[Hypertrophic stenosis of the pylorus. Ultrasound and traditional diagnosis. Comparison of methods].

Hypertrophic pyloric stenosis (HPS) is the most frequent cause of abdominal surgery during the first months of life. A new diagnostic approach to this type of pathology is given by ultrasound examination which offers the opportunity to perform a precise study of pyloric muscle thickness, pyloric diameter width and pyloric muscle length. Ultrasound provides a quick diagnostic tool sparing radiation exposure to the patient. X-ray study is only to be reserved to the few cases in which clinical and ultrasound data are doubtful and--in all instances--to rule-out other possible causes of gastric outlet obstruction. We report 20 infants (14 males and 6 females) referred with clinical suspicion of HPS. This diagnosis has been confirmed by ultrasound in 12 cases, suspected in 1 and excluded in 7 cases. Upper gastrointestinal tract series confirmed the presence of HPS in 13 cases; discovered a huge gastroesophageal reflux in one and showed normal findings in 6 cases.