Not all anti-reflux treatment failures are due to persistence of abnormal esophageal acid exposure.

Dear Editor, we read with interest the article by Witteman et al. on the efficacy of revisional laparoscopic anti-reflux surgery (rLARS) performed in 15 patients, who previously underwent transoral incisionless fundoplication (TIF). The authors concluded that rLARS (e.g., revisional laparoscopic Nissen fundoplication) was feasible and safe after unsuccessful TIF, performed using EsophyX-device, resulting in objective reflux control although a relative increase in dysphagia rate (33%) occurred. In their study, all patients reported troublesome chronic GERD symptoms but did not record an adequate symptom relief after TIF (evaluated with validated questionnaire HRQL). The standard 24-h pH-metric evaluation was abnormal in all patients before TIF and in 73% of the patients after unsuccessful TIF, while esophageal acid exposure time became normal (mean value) in all the 15 patients after rLARS. This study provided interesting information about the efficacy of rLARS in patients who previously underwent unsuccessful anti-reflux endoscopic procedures and, at the same time, underlined that TIF could not be considered as effective as fundoplication for GERD treatment due to the high rate of therapeutic failure (35% in this series). However, the strength of these data would have been improved if the results of association between symptoms and reflux events (Symptom Index and Symptom Association Probability) before and after TIF and rLARS were also reported in order to exclude an association between symptoms and persisting acid reflux episodes and to investigate other causes of refractory symptoms such as gastric or supra-gastric belching by means of impedance-pH monitoring. Indeed, a recent study showed that LARS alters the belching pattern, reducing gastric belching (air venting from the stomach) and increasing supra-gastric belching (no air venting from the stomach). This phenomenon has been advocated to explain the persistence of reflux-like symptoms after surgery and it has been suggested that partial fundoplication rather than complete fundoplication would have a better impact in this regard since it is able to decrease gastric belching in a lesser extent and thus to cause fewer gas-related symptoms. It is reasonable to believe that the same negative phenomenon on belching could be determined also by TIF procedures and thus, it is not possible to exclude that some of the 15 patients (or at least the 4 patients with normal acid exposure after TIF) who did not respond satisfactory to the endoscopic procedures, may have an abnormal supra-gastric belching underlying their reflux-like symptoms. In this regard, although impedance-pH data are not available, we believe that details on symptom-acid reflux association by using both SI and SAP would be useful to consider a different cause of TIF failure rather than persisting abnormal acid reflux. Moreover, we encourage investigators to use the more recent technologies such impedance-pH testing when they plan to perform studies aimed to assess the role of surgical or endoscopic therapies in controlling GERD.