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Flashcards in Tombazzi - Gallbladder Deck (56)
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1

What are the components of bile (and their functions)?

- BILE ACIDS: solubilization of cholesterol and modulation of intestinal motility -> essential for fat absorption 

- PHOSPHOLIPID: solubilization of cholesterol and protection of bile duct epithelium 

- IgA and IgM: bacteriostasis 

- MUCUS: prevention of bacterial adhesion 

- GLUTATHIONE: induction of bile flow 

- 500-600mL per day, and isoosmotic w/plasma 

2

What 3 types of stones can form in the gallbladder?

- CHOLESTEROL: more frequent, yellow-white, Ca salts of unconjugated bilirubin, matrix of mucin glyoprotein, only occasionally seen by x-ray 

- BLACK (pigmented): hemolysis, liver disease, age, TPN, pure calcium bilirubinate, calcium copper, mucin glycoprotein

- BROWN (pigmented): primary biliary, infection, prior surgery, duodenal diverticula, calcium salts and deconjugated bilirubin (high activity of beta-glucuronidase), cytoskeleton of bacteria, DEC biliary secretory IgA

3

Describe cholesterol metabolism. Hypersecretion? Risk factors for cholesterol stones?

- Total body pool of cholesterol: 1) syn from acyl-CoA, 2) dietary absorption, 3) cholesterol pool 

1. Solubilized and secreted unmodified in bile, and converted to bile acids -> most important ways body gets rid of cholesterol 

- HYPERSECRETION:

1. Estrogen: INC receptors for lipoproteins, INC free cholesterol 

2. Progesterone: DEC synthesis of cholesterol ester from free cholesterol 

- RISK FACTORS: female, older, obese, pregnant pts after delivery

- NOTE: remember all of these risk factors, and how they happen

4

What are the 3 most important contributing factors to the pathophys of cholesterol stone formation?

- Cholesterol supersaturation 

- Accelerated nucleation 

- Gallbladder hypomotility

- REMEMBER: balance b/t bile acid (good guy) and cholesterol (bad guy) is what is important

1. Cholesterol virtually insoluble in water, but bile acids, due to their unique amphiphatic properties, are able to solubilize cholesterol and phospholipid

5

What are 6 causes of cholesterol hypersecretion?

- OBESITY: hyperlipoproteinemia -> INC cholesterol synthesis (INC HMG CoA activity) 

- PROGESTERONE: oral contraceptives INC free cholesterol -> INH AcoA CAT, DEC conversion of cholesterol to cholesterol ester stores

- ESTROGENS: INC cholesterol uptake via INC lipoprotein B and E receptors

- AGE: age-related DEC in 7-alpha-hydroxylase 

- MARKED WEIGHT REDUCTION: mobilization of tissue cholesterol 

- ILEAL DISEASE, bypass, or resection: impaired bile acid absorption or excessive losses 

6

What is this?

Abetalipoproteinemia: small bowel mucosa shows characteristic CLEAR ENTEROCYTES due to lipid accumulation 

- Usually present as babies with failure to thrive

- Can’t get TG’s out of enterocytes, so they build up, and you get foamy, or frothy appearance from buildup of TG’s and lipoproteins in the enterocytes

- Note the difference b/t normal and diseased in the attached image 

7

What is the cholesterol saturation index? How can cholesterol in bile be found?

- CSI: ratio of amt of cholesterol in a bile sample to its max cholesterol micellar-holding capacity -> max amt of cholesterol you can deal with considering the amt of bile acid you have available 

- Bile that has a CSI >1 is supersaturated

- Cholesterol in bile can be found as the following: 

1. Mixed micelle: bile acids (BA), cholesterol, bilirubin, PC (phosphatidyl choline)

2. Simple micelle: BA, cholesterol, bilirubin

3. Vesicles: 10x larger, no bile salts -> when these converge, you get stones 

4. Multi-lamellar vesicles: unstable, and permit crystals formation

8

How can enterohepatic recirculation affect gallstone formation?

- Not enough bile acid can lead to imbalance b/t bile acids and cholesterol, so anything that can interfere with this circulation can get you into trouble

- Cycle occurs 6-10x daily 

- Actively transported through the hepatocyte, stored in gallbladder, sent to small bowel, low absorption in jejunum, then active/passive absorption in ileum, and transport back to liver 

9

What is accelerated nucleation?

- People who develop crystals much more quickly than others: some of these reasons we know, and others we do not

1. INC CSI = too much cholesterol for bile acid 

- Crystal formation: aggregation process by which a crystal particle is formed from supersaturated bile

1. Crystals generation: vesicular fusion and aggregation

10

If 2 pts have cholesterol hyper-secretion, will they both have gallstones?

 

- MAYBE: don't need to remember all of these in attached image, but know that there are other contributing factors -> 2 pts could have cholesterol hyper-secretion and 1 could have gallstones, and the other not 

1. Hyper-secretion and hyper-saturation are 2 different things

- Several factors identified that promote or INH the kinetics of cholesterol crystal formation: 

1. Concentrating bile and secretion of mucin glycoprotein INC cholesterol crystal formation 

2. Changes in bile composition, incl high cholesterol saturation and INC deoxycholate content enhance cholesterol crystallization 

11

How can gallbladder emptying affect the formation of cholesterol stones? Provide an example.

- TPN: no food in duodenum, but gallbladder does not know, and NOT contract -> risk factor for stones

- Even w/o TPN, some ppl have more gallbladder activity than others

- People with gallstones tend to have hypo-active gallbladders, or delayed emptying 

12

What are the gallbladder events in cholesterol gallstone formation? Possible risk factors? Tx?

- Possible RISK FACTORS: 

1, Defective acidification of gallbladder bile 

2. > pH higher precipitation of calcium salts

3. Gallbladder stasis can produce INC mucin secretion from gallbladder epithelium, and interfere with mechanical emptying

4. Decreased response to CCK

- TX: remove gallbladder -> 95% of the time, you correct the problem

1. For most people, this is a gallbladder disease, with the exception of brown stones

13

What 4 factors are implicated in the pathophys of cholesterol gallstone formation?

- Hepatic cholesterol hypersecretion 

- INC intestinal conversion to deoxycholate (2o bile acid)

- Mucin hypersecretion 

- Gallbladder hypomotility 

14

What are the clinical risk factors for black gallstone?

- Hemolysis, i.e., pts with sickle cell

1. A lot of bilirubin, which can precipitate with Ca salt, giving you small, hard stones (cholesterol stones are softer) 

- Advancing age 

- Long-term TPN 

- Cirrhosis 

- High level of unconjugated bilirubin is main component -> beta-glucuronidase is the enzyme that un-conjugates bilirubin

15

What are the risk factors for brown pigmented stones?

- Infection, primary biliary stones (formed in bile ducts, not gallbladder), prior surgery

1. Pts with intervention in the bile ducts; more frequently in older patients

- DEC biliary secretory IgA

- High activity of B-glucuronidase

- Develop infection, inflammation, and bigger, softer, brown stones

16

Describe the anatomy of the extrahepatic biliary tree.

- Note that the common bile duct (CBD) passes through pancreas before duodenum, getting together with main pancreatic duct

 

17

What are the clinical manifestations of biliary colic?

- Abdominal pain 

18

What are the clinical manifestations of acute cholecystitis?

- Abdominal pain 

- FEVER

- Abdominal US: thickening of gallbladder wall and pericholecystic fluid (CT can also help) 

1. Diagnostic

19

What are the clinical manifestations of choledocolithiasis with cholangitis?

- Abdominal pain 

- Fever 

- JAUNDICE 

20

What are the clinical manifestations of biliary pancreatitis?

- Abdominal pain 

- INC amylase 

21

ER: 50-y/o obese F w/epigastric, RUQ abdominal pain (7/10) that lasts around 30 mins. Severe pain that goes up, stays there, then starts going down. No fever, but some tenderness in RUQ. No rebound or irritation.

You give her something for pain, and 30 mins later she is fine, and wants to eat.

What is going on? What should you do?

 

- BILIARY COLIC

- Send pt home, but tell her this can happen again

- Will need to schedule a surgery to take the gallbladder out

 

22

Pt. previously seen for biliary colic comes back w/severe pain that lasts longer, and travels to shoulder. Feeling sick: febrile, tachycardic, hypotensive, high WBC, tachypnic.

What is going on? What should you do?

- ACUTE COLECYSTITIS

- Stone trying to come out for longer period of time, and gallbladder distended, leading to inflammation (not the same as infection)

- These pts need to be admitted to hospital:

1. Give IV AB

2. Call surgeons -> gallbladder can rupture, leading to peritonitis, sepsis, and high rate of mortality

23

30-y/o F who delivered 1 wk ago (high estrogen and progesterone) presents w/abdominal pain, jaundice, dark urine, stools a little lighter. 

What is going on? What should you do?

- CHOLANGITIS 

- Stone fighting to get through made it, went into CBD, and obstructed it -> bile can't get through, and is backtracking, entering blood, and causing jaundice 

- Admit to hospital -> may call surgeons, but def call GI doc who can go in by endoscopy, make cut, and clean

1. If you don’t do anything, infection goes into liver, blood, and causes sepsis: needs to be treated within 24 hours

24

What is biliary pancreatitis? Presentation? Dx?

- Stone obstructing bile ducts AND main pancreatic duct, INC pressure in main pancreatic duct, and causing inflammation of pancreas

- Pain is a belt pain that wraps around to back, and is worse when lying down flat on bed

- INC in amylase and lipase

- DIAGNOSIS: 2 of these 3 changes: 

1. Clinical -> severe pain (7 or 8/10, frequently with N/V)

2. INC in amylase/lipase

3. Changes in CT

25

What clinical features are key to diagnosing the spectrum of gallbladder disease?

- Biliary colic = only pain

- Add fever and high WBC, inflammation = acute cholecystitis 

- Jaundice = choledocholithiasis with cholangitis 

- INC amylase, changes on CT = biliary pancreatitis

26

What is the tx for choledocholithiasis?

- Stones extraction by endoscopic retrograde cholangiography (ERCP): attached image shows filling defects consistent with choledocholithiasis

1. 10% of patients with cholelithiasis will have choledocholithiasis

2. Sent to surgeons to get rid of gallbladder (cholecystectomy) when choledocholithiasis is resolved

- Choledocholithiasis is found in 12% to 15% of patients who undergo cholecystectomy

1. Cholecystectomy: most common elective abdominal operation 

27

What is a sphincterotomy?

- Small incision in the opening of the bile duct, which can help small gallstones and bile to drain appropriately 

- Balloon extraction of common bile duct stones after sphincterotomy attached here 

28

What is this? Describe the histo and gross appearance. Arrows?

Acute cholecystitis: just means inflammation; have to see + cholelithiasis for stones too

- HISTO: no specific morphologic differences b/t acute acalculous and calculous cholecystitis, save the absence of stones in the acalculous form.

1. Arrows: neutrophils -> in glands, not just lamina propria

- GROSS: enlarged and tense bright red, blotchy to green-black discoloration, imparted by subserosal hemorrhages

1. Frequently covered by a fibrinous or even fibrinopurulent exudate

- INC over holidays, and a lot of these are taken out

29

What is this?

- Calculous cholecystitis can have various exudates, from turbid bile to pus

- When the exudate is virtually pure pus, the condition is referred to as gallbladder empyema

Empyema: pus within an anatomic pocket 

30

What is this?

- Calculous cholecystitis: obstructing stone is usually present in the neck of the gallbladder or the cystic duct