-controlled renal denervation trials using second-generation technology showed similar consistent decreases in blood pressure.4
1 Mahfoud et al, Catheter-based renal denervation in hypertension: heading for new shores, J Hypertens. 2018 January ; 36(1): 41–42
2 Sverre E. Kjeldsen, Krzysztof Narkiewicz, Michel Burnier & Suzanne Oparil (2018) Renal denervation achieved by endovascular delivery of ultrasound in RADIANCE-HTN SOLO or by radiofrequency energy in SPYRAL HTN-OFF and SPYRAL-ON lowers blood pressure, Blood Pressure, 27:4, 185-187, DOI: 10.1080/08037051.2018.1486178
3 Fisher et al, Central Sympathetic Overactivity: Maladies and Mechanisms, Auton Neurosci. 2009 June 15; 148(1-2): 5–15. doi:10.1016/j.autneu.2009.02.003
4 Schmieder et al, European Society of Hypertension Position Paper on Renal Denervation 2018, Journal of Hypertension 2018 Oct;36(10):2042-2048.