Gallstones Flashcards
1
Q
Types of gallstones
A
- Cholesterol (75%)
- Pigment: black (20%) or brown (4.5%)
- In US most are cholesterol monohydrate crystals w/ Ca-bili/carbonate/phosphate precipitates
- Risk factors for gallstones: age (older= higher risk), female, ethnicity (native american>white, hispanic), family Hx
- 4 Fs: forty (40 yo) female, fair and fat
- Other factors: obesity, western diet, meds, pregnancy (increased progesterone leads to stasis of bile, increased estrogen leads to increased cholesterol secretion)
- Obesity has drastic risk factor effects for women, but not so much men
2
Q
Pathophysiology of cholesterol stones
A
- Hepatic hyper secretion of biliary cholesterol is main cause of cholesterol stones
- Supersaturated bile from cholesterol partly due to decreased secretion of bile salts and phospholipids into bile
- Hyposecretion of solubilizing lipids + hypersecretion of biliary cholesterol -> cholesterol stone
- Other things required to form the cholesterol stone: time and heterogenous pro nucleating agents (mucin gel), which encourages the precipitation of cholesterol monohydrate crystals
3
Q
Pathophysiology of pigment stones
A
- Black: seen in chronic hemolysis (thalassemia, hereditary spherocytosis, SCD) and cirrhosis
- Black stones due to large increases in unconjugated bilirubin in bile, which leads to Ca-bili polymers and thus stones
- Brown stones: unique b/c they can be formed in ducts (or gallbladder), while other types form in gallbladder and move to ducts
- Composed of Ca + unconjugated bili, cholesterol, FAs, mucin, bile salts, phospholipids
- Seen in roundworm infections, E coli infections (dead parasites are the stone nucleus), formation requires bile stasis associated w/ infection
4
Q
Natural Hx and Sx of gallstones 1
A
- Most gallstones are ASx
- Complications cause Sxs to begin
- Intermittent obstruction of cystic duct (gallbladder neck) can cause biliary pain (RUQ)
- Stone impacted in cystic duct can cause cholecystitis and RUQ pain
- Stone in cystic duct that compresses or fistulizes w/ common hepatic duct can cause mirizzi syndrome (obstructive jaundice)
5
Q
Natural Hx and Sx of gallstones 2
A
- Stone in the distal bile duct (near ampulla) can cause jaundice, biliary pain, acute biliary pancreatitis, ascending cholangitis (life-threatening)
- Can get stone eroding through wall of gallbladder into duodenum
- Very rarely, long standing cholelithiasis can lead to gallbladder CA
6
Q
Intermittent gallstone obstruction
A
- Intermittent RUQ or epigastic pain, severe but poorly localized and w/ nausea
- Pain may come on after meals
- No acute inflammation of GB
- PE: often nl, may have mild RUQ/epigastric tenderness
- Labs are nl, Dx via abd US (US sensitive to stones in GB but not for stones in common bile duct), more are not Rx (Rx is cholecystectomy)
- Most cases are ASx, low complication rate
7
Q
Acute cholecystitis
A
- Persistently impacted stone in cystic duct leading to acute inflammation, 50% w/ bacterial infxn
- Sx are severe epi/RUQ pain radiating to back, R shoulder (scapula) for >6 hr, often N/V
- PE: mild fever, RUQ tenderness w/ inspiratory arrest on pressure (murphy’s), 1/3rd have palpable GB, may see mild jaundice (rare)
- Labs: leukocytosis, may have mildly elevated bili (rare), amylase, lipase, transaminases
- If jaundice or high bili (>4) think other problems (choledocholithiasis)
- Dx via abd US, CT, HIDA
- NHx: 50% resolve, 10% local perf
- Rx: cholecystectomy, perQ drainage (esp if cirrhotic)
8
Q
Choledocholithiasis
A
- Stone in common bile duct (CBD), usually intermittent obstruction
- Intermittent RUQ or epigastic pain, severe but poorly localized and w/ nausea
- PE: often nl, pts often jaundiced
- Painless jaundice indicates malignancy, esp if GB is palpable (GB, pancreatic, hepatic)
- Labs: elevated AP, bili (if bili > 10 think malignancy or hemolysis), AST/ALT often elevated
- Dx: abd US, MRCP (very useful), ERCP, EUS
- Complications can be severe
- Rx: Stone removed by ERCP, possibly cholecystectomy
9
Q
Cholangitis
A
- Obstruction of CBD causing bile stasis and bacterial superinfxn in static bile (possible bacteremia), obstruction usually due to stone
- If it is a chronic process (pancreatic tumor) gallbladder will be enlarged, if acute (stone) GB does not have time to enlarge
- Sx/PE: Charcot’s triad (or reynold’s pentad) consisting of jaundice, fever, RUQ pain +/ hypotension (sepsis), AMS
- Labs: leukocytosis, high bili (D), elevated AP, positive blood Cx
- Organisms: E Coli and Klebsiella most common (bacteria ascend from duodenum or translocated from portal vein)
- Dx: abd US, ERCP
- NHx: high mortality rate, decompression decreases mortality
- Rx: emergency ERCP for stone removal or biliary decompression (surgery/stent if tumor)
10
Q
Imaging for stones 1
A
- Abd US: look for acoustic shadowing of GB, not very good for picking up stones in CBD (poor sens, good spec)
- Pericholecystic fluid and GB wall thickened to 4mm for cholecystitis Dx
- Cholescintigraphy (HIDA): more useful for cholecystitis (nl scan excludes cholecystitis, but positive can be due to other paths)
- Radioactive agents injected and excreted into bile, if contrast not seen in GB w/in 30-60 min then there is obstruction of CD
- HIDA better than US for cholecystitis
11
Q
Imaging for stones 2
A
- CT: only good for complications like abscess, perforation, pancreatitis
- MRCP: very good for large stones (>3mm) and noninvasive (best for pregnant women)
- But bad for stones in ampulla, cannot detect small stones in CBD, and is expensive
- EUS (endoscopic US): better resolution than abd US, good at detecting CBD stones and better than MRCP in detecting small stones
- ERCP: Usually last test done, used for therapeutic purposes so want to do it when there is high certainty for stone
12
Q
Biliary pain colic
A
- Steady pain that has gradual onset (15min-1hr), stays there and then resolves
- 1/3rd of pts have acute onset pain
- If >6 hrs think cholecystitis
- Pain is felt epi>RUQ>LUQ, many pts have pain radiating to R shoulder/scapula, lower abd
- Variable time btwn attacks, cholecystectomy to be considered in those w/ recurring episodes
13
Q
Non-surgical Rx
A
- Ursodeoxycholic acid: thins bile by reversing supersaturation of cholesterol
- May help to dissolve non-calcified small stones
- But does not address GB stasis
14
Q
Cholecystectomy
A
- Open: very good at relieving Sx, rare complications
- Most mortality due to cardiac disease
- Laparascopic: very low mortality as well
15
Q
ERCP
A
- ERCP w/in 48 hrs of presentation of cholangitis and/or choledocholithiasis
- Longer than 48 hrs results in prolonged hospital stay, longer than 72 hrs and poor outcomes increase (organ failure/death)
- Leukocytosis and high BUN after-> send to ICU
