Andrea Winthrop and Jill Whitehouse
MICROGASTRIA
Congenital microgastria is a rare anomaly that is characterized by failure of the primitive foregut to differentiate into a stomach during weeks 4 to 8 of gestation, thus resulting in a small tubular stomach usually associated with megaesophagus and incomplete gastric rotation (Fig. 400-1). Isolated microgastria is uncommon,1 with associated anomalies such as asplenia, situs inversus, limb hypoplasia, intestinal malrotation, laryngotracheal clefts, and cardiac abnormalities being common.2,3 Only about 60 cases have been described.
CLINICAL MANAGEMENT AND OUTCOME
Typically, patients present with recurrent vomiting, failure to thrive, and recurrent respiratory infections due to the reduced gastric volume and associated megaesophagus. Patients will often have persistent diarrhea due to dumping syndrome resulting from the lack of gastric capacity. Diagnosis of microgastria is by upper GI contrast studies that demonstrate the typical findings of a very small stomach. When identified, screening for associated anomalies is warranted.
FIGURE 400-1. Upper GI radiograph showing the typical small-volume tubular stomach, incomplete rotation, and gastroesophageal reflux in a patient with microgastria.
The approach to management of microgastria is controversial. Case reports describe successes and failures of medical and surgical management approaches.4,5 Medical management was associated with poor growth, delay in cognitive development, and dumping syndrome, so that surgical therapy was recommended. However, improved technologies that allow routine use of gastric or jejunal slow-drip feedings has been reported to have successful outcomes.6 This approach prevents gastroesophageal reflux and allows appropriate nutrition for growth. Proton-pump inhibitor therapy may be beneficial since it can reduce gastric fluid volumes. Small oral feedings may be administered to allow appropriate development of feeding skills. Parenteral supplementation should not be required if jejunal feeding can be maintained. In children where drip feeds are tolerated gastric volume may increase significantly over the first years of life, and the patient can eventually be converted to bolus or ad lib feeds.
FIGURE 400-2. Neonate with massive pneumoperitoneum from gastric perforation.
If medical management is unsuccessful, some sort of surgical therapy can be attempted. There are only a few case reports with acceptable outcomes following gastric augmentation procedures combined with some form of fundoplication. The most common type of augmentation performed is the Hunt-Lawrence pouch, which involves the creation of a Roux-en-Y double-row jejunal reservoir.1 Early follow-up results suggest improved gastric capacity and minimal reflux with this technique, leading to an increase in oral intake and improved growth. Long-term follow-up reports are limited, with only 2 patients that are described in the literature that demonstrate normal social and cognitive function.
GASTRIC PERFORATION
Neonatal gastric perforation usually occurs during the first week of life, caused by trauma, ischemia, or rarely, as a spontaneous event.7,8 The overall reported incidence is 1 in 2900 births, and it is more common in males. Traumatic perforations usually are attributed to gastric intubation or gastric overdistention from bag-mask ventilation, esophageal intubation, or positive-pressure ventilation in the setting of a tracheoesophageal fistula. Ischemic insults are not entirely understood, but typically are associated with prematurity, birth asphyxia, neonatal stress, or necrotizing enterocolitis. Spontaneous perforations occur both in healthy infants as well as premature or low-birth-weight patients.9The most plausible etiology is multifactorial, but may involve a congenital defect of the gastric wall musculature.
Gastric perforation in older infants and children may result from peptic ulcer disease.10 It is also associated with blunt trauma in the context of improper seat belt use in high-speed motor vehicular crashes.11
CLINICAL MANAGEMENT AND OUTCOME
Infants with gastric perforation present with symptoms of lethargy, poor feeding, and abdominal distension. The site of perforation is usually on the greater curvature of the stomach near the cardia. Abdominal radiographs reveal a massive pneumoperitoneum (Fig. 400-2). Emergent management includes tube decompression of the stomach, antibiotic therapy, and operative intervention.12
Occasionally, paracentesis to relieve the pneumoperitoneum may be necessary during preoperative resuscitation due to abdominal compartment syndrome with resultant hemodynamic and respiratory compromise. Early diagnosis, fluid resuscitation, and prevention of sepsis improve outcome. Survival rates approach 75% to 80%. Morbidity and mortality from gastric perforation occurs in the setting of extensive enterocolitis, sepsis, and multiorgan failure.