Gallstones: Watch and wait, or intervene?
ABSTRACT
Gallstones are common in the United States, affecting an estimated 1 in 7 adults. Fortunately, they are asymptomatic in up to 80% of cases, and current guidelines do not recommend cholecystectomy unless they cause symptoms. Laparoscopic cholecystectomy is the standard treatment for symptomatic gallstones, acute cholecystitis, and gallstone pancreatitis.
KEY POINTS
- Abdominal pain is the primary symptom associated with gallstones.
- Abdominal ultrasonography is the diagnostic test of choice to detect gallstones and assess for findings suggestive of acute cholecystitis and dilation of the common bile duct.
- First-line therapy for asymptomatic gallstones is expectant management.
- First-line therapy for symptomatic gallstones is cholecystectomy.
ABDOMINAL ULTRASONOGRAPHY FOR DIAGNOSIS
Transabdominal ultrasonography, with a sensitivity of 84% to 89% and a specificity of up to 99%, is the test of choice for detecting gallstones.29 The characteristic findings of acute cholecystitis on ultrasonography include enlargement of the gallbladder, thickening of the gallbladder wall, presence of pericholecystic fluid, and tenderness elicited by the ultrasound probe over the gallbladder (sonographic Murphy sign).
Scintigraphy as a second test
Acute cholecystitis is primarily a clinical diagnosis and typically does not require additional imaging beyond ultrasonography. When there is discordance between clinical and ultrasonographic findings, the most accurate second imaging test is scintigraphy of the biliary tract, usually performed with technetium-labeled hydroxy iminodiacetic acid. Given intravenously, the radionuclide is rapidly taken up by the liver and then secreted into the bile. In acute cholecystitis, the cystic duct is functionally occluded and the isotope does not enter the gallbladder, creating an imaging void compared with a normal appearance.
Scintigraphy is more sensitive than abdominal ultrasonography, with a sensitivity of up to 97% vs 81% to 88%, respectively.29,30 The tests have about equal specificity.
Even though scintigraphy is more sensitive, abdominal ultrasonography is often the initial test for patients with suspected acute cholecystitis because it is more widely available, takes less time, does not involve radiation exposure, and can assess for the presence or absence of gallstones and dilation of the intra- and extrahepatic bile ducts.
Looking for stones in the common bile duct
When acute cholangitis due to choledocholithiasis is suspected, abdominal ultrasonography is a prudent initial test to look for gallstones or biliary dilation suggesting obstruction by stones in the common bile duct. Abdominal ultrasonography has only a 22% to 55% sensitivity for visualizing stones in the common bile duct, but it has a 77% to 87% sensitivity for detecting common bile duct dilation, a surrogate marker of stones.31
The normal bile duct diameter ranges from 3 to 6 mm, although mild dilation is often seen in older patients or after cholecystectomy or Roux-en-Y gastric bypass surgery.32,33 Bile duct dilation of up to 10 mm can be considered normal in patients after cholecystectomy.34 A normal-appearing bile duct on ultrasonography has a negative predictive value of 95% for excluding common bile duct stones.31
Endoscopic ultrasonography (EUS), magnetic resonance cholangiopancreatography (MRCP), and endoscopic retrograde cholangiopancreatography (ERCP) have similar sensitivity (89%–94%, 85%–92%, and 89%–93%, respectively) and specificity (94%–95%, 93%–97%, and 100%, respectively) for detecting common bile duct stones.35–37 EUS is superior to MRCP in detecting stones smaller than 6 mm.38
ERCP should be reserved for managing rather than diagnosing common bile duct stones because of the risk of pancreatitis and perforation. Patients undergoing cholecystectomy who are suspected of having choledocholithiasis may undergo intraoperative cholangiography or laparoscopic common bile duct ultrasonography.
WATCH AND WAIT, OR INTERVENE?
Asymptomatic gallstones
Standard treatment for these patients is expectant management. Cholecystectomy is not recommended for patients with asymptomatic gallstones.47 Nevertheless, some patients may benefit from prophylactic cholecystectomy. We and others48 suggest considering cholecystectomy in the following patients.
Patients with chronic hemolytic anemia (including children with sickle cell anemia and spherocytosis). These patients have a higher risk of developing calcium bilirubinate stones, and cholecystectomy has improved outcomes.49 It should be noted that most of these data come from pediatric populations and have been extrapolated to adults.
Native Americans, who have a higher risk of gallbladder cancer if they have gallstones.2,50
Conversely, calcification of the gallbladder wall (“porcelain gallbladder”) is no longer considered an absolute indication for cholecystectomy. This condition was thought to be associated with a high rate of gallbladder carcinoma, but analyses of larger, more recent data sets found much smaller risks.51,52 Further, cholecystectomy in these patients was found to be associated with high rates of postoperative complications. Thus, prophylactic cholecystectomy is no longer recommended in asymptomatic cases of porcelain gallbladder.
In addition, concomitant cholecystectomy in patients undergoing bariatric surgery is no longer considered the therapeutic standard. Historically, cholecystectomy was performed in these patients because of the increased risk of gallstones associated with rapid weight loss after surgery. However, research now weighs against concomitant cholecystectomy with bariatric surgery and most other abdominal surgeries for asymptomatic gallstones.53
