Chapter 124: Surgical Diseases of the Newborn: Alimentary Tract Obstruction

I. ESOPHAGEAL ATRESIA

1. Definitions

   1. Type C esophageal atresia is the most common type, accounting for up to 85% of cases. It consists of proximal esophageal atresia with distal tracheoesophageal fistula.

   2. Type A esophageal atresia is the second most common type, accounting for about 10% of cases. This is a pure esophageal atresia without fistula.

   3. Other forms of esophageal atresia are less common.

2. Pathophysiology

   1. Embryologic failure of migration and separation of longitudinal tracheoesophageal fold. Normally, folding results in larynx and trachea anteriorly and esophagus posteriorly.

3. Clinical presentation

   1. Polyhydramnios due to proximal esophageal obstruction; fetus cannot swallow amniotic fluid.

   2. Neonates display feeding intolerance, excess salivation, and respiratory distress from aspiration of feeds.

   3. In type C, gastric distention may cause respiratory compromise, and gastric reflux into airway may cause chemical pneumonitis and pneumonia.

4. Diagnosis

   1. Prenatal ultrasound may show small or absent gastric bubble if pure esophageal atresia.

   2. Inability to pass an orogastric tube. The chest radiograph shows an orogastric tube in the proximal esophagus. Air below the diaphragm confirms presence of a distal fistula.

   3. VATER/VACTERL association (vertebral defects, anal atresia, tracheoesophageal fistula, and radial or renal dysplasia/vertebral defects, anal atresia, cardiac malformations, tracheoesophageal fistula, renal dysplasia, and limb abnormalities) workup necessary.

5. Management

   1. Preoperative optimization is focused on minimizing risk of aspiration and gastric distention.

      1. Place Replogle tube in proximal esophageal pouch to evacuate oral secretions.

      2. Keep baby in upright position (45 degrees) to lessen risk of reflux and aspiration.

      3. If possible, avoid positive-pressure ventilation.

      4. If mechanical ventilation is necessary, low tidal volumes and inspiratory pressures are preferable. In select babies, high-frequency oscillatory ventilation may provide gentler ventilation.

      5. Broad-spectrum antibiotics should be administered.

      6. VATER/VACTERL association workup should be performed. This includes an echocardiogram prior to surgery to assess for cardiac and aortic arch anomalies.

   2. Goals of operative therapy are to ligate fistula and establish esophageal continuity if possible.

      1. Repair via open or thoracoscopic techniques.

      2. If long-gap esophageal atresia (>3 vertebral bodies) is present, one may not be able to perform immediate esophageal anastomosis and a gastrostomy tube should be placed.

      3. If defect cannot be bridged with native esophagus, use of gastric or intestinal conduits may be necessary.

II. DUODENAL OBSTRUCTION

1. Definition. Duodenal luminal obstruction can be classified as complete or partial; as pre- or postampullary; and as caused by intrinsic or extrinsic problems.

2. Pathophysiology

   1. Intrinsic obstruction results from either failure of endodermal proliferation or luminal recanalization.

   2. Atresia may occur in the setting of external compression, such as annular pancreas.

3. Internal duodenal obstruction

   1. Results from classic atresia with resultant stenosis or complete obstruction.

   2. Frequently associated with trisomy 21 (33%).

4. External duodenal obstruction

   1. Annular pancreas. Occurs secondary to incomplete rotation of ventral pancreatic bud, resulting in ring of pancreatic tissue that encircles second portion of duodenum. Results in either complete or partial obstruction.

   2. Malrotation. Abnormal midgut rotation and fixation causing complete or partial ...