Gastroesophageal reflux and congenital gastrointestinal malformations

Although the outcome of newborns with surgical congenital diseases (e.g., diaphragmatic hernia; esophageal atresia; omphalocele; gastroschisis) has improved rapidly with recent advances in perinatal intensive care and surgery, infant survivors often require intensive treatment after birth, have prolonged hospitalizations, and, after discharge, may have long-term sequelae including gastro-intestinal comorbidities, above all, gastroesophageal reflux (GER). This condition involves the involuntary retrograde passage of gastric contents into the esophagus, with or without regurgitation or vomiting. It is a well-recognized condition, typical of infants, with an incidence of 85%, which usually resolves after physiological maturation of the lower esophageal sphincter and lengthening of the intra-abdominal esophagus, in the first few months after birth. Although the exact cause of abnormal esophageal function in congenital defects is not clearly understood, it has been hypothesized that common (increased intra-abdominal pressure after closure of the abdominal defect) and/or specific (e.g., motility disturbance of the upper gastrointestinal tract, damage of esophageal peristaltic pump) pathological mechanisms may play a role in the etiology of GER in patients with birth defects. Improvement of knowledge could positively impact the long-term prognosis of patients with surgical congenital diseases. The present manuscript provides a literature review focused on pathological and clinical characteristics of GER in patients who have undergone surgical treatment for congenital abdominal malformations.