Cholelithiasis / Cholecystitis Flashcards
Epidemiology of gallstones
Fair, fat (BMI>30), female, forty (age >40), fertile, low fibre diet (increased cholesterol reabsorption).
What forms gallstones?
Formed from constituents of bile (cholesterol, bile pigments, phospholipids).
What determines type of stone formed?
Relative concentrations determine stone formed (i.e. cholesterol will only crystallise into stones when bile is supersaturated with cholesterol relative to bile and phospholipid content).
Features of cholesterol stones?
Large, often solitary.
Radiolucent stones.
Features of pigment stones?
Small, radiolucent.
Less common.
May be ass/w haemolytic anaemia (increased pigment from Hb).
What is biliary colic?
Transient obstruction of gallbladder (cystic duct neck) due to impacted stone. Resolves when stone falls back into GB/passes into CBD.
What is the pain of biliary colic?
Severe gripping pain.
- often ass/w meals
- maximal in epigastrium and R hypochondriac region w/ radiation to the back
- continous over several hours (but may wax and wane in intensity); usually lasts at least 15min
GB appearance in acute cholecystitis?
Thickened, inflammed, oedematous +/- gangrenous
What is empyema of GB?
Unrelieved obstruction in presence of infected bile. Tender mass + rigours + marked pyrexia.
Common organisms found in bile?
E. coli; Klebsiella aerogenes; Strep faecalis; Staphylococci; Clostridia; Salmonella.
CF of acute cholecystitis?
- severe pain R hypochondrium; radiation to R subscap / shoulder
- tachycardia / pyrexia / vomiting / leukocytosis
- marked abdo tenderness of GB
- Murphy’s +ve
What is Murphy’s sign?
Catching of breath at height of inspiration while GB is palpated.
Ddx of acute cholecystitis?
- PUD
- High retrocaecal appendicitis
- Acute pancreatitis
- MI
- Basal pneumonia
What is chronic cholecystitis?
Repeated bouts of biliary colic / acute cholecystitis –> fibrosis –> contraction of GB –> chronic inflammatory change with marked wall thickening.
Hx of chronic cholecystitis?
Recurrent flatulence, fatty food intolerance and RUQ pain. Pain worse after meals and ass/w feeling of distension and heart burn.
Ddx of chronic cholecystitis?
- PUD
- Hiatus hernia
- myocardial ischaemia
- Chronic pancreatitis
- GI neoplasia
What is Couvoisier’s law?
Fibrosed GBs that contain stones cannot distend when pressure increases in the obstructed biliary tree. If GB palpable in presence of jaundice, jaundice unlikely to be due to stones.
What is a mucocoele?
GB outlet obstruction in absence of infection. Imprisoned bile is absorbed, clear mucous continues to be secreted into distended GB.
Presentation of mucocoele?
Hx of biliary colic + non-tender piriform swelling in R hypochondriac + lack of systemic upset + afebrile
What is choledocholithiasis?
Gallstone in CBD
Complications of choledocholithiasis?
Stones may pass spontantenously or give rise to:
- obstructive jaundice
- cholangitis
- acute pancreatitis
When do gallstones cause acute pancreatitis?
When small stone obstructs ampulla of Vater.
Is choledocholithiasis generally painful?
NO! Little muscle in CBD wall; unless impeded flow through Sphincter of Oddi.
Pathophysiology of choledocholithiasis?
Impaction at sphincter impeded bile flow: jaundice, pale stools, dark urine.
Generally lasts several days.
What is gallstone ileum?
Gallstoe perforates the gallbladder; ulcerates into duodenum; passes on to obstruct the terminal ileum.
Uncommon form of intestinal obstruction.
What is cholangitis (inc CFx)?
Infection of the bile ducts causing RUQ pain, jaundice, fever + rigors.
What is Charcot’s triad?
Fever, jaundice, RUQ pain.
Indicates cholangitis.
Ix in suspected biliary colic / cholecystitis?
- LFT: may show cholestatic picture.
- Prothrombin time: prolongation may occur over a longer period due to Vit K (fat soluble) malabsorption
- Ultrasound examination may demonstrate stones in the gallbladder or bile ducts.
- ERCP: In the presence of duct dilation or stones, endoscopic retrograde cholangiopancreatography (ERCP) is usually performed. Dx and Rx —> allows spincterotomy and removal of stones.
- MRCP: Magentic resonance cholangiopancreatography and endoscopic ultrasound (EUS) help image biliary tree.
- Haemolysis screen: if pigment stones suspected or found operatively.
Mx of gallstones?
- Cholecystectomy
- Medical dissolution (ursodeoxycholic acid up to 2years)
- Shockwave lithotripsy (limited efficacy)
- Sphincterectomy via ERCP
- If stones in biliary tree: (jaundice, cholangitis, pancreatitis) ==> IV ABs (prevent infection esp cholangitis).
U/S features of gallstone?
- Echogenic
- Round
- Mobile
- Acoustic shadow
Normal size of bile duct on U/S?
