Acute Cholecystitis
Gallstone Disease Overview
Spectrum of Gallstone Disease Presentation
Be aware that gallstone disease can present as ANY of the following:
| Condition | Pathophysiology | Clinical and biochemical manifestations | Key investigations | Management |
|---|---|---|---|---|
| Cholelithiasis | Presence of gallbladder stone |
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Elective laparoscopic cholecystectomy if symptomatic |
| Choledocholithiasis | Presence of common bile duct stone |
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Bile duct clearance + laparoscopic cholecystectomy |
| Acute cholecystitis | Persistent cystic duct obstruction → gallbladder inflammation |
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IV fluids + antibiotics → early laparoscopic cholecystectomy |
| Acute cholangitis | Common bile duct obstruction → ascending bacterial infection | Charcot’s triad:
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IV antibiotics + urgent ERCP |
| Gallstone pancreatitis | Stone impacts at ampulla of Vater → pancreatic duct obstruction → pancreatitis |
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Supportive (IV fluids, analgesia, optimise nutrition) → cholecystectomy after recovery |
Background Information
Definition
Acute cholecystitis is defined as an acute inflammation of the gallbladder, most commonly due to obstruction of the cystic duct by gallstones
Aetiology
~90-95% cases are calculous cholecystitis [Ref]
- Cholelithiasis (gallbladder stones) → cystic duct obstruction → bile stasis → chemical irritation of the gallbladder mucosa → inflammation
- Secondary bacterial infection (most commonly E. coli, Klebsiella species, enterococcus) often develop after initial sterile inflammation
A minority of cases are acalculous (occurs in the absence of gallstones) [Ref]
- Typically seen in critically ill or post-operative patients
- The pathogenesis in these cases is multifactorial, involving gallbladder stasis, ischemia, and infection
Risk Factors
Risk factors for calculous cholecystitis (i.e. gallstone formation): [Ref1][Ref2]
| Cholesterol gallstone (most common) | 5 Fs
Other risk factors
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| Pigmented gallstone | Causes of chronic haemolysis
Other causes
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Risk factors for acalculous cholecystitis: [Ref]
- Critical illness
- Diabetes
- HIV
- Atherosclerotic cardiovascular disease
- IV nutrition
Diagnosis
Diagnostic criteria for acute cholecystitis: [Ref]
- 1 local sign or symptom, and
- 1 systemic sign of inflammation, and
- Confirmatory imaging findings
Clinical Features and Blood Tests
| Local sign or symptom |
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| Systemic sign of inflammation |
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| LFTs |
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In typical exam questions, the presence of cholestasis signs (i.e. jaundice, hyperbilirubinaemia, ↑ GGT, ALP) should point away from acute cholecystitis, and acute cholangitis is more likely (or simply choledocholithiasis if there are no signs of inflammation)
However, in practice absence of cholestasis is NOT a diagnostic criterion for acute cholecystitis. Mild elevations in bilirubin and liver enzymes can occur in acute cholecystitis without choledocholithiasis, and their presence does not preclude the diagnosis. However, frank jaundice or marked cholestasis should prompt evaluation for concomitant choledocholithiasis or other biliary pathology.
The classic table of biliary colic vs acute cholecystitis vs ascending cholangitis:
| Condition | Pain (RUQ / epigastric) | Signs of inflammation (fever / ↑ WCC / ↑ CRP) | Signs of biliary obstruction (jaundice / hyperbilirubinaemia) |
|---|---|---|---|
| Cholelithiasis (biliary colic) | Yes | No | No |
| Choledocholithiasis | Yes | No | Yes |
| Acute cholecystitis | Yes | Yes | No |
| Ascending cholangitis | Yes | Yes | Yes |
Imaging
1st line: abdominal ultrasound [Ref]
- Thickening of the gallbladder (≥5mm) (due to inflammation)
- Pericholecystic fluid
- Tenderness when the ultrasonographic probe is pushed against the gallbladder (ultrasonographic Murphy’s sign)
2nd line tests: [Ref]
- CT abdomen with IV contrast – useful to identify complications
- MRI
- Gold standard confirmatory test: HIDA scan (cholescintigraphy) (but its use is limited by availability, time, and radiation exposure)
Management
Uncomplicated Cholecystitis
Initial Management
Initial management involves supportive care:
- IV fluid resuscitation as appropriate
- Analgesia (NSAIDs like diclofenac are commonly used)
- Empirical antibiotics (targeting enteric Gram-negative and anaerobic organisms)
Definitive Management
Offer definitive management to ALL patients:
- Gold standard: early laparoscopic cholecystectomy (within 1 week of diagnosis)
- If the patient is not fit for surgery (and does not improve after initial management):
- Percutaneous cholecystostomy (gallbladder drainage)
- Followed by delayed cholecystectomy (>6 weeks after drainage) if possible
Complicated Cholecystitis
Overview of key acute complications: [Ref]
| Complication | Diagnosis | Management |
|---|---|---|
| Gangrenous cholecystitis (ischaemic necrosis of the gallbladder) – most common complication |
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| Gallbladder perforation (may lead to biliary peritonitis or pericholecystic abscess) |
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| Gallbladder empyema |
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Chronic perforation can result in choledoenteric fistula formation (which can lead to gallstone ileus)
Emphysematous cholecystitis is a rare but life-threatening form of acute cholecystitis characterised by air within the gallbladder wall, caused by gas-forming bacteria (e.g. Clostridium species)