Review
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World J Cardiol. Aug 26, 2014; 6(8): 814-823
Published online Aug 26, 2014. doi: 10.4330/wjc.v6.i8.814
Renal sympathetic nervous system and the effects of denervation on renal arteries
Arun Kannan, Raul Ivan Medina, Nagapradeep Nagajothi, Saravanan Balamuthusamy
Arun Kannan, Saravanan Balamuthusamy, Department of Medicine, University of Arizona, Tucson, AZ 85721, United States
Raul Ivan Medina, Saravanan Balamuthusamy, Vascular and Interventional Nephrology, Angiocare, Tucson, AZ 85721, United States
Nagapradeep Nagajothi, Cardiovascular Consultants, Canton, OH 44710, United States
Author contributions: Kannan A and Balamuthusamy S made substantial contributions to conception and design, acquisition of data; Kannan A, Medina RI and Nagajothi N contributed by drafting the article and revising it critically for important intellectual content; and Balamuthusamy S contributed to the final approval of the version to be published.
Correspondence to: Saravanan Balamuthusamy, MD, FASN, Assistant Professor, Director of Vascular and Interventional Nephrology, Angiocare, 224 W Exchange St, Tucson, AZ 85721, United States. sbalamuthusamy@email.arizona.edu
Telephone: +1-520-3276265 Fax: +1-520-3279300
Received: January 20, 2014
Revised: March 18, 2014
Accepted: June 10, 2014
Published online: August 26, 2014
Processing time: 240 Days and 10.3 Hours
Abstract

Resistant hypertension is associated with chronic activation of the sympathetic nervous system resulting in various comorbidities. The prevalence of resistant hypertension is often under estimated due to various reasons. Activation of sympathetic nervous system at the renal- as well as systemic- level contributes to the increased level of catecholamines and resulting increase in the blood pressure. This increased activity was demonstrated by increased muscle sympathetic nerve activity and renal and total body noradrenaline spillover. Apart from the hypertension, it is hypothesized to be associated with insulin resistance, congestive heart failure and obstructive sleep apnea. Renal denervation is a novel procedure where the sympathetic afferent and efferent activity is reduced by various techniques and has been used successfully to treat drug-resistant hypertension improvement of various metabolic derangements. Renal denervation has the unique advantage of offering the denervation at the renal level, thus mitigating the systemic side effects. Renal denervation can be done by various techniques including radiofrequency ablation, ultrasound guided ablation and chemical ablation. Various trials evaluated the role of renal denervation in the management of resistant hypertension and have found promising results. More studies are underway to evaluate the role of renal denervation in patients presenting with resistant hypertension in different scenarios. Appropriate patient selection might be the key in determining the effectiveness of the procedure.

Keywords: Resistant Hypertension, Sympathetic nervous system, Sympathectomy, Renal denervation, Radiofrequency ablation

Core tip: Resistant Hypertension is a serious condition that could result in various comorbidities, if left untreated. The pathogenesis involves activation of sympathetic nervous system at the renal level and systemic level. Surgical therapy targeted at the systemic level has serious systemic side effects. Renal denervation offers an unique way of mitigating the chronic activation of sympathetic nervous system and controlling the high blood pressure.