HPB Flashcards
Which segments are resected in left trisectionectomy?
Left hemiliver: 2,3,4 and right anterior section: 5 and 8.
This operation is also known as extended left hemihepatectomy.
Which segments are resected in right trisectionectomy?
Right hemiliver: 5,6,7,8 and segment 4.
This operation is also known as extended right hemihepatectomy.
Name second order divisions of hepatic artery.
Right anterior and right posterior
Left medial and left lateral
What is the surface marking for left intersectional plane?
Umbilical fissure and line of attachment of falciform ligament.
Intersectional plane is a plane between two sections of the liver.
Right intersectional plane does not have surface markings.
Name 3 parts of the caudate lobe.
Bulbous part (Spigelian lobe) to the left of IVC
Paracaval part
Caudate process - merges indistinctly with right liver.
What is a hanging manoeuvre?
Lifting up on a tape placed through tunnel between anterior surface of IVC (in the midplane of the vessel where there are no draining veins) and caudate lobe (paracaval part).
What is a replaced (aberrant) artery?
An artery in an unusual location that is a sole supply to that particular volume of liver.
Accessory artery is an artery that is present in addition to the normal structure.
Where does the replaced right hepatic artery commonly originate from?
SMA and runs posterior to CBD
Present in about 25% of individuals.
Where does the left replaced hepatic artery originate from?
Left gastric artery
Why, during left hepatectomy, the left hepatic bile duct should be ligated close to umbilical fissure?
To avoid injury to a potential right sectional duct if anatomical anomaly is present. In 20% of individuals the right posterior bile duct inserts into the left bile duct.
What is Hjortsjo’s crook?
Anatomical feature where the right posterior duct hooks over the origin of the right anterior portal vein.
If right anterior pedicle is being clamped too close to its origin, the right posterior duct might be injured.
Which section of the biliary tree is commonly used for high biliary enteric anastomosis and why?
Left hepatic duct due to its long extrahepatic course along the base of segment 4.
What are the important variations of bile ducts draining the left hemiliver?
Multiple ducts from sg4
Ducts from sg4 and 3 form common channel before insertion of duct from sg2
Sg4 duct insertion shifted to right or left.
These variations are very common and the prevailing pattern of B4 joining the left lateral sectional duct is present only in 30% of individuals.
Name important variations of bile ducts draining right hemiliver.
No right hepatic duct with separate entries of right posterior and right anterior into left hepatic duct
Shift of right bile duct insertion inferiorly
Describe the course of left portal vein
Horizontal portion located under sg4 and a vertical (umbilical) part located in the umbilical fissure.
The junction of transverse and umbilical portions of the left PV is marked by attachment of ligamentum venosum
The left PV terminates in the ligamentum teres at the free edge of the left liver.
Describe anatomical variant to the right portal vein system (generally rare)
Absent right portal vein with right anterior and right posterior originating independently from main PV
Describe location of hepatic veins
Right- right intersectional plane
Middle - midplane of the liver
Left - left intersectional plane
What is an umbilical vein in an adult liver?
Tributary to the left hepatic vein that normally drains the most leftward part of sg4
Describe anatomical variant of right hepatic vein present in 10% individuals.
Two veins present: right superior (7 and 8) and right inferior (5 and 6)
What structures connect the liver to the abdominal wall dorsally?
Coronary ligament, right and left triangular ligaments.
What is ligamentum teres?
Obliterated left umbilical vein
Runs in the free edge of the falciform, from the umbilicus to the termination of the umbilical portion of the left portal vein.
Describe the plate system of the liver
Cystic, hilar, umbilical and Arantian
What is the critical volume of the future liver remnant in a healthy liver?
25%
Describe the borders of Calot’s triangle
Inferior edge of the liver, CHD and cystic duct.
What are the three patterns of confluence of the cystic duct and CHD?
Angular 75%
Parallel 20% (insertion lower than normal, cystic duct running in parallel to CHD before insertion)
Spiral 5%
Describe anatomical variations of the cystic artery
Cystic artery coming of the hepatic artery proper or the left hepatic artery and running anterior to CHD
Cystic artery arising from the gastroduodenal or aberrant right hepatic - can be located inferior to the Cystic duct
Why is it important to avoid penetration of the cystic plate during cholecystectomy?
In about 10% of patients there is a large peripheral bile duct immediately deep to the plate, disruption of which will cause copious bile leakage.
The origin of middle hepatic vein is also in this region.
What is the normal internal diameter of CBD measured radiologically?
Up to 8mm
External diameter in non fasting state might reach up to 13mm
CBD can be as small as 3mm - caution during cholecystectomy if cystic duct appreas more than 2mm!
What is the most important clinical anomaly with regards to right hepatic duct?
Its low insertion as it can be mistaken as the cystic duct
What is the usual course of the right hepatic artery in relation to bile duct?
Posterior 80%
What is unique about blood supply to bile ducts?
Supplied only by hepatic artery, not portal vein.
First order comprises afferent vessels from hepatic artery, second order longitudinal (marginal) arteries that run in parallel to the long axis of the bile duct and third order is an arterial plexus encasing bile ducts.
What is the most constant and important artery supplying the bile duct?
Posterior superior pancreaticoduodenal artery