EsophAguS Deviation During RadiofrequencY Ablation of Atrial Fibrillation: The EASY AF Trial

BACKGROUND

Injury to the esophagus has been reported in a high percentage of patients undergoing ablation of atrial fibrillation (AF).

OBJECTIVES

This study assessed the incidence of esophageal injury in patients undergoing ablation of AF with and without an esophageal deviating device.

METHODS

This prospective, randomized, multicenter, double-blinded, controlled Food and Drug Administration investigational device exemption trial compared the incidence of ablation-related esophageal lesions, as assessed by endoscopy, in patients undergoing AF ablation assigned to a control group (luminal esophageal temperature [LET] monitoring alone) compared with patients randomized to a deviation group (esophagus deviation device + LET). This novel deviating device uses vacuum suction and mechanical deflection to deviate a segment of the esophagus, including the trailing edge.

RESULTS

The data safety and monitoring board recommended stopping the study early after randomizing 120 patients due to deviating device efficacy. The primary study endpoint, ablation injury to the esophageal mucosa, was significantly less in the deviation group (5.7%) in comparison to the control group (35.4%; P < 0.0001). Control patients had a significantly higher severity and greater number of ablation lesions per patient. There was no adverse event assigned to the device. By multivariable analysis, the only feature associated with reduced esophageal lesions was randomization to deviating device (OR: 0.13; 95% CI: 0.04-0.46; P = 0.001). Among control subjects, there was no difference in esophageal lesions with high power/short duration (31.8%) vs other radiofrequency techniques (37.2%; P = 0.79).

CONCLUSIONS

The use of an esophageal deviating device resulted in a significant reduction in ablation-related esophageal lesions without any adverse events.

Protection of the esophagus during catheter ablation of atrial fibrillation

Esophageal injury still occurs with high frequency during ablation of atrial fibrillation (AF). The purpose of this study is to provide a review of methods to protect the esophagus from injury during AF ablation. Despite advances in imaging and ablation, the potential risk of esophageal injury during AF ablation remains an important concern with a high occurrence of esophageal injury (≈15%). There have been numerous studies evaluating varied techniques for esophageal protection including active cooling and displacement of the esophagus. These techniques are reviewed in this manuscript as well as the role of esophageal protection in managing patients undergoing AF ablation procedure.

Evaluation of a novel esophageal retractor utilizing vacuum suction and mechanical force for deviating the esophagus

BACKGROUND

Deviation of the esophagus prevents esophageal injury during atrial fibrillation ablation.

OBJECTIVES

This study is to evaluate, in animals, safety and effectiveness of a novel esophageal retractor that utilizes vacuum suction and mechanical force to deviate the esophagus.

METHODS

Following general anesthesia, a radiopaque ruler was placed behind the animal perpendicular to the esophagus. The esophageal retractor was inserted and esophagram was completed. Suction force (280-300 mm Hg) was applied to the distal aspect of the device that resulted in adherence of the esophagus in a circumferential manner. Then movement of a deflecting arm was used to deviate the esophagus. Four animal studies completed: (a) deviation distance and presence of trailing edge; (b) effect of 1 hour continuous suction and deviation upon esophageal cellular architecture; (c) impact on luminal esophageal temperature (LET) during high power ablation; and (d) compatibility of esophageal retractor with electroanatomic mapping system.

RESULTS

The distance of deviation to the right (26.6 ± 2.5 mm) was higher than to the left (18.7 ± 2.3 mm; P < .01). There was no esophageal trailing edge in 65/68 deviations (96%). With continuous suction for 1 hour, pathology revealed small, <1mm, circular area of hyperemia in the esophageal mucosa. During high power ablation, the maximum increase in LET was 0.2°C. Finally, there was no interference between the device and electro-anatomical mapping system.

CONCLUSION

In animal models, the esophageal retractor utilizing vacuum suction was successful at deviating the esophagus without significant trailing edge and with minor (1 mm) injury with prolonged continuous suction.

Prevention of atrial-esophageal fistula after catheter ablation of atrial fibrillation

PURPOSE OF REVIEW

The formation of atrial-esophageal fistula after catheter ablation for atrial fibrillation is a rare but devastating complication with high mortality. Prevention is of utmost importance. We review the usefulness of currently available preventive measures.

RECENT FINDINGS

Recent studies using endoscopy after atrial fibrillation ablation show the development of esophageal ulcerations in 14-17% of the patients. Risk factors for the occurrence of esophageal ulcerations seem to be a high esophageal luminal temperature during ablation, increased power during energy application at the posterior left-atrial wall, a short left atrium-to-esophagus distance, the use of nasogastric tubes and general anesthesia. The main available tools for prevention of atrial-esophageal fistula include: 1) Assessment of the esophagus position in the preprocedural CT/MRI scan. Its usefulness is limited by the potential of the esophagus to move. 2) Tagging of the esophagus and real-time visualization of its course during the procedure. This can be achieved by introduction of a catheter into the esophagus and visualization in the three-dimensional electroanatomical system, by intracardiac ultrasound or by fluoroscopy. 3) Continuous monitoring of the esophageal luminal temperature during ablation with special temperature sensors. 4) Reduction of power during energy application at the posterior left-atrial wall in close proximity to the esophagus. Despite application of preventive measures, cases of atrial-esophageal fistulas have been reported.

SUMMARY

Several measures for prevention of atrial-esophageal fistula formation are available nowadays. Although these measures cannot completely eliminate the risk of fistula, it appears prudent to apply a combination of them during atrial fibrillation ablation.