scholarly journals Technical advance in silico and in vitro development of a new bipolar radiofrequency ablation device for renal denervation

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Noel Pérez ◽  
Karl Muffly ◽  
Stephen E. Saddow
Keyword(s):  
Radiofrequency Ablation ◽  
Renal Artery ◽  
Resistant Hypertension ◽  
In Silico ◽  
Renal Denervation ◽  
Bipolar Electrode ◽  
Ablation Zone ◽  
Catheter Design ◽  
Basket Catheter

Abstract Background Renal denervation with radiofrequency ablation has become an accepted treatment for drug-resistant hypertension. However, there is a continuing need to develop new catheters for high-accuracy, targeted ablation. We therefore developed a radiofrequency bipolar electrode for controlled, targeted ablation through Joule heating induction between 60 and 100 °C. The bipolar design can easily be assembled into a basket catheter for deployment inside the renal artery. Methods Finite element modeling was used to determine the optimum catheter design to deliver a minimum ablation zone of 4 mm (W) × 10 mm (L) × 4 mm (H) within 60 s with a 500 kHz, 60 Vp-p signal, and 3 W maximum. The in silico model was validated with in vitro experiments using a thermochromic phantom tissue prepared with polyacrylamide gel and a thermochromic ink additive that permanently changes from pink to magenta when heated over 60 °C. Results The in vitro ablation zone closely matched the size and shape of the simulated area. The new electrode design directs the current density towards the artery walls and tissue, reducing unwanted blood temperature increases by focusing energy on the ablation zone. In contrast, the basket catheter design does not block renal flow during renal denervation. Conclusions This computational model of radiofrequency ablation can be used to estimate renal artery ablation zones for highly targeted renal denervation in patients with resistant hypertension. Furthermore, this innovative catheter has short ablation times and is one of the lowest power requirements of existing designs to perform the ablation.

scholarly journals In Silico and in Vitro Development of a New Bipolar Radiofrequency Ablation Device for Renal Denervation

2021 ◽  
Author(s):  
Noel Pérez ◽  
Karl Muffly ◽  
Stephen E. Saddow
Keyword(s):  
Radiofrequency Ablation ◽  
Computational Model ◽  
Resistant Hypertension ◽  
Renal Denervation ◽  
Ablation Zone ◽  
Power Requirement ◽  
Bipolar Electrodes ◽  
Catheter Design ◽  
Basket Catheter

Abstract Background: Renal denervation with radiofrequency ablation has become an accepted treatment for drug-resistant hypertension. However, there is a continuing need to develop new catheters for high-accuracy, targeted ablation. We, therefore, developed a radiofrequency ablation device with a basket catheter and bipolar electrodes for controlled, targeted ablation through Joule heating induction between 60°C and 100°C.Methods: Finite element modeling was used to determine the optimum catheter design to deliver a minimum ablation zone of 4 mm (W) x 10 mm (L) x 4 mm (H) within 60 seconds with a 500 kHz, 60 Vp-p signal, and 0.9 W maximum. The computational model was validated using in vitro phantom tissue impregnated with a color-changing thermochromic pigment.Results: The in vitro ablation zone closely matched the size and shape of the simulated area. The new electrode design directs the current density towards the artery walls and tissue, reducing unwanted blood temperature increases by focusing energy on the ablation zone. In contrast, the basket catheter design does not block renal flow during renal denervation.Conclusions: This computational model of radiofrequency ablation can be used to estimate renal artery ablation zones for highly targeted renal denervation in patients with resistant hypertension. Furthermore, this innovative catheter has short ablation times and the lowest power requirement of existing designs to perform the ablation.

scholarly journals 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

2017 ◽  
pp. 601-614 ◽  
Author(s):  
M. TÁBORSKÝ ◽  
D. RICHTER ◽  
Z. TONAR ◽  
T. KUBÍKOVÁ ◽  
A. HERMAN ◽  
...  
Keyword(s):  
Renal Artery ◽  
Resistant Hypertension ◽  
Renal Denervation ◽  
Single Point ◽  
Renal Tissue ◽  
Renal Nerves ◽  
Multiple Point ◽  
Renal Nerve ◽  
Jude Medical ◽  
Novel Strategy

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 FlexTM, Medtronic versus EnligHTNTM, 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.

MRI-based detection of renal artery abnormalities related to renal denervation by catheter-based radiofrequency ablation in drug resistant hypertensive patients

2018 ◽  
Vol 28 (8) ◽  
pp. 3355-3361 ◽  
Author(s):  
Monica Sigovan ◽  
Salim Si-Mohamed ◽  
Pierre-Yves Courand ◽  
Brahim Harbaoui ◽  
Marc Sapoval ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Renal Artery ◽  
Renal Denervation ◽  
Drug Resistant ◽  
Hypertensive Patients

scholarly journals Renal Denervation Using an Irrigated Radiofrequency Ablation Catheter in Patients with Resistant Hypertension

2014 ◽  
Vol 22 (1) ◽  
pp. 73-80
Author(s):  
Rodolfo Staico ◽  
Luciana Armaganijan ◽  
Dalmo Moreira ◽  
Marcio Sousa ◽  
Flavio Borelli ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Resistant Hypertension ◽  
Renal Denervation ◽  
Ablation Catheter

scholarly journals Distal renal denervation: cardioprotection in patients with resistant hypertension

2020 ◽  
Vol 19 (4) ◽  
pp. 2225
Author(s):  
E. S. Sitkova ◽  
V. F. Mordovin ◽  
S. E. Pekarsky ◽  
T. M. Ripp ◽  
A. Yu. Falkovskaya ◽  
...  
Keyword(s):  
Renal Artery ◽  
Resistant Hypertension ◽  
Renal Denervation ◽  
Myocardial Damage ◽  
Left Ventricular ◽  
Double Blind Study ◽  
Double Blind ◽  
Damage Area ◽  
Main Renal Artery ◽  
Group 2

Aim. To study the effectiveness of using the anatomically optimized distal renal denervation (RDN) in comparison with the standard approach for reducing myocardial damage and left ventricular (LV) hypertrophy in patients with resistant hypertension (HTN).Material and methods. The randomized double-blind study of the efficacy and safety of distal RDN compared to conventional main renal artery intervention (ClinicalTrials.gov NCT02667912) for the treatment of resistant HTN included 26 patients. All patients were divided into two groups: group 1 (n=16) — distal RDN, group 2 (n=10) — conventional RDN. In addition to 24-hour blood pressure (BP) monitoring, initially and 12 months after the intervention, contrast- enhanced cardiac magnetic resonance imaging was performed to determine the left ventricular mass and non-coronary myocardial damage area. All patients signed informed consent. Twenty-four patients completed the present study.Results. After 12 months, the mean 24-hour BP significantly decreased after both distal RDN (from 167,2±28,5/93,2±19,3 to 147,0±13,7/81,5±9,3 mm Hg (p<0,05)) and conventional RDN (from 157,5±22,5/90,6±23,9 to 139,9±17,7/80,0±16,7 (p<0,05)). Also in both cases, a trend to LV mass decrease was revealed: from 252,6±85,2 to 221,0±60,3 gm (p=0,096) after the distal RDN; from 214,3±54,1 to 186,4±48,1 gm (p=0,071) after the conventional RDN. In contrast, the myocardial damage area decreased only after distal RDN (from 2,33±1,33 to 1,35±0,67 cm3 (p=0,02)) and did not change after conventional RDN.Conclusion. In comparison with the conventional main renal artery intervention, distal RDN in patients with resistant HTN has an additional cardioprotective effect — a decrease in LV myocardial damage area.

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