Changes in pyloric tumor of infantile hypertrophic pyloric stenosis before and after pyloromyotomy

Sixteen of 24 infants with vomiting were examined by real-time sonography, which established the diagnosis of hypertrophic pyloric stenosis (HPS); 12 underwent surgery. Of the three parameters measured, pyloric muscle wall thickness was the most reliable and accurate for the diagnosis of HPS. We suggest that a muscle wall thickness of 4 mm or more and stenosis index greater than 50% are standard findings in patients with HPS. Serial real-time sonography following pyloromyotomy showed that the pyloric tumor changed significantly during the 1st postoperative week and returned to normal size by the end of the 4th week.Offprint requests to: Z. X. Shen