Abstract 11601: Acute Effect of Percutaneous Renal Sympathetic Denervation on Renal Hemodynamics Using a Novel Radiofrequency Ablation Catheter in a Swine Model
Introduction: Sympathetic overdrive is accompanied by impaired renal blood flow, whereas the effect of acute renal denervation on autoregulation of renal hemodynamics has yet to be elucidated.
Hypothesis: Renal sympathetic denervation, performed using a novel radiofrequency ablation catheter, might have an acute effect on renal hemodynamics assessed by average peak velocity (APV), renal flow reserve (RFR) and resistive index (RI).
Methods: We studied renal haemodynamics in 9 anaesthetized female juvenile farm swines (mean age 6 months, mean weight 34.5 kg). The renal angiogram percutaneously performed through femoral artery found no renal artery stenosis in all subjects. A 0.014-inch Doppler flow wire was introduced in the renal artery for the measurement of the APV under baseline and hyperemic condition that was induced by the bolus intrarenal administration of dopamine (50μ g/kg). RFR was calculated as the ratio of hyperemic to basal peak velocity. RI was estimated as (peak systolic velocity - end-diastolic velocity)/peak systolic velocity. APV, RFR and RI were measured before and post renal sympathetic denervation. The sympathetic denervation was achieved via the lumen of the main renal artery with the novel catheter connected to a radiofrequency generator from St. Jude Medical according to pre-specified algorithm.
Results: In all animals, APV post ablation compared to APV before ablation was 300% higher (65.16±39.78 vs 21.79±8.53 cm/sec, p<0.0001). Radiofrequency ablation resulted in reduced RFR (1.51±0.59 vs 2.96±1.33, p<0.0001) and RI (0.66±0.07 vs 0.74±0.07, p=0.003), while no significant changes in the diameter of the renal artery was observed after dopamine administration (p=NS).
Conclusions: Catheter-based renal sympathetic denervation acutely augmented APV 3-fold, and significantly decreased RFR and RI in healthy swines. These results underscore the potent and acute effect of renal artery denervation by the radiofrequency ablation catheters on renal hemodynamic balance even in a healthy animal setting.
- © 2011 by American Heart Association, Inc.