Parasites and Biliary stones

Choledocholithiasis ٧٤
Patients with partial obstruction are at increased risk compared to those
with complete obstruction. Infection is generally thought to occur through
direct extension of bacteria from the duodenum. Increased colonisation
with coliforms (the most commonly isolated organisms in cholangitis)
within the proximal small intestine may predispose to bactobilia (e.g. in
the elderly with achlorhydria). Haematogenous spread through the portal
venous system could be another route. Effectiveness of the reticulo-
endothelial system may be compromised in the setting of increased bile
(Van Erpecum, 2006).
Small gallstones, excess cholesterol crystals (possibly related to high
pro-nucleating biliary mucin levels) and good gallbladder emptying are
associated with increased risk of pancreatitis (Venneman et al., 2005).
Apparently, good gallbladder emptying promotes migration to the bile
ducts, especially in the case of small gallstones and sludge. Large bile-
duct stones lead to more proximal obstruction, with jaundice but no reflux
into the pancreatic duct. In contrast, small stones could lead to more distal
obstruction, with potential reflux of bile into the pancreatic duct. Bile
reflux into the pancreatic duct (common channel hypothesis), pancreatic
duct hypertension or functional obstruction at the sphincter of Oddi could
then induce a common pathway of pancreatic duct injury with release of
activated pancreatic enzymes into the glandular interstitium, thus
triggering the release of cytokines and a bout of acute pancreatitis
(Lightner and Kirkwood, 2001).
Diagnosis of choledocholithiasis:
Laboratory diagnosis:
Patients presenting with common bile duct stones often have
cholestatic liver function tests. Elevated serum gamma glutamyl