**6. Choledocholithiasis**

#### **6.1 Pathogenesis and classification**

Common bile duct stones have been noted in 10–19% of patients with cholelithiasis, and this incidence increases to about 80% with age over 90 years old [14]. Choledocholithiasis usually results from dropped stone of the gallbladder and passed through the cystic duct. These secondary bile duct stones are cholesterol stones in most cases and black stones in certain cases. These characteristic stones are formed in the presence of cholesterol saturation, nucleating factors, and biliary stasis. On the contrary, primary bile duct stones are associated with biliary stasis and infection of bacteria [15].

#### **6.2 Clinical manifestation**

Patients with choledocholithiasis may present with biliary colic, bile duct obstruction, bilirubinuria, pruritis, jaundice. Nausea and vomiting with intermittent or constant epigastric or right upper quadrant pain are occurred in cases of early phase of the biliary obstruction [16]. The clinical course may be complicated by acute gallstone pancreatitis, cholangitis, or rarely, hepatic abscess.

#### *6.2.1 Cholangitis*

Cholangitis is the most rapid fatal complication of gallstones and occurs resulting from biliary tree bacteria infection in the setting of biliary tree obstruction.

Bile duct obstruction including bile duct stone impaction results in decreased antibacterial defenses, allowing bacteria to gain access to the biliary tree. As biliary pressure rises with obstruction, bacteria with endotoxins leak into the systemic circulation and cause the sepsis [17]. Mortality of this condition approaches approximately 100% if the patients subject to needed drainage interventions [18]. Early diagnosis and immediate treatment are imperative for successful outcome.

#### *6.2.2 Charcot's triad and Reynord's pentad*

Fever, right upper quadrant pain, and jaundice is *Charcot's triad*, presenting in 50–70% of patients with cholangitis at presentation. Hypotension and altered mental status are known as *Reynold's pentad* in addition to Charcot's triad.

#### **6.3 Treatment of cholangitis**

Patients with cholangitis can become a severe condition in a short period of time, and rapid initiation of treatment is needed. Drainage of the biliary tree is the central of therapy for patients with acute cholangitis [17]. When biliary decompression by the drainage is not achieved, hepatic abscesses are unavoidable. Mortality approaches 100% in patients who are not subjected to needed drainage interventions after failure of conservative treatment [19]. Endoscopic retrograde cholangio-pancreatograph (ERCP) with bile duct clearance is a best choice of treatment of acute cholangitis and superior to the other drainage method including percutaneous transhepatic, and surgical drainage methods [20]. There are some endoscopic treatment options; The placement

of naso-biliary catheters or biliary stents to sphincterotomy and stone extraction. Sphincterotomy with bile duct clearance is preferred in patients with responded to antibody therapy.
