Parasites and Biliary stones

Summary and conclusion ١٣٧
Summary and conclusion
Gall stone disease remains one of the most common medical
problems leading to surgical intervention. The risk factors predisposing to
gallstone formation include obesity, diabetes mellitus, estrogen and
pregnancy, hemolytic diseases, and cirrhosis . It is important to remember
that gallstones can lead to a variety of other complications including
choledocholithiasis. About 15% of patients with gallstones have
choledocholithiasis. Stones in the common duct usually originate in the
gallbladder but may also form de novo in the bile duct. Stones from gall
bladder which migrate up to the intra-hepatic ducts leading to formation
of Hepatolithiasis.
Helminthic invasion of the human biliary tract is a prominent
medical and surgical problem especially in tropical and subtropical areas
where these parasites are endemic. Helminthic infestation may affect the
liver and/or the biliary tract either during passage of worms through these
structures or because these organs serve as their natural habitat. The
parasitic infestations affecting the biliary tract including the nematode
Ascaris lumbricoides, the trematodes Opisthorchis viverrini and
felineus, Clonorchis sinensis, Dicrocoeliasis and Fasciola hepatica, and
the cestodes Echinococcus granulosus and multilocularis, also some
protozoa can cause biliary tract disease as Cryptosporidium, and
Giardiasis.
Biliary parasites cause necrosis, inflammation, fibrosis, strictures,
and cholangiectasis of the bile ducts by several mechanisms:As a direct
result of the irritating chemical composition of the parasite, parasitic
secretions, or eggs;Physical obstruction of the bile ducts;Induction of
formation of biliary stones(act as a nidus for stone); and Introduction of
bacteria into the biliary system during migration from the duodenum.