From the Guidelines
Gallstones larger than 1 cm are considered a significant risk factor for complications and are often an indication for surgical removal (cholecystectomy), even if they're not currently causing symptoms. These larger stones are more likely to cause blockages in the bile ducts, leading to complications such as acute cholecystitis (gallbladder inflammation), pancreatitis, or cholangitis (bile duct infection) 1. Additionally, large gallstones have a higher risk of eroding through the gallbladder wall into adjacent organs, potentially causing fistula formation or gallstone ileus (intestinal obstruction). The risk increases further if the patient has diabetes, is immunocompromised, or has a history of previous gallstone-related symptoms. While smaller stones might be managed conservatively with observation in asymptomatic patients, stones larger than 1 cm generally warrant discussion about elective cholecystectomy to prevent future complications. The size threshold is important because larger stones are less likely to pass spontaneously if they enter the bile ducts and more likely to cause complete obstructions with more severe consequences. Some key points to consider include:
- The increased risk of gallbladder cancer in patients with large stones (> 3 cm) 1
- The importance of assessing the patient's treatment goals and attitudes in determining the best course of action 1
- The potential benefits and risks of surgical and nonsurgical interventions, including laparoscopic cholecystectomy and oral bile acids 1
- The need for ongoing monitoring and follow-up to prevent future complications and detect any potential issues early on 1.
From the FDA Drug Label
The chance of gallstone dissolution is increased up to 50% in patients with floating or floatable stones (i. e. those with high cholesterol content), and is inversely related to stone size for those < 20 mm in maximal diameter. Complete dissolution was observed in 81% of patients with stones up to 5 mm in diameter. Patients with stones > 20 mm in maximal diameter rarely dissolve their stones.
The risk factor for a gallstone larger than 1cm is stone size. The chance of gallstone dissolution is inversely related to stone size for those < 20 mm in maximal diameter. Specifically, patients with stones larger than 1cm (10mm) but less than 20mm have a lower chance of dissolution compared to those with stones up to 5mm. Patients with stones larger than 20mm rarely dissolve their stones 2.
From the Research
Gallstone Size and Risk Factors
- A gallstone larger than 1cm is considered a risk factor for certain complications, including gallbladder cancer 3.
- Studies have shown that patients with larger gallstones are at increased risk for gallbladder cancer, with an odds ratio of 2.4 for stones 2.0 to 2.9 cm in diameter and 10.1 for stones 3 cm or larger 3.
- However, the relationship between gallstone size and other complications, such as acute biliary pancreatitis and acute cholecystitis, is not as clear-cut.
- One study found that patients with at least one gallstone smaller than 5 mm in diameter have a more than 4-fold increased risk of presenting with acute biliary pancreatitis 4.
Complications of Gallstones
- Common complications of gallstones include cholecystitis, choledocholithiasis, gallstone pancreatitis, and ascending cholangitis 5.
- Acute cholecystitis is typically diagnosed using ultrasonography, which has a sensitivity of approximately 81% and a specificity of approximately 83% 6.
- Laparoscopic cholecystectomy is the treatment of choice for most patients with biliary colic or acute cholecystitis 5.
Management of Gallstones
- The management of gallstones depends on the presence and severity of symptoms, as well as the size and number of stones.
- For patients with asymptomatic gallstones, a policy of watchful waiting may be warranted, although this approach is not recommended for patients with small stones (<5 mm) due to the increased risk of acute biliary pancreatitis 4.
- Early cholecystectomy within 24 hours of admission has been proposed for patients with mild gallstone pancreatitis, and has been shown to reduce length-of-stay and endoscopic retrograde cholangiopancreatography (ERCP) rates 7.