A 28 yo F presents to the ED as an unrestrained driver in an MVC. She hit a tractor trailer at an unknown speed. She is pale and hypotensive on arrival. A CT scan is shown below. What's the diagnosis? (scroll down for answer)

Answer: Grade V Liver Laceration

• The liver is the most commonly injured organ in blunt trauma to the abdomen and 2nd most commonly injured in penetraing trauma to the abdomen
• Most common mechanism is MVC
• Can occur with penetraing injury to chest or abdomen due to rising of liver during expiration 
• Diagnosis:
• US: Sensitivity:  63-100%    Specificity:  95-100%
• CT: Sensivity:  92-97%     Specificity: 98.7%
• Grading:
• Grade I
• Hematoma: subcapsular, nonexpanding <10 cm surface area
• Laceration: capsular tear, nonbleeding, < 1cm parenchymal depth
• Grade II
• Hematoma: subcapsular, nonexpanding 10-50% surface area or intraparenchymal nonexpanding < 10 cm diameter
• Laceration: capsular tear, active bleeding, 1-3cm parenchymal depth < 10 cm length
• Grade III
• Hematoma: subcapsular, > 50% surface area or expanding, ruptured subcapsular hematoma w/ active bleeding or intraparenchymal hematoma > 10cm 
• Laceration: capsular tear > 3cm parenchymal depth 
• Vascular injury w/ active bleeding contained w/in liver parenchyma
• Grade IV
• Laceration: parenchymal disruption involving 25-75% of hepatic lobe or 1-3 Couinaud's segments w/in a single lobe
• Grade V
• Laceration: parenchymal disruption involving > 75% of hepatic lobe or > 3 Couinaud's segments w/in a single lobe
• Vascular: Juxtahepatic venous injury (retrohepatic vena cava/central major hepatic veins)
• Grade VI
• Vascular: Hepatic avulsion
• Management
• Nonoperative management is preferrred for hemodynamically stable patients (regardless of severity of injury)
• Even if patient is hemodynamically stable, if active extravasation is seen on CT scan, patient may need arteriography and possibly embolization
• Reasons a patient should not be managed nonoperatively: 
• Hemodynamically unstable (after initial recusiation)
• Inability for facility to provide close monitoring or capabilites to provide hepatic embolization
• Other indication for laparatomy (peritonitis)
• GSW (relative contraindication) 

 References:

Ahmed N, Vernick JJ. Management of liver trauma in adults. J Emerg Trauma Shock. 2011;4(1):114-119.

Maung A, Rohs TJ Jr, Sangosanya A, Schuster K, Seamon M, Tchorz KM, Zarzuar BL, Kerwin A, Eastern Association for the Surgery of Trauma. J Trauma Acute Care Surg. 2012 Nov;73(5 Suppl 4):S288-93

American Association for the Surgery of Trauma Organ Injury Scale I: spleen, liver, and kidney, validation based on the National Trauma Data Bank. Tinkoff G, Esposito TJ, Reed J, Kilgo P, Fildes J, Pasquale M, Meredith JW J Am Coll Surg. 2008;207(5):646

Lee E.S., Shin CI. (2014) Trauma and Postoperative Changes of the Liver. In: Choi B. (eds) Radiology Illustrated: Hepatobiliary and Pancreatic Radiology. Radiology Illustrated. Springer, Berlin, Heidelberg.