Function and morbidity of the esophagus and respiratory system in the growing child with esophageal atresia

Background: Esophageal atresia (EA) is a congenital malformation that consists of various degrees of discontinuity of the esophagus and affects about 1:3000 live births. EA is usually corrected at birth with survival rates over 90%, which has shifted the focus towards improvement of associated morbidity and health-related quality of life. The aims of this thesis were to investigate how morbidity in the esophagus and respiratory system in children with EA relates with diagnostic and function tests included in the follow-up programme after EA repair and evaluate the efficacy of the recommended proton pump inhibitor (PPI) prophylaxis. Methods: The study population consists of 169 children treated for EA in the Department of Pediatric Surgery at University Children’s Hospital, Uppsala between 1994 and 2018. The patients participated in the multidisciplinary follow-up programme that was established in 2011 for patients with EA. The thesis is based on four observational studies that investigated the outcome of the patients and generalisability of the results; risk factors for anastomotic strictures and the efficacy of PPI-treatment regimen in reducing its incidence; pulmonary function and risk factors for pulmonary function impairment; and association between ambulatory 24h pH test, endoscopic findings of esophagitis and hiatal hernia, symptoms of gastroesophageal reflux (GER), and histopathological esophagitis. The studies were approved by the Regional Committee for Medical Research Ethics. Results: The demographics and outcome of our study population are comparable with centres of higher caseload, showing low mortality rate but significant morbidity, especially considering anastomotic strictures and patients with long gap EA. Long gap EA, higher birth weight, and anastomotic tension were independent risk factors of anastomotic stricture formation. Prophylactic PPI-treatment did not reduce anastomotic strictures compared with symptomatic PPI-treatment. Respiratory morbidity and obstruction of the airways were common in children and adolescents after EA repair. The risk for pulmonary function impairment increased with lower birth weight and older age at follow-up. Neither ambulatory 24h pH-metry, clinical symptoms of GER nor endoscopic esophagitis were reliable tools to identify histopathological esophagitis in children and adolescents after EA repair and cannot replace esophageal biopsies. Conclusion: The poor correlation between clinical symptoms and morbidity of the esophagus and respiratory system justifies the need of clinical follow-up programmes in patients with EA. A general recommendation to stop prophylactic PPI-treatment after EA repair cannot be supported, however, sufficient evidence is available to support randomised controlled studies