BILIARY DISEASE
Physiology
Bile composition: cholesterol, bilirubin, bile acids, lecithin
Cholesterol is most soluble if >50% bile acids present
Most bile acids (95%) reabsorbed, mostly in terminal ileum (may recirculate 2-3x/meal)
↑bile acid loss = ↓[bile acid] = ↑lithogenicity (stone formation)
#1 type (70%) of gallstones = mixed (high [cholesterol])
Black stones (20%): sterile, due to hemolysis
Brown stones: infected bile, found in bile ducts
Imaging
---Ultrasound
Highly sensitive for detecting gallstones
Findings with acute cholecystitis: thick GB wall, pericholecystic fluid, stone + acoustic shadow
Air in lumen/GB wall = acute emphysematous cholecystitis
May see dilated bile ducts
Only 15% of gallstones are visible on xray
---HIDA
IV dye → taken up liver and excreted in bile → fills GB
No filling in 4 hours = cystic duct obstruction (normal filling time = 30 mins)
Sensitivity: 96%; Specificity 93%
False + in patients with hepatitis or on TPN
HIDA is used after U/S shows gallstones but no other abnormalities (but cholecystitis suspected)
--CT: best for mass work up, not for gallstones
--MRC: good for localizing CBD stones and biliary tract abnormalities (strictures)
Jaundice
Light stools & dark, tea colored urine, pruritis
Severe, sharp pain = calculous disease
Dull, vague ache (+ weight loss) = malignancy (pancreatic head tumor)
Courvoisier’s sign: palpable, nontender GB
Bile duct obstruction: ↑direct bili (urine), ↓urine urobilinogen (made by gut bacteria)
Biliary colic
Due to transient obstruction of cystic duct
Often postprandial, especially with larger, more fatty meals (pain onset ~ 30 mins after meal)
Dull, visceral, steady pain lasting < 4 hours
Patients exhibit writhing movements
Pain rarely relieved by anything
Acute cholecystitis
Acute inflammation/infection of GB (stone obstructing cystic duct)
Sharp, well localized, steady pain, > 4 hours
Fever, Murphy’s sign, Boa’s sign (R subscapular pain), ↑WBC (left shift)
Mild hyperbilirubinemia
Rx: NPO, IVF, ABX, cholecystectomy within 3 days (sick patients get choleycystostomy instead)
Acute gangrenous cholecystitis: 20% mortality
Acute acalculous cholecystitis (sludge): ICU patients, patients on TPN; Rx: percutaneous cholecystostomy
Acute emphysematous cholecystitis
Gas forming bacteria, increased perforation risk
Older, diabetic patients
Rx: ABX, cholecystectomy
Choledocholithiasis
Stone in CBD, fluctuating jaundice, history of biliary colic
U/S shows dilated CBD (>5mm), but misses 50% of CBD stones; MRCP or ERCP is best
↑Total bili, ↑direct bili, ↑alk phos
Rx: ERCP followed by cholecystectomy when bilirubin normalizes
Acute cholangitis
Infected stone in CBD
Charcot’s triad: fever, RUQ pain, jaundice
Rx: NPO, IVF, ABX, urgent ERCP followed by cholecystectomy once patient stabilizes
(doing cholecystectomy on initial presentation results in high mortality)
Acute suppurative cholangitis
Pus in bile ducts
Reynold’s pentad: Charcot’s + hypotension, altered mental status
Rx: urgent CBD decompression (ERCP preferred; alternatively cholecystostomy)
Acute gallstone pancreatitis
Due to small stones + sludge (not large stone) passing through the CBD and blocking/irritating pancreatic duct
Elevated amylase/lipase
Rx: observation (NPO/IVF/serial exams), ERCP with sphincterotomy if pancreatitis doesn’t improve
Cholecystectomy once pancreatitis resolves (otherwise gallstone pancreatitis recurs in 30-60%)
Gallstone ileus
Stone erodes through GB into duodenum (fistula forms)
Stone obstructs terminal ileum resulting in small bowel obstruction
AXR: air in biliary tree
U/S: good but air may block visualization of stone
CT with contrast is study of choice
Rx: laparotomy + enterolithotomy (removal of stone from small intestine)
Px: patients usually elderly with comorbities; thus do not perform cholecystectomy or fistula repair (hi mortality)
GB cancer
If localized to GB: cholecystectomy
If spread to liver: wedge resection of GB bed, liver
5 yr survival < 5%
Extrahepatic bile duct malignancies
Rare; patients usually in their 50s-70s
Increased risk in patients with ulcerative colitis, PSC (sclerosing cholangitis), choledochal cyst, parasitic disease
Spreads locally but rarely metastasizes (curative resection is rare)
S/Sx: progressive jaundice, Courvoisier’s sign
Prox 1/3 tumors: resect ducts if possible; 5 yr survival 5%
Mid 1/3 tumors: resect; 5 yr survival 10%
Distal 1/3 tumors: Whipple; 5 yr survival 35%
Congenital choledochal cysts
Cystic enlargement of bile duct
Usually females in teens, 20s
S/Sx: abdominal pain, jaundice, mass
Imaging shows extrahepatic duct dilatation without obstruction
Rx: total excision with follow up for strictures
Bile duct injury
90% of bile duct strictures iatrogenic (laparoscopic cholecystectomy higher incidence than open cholecystectomy)
If injury suspected intraop, perform cholangiography
Ducts <3mm may be ligated; otherwise repair immediately
If suspected post op (pain, jaundice, sepsis): U/S, HIDA, or CT
Rx: depends on extent of bile duct injury; ERCP with sphincterotomy and stent for small injury; otherwise choledochojejunostomy
Laparoscopic cholecystectomy (vs open)
Advantages: ↓post op pain, ↓wound complications, ↓pulmonary complications
Disadvantages: cost, ↑injury to bile ducts / intestine / vessels