Anaesthesia for pyloromyotomy: a review (the Hospital for Sick Children, Toronto).

A PREVIOUS PAPER 1 reviewed the anaesthetic management of 441 patients operated on for pyloric stenosis at the Hospital For Sick Children, Toronto, from 1957 to 1960 inclusive. This paper covers an additional 537 patients treated surgically from 1961 to 1965, and compares the two groups. The entire series comprises 978 cases. The incidence of pyloric stenosis in the western world varies from 2 to 4 per 1000 live births; it is the commonest condition requiring surgery in the first six months of life. In contrast, Charis ~ has noted a greatly decreased incidence in Israel (0.4 per 1000 live births) and Iran (0.08 per 1000 live births). The lesion is present at birth and one of our cases was diagnosed the day after birth. However, symptoms rarely occur prior to two weeks of age. Multifactorial genetic factors may be involved. Carter has noted an increased incidence in children following the occurrence of pyloric stenosis in the mother. 3 Studies of monozygotous twins show a 30 per cent incidence in the second twin, but in our series only one pair of four sets of twins ('255) was affected. Also, a seasonal variation has been reported, with increased incidence in the spring and fall not accounted for by any change in birth rate# Many theories as to the cause of this condition have been presented. Some authors "~ suggest that there is an arrest or delay in the development of the nerve cells of the nettrogenic plexus so that they resemble those of a normal baby of an earlier age, but this has not been demonstrated in all cases. 6