Abstract
A “work hypertrophy” due to spasm of the pyloric portion is widely accepted as basic cause of infantile hypertrophic pyloric stenosis. From the view of above hypothesis, electromyographical investigation has been performed on the pylorus of 12 ill infants and 5 control patients. Prior to Ramstedt's operation, electrical activities were recorded for the purpose of detecting changes between the tumor and the unhypertrophied antrum.
Results are as follows:
1) Electrical activities were classified to two different types, regular and irregular discharge patterns. However, there existed any pecuriarity of pattern in neither tumor nor unhypertrophied antrum.
2) Synchronization of the regular patterns of the two sites was demonstrated in half of the infants, and suggests propagation of excitation from one to another site. On the other hand, desynchronization of the patterns of the two sites occured in the residual infants. This latter phenomenon is possibly ascribed to abnormal excitation of the gastric wall muscle or disturbance of propagation in the pyloric portion.
3) Mean values of the discharge intervals of the regular patterns at the tumor were calculated in 9 infants and ranged from 22.6 sec. to 29.7 sec. with an average of 25.4 sec. It is apparent that the discharge intervals were markedly prolonged in comparison with an average of 18.1 sec. of the control patients. The prolongation of the discharge intervals was also revealed in the unhypertrophied antrum. The prolonged discharge intervals are probably referred to excited state of the pyloric portion.
4) From the unusual electrical activities mentioned above, the dysfunction of the whole pylorus is considered to be present, indicating that the stomach of these infants tends to lose the ability to propel its contents into the distal region.
