Editing Liver injury


== Grading ==

* Most blunt trauma leads to low-grade injuries, since higher-grade injuries are big lacerations
* Grade IV and V injuries are really rare, like 0.1% of liver trauma

{| class="wikitable"
|AAST Grade
|'''Imaging Criteria (CT Findings)'''
|Operative Criteria
|Pathologic Criteria
|-
|I
|'''Subcapsular hematoma <10% surface area''' 
|Subcapsular hematoma <10% surface area 
|Subcapsular hematoma <10% surface area 
|-
|
|'''Parenchymal laceration <1 cm depth'''
|Parenchymal laceration <1 cm depth
|Parenchymal laceration <1 cm depth
|-
|
| 
|Capsular tear 
|Capsular tear 
|-
|II
|'''Subcapsular hematoma 10-50% surface area; intraparenchymal hematoma <10 cm in diameter'''
|Subcapsular hematoma 10-50% surface area; intraparenchymal hematoma <10 cm in diameter
|Subcapsular hematoma 10-50% surface

area; intraparenchymal hematoma

<10 cm in diameter
|-
|
|'''Laceration 1-3 cm in depth and'''

'''≤10 cm length'''
|Laceration 1-3 cm in depth and

≤10 cm length
|Laceration 1-3 cm in depth and

≤10 cm length
|-
|III 
|'''Subcapsular hematoma >50% surface area;'''

'''ruptured subcapsular or parenchymal'''

'''hematoma''' 
|Subcapsular hematoma >50% surface area or

expanding; ruptured subcapsular or

parenchymal hematoma
|Subcapsular hematoma >50% surface area;

ruptured subcapsular or intraparenchymal

hematoma 
|-
|
|'''Intraparenchymal laceration >10 cm'''
|Intraparenchymal hematoma >10 cm
|Intraparenchymal hematoma >10 cm
|-
|
|'''Laceration >3 cm depth'''
|Laceration >3 cm depth
|Laceration >3 cm depth
|-
|
|'''Any injury in the presence of a liver'''

'''vascular injury or active bleeding'''

'''contained within liver parenchyma'''
|
|
|-
|IV
|'''Parenchymal disruption involving'''

'''25-75% of a hepatic lobe'''
|Parenchymal disruption involving

25-75% of a hepatic lobe
|Parenchymal disruption involving

25-75% of a hepatic lobe
|-
|
|'''Active bleeding extending beyond the'''

'''liver parenchyma into the peritoneum'''
|
|
|-
|V
|'''Parenchymal disruption >75% of hepatic lobe'''
|Parenchymal disruption >75% of hepatic lobe
|Parenchymal disruption >75% of hepatic lobe
|-
|
|'''Juxtahepatic venous injury to include'''

'''retrohepatic vena cava and central'''

'''major hepatic veins'''
|Juxtahepatic venous injury to include

retrohepatic vena cava and central

major hepatic veins
|Juxtahepatic venous injury to include

retrohepatic vena cava and central

major hepatic veins
|}
''Vascular injury is defined as a pseudoaneurysm or arteriovenous fistula and appears as a focal collection of vascular contrast that decreases in attenuation with delayed imaging. Active bleeding from a vascular injury presents as vascular contrast, focal or diffuse, that increases in size or attenuation in delayed phase. Vascular thrombosis can lead to organ infarction.''

''Grade based on highest grade assessment made on imaging, at operation or on pathologic specimen.''

''More than one grade of liver injury may be present and should be classified by the higher grade of injury.''

''Advance one grade for multiple injuries up to grade III.''


== Management ==

* Requirements for non-op management
** Haemodynamic stability
** Not necessarily inappropriate for higher grade injuries
** Best if patients can provide a reliable physical examination
** Often, grade I or II injuries require no intervention
* Non-op management
** Bed rest one day longer than the grade of injury (this is an historic recommendation - modern says ambulation is safe)
** Serial examination, Hb
** Need the ability to closely observe and manage with laparotomy if deterioration - consider transfer to such a facility
* Interventional radiology
** Embolisation indications
*** Stable patient with clear active haemorrhage on CT
** Combined theatre can be very effective
* Indications for operation
** Unstable
** Historically, any penetrating liver injury - however this dogma has been challenged, and stable patients with localised tenderness and reliable exam do not necessarily need exploration
** Free intra-abdominal haemorrhage
*** Free blood in paracolic gutters, pelvis, or tracking along periportal triads is evidence of significant hepatic injury and almost mandates exploration
* Immediate laparotomy
** Preparation:
*** Consider REBOA
*** MTP
*** Should have large bore central venous access from top half of torso (in case retrohepatic caval injury)
*** Equipment
**** Topical haemostatic agents
**** APC
**** Cell saver
**** Good assistant
** Aims of liver bleed laparotomy:
*** Stop the bleeding
*** Remove obviously devitalised liver tissue
*** Stop or control bile leaks
** Positioning
*** Prep and drape from clavicles to knees
** Incision
*** If high-grade injury is known or suspected, chevron incision
*** Otherwise generous midline
** Manoeuvres
*** Pringle - umbilical tape around porta hepatis, or insert a finger through the foramen of Winslow and apply a Satinsky clamp or non-crushing intestinal clamp. Limit to 15 minutes if you can, but Schein's says technically safe for up to 60 mins.
*** Cattell-Braasch - medial visceral rotation on right side of abdomen
*** Heaney - total vascular exclusion of the liver in extensive liver/IVC injuries
** Assessment
*** Pack four quadrants beginning with suspected site of haemorrhage
*** Liver packing - posterior paracaval, lateral anterior, and posteroinferior. Don't usually pack within liver tears, which can cause worsening of bleeding when they are pulled out.
*** Anaesthesia catch up
*** Temporise spillage or contamination - 5-20% of major hepatic injuries are associated with hollow viscous injury
*** May need to mobilise liver along falciform and triangular ligaments - but think about this carefully if you suspect a retrohepatic venous injury, as the tamponade can be released causing massive bleeding

=== Stepwise approach to liver bleeding ===

*** '''Initial move in all patients with liver bleeding:'''
**** Pack and allow anaesthetist to catch up
**** When resuscitation is optimised, remove packs
**** If still bleeding, perform Pringle manoeuvre. If bleeding persists, either there is aberrant arterial circulation or this is hepatic vein/IVC bleeding (which should be packed and left alone by non-HPB surgeons).
**** Explore liver gently to identify and control injuries
*** '''Superficial injury:'''
**** '''Haemostatic agents''' e.g. Tisseel, Surgicell
***** Good for large raw areas
**** '''Suture repair''' (hepatorrhaphy)
***** Large suture, can be absorbable or non-absorbable depending on who you read.
***** Tight enough to achieve haemostasis but not too tight to pull through tissue.
***** Requires a gentle touch and somewhat intact capsule
***** Need to avoid overzealous ligation
***** Ligation of specific branches of PV or HA is rarely needed, but can be done
**** '''APC'''
*** '''Deep injury'''
**** Packing as damage control is often the right way to start off, allowing resuscitation and later definitive management
***** Pack behind, above and below
**** Can do finger fracture deep into wound to look for actively bleeding vessels, but try not to make the situation worse
**** '''Clipping''' of lacerated vessels
**** '''Tractotomy''' for penetrating hepatic trauma
***** Could also tamponade the tract using something like a Penrose drain dragged through the laceration
**** '''Mesh wrap''' for compression
**** Lobectomy is not really performed for trauma
***** Can do debridement of devitalised liver tissue to facilitate vascular control, though
*** Frequently there will be persistent oozing after control of specific bleeding sites - can use an '''omental patch''', this is especially useful for large raw liver surfaces resulting from debridement or tractotomy
*** '''Decide on damage control or definitive'''
**** The simplest approach is just to pack tightly, leave the abdomen open and come back with more experienced surgeons (this is the old-fashioned approach to liver trauma too)
**** If packs are holding, but patient needs resuscitation (cold/coagulopathic/other issues) then best to pack and leave abdomen open
***** Especially when temp gets <32 and acidosis. Large vessel bleeding needs to be controlled prior to this.
**** If just pack the abdomen and leave open, often do a CT and check for anything you can embolise (small venous bleeders will be stopped by the packs, while arterial bleeders will continue)
**** In most patients, further exploration and potential repair is appropriate

== Porta hepatis injuries ==

* Rare, complex, lethal
* Portal vein - repair (25% injury) vs ligation (can be tolerated but highly lethal)
* Hepatic artery - ligation possible but may well result in post-op liver failure, intra-hepatic cholangiopathy, cholangitis and abscesses
* CBD - biliary reconstruction is possible. In damage control situation, drain and temporise.

== Retrohepatic IVC injury ==

* Lethal
* A contained retrohepatic haematoma does not require immediate exploration
** Often hard to establish the degree of containment though.
* Basic approach
** If identified after liver mobilisation, restore containment as much as possible with packing
** Get suprahepatic control of IVC by extending incision
** Try to suture a chest tube/ETT in between the two ends of IVC with purse string to temporise things

== Complications of liver injury ==

* Bile leak
** CT cholangiogram to define injury, if bilirubin ok; otherwise MRCP

[[Category:Trauma]]
[[Category:Liver]]