What Are the Important Diagnoses to Consider?

Severe reflux, esophageal atresia, and pyloric stenosis should be considered in a patient with this presentation. Intussusception may also be part of the differential but usually results in intermittent pain and vomiting.

Severe reflux is usually a medical diagnosis and common at this age. Treatment includes oral medication for gastric acid secretion such as H2 receptor blockers and/or proton pump inhibitors. Esophagogastroduodenoscopy (EGD) may be considered as well as placement of a pH probe.

Pyloric stenosis (PS) is a potentially life-threating condition in which the pyloric musculature becomes hypertrophied leading to gastric outlet obstruction. The muscle is usually normal at birth and hypertrophies in the first few weeks to months of life. Children with PS present with feeding difficulties, weight loss, significant dehydration, and electrolyte disturbances. The vomiting is usually non-bilious as the thick pylorus prevents bile regurgitation. Interestingly, the pyloric hypertrophy generally resolves if left untreated. Historically, the treatment was frequent but small feedings until spontaneous resolution and thus why PS remains a medical and not surgical emergency. With the advances in surgical treatment and technique, the preferred method after medical stabilization is via a small incision and pyloromyotomy (incising of the pyloric muscle), immediately relieving the gastric outflow obstruction.

Briefly Review the Historical Overview of Pyloric Stenosis

Reports of PS exist as early as the 15th century, however, the modern description is owed to Hirschsprung who reported clinical and autopsy findings of pyloric hypertrophy in 1887. Initially, PS was uniformly fatal in the first weeks to months, with most infants succumbing to malnutrition and dehydration. Early surgical intervention was via full thickness incision of the pyloric musculature and transverse closure. This was successful but mortality rates were still as high as 50%. In the early 20th century, Ramstedt introduced the suture-less technique of longitudinal division of the pyloric muscle while leaving the mucosa intact. This modification still serves as the basis for current operative management. Presently, advances in minimally invasive surgery make the laparoscopic approach the preferred method owing to decreased wound complications and a shorter length of stay.

What Is the Incidence of Pyloric Stenosis?

The incidence of PS is 1.8 per 1,000 births. There is a significant male predominance of 5:1 for development of pyloric stenosis.

What Is the Most Likely Age for Presentation?

Pyloric stenosis can present from infancy to around four months of age. Most patients typically present between 3 and 10 weeks.

Is There a Genetic Component to Pyloric Stenosis?

To date, five genetic loci have been identified for idiopathic infantile pyloric stenosis. Pyloric stenosis is also associated with the following congenital syndromes: trisomy 21, trisomy 18, Cornelia de Lange, Apert, Opitz FG, Marden-Walker, Smith-Lemli-Opitz, Zellweger, duplication 1q, duplication 9q, deletion 11q, ring 12, Denys–Drash, and paramyotonia congenita.

What Are the Risk Factors for Development of Pyloric Stenosis?

Risk for development of PS can be divided into maternal and infant factors.

Maternal factors include: smoking of >10 cigarettes/day in early pregnancy, erythromycin use, age <25 years, and being overweight (but not obese).

Infant factors include: Very preterm infants, delivery by cesarean section and a birth order <2.

It has been suggested that infant exposure to prostaglandins (usually for congenital heart disease) may relay an increased risk of development of PS.

Preterm infants are generally diagnosed at a later post gestational age.