Hepatobiliary anatomy

Question 1

What is the falciform ligament and its path and attachments

Answer 1

• The falciform ligament is attached to the anterior convexity approximately in the middle to the notch made by the ligamnetum teres on the lower border
o The notch is to the left of the gallbladder fossa
o The upper attachment of the falciform ligament sweeps to the left along the upper surface of the liver as the triangular ligament (is the embryonic left leaf of the falciform ligament)
o The right leaf in embryology passes backwards just anterior to the IVC to become the upper layer of the coronary ligament- it cannot be seen from the front

Question 2

What are the different ligaments of the liver?

Answer 2

• the falciform passes down the middle of the liver and attaches to a notch made by the ligamentum teres (remnant of left umbilical vein) inferiorly
• —- superiorly - the embryologic left leaf becomes the left triangular ligament, the right passes just anterior to the IVC to become the upper layer of the coronary ligament
• the inferior coronary ligament joins to the superior to the form right triangular
• ligamentum venosum - occupies fissure for ligamentum venosum (ductus venosum remnant)
• hepatoduodenal and hepatogastric ligaments form the lesser omentum
• ligamentum teres continues on the underside from falciform in fissure for ligamnetum teres

Question 3

What are the anatomic lobes of the liver

Answer 3

• left and right lobes divided by the falciform ligament
• Caudate lobe between the IVC and ligamentum venosum, the caudate process connects to the right lobe
  o functionally part of the left lobe (in that they deliver bile to left duct and artery supply from left artery)
  •Quadrate lobe: lies between the gallbladder fossa and fissure for ligamentum teres
  o Most is functionally part of the left lobe

Question 4

What is the Porta Hepatidis?

Answer 4

• The porta hepatis is at the hilum and is enclosed by the lesser omentum
o At its left the 2 layers of the lesser omentum is attached to the ligamentum venosum
o The porta hepatis is transverse slit perforated by the left and right hepatic ducts, right and left branches of the hepatic artery and portal vein
o Posterior to anterior they lie Vein, artery, duct
o The cystic duct lies in close contact with the right end of the porta and several lymph nodes lie here
o The vessles together with the nerves of the liver life in the free edge of the lesser omentum

Question 5

What are the sectors of the liver?

Answer 5

• 4 main anatomical segments: based on blood supply and biliary drainage
o Left lateral: is the left anatomical lobe
o Left medial: is the caudate and most of the quadrate, with the fissures of ligamentum teres and ligamentum venosum demarcating the left segments
o Right anterior
o Right posterior
• Right is divided from the left is along the IVC groove and gallbladder fossa posteriorly (no demarcation anteriorly)
• Right anterior and posterior are divided by a line oblique and medially, from the middle of the right lobe to the IVC groove

Question 6

What are the liver segments?

Answer 6

• Based on bloods supply to each sector
• I: caudate lobe
• II: left lateral
• III and IV: lateral and medial parts of left medical sector
• V and VIII are the lower and upper of the right anterior sector
• VI and VII are the lower and upper parts of the right posterior sector

Question 7

Outline the arterial blood supply to the liver?

Answer 7

• Hepatic artery  branches into a Y  right hepatic passes behind the common hepatic duct and divides into anterior and posterior segmental branches
o Left branch medial and lateral segmental branches

Question 8

What is the venous drainage of the liver?

Answer 8

• Venous supply: carried into the liver by the portal vein  divides into right and left branches at porta hepatidis
o Portal arteries, hepatic arteries and hepatic bile ducts run in portal canals histologically
o From portal canals venous blood passes into the sinusoids between rows of liver cells, mixing with arterial blood  passes to centre of each lobule to the centre vein drain into each major hepatic vein
o 3 main hepatic veins drain into the IVC just below the central tendon of the diaphragm
 The right, middle and left hepatic veins
 The middle frequently joins the left
o Small caudate vein drains caudate lobe and enters just below the main veins entering the IVC
• All arteries are end arteries in the liver (though collaterals often supply)

Question 9

Outline the lymphatic drainage of the liver?

Answer 9

• 3-4 hepatic nodes at porta hepatidis (also receive lymph from gallbladder)  drain along the hepatic artery to the retropyloric nodes  coeliac nodes
o Retrograde involvement from stomach carcinoma to the retropyeloric nodes into the hepatic can cause obstructive jaundice
• Bare area drains via extraperitoneal lymphatics that perforate the diaphragm and drian to the mediastinum

Question 10

What are the structural parts of the gallbladder and their relations?

Answer 10

• Has a Fundus, body and neck
• Lies in gallbladder fossa on the right lobe of the liver adjacent to the quadrate lobe
• The fundus projects below the lower liver border and touches the parietal peritoneum of the anterio abdominal wall at the tip of the 9th costal cartiledge, lateral to the right rectus sheath
o Palpable here in obstructive disease
o Also lies on the commencement of the transverse colon at hepatic flexure
• The body passes up and back and is in contact with first part of the duodenum
• The neck lies highest just next to the free edge of the lesser omentum and continues as the cystic duct for 2-3 cm and is 2-3mm wide and joins the common hepatic duct in the lesser omentin, in front of the hepatic artery and its cystic branch
• Pathologically hartmans pouch may form: a small diverticulum located at where the neck joins the cystic duct  is the site of stone impaction
• Fundus and body are adhered to the liver by connective tissue and small cystic veins pass by this from gallbladder to liver
o Peritoneum passes over the gallbladder

Question 11

Calot’s triangle? and its contents?

Answer 11

Calot’s triangle is orientated so that its apex is directed at the liver. The borders are as follows:

Medial – common hepatic duct.
Inferior – cystic duct.
Superior – inferior surface of the liver.

Contents
Right hepatic artery – formed by the bifurcation of the proper hepatic artery into right and left branches.
Cystic artery – typically arises from the right hepatic artery and traverses the triangle to supply the gall bladder.
Lymph node of Lund – the first lymph node of the gallbladder.
Lymphatics

Question 12

What are the 3 parts of the bile duct?

Answer 12

• Considered in 3 parts
o Upper third (supraduodenal): lies in the free edge of the lesser omentum, in front of the portal vein, and right to the hepatic vein, where the lesser omentum forms the anterior border of the epiploic foramen
 Here it is accessible for choledochotomy for stone removal or drain insertion
o He middle (retroduodenal): runs behind the first part of the duodenum, sloping to the right, away from the portal vein which becomes to lie on the left, with the gastroduodenal artery. The IVC is behind the duct
o The lower (paraduodenal): slopes furtehr top the right in a grooved between the back of the head of the pancreas and seconda part of the duodenu, and in front of the right renal vien
 Head of pancreas neoplasm may obstruct here
 Joins the pancreatic duct at an angle of 60 degress at hepatipancreatic ampulla (Ampulla of vater)
• The end of the ampulla is surrounded by the ampullary sphincter (of Oddi)
• The ampulla opens to the posteriomedial wall of the second part of the duodenum at the major duodenal papilla (10mc from the pylorus)
 Further sphincters may cover bile duct and pancreatic ducts (3 in total)

Question 13

Blood supply to bile ducts?

Answer 13

• Bile duct: branches from cystic, hepatic and gastroduodenal arteries, forming anastomotic borders on left and right borders
o Ligation of cystic artery should not happen close to the bile duct to avoid compromise
• Supraduodenal part receives supply from below
• The retroduodenal artery – a branch of the gastroduodenal artery and joins the posterior superior pancreatico duodenal artery form a major supply

Question 14

What are the 5 sites of portosystemic anastamosis?

Answer 14

• Five sites of portal systemic anastomoses: lower end of oeseophagus, upper anal canal, bare area of the liver, periumbilical region and retroperitoneal areas
o Portal HTN 80% blood is shunted here, so 20% reaches thed liver

Question 15

What is the path of the portal vein and its tributaries?

Answer 15

• Once the SMA receives the splenic vein behind the head of the pancreas becomes portal vein
• The portal vein lies infront of the IVC, passes upwards behind the pancreas and first part of the duodenum. It the looses contact with th IVC by passing into the lesser omentum, where it runs near vertically up in the portal triad and reaches the portahepatidis
o At the porta it divides T shaped to the left and right branches
• Below the first part of the duodenum the bile duct and hepatic artery are curved away from it , the bile duct curves to the right behind the pancreas, and the hepatic artery to the left and infront of the pancreas to the coeliac trunk
• Portal vein also received right and left gastric vein, superior pancreaticoduodenal vein tributaries
• Cystic vein joins the right branch of the portal vein
• Periumbilical veins running with the ligamentum teres join the left brancgh

Question 16

Relations of each of the parts of the pancreas?

Answer 16

•The head: is C shaped in the concavity of the duodenum
o Lies over the IVC and left and right renal veins at L2
oPosterior surface is indented by the bile duct (which occasionally may tunnel it)
oThe anterior surface of the head lies in both the supracolic and infracolic compartments
oSome of the head is bare as the attachments for the leaves of the greater omentum and transverse colon are wide apart

•The uncinate process lies Infront of the aorta, but behind the superior mesenteric vein and artery

•The neck lies Infront of the superior mesenteric and portal veins, continuous with the head to the right and body to the left
o Transverse mesocolon is attached to the lower border of the neck (which lies in the stomach bed)

•The body: slopes across the left renal vein and aorta, left crus of the diaphragm, left psoas muscle, and lower pole of the left suprarenal gland, to the hilum of the left kidney
oThe upper border – crosses the aorta at the origin of the coeliac trunk
The splenic artery passes left along the upper border- appearing above in crests of its waves
o Its lower border crosses the origin of the SMA
oThe splenic vein lies behind the body and is joined by the Inferior mesenteric vein behind the body, in front of the left renal vein (which lies on the left psoas)
oAttachment of mesocolon means most of the body lies in the lesser sac as the stomach bed

•The tail: passes forward from the anterior surface of te left kidney at the level of the hilum, lies within the two layers of the lienorenal ligament (thus touches the hilum of the spleen) and is accompanied by the spleic artery, vein and lymphatics

Question 17

what is the tuber omentale

Answer 17

oThe tuber omentale – is a slight convexity of pancreatic tissue on the anterior surface towards the right side of the body

Question 18

foetal development of pancreas and duct system?

Answer 18

• Develops as two buds separate buds from the endoderm at the junction of the midgut and foregut
• The ventral bud – grows into the mesogastrium in common with the outgrowth of the bile duct
• The dorsal bud – grows as a separate bud into the dorsal mesogastrium
• Rotation of the duodenum which becomes plastered to the posterior abdominal wall, carries the ventral bud with the bile duct to lie posteriorly and retroperitoneal
• The duodenal wall grows assymetrically, causing the once diametrically opposed ducts openings to be carried around to lie in line with eachother
o The two parts of the gland then fuse, along with the ducts to become the pancreas
o The duodenal end of the dorsal duct becomes the accessory duct
o The rest of the dorsal duct fuses with the ventral to become the main duct
o Acini develop as growths from the terminal ducts, islet cells have the same origin but become separated and develop endocrine function