NTRODUCTIONThe liver is the most frequently injured abdominal organ. Most hepatic injuries are relatively minor and heal spontaneously with nonoperative management which consists of observation, and possibly arteriography and embolization [1,2]. Operative intervention to manage the liver injury is needed in about 14 percent of patients including those who initially present with hemodynamic instability or those who fail nonoperative management [2,3].The diagnosis and management of hepatic injury in adults is reviewed here. Surgical techniques to manage liver injury are discussed in detail elsewhere. (See "Surgical techniques for managing hepatic injury".)MECHANISM OF INJURYThe liver is the most commonly injured organ in blunt abdominal trauma and the second most commonly injured organ in penetrating abdominal trauma [3-6]. The liver is a highly vascular organ located in the right upper quadrant (figure 1) of the abdomen and is susceptible to injury from traumatic mechanisms. Among patients with blunt injury, motor vehicle collision is the most common injury mechanism [3]. In patients with penetrating liver injury, the severity of injury depends upon the trajectory of the missile or implement and injuries can range from simple parenchymal to major vascular laceration.The liver margin, which can usually be palpated 2 to 3 cm below the right rib margin, rises and falls with the diaphragm during respiration. The dome of the liver rises as high as the level of T4 (nipple) with expiration. Thus, injuries to the chest wall are often associated with significant injury to the liver. Similarly, the inferior margin of the liver descends to as low as T12 with deep inspiration, and injuries, particularly penetrating injuries, have the potential to injure the liver lower in the abdomen than might be expected. The posterior portion of the right lobe (figure 2) is the most common site of hepatic injury in blunt trauma [7].TRAUMA EVALUATIONWe perform the initial resuscitation, diagnostic evaluation and management of the trauma patient with blunt or penetrating trauma based upon protocols from the Advanced Trauma Life Support (ATLS) program, established by the American College of Surgeons Committee on Trauma. The initial resuscitation and evaluation of the patient with blunt or penetrating abdominal or thoracic trauma is discussed in detail elsewhere.

(See "Initial evaluation and management of blunt abdominal trauma in adults".) (See "Initial evaluation and management of abdominal gunshot wounds in adults".) (See "Initial evaluation and management of abdominal stab wounds in adults".) (See "Initial evaluation and management of blunt thoracic trauma in adults".) (See "Initial evaluation and management of penetrating thoracic trauma in adults".)

Hemodynamically unstable trauma patients should be transferred immediately to the operating room for evaluation and management. If the clinical setting allows, a Focused Assessment with Sonography for Trauma (FAST) exam, diagnostic peritoneal lavage (DPL), or computerized tomography (CT) may be performed. The choice of test and their value in the diagnostic evaluation of the trauma patient is discussed in detail elsewhere.

(See "Initial evaluation and management of blunt abdominal trauma in adults", section on 'Ultrasound' and "Initial evaluation and management of abdominal gunshot wounds in adults", section on 'Ultrasound' and "Initial evaluation and management of abdominal stab wounds in adults", section on 'Ultrasound'.) (See "Initial evaluation and management of blunt abdominal trauma in adults", section on 'Diagnostic peritoneal lavage (DPL)' and "Initial evaluation and management of abdominal stab wounds in adults", section on 'Diagnostic peritoneal tap and diagnostic peritoneal lavage' and "Initial evaluation and management of abdominal gunshot wounds in adults", section on 'Diagnostic peritoneal lavage'.)

Plain films obtained during the trauma evaluation are generally nonspecific but may demonstrate right-sided rib fractures, which increase the suspicion for liver injury.Specific elements of the history, physical examination, and imaging evaluation that pertain to liver injury are discussed below.History and physical examinationA history of trauma to the right upper quadrant, right rib cage, or right flank should increase the suspicion for liver injury. The patient may complain of pain in the right upper abdomen, right chest wall, or the right shoulder due to diaphragmatic irritation. Abdominal tenderness and peritoneal signs are the most common findings indicative of intraabdominal injury; however, these are not sensitive or specific for liver injury. Physical findings associated with liver injury include right upper quadrant or generalized abdominal tenderness, abdominal wall contusion or hematoma (eg, seat belt sign), right lower chest wall tenderness, contusion, or instability due to rib fractures. Specific attention should be paid to any wounds that penetrate the right chest, abdomen, flank, or back, remembering that significant liver damage can occur without a wound in close proximity to it. A negative history and exam does not reliably exclude liver injury.In the setting of injury, many patients have altered mental status (eg, neurologic injury, intoxication) or are intubated and sedated and cannot relate their symptoms or medical history. Any preexisting medical conditions should be identified, particularly those requiring antiplatelet or anticoagulant therapy. (See "Overview of inpatient management in the adult trauma patient", section on 'Patient assessment'.)Associated injuriesOther injuries are present in about 80 percent of patients with hepatic injury. In one series of 146 cases of hepatic injury, chest injury was the most commonly associated injury overall and the spleen was the most commonly injured intraabdominal organ [8]. Other injuries associated with a blunt mechanism include lower rib fractures, pelvic fracture, and spinal cord injury.Injuries associated with penetrating mechanisms depend upon the implement and missile trajectory. Injuries to adjacent organs can occur in conjunction with liver laceration and include injuries to the vena cava, extrahepatic portal structures, colon, diaphragm, right lung, duodenum, and right kidney.Laboratory studiesThere are no specific laboratory tests diagnostic for hepatic injury. An initially elevated white blood cell count in the trauma patient is common and frequently related only to the physical stress of trauma. A finding of anemia is similarly nonspecific. The degree of anemia is related to the volume of blood lost, which can be from sites other than the liver, and the nature (crystalloid versus colloid) and volume of fluid resuscitation. The time course for developing anemia following posttraumatic hemorrhage is variable and related to the rapidity of exogenous fluid administration, and endogenous fluid shifts. Thus, the absence of anemia at the time of initial patient presentation does not rule out significant liver trauma-related bleeding.DIAGNOSISA diagnosis of liver injury may be suspected in the hemodynamically stable patient based upon mechanism of injury, physical examination or laboratory findings. However, imaging, usually using computed tomography (CT) of the abdomen definitively confirms the injury and defines the injury grade. Pooling of intravenous contrast in or around the liver implies ongoing bleeding and the need for intervention [9,10]. CT scanning also identifies associated intraabdominal and chest injuries.The Focused Assessment with Sonography in Trauma (FAST) exam is more commonly used in hemodynamically unstable patients. However, a negative FAST examination is not adequate to exclude liver injury, particularly intraparenchymal injury. On FAST examination, signs of liver injury include findings of a hypoechoic (ie, black) rim of subcapsular fluid, intraperitoneal fluid around the liver, or fluid in Morrisons pouch (hepatorenal space). Although diagnostic peritoneal aspiration/lavage (DPA/DPL) has largely been replaced by the FAST examination in most major trauma centers, it may still be useful in selected patients, if the FAST is equivocal.Organ-based ultrasound imaging, and magnetic resonance imaging (MRI) are of limited value in the initial diagnosis of liver injury. Organ-based ultrasound imaging and MRI are time-consuming to perform, and may put the patient in a location remote from ready access and intervention. However, MRI may be useful in a subset of hemodynamically stable patients who cannot undergo CT scan (eg, allergic to IV contrast), and patients with suspected extrahepatic ductal injury. (See "Management of duodenal and pancreatic trauma in adults", section on 'Magnetic resonance cholangiopancreatography' and "Magnetic resonance cholangiopancreatography", section on 'Pancreatic duct disruption'.)Arteriography is generally reserved for patients who have indications for hepatic embolization to manage intrahepatic arterial hemorrhage. (See 'Hepatic embolization' below.)HEPATIC INJURY GRADINGWe use the American Association for the Surgery of Trauma (AAST) classification system, the most widely accepted injury grading scale, to grade hepatic injuries [3,11]. In a study of the solid organ injuries in the National Trauma Data Bank (NTDB) in 2008, 67 percent of hepatic injuries were grade I, II, or III [3].The AAST grading system is most useful for predicting the likelihood of success with nonoperative management, which is higher for low-grade injuries (Grade I, II, III) compared with high-grade injuries (Grade IV, V). Patients with Grade VI injuries are universally hemodynamically unstable, mandating surgical intervention. The grades of hepatic injury are as follows:

Grade I Hematoma: subcapsular 75 percent of a hepatic lobe, >3 Couinaud segments (figure 2) within a single lobe. Vascular: juxtahepatic venous injuries (retrohepatic vena cava, central major hepatic veins) (image 8). Grade VI Hepatic avulsion.

APPROACH TO MANAGEMENTImproved speed and sensitivity of diagnostic imaging, most notably CT scanning, accompanied by advances in critical care monitoring have promoted a shift from operative to nonoperative management for most hemodynamically stable patients with hepatic injury. This practice has been associated with a decline in morbidity and mortality [1,2,4,8,12-17]. (See 'Morbidity and mortality' below.)The management strategy (operative or nonoperative) depends upon the hemodynamic status of the patient, grade of liver injury, and presence of other injuries and medical comorbidities.

The hemodynamically unstable trauma patient with a positive Focused Assessment with Sonography for Trauma (FAST) scan or positive diagnostic peritoneal lavage or aspirate (DPA/DPL) requires emergent abdominal exploration to determine the source of intraperitoneal hemorrhage. When the source of bleeding is the liver, exploratory laparotomy is performed and control of bleeding may be through a damage-control approach or by using specific techniques for liver hemostasis depending upon the presence and extent of associated injuries and the extent of the liver injury. (See "Surgical techniques for managing hepatic injury", section on 'Techniques for liver hemostasis'.) Patients with blunt liver injury who are hemodynamically stable and who do not have other indications for abdominal exploration can be observed [1,2,4,5,8,12,17-23]. Hemodynamically stable patients with right-sided penetrating thoracoabdominal injuries that lacerate the liver can also be observed, provided there are no associated intraabdominal injuries. Patients with higher grade injuries fail nonoperative management more commonly than those with lower grade injuries, but these patients should still be offered nonoperative management so long as they remain hemodynamically stable. In general, patients who meet the criteria for the observation of liver injury but who require intervention to treat extra-abdominal injuries (eg, leg fracture stabilization) can also be observed. (See 'Nonoperative management' below.)Surgical exploration is indicated in nonoperatively managed patients who continue to bleed (ongoing blood transfusion, hemodynamic instability), and in some patients who manifest a persistent systemic inflammatory response (ileus, fever, tachycardia, oliguria). The management of grade III injuries and higher often requires a combined angiographic and surgical approach. (See 'Hepatic embolization' below and "Surgical techniques for managing hepatic injury".)

NONOPERATIVE MANAGEMENTNonoperative management is the treatment of choice for hemodynamically stable patients with hepatic injury and consists of observation and supportive care with the adjunctive use of arteriography and hepatic embolization. Retrospective reviews of the National Trauma Data Bank and other observational studies have found that more than 80 percent of patients with blunt hepatic injury can be treated nonoperatively with success rates (defined as no need for operative intervention for the hepatic injury) in >90 percent of patients [1,5,16,18,23-26]. A review of the National Trauma Data Bank identified 35,510 hepatic injuries over a 10-year period from 1994 to 2003 [5]. Of these, 91 percent of adults were successfully managed nonoperatively. Over the study period, the percentage of patients with liver injury managed nonoperatively rose from 75 to 82 percent, but the overall mortality associated with liver trauma remained unchanged at about 15 percent.Successful nonoperative management requires appropriate patient selection and the availability of resources including availability of intensive care unit beds, blood bank support, immediate operating room availability, and surgeons and interventional angiographers experienced in managing hepatic injury.Patients who are hemodynamically stable but demonstrate extravasation from the liver on computed tomography (CT) of the abdomen have higher failure rates with nonoperative management, and these patients should undergo arteriography and possible liver embolization followed by continued observation and serial hemoglobin determination. (See 'Hepatic embolization' below.)Contraindications to nonoperative managementContraindications to nonoperative management of liver injury include the following [1,27,28]:

Hemodynamic instability after initial resuscitation Other indication for abdominal surgery (eg, peritonitis) Gunshot injury (relative contraindication)

Nonoperative management of gunshot wounds remains controversial even though nonoperative management of patients with isolated penetrating hepatic injuries due to abdominal stab wounds has been practiced routinely at many trauma centers for several years [29]. Nonoperative management of these patients fails in up to one-third of patients due to ongoing bleeding, or the development of abdominal compartment syndrome [15,20,28,30]. Missed injuries to the gastrointestinal tract are also a concern.ObservationNonoperatively managed patients should be admitted to a monitored unit and initially placed on bed rest [1]. Patients must be closely monitored by nursing and medical staff, and sufficient flexibility should be available to allow urgent/emergent intervention (arteriography or surgery). (See 'Failure of nonoperative management' below.)Large observational studies support the practice of discharging patients with liver injury who are being observed to home provided they have a normal abdominal examination and stable hemoglobin for at least 24 hours, regardless of the grade of injury. The length of observation is based solely on clinical criteria [31,32].Patients with liver injury or other severe injuries who require hospitalization are at a high risk for thromboembolism and should receive thromboprophylaxis; however, chemical thromboprophylaxis may need to be delayed due to an increased risk of bleeding (eg, cerebral injury). Provided there are no other contraindications to pharmacologic prophylaxis, we typically initiate treatment when the hemoglobin has stabilized with less than 1 g hemoglobin decrement over a 24-hour period of time. Pharmacologic prophylaxis does not appear to increase nonoperative management failure rates or blood transfusion requirements [33,34]. (See "Overview of inpatient management in the adult trauma patient", section on 'Thromboprophylaxis'.)Hepatic embolizationHepatic embolization requires special imaging facilities and a vascular interventionalist (ie, interventional radiology, vascular surgeon) experienced with celiac artery catheterization and embolization techniques. Success rates for embolization vary depending upon institution, embolization technique, arterial accessibility, operator skill, and the type of embolization material used. In some centers, hepatic embolization has replaced the need for initial operative intervention.Hepatic embolization appears to be most successful when used preemptively in hemodynamically stable patients who demonstrate extravasation of contrast on the initial abdominal CT scan. In retrospective reviews, technical success ranges from 68 to 87 percent and the incidence of recurrent hemorrhage is low [13,27,35-37].Hepatic embolization can also be used to treat patients who have failed observational management [13,38,39], and adjunctively to manage patients with ongoing bleeding or rebleeding from the liver after surgical management (algorithm 1) [38].Depending upon the nature of the injury and technical factors, embolization coils, microspheres, absorbable gelatin sponge, or endogenous clot can be used to interrupt blood flow in the main hepatic artery or branch vessels. Ischemic complications related to angioembolization are not uncommon and may lead to a need for surgical debridement or liver resection [40-42]. (See 'Morbidity and mortality' below.)Benefits and risks of nonoperative managementWhen nonoperative management is successful, the risks inherent to surgery and anesthesia are eliminated. However, disadvantages associated with nonoperative management include an increased risk of missed intraabdominal injury, particularly hollow viscus injury, transfusion-related illness, and risks associated with embolization techniques, such as hepatic necrosis. (See 'Morbidity and mortality' below.)Patients with missed gastrointestinal hollow viscus injury present with worsening abdominal pain and peritoneal signs, generally by postinjury day four. These patients require operative intervention, and, during exploration, the liver injury should also be evaluated. (See "Traumatic gastrointestinal injury in the adult patient" and "Surgical techniques for managing hepatic injury".)Blood transfusion is associated with many complications that can include intravascular volume overload (Transfusion Associated Circulatory Overload [TACO]), transfusion-related acute lung injury (TRALI), hypothermia, coagulopathy, immunologic and allergic reactions as well as immunomodulation (Transfusion Related Immune Modulation, TRIM). Some clinicians feel these risks may outweigh the benefits of aggressive nonoperative management strategies, particularly in patients with high-grade liver injuries. The risks associated with blood transfusion are discussed in detail elsewhere. (See "Use of blood products in the critically ill", section on 'Complications' and "Transfusion reactions caused by chemical and physical agents", section on 'Transfusional volume overload (TACO)' and "Transfusion-related acute lung injury (TRALI)" and "Leukoreduction to prevent complications of blood transfusion", section on 'Immunosuppression'.)Hepatic embolization is associated with additional risks that include bleeding, arterial access site complications, hepatic necrosis, liver/subdiaphragmatic abscess, inadvertent embolization of other organs (eg, bowel, pancreas) or lower extremities, allergic reaction to contrast, and contrast-induced nephropathy. The risk of contrast-induced nephropathy may be greater when embolization is performed following contrast CT scan, particularly in patients who may already be volume depleted. Contrast-induced nephropathy and its prevention are discussed in detail elsewhere. (See "Pathogenesis, clinical features, and diagnosis of contrast-induced nephropathy" and "Prevention of contrast-induced nephropathy".)Failure of nonoperative managementFailure of nonoperative management (observation and/or embolization) is defined as the need for operative intervention, and is generally related to bleeding that becomes apparent by the need for ongoing fluid resuscitation or transfusion, or hemodynamic instability. Hypotension may be absolute or relative, or manifested as persistent tachycardia despite adequate fluid resuscitation.Failure rates for nonoperative management of hepatic injury are generally low [9,30,36]. In a retrospective review of 591 patients managed nonoperatively for blunt liver injury, 6 percent failed nonoperative management with about half of these due to ongoing bleeding from other injuries [35]. Patients with grade IV or V injuries are more likely to fail nonoperative management.In one study, logistic regression found that blood transfusion 3 units (odds ratio 10.8, 95% CI 1.6-72.2) was an independent risk factor for surgical intervention [40]. Most protocols allow for continued observation with up to 4 units of blood transfusion related to the hepatic injury.Patients who become hemodynamically unstable, by definition, have failed nonoperative management, and should be taken immediately to the operating room for abdominal exploration. Arteriography with embolization should not be pursued under these circumstances given the time needed to set up the interventional radiology suite, get personnel in place, and perform the embolization procedure.Follow-up careThere are few data to guide the routine care and follow-up of patients with hepatic injury who have been managed nonoperatively. No definitive recommendations have been established regarding the need or timing of follow-up imaging, the need for or duration of bed rest, the timing of return to daily activities and/or exercise, or the timing to initiate prophylactic or therapeutic anticoagulation [6,43]. Although it is a common recommendation that patients avoid strenuous activities for several weeks, this remains intuitive with few data to support this practice [28]. For patients with higher grade injuries, we restrict strenuous physical activity for a longer period of time, which, for Grade V injury, can be as long as three months. SURGICAL MANAGEMENTThe operative management of liver injuries that require surgical intervention can be a challenge even for experienced surgeons due to the complex nature of the liver, its size, vascularity, dual blood supply (portal, hepatic arterial), and its rich and difficult-to-access venous drainage. In hemodynamically unstable patients, damage control techniques provide temporary control of bleeding and allow anesthesia staff to resuscitate the patient. Definitive management of bleeding from the liver is accomplished using a variety of techniques. The surgical management of hepatic injury is discussed in detail elsewhere. (See "Surgical techniques for managing hepatic injury".)MORBIDITY AND MORTALITYMortality rates for hepatic injury vary according to the grade of the injury and have improved over time with the introduction of nonoperative management strategies and the use of perihepatic packing [14]. Since mortality is unusual with Grade I and II injuries, the greatest reduction in operative mortality has occurred for higher grade liver injuries (Grade III, IV, V). Overall mortality for these higher grade injuries ranges from 10 to 42 percent [21,22,39,44,45]. However, many studies do not include mortality related to juxtahepatic injury, for which mortality rates remain extremely high (77 percent in one series) [23].Complications are common following the management of liver injuries. The incidence of complications increases with the grade of liver injury [20,46]. In a series of 669 patients, complications developed in 5, 22, and 52 percent of patients with grade III, IV, and V injuries, respectively [45]. Complications associated with lower grade injuries (grade I, II) are rare.Biliary tree disruption with formation of biloma and/or persistent bile leak is a frequent complication of nonoperative management for liver injury. The incidence of bile leak ranges from 0.5 to 21 percent [36,47,48]. Bile leak manifests as abdominal pain or a persistent systemic inflammatory response syndrome (SIRS) with fever, tachycardia, and leukocytosis. Repeat abdominal CT scan establishes the diagnosis. Biliary tree disruption with persistent bilious drainage can often be successfully managed by endoscopic retrograde cholangiopancreatography and stent placement. However, findings on abdominal CT consistent with bile ascites and/or persistent hemoperitoneum warrant laparoscopic evaluation with abdominal irrigation and drainage to remove the bile, which is very irritating to the peritoneum. Findings consistent with perihepatic abscesses can usually be managed with antibiotics and percutaneous drainage techniques, but surgery may be needed if interventional techniques fail to provide adequate drainage [46].Hepatic necrosis to some extent commonly occurs following angioembolization for hepatic injury, but may also be seen following laparotomy and hepatorrhaphy [39,41]. The combination of hepatic injury and ischemia induced by embolization may predispose to major hepatic necrosis, particularly in patients who have previously undergone surgery [41]. Major hepatic necrosis is managed surgically with repeated resectional debridement in conjunction with interventional drainage procedures, or hepatic lobectomy [41,42]. Early lobectomy rather than repeated debridement may be associated with a lower overall complication rate and the need for fewer procedures. (See "Surgical techniques for managing hepatic injury", section on 'Liver resection'.)SUMMARY AND RECOMMENDATIONS

Hepatic injury can result from blunt or penetrating chest or abdominal trauma. Following blunt trauma, the liver is the most commonly injured organ. Penetrating injury to the liver is frequently associated with injuries to adjacent structures that can be associated with mortality rates exceeding 75 percent in some studies. (See 'Introduction' above and 'Associated injuries' above.) We perform initial resuscitation, diagnostic evaluation, and management of the trauma patient based upon protocols from the Advanced Trauma Life Support (ATLS) program developed by the American College of Surgeons Committee on Trauma. Hemodynamically unstable patients with a positive Focused Assessment with Sonography for Trauma (FAST) exam or diagnostic peritoneal lavage or aspirate (DPL/DPA) require operative surgical exploration to determine the source of life-threatening hemorrhage, which may be due to liver injury. (See 'Trauma evaluation' above and 'Approach to management' above.) A suspicion of hepatic injury is increased with right upper quadrant and/or right chest trauma; however, the clinical history and physical examination are not sufficiently sensitive or specific for the presence of liver injury. (See "Management of splenic injury in the adult trauma patient", section on 'Trauma evaluation' and 'Trauma evaluation' above.) Computed tomography (CT) of the abdomen identifies the presence of liver injury and defines its severity in hemodynamically stable patients. Hepatic injury is graded (I through VI) depending upon the extent and depth of liver hematoma and/or laceration as identified on abdominal CT, or at the time of surgery. Higher grades of hepatic injury correlate with increasing morbidity and mortality. (See 'Hepatic injury grading' above and 'Morbidity and mortality' above.) For hemodynamically stable patients with liver injury, we suggest nonoperative management over definitive surgical intervention, regardless of hepatic injury grade (Grade 2C). Observation involves monitored care, serial abdominal examination, and serial hemoglobin assessment and potentially hepatic embolization. Failure of nonoperative management (ongoing transfusion, hemodynamic instability) indicates the need for hepatic embolization or surgery. (See 'Observation' above.) For hemodynamically stable patients with liver injury who demonstrate pooling of intravenous contrast on initial or subsequent abdominal CT scan, we suggest hepatic embolization rather than nonoperative management without embolization (Grade 2C). Hepatic embolization requires specialized imaging facilities and an appropriately-trained interventionalist experienced with celiac artery catheterization. Failure of hepatic embolization to control bleeding indicates the need for surgery. (See 'Hepatic embolization' above.) Mortality has decreased with the introduction of nonoperative management strategies and damage control techniques [14]. Mortality for low-grade (I, II, III) injuries is rare, but for high-grade injuries ranges from 10 to 42 percent (IV, V, VI). Complications related to nonoperative management are common and include bile leak that can lead to ascites, biloma, or abscess, and hepatic necrosis related to angioembolization. (See 'Morbidity and mortality' above.)

Use of UpToDate is subject to the Subscription and License Agreement.REFERENCES