Copyright 2010 by ESPGHAN and NASPGHAN. Unauthorized reproduction of this article is prohibited. Evaluation of Esophageal Motility Using Multichannel Intraluminal Impedance in Healthy Children and Children With Gastroesophageal Reflux Maria Rita Di Pace, Anna Maria Caruso, Pieralba Catalano, Alessandra Casuccio, and Enrico De Grazia ABSTRACT Objective: Multichannel intraluminal impedance (MII) directly evaluates esophageal bolus transport. There is a good correlation between MII and manometry in healthy adults, but there are no reports concerning children. The aim of the present study was to determine normal values of esophageal motility using only impedance measurements in healthy children and in a pediatric population with gastroesophageal reflux (GER). Patients and Methods: We described in the present study 60 children submitted to pH-MII for 24 hours for suspected GER. Patients were divided into 2 different groups on the basis of their pH-MII report. Group 1 patients showed acid GER, whereas group 2 patients had negative pH-MII analysis for GER despite symptoms. We described impedance reflux and motility parameters on 10 standardized swallows: number of reflux, mean acid clearing time, median bolus clearing time, bolus presence time, total bolus transit time, segmental transit time, and total propagation velocity. Results: In group 1, the median mean acid clearing time was 151 seconds, whereas the median mean bolus clearing time was 25 seconds. In group 2 patients, all of the reflux parameters were normal. In group 1 the median bolus presence time at each measuring site, the median total bolus transit time, and the median segmental transit time were significantly greater and total propagation velocity lower than values reported in group 2 (P < 0.001), if compared with those described for adult patients. Conclusions: The pH-MII is an ideal test in children because it studies GER with its characteristics and motility pattern. Our report summarizes for the first time impedance motility parameters in healthy children. Key Words: esophageal motility, gastroesophageal reflux, multichannel intraluminal impedance (JPGN 2011;52: 26–30) T he main motor functions of the esophagus are to clear swallowed contents effectively into the stomach and prevent the reflux of gastric contents back into the esophagus. Esophageal manometry is considered the criterion standard for studying the esophageal motility, but it is only an indirect assessment. Actually, so far, esophageal motility studies have been performed using either radiology or scintigraphy, but the applicability of these techniques is limited, especially in children, because of the exposure to radiation. Multichannel intraluminal impedance (MII) is a new, nonradiation technique, which has been used to evaluate esophageal bolus transport and which can provide a functional outcome of the esophageal motor function. Validation studies have found an excellent correlation between MII and videofluoroscopy. There is also a good correlation between MII and manometry in healthy subjects and in patients with gastroesophageal reflux (GER) disease (1–3). GER is common in children: on the basis of literature review, >80% of premature infants may present with some GER symptoms, whereas the prevalence of this condition decreases to 20% to 30% in infants and to 2% to 7% in older children (4 – 6). MII has been used as a diagnostic test for GER disease in children. The main advantage over traditional pH monitoring is its ability to detect both acid and nonacid GER and to differentiate between liquid and gas GER. With multiple impedance sensors, the MII technique routinely detects the proximal extent of a GER episode (7–11). In patients with GER disease, failed peristalsis and hypo- tensive peristaltic sequences in the esophagus may be observed, and often the severity of peristaltic dysfunction is correlated with the prevalence of symptoms (12–14). Tutuian et al (15) described impedance motility parameters and reported normal values for impedance changes with liquid and viscous swallows, but there are no reports concerning healthy children and children with GER. The aim of the present study was to determine normal values of esophageal motility based on impedance changes, using only impedance measurements in healthy children and in a pediatric population with GER. PATIENTS AND METHODS Patients The present study was performed during a 1-year period between April 2008 and September 2009. Among all patients submitted to pH-MII for 24 hours with motility analysis for sus- pected GER, we selected and described only 60 patients with a mean age of 7.5 years (range 5–10 years). All of the patients complained of either typical or atypical ‘‘supraesophageal’’ GER symptoms. Five patients underwent, 2 years earlier, an isolated pH monitoring that was negative for GER. Patients were divided into 2 different groups on the basis of their pH-MII report. There were no important differences regarding age and sex in 2 groups (group 1: mean age 7 years  1.5, 16 girls and 14 boys; group 2: mean age 8.3 years  1.5, 17 girls and 13 boys). We have based our evaluation of pathological GER on number and height of reflux, presence of pH-only and re-reflux, and Received January 29, 2010; accepted May 10, 2010. From the Pediatric Surgical Unit, Department of Mother and Child Care, University of Palermo, Palermo, Italy. Address correspondence and reprint requests to Anna Maria Caruso, Division of Pediatric Surgery, University of Palermo, Via Alfonso Giordano 3, Palermo, Italy (e-mail: annacaruso2@libero.it). The authors report no conflicts of interest. Copyright # 2010 by European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition DOI: 10.1097/MPG.0b013e3181e72c24 ORIGINAL ARTICLE:GASTROENTEROLOGY 26 JPGN  Volume 52, Number 1, January 2011