Gallstones are present in 10-20% of the population. They are most common in women, and the prevalence increases with age.
Gallstones are of two types:
■ Cholesterol gallstones account for 80% of all gallstones in the Western world. Cholesterol is held in solution by the detergent action of bile salts and phospholipids, with which it forms micelles and vesicles. Cholesterol gallstones only form in bile which has an excess of cholesterol, either because there is a relative deficiency of bile salts and phospholipids or
a relative excess of cholesterol (supersaturated or lithogenic bile). The formation of cholesterol crystals and gallstones in lithogenic bile is promoted by factors that favour nucleation, such as mucus and calcium. Gallstone formation is further promoted by reduced gall bladder motility and stasis. The mechanism of cholesterol gallstone formation in patients with risk factors (Table 4.12) is frequently multifactorial (cholesterol supersaturation, nucleation factors and reduced gallbladder motility).
■ Pigment stones consist of bilirubin polymers and calcium bilirubinate. They are seen in patients with chronic haemolysis, e.g. hereditary spherocytosis and sickle cell disease, in which bilirubin production is increased, and also in cirrhosis. Pigment stones may also form in the bile ducts after cholecystectomy and with duct strictures.
Most gallstones never cause symptoms, and cholecystectomy is not indicated in asymptomatic cases. The complications are summarized in Fig. 4.8.
Biliary pain (colic) is the term used for the pain associated with the temporary obstruction of the cystic or CBD by a stone.
There are recurrent episodes of severe constant pain in the upper abdomen, which subsides after several hours. The pain may radiate to the right shoulder and right subscapular region and is often associated with vomiting. Examina-tion is usually normal.
|Table 4.12 Risk factors for cholesterol gallstones|
Fig. 4.8 The complications of gallstones.
The diagnosis is usually made on the basis of a typical history and an US showing gallstones. Increases of serum alkaline phosphatase and bilirubin during an attack support the diagnosis of biliary pain. The absence of inflam-matory features (fever, white cell count and local peritonism) differentiates this from acute cholecystitis.
The treatment is analgesia and elective cholecystectomy. Abnormal liver biochemistry or a dilated CBD on ultrasonography is an indication for pre-operative MRCP. CBD stones identified on imaging are removed at ERCP or sometimes at the same time as cholecystectomy.
Acute cholecystitis follows the impaction of a stone in the cystic duct or neck of the gall bladder. Very occasionally acute cholecystitis may occur without stones (acalculous cholecystitis).
The initial clinical features are similar to those of biliary colic. However, over a number of hours there is progression to severe pain localized in the right upper quadrant, which is associated with a fever and tenderness and muscle guarding on examination. The tenderness is worse on inspiration (Murphy's sign). Complications include an empyema (pus) and perforation with perito-nitis. The diagnosis of acute cholecystitis is usually straightforward. The differential diagnosis is from other causes of severe right upper quadrant pain (p. 68).
■ White cell count shows leucocytosis.
■ Serum liver biochemistry may be mildly abnormal.
■ Abdominal US shows gallstones and a distended gall bladder with a thickened wall. There is focal tenderness directly over the visualized gall bladder (sonographic Murphy's sign).
The initial treatment is conservative, with nil by mouth, intravenous fluids, pain relief and intravenous antibiotics, e.g. cefotaxime. Cholecystectomy is usually performed within 48 hours of the acute attack, and always if compli-cations (see above) develop.
Chronic inflammation of the gall bladder is often found in association with gallstones. On US examination this may appear as a small shrunken gall bladder. There is no evidence that this produces any symptoms, and chole-cystectomy is not indicated. Chronic right hypochondrial pain and fatty food intolerance are likely to be functional in origin and gallstones an incidental finding.
This is an infection of the biliary tree and most often occurs secondary to CBD obstruction by gallstones (choledocholithiasis). Other causes are benign biliary strictures following biliary surgery or associated with chronic pancrea-titis, PSC, HIV cholangiopathy (p. 52) and in patients with biliary stents. Bile duct obstruction due to cancer of the head of pancreas or bile duct (cho-langiocarcinoma) can also cause cholangitis and this is more likely after ERCP. In the Far East, parts of eastern Europe and the Mediterranean, biliary parasites can cause blockage and cholangitis.
The classic description of cholangitis with fever, jaundice and right upper quadrant pain (Charcot's triad) is not always present, although most patients have fever often with rigors. Jaundice is cholestatic in type, and therefore the urine is dark, the stools pale and the skin may itch. Elderly patients may present with non-specific symptoms such as confusion and malaise.
■ White cell count shows leucocytosis.
■ Blood cultures are positive (E. coli, Enterococcus. faecalis, sometimes anaerobes) in about 30% of patients.
■ Liver biochemistry shows a cholestatic picture with a raised serum bilirubin and alkaline phosphatase.
■ US shows a dilated CBD and may show the cause of the obstruction.
■ MRCP can further assess the site and cause of obstruction.
■ ERCP is the definitive investigation and will also allow biliary drainage (see below). It will show the site of obstruction and the cause, and bile can be sampled for culture and cytology (if a malignant cause is suspected).
Treatment of acute cholangitis includes resuscitation and volume replace-ment in shocked patients, pain relief, treatment of infection with appropriate intravenous antibiotics and relief of obstruction by biliary drainage. Bacterial infection may be polymicrobial and a suitable antibiotic regimen is a third-generation cephalosporin, e.g. cefotaxime (ciprofloxacin if allergic), plus metronidazole. An alternative regimen is amoxicillin, gentamicin (with appro-priate monitoring) and metronidazole. In endemic areas primary parasite infection must also be treated.
Biliary drainage and/or clearance is usually achieved at ERCP with or without sphincterotomy. The urgency of this procedure depends on the clini-cal condition of the patient and the initial response to antibiotics. Stones can be removed from the CBD, and a stent can be placed in the biliary tree if stones cannot be removed or to relieve obstruction in patients with cancer of the head of pancreas or CBD. Antibiotics are continued after biliary drain-age until symptom resolution, usually 7-10 days.
Common bile duct stones (choledocholithiasis)
CBD stones may also be asymptomatic with no features of cholangitis and present with abnormal liver biochemistry, usually with a cholestatic picture. US will usually show gallbladder stones and may show the obstructed CBD containing a stone. MRCP is more sensitive than transabdominal US and is sometimes performed if there is a high index of suspicion and the latter is negative. An alternative technique for imaging the biliary system is endo-scopic US.
1. Ethics and communication
2. Infectious diseases
3. Gastroenterology and nutrition
4. Liver, biliary tract and pancreatic disease
Liver, biliary tract and pancreatic disease
LIVER BIOCHEMISTRY AND LIVER FUNCTION TESTS
SYMPTOMS AND SIGNS OF LIVER DISEASE
NON - ALCOHOLIC FATTY LIVER DISEASE (NAFLD)
COMPLICATIONS AND EFFECTS OF CIRRHOSIS
TYPES OF CHRONIC LIVER DISEASE AND CIRRHOSIS
PRIMARY SCLEROSING CHOLANGITIS
BUDD - CHIARI SYNDROME
LIVER DISEASE IN PREGNANCY
CARCINOMA OF THE PANCREAS
NEUROENDOCRINE TUMOURS OF THE PANCREAS
5. Haematological disease
Assessment and treatment of suspected neutropenic sepsis
INHERITED HAEMOLYTIC ANAEMIAS
ACQUIRED HAEMOLYTIC ANAEMIA
THE WHITE CELL
HAEMOSTASIS AND THROMBOSIS
6. Malignant disease
COMMON INVESTIGATIONS IN MUSCULOSKELETAL DISEASE
COMMON REGIONAL MUSCULOSKELETAL PROBLEMS
THE SERONEGATIVE SPONDYLOARTHROPATHIES
Clinical features, Investigations
INFECTION OF JOINTS AND BONES
AUTOIMMUNE RHEUMATIC DISEASES
SYSTEMIC INFLAMMATORY VASCULITIS
DISEASES OF BONE
8. Water, electrolytes and acid–base balance
WATER AND ELECTROLYTE REQUIREMENTS
BODY FLUID COMPARTMENTS
REGULATION OF BODY FLUID HOMEOSTASIS
PLASMA OSMOLALITY AND DISORDERS OF SODIUM REGULATION
DISORDERS OF POTASSIUM REGULATION
DISORDERS OF MAGNESIUM REGULATION
DISORDERS OF ACID - BASE BALANCE
9. Renal disease
INVESTIGATION OF RENAL DISEASE
URINARY TRACT INFECTION
HYPERTENSION AND THE KIDNEY
RENAL CALCULI AND NEPHROCALCINOSIS
URINARY TRACT OBSTRUCTION
ACUTE RENAL FAILURE/ACUTE KIDNEY INJURY
CHRONIC KIDNEY DISEASE
RENAL REPLACEMENT THERAPY
CYSTIC RENAL DISEASE
TUMOURS OF THE KIDNEY AND GENITOURINARY TRACT
DISEASES OF THE PROSTATE GLAND
10. Cardiovascular disease
COMMON PRESENTING SYMPTOMS OF HEART DISEASE
INVESTIGATIONS IN CARDIAC DISEASE
ISCHAEMIC HEART DISEASE
VALVULAR HEART DISEASE
PULMONARY HEART DISEASE
ARTERIAL AND VENOUS DISEASE
DRUGS FOR ARRHYTHMIAS
DRUGS FOR HEART FAILURE
DRUGS AFFECTING THE RENIN - ANGIOTENSIN SYSTEM
NITRATES, CALCIUM - CHANNEL BLOCKERS AND POTASSIUM - CHANNEL ACTIVATORS
11. Respiratory disease
12. Intensive care medicine
13. Drug therapy, poisoning, and alcohol misuse
14. Endocrine disease
PITUITARY HYPERSECRETION SYNDROMES
THE THYROID AXIS
MALE REPRODUCTION AND SEX
FEMALE REPRODUCTION AND SEX
THE GLUCOCORTICOID AXIS
THE THIRST AXIS
DISORDERS OF CALCIUM METABOLISM
DISORDERS OF PHOSPHATE CONCENTRATION
ENDOCRINOLOGY OF BLOOD PRESSURE CONTROL
DISORDERS OF TEMPERATURE REGULATION
15. Diabetes mellitus and other disorders of metabolism
16. The special senses
COMMON NEUROLOGICAL SYMPTOMS
COORDINATION OF MOVEMENT
THE CRANIAL NERVES
COMMON INVESTIGATIONS IN NEUROLOGICAL DISEASE
UNCONSCIOUSNESS AND COMA
STROKE AND CEREBROVASCULAR DISEASE
EPILEPSY AND LOSS OF CONSCIOUSNESS
NERVOUS SYSTEM INFECTION AND INFLAMMATION
HEADACHE, MIGRAINE AND FACIAL PAIN
SPINAL CORD DISEASE
DEGENERATIVE NEURONAL DISEASES
DISEASES OF THE PERIPHERAL NERVES