How is the pathogenesis of acute cholecystitis?

When stone is embedded in cystic duct, and causes chronic obstruction rather than transient biliary pain. Stasis of bile results in damage of gall bladder mucosa, and release of intracellular enzymes and inflammatory cascades. Enteric bacteria can be cultured from gall bladder bile in half of pt w/acute cholecystitis. Cause of obstruction is stone in cystic duct/ gall bladder neck/ Hartman's pouch (90%). It is a disease of the young, healthy women w/ good prognosis. remaining 10% have absence of gall stones (acalculous cholecystitis) and occurs more for critically ill pts.