Diagnosis and treatment of primary hypertrophic pyloric stenosis (HPS) in older children

Hypertrophic pyloric stenosis (HPS) is the most important cause of non-bilious vomiting during infancy and it is usually idiopathic. It is very rare in older children and adolescents, in which gastric outlet obstruction (GOO) is more typically secondary to other conditions. Gastrointestinal malformation are frequently associated with Down syndrome and some of them (especially duodenal abnormalities) can be detected quite late. In infants the standard treatment of HPS is represented by a Ramstedt pyloromyotomy, while in adults a distal gastric resection is more indicated and it is usually associated to a Billroth I or II reconstruction. Case report: We present an unusual case of a 12-year-old girl with Down syndrome, diagnosed with late-onset HPS. She came to our attention with periodic non-bilious vomiting and growth delay. She underwent multiple imaging examinations, which highlighted the presence of an HPS. Based on patient's age and the thickness of the pyloric muscle, we decided to perform a partial gastrectomy with a Roux-en-y reconstruction. Patient was discharged on the X day. She is now on follow up, gains weight and presents good conditions. Discussion: HPS is rare but possible during childhood and adolescence. Diagnosis is usually performed through ultrasounds (US) and upper gastrointestinal radiological series (UGI), but sometimes further examinations are required (abdominal MRI, esophagogastroduodenoscopy). In older children since less invasive techniques are not effective, we have to consider partial gastrectomy. Based on our experience, Roux-en-y reconstruction is a valid option, associated with poor complication and good quality of life.