TY - JOUR
T1 - Strategies to improve the efficacy of epicardial linear ablation on the beating heart
AU - Watanabe, Yoshiyuki
AU - Schill, Matthew R.
AU - Kazui, Toshinobu
AU - Melby, Spencer J.
AU - Schuessler, Richard B.
AU - Damiano, Ralph J.
N1 - Publisher Copyright:
Copyright © 2016 by the International Society for Minimally Invasive Cardiothoracic Surgery.
PY - 2016
Y1 - 2016
N2 - Objective: Creating transmural linear lesions on the beating heart is an important component of minimally invasive surgical ablation for atrial fibrillation. Animal studies have shown poor efficacy for surface bipolar radiofrequency ablation (RFA). Clinicians have developed strategies including multiple device applications and vena caval occlusion (VCO) to improve ablation efficacy. These techniques were evaluated in an acute porcine model. Methods: In the first experiment, an RFA device was used to perform two 40-second epicardial ablations on the right atrium of six pigs. Ablations were performed with and without VCO. Ultrasonic flow probes were used to verify VCO. In the second experiment, an RFA device was used to perform two 40-second epicardial ablations at six locations on the left and right atria of six pigs. All animals were sacrificed. The hearts were removed and stained with 2,3,5-triphenyltetrazolium chloride. Sections were examined using digital photography. Results: With VCO, 42 (81%) of 52 sections were transmural; without VCO on the RA, only 12 (24%) of 50 sections were transmural (P < 0.01). In thick (>2 mm) tissue, 10 (59%) of 17 VCO sections were transmural compared with only two (8%) of 24 with normal caval blood flow. Compared with a single ablation, multiple device applications improved transmurality on the LA but not the RA (92% vs 71%, P < 0.05). Conclusions: In an acute animal model, VCO improved the efficacy of beating-heart RFA on the RA. Multiple device applications improved the efficacy of RFA on the LA.
AB - Objective: Creating transmural linear lesions on the beating heart is an important component of minimally invasive surgical ablation for atrial fibrillation. Animal studies have shown poor efficacy for surface bipolar radiofrequency ablation (RFA). Clinicians have developed strategies including multiple device applications and vena caval occlusion (VCO) to improve ablation efficacy. These techniques were evaluated in an acute porcine model. Methods: In the first experiment, an RFA device was used to perform two 40-second epicardial ablations on the right atrium of six pigs. Ablations were performed with and without VCO. Ultrasonic flow probes were used to verify VCO. In the second experiment, an RFA device was used to perform two 40-second epicardial ablations at six locations on the left and right atria of six pigs. All animals were sacrificed. The hearts were removed and stained with 2,3,5-triphenyltetrazolium chloride. Sections were examined using digital photography. Results: With VCO, 42 (81%) of 52 sections were transmural; without VCO on the RA, only 12 (24%) of 50 sections were transmural (P < 0.01). In thick (>2 mm) tissue, 10 (59%) of 17 VCO sections were transmural compared with only two (8%) of 24 with normal caval blood flow. Compared with a single ablation, multiple device applications improved transmurality on the LA but not the RA (92% vs 71%, P < 0.05). Conclusions: In an acute animal model, VCO improved the efficacy of beating-heart RFA on the RA. Multiple device applications improved the efficacy of RFA on the LA.
KW - Atrial fibrillation
KW - Epicardial ablation
KW - Multiple ablations
KW - Radiofrequency ablation
KW - Vena caval occlusion
UR - http://www.scopus.com/inward/record.url?scp=85002251309&partnerID=8YFLogxK
U2 - 10.1097/IMI.0000000000000319
DO - 10.1097/IMI.0000000000000319
M3 - Article
C2 - 27930603
AN - SCOPUS:85002251309
SN - 1556-9845
VL - 11
SP - 414
EP - 419
JO - Innovations: Technology and Techniques in Cardiothoracic and Vascular Surgery
JF - Innovations: Technology and Techniques in Cardiothoracic and Vascular Surgery
IS - 6
ER -