69. Liver and biliary trauma

1. Definition

• Liver trauma → injury to the liver parenchyma, capsule, hepatic veins, retrohepatic vena cava or portal structures from blunt or penetrating force
• Biliary trauma → injury to the gallbladder or bile ducts, from external trauma or during surgery (iatrogenic bile duct injury)

2. Epidemiology

• Liver → most commonly injured solid organ in penetrating trauma; second after the spleen in blunt trauma (in many series now the most common in blunt too)
• Blunt (road traffic collisions, falls) → about 80% in Europe; penetrating (stab, gunshot) more in some countries
• Right lobe injured far more than the left (larger, fixed, near the ribs)
• Non-operative management → succeeds in over 80–90% of haemodynamically stable blunt injuries
• Extrahepatic bile duct injury from external trauma → rare (under 1% of abdominal trauma), often with duodenal, pancreatic or vascular injuries
• Iatrogenic bile duct injury → 0.3–0.5% of laparoscopic cholecystectomies (most common cause of bile duct injury)
• Mortality → about 10% in all; over 50% with retrohepatic caval or hepatic vein injury

3. Aetiology and risk factors

Anatomy (revision)

• Couinaud segments I–VIII; Cantlie's line (gallbladder fossa to IVC) divides right and left lobes
• Dual blood supply → portal vein (75% of flow) and hepatic artery (25%)
• Hepatic veins drain into the retrohepatic IVC; short and hard to reach
• Portal triad in the hepatoduodenal ligament (free edge of the lesser omentum) → CBD (lateral), hepatic artery (medial), portal vein (posterior); Pringle manoeuvre clamps it
• Ligaments → falciform, coronary, triangular; bare area
• Gallbladder fixed in its fossa; CBD in the hepatoduodenal ligament

Mechanisms

• Blunt:
  • Direct crush against the ribs and spine
  • Deceleration → shear at the ligaments and hepatic veins (tears between segments, caval injuries)
• Penetrating → stab (lower energy), gunshot (cavitation, more damage)
• Iatrogenic → liver biopsy, PTC, laparoscopic cholecystectomy (misidentification of the CBD as the cystic duct, thermal injury)
• Risk factors → lower right rib fractures, seat-belt injuries, coagulopathy, cirrhosis, large liver

4. Pathogenesis

• Bleeding → main early killer; portal and hepatic venous bleeding is low-pressure, so many stop on their own; arterial bleeding continues
• Subcapsular haematoma → may rupture later (delayed bleeding)
• Bile leak → biloma, bile peritonitis (chemical then infected)
• Haemobilia → fistula between an artery (or pseudoaneurysm) and a bile duct → bleeding into the bile ducts
• Bilhaemia → bile into the hepatic veins (rare)
• Devitalised liver → necrosis, abscess
• Lethal triad in massive bleeding → hypothermia, acidosis, coagulopathy (with hypocalcaemia, the "lethal diamond")

5. Classification

AAST liver injury scale (2018)

• Grade I → subcapsular haematoma < 10% surface; laceration < 1 cm deep
• Grade II → subcapsular haematoma 10–50%; intraparenchymal haematoma < 10 cm; laceration 1–3 cm deep, < 10 cm long
• Grade III → subcapsular haematoma > 50% or expanding; intraparenchymal haematoma > 10 cm; laceration > 3 cm deep; any vascular injury or active bleeding contained in the liver
• Grade IV → parenchymal disruption of 25–75% of a lobe; active bleeding beyond the liver into the peritoneum
• Grade V → disruption > 75% of a lobe; juxtahepatic venous injury (retrohepatic IVC, central hepatic veins)
• (Grade VI, hepatic avulsion, removed in the 2018 revision)

WSES (World Society of Emergency Surgery)

• Minor (AAST I–II), moderate (III), severe (IV–V or any haemodynamically unstable patient)

Bile duct injury (iatrogenic)

• Strasberg → A (cystic duct or duct of Luschka leak), B (occluded aberrant right duct), C (transected aberrant right duct), D (lateral injury to the CBD), E1–E5 (transection or stricture of the main duct by level: Bismuth types 1–5)

6. Clinical picture

Symptoms

• RUQ pain, right shoulder tip pain (Kehr's sign on the right; diaphragm irritation)
• Abdominal pain, distension
• Symptoms of blood loss → thirst, dizziness, confusion
• Biliary injury → pain, distension, fever, jaundice days later (biloma, bile peritonitis)
• Haemobilia → Quincke's triad: RUQ pain, jaundice, upper GI bleeding (haematemesis or melaena), often weeks later

Signs

• Haemorrhagic shock → tachycardia, hypotension, cool skin
• RUQ tenderness, guarding; peritonism; distension
• Lower right rib fractures, seat-belt bruising
• Penetrating wounds of the lower right chest or RUQ (thoracoabdominal)
• Bile leak → bile in a drain, ascites, jaundice, fever

7. Diagnosis

• ATLS primary survey (ABCDE); FBC, crossmatch, coagulation, lactate, base deficit, blood gas
• eFAST → free fluid in the abdomen (Morison's pouch) in an unstable patient → straight to theatre
• CT with IV contrast (arterial and portal phases) → stable patients; gold standard:
  • Grade of injury
  • Contrast blush (active arterial bleeding) or pseudoaneurysm → angioembolisation
  • Other injuries (spleen, kidneys, bowel)
• Delayed (excretory) phase → bile leak
• Bile leak → HIDA scan; MRCP; ERCP (diagnosis and treatment)
• Haemobilia → CT angiography, angiography (diagnostic and therapeutic); endoscopy shows blood from the ampulla
• Diagnostic peritoneal lavage → rarely now (when FAST not available)
• Laparoscopy → penetrating thoracoabdominal wounds (diaphragm)

8. Differential diagnosis

• Splenic injury, renal injury, pancreatic or duodenal injury
• Hollow viscus injury (bowel, mesentery)
• Rib fractures alone, chest injury (haemothorax)
• Retroperitoneal haematoma, pelvic fracture bleeding

9. Treatment

Conservative

• Non-operative management (NOM) → standard for haemodynamically stable patients, any grade:
  • Conditions → stable (or responds to fluids), no peritonitis, no other injury needing laparotomy, CT available, ICU or HDU monitoring, surgeon and theatre available 24 hours
  • Serial examination, serial haemoglobin, bed rest (short), VTE prophylaxis after 24–48 hours if no bleeding
  • Failure of NOM → about 5–10%; most in the first 24–72 hours
• Angioembolisation → active contrast blush on CT in a stable patient, pseudoaneurysm, haemobilia, or after packing (hybrid approach)
• Selected stab wounds in stable patients without peritonitis → NOM in expert centres
• Bile leak or biloma → percutaneous drainage plus ERCP with sphincterotomy and stent (lowers duct pressure; leak heals)
• Follow-up CT → only for symptoms or high grades; avoid contact sport for 3–6 months (grades III–V)

Surgical

• Indications for laparotomy → haemodynamic instability (non-responder), peritonitis, other injuries needing surgery, failed NOM, gunshot wounds in most centres
• Damage control resuscitation → massive transfusion protocol (red cells, plasma, platelets 1 : 1 : 1), tranexamic acid within 3 hours, permissive hypotension, warming, calcium
• Damage control laparotomy:
  1. Midline laparotomy; pack all four quadrants
  2. Manual compression of the liver
  3. Perihepatic packing → packs above, below and behind the liver to compress it (not packs inside a laceration)
  4. Pringle manoeuvre → clamp the hepatoduodenal ligament; bleeding stops → arterial or portal source; continues → hepatic veins or retrohepatic IVC
  5. Control bleeding → ligation of vessels in the wound (hepatotomy and direct ligation), suture, haemostatic agents, balloon tamponade for tracts (gunshot)
  6. Resectional debridement of dead liver (not formal anatomical resection in the acute phase)
  7. Temporary abdominal closure (vacuum dressing); ICU to correct the lethal triad
  8. Relook in 24–48 hours → remove packs, definitive repair
• Severe juxtahepatic venous injury → packing; total vascular exclusion, atriocaval shunt (Schrock) → high mortality
• REBOA and hybrid theatre → selected centres
• Liver transplantation → rare, for total devastation
• Gallbladder injury → cholecystectomy
• Extrahepatic bile duct injury:
  • Small lateral tear → primary repair over a T-tube or stent
  • Transection or loss of length → Roux-en-Y hepaticojejunostomy (best when patient is stable; drain first in damage control)
  • Iatrogenic injury found at surgery → call an HPB surgeon; if not available, drain and transfer
  • Late strictures → hepaticojejunostomy in an HPB centre

10. Complications

• Bleeding → early death; delayed bleeding after NOM
• Bile leak, biloma, bile peritonitis
• Haemobilia, pseudoaneurysm
• Liver abscess, infected haematoma
• Abdominal compartment syndrome (after packing and massive transfusion)
• Hepatic necrosis (after embolisation), gallbladder ischaemia
• Biliary stricture, secondary biliary cirrhosis (bile duct injury)
• Lethal triad, multiorgan failure, ARDS