Comparison of preoperative sonography with intraoperative findings in congenital hypertrophic pyloric stenosis.

In 17 infants with hypertrophic pyloric stenosis, the pyloric diameter was measured preoperatively by ultrasound. The mean pyloric diameter was 15.12 +/- 2.11 mm (mean +/- SD), range 11 to 19 mm. During pyloromyotomy, the hypertrophic pylorus was precisely measured craniocaudally and dorsoventrally, and measurements were obtained concerning muscular thickness and length of the pylorus. The preoperative and intraoperative measurements were subsequently compared. Differences of 0.76 +/- 1.68 mm and 1.24 +/- 2.04 mm were found for the dorsoventral and craniocaudal diameters, respectively. The intraoperative measurements were consistently greater than the sonographic findings. The length of the pylorus averaged 22.0 +/- 2.66 mm, the muscular thickness 6.53 +/- 1.68 mm, respectively. This prospective study confirms the diagnostic value of sonography in congenital hypertrophic pyloric stenosis.