Plain x-rays are useful to rule out the presence of free air. The presence of a dilated stomach bubble is suggestive but not diagnostic of pyloric stenosis. Criteria for making the diagnosis include pyloric muscle thickness greater than 4 mm, an overall pyloric diameter greater than 14 mm, or length greater than 26 mm. A UGI confirms the diagnosis of IHPS, but it is not routinely performed unless ultrasound is nondiagnostic. Upper GI endoscopy has been used as an adjunct diagnostic tool in select cases of IHPS when other imaging tests are inconclusive or when the infant presents with atypical clinical features.
Immediate treatment requires correction of fluid loss, electrolytes, and acid-base imbalance.
The child should have nothing by mouth preoperatively and until 12-24 hours after surgery. The ongoing replacement should be guided by the clinical response to fluid replacement therapy, ie, skin turgor, moist mucous membranes, urine output, and by serum pH and electrolytes balance. The Ramstedt pyloromyotomy is the procedure of choice and is performed through a short transverse incision or laparoscopically. The underlying antro-pyloric mass is split leaving the mucosal layer intact. The infant should be hospitalized for initial medical treatment and a surgeon should be consulted.