Biliary system Flashcards
What is the anatomy of the biliary system?
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What do gallstones describe?
Stone formation in the gallbladder.
What is biliary colic?
When gallstones become SYMPTOMATIC with cystic duct obstruction or if passed into the common bile duct.
What does bile contain? (x3)
Cholesterol, phospholipids, bile pigments (broken down Hb).
What is the aetiology of gallstones and biliary colic? (x3)
o Depends on the concentration of bile contents.
o MIXED STONES: faceted (many sides) and contain cholesterol, calcium bilirubinate, phosphate and protein.
o PURE CHOLESTEROL STONES (10%): large, often solitary.
o PIGMENT STONES (10%): small, friable (easily crumbled), and irregular. Black stones of calcium bilirubinate (increased bilirubin secondary to haemolytic disorders or cirrhosis), brown stones due to bile duct infestation by liver fluke (parasite).
What is the role of the ileum? (x2)
Reabsorption of Vitamin B12 and conjugated bile salts.
What are the risk factors of mixed stones?
Associated with older age, female, obesity, parenteral nutrition, drugs (oral contraception, octreotide (statin)), family history, ethnicity (Pima Indians), interruption of the enterohepatic recirculation of bile salts (e.g. Crohn’s Disease), terminal ileal resection.
What are the risk factors of cholesterol stones?
Similar as mixed stones: age, female, obesity, and Admiran’s triangle (increased risk of cholesterol stone is low lecithin (phospholipid), low bile salts and high cholesterol).
What are the risk factors of pigment stones?
Haemolytic disorders such as sickle cell, thalassemia and hereditary spherocytosis.
What is the epidemiology of gallstones and biliary colic? Prevalence, age, gender.
Very common – 10% prevalence in the UK. More common with age. 3x more females in younger population but equal sex ratio after 65 years.
What percentage of patients are asymptomatic with gallstones?
90%. Found incidentally.
What are the symptoms associated with biliary colic? (x3) The group of symptoms in the final presentation?
o BILIARY COLIC: sudden onset, severe RUQ or epigastric pain, constant in nature. May radiate to right scapula, often precipitated by a fatty meal. Can last hours, may be associated with N&V.
o ACUTE CHOLECYSTITIS: patient systemically unwell, fever, vomiting, prolonged and continuous upper abdominal pain (RUQ and epigastric) that may be referred to right shoulder (due to diaphragmatic irritation).
o ASCENDING CHOLANGITIS: classical association between RUQ pain, jaundice and rigors (sudden, shivering cold feeling) – CHARCOT’S TRIAD. If combined with hypotension (septic shock) and confusion, it is known as Reynold’s pentad.
What are the signs of biliary colic on examination? (x3)
o BILIARY COLIC: RUQ or epigastric tenderness.
o ACUTE CHOLECYSTITIS: tachycardia, pyrexia, RUQ or epigastric tenderness with guarding +/- rebounding. Murphy’s sign is elicited by placing a hand at the costal margin in the RUQ and asking the patient to breathe deeply. Palpable gallbladder mass in some patients. A phlegmon (RUQ mass of inflamed adherent omentum and bowel) may be palpable.
o ASCENDING CHOLANGITIS: pyrexia, RUQ pain, jaundice.
What investigations can be performed for biliary colic and gallstones? (x4 (x4))
o BLOODS: FBC (increased WBC in cholecystitis or cholangitis), LFT (increased ALP, increased bilirubin in ascending cholangitis; there may be increased transaminases), blood cultures, amylase (test risk of pancreatitis).
o USS: demonstrates gallstones. Increased thickness of gallbladder wall and can examine for presence of dilatation of biliary tree indicative of obstruction.
o AXR: are infrequently radio-opaque
o OTHER IMAGING: erect CT (to exclude perforation as a differential), CT, MRCP, ERCP.
How is mild gallstones/biliary colic managed?
Conservative, avoidance of fat in diet.
How are severe biliary colic symptoms managed conservatively? (x4) What if symptoms fail to improve or worsen?
Admission, IV fluids, analgesia, antiemetics, antibiotics if there are signs of infection (cholecystitis and cholangitis). IF SYMPTOMS FAIL TO IMPROVE: a localised abscess or empyema (pus in gallbladder) should be suspected which can be drained by cholecystectomy and pigtail catheter.
What is there evidence of obstruction in biliary colic? (x2)
Urgent biliary drainage by ERCP or percutaneous transhepatic cholangiogram.
How can gallstones be managed surgically? Time difference?
Laparoscopic cholecystectomy +/- on table cholangiogram. In an acute setting, performed within 72 hours of symptoms onset, or after several weeks for inflammation to settle.
What are the complications associated with gallstones within the gallbladder? (x6)
Biliary colic, cholecystitis, mucocele (gallbladder distension from mucous build-up secreted from gallbladder wall), gallbladder empyema (gallbladder distension from pus), porcelain gallbladder, predisposition to gallbladder cancer.
What is porcelain gallbladder?
Calcification of gallbladder.
What are the complications associated with gallstones outside the gallbladder? (x8)
Obstructive jaundice, pancreatitis, ascending cholangitis, perforation and pericholecystic (around gallbladder) abscess or bile peritonitis, cholecystenteric fistula (to small bowel, usually duodenum), gallstone ileus, Mirizzi syndrome (common hepatic duct obstruction by an extrinsic compression from an impacted stone in the cystic duct), Bouveret’s syndrome (gallstones causing gastric outlet obstruction).
Why is gallbladder necrosis (as a complication/presentation) rare?
Because of dual blood supply – hepatic artery via cystic artery, and from small branches of the hepatic artery in the gall bladder fossa.
What is gallstone ileus?
Impaction of gallstone in small intestine, usually distal ileum, leading to small bowel obstruction. From gradual erosion of stone and fistula formation into small bowel.
What is the definition of an impacted stone?
Impacted stone is defined as the stone that has remained in the same position for at least two months with failure in visualization of the contrast material in the ureter distal to the stone.
What does dyspeptic mean?
Indigestion.
What are the complications of a cholecystectomy? (x7)
Bleeding, infection (cholangitis), bile leak (leading to peritonitis), bile duct injury, pancreatitis, post-cholecystectomy syndrome (persistent dyspeptic (indigestion) symptoms arising from alterations in bile flow because there is loss of reservoir function), port-size hernias.
What is the prognosis of biliary colic/gallstones?
In most cases, gallstones are benign and do not cause significant problems. 2% with gallstones develop symptoms annually. If they become symptomatic, surgery is an effective treatment.
What is cholecystitis?
Inflammation of the gallbladder.
