**3. Classification**

The severity of liver injuries is classified according to the American Association for the Surgery of Trauma (AAST) grading scale. This scale is based on parenchymal level of injury and number of liver segments affected.

To understand the classification of liver trauma, it is essential to master the anatomy of the liver. The division of the liver by the Couinaud segments occurs through the branching of the portal triad, composed of the branch of the portal vein, the hepatic artery, and the bile duct. The ramifications of these vessels cause the portal blood to be mixed with the blood in the hepatic artery in the portal spaces, which drains into the centrilobular vein, subsequently into the sublobular veins, and through the two hepatic veins, which end in the inferior vena cava. **Table 1** shows the classification of liver trauma according to the AAST.

The degree of liver injury and hemodynamic instability are important determinants in the mortality rates of patients with liver trauma as well as to determine the type of treatment to be instituted [2]. The concomitance of intra-abdominal injuries with liver trauma is common in penetrating trauma, and it is also a relevant factor


**55**

**Figure 1.**

*Liver Trauma Management*

**4. Diagnosis**

*DOI: http://dx.doi.org/10.5772/intechopen.92351*

very useful if there is vascular involvement.

unnecessary laparotomies [8].

liver trauma.

AAST degree and the patient's physiological state [7].

in the management. [6] However, in many cases, there is no correlation between the

Most patients have grade I injuries, and the incidence gradually decreases as the degree of injury increases, as shown by a study conducted with 300 patients between 2003 and 2013 at the Department of Surgery and Emergency, in Kartal [2]. It was found that the prognostic factors [2] related to the worst outcome were high levels of AST, ALT, LDH, INR, and creatinine and low levels of platelets and fibrinogen at admission, which were also associated with liver injuries of grades IV and V.

Currently, the most useful complementary exams in the diagnosis of liver trauma are abdominal ultrasound and computed tomography (CT) with intravenous contrast. Abdominal ultrasound is the initial image exam, with a sensitivity of 82–88% and specificity of 99%, to detect intra-abdominal injuries, although it must be taken into account that the accuracy depends on the examiner's experience [8]. Computed tomography is the most sensitive and specific technique for determining the extent and severity of liver trauma and is the imaging test that provides us with more information on polytrauma patients, since it offers an excellent view of the skull, chest, abdomen and pelvis, bone structures, viscera, and soft tissues. The arrival of helical technology has improved the resolution, reduced the duration of the exam, and allowed the three-dimensional reconstruction of the images, which is

Diagnosis by peritoneal lavage (LPD), with the advent of new imaging techniques, has fewer indications. Although it has an accuracy of 98% to detect intraperitoneal blood, it lacks specificity of the injured organ, which causes many

In patients with hemodynamic instability, the Focused Assessment with Sonography for Trauma (FAST) is the exam of choice due to its sensibility to detect free fluid in the abdomen, and it can be done faster than CT as an initial exam. **Figures 1, 2**, and **3** show some possible changes in abdominal CT in patients with

Some more recent studies have shown the role of two-dimensional and threedimensional [15] ultrasonography (US) in the trauma of massive viscera, such as the liver. There is evidence that the regular US is not capable of having high

*Hemorrhagic hepatic lacerations (A) in the right hepatic lobe and (B) close to the hilum. Hypodense areas of linear morphology that come into contact with the capsule (arrows). They associate free liquid (asterisks).*

#### **Table 1.** *Classification of hepatic trauma (AAST).*

#### *Liver Trauma Management DOI: http://dx.doi.org/10.5772/intechopen.92351*

in the management. [6] However, in many cases, there is no correlation between the AAST degree and the patient's physiological state [7].

Most patients have grade I injuries, and the incidence gradually decreases as the degree of injury increases, as shown by a study conducted with 300 patients between 2003 and 2013 at the Department of Surgery and Emergency, in Kartal [2]. It was found that the prognostic factors [2] related to the worst outcome were high levels of AST, ALT, LDH, INR, and creatinine and low levels of platelets and fibrinogen at admission, which were also associated with liver injuries of grades IV and V.
