Fiser Chapter 32 BILIARY SYSTEM Flashcards
Gallbladder function
Stores bile
Concentrates bile by active resorption of NaCl and water (has more sodium, bile salts, and cholesterol than hepatic bile; hepatic bile has more chloride)
Postprandial emptying (maximum at 2 hours)
Cholecystectomy -> decreased total bile salt pools
45yo man with UC presents with jaundice, fatigue, pruritis, weight loss, and RUQ pain
Primary sclerosing cholangitis: associated with UC, pancreatitis, DM
Multiple strictures throughout hepatic ducts (string of beads)
Leads to portal HTN, hepatic failure (progressive fibrosis of intrahepatic and extrahepatic ducts) -> cirrhosis, cholangiocarcinoma
Tx: PTC tube drainage, choledochojejunostomy or balloon dilatation of dominant strictures may provide symptomatic relief, cholestyramine to decrease bile acids and pruritis, UDCA (ursodiol) to decrease bile acids and improve liver enzyms; LIVER TXP EVENTUALLY NEEDED FOR MOST; Colon resection does NOT help PSC
Cholangitis dx
Elevated AST/ALT, bilirubin, alk phos, WBC
US shows dilated CBD (> 8 mm, > 10 mm after cholecystectomy) if d/t biliary obstruction
GB wall normal size
< 4 mm
Pigmentes stones
Most common worldwide
- Calcium bilirubinate stones: from increased bilirubin load, decreased hepatic function, and bile stasis -> solubilization of unconjugated bilirubin with precipitation; dissolution agents (monooctanoin) do NOT work
- Black stones: Hemolytic disorders, cirrhosis, ileal resection (loss of bile salts), chronic TPN; tx cholecystectomy if symptomatic
Cholecystitis most common organisms
E coli (#1), Klebsiella, Enterocococcus
Biliary colic
Transient cystic duct obstruction caused by passage of gallstone
RESOLVES IN 4-6 HOURS
Patient with sepsis following lap chole
- Fluid resuscitation, stabilize
- US to look for dilated intrahepatic ducts or fluid collection (cystic duct leak versus transection)
- Could also be cholangitis
Charcot’s triad
RUQ pain, fever, jaundice
Reynaud’s pentad: altered mental status and shock
Diabetic with severe rapid-onset abdominal pain, nausea, vomiting, sepsis, gas in gallbladder wall on plain film
Emphysematous gallbladder disease: risk of perforation
Usually d/t clostridium perfringens
Tx: emergent cholecystectomy, percutaneous drainage if unstable
Enterohepatic circulation
- Bile secreted by hepatocytes (80%) and bile canalicular cells (20%); broken down in gut to stercobilin (makes stool brown); reabsorbed
- Terminal ileum: active resorption of conjugated bile salts; Small intestine (45%) and colon (5%): passive resorption of non-conjugated bile salts
- Absorbed bile gets converted to urobilinogen and eventually urobilin, which is released in urine (yellow color)
Drugs that affect sphincter of Oddi
Morphine: contracts (why meperidine used to be used)
Glucagon: relaxes
Cholesterol and bile acid synthesis
HMG CoA -> (HMG CoA reductase) -> cholesterol -> (7-alpha-hydroxylase) -> bile salts (acids)
HMG CoA reductase is rate limiting step in cholesterol synthesis
Shock after lap chole causes
First 24 hours: hemorrhagic shock from clip that fell off cystic artery
After 24 hours: septic shock from accidental clip on CBD with subsequent cholangitis
Gallstone risk factors
> 40yo
Female
Obesity
Pregnancy
Rapid weight loss
Vagotomy
TPN (pigmented stones)
Ileal resection (pigmented stones)
Most sensitive test for cholecystitis
CCK-CS test (cholecystokinin cholescintigraphy), also uses HIDA scan (technetium taken up by liver and excreted in biliary tract)
Indications for cholecystectomy afterward:
- GB not seen (stone in cystic duct)
- Take >60 min to empty (chronic cholecystitis)
- EF < 40% (biliary dyskinesia)
Cystic vein
Drain into R branch of portal vein
Best treatment for late CBD stone
ERCP (sphincterotomy allows for removal of stone)
Risks: bleeding, pancreatitis, perforation
Most common cause of positive bile cultures
Postoperative strictures, usually E coli, or polymicrobial
Longitudinal blood supply of hepatic and common bile ducts
Right hepatic artery (9 oclock on ERCP), gastroduodenal artery retroduodenal branches (3 oclock on ERCP)
Pancreatic duct normal size
< 4 mm
Rokitansky-Aschoff sinuses
Epithelial invaginations in GB wall, formed from increased gallbladder pressure
Patient with sepsis, cholangitis, and jaundice
Bile duct stricture: cancer until proven otherwise (unless history of pancreatitis or biliary surgery)
Dx: MRCP to define anatomy, look for mass -> ERCP with brush biopies
Tx: if d/t ischemia or chronic pancreatitis -> choledochojejunostomy (best long-term solution), otherwise if cancer then appropriate workup
Todani classification of choledochal cysts
I: saccular or fusiform dilatation of a portion or whole CBD
II: isolated diverticulum from CBD
III: right by duodenum
IV: multiple (extrehepatic +/- intrahepatic)
V: intrahepatic (if multiple intrahepatic, is Carroli’s disease)
Cystic artery anatomy
Branches off right hepatic artery
Found in triangle of Calot (cystic duct latera, CBD medial, liver superior)
Most common route of bacterial infection of bile
Dissemination from portal system (NOT retrograde through sphincter of ODD)
Benign neuroectoderm tumor of gallbladder
Granular cell myoblastoma: can occur in biliary tract with signs of cholecystitis
Tx: cholecystectomy
CBD normal size
< 8 mm (< 10 mm after chole)
Causes of bile duct strictures
- Ischemia after lap chole (most important cause)
- Chronic pancreatitis
- Gallbladder cancer
- Bile duct cancer
Indications for asymptomatic cholecystectomy
Patients undergoing liver transplant, or gastric bypass procedure (if stones are present)
Cystic lymphatics are where
Right side of common bile duct
Galbladder wall layers
Mucosa (columnar epithelium)
No submucosa
Speckled cholesterol deposits on gallbladder wall
Cholesterolosis
Patient with persistent nausea, emesis, jaundice after lap chole: first step
Get US to look for fluid collection
- Fluid collection (bile leak): percutaneous drainage -> if bilious get ERCP
- > if cystic duct remnant leak, small injuries to hepatic or common bile duct, or leak from duct of Luschka -> sphincterotomy
- Dilated hepatic ducts and no fluid collection (completely transected CBD): PTC tube initially, then hepaticojejunostomy or choledochojejunostomy
Old Asian woman with episodic RUQ pain, fever, jaundice, and cholangitis
Choledochal cyst: 90% are extrahepatic, most type 1, 15% risk of cholangiocarcinoma
In infant can present like biliary atresia; caused by abnormal reflux of pancreatic enzymes during uterine development
Patient after PTC tube presents with UGI bleed, jaundice, and RUQ pain
Hemobilia: fistula between bile duct and hepatic arterial system (most commonly)
Most commonly occurs with trauma or percutaneous instrumentation to liver (PTC tube)
Dx: angiogram
Tx: angioembolization; operation if that fails
Bile essential functions
Fat-soluble vitamin absorption
Essential fat absorption
Bilirubin and cholesterol excretion
Nerve fibers of gallbladder
Parasympathetic fivers from Left (anterior) vagus trunk
Sympathetic fibers from T7-T10 (splanchnic and celiac ganglions)
Old patient with SBO and pneumobilia on plain film
Gallstone ileus: fistula between gallbladder and duodenum that releases stone, causing SBO
TI most common site of obstruction
Tx: Remove stone through enterotomy proximal to obstruction; perform cholecystectomy and fistula resection if patient can tolerate it
Cholesterol stones
Caused by stasis, calcium nucleation, and increased water reabsorption from GB; also by decreased lecithin and bile salts
Most common type in US
Bacteria causes cholecystitis, pneumobilia bile infection, emphysematous gallbladder disease
Cholangitis: E coli (#1) and kleb
Cholecystitis: E coli (#1), kleb, enterococcus
Pneumobilia bile infection from postop stricture: E coli, or often polymicrobial
Emphysematous GB disease: Clostridium perfringens
Most common biliary tract cancer
Gallbladder adenocarcinoma (rare but most common cancer of biliary tract), 4x more common than bile duct cancer; most have stones
Most common met site is liver: first to segments IV and V
First nodes are cystic duct nodes (right side)
15% risk in patients with porcelain GB (they need cholecystectomy if found)
High incidence of tumor implants in trocar sites when discovered after lap chole
5% 5-year survival
hormones that increase and decrease bile excretion
Increase: CCK, secretin, vagal input (CCK and secretin cells highest concentration in duodenum)
-CCK causes constant, steady, tonic GB contraction
Decrease: somatostatin, sympathetic stimulation
Gallbladder polyp tx
If > 1 cm or < 60yo, worry about malignancy
Tx: cholecystectomy
Indications for immediate and pre-op ERCP
Immediate:
-Jaundice, cholangitis, US shows stone in CBD (signs that CBD stone is present)
Pre-op ERCP: Any of following for > 24 hours
-AST or ALT > 200, bilirubin > 4, amylase or lipase > 1,000
Causes of cholangitis; complications
Causes:
- Bile duct obstruction (most commonly gallstones; also indwelling PTC tube)
- Stricture, neoplasm, choledochal cysts, duodenal diverticula
Complications:
- Systemic bacteremia: colovenous reflux (occurs at > 200 mm Hg)
- Renal failure (#1 serious complication; related to sepsis)
- Stricture and hepatic abscess are late complications
Location of gallbladder relevant to liver
Beneath segments IV and V
Cholecystitis tx
Cholecystectomy
Very ill: cholecystostomy tube
Thickened nodule of mucosa and muscle on gallbladder wall
Adenomyomatosis: associated with Rokitansky-Aschoff sinus, NOT premalignant, does NOT cause stones but can cause RUQ pain
Tx: cholecystectomy
CBD transection tx
Symptoms 7 days or sooner: hepaticojejunostomy immediately
Late symptoms after 7 days: hepaticojejunostomy 6-8 weeks after injury (tissue too friable at this time point)
RUQ pain, leukocytosis, US shows thickened wall, sludge, and pericholecystic fluid but no stones, HIDA scan positive: diagnosis, etiology, tx
- Acalculous cholecystitis: bile stasis (narcotic, fasting) -> distention and ischemia; also increased viscosity d/t/ dehydration, ileus, transfusion
- Most commonly burns, prolonged TPN, trauma, or major surgery
- Cholecystectomy, percutaneous drainage if unstable
Best initial test for RUQ pain and jaundice
US: 95% sensitive for stones
Stones: Hyperechoic focus, posterior shadowing, movement of focus with changes in position
Cholecystitis: stones, wall thickening (> 4 mm), pericholecystic fluid
Obstruction: dilated CBD (> 8 mm)
Cholangitis tx
- Fluid resuscitation
- Antibiotics
- Emergent ERCP with sphincterotomy and stone extraction
- PTC tube to decompress biliary system if ERCP fails
- If d/t infected PTC tube, change the tube
Elderly male with UC, PSC, presents with pain jaundice, weight loss, pruritis, found to have high bilirubin and alk phos, and on MRCP focal bile duct stenosis (but no history of biliary surgery or pancreatitis)
Cholangiocarcinoma, risk factors: C sinensis, UC, choledochal cysts, PSC, chronic bile duct infection; invades contiguous structures early
Dx: MRCP to define anatomy and look for mass; focal bile duct stenosis in patients without a history of biliary surgery or pancreatitis is highly suggestive of bile duct CA
Pnuemobilia causes
Most commonly occurs with previous ERCP and sphincterotomy
Can also occur with cholangitis or erosion of biliary system into duodenum (gallstone ileus)
Mirizzi syndrome
Compression of common hepatic duct by 1) stone in GB infundibulum, or 2) inflammation arising from the gallbladder or cystic duct extending to the contiguous hepatic duct, causing common hepatic duct stricture
Tx: cholecystectomy, may need hepaticojejunostomy for hepatic duct stricture
Antibiotic that can cause gallbladder sludging and cholestatic jaundice
Ceftriaxone
Ducts of Luschka
Biliary ducts in the GB fossa that can leak after chole
Percentage of patients undergoing cholecystectomy who will have a reained CBD stone
< 5%
and 95% of these are cleared with ERCP
Patient with jaundice and then RUQ pain, found to have gallbladder adenocarcinoma, what is tx?
Open cholecystectomy (sufficient if muscle not involved; lap chole contraindicated)
Wedge resection of segements IVb and V (if in muscle)
Formal resection of segments IVb and V (if beyond muscle and still resectable)
How does the gallbladder normally fill?
Contraction of sphincter of Oddi at ampulla of Vater
CBD and CHD do NOT have peristalsis
Cholangiocarcinoma tx
Upper 1/3 bile duct (Klatskin tumors): most common type, worst prognosis, usually unresectable
-Can try lobectomy and stenting of contralateral bile duct if localized to either R or L lobe
Middle 1/3: hepaticojejunostomy
Lower 1/3: Whipple
Unresectable: palliative stenting
20% 5-year survival
Gallstone types
Nonpigmented (cholesterol)
Pigmented (calcium bilirubinate and black stones)
Brown stones
Treatment of anastomotic leak after transplant or hepaticojejunostomy
Perc drainage of fluid collection, followed by ERCP with temporary stent (leak will heal)
Delta bilirubin
Bound covalently to albumin, t 1/2 18 days, may take a while to clear after long-standing jaundice
Brown stones
- Primary CBD stones, most commonly formed in ducts, Asians (brown and cholesterol stones found in CBD are secondary stones)
- Infection (E coli most common) -> beta-glucuronidase production -> deconjugation of bilirubin -> calcium bilirubinate formation
- Need to check for ampullary stenosis, duodenal diverticula, abnormal sphincter of Oddi
- Almost all patients with primary stones need a biliary drainage procedure - sphincteroplasty (90% success)
Patient with persistent RUQ pain, referred to R shoulder and scapula, nausea, vomiting, anorexia, frequently after a fatty meal, positive Murphy’s sign, elevated WBC and alk phos
Cholecystitis: cystic duct obstruction -> wall distension and inflammation
Suppurative cholecystitis: frank purulence in GB, associated with sepsis and shock
Woman with jaundice, fatigue, pruritis, xanthomas, positive antimitochondrial antibodies
Primary biliary cirrhosis: cholestasis -> cirrhosis -> portal hypertension
NO increased risk of cancer
Tx: Liver transplant
Tx of intraoperative CBD injury
< 50 % circumference: probably primary repair; otherwise need hepaticojejunostomy or choledocho jejunostomy
