LUMINAL CROSS-SECTIONAL AREA AND TENSION-STRAIN RELATION OF THE PORCINE BILE-DUCT

The bile duct is a distensible tube serving to transport bile from the liver and gallbladder to the duodenum. The purpose of this study was to characterize the luminal cross-sectional area (CSA) and tension-str ain properties during distension of the normal isolated porcine common bile duct in vitro. An impedance planimetric system located inside a balloon was used. Eleven porcine bile ducts were examined in two locat ions, in the hepatic duct and in the common bile duct. The CSAs obtain ed in the common bile duct were significantly higher than those in the hepatic duct in the pressure range 0-8 kPa (P < 0.001). The circumfer ential wall tension (T) - strain (epsilon) relations for both location s fitted to the exponential equation T = a.e(b-epsilon) With determina tion coefficients of 0.97 +/- 0.02. The a and b constants were not sta tistically different between the two locations indicating that the ela stic properties did not differ. In conclusion, the luminal CSAs were l arger in the common bile duct when compared to the hepatic duct and th e tension-strain relations did not differ between the two segments of the bile duct.