Denervation Procedure Research Articles

Partial Wrist Denervation: The Evidence Behind a Small Fix for Big Problems.

Wrist denervation addresses symptomatic wrist pain without the morbidity and complication profile of more extensive surgical procedures aimed to correct the underlying pathology. The concept of wrist denervation is not new, but its practical application has been modified over the past 50 years. A variety of techniques have been described for various indications, with generally good results. In the United States, a simple, single incision partial denervation consisting of neurectomies of the anterior and posterior interosseous nerves is most commonly performed. Although data on this procedure are limited, most patients are satisfied with pain relief in the short term. There is no evidence that partial denervation procedures alter proprioception of the wrist, and this procedure shows promise as a good option for palliating pain without prolonged postoperative immobilization or leave from work. Preoperative injections do not seem to correlate well with postoperative results. Future studies are needed to assess the duration of relief and possible acceleration of underlying pathology.

Is there a Title Role for Renal Sympathetic Denervation in Patients with Symptomatic Myocardial Bridging Refractory to Clinical Treatment and Ventricular Arrhythmias?

The connection concerning the autonomic nervous system and coronary spasm during the systole is multifaceted. An augmentation in sympathetic activity, due to pain caused by angina and the several transient ischemic episodes may origin an augment in noradrenaline, the neurotransmitter of efferent sympathetic fibers, triggering more vasoconstriction by stimulating vascular smooth muscle cells, besides may lead the cardiac hypertrophy. Based on these concepts we aim to find a role to renal sympathetic denervation in patients with symptomatic myocardial bridging refractory to standard clinical treatment and ventricular arrhythmias. In conclusion, our findings suggest that RSD can be a role in myocardial bridging treatment, augmenting the LVEF, diminishing the LV mass and the number of transient ischemic segments measured by CMRI, besides to reduce the number of individuals presenting symptoms, the mean of NSVT recorded by 24-hour-Holter monitoring, and the number of patients with SVT inducible by the EPS. Perhaps such benefits are due to the decrease in the LV mass and sympathetic cardiac activity, consequently, there being less constriction of the arteries with myocardial bridges and less ventricular arrhythmias.We report preliminary data on 6 patients with controlled hypertension, with normal renal function, with symptomatic myocardial bridging refractory to clinical treatment and ventricular arrhythmias who underwent a pilot renal sympathetic denervation (RSD) procedure. At baseline, the 6 (100%) patients presented symptoms while 6 months after RSD only 1 (17%) subject still complained of the symptoms (P=0.0152). Our findings suggest that RSD can play a role in myocardial bridging treatment, augmenting LVEF, diminishing LV mass and the number of transient ischemic segments measured by CMRI.

Role of afferent and efferent renal nerves in the development of AngII-salt hypertension in rats.

Hypertension is the leading modifiable risk factor for death worldwide, yet the causes remain unclear and treatment remains suboptimal. Catheter‐based renal denervation (RDNX) is a promising new treatment for resistant hypertension, but the mechanisms underlying its antihypertensive effect remain unclear. We recently found that RDNX attenuates deoxycorticosterone acetate‐salt hypertension and that this is dependent on ablation of afferent renal nerves and is associated with decreased renal inflammation. To determine if this is common to other models of salt‐sensitive hypertension, rats underwent complete RDNX (n = 8), selective ablation of afferent renal nerves (n = 8), or sham denervation (n = 8). Mean arterial pressure (MAP) and heart rate were measure by telemetry and rats were housed in metabolic cages for measurement of sodium and water balance. Rats were then subjected to angiotensin II (AngII)‐salt hypertension (10 ng/kg/min, intravenous + 4% NaCl diet) for 2 weeks. At the end of the study, renal T‐cell infiltration was quantified by flow cytometry. AngII resulted in an increase in MAP of ~50 mmHg in all three groups with no between group differences, and a transient bradycardia that was blunted by selective ablation of afferent renal nerves. Sodium and water balance were unaffected by AngII‐salt treatment and similar between groups. Lastly, AngII infusion was not associated with T‐cell infiltration into the kidneys, and T‐cell counts were unaffected by the denervation procedures. These results suggest that AngII‐salt hypertension in the rat is not associated with renal inflammation and that neither afferent nor efferent renal nerves contribute to this model.

CRT-600.15 Safety and Performance Of Diagnostic Electrical Mapping of Renal Nerves in Hypertensive Patients and/or Potential Candidates for a Renal Sympathetic Denervation (RDN) Procedure

As the exact location of renal nerves cannot be visualized, renal sympathetic denervation (RDN) remains a so-called blind procedure. The aim to the present study is to assess the safety and feasibility of renal nerve stimulation using the ConfidenHTTM mapping system. The technology could help to

Lumbar facet joint injection in treating low back pain: Radiofrequency denervation versus SHAM procedure. Systematic review

The lumbar facet joints have been implicated as one of the causes of low-back pain syndromes. About 15–40% of patients who presented with chronic low-back pain was attributed to lumbar facet joint pain. The purpose of this study was to analyse whether radiofrequency denervation is better than SHAM procedure in treating chronic low-back pain caused by lumbar zygapophysial joints pathology. From the four identified randomised control trials, there is conflicting evidence at an intermediate 3–6-month stage, however; one study demonstrates statistical significance of radiofrequency denervation at 3 months. Longer-term follow-up is needed to prove the efficacy of radiofrequency denervation technique.

BP.06.05] RENAL NERVE STIMULATION IDENTIFIES AORTICORENAL INNERVATION AND PREVENTS INADVERTENT ABLATION OF PARASYMPATHETIC NERVES DURING RENAL SYMPATHETIC DENERVATION

Objective: Recently we reported the use of renal nerve stimulation (RNS) during renal denervation (RDN) procedures. We hypothesized that electrical stimulation of the sympathetic nerve tissue in the renal artery would lead to an increase in BP and vagal stimulation would cause a decrease in BP. The objective of the current study is to report the different patterns of BP and heart rate responses elicited by RNS prior to RDN. Design and method: Thirty-five patients with drug-resistant hypertension were included. RNS was performed under general anesthesia at four sites in the right and left renal arteries, both before and immediately after RDN. RNS-induced BP and heart rate changes were monitored. Results: A total of 289 RNS sites in 35 patients were analyzed. An increase in systolic BP of >10 mmHg was regarded as a positive BP response to RNS. This pattern of response was observed in 180 sites (62%). 86 RNS sites (30%) showed an indifferent response with BP changes >10 mmHg. At 13 sites (4.5%) RNS elicited a decrease in BP up to -8 mmHg. However, 10 RNS sites (3.5%) showed a pronounced vagal response with hypotension and sinus arrests ranging between 4224–10272 milliseconds. These sites were distributed among two patients. Conclusions: RNS identified sympathetic and parasympathetic nerve tissue in the renal arteries. RNS can be potentially used to map nerve bundles and guide selective ablation of sympathetic nerve fibers and prevent inadvertent ablation of parasympathetic nerve tissue during RDN.

Peripheral denervation participates in heterotopic ossification in a spinal cord injury model.

We previously reported the development of a new acquired neurogenic HO (NHO) mouse model, combining spinal cord transection (SCI) and chemical muscle injury. Pathological mechanisms responsible for ectopic osteogenesis after central neurological damage are still to be elucidated. In this study, we first hypothesized that peripheral nervous system (PNS) might convey pathological signals from injured spinal cord to muscles in NHO mouse model. Secondly, we sought to determine whether SCI could lead to intramuscular modifications of BMP2 signaling pathways. Twenty one C57Bl6 mice were included in this protocol. Bilateral cardiotoxin (CTX) injection in hamstring muscles was associated with a two-stage surgical procedure, combining thoracic SCI with unilateral peripheral denervation. Volumes of HO (Bone Volume, BV) were measured 28 days after surgery using micro-computed tomography imaging techniques and histological analyses were made to confirm intramuscular osteogenesis. Volume comparisons were conducted between right and left hind limb of each animal, using a Wilcoxon signed rank test. Quantitative polymerase chain reaction (qPCR) was performed to explore intra muscular expression of BMP2, Alk3 and Id1. Nineteen mice survive the complete SCI and peripheral denervation procedure. When CTX injections were done right after surgery (n = 7), bilateral HO were detected in all animals after 28 days. Micro-CT measurements showed significantly increased BV in denervated paws (1.47 mm3 +/- 0.5) compared to contralateral sides (0.56 mm3 +/-0.4), p = 0.03. When peripheral denervation and CTX injections were performed after sham SCI surgery (n = 6), bilateral HO were present in three mice at day 28. Quantitative PCR analyses showed no changes in intra muscular BMP2 expression after SCI as compared to control mice (shamSCI). Peripheral denervation can be reliably added to spinal cord transection in NHO mouse model. This new experimental design confirms that neuro inflammatory mechanisms induced by central or peripheral nervous system injury plays a key role in triggering ectopic osteogenesis.

Early morphologic alterations in renal artery wall and renal nerves in response to catheter-based renal denervation procedure in sheep: difference between single-point and multiple-point ablation catheters.

Renal sympathetic hyperactivity is critically involved in hypertension pathophysiology; renal denervation (RDN) presents a novel strategy for treatment of resistant hypertension cases. This study assessed effects of two RDN systems to detect acute intravascular, vascular and peri-vascular changes in the renal artery, and renal nerve alterations, in the sheep. The procedures using a single-point or multi-point ablation catheters, Symplicity Flex(TM), Medtronic versus EnligHTN(TM), St. Jude Medical were compared; the intact contralateral kidneys served as controls. Histopathological and immunohistochemical assessments were performed 48 h after RDN procedures; the kidney and suprarenal gland morphology was also evaluated. Special staining methods were applied for histologic analysis, to adequately score the injury of renal artery and adjacent renal nerves. These were more pronounced in the animals treated with the multi-point compared with the single-point catheter. However, neither RDN procedure led to complete renal nerve ablation. Forty-eight hours after the procedure no significant changes in plasma and renal tissue catecholamines were detected. The morphologic changes elicited by application of both RDN systems appeared to be dependent on individual anatomical variability of renal nerves in the sheep. Similar variability in humans may limit the therapeutic effectiveness of RDN procedures used in patients with resistant hypertension.

Long-term effect of parasympathetic or sympathetic denervation on intestinal epithelial cell proliferation and apoptosis

Intestinal epithelial tissue is constantly regenerated as a means to maintain proper tissue function. Previous studies have demonstrated that denervation of the parasympathetic or sympathetic nervous system to the intestine alters this process. However, results are inconsistent between studies, showing both increases and decreases in proliferation after denervation of the parasympathetic or sympathetic. The effect appears to correlate with (1) the timing post-denervation, (2) denervation-induced changes in food intake, (3) the denervation technique used, and (4) which intestinal segment is investigated. Thus, we proposed that parasympathetic or sympathetic denervation does not have an effect on intestinal epithelial regeneration when you (1) evaluate denervation after long-term denervation, (2) control for post-surgical changes in food intake, (3) use minimally invasive surgical techniques and (4) include a segmental analysis. To test this, adult male Sprague Dawley rats underwent parasympathetic denervation via subdiaphragmatic vagotomy, sympathetic denervation via celiacomesenteric ganglionectomy, a parasympathetic denervation sham surgery, or a sympathetic denervation sham surgery. Sham surgery ad libitum-fed groups and sham surgery pair-fed groups were used to control for surgically induced changes in food intake. Three weeks post-surgery, animals were sacrificed and tissue from the duodenum, jejunum, and ileum was excised and immunohistochemically processed to visualize indicators of proliferation (bromodeoxyuridine-positive cells) and apoptosis (caspase-3-positive cells). Results showed no differences between groups in proliferation, apoptosis, or total cell number in any intestinal segment. These results suggest that parasympathetic or sympathetic denervation does not have a significant long-term effect on intestinal epithelial turnover. Thus, intestinal epithelial regeneration is able to recover after autonomic nervous system injury. Impact statement This study investigates the long-term effect of autonomic denervation on intestinal epithelial cell turnover, as measured by proliferation, apoptosis, and total cell number. Although previous research has established that autonomic denervation can alter intestinal epithelial turnover under short-term conditions, here we establish for the first time that these changes do not persist long-term when you control for surgical-induced changes in food intake and use targeted denervation procedures. These findings add to the base of knowledge on autonomic control of tissue turnover, highlight the ability of the intestinal epithelium to recover after autonomic injury and reveal possible implications of the use of ANS denervation for disease treatment in humans.

4119Early morphologic alterations in renal artery wall and renal nerves in response to catheter-based renal denervation procedure in sheep: difference between single-point and multiple-point ablation

4119Early morphologic alterations in renal artery wall and renal nerves in response to catheter-based renal denervation procedure in sheep: difference between single-point and multiple-point ablation

Pelvic denervation procedures for dysmenorrhea.

Chronic pelvic pain and dysmenorrhea are common conditions affecting reproductive-age women. Surgical pelvic denervation procedures may be a treatment option for women with midline dysmenorrhea, in which medical management is declined by the patient, ineffective at managing symptoms, or medically contraindicated. This review describes the surgical techniques and complications associated with pelvic denervation procedures as well as the current evidence for these procedures in women with primary dysmenorrhea and dysmenorrhea secondary to endometriosis. Presacral neurectomy is the preferred pelvic denervation procedure in patients with primary dysmenorrhea and midline chronic pelvic pain associated with endometriosis. In patients with endometriosis presacral neurectomy is a useful adjunct to excision or ablation of all endometrial lesions to improve postoperative pain relief. There is no additional patient benefit of performing combined presacral neurectomy and uterine nerve ablation procedures. Pelvic denervation procedures can be performed safely and quickly with a low risk of complication if the surgeon is knowledgeable and skilled in operating in the presacral space. Patients should be adequately counseled on expected success rates and potential complications associated with pelvic denervation procedures.

Sympathetic Response and Outcomes Following Renal Denervation in Patients With Chronic Heart Failure: 12-Month Outcomes From the Symplicity HF Feasibility Study

BackgroundHeart failure (HF) is associated with chronic sympathetic activation. Renal denervation (RDN) aims to reduce sympathetic activity by ablating the renal sympathetic nerves. We investigated the effect of RDN in patients with chronic HF and concurrent renal dysfunction in a prospective, multicenter, single-arm feasibility study. Methods and ResultsThirty-nine patients with chronic systolic HF (left ventricular ejection fraction [LVEF] <40%, New York Heart Association class II-III,) and renal impairment (estimated glomerular filtration rate [eGFR; assessed with the use of the Modification of Diet in Renal Disease equation] < 75 mL • min−1 • 1.73 m−2) on stable medical therapy were enrolled. Mean age was 65 ± 11 years; 62% had ischemic HF. The average number of ablations per patient was 13 ± 3. No protocol-defined safety events were associated with the procedure. One subject experienced a renal artery occlusion that was possibly related to the denervation procedure. Statistically significant reductions in N-terminal pro–B-type natriuretic peptide (NT-proBNP; 1530 ± 1228 vs 1428 ± 1844 ng/mL; P = .006) and 120-minute glucose tolerance test (11.2 ± 5.1 vs 9.9 ± 3.6; P = .026) were seen at 12 months, but there was no significant change in LVEF (28 ± 9% vs 29 ± 11%; P = .536), 6-minute walk test (384 ± 96 vs 391 ± 97 m; P = .584), or eGFR (52.6 ± 15.3 vs 52.3 ± 18.5 mL • min−1 • 1.73 m−2; P = .700). ConclusionsRDN was associated with reductions in NT-proBNP and 120-minute glucose tolerance test in HF patients 12 months after RDN treatment. There was no deterioration in other indices of cardiac and renal function in this small feasibility study.

Effect of applied energy in renal sympathetic denervation with magnetic resonance guided focused ultrasound in a porcine model

BackgroundPast catheter-based and focused ultrasound renal denervation studies have indicated that procedure efficacy is related to the number of ablations performed or the amount of energy used for the ablation. This study extends those prior results and investigates energy level effects on the efficacy of MR guided focused ultrasound renal denervation performed in a porcine model.MethodsTwenty-four normotensive pigs underwent unilateral denervation at three intensity levels. The applied intensity level was retrospectively de-rated to account for variability in animal size. Efficacy was assessed through evaluating the norepinephrine present in the kidney medulla and through histological analysis. The treatment was performed under MRI guidance including pre- and post-procedure T1-weighted and quantitative T1 and T2 imaging. During treatment, the temperature in the near field of the ultrasound beam was monitored in real time with MR temperature imaging. Energy delivery in the regions surrounding the renal artery was independently confirmed through an invasive fiberoptic temperature probe placed in the right renal artery.ResultsAnimals that underwent denervation at a de-rated acoustic intensity of greater than 1.2 kW/cm2 had a significantly lower norepinephrine concentration in the kidney indicating successful denervation. Images obtained during the treatment indicated no tissue changes in the kidneys as a function of the procedure but there were significant T1 changes present in the right lumbar muscles, although only one animal had indication of muscle damage at the time of necropsy.ConclusionsWhile MR guided focused ultrasound renal denervation was found to be safe and effective in this normotensive animal model, the results indicated the need to incorporate patient-specific details in the treatment planning of MRgFUS renal denervation procedure.

The effects of acute renal denervation on kidney perfusion and metabolism in experimental septic shock

BackgroundPerfusion deficits likely play an important role in the development of renal dysfunction in sepsis. Renal denervation may improve kidney perfusion and metabolism.MethodsWe randomized 14 female sheep to undergo bilateral surgical renal denervation (n = 7) or sham procedure (n = 7) prior to induction of sepsis. Renal blood flow (RBF) was measured with a pre-calibrated flowprobe. Laser Doppler probes were implanted to measure cortical and medullary perfusion. Cortical glucose, lactate and pyruvate levels were measured using the microdialysis technique. Creatinine clearance was determined. Sepsis was induced by peritonitis and fluid resuscitation was provided to avoid hypovolemia.ResultsRBF and cortical perfusion were higher in the denervated group during the first 6 h after induction of sepsis (P < 0.001 and P < 0.05, respectively), while medullary perfusion decreased similarly in both groups. After hypotension developed, RBF decreased to similar levels in both groups. Cortical pyruvate and lactate levels were lower in the denervated animals (P < 0.001 and P < 0.001, respectively). There were no differences between groups in creatinine clearance, urine output or time to oliguria.ConclusionDenervation thus caused an early increase in RBF that was distributed towards the kidney cortex. Although associated with an attenuation of early cortical metabolic alterations, denervation failed to prevent the deterioration in renal function.

Redo renal denervation using amulti-electrode radiofrequency system in patients with persistent therapy-resistant hypertension.

ObjectivesRenal sympathetic denervation has been studied as a potential therapeutic option for patients with therapy-resistant hypertension; however, a significant proportion of patients do not show a significant reduction in blood pressure and are classified as non-responders. The objective of the present study was to assess whether a redo renal denervation procedure increases response rates.MethodsWe present a case series of three consecutive renal denervation non-responders treated with the multi-electrode radiofrequency St. Jude EnligHTN catheter after an average of 22 months. Patients were followed for 6 months.ResultsMean age was 66 years and two patients were male. Patients were previously treated using either ReCor’s Paradise system, the Vessix V2 system or the Covidien OneShot system. Mean office blood pressure one year after the initial procedure was 187/102 mm Hg with a mean 24 h ambulatory blood pressure of 166/102 mm Hg. All patients underwent a successful redo procedure using the EnligHTN system because of persistent therapy-resistant hypertension. At 6 months a significant drop in both office and ambulatory blood pressure of −27/−6 mm Hg and −15/−13 mm Hg, respectively, was observed. No significant renal artery stenosis was observed at 6 months.ConclusionsIn patients with therapy-resistant hypertension who do not respond to an initial renal denervation procedure, a redo procedure using the St. Jude EnligHTN system may help to significantly improve blood pressure control.

Targets and End Points in Cardiac Autonomic Denervation Procedures.

Autonomic denervation is an alternative approach for patients with symptomatic bradycardia. No consensus exists on the critical targets and end points of the procedure. The aim of this study was to identify immediate end points and critical atrial regions responsible for vagal denervation. We enrolled 14 patients (50% men; age: 34.0±13.8 years) with cardioinhibitory syncope, advanced atrioventricular block or sinus arrest, and no structural heart disease. Anatomic mapping of ganglionated plexuses was performed, followed by radiofrequency ablation. Heart rate, sinus node recovery time, Wenckebach cycle length, and atrial-His (AH) interval were measured before and after every radiofrequency pulse. Wilcoxon signed-rank test was used for comparison. Significant shortening of the R-R interval (P=0.0009), Wenckebach cycle length (P=0.0009), and AH intervals (P=0.0014) was observed after ablation. The heart rate elevation was 23.8±12.5%, and the Wenckebach cycle length and AH interval shortening was 18.1±11% and 24.6±19%, respectively. Atropine bolus injection (0.04 mg/kg) did not increase heart rate further. Targeting a single spot of the left side (64% of the patients) or right side (36%) of the interatrial septum was observed to be responsible for ≥80% of the final R-R and AH interval shortening during ablation. Targeting specific sites of the interatrial septum is followed by an increase in heart rate and atrioventricular nodal conduction properties and might be critical for vagal attenuation. The R-R interval, Wenckebach cycle length, and AH interval shortening, associated with a negative response to atropine, could be considered immediate end points of the procedure.

VP101 Medical Devices For Treatment-resistant Hypertension: Health Technology Assessment Report

INTRODUCTION:While optimal medical therapy (OMT) represents the current standard of care for treatment-resistant hypertension, non-pharmaceutical therapeutic approaches, such as renal denervation and carotid baroreceptor stimulation therapy, have been proposed. The present Health Technology Assessment (HTA) project was aimed at assessing benefits and risk of those approaches versus OMT.METHODS:A systematic review of evidence on effectiveness and safety was performed together with a review of economic studies. A contextual analysis of market availability and use of the technology in Italy was also performed.RESULTS:In Italy, ninety-nine renal denervation procedures were performed in 2014. Ten studies from six trials were included in the review and meta-analysis. No evidence of dominance or increased harms of renal denervation compared to OMT were found. Four economic evaluations were included and reported dominance of renal denervation. These were based on short-term clinical data and three evaluations used the same Markov model assuming dominance of renal denervation. Estimated average prospective cost of the procedure was EUR6,129.90 (range EUR3,821.15 – EUR9,714.23). We updated the results of an earlier assessment published by an Italian Regional agency on carotid baroreceptor stimulation therapy (1). None of the three studies identified as ongoing in 2015 were completed or had published preliminary results and the technology was not assessed further within the present HTA project.CONCLUSIONS:Even if follow-up was limited to 6 months, randomised evidence showed no benefits of the procedure. Economic evaluations were unreliable, based on unrealistic assumptions of effectiveness and contrived therapy regimes. Further investment in renal denervation should await the results of well-designed and adequately followed-up trials assessing the impact of renal denervation on major cardiovascular events compared to OMT. Future economic evaluations should be based on realistic assumptions of cost and effectiveness.

Bilateral supernumerary renal arteries with variant ureteric relation and their embryological and clinical significance

Variations in the renal vasculature always deserve a special attention owing to its higher prevalence and wider range. A thorough knowledge of the normal morphology and the variations in the origin, course, branches and distribution of the renal vasculature are essential for the successful outcome of the surgical interventions in this region without dreadful complications. During routine dissection for the undergraduate medical students following the standard procedures, dissection of the retroperitoneal region in a male cadaver, revealed bilateral variations in the number, origin, course and branches of the renal arteries.The renal arteries with its branches were dissected out meticulously and the variations encountered were documented. Bilateral supernumerary renal arteries with extra-hilar and pre-hilar branches were observed. In addition, it was found that the supernumerary inferior pre- caval right renal artery had a variant course in relation to ureter before entering the hilum of the right kidney. The variant renal arteries documented in the present study with their embryological correlation is clinically important in the urological management, especially during the laparoscopic donor nephrectomy, where the field of vision is limited and also in the endovascular renal artery denervation procedure, which is an useful adjuvant for the patients having drug-resistant primary hypertension.

Bilateral Supernumerary Renal Arteries with variant Ureteric Relation and their Embryological and Clinical Significance

AbstractVariations in the renal vasculature always deserve a special attention owing to its higher prevalence and wider range. A thorough knowledge of the normal morphology and the variations in the origin, course, branches and distribution of the renal vasculature are essential for the successful outcome of the surgical interventions in this region without dreadful complications. During routine dissection for the undergraduate medical students following the standard procedures, dissection of the retroperitoneal region in a male cadaver, revealed bilateral variations in the number, origin, course and branches of the renal arteries.The renal arteries with its branches were dissected out meticulously and the variations encountered were documented. Bilateral supernumerary renal arteries with extra-hilar and pre-hilar branches were observed. In addition, it was found that the supernumerary inferior pre- caval right renal artery had a variant course in relation to ureter before entering the hilum of the right kidney. The variant renal arteries documented in the present study with their embryological correlation is clinically important in the urological management, especially during the laparoscopic donor nephrectomy, where the field of vision is limited and also in the endovascular renal artery denervation procedure, which is an useful adjuvant for the patients having drug-resistant primary hypertension.

Renal denervation for uncontrolled hypertension: critical review of the evidence.

Hypertension (HTN) is a major global public health problem. Endovascular catheter-based radiofrequency ablation of renal sympathetic nerve endings (renal denervation) is a novel treatment option for uncontrolled HTN. Early clinical studies primarily in Australia and Europe established renal denervation as a well tolerated and feasible procedure that resulted in a sustained reduction in blood pressure among individuals with severe resistant HTN. A recent randomized controlled trial in the United States using a sham procedure in the control arm, however, did not show a significant additional benefit in blood pressure lowering from renal denervation. This review summarizes and critically examines the evidence for renal denervation in HTN management and identifies areas for future research. Renal denervation is a potentially promising treatment option for drug-resistant uncontrolled HTN. Future efforts should focus on refining the denervation technology and identifying individuals who are most likely to benefit from the denervation procedure.