Parasites and Biliary stones

Treatment of calcular obstructive jaundice ٨٢
within the bile duct. This causes plasma formation on the surface of the
stone, allowing more absorption of laser light, and results in an acoustic
shockwave that can fragment the stone. Laser lithotripsy can be
performed under direct vision using cholangioscopy using mini scopes or
can be performed under fluoroscopic control using standard equipment.
More recently the development of software coupled to the laser allows
differentiation of light reflected back from bile duct epithelium compared
to light reflected back from a stone. This causes a discontinuation of the
laser pulse, and reduces any potential thermal injury to the epithelium
(Behjou et al., 1997).
Electrohydraulic lithotripsy (EHL) uses direct high voltage to
generate a shockwave, through a liquid medium, to fragment the CBDS.
The procedure has been performed successfully under cholangioscopic
guidance (Arya et al., 2004), or under fluoroscopic control using a
balloon catheter (Moon et al., 2004). The advantage of direct
visualisation is to control the shockwave being applied to the stone rather
than on the ductal wall and so reducing the complications. However, the
disadvantage is the cost, and the expertise required in cholangioscopic
techniques (Hixson et al., 1992).
Stenting as definite treatment of bile duct stones:
Insertion of an endoprothesis may be required on a temporary basis
for difficult to retrieve choledocholithiasis. There is a potential advantage
of pigtail stents over straight stents in that the duodenal portion of the
stent comes out at an angle and may keep the biliary orifice open more
effectively. If the stent becomes occluded after several months, it still has
the potential to keep the common bile duct stones from impacting. Pigtail
stents also have a lower rate of stent migration. The evidence for the use