To the Editor— Esophageal thermal probes and esophageal lesions during cryoablation

Abstract

May esophageal thermal probes (ETPs) produce esophageal thermal lesions (ETLs)? This question surfaced in the literature years ago, so far confined to radiofrequency ablation procedures. The article by Miyazaki et al 1 Miyazaki S. Nakamura H. Taniguchi H. Hachiya H. Takagi T. Watanabe T. Niida T. Hirako K. Iesaka Y. Gastric hypomotility after second-generation cryoballoon ablation—unrecognized silent nerve injury after cryoballoon ablation. Heart Rhythm. 2017; 14: 670-677 Abstract Full Text Full Text PDF PubMed Scopus (43) Google Scholar is now exporting the subject to the framework of cryoablation. Its aim was to investigate the incidence of gastric hypomotility, but as a side result, the authors found that the occurrence of ETLs was higher in patients who had luminal esophageal temperature (LET) monitoring: 8 in the 40 monitored patients and only 1 in the 64 nonmonitored ones. However, such a conclusion is biased by the fact that erythemas are given the same importance as serious lesions. Removing them from the count reduces the ratio of real lesions between the 2 groups to 2:1, which is not statistically meaningful. These findings simply confirm that ETPs may cause some irritation due to mechanical contact, which is a really minor risk compared with the one entailed by blind cooling. It is important to remark that the nadir LET reached when real ETLs were observed was actually in a dangerous range (6.3°C ± 3.7°C), which may have been the cause of the 2 esophageal erosions (eg, Metzner et al 2 Metzner A. Burchard A. Wohlmuth P. et al. Increased incidence of esophageal thermal lesions using the second-generation 28-mm cryoballoon. Circ Arrhythm Electrophysiol. 2013; 6: 769-775 Crossref PubMed Scopus (135) Google Scholar recognize that a safe value of the cutoff LET to prevent ETLs is 10°C). Finally, the authors say that “preprocedural transesophageal echocardiography (TEE) was performed in 47 patients” without specifying how patients are distributed in the 2 groups. We recall that there is large evidence that TEE can produce lesions (see, eg, Kumar et al 3 Kumar S. Brown G. Sutherland F. et al. The transesophageal echo probe may contribute to esophageal injury after catheter ablation for paroxysmal atrial fibrillation under general anesthesia: a preliminary observation. J Cardiovasc Electrophysiol. 2015; 26: 119-126 Crossref PubMed Scopus (32) Google Scholar ). Gastric hypomotility after second-generation cryoballoon ablation—Unrecognized silent nerve injury after cryoballoon ablationHeart RhythmVol. 14Issue 5PreviewFew data are available on gastric hypomotility (GH) after cryoballoon pulmonary vein isolation. Also, the use of esophageal temperature monitoring for the prevention of endoscopically detected esophageal lesions (EDELs) is not well established. Full-Text PDF Reply to the Editor— Esophageal thermal probes and esophageal lesions during cryoablationHeart RhythmVol. 14Issue 10PreviewWe thank Dr Anfuso for his thoughts. The exact mechanism of fistula formation is not defined. However, since the occurrence of fistulae is rare, all published studies evaluating the impact of protective measures have considered the occurrence of endoscopically detected esophageal lesions (EDELs) as the end point. Although preprocedural transesophageal echocardiography (TEE) could be a potential risk of EDELs,1 there was no significant difference in the performance of TEE between patients with and without EDELs in our study (Table 3). Full-Text PDF