The Liver and Biliary Tree Flashcards
Ultrasound
Non-invasive so the first imaging investigation of choice in biliary or pancreatic disease.
Computerised Tomography
Particularly if carried out on a helical or multi-slice scanner provides good views. It is useful for diagnosing and staging suspected tumours and identifying severity of pancreatitis.
Magnetic Resonance Imaging
Non-invasive - useful for imaging the bile and pancreatic ducts– this is known as magnetic resonance cholangiopancreatography (MRCP).
MRI is also used for assessment of malignant tumours.
Endoscopic Ultrasound
An ultrasound transducer on the end of an endoscope – provides good images of the pancreas, bile duct and gallbladder.
It is safer than ERCP particularly with regard to pancreatitis.
ERCP
Endoscopic retrograde cholangiopancreatography – a side viewing endoscope is passed into the duodenum – the bile or pancreatic ducts can be cannulated and sphincterotomy and stone extraction is also possible.
Complications can include acute pancreatitis, bleeding, perforation and cholangitis.
Percutaneous transhepatic cholangiography
Percutaneous access to the biliary tract is mainly used in patients with a hilar obstruction or where ERCP has failed to relieve the biliary obstruction.
Liver or Pancreatic Biopsy
If the patient has a liver or pancreatic tumour which is suspicious of malignancy biopsy is not usually necessary and may risk causing peritoneal metastases.
Liver biopsy is used for parenchymal disease e.g. cirrhosis and pancreatic biopsy when the diagnosis is uncertain.
Gallstones - Bile and Types of Stones
Bile contains cholesterol, bile pigments (from broken down haemoglobin) and phospholipids. If the concentrations vary different stones may form:
- Pigment stones - <10% - small and irregular stones caused by haemolysis.
- **Cholesterol stones - **75% - large, often solitary stones caused by being female, age or obesity.
- **Mixed stones - **may contain calcium salts, pigment and cholesterol.
Gallstones - Epidemiology and Risk Factors
- Epidemiology – gallstones affect 8% of patients over the age of 40 although 90% are asymptomatic.
- Predisposing factors – female sex (3 times more common), obesity, age (10% of >50 year olds and 30% of >70 year olds), haemolytic anaemia, hyperlipidaemia, Crohn’s disease and pregnancy.
- Amirand’s triangle – increased cholesterol and decreased lecithin and bile salts increase the risk.
Gallstones - Complications
Can occur in the:
- Gallbladder - biliary colic, acute or chronic Cholecystitis, empyema, mucocoele, carcinoma or Mirizzi’s syndrome
- Bile ducts - obstructive jaundice, pancreatitis or cholangitis.
- Gastrointestinal tract - gallstone ileus.
Acute Cholecystitis - Definition
Follows stone or sludge impaction in the neck of the gallbladder which may cause continuous epigastric or right upper quadrant pain (can be referred to the right shoulder), vomiting, fever, local peritonism or a gallbladder mass.
The main difference from biliary colic is the **inflammatory component - **local peritonism, fever and a raised white cell count.
If the gallstone moves into the **common bile duct **obstructive jaundice and cholangitis (infection of the bile duct) may also occur.
Acute Cholecystitis - Phlegmon and Murphy’s Sign
- Phlegmon – a RUQ mass of inflamed adherent omentum and bowel which may be palpable.
- Murphy’s sign – lay 2 fingers over the right upper quadrant and ask the patient to breathe in. This causes pain and arrest of inspiration as an inflamed gallbladder impinges on your fingers. However the test can only be called positive if the same action in the LUQ does not cause pain.
Acute Cholecystitis - Investigations
- Bloods – FBC (raised WCC), U+Es, LFTs, and amylase.
- Ultrasound - thick wall and shrunken gallbladder, pericholecystic fluid, stones or dilated common bile duct if >6mm.
- HIDA cholescintigraphy - a radioisotope scan – HIDA is taken up by the liver and excreted in the bile – if the cystic duct is patent it will effectively fill the gallbladder excluding cholecystitis. It can be useful if diagnosis is still uncertain following an ultrasound although rarely performed.
Acute Cholecystitis - Management
Keep nil by mouth, give pain relief, IV fluids, antibiotics e.g. 1.5g cefuroxime IV TDS and consider cholecystectomy within 72 hours – laparoscopic if definitely no perforation.
If surgery is delayed relapse occurs in 18% and may be associated with more complications.
Chronic Cholecystitis - Definition and Differential
There is chronic inflammation ± colic which leads to ‘flatulent dyspepsia’. Symptoms include vague abdominal discomfort, distension, nausea, flatulence and fat intolerance.
If symptoms persist – consider hiatus hernia, IBS, peptic ulcer, relapsing pancreatitis or tumour.
Chronic Cholecystitis - Investigation and Management
- Investigations – ultrasound to image the stones and assess dilation of the common bile duct.
- Management – cholecystectomy and if ultrasound shows a dilated CBD with stones an ERCP (endoscopic retrograde cholangiopancreatography) and sphincterotomy before surgery.
Biliary Colic
Gallstones are symptomatic – pain is caused by gallbladder muscle spasms against a stone stuck in the neck of the gallbladder (Hartmann’s pouch) or the cystic duct.
There is continuous epigastric or right upper quadrant pain (can radiate to the back) which can be severe causing patients to be sweaty, pale and tachycardic.
There may also be nausea, vomiting and in some cases jaundice. Patients are unable to lie still on the bed (unlike acute cholecystitis where patients lie very still).
Management – give analgesia, rehydrate, keep NBM, ultrasound and elective cholecystectomy.
Obstructive Jaundice with CBD Stones
If LFTs are worsening perform an ERCP with sphincterotomy ± biliary trawl or cholecystectomy or open surgery with CBD exploration may be required.
Chalangitis
Infection of the bile duct causing right upper quadrant pain, jaundice and rigors (Charcot’s triad).
Treat with antibiotics - 1.5g Cefuroxime IV TDS and 500mg Metronidazole IV TDS.
Gallstone Ileus
A stone erodes through the gallbladder into the duodenum and may then obstruct the terminal ileum.
Abdo x-ray shows air in the common bile duct (pneumobilia), small bowel fluid levels and a visible gallstone.
Treatment is removal of the stone via enterotomy.
Mucocoele
An obstructed gallbladder fills with mucus secreted by the walls.
Silent Gallstones
Perform elective surgery on those with sickle cell or the immunosuppressed.
Mirizzi’s Syndrome
A stone in the gallbladder presses on the bile duct causing jaundice.
Cholecystectomy - Procedure
An open cholecystectomy is only indicated in difficult cases or when a laproscopic procedure has failed.
The gallbladder is dissected off the liver, the cystic artery and cystic duct are then identified, ligated and divided (there is no cystic vein).
Great care is taken to not damage the bile duct.
