The liver
Anatomy:
It is composed of two lobes (Rt. and lt. ) and each lobe is further
divided into segments (8 segments ) . Functional Rt. lobe is composed
of (segment V-VIII) while functional Lt. lobe is composed of
segments I- IV). The liver is fixed in place by two ligaments, the
Falciform ligaments and Teres ligament . The lesser omentum is a
peritoneal reflection between the stomach and the liver.
80% of liver blood supply is from the portal vein and 20% from the
hepatic artery (from Celiac trunk). The RT hepatic artery supplies
the majority of liver parenchyma. Within the hilum of the liver , the
portal vein , hepatic artery and bile duct are present within the free
edge of the lesser omentum or the hepatoduodenal ligament ( the bile
duct is within the free edge , the hepatic artery above and medial and
the portal vein lies posterior).
Venous drainage of the liver is via three large hepatic veins into the
IVC immediately below the diaphragm.
Functions of the liver:
1. Maintaining core body tempt.
2. PH balance and correction of lactic acidosis.
3. Synthesis of clotting factors.
4. Glucose metabolism
5. Urea formation from protein catabolism.
6. Bilirubin formation
7. Drug and hormone metabolism
8. Removal of gut endotoxins and foreign antigens
liver function tests:
Bilirubin 5-17 micromol/L
Conjugated < 5 micromol/l
And non conjugated
Alkaline phosphatase (ALP) 5-130iu/L
Aspartate transaminase (AST) 5-40iu/L
Alanine transaminase (ALT) 5-40iu/L
Gamma-glutamyl transpeptidase(GGT) 10-48iu/L
Albumen 35-50G/L
Prothrombin time (PT) 12-16 seconds
Acute liver failure :
Etiology:
1. viral hepatitis
2. drug reactions (halothane, NSAIDs, antidepressants)
3. paracetamol overdose
4. mushroom poison
5. shock and multiorgan failure
6. acute Budd-Chiari syndrome
7. Wilsons disease
8. fatty liver of pregnancy
Clinical features :
In the early stages there are no objective signs but in severe
conditions there will be jaundice and neurological signs of liver
failure (liver flap, drowsiness, confusion and coma)
Supportive therapy for acute liver failure:
1. fluid and electrolytes balance
2. acid base balance and glucose monitoring
3. nutrition support
4. renal function (dialysis)
5. respiratory support(ventilation)
6. monitoring and treatment of cerebral oedema
7. treatment of bacterial and fungal infections
Features of chronic liver disease
Lethargy, fever, jaundice, wasting, coagulopathy, hyper dynamic
circulation, hepatic encephalopathy, portal hypertension, ascites,
esophageal varices, splenomegaly, spider nevi, and palmer erythema.
Imaging of the liver
1. Ultrasound (US):
First line, safe and available
Operator dependant
Can detect gallstones, bile duct dilatation, and tumors of the
liver
2. Spiral computerized tomography (CT)
It is useful for detection of small (early) liver lesions and give
a good idea about its nature and vascularity. In addition it
can differentiate between inflammatory lesions of the liver
and haemangiomas. It can measure the density of liver
lesions which can be useful in cystic lesions
3. Magnetic resonance imaging (MRI)
As effective as spiral CT but it has several advantages as it
doesn’t require contrast media to visualize the liver and biliary
tree (MRCP). It is useful in imaging of portal vein or hepatic
arteries without the need for arterial cannulation
4. Endoscopic retrograde cholangiopancreatography (ERCP)
5. Percutaneous transhepatic cholangiopancreatogrphy (PTC)
6. Angiography
7. Nuclear medicine scanning
8. Laparoscopy and laparoscopic ultrasound
9. Fluorodeoxyglucose positron emission tomography(FDG-PET)
Liver trauma:
Uncommon, serious and associated with significant morbidity and
mortality.
1. Blunt traumatic injuries: contusion, laceration, and avulsion
injuries.
2. Penetrating injuries: stab wound and gunshot wound
Diagnosis:
1. Clinical suspicion: all upper abdominal and lower chest stab
wounds or severe crushing injury should be considered seriously as a
possibility of liver injury.
2. Clinical findings: signs of external trauma, signs of hemodynamic
instability (hypotension or shock, tachycardia, pale clammy skin etc..
3. Ultrasound of the abdomen: may show free fluid in the abdomen
or laceration of the liver
4. Oral and intravenous enhanced CT scan of the abdomen and chest.
It will show parenchymal damage of the liver and other associated
organs like the spleen or lungs as well as their vessels
5. Peritoneal lavage; to confirm hemoperitoneum
6. Laparoscopy
Management of liver injuries:
1. Penetrating injuries:
Resuscitation:
Initial survey (ABCDE),
IV large bore cannulas
Blood sample for full investigations
IV fluids and blood (fresh)
Surgery for all injuries
2. Blunt trauma :
Resuscitation
Surgery or conservative management
Complications of liver injuries:
1. Subcapsular hematoms ; conservative treatment
2. Liver abscess ; aspiration under us guide and antibiotics
3. Bile collection ; aspiration under us guide
4. Biliary fistula ; biliary decompression by nasobiliary or
percutaneous drainage or endoprosthesis or resection of liver
segment
5. Hepatic artery aneurysm
6. Arteriovenous fistula
7. Arteriobiliary fistla
8. Liver failure : in severe complicated injuries
Chronic liver diseases
1. Budd-chiari syndrome
2. Primary sclerosing cholangitis
3. Primary biliary cirrhosis
4. Carolis disease
5. Simple cystic disease
6. Polycystic liver disease
Liver infections
1. Viral hepatitis
Hepatitis A:
Infective hepatitis, self limiting, supportive treatment.
Hepatitis B:
Produce more serious damage with the development of liver
cirrhosis and primary liver cancer. It may present as acute
hepatitis or at a later stage due to the complications of cirrhosis,
mostly ascites or variceal bleeding.
Treatment of acute hepatitis is supportive.
Treatment of chronic form depend on the type of complications.
In established end stage cirrhosis antiviral therapy to eradicate
the virus followed by liver transplantation.
Hepatitis C:
It has become one of the most common causes of chronic liver
diseases. Usually transmitted by blood transfusion. Clinical
presentation and complications are similar to hepatitis B, and the
treatment is also similar.
2. Ascending cholangitis :
Bacterial infection of biliary tree usually due to obstruction of
biliary tree.
Presentation: jaundice, rigor and tender hepatomegally.
Diagnosis: Ultrasound shows dilated bile ducts, obstructive
picture of liver function tests , and isolation of pathogeneic
bacteria from blood on culture .
Treatment: antibiotics ( 3rd generation cephalosporin), iv fluid for
rehydration, endoscopic or percutaneous drainage of biliary tree
and removal of stones (usually present)
3. Pyogenic liver abscess:
Common in old age patients, diabetics and those on
immunosuppressive.
Presentation: fever, anorexia, malaise and RT upper quadrant
discomfort.
Diagnosis: US or CT that showed multiloccular cystic mass. This
is confirmed by aspiration and culture of the aspirate(commonly
streptococcus milleri and E. coli) or less commonly other enteric
organisms.
Treatment: penicillin, aminoglycosides and metronidazole, or
cephalosporins and metronidazole.
Percutaneous drainage under ultrasound guide
4. Amoebic liver abscess:
Reach the liver from the colon via portal circulation. The abscess
is diagnosed by aspiration and treated by metronidazole.
5. Hydatid disease of the liver :
Common in Iraq and Mediterranean countries. Caused by
Ecchinococcus granulosus. Ova are ingested by human and reach
the liver through portal blood.
Usually asymptomatic until it reach a large size when it might
cause slight RT upper abdominal discomfort.
Diagnosis:
Multiloculated cyst by ultrasound supported by the finding of a
floating membrane within the cyst on CT scan.
Rapture of the cyst might lead to dissemination of large number of
daughter cysts into the peritoneal cavity. Liver cysts can also
rupture through the diaphragm, producing empyema, into the
biliary tree producing obstructive jaundice or into the stomach.
Serology by ELISA test for Abs is comfirmatory to the diagnosis.
Treatment:
Medical treatment by albendazole or mebendazole should be tried
first.
Failure of medical treatment usually require surgical intervention
(liver resection or local excision of the cyst with deroofing . biliary
communication should be sutured
Liver tumors
I. Benign liver tumors
1. Haemangioma:
Most common benign tumor with increasing reporting.
Abnormal plexus of vessels. Diagnosis by US and CT with
delayed contrast enhancement (slow contrast enhancement).
Often multiple and require no treatment unless it is giant
and symptomatic.
2. Hepatic adenoma:
Rare tumors. Has malignant potential. More common in
females receiving contraceptive pills. Diagnosed by CT(well
circumscribed and vascular tumor), but it is difficult to be
differentiated from malignant tumors by radiology only so
diagnosis is confirmed by percutaneous biopsy or surgical
resection of the tumor with histological confirmation .
Treatment is surgical excision.
3. Focal nodular hyperplasia:
Unusual tumor of unknown etiology occurs in middle aged
females.
US show a solid tumor. CT scan shows central scarring and
well vascularized lesion. Sulphur colloid scan may
differentiate FNH from adenoma or metastatic carcinoma.
II. Malignant liver tumors:
1. Hepatocellular carcinoma:
One of the most common cancers and its incidence is
increasing due to the association with chronic liver
diseases (HBV and HCV).
Symptoms are either of chronic liver disease (malaise,
jaundiced, ascites, variceal bleeding, encephalopathy) or
with symptoms of advanced cancer (anorexia and
weight loss).
Treatment : either resection of the tumor or liver
transplantation depending on the age of underlying liver
disease , the size and site of the tumor , and the
availability of organ transplantation .
There is little evidence that chemotherapy will improve
the prognosis and it may damage the remaining liver
tissue.
AFP and imaging are used for follow up
2. Cholangiocarcinoma:
Typically presented with painless obstructive jaundice .
Slowly growing tumors. Usually at confluence of Rt and
Lt hepatic ducts producing fibrotic lesion with tight
duct stricture.
Lesions in the distal bile ducts are usually polypoidal
causing obstruction with lymphatic metastasis.
Diagnosis by US which shows dilated intrahepatic bile
ducts.
MRI with MRCP will confirm the diagnosis and
determine the extent of the tumor. ERCP and brush
cytology will provide tissue diagnosis.
Treatment: surgical resection offers the only possibility
of cure and the best form of palliation. Radical resection
of the liver paracnchyma associated with the affected
bile duct is the best treatment.
3. Carcinoma of gall bladder:
Unknown etiology but usually associated with gall
stones .
It may be diagnosed incidentally after cholecystectomy
for gallstones or the patient may present with pain or
obstructive jaundice (advanced tumors).
In those with incidental tumor limited to the mucosa of
gall bladder the prognosis is good while those with
transmural involvement or obstructive jaundice the
prognosis is poor.
Radical excision offers the only hope for cure.
Chemotherapy is of no benefit.
In advanced irresectable disease relieve of symptoms
can be achieved by biliary endoprosthesis.