Abstract
A series of experiments was carried out to clarify the significance and indication of pyloromyotomy or pyloroplasty as a drainage operation obtaining the following results. Pyloromyotomy suppresses the state of abnormal excitation of the pyloric portion, resulting in the decrease of contraction pressure of the pylorus, when an incision is done long enough. Pyloroplasty after Heineke-Mikulicz, however, is more effective as a drainage operation. The fundamental significance of pyloromyotomy seems to be in reducing the contractile force of the circular muscle at the pyloric region maintaining the sphincteric function. And that of pyloroplasty is in its effect in sacrificing the sphincteric function of the pylorus and in widening its lumen to result in a greater drainage effect. Thus, pyloroplasty is indicated when severe excitation of the remaining pyloric portion is present and the powerful drainage effect is desired even sacrificing the sphincteric function of the pylorus. On the other hand, pyloromyotomy has an indication when the less drainage effect seems sufficient and preservation of the sphincteric function of the pylorus is needed.
