MAINZ, GERMANY. The accidental creation of a fistula (hole) between the back wall of the left atrium and the esophagus is a rare but often fatal complication of pulmonary vein ablation. In early 2005 it was estimated that about 20 cases had occurred worldwide which would correspond to an incidence of 0.05% or less. The creation of an atrioesophageal fistula would appear to be more common when using the circumferential (Pappone) ablation approach than when using the segmental (Haissaguerre/Natale) approach. Clearly, avoiding lesion creation in the part of the left atrium that abuts the esophagus would be an effective way of avoiding a fistula, but would doing so reduce the likelihood of the ablation being successful? A team of German researchers set out to answer this question.
Their clinical trial involved 43 paroxysmal afibbers (28 men, 15 women) with an average age of 62 years. Seventy percent of the patients had idiopathic afib (lone afib of no known cause). The study participants were divided into 2 groups. Group A underwent a standard segmental pulmonary vein isolation (PVI) creating lesions to completely isolate (electrically) each pulmonary vein from the left atrium regardless of the anatomical relationship between the ablation sites and the esophagus. An average of 3.7 veins were successfully isolated and 67% of the patients had all veins completely isolated.
During the ablation of the remaining patients (Group B) special care was taken to avoid ablation over the esophagus (a stomach tube was inserted in the esophagus so that its location was clearly visible in fluoroscopy imaging). In Group B only 55% of the patients had all veins successfully isolated and the mean number of successfully isolated veins was 3.2. The study participants were followed up with ECGs and extended Holter monitoring for a minimum of 6 months. At the end of 3 months, 90% of patients in Group A and 95% of those in Group B were afib-free. Corresponding numbers at 6 months were 81% and 82%. However, one patient in Group A and 4 in Group B were treated with amiodarone. Assuming this treatment was continued would result in a complete success rate (no afib, no antiarrhythmics) of 76% in Group A and 64% in Group B.
The researchers also compared the outcome in patients where the PVI was performed without relevant changes due to the location of the esophagus and in those in which the ablation strategy was adjusted due to the proximity of the esophagus to the pulmonary veins. The freedom from afib (with or without antiarrhythmics) in the two groups after 6 months was 85% and 75% respectively. The researchers conclude that avoiding lesion creation in the vicinity of the esophagus does not have a significant effect on afib recurrence rate during short-term and mid-term follow-up.
Kettering, K, et al. Segmental pulmonary vein ablation: success rates with and without exclusion of areas adjacent to the esophagus. PACE, Vol. 31, June 2008, pp. 652-59