Symptom analysis improves GERD diagnosis and may be helpful to define a successful surgical approach.

To the editor, We read with interest the article by Koch et al. that randomly allocated 125 patients with documented chronic gastroesophageal reflux disease (GERD) to either laparoscopic floppy Nissen fundoplication (n = 62) or laparoscopic Toupet fundoplication (n = 63). Both procedures proved to be equally effective in improving quality of life and both typical and atypical reflux-related symptoms. The authors also indicated that laparoscopic Toupet fundoplication was characterized to have a high ability to belch and a reduced rate of postoperative dysphagia. The authors opted to use the current gold standard for GERD diagnosis (i.e., impedance-pH testing), and thus, they carefully and objectively defined the inclusion criteria for undergoing surgical fundoplication. Indeed, they considered patients for surgery who had a total number of refluxes higher than 73 per 24 h, a DeMeester score higher that 14.7, or a positive association between symptoms and reflux events by means of the symptom index (SI). One-year postsurgery impedance-pH studies clearly showed a marked decrease of reflux episodes (total, acid, proximal, upright, and recumbent refluxes) and a DeMeester score that paralleled the large improvement of GERD symptoms and quality of life, thus supporting the usefulness of impedance-pH testing in selecting GERD patients for surgery. However, even though this study provides relevant novel data on the potential application of impedance-pH technology for the surgical management of GERD patients, we believe that the interpretation of their findings would be improved if the results of symptom association analysis after surgery were also reported. Few data are reported about SI (i.e., only preoperative information, and without describing whether the association was positive for acid and/or nonacid reflux episodes), and no data are provided for symptom association probability (SAP), which is considered by several authors to be the best index demonstrating an association between symptoms and reflux events. Indeed, SAP is based on statistical parameters, is not generated by chance, and clearly explores the relationship between symptoms and refluxes. Although SI has the advantage of being easy to calculate, it does not take into account the total number of reflux episodes with the likelihood risk that a symptom is found to be associated with reflux by chance. Therefore, because impedancepH permits the measurement of all types of reflux and correlates them to symptoms, it increases the diagnostic yield by using a symptom association analysis mode such as SI or SAP. In fact, previous studies have shown that GERD patients, particularly those found to have no mucosal injuries at upper endoscopy, frequently have a normal distal acid exposure time and therefore a low acidrelated DeMeester score. Using these parameters, it has been observed that GERD patients have symptoms associated not only with acid reflux but also with weakly acidic reflux; this may explain the increased proton pump inhibitor failure observed in endoscopy-negative patients, thus supporting the use of alternative surgical or endoscopic therapies in this patient population. So far, data concerning the SI and SAP for acidic and weakly acidic reflux should be reported in order to know whether surgical procedures are effective in relieving symptoms associated with weakly acidic reflux. Furthermore, the authors recorded quality-of-life information and grouped symptoms in typical, atypical, gasbloated, and bowel dysfunction. However, few data have been provided about their impact and relation to GERD. For instance, very little information has been provided regarding the functional and atypical symptoms associated with GERD before surgery and how these symptoms changed after surgery. Previous studies demonstrated an important overlap between functional dyspepsia, irritable bowel syndrome, or atypical symptoms and GERD. Moreover, these studies hypothesized an important impact of these overlapping entities in determining the medical therapeutic failure in refractory patients. It is important to know whether surgery was able to modify the atypical symptoms, gas bloat, and bowel dysfunction and their relation with GERD, thus supporting the major impact of surgery rather than medical treatment in the management of patients with overlapping entities. In conclusion, Koch et al. provided encouraging data about the efficacy of surgery in impedance-pH-proven GERD, but we believe that more information about symptom\u2013reflux correlation and more details on extraesophageal symptoms and their relation with GERD would improve their results