The gall-bladder rests on the underside of the LIVER and joins the common hepatic duct via the cystic duct to form the common BILE DUCT. The gall-bladder acts as a reservoir and concentrator of BILE, alterations in the composition of which may result in the formation of gallstones, the most common disease of the gallbladder.
Gall-stones aﬀect 22 per cent of women and 11 per cent of men. The incidence increases with age, but only about 30 per cent of those with gall-stones undergo treatment as the majority of cases are asymptomatic. There are three types of stone: cholesterol, pigment and mixed, depending upon their composition; stones are usually mixed and may contain calcium deposits. The cause of most cases is not clear but sometimes gall-stones will form around a ‘foreign body’ within the bile ducts or gall-bladder, such as suture material. BILIARY COLIC Muscle ﬁbres in the biliary system contract around a stone in the cystic duct or common bile duct in an attempt to expel it. This causes pain in the right upper quarter of the abdomen, with nausea and occasionally vomiting. JAUNDICE Gall-stones small enough to enter the common bile duct may block the ﬂow of bile and cause jaundice. ACUTE CHOLECYSTITIS Blockage of the cystic duct may lead to this. The gall-bladder wall becomes inﬂamed, resulting in pain in the right upper quarter of the abdomen, fever, and an increase in the white-blood-cell count. There is characteristically tenderness over the tip of the right ninth rib on deep inhalation (Murphy’s sign). Infection of the gall-bladder may accompany the acute inﬂammation and occasionally an EMPYEMA of the gall-bladder may result. CHRONIC CHOLECYSTITIS A more insidious form of gall-bladder inﬂammation, producing non-speciﬁc symptoms of abdominal pain, nausea and ﬂatulence which may be worse after a fatty meal.
Diagnosis Stones are usually diagnosed on the basis of the patient’s reported symptoms, although asymptomatic gall-stones are often an incidental ﬁnding when investigating another complaint. Conﬁrmatory investigations include abdominal RADIOGRAPHY – although many gall-stones are not calciﬁed and thus do not show up on these images; ULTRASOUND scanning; oral CHOLECYSTOGRAPHY – which entails a patient’s swallowing a substance opaque to X-rays which is concentrated in the gall-bladder; and endoscopic retrograde cholangiopancreatography (ERCP) – a technique in which an ENDOSCOPE is passed into the duodenum and a contrast medium injected into the biliary duct.
Treatment Biliary colic is treated with bed rest and injection of morphine-like analgesics. Once the pain has subsided, the patient may then be referred for further treatment as outlined below. Acute cholecystitis is treated by surgical removal of the gall-bladder. There are two techniques available for this procedure: ﬁrstly, conventional cholecystectomy, in which the abdomen is opened and the gall-bladder cut out; and, secondly, laparoscopic cholecystectomy, in which ﬁbreoptic instruments called endoscopes (see FIBREOPTIC ENDOSCOPY) are introduced into the abdominal cavity via several small incisions (see MINIMALLY INVASIVE SURGERY (MIS)). Laparoscopic surgery has the advantage of reducing the patient’s recovery time. Gall-stones may be removed during ERCP; they can sometimes be dissolved using ultrasound waves (lithotripsy) or tablet therapy (dissolution chemotherapy). Pigment stones, calciﬁed stones or stones larger than 15 mm in diameter are not suitable for this treatment, which is also less likely to succeed in the overweight patient. Drug treatment is prolonged but stones can disappear completely after two years. Stones may re-form on stopping therapy. The drugs used are derivatives of bile salts, particularly chenodeoxycholic acid; side-eﬀects include diarrhoea and liver damage.