PO-690-05 NOVEL LAPAROSCOPY-BASED RENAL DENERVATION FOR MODULATING AF INDUCIBILITY USING A SWINE MODEL

Abstract

Renal denervation (RDN) may control atrial fibrillation (AF) by modulating autonomic tone. The study aimed to validate the acute effects of a novel laparoscopy-based RDN for modulating AF inducibility using a swine model. Each 4 swine were assigned for the sham operation and laparoscopy-based RDN. Vagal nerve stimulation (VNS; 10 Hz, 50 ms, 5-20 V, 30 sec) was performed at the right vagal nerve to enhance AF inducibility. Burst atrial pacing (100 ms, 1-5 V, 90 sec) at the right atrium was used to induce AF. Atrial effective refractory period (AERP) and AF duration were compared before and after the sham operation or RDN. Laparoscopy-based RDN was done using an instrument with linear bipolar electrodes that wraps around the renal artery (Figure 1A). It delivers the radiofrequency energy to the adventitia to ablate renal sympathetic nerves. Both proximal and distal parts of renal artery were ablated (Figure 2A). Renal arterial biopsy was done and stained with tyrosine hydroxylase to identify sympathetic nerves and compared between both groups. For the sham group, VNS significantly reduced AERP from median 180 to 150 ms and 170 to 150 ms before and after the sham operation, respectively (both p =0.009) (Figure 2A). VNS numerically increased AF duration from median 4.5 to 10.5 sec and 6.0 to 9.5 sec before and after the sham operation (p =0.06 and 0.11, respectively) (Figure 2B). The effect of VNS on AF duration was significant (p =0.005), while the sham operation did not (p =0.79). For the RDN group, VNS numerically reduced AERP from 160 to 130 ms and 180 to 160 ms before and after RDN (p =0.24 and 0.54, respectively) (Figure 2A). VNS did not induce significant difference in AF duration regardless of RDN. However, RDN significantly reduced AF duration regardless of VNS (from mean 23.0 to 4.8 sec; difference between means 18.3 sec (95% CI 6.4-30.1 sec); p =0.03) (Figure 2B). The effect of RDN on AF duration was significant (p =0.003). In histology analysis, renal sympathetic nerve tissue was degenerated after laparoscopic RDN, whereas normal renal sympathetic nerves were intact in the sham group (Figure 2B). A novel laparoscopy-based RDN significantly reduced AF inducibility in swine models. The long-term effect of this novel laparoscopy-based RDN would be investigated.View Large Image Figure ViewerDownload Hi-res image Download (PPT)