Different Sound Power HIFU Ablation Experimental Study Of Renal Sympathetic Nerve In A Canine Model

Backgrounds and Objective: Excessive activation of thesympathetic nervous system has been considered the most importanthypertension initiating and maintaining factors. In recent years, althoughcatheter—based renal sympathetic denervation antihypertensive efficacysignificantly, but still exist some limitations. Therefore it is necessary toexplore more safe and efficient method of the ablation of renalsympathetic denervation.Previous studies in our group, confirming thehigh intensity focused ultrasound can be achieved non-invasive ablationof renal sympathetic nerve in vitro. This study discusses the differentsound power high intensity focused ultrasound in dogs with renalsympathetic nerve damage, and security research after ablation.Methods: Twelve healthy dog, randomly divided into4groups,(ablation sound power150W group,200W Group,250W group) andcontrol group, respectively.Ablation group, for the treatment of bilateralrenal artery proximal, middle and renal hilum segment of the target area,two dimensional ultrasound and color Doppler flow imaging showed thebest long axis of the ablation level, the ablation process is a continuousline scan, line length10mm, scanning speed of6mm/s. Linescan2, thetwo scan line an angle of90°, the scanning line was "+" font, thescanning line at the center of the crossing point of the renal artery position. The control group dogs fixed on the treatment table, without anyablation treatment. Observe the ablation and postoperative experimentaldogs in the vital signs and general condition. Six days after the dogs wereput to death, renal artery and surrounding tissue sent to histological andimmuno-histochemical examination.Results: After different sound power HIFU ablation, pathologicalexamination showed that ablation of renal sympathetic injury, and thegreater the sound power ablation, the more severe nerve injury;mmunohistochemical indicates that ablation group all renal arterystructure and endothelial cells continuously complete, the realization ofhigh intensity focused ultrasound can safety in vitro non-invasive ablationof renal sympathetic nerve was no significant difference with the controlgroup.Conclusions: High-intensity focused ultrasound ablation is safe andeffective canine renal sympathetic, and the degree of nerve damageassociated with HIFU irradiation dose. Ablation sound power increases,the more severe renal sympathetic nerve damage, renal artery showed noobvious damage. To provide a basis for clinical trials.