Chapter 32 - Biliary System Flashcards
What blood vessels supply the hepatic and CBD?
Right hepatic and retroduodenal branches of the GDA.
Injuring these can lead to stricture.
What side of the CBD are the lymphatics on?
Right.
This is important for hepatoduodenal/portal node dissections done with GB cancer.
What type of cells makes up the mucosa of the gallbladder? Is there submucosa?
Columnar epithelium
NO submucosa
What will relax the sphincter of Oddi?
Glucagon (can use intraop to try to clear stones in choledocholithiasis)
What is the normal size of the GB wall? Pancreatic duct?
GB wall: 2-4 mm
Pancreatic duct: 1.5-3.5 mm
Where is the highest concentration of CCK and secretin cells? Discuss CCK.
- Duodenum
- response to fatty acids
- produced by I cells
- stimulates GB contraction, Oddi relax, panc secrx
- produces some satiety
- inhibited by somatostatin
What are Rokitansky-Aschoff sinuses?
Invagination of the epithelium of the wall of the gallbladder; formed from increased gallbladder pressure
What are the ducts of Luschka?
Biliary ducts that attach to the GB in the fossa that can leak after chole
What stimulates increased bile excretion?
What kind of channel is secretion dependent on?
- secretin (most potent), CCK, vagal input
- chloride channel, active transport
- bile has high concentration of bicarb
- secretes around 1L/day
What biochem signals cause decreased bile excretion?
VIP, somatostatin, sympathetic stimulation
What are the 3 essential functions of bile?
- fat-soluble vitamin absorption (emulsifies lipids)
- bilirubin excretion
- cholesterol excretion
How does the gallbladder form concentrated bile?
Active resorption of Na and H20
How many times a day does the bile salt pool cycle?
4-8 times/day
Where does active resorption of conjugated bile acids occur? Passive resorption of nonconjugated bile acids?
Active: terminal ileum (50%), passive: small intestine and colon
Where is bile secreted from?
Bile canalicular cells (20%), hepatocytes (80%)
What is the breakdown product of conjugated bilirubin that gives stool brown colon?
Stercobilin
What is the breakdown product of conjugated bilirubin that gets reabsorbed and released in urine?
Urobilin
Pathway of cholesterol and bile acid synthesis?
HMG CoA –> (HMG CoA reductase) –> cholesterol –> (7-alpha-hydroxylase) –> bile acids
What is the rate-limiting step in cholesterol synthesis?
HMG CoA reductase
What causes stones in obese people? In thin people?
Obese: overactive HMG CoA reductase
Thin: underactive 7-alpha-hydroxylase
What % of the population has gallstones?
10%
What causes nonpigmented stones?
Increase cholesterol insolubilization; caused by stasis, calcium nucleation by mucin glycoproteins, increased water reabsorption from gallbladder; decreased lecithin and bile acids
What is the most common type of stone found in the US?
Nonpigmented (75%)
What is the most common type of stone found worldwide?
Pigmented
What causes pigmented stones?
Solubilization of unconjugated bilirubin with precipitation of calcium bilirubinate and insoluble salts
What causes black stones?
Hemolytic disorders or cirrhosis; also in pts with chronic TPN, ileal resection; increased bilirubin load, decreased hepatic function and bile stasis
What causes brown stones? Where are they found?
Infection causing deconjugation of bilirubin; found in CBD, formed in ducts
Most common bacteria causing brown stones?
E. coli
What pathologies need to be checked for in a patient with brown stones?
Ampullary stenosis, duodenal diverticula, abnormal sphincter of Oddi
Cholecystitis is caused by what?
Obstruction of the cystic duct by gallstone
What is suppurative cholecystitis?
Associated with frank purulence in the GB, can be associated with sepsis and shock
Most common organisms in acute cholecystitis?
E. coli, klebsiella, enterococcus
Risk factors for stone formation?
Age >40, female, obesity, pregnancy, rapid wt loss, vagotomy, TPN, ileal resection
Sensitivity of US in picking up stones?
95%
What is the definition of biliary dyskinesia (percentage of volume excreted over certain time)?
- Twenty minutes after the injection of CCK, an ejection fraction of less than 35% is considered abnormal.
- Or <40% of gallbladder volume excreted after CCK over 1 hour.
- Tx w/ cholecystectomy.
Causes of air in the biliary system?
Previous ERCP and sphincterotomy, cholangitis, erosion of the biliary system into duodenum (gallstone ileus)
What are signs of acalculous cholecystitis? Pathology?
Thickened wall, RUQ pain, elevated WBCs; bile stasis leading to distention and ischemia
When does acalculous cholecystitis occur?
After burns, prolonged TPN, trauma, other major surgery
Diagnosis of acalculous cholecystitis?
US shows sludge, GB wall thickening, pericholecystic fluid; HIDA (+)
What is the common organism causing emphysematous gallbladder disease?
C. perfringens
What is gallstone ileus?
Fistula between GB and duodenum that releases stone, causing SBO
usually elderly patient
can see pneumobilia on plain film with stone in RLQ
Most common site of obstruction in gallstone ileus?
Terminal ileum
Treatment for gallstone ileus?
Remove stone with enterotomy proximal to obstruction (enterolithotomy), usually through laparotomy incision, may need bowel resection if necrosis/ischemia/perforation, inspect the whole bowel.
Perform chole and fistula resection if pt is low risk (ASA 1 or 2). If high risk, do lap chole later.
What is the benefit of interoperative cholangiography?
Allows for intraoperative detection of biliary injury. Studies have not definitively shown benefit in preventing injury.
In what % of patients does the right posterior duct enter the CBD separately? What segment is it from?
10%, segment 6 or 7
What is the treatment if the right posterior duct is injured during lap chole?
If >2mm, need to open and perform hepatico-j
Treatment for intraop CBD injury?
- If <50% circumference - perform primary repair
- all other cases - hepaticoj or choledochoj
What is the workup for persistent nausea and vomiting or jaundice following lap chole?
- US for fluid collection: if collection, perc drain
- bilious drainage: ERCP and stent vs repair
- no fluid collection, dilated hepatic ducts - concern for transected bile duct
Treatment for anastamotic leaks following transplant or hepaticoj?
ERCP and stents
Treatment for sepsis following lap chole?
Fluid resuscitation, stabilize; concern for complete transection of CBD and cholangitis
Most common situation in which CBD or hepatic duct strictures occur?
After lap chole
What is the most important cause of late postoperative biliary strictures?
Ischemia (injury to R hepatic artery); can also be caused by chronic pancreatitis, stricture of biliary enteric anastomosis
Diagnosis of CBD or hepatic duct stricture?
ERCP; US will show dilated ducts
Treatment of CBD or hepatic duct strictures?
ERCP with sphincterotomy and possible stent placement; PTC tube if that fails
7d post injury, hepaticoj 6-8wks after injury
What causes hemobilia?
Fistula between bile duct and hepatic arterial system; most commonly occurs with trauma, also infections, primary gallstones, aneurysms, tumors
Presentation of hemobilia?
UGI bleed, jaundice, RUQP
Diagnosis of hemobilia? Treatment?
- Start with resuscitation and ABCs
- EGD is first test for UGIB
- Angiogram is diagnostic and therapeutic w/ embolization
- Operation if that fails
What is the most common cancer of the biliary tract?
Gallbladder adenocarcinoma
What is the most common site of mets from gallbladder adenocarcinoma?
Liver
What % of patients w/ GB cancer present with stage IV disease?
90%
Symptoms of gallbladder CA?
Where does it spread first? How do you know if it will? What do you do?
- Painless jaundice 1st, then RUQ pain (could be cholangitis at this point). Chronically - weight loss, fatigue, loss of appetite.
- Spreads lymphatically to cystic duct nodes first.
- Any GB cancer past mucosa can spread.
- Do liver bed excision.
- N1 - portal and perihepatic
- N2 - para-aortic, celiac
Treatment based on stage of GB CA?
- Stage I (mucosa): chole
- Stage II+ (into muscle): wide resection around liver bed - 2-3cm margins, regional lymphadenectomy, may need Whipple, lobectomy or resection of CBD
Contraindication for lap chole?
Gallbladder CA - high incidence of tumor implants in trocar sites.
Inability to tolerate pneumoperitoneum.
General contraindications for surgery.
Not recommended in ASA III/IV or septic pts w/ milder disease.
5-yr survival of gallbladder CA?
5%
Risk factors for bile duct cancer (cholangiocarcinoma)?
C. sinensis infection, typhoid, UC, choledochal cysts, sclerosing cholangitis, congenital hepatic fibrosis, chronic bile duct infection
Symptoms of cholangiocarcinoma?
Early: painless jaundice, can also get cholangitis; late: wt loss, anemia, pruritis; persistent increase in alk phos and bilirubin
Diagnosis of cholangiocarcinoma?
- CA19-9, CEA, AFP
- Initial CT/MRI/US: dx if typical findings
- proximal lesion → MRCP: dx if typical findings
- distal lesion, or MRCP not typical → ERCP
- still not typical after ERCP → MRI/CT guided bx
What does the discovery of a focal bile duct stenosis in pts without h/o biliary surgery or pancreatitis suggest?
Bile duct ca
Treatment for Klatskin tumor?
- Lobectomy and stenting of contralateral bile duct if localized to right or left lobe; usually unresectable (MDCT, MRCP, ERCP, bx)
- Resectability often determined at surgery. Cannot have…
- retropancreatic, paraceliac nodal metastases, liver mets
- invasion of the portal vein or main hepatic artery
- extrahepatic adjacent organ invasion
- disseminated disease
Where are Klatskin tumors?
In upper 1/3 of bile duct; most common type, worst prognosis
Treatment for cholangiocarcinoma in upper 1/3? Middle 1/3? Lower 1/3? Locally advanced upper?
- Upper: involving the confluence (hilar CCa) require duct resection and partial hepatectomy
- Middle: bile duct resection w/ regional LADx and hepaticojejunostomy
- Lower: Whipple (pancreaticoduodenectomy)
5-yr survival for cholangio?
20%
What % of choledochal cysts are extrahepatic?
90%
What is the cancer risk with choledochal cysts?
15% (require resection)
Symptoms of choledochal cyst?
Episodic pain, fever, jaundice, cholangitis
Choledochal cyst presentation in infants?
Similar to biliary atresia
Possible cause of choledochal cysts?
Abnormal reflux of pancreatic enzymes during development secondary to bad angle of insertion
Most common type of choledochal cyst?
Type I: saccular or fusiform dilation of extrahepatic ducts
Treatment for choledochal cyst?
Excision with hepaticoj and chole; type IV partially intrahepatic/type V totally intrahepatic will need liver resection
What patients have primary sclerosing cholangitis?
Men in 4-5th decade; associated with retroperitoneal fibrosis, Riedel’s thyroiditis, pancreatitis, UC, DM
Symptoms of PSC?
Fatigue, fluctuating jaundice, pruritus, wt loss, RUQ pain
Does PSC get better after colon resection for UC?
NO
Consequences and complications of PSC?
Portal HTN and hepatic failure (scarring and patching with progressive fibrosis of intra/extrahepatic ducts); chirrhosis, cholangiocarcinoma
Diagnosis of PSC? Treatment?
ERCP showing multiple strictures and dilations; transplant needed long term, PTC drainage/choledochoj may be effective, balloon dilation for symptomatic relief
Treatment for pruritus symptoms in PSC. Temporizing management? Definitive management?
- Cholestyramine; though medication often has little effect.
- Stenting can temporize.
- Definitive treatment will be with a transplant.
- Disease will recur in the transplant, but not usually enough to cause severe symptoms.
Primary biliary cirrhosis occurs in what size ducts?
Medium-sized hepatic ducts
Consequences of PBC?
Cholestasis –> cirrhosis –> portal HTN
Symptoms of PBC?
Fatigue, pruritus, jaundice, xanthomas
What type of antibodies are associated with PBC?
Antimitochondrial antibodies
Cancer risk with PBC?
No increased risk of cancer
Treatment for PBC?
Transplant
What is Charcot’s triad?
RUQ pain, jaundice, fever - indicates cholangitis
What is Reynold’s pentad
RUQ pain, jaundice, fever, altered mental status, shock - suggests sepsis from cholangitis
Most common organisms in cholangitis?
E. coli and Klebsiella
Late complications of cholangitis?
Stricture and hepatic abscess
1 serious complication of cholangitis?
Renal failure; related to sepsis
Most common etiology of cholangitis? Other causes?
Gallstones; also biliary strictures, neoplasm, chronic pancreatitis, congenital choledochal cysts, duodenal diverticula
What is the cause of systemic bacteremia from cholangitis?
At >20mmHg, cholovenous reflux occurs –> systemic bacteremia
Treatment for cholangitis?
Fluid resus, abx, ERCP with sphincterotomy nd stone extraction, if fails - PTC
What is oriental cholangiohepatitis?
Recurrent cholangitis from primary CBD stones; in Asia; caused by C. sinensis, A. lumbricoides, T. trichiuria, E. coli
What is the most common cause of shock following lap chole early (1st 24h)? Late (after 1st 24h)?
Early: hemorrhagic shock from clip that fell off cystic artery
Late: septic shock from accidental clip on CBD with subsequent cholangitis
What is adenomyomatosis?
Thickened nodule of mucosa and muscle associated with Rokitansky-Aschoff sinus; not premalignant, does not cause stones; tx: chole
What is granular cell myoblastoma?
Benign neuroectoderm tumor of the GB; can occur in biliary tract with signs of cholecystitis; tx: chole
What is cholesterolosis?
Speckled cholesterol deposits on GB wall
What size GB polyp more likely to be malignant?
- >1cm
- most are cholesterol polyps w/o cancer potential
- most are asymptomatic
- tx: most get f/u US q6m x2yr; chole if…
- sx and no other cause
- 10 mm
- PSC
- associated gallstones
What is delta bilirubin?
Bound to albumin covalently, half-life 18d, may take a while to clear after long-standing jaundice
What is Mirizzi syndrome?
Compression of the common hepatic duct by a stone in the infundibulum of the GB or inflammation arising from the GB or cystic duct; causing stricture and hepatic duct obstruction
What abx can cause gallbladder sludging and cholestatic jaundice?
Ceftriaxone
What are indications for asymptomatic cholecystectomy?
Pts undergoing liver TXP, gastric bypass, or PNET resection
How do you manage an abdominal abscess caused by a previously spilled gallbladder stone?
Laparoscopic drainage and FB removal
How does splanchnic nerve stimulation affect bile flow?
decreases it (inhibitory to motor activity)
Discuss bile leak s/p lap chole.
- Psx: within 1 week, jaundice, elevated bilirubin; RUQ pain, fevers, chills
- Etiology: inflammation dislodges clips
- Dx: US or CT
- Tx: perc drain of fluid, endoscopic biliary stent
- re-eval in 6 wks: no resolution - MRCP/ERCP
- find CBD injury, then repair once inflammation has resolved
- septic shock and peritonitis: ex-lap and wide drainage, temporize
- re-eval in 6 wks: no resolution - MRCP/ERCP
What is the primary source of bilirubin in the body?
breakdown of RBCs (senescence vs hemolysis)
Cholangiocarcinoma most common morphology?
Most favorable histology?
- Nodular
- Papillary
- Usually 50-70y M w/ PSC, UC, biliary infection, choledochal cysts
Describe enterohepatic circulation.
- Bile salts synthesized from cholesterol in liver, where they are conjugated to either glycine or taurine to form the primary bile salts: cholic acid and chenodeoxycholic acid.
- Once secreted into the bile, they pass into duodenum, are absorbed in small intestine (mostly terminal ileum).
- The portal system returns the bile salts to the liver.
- Extremely conservative: 95% of bile pool recycled.
- Of ~2-4g into duodenum/day, ~0.6g makes it to the colon.
- Colon bacteria form secondary bile salts: deoxycholate and lithocholate. A small amount is reabsorbed passively.
What is the most common cause of a benign biliary stricture?
previous lap chole
What is the Bismuth-Corlette classification for perihilar cholangiocarcinomas?
- Type I tumors involve the common hepatic duct.
- Type II tumors are at the hepatic bifurcation.
- Type III tumors involve the secondary hepatic ducts on one side.
- Type IV tumors involve the secondary hepatic ducts on both sides.
What is the management of unresectable cholangiocarcinoma? What is the role of chemotherapy?
Palliative stent placement or bypass.
Chemotherapy does not help much and therefore has little role.
The only treatment that improves survival is surgical resection with adequate margins.
What if gallbladder cancer involves the infundibulum? What happens to the resection?
must include CBD and hepaticojejunostomy
Endoscopic retrograde cholangiopancreatography is performed and demonstrates a mass in the second portion of the duodenum at the ampulla of Vater.
A double-contrast upper gastrointestinal series reveals “soap bubble” or “paint brush” sign.
What is this?
small bowel villous adenoma
Approximately 25% of these villous and tubulovillous adenomas harbor malignancy
Treatment of choice for high-risk patients with acute cholecystitis?
Percutaneous transhepatic cholecystostomy
The diagnostic modality of choice in a patient with a known gallbladder polyp for reassessment of characteristics would be?
US
How do you manage sphincter of Oddi dysfunction?
- rule out other causes
- if fulfills clinical criteria, and sx do not include abnormal LFTs and dilation of CBD, get manometry study
- tx: endoscopic sphincterotomy
How do you make the incision in choledochotomy?
Longitudinally, below the insertion of the cystic duct.
- The blood supply to the extrahepatic bile duct runs along the duct at the 3-o’clock and 9-o’clock positions. A transverse incision would risk compromise of the blood supply to the bile duct.
- The incision should be made in the common bile duct rather than the common hepatic duct to avoid postsurgical proximal bile duct stenosis that would require a more complex repair.
Management of gallstone pancreatitis
- resuscitation
- RUQ US
- manage choledocholithiasis/cholangitis if found
- serial assessment until resolution of pain
- cholecystectomy only once there is resolution of pancreatitis
Relative contraindications to laparoscopic transcystic common bile duct exploration
- stones above the cystic duct
- small cystic duct (<3 mm)
- gallstones greater than 6-8 mm
- >8 gallstones in the duct
ultrasound findings best describe cholesterolosis of the gallbladder
Multiple, hyperechoic, pedunculated, non-shadowing
When does a gallbladder adenoma begin to increase risk for cancer?
Follows adenoma-carcinoma sequence (like colon cancer). Risk increases at 10 mm.
