Epidemiological evaluation of hepatic trauma victims undergoing surgery

Objective: to evaluate the epidemiological variables and diagnostic and therapeutic modalities related to hepatic trauma patients undergoing laparotomy in a public referral hospital in the metropolitan region of Vitória-ES. Methods: we conducted a retrospective study, reviewing charts of trauma patients with liver injuries, whether isolated or in association with other organs, who underwent exploratory laparotomy, from January 2011 to December 2013. Results: We studied 392 patients, 107 of these with liver injury. The male: female ratio was 6.6 : 1 and the mean age was 30.12 years. Penetrating liver trauma occurred in 78.5% of patients, mostly with firearms. Associated injuries occurred in 86% of cases and intra-abdominal injuries were more common in penetrating trauma (p <0.01). The most commonly used operative technique was hepatorrhaphy and damage control surgery was applied in 6.5% of patients. The average amounts of blood products used were 6.07 units of packed red blood cells and 3.01 units of fresh frozen plasma. The incidence of postoperative complications was 29.9%, the most frequent being infectious, including pneumonia, peritonitis and intra-abdominal abscess. The survival rate of patients suffering from blunt trauma was 60%, and penetrating trauma, 87.5% (p <0.05). Conclusion: despite technological advances in diagnosis and treatment, mortality rates in liver trauma remain high, especially in patients suffering from blunt trauma in relation to penetrating one.


INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION
Trauma is a public health problem of great magnitude in Brazil.It is one of the leading causes of death today, due to the increase in urban violence and the technological advancement of the automotive industry, which enabled the production of increased power vehicles 1,2 .
Abdominal trauma can be classified into two distinct types: penetrating or blunt.Blunt trauma is usually due to accidents involving motor vehicles, falls, explosions and sports injuries.Penetrating trauma, on its turn, can be caused by stabbing or gunshot projectiles 3 .
The high rates of liver injury are justified by its size and anatomical position 5.6 .The right lobe of the liver, being the portion of the bulkier hepatic parenchyma, is the most affected region in abdominal injuries 7 .
This study aims to assess the epidemiological variables of, and the diagnostic and therapeutic modalities applied to, patients submitted to surgical treatment of liver trauma at a referral hospital for trauma.

METHODS METHODS METHODS METHODS
We conducted a retrospective review of medical records of patients undergoing laparotomy in the period from January 2011 to December 2013, at the Hospital Estadual São Lucas, a referral center for trauma, located in the Metropolitan Region of Vitória-ES.
We included trauma patients with liver injury, isolated or in association with other intra or extra-abdominal organs.We excluded surgical re-approaches in patients operated on in other services and subsequently transferred to our hospital.The sample therefore comprised 107 patients undergoing surgery for hepatic injury during this period.
The variables analyzed were: age, gender, date and time of admission, the first operation time, length of stay, mechanism of injury, the presence of associated intra or extra-abdominal lesions, surgical technique, the intraoperative need for blood products, need for peri-hepatic drainage, postoperative complications and mortality.
The collected data were tabulated in electronic spreadsheets and statistical analyzes were performed according to Levine et al., at 2012 8 .We carried out a descriptive analysis of the categorical variables, expressed in absolute numbers and percentages, and the continuous ones as position measurements.To compare the trauma mechanisms in relation to the categorical variables, we used the chi-square test.We considered a p value <0.05 as statistically significant.
This study was approved by the Ethics in Research Committee of the Santa Casa de Misericórdia de Vitória -EMESCAM, on 30 of April 2014, under number 632.212.

RESULTS RESULTS
During the study period, from January 2011 to December 2013, 392 patients underwent laparotomy, 107 of them sustaining liver injury.Of these, 93 were male (86.9%) and 14 female (13.1%).The mean age of patients suffering liver trauma was 30.12 years, ranging from 14 to 72 (median 28), and 83.2% were in the first four decades of life.
Considering the anatomical site of liver injury, the right lobe was the most affected (46.73%), followed by the left one (25.23%)(Table 1).The caudate lobe was less affected, only in one case (0.93%).Simultaneous injury of right and left lobes or the right and caudate lobes occurred in 5.61% and 0.93% of patients, respectively.
As for the associated extra-abdominal lesions (Table 3), there was a higher incidence of head injury associated with blunt trauma (30% of cases) when compared with penetrating trauma (10.9% of cases).
The time between hospital admission and the first surgery was less than two hours in 48.8%, between two and four hours in 17.9% patients and more than four hours in 33.3%.The average hospitalization time for patients with blunt trauma was 13.96 days, and for patients with penetrating trauma, 12.23 days.
Regarding the surgical technique used to control liver bleeding, the most used was hepatorrhaphy (80.37%) (Table 5).Cauterization of the liver injury has been reported in four patients (3.74%), being a single and sufficient measure to stop bleeding in two of these patients.It was also described the use of topical hemostatic agents in two cases (1.87%) and omentum transposition in only one case (0.93%).In 12 patients (11.21%) no measures of hemostasis were necessary, since the liver injury showed no active bleeding.Segmentectomy was performed in two patients (1.87%) and only one (0.93%) required left hepatectomy.Damage control surgery was performed in seven patients (6.54%).Eighteen patients (16.82%) needed further surgical intervention, mostly to withdraw textiles from the peritoneal cavity.Laparotomy was not therapeutic in four patients (3.74%).Twenty-eight patients required blood products transfusion during surgery (26.2%) and the average amount of blood products used was 6.07 units of packed red blodd cells and 3.01 fresh plasma units.Perihepatic drains were placed in 27 cases (25.2%), a Penrose drain being the most commonly used (n=15).
The incidence of postoperative complications was 29.9%, and the most frequent were infectious, including pneumonia, peritonitis and intra-abdominal abscess, which represented 73.9% of complications.Hemobilia occurred in one patient, who was treated with hepatic artery embolization.
The survival rates were 60% in patients with blunt trauma, and in patients with penetrating trauma, 87.5% (p<0.05)(Table 6).The mortality rate was 17.8% (n=19), the most common causes of death being hemorrhagic shock, responsible for ten deaths (52.6%), and septic shock, amounting to four deaths (21%).

DISCUSSION
DISCUSSION DISCUSSION DISCUSSION DISCUSSION Hepatic trauma occurred more frequently in males (86.9%) in the first four decades of life (83.2%).These results are similar to those reported by many researchers 2,3,9,10 .The highest incidence of trauma in young adult males is associated with increased risk behavior due to exposure to alcohol and illicit drugs 10 .
Due to the increase of traffic accidents and violence in Brazil, the proportion of trauma admissions has gradually increased and hence the proportion of government spending.Likewise, hospital costs are directly proportional to the length of hospital stay 10 .In this study, the average hospitalization time for patients with blunt trauma was 13.96 days, and for patients with penetrating trauma, 12.23 days, agreeing with the average found in the literature 9 .
Lima et al. studied the epidemiology of abdominal trauma undergoing laparotomy and, as well as in our work, observed that there was a higher prevalence of trauma on weekends 10 .
Mortality in hepatic trauma in most studies is close to 20%, considering all cases admitted to hospital 9 .The mortality rate in this study was 17.8%.Of the eleven deaths from penetrating trauma, ten were the result of gunshot wounds.
Other intra-abdominal injuries concomitant with liver lesions were more common in penetrating trauma (p<0.01), as shown in table 6.In penetrating abdo-   minal trauma, the injuries of large intra-abdominal vessels stand out 11 .In this study, all eight injuries of large intraabdominal vessels were caused by penetrating trauma, seven of them by firearms.The vessels involved were: inferior vena cava, middle hepatic vein, splenic artery, right common iliac artery and vein, superior mesenteric vein and artery.Hepatorrhaphy was the most used surgical technique to control liver bleeding.Other techniques include direct ligation of bleeding vessels, cauterization, the use of topical hemostatic agents, partial liver resection and hepatic artery ligation.In selected cases, refractory bleeding can be controlled with liver packing, the damage control surgery 6 .
The damage control surgery was performed in seven cases (6.54%) and patient survival was 100%, which confirms damage control as a measure which increases the survival rate of seriously injured patients who face the so-called triad of death -hypothermia, coagulopathy and metabolic acidosis 6,11,12 .
Research on the surgical treatment of hepatic injury began to grow in the early twentieth century.The maneuver of Pringle and liver packing technique were described in 1908, giving rise to the concept of damage control surgery 11,13 .Liver packing became a common practice a few years later, during the two Great World Wars.At that time, mortality related to hepatic trauma was 60% 13,14 .
After World War II, the mortality of liver trauma decreased due to increased experience in the repair of injuries.This led to the abandonment of surgery for damage control, which at the time was associated with a high incidence of late onset sepsis and rebleeding after packing removal.From the 70s on, surgery for damage control regained its importance in selected patients 14 .
Until the early 90s, surgical treatment was the standard treatment of liver injury 15 .Since then, the diagnostic and therapeutic approach to abdominal trauma victim suffered intense changes 6 .Initially, it was found that most liver injuries spontaneously stopped bleeding 6.16 .In 1908, Pringle had suggested that minor liver damage occasionally could heal without surgical intervention 13 .However, little had been published about non-operative treatment until the 80's and the surgeons were resistant to conservative treatment, especially in blunt trauma 16,17 .This resistance resulted primarily from three factors: the belief that liver bleeding would not cease unless surgically controlled; the concern that the lack of bile drainage would result in biliary fistulas and infectious complications; and the concern about associated lesions in face of a positive peritoneal lavage 17 .
With technological advances in imaging and greater accessibility to computed tomography and FAST (Focused Assessment with Sonography for Trauma), conservative treatment has become possible for patients with hemodynamically stable hepatic trauma 15,18 , which contributed to reduce unnecessary laparotomy 7,12,[18][19][20][21] .Thus, there is a tendency to avoid routine laparotomy, especially for patients with hepatic trauma who are hemodynamically stable and displsy signs of peritonitis 19 .
Besides the advantage of avoiding the morbidity of an unnecessary laparotomy 15 , conservative treatment has shown other advantages over the surgical one, such as lower complication rates, less need for blood products transfusions, shorter hospital stay, especially in Intensive Care Units, and lower mortality 15,16,19,21 .
FAST is an exam with high sensitivity for the diagnosis of hemoperitoneum in hemodynamically unstable patients, as well as to identify liver damage 18.22 .A major advantage of this test is that it can be done at the bedside, without the need to move the patient from the emergency room 18 .
On the other hand, when the patient is hemodynamically stable, triple contrast CT is the method of choice in patients with blunt abdominal trauma.Computed tomography allows to determine the extent of liver damage, document the presence of active bleeding and detect associated lesions 22 .It is very useful in defining the severity of liver injury and the decision of conservative treatment 18 .
The diagnostic peritoneal lavage (PL) is a useful test for the diagnosis of hemoperitoneum when the patient is hemodynamically unstable and has sensory changes, and when there's no ultrasonography and CT available in the institution.Therefore, the PL can be replaced by ultrasound and, in more stable patients, CT 22 .
According to Zago et al., there has been a decrease in the incidence of penetrating trauma and increased incidence of blunt trauma in Brazil in recent years 9 .However, this study found a higher prevalence of penetrating trauma (76.2%).This discrepancy can be explained by the fact that our study only examined the operated patients, and patients treated conservatively -most victims of blunt trauma -were not counted.It is noteworthy that the conservative treatment of hepatic trauma in patients with hemodynamic stability has become standard in most trauma centers 16,22 .
In this study, the right lobe of the liver was the most affected, which was also demonstrated by Talving et al. 23 .According to Romano et al., the right lobe is the most affected because it is the most voluminous part of the hepatic parenchyma 7 .Associated lesions were found in 72 patients (85.7%).The high number of associated injuries is a major challenge for the management of patients because their presence hinders the decision of conservative treatment 2,3 and often determines the evolution of the patient 12 .
We observed a low incidence of postoperative complications (29.9%).This complication rate obtained is below the parameters found in some studies on the epidemiology of liver trauma, the rates varying from 36 to 38.9% 9,24 .
We found (Table 6) that the mortality rate for patients with hepatic injury was greater for blunt trauma (40%) than for penetrating one (12.5%),possibly due to the higher rates of cranial injuries associated with blunt trauma.Zago et al. found similar results, with a mortality rate of 26.5% for blunt trauma and 15.8% for the penetrating one 9 .
Despite technological advances in diagnosis and treatment, and the systematization of care for polytrauma proposed by the Advanced Trauma Life Support (ATLS®), morbidity and mortality rates in liver trauma remain high 7,24,25 .Therefore, liver trauma is a serious public health problem with significant social and economic costs, especially since it affects people of working age.
Source: Medical records of Hospital Estadual São Lucas (January 2011 to December 2013).
Source: Medical records of Hospital Estadual São Lucas (January 2011 to December 2013).

Table 5 -Table 5 -Table 5 -Table 5 -Table 5 -
Surgical techniques applied in the treatment of patients sustaining liver trauma.
Source: Medical records of Hospital Estadual São Lucas (January 2011 to December 2013).* In some patients, more than one approach was performed

Table 6 -Table 6 -Table 6 -Table 6 -Table 6 -
Associated intra-abdominal lesions and survival rate in blunt and penetrating trauma in patients sustaining liver trauma.