HPB Flashcards

1
Q

Which segments are resected in left trisectionectomy?

A

Left hemiliver: 2,3,4 and right anterior section: 5 and 8.
This operation is also known as extended left hemihepatectomy.

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2
Q

Which segments are resected in right trisectionectomy?

A

Right hemiliver: 5,6,7,8 and segment 4.
This operation is also known as extended right hemihepatectomy.

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3
Q

Name second order divisions of hepatic artery.

A

Right anterior and right posterior
Left medial and left lateral

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4
Q

What is the surface marking for left intersectional plane?

A

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.

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5
Q

Name 3 parts of the caudate lobe.

A

Bulbous part (Spigelian lobe) to the left of IVC
Paracaval part
Caudate process - merges indistinctly with right liver.

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6
Q

What is a hanging manoeuvre?

A

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).

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7
Q

What is a replaced (aberrant) artery?

A

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.

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8
Q

Where does the replaced right hepatic artery commonly originate from?

A

SMA and runs posterior to CBD
Present in about 25% of individuals.

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9
Q

Where does the left replaced hepatic artery originate from?

A

Left gastric artery

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10
Q

Why, during left hepatectomy, the left hepatic bile duct should be ligated close to umbilical fissure?

A

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.

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11
Q

What is Hjortsjo’s crook?

A

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.

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12
Q

Which section of the biliary tree is commonly used for high biliary enteric anastomosis and why?

A

Left hepatic duct due to its long extrahepatic course along the base of segment 4.

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13
Q

What are the important variations of bile ducts draining the left hemiliver?

A

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.

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14
Q

Name important variations of bile ducts draining right hemiliver.

A

No right hepatic duct with separate entries of right posterior and right anterior into left hepatic duct

Shift of right bile duct insertion inferiorly

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15
Q

Describe the course of left portal vein

A

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.

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16
Q

Describe anatomical variant to the right portal vein system (generally rare)

A

Absent right portal vein with right anterior and right posterior originating independently from main PV

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17
Q

Describe location of hepatic veins

A

Right- right intersectional plane
Middle - midplane of the liver
Left - left intersectional plane

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18
Q

What is an umbilical vein in an adult liver?

A

Tributary to the left hepatic vein that normally drains the most leftward part of sg4

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19
Q

Describe anatomical variant of right hepatic vein present in 10% individuals.

A

Two veins present: right superior (7 and 8) and right inferior (5 and 6)

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20
Q

What structures connect the liver to the abdominal wall dorsally?

A

Coronary ligament, right and left triangular ligaments.

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21
Q

What is ligamentum teres?

A

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.

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22
Q

Describe the plate system of the liver

A

Cystic, hilar, umbilical and Arantian

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23
Q

What is the critical volume of the future liver remnant in a healthy liver?

A

25%

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24
Q

Describe the borders of Calot’s triangle

A

Inferior edge of the liver, CHD and cystic duct.

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25
Q

What are the three patterns of confluence of the cystic duct and CHD?

A

Angular 75%
Parallel 20% (insertion lower than normal, cystic duct running in parallel to CHD before insertion)
Spiral 5%

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26
Q

Describe anatomical variations of the cystic artery

A

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

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27
Q

Why is it important to avoid penetration of the cystic plate during cholecystectomy?

A

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.

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28
Q

What is the normal internal diameter of CBD measured radiologically?

A

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!

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29
Q

What is the most important clinical anomaly with regards to right hepatic duct?

A

Its low insertion as it can be mistaken as the cystic duct

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30
Q

What is the usual course of the right hepatic artery in relation to bile duct?

A

Posterior 80%

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31
Q

What is unique about blood supply to bile ducts?

A

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.

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32
Q

What is the most constant and important artery supplying the bile duct?

A

Posterior superior pancreaticoduodenal artery

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33
Q

Describe the course of marginal arteries supplying bile ducts

A

3 and 9 o clock position in relation to CBD/CHD, sometimes at 12 o clock.

Sometimes run across the top of the confluence of the right and left bile ducts - hilar marginal artery - provides shunt between right and left hepatic arteries.

34
Q

Why do choledocho-choledochotomies often fail?

A

Due to transection of the blood supply from either superior PDA (inferior portior) or high in the hilum.

Therefore usually bile duct is trimmed to within 1cm of the confluence in the hilum and hepatico-jejunostomy is fashioned.

35
Q

What is the relation of the neck of pancreas to SMA and PV?

A

Neck is anterior to the vessels.

36
Q

Describe the pancreatic zymogen activation cascade

A

Acinar cells secrete trypsinogen.
This is activated to trypsin in DU by enteropeptidase.

Trypsin activates chymotrypsinogen (chymotrypsin), proelastase (elastase) and procarboxypeptidase (carboxypeptidase).

37
Q

Name four types of pancreatic islet cells and their products.

A

Alpha - glucagon
Beta - insulin
Delta - somatostatin
Gamma - pancreatic polypeptide

38
Q

Describe the commonest pattern of pancreatic ductal anatomy.

A

Ventral duct of Wirsung unites with dorsal accessory duct of Santorini at the genu (bend).

Ventral duct enters DU at the major papilla and dorsal duct at the minor papilla 2cm above and 5mm anterior to major papilla.

Uncinate process is served by its own duct which joins the main PD .

39
Q

Describe anatomical variations in pancreatic ductal anatomy.

A

Ventral and dorsal ducts not uniting and draining separately - pancreatic divisium.

Dorsal duct loose connection to DU.

Ventral duct regression with drainage via dorsal duct and minor papilla.

40
Q

Describe blood supply to the pancreas.

A

Head and neck are supplied by anterior and posterior arcades supplied by superior (GDA) and inferior (SMA) pancreaticoduodenal arteries.
Neck is a watershed area.
Body and tail are supplied by branches from splenic artery (3 branches, most medial is dorsal pancreatic artery which anastomoses with pancreaticoduodenal arcade.

41
Q

Name the three branches from the splenic artery to the pancreas.

A

Dorsal pancreatic
Pancreatica magna
Caudal pancreatic
They anastomose with each other via transverse pancreatic artery

42
Q

What is the Appleby procedure?

A

Resection of the coeliac axis together with the pancreatic body tumour. The backflow via SMA, inferior duodenopancreatic and GDA is the only arterial blood supply to the liver and the stomach (via right gastoepiploic).

43
Q

Describe the venous drainage of the pancreas.

A

Body and tail drain into splenic vein via short tributaries.
Head and uncinate process drains via anteroinferior pancreaticoduodenal and right gastroepiploic vein which form gastrocolic trunk which then drains into SMV.
Anteroinferior vein anastomoses with anterosuperior vein which drains into portal vein.
Posteriorly there is posterosuperior pancreaticoduodenal vein which drains into portal vein.

44
Q

When is it indicated to perform resection of Ln9?

A

These are lymph nodes around the coeliac axis. Should be resected in tumour involving the body of the pancreas.

45
Q

What stations are lymph nodes in the pancreaticoduodenal groove?

A

Anteriorly Ln17
Posteriorly Ln13

46
Q

Describe anatomical relations of the pancreas posteriorly.

A

Right kidney, right gonadal vein, IVC, aorta, retropancreatic fat, left adrenal, left renal vein, left kidney. All of these structures lie behind the anterior renal fascia. Oncological resections should be in the plane behind the anterior renal fascia.

In addition: splenic vein, SMV,PV,SMA.

47
Q

Describe the anatomical relations of the pancreas anteriorly.

A

Covered by peritoneum which is the posterior wall of the lesser sac. Then posterior wall of the stomach. Transverse mesocolon and IMV inferiorly. Right and left extremities of the transverse colon are related to the head and tail of the gland.

48
Q

Name the tributaries to the gastrocolic trunk in its most common variant

A

Right gastroepiploic pancreaticoduodenal veins
Superior right colic vein

Drains into SMV

49
Q

Name symptoms and signs of liver failure

A

Confusion (encephalopathy)
Loss of consciousness
Hypoglycemia
Coagulopathy
Jaundice

50
Q

Name common causes of postoperative acute liver failure

A

Not enough volume
Impaired function of the remnant (e.g. due to previous chemotherapy, impaired defence mechanisms against oxidative stress induced during Pringle manouvre)

51
Q

What is ischaemic preconditioning?

A

A process in which temporary occlusion of liver blood flow followed by its release has been shown to be beneficial in terms of increasing resistance to subsequent injury

52
Q

Describe signs and symptoms in chronic liver failure

A

Hypoalbuminaemia
Oedema
Jaundice
Impaired ammonia clearance
Coagulopathy
Encelopathy
Splenomegaly
Varices
Ascities

53
Q

Name some of the causes of liver failure

A

Infectious: Hep C, hep B
Autoimmune: PSC, PBC
Genetic: Wilson’s disease, alpha 1 antitrypsin deficiency
Nutritional: alcohol abuse

54
Q

Name the components of Child Pugh score

A

Bilirubin
Albumin
INR
Encephalopathy
Ascites

55
Q

What is 1 year survival with different Child Pugh scores?

A

A (5-6) 100%
B (7-9) 80%
C (10-15) 45%

56
Q

What is Cori cycle?

A

Anaerobic metabolism in the muscle leads to production of lactic acid and acidosis.

Cori cycle recycles lactic acid and prevents lactic acidosis.

Lactate is taken up by the liver and is converted into glucose. Glucose is then exported into muscle which can use it for glycolysis which generates ATP in anaerobic conditions.

57
Q

Describe how does the liver deal with ammonia?

A

Enterocytes use glutamine for metabolism which results in a waste product ammonia. This travels in PV to the liver where it is converted into urea.

58
Q

Why do patients have increased risk of bacterial infection after hepatectomy?

A

Due to reduced volume the phagocytosis capacity and synthetic capacity is reduced. Ischaemia during surgery might further contribute to Impaired immunity.

59
Q

What is hepatic encephalopathy?

A

Reversible neuropsychiatric syndrome characterised by cerebral oedema and raised ICP. There is risk of brain herniation and death.
Contributing factors: raised ammonia, lactate and glutamine.

60
Q

What is the aim of treatment in hepatic encephalopathy?

A

Reduce ammonia levels
Induce mild hypothermia
Reduce blood -brain ammonia transfer
Decrease brain lactate synthesis
Reduce inflammation

61
Q

When is AST and ALT elevated and when is ALP and gamma-GT elevated?

A

AST and ALT are hepatocyte enzymes released when thee is hepatocyte injury - ischaemia, hepatitis, sepsis, cancer.
ALP is expressed in biliary epithelium - cholangitis.
gamma GT is expressed both in hepatocytes and biliary epithelium and is typically elevated in cancer and high alcohol consumption.

62
Q

Describe indocyanine green clearance test.

A

This is an example of dynamic liver function test, ie. reflects liver function in response to a challenge. ICG is given as injection and in healthy liver is rapidly absorbed by hepatocytes and excreted into bile without enterohepatic circulation. Most of it will be cleared from blood within the first 15min. This test can be supplementary in pre-operative assessment of liver function.

63
Q

Describe how nuclear medicine in combination with CT can be used in preoperative assessment of future liver remnant.

A

Technetium (gamma emitting radioisotope) - mebrofenin is taken up by hepatocytes and this can be detected using a gamma camera. Combining this method with CT can produce a 3D image of liver function which can be related to liver volume, i.e. segmental liver function and functional volume can be calculated to estimate if it is safe to proceed with resection or when it is advisable to utilize PVE preoperatively.

64
Q

Is failure to synthesize urea a factor in early post operatvie liver failure?

A

Unlikely, as studies show that major hepatic resection did not decrease urea synthesis, in fact it increased 2.6 fold.

65
Q

What is the main hepatic protection system against most forms of stress?

A

Glutathione synthesis in the hepatocytes. Glutathione is the main oxygen free radical scavenger in the liver.

66
Q

Name intraoperative techniques for hepatic blood flow measurement.

A

Ultrasonic flow measurement and Doppler ultrasound measurements - both measure flow in PV and hepatic artery.

67
Q

Name a non - invasive method for hepatic flow measurement.

A

MRI flow studies. Can calculate flow per unit of liver volume.

68
Q

What is the typical absolute flow rate in PV and hepatic artery pre- and post major resection?

A

PV: pre 840ml/min, post 805ml/min
Hepatic artery: pre 450ml/min and post 270ml/min

69
Q

What happens to relative blood flow (relative to liver volume) in PV and HA after resection?

A

HA remains constant and PV increases (nearly doubles).

70
Q

Describe the role of the liver in innate immunity.

A

Contains 85% of body’s reticuloendothelial system (Kupffer cells) - responsible for clearing pathogens from the bloodstream.
In addition, produces acute phase proteins and opsonins which coat bacteria and facilitate phagocytosis.

71
Q

How long does it take for liver to fully regenerate after major resection?

A

6-12 weeks, process is impaired and might lead to scarring and cirrhosis in presence of fibrosis.

72
Q

What is canal of Hering?

A

Most distal branch of biliary tree. Contains hepatic progenitor cells.

73
Q

Describe the role of hepatic progenitor cells in liver regeneration.

A

Important in fibrotic / cirrhotic liver and during chronic or severe injury. HPC can develop into either hepatocytes or biliary cell populations under the influence of factors secreted by macrophages.

74
Q

What is small for size syndrome?

A

Typically occurs in patients after split liver transplantation where a small volume of transplanted liver is unable to cope with high portal vein flow in patients with previous cirrhosis.
Characterized by development of ascities, portal hypertension and liver dysfunction in an otherwise healthy liver transplant.

Can also develop in patients post major resection (rare) but aetiology is thought to be due to failure of regeneration rather than excessive blood flow.

75
Q

Describe strategies to limit or prevent small for size syndrome.

A

Partial porto-caval shunt or ligation of splenic artery to decrease flow in portal vein.

76
Q

What changes to the liver parenchyma can be induced by chemotherapy?

A

Increased fragility
Steatosis
Stetohepatitis
Sinusoidal dilatation

77
Q

For how long does the resection need to be postponed after chemotherapy?

A

min 6 weeks.

78
Q

When can major resction be performed after PVE?

A

6 weeks later - this is based on volume increase.
Recent studies suggest that PVE might result in improvement in liver function per unit vol before increase in volume itself, potentially opening up a possibility of performing resections earlier than 6 weeks post PVE.

79
Q

What is liver venous deprivation?

A

Combination of PVE and hepatic vein embolisation (HVE) to completely deprive a volume of liver of its blood flow and lead to enhanced future liver remnant growth.

80
Q

What is ALPPS procedure?

A

Used in patients in whom there is insufficient future liver remnant volume and PVE is either not possible or failed.

First stage: transection of liver parenchyma along the line of proposed resection (between seg 2-3 and 4) and ligation of portal vein flow to seg 4-8 (they retain arterial flow and biliary drainage).

1-2 weeks later the future liver remnant increased in volume, the right side 4-8 +1 is removed.