Gallbladder Flashcards
- Isotonic fluid
- Major solute components of bile by moles percent include bile acids (80%), lecithin and traces of other phospholipids (16%), and unesterified cholesterol (4.0%)
- total daily basal secretion of hepatic bile ~500— 600 mL
HEPATIC BILE
- cholic acid and chenedeaexycholic acid (CDCA)
+ synthesized from cholesterol in the liver - conjugated with glycine or taurine.
- secreted into the bile
Primary bile acid
- deoxycholate and lithecholate
- formed in the colon as bacterial metabolites of the primary
acids - ursodeoxycholic acid (UDCA)
+ astereoisomer of CDCA
Secondary bile acids
BILE ACID FUNCTIONS
- biliary excretion of cholesterol
- facilitate the normal intestinal absorption of dietary fats
- serve as a major physiologic driving force for hepatic bile flow
- aid in water and electrolyte transport in the small bowel and colon
- normal bile acid pool size is ~2-4 g
- bile acid pool circulates ~5—10 times daily
- Intestinal reabsorption of the pool is about 95% efficient
- fecal loss of bile acids is in the range of 0.2-0.4 g/d
- maximum rate of synthesis is ~5 g/d
- bile acids are absorbed by passive diffusion
- active transport mechanism for conjugated bile acids in the
distal ileum - reabsorbed bile acids enter the portal bloodstream ,taken
up rapidly by hepatocytes, reconiugated, and resecreted into bile
ENTEROHEPATIC CIRCULATION
- high-pressure zone of resistance to bile flow from the CBD
into the duodenum - Its tonic contraction serves to
+ prevent reflux of duodenal contents into the pancreatic and bile ducts
+ promote filling of the gallbladder
Sphincter of Oddi (SOD)
- major factor controlling the evacuation of the gallbladder
- released from the duodenal mucosa in response to the ingestion of fats and amino acids
- powerful contraction of the gallbladder
- decreased resistance of the SOD
- enhanced flow of biliary contents into the duodenum
Cholecystokinin (CCK)
normal capacity of the gallbladder is ____ of bile
~30 ml
clinically innocuous entity in which a partial or complete septum (or fold) separates the fundus from the body
Phrygian Cap
Anomalies of position or suspension
A. intrahepatic.
B. Left sided
C. Transverse.
D. Retrodisplaced.
Types of Gallstone
- account for >90% of all gallstones in Western industrialized
countries - contain >50% cholesterol monohydrate plus an admixture
of calcium salts, bile pigments, proteins, and fatty acids
Cholesterol stones
Types of Gallstone
- composed primarily of calcium bilirubinate
- contain <20% cholesterol
- classified into “black” and “brown” types
- Brown type are formed secondary to chronic biliary infection
Pigment stones
- thick, mucous material that reveals lecithin-cholesterol
liquid crystals, cholesterol monohydrate crystals, calcium
bilirubinate, and mucin gels - crescent-like layer in the most dependent portion of the
gallbladder
BILIARY SLUDGE
BILIARY SLUDGE
The presence of biliary sludge implies two abnormalities:
(1) the normal balance between gallbladder mucin secretion and elimination has become deranged
(2) nucleation of biliary solutes has occurred
key changes that contribute to a “cholelithogenic state”
- a marked increase in cholesterol saturation of bile during the third trimester
- sluggish gallbladder contraction in response to a standard
meal, resulting in impaired gallbladder emptying.
Pregnancy
Other conditions associated with cholesterol-stone or biliarysludge formation:
- pregnancy
- rapid weight reduction through a very-low-calorie diet
cholesterol gallstone disease occurs because of several defects
(1) bile supersaturation with cholesterol
(2) nucleation of cholesterol monohydrate with subsequent crystal retention and stone growth,
(3) abnormal gallbladder motor function with delayed emptying and stasis.
- composed of either pure calcium bilirubinate or polymer-like complexes with calcium and mucin glycoproteins
- more common in patients who have chronic hemolytic states, liver cirrhosis, Gilbert’s syndrome, or cystic fibrosis, ileal diseases, ileal resection, or ileal bypass
- Enterohepatic recycling of bilirubin in ileal disease states contributes to their pathogenesis
Black pigment stones
- are composed of calcium salts of unconjugated bilirubin with varying amounts of cholesterol and protein
- presence of increased amounts of unconjugated, insoluble bilirubin in bile that precipitates to form stones
- frequent in Asia and is offen associated with infections in the gallbladder and biliary tree
Brown pigment stones
- Rapid
- Accurate identification of gallstone
- “Real-time” scanning allows assessment of GB volume, contractility
- Stones as small as 1.5 mm in diameter may be confidently identified provided that firm criteria are used (e.g., acoustic
“shadowing” of opacities that are within the gallbladder lumen and that change with the patient’s position by gravity)
Gallbladder Ultrasound
- low cost
- readily available
- detect gallstones containing sufficient calcium to be
radiopaque (10-15% of cholesterol and ~50% of pigment
stones)
Plain Abdominal X-ray
- Accurate identification of cystic duct obstruction
- Contraindicated in pregnancy
- Indicated for confirmation of suspected acute cholecystitis
Radioisotope Scans (HIDA, DIDA, etc.)
- most specific and characteristic symptom of gallstone disease
- constant and often long-lasting pain
- visceral pain is characteristically a severe, steady ache or fullness in the epigastrium or right upper quadrant (RUQ) of the abdomen with frequent radiation to the interscapular area, right scapula, or shoulder
- begins quite suddenly and may persist with severe intensity for 30 min to 5 h, subsiding gradually or rapidly.
Biliary colic
An episode of biliary pain persisting beyond 5h should raise the suspicion of
acute cholecystitis
An elevated level of serum bilirubin and/or alkaline phosphatase suggests a
common duct stone
Fever or chills (rigors) with biliary pain usually imply a complication,
- cholecystitis,
- pancreatitis,
- cholangitis.
- a minimal-access approach for the removal of the gallbladder together with its stones
- Advantages
> markedly shortened hospital stay
> minimal disability
> decreased cost y,
> procedure of choice for most patients referred for elective cholecystectomy - gold standard” for treating symptomatic cholelothiasis
Laparoscopic cholecystectomy
- Acute inflammation of the gallbladder wall
- usually follows obstruction of the cystic duct by a stone
- evoked by three factors:
> mechanical inflammation
> chemical inflammation
> bacterial inflammation - Frequently isolated organisms
» Escherichia coli, Klebsiella spp., Streptococcus spp., and Clostridium spp
ACUTE CHOLECYSTITIS
- Pain radiate to the interscapular area, right scapula, or shoulder
- Anorexia, nausea and vomiting
- Jaundice is unusual early in the course
ACUTE CHOLECYSTITIS
triad of ACUTE CHOLECYSTITIS
- RUQ tenderness,
- fever,
- leukocytosis
- rare complication in which a gallstone becomes impacted
in the cystic duct or neck of the gallbladder causing
compression of the CBD, resulting in CBD obstruction and
jaundice - Ultrasound shows gallstone lying outside the hepatic duct y
- ERCP, PTC, MRCP -characteristic extrinsic compression of the CBD
- Surgery consists of removing the cystic duct, diseased
gallbladder, and the impacted stone
Mirizzi’s syndrome
- Disordered motility of the gallbladder
- Infusion of CCK can be used to measure the gallbladder
ejection fraction during cholescintigraphy. - Criteria
> recurrent episodes of typical RUG pain characteristic of biliary tract pain
> abnormal CCK cholescintigraphy. demonstrating a gallbladder ejection fraction of <40%
> infusion of CCK reproducing the patient’s pain - identification of a large gallbladder on ultrasound examination
ACALCULOUS CHOLECYSTOPATHY
- thought to begin with acute cholecystitis (calculous or
acalculous) followed by ischemia or gangrene of the
gallbladder wall and infection by gas-producing organisms - frequently cultured
> Anaerobes- Clostridium welchii or C. perfringens
> aerobes,- F. coli - clinical manifestations are indistinguishable from those of
nongaseous cholecystitis - plain abdominal film
> gas within the gallbladder lumen, dissecting within the gallbladder wall to form a gaseous ring, or in the pericholecystic tisues.
EMPHYSEMATOUS CHOLECYSTITIS
- Chronic inflammation of the gallbladder wall
- result from repeated bouts of subacute or acute cholecystitis or from persistent mechanical irritation of the gallbladder wall by gallstones
- may be asymptomatic for years, which may progress to symptomatic gallbladder disease or to acute cholecystitis, or may present with complications
CHRONIC CHOLECYSTITIS
TREATMENT OF empyema, emphysematous cholecystitis, or
perforation is suspected or confirmed
Urgent (emergency) cholecystectomy or cholecystostomy
- most common biliary anomalies of clinical relevance encountered in infancy
- clinical picture is one of severe obstructive jaundice during the first month of life, with pale stools
- diagnosis is confirmed by surgical exploration
and operative cholangiography
BILIARY ATRESIA AND HYPOPLASIA
- Passage of gallstones into the CBD occurs in ~10—15% of
patients with cholelithiasis - 25% of elderly patients may have calculi in the CBD at the
time of cholecystectomy - Undetected duct stones are left behind in ~1—5% of
cholecystectomy patients - cholesterol stones
CHOLEDOCHOLITHIASIS
- Primary calculi arising de novo in the ducts
- Develops in patients with:
> hepatobiliary parasitism or chronic, recurrent cholangitis
> Caroli’s disease
> dilated, sclerosed, or strictured ducts
> MDR3 (ABCB4) gene defect
CHOLEDOCHOLITHIASIS
Brown pigment stones
Charcot’s triad
- biliary pain
- jaundice
- spiking fevers with chills
- is most common cholangitis
- respond relatively to supportive measures and antibiotics
Nonsuppurative acute cholangitis
- “pus under pressure “ cholangitis
>» mental confusion, bacteremia, and septic shock
>» ERCP with endoscopic sphincterotomy
Suppurative acute cholangitis
- Painless jaundice
- absence of a palpable gallbladder in most patients with biliary obstruction from duct stones
OBSTRUCTIVE JAUNDICE
the presence of a palpably enlarged gallbladder suggests that the biliary obstruction is secondary to an underlying malignancy rather than to calculous disease
Courvoisier’s law
Serum bilirubin levels 20 mg/dl suggests
neoplastic obstructions
Elevated serum alkaline phosphate levels precedes
clinical jaundice
- preoperatively by endoscopic retrograde cholangiogram (ERC)
- MRCP
- intraoperatively at the time of cholecystectomy
Cholangiography
CBD stones should be suspected in gallstone patients who have any of the following risk factors:
(1) a history of jaundice or pancreatitis
(2) abnormal tests of liver function
(3) ultrasonographic or MRCP evidence of a dilated CBD or stones in the duct
