Letters to the Editor
To the Editor: We sincerely appreciate the interest of Dr Loots and colleagues in our article (1) and we thank them for their comments.
We agree that the term “healthy children” can be considered inappropriate because these children underwent pH-multichannel intraluminal impedance for suspected symptomatic gastroesophageal reflux (GER). However, this term has been used to distinguish patients with GER and patients without GER in a study conducted for the evaluation of GER. We know that for ethical reasons we cannot have completely healthy children as a control group. The used criteria have been previously considered by other authors for the interpretation of conventional pH-metry and multichannel impedance tracings in the pediatric age group (2–4).
Only for specific impedance motility parameters we have considered adults parameters (5,6), but, as far as we know, no motility study in children based on pH-multichannel intraluminal impedance has been published. We agree that these data are not completely transferable to children, but in a previously published study (7,8) on patients with esophageal atresia and congenital diaphragmatic hernia, we underscored some important differences between “healthy” children and patients with congenital malformations.
We have decided to exclude in this first analysis patients with nonacidic reflux; we agree that nonacidic GER episodes are important in terms of esophageal lesions (9,10), and therefore we believe that the characteristics of reflux (acidic or nonacidic) may influence the esophageal motility.
The need to evaluate a homogeneous group of patients (only with acidic GER) has influenced the number of enrolled patients studied, which was small. Therefore, our results should be interpreted with caution and should be considered preliminary data. Further analysis in children with GER and in children with congenital malformation is worthwhile.
1. Di Pace MR, Caruso AM, Catalano P, et al
. Evaluation of esophageal motility using multichannel intraluminal impedance in healthy children and in children with gastroesophageal reflux. J Pediatr Gastroenterol Nutr 2011; 52:26–30.
2. Mattioli G, Pini-Prato A, Gentilini V, et al
. Esophageal impedance/pH monitoring in pediatric patients: preliminary experience with 50 cases. Dig Dis Sci 2006; 51:2341–2347.
3. Vandenplas Y, Belli D, Boige N. A standardised protocol for the methodology of esophageal pH monitoring and interpretation of the data for the diagnosis of gastroesophageal reflux. Statement of the European Society of Pediatric Gastroenterology and Nutrition. J Pediatr Gastroenterol Nutr 1992; 14(S2):467–471.
4. Rudolph CD, Mazur LJ, Liptak GS, et al
. Guidelines for evaluation and treatment of gastroesophageal reflux in infants and children: recommendations of the North American Society of Pediatric Gastroenterology and Nutrition. J Pediatr Gastroenterol Nutr 2001; 32(S2):S1–S31.
5. Shay S, Tutuian R, Sifrim D, et al
. Twenty-four hour ambulatory simultaneous impedance and pH monitoring: a multicenter report of normal values from 60 healthy volunteers. Am J Gastroenterol 2004; 99:1037–1043.
6. Tutuian R, Vela MF, Balaji NS, et al
. Esophageal function testing with combined multichannel intraluminal impedance and manometry: multicenter study in healthy volunteers. Clin Gastroentrol Hepat 2003; 1:174–182.
7. Di Pace MR, Caruso AM, et al. Evaluation of oesophageal motility and reflux in children treated for esophageal atresia with the use of combined multichannel intraluminal impedance and pH monitoring. J Pediatr Surg
2011. In press.
8. Di Pace MR, Caruso AM, Catalano P, et al. Evaluation of oesophageal motility and reflux in children treated for congenital diaphragmatic hernia with the use of combined multichannel intraluminal impedance and pH monitoring. J Pediatr Surg
. In press.
9. Wang VS, Feldman N, Maurer R. Esophageal motility in nonacid reflux compared with acid reflux. Dig Dis Sci 2009; 54:1926–1932.
10. Gutschow CA, Bludau M, Vallböhmer D, et al
. NERD,GERD, and Barrett's esophagus: role of acid and non-acid reflux revisited with combined pH-impedance monitoring. Dig Dis Sci 2008; 53:3076–3081.