Retro-cardiac esophageal mobility and deflection to prevent thermal injury during atrial fibrillation ablation: an anatomic feasibility study

Background Atrial fibrillation (AF) ablation often causes minor esophageal (ESO) injury, and sometimes lethal posterior left atria (PLA)-ESO fistula. Avoidance techniques (energy reduction and/or complete target avoidance) provide questionable ESO protective value, and are likely associated with increased AF recurrence. Methods and results Potential independent mobility, deflectability and age-related anatomic factors, assessed by multi-position, and age-progressive thoracic computed tomography scans, show (1) mobility of the retro-cardiac ESO-PLA juxtaposition, (2) age-related increased thermal ablation vulnerability; and also, age-increased potential for retro-cardiac ESO mobility and deflectability to avoid collateral injury; and that (3) the retro-cardiac vertebral bodies and the descending aorta create a patient-specific esophageal corridor which defines the resting supine esophageal position and the subsequent PLA-ESO crossing points. Conclusion A small, 1–3 mm, increase in separation of the ESO relative to the PLA occurs when moving the patient from supine to lateral and from supine to prone position. Because of the concave spine; the PLA-ESO area of apposition increases. Patient rotation of 90° and 180° does not create enough passive PLA-ESO separation to avoid collateral ESO thermal energy; but, active repositioning lateral and out of ESO corridor appears feasible.