Role of lower esophageal sphincter incompetence in recurrent pneumonia after repair of esophageal atresia

Recent Advances in the Genetic Pathogenesis, Diagnosis, and Management of Esophageal Atresia and Tracheoesophageal Fistula: A Review

Infants born with esophageal atresia and tracheoesophageal fistula, a complex congenital malformation occurring in 1/2500-4000 live births, may suffer threats to their cardiac, respiratory, and digestive health in addition to anomalies that may exist in the genitourinary and musculoskeletal systems. Optimal care for these patients throughout their lives is best achieved through a coordinated, multidisciplinary approach that our health care system is not always well-equipped to provide. This review, though not exhaustive, highlights the components of care that pertain to initial surgical reconstruction and subsequent diagnosis and management of the complications that are most frequently encountered. Authors from among the many specialties involved in the care of these patients summarize the current best practice with attention to the most recent advances. Assessment and improvement of quality of life and transition to adult specialists as children grow to adulthood is also reviewed.

Gastroesophageal Reflux Disease and Aerodigestive Disorders

This relationship between gastroesophageal reflux and airway disorders is complex, possibly bidirectional, and not clearly defined. The tools used to investigate gastroesophageal reflux are mostly informative about involvement of gastroesophageal reflux within the gastrointestinal tract, although they are often utilized to study the relationship between gastroesophageal reflux and airway issues with are suspected to occur in relation to reflux. These modalities often lack specificity for reflux-related airway disorders. Co-incidence of gastroesophageal reflux and airway disorders does not necessarily infer causality. While much of our focus has been on managing acidity, controlling refluxate is an area that has not been traditionally aggressively pursued. Our management approach is based on some of the evidence presented, but also often from a lack of adequate study to provide further guidance.

Current Controversies in the Surgical Treatment of Esophageal Atresia

Background and Aims:

Esophageal atresia (EA) with or without tracheo-esophageal fistula (TEF) is a rare condition that can be nowadays succesfully treated. The current interest therefore is focused on the management of the difficult cases, on thoracoscopic approach, and on some aspects of the long-term results.

Methods:

The current strategies for the difficult or impossible anastomoses in pure and long-gap EA, the introduction of thoracoscopic repair and the causes, mechanisms and management of post-operative gastro-esophageal reflux (GER) are reviewed.

Results:

Methods of esophageal elongation and multi-staged repair of pure and long-gap EA allow anastomosis but with functional results that are often poor. Esophageal replacement with colon or stomach achieves at least similar results and often requires less procedures. Thoracoscopic repair is a promising adjunct, but the difficulties for setting it as a gold-standard are pointed out. GER is a part of the disease and its surgical treatment, that is often required, is burdened by high failure rates.

Conclusions:

EA with or without TEF can be successfully treated in most cases, but a number of unsolved issues remain and the current approach to difficult cases will certainly evolve in the future.

Late pulmonary function following repair of tracheoesophageal fistula or esophageal atresia

Although tracheoesophageal fistula and esophageal atresia (TEF-EA) are surgically correctable, late respiratory complications have been reported. We administered a respiratory and gastrointestinal symptom questionnaire and performed standard pulmonary function tests (PF T's) and methacholine challenge testing on an unselected group of 25 subjects with TEF-EA who underwent surgery at our institution between 1963 and 1985. Results were compared to predicted normals, as well as 10 sibling controls. While the mean values of lung function test results for the TEF-EA group were within the normal range, they were significantly different from their siblings. Thirteen of the 25 TEF-EA group (52%), but none (0%) of the controls, had abnormal pulmonary function. This was classified as restrictive in 9 (36%), obstructive in 3 (12%), and mixed in 1. In addition, airway hyperreactivity [defined as a positive methacholine challenge (PC20 < or = 8 mg/mL)], was found in 6 of 18 TEF-EA subjects and 4 of the 9 controls who were evaluated. Comparison of TEF-EA subjects with normal and abnormal PFTs showed no difference in the incidence of tracheomalacia, esophageal strictures or dilatation, recurrent pneumonias, or gastroesophageal reflux. The respiratory symptom score in the subjects and controls was similar, and did not correlate with abnormal pulmonary function. The cause of the pulmonary function abnormalities remains unexplained.

Lung function abnormalities in repaired oesophageal atresia and tracheo-oesophageal fistula

BACKGROUND

Respiratory complications are common after neonatal repair of oesophageal atresia and tracheo-oesophageal fistula. The prevalence of lung function abnormalities and the relation between gastrointestinal complications and lung function has not been studied in a large number of patients.

METHODS

Lung volumes and flow-volume loops were measured in 155 patients without spinal curvature aged 6-37 years who had undergone surgery for oesophageal atresia and tracheo-oesophageal fistula.

RESULTS

Sixty four of the 155 patients had evidence of mild lower airways disease, with values for FEV1 more than two standardised scores below the predicted value in 39 (25%) and above 2 standardised scores for the residual volume (RV)/total lung capacity (TLC) ratio in 64 (41%). Restrictive lung disease (TLC more than 2 standardised scores below predicted) was present in 28 (18%). Severe lung function abnormalities were present in under 10% of the 155. Half the subjects had some evidence of extra-thoracic tracheal obstruction, with a high ratio of expiratory to inspiratory flow for peak flow in 76 (50%) and at 50% of vital capacity in 59 (38%). Patients with radiological gastro-oesophageal reflux in early childhood had more airways obstruction and smaller lung volumes. Patients with current gastrointestinal symptoms were similar in their lung function to symptom free patients.

CONCLUSIONS

Minor lung function abnormalities are common in patients after repair of oesophageal atresia. Early diagnosis and management of gastro-oesophageal reflux may help to minimise these lung function abnormalities.

Predictive value of oesophageal pH variables in children with gastro-oesophageal reflux

Sixty three 24 hour oesophageal pH studies were performed in children with known or suspected gastro-oesophageal reflux and their progress was followed for at least a year. Forty two studies were of children who were well at follow up who were not receiving medical treatment for gastro-oesophageal reflux, and had not required antireflux surgery. Twenty one studies were from children who were still on treatment for gastro-oesophageal reflux or had undergone antireflux surgery. The results were analysed using non-parametric statistics to assess the value of pH recordings in predicting which children were likely to have continuing problems. Sleep reflux (minutes/hour) and acid clearing time were the most highly significant variables (p less than 0.0005 and p less than 0.0001 respectively). The results suggest that either sleep gastro-oesophageal reflux of more than 6.4 minutes/hour or an acid clearing time of seven minutes or more are good predictors of the clinical outcome (specificity 88.1%, sensitivity 81.0%). Three of the five children with false positive results were under 10 months of age. Positive results in this age group should therefore be interpreted with caution.

Esophageal manometrical assessment after esophageal circular myotomy for wide-gap esophageal atresia

We treated 3 children with wide-gap esophageal atresia by a circular myotomy of Livaditis technique, after which no postoperative complaints, such as heartburn, vomiting or dysphagia, were seen. Esophageal manometry, performed to evaluate the postoperative esophageal motor function revealed; (1) that lower esophageal sphincter pressure (LESP) increased gradually with time, (2) esophageal contraction waves (ECW) were evident at the site of the circular myotomy with swallowing, though these contractions were simultaneous; and (3) relaxation of the LES with swallowing was evident. These findings, as determined by the esophageal manometrical assessments, indicate that there is no difference between the postoperative esophageal function after either repair with a circular myotomy or primary anastomosis for esophageal atresia.

Etiologic factors in long-term respiratory function abnormalities following esophageal atresia repair

Recurrent respiratory illnesses are frequent in infants following repair of esophageal atresia and functional abnormalities of respiratory and esophageal function are often seen in older children. Recurrent aspiration is a potential cause of these respiratory abnormalities, but a relationship between abnormalities of gastrointestinal and respiratory mechanics has not been adequately investigated. We sought an association between lower esophageal sphincter (LES) incompetence, gastroesophageal reflux (GER), and respiratory function abnormalities in 18 subjects (age 12 to 21 years) following repair of esophageal atresia (Vogt type 111B). In each subject, measurements were made of spirometry, lung volumes assessed by plethysmography, esophageal manometry recorded using a constantly infused fluid-filled trilumen catheter to assess LES pressure and esophageal motility, and esophageal pH monitoring to detect GER. Subjects were grouped according to the presence or absence of a radiologically supported diagnosis of pneumonia in the first 4 years of life. Lung volumes were mildly but significantly decreased in the "pneumonia" group compared with the "nonpneumonia" group. There was no association between abnormalities of respiratory function and abnormal LES pressure or the presence of GER. These data suggest that pneumonia in esophageal atresia infants is associated with mild long-term lung damage. LES dysfunction and GER do not appear to play a major role in this process.

Long-term evaluation of esophageal and pulmonary function in patients with repaired esophageal atresia and tracheoesophageal fistula

Patients who have undergone repair of esophageal atresia and tracehoesophageal fistula as infants have been noted to have residual esophageal dysmotility and pulmonary dysfunction during their childhood years. However, limited information is available about the long-term follow-up of these patients. In this study we performed esophageal and pulmonary function studies on 12 adults who had required surgical repair of these defects in the first week of life. Most patients had symptoms of dysphagia and heartburn at time of evaluation. Pathologic gastroesophageal reflux was documented in 67% of patients and esophagitis was noted in 34%. All patients had esophageal motility abnormalities characterized by low-amplitude nonperistaltic waves throughout most of the esophagus. In addition, although most patients had no respiratory symptoms, mild restrictive lung volumes were noted in many patients. However, airflow obstruction and airway hyperreactivity were not present. These data demonstrate that clinical symptoms and abnormal esophageal manometry and pulmonary function persist well into the third and beginning of the fourth decade after repair of esophageal atresia and tracheoesophageal fistula in infancy.

Disorders of the esophageal motor activity in atresia of the esophagus

Esophageal dysfunction has been reported after successful repair of esophageal atresia but its nature has not been clearly defined. We studied esophageal motility in 20 newborns with esophageal atresia by recording intraluminal pressure of both proximal and distal segments. The investigation was made by pressure monitoring of the upper pouch via the mouth and of the distal segment via the gastrostomy. In all cases we found motility disorders. Two patients (12.5%) showed incomplete relaxation of the upper esophageal sphincter. The resting pressure of the esophageal body in both segments was constantly positive in all cases. Lower esophageal sphincter (LES) function was normal in all but two patients (16.7%) in whom the LES pressure was reduced and one case (8.4%) with incomplete relaxation of the LES. These studies suggest that motility disorders are also present in esophageal atresia before surgery.

Results of treatment of gastroesophageal reflux with bethanechol

Thirty-seven infants and children with gastroesophageal reflux were studied with prolonged esophageal pH monitoring before and during treatment with bethanechol. Total reflux scores improved by 69% (P = 6.47 X 10(-7) during bethanechol therapy. This improvement resulted primarily from decreases in the frequency and the duration of reflux episodes occurring more than two hours after feeding. Our findings indicate that infants and children with gastroesophageal reflux may safely be treated with bethanechol; thus the need for surgery is avoided.

Gastroesophageal reflux in association with congenital heart disease

The clinical course of 19 infants with severe respiratory symptoms associated with the presence of both congenital heart disease and gastroesophageal reflux is described. Down Syndrome or central nervous system disease was present in 12 of the 19 infants. The identification of reflux as a major or additional cause of the respiratory complications was often overlooked. Medical therapy alone was successful in only one of the 19 patients. Early repair or palliation of the cardiac malformation with or without subsequent antireflux surgical procedure was associated with relief of the symptoms in 13 patients.

Esophageal function in esophageal atresia

In order to determine the spectrum of esophageal dysfunction in repaired esophageal atresia, 14 patients were evaluated with esophageal manometry, intraluminal pH recording, and radiology. Nine patients had no difficulty in swallowing but six had symptoms suggestive of gastroesophageal (GE) reflux. On pH recording, six had evidence of GE reflux. Basal sphincter pressure was 22 mm Hg in both reflux and nonreflux patients. No patient had manometric evidence of peristalsis in the proximal esophagus, but six had peristalsis in the distal esophagus. On radiology all had a normal peristaltic stripping wave in the cervical esophagus, and peristalsis was absent in the proximal thoracic esophagus in all patients but present in the distal esophagus in five of the 10 patients studied. Esophageal dysfunction is present in all patients with repaired esophageal atresia even when symptoms are absent.

Patterns of gastroesophageal reflux in children following repair of esophageal atresia and distal tracheoesophageal fistula

We studied gastroesophageal reflux (GER) in 25 children between 3 and 83 mo post-repair of esophageal atresia and distal tracheoesophageal fistula (EATEF). The incidence of GER was determined by 18-24 hr pH monitoring of the distal esophagus and gastroesophageal scintiscan following the ingestion of 99mTc sulfur colloid in apple juice. Gastric emptying was also assessed in 20 children. Only 17 of 25 (68%) children had significant GER by esophageal pH monitoring, and 13 of 20 (65%) had significant GER by gastroesophageal scintiscan. Significant GER was found in 10 of 12 (83%) patients wih recurrent vomiting, respiratory symptoms or severe esophagitis. Three of these 10 patients required an operation to control GER. Significant GER occurred in continuous, discontinuous and mixed patterns. The discontinuous pattern was seen in 11 of 17 (65%) children, and was associated with slow gastric emptying. The only factor during the repair of EATEF that subsequently was associated with a higher incidence of significant GER (88% vs. 59%) and slow gastric emptying (11.2 +/- 4.2% vs. 25.9 +/- 3.7% gastric emptying at 30 min, p less than 0.05) was excessive tension at the esophageal anastomosis. Many children with EATEF do not have significant GER, but in those with significant GER slow gastric emptying seems to be important.

Gastroesophageal reflux in infants and children comparative accuracy of diagnostic methods

To assess the diagnostic accuracy of methods employed for detection of gastroesophageal reflux, 30 infants and children with symptoms of GER were evaluated by upper gastrointestinal series, gastroesophageal scintiscan, measurement of mean resting lower esophageal sphincter pressure, esophageal intraluminal PH measurement (acid reflux test), and endoscopy. Fifteen control patients were also evaluated by the above studies. GER was demonstrated by UGI in 15 and by GE scintiscan in 17 study patients. LESP less than 15 mm Hg was noted in 12 and a positive acid reflux test was obtained in 29 study patients. Esophagitis was detected in two (of 30) study patients radiographically and in 15 (of 21) study patients by upper gastrointestinal endoscopy. Pulmonary aspiration of gastric contents was not detected by the radionuclide method. None of the 15 control patients had GER demonstrated with any of the above methods. These studies indicate that (1) the acid reflux test correlates most closely with symptoms of GER; (2) THE GE scintiscan is complementary to the UGI in the diagnosis of GER, i.e., the combination increases sensitivity; (3) normal LESP does not necessarily exclude GER; and (4) endoscopy is superior to the UGI in detecting the presence of esophagitis.

Use of bethanechol for the treatment of gastroesophageal reflux

A double-blind crossover study utilizing bethanechol was performed among 45 pediatric-aged patients with gastroesophageal reflux. Thirty young children (age = less than 1 year) were studied. These infants did significantly better while taking bethanecol than when they were receiving placebo. Fifteen children (age greater than 1 year) were also studied. These patients also had significant clinical improvement while on the drug when compared to the period when they were receiving placebo. Esophageal pH probe testing after the oral administration of bethanecol showed a significant decrease in frequency and duration of episodes of gastroesophageal reflux. This improvement may be secondary to the increases in lower esophageal sphincter pressure and persistaltic activity seen during esophageal manometrics. Bethanechol should be considered for pediatric-aged patients who are not benefited by conventional medical therapeutic regimens.

Lung function in children following repair of tracheoesophageal fistula

Lung function and bronchial reactivity by methacholine challenge were studied in 24 patients seven to 18 years after repair of type I tracheoesophageal fistula. Only one patient had no abnormalities of the variables tested. Thirteen patients had obstructive airways disease, five had a restrictive defect, and 15 had a positive methacholine challenge. It is postulated that continuing subclinical aspiration of esophageal contents causes lung damage and renders the airways hyperreactive.