Management of blunt or penetrating injuries to the liver remains a significant challenge. Despite its protected location, the liver is the most frequently injured intra-abdominal organ. Violent behaviour and road traffic accidents account for the majority of liver injuries. Liver injuries secondary to blunt trauma are typical in Europe, while penetrating injuries are the most frequent in North America. Associated injuries to other organs, uncontrolled haemorrhage from the liver and subsequent development of septic complications contribute to morbidity and death.

Two types of blunt liver trauma have been described. Deceleration injuries occur in road traffic accidents and in falls from a height when, on impact, the liver continues to move, thereby producing a laceration of its relatively thin capsule and parenchyma at the sites of attachment to the diaphragm. Penetrating injuries are usually associated with gunshot or stab wounds, with the former usually resulting in more tissue damage due to the cavitation effect as the bullet traverses the liver substance.

The severity of liver trauma ranges from a minor capsular tear, with or without parenchymal injury, to extensive disruption involving both lobes of the liver with associated hepatic vein or vena caval injury. The Organ Injury Scaling Committee of the American Association for the Surgery of Trauma produced a Hepatic Injury Scale which was revised in 1994 and is currently regarded as the standard by which hepatic injuries are described. Grade I or II injuries are considered minor; they represent 80-90 per cent of all cases and usually require minimal or no operative treatment. Grade III-V injuries are generally considered severe and often require surgical intervention, while grade VI lesions are regarded as incompatible with survival.

Patient assessment and initial investigation. A conscious patient, who is haemodynamically unstable following blunt trauma and has generalized peritonism, should undergo immediate laparotomy without further investigation. If the patient is neurologically impaired or physical signs are equivocal, a diagnostic peritoneal lavage (DPL) should be undertaken and an immediate laparotomy performed if the test is positive. However, if the patient is haemodynamically stable, further radiological assessment should be undertaken.

A gunshot wound to the abdomen is an indication for laparotomy regardless of the physical signs, as it is difficult to assess the damage caused by a bullet without surgical exploration. Urgent laparotomy is also indicated in patients who have sustained a stab wound to the abdomen and are haemodynamically unstable. If the patient is stable and a liver injury is suspected, imaging studies should be performed.

Abdominal ultrasonography is often used as the initial radiological techniqu. Early and rapid assessment can be obtained and many major trauma centres are now using abdominal ultrasonography and computed tomography (CT) in preference to DPL.

Although CT is very useful in the evaluation of stable patients with abdominal trauma, most authors agree that unstable patients, with either blunt or penetrating trauma, are unlikely to benefit from this investigation because of the valuable time that it requires.

Diagnostic laparoscopy has been used successfully in penetrating trauma, but its role in blunt abdominal trauma is not well defined. The benefits of laparoscopic assessment include reducing negative and non-therapeutic laparotomy rates, patient morbidity rates, hospital stay and treatment costs. Limited therapeutic intervention may also be possible in a small number of patients.

Non-operative management

The recognition that 50-80 per cent of liver injuries stop bleeding spontaneously has led to a non-operative approach for blunt liver trauma in haemodynamically stable patients. Furthermore, CT has contributed to a generalized acceptance of this method as an effective therapeutic strategy for liver injuries.

Non-operative management of blunt liver trauma has been shown to be safe in selected patients, thereby reducing the number of unnecessary laparotomies. Of all the variables evaluated, haemodynamic stability appears to be the most crucial and has become the decisive factor in favour of undertaking non-operative management.

Operative management

The intraoperative management of complex hepatic injuries remains a formidable challenge for the surgeon. Based on the clinical experience from large trauma centres, the evolution in management has included early mobilization of the liver and extended portal occlusion times. The preferred operative techniques are resectional debridement, hepatetomy and direct suture ligation or perihepatic packing. Deep liver sutures, anatomical resection, hepatic artery ligation and retrohepatic caval shunts have a limited, more defined, role for selected injuries. Finally, increasing emphasis has been placed on the importance of recognition and avoidance of complications to improve patient outcome.

Complications

They have been reported in up to 64 per cent of patients. Associated injuries and the extent of liver injury seem to be the most important factors predisposing to postoperative problem. Liver-related complications appear to be less frequent in patients managed without operation than in those managed surgically. Major complications include haemorrhage, intra-abdominal abscesses, perihepatic collections of bile (bilomas) and biliary fistulas. Rebleeding in the postoperative period is a challenging problem. Delayed haemorrhage is the most common complication of the non-operative management of hepatic injuries and is the usual indication for a delayed operation. Coagulopathy, inadequate initial surgical repair and missed retrohepatic venous injury may result in further haemorrhage. Confirmed coagulation defects should be corrected as rapidly as possible with fresh frozen plasma and platelet transfusions.

Some authors recommend reoperation after transfusion of 10 units of blood in 24 h, but the limit of 6 units in the first 12 h seems more reasonable. In cases with slow rebleeding when the limit of 6 units has not been exceeded, arteriography with embolization of the bleeding vessels may be helpful.

Intra-abdominal sepsis in the postoperative period occurs in approximately 7-12 per cent of patients. Predisposing factors include the presence of shock and increased transfusion requirements, increased severity of liver injury, associated injuries such as small bowel or colonic perforation, the use of perihepatic packs, superficial suturing of deep lacerations with intrahepatic haematoma formation, and the presence of devitalized parenchyma. Prophylactic antibiotics should be administered at induction of anaesthesia if laparotomy is being undertaken. If sepsis occurs, early diagnosis and aggressive treatment with drainage of any collection and appropriate intravenous antibiotic administration should be undertaken. Percutaneous transcatheter drainage has revolutionized the treatment of postoperative abscesses, and has resulted in reduced morbidity and minimal mortality rates.

Biliary leakage following liver trauma occurs in approximately 2-8 per cent of cases, although a higher incidence is observed following resection for hepatic injuries. It usually ceases spontaneously within 2 weeks of operation, but prolonged drainage of up to 3 months has been reported. Factors associated with prolonged bile drainage are the presence of distal obstruction, infection and the presence of foreign body material.

Other complications following surgery for liver trauma are respiratory problems (in up to 40 per cent of cases), wound sepsis (in up to 29 per cent of patients), liver failure, hyperpyrexia (which occurs in up to 64 per cent of cases and may be due to resorption of devitalized parenchyma and hepatocellular regeneration) and acalculous cholecystitis. Pancreatic, duodenal or small bowel fistulas may also develop. Management of most of the complications of liver trauma requires a multidisciplinary approach using the combined efforts of experienced interventional radiologists, endoscopists and surgeons.

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