Hepatobiliary Flashcards
What structures are in the portal triad? What is their relationship to one another?
- common bile duct laterally
- proper hepatic artery medially
- portal vein posteriorly
What separates the right and left lobes of the liver?
Cantile’s Line between the gallbladder fossa and IVC
Describe the venous drainage of the liver.
- three hepatic veins that empty into the IVC
- the middle and left usually merge before draining into the IVC
What are the most common variations for liver vascular anatomy?
- replaced right off the SMA, traveling behind the pancreas and CBD
- replaced left off the left gastric, traveling in the gastrohepatic ligament
How is symptomatic cholelithiasis managed in pregnancy?
- lap chole during the second trimester
- place ports via Hassan technique, keep pneumoperitoneum as low as possible, and place a bump under the right side to offload the cava
How should you manage a CBD stone identified during IOC?
- attempt to flush stone, can give glucagon twice
- transcystic CBD exploration
- laparoscopic CBD exploration
- post-op ERCP
What should you do if you can’t visualize the hepatic ducts on IOC?
- pull the catheter back and try flushing it again
- put the patient in T-burg to promote back filling
- convert to open to investigate an injury to the hepatic duct
When should cholecystectomy be performed for gallstone pancreatitis?
- preferably during the index admission after clinical resolution of pancreatitis
- may need to wait and do an interval chole at 6 weeks if there is a significant peripancreatic collection; perform ERCP with sphincterotomy then wait for collection to mature/regress
What is the Rigler triad?
- bowel obstruction, gallstone seen in intestine, pneumobilia on imaging
- which, together, suggest gallstone ileus
How is gallstone ileus treated?
- enterotomy proximal to obstruction, milk stone back to remove
- avoid cholecystectomy and fistula at the same time as a combined procedure has higher morbidity and recurrence rates are low
Most gallbladder polyps are what?
benign hyperplastic polyps
How are gallbladder polyps managed?
- cholecystectomy if symptomatic, larger than 1cm, or associated with cholelithiasis
- serial imaging if over 6mm
- treat as cancer until proven otherwise if larger than 18mm
What is the hepatic vein pressure gradient?
- the gradient between the wedged hepatic vein pressure and the free hepatic vein pressure
- defines portal hypertension when > 6
How is portal hypertension defined?
as a hepatic vein pressure gradient greater than 6mmHg
What are the sites of collateral circulation that form in patients with portal hypertension?
- distal esophagus (esophageal submucosal veins to proximal gastric veins)
- rectum (IMV to pudendal vein)
- umbilicus (vestigial umbilical vein to left portal vein)
How is portal hypertension treated?
- splanchnic vasoconstrictors like vasopressin and octreotide in the acute setting
- non-selective beta blockers like propanolol and nadolol for prophylaxis
- esophageal banding
- TIPS
What are the surgical options for patients with portal hypertension?
- gastroesophageal devascularization (total of the greater curvature and upper ⅔ of lesser curvature; circumferential of lower 7.5cm of esophagus)
- portosystemic shunts (selective, nonselective, partial)
Which patients with portal hypertension are most likely to benefit from gastroesophageal devascularization?
those with extensive portal venous thrombosis and no options for portosystemic shunts
What is a selective portosystemic shunt?
- a surgical treatment of portal hypertension which decompresses only part of the portal venous system
- good for variceal bleeding but does not help ascites
- usually splenorenal (aka Warren shunt)
What is a partial portosystemic shunt?
a surgical treatment of portal hypertension in which a side to side anastomosis is created and calibrated by the size of the interposition graft placed between the portal vein and vena cava
What is a nonselective portosystemic shunt?
- one that decompresses the entire portal venous system
- most commonly a side-to-side portocaval shunt
- cons: high rate of encephalopathy and makes transplant more difficult
What are the differences between a selective and nonselective portosystemic shunts?
- selective (e.g. splenorenal) decompress only part of the portal venous system whereas nonselective (e.g. portocaval) decompress it all
- selective treat variceal bleeding while nonselective treat ascites
- nonselective are more often complicated by encephalopathy and make transplant more difficult
What is the most common pathogen found in a pyogenic liver abscess?
E. coli
What is the treatment of a pyogenic liver abscess?
perc drain and antibiotics
What is the treatment of an amebic liver abscess?
- diagnose with serology
- treat with metronidazole, usually don’t require drainage
How is an echinococcal liver cyst diagnosed and treated?
- usually see a double walled cyst on CT
- diagnose with serology
- treat with albendazole followed by surgical excision
- if you aspirate or spill you can cause anaphylaxis
What hepatic vein pressure gradient is typically required for variceal rupture? What pressure is used to define portal hypertension?
- hypertension is defined as pressure gradient > 6mmHg
- rupture occurs at a pressure gradient > 12mmHg
What are the components of the Child-Turcotte-Pugh score?
- bilirubin
- albumin
- prothrombin time
- encephalopathy
- ascites
What are the components of the MELD-Na score?
- INR
- Na
- bilirubin
- creatinine
What MELD score suggests that a patient would have a survival benefit following transplant?
MELD > 15
How are umbilical hernias managed in cirrhotics with ascites?
- control ascites medically first
- if this doesn’t work, can use intermittent paracentesis, temporary PD catheter, or TIPS
- okay to use mesh in the elective setting
- would repair at the time of transplant if eligible
- close in layers without mesh and aggressively control ascites (with intermittent paracentesis) post-op if done urgently
If you urgently repair an umbilical hernia in a cirrhotic with poorly controlled ascites, how should you control ascites post-operatively?
- avoid leaving a drain as this can lead to large, uncontrolled fluid shifts and hypotension
- instead, opt for intermittent paracenteses
How is symptomatic cholelithiasis managed in cirrhotics?
medical optimization until cirrhosis is compensated, then lap chole
Choledochal Cysts
- etiology?
- complications?
- etiology is unclear but likely secondary to an anomalous biliary-pancreatic duct junction with reflux of pancreatic enzymes
- complicated by pain, biliary obstruction, cirrhosis, and malignant transformation
How are choledochal cysts classified and managed?
- type I: fusiform dilation of extra hepatic biliary tree, treat with resection and hepaticojejunostomy
- type II: saccular diverticulum of CBD, treat with excision but will likely require RNY reconstruction
- type III: dilation of intramural duct (aka choledochocele), treat with transduodenal excision or sphincteroplasty
- type IVa: multiple intra- and extra-hepatic ductal dilations, treat with hepatic resection and biliary reconstruction
- type IVb: multiple extra-hepatic ductal dilations: treat with excision and hepaticojejunostomy
- type V: multiple intrahepatic ductal dilations, treat with partial liver resection versus transplantation depending on distribution of disease
How are simple hepatic cysts managed?
laparoscopic fenestration or enucleation as aspiration alone has a 100% recurrence rate
What is the most common liver tumor?
hemangiomas
What are hepatic hemangiomas? How are they diagnosed and treated?
- they are the most common liver tumor and are congenital vascular malformations
- can present with pain, compressive symptoms, or (rarely) hemorrhage
- are hypointense with central enhancement on the arterial phase and persistent enhancement on delayed series
- are hypointense on T1 and hyper intense on T2
- observed regardless of size when asymptomatic since they don’t have a risk of rupture; resection for symptomatic disease
What is Kasabach-Merritt syndrome?
consumptive coagulopathy secondary to a hepatic hemangioma
What is the most likely diagnosis for a hypointense liver lesion on CT with central enhancement on arterial phase and persistent enhancement on delayed series?
hepatic hemangioma (no risk of rupture regardless of size, resect for symptoms)
What is the treatment for hepatic hemangiomas?
resection for symptoms but since they have no risk of rupture, they can be observed if asymptomatic
What are the two most common hepatic tumors?
- hemangiomas
- focal nodular hyperplasia
What is the most likely diagnosis for a liver lesion on CT that is well demarcated with rapid arterial enhancement and central stellate scar?
focal nodular hyperplasia
Which population is most likely to have focal nodular hyperplasia of the liver? How are these diagnosed and treated?
- second most common liver tumor
- most often in women aged 30-50
- seen on CT as well demarcated with rapid arterial enhancement and a central stellate scar
- require no treatment since they have no malignant potential and no bleeding risk
What is a sulfur colloid uptake test?
- a nuclear medicine scan
- positive uptake reflects the presence of Kupffer cells
- thus positive uptake is suggestive of FNH rather than hepatic adenoma
Describe the risk factors, complications, diagnosis and treatment of hepatic adenomas.
- associated with OCP and androgen steroid use
- 10% risk of malignant transformation
- 30% risk of spontaneous bleed when > 5cm and higher risk of rupture with greater size in general
- also complicated by pain, abdominal fullness, and abnormal LFTs
- have arterial enhancement with washout on portal phase and a smooth surface on CT
- for smaller lesions, can discontinue OCPs and they may regress
- for those > 4cm or that fail to regress, should resect
- if ruptured, send to IR and then resect electively
How are hepatic adenomas treated?
- for smaller lesions, stop OCPs and watch for regression
- for those > 4cm or that fail to regress, resect
- for ruptured, send to IR then resect electively
Which benign hepatic tumors should be resected?
- symptomatic hemangiomas
- adenomas > 4cm, that fail to regress with cessation of OCPs, or that rupture
What hepatic tumor is suggested by the following CT findings:
- hypointense with central enhancement on the arterial phase and persistent enhancement on delayed series
- well demarcated with rapid arterial enhancement and central stellate scar
- smooth surface with arterial enhancement and portal phase washout
- hepatic hemangiomas
- focal nodular hyperplasia
- adenoma
What is the risk of rupture for hepatic adenomas?
- increases with size
- greater than 30% when > 5cm
What is the malignant risk for hepatic adenomas?
10%
How are ruptured hepatic adenomas treated?
IR embolization followed by elective resection after recovery
What is the most common site of metastasis for HCC?
the lungs
What are the risk factors for HCC?
- HBV/HCV
- cirrhosis of any etiology
- inherited errors of metabolism including a1AT deficiency and hemochromatosis
- aflatoxin
How does HCC appear on CT scan?
- hypervascular and thus hyperintense during the arterial phase
- hypodense during the delayed
How is HCC diagnosed?
- CT finding a hyperintense lesion during arterial phase with hypodense during delayed
- that with an elevated AFP is sufficient without biopsy
- no role for HCC
How is HCC managed?
- can perform resection for cure if it is a solitary mass without major vascular invasion and the patient has adequate liver function (need 25% remnant liver for those without cirrhosis and 30-40% for those with Childs class A disease)
- if patient doesn’t have sufficient remnant liver, than consider pre-op portal vein embolization of the diseased side
- transplant is indicated for those with severe cirrhosis if Milan criteria are met
- for those that aren’t surgical candidates, can consider ablation, arterially directed therapies, and external beam radiation
What are the milan criteria for HCC?
transplant indicated for cure if there is a single HCC lesion less than 5cm or 3 lesions fewer than 3cm with no gross vascular or extrahepatic spread
How much liver remnant is required for resection of HCC? What if this isn’t available?
- require 25% for those without cirrhosis and 30-40% for those with Childs Class A disease
- alternatives are pre-op portal vein embolization of the diseased side or transplantation
HCC
- risk factors are HCV/HBV, cirrhosis, a1AT deficiency, hemochromatosis, aflatoxin exposure
- diagnosed with characteristic imaging findings and elevated AFP
- appears hyperintense during arterial phase of CT and hypodense during the delayed phase
- most commonly metastasizes to the lungs
- can resect if patient has sufficient liver remnant and there is no major vascular invasion or metastasis
- those without cirrhosis need 25% remnant, those with Childs Class A disease need 30-40%
- for those without sufficient remnant, consider pre-op embolization of the diseased side or transplantation
- for transplant, must meet Milan criteria with a single lesion less than 5cm or three lesions less than 3cm and without gross vascular or extrahepatic spread
- treat with neoadjuvant chemotherapy prior to transplantation
- for those that aren’t surgical candidates, consider ablation for lesions <5cm, transarterial chemoembolization for tumors >5cm, and external beam radiation for those not in a good position for the other two
When should you consider the following locoregional therapies for HCC?
- ablation
- transarterial chemoembolization
- radiation
- ablation for smaller lesions < 5cm
- TACE for tumors > 5cm
- radiation for those that are in a bad position for ablation or TACE`
What are the risk factors for cholangiocarcinoma?
all related to inflammation of the bile ducts
- primary sclerosing cholangitis
- bile duct stones
- choledochal cysts
- liver fluke infections
- HBV/HCV
How are intra-hepatic cholangiocarcinomas managed?
- no indication for pre-op biopsy
- diagnostic lap to rule out metastatic disease (nodes beyond porta hepatis is a contraindication to resection)
- hepatic resection with negative margin is the goal
How are extra-hepatic cholangiocarcinomas managed?
- hilar masses is resection with roux-en-y hepaticojejunostomy (contralateral hemi-liver must have portal triad uninvolved by tumor)
- distal masses require Whipple
- both require lymphadenectomy
How is cholangiocarcinoma resected?
- basic principle is resection with negative margin
- start with diagnostic laparoscopy as nodal involvement beyond porta hepatis is a contraindication
- singular intra-hepatic masses should be treated with hepatic resection (e.g. wedge, segmentectomy, etc.)
- hilar are resected with roux-en-y reconstruction and lymphadenectomy
- more distal extra-hepatic are resected with Whipple and lymphadenectomy
Describe the treatment for the following forms of cholangiocarcinoma:
- singular intra-hepatic lesion
- multiple intra-hepatic lesions
- singular intra-hepatic lesion with lymph node mets beyond the porta hepatis
- singular intra-hepatic lesion with distant nodal involvement
- hilar lesion with uninvolved portal triad for contralateral liver
- hilar lesion with involvement of contralateral portal triad
- distal lesion
- singular intra-hepatic lesion: liver resection
- multiple intra-hepatic lesions: unresectable
- singular intra-hepatic lesion with lymph node mets beyond the porta hepatis: unresectable
- singular intra-hepatic lesion with distant nodal involvement: unresectable
- hilar lesion with uninvolved portal triad for contralateral liver: resection with roux-en-y reconstruction and lymphadenectomy
- hilar lesion with involvement of contralateral portal triad: unresectable
- distal lesion: Whipple with lymphadenectomy
What are the risk factors for gallbladder carcinoma?
- chronic inflammation
- porcelain gallbladder
- polyps > 1cm
- typhoid infection, primary sclerosing cholangitis
- IBD
How is gallbladder carcinoma managed?
- T1a tumors involving the lamina propria only require cholecystectomy
- T1b or greater involving the muscle layer require cholecystectomy with limited hepatic resection (IVb and V) and portal lymphadenectomy
If a patient with CRC and isolated liver mets receives neoadjuvant FOLFOX and restaging shows a complete radiology response, what is the next step?
hepatic resection since complete pathologic response is rare
For a patient with asymptomatic cholelithiasis and a 5mm gallbladder polyp, what is the best next step?
cholecystectomy since polyps associated with cholelithiasis have a higher rate of malignant transformation
Which test has the highest NPV for choledocholithiasis?
normal GGT has a 97% NPV
What is the significance of HCC found in a young patient without cirrhosis?
- most likely this is a fibrolamellar variant, which has a better prognosis and is less likely to recur
- neurotensin is a marker to confirm
What is neurotensin?
a marker used to diagnose the fibrolamellar variant of HCC
What is the next step for a patient with an incidentally discovered gallbladder adenocarcinoma that invades the muscularis?
RTOR for resection of segments IVb and V along with lymphadenectomy
What is the most common cause of isolated gastric varices?
splenic vein thrombosis secondary to pancreatitis
What is the treatment for isolated gastric varices?
most often due to splenic vein thrombosis, thus treatment is splenectomy
For a patient that is four weeks out from a car accident with liver laceration managed non-operatively and now has upper GI bleed…
- What is the diagnosis?
- What is the next step?
- What is the treatment?
- diagnosis is hemobilia from hepatic artery-biliary duct fistula
- first step is EGD and will likely find blood coming from the duodenal papilla
- treat with angioembolization
Which segments are resected in each of the following:
- right liver resection
- left liver resection
- left lateral segmentectomy
- extended right
- extended left
- right liver resection: 5-8
- left liver resection: 2-4 +/- 1
- left lateral segmentectomy: 2-3
- extended right: 5-8 + 4
- extended left: 2-4 + 5 and 8
