PYLORIC STENOSIS
Not congenital (symptoms are not present at birth)
More common in boys (4:1)
Pylorus thickened, elongated and lumen narrowed due to hypertrophy of circular muscle
Increased incidence in 0 and B groups
Increased risk in Turner syndrome and Trisomy 18
Erythromycin or azithromycin exposure, in the first 2 weeks of life - increased incidence
Clinical features
The classical presentation is non-bilious, projectile vomiting between 2 - 8 weeks of age
Persistent vomiting à dehydration, malnutrition, hypokalemic, hypochloraemic alkalosis and paradoxical aciduria
Visible gastric peristaltic waves moving from left to right across the upper abdomen
Palpation of the pyloric tumor (olive-shaped) in the epigastrium or right upper quadrant is pathognomic
X-ray after barium meal shows string sign or double neck sign and shoulder sign
Diagnosis confirmed by USG
Persistent pyloric muscle thickness more than 3 to 4 mm
Pyloric canal length more than 15 to 18 mm in the presence of functional gastric outlet obstruction
Pyloric thickness (serosa to serosa) of 15 mm or greater
Target sign on transverse images of the pylorus
Failure of the channel to open during a minimum of 15 minutes of scanning
Retrograde or hyperperistaltic contractions
Antral nipple sign (prolapse of redundant mucosa into the antrum, which creates a pseudomass)
Double-track sign (redundant mucosa in the narrowed lumen, which creates 2 mucosal outlines)
Ramstedt’s operation (pyloromyotomy) is the treatment of choice. The hypertrophied circular muscle fibres are cut longitudinally without damaging the mucosa