Background: Precisely map and ablate the aortorenal ganglion (ARG) using noninvasive ultrasound technology to evaluate therapeutic effects and mechanisms in hypertension and related organ involvement.
Methods: A noninvasive dual-frequency ultrasound with a 3-dimensional targeting system was utilized to precisely map and ablate the ARG in a hypertensive canine model (2-kidney, 1-clip). Blood pressure changes from ultrasound stimulation served as a real-time evaluation metric, leading to an ultrasound stimulation-ablation-re-stimulation-supplementary ablation protocol for comprehensive ablation. Follow-up assessments at 1, 3, and 6 months post-ablation included evaluations of blood pressure, ventricular fibrosis and hypertrophy, cardiac function, and both local and systemic sympathetic nerve activity.
Results: One month postultrasound-targeted ARG ablation, there was a significant reduction in systolic blood pressure (∆ = -8.67±2.07 mm Hg; P<0.05), with further decreases at 3 months (∆ = -14.17±3.49 mm Hg; P<0.001) and 6 months (∆ = -24.83±4.49 mm Hg; P<0.001). Histological and echocardiographic assessments indicated improvements in ventricular fibrosis and hypertrophy, along with an enhanced left ventricular ejection fraction. Moreover, a reduction in sympathetic nerve activity was observed in the body, heart, and kidneys. In addition, aortic and adrenal tissue integrity, as well as normal liver and kidney functions, with no significant differences between the hypertension model and ARG ablation groups were observed.
Conclusions: Ultrasound-targeted ablation of the ARG significantly reduces blood pressure, suppresses sympathetic nerve activity in the systemic, cardiac, and renal regions, and alleviates hypertension-induced ventricular remodeling, offering a promising therapeutic strategy for hypertension and related cardiovascular diseases.
Keywords: ablation techniques; hypertension; sympathetic ganglia; sympathetic nervous system; ultrasonography; ventricular remodeling.