The liver is the largest solid abdominal organ with a relatively fixed position, which makes it prone to injury. The liver is the second most commonly injured organ in abdominal trauma, but damage to the liver is the most common cause of death after abdominal injury (see the images below). The most common cause of liver injury is blunt abdominal trauma, which is secondary to motor vehicle accidents in most instances.
In the past, most of these injuries were treated surgically. However, surgical literature confirms that as many as 86% of liver injuries have stopped bleeding by the time surgical exploration is performed, and 67% of operations performed for blunt abdominal trauma are nontherapeutic.
Philipoff et al have proposed that a stiff, cirrhotic liver may represent an important risk factor for blunt gallbladder injury. Almost all gallbladder injuries following blunt trauma are associated with other significant intra-abdominal injuries, and in the setting of acute trauma, the authors recommend an open procedure to facilitate exploration to rule out associated injuries. Cholecystectomy remains the definitive management for gallbladder trauma. Gallbladder rupture is seen in less than 1% of cases of blunt abdominal trauma.
Conservative, nonoperative management has become the treatment of choice for blunt hepatic trauma in hemodynamically stable patients. The increased use of nonoperative management has been facilitated by advancements such as higher-resolution CT, increased availability of interventional procedures such as angiography and embolization, image-guided percutaneous drainage, and endoscopy. Such advancements have also helped to quickly identify the need for urgent laparotomy and attention to visceral and vascular injuries.
Almost 80% of adults and 97% of children are treated conservatively by using careful follow-up imaging studies.
For hepatic lesions that are grade 1 through 3, according to the American Association for the Surgery (AAST) (see below), nonoperative management is indicated if there is no injury to abdominal organs. Surgical intervention is required for any lesions higher than grade IV in which there is hemorrhagic risk or recurrence.
AAST Liver Trauma Classification
The AAST has classified liver trauma injuries as follows
Grade I: hematoma: subcapsular <10% surface area; laceration: capsular tear <1 cm parenchymal depth.
Grade II: hematoma: subcapsular 10-50% surface area; intraparenchymal <10 cm diameter; laceration: capsular tear 1-3 cm parenchymal depth, <10 cm in length.
Grade III: hematoma: subcapsular >50% surface area of ruptured subcapsular or parenchymal hematoma; intraparenchymal hematoma >10 cm or expanding; laceration: >3 cm parenchymal depth.
Grade IV: laceration: parenchymal disruption involving 25-75% hepatic lobe or 1-3 Couinaud segments.
Grade V: laceration: parenchymal disruption involving >75% of hepatic lobe or >3 Couinaud segments within a single lobe; vascular: juxtahepatic venous injuries (ie, retrohepatic vena cava/central major hepatic veins).
Grade VI: hepatic avulsion.
The World Society of Emergency Surgery (WSES) has presented the following classifications utilizing the AAST grading system
Grade I (minor hepatic injury): AAST grade I-II hemodynamically stable either blunt or penetrating lesions.
Grade II (moderate hepatic injury): AAST grade III hemodynamically stable either blunt or penetrating lesions.
Grade III (severe hepatic injury): AAST grade IV-VI hemodynamically stable either blunt or penetrating lesions.
Grade IV (severe hepatic injury): AAST grade I-VI hemodynamically unstable either blunt or penetrating lesions.
Plain radiographic findings are nonspecific, but they may be useful in showing the extent of associated skeletal trauma. Contrast-enhanced CT scanning remains the examination of choice in patients with blunt abdominal trauma.
Radionuclide study with technetium-99m (99mTc) iminodiacetic acid (IDA) is the examination of choice in patients in whom bile leaks are suspected. Magnetic resonance imaging (MRI) has yet to find a role but can be used to monitor liver injury. Magnetic resonance cholangiopancreatography (MRCP) may be used for the diagnosis and follow-up observation of bile duct injuries.
Angiography is useful in localizing the site of hemorrhage and in providing an opportunity for the interventional radiologist to proceed to transcatheter embolization of bleeding sites.
The original guidelines of Practice Management for Nonoperative Management of Blunt Injury to the Liver and Spleen (Eastern Association for the Surgery of Trauma guideline) remain valid, supported by the accumulation of a large amount of data. Stassen et al reviewed 176 papers, of which 94 were used to create the current practice management guideline for the selective nonoperative management of blunt hepatic injury.
The review concluded that nonoperative management of blunt hepatic injuries currently is the treatment modality of choice in hemodynamically stable patients, irrespective of the grade of injury or patient age. However, nonoperative imaging of blunt trauma should only be considered when reliable monitoring, serial clinical evaluations, and an operating room available for urgent laparotomy are readily available. Patients who are hemodynamically unstable and have peritonitis still warrant emergent operative intervention. Ready availability of CT, angiography, percutaneous drainage, ERCP, and laparoscopy remain important adjuncts to nonoperative management of hepatic injuries.
The authors add that despite the explosion of literature on this topic, many questions regarding nonoperative management of blunt hepatic injuries remain without conclusive answers in the literature.
Grade 1 hepatic injury in a 21-year-old man with a stabbing injury to the right upper quadrant of the abdomen. Axial, contrast-enhanced computed tomography (CT) scan demonstrates a small, crescent-shaped subcapsular and parenchymal hematoma less than 1 cm thick.
Grade 1 hepatic injury in a 21-year-old man with a stabbing injury to the right upper quadrant of the abdomen. Diagram of the CT scan in the previous image.
For more information, see Blunt Abdominal Trauma in Emergency Medicine, Penetrating Abdominal Trauma in Emergency Medicine, and Penetrating Abdominal Trauma.
Limitations of techniques
Plain radiographs cannot depict liver trauma directly, and radiographic findings may be completely normal. In penetrating abdominal trauma, overall sensitivity of focused ultrasonography is 46%, and specificity is 94%.
Emergency ultrasonographic findings based on the demonstration of free fluid and/or parenchymal injury demonstrate the overall sensitivity of ultrasonography for detection of blunt abdominal trauma to be 72%. However, the sensitivity is higher (98%) for injuries of grade 3 or higher. However, negative ultrasonographic findings do not exclude hepatic injury.
Angiographic images can fail to depict active bleeding, and false-negative or false-positive diagnoses can occur with liver trauma.