A-30 | Radio Frequency Renal Denervation has High Specificity for Renal Nerves with Minimal Observable Effects to the Non-Target Perivascular Tissue (2022)

BackgroundRadio frequency (RF) renal denervation (RDN) safely and durably lowers blood pressure in uncontrolled hypertensive patients. Histological evidence and sham-RCTs support the safety and efficacy of RDN. In this study the specificity of tissue ablation by RF RDN in the renal artery perivascular tissues was evaluated in a normotensive swine model.MethodsHistopathologic analyses were performed on RF treated regions in a porcine model (N=14). Simultaneous RF ablations with 4 electrodes in a helical pattern were delivered in each renal artery and suitable bifurcation branch segments using the Symplicity Spyral RDN system (Medtronic). Serial histological tissue samples were harvested at 7 (N=6 pigs, n=12 vessels) and 28 days (N=8 pigs, n=16 vessels) post procedure to evaluate the response of surrounding anatomic tissue (including ureter, kidney, lymph nodes, skeletal muscles, adrenal glands, and renal nerves) to RF energy.ResultsRF ablative zones primarily consisted of perivascular cell disruption and inflammation within the adipose tissue and renal nerves, creating a distinct lesion footprint confined to the fat tissue. RF-induced cell disruption to the non-target perivascular tissues including ureter, kidney, renal lymph nodes, skeletal muscles was rare (Figure). There was no evidence of ablation involving the adrenal glands. Renal artery nerve disruption and downstream axonal loss were sustained to 28 days.ConclusionsDisclosuresA. V. Finn: Abbott: Consulting; Boston Scientific Corp.: Consulting; Edwards Lifesciences: Consulting; Medtronic: Consulting; Amgen: Consulting; Biosensors: Consulting; Celonova: Consulting; Cook Medical: Consulting; CSI: Consulting; Lutonix Bard: Consulting; Terumo Corporation: Consulting; NIH R01 HL141425 Leducq Foundation Grant: Principal Investigator for a Research Study; A. Sharp: Medtronic: Consulting; Philips: Consulting; Recor Medical: Consulting; S. Tunev: Medtronic: Employed or Salary; F. Mahfoud: Medtronic: Consulting; Bayer: Consulting; Boehringer Ingelheim: Consulting; Recor Medical: Consulting; M. Schlaich: Medtronic: Consulting; Abbott: Consulting; Novartis: Consulting; Servier: Consulting; Pfizer: Consulting; Boehringer Ingelheim: Consulting; D. Lee: Medtronic: Advisory Board/Board Member; J. Trudel: Medtronic: Employed or Salary; D. Hettrick: Medtronic: Employed or Salary; D. E. Kandzari: Medtronic: Consulting and Principal Investigator for a Research Study; Ablative Solutions: Principal Investigator for a Research Study BackgroundRadio frequency (RF) renal denervation (RDN) safely and durably lowers blood pressure in uncontrolled hypertensive patients. Histological evidence and sham-RCTs support the safety and efficacy of RDN. In this study the specificity of tissue ablation by RF RDN in the renal artery perivascular tissues was evaluated in a normotensive swine model. Radio frequency (RF) renal denervation (RDN) safely and durably lowers blood pressure in uncontrolled hypertensive patients. Histological evidence and sham-RCTs support the safety and efficacy of RDN. In this study the specificity of tissue ablation by RF RDN in the renal artery perivascular tissues was evaluated in a normotensive swine model. MethodsHistopathologic analyses were performed on RF treated regions in a porcine model (N=14). Simultaneous RF ablations with 4 electrodes in a helical pattern were delivered in each renal artery and suitable bifurcation branch segments using the Symplicity Spyral RDN system (Medtronic). Serial histological tissue samples were harvested at 7 (N=6 pigs, n=12 vessels) and 28 days (N=8 pigs, n=16 vessels) post procedure to evaluate the response of surrounding anatomic tissue (including ureter, kidney, lymph nodes, skeletal muscles, adrenal glands, and renal nerves) to RF energy. Histopathologic analyses were performed on RF treated regions in a porcine model (N=14). Simultaneous RF ablations with 4 electrodes in a helical pattern were delivered in each renal artery and suitable bifurcation branch segments using the Symplicity Spyral RDN system (Medtronic). Serial histological tissue samples were harvested at 7 (N=6 pigs, n=12 vessels) and 28 days (N=8 pigs, n=16 vessels) post procedure to evaluate the response of surrounding anatomic tissue (including ureter, kidney, lymph nodes, skeletal muscles, adrenal glands, and renal nerves) to RF energy. ResultsRF ablative zones primarily consisted of perivascular cell disruption and inflammation within the adipose tissue and renal nerves, creating a distinct lesion footprint confined to the fat tissue. RF-induced cell disruption to the non-target perivascular tissues including ureter, kidney, renal lymph nodes, skeletal muscles was rare (Figure). There was no evidence of ablation involving the adrenal glands. Renal artery nerve disruption and downstream axonal loss were sustained to 28 days. RF ablative zones primarily consisted of perivascular cell disruption and inflammation within the adipose tissue and renal nerves, creating a distinct lesion footprint confined to the fat tissue. RF-induced cell disruption to the non-target perivascular tissues including ureter, kidney, renal lymph nodes, skeletal muscles was rare (Figure). There was no evidence of ablation involving the adrenal glands. Renal artery nerve disruption and downstream axonal loss were sustained to 28 days. Conclusions DisclosuresA. V. Finn: Abbott: Consulting; Boston Scientific Corp.: Consulting; Edwards Lifesciences: Consulting; Medtronic: Consulting; Amgen: Consulting; Biosensors: Consulting; Celonova: Consulting; Cook Medical: Consulting; CSI: Consulting; Lutonix Bard: Consulting; Terumo Corporation: Consulting; NIH R01 HL141425 Leducq Foundation Grant: Principal Investigator for a Research Study; A. Sharp: Medtronic: Consulting; Philips: Consulting; Recor Medical: Consulting; S. Tunev: Medtronic: Employed or Salary; F. Mahfoud: Medtronic: Consulting; Bayer: Consulting; Boehringer Ingelheim: Consulting; Recor Medical: Consulting; M. Schlaich: Medtronic: Consulting; Abbott: Consulting; Novartis: Consulting; Servier: Consulting; Pfizer: Consulting; Boehringer Ingelheim: Consulting; D. Lee: Medtronic: Advisory Board/Board Member; J. Trudel: Medtronic: Employed or Salary; D. Hettrick: Medtronic: Employed or Salary; D. E. Kandzari: Medtronic: Consulting and Principal Investigator for a Research Study; Ablative Solutions: Principal Investigator for a Research Study A. V. Finn: Abbott: Consulting; Boston Scientific Corp.: Consulting; Edwards Lifesciences: Consulting; Medtronic: Consulting; Amgen: Consulting; Biosensors: Consulting; Celonova: Consulting; Cook Medical: Consulting; CSI: Consulting; Lutonix Bard: Consulting; Terumo Corporation: Consulting; NIH R01 HL141425 Leducq Foundation Grant: Principal Investigator for a Research Study; A. Sharp: Medtronic: Consulting; Philips: Consulting; Recor Medical: Consulting; S. Tunev: Medtronic: Employed or Salary; F. Mahfoud: Medtronic: Consulting; Bayer: Consulting; Boehringer Ingelheim: Consulting; Recor Medical: Consulting; M. Schlaich: Medtronic: Consulting; Abbott: Consulting; Novartis: Consulting; Servier: Consulting; Pfizer: Consulting; Boehringer Ingelheim: Consulting; D. Lee: Medtronic: Advisory Board/Board Member; J. Trudel: Medtronic: Employed or Salary; D. Hettrick: Medtronic: Employed or Salary; D. E. Kandzari: Medtronic: Consulting and Principal Investigator for a Research Study; Ablative Solutions: Principal Investigator for a Research Study