Manometric study of lower esophageal sphincter in children with primary acid gastroesophageal reflux and acid gastroesophageal reflux secondary to food allergy.

PURPOSE: The comparison of values of selected lower esophageal sphincter (LES) manometric parameters measured in children suspected of gastroesophageal reflux disease (GERD) (preliminary study) and in children with primary acid GER and acid GER secondary to cow's milk allergy and/or other food (CMA/FA) in relation to the duration of the disease (prospective study).

MATERIAL AND METHODS: A 24-hour esophageal pH monitoring was performed on 264 children of both sexes suspected of GERD (mean age x=20.78+/-17.23 months). Pathological acid gastroesophageal reflux (GER) was diagnosed and divided into primary and secondary reflux in 138 children (52.3%). 76 patients (28.8%) (x=25.2+/-27.28 months) with primary GER made up Group 1. Group 2 consisted of 62 patients (23.5%) (x=21.53+/-17.79 months) with GER secondary to CMA/FA. 32 patients (12.1%) (x=23.7+/-12.63 months) with CMA/FA symptoms made up Group 3 (reference group). Prospective assessment of LES manometric parameters, i.e. resting LES pressure and LES length, was performed on 138 children with GER. Manometric parameters, resting LES pressure and LES length, measured at the preliminary study (0) and control studies (after 1, 2 and 8 years), were prospectively assessed in 138 children. The assessment resulted from clinical observation and/or conservative treatment.

RESULTS: The mean value of resting LES pressure (mm Hg) before treatment was x=11.75+/-3.98 in Group 1, x=11.05+/-3.31 in Group 2, and x=14.17+/-3.86 in Group 3 (reference group). After 2 years of clinical observation, the mean value of resting LES pressure accounted for x=13.71+/-3.88 in Group 1, x=13.01+/-2.94 in Group 2, and x=17.92+/-3.36 in Group 3. The mean LES length (cm) before treatment accounted for x=1.68+/-0.72 in Group 1, x=1.78+/-0.70 in Group 2, and x=2.0+/-0.86 in Group 3. After 2 years of clinical observation, the mean LES length was x=2.80+/-0.40 in Group 1, x=2.76+/-0.40 in Group 2, and x=2.97+/-0.48 in Group 3. 12 children with persistent GERD (Group 1) and 8 children with persistent GERD and food allergy (Group 2) underwent manometric evaluation of LES after 8 years. No statistical differentiation of the mean values of resting LES pressure and LES length were shown in examined children of Groups 1 and 2 during prospective studies.

CONCLUSIONS: Manometric studies of LES assessing only resting LES pressure and its length in the examined children with acid GER do not clearly differentiate GER into primary and secondary refluxes to food allergy.