Abstract

Background

Luminal esophageal temperature (LET) monitoring does not prevent esophageal injury following Cryoballoon (CB) pulmonary vein isolation (PVI) although LET < 12°C has been shown to be associated with an increased likelihood of mucosal lesions.

Objective

Detailed analysis of LET data may better predict the risk for esophageal injury (mucosal lesions, periesophageal edema and food retention), and thus, streamline additional work-up/therapy to prevent progression to fistula.

Methods

LET data (S-Cath Circa, 12 thermocouples) of consecutive patients with CB-PVI were analyzed offline. Freezing cycles were stopped when LET reached 18.0°C. LET-minima, duration of LET fall, area under the minimum LET curve of any thermocouple (AUCmin) and summed-up AUC of all individual LET-curves of the 12 thermocouples (3D-AUC) were calculated and correlated with the results of endoscopy (EGD [mucosal lesions, food retention]) and endoscopic ultrasound (EUS [edema]). The calculated parameters were analyzed with regard to their ability to predict (sensitivity) or exclude (specificity) esophageal injury.

Results

Following CB-PVI, 99 patients were studied by EGD+EUS (n=64) or EGD alone (n=35). Mucosal lesions were rare (1/99) but periesophageal injury quite common (32/64), in detail food retention (19/99) and periesophageal edema (22/64). Procedural data of PVI (including freezing cycles and balloon temperatures) were not different between patients with/without esophageal injury.
None of the LET-parameters (minimum, duration, AUCmin and 3D-AUC) differed significantly for patients with/without esophageal injury (calculated for any temperature fall from baseline and for different cutoff values [duration and AUC below 30°C, 27°C, 24°C or 21°C]). The maximum Youden-index (sensitivity + specificity – 1) was < 0.25 for all calculations, the ROC-curves followed the bisector-curve and did not show any predictive value.

Conclusion

Neither arbitrarily defined LET-limits nor calculated LET-parameters are helpful to predict esophageal injury following CB-PVI. Although mucosal esophageal lesions are rare, the relevance of the observed periesophageal injury is not well understood and the optimal follow-up strategy remains unknown.