Mediastinal and esophageal injuries following radiofrequency ablation of atrial fibrillation

Aims: Radiofrequency (RF) catheter ablation is a potentially curative treatment of atrial fibrillation (AF). Esophageal wall changes varying from erythema up to ulcers following pulmonary vein isolation (PVI) have been described in up to 47% of the patients (Schmidt M. et al, Europace 2008). Although esophageal changes are frequently reported, the dramatic development of a left atrial-esophageal (LA-eso) fistula is rare. Nevertheless endoscopic visible esophageal lesions may just represent „the tip of the iceberg“. To the best of our knowledge mediastinal changes following PVI have not been studied by endosonography (EUS) before. To investigate the more subtle changes and injuries to the posterior wall of the LA, the periesophageal connective tissue and the whole wall of the esophagus we performed esophagogastroduodenoscopy (EGD) combined with radial EUS in patients requiring AF-ablation.

Methods: Twenty patients (pts., 6 females, mean age 60±8 years, range 46–75 years) underwent EGD and EUS (PENTAX EG 3670) prior to and following PVI within 48 hours, done by an experienced EUS-endoscopist.

Results: In all patients a regular endoscopic and endosonographic contact area between the LA and the esophagus could be demonstrated prior to PVI. After PVI morphological changes in the periesophageal connective tissue and the posterior wall of the LA occurred in five patients (25%), including periesophageal accumulation of liquid, swelling of the posterior wall of the LA also beyond the site of ablation and abolishment of the regular esophageal mucosa layer with edema. No esophageal mucosa alterations were found by EGD. The observed changes resolved within one week in four patients till the control EUS (one patient refused the control). No atrio-esophageal fistula occurred during follow-up.

Conclusions: Recently published changes in the esophagus after PVI like ulcers or erythema could not be demonstrated in this study, yet structural changes in the mediastinum, that were only visible by endosonography, occurred in 25% of the pts in the present study. This may indicate a higher than expected peri-esophageal injury due to PV ablation. In future, EUS may be helpful to develop strategies preventing mediastinal and esophageal injuries changes during AF-ablation.