Liver trauma
General
Liver injuries are fortunately uncommon
because of the liver’s position under the diaphragm protected by the chest
wall. However, when they do occur they are serious injuries
Diagnosis of
liver injury
The liver is an extremely well-vascularised
organ and blood loss is therefore the major early complication of liver
injuries. Clinical suspicion of a possible liver injury is essential as a
laparotomy by an inexperienced surgeon with inadequate preparation
preoperatively is doomed to failure. All lower chest and upper abdominal stab
wounds should be suspect, especially if considerable blood volume replacement
has been required. Similarly, severe crushing injuries to the lower chest or
upper abdomen often combine rib fractures, haemothorax and damage to the spleen
and/or liver. Patients with a penetrating wound will require a laparotomy
and/or thoracotomy once active resuscitation is underway. Owing to the opportunity
for massive ongoing blood loss and the rapid development of a coagulopathy,
the patient should be directly transferred to the operating suite whilst blood
products are obtained and volume replacement is ongoing. Patients with blunt
trauma who are haemodynamically stable but have objective clinical signs, such
as upper abdominal tenderness and guarding, should have an oral and intravenous
contrast enhanced CT scan of the chest and abdomen. This will demonstrate
evidence of parenchymal damage to the liver or spleen as well as associated
traumatic injuries to their feeding vessels. Free fluid can also be clearly
established and a diagnostic aspirate performed. The chest scan will help to
exclude injuries to the great vessels and demonstrate damage to the lung
parenchyma. Additional investigations which may be of value include peritoneal
lavage, which can confirm the presence of haemoperitoneum, and laparoscopy,
which can demonstrate an associated diaphragmatic rupture.
Initial
management of liver injuries
Penetrating
The initial management of a patient with an
upper abdominal penetrating injury is the basis of resuscitation. The initial
survey assesses the patients airway patency, breathing pattern and circulation.
Peripheral venous access is gained with two large-bore cannulae and blood sent
for cross match of 10 units of blood, full blood count, urea and electrolytes,
liver function tests, clotting screen, glucose and amylase. Initial volume
replacement should be with colloid or 0-negative blood if necessary. Arterial
blood gases should be obtained and the patient intubated and ventilated if the
gas exchange is inadequate. Intercostal chest drains should be inserted if
associated pneumothorax or haemothorax is suspected. Once initial resuscitation
has been commenced the patient should be transferred to the operating theatre
with further resuscitation being performed on the operating table. The necessity
for fresh frozen plasma and cryoprecipitate should be discussed with the blood
transfusion service immediately the patient arrives, as these patients rapidly
develop irreversible coagulopathies due to a lack of fibrinogen and clotting
factors. Standard coagulation profiles are inadequate to evaluate this acute
loss of clotting factors, and factors should be given empirically, aided by the
results of thromboelastography (TEG), if available (Fig.
52.9).
Blunt trauma
With severe blunt injuries the plan for
resuscitation and management is as outlined above for penetrating injuries. For
the patient whose vital signs are normal, imaging may be performed to evaluate
further the nature of the injury. The basic surgical management differs between
penetrating and blunt injuries thought to involve the liver. Penetrating
injuries should be explored, whereas blunt injuries can be treated
conservatively. The indication for discontinuing conservative treatment for
blunt trauma would be evidence of ongoing blood loss despite correction of any
underlying coagulopathy and the development of signs of generalised peritonitis.
The surgical approach to liver trauma
The surgical approach is partly dictated by
the nature of the suspected injury. Good access is vital. A rooftop incision
gives excellent visualisation of the liver and spleen and, if necessary, can
be extended upwards for a median sternotomy. A stab incision in the liver can be
sutured with a fine absorbable monofilament suture. If necessary, this may be
facilitated by producing vascular inflow occlusion by placing an atraumatic
clamp across the foramen of Winslow (the Pringle manoeuvre). Lacerations to
the hepatic artery should be identified by placing
an atraumatic bulldog clamp on the proximal vessel prior to repair with 5/0 or
6/0 Prolene suture. If unavoidable the hepatic artery may be ligated, although
parenchymal necrosis and abscess formation will result in some individuals.
Portal vein injuries should be repaired with 5/0 Prolene, again with exposure of
the vessel being facilitated by the placement of an atraumatic vascular clamp.
The blunt trauma of deceleration injuries often produces lacerations of the
liver parenchyma adjacent to the anchoring ligaments of the liver. These may be
amenable to suture with an absorbable monofilament suture. -Again, inflow
occlusion may facilitate this suturing and, if necessary, the sutures can be
buttressed to prevent them cutting through the liver parenchyma. With more
severe deceleration injuries a portion of the liver may be avulsed from anterior
to posterior. These injuries are more complex as they are associated with a
devitalised portion of the liver and often major injuries to the hepatic veins
and IVC. The initial management of liver injuries is to pack the liver to
produce haemostasis. This is effective for the majority of liver injuries if the
liver is packed against the natural contour of the diaphragm by packing from
below Large abdominal packs should be used to ease their removal, and the
abdomen closed to facilitate compression of the parenchyma. Care should be taken
to avoid over-zealous packing as this may produce pressure necrosis on the liver
parenchyma. Crush injuries to the liver often result in large parenchymal
haematomas and diffuse capsular lacerations. Suturing is usually ineffective,
and packing is the most useful method of providing haemostasis. Necrotic tissue
should be removed, but poorly perfused but viable liver left in
situ. If packing is necessary the patient should have the packs removed
after 48 hours, and commonly no further surgical intervention is required.
Antibiotic cover is advisable and full reversal of any coagulopathy is
essential. If a major liver vascular injury was suspected at the time of the
initial laparotomy then referral to a specialist centre should be considered. A
common surgical approach under these circumstances would be to place the
patient on veno-venous bypass using cannulae in the femoral vein via a long
saphenous cutdown and being returned, via a roller pump, to the superior vena
cava (SVC) via an internal jugular line. Venovenous bypass allows the IVC to
be safely clamped to facilitate caval or hepatic vein repair. A rapid-infuser
blood transfusion machine facilitates the delivery of a large volume of blood
instantaneously. Once prepared, the patient is re laparotomised via the rooftop
incision with a midline extension to the xiphisternum. The liver is mobilised by
division of the supporting ligaments, and complete vascular isolation of the
liver achieved by occluding the hilar inflow and the IVC above the renal veins
and at the level of the diaphragm with atraumatic vascular clamps. Venous return
is provided by the
Other complications of liver trauma
By far the most important complication of
blunt or penetrating trauma to the liver is sudden massive blood loss. There
are, however, other presentations and complications which require specific
investigation and treatment. A subcapsular or intrahepatic haematoma requires no specific intervention and should be allowed to
resolve spontaneously. Attempts to aspirate these lesions may result in the
development of a liver abscess due to
contamination. Abscesses may also form as a result of secondary infection of an
area of extensive parenchymal ischaemia, especially after penetrating trauma.
Treatment under these circumstances is with appropriate systemic antibiotics and
aspiration under ultrasound guidance once the necrotic tissue has liquefied. Biliary
fistulae are a rare but important complication of liver trauma and may be
difficult to control. The main aspects to management are to drain any
intraperitoneal bile collections externally by percutaneous drainage under
ultrasound guidance. This is followed by endoscopic or percutaneous
cholangiography to determine the site of the biliary fistula and decompress the
biliary tree by nasobiliary drainage or endoprosthesis insertion. If this fails
to control the fistula the affected portion of the liver may require to be
resected. Late vascular complications include hepatic
artery aneurysms and arteriovenous and
arteriobiliary fistulae (Figure 52.10). These are best treated nonsurgically
by a specialist hepatobiliary interventional radiologist. The feeding vessel can
be embolised transarterialy. Evidence of liver
failure may be seen with extensive liver trauma. If the blood supply and
biliary drainage of the liver are intact this will usually reverse with
conservative supportive treatment.
Long-term
outcome of liver trauma
The capacity of the liver to recover from
extensive trauma is remarkable, and parenchymal regeneration occurs rapidly.
Late complications are rare but the development of biliary tract strictures many
years after recovery from liver trauma has been reported. The treatment depends
on the mode of presentation and the extent and site of stricturing. A segmental
or lobar stricture associated with atrophy of the corresponding area of liver
parenchyma and compensatory hypertrophy of the other liver lobe may be treated
expectantly. A dominant extra hepatic bile duct stricture associated with
obstructive jaundice may be treated initially with endobiliary balloon
dilatation or stenting but will usually require surgical correction using a
Roux-en-Y hepatodochojejunostomy.