Abstract
Marshall bundle ablation via retrograde ethanol infusion into the vein of Marshall (VoM) is one of the few adjunctive approaches complementary to the success of pulmonary vein (PV) isolation during catheter ablation for persistent atrial fibrillation (AF). VoM ablation also increases the success and durability of mitral isthmus block for the management of peri-mitral flutter. Despite its promise, the adoption of VoM ablation is limited due to anatomical variations that result in a steep learning curve. Successful Marshall bundle ablation requires accurate identification and successful cannulation of the VoM with an appropriate-size balloon to achieve adequate occlusion, followed by non-traumatic ethanol infusion. VoM ablation is often performed before wide-area circumferential ablation of the left-sided PVs. Mitral isthmus ablation to achieve mitral annular block is always recommended after VoM ablation to minimize the risk of peri-mitral flutter. This paper discusses a step-by-step approach for successful Marshall bundle ablation with tips and tricks for difficult cases based upon the performance of over 500 cases performed at the Ohio State University Medical Center.