Evaluation of biliary pressure by perfusion method and its significance

The present authors have made it a rule to use a modified Mellet-Guy's method for measuring pressure in the bile duct. The determined manometric pressure expressed in curve has been classified into (a) basal pressure, (b) rising time, (c) perfusion pressure, (d) dumping time and (e) residual pressure. The basal pressure (a) represents a static pressure free from any load in the bile duct. The rising time (b) varies with factors including the measuring apparatus, ductal elasticity and capacity, resistance at the choledochal terminal, and the volume of physiological saline infused. The perfusion pressure (c) is likely to undergo interference of a variety of factors such as the ductal diameter, mural elasticity and thickness, resistance at the choledochal terminal, along with the measuring apparatus. The dumping time (d), free from the influence of the measuring apparatus, is considered to be an important guide for us to guess the condition of choledochal terminal. The residual pressure (e) and the trend of manometric pressure curve help us to surmise the choledochal terminal resistance and the presence of ductal abnormalities. After all, among the above factors, the dumping time and the residual pressure are apparently available for objective evaluation of bile duct pressure.