Definition
Gallbladder stones are crystals deposited in the gallbladder and have a prevalence of about 5-25%, with a higher prevalence in Western populations, women and elderly people. Depending on the composition of the stones, gallbladder stones can be classified as cholesterol stones, bile pigment stones and mixed stones (both cholesterol stones and bile pigment stones).
Susceptible groups
The formation of gallbladder stones is associated with a change in the balance between nucleating and inhibiting factors in the bile. The causes of stone formation include excess cholesterol in the bile, low levels of bile salts, reduced gallbladder motility, and reduced levels of phosphatidylcholine molecules, the latter organizing the formation of cholesterol 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 people 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 of the liver , Crohn’s disease and impaired gallbladder contraction (e.g., post-gastrectomy or post-vagotomy). Hemolysis and chronic bacterial or parasitic infections are often considered to be the main risk factors for gallstones, but all three of these factors can often be avoided.
Prevention
Although some 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.
Early detection of sickle cell anemia, so that appropriate measures can be taken to prevent the occurrence of hemolysis, or prophylactic antibiotics for post-splenectomy patients and patients with splenic infarction to prevent infection and thus prevent the occurrence 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 patients 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, and there is no evidence to suggest that the above methods of gallstone prevention are effective.
Clinical presentation
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, acute pancreatitis, obstructive jaundice and less common complications such as acute cholangitis and intestinal obstruction. Among them, acute pancreatitis and cholangitis may become life-threatening complications, with a mortality rate of 3%-20% for the first episode of acute pancreatitis and 24% for acute cholangitis.
Other complications can often occur with biliary colic alone, and patients with a history of biliary colic attacks are at higher risk for complications. Although studies have shown an association between gallstones and biliary tract tumors, there is no evidence of a causal relationship, and it is likely that some of the risk factors are the same between them.
Related tests
Ultrasound is the first-line test for the diagnosis of gallstones today, and its accuracy is high (90% sensitivity and 88% specificity), even when performed by a non-imaging physician. Imaging manifestations of acute cholecystitis include thickening of the gallbladder wall (>4 mm), enlargement of the gallbladder (>8 cm in long diameter and >4 cm in short diameter) or fluid accumulation around the gallbladder. Complicated acute pancreatitis should be suspected when epigastric pain is present and radiates to the back. Together with total abdominal pressure, elevated blood and urine amylase, elevated blood lipase and imaging support, such as pancreatic swelling with peripancreatic exudate, 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
Distinguishing between asymptomatic and symptomatic gallstones is sometimes difficult because symptoms are sometimes mild and each person has a different level of sensitivity. Although complications of gallstones can be diagnosed by the above criteria, it is difficult to confirm whether symptoms are related to gallstones in patients suspected of having epigastric pain and dyspepsia. There is no evidence that lifestyle changes, such as reduced fat intake and increased exercise, can reduce or prevent symptoms. Treatment is not recommended for patients with asymptomatic gallstones (whether cholesterol stones, bile pigment stones, or mixed stones) unless the gallbladder is porcelain (due to its association with gallbladder cancer). Although this remains controversial, surgery is not recommended for patients with asymptomatic gallstones due to the complications that arise after surgical intervention.
If an asymptomatic patient with gallstones happens to require a major abdominal surgery, it seems reasonable to recommend a concomitant cholecystectomy, since the postoperative adhesions will make it difficult to perform a cholecystectomy in the future. However, there is no RCT or systematic evaluation to support the above recommendation.
2. Symptomatic gallstones
Cholecystectomy is the primary treatment for gallbladder stones, and RCTs, systematic evaluations, and cohort studies have shown that extracorporeal shock wave lithotripsy and ursodeoxycholic acid have a low cure rate. 27% of patients treated with ursodeoxycholic acid for gallstones had their stones dissolve, and 55% of carefully selected patients treated with extracorporeal microwave lithotripsy had their stones disappear. Although some patients were able to eliminate stones with these methods, the recurrence rate of stones remained high, reaching more than 40% within 4 years. After three months of ursodeoxycholic acid, 26% of patients had no recurrence of biliary colic, compared with 33% in the placebo group. In addition, approximately 2% of patients taking ursodeoxycholic acid developed complications, which is similar to the annual complication rate in patients not taking medication.
In patients whose systemic status does not allow cholecystectomy, percutaneous cholecystostomy (temporary drainage of bile outside the body through a catheter under imaging guidance) may play an emergency role, although systematic evaluations have shown that the value of percutaneous cholecystostomy is unclear. Once the patient’s general condition improves, cholecystectomy may be considered.
3. Pros and cons of cholecystectomy
Cholecystectomy is often performed laparoscopically because it has the advantages of short hospital stay, less pain, early recovery and smaller scars. After cholecystectomy, a small percentage of patients may develop fat intolerance, and thus a low-fat diet is often recommended for such patients; however, there is no evidence of the exact role of a low-fat diet.
For patients with symptomatic gallstones and common bile duct stones, the treatment options include open cholecystectomy + common bile duct exploration, laparoscopic cholecystectomy + common bile duct exploration, and laparoscopic cholecystectomy + endoscopic sphincterotomy (preoperative, intraoperative, and postoperative).
4.The best time for surgery
The timing of surgery for different indications is still controversial. In patients with episodes of biliary colic, there is no medical reason to postpone surgery, although medical resources may be limited (some surgeons may also advise some patients to lose weight before performing surgery).
The optimal timing of cholecystectomy in patients with acute cholecystitis is also controversial. Conventional wisdom suggests that it is best to allow the inflammation to stabilize for at least 6 weeks before performing cholecystectomy. Relevant systematic evaluations have shown that surgical treatment within 1 week from the onset of symptoms prevents more serious complications while waiting for surgery. Early LC reduced the length of hospital stay by an average of 4 days without increasing the incidence of surgical complications (5-6% in each group) or the need for conversion to open surgery (approximately 20% in each group).
Patients awaiting surgery may have prolonged pain, pancreatitis, and obstructive jaundice, although the majority of complications are recurrence or non-remission of acute cholecystitis. An RCT study showed that the complication rate of LC after 7-45 days of attack was 2-3 times higher than that of early surgical treatment, and thus surgical treatment is not recommended during this period.