Key practice points: gallstones

Gallbladder perforation is a complication in 10% of patients with acute cholecystitis.
Ultrasound is highly sensitive and specific for diagnosing cholelithiasis.
Cholecystectomy is the definitive treatment for symptomatic cholelithiasis.
Dissolution therapy with ursodeoxycholic acid should be reserved for patients who are at high risk of surgery. Small (<1.5 cm diameter) noncalcified stones that float on oral cholecystography are suitable for dissolution therapy.

Choledocholithiasis

In the United States, most bile duct stones are cholesterol stones that have migrated from the gallbladder. Ten percent to 15% of patients who undergo cholecystectomy have concomitant bile duct stones, and 1–4% exhibit residual postoperative choledocholithiasis, even after the common bile duct is explored. Conversely, more than 80–90% of patients with choledocholithiasis have gallbladder stones. The incidence of choledocholithiasis increases with age; one-third of octogenarians who undergo cholecystectomy have coexistent bile duct stones. The prevalence of choledocholithiasis and intrahepatic stones is higher in Asian societies. These populations have higher incidences of pigment stones, which usually are formed de novo in the bile ducts.

Clinical presentation

Unlike with gallbladder stones, most patients with bile duct stones develop symptoms. Some remain asymptomatic for decades while others present suddenly with potentially life-threatening cholangitis or pancreatitis. Patients with choledocholithiasis often present with biliary colic indistinguishable from the pain of cystic duct obstruction. The pain is steady, lasts for 30 min to several hours, and is located in the epigastrium and right upper quadrant.

Cholangitis is the result of superimposed infection in the setting of a biliary obstruction. The Charcot classic triad of right upper quadrant pain, fever, and jaundice may be present in only 50–75% of patients with acute cholangitis. Ten percent of episodes are marked by a fulminant course with hemodynamic instability and encephalopathy. Reynolds pentad refers to the constellation of the Charcot triad plus hypotension and confusion.

Diagnostic investigation

Laboratory studies

Immediately after an attack, levels of serum aminotransferases are often elevated because of hepatocellular injury. Alkaline phosphatase levels are often elevated, mildly in asymptomatic patients, and not more than five times higher than normal in symptomatic patients. Most symptomatic patients have hyperbilirubinemia; the bilirubin level is in the range of 2–14 mg/dL. Higher elevations of alkaline phosphatase or bilirubin levels suggest malignant obstruction of the biliary tree.

Structural studies

In contrast to gallbladder stones, bile duct stones are not readily detected by ultrasound; the sensitivity is less than 20%. The technological advances of helical CT scanning have led to improved accuracy in sensitivity and specificity of 80–85% in detecting bile duct stones. Endoscopic retrograde cholangiopancreatography (ERCP) is the procedure of choice for evaluating patients with suspected choledocholithiasis. ERCP has a sensitivity of 90% for diagnosing choledocholithiasis and has the advantage of facilitating therapeutic sphincterotomy and stone extraction. Endoscopic ultrasound can detect 95% or more of common bile duct stones but current instruments cannot extract stones. Magnetic resonance (MR) cholangiography has a sensitivity similar to ERCP for detecting bile duct stones. It may be used in the initial evaluation of patients for whom the index of suspicion for stones is only low or moderate, to avoid unnecessary exposure to the risks of ERCP.

There is no consensus on the optimal evaluation of choledocholithiasis in patients undergoing elective cholecystectomy for gallstone disease. If open cholecystectomy is planned, intraoperative cholangiography and common bile duct palpation can be used. If stones are found, the common bile duct should be explored and stones should be extracted. Several alternative strategies are available to patients undergoing planned laparoscopic cholecystectomy. One strategy involves minimal preoperative assessment, including ultrasound and CT scanning. An intraoperative cholangiogram is performed during the laparoscopic procedure. Those patients with documented intraductal stones undergo stone extraction laparoscopically or by open cholecystectomy. Alternatively, ERCP with endoscopic sphincterotomy could be performed postoperatively. A second strategy identifies patients preoperatively at high or low risk of coexisting choledocholithiasis on the basis of the biochemical profile and the presence or absence of biliary tract dilation on ultrasound. Patients at high risk undergo preoperative endoscopic ultrasonography or ERCP; those with confirmed biliary stones undergo endoscopic stone extraction. When the stones are cleared from the bile duct, the patient then proceeds to laparoscopic cholecystectomy. Patients with a low risk of choledocholithiasis undergo laparoscopic cholecystectomy with intraoperative cholangiography, as previously described. Benefits and risks are associated with each strategy; the approach is largely determined by the resources available at individual institutions.

Management and course

Common bile duct stones, even if asymptomatic, require therapy because of the high complication rate (e.g. cholangitis and pancreatitis). Secondary biliary cirrhosis may develop in cases of persistent biliary obstruction (i.e. >5 years). In such cases, reversal of portal hypertension and cirrhosis has been reported, suggesting that even late efforts to relieve obstruction are warranted. Definitive therapy involves common bile duct exploration and stone extraction but this procedure increases the operative mortality rate of a cholecystectomy from 0.5% to 3–4%. The perioperative mortality rate for patients younger than age 60 is 1.5%, whereas the risk for patients older than 65 is 5–10%.

On the basis of this high mortality rate, endoscopic sphincterotomy and stone extraction represent a favorable approach, especially in older patients. The risk of recurrent symptoms is high if patients have intact gallbladders; therefore, cholecystectomy should be performed. In elderly patients with severe comorbid illness, however, the surgical risks may outweigh the risk of recurrent gallstone symptoms. Endoscopic sphincterotomy alone may be an acceptable therapy for these patients. If bile duct stones cannot be extracted endoscopically, long-term internal stenting is also a therapeutic option for this high-risk group.

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