Definition:
Gallbladder stones are crystals deposited in the gallbladder and have a prevalence of approximately 5-25%, with a higher prevalence in Western populations, women and the elderly. Depending on the composition of the stones, gallbladder stones can be classified as cholesterol stones, bile pigment stones and mixed stones (both cholesterol and bile pigment stones).
Predisposed population.
The formation of gallbladder stones is associated with a change in the balance between nucleation- and nucleation-inhibiting factors in the bile. The causes that contribute to stone formation are: excess cholesterol in the bile, low levels of bile salts, reduced gallbladder motility, and reduced levels of phosphatidylcholine molecules, the latter organizing cholesterol to form crystals.
The main risk factors for cholesterol stones are.
Female, pregnancy, high estrogen use, aging, race (higher prevalence in Native American Indians and lower prevalence in black Americans and in populations from China, Japan, India and Thailand), genetics, obesity, high triglyceride levels, low HDL levels, sudden weight loss, high energy diet, refined carbohydrate diet, lack of exercise, cirrhosis, Crohn’s disease and gallbladder contraction disorders (e.g. post-gastrectomy or post-vagotomy).
Hemolysis and chronic bacterial or parasitic infection are often considered major risk factors for gallstones, but all three of these factors can often be managed to be avoided.
Prevention.
Although certain risk factors associated with gallstones such as obesity, sudden weight loss, high energy diet, refined carbohydrate diet, and lack of exercise can be avoided by lifestyle changes, there is no evidence that lifestyle changes are effective in reducing the incidence of gallstones.
Another way to prevent gallstones is to remove the gallbladder, for those undergoing bariatric surgery (since sudden weight loss is also a risk factor for gallstone formation) and for those with symptomatic gallstones. If other major abdominal surgery is required at the same time, the gallbladder can be removed together to avoid further surgery. There is no evidence to support prophylactic cholecystectomy in patients without stones in the gallbladder.
Clinical presentation.
Associated symptoms occur in approximately 2-4% of patients with gallstones each year. The most common symptom is biliary colic (pain in the right upper abdomen lasting more than half an hour), usually without fever. If fever is present, it is often indicative of cholecystitis or cholangitis. Other symptoms include epigastric pain and nausea after eating fatty or fried foods, bloating, and frothy and putrid smelling stools.
Complications of gallstones include cholecystitis (0.3%-0.4% per year), acute pancreatitis (0.04%-1.5% per year), obstructive jaundice (0.1%-0.4% per year), and less common complications such as acute cholangitis and intestinal obstruction.
Among them, acute pancreatitis and cholangitis can be life-threatening complications, with a mortality rate of 3-20% for the first episode of acute pancreatitis and 24% for acute cholangitis.
Related tests.
Ultrasound is nowadays the first-line test for the diagnosis of gallstones and has a high accuracy rate (sensitivity of 90% and specificity of 88%) even when performed by a non-imaging physician.
When local or systemic inflammatory manifestations are present, such as Murphy’s sign (pressure pain under the right upper abdominal rib cage during deep breathing; sensitivity 65%, specificity 87%), fever, and elevated leukocytes or CRP, acute cholecystitis is suspected and can be confirmed by ultrasound, CT, or MRI. Imaging manifestations of acute cholecystitis include thickening of the gallbladder wall (>4 mm), enlargement of the gallbladder (long diameter >200 px, short diameter >100 px) or peribiliary effusion.
Complicated acute pancreatitis should be suspected when epigastric pain is present and radiates to the back. This, together with total abdominal pain, elevated blood and urine amylase, elevated blood lipase and imaging support, such as pancreatic swelling with peripancreatic exudate, can help confirm the diagnosis.
Ultrasonography can be used selectively when the patient presents with symptoms related to gallstones and is in good general condition without manifestations of acute cholecystitis, acute pancreatitis, obstructive jaundice or cholangitis, and regular follow-up with their general surgery department is recommended. If complications are suspected, immediate surgical consultation is necessary, as early detection and treatment of complications usually have a better prognosis. The main signs indicating the presence of complications are: fever, chills, hypotension, epigastric pain radiating to the back, darkening of the urine, jaundice, positive Murphy’s sign, total abdominal cramps, and positive urinary bilirubin. According to the clinical manifestations, laboratory tests such as routine blood, CRP, blood and urine amylase, blood and urine lipase, alkaline phosphatase and imaging tests such as ultrasound, CT, MRI, MRCP, EUS should be performed to further confirm the presence or absence of complications.
Treatment.
1. Asymptomatic gallstones.
There is no evidence that lifestyle changes such as reduced fat intake and increased exercise can reduce or prevent the development of symptoms. Treatment is not recommended for patients with asymptomatic gallstones (whether cholesterol stones, biliary pigment stones, or mixed stones) unless the gallbladder is porcelain (due to its association with gallbladder cancer). Surgery is not recommended for patients with asymptomatic gallstones.
2. Symptomatic gallstones.
Cholecystectomy is the main method of treatment for gallbladder stones.
3.Pros and cons of cholecystectomy.
Cholecystectomy is often performed laparoscopically because of its advantages such as short hospital stay, less pain, early recovery and small scars. After cholecystectomy, a small number of patients may develop fat intolerance, thus a low-fat diet is often recommended for such patients.
4. The best time for surgery.
The best time to perform cholecystectomy in patients with acute cholecystitis is also highly controversial. The traditional view is that it is best to allow the inflammation to stabilize for at least 6 weeks before performing cholecystectomy. Systematic evaluations have shown that surgical treatment within 1 week of symptom onset prevents more serious complications while waiting for surgery. The average length of hospital stay was reduced by 4 days without increasing the incidence of surgical complications or the need for conversion to open surgery.