Gallstones

Question 1

Define gallstones and summarise its epidemiology.

Answer 1

Definition: Stone formation in the gall bladder.

Epidemiology: Very common (UK prevalence approx. 10%), more common with age, 3x more females in younger population but equal sex ratio after 65 years.

Question 2

Summarise the aetiology/risk factors of gallstones

Answer 2

Aetiology:
-Mixed stones: contain cholesterol, calcium bilirubinate, phosphate and protein (80%) Associated with older age, female, obesity, parenteral nutrition, drugs, family history, ethnicity (e.g. Prima Indians), interruption of enterohepatic recirculation of bile salts (e.g. Crohn’s disease)

• Pure cholesterol stones (10%): Similar associations as mixed stones.
• Pigment stones (10%): Black stones made of calcium bilirubinate (increased bilirubin secondary to haemolytic disorders, cirrhosis), brown stones due to bile duct infestation by liver fluke. Associated with haemolytic disorders (e.g. sickle cell, thalassemia, hereditary spherocytosis).

Question 3

Describe the history/presenting symptoms of gallstones

Answer 3

Asymptomatic (90%): found incidentally.
- Biliary colic: Sudden onset, severe right upper quadrant or epigastric pain, constant in nature. May radiate to right scapula, often precipitated by a fatty meal. Can last hours, may be associated with nausea and vomiting.

• Acute cholecystitis: Patient systemically unwell, fever, prolonged upper abdominal pain that may be referred to the right shoulder due to diaphragmatic irritation.
• Ascending cholangitis: Classical association between right upper quadrant pain, jaundice and rigors (Charcot’s triad). if combined with hypotension and confusion, it is known as Reynold’s pentad.

Question 4

What are the signs of gallstones upon physical examination?

Answer 4

• Biliary colic: Right upper quadrant or epigastric tenderness.
• Acute Cholecystitis: Tachycardia, pyrexia, right upper quadrant or epigastric tenderness. There may be guarding +/- rebound. Murphy’s sign is elicited by placing a hand at the costal margin in the RUQ and asking the patient to breathe deeply. Patient stops breathing as the inflamed gallbladder descends and contacts the palpating fingers.
• Ascending cholangitis: Pyrexia, right upper quadrant pain, jaundice.

Question 5

What investigations are used to identify gallstones?

Answer 5

• Bloods: FBC (increase in WBC in cholecystitis or cholangitis), LFT (increase AlkPhos, increase bilirubin in ascending cholangitis; may be increase in transaminases), blood cultures, amylase (risk of pancreatitis).
• USS: Demonstrated gallstones (acoustic shadow within the gallbladder), increase thickness of gallbladder wall and can examine for presence of dilation of biliary tree indicative of obstruction.
• AXR: Gallstones are infrequently radio-opaque (10%)
• Other imaging: Erect CXR (to exclude perforation as a differential diagnosis), CT scanning, magnetic resonance cholangiopancreatography (MRCP) or endoscopic retrograde cholangiopancreatography (ERCP)

Question 6

How is gallstones managed?

Answer 6

• Mild symptoms: Conservative, avoidance of fat in diet.
• Severe biliary colic: Admission, IV fluids, analgesia, antiemetics and antibiotics if there are signs of infection (cholecystitis and cholangitis).

If symptoms fail to improve or worsen, a localized abscess or empyema should be suspected.
This can be drained percutaneously by cholecystostomy and pigtail catheter.
If there is evidence of obstruction, urgent biliary drainage by ERCP or percutaneous
transhepatic cholangiogram.

• Surgical: Laparoscopic cholecystectomy on table cholangiogram, In acute setting, performed within 72 hours of symptom onest, or after several weeks for inflammation to settle.

Question 7

What are the complications of gallstones?

Answer 7

• Stones within gallbladder: Biliary colic, cholecystitis, mucocoele or gallbladder empyema,
  porcelain gallbladder, predisposition to gallbladder cancer (rare).
• Stones outside gallbladder: Obstructive jaundice, pancreatitis, ascending cholangitis,
  perforation and pericholecystic abscess or bile peritonitis, cholecystenteric fistula, gallstone
  ileus, Mirizzi syndrome (common hepatic duct obstruction by an extrinsic compression
  from an impacted stone in the cystic duct), Bouveret’s syndrome (gallstones
  causing gastric outlet obstruction).

-Of cholecystectomy: Bleeding, infection, bile leak, bile duct injury (0.3% laparoscopic,
0.2% open), post-cholecystectomy syndrome (persistant dyspeptic symptoms), port-site
hernias.

Question 8

Summarise the prognosis for patients with gallstones

Answer 8

In most cases gallstones are benign and do not cause significant problems
(2% with gallstones develop symptoms annually). If they become symptomatic, surgery is an
effective treatment.