PVI-induced periesophageal vagal nerve injury detected by Electrogastrography

Abstract Background Atrio-esophageal fistula (AEF) is the most dreaded complication of pulmonary vein isolation (PVI), and its incidence has remained unchanged. Pathophysiology of fistula formation is incompletely understood but inflammation and acidic reflux (worsened by damage to the periesophageal vagal plexus) play a role. Vagal fibers innervate gastric motoric function, and ablation-induced vagal nerve injury (VNI) may be assessed by clinical signs of gastroparesis (e.g., food retention) or by electrogastrography (EGG). EGG records gastric "slow waves" (Fig. 1A+B), and VNI is diagnosed by (1) loss of power amplification following food-ingestion (Fig. 1C[III]+2A) and/or (2) gastric electrical arrhythmia (Fig. 1C[IV]+2B). Methods In patients undergoing catheter ablation for atrial fibrillation (AF) with radiofrequency (RF), cryoballoon (CB), or pulsed-field (PFA) energy, 4-channel-EGG (Fig. 1) was recorded before and after ablation. Ablation-induced VNI and its association to endoscopically detected esophageal injury and symptoms were assessed. Results From February 2021 to August 2024, 169 patients (70 [62/75] years, 57% male) were studied. Ablation-induced VNI was detected in 36/169 (RF: 24/116; CB: 12/33; PFA: 0/20) with significant differences in power amplification and gastric arrhythmia in patients without (wo/) vs. with (w/) VNI (Fig. 2). VNI overlapped poorly with food retention (44%) and mucosal lesions (11%). Clinical symptoms associated with VNI were bloating (19%), retrosternal burning (6%), nausea and vomiting (6%). Pre-existing esophageal inflammation (61/169) was associated with a trend for an increased likelihood of VNI (30% with vs. 17% without pre-existing esophagitis); p=0.077. Conclusion Periesophageal injury is a common finding following RF- and CB- but not with PFA-PVI, and VNI may be detected by EGG. Ablation-induced VNI (1) helps to explain unspecific upper gastrointestinal symptoms following catheter ablation of AF, and (2) may play a role in the complex pathophysiology of AEF-generation following PVI with thermic energy sources.