Acute Cholecystitis
Acute inflammation of the gallbladder, most commonly caused by obstruction of the cystic duct by gallstones, leading to distension, ischemia, and potential infection.
Acute cholecystitis is acute inflammation of the gallbladder, most commonly precipitated by obstruction of the cystic duct [1]. It is a complication of gallstone disease [1].
Let's break this down from first principles:
- "Chole-" = bile (Greek: cholē)
- "-cyst-" = bladder/sac (Greek: kystis)
- "-itis" = inflammation
So cholecystitis literally means "inflammation of the bile sac." The acute form implies a sudden, clinically significant inflammatory episode — as opposed to chronic cholecystitis, which is a smouldering, fibrotic process from repeated insults.
The key distinction to grasp early: this is not simply a stone blocking a duct and causing pain (that's biliary colic). Acute cholecystitis is what happens when the obstruction persists, the gallbladder becomes distended, and a cascade of chemical inflammation followed by secondary bacterial infection ensues [1][2][3].
Biliary Colic vs Acute Cholecystitis — The Core Distinction
Biliary colic = transient obstruction of the cystic duct → visceral pain only, self-limiting ( < 6 hours), no peritoneal signs, afebrile. The stone dislodges, gallbladder relaxes, pain resolves.
Acute cholecystitis = persistent obstruction → ongoing distension → chemical then bacterial inflammation → parietal peritoneal irritation → fever, Murphy's sign, prolonged pain ( > 6 hours), leukocytosis. The stone does NOT dislodge [2][4].
2. Epidemiology
- Gallstone disease affects approximately 10–15% of the adult population in Western countries; the prevalence in Hong Kong/Southern China is somewhat lower but rising with Westernisation of diet (higher fat, higher calorie intake) [2].
- Acute cholecystitis develops in ~1–3% of patients with symptomatic gallstones per year [2]. Once you become symptomatic with biliary colic, the risk of progression to cholecystitis or other complications is < 5% per year [2].
- Female predominance — follows the gallstone demographic ("5F" mnemonic: Fat, Female, Forty, Fertile, Family history) [2][4].
- In Hong Kong, there is additional relevance of pigment stones secondary to:
- Acalculous cholecystitis accounts for approximately 5–10% of all acute cholecystitis cases and is predominantly seen in critically ill, hospitalised patients [2][3].
- Peak incidence: 5th–6th decade
- Female:Male ratio approximately 3:1 (mirrors gallstone prevalence)
- Acalculous cholecystitis does not follow this sex distribution — it occurs in the critically ill regardless of sex
3. Risk Factors
Risk factors for acute cholecystitis are essentially the risk factors for gallstones (since calculous cholecystitis is 90–95% of cases) plus factors that promote cystic duct obstruction and biliary stasis.
| Category | Risk Factors | Mechanism |
|---|---|---|
| Demographics ("5F") | Fat, Female, Forty, Fertile, Family history | Oestrogen increases hepatic cholesterol secretion and decreases bile acid secretion → supersaturated/lithogenic bile; progesterone decreases GB motility |
| Metabolic | Obesity, rapid weight loss, diabetes mellitus, metabolic syndrome | Obesity → ↑ cholesterol secretion; rapid weight loss → bile stasis + cholesterol supersaturation; DM → autonomic neuropathy causing GB hypomotility |
| Haematological | Chronic haemolysis (G6PD deficiency, thalassaemia, hereditary spherocytosis, sickle cell disease) | Excess unconjugated bilirubin in bile → black pigment stones (calcium bilirubinate) |
| Hepatic | Liver cirrhosis | Impaired bile acid synthesis + hypersplenism (haemolysis) → pigment stones |
| GI | Crohn's disease (terminal ileum), ileal resection | Loss of bile acid reabsorption in terminal ileum → depleted bile acid pool → cholesterol supersaturation |
| Drugs | OCP, oestrogen replacement, octreotide, ceftriaxone, fibrates | OCP/oestrogen: lithogenic bile; octreotide: GB stasis; ceftriaxone: precipitates in bile; fibrates: ↑ biliary cholesterol excretion |
| Dietary/Lifestyle | High-fat diet, prolonged fasting, TPN | Fasting/TPN → no CCK stimulation → GB stasis → sludge → stones |
| Infections (HK relevant) | Clonorchis sinensis, Ascaris lumbricoides, RPC | Parasites cause epithelial damage → bacterial translocation → β-glucuronidase deconjugates bilirubin → brown pigment stones |
| Family history | 1st degree relative with gallstones | 2× risk; polygenic susceptibility (ABCG8 transporter gene variants) |
Acalculous cholecystitis classically occurs in hospitalised/critically ill patients [2][3]:
- Dehydration → bile inspissation
- Shock / systemic hypoperfusion → gallbladder ischaemia (microvascular occlusion)
- TPN → no enteral feeding → no CCK release → gallbladder stasis (↓CCK)
- Extensive burns, major operations, multiple trauma
- Sepsis / multi-organ dysfunction
- Prolonged ICU stay
The underlying mechanism is gallbladder ischaemia + bile stasis rather than mechanical obstruction by a stone [2][3].
Why Acalculous Cholecystitis is More Dangerous
Acalculous cholecystitis carries a higher mortality (up to 30–50% in some series) compared with calculous cholecystitis (~1–4%) because: (1) it occurs in already critically ill patients, (2) the ischaemic mechanism predisposes to earlier gangrenous change and perforation, and (3) the diagnosis is often delayed because these patients cannot communicate symptoms clearly and signs are masked by their primary illness [3].
4. Anatomy and Function
Understanding the anatomy is essential because it directly explains the pathophysiology, clinical signs, surgical approach, and complications.
The gallbladder consists of: fundus, body, infundibulum (Hartmann's pouch), and neck [2][6].
- Fundus: The blind, rounded end that projects beyond the inferior border of the liver. It contacts the anterior abdominal wall at the tip of the 9th costal cartilage where the right lateral margin of the rectus abdominis crosses the costal margin — this is the Murphy's point, where you palpate for Murphy's sign.
- Body: The main portion, lies in a fossa on the visceral surface of the liver (segments IV and V).
- Infundibulum (Hartmann's pouch): A saccular outpouching at the junction of the body and neck. This is the most common site for stone impaction — stones collect here by gravity and get jammed into the narrow transition to the cystic duct. This is also where stones impact in Mirizzi syndrome, compressing the adjacent common hepatic duct [6].
- Neck: Tapered, S-shaped portion that leads into the cystic duct. Contains mucosal folds (spiral valves of Heister) which do not have a true sphincter function but can trap small stones.
- The cystic duct (typically 2–4 cm long) connects the gallbladder neck to the common hepatic duct, forming the common bile duct (CBD).
- Calot's triangle (hepatocystic triangle): Bounded by the cystic duct inferiorly, the common hepatic duct medially, and the inferior surface of the liver superiorly. The cystic artery (usually a branch of the right hepatic artery) runs through this triangle.
- Calot's triangle is the critical zone of dissection during cholecystectomy — inflammation in acute cholecystitis causes oedema and adhesions here, making surgery hazardous.
- Cystic artery: Usually a branch of the right hepatic artery (in ~75% of individuals). It is an end-artery — there is no collateral supply to the gallbladder.
- Why does this matter? In acute cholecystitis, the distended, inflamed gallbladder wall compresses its own blood supply. An end-artery with no collaterals → ischaemia → gangrenous cholecystitis (occurs in ~20% of cases) [3].
- Venous drainage is via small cystic veins directly into the liver (segments IV and V) and partly via the cystic vein into the portal vein.
- Lymphatic drainage flows to the cystic duct lymph node (Lund's node / node of Calot) → hepatic nodes → coeliac nodes.
- Sympathetic: from the coeliac plexus (T7–T9).
- Parasympathetic: from the vagus nerve.
- Visceral afferents travel with sympathetic fibres to T7–T9 dermatomes — this explains why:
- Biliary colic/cholecystitis pain is felt in the epigastrium/RUQ (T7–T9 dermatomes)
- Pain can radiate to the right shoulder tip/interscapular area via the phrenic nerve (C3–C5), because the diaphragmatic peritoneum overlying the gallbladder fossa shares the same nerve supply (referred pain / Boas sign)
- Storage and concentration of bile: Between meals, the sphincter of Oddi is tonically contracted, diverting bile into the gallbladder. The gallbladder concentrates bile 5–10× by absorbing water and electrolytes.
- Contraction and bile release: After a fatty meal, cholecystokinin (CCK) is released from I-cells of the duodenal mucosa → CCK causes gallbladder smooth muscle contraction + relaxation of sphincter of Oddi → bile ejected into the duodenum.
- Why fatty meals trigger biliary colic: CCK-mediated contraction forces a stone against the cystic duct orifice or Hartmann's pouch → obstruction → increased intraluminal pressure → pain.
5. Aetiology
The most common cause — obstruction of the cystic duct by an impacted gallstone [1][2][3].
The stone typically impacts at Hartmann's pouch or the cystic duct itself. The type of stone matters for understanding the underlying disease but the pathophysiology of obstruction is the same regardless of stone type.
Types of gallstones (Hong Kong relevance):
| Stone Type | Composition | Appearance | Radiology | Prevalence | HK-Relevant Causes |
|---|---|---|---|---|---|
| Cholesterol stones | > 50% cholesterol | Yellow-green, often solitary, large | Radiolucent (only ~15% radio-opaque on AXR) | ~85% in Western populations; slightly less in HK | Obesity, OCP, metabolic syndrome, rapid weight loss |
| Black pigment stones | Calcium bilirubinate polymers, < 30% cholesterol | Black, small, multiple, hard | Radio-opaque | More common in HK/Asia | Haemolysis (G6PD, thalassaemia), chronic liver disease |
| Brown pigment stones | Calcium bilirubinate + bacterial cell bodies, < 30% cholesterol | Brown, soft, earthy | Radio-opaque | Common in HK/Asia | Bacterial infection — β-glucuronidase (from E. coli/Klebsiella) deconjugates bilirubin; RPC (Clonorchis sinensis, Ascaris lumbricoides) |
| Mixed stones | Mixture of cholesterol + pigment | Variable | Variable | Most common overall | Variable |
Most gallstones are mixed stones [4].
Not associated with gallstones. Caused by microvascular occlusion within the gallbladder wall leading to ischaemia and secondary infection [3].
Risk factors: hospitalised/critically ill patients — dehydration, shock, TPN, burns, sepsis, major surgery, prolonged illness with multi-organ dysfunction [2][3].
- Tumour obstructing the cystic duct ( < 1%) [2]
- Biliary sludge (micro-lithiasis / biliary "mud"): precipitated calcium bilirubinate granules and cholesterol microcrystals in thick mucus; functionally behaves like small stones
- Parasitic (Ascaris blocking cystic duct — very rare)
6. Pathophysiology
This is the most important section for understanding everything else. Let's walk through the cascade step by step.
Step 1 — Obstruction: A gallstone impacts at Hartmann's pouch or the cystic duct → complete obstruction → no bile can enter or leave the gallbladder [2][3].
Step 2 — Distension: The gallbladder mucosa continues to secrete mucus but nothing can drain → progressive distension → raised intraluminal pressure [2].
Step 3 — Chemical inflammation (first 48 hours): Stagnant bile becomes concentrated. Lysolecithin, a normal bile constituent, reaches toxic concentrations and acts as a mucosal toxin, initiating chemical inflammation [2][3]. Phospholipase A converts lecithin (phosphatidylcholine) in bile to lysolecithin. Inflammatory mediators, particularly prostaglandins, are released, propagating the inflammatory response [2].
This is why NSAIDs (prostaglandin synthesis inhibitors) are first-line analgesics in biliary colic and cholecystitis — they directly target this pathophysiological mechanism.
Step 4 — Wall oedema and vascular compromise: The inflammatory oedema thickens the gallbladder wall. The distended gallbladder compresses its own blood supply (remember, the cystic artery is an end-artery). This creates a vicious cycle: ischaemia → more inflammation → more oedema → more ischaemia.
Step 5 — Secondary bacterial infection (15–30% of cases): Bacteria contaminate the biliary system secondarily — they do not initiate the process [2]. Common organisms include:
- Gram-negative rods: Escherichia coli (most common), Klebsiella pneumoniae, Enterobacter spp.
- Gram-positive: Enterococcus spp. [2]
- Anaerobes: Bacteroides fragilis (especially in severe/gangrenous cases)
These are enteric organisms — they reach the gallbladder via ascending infection from the duodenum through the cystic duct, or via haematogenous/lymphatic spread.
Step 6 — Complications if untreated:
- Empyema: Bacterial superinfection → pus fills the gallbladder
- Gangrenous cholecystitis (~20%): Ischaemic necrosis of the gallbladder wall [3]
- Perforation: Necrotic wall ruptures → localised (walled off by omentum) or free → biliary peritonitis
- Emphysematous cholecystitis: Infection by gas-forming organisms (e.g., Clostridium welchii/perfringens) → gas in the gallbladder wall
When the cystic duct is obstructed for a prolonged period without significant infection:
- All bilirubin within the gallbladder is absorbed by the mucosa
- The gallbladder fills with colourless mucoid fluid ("white bile")
- This is a mucocele (hydrops) — a distended gallbladder full of sterile mucus [2]
Microvascular occlusion within the gallbladder → ischaemia → inflammation → secondary infection [3].
The mechanism is fundamentally different from calculous cholecystitis:
- No stone → no mechanical obstruction
- Instead, systemic hypoperfusion (shock, sepsis) + bile stasis (TPN, fasting, opioids reducing GB motility) → gallbladder wall ischaemia
- The ischaemic mucosa is more susceptible to bacterial invasion
- Progresses to gangrene and perforation faster than calculous cholecystitis
7. Classification
| Type | Proportion | Mechanism |
|---|---|---|
| Calculous cholecystitis | 90–95% | Gallstone impaction in cystic duct / Hartmann's pouch |
| Acalculous cholecystitis | 5–10% | Microvascular occlusion / ischaemia in critically ill patients |
| Tumour-related | < 1% | Neoplasm obstructing cystic duct |
The Tokyo Guidelines classify acute cholecystitis by severity, which directly guides management [2]:
| Grade | Severity | Criteria | Management Implication |
|---|---|---|---|
| Grade I (Mild) | No organ dysfunction, mild inflammatory changes in the gallbladder | Acute cholecystitis in an otherwise healthy patient with no organ dysfunction | Early laparoscopic cholecystectomy |
| Grade II (Moderate) | Presence of any one of: WBC > 18,000/μL, palpable tender RUQ mass, symptom duration > 72 hours, marked local inflammation (gangrenous cholecystitis, pericholecystic abscess, hepatic abscess, biliary peritonitis, emphysematous cholecystitis) | Difficult cholecystectomy expected; may need delayed surgery or drainage | Early or delayed LC depending on local expertise; consider drainage if high-risk |
| Grade III (Severe) | Organ/system dysfunction: cardiovascular (hypotension requiring vasopressors), neurological (decreased consciousness), respiratory (PaO₂/FiO₂ < 300), renal (oliguria, Cr > 2.0 mg/dL), hepatic (PT-INR > 1.5), haematological (platelets < 100,000/μL) | Urgent organ support + gallbladder drainage (percutaneous cholecystostomy); cholecystectomy after stabilisation | Percutaneous cholecystostomy or emergent cholecystectomy |
Tokyo Guidelines — Exam Relevance
You don't need to memorise every number, but know the principle: Grade I = early cholecystectomy; Grade II = consider local expertise for early vs delayed; Grade III = stabilise + drain first, operate later. The grading is based on presence of organ dysfunction and local inflammation severity.
| Acute Cholecystitis | Chronic Cholecystitis | |
|---|---|---|
| Onset | Sudden | Insidious / recurrent |
| Pathology | Acute inflammation, oedema, possible necrosis | Chronic inflammatory infiltrate, fibrosis, mucosal atrophy, wall thickening |
| Association | Cystic duct obstruction by stone | Repeated acute episodes or chronic irritation by stones |
| Clinical | Fever, Murphy's sign, prolonged pain | Recurrent biliary colic, vague RUQ discomfort |
| Complications | Empyema, gangrene, perforation | Porcelain gallbladder, gallbladder carcinoma |
8. Clinical Features
| Symptom | Description | Pathophysiological Basis |
|---|---|---|
| RUQ / epigastric pain | Sudden onset, steady (not truly colicky — the gallbladder has no peristalsis), severe, persists > 6 hours (unlike biliary colic which resolves < 6 hours) [1][2] | Initially visceral pain (poorly localised, epigastric) from gallbladder distension stimulating visceral afferents (T7–T9). As inflammation extends to the parietal peritoneum overlying the gallbladder → pain localises to the RUQ (somatic, well-localised) |
| Radiation to right shoulder / interscapular area (Boas sign) | Pain may radiate to the right scapular tip or right shoulder [2] | Referred pain — the diaphragmatic peritoneum overlying the gallbladder fossa is innervated by the phrenic nerve (C3–C5), which shares dermatomes with the shoulder. Inflammation irritating this peritoneum → brain misinterprets pain as originating from the shoulder |
| Exacerbated by movement | Patient lies still, reluctant to move [2] | Peritoneal irritation — any movement stretches the inflamed parietal peritoneum, worsening pain |
| Fever | Low-grade initially (37.5–38.5°C); high-grade (> 39°C) suggests complications (empyema, gangrene, perforation) [1] | Inflammatory cytokines (IL-1, IL-6, TNF-α) from the inflamed gallbladder → hypothalamic thermoregulatory set-point ↑ |
| Nausea and vomiting | Very common [1][2] | Visceral afferents from the inflamed gallbladder stimulate the vomiting centre in the medulla (vagal pathway); also ileus from peritoneal inflammation |
| Anorexia | Loss of appetite [2] | Systemic inflammatory response + visceral discomfort → appetite suppression |
| History of biliary colic | Many patients have prior episodes of postprandial RUQ pain that resolved spontaneously | Previous transient cystic duct obstruction events; the current episode is one where the stone did not dislodge |
| Fatty food intolerance | May report that pain was precipitated by a fatty meal | CCK release from duodenal I-cells after fat ingestion → gallbladder contraction against an obstructed cystic duct |
| No tea-coloured urine (usually) | Absence of dark urine / jaundice in uncomplicated cases [1] | The obstruction is at the cystic duct — bile can still flow from the liver through the CBD into the duodenum. Bilirubin metabolism is unaffected. If jaundice IS present, think of: (1) Mirizzi syndrome, (2) concurrent choledocholithiasis (double impaction ~7%), or (3) severe inflammation causing oedema compressing the CBD (rare) |
Pain > 6 Hours = Think Cholecystitis
The single most important clinical clue distinguishing biliary colic from acute cholecystitis is duration of pain. Biliary colic resolves in < 6 hours as the gallbladder relaxes and the stone falls back. If pain persists beyond 6 hours, suspect acute cholecystitis — the stone is impacted and inflammation has begun [2][4].
| Sign | Description | Pathophysiological Basis |
|---|---|---|
| Murphy's sign (positive) | Inspiratory arrest during deep palpation of the RUQ [1]. The examiner places fingers under the right costal margin at the midclavicular line and asks the patient to take a deep breath. The descending diaphragm pushes the inflamed gallbladder onto the examiner's fingers → sharp pain → patient catches their breath (inspiratory arrest). Negative in acute cholangitis (the gallbladder is not the site of inflammation in cholangitis — the bile duct is). | The inflamed gallbladder fundus contacts the parietal peritoneum of the anterior abdominal wall at the tip of the 9th costal cartilage. On inspiration, the diaphragm descends → liver moves inferiorly → the inflamed gallbladder is pressed against the palpating hand → sudden exacerbation of peritoneal pain → reflex arrest of inspiration |
| RUQ tenderness [1] | Localised tenderness on palpation of the RUQ | Parietal peritoneal inflammation overlying the gallbladder |
| Guarding [1] | Voluntary or involuntary contraction of abdominal wall muscles over the RUQ | Reflex protective spasm of the rectus abdominis to splint the inflamed area and prevent further peritoneal stretch |
| Rebound tenderness [1] | Pain on sudden release of pressure over the RUQ | Rapid decompression of the anterior abdominal wall causes sudden movement of the inflamed parietal peritoneum |
| Low-grade fever (37.5–38.5°C) | Temperature 37.5°C in the case vignette [1] | Systemic inflammatory response. Higher fevers ( > 39°C) + rigors suggest complicated disease (empyema, perforation) or concomitant cholangitis |
| Tachycardia | Heart rate > 100 bpm in more severe cases | Sympathetic activation secondary to pain and systemic inflammatory response |
| No jaundice (typically) [1] | Sclera and skin are not yellow in uncomplicated cases | The obstruction is in the cystic duct, NOT the CBD. Bilirubin can still drain through the common hepatic duct → CBD → duodenum |
| Palpable gallbladder (occasionally) | A tender RUQ mass may be palpable in some cases | Distended, inflamed gallbladder (especially if empyema or mucocele develops) |
| Sonographic Murphy's sign | Pain elicited when the ultrasound probe is pressed over the gallbladder | Same principle as clinical Murphy's sign, but more accurate because the probe is directly over the gallbladder (the examiner can see exactly where they are pressing) |
Why Murphy's Sign is Negative in Cholangitis
In acute cholangitis, the problem is in the CBD (common bile duct), not the gallbladder. The gallbladder may not be inflamed at all. Pressing on the gallbladder area doesn't reproduce the pain of cholangitis. If Murphy's sign is positive, think cholecystitis. If negative with Charcot's triad (fever, RUQ pain, jaundice), think cholangitis.
This is a very high-yield comparison for exams [2][4]:
| Feature | Biliary Colic | Acute Cholecystitis |
|---|---|---|
| Mechanism | Transient obstruction at Hartmann's pouch / cystic duct | Persistent obstruction → inflammation |
| Duration | < 6 hours (typically 30 min to 4–5 hours) | > 6 hours, often days |
| Character | Steady (despite the name "colic", it is NOT truly colicky — no peristalsis in GB) | Steady, more severe |
| Fever | Absent (afebrile) | Present |
| Peritoneal signs | Absent (purely visceral pain, no true inflammation) | Present (Murphy's sign, guarding, rebound) |
| Lab | Normal WBC, normal CRP | ↑ WBC, ↑ CRP |
| Natural history | Self-resolves when stone dislodges, gallbladder relaxes | Does NOT self-resolve; persists and may progress to complications |
Certain clinical findings should alert you to complicated cholecystitis:
| Complication | Clinical Clues | Pathophysiology |
|---|---|---|
| Gallbladder empyema | Tender RUQ mass + septic-looking (high fever, rigors, diaphoresis) [3] | Pus fills the obstructed gallbladder → essentially an abscess |
| Gangrenous cholecystitis (~20%) [3] | High fever, signs of sepsis, often elderly or diabetic. May paradoxically have less localised pain (destroyed sensory nerves in necrotic wall) | Ischaemic necrosis of gallbladder wall from distension compressing the end-artery (cystic artery) |
| Perforation | Sudden worsening of pain → diffuse peritonitis OR localised abscess (often walled off by omentum) [3] | Necrotic wall ruptures. Free perforation → biliary peritonitis; contained → pericholecystic abscess |
| Emphysematous cholecystitis | Insidious onset, abdominal crepitus on palpation [3]. More common in diabetics and elderly males | Gas-forming organisms (Clostridium welchii/perfringens) infect the ischaemic GB wall → gas within the wall and lumen |
| Cholecystoenteric fistula / Gallstone ileus | Signs of small bowel obstruction (colicky abdominal pain, vomiting, distension, absolute constipation) [3] | Chronic inflammation → gallbladder adheres to adjacent duodenum/colon → stone erodes through → enters bowel → impacts at ileocaecal valve (narrowest point) |
Complications of gallstone disease [1]:
- Mucocele of gallbladder
- Empyema of gallbladder
- Rupture of gallbladder
- Acute cholangitis
- Acute pancreatitis
- Cholecystoduodenal fistula
- Liver abscess
This is an essential "bird's-eye view" table [4]:
| Biliary Colic | Acute Cholecystitis | Choledocholithiasis | Acute Cholangitis | |
|---|---|---|---|---|
| Mechanism | Stone transiently obstructs cystic duct/Hartmann's pouch | Persistent cystic duct obstruction → inflammation | Stone migrates into CBD → obstructive jaundice | CBD obstruction + bacterial infection of biliary tree |
| Pain | RUQ < 6h | RUQ > 6h | RUQ ± | RUQ (part of Charcot's triad) |
| Fever | No | Yes | No (unless concurrent infection) | Yes |
| Jaundice | No | No (usually) | Yes (cholestatic LFT) | Yes |
| Key sign | — | Murphy's sign +ve | — | Charcot's triad; Reynold's pentad |
| Labs | Normal | ↑ WBC, ↑ CRP | Cholestatic LFT (↑ ALP, ↑ GGT, ↑ Bilirubin) | ↑ WBC, ↑ CRP + cholestatic LFT |
| Key imaging | USG: stone + posterior shadow | USG: 5 cardinal signs | USG: dilated CBD + stone | USG: dilated CBD + stone |
| Management | Analgesics → elective LC | Resuscitation, IV antibiotics → LC | Biliary decompression (ERCP) → LC | Resuscitation, IV Abx, biliary decompression → LC |
High Yield Summary
Definition: Acute inflammation of the gallbladder, most commonly due to cystic duct obstruction by an impacted gallstone (90–95% calculous).
Key Epidemiology: Follows gallstone demographics — 5F (Fat, Female, Forty, Fertile, Family). HK-relevant: pigment stones from haemolysis (G6PD, thalassaemia) and RPC (Clonorchis sinensis).
Pathophysiology cascade: Stone impacts → cystic duct obstruction → GB distension → bile stasis → chemical inflammation (lysolecithin, prostaglandins) in first 48h → secondary bacterial infection (E. coli, Klebsiella, Enterococcus) in 15–30% → empyema/gangrene/perforation if untreated.
Acalculous cholecystitis (5–10%): Critically ill patients; mechanism is microvascular ischaemia, NOT stone obstruction; higher mortality.
Key clinical distinction from biliary colic: Pain > 6 hours, fever, peritoneal signs (Murphy's sign), leukocytosis. Biliary colic: < 6h, no fever, no peritoneal signs.
Murphy's sign: Inspiratory arrest during RUQ palpation — inflamed GB is pushed onto examiner's hand by descending diaphragm. Negative in cholangitis.
Usually NO jaundice in uncomplicated cholecystitis (obstruction is at the cystic duct, not the CBD). If jaundice is present → think Mirizzi syndrome, double impaction, or concurrent choledocholithiasis.
Complications: Mucocele, empyema, gangrenous cholecystitis (20%), perforation, emphysematous cholecystitis, cholecystoenteric fistula/gallstone ileus, liver abscess.
USG 5 cardinal signs: (1) Gallstones, (2) Distended GB ( > 4 × 10 cm), (3) Wall thickening > 3 mm, (4) Pericholecystic fluid, (5) Sonographic Murphy's sign.
Tokyo Guidelines severity grading: Grade I (mild) → early LC; Grade II (moderate) → early/delayed LC; Grade III (severe) → stabilise + drain first.
Active Recall - Acute Cholecystitis
[1] Lecture slides: GC 200. RUQ pain, jaundice and fever Cholecytitis and cholangitis Imaging of GI system.pdf (p3–5) [2] Senior notes: felixlai.md (Cholecystitis sections, pp. 553–555; Gallstones overview, p. 508) [3] Senior notes: maxim.md (Acute calculous cholecystitis, Acute acalculous cholecystitis, pp. 130–136) [4] Senior notes: maxim.md (Gallstone diseases overview, stone composition table, symptomatic gallstones summary, pp. 130–131) [5] Senior notes: maxim.md (Recurrent pyogenic cholangitis, p. 136) [6] Senior notes: felixlai.md (Mirizzi syndrome — Gallbladder anatomy, pp. 572–573)
Differential Diagnosis of Acute Cholecystitis
When a patient presents with RUQ pain, fever, and signs of peritoneal irritation, acute cholecystitis is high on the list — but it is far from the only diagnosis. The differential is broad because the RUQ is a "busy neighbourhood": the gallbladder, liver, hepatic flexure of the colon, right kidney, right adrenal, duodenum, head of pancreas, right lower lung, and right hemidiaphragm all live here. Referred pain from distant structures (heart, right lung) can also localise to the RUQ.
The key to a logical differential is to think anatomically and then refine based on clinical features, lab findings, and imaging.
Detailed Differential Diagnosis
This is the single most critical distinction on exams and in clinical practice [2][3][4].
Biliary colic is caused by transient obstruction of Hartmann's pouch or the cystic duct by a gallstone — the gallbladder contracts (often in response to a fatty meal via CCK), presses a stone against the outlet, intraluminal pressure rises, and visceral pain occurs. Crucially, there is no true gallbladder wall inflammation [2][3].
| Feature | Biliary Colic | Acute Cholecystitis |
|---|---|---|
| Obstruction | Transient — stone dislodges when GB relaxes | Persistent — stone remains impacted |
| Duration | Onset ≥ 30 min, plateaus within 1 hour, resolves completely < 6 hours | Persists > 6 hours, often days [2] |
| Severity | Moderate to severe | Usually more severe than uncomplicated biliary colic [2] |
| Character | Steady (NOT truly colicky — there is no peristalsis in the GB/cystic duct) [3] | Steady, constant |
| Peritoneal signs | Absent — pain is entirely visceral, no true wall inflammation [2] | Present — Murphy's sign, guarding, rebound (parietal peritoneum involved) [2] |
| Fever | Afebrile with normal labs [2] | Febrile with leukocytosis and ↑ CRP |
| Associated symptoms | Nausea/vomiting possible, but patient looks well between attacks | Anorexia, nausea, vomiting, malaise — patient looks unwell [2] |
| Natural history | Self-resolves when GB relaxes and stone falls back | Does NOT resolve spontaneously; progresses if untreated |
Why is biliary colic "steady" and not truly colicky? The gallbladder is a muscular sac with tonic contraction — it does not have the rhythmic peristalsis of the intestine (which gives the classical crescendo-decrescendo "colicky" pattern). The name "biliary colic" is actually a misnomer [3].
The 6-Hour Rule
Suspect acute cholecystitis if pain persists > 6 hours [3]. This is the single most reliable bedside clue that the pathology has moved beyond simple biliary colic to established inflammation. If pain resolves within 6 hours, it was likely biliary colic.
Charcot's triad (50–70%): Fever + RUQ pain + Jaundice [6][7] Reynold's pentad ( < 10%): Charcot's triad + Hypotension + Altered mental status [6][7]
This is a bacterial infection of the biliary tree secondary to CBD obstruction — fundamentally different from cholecystitis, where the problem is at the cystic duct/gallbladder [6][7].
How to differentiate from cholecystitis:
- Jaundice: Present in cholangitis (CBD obstruction prevents bilirubin from reaching the duodenum → conjugated hyperbilirubinaemia); usually absent in uncomplicated cholecystitis (the cystic duct obstruction does not block the CBD) [1][2]
- Tea-coloured urine: Present in cholangitis (conjugated bilirubin is water-soluble → filtered by kidneys); absent in cholecystitis ("No tea-colored urine" as per the lecture case vignette) [1]
- Murphy's sign: Positive in cholecystitis; typically negative in cholangitis (the gallbladder itself is not the inflamed organ)
- Cholestatic LFT pattern: Prominent in cholangitis (↑↑ ALP, ↑↑ GGT, ↑ conjugated bilirubin); may be mildly elevated or normal in cholecystitis [2][6]
- Blood culture is essential in cholangitis (bacteraemia is common) [7]
Why does cholangitis cause altered mental status? CBD obstruction + bacterial infection → cholangio-venous reflux (infected bile under pressure refluxes into the bloodstream through the hepatic sinusoids) → Gram-negative bacteraemia/sepsis → septic shock → encephalopathy. This is the pathophysiology behind Reynold's pentad.
A gallstone that has migrated from the gallbladder through the cystic duct into the common bile duct [4]. This causes obstructive jaundice without necessarily causing infection (that distinction is what separates choledocholithiasis from cholangitis).
How to differentiate from cholecystitis:
- Jaundice is the hallmark — cholestatic LFT pattern (↑ ALP, ↑ GGT, ↑ conjugated bilirubin)
- Pain may be present but fever is typically absent (unless cholangitis develops)
- USG shows dilated CBD with gallstone rather than the 5 cardinal signs of cholecystitis [4]
- Can coexist with cholecystitis ("double impaction" — stone simultaneously in cystic duct AND distal CBD, ~7%) [4]
Epigastric pain that radiates to the back, often severe, constant, improved by sitting up or leaning forward, exacerbated by movement [8][9]. Gallstones are the most common cause of acute pancreatitis (a stone impacts at the ampulla of Vater, obstructing the pancreatic duct → duodeno-pancreatic reflux → premature trypsinogen activation → autodigestion) [8][9].
How to differentiate from cholecystitis:
- Location: Epigastric > RUQ (although overlap exists, especially with gallstone pancreatitis)
- Radiation: To the back (retropancreatic inflammation of the retroperitoneal structures) vs. right shoulder in cholecystitis
- Relief posture: Sitting up/leaning forward relieves pancreatitis pain (takes the pancreas away from the retroperitoneum); movement worsens cholecystitis pain
- Amylase/Lipase: Markedly elevated ( > 3× upper limit of normal) in pancreatitis; may be mildly elevated in cholecystitis but not to the same degree [8]
- Cullen's sign (periumbilical bruising) and Grey Turner's sign (flank bruising) — pathognomonic for severe necrotising pancreatitis (retroperitoneal haemorrhage tracking along tissue planes) — NOT seen in cholecystitis [9]
- Tetany from transient hypocalcaemia — fat saponification (liberated fatty acids bind calcium) — unique to pancreatitis [9]
Gallstone Pancreatitis and Cholecystitis Can Coexist
Since both are complications of gallstone disease, a patient can present with features of both acute cholecystitis AND acute pancreatitis simultaneously. Always check amylase/lipase in a patient with suspected cholecystitis, and always look at the gallbladder on imaging in a patient with pancreatitis [8].
- Uncomplicated PUD: Epigastric pain related to meals (duodenal ulcer: pain relieved by eating; gastric ulcer: pain worsened by eating). No fever, no peritoneal signs. Can be distinguished by history and endoscopy.
- Perforated peptic ulcer: Sudden-onset, severe epigastric pain → becomes generalised → board-like rigidity → peritonitis. Air under the diaphragm on erect CXR (pneumoperitoneum). Usually no fever initially (chemical peritonitis from gastric acid, not infection).
- Valentino's sign: Gastric/duodenal contents tracking down the right paracolic gutter → pain localises to the RLQ, mimicking acute appendicitis [10]
- Distinguished from cholecystitis by the abrupt onset ("thunderclap"), absence of preceding biliary symptoms, and pneumoperitoneum on imaging
Classically begins as periumbilical pain (visceral, poorly localised via T10 dermatome) then migrates to the RLQ (McBurney's point) as parietal peritoneal inflammation develops [10].
How to differentiate from cholecystitis:
- Location: RLQ (McBurney's point) vs. RUQ
- Migration pattern: Periumbilical → RLQ (appendicitis) vs. epigastric → RUQ (cholecystitis)
- Murphy's sign: Positive in cholecystitis, NOT in appendicitis
- Appendicitis-specific signs [10]: Pointing sign (McBurney's point), Rovsing's sign (RLQ pain on LLQ palpation), Psoas sign (retrocaecal appendix), Obturator sign (pelvic appendix)
- Age: Appendicitis peaks in 10–30 years; cholecystitis peaks in 40–60 years
However, beware:
- A high-riding/retrocaecal appendix can present with RUQ pain mimicking cholecystitis
- Right-sided diverticulitis (more common in Asian populations) can mimic either [10]
Inflammation of the liver parenchyma from viral (HAV, HBV, HCV, HEV), alcoholic, drug-induced, or autoimmune causes [2].
How to differentiate from cholecystitis:
- Hepatocellular LFT pattern: Markedly ↑ AST and ALT (often > 10× ULN) with only mild ↑ ALP — this is the opposite of the cholestatic pattern seen in biliary obstruction
- Jaundice: Often present (hepatocyte dysfunction → impaired bilirubin conjugation/excretion)
- Tender hepatomegaly: Diffuse liver tenderness rather than focal RUQ/gallbladder point tenderness
- No Murphy's sign: The gallbladder is not inflamed
- Viral serology (HBsAg, anti-HAV IgM, etc.) clinches the diagnosis
- Pyogenic liver abscess: Fever, RUQ pain, tender hepatomegaly, swinging fevers, rigors. Often secondary to biliary tract disease (ascending cholangitis) or portal pyaemia (from appendicitis, diverticulitis). Blood cultures often positive.
- Amoebic liver abscess: Travel history (endemic areas), diarrhoea, RUQ pain, tender hepatomegaly. Amoebic serology positive.
How to differentiate from cholecystitis:
- Hepatomegaly more prominent than gallbladder tenderness
- Murphy's sign negative (the gallbladder is not the source)
- USG/CT: Well-defined hepatic collection (abscess cavity) rather than the 5 cardinal signs of cholecystitis
- Liver abscess is listed as a complication of gallstone disease in the lecture slides — so the two can coexist [1]
This is a classic "trap" in exams. Basal pneumonia or pleurisy on the right side can cause referred RUQ pain via irritation of the diaphragmatic pleura (phrenic nerve, C3–C5 — same dermatomes as the shoulder/RUQ).
How to differentiate from cholecystitis:
- Respiratory symptoms: Cough (productive/dry), dyspnoea, pleuritic chest pain (sharp, worse on inspiration — different quality from the steady visceral pain of cholecystitis)
- Chest examination: Bronchial breathing, crepitations, dullness to percussion, decreased air entry over the right base
- CXR: Consolidation or pleural effusion in the right lower lobe
- Abdominal examination: May have RUQ tenderness but Murphy's sign is negative and there are no gallbladder-specific USG findings
An inferior MI (right coronary artery territory) can present with epigastric pain that mimics biliary or pancreatic pathology [2][8]. The inferior surface of the heart sits on the diaphragm; ischaemic pain from the inferior myocardium can be referred to the epigastrium via vagal afferents.
How to differentiate from cholecystitis:
- Cardiovascular risk factors: Hypertension, diabetes, smoking, hyperlipidaemia, family history of IHD
- Associated features: Diaphoresis, breathlessness, radiation to jaw/left arm, haemodynamic instability
- ECG: ST elevation in leads II, III, aVF (inferior MI)
- Troponin: Elevated
- Murphy's sign negative, normal abdominal USG
Always Do an ECG in Acute Upper Abdominal Pain
This is a commonly tested point. An inferior MI can perfectly mimic an acute abdomen. Every patient presenting with acute epigastric or RUQ pain should have an ECG — missing an MI is a life-threatening error. The mnemonic is simple: if the pain is above the umbilicus, think of the heart.
- Pain typically lasts < 6 hours and occurs intermittently [5]
- Normal laboratory and radiological tests [5]
- Diagnosis of exclusion after structural causes are ruled out
- Sphincter of Oddi dysfunction: biliary-type pain caused by functional obstruction at the sphincter of Oddi (spasm or stenosis), without stones
RUQ-specific [11]:
- Subphrenic abscess: Post-operative, fever, referred shoulder tip pain
- Fitz-Hugh-Curtis syndrome: Perihepatitis secondary to PID (Chlamydia trachomatis or Neisseria gonorrhoeae) — RUQ pain in a young sexually active female with vaginal discharge. Laparoscopy shows "violin-string" adhesions between liver capsule and anterior abdominal wall
Urological:
- Right renal/ureteric colic: Colicky flank pain radiating to the groin (loin-to-groin), haematuria, restless patient (in contrast to cholecystitis patients who lie still)
- Right pyelonephritis: Fever + loin pain + dysuria/frequency; costovertebral angle tenderness; pyuria on urinalysis
Gynaecological (in females of reproductive age):
- Ruptured ovarian cyst, ovarian torsion, ectopic pregnancy, PID — always ask about LMP, sexual history, vaginal discharge
- β-hCG is mandatory in any woman of reproductive age with acute abdominal pain
| Differential | Key Distinguishing Feature(s) | Key Investigation to Differentiate |
|---|---|---|
| Biliary colic | Pain < 6h, afebrile, no peritoneal signs | USG: stones but no wall thickening/pericholecystic fluid |
| Acute cholangitis | Charcot's triad (fever + jaundice + RUQ pain), Murphy negative | Blood cultures, cholestatic LFT, USG: dilated CBD |
| Choledocholithiasis | Jaundice, cholestatic LFT, no fever | USG/MRCP: dilated CBD + stone |
| Acute pancreatitis | Epigastric, radiates to back, leaning forward relieves | Amylase/lipase > 3× ULN, CT abdomen |
| Perforated PUD | Sudden "thunderclap" onset, board-like rigidity | Erect CXR: pneumoperitoneum |
| Acute appendicitis | Periumbilical → RLQ migration, McBurney's point | CT abdomen (or USG in young/pregnant) |
| Acute hepatitis | Hepatocellular LFT (↑↑ AST/ALT), tender hepatomegaly | Viral serology |
| Liver abscess | Swinging fever, hepatomegaly, no Murphy's sign | USG/CT: hepatic collection |
| Right basal pneumonia | Cough, respiratory signs, pleuritic pain | CXR: consolidation |
| Inferior MI | Cardiac risk factors, diaphoresis, radiation to jaw/arm | ECG + Troponin |
| Renal colic | Loin-to-groin, restless, haematuria | CT KUB, urinalysis |
| Gynaecological | LMP, sexual history, vaginal discharge | β-hCG, pelvic USG |
High Yield Summary
Structured approach: Think anatomically — RUQ structures (gallbladder, liver, hepatic flexure, right kidney) + referred pain sources (right lung base, heart, right hemidiaphragm).
The single most important DDx: Biliary colic vs. acute cholecystitis — distinguished by duration ( < 6h vs. > 6h), fever, peritoneal signs (Murphy's), and leukocytosis.
Jaundice present? Think cholangitis (Charcot's triad), choledocholithiasis, Mirizzi syndrome, or hepatitis — NOT uncomplicated cholecystitis (cystic duct obstruction does not block the CBD).
Epigastric > RUQ? Think pancreatitis (radiates to back, relieved by leaning forward, ↑ amylase/lipase) or PUD/perforated PUD (pneumoperitoneum on CXR).
Always do an ECG in acute upper abdominal pain to exclude inferior MI.
Always check β-hCG in women of reproductive age to exclude ectopic pregnancy.
Hong Kong specific: Right-sided diverticulitis is more common in Asian populations and can mimic RUQ/RLQ pathology.
Active Recall - Differential Diagnosis of Acute Cholecystitis
References
[1] Lecture slides: GC 200. RUQ pain, jaundice and fever Cholecytitis and cholangitis Imaging of GI system.pdf (p3–5) [2] Senior notes: felixlai.md (Cholecystitis sections, pp. 553–556) [3] Senior notes: maxim.md (Acute calculous cholecystitis, Biliary colic, pp. 130–131) [4] Senior notes: maxim.md (Symptomatic gallstones summary table, Courvoisier's Law, p. 130) [5] Senior notes: felixlai.md (Differential diagnosis of biliary colic, pp. 510–511) [6] Senior notes: felixlai.md (Acute cholangitis, pp. 520–521) [7] Senior notes: maxim.md (Acute cholangitis, p. 135) [8] Senior notes: felixlai.md (Acute pancreatitis — clinical manifestation and DDx, pp. 579–580) [9] Senior notes: maxim.md (Acute pancreatitis, p. 138) [10] Senior notes: maxim.md (Acute appendicitis — differential diagnosis, p. 87) [11] Senior notes: maxim.md (Acute abdomen differential diagnosis by region, p. 43)
Tokyo Guidelines (TG18/TG13) — The Standard Diagnostic Framework
The Tokyo Guidelines provide a structured, internationally accepted framework for diagnosing acute cholecystitis. The principle is straightforward: you need local inflammation + systemic inflammation + imaging confirmation [2][3][4].
Think of it as a three-legged stool — each leg strengthens the diagnosis:
| Component | Criteria | What it Represents |
|---|---|---|
| A: Local signs of inflammation | Murphy's sign | Direct evidence of gallbladder/parietal peritoneal inflammation |
| RUQ mass / pain / tenderness | ||
| B: Systemic signs of inflammation | Fever | The body's systemic inflammatory response to the local process |
| Leukocytosis | ||
| Elevated CRP level | ||
| C: Imaging findings | Imaging findings characteristic of acute cholecystitis (USG or hepatobiliary scintigraphy) | Objective confirmation that the gallbladder is the source |
Interpretation [2]:
- Suspected diagnosis = One item in A + One item in B (clinical diagnosis without imaging)
- Definite diagnosis = One item in A + One item in B + One item in C (clinically confirmed by imaging)
Why Three Components?
Any single component alone is insufficient. Local signs (A) can occur with many RUQ pathologies. Systemic signs (B) occur with any infection/inflammation. Imaging findings (C) such as wall thickening occur in non-acute conditions (e.g., chronic cholecystitis, hypoalbuminaemia, heart failure, hepatitis). You need the convergence of all three to make a definite diagnosis. The "suspected" category exists because imaging may not always be immediately available — in the right clinical context, A + B is enough to initiate treatment while awaiting imaging [2].
Exam Tip: Definite vs Suspected
A very common exam mistake is to say "USG confirms the diagnosis." USG alone does NOT confirm acute cholecystitis — wall thickening and pericholecystic fluid have other causes. You need the clinical picture (A + B) PLUS imaging (C) for a definite diagnosis. Conversely, if the clinical picture is classic (A + B) but USG is equivocal, you can still have a suspected diagnosis and proceed with treatment [2][3].
The following algorithm represents the practical clinical approach when you suspect acute cholecystitis. It integrates history, examination, lab work, and imaging in a logical sequence.
Investigation Modalities
When you suspect acute cholecystitis, you need investigations for three purposes:
- Confirm the diagnosis (USG ± HIDA/MRCP)
- Assess severity and rule out complications (bloods, CT)
- Exclude differentials and identify coexisting biliary pathology (LFT, amylase, ECG, CXR)
Investigations to order [3][4]:
- Bloods: CBC D/C, LRFT, amylase, clotting, blood C/ST, X-match, lipid profile [3]
- USG abdomen (1st-line imaging) [3]
- CT abdomen + pelvis (to rule out complications) [3]
- HIDA scan or MRCP (if USG inconclusive) [3][4]
A. Laboratory Investigations
| Finding | Interpretation | Pathophysiological Basis |
|---|---|---|
| Leukocytosis (WBC > 10,000/μL) | Systemic inflammatory response; part of Tokyo criteria component B | Inflammatory cytokines from the inflamed gallbladder stimulate the bone marrow to release neutrophils |
| ↑ Band forms (left shift) | Active, ongoing acute bacterial infection — bone marrow is releasing immature neutrophils to meet demand | The marrow cannot mature neutrophils fast enough during acute infection → immature "band" forms are released prematurely |
| Very high WBC ( > 18,000) | Suggestive of complicated cholecystitis — gangrenous cholecystitis, perforation, or associated cholangitis [2] | Severe infection/necrosis → massive cytokine release → vigorous marrow response |
This is a subtle but critical point:
Liver chemistry is usually NORMAL in uncomplicated acute cholecystitis [2]. Why? Because the obstruction is at the cystic duct — bile can still flow freely from the liver through the common hepatic duct → CBD → duodenum. Bilirubin conjugation, excretion, and bile acid metabolism are all intact.
| Finding | Interpretation |
|---|---|
| Normal LFT | Supports uncomplicated acute cholecystitis (obstruction limited to GB) |
| Mild elevation of bilirubin, ALP, transaminases | Can occur due to pericholecystic inflammation affecting adjacent liver parenchyma (segments IV/V); does NOT necessarily indicate CBD obstruction [2] |
| ↑↑ Bilirubin and ↑↑ ALP (cholestatic pattern) | NOT common in cholecystitis — should raise concern about complicating conditions such as cholangitis and choledocholithiasis [2], or Mirizzi syndrome [2] |
| Markedly ↑ AST/ALT ( > 10× ULN) | Think acute hepatitis rather than cholecystitis |
LFT as a Diagnostic Compass
The LFT pattern tells you WHERE the obstruction is:
- Normal LFT → cystic duct obstruction only (cholecystitis)
- Cholestatic pattern (↑ ALP, ↑ GGT, ↑ conjugated bilirubin) → CBD obstruction (choledocholithiasis/cholangitis)
- Hepatocellular pattern (↑↑ AST/ALT) → liver parenchymal disease (hepatitis)
This is a powerful bedside tool for narrowing your differential before any imaging.
| Finding | Interpretation |
|---|---|
| Normal or mildly elevated | Consistent with cholecystitis (mild elevation can occur from pericholecystic inflammation involving the adjacent pancreatic head/duodenum) |
| > 3× upper limit of normal | Suggests concurrent acute pancreatitis (gallstone pancreatitis — a stone has migrated to the ampulla of Vater) |
Always check amylase/lipase in suspected cholecystitis to exclude concurrent gallstone pancreatitis [3].
- Needed pre-operatively (cholecystectomy is the definitive treatment)
- Prolonged PT may indicate vitamin K malabsorption from bile duct obstruction (fat-soluble vitamin absorption requires bile salts for micelle formation) or underlying liver disease
- Should be taken if there is high-grade fever, rigors, or suspicion of sepsis
- Helps guide targeted antibiotic therapy if secondary bacterial infection is present
- Particularly important if cholangitis is suspected (bacteraemia is common in cholangitis)
- Cholecystectomy carries a risk of haemorrhage (especially from the cystic artery or aberrant hepatic arterial anatomy)
- Blood should be available in case of intraoperative bleeding or conversion to open surgery
- CRP: Marker of systemic inflammation; part of Tokyo criteria component B. Serial CRP is useful for monitoring treatment response.
- RFT (Renal function tests): Baseline assessment; dehydration from vomiting; pre-operative assessment; needed for severity grading (Tokyo Grade III includes renal dysfunction — Cr > 2.0 mg/dL)
- Lipid profile: Identifies risk factors for cholesterol gallstones (hyperlipidaemia) [3]
B. Imaging Investigations
USG is the first-line imaging modality for suspected acute cholecystitis [2][3][4]. It is readily available, non-invasive, no radiation, relatively quick, and can be performed at the bedside in an acutely unwell patient.
The 5 Cardinal USG Signs of Acute Cholecystitis [3]:
5 cardinal signs of acute cholecystitis — important! [3]
| Cardinal Sign | Description | Pathophysiological Basis |
|---|---|---|
| 1. Presence of gallstones | Hyperechoic focus with posterior acoustic shadowing, gravity-dependent (rolling stone sign when patient turns lateral) [4] | The stone is the cause of cystic duct obstruction. The stone is denser than bile → reflects ultrasound waves back (hyperechoic) and blocks transmission of sound beyond it (acoustic shadow). Gravity-dependent because stones are heavy and settle to the dependent part of the GB. |
| 2. Distended gallbladder ( > 4 × 10 cm) | Enlarged, tense gallbladder | Cystic duct obstruction → ongoing mucus secretion with no drainage → progressive GB distension |
| 3. GB wall thickening > 3 mm | Thickened, sometimes with double wall sign (indicating oedema) [2] | Inflammatory oedema of the gallbladder wall. The "double wall" or "halo" sign represents fluid (oedema) separating the layers of the GB wall. |
| 4. Pericholecystic fluid / stranding | Free fluid seen around the gallbladder | Inflammatory exudate weeping from the inflamed, oedematous GB wall into the surrounding peritoneal space |
| 5. Sonographic Murphy's sign | Pain elicited when the ultrasound transducer is pressed directly over the visualised gallbladder [2] | Same principle as clinical Murphy's sign, but more accurate because the examiner can see exactly where they are pressing — directly over the GB, not just "somewhere under the right costal margin" |
Sensitivity and Specificity:
- Sensitivity for gallstones: ~95%
- Sensitivity for acute cholecystitis (combined signs): ~85–90%
- Specificity: ~80% (wall thickening and pericholecystic fluid can occur in other conditions)
Limitations of USG [4]:
- Operator-dependent — accuracy varies with sonographer experience
- Limited by body habitus (excessive body fat) — sound waves attenuate in adipose tissue
- Limited by bowel gas — gas reflects ultrasound completely, obscuring structures behind it (especially distal CBD)
- Small stones ( < 3 mm) or stones in the cystic duct may be missed
- Cannot reliably visualise the distal CBD (bowel gas from the duodenum overlies it)
Why 'Sonographic Murphy' is Better than 'Clinical Murphy'
Clinical Murphy's sign depends on the examiner pressing roughly where they think the GB is — under the right costal margin at the midclavicular line. But anatomical variation means the GB isn't always exactly there. With sonographic Murphy's, you can SEE the gallbladder on the screen and press directly on it. This is why sonographic Murphy's sign has higher sensitivity (~90%) and specificity for acute cholecystitis than clinical Murphy's sign (~65%) [2].
GB Wall Thickening — Not Pathognomonic!
GB wall thickening > 3 mm is a cardinal sign of cholecystitis BUT it is NOT specific. Other causes of GB wall thickening include: hypoalbuminaemia (ascites, nephrotic syndrome), congestive heart failure, acute hepatitis, liver cirrhosis/portal hypertension, and adenomyomatosis. This is why you need all three Tokyo criteria components (A + B + C) — wall thickening alone does not equal cholecystitis.
What else to look for on USG:
- CBD diameter: Normal CBD ≤ 6 mm (add 1 mm per decade of life over age 60; rule of thumb: 0.1 cm for every 10 years old [5]). Dilated CBD suggests coexisting choledocholithiasis or distal obstruction.
- Intrahepatic duct dilatation: Suggests proximal biliary obstruction
- Liver parenchyma: Look for abscess (liver abscess is a complication of gallstone disease [1])
- Causes of dilated CBD [5]: obstruction, aging, post-cholecystectomy
"HIDA" = Hepatobiliary IminoDiacetic Acid. The full name of the tracer is 99mTc-hepatic 2,6-dimethyliminodiacetic acid [2].
Principle:
- A radiotracer (99mTc-HIDA) is injected intravenously
- It is taken up by hepatocytes (like bilirubin) and excreted into the biliary system
- A gamma camera tracks the radiotracer as it flows through the bile ducts and into the gallbladder and duodenum
- Normal: the gallbladder should be visualised within 30 minutes (tracer fills the GB via the cystic duct) and the duodenum within 60 minutes [2]
Key Finding in Acute Cholecystitis:
- Non-visualisation of the gallbladder after 4 hours = cystic duct obstruction [2][3][5]
- The tracer fills the bile ducts and duodenum normally, but cannot enter the gallbladder because the cystic duct is blocked (by the impacted stone or surrounding oedema)
- A normal HIDA scan effectively excludes acute cholecystitis [2]
Sensitivity and Specificity:
- Sensitivity: ~95–97% (highest of all modalities for acute cholecystitis)
- Specificity: ~90%
When to use:
- Indicated when diagnosis remains unclear following abdominal USG or in atypical cases [2]
- Inconclusive USG [3]
- Acalculous cholecystitis (where stones are absent but cystic duct dysfunction is suspected)
Limitations [2]:
- Expensive and long study duration (up to 4 hours) → limits use as a first-line test
- Depends on hepatic excretion of bile → may not be useful in jaundiced patients (hepatocytes cannot excrete the tracer effectively when bilirubin is very high — bilirubin > 5 mg/dL significantly impairs accuracy) [2]
- False positives: prolonged fasting ( > 24 hours), TPN, chronic cholecystitis, severe hepatic disease — all cause non-filling of the GB without acute obstruction
- Morphine augmentation can improve specificity: morphine contracts the sphincter of Oddi (↑ SoD pressure), forcing any tracer in the CBD back up into the gallbladder — if the GB still doesn't fill, obstruction is confirmed [3]
"MRCP" — magnetic resonance imaging specifically optimised for the biliary and pancreatic ductal systems.
Principle:
- Non-contrast, T2-weighted MRI sequence [5]
- Bile and pancreatic juice are bright (high signal) on T2 because they are fluid — this gives a beautiful "cholangiogram-like" image of the biliary tree without any contrast injection or invasive instrumentation
Role in Acute Cholecystitis:
- Superior to USG in detecting stones in the cystic duct [2] — the cystic duct is a notoriously difficult area for USG (small, tortuous, obscured by overlying bowel)
- Evaluate intrahepatic and extrahepatic bile ducts comprehensively [2]
- Useful when:
- USG is inconclusive [3]
- You suspect coexisting choledocholithiasis (CBD stones)
- You need to assess biliary anatomy pre-operatively (e.g., Mirizzi syndrome, anatomical variants)
- Avoids complications associated with ERCP but is NOT therapeutic — it is purely diagnostic [5]
Limitations:
- Less readily available than USG
- Time-consuming (~30–45 minutes)
- Patient must lie still (difficult in acutely unwell or claustrophobic patients)
- Contraindicated in patients with certain metallic implants/pacemakers
- Cannot be performed at the bedside
Role in Acute Cholecystitis:
- Usually unnecessary for diagnosis of uncomplicated acute cholecystitis [2] — USG is sufficient
- CT is primarily used to:
- Detect complications: empyema, emphysematous cholecystitis (gas in GB wall — pathognomonic), perforation (pericholecystic abscess, free fluid), gangrenous cholecystitis [2][3]
- Exclude alternative diagnoses when the clinical picture is unclear (acute pancreatitis, perforated PUD, appendicitis, liver abscess, malignancy)
- Evaluate extent of inflammation in difficult cases
CT Findings in Acute Cholecystitis:
- Gallbladder wall oedema/thickening [2]
- Pericholecystic fat stranding
- Distended gallbladder
- Gallstones (CT only detects ~75% of gallstones because cholesterol stones are isodense to bile — USG is far superior for stones) [5]
- Gas in GB wall or lumen → emphysematous cholecystitis (air is black on CT → very conspicuous)
- Discontinuity of GB wall → perforation
- Rim enhancement of GB wall on contrast-enhanced CT → gangrenous cholecystitis
Limitations:
- Not useful for detecting gallstones compared to USG (only 75% sensitivity) [5]
- Radiation exposure
- IV contrast carries risk of allergic reaction and contrast nephropathy
These are not diagnostic for cholecystitis but are part of the acute abdomen workup:
AXR:
- Only ~15% of gallstones are radio-opaque on plain X-ray (only calcified stones) [4] — so AXR is insensitive for gallstones
- Mercedes Benz sign: A triradiate fissure pattern within a gallstone due to gas trapped in crevices of the stone — specific but rarely seen [4]
- May show porcelain gallbladder (calcified GB wall — associated with GB carcinoma)
- May show signs of complications: pneumobilia (gas in biliary tree → cholecystoenteric fistula), dilated bowel loops (gallstone ileus)
Erect CXR:
- Rule out right basal pneumonia/pleuritis (a common differential for RUQ pain)
- Rule out pneumoperitoneum (air under the diaphragm → perforated viscus, not cholecystitis)
- Check for pleural effusion (reactive effusion from subdiaphragmatic inflammation)
Useful in choledocholithiasis [5] — very high sensitivity for detecting small CBD stones (even < 5 mm) that are missed by transabdominal USG (distal CBD is obscured by duodenal gas).
- Not routinely used for diagnosing cholecystitis itself
- May be useful when clinical suspicion of concurrent CBD stones is high but MRCP is inconclusive or unavailable
- NOT a first-line diagnostic tool for cholecystitis — ERCP is invasive and carries risks (pancreatitis, perforation, bleeding)
- Both diagnostic and therapeutic [5]
- Reserved for when there is confirmed/suspected choledocholithiasis or cholangitis coexisting with cholecystitis
- Therapeutic role: sphincterotomy + stone extraction from the CBD; biliary stenting for decompression
| Investigation | Primary Role | Key Findings in Acute Cholecystitis | When to Use |
|---|---|---|---|
| CBC D/C | Confirm systemic inflammation | Leukocytosis, left shift; very high WBC → complications | All patients |
| LFT | Differentiate biliary level of obstruction | Usually NORMAL; mild ↑ possible; marked cholestatic pattern → choledocholithiasis/cholangitis | All patients |
| Amylase/Lipase | Exclude concurrent pancreatitis | Normal or mildly ↑; > 3× ULN → pancreatitis | All patients |
| CRP | Monitor inflammation | Elevated; serial CRP tracks response | All patients |
| Blood C/ST | Guide antibiotic therapy | Identify causative organism | If febrile / septic |
| Clotting, X-match | Pre-operative assessment | — | All patients (pre-op) |
| USG abdomen | 1st-line imaging | 5 cardinal signs | All patients |
| HIDA scan | 2nd-line; functional test | Non-visualisation of GB | Inconclusive USG |
| MRCP | 2nd-line; anatomical detail | Cystic duct stones; biliary anatomy | Inconclusive USG; suspected CBD stones |
| CT abdomen | Rule out complications | GB wall oedema; gas in wall; perforation | Suspected complications or unclear diagnosis |
| AXR | Acute abdomen screening | Usually unhelpful (only 15% stones radio-opaque) | Part of acute abdomen workup |
| Erect CXR | Exclude differentials | Rule out pneumonia, pneumoperitoneum | All patients with acute abdomen |
| ECG | Exclude inferior MI | ST changes in II, III, aVF | Upper abdominal pain, cardiac risk factors |
Once the diagnosis is confirmed, severity grading directly guides management [2][7]:
| Grade | Severity | Criteria | Management Direction |
|---|---|---|---|
| Grade I (Mild) | No organ dysfunction, mild GB inflammation | Acute cholecystitis that does not meet criteria for Grade II or III. Healthy patient with mild inflammatory changes making cholecystectomy safe and low-risk [2] | Early laparoscopic cholecystectomy |
| Grade II (Moderate) | Marked local inflammation, no organ failure | ≥ 1 of: Leukocytosis > 18,000/μL; palpable tender RUQ mass; duration > 72 hours; marked local inflammation (gangrenous cholecystitis, pericholecystic abscess, hepatic abscess, biliary peritonitis, emphysematous cholecystitis) [2] | Early LC if experienced centre, OR antibiotics followed by delayed/interval LC |
| Grade III (Severe) | Organ/system dysfunction | Any of: CVS dysfunction (hypotension requiring vasopressors — dopamine ≥ 5 μg/kg/min or any norepinephrine); neurological (decreased consciousness); respiratory (PaO₂/FiO₂ < 300); renal (oliguria, Cr > 2.0 mg/dL); hepatic (PT-INR > 1.5); haematological (platelets < 100,000/μL) [2] | Urgent organ support + gallbladder drainage (percutaneous cholecystostomy) → delayed LC after stabilisation |
Severity Grading — The Clinical Logic
The grading essentially asks: "Can this patient safely tolerate surgery right now?"
Grade I: Yes → operate early. Grade II: Maybe — the local inflammation is severe and makes surgery technically difficult, but the patient's physiology is intact. Consider local expertise. Grade III: No → the patient has organ failure. Stabilise first, drain the gallbladder, and operate later when the patient can tolerate anaesthesia [2][7].
High Yield Summary
Tokyo Guidelines Diagnostic Criteria: A (local signs: Murphy's, RUQ tenderness/mass) + B (systemic signs: fever, leukocytosis, ↑CRP) + C (imaging confirmation) → Suspected = A + B; Definite = A + B + C.
First-line imaging: USG abdomen — look for the 5 cardinal signs: (1) gallstones, (2) distended GB > 4 × 10 cm, (3) wall thickening > 3 mm, (4) pericholecystic fluid, (5) sonographic Murphy's sign.
Second-line imaging: HIDA scan (non-visualisation of GB = cystic duct obstruction; highest sensitivity ~97% but expensive, slow, unreliable in jaundice) or MRCP (superior for cystic duct/CBD stones, non-invasive, no contrast, but NOT therapeutic).
CT abdomen: Not for diagnosis — for ruling out complications (emphysematous cholecystitis, perforation, abscess) and alternative diagnoses.
LFT is usually NORMAL in uncomplicated cholecystitis. A cholestatic pattern should prompt consideration of concurrent choledocholithiasis/cholangitis or Mirizzi syndrome.
Very high WBC ( > 18,000) suggests complicated disease — gangrenous cholecystitis, perforation, or cholangitis.
Severity grading (Tokyo): Grade I → early LC; Grade II → early/delayed LC; Grade III → stabilise + drain → delayed LC.
Active Recall - Diagnosis of Acute Cholecystitis
[1] Lecture slides: GC 200. RUQ pain, jaundice and fever Cholecytitis and cholangitis Imaging of GI system.pdf (p3–5) [2] Senior notes: felixlai.md (Cholecystitis — Diagnosis sections, pp. 555–558; Severity grading, p. 558) [3] Senior notes: maxim.md (Acute calculous cholecystitis — Investigations, p. 131; Diagnostic criteria table, p. 131) [4] Senior notes: maxim.md (Biliary colic — Investigations, USG findings, p. 130; Symptomatic gallstones summary table, p. 130) [5] Senior notes: maxim.md (HBP investigations — USG, HIDA, MRCP, ERCP, CT, EUS, p. 119) [7] Senior notes: felixlai.md (Tokyo Guidelines severity grading table, p. 558)
Management of Acute Cholecystitis
The management of acute cholecystitis rests on three pillars, applied in sequence:
- Resuscitation and supportive care — stabilise the patient
- Medical treatment — control infection, inflammation, and symptoms
- Definitive treatment — remove the gallbladder (the source of the problem) to prevent recurrence
The timing and approach to definitive treatment depend on the Tokyo Guidelines severity grading (Grade I–III), the duration of symptoms, and the patient's fitness for surgery.
Think of it this way: the gallbladder with its stone is a ticking bomb. Medical treatment defuses the immediate crisis. Surgery removes the bomb entirely.
These measures apply to ALL patients regardless of severity grade. The aim is to stabilise the patient's physiology before any definitive intervention.
| Measure | Details | Rationale |
|---|---|---|
| Nil by mouth (NPO) [2][3] | No oral intake until inflammation subsides (bowel rest) | Eating (especially fat) → CCK release → gallbladder contraction against the obstructed cystic duct → worsens distension, pain, and inflammation. NPO removes this stimulus. Also prepares patient for possible surgery. |
| IV fluids [2][3] | Crystalloid resuscitation (e.g., normal saline, Hartmann's solution) | Patients are often dehydrated from vomiting, poor oral intake, and third-spacing from inflammation. Adequate hydration maintains renal perfusion and corrects electrolyte disturbances. |
| Continuous monitoring of vitals [2] | Heart rate, blood pressure, temperature, respiratory rate, urine output (I/O charting) | Detect early signs of clinical deterioration (sepsis, perforation), monitor response to treatment. Tachycardia and hypotension suggest progression to septic shock (→ Grade III). |
| Blood tests including cross-match [2] | CBC D/C, LRFT, amylase, clotting, CRP, blood C/ST, group & cross-match [3] | Baseline assessment, pre-operative preparation, monitor inflammatory trend, identify coexisting biliary pathology, have blood available if surgery is needed urgently |
2. Medical Treatment
Pain control with NSAIDs [2]
-
First-line: NSAIDs (e.g., diclofenac, ketorolac, indomethacin)
- Why NSAIDs first? The early inflammation in cholecystitis is mediated by prostaglandins released from the chemically irritated gallbladder mucosa (lysolecithin → phospholipase A → prostaglandins). NSAIDs inhibit cyclooxygenase (COX) → block prostaglandin synthesis → directly target the pathophysiological mechanism. They also reduce gallbladder pressure by relaxing smooth muscle. Evidence shows NSAIDs can reduce progression from biliary colic to cholecystitis.
- Contraindications: renal impairment, peptic ulcer disease, coagulopathy, aspirin-sensitive asthma
-
Second-line: Opioids (e.g., pethidine, morphine)
- Used when NSAIDs are contraindicated or insufficient
- Historical concern about morphine: It was traditionally taught that morphine causes sphincter of Oddi spasm and should be avoided. Current evidence suggests this is clinically insignificant at therapeutic doses, and morphine can be used safely. Pethidine was historically preferred but has no proven advantage and carries risk of seizures with repeated dosing.
-
Adjuncts: Paracetamol (IV or oral), antispasmodics (hyoscine butylbromide)
Acute cholecystitis is primarily an inflammatory process but secondary infection of gallbladder can occur as a result of cystic duct obstruction and bile stasis [2]
Antibiotics are given because:
- 15–30% of cases develop secondary bacterial infection
- You cannot reliably distinguish sterile chemical inflammation from infected cholecystitis clinically
- Antibiotics prevent progression to empyema, gangrene, and sepsis
- They are essential for treatment of pericholecystic abscess, emphysematous cholecystitis, and biliary sepsis [2]
Empirical antibiotic regimens — must cover Gram-negative aerobes and anaerobes [2]:
| Regimen | Components | Coverage | Notes |
|---|---|---|---|
| 1st line (mild-moderate) | IV Augmentin (Amoxicillin/clavulanate) [3] | Gram-positive, Gram-negative, anaerobes | Simple, well-tolerated; the "workhorse" for community-acquired biliary infections |
| Option 2 | Ampicillin-sulbactam | Similar broad spectrum | β-lactam/β-lactamase inhibitor combination |
| Option 3 (severe) | Piperacillin-tazobactam (Tazocin) [12] | Extended Gram-negative cover including Pseudomonas, plus anaerobes | Reserved for severe/complicated cases or hospital-acquired infections |
| Option 4 | Metronidazole + 3rd-generation cephalosporin (e.g., Ceftriaxone) [2] | Cephalosporin covers Gram-negatives; Metronidazole covers anaerobes | Alternative when β-lactam/inhibitor combinations are not available or contraindicated |
| Option 5 | Metronidazole + Fluoroquinolone (e.g., Ciprofloxacin / Levofloxacin) [2] | Fluoroquinolone covers Gram-negatives; Metronidazole covers anaerobes | Use in penicillin-allergic patients; note rising fluoroquinolone resistance |
Why cover anaerobes? In complicated cholecystitis (gangrene, perforation, empyema), the ischaemic, necrotic gallbladder wall creates an anaerobic environment where organisms like Bacteroides fragilis and Clostridium species thrive. Metronidazole ("metro" = targeting anaerobic metabolism) is the classic anti-anaerobic agent.
Antibiotic Choice in Practice
3. Definitive Surgical Treatment
The gallbladder is the source of the problem (it contains the stones, it is the organ that becomes inflamed). As long as it remains in situ, the patient is at risk of recurrent cholecystitis, empyema, gangrene, and gallstone migration into the CBD. Therefore:
The definitive treatment for acute cholecystitis is cholecystectomy — removal of the gallbladder.
Cholecystectomy (removal of gallbladder) — open or laparoscopic, delayed or early [1]
Laparoscopic cholecystectomy is the 1st-line definitive treatment for most patients [3][4].
Laparoscopic vs Open Cholecystectomy:
| Laparoscopic Cholecystectomy | Open Cholecystectomy | |
|---|---|---|
| Pros [1] | Less pain | Direct visualisation of anatomy |
| Shorter hospital stay | Easier to handle severe inflammation/adhesions | |
| Faster recovery | No pneumoperitoneum-related risks | |
| Better cosmesis | ||
| Cons [1] | Technically demanding [1] | More pain, longer hospital stay |
| Higher conversion rate [1] | Larger wound → higher wound infection rate | |
| More serious complications (bile duct injury) [1] | Longer recovery, poor cosmesis |
Indications for cholecystectomy [8][9]:
- Symptomatic gallstones with or without complications
- Acalculous cholecystitis
- Asymptomatic gallstones in high-risk patients:
- Increased risk of gallbladder cancer: GB polyps > 1 cm, porcelain gallbladder, large gallstones > 3 cm [9]
- Increased risk of gallstone complications: patients on long-term TPN, haemolytic disorders, gastric bypass (altered anatomy)
- Concomitant liver surgery
Indications for conversion to open [9]:
- Cannot tolerate pneumoperitoneum (e.g., cardiopulmonary comorbidities — CO₂ insufflation increases intra-abdominal pressure → decreased venous return → cardiac compromise)
- Refractory coagulopathy
- Multiple prior abdominal surgeries (extensive adhesions)
- Gallbladder carcinoma (risk of tumour seeding from port sites)
- Failure to achieve the critical view of safety (anatomy unclear, bleeding, bile duct injury suspected)
Conversion is NOT Failure
Conversion of laparoscopic into open procedure in face of a difficult laparoscopic procedure should never be viewed as surgical failure or complication but rather as a way to avoid potential injury to patients [8]. This is a fundamental surgical principle. The safest operation is the one you can perform well — if laparoscopic conditions are unsafe, converting to open is the right decision.
This is one of the most important management decisions and a high-yield exam topic [1].
Early or delayed surgery [1]:
| Early Surgery | Delayed Surgery (Interval) | |
|---|---|---|
| Timing | Within 48–72 hours of symptom onset [1] | Conservative treatment first → interval surgery in 8–12 weeks [1] |
| Advantages [1] | Avoid urgent operation | Avoid misdiagnosis |
| Avoid recurrent symptoms | Easier dissection | |
| Avoid readmission | Less septic complications | |
| Shorter hospital stay | Less serious complications | |
| Disadvantages [3] | Higher risk of bleeding and post-op infections; higher risk of converting to open [3] | Separate admission; fibrosis causes difficulty in mobilising GB; chance of recurrence while waiting for OT [3] |
"Early cholecystectomy is safe without increasing the risk of complications" [1]
The current evidence and guideline position:
- Early cholecystectomy should always be recommended unless contraindicated [7]
- 2013 Tokyo Guidelines: Surgery within 72 hours of symptom onset [7]
- 2018 Tokyo Guidelines: Even if > 72 hours has passed since symptom onset, there are still benefits to performing cholecystectomy early; recommended early LC in low-risk patients regardless of how much time has passed [7]
- 2016 WSES Guidelines: Early LC as long as completed within 10 days of symptom onset. Symptoms > 10 days → should not undergo early cholecystectomy (allow inflammation to subside) [7]
Why is early LC easier? [3]
- Initial inflammation: pericholecystic fluid in the dissection plane → easier dissection [3] — the oedema fluid actually creates a natural plane around the gallbladder that the surgeon can exploit
- After 72 hours: dense adhesions form at Calot's triangle [3] — fibrotic adhesions obliterate tissue planes, making identification of the cystic duct and artery hazardous
| Grade | Management [2][7] |
|---|---|
| Grade I (Mild) | Early laparoscopic cholecystectomy |
| Grade II (Moderate) | Early LC if experienced centre with low anticipated operative risk OR IV antibiotics → delayed/interval LC if high operative risk or inexperienced centre |
| Grade III (Severe) | Organ support + IV antibiotics + gallbladder drainage (percutaneous cholecystostomy) → delayed LC after physiological recovery |
This is the single most important concept in cholecystectomy safety [8][9]:
Critical View of Safety (CVS) [9]:
- Hepatocystic triangle clearance — Calot's triangle dissected free of all fat and fibrous tissue
- Cystic plate clearance — the lower third of the gallbladder separated from the liver bed
- Only two structures seen entering the gallbladder: the cystic duct and cystic artery [9]
Why is this so critical? Misidentification of the cystic duct is the commonest cause of biliary injury [8]. If the surgeon mistakes the CBD for the cystic duct and clips/divides it, the patient develops a devastating bile duct injury. The CVS ensures that the ONLY structures being divided are those that enter the gallbladder directly — nothing else.
If the critical view cannot be achieved [8]:
- Perform intraoperative cholangiography (IOC) to delineate anatomy
- Convert to open procedure
- Consider subtotal (partial) cholecystectomy — advocated when ductal and vascular structures in the triangle of Calot cannot be safely identified in the setting of severe acute inflammation [8]
- A bail-out procedure when the "critical view" is unachievable due to severe inflammation, dense adhesions, or Mirizzi syndrome
- The gallbladder fundus and body are removed, but the Hartmann's pouch/infundibulum is left behind (either closed or left open with a drain)
- Avoids dangerous dissection near the CBD and hepatic artery
- Leaves a small gallbladder remnant that may rarely develop recurrent stones or malignancy — but this is preferable to a bile duct injury
4. Gallbladder Drainage (Non-Surgical Decompression)
When the patient cannot undergo cholecystectomy (too sick, organ failure, high surgical risk), you need an alternative way to decompress the infected, distended gallbladder.
Cholecystostomy — Drainage of the gallbladder. Open or percutaneous [1]
Indications for gallbladder drainage [1][7]:
- High surgical risk [1]
- Haemodynamically unstable [1]
- Difficult cholecystectomy [1]
- Severe acute cholecystitis (Grade III) [7]
- Late presentation > 72 hours after onset of symptoms (where early LC is not feasible) [7]
- Failure of medical (antibiotic) therapy [7]
- Contraindication to general anaesthesia [7]
- Not responding to antibiotics while waiting for interval LC [3]
Percutaneous cholecystostomy [7]:
- Decompresses and drains the distended, inflamed, hydropic or purulent gallbladder [7]
- Indicated in management of acute cholecystitis in frail patients who are not fit for general anaesthesia [7]
- Can be placed under USG or CT guidance
Technique:
- Catheter is inserted over a guidewire that has been passed through the abdominal wall, through the liver, and into the gallbladder [7]
- By passing the catheter through the liver, the risk of bile leak around the catheter is minimised [7] — the liver parenchyma seals around the catheter tract (tamponade effect), preventing bile from tracking into the peritoneal cavity
- The catheter allows continuous drainage of infected bile/pus
It is both diagnostic AND therapeutic [2]: infected gallbladder is decompressed, bile can be sent for culture and sensitivity, and in calculous disease stones can potentially be extracted via the tube.
Specific complications of percutaneous cholecystostomy [3]:
- Catheter migration (dislodgement)
- Bile leakage around the tube
- Bowel injury (from needle insertion)
After stabilisation → definitive treatment is interval cholecystectomy [2][7]
Endoscopic drainage: if percutaneous cholecystostomy is not feasible [3]:
| Method | Technique | Notes |
|---|---|---|
| Endoscopic transpapillary gallbladder drainage (ETGBD) via ERCP | ERCP to place a drainage catheter into the gallbladder via the cystic duct [7]. The catheter end is either brought out through the nose as a nasobiliary drain (NB tube — pink with sideholes) or left to drain internally into the duodenum | NB tube is relatively contraindicated in confused patients (risk of self-removal, aspiration) [7]. Requires a patent cystic duct (if completely obstructed by stone, catheter cannot pass). |
| EUS-guided gallbladder drainage (EUS-GBD) | Transmural drainage using EUS guidance to access the inflamed gallbladder with a needle puncture, followed by dilation and stent placement over a guidewire [7] | Newer technique; useful when percutaneous and transpapillary approaches are not feasible. Uses a lumen-apposing metal stent (LAMS) to create a direct fistula between the GB and the stomach/duodenum. |
5. Management of Specific Situations
Management: laparoscopic cholecystectomy or gallbladder drainage (if unfit) [3]
If investigations suggest coexisting CBD stones (cholestatic LFT, dilated CBD, visible CBD stone):
- Pre-operative ERCP → sphincterotomy + CBD stone extraction → followed by LC (two-stage approach)
- OR LC with intraoperative cholangiography (IOC) → laparoscopic CBD exploration if stones confirmed (single-stage approach)
- The approach depends on local expertise and resources
Emergency LC (or open cholecystectomy) is indicated for [3][4]:
- Gangrenous cholecystitis
- Gallbladder perforation
- Emphysematous cholecystitis
- Disease progression despite best supportive care
These are surgical emergencies — the necrotic/infected gallbladder must be removed urgently to prevent biliary peritonitis and overwhelming sepsis.
| Timing | Complication | Mechanism / Details |
|---|---|---|
| Immediate | Bleeding (cystic artery, liver bed) | Inadequate clip/cautery; aberrant vascular anatomy |
| Bile duct injury (most feared) | Misidentification of CBD as cystic duct [8] — hence the critical view of safety | |
| Bowel injury (trocar insertion) | During port placement for laparoscopy | |
| Early | Bile leak (cystic duct stump) | Clip slippage or necrosis of stump |
| Wound infection | More common with open approach; higher in contaminated/emergency cases | |
| Retained CBD stones | Stones migrated to CBD pre/during surgery; diagnosed by IOC or post-op symptoms | |
| Subhepatic collection/abscess | Bile or blood accumulation in the gallbladder fossa | |
| Late | Post-cholecystectomy syndrome | Persistent RUQ pain after surgery; causes include retained CBD stone, sphincter of Oddi dysfunction, bile duct stricture |
| Incisional hernia | Especially at port sites (laparoscopic) or incision (open) | |
| Bile duct stricture | Late consequence of thermal or ischaemic injury during dissection |
Cardiopulmonary Risks of Laparoscopy
Pneumoperitoneum (CO₂ insufflation to ~15 mmHg) increases intra-abdominal pressure → compresses IVC → decreases venous return → decreases cardiac output. CO₂ absorption → hypercapnia → respiratory acidosis. The reversed Trendelenburg position (head up) further reduces venous return. These are why patients with severe cardiopulmonary disease may not tolerate laparoscopic cholecystectomy and may need an open approach [9].
| Scenario | Initial Management | Definitive Treatment |
|---|---|---|
| Grade I (Mild) | NPO, IVF, IV Augmentin, analgesia | Early LC (within 72h) |
| Grade II (Moderate) | NPO, IVF, IV Abx, analgesia | Early LC (experienced centre) OR Interval LC (6–8 wk) |
| Grade III (Severe) | Resuscitation, organ support, IV Tazocin | Percutaneous cholecystostomy → Delayed LC |
| Complicated (gangrene/perforation/emphysematous) | Emergency resuscitation, IV Abx | Emergency LC or open cholecystectomy |
| Acalculous | NPO, IVF, IV Abx | LC or percutaneous cholecystostomy (if unfit) → interval LC |
| Unfit for surgery | NPO, IVF, IV Abx | Percutaneous cholecystostomy or endoscopic drainage |
High Yield Summary
Initial management for ALL grades: NPO, IV fluids, IV antibiotics, analgesia (NSAIDs first-line), monitoring.
Antibiotic choice: Mild = IV Augmentin; Severe = IV Tazocin. Must cover Gram-negatives and anaerobes.
Definitive treatment: Laparoscopic cholecystectomy — 1st-line for most patients. Open cholecystectomy if laparoscopic not feasible or contraindicated.
Timing: Early LC (within 72h) is preferred — shorter hospital stay, avoids readmission, avoids recurrence, early inflammation creates easier dissection planes. After 72h, dense adhesions form. "Early cholecystectomy is safe without increasing the risk of complications" (lecture slide).
Tokyo-guided approach: Grade I → Early LC; Grade II → Early or delayed LC; Grade III → Stabilise + drain → delayed LC.
Drainage indications: High surgical risk, haemodynamically unstable, difficult cholecystectomy, Grade III, failed antibiotics, contraindication to GA. Percutaneous cholecystostomy is 1st-line drainage. Pass catheter through the liver to minimise bile leak.
Critical View of Safety: Hepatocystic triangle clearance + cystic plate clearance + only 2 structures (cystic duct and artery) entering the GB. Misidentification of the cystic duct is the commonest cause of biliary injury.
Emergency LC/open: Gangrene, perforation, emphysematous cholecystitis, disease progression despite best supportive care.
Active Recall - Management of Acute Cholecystitis
References
[1] Lecture slides: GC 200. RUQ pain, jaundice and fever Cholecytitis and cholangitis Imaging of GI system.pdf (p8–12) [2] Senior notes: felixlai.md (Cholecystitis — Treatment sections, pp. 557–561) [3] Senior notes: maxim.md (Acute calculous cholecystitis — Initial management, Definitive treatment, Early vs Interval LC, GB drainage, pp. 131–132) [4] Senior notes: maxim.md (Symptomatic gallstones summary table — management approach, p. 130) [7] Senior notes: felixlai.md (Severity grading, timing of surgery guidelines, gallbladder drainage overview, pp. 558–561) [8] Senior notes: felixlai.md (Cholecystectomy — CVS, indications, partial cholecystectomy, pp. 513–515) [9] Senior notes: maxim.md (Cholecystectomy — indications, approach, CVS, operative procedure, pp. 133–134) [12] Senior notes: maxim.md (Acute cholangitis — Acute management RAD, IV Tazocin for severe, p. 135)
Complications of Acute Cholecystitis
Complications arise when acute cholecystitis is untreated or inadequately treated, allowing the pathophysiological cascade to progress beyond simple chemical inflammation into tissue destruction, infection, and structural damage. Understanding these complications follows logically from the pathophysiology we've already covered:
Stone impaction → distension → chemical inflammation → oedema → vascular compromise (end-artery cystic artery compressed) → ischaemia → necrosis → secondary infection → structural breakdown
Let's categorise these into: (A) Complications of the disease itself and (B) Complications of gallstone disease more broadly (since cholecystitis is a complication of gallstones, and gallstones cause additional problems beyond the gallbladder).
A. Direct Complications of Acute Cholecystitis
These represent progression of the acute inflammatory and infective process within the gallbladder, arranged roughly in order of the pathophysiological cascade.
Mucocele of gallbladder [1]
Pathophysiology:
- Prolonged impaction of a stone in the cystic duct without significant cholecystitis (i.e., obstruction without marked infection) [13]
- Bile trapped within the gallbladder is gradually absorbed by the gallbladder mucosa — all the bilirubin is reabsorbed
- However, the gallbladder epithelium continues to secrete mucus — so the gallbladder progressively distends with colourless, mucoid fluid ("white bile") [13]
- The gallbladder becomes massively distended but typically non-tender (because there is no active inflammation) [13]
Clinical features:
- Palpable, non-tender RUQ mass (distended gallbladder)
- May remain asymptomatic for a prolonged period
Why does it matter?
- Mucocele can progress to oedema of the gallbladder wall, secondary infection, inflammation, and perforation [13]
- Early cholecystectomy is generally indicated to avoid complications [13]
Empyema of gallbladder [1]
Pathophysiology:
- When secondary bacterial infection of an obstructed gallbladder becomes overwhelming, the gallbladder fills with frank pus — this is an empyema (from Greek empyein = to suppurate)
- Essentially, the gallbladder becomes an intra-abdominal abscess
- The same enteric organisms (E. coli, Klebsiella, Enterococcus, anaerobes) that cause secondary infection in uncomplicated cholecystitis are responsible, but the bacterial load is much higher
Clinical features [3]:
- Tender RUQ mass + septic-looking [3]
- High-grade fever ( > 39°C), rigors, diaphoresis
- Markedly elevated WBC (often > 18,000)
- Patient appears toxic/systemically unwell
Management:
- Urgent IV antibiotics + emergency cholecystectomy or percutaneous cholecystostomy if unfit for surgery
- Empyema is a surgical emergency — untreated empyema progresses to gangrene and perforation
Gangrenous cholecystitis — MOST common complication of cholecystitis [2]
Pathophysiology:
- The distended, inflamed gallbladder compresses its own blood supply (cystic artery — an end-artery with no collaterals)
- Progressive ischaemia → ischaemic necrosis of the gallbladder wall [2][3]
- Occurs in approximately 20% of cases of acute cholecystitis [3]
- More common in elderly, diabetics, and immunocompromised patients (impaired microcirculation)
Clinical features:
- Presence of a sepsis-like picture suggests the diagnosis [2]
- High fever, tachycardia, hypotension, leukocytosis
- Paradoxically, localised RUQ pain may decrease — because the sensory nerves in the gallbladder wall have been destroyed by necrosis (a dangerous sign that can be falsely reassuring)
- High WBC count is suggestive of a complicated form of cholecystitis such as gangrenous cholecystitis, perforation or associated cholangitis [2]
Diagnosis:
- CT abdomen: irregular/asymmetric wall thickening, lack of mural enhancement (ischaemic wall doesn't enhance with contrast), intraluminal membranes (sloughed mucosa), pericholecystic gas or fluid
- USG may show stranding, intraluminal membranes
Management:
- Emergency laparoscopic cholecystectomy or open cholecystectomy [3][4] — this is one of the indications for emergency surgery
- Delay increases the risk of perforation
Gangrenous Cholecystitis — The Silent Escalation
Be vigilant for the patient whose localised RUQ pain paradoxically improves while systemic signs (fever, tachycardia, rising WBC) worsen. This suggests the sensory nerves in the gallbladder wall have been destroyed by necrosis — the gallbladder is gangrenous. This is NOT improvement; it is catastrophic progression.
Rupture of gallbladder [1]
Pathophysiology:
- Occurs after development of gangrene (perforation in ischaemic areas) [2]
- The necrotic, devitalised wall gives way → bile and pus leak out
Types of perforation [2]:
- Localised (contained) perforation — most common
- Free perforation
- Uncontained leak of bile and pus into the general peritoneal cavity
- Results in generalised peritonitis [2] — a surgical catastrophe
- High mortality (~30%) — bile is extremely irritating to the peritoneum (chemical peritonitis) combined with bacterial contamination (septic peritonitis)
- Intrahepatic perforation
- Abscess forms within the liver parenchyma adjacent to the gallbladder fossa (segments IV/V)
- Perforation into adjacent organs (duodenum, colon)
- Leads to cholecystoenteric fistula formation (see below)
Clinical features:
- Contained: Persistent fever despite antibiotics, ongoing RUQ pain, possible palpable mass
- Free: Sudden worsening of pain → diffuse abdominal rigidity, rebound tenderness, hemodynamic instability, septic shock
Management:
- Emergency surgery (cholecystectomy + lavage)
- Abscess → percutaneous drainage ± delayed cholecystectomy
Emphysematous cholecystitis [2][3]
This is a rare but life-threatening variant of acute cholecystitis.
Pathophysiology:
- Caused by secondary infection of the gallbladder wall with gas-forming organisms such as Clostridium perfringens [2]
- Other gas-formers include E. coli, Klebsiella, and anaerobic streptococci
- The ischaemic, necrotic gallbladder wall provides an ideal anaerobic environment for these organisms to proliferate and produce gas (by fermentation of glucose in tissue)
- Gas accumulates within the gallbladder wall and lumen
- Insidious onset [3] — may initially appear similar to uncomplicated cholecystitis
- Abdominal crepitus adjacent to gallbladder may be detected [2] — subcutaneous gas tracking from the inflamed gallbladder
- Unconjugated hyperbilirubinaemia may be present due to haemolysis induced by Clostridial infection [2] — Clostridium perfringens produces alpha-toxin (lecithinase/phospholipase C) that destroys red cell membranes → intravascular haemolysis → unconjugated bilirubin rises
- More common in diabetic patients (60–75% of cases) and elderly males — diabetes impairs microcirculation, predisposing to ischaemia
Diagnosis:
- AXR/CT: Gas in the gallbladder wall or lumen — pathognomonic finding
- On AXR: curvilinear gas outlining the gallbladder wall
- On CT: air densities (black) within the wall and lumen — very conspicuous
- CT A+P to rule out complications (e.g., empyema, emphysematous cholecystitis, perforation) [3]
Management:
- Emergency cholecystectomy [3][4] — this is a surgical emergency, as the risk of perforation is very high
- Broad-spectrum IV antibiotics including anti-anaerobic cover (metronidazole, plus piperacillin-tazobactam or carbapenems)
- High mortality (~15–25%) if untreated
Pneumobilia — Differential Diagnosis
Gas in the biliary system (pneumobilia) on imaging is NOT always emphysematous cholecystitis. Other causes include [6]: post-ERCP (sphincterotomy disrupts the barrier to duodenal air reflux), post-cholecystectomy, cholecystoenteric fistula (gas refluxes from bowel), blunt abdominal trauma, and sphincter of Oddi incompetence. Always correlate with clinical context.
Cholecystoduodenofistula [1] Cholecystoenteric fistula → Gallstone ileus [2][6]
This is one of the most fascinating complications in surgery — a gallstone causing bowel obstruction.
- Fistula formation is more often due to long-standing pressure necrosis from stones than to acute cholecystitis [2]
- A large gallstone in the gallbladder chronically presses against the adjacent duodenal or colonic wall → pressure necrosis → erosion through both walls → formation of a direct communication (fistula) between the gallbladder and bowel lumen
- Cholecystoduodenal fistula is the most common type [6]
- Once the fistula is formed, the gallstone can pass from the gallbladder directly into the bowel lumen
Types of cholecystoenteric fistula [6]:
| Fistula Type | Frequency | Consequence |
|---|---|---|
| Cholecystoduodenal | Most common | Gallstone ileus (mechanical SBO) |
| Cholecystocolic | Less common | Usually asymptomatic (colon is wide enough to pass the stone) [6] |
| Cholecystogastric | Rare | Bouveret's syndrome (see below) |
Gallstone ileus:
- Passage of gallstone through a cholecystoenteric fistula may lead to development of mechanical bowel obstruction usually in the terminal ileum [2]
- Why the terminal ileum? The terminal ileum, 2 feet proximal to the ileocaecal valve, is the narrowest portion of the small bowel [6]. A gallstone large enough to erode through the gallbladder wall (typically > 2.5 cm) will pass through the wider proximal small bowel but become impacted at this narrowest point.
Bouveret's syndrome [6]:
- Stone stuck at duodenum/stomach, causing gastric outlet obstruction (GOO) [6]
- A very large stone passes through a cholecystoduodenal fistula and impacts in the duodenal bulb or pylorus
Clinical features [6]:
- Features of distal small bowel obstruction: colicky abdominal pain, abdominal distension, vomiting (may be faeculent), absolute constipation
- Often elderly patients with a long history of gallstone disease
Investigations [6]:
- AXR: Rigler's triad [6]:
- Pneumobilia (gas in the biliary tree — air refluxes from the bowel through the fistula into the biliary system; present in ~40%)
- Small bowel obstruction (dilated small bowel loops with air-fluid levels)
- Ectopic gallstone (usually in the RIF, stuck near the ileocaecal valve; radio-opaque stone visible in ~10%)
- CT abdomen: GB wall thickening, Rigler's triad — CT is much more sensitive than AXR for detecting all three components [6]
Management [6]:
- Enterolithotomy to relieve SBO [6]
- Exploratory laparotomy → proximal enterotomy (NOT over the stone because of ulceration at the impaction site) → milk the stone proximally for extraction [6]
- Why not enterotomy at the stone? The bowel wall at the impaction site is ulcerated, oedematous, and friable from pressure necrosis — suturing over inflamed, unhealthy tissue risks anastomotic breakdown and leak. By milking the stone backwards (proximally) to healthier bowel, the enterotomy can be made in normal tissue, which heals reliably.
- Same-session or elective cholecystectomy + fistula repair [6]
- There is debate about whether to address the fistula and gallbladder at the same operation (one-stage) or defer it. In the acutely obstructed, elderly patient, the priority is relieving the obstruction first; gallbladder surgery can wait.
These are listed from the lecture slides as complications of gallstone disease [1]:
| Complication | Where the Stone Is | Pathophysiology |
|---|---|---|
| Mucocele of gallbladder [1] | Cystic duct (prolonged obstruction, minimal inflammation) | Bile absorption, mucus secretion → distension with "white bile" |
| Empyema of gallbladder [1] | Cystic duct (persistent obstruction + bacterial superinfection) | Pus fills the obstructed gallbladder |
| Rupture of gallbladder [1] | Cystic duct (advanced gangrenous cholecystitis) | Necrotic wall perforates → localised abscess or generalised peritonitis |
| Acute cholangitis [1] | CBD (obstruction + ascending infection) | Bile stasis + bacterial contamination → biliary sepsis; Charcot's triad / Reynold's pentad |
| Acute pancreatitis [1] | Ampulla of Vater (stone impacts at the papilla) | Obstruction of pancreatic duct → duodeno-pancreatic reflux → premature enzyme activation → autodigestion |
| Cholecystoduodenofistula [1] | Gallbladder wall eroding into duodenum | Chronic pressure necrosis → fistula → gallstone ileus |
| Liver abscess [1] | Biliary system (ascending infection) | Ascending cholangitis → cholangiovenous reflux → hepatic abscess; or direct intrahepatic perforation of gallbladder |
And from the comprehensive gallstone complications framework [13]:
In the gallbladder:
- Calculous cholecystitis
- CA gallbladder (chronic inflammation → dysplasia → carcinoma)
- Mucocele/hydrops
In the bile duct:
- Choledocholithiasis ± acute cholangitis
- Gallstone pancreatitis
- Obstructive jaundice
Perforation to other sites:
- Bowel: cholecystoenteric fistula → gallstone ileus
- Liver: liver abscess
- CBD: Mirizzi syndrome [13]
Recurrent episodes of acute cholecystitis or persistent smouldering inflammation lead to chronic cholecystitis, which has its own serious long-term complications:
| Complication | Pathophysiology |
|---|---|
| Porcelain gallbladder [14] | Chronic inflammation → extensive scarring → calcification of the gallbladder wall. 2–3% risk of malignancy. All porcelain gallbladders should be removed (absolute indication for cholecystectomy). |
| Gallbladder carcinoma (CA gallbladder) [14] | Chronic inflammation → chronic mucosal irritation → dysplasia-carcinoma sequence. 95% of GB carcinoma patients have gallstones. Recurrent inflammation and biliary stasis may predispose to malignancy [15]. |
| Mirizzi syndrome [15] | Large stone impacted in Hartmann's pouch → extrinsic compression of common hepatic duct → obstructive jaundice. Chronic inflammation may erode through the bile duct wall → cholecystobiliary fistula [15]. Classified by Csendes classification (Types I–V) [15]. |
Since cholecystectomy is the definitive treatment, its complications are directly relevant to the management of acute cholecystitis.
| Timing | Complication | Mechanism / Pathophysiology | Management |
|---|---|---|---|
| Immediate | Conversion to open surgery (5% elective, 25% emergency) — NOT a failure [16] | Dense adhesions, bleeding, unclear anatomy | Continue as open procedure |
| GA risks, bleeding | — | — | |
| Damage to neighbouring structures: bile duct, cystic artery, duodenum, transverse colon, hepatic flexure [16] | Misidentification during dissection; pneumoperitoneum-related injury | Intraoperative repair | |
| Early | Biliary leakage (from cystic duct stump or duct of Luschka; ~0.5%) [16] | Clip slippage, thermal injury to small ducts, duct of Luschka (aberrant small duct draining directly from liver bed into the GB fossa) | If noted intra-op: repair + T-tube. If delayed (post-op D2–10; fever, RUQ pain, deranged LFT): USG/CT → HIDA/MRCP → ERCP stent (minor) or laparotomy + lavage + Roux-en-Y hepaticojejunostomy (major) [16] |
| Bleeding | Liver bed (middle hepatic vein close to GB fossa), cystic artery, trocar site [16] | Surgical haemostasis | |
| Post-op jaundice | Dropped/missed CBD stones | ERCP stone extraction | |
| Cholangitis | Infected retained stone | IV antibiotics + ERCP | |
| Post-op diarrhoea | Initial uncoordinated excessive bile salt excretion + fat malabsorption [16] — without the gallbladder to store and concentrate bile, bile drips continuously into the duodenum; the ileum may not reabsorb all bile salts → bile salts reach the colon → secretory diarrhoea | Usually self-limiting; cholestyramine if persistent | |
| Late | Bile duct stricture | Thermal/ischaemic injury during dissection → fibrosis → stricture | Reconstruction ± hepaticojejunostomy [16] |
| Subphrenic abscess | Infected subhepatic collection | Drainage + antibiotics [16] | |
| Post-cholecystectomy syndrome | Persistent symptoms (e.g., biliary colic, diarrhoea) after operation [16] — causes include retained CBD stone, sphincter of Oddi dysfunction, bile duct stricture, or functional GI disorder | Investigate with MRCP/ERCP; treat underlying cause | |
| Post-cholecystectomy choledocholithiasis | Bile stasis from increased CBD calibre (loss of GB storing function) [16] | ERCP stone extraction |
Duct of Luschka — A Subtle Surgical Pitfall
The duct of Luschka is a small aberrant bile duct that drains directly from the liver parenchyma (typically segment V) into the gallbladder fossa — NOT into the cystic duct. During cholecystectomy, when the gallbladder is dissected off the liver bed, this duct can be inadvertently transected, causing bile leak post-operatively. It is easily missed intraoperatively because it is tiny and often not visible until the gallbladder is removed. This is why a drain is sometimes placed in the gallbladder fossa after difficult cholecystectomies.
High Yield Summary
Most common complication: Gangrenous cholecystitis (~20%) — ischaemic necrosis of GB wall due to distension compressing the end-artery (cystic artery). Suspect when septic picture develops; paradoxical decrease in local pain (nerve destruction) with worsening systemic signs.
Complications of gallstone disease (lecture slides): Mucocele, empyema, rupture of gallbladder, acute cholangitis, acute pancreatitis, cholecystoduodenofistula, liver abscess.
Emphysematous cholecystitis: Gas-forming organisms (Clostridium perfringens) infect the ischaemic GB wall. More common in diabetics. Pathognomonic finding: gas in GB wall on CT/AXR. Unconjugated hyperbilirubinaemia from Clostridial haemolysis. Emergency cholecystectomy needed.
Gallstone ileus: Stone erodes through GB into duodenum (cholecystoenteric fistula) → stone impacts at terminal ileum (narrowest point of SB). Rigler's triad on AXR/CT: pneumobilia + SBO + ectopic gallstone. Management: enterolithotomy (proximal enterotomy, NOT over the stone) ± cholecystectomy + fistula repair.
Perforation: Usually contained by omentum → pericholecystic abscess. Free perforation → biliary peritonitis (high mortality). Perforation into bowel → fistula.
Long-term: Recurrent cholecystitis → chronic cholecystitis → porcelain GB (calcification, 2–3% malignancy risk) → CA gallbladder.
Cholecystectomy complications: Bile duct injury (most feared — from misidentification of CBD as cystic duct; prevented by Critical View of Safety), biliary leakage (cystic duct stump or duct of Luschka), post-cholecystectomy syndrome, post-op diarrhoea.
Active Recall - Complications of Acute Cholecystitis
References
[1] Lecture slides: GC 200. RUQ pain, jaundice and fever Cholecytitis and cholangitis Imaging of GI system.pdf (p5) [2] Senior notes: felixlai.md (Complications of cholecystitis, pp. 561–562) [3] Senior notes: maxim.md (Acute calculous cholecystitis — Complications, p. 131) [4] Senior notes: maxim.md (Definitive treatment — emergency LC for complicated cholecystitis, p. 131) [6] Senior notes: maxim.md (Gallstone ileus, Rigler's triad, Bouveret's syndrome, pneumobilia DDx, p. 132) [13] Senior notes: felixlai.md (Complications of gallstones — in gallbladder, bile duct, and perforation sites, pp. 518–519) [14] Senior notes: maxim.md (Chronic cholecystitis — porcelain GB, CA gallbladder, p. 132) [15] Senior notes: maxim.md (Mirizzi syndrome — definition, Csendes classification, CA gallbladder association, p. 132) [16] Senior notes: maxim.md (Cholecystectomy — specific complications: immediate, early, late, pp. 133–134)
High Yield Summary
Definition: Acute inflammation of the gallbladder, most commonly due to cystic duct obstruction by an impacted gallstone (90–95% calculous).
Key Epidemiology: Follows gallstone demographics — 5F (Fat, Female, Forty, Fertile, Family). HK-relevant: pigment stones from haemolysis (G6PD, thalassaemia) and RPC (Clonorchis sinensis).
Pathophysiology cascade: Stone impacts → cystic duct obstruction → GB distension → bile stasis → chemical inflammation (lysolecithin, prostaglandins) in first 48h → secondary bacterial infection (E. coli, Klebsiella, Enterococcus) in 15–30% → empyema/gangrene/perforation if untreated.
Acalculous cholecystitis (5–10%): Critically ill patients; mechanism is microvascular ischaemia, NOT stone obstruction; higher mortality.
Key clinical distinction from biliary colic: Pain > 6 hours, fever, peritoneal signs (Murphy's sign), leukocytosis. Biliary colic: < 6h, no fever, no peritoneal signs.
Murphy's sign: Inspiratory arrest during RUQ palpation — inflamed GB is pushed onto examiner's hand by descending diaphragm. Negative in cholangitis.
Usually NO jaundice in uncomplicated cholecystitis (obstruction is at the cystic duct, not the CBD). If jaundice is present → think Mirizzi syndrome, double impaction, or concurrent choledocholithiasis.
Complications: Mucocele, empyema, gangrenous cholecystitis (20%), perforation, emphysematous cholecystitis, cholecystoenteric fistula/gallstone ileus, liver abscess.
USG 5 cardinal signs: (1) Gallstones, (2) Distended GB ( > 4 × 10 cm), (3) Wall thickening > 3 mm, (4) Pericholecystic fluid, (5) Sonographic Murphy's sign.
Tokyo Guidelines severity grading: Grade I (mild) → early LC; Grade II (moderate) → early/delayed LC; Grade III (severe) → stabilise + drain first.
High Yield Summary
Structured approach: Think anatomically — RUQ structures (gallbladder, liver, hepatic flexure, right kidney) + referred pain sources (right lung base, heart, right hemidiaphragm).
The single most important DDx: Biliary colic vs. acute cholecystitis — distinguished by duration ( < 6h vs. > 6h), fever, peritoneal signs (Murphy's), and leukocytosis.
Jaundice present? Think cholangitis (Charcot's triad), choledocholithiasis, Mirizzi syndrome, or hepatitis — NOT uncomplicated cholecystitis (cystic duct obstruction does not block the CBD).
Epigastric > RUQ? Think pancreatitis (radiates to back, relieved by leaning forward, ↑ amylase/lipase) or PUD/perforated PUD (pneumoperitoneum on CXR).
Always do an ECG in acute upper abdominal pain to exclude inferior MI.
Always check β-hCG in women of reproductive age to exclude ectopic pregnancy.
Hong Kong specific: Right-sided diverticulitis is more common in Asian populations and can mimic RUQ/RLQ pathology.
High Yield Summary
Tokyo Guidelines Diagnostic Criteria: A (local signs: Murphy's, RUQ tenderness/mass) + B (systemic signs: fever, leukocytosis, ↑CRP) + C (imaging confirmation) → Suspected = A + B; Definite = A + B + C.
First-line imaging: USG abdomen — look for the 5 cardinal signs: (1) gallstones, (2) distended GB > 4 × 10 cm, (3) wall thickening > 3 mm, (4) pericholecystic fluid, (5) sonographic Murphy's sign.
Second-line imaging: HIDA scan (non-visualisation of GB = cystic duct obstruction; highest sensitivity ~97% but expensive, slow, unreliable in jaundice) or MRCP (superior for cystic duct/CBD stones, non-invasive, no contrast, but NOT therapeutic).
CT abdomen: Not for diagnosis — for ruling out complications (emphysematous cholecystitis, perforation, abscess) and alternative diagnoses.
LFT is usually NORMAL in uncomplicated cholecystitis. A cholestatic pattern should prompt consideration of concurrent choledocholithiasis/cholangitis or Mirizzi syndrome.
Very high WBC ( > 18,000) suggests complicated disease — gangrenous cholecystitis, perforation, or cholangitis.
Severity grading (Tokyo): Grade I → early LC; Grade II → early/delayed LC; Grade III → stabilise + drain → delayed LC.
High Yield Summary
Initial management for ALL grades: NPO, IV fluids, IV antibiotics, analgesia (NSAIDs first-line), monitoring.
Antibiotic choice: Mild = IV Augmentin; Severe = IV Tazocin. Must cover Gram-negatives and anaerobes.
Definitive treatment: Laparoscopic cholecystectomy — 1st-line for most patients. Open cholecystectomy if laparoscopic not feasible or contraindicated.
Timing: Early LC (within 72h) is preferred — shorter hospital stay, avoids readmission, avoids recurrence, early inflammation creates easier dissection planes. After 72h, dense adhesions form. "Early cholecystectomy is safe without increasing the risk of complications" (lecture slide).
Tokyo-guided approach: Grade I → Early LC; Grade II → Early or delayed LC; Grade III → Stabilise + drain → delayed LC.
Drainage indications: High surgical risk, haemodynamically unstable, difficult cholecystectomy, Grade III, failed antibiotics, contraindication to GA. Percutaneous cholecystostomy is 1st-line drainage. Pass catheter through the liver to minimise bile leak.
Critical View of Safety: Hepatocystic triangle clearance + cystic plate clearance + only 2 structures (cystic duct and artery) entering the GB. Misidentification of the cystic duct is the commonest cause of biliary injury.
Emergency LC/open: Gangrene, perforation, emphysematous cholecystitis, disease progression despite best supportive care.
High Yield Summary
Most common complication: Gangrenous cholecystitis (~20%) — ischaemic necrosis of GB wall due to distension compressing the end-artery (cystic artery). Suspect when septic picture develops; paradoxical decrease in local pain (nerve destruction) with worsening systemic signs.
Complications of gallstone disease (lecture slides): Mucocele, empyema, rupture of gallbladder, acute cholangitis, acute pancreatitis, cholecystoduodenofistula, liver abscess.
Emphysematous cholecystitis: Gas-forming organisms (Clostridium perfringens) infect the ischaemic GB wall. More common in diabetics. Pathognomonic finding: gas in GB wall on CT/AXR. Unconjugated hyperbilirubinaemia from Clostridial haemolysis. Emergency cholecystectomy needed.
Gallstone ileus: Stone erodes through GB into duodenum (cholecystoenteric fistula) → stone impacts at terminal ileum (narrowest point of SB). Rigler's triad on AXR/CT: pneumobilia + SBO + ectopic gallstone. Management: enterolithotomy (proximal enterotomy, NOT over the stone) ± cholecystectomy + fistula repair.
Perforation: Usually contained by omentum → pericholecystic abscess. Free perforation → biliary peritonitis (high mortality). Perforation into bowel → fistula.
Long-term: Recurrent cholecystitis → chronic cholecystitis → porcelain GB (calcification, 2–3% malignancy risk) → CA gallbladder.
Cholecystectomy complications: Bile duct injury (most feared — from misidentification of CBD as cystic duct; prevented by Critical View of Safety), biliary leakage (cystic duct stump or duct of Luschka), post-cholecystectomy syndrome, post-op diarrhoea.
Acute Cholangitis
Acute bacterial infection of the biliary tract due to obstruction, classically presenting with Charcot's triad of fever, jaundice, and right upper quadrant pain.
Acute Pancreatitis
Acute inflammatory condition of the pancreas caused by premature activation of pancreatic enzymes, leading to autodigestion, edema, and potentially hemorrhagic necrosis of pancreatic tissue.