66. Cholecystitis

1. Definition

• Acute cholecystitis → acute inflammation of the gallbladder, usually from obstruction of the cystic duct by a stone
• Acute calculous cholecystitis → 90–95%
• Acalculous cholecystitis → inflammation without stones; critically ill patients (5–10%)
• Chronic cholecystitis → long-standing inflammation and fibrosis from repeated attacks
• Variants → empyema (pus), gangrenous, emphysematous (gas-forming), perforated, xanthogranulomatous

2. Epidemiology

• Acute cholecystitis → develops in about 10–20% of patients with symptomatic gallstones
• Women more than men (calculous); older men in gangrenous and emphysematous forms
• Acalculous → ICU patients, burns, trauma, major surgery, sepsis, TPN; mortality up to 30–50%
• Emphysematous → men, diabetes (about half), vascular disease
• 20% of emergency general surgery admissions in some series relate to gallstones

3. Aetiology and risk factors

• Calculous:
  • Stone stuck in Hartmann's pouch or cystic duct
  • Risk factors as for gallstones (female, obesity, pregnancy, rapid weight loss)
• Acalculous:
  • Critical illness, sepsis, shock, mechanical ventilation
  • Burns, major trauma, major surgery (cardiac)
  • Total parenteral nutrition, long fasting (stasis)
  • Opioids, blood transfusion
  • Infections → CMV, Salmonella typhi, HIV-related (cryptosporidium)
  • Vasculitis, diabetes
• Emphysematous → Clostridium perfringens, E. coli; ischaemia of the wall

4. Pathogenesis

Calculous

1. Stone blocks the cystic duct
2. Gallbladder distends; mucosa releases phospholipase A, which turns lecithin into toxic lysolecithin → chemical inflammation
3. Wall oedema, raised pressure → venous then arterial compromise
4. Secondary bacterial infection (about 50%: E. coli, Klebsiella, Enterococcus, anaerobes)
5. Untreated → empyema, gangrene, perforation
6. Perforation types (Niemeier):
   • I → free perforation, biliary peritonitis
   • II → localised, pericholecystic abscess (most common)
   • III → cholecystoenteric fistula
7. Inflamed gallbladder stuck to the duodenum, colon, omentum → mass

Acalculous

• Stasis (fasting, opioids) and ischaemia (low flow, shock) → concentrated bile injures the wall → early gangrene and perforation

Chronic

• Repeated attacks → thick fibrotic wall, small contracted gallbladder, Rokitansky-Aschoff sinuses
• Calcified wall → porcelain gallbladder

5. Classification

Tokyo Guidelines 2018 (TG18): severity

• Grade I (mild) → no organ dysfunction; mild local inflammation; healthy patient
• Grade II (moderate) → any of:
  • White cell count over 18 × 10⁹/L
  • Palpable tender RUQ mass
  • Symptoms over 72 hours
  • Marked local inflammation (gangrene, abscess, emphysematous, biliary peritonitis)
• Grade III (severe) → organ dysfunction: cardiovascular (needs vasopressors), neurological (confusion), respiratory (PaO₂/FiO₂ under 300), renal (oliguria, creatinine over 176 µmol/L), hepatic (INR over 1.5), haematological (platelets under 100 × 10⁹/L)

Tokyo diagnostic criteria

• A Local → Murphy's sign; RUQ mass, pain or tenderness
• B Systemic → fever, raised CRP, raised white cell count
• C Imaging → typical findings
• Suspected → one A + one B; definite → A + B + C

By type

• Calculous, acalculous; acute, chronic; empyema, gangrenous, emphysematous, perforated, xanthogranulomatous

6. Clinical picture

Symptoms

• Constant RUQ pain over 6 hours (unlike colic), worse on breathing and movement
• Radiates to the right shoulder or scapula (diaphragm irritation)
• Nausea, vomiting, anorexia
• Fever, malaise
• Previous attacks of biliary colic
• Elderly and diabetic patients → few symptoms, more gangrene
• Acalculous → unexplained fever, sepsis, rising LFTs in an ICU patient
• Chronic → recurrent episodes of colic, fatty food intolerance, dyspepsia

Signs

• Fever, tachycardia
• RUQ tenderness, guarding
• Murphy's sign → patient stops breathing in when the examiner's fingers under the right costal margin meet the inflamed gallbladder; not seen on the left side (control)
• Boas' sign → hyperaesthesia below the right scapula
• Palpable tender mass (gallbladder with omentum wrapped around it) in about 30%
• Mild jaundice (10%) → oedema near the CBD, Mirizzi, or CBD stone
• Peritonitis → perforation

7. Diagnosis

• Bloods:
  • FBC → leucocytosis
  • CRP
  • LFT → mild rise in bilirubin, ALP; marked rise suggests CBD stone or Mirizzi
  • Amylase or lipase → exclude pancreatitis
  • U&E, lactate, blood cultures if septic; organ function for Tokyo grading
• Ultrasound → first test:
  • Gallstones, stone impacted in the neck
  • Thick wall over 4 mm, wall oedema ("double-wall sign")
  • Pericholecystic fluid
  • Distended gallbladder
  • Sonographic Murphy's sign
• HIDA scan (hepatobiliary scintigraphy) → most sensitive and specific: gallbladder does not fill (cystic duct blocked); used if ultrasound unclear
• CT → complications (gangrene, abscess, perforation, gas in the wall in emphysematous), alternative diagnoses
• MRCP → suspected CBD stones
• Chest X-ray, ECG → exclude chest and heart causes; air under the diaphragm
• Plain X-ray → gas in the gallbladder wall (emphysematous), calcified wall (porcelain)

8. Differential diagnosis

• Biliary colic (shorter, no fever, no inflammation)
• Acute cholangitis (jaundice, high fever, rigors)
• Acute pancreatitis
• Perforated peptic ulcer
• Acute appendicitis (high, retrocaecal, in pregnancy)
• Right lower lobe pneumonia, myocardial infarction
• Hepatitis, liver abscess, Fitz-Hugh-Curtis syndrome (gonococcal perihepatitis)
• Right pyelonephritis, renal colic
• Gallbladder cancer

9. Treatment

Conservative

• Initial care (all):
  1. Admit, nil by mouth or light diet, IV fluids
  2. Analgesia → NSAIDs, opioids
  3. Antibiotics → e.g. co-amoxiclav, or cefuroxime with metronidazole, piperacillin-tazobactam for severe (local guidance)
  4. Antiemetics, VTE prophylaxis
  5. Assess fitness (Charlson comorbidity index, ASA) and Tokyo grade
• Antibiotics → stop within 24 hours after cholecystectomy for grade I–II (no benefit after)
• Percutaneous cholecystostomy (ultrasound- or CT-guided drain) → unfit patients (grade II not fit, grade III not fit), acalculous cholecystitis, failure of conservative care
  • Drain stays 4–6 weeks; tubogram before removal; interval cholecystectomy if fit
• Endoscopic gallbladder drainage → EUS-guided gallbladder stent (lumen-apposing metal stent) or transpapillary stent → for patients unfit for surgery

Surgical

• Early laparoscopic cholecystectomy → standard of care:
  • Best within 72 hours of symptoms, but can be done up to 7–10 days (index admission)
  • Compared with delayed surgery (6–12 weeks) → shorter total stay, fewer readmissions, same or lower complication rate (CHOCOLATE, ACDC trials; Cochrane)
  • Up to 20–30% wait for delayed surgery then return with another attack
• Tokyo-guided plan:
  • Grade I → early laparoscopic cholecystectomy
  • Grade II → early laparoscopic cholecystectomy in an experienced centre; if not possible or unfit → antibiotics, drainage, then delayed surgery
  • Grade III → organ support, antibiotics; early cholecystectomy only in selected fit patients in expert centres; otherwise urgent drainage (cholecystostomy) and later surgery
• Technique notes:
  • Decompress a tense gallbladder with a needle first
  • Aim for the critical view of safety; if not possible → bail-out (subtotal cholecystectomy, fundus-first, conversion)
  • Drain the bed if needed
• Emergency surgery → perforation with peritonitis, emphysematous or gangrenous cholecystitis (with sepsis)
• Acalculous → cholecystostomy first; cholecystectomy if gangrene, perforation or drainage fails
• Chronic cholecystitis → elective laparoscopic cholecystectomy
• Porcelain gallbladder → cholecystectomy (cancer risk, lower than once thought)

10. Complications

• Empyema → gallbladder full of pus; spiking fever, sepsis
• Gangrene and perforation → abscess, biliary peritonitis (mortality up to 30%)
• Cholecystoenteric fistula → gallstone ileus
• Mirizzi syndrome
• Emphysematous → gangrene, perforation; mortality about 15%
• Sepsis, multiorgan failure
• Surgery → bile duct injury (higher in acute inflammation), bile leak, bleeding, conversion to open (up to 10–25%), subhepatic abscess
• Cholecystostomy → dislodgement, bile leak, recurrent cholecystitis

Prognosis

• Mild cholecystitis → good; mortality under 1%
• Acalculous and severe → mortality 10–50%