Introduction: It is well recognized that corrected bile duct diameters, as measured by endoscopic retrograde cholangiography (ERC), are often significantly greater than the corresponding ultrasound measurement. This can be attributed to variation in bile duct distensibility and is particularly noted in post cholecystectomy patients, possibly due to loss of the gall bladder reservoir effect. It has been suggested that increased bile duct distensibility may be related to the post-cholecystectomy syndrome. We have observed a similar discrepancy between ultrasound and per-operative cholangiography (POC). This trial investigates whether the discrepancy between ultrasound and POC measurements has clinical significance.
Method: Seventy-five patients with normal pre-operative ultrasound and POC undergoing standard open cholecystectomy (with benzodiazepine pre-medication) in 1990 were identified. After allowance for magnification, maximum biliary diameters were obtained for the proximal extra-hepatic bile duct. Follow-up was obtained in 67 patients from clinical case notes and contact with general practitioners.
Results: Considerable variation of bile duct distensibility was recorded (range 83% to 410%) with 12 cases having POC biliary diameters outside radiological guidelines (12 mm as recorded on the radiograph). This distension is shown to increase with age. After 4 years, 16 patients had recurrent abdominal pain of which nine had undiagnosed right upper quadrant pain. There were no clinical cases of retained stone post-operatively. There was no correlation between POC measured bile duct diameter or distensibility and post-operative or long term problems. This study suggests that the bile duct has a normal variation of distensibility which increases with age and that radiological guidelines, as regards the upper limit for normal POC biliary diameters can be relaxed.