[Infantile hypertrophic pyloric stenosis. A 25-year study from the county of Viborg].

In order to investigate an apparent decline in the incidence of infantile hypertrophic pyloric stenosis (IHPS), all cases of IHPS from 1973-1997 in the county of Viborg were studied retrospectively. One hundred and fourty-seven patients were found, with a significant decrease in incidence in the last five year period. Ninety-two percent were males, 14% had a family history of IHPS. Eleven percent had a birthweight < 2500 g, as opposed to 5-6% in the normal population. Pyloric stenosis presents in one to four weeks after birth in 70% and in 5-12 weeks in 28%. The diagnosis was reached solely through the the clinical picture in 105 cases. Twenty-three were examined with upper gastrointestinal radiography, six were false negative, abdominal ultrasound was performed in 21 cases and was false negative in four. Five patients were reoperated because of an inadequate first operation. Postoperative complications with wound infections were seen in eight patients. A high degree of accuracy of diagnosis can only be achieved through the clinical picture.