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International audience; Purpose: To assess the variability of renal artery (RA) anatomy and presence of RA-pathology in patients with mild-to-moderate hypertension enrolled in the RADIANCE-HTN SOLO trial.Background: RADIANCE-HTN SOLO was a multicenter, international, blinded, randomized, sham-controlled trial evaluating ultrasound-based endovascular renal denervation (RDN) in patients with mild-to-moderate hypertension while off antihypertensive medications.Methods: Eligible subjects had pre-randomization renal CT- or MR- angiography (CTA, MRA) to confirm anatomic suitability and to define RA ablation sites. All images were sent for independent review for evaluation of RA anatomy and other vascular pathology.Results: A total of 324 patients underwent RA imaging (282 CTA and 42 MRA). Of those, 178 had simple anatomy with a single left and single right RA with mean diameters of 5.4 ± 0.9 and 5.1 ± 0.8 mm and mean lengths of 40.0 ± 12.9 and 52.0 ± 13.1 mm, respectively. Twenty-seven patients (8.3%) had unilateral or bilateral dual RAs with mean diameters of 4.0 ± 0.9 mm on the left and 3.9 ± 0.9 mm on the right. Forty percent (129/324) of patients had at least 1 accessory RA, with mean accessory diameters of 2.4 ± 0.8 mm on the left and 2.3 ± 0.8 mm on the right. Twenty-eight patients (8.6%) had at least 1 short (

Summary Background Endovascular renal denervation reduces blood pressure in patients with mild-to-moderate hypertension, but its efficacy in patients with true resistant hypertension has not been shown. We aimed to assess the efficacy and safety of endovascular ultrasound renal denervation in patients with hypertension resistant to three or more antihypertensive medications. Methods In a randomised, international, multicentre, single-blind, sham-controlled trial done at 28 tertiary centres in the USA and 25 in Europe, we included patients aged 18–75 years with office blood pressure of at least 140/90 mm Hg despite three or more antihypertensive medications including a diuretic. Eligible patients were switched to a once daily, fixed-dose, single-pill combination of a calcium channel blocker, an angiotensin receptor blocker, and a thiazide diuretic. After 4 weeks of standardised therapy, patients with daytime ambulatory blood pressure of at least 135/85 mm Hg were randomly assigned (1:1) by computer (stratified by centres) to ultrasound renal denervation or a sham procedure. Patients and outcome assessors were masked to randomisation. Addition of antihypertensive medications was allowed if specified blood pressure thresholds were exceeded. The primary endpoint was the change in daytime ambulatory systolic blood pressure at 2 months in the intention-to-treat population. Safety was also assessed in the intention-to-treat population. This study is registered with ClinicalTrials.gov , NCT02649426 . Findings Between March 11, 2016, and March 13, 2020, 989 participants were enrolled and 136 were randomly assigned to renal denervation (n=69) or a sham procedure (n=67). Full adherence to the combination medications at 2 months among patients with urine samples was similar in both groups (42 [82%] of 51 in the renal denervation group vs 47 [82%] of 57 in the sham procedure group; p=0·99). Renal denervation reduced daytime ambulatory systolic blood pressure more than the sham procedure (−8·0 mm Hg [IQR –16·4 to 0·0] vs –3·0 mm Hg [–10·3 to 1·8]; median between-group difference –4·5 mm Hg [95% CI –8·5 to –0·3]; adjusted p=0·022); the median between-group difference was –5·8 mm Hg (95% CI –9·7 to –1·6; adjusted p=0·0051) among patients with complete ambulatory blood pressure data. There were no differences in safety outcomes between the two groups. Interpretation Compared with a sham procedure, ultrasound renal denervation reduced blood pressure at 2 months in patients with hypertension resistant to a standardised triple combination pill. If the blood pressure lowering effect and safety of renal denervation are maintained in the long term, renal denervation might be an alternative to the addition of further antihypertensive medications in patients with resistant hypertension. Funding ReCor Medical.

The aim of this study was to understand the anatomy of periarterial nerve distribution in human accessory renal arteries (ARAs).Renal denervation is a promising technique for blood pressure control. Despite the high prevalence of ARAs, the anatomic distribution of periarterial nerves around ARAs remains unknown.Kidneys with surrounding tissues were collected from human autopsy subjects, and histological evaluation was performed using morphometric software. An ARA was defined as an artery arising from the aorta above or below the dominant renal artery (DRA) or an artery that bifurcated within 20 mm of the takeoff of the DRA from the aorta. The DRA was defined as an artery that perfused50% of the kidney.A total of 7,287 nerves from 14 ARAs and 9 DRAs were evaluated. The number of nerves was smaller in the ARA than DRA (median: 30 [interquartile range: 17.5 to 48.5] vs. 49 [interquartile range: 36 to 76]; p 0.0001). In both ARAs and DRAs, the distance from the arterial lumen to nerve was shortest in the distal, followed by the middle and proximal segments. On the basis of the post-mortem angiography, ARAs were divided into large (≥3 mm diameter) and small (3 mm) groups. The number of nerves was greatest in the DRA, followed by the large and small ARA groups (53 [41 to 97], 38 [25 to 53], and 24.5 [10.5 to 36.3], respectively; p = 0.001).ARAs showed a smaller number of nerves than DRAs, but these results were dependent on the size of the ARA. Ablation, especially in large ARAs, may allow more complete denervation with the potential to further reduce blood pressure.

Summary Background Early studies suggest that radiofrequency-based renal denervation reduces blood pressure in patients with moderate hypertension. We investigated whether an alternative technology using endovascular ultrasound renal denervation reduces ambulatory blood pressure in patients with hypertension in the absence of antihypertensive medications. Methods RADIANCE-HTN SOLO was a multicentre, international, single-blind, randomised, sham-controlled trial done at 21 centres in the USA and 18 in Europe. Patients with combined systolic–diastolic hypertension aged 18–75 years were eligible if they had ambulatory blood pressure greater than or equal to 135/85 mm Hg and less than 170/105 mm Hg after a 4-week discontinuation of up to two antihypertensive medications and had suitable renal artery anatomy. Patients were randomised (1:1) to undergo renal denervation with the Paradise system (ReCor Medical, Palo Alto, CA, USA) or a sham procedure consisting of renal angiography only. The randomisation sequence was computer generated and stratified by centres with randomised blocks of four or six and permutation of treatments within each block. Patients and outcome assessors were blinded to randomisation. The primary effectiveness endpoint was the change in daytime ambulatory systolic blood pressure at 2 months in the intention-to-treat population. Patients were to remain off antihypertensive medications throughout the 2 months of follow-up unless specified blood pressure criteria were exceeded. Major adverse events included all-cause mortality, renal failure, an embolic event with end-organ damage, renal artery or other major vascular complications requiring intervention, or admission to hospital for hypertensive crisis within 30 days and new renal artery stenosis within 6 months. This study is registered with ClinicalTrials.gov, number NCT02649426. Findings Between March 28, 2016, and Dec 28, 2017, 803 patients were screened for eligibility and 146 were randomised to undergo renal denervation (n=74) or a sham procedure (n=72). The reduction in daytime ambulatory systolic blood pressure was greater with renal denervation (−8·5 mm Hg, SD 9·3) than with the sham procedure (−2·2 mm Hg, SD 10·0; baseline-adjusted difference between groups: −6·3 mm Hg, 95% CI −9·4 to −3·1, p=0·0001). No major adverse events were reported in either group. Interpretation Compared with a sham procedure, endovascular ultrasound renal denervation reduced ambulatory blood pressure at 2 months in patients with combined systolic–diastolic hypertension in the absence of medications. Funding ReCor Medical.

Aims Circumferential ablation of renal sympathetic nerves using catheter-based ultrasound energy was studied in a preclinical in vivo model. The aim was to investigate the benefit of cooling the arterial wall and the extent of renal nerve injury based on histopathology, and to correlate the injury with kidney norepinephrine levels. Methods and results Computer simulations of the ultrasound transducer within the cooling balloon demonstrated a circumferentially uniform heating profile. In vivo characterisation was performed in 10 normotensive pigs. Nine were treated bilaterally with ultrasound and survived for seven days (n=8) or were sacrificed acutely (n=1). Acutely, TTC staining of the renal arteries treated with ultrasound energy in the presence of cooling demonstrated viable tissue consistent with preservation of the arterial medial layer. Histological studies demonstrated no endothelial injury and minimal to no injury to the media of the renal arterial wall at seven days. Overall, circumferential nerve damage with up to 76% of nerve bundles affected within 7.5 mm of the arterial lumen was observed. Kidney norepinephrine (NEPI) levels were significantly reduced in all animals compared to a non-treated control animal (n=1) and correlated with the degree of nerve damage. A greater reduction in NEPI and a greater percentage of affected nerves was observed in arteries treated with two or three bilateral ultrasound emissions. Conclusions Catheter-based ultrasound delivered within a cooling balloon is effective at targeting the majority of the renal nerves circumferentially, resulting in significantly decreased kidney NEPI levels without damaging the arterial wall in a porcine model.

Aims The Paradise Ultrasound Renal Denervation System is a next-generation catheter-based device which was used to investigate whether the target ablation area can be controlled by changing ultrasound energy and duration to optimise nerve injury while preventing damage to the arterial wall. Methods and results Five ultrasound doses were tested in a thermal gel model. Catheter-based ultrasound denervation was performed in 15 swine (29 renal arteries) to evaluate five different doses in vivo, and animals were euthanised at seven days for histopathologic assessment. In the gel model, the peak temperature was highest in the low power-long duration (LP-LD) dose, followed by the mid-low power-mid duration (MLP-MD) dose and the mid-high power-short duration (MHP-SD) dose, and lowest in the mid power-short duration (MP-SD) dose and the high power-ultra short duration (HP-USD) dose. In the animal study, total ablation area was significantly greater in the LP-LD group, followed by the MLP-MD group, and it was least in the HP-USD, MP-SD and MHP-SD groups (p=0.02). Maximum distance was significantly greater in the LP-LD group, followed by the MLP-MD group, the MHP-SD group, and the HP-USD group, and shortest in the MP-SD group (p=0.007). The short spare distance was not different among the five groups (p=0.38). Renal artery damage was minimal, while preserving significant nerve damage in all groups. Conclusions The Paradise Ultrasound Renal Denervation System is a controllable system where total ablation area and depth of ablation can be optimised by changing ultrasound power and duration while sparing renal arterial tissue damage but allowing sufficient peri-arterial nerve damage.

The ReCor Medical Paradise® Renal Denervation System delivers ultrasound energy to perform targeted circumferential denervation to the renal afferent and efferent sympathetic nerves with the goal of achieving a reduction in systemic arterial blood pressure, and mitigating end organ effects due to sympathetic over-activity. Ultrasound energy is a controllable energy source which does not require direct tissue contact to heat the tissue providing a unique therapeutic advantage in the application of renal denervation. The Paradise System has been designed to deliver energy to create an optimized tissue thermal profile to achieve targeted ablation of nerves surrounding the renal artery, while preserving the integrity of the renal arterial wall through a unique cooling mechanism. The tissue thermal profile has been optimized through pre-clinical in vitro and in vivo testing. Feasibility clinical studies have demonstrated the safety and effectiveness in controlling resistant hypertension of the system out to 12 months. On-going and future clinical studies will allow for a continued assessment of the overall safety, effectiveness, and durability of the Paradise System.