In the past few years several papers1 on acute appendicitis have stressed the role of increased intraluminal pressure as a factor in the development of the lesion. Since the maximum intraluminal pressure can never exceed the pressure at which the appendix will empty into the cecum, studies were undertaken on the initial resistance to perfusion of unselected normal and diseased appendixes both in situ and after excision.
Eighteen appendixes were studied in situ. After the appendix was delivered into the wound it was held by an Allis clamp applied to the mesentery as it joined the tip, and a transfusion cannula was passed into the lumen of the organ through the tip. The cannula was then connected to an easily controlled pressure system (water) with a glass tube side arm in which the fluid level could be observed. The pressure was slowly raised, and the height at which