Laparoscopic treatment of common bile duct stones. Phantom experiments using electrohydraulic and pulsed dye laser lithotripsy.

To evaluate the feasibility of laparoscopic transcystic lithotripsy of common bile duct stones, a phantom model comprising bovine liver and biliary tract tissue integrated within a laparoscopic trainer was built. A 9 French cholangioscope was introduced via the cystic duct into the common bile duct in which a human gall stone of known composition had been introduced. Lithotripsy was performed using either a laser or electrohydraulic probe passed through the working channel of the cholangioscope following which the stone fragments were manipulated into the duodenum through the papilla of Vater using the choledochoscope. A total of 20 lithotripsies with each energy form were performed. Lithotripsy was successful in breaking the stones into fragments smaller than 6 mm. The energy expenditure was comparable with a mean of 49 J for laser lithotripsy (range 9 to 159 J), and 53 J (range 16 to 160 J) for electrohydraulic wave lithotripsy. The lithotripsy time measured from introduction of the cholangioscope until its removal was a mean of 30 minutes for electrohydraulic wave lithotripsy and 41 minutes for dye laser lithotripsy. This difference was statistically significant. Macroscopic tissue damage to the common bile duct wall was not observed following any procedure. An additional experiment was performed to evaluate damage that could be caused to the wall of the common bile duct. Both electrohydraulic shock wave and pulsed dye laser lithotripsy without optical feedback regulation caused severe tissue defects when there was tissue contact or distance less than 2 mm. With optical feedback regulation however, no tissue damage was induced by laser lithotripsy.(ABSTRACT TRUNCATED AT 250 WORDS)