Improved outcomes for hepatic trauma in England and Wales over a decade of trauma and hepatobiliary surgery centralisation

This study reports the frequency and extent of hepatic trauma in England, submitted to TARN, depicting the clinical features, management and outcomes of these injuries over a decade. Hepatic injury is mainly found in a young male population, is due to blunt trauma and predominantly managed conservatively, conforming with other large, contemporary, population-based studies in Europe [5], the Far East [6] and the USA [3, 11]. A predominance of penetrating trauma is found in single-centre South African studies, quoting rates of over 90%, with an increased need for surgical intervention [20, 21], compared to only 19% over-all in our series and 22% in a contemporary North American series [11]. This is attributed to the on-going predominance of firearm injuries in South Africa [20].

In each year of this study the frequency of liver injuries reported to TARN has increased. This may be due to the total increase in trauma volume in the UK as well as the accuracy of reporting and recording of trauma cases (TARN membership increased from 50 to 100% of all trauma receiving hospitals in England and Wales over the study period). The over-all mortality rate in this series of 16.4% compares favourably to the other UK (Scottish) based series reporting outcomes over the period 1992–2002 [5], which had a mortality rate of 42%. This high rate was largely attributed to the inclusion of patients who presented with catastrophic head injury, spinal cord transection, thoracic injuries, or massive haemorrhage who subsequently had liver injuries discovered at post mortem. The American College of Surgeons’ National Trauma Data Bank reported 35,510 hepatic injuries from 1994 to 2003. Over-all liver injury mortality remained relatively constant, averaging 16.8% [11]. In Taiwan, an over-all mortality rate of 8.3% was reported in 3196 cases of hepatic trauma admitted between 2007 and 2008 [6]. Mortality rates were significantly increased in the patients aged over 64 years; with head, chest, or other abdominal injuries; and with associated renal failure or liver cirrhosis [6]. Similarly, our study found that not only the severity of liver trauma but also the severity of concomitant extrahepatic injuries and existing comorbidities, as measured by the Charlson comorbidity index, had a major impact on survival.

Trends toward the non-operative management of blunt hepatic trauma have been widely documented [9, 10, 22, 23] with recent evidence showing that the integration of CT in early trauma-room management and a shift towards conservative management in hemodynamically stable patients results in improved survival in most [8, 10] but not all [12] series. Our series demonstrated an over-all 5.5% rate of liver specific operations compared to 16.7% in Taiwan [6] and 8.1% in the USA [11]. This emphasis on non-operative management has reduced the exposure of surgeons to operative intervention for liver trauma.

Our study has shown that being treated in a unit with an on-site HPB service increased the odds of survival. There is an improvement in risk adjusted mortality over time which disappears when the logistic regression model includes care in a HPB centre, therefore the observed improvement over time can be attributed to increased exposure to specialist HPB care. The mechanism whereby improved outcomes are associated with increasing HPB specialisation and centralisation in high volume centres may include: HPB surgeons having experience in complex haemostatic techniques that are not routinely used by others; training in vascular and transplant surgery; and detailed understanding of the complexities of liver anatomy. Other factors, such as recognising the need for experienced and early assistance and familiarity with managing post-operative complications (such as bile leaks) also likely contribute. Moreover, institutional factors, such as on-call interventional radiology and endoscopy, experienced theatre and nursing staff greatly contribute to the volume-outcome effect in hepatobiliary surgery [24]. One implication of our study is the need to improve training and exposure to hepatobiliary and pancreatic trauma surgery. Attachments to HPB units during general surgical training will facilitate this. Trauma courses, often using cadavers and simulation, are available and trainees should be encouraged to undertake these.

Chronological improvements in management found in this study included promptness of CT scanning and increased use of tranexamic acid. Our series reported the highest rate of CT scanning in 2013–2014 (88.9%). Recommendations on the use of CT for hemodynamically stable patients are well established according to Advanced Trauma Life Support (ATLS^®) principles. The remaining 11% of patients may have warranted an immediate laparotomy due to haemodynamic instability or peritonitis, as recommended in other trauma practice management guidelines [25]. In the TARN registry detailed hepatic injury descriptors were more commonly obtained from ultrasound scans and operative or autopsy reports in the earlier years of the study, explaining the lower rates of CT scanning. Detailed information about the imaging modality used is often not available in other large series [3, 6, 11]. In a study spanning 25 years, Petrowsky et al. [8] examined changes in diagnostic modalities in hepatic trauma, finding that in the early study period (1986–1996), the majority of liver injuries were diagnosed by diagnostic peritoneal lavage followed by laparotomy. 72% were diagnosed by CT from 1997 to 2010, with this mode of scanning subsequently replacing ultrasound as the gold standard for diagnosis [8]. Use of tranexamic acid became routine after 2011, when the results of the CRASH-2 trial showed reduced mortality in trauma patients treated with early tranexamic acid [26].

The main strength of this study lies in the robust national data collection (using the electronic data collection and reporting system) and trained independent coders with stringent validation procedures. The series focussed on a time period where rapid changes were occurring to trauma service provision and HPB services in the UK. Liver trauma outcomes are favourable in the face of this evolving change. Further broad-based analyses comparing trauma outcomes prior to and after the formal accreditation of major trauma centres (MTCs) in 2010 and 2012 are also required to gain an appreciation of the changes that these have achieved. Thus far, significant improvements in the proportions of patients discharged with a good recovery (compared to disability) have been recorded [27] but overall improvements in mortality may take longer to demonstrate.

In summary, our series of over 4000 patients with hepatic trauma indicates that UK mortality rates are comparable to other large international series. Increased exposure to specialist hepatopancreatico-biliary teams in major trauma cases has improved outcomes for hepatic trauma in England and Wales over this decade.