Esophageal Protective Devices for Catheter Ablation: Changes in the Relevant Anatomical Structures
Authors: Shahzad Akmal , Martin Charys M , Barbeau Michele L 
Published: June 2021

Background

Atrial fibrillation (AF) is the most common cardiac arrhythmia in North America and is a major risk factor for stroke, congestive heart failure, and death. An increasingly popular first line of treatment is a minimally invasive procedure called radiofrequency catheter ablation (RFA) which mainly targets the pulmonary veins of the left atrium (LA). This procedure boasts high success rates, but in rare cases, patients may develop a fatal atrial esophageal fistula (AEF). Esophageal protective devices may mitigate the risk of developing a fistula but their effects on the anatomical structures within the posterior mediastinum are not well understood. The primary objective of our study is to evaluate the changes in the esophagus‐left atrium relationship with the insertion of an esophageal protective device.

Methods

Using 13 fresh cadaveric torsos we performed computed tomography (CT) scans prior to the insertion of a novel esophageal protective device (pre‐scan) and while the device was inserted in the esophageal lumen (post‐scan). The width of the esophagus, anterior‐posterior dimension, and the distance from the centerline of the esophagus to the left atrial pericardium were measured and compared between pre‐scans (no device) and post‐scans (device inserted). An additional standardizing measurement was taken between the vertebral column and the left atrium (VC‐LA) to evaluate the extent of heart displacement with the insertion of the device. Lastly, the shortest esophagus‐left atrial distance was marked by a point and mapped to previously defined regions of the LA after 3D reconstruction of the esophagus and LA. Measurements were performed using digital calipers in Mimics®.

Preliminary Results

A paired t‐test between VC‐LA measurements (n = 8) revealed no significant differences between pre‐ and post‐scans indicating that the insertion of the device does not move the heart dramatically. A Wilcoxon signed‐rank test was used to evaluate the differences in the mean esophageal widths between scans (n = 5). Of these 5 specimens, 3 demonstrated significant widening of the esophagus with device insertion (p< .001), 1 demonstrated significant esophageal narrowing (p< .001), and 1 demonstrated no significant differences in esophageal width. Data collection is ongoing.

Discussion/Conclusion

Preliminary data indicates that the position of the heart is not significantly affected by the insertion of the device. Thus, our esophagus to left atrial measurement will be indicative of changes in the position of the esophagus relative to the stationary heart. Preliminary esophageal width data revealed significant widening in 3 specimens while the device was inserted, which we expect will decrease the anterior‐posterior dimension of the esophagus. Future data on the shortest esophagus‐pericardial relationship will allow us to determine positional changes in the esophagus between pre‐ and post‐scans. In conclusion, data from this novel study will provide an anatomical basis for the design and implementation of an esophageal protective device used in catheter ablation procedures in order to effectively mitigate the risk of developing an AEF.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.