What are the functions of cholecystokinin?
(where does it come from and what stimulates its release?)
- contration of smooth muscle of gallbadder -> release of bile
- relaxation of sphincter of Oddi -> allows bile flow into duodenum
released by cells in duodenum upon detecting fats/peptides following a meal
What is the most common cause of biliary tract disease?
-cholelithiasis
What is the presentation of cholelithiasis?
- can be present for decades without symptoms
- 70-80% remain asymptomatic
Presentation (biliary colic):
- RUQ pain
- dull
- postprandial
- constant but usually <6 hours
- may radiate to back or epigastrium
-nausea/vomiting
What are the main types of gall stones?
- cholesterol stones (>50% cholesterol)
- pigmented stone (unconjugated bilirubin and calcium salts)
- unconjugated hyperbilirubinemia -> black pigmented stones
- biliary tract infection -> deconjugation of bilirubin in the biliary tract (bacterial glucuronidase) -> brown pigmented stones
What types of gallstones can appear on an XR?
-black pigmented stones; 50-75% (calcium salts)
brown pigmented stones contain <u>calcium soaps</u> which are not radioopaque
What is the epidemiology of cholesterol and pigment stones?
10-20% of adults in developed countries are affected
Cholesterol:
- 90% of stones in US and western Europe
- 75% prevalence in Native Americans
Pigmented stones:
-predominant in non-Western countries (due to incidence of bacterial and parasitic infection)
What are the major risk factors for developing cholesterol stones?
The F’s:
- 40’s
- female
- fertile (pre-menopausal; estrogen contributes to development)
- fat (elevated cholesterol)
- fair skinned (white)
- family history
How do cholesterol stones develop?
- supersaturation of cholesterol in bile
- hypomotility of gallbladder
- cholesterol nucleation
- hypersecretion of mucous
What are causes of black pigmented stone?
any cause of uncongjugated hyperbilirubinemia:
- hemolytic anemia
- ileal dysfunction
What bacteria are the main causes of brown pigmented stones?
- Ascaris lumbricoides
- E. coli
- Clinorchis sinesis (liver fluke)
What are possible complications of cholelithiasis?
- cholecystits
- empyema (pus-filled gallbladder)
- perforation/fistula -> gallstone ileus (when into small bowel)
- cholangitis
- obstructive cholestasis
- pancreatitis
- gallbladder carcinoma
What complications are more typical of small and big stones?
Small stone -> obstruction:
the smaller the stone, the more likely
- “gravel” most common
- large stones are too big to enter the cystic duct
Large stones -> erosion:
- perforation/fistula
- when into small bowel and obstructs bowel (typically at ileocecal junction) -> gallstone ileus/Bouveret syndrome
- pneumobilia from enteric gas entering biliary tract
What is acute cholecystits?
Causes?
inflammation of the gallbladder due to checmical irritation
Calculous cholecystitis:
- obstrucion due to stone (90%)
- typiclally has previously had symptomatic cholelithiasis
Acalculous cholecystitis:
-no stone, likely caused by ischemia due to cystic artery compromise
How does acute cholecystitis present?
Both likely to present with:
- fever (mild), sweating
- anorexia
- N/V
- tachycardia
Calculous cholecystitis:
- progressive RUQ/epigastric
- Murphy sign
- lasts >6 hours (unlike cholelithiasis)
Acalculous cholecystitis:
- symptoms of precipitating condition
- might have no symptoms indicative of gallbladder
What is the course of acute cholecystits?
Calculous cholecystitis:
- typically sudden onset
- lasts >6 hours but may resolve spontaneouly (typically <24 hours but possibly up to 10 days)
- occasionally does not resolve and instead gets progressively worse -> requires cholecystectomy
Acalculous cholecystitis:
- insidious onset, possibly no symptoms related to gallbladder
- always requires cholecystectomy
- fatal if untreated
What is the appearance of the gallbladder in acute cholecystitis?
- enlarged and inflammed
- stone present in neck or cystic duct if calculous cholecystitis
What is chronic cholecystitis?
(cause?)
Causes:
- 90% of cases associated with cholelithiasis
- repeated episodes of acute cholecystitis
- many cases occur w/o previous acute cholecystitis
What variable features are there of chronic cholecystitis?
Rokitansky-Aschoff sinuses:
-outpouchings of mucosal epithelium through gallbladder wall
Porcelain gallbladder:
- dystrophic calcification of gallbladder
- appears on XR as white outline around gallbladder
- risk of gallbladder carcinoma
Xanthogranulomatous cholecystitis:
- massively thicked wall due to rupture of Rokitansky-Aschoff sinuses
- foamy macrophages
Hydrops gallbladder:
-dilated gallbladder, filled with clear fluid
What are risk factors of both acute and chronic cholecystitis?
- cholangitis/sepsis
- perforation/absecess
- rupture -> peritonitis
- fistula -> gallstone ileus
- gallbladder carcinoma (particularly in chronic w/ procelain gallbladder)
What is the most common cancer of the extrahepatic biliary tree?
-gallbladder adenocarcinoma
How does gallbladder adenocarcinoma present?
Usually insidious and is not detected until surrounding structures invaded -> high mortality
-symptoms usually identical to cholelithiasis which is the most common underlying cause
What is an ERCP?
endoscopic retrograde cholangiopancreatography:
- injection of dye through ampulla of Vater to see biliary tree and pancreatic duct
- diagnostic -> detection/localiztion of obstruction
- therapeutic -> canulation, sphincterotomy, removal of stone
-invasive procedure
What comlications can occur with an ERCP and what should be assessed prior to an ERCP?
Complications:
- panreatitis
- perforation
- bleeding
- infection
Assesment prior to:
- INR (bleeding risk)
- creatinine/BUN (dye is used)
- pregnancy test
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Liver Tests12
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General Features of Liver Disease30
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Infectious Liver Disease22
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Drug, Alcohol, and Metabolic Liver Disease42
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Cholestasis22
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Autoimmune Hepatitis/Cholangiopathies7
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Structural and Circulatory Disorders20
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Hepatic Complications in Pregnancy10
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Liver Nodules and Tumors28
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Gallbladder23
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Pancreas34
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Viral Hepatitis Pharm40
