Peristaltic Waves in Pyloric Stenosis
A 5-week-old full-term male infant presented to our institution with a history of multiple episodes of projectile, nonbilious vomiting. Laboratory investigations revealed a hypokalemic, hypochloremic metabolic alkalosis. On physical examination, an olive-shaped mass that was 2 cm long was palpated in the lower inner aspect of the right upper quadrant, and abdominal peristaltic waves were observed (see Video). Ultrasonography showed pyloric stenosis. Infantile pyloric stenosis causes gastric-outlet obstruction caused by hypertrophy of the pylorus. The diagnosis is currently made on the basis of the clinical history and ultrasonographic measurements of pyloric thickness. The classic pathognomonic signs of this disorder (a palpable olive-shaped mass and peristaltic waves) are less commonly observed today than in the past, owing to earlier diagnosis. The patient underwent pyloromyotomy and had an uneventful postoperative course.