Hepatobiliary Flashcards
What separates the right and left lobes of the liver?
Cantlie’s line (between the gallbladder fossa and IVC)
Describe the classic venous drainage of the liver?
- right hepatic vein directly into the IVC
- middle and left hepatic veins merge before draining into the IVC
What is the most common variant for hepatic arterial anatomy? Where does it course?
a replaced right off the SMA, traveling behind the pancreas and CBD
What is the most common variant for the left hepatic artery?
a replaced left off the left gastric, coursing in the gastrohepatic ligament
How should you manage symptomatic cholelithiasis in pregnancy?
- lap cholecystectomy in the second trimester
- enter via Hassan technique
- keep pneumoperitoneum low
- bump the right side to offload the vena cava
Which patients may benefit from a prophylactic cholecystectomy?
- sickle cell anemia
- porcelain gallbladder
- polyp > 1cm
- stone > 2.5cm
- known gallstones undergoing bariatric surgery
What is the next step if a CBD stone is noted on IOC?
administer 1mg of glucagon and attempt to flush out the stone, can attempt this twice
What are indications for trans cystic rather than direct CBD exploration?
- cystic duct > 4mm
- CBD < 8mm
- stone < 10mm
- fewer than 5 stones
- stone distal to cystic duct/CBD confluence
What are the next steps if hepatic ducts are not visualized on IOC?
- pull back the catheter and try flushing again
- put the patient in Trendelenburg
- convert to open to investigate possible injury
What is the role for ERCP in those with gallstone pancreatitis?
- indicated for patients with signs of cholangitis
- but there is no improvement in outcomes with early ERCP as the stone will likely pass on its own
When should cholecystectomy be performed for pancreatitis?
- usually during index admission
- can wait 6 weeks if there are significant peripancreatic fluid collections but should have ERCP/sphincterotomy in meantime
What is Rigler’s triad?
suggestive of gallstone ileus:
- pneumobilia
- bowel obstruction
- gallstone seen in intestine
How should you treat gallstone ileus?
- enterotomy proximal to obstruction to remove stone
- do not perform cholecystectomy concurrently
What is Mirizzi syndrome?
when a cystic duct stone causes external compression and obstruction of the common hepatic duct
How is Mirizzi syndrome managed?
- cholecystectomy
- consider repair of common hepatic duct or even HJ if there is a large fistula
What is the most common etiology of gallbladder polyps?
most are benign hyper plastic polyps
How should gallbladder polyps be treated?
- symptomatic: cholecystectomy
- 6-9mm: serial imaging
- concurrent stones: cholecystectomy regardless of size
- 10-18mm: cholecystectomy
- > 18mm: treat as cancer until proven otherwise
What is the gold standard for diagnosing portal hypertension?
a wedged-to-free gradient of > 6mmHg
What does the site of increased portal resistance say about the etiology of portal hypertension?
- pre-sinusoidal: schistosomiasis
- sinusoidal: EtOH or viral hepatitis
- post-sinusoidal: Budd-Chiari syndrome
What are the indications for TIPS?
- acute or recurrent vatical bleeding
- refractory ascites
- Budd-Chiari syndrome
- hepatic hydrothorax
What is the feared complication of TIPS?
worsening encephalopathy
Name two splanchnic vasoconstrictors to help with the treatment of portal hypertension.
octreotide and vasopressin
What are the three types of portosystemic shunts?
- selective (e.g. splenorenal), which are good for variceal bleeding and have lower risk of encephalopathy
- partial non-selective (e.g. interposition graft between PV and IVC), where flow is calibrated by size of the graft
- non-selective (e.g. PV-IVC anastomosis), which has a high rate of encephalopathy and would complicate a potential transplant
What is the most common type of liver abscess?
pyogenic, usually secondary to biliary tract infection or GI source
Describe the etiology and management of pyogenic hepatic abscess.
- usually secondary to biliary or GI source
- most common pathogen is E. coli
- treat with perm drainage and antibiotics
How are amoebic liver abscesses diagnosed and treated?
- usually seen in patients who recently traveled to Mexico
- diagnosed with circulating anti-amoebic antibodies
- treated with flagyl and rarely need drainage
Describe an echinococcal or “hydatid” cyst on imaging.
characteristic double walled cyst
How is an echinococcal/hydatid cyst diagnosed and treated?
- characteristic double walled cyst on imaging
- positive ELISA
- treat with albendazole and drainage versus resection
Why are choledochal cysts problematic?
they can cause pain, obstruction, cirrhosis, and malignancy
What are the types of choledochal cysts?
- I: fusiform extra hepatic dilatation
- II: saccular diverticulum of CBD
- III: dilatation fo intramural duct
- IVa: multiple dilatations of intra-and extra-hepatic ducts
- IVb: multiple extrahepatic ducts
- V: multiple dilatations of intrahepatic ducts
How are the various types of choledochal cysts treated?
- I: resection with HJ
- II: excision
- III: transduodenal excision or sphincteroplasty versus endoscopic drainage
- IVa: hepatic resection and biliary reconstruction
- IVb: excision and HJ
- V: transplantation
How should simple hepatic cysts be treated?
- observation if asymptomatic
- lap cyst fenestration if symptomatic
- 100% recurrence with aspiration so only utilized if etiology is unclear
What is the most common liver tumor?
hepatic hemangioma
Describe the presentation, imaging, and treatment of hepatic hemangiomas.
- the most common liver tumor
- have a female predominance
- usually asymptomatic but can present with pain, compressive symptoms, or consumptive coagulopathy
- CT findings: hypodense pre-contrast, peripheral to central enhancement in arterial phase, persistent enhancement on delayed series
- MRI findings: hypointense on T1, hyperintense on T2
- most can be observed but can resect for symptoms or rupture
What is Kasabach-Merritt syndrome?
- associated with hepatic hemangioma
- it is a consumptive coagulopathy and thrombocytopenia
Describe the presentation, imaging, and management of focal nodular hyperplasia.
- 2nd most common liver tumor
- usually asymptomatic
- CT: well demarcated, rapid arterial enhancement with central stellate scar
- MRI: hypo intense with central scar on T1, isointense with hyper intense scar on T2
- requires no intervention
Describe the presentation, imaging, and management of hepatic adenomas.
- associated with OCP and androgen steroid use
- carries a 10% risk of malignancy and a 30% risk of spontaneous hemorrhage if > 5cm
- CT: arterial enhancement with washout on PV phase
- MRI: mildly hyper intense on T1 and T2
- for smaller lesions, discontinue OCPs
- for larger lesions > 5cm, in males, and with no regression after stopping OCPs, you should resect
- if ruptured, send to IR with interval resection in the elective setting
Describe the CT findings for:
- hepatic hemangioma
- FNH
- adenoma
- HCC
- hemangioma: hypodense pre-contrast, peripheral to central arterial enhancement, delayed washout
- FNH: rapid arterial enhancement with central stellate scar
- adenoma: arterial enhancement with rapid washout
- HCC: hypervascular, hyperintense during arterial phase, hypodense during the delayed phase
Describe the MRI findings for:
- hepatic hemangioma
- FNH
- adenoma
- hemangioma: hypointense on T1, hyperintense on T2
- FNH: hypointense on T1, isodense on T2 with hyper dense scar
- adenoma: hyperintense on T1 and T2
Describe the management of hepatic adenomas.
- for small lesions, stop OCPs and monitor for regression
- if there is no regression or if tumors are found in men or are larger than 5cm, resection
- if they rupture, embolize and then perform interval, elective resection
What tumor marker is associated with HCC?
AFP
How does HCC appear on CT?
- hyper vascular
- hyper-intense during arterial phase
- hypodense during delayed phase
Which HCC lesions should be resected?
those without major vascular invasion in patients with adequate liver function (child class A without portal hypertension)
How much functional liver remnant is required to allow for resection of a liver mass?
- no cirrhosis: 20-25%
- child A: 30-40%
What is the preferred management for HCC in a patient with mdoerate-to-severe cirrhosis?
neoadjuvant chemotherapy and transplantation if they meet Milan criteria
What are the Milan criteria?
- criteria for transplantation in those with HCC
- one lesion < 5cm or three sessions < 3cm, all without vascular or extra hepatic spread
- give neoadjuvant chemotherapy
What is the role for loco regional HCC therapy?
- usually for patients who are not candidates for surgical, curative therapy
- ablation is best for lesions < 5cm
- transarterial chemoembolization is best for lesions > 5cm
- external beam radiation is best for lesions that are not amenable to either due to location
What is the surgical treatment for the following types of cholangiocarcinoma:
- intra-hepatic
- extra-hepatic
- hilar
- distal
- intra-hepatic: resection with negative margin
- extra-hepatic: resection with negative margin and lymphadenectomy
- hilar: resection with HJ
- distal: whipple
What is the pathologic difference between a T1a and T1b gallbladder carcinoma?
- T1a invades lamina propria
- T1b invades the muscular layer
What is the surgical treatment of gallbladder carcinoma?
- T1a: cholecystectomy
- T1b: cholecystectomy with resection of IVb and V and portal lymphadenectomy
What hepatic vein pressure gradient is typically required for variceal rupture?
> 12mmHg
What are the components of the Child’s score?
- bilirubin
- albumin
- prothrombin time
- encephalopathy
- ascites
What are the components of the MELD score?
- INR
- bilirubin
- Cr
- Na
A patient with CRC and isolated liver mets receives neoadjuvant FOLFOX therapy and restating shows complete radiologic response, what is the next step?
to perform a hepatic resection since complete pathologic response is rare
How should you manage a patient with an asymptomatic 5mm polyp and cholelithiasis?
cholecystectomy because the risk of transformation for polyps is higher with concurrent gallstones
Which test has the highest negative predictive value test for choledocholithiasis?
normal GGT has a 97% negative predictive value
What is the significance of HCC found in a young patient without cirrhosis?
- these are usually of the fibrolamellar variant and carry a better prognosis with lower risk of recurrnce
- the pertinent biomarker is then neurotensin
What is neurotensin?
a biomarker for the fibrolamellar variant of HCC, which carries a better prognosis and is seen in younger patients without cirrhosis
What should the next steps be for an incidental diagnosis of stage Ib gallbladder adenocarcinoma?
- staging CT C/A/P
- tumor markers with CA 19-9 and CEA
- RTOR for resection of IVb and V and portal lymphadenectomy
- do not need to resect port sites
True or false, you should resect port sites if returning to the OR for gallbladder adenocarcinoma.
false, there is no oncologic benefit
What is the significance of isolated gastric varices and how should this be managed?
- typically results from splenic vein thrombosis secondary to pancreatitis
- treat with splenectomy
Patient is four weeks after hospitalization from a car accident resulting in a liver laceration that was managed non-operatively. They now return with UGIB. What is the next step?
- start with EGD
- if blood is coming from ampulla, consider artery-biliary duct fistula and refer to IR for embolization
