L'invention concerne un catheter intravasculaire pour une ablation de tissu perivasculaire et/ou periuretral, qui comprend de multiples aiguilles avancees a travers des tubes de guidage supportes qui s'etendent avec des extremites ouvertes autour d'un axe central pour venir en prise avec la surface interieure de la paroi de l'artere renale ou d'un autre vaisseau d'un corps humain permettant l'injection d'un fluide d'ablation pour retirer un tissu, et/ou des fibres nerveuses dans la couche externe ou enfoncees dans la couche externe du vaisseau, ou dans un tissu prostatique. Le systeme comprend egalement des moyens pour limiter et/ou ajuster la profondeur de penetration du fluide d'ablation dans le tissu de la paroi de vaisseau et au-dela de celui-ci. Le mode de realisation prefere du catheter comprend des structures qui fournissent un support radial et lateral aux tubes de guidage de telle sorte que les tubes de guidage s'ouvrent uniformement et maintiennent leur position contre la surface interieure de la paroi de vaisseau lorsque les aiguilles d'injection pointues sont avancees pour penetrer dans la paroi de vaisseau.

AIMS:We report the use of a novel endovascular approach using chemical neurolysis, via periadventitial injection of dehydrated ethanol (EtOH) to perform renal artery denervation.METHODS AND RESULTS:A novel, three-needle delivery device was introduced into the renal arteries of adult swine using fluoroscopic guidance. EtOH was injected bilaterally with one injection per artery, via the three needles into the adventitial and periadventitial space, using EtOH doses 0.15 ml/artery; n=3, 0.30 ml/artery; n=3, and 0.60 ml/artery; n=3, with saline injection as a sham control (0.4 ml/artery; n=3), and naive subjects (n=7) as a true negative control. The renal parenchymal norepinephrine (NE) concentration at two-week follow-up was the primary efficacy endpoint. The mean renal NE reduction was 54%, 78% and 88% at doses of 0.15 ml, 0.30 ml and 0.60 ml, respectively (p<0.0001 vs. controls). Histological examination revealed marked, and deep, circumferential renal nerve injury at depths of 2-8 mm from the intimal surface. There was no evidence of device-related or EtOH-induced injury to the intimal layers. In some samples at the higher EtOH doses, there was focal loss of smooth muscle cells in the outer media. Angiography at 45 days demonstrated normal appearing renal arteries with no detectable stenoses (n=8).CONCLUSIONS:Circumferential adventitial delivery of very low doses of EtOH may be a promising alternative to energy-based systems to achieve dose-dependent, and predictable renal denervation. Further study is warranted.