title: Renal sympathetic nerve denervation using intraluminal ultrasound within a cooling balloon preserves the arterial wall and reduces sympathetic nerve activity.
abstract: OBJECTIVE
  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.
  
  
  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.
authors: National Institute of Health and Medical Research (INSERM) UMR-1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France.
authors: Atul
authors: A
authors: Pathak
authors: Leslie
authors: L
authors: Coleman
authors: Austin
authors: A
authors: Roth
authors: James
authors: J
authors: Stanley
authors: Lynn
authors: L
authors: Bailey
authors: Peter
authors: P
authors: Markham
authors: Sebastian
authors: S
authors: Ewen
authors: Charlotte
authors: C
authors: Morel
authors: Fabien
authors: F
authors: Despas
authors: Benjamin
authors: B
authors: Honton
authors: Jean Michel
authors: JM
authors: Senard
authors: Jean
authors: J
authors: Fajadet
authors: Felix
authors: F
authors: Mahfoud
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D003080:Cold Temperature; D004867:Equipment Design; D005260:Female; D007668:Kidney / Q000098:blood supply*; D008297:Male; D023421:Models, Animal; D009638:Norepinephrine / Q000378:metabolism; D012077:Renal Artery / Q000294:innervation* / Q000378:metabolism / Q000473:pathology; D034421:Sus scrofa; D013562:Sympathectomy / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D013564:Sympathetic Nervous System / Q000293:injuries / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D013997:Time Factors; D059708:Ultrasonic Surgical Procedures / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D062666:Vascular Access Devices
chemical_list: D009638:Norepinephrine