Gallbladder and Biliary Tract Flashcards
What is the function of the gallbladder?
Concentrate and store bile and deliver it to duodenum in response to meals
Bile ducts regulate storage
What is the size and location of the gallbladder?
Size of the common bile duct?
7-10 cm in length
Separation of left and right liver lobes
7-11 cm long; 5-10 mm diameter
What are the components of the gallbladder?
Fundus: Rounded blind end, contains smooth muscle
Corpus: Main storage area; contains most elastic tissue
Neck: Funnel shaped, deep in fossa (Hartmann’s Pouch) connect to cystic duct
How much bile is produced?
What increases and decreases secretion?
What is the gallbladder’s role during fasting and its capacity?
Bile produced continuously 500 ml to 1000 ml
Bile secretion increases with vagal stimulation and secretin release
Bile secretion decreases with splanchnic stimulation
Fasting state: 80% bile stored in gallbladder. Gallbladder mucosa greatest absorptive power per unit area of any body structure. Capacity: 30-50 ml; 300 ml when obstructed
What does the gallbladder due to the ion composition of bile?
Increase in sodium, bile acid anions
Decrease in chloride and bicarbonate
What is the motor function of the fasting gallbladder?
What is the motor function during the emptying?
Receptive relaxation of gall bladder to allow filling
Tonic contractions of sphincter of Oddi for pressure gradient to develop
Coordinated gallbladder contraction, SO relaxation and meal intake gallbladder empties 50 to 70% contents in 30 to 40 minutes within eating; refills 60 to 90 minutes
What is the main stimulus for emptying?
What determines sphincter motility?
CCK
Basal contractile presssure and response to CCK and MMCs
What is the gallbladder innervation pattern?
How specific is the sensory pattern?
Nerves from vagus and sympathetic plexus passing celiac plexus
Preganglionic sympathetics from T8/9
Cannot differentiate specific biliary tract site by pain pattern
How many Americans have gallstones?
20 million
What are the types of gallstones?
Cholesterol – Western countries
Pigment – Bilirubin deposition
What is the process of the formation of gallstones?
Cholesterol: Imbalance between ratio of cholesterol (hypersecretion) and BA’s or phospholipids (hyposecretion)
Supersaturation of cholesterol not necessarily sufficient
Nucleation must also occur (protein secretion)
Motility disorder resulting in long residence times can also contribute
What is the epidemiology of gallstones? (Race, Age, Sex)
Young, women
Men: Increase with age
Native Americans: 60-70% prevalence
White adults: 10-15%
Black Americans, East Asian, Sub-Saharan Africans reduced risk
What are the risk factors for choleterol gallstones?
Increasing age
Women
Pregnancy and parity
Exogenous estrogens
Race
Family history
Obesity
Rapid weight loss
Physical inactivity
What is biliary sludge?
What is it associated with?
Biliary sludge: Calcium bilirubinate and cholesterol crystals embedded in mucus gel
Associated with drugs like ceftriaxone, octreotide, thiazide, diuretics, parenteral nutrition
What is the association between obesity and gallstones?
10-25% overweight men and women on strict diet
7.8% patients post-gastric bypass
Women with weight loss 9-22 lbs/2 year period at risk
What is the association between pregnancy and gallstones?
Biliary sludge and gallstones – 30% during pregnancy, 12% post-partum
1-3% post-partum women have cholecystectomy within first year
Increased estrogen levels during pregnancy; super saturated bile/sluggish GB motility
Majority: Sludge/gallstones dissolve spontaneously after partition,
What other diseases are associated with cholesterol gallstones?
Cirrhosis, chronic hemolysis, ileal crohn’s disease at risk for black pigment stones
What determines the manifestation of inflammatory biliary disorders?
Site of obstruction determines manifestation
What is acute cholecystitis?
Who gets it?
What causes it?
Inflammation of the gallbladder causing a syndrome of prolonged (>4 to 6 hours) steady, right epigastric pain
Associated with gallstone obstruction of the cystic duct
Typically develops in patients with history of symptomatic gallstones
Pathogenesis: Ductal obstruction plus additional irritant (lysolecithin in bile?)
What is the clinical picture of acute cholecystitis?
How are the lab values?
Ill-appearing, febrile tachycardic
Steady right epigastric pain with fever, leukocytosis
Lies still (Parietal Peritoneal Inflammation) May have Murphy’s Sign
LFT not usually abnormal
What diagnostic studies are done for acute cholecystitis?
Ultrasonography study: Detects stones, gallbladder wall thickening, edema, “Murphy’s Sign”
Cholescintigraphy – Technetium labeled hepatic iminodiacetic acid, injected IV, uptake by hepatocyte, checks if flow into the gall bladder within 30-60 minutes
What is the treatment of acute cholecystitis?
Laparoscopic Cholestectomy
Risks for complications due to variations in anatomy
Cholesectomy rate increased in the past decade in young
What is acute cholangitis?
What does it result in?
How threatening is it?
What pathophysiology is responsible for its complications?
Blockage in common bile duct
Results in stasis/infection in biliary tract
Severity mild to life-threatening
Obstruction raises intrabiliary pressure, increases permeability of bile ductules, permits bacterial/toxic translocation from portal circulation or ascending from duodenum
What are the causes of acute cholangitis?
CBD Biliary calculi
Benign stenosis
What bacteria are associated with acute cholangitis?
Gram negatives typically
E. coli, Klebsiella, Enterobacteria
What are the manifestations of acute cholangitis?
Charcot’s Triad: Fever Jaundice and Abdominal Pain (50% to 70%)
Confusion/hypotension occur with suppurative cholangitis
Associated with significant morbidity and mortality
Septic shock/multi-organ failure can occur
What are the lab tests with acute cholangitis?
What diagnostic studies can be done?
Elevated WBCs
Cholestatic pattern in LFT (Alk. Phos, GGT) and bilirubin elevation
Transabdominal US for larger stones
Magnetic Resonance Cholangiopancreatography for minute stones
Endoscopic retrograde cholangiopancreatograhy (ERCP) useful for diagnosis and most importantly drainage
What is gallstone pancreatitis?
How is it treated?
Obstructive stones in distal common bile duct or at the ampulla of vater
ERCP to extract and drain ducts in case of concurrent cholangitis
What defines acalculous cholecystitis?
Who typically has it?
How often?
How serious?
No stones
Usually in critically ill patients
10% of cholecystitis
High morbidity and mortality
Primary Sclerosing Cholangitis
What is it?
What is it associated with?
What is its survival?
What is its histology?
What is its radiographic appearance?
What are the complications?
Chronic progressive disorder of unknown etiology. Inflammation, fibrosis, stricturing of medium/large ducts in intrahepatic/extra-hepatic biliary tree
Majority of PSC patients have underlying IBD/ulceratrive colitis (as high as 90%); Routinely screen UC patients for this disorder
Median survival with liver transplantation after dx is 10 to 12 years
Histology: Onion skinning
Radiographic appearance: Narrowing of bile duct with dilation behind it
Complications: Coagulopathy (Vit K def) and bone disease (Vit D def)
What is the health impact of biliary disease?
Why might this be problematic?
700,000 cholecystectomies performed yearly
Possibly overly aggressive in removal
Difficulty in identification of gallbladder issue
Patient history of abdominal pain is confounding
What is biliary colic?
Describe distribution of pain
Describe other symptoms/signs
Not colic – Typically constant in nature; episodic pain
Begins usually mid-episgastrium, intense within 15 to 30 minutes, severe, steady 3 to 5 hours (right shoulder/interscapular area)
Unlike cardiac pain, restless patient (moving and repositioning for relief)
Nausea, vomiting, diaphoresis may accompany
What are myths associated with gallbladder disorders?
Biliary pain often unrelated to mealtime events, often nocturnal
GI symptoms such as dyspepsia, heartburn, bloating , fatty food intolerance are not suggestive per se
Not a chronic continuous process
Not associated with eliminations
What is the issue with assuming RUQ pain is gallbladder?
Chronic RUQ is almost never caused by gallbladder disease
Post-cholecystectomy syndrome from stone removal
RUQ pain can just be referred from elsewhere
What is a group I gallbladder disorder?
What should be done?
Typical biliary symptoms and gallstones
Very likely to develop recurrent problems
Cholesectomy indicated
What is a group II gallbladder disorder?
What should be done?
Atypical symptoms and gallstones
Worrisome group: symptom relief post-op occurs most likely in patients with biliary pain but symptom persistence of gas/flatulence 40%
Post-cholecystectomy risk so surgery with caution
What is a group III gallbladder disorder?
What should be done?
Gallstones without symptoms
20% of adults have gallstones, not sufficient indication
No surgery
What is a group IV gallbladder disorder?
What should be done?
Typical symptoms without gallstones (functional disorder)
Biliary dyskinesia
Rome III criteria for functional gallbladder disorder
Consider gallbladder ejection fraction – Less than 40% after IV CCK over 30 minutes considered dysfunctional
