Anesthetic Considerations in Tracheoesophageal Fistula

TRACHEOESOPHAGEAL FISTULA

Pathophysiology

There are several types of tracheoesophageal fistula (Figure 42–3). The most common (type IIIB) is the combination of an upper esophagus that ends in a blind pouch and a lower esophagus that connects to

the trachea. Breathing results in gastric distention, whereas feeding leads to choking, coughing, and cyanosis (three Cs). The diagnosis is suspected by failure to pass a catheter into the stomach and con-firmed by visualization of the catheter coiled in a blind, upper esophageal pouch. Aspiration pneumo-nia and the coexistence of other congenital anoma-lies (eg, cardiac) are common. These may include the association of vertebral defects, anal atresia, tracheoesophageal fistula with esophageal atresia, and radial dysplasia, known as the VATER syn-drome. The VACTERL variant also includes cardiac and limb anomalies. Preoperative management is directed at identifying all congenital anomalies and preventing aspiration pneumonia. This may include maintaining the patient in a head-up position, using an oral-esophageal tube, and avoiding feedings. In some instances gastrostomy may be performed under local anesthesia. Definitive surgical treatment is usually postponed until any pneumonia clears or improves with antibiotic therapy.

Anesthetic Considerations

These neonates tend to have copious pharyngeal secretions that require frequent suctioning before and during surgery. Positive-pressure ventilation is avoided prior to intubation, as the resulting gas-tric distention may interfere with lung expansion. Intubation is often performed awake and without muscle relaxants. These neonates are often dehy-drated and malnourished due to poor oral intake.

The key to successful management is correct endotracheal tube position. Ideally, the tip of the tube lies distal to the fistula and proximal to the carina, so that anesthetic gases pass into the lungs instead of the stomach. This is impossible if the fis-tula connects to the carina or a mainstem bronchus. In these situations, intermittent venting of a gastros-tomy tube may permit positive-pressure ventilation without excessive gastric distention. Suctioning of the gastrostomy tube and upper esophageal pouch tube helps prevent aspiration pneumonia. Surgical division of the fistula and esophageal anastomosis is performed via a right extrapleural thoracotomy with the patient in the left lateral position. A precordial stethoscope should be placed in the dependent (left) axilla, since obstruction of the mainstem bronchus during surgical retraction is not uncommon. A drop in oxygen saturation indicates that the retracted lung needs to be reexpanded. Surgical retraction can also compress the great vessels, trachea, heart, and vagus nerve. Blood pressure should be continu-ously monitored with an arterial line. These infants often require ventilation with 100% oxygen. Blood should be immediately available for transfusion. Postoperative complications include gastroesopha-geal reflux, aspiration pneumonia, tracheal com-pression, and anastomotic leakage. Most patients must remain intubated and receive positive-pressure ventilation in the immediate postoperative period. Neck extension and instrumentation (eg, suction-ing) of the esophagus may disrupt the surgical repair and should be avoided.