title: Electrical stimulation-based evaluation for functional modification of renal autonomic nerve activities induced by catheter ablation.
abstract: Catheter ablation of the renal artery can be performed without apparent angiographic stenosis. This suggests that renal nerve function can be attenuated with minor structural damage to the renal artery.
  
  
  
  To clarify this hypothesis, we examined the relationship between electrical nerve stimulation (ENS)-induced blood pressure (BP) response and severity of histological injury of the renal artery using an acute canine model of renal artery ablation.
  
  
  
  An irrigation catheter was inserted into the renal arteries of 8 dogs, and radiofrequency current was delivered at 15, 20, or 25 W. ENS was applied to each artery before and after ablation.
  
  
  
  Before ablation, ENS increased the BP and heart rate from 145 ± 15/86 ± 13 to 189 ± 21/111 ± 19 mm Hg and from 116 ± 9 to 130 ± 6 beats/min, respectively. Heart rate variability indices and serum catecholamine levels were elevated concomitantly. After ablation, the ENS-induced increase in BP and heart rate were markedly attenuated after 15 W ablation and those were nearly completely inhibited after 20 or 25 W ablation. An increase in heart rate variability indices and serum catecholamine levels became insignificant regardless of the applied energy. Renal artery angiograms revealed stenotic lesions only after 25 W ablation procedures. Histological studies showed mild to moderate injury of the arterial wall and autonomic nerves caused by 20 and 25 W ablation procedures, whereas only minor changes caused by 15 W ablation.
  
  
  
  Functional renal autonomic nerve ablation is potentially performable with the guidance of ENS.
authors.affiliation: Cardiovascular Research of Graduate School of Health Sciences. Electronic address: masaomi@clg.niigata-u.ac.jp.
authors.forename: Masaomi
authors.initials: M
authors.lastname: Chinushi
authors.affiliation: Cardiovascular Research of Graduate School of Health Sciences.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Cardiovascular Research of Graduate School of Health Sciences.
authors.forename: Osamu
authors.initials: O
authors.lastname: Saitoh
authors.affiliation: Cardiovascular Research of Graduate School of Health Sciences.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Furushima
authors.affiliation: Cardiovascular Biology and Medicine.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Iijima
authors.affiliation: Cardiovascular Biology and Medicine.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Izumi
authors.affiliation: Cardiovascular Biology and Medicine.
authors.forename: Akinori
authors.initials: A
authors.lastname: Sato
authors.affiliation: Pathology of Graduate School of Health Sciences, Niigata University School of Medicine, Niigata, Japan.
authors.forename: Mika
authors.initials: M
authors.lastname: Sugai
authors.affiliation: Pathology of Graduate School of Health Sciences, Niigata University School of Medicine, Niigata, Japan.
authors.forename: Mitsuya
authors.initials: M
authors.lastname: Iwafuchi
mesh_terms: D000818:Animals; D017776:Autonomic Pathways / Q000503:physiopathology* / Q000601:surgery; D017115:Catheter Ablation / Q000379:methods*; D004195:Disease Models, Animal; D004285:Dogs; D004558:Electric Stimulation; D006973:Hypertension / Q000503:physiopathology / Q000601:surgery*; D007668:Kidney / Q000098:blood supply / Q000294:innervation*; D012077:Renal Artery / Q000294:innervation / Q000601:surgery*; D013562:Sympathectomy / Q000379:methods*
keywords: Ablation; Autonomic nerve; Denervation; Electrical stimulation; Hypertension