1. Epidemiology and aetiology
Approximately 9 per cent of adults aged over 60 have gallstones, equating to 5.5 million people in the UK. Many patients with gallstones never develop symptoms.
However, patients with asymptomatic gallstones develop gallstone-related problems at a rate of 1-4 per cent per year.
The most common problems caused by gallstones are biliary colic (56 per cent of cases) and acute cholecystitis (36 per cent). Other problems include jaundice, ascending cholangitis, pancreatitis, gallstone ileus and gall bladder cancer.
The clinical features of gallstone disease depend on the location of the stone (see figure).
Gallstone disease is a leading cause of hospital admissions for GI related problems.
Between April 2005 and March 2006, there were 49,077 cholecystectomy procedures in England.
Why gallstones form is not clear, but there are known risk factors (see box). They can occur in all age groups but incidence increases with age.
The old adage 'fat, fertile, female and forty' tells only part of the story; oestrogen causes more cholesterol to be excreted into bile and obesity (BMI>30) is a risk factor.
There is also a genetic component to gallstone risk, accounting for 25 per cent of the phenotypic variance seen in twins. This means a fifth 'f', family history, can be added to the adage.
Other risk factors include pregnancy, rapid weight loss for instance after bariatric surgery, parenteral nutrition, loss of bile salts from terminal ileitis or following ileal resection, diabetes and haemolytic disease.
Gallstones risk factors
- Increasing age.
- High fat/low fibre diet.
- Female sex (twice the risk in men).
- Family history.
- Pregnancy (risk increases with number of pregnancies).
- Rapid weight loss.
- Total parenteral nutrition.
- Loss of bile salts (ileal disease or resection).
- Cystic fibrosis.
- Haemolytic disease.
A history is crucial in making the diagnosis of gallstone-related problems. Examination helps identify any biliary inflammation and exclude the presence of hepatomegaly.
Abnormal liver function tests can indicate the presence of a bile duct stone. An ultrasound scan is the key diagnostic test for identifying the presence of stones, biliary tract dilation and thickening of the gall bladder wall indicative of chronic disease.
Ultrasound can accurately detect up to 98 per cent of gallstones but a negative scan does not exclude the diagnosis.
Pain in the upper abdomen, on the right side, is the most common presentation of biliary colic.
Nausea and vomiting often accompany the pain.
The pain is colicky, tends to build to a crescendo then subsides, and is often relieved by vomiting.
Symptoms usually last less than eight hours and there is no inflammation or fever, tenderness in the right upper quadrant or leucocytosis.
Biliary colic and cholecystitis share many symptoms, and can be hard to distinguish.
Symptoms of cholecystitis tend to last longer than eight hours, and there are usually indicators of inflammation such as pyrexia, tenderness in the right upper quadrant and leucocytosis.
Jaundice can occur when a gallstone migrates into the common bile duct, or if a stone within the neck of the cystic duct compresses the common hepatic duct (Mirizzi's syndrome).
An infection within a partially or completely obstructed bile duct can result in ascending cholangitis. Stasis leads to an increase in the resident bacterial flora.
During the passage of stones from the gall bladder into the bowel, transitory obstruction of the biliopancreatic duct occurs in the region of the ampulla, which initiates premature activation of enzymes within the pancreas leading to pancreatitis.
The resulting pain is classically epigastric, constant, radiating through to the back and relieved by bending forwards. Vomiting is often profuse.
Gallstones may fistulate directly into the duodenum from the gall bladder during a period of often silent inflammation.
The stone can impact at the narrowest section of small bowel, leading to obstruction known as gallstone ileus.
Acute biliary colic or cholecystitis can be treated with analgesia at home.
Diclofenac (75-100mg) or an opioid such as pethidine are very effective used in combination or separately. Since vomiting is a common symptom, a suppository or an injection is recommended.
If infection is suspected, oral levofloxacin provides good cover against coliform bacteria and is the antibiotic of choice. If pain continues after 24 hours or with accompanying fever, the patient should be admitted to hospital with suspected acute cholecystitis.
Drug dissolution therapy
Ursodeoxycholic acid has been shown to be useful in the prevention of gallstones. However, it does not appear to be useful once the gallstones have developed.
Laparoscopic cholecystectomy is the procedure of choice for treating biliary colic and cholecystitis.
A Cochrane review concluded that early laparoscopic cholecystectomy (less than seven days from onset of symptoms) is safe and shortens hospital stay.
Another study has demonstrated a 28.5 per cent re-admission rate with gallstone-related complications in patients on the waiting list for surgery following an emergency admission with acute cholecystitis.
The NHS Institute for Innovation and Improvement has therefore recommended that cholecystectomy should be offered to all patients presenting as an emergency with symptomatic gallstones on that admission, or as soon as possible afterwards.
All patients diagnosed with gallstone pancreatitis should undergo surgery to remove their gallstones, usually by laparoscopic cholecystectomy, during the same hospital admission or at the earliest opportunity thereafter. In frail patients, endoscopic retrograde cholangiopancreatography (ERCP) can be used.
In many trusts, laparascopic cholecystectomy is offered as a day-case procedure. The national average rate of day case laparoscopic cholecystectomy is 6.4 per cent. But the highest performing trusts achieve a rate of 40-50 per cent.
The NHS Institute for Innovation and Improvement recommends that the default is day case and that an overall day case rate of 75 per cent is achievable.
Bile duct surgery
Patients with abnormal liver function indicating suspected duct stones can be treated in a number of ways.
The decision largely depends upon the expertise available.
ERCP followed by cholecystectomy is most commonly used Laparoscopic ultrasound and bile duct exploration avoids interval tests and negative scans or investigation.
However, ascending cholangitis is a clear indication for emergency biliary decompression by ERCP or percutaneous transhepatic cholangiography.
Patients with asymptomatic gallstones develop gallstone-related problems at a rate of 1-4 per cent per year.Prophylactic cholecystectomy in patients without symptoms is generally unnecessary because the risk of the procedure outweighs the benefits.
But in a young patient with gallstones, the balance may favour treatment since they have a higher risk of developing problems.
In general, the decision to treat should be made on a case by case basis, taking into account the age of the patient, the ultrasound findings and the presence of any symptoms.
Complications of cholecystectomy include haematoma in the gall bladder bed, infection, bile leak, inadvertent injury to bowel or bile duct and retained stone in the bile duct.
The most serious is bile duct injury, occurring at a rate of 0.2 per cent in both laparoscopic and open surgery.
Contributed by Mr Grant Sanders, locum consultant in GI surgery, Derrisford Hospital, Plymouth.