Abstract 15328: Acute and Chronic Effects of Percutaneous Renal Sympathetic Denervation on Renal Hemodynamics Using a Novel Catheter for Radiofrequency Ablation: Data from an Animal Study
Introduction: Sympathetic overdrive impairs renal blood flow, whereas the effect of renal sympathetic denervation (RSD) on acute and chronic autoregulation of renal hemodynamics has yet to be adequately explored. Hypothesis: RSD performed using a novel radiofrequency ablation catheter, should have an acute and chronic (1 month post ablation) effect on renal hemodynamics: 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 angiograms, 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 RSD (acutely and after 1 month). RSD 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 acutely post RSD compared to APV before ablation was higher (65.16±39.78 vs 21.79±8.53 cm/sec, p<0.0001), while RSD 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). APV 1 month after ablation compared to APV before ablation was significantly higher (30.21±13.14 vs 21.79±8.53 cm/sec, p=0.035). Moreover, RSD reduced after 1 month RFR (1.36±0.25 vs 2.96±1.33, p<0.0001) and RI (0.48±0.15 vs 0.74±0.07, p=0.003), while no significant changes in the diameter of the renal artery were observed after dopamine administration (p=NS).
Conclusions: Catheter-based RSD augmented APV and decreased RFR and RI, acutely and at 1 month post ablation in healthy swines. These results support the potent acute and chronic effect of RSD by radiofrequency ablation on renal hemodynamic balance even in a healthy animal setting.
- © 2012 by American Heart Association, Inc.