Congenital TEF is most frequently associated with esophageal atresia (EA). Thomas Durston first described EA in 1670. In 1696, Thomas Gibson described TEF with EA. However, it was not until 1939 that Thomas Lanman and Logan Leven reported a successful staged repair. This was soon followed by the first report of a primary repair by Cameron Haight in 1941.1
Congenital TEF occurs in about 1 of every 3000 to 4000 live births.2 The prevalence increases with advancing maternal age and maternal diabetes, and there is a genetic predisposition in children born to affected parents.3 TEF and EA are believed to develop during the fourth week of gestation after the lung bud has begun to separate from the foregut. This is usually followed by separation of the trachea from the esophagus, which begins at the level of the carina and moves cephalad toward the larynx. It is postulated that abnormal endoderm–mesoderm interactions that occur early in development cause incorrect signaling and inappropriate separation and development of the tracheobronchial tree and esophagus.4
Diagnosis and Preoperative Assessment
TEF and EA were first classified by Gross with a lettering system and Ladd with a numbering system. It is now more common to describe them in terms of the anatomic abnormalities of the esophagus and trachea. The most common variant is EA with distal TEF (85%) (Fig. 58-1A), followed by EA alone without TEF (7%) (Fig. 58-1B) and TEF alone without EA (N- or H-type) (4%) (Fig. 58-1C). Other very rare variants include EA with proximal TEF (Fig. 58-1D) and EA with proximal and distal TEF (Fig. 58-1E).1,2
With advances in surgical management of TEF and EA, neonates who undergo successful repair can be expected to live near-normal lives. However, both TEF and EA are associated with other congenital abnormalities in 30% to 50% of patients, and these anomalies can have a significant impact on long-term outcomes. Associated defects include cardiac, gastrointestinal, neurologic, skeletal, and genitourinary. The most common cardiac defects are atrial and ventricular septal defects, patent ductus arteriosus, tetralogy of Fallot, and aortic arch abnormalities.5 The most common gastrointestinal abnormality is imperforate anus, which occurs in 10% of patients.
These patients also may have multiple congenital defects that have been given the acronym VACTERL (Vertebral, Anal, Cardiac, Tracheoesophageal fistula with Esophageal atresia, Renal, Limb). The presence of any three abnormalities determines this designation. The search for additional congenital abnormalities is critical owing to their impact on management strategies and overall survival.1,2
The first sign of possible TEF/EA is typically picked up during prenatal ultrasound with the observation of maternal polyhydramnios and the absence of a fetal stomach bubble. This is especially true with EA alone, in which the fetus is unable to swallow the amniotic fluid as a consequence of the blind proximal esophageal pouch. In patients with TEF alone without EA or the more common EA with distal TEF, polyhydramnios may be absent on account of the distal fistula.6,7 However, prenatal imaging has only a 44% positive predictive value. Clinical suspicion remains the key to early diagnosis.8 If not diagnosed prenatally, these patients present soon after birth with excessive drooling and pooling of saliva in the posterior pharynx that is refractory to frequent suctioning. They also have persistent coughing, choking, and cyanosis, especially with the first feeding attempts. In patients with EA with distal TEF, reflux of gastric contents leads to aspiration pneumonitis and respiratory distress with resulting bradycardia, apnea, and sepsis. In patients with TEF without EA, the diagnosis may be delayed. These patients may present later in life as adults, with recurrent coughing and choking while eating and with resulting pneumonia and respiratory infection. Less than 20 adult cases have been reported in the literature.9
The simplest means of diagnosis is to insert a firm, radiopaque nasogastric tube (8F in preterm and 10F in term infants). This typically passes no further than 10 to 12 cm in patients with EA, the end of the blind pouch (normal distance to gastric cardia is 17 cm). A chest radiograph and an abdominal radiograph then should be performed to confirm the location of the tube and to estimate the distance of the esophageal gap caused by the atresia. An esophagram can be used cautiously to diagnose TEF without EA, although precautions against aspiration of barium must be taken, with care to suction the airway clear at completion of the procedure. Bronchoscopy and esophagoscopy typically are confirmatory, although the anomaly may be missed at esophagoscopy because of its anterior location and if the fistula is in the proximal third of the esophagus.9,10 Recently, CT scanning with sagittal cuts of the thorax has been used to identify the interpouch distance in EA. Axial slices may be added when additional information is needed. This noninvasive testing may assist with preoperative planning and can help to identify other associated congenital abnormalities.11 In patients presenting later in life, prone barium swallow examinations can frequently establish the diagnosis.9,10 Once the diagnosis of TEF/EA is made, a careful search must be made for additional congenital abnormalities. Physical examination will identify imperforate anus and some limb and cardiac defects. Additional studies include echocardiography, renal ultrasound, and spine and limb radiographs.
EA with distal TEF (85%) (A) is the most common variant, followed by EA alone without TEF (7%) (B) and TEF alone without EA (N- or H-type) (4%) (C). Other very rare variants include EA with proximal TEF (D) and EA with proximal and distal TEF (E).
Preoperatively, maneuvers to decrease the risk of aspiration should be initiated, including continuous nasogastric suction, maintenance of head elevation, and administration of prophylactic antibiotics (e.g., ampicillin and gentamicin). IV fluids also should be started (e.g., 10% dextrose solution) or parenteral nutrition if surgical correction needs to be delayed. In patients with severe pneumonitis and respiratory distress, intubation and mechanical ventilation may be required. Bag mask ventilation should be avoided. In critically ill patients, a gastrostomy tube may be necessary to prevent gastric distention and reflux.
The need to investigate congenital abnormalities cannot be overemphasized. Multiple studies have shown that the two independent predictors of mortality are low birth weight and cardiac abnormalities.12 In some cases, the cardiac defect may need to be corrected first or concurrently with the TEF/EA repair.13
Anesthetic management can be complicated in these patients even without associated abnormalities. Gastric distention must be avoided or managed during positive-pressure ventilation. Airway management includes either single-lung ventilation, endotracheal tube positioning distal to the fistula, or balloon occlusion of the fistula.8 Ligation of the TEF and primary repair constitute the procedures of choice, with staged repair being largely historical.12,14 Unless there is a right-sided aortic arch, the operative approach is via a right posterolateral thoracotomy using an extrapleural approach. The interspace of the thoracotomy varies depending on the location of the atretic esophageal segment. Usually, the fourth intercostal space is preferred. Careful blunt dissection is performed to separate the pleura from the chest wall and the apex of the chest down to the level of the sixth rib. The azygos vein is divided. This usually exposes the distal TEF. It is then encircled and ligated. Bronchoscopy can be used to identify the fistula and rule out any additional fistulas. Esophageal tissue may be left on the trachea to assist with fistula closure and prevent tracheal stenosis.
Next, the upper pouch is dissected off the trachea up to the thoracic inlet. The dissection is facilitated by having the anesthesiologist push on the nasogastric tube, which brings the esophagus into the operative field. The distal pouch then is dissected as necessary to increase the length and decrease the interpouch distance. In addition, transverse circular myotomies can be used to increase esophageal length. Finally, the pouches are opened, and a single-layer end-to-end esophagoesophagostomy is performed. A transanastomotic nasogastric feeding tube should be inserted before completion of the anastomosis. A primary anastomosis should be performed if at all possible. Gastric mobilization may be required. Repair of gaps of up to 6 cm have been reported.15 A chest tube is placed away from the anastomosis in the extrapleural space, and the wound is closed. If repair is impossible despite all efforts, the esophagus is sewn to the prevertebral fascia and closed. Daily dilations of the upper pouch are performed until the gap is shortened enough for primary anastomosis, usually in 1 to 2 months. If primary repair is still not possible, esophageal replacement with stomach, colon, and jejunum may be necessary.
Thoracoscopic techniques have been used to avoid thoracotomy. Patients are positioned 45 degrees from prone, three to four ports are placed, and carbon dioxide insufflation is used to develop a working space. The fistula is clipped, and the anastomosis is performed with intra- or extracorporeal knot tying. A multi-institutional study demonstrated comparable results with open techniques, although advanced minimally invasive skills are required.16,17 In patients with TEF without EA, the fistula frequently is located more proximally in the esophagus. This allows for a transcervical approach to repair, especially if the fistula is cephalad to the T2 vertebral body, and again emphasizes the need for careful preoperative localization.18
Early and late postoperative complications are frequent, and careful attention to detail is warranted. Early complications include esophageal leak (20%), missed fistula, and recurrent fistula (10%).2 Anastomotic leak should be suspected in patients with new air leaks, pneumothorax, or salivary drainage from the chest tube. Diagnosis is confirmed by barium esophagram. These leaks can be treated conservatively, especially if an extrapleural approach was used, in which the keys to management are adequate drainage, H2-blockers, and gastric decompression. Large leaks with sepsis may require esophagectomy, cervical esophagostomy, and gastrostomy tube placement with delayed repair several months later after full recovery. Recurrent fistula usually requires repeat surgery, but endoscopic management with injection of fibrin adhesives into the fistulous tract shows promise, although this approach usually requires multiple procedures.19
Long-term complications include strictures, gastroesophageal reflux, and respiratory complications. Strictures can occur in up to 40% of patients following repair and are seen mostly in the setting of previous anastomotic leak, recurrent fistula, or ongoing reflux.2 Barium esophagram and esophagoscopy are diagnostic. Management usually requires multiple dilations and aggressive treatment of reflux. Gastroesophageal reflux can be a significant problem for these patients. This is likely a consequence of esophageal dysmotility. Most patients respond to medical management and behavioral modifications, but a significant number require surgical antireflux procedures. Indications include failed medical therapy, failure to thrive, recurrent pneumonias, refractory strictures, and Barrett esophagus. Nissen fundoplication may not be the best choice of fundoplication because of the esophageal dysmotility. A floppy Nissen or partial fundoplication may be the better choice (see Chapters 39 and 40). These patients require lifelong follow-up. Esophageal cancer can occur in the setting of long-standing reflux.
Respiratory complications are a frequent cause of readmission in patients with TEF/EA, especially in the first year of life, with a significant decrease in frequency after age 2 years. Recurrent pneumonias, chronic cough, wheezing, and aspiration secondary to reflux can be persistent problems that slowly abate over time. In addition, tracheomalacia is a challenging complication that may develop. Early abnormal tracheal development leads to redundant membranous trachea, predisposing to anteroposterior collapse. Bronchodilators may worsen the condition because of relaxation of the tracheal smooth muscle. While most patients improve with time, a few may require intervention. Aortopexy of the aorta to the posterior aspect of the sternum via a left thoracotomy allows the trachea to be fixed more anteriorly, preventing airway collapse. Tracheal stent placement has been used, but with mixed results. Tracheostomy may be required in refractory cases.2 Overall, the results have been excellent with primary repair of TEF/EA, with survival approaching 100% in children without associated congenital abnormalities. While the initial care and management in the first two years of life is complicated with frequent emergency room visits, hospital readmissions, multiple surgical procedures, and numerous radiologic imaging studies, most children can look forward to essentially normal lives.20