**1.2 Liver transplantation as a valuable option due to trauma**

The isolated trauma of the liver are a rare event in blunt injuries of severely injured patients; yet liver injuries probably lead to a clear increase in post-trauma mortality due to the complex functioning of this organ. The immunological changes caused by blunt liver trauma are just as difficult to classify as the specific mortality. As the liver injury increases in severity, other organ systems become involved, so that total mortality results from the cumulation of all damaged organs. However, there are definitive indications leading to speculation that liver involvement superproportionally increases total mortality (13-16). The mortality rate after liver trauma documented in the literature has a wide spread and ranges between 7 and 36% (17, 18). This is differentiated between early mortality, mainly due to blood loss, and late mortality. Late mortality is frequently based on secondary complications from intensive medical treatment in connection with immunological failure after a trauma which can cause sepsis/SIRS and multi-organ failure. The actual specific significance of liver injury for the emergency of such complications in this event is to date not yet fully understood.

The liver is crucial to the post-traumatic recovery of a severely injured patient. This is where proteins are formed, which constitute among other things components for coagulation and non-specific defense. It has a decisive effect on inflammatory processes and represents the center of the energy metabolism. Moreover, the Kupffer cells represent the largest macrophage pool in humans. The knowledge that liver damage alone negatively affects both early and late mortality may be an initial approach leading to organ-specific post-traumatic treatment.

In this context, it must be kept clearly in mind that the last two decades have seen a clear paradigm change concerning surgical treatment for liver injuries (19). With the introduction of computer tomography and the availability of clotting factors, conservative treatment of the liver injury became the method of choice for hemodynamically stable patients after blunt liver trauma (20). Different studies have shown that 71-89% of all patients with blunt liver trauma can be successfully conservatively treated. As a result, the survival rate is 85 to 94% (21). There is also agreement that despite all the opportunities for intensive fluid, blood and coagulation substitution, hemodynamically unstable patients must still be operated on (22).

Here, the management of a liver injury aims to control hemorrhage, preserve sufficient hepatic function and prevent secondary complications. If an adequate control of the bleeding cannot be achieved despite exhausting the current therapy options, the indication for liver transplant (LT) needs to be assessed critically in individual cases. These cases are extremely scarce in the clinical daily routine (23).

Nonetheless, LT are carried out due to acutely uncontrollable liver injuries in exceptional cases only. For this, indication is judged critically and discussed controversially due to usually existing secondary injuries, early septic complications, and poor general condition. Due to poor results, LT in these patients is occasionally described as "waste of organs", however based on insufficient data (24, 25).

Patients with subacute and chronic results of a liver injury need to be considered differently from the acute and due to their initial position very special group of surgically uncontrollable patients with liver trauma. However, they share the fact that also the indication for transplantation for instance in patients with "shock liver" in the context of polytrauma or with induced liver failure after a longer intensive therapy need to be measured (26, 27).
