[Renal sympathetic denervation--physical-antomical basics, procedure, and analysis of clinical and technical...

Evidence from human and animal models indicate that excessive central sympathetic nerve activity (SNA) plays a pathogenic role in triggering and sustaining hypertension. Thus, treatments targeting this neurogenic (sympathetic) triggered hypertension were evaluated and renal sympathetic denervation (RND) showed promising results. However, little is known about the parameters influencing efficacy of high frequency energy in the arterial model.

Data from all 40 consecutive patients suffering from therapy-resistant hypertension who underwent RND and completed a 1-year follow-up were retrospectively analyzed. We focussed on procedural success, complications and efficacy (office-blood pressure, 24-h-blood pressure) and its correlations to quantity of ablations and intima media thickness.

In all patients (65.9 ± 11.6 years (range 42-83); 72.5% male) the procedure was successful. Ablations with arterial access from the upper extremity were technically unsuccessful. With the use of 13.6 ± 1.7 (10-17) ablations, office-blood pressure (1-year) could be reduced from 162/89 mmHg to 142/82 mmHg and 24-h-blood pressure from 149/83 mmHg to 139/79 mmHg, respectively, including a medium to strong correlation to quantity of ablations (r = 0.57, r = 0.63) while documenting only a weak correlation to IMT (r = -0.29, r = -0.25).

In comparison to the Simplicity studies, the hypertension lowering effects were less profound but consistently present over time in the 24-h-blood pressure assessments. The positive correlation of the quantity of ablations we found seems to be plausible regarding the unpredictable allocations of the sympathetic nerves i.e. in profoundly kinking vessels in hypertensives. The physics of high-frequency energy application in the arterial model needs further research.