Hepatobiliary Flashcards
What encases the liver
Glisson’s capsule
What exists between the diaphragm and superior surface of the liver
Subphrenic recesses (separated into right and left by the falciform ligament)
What divides the liver into right and left lobes
- Falciform ligament (anteriorly and superiorly)
- Sagittal fissures (posteroinferiorly)
Associations of the visceral surface of the liver
- Abdominal oesophagus
- Stomach
- Duodenum
- Hepatic flexure
- Right kidney
- Right suprarenal gland
Where is the subhepatic space
Space between supracolic compartment and inferior surface of liver
What denotes the space between the right visceral surface of the liver and the right kidney
Morrison’s pouch (Hepatorenal recess)
Associations of superior surface of liver
Diaphragm
Where does the bare area exist
Between the two layers of the coronary ligament on the posterior surface
What forms the right sagittal fissure
- Anteriorly = groove of the GB
- Posteriorly = IVC
What forms the left sagittal fissue
- Anteriorly = fissure of the round ligament (ligamentum teres)
- Posteriorly = ligamentum venosum (fetal remnant of ductus venosus)
Liver blood flow in L/min
1500
Liver blood flow contributors
- 30% from the hepatic artery (branch of the coeliac artery)
- 70% from the portal vein
Describe the course of the falciform ligament
- Passes up from umbilicus
- Runs over dome of the liver
- Separates into upper leaf of coronary ligament (right part) and left triangular ligament
What is the fate of the left triangular ligament
Joins the lesser omentum in the fissure for the ligamentum venosum
Contents and orientation of free edge of lesser omentum
- Bile duct (right)
- Hepatic artery (left)
- Portal vein (posterior)
Contents and orientation of porta hepatis
- Common hepatic duct anteriorly
- Hepatic artery in the middle
- Portal vein posteriorly
What delineates the quadrate and caudate lobes
- Left and right sagittal fissures
- Transverse porta hepatis
What forms the functional divide of the liver
Plane which passes through the GB fossa and IVC fossa
How many surgical liver segments are there
8
What supports the two functional lobes
Both lobes have their own:
- Primary branch of the hepatic artery
- Primary branch of the hepatic portal vein
- Drained by its own hepatic duct
How do lipids bypass the liver
Via the lymphatic system
Where do the hepatic portal vein and hepatic artery divide into right and left branches
Level of the porta hepatis
Describe the course of the hepatic veins
- Right, middle, and left
- Intersegmental in their distribution
- Drain into the IVC
Describe the vasculature of the caudate lobe
Has its own hepatic vein which drains directly into the IVC
What percentage of total lymph drained by the thoracic duct comes from the liver
25-50%
Where do the hepatic lymph nodes lie
Along the hepatic vessels and ducts in the lesser omentum
Describe the lymph journey from the liver
- Formed in the perisinusoidal spaces of Disse
- Drains to deep lymphatics in the intralobular triads
- Joined by superficial lymph from the visceral and diaphragmatic surfaces
- Drain into hepatic nodes
- Drain into colic nodes
- Drain into cisterna chyli
Posterior liver surface drainage
- Phrenic and posterior mediastinal lymph nodes
- Join the right lymphatic and thoracic ducts
Define a portal system
One with capillaries at each end
What does the portal venous system drain
- Abdominal part of the alimentary canal
- Spleen
- Pancreas
- GB
How does the portal vein enter the free edge of lesser omentum
Via foramen of Wilmslow
Describe the course of the portal vein
- Formed via SMV and splenic vein
- Enters free edge of lesser omentum
- Ascends to porta hepatis
- Divides into right and left hepatic branches
- Breaks into capillaries running between the lobules of the liver
List the 5 sites of porto-systemic anastomoses
- Oesophageal branch of left gastric vein and oesophageal tributaries of the azygous
- Superior rectal branch of IMV and inferior rectal vein
- Portal tributaries of the mesentery and the retroperitoneal veins
- Portal veins of the liver and veins of the abdominal wall
- Portal branches in the liver and veins of the diaphragm
What is bile composed of
- Bile acid
- Bile salts
- Bile pigments
How are bile pigments formed
- Hb is broken down in the spleen
- Bilirubin is transported to the liver bound to albumin
- Bilirubin is conjugate to glucuronic acid in the hepatocytes
What stimulates contraction of the GB
CCK
What is glycogenesis
Conversion of glucose to glycogen
What is glycogenolysis
Conversion of glycogen back to glucose
What is gluconeogenesis
Production of glucose from amino acids
How does glucose become stored as fat
- Converted to FFAs
- FFAs transported to adipose tissue
- Combined with glycerol
- Stored as triglycerides
What role does the liver play in vitamin D activation
Forms the first hydroxylation to form 25-hydroxycholecalciferol
What are the two stages of detoxification
- Increase in water solubility of the substrate
2. Reduction in biological activity and toxic activity
What vitamins are stored in the liver
A, D, E, K, B12
What is the role of Kuppfer cells
- Phagocytic cells
- Removes bacteria, debris, and old RBCs
When does bilirubin become detectable as jaundice
> 40
What happens to bilirubin in the bile
- Converted to urobilinogen by intestinal bacteria (absorbed, recirculated, excreted in urine)
- Some urobilinogen remains in the bowel as Stercobilinogen
Pre-hepatic jaundice hyperbilirubinaemia type
Unconjugated
Associated laboratory findings with pre-hepatic jaundice
- No bilirubin in the urine
- Raised urobilinogen in the urine
- Reticulocytosis
- Anaemia
- Raised LDH
- Reduced haptoglobin
Name the two congenital unconjugated hyperbilirubinaemias
- Gilbert’s syndrome
- Crigler-Najar syndrome
Name the two congenital conjugated hyperbilirubinaemia
- Dubins-Johnson syndrome
- Rotor’s syndrome
Causes of intrahepatic cholestasis
- Hepatitis
- Drugs
- Cirrhosis
- PBC
Laboratory tests to support cholestatic jaundice
- Bilirubin in the urine (dark)
- No urobilinogen in the urine (no bilirubin enters the bowel)
- Raised ALP and GGT
Describe the course of bile through the liver
- Hepatocytes secrete bile into the bile canaliculi
- Canaliculi drain into interlobular biliary ducts
- Drain into the large collecting bile ducts of the intrahepatic portal triad
Components of the portal triad
- Portal vein
- Hepatic artery
- Bile duct
What forms the common hepatic duct
Joining of the right and left hepatic ducts which drain the right and left livers
What forms the common bile duct
- Common hepatic duct
2. Cystic duct
Length of bile duct
9cm
Describe the course of the CBD
- Lies 4cm above duodenum
- Passes behind duodenum
- Runs in groove on posterior aspect of the head of pancreas
- Opens into medial aspect of 2nd part of duodenum
Outline the arterial supply of the CBD
- Cystic artery - supplies proximal part
- Right hepatic artery - supplies middle part
- Posterior superior pancreaticoduodenal and gastroduodenal artery - supply the retroduodenal part
Venous drainage of the CBD
Directly to the liver
Capacity of the GB
50ml
Position of the GB relative to the duodenum
- Anterior to superior part
- Intimately related
Outline the 3 parts of the GB
- Fundus = wide blunt end related to tip of 9th costal cartilage in MCL
- Body = main portion that contacts liver/transverse colon/superior duodenum
- Neck = narrow end directed towards porta hepatis
What is Hartmann’s pouch
Pouch present on the ventral aspect of the GB just proximal to the neck
What is the valve of Heister
Spiral mucosal valve in the cystic duct
Course of the cystic duct
Courses between the layers of the lesser omentum
Arterial supply to cystic duct and GB
Cystic artery
What forms Callot’s triangle
- Inferior liver
- Cystic duct
- Common hepatic duct
Significance of Callot’s triangle
Cystic artery lies within
Outline the innervation of the GB
- Sympathetic = coeliac plexus
- Parasympathetic = vagus
- Somatic = right phrenic nerve
Outline the physiological effects of cholecystectomy
- Loss of concentrating effect of the GB can lead to increased flow of bile
- Fat intolerance
Role of Lecithin in bile
Aid solubility of cholesterol
Role of bile salts
To emulsify fats
Two main bile salts
- Cholic acid
2. Chenodeoxycholic acid
Daily bile salt excretion
4g/day
Most common type of gallstone
Mixed stones
Cause of ‘strawberry’ GB
Cholesterosis of the GB (lipid-laden macrophages accumulate in the GB wall)
In what situation is a mucocele formed in the GB
When a stone becomes impacted but the GB is empty and there is no super-added infection
Cause of biliary colic
Gallstone impaction in the cystic duct
Treatment of biliary colic
- Analgesia, rehydration, NBM
- Elective cholecystectomy if imaging consistent with gallstones
Management of acute cholecystitis
Cholecystectomy (preferably within 48 hours)
Management of cholangitis
- Fluid resus
- Broad spectrum abx
- Early ERCP
Management of gallstone ileus and important considerations
- Laparotomy and removal of stone from small bowel
- Do NOT interfere with fistula between GB and duodenum
How do gallstones cause pancreatitis
Transient blockage of the ampulla of vater
Fistula seen in gallstone ileus
Cholecystoenteric fistula
What is normal CBD dilatation
6mm plus 1mm for every decade after 60
Risks of ERCP
- Bleeding
- Duodenal perforation
- Cholangitis
- Pancreatitis
Contraindications to laparoscopic cholecystectomy
- Jaundice
- Cirrhosis
- Previous upper abdominal surgery
- Empyema/gangrene
- Morbid obesity
- Pregnancy
Complication of cholecystectomy procedure
- Haemorrhage from slipped tie of GB bed
- Biliary leak
- Missed stone
- Biliary stricture
- Wound complication
- Post-site hernia
Management of cystic stump bile leak
- ERCP
- Sphincterotomy
- Stent
Indication for CBD exploration
- Failure of ERCP
- Intraoperative cholangiography confirms stones
What is used to drain the CBD following CBD exploration
14G T-tube
Describe the falciform ligament
Two-layered fold of peritoneum ascending from umbilicus to anterior and superior aspects of the liver
What is the ligamentum teres
Obliterated remains of the left umbilical vein which, in utero, brings blood from the placenta back to the fetus
What is the ligamentum venosum
Fibrous remnant of the fetal ductus venosus that shunts blood from the left umbilical vein to the IVC
Describe the left triangular ligament
Formed from the left leaf of the falciform ligament and is continuous with the lesser omentum
What proportion of PSC patients have UC
50-70%
Method of stone removal in gallstone ileus
Proximally sited terminal ileal enterotomy and leave the GB
Aschoff-Rokitansky sinuses
The result of hyperplasia and herniation of epithelial cells through the fibromuscular layer of the gallbladder wall in chronic cholecystitis
Most common bacterial cause of liver abscesses
Klebsiella and E.coli most common - both gram -ve rods
What percentage of laparoscopic cholecystectomy should be day case
60%
What percentage of gallstones are radio-opaque
15%
Most common site of porto-systemic bleeding
Between left gastric veins and azygous system
Preceding symptom in primary biliary cholangitis
Pruritus (precedes jaundice)
Cause of amoebic liver disease
Entamoeba histolytica
Cause of liver fluke (Fasciola hepatica)
Parasitic trematobe
Treatment of liver fluke
Triclabendazole
At what spinal level does the pancreas cross
L1-2
Posterior relations of the head of the pancreas
IVC, right renal artery and vein, left renal vein
Describe the uncinate process
Projects from the inferior aspect of the head and lies between the aorta and SMA
Orientation of pancreatic neck to portal vein
Lies anterior to its origin (SMV joins splenic vein)
Spinal level of pancreatic body
L2
Where does the tail of the pancreas lie
Within the splenorenal ligament and in close relation to the splenic hilum
Describe the course of the main pancreatic duct
- Begins in the tail
- Runs through the gland parenchyma to the head
- Unites with the CBD to form the ampulla of vater
Describe the course of the accessory pancreatic duct
Opens into the duodenum at the summit of the minor duodenal papilla
Blood supply to the tail of the pancreas
Splenic artery
Pancreatic exocrine daily fluid volume
1.5L
Where are the proteolytic enzymes secreted from
Acinar cells
How is trypsinogen activated to trypsin
By enterokinase in the duodenum and the alkaline environment
Which three enzymes does trypsin activate
- Chymotrypsin
- Proelastase
- Procarboxypeptidase
Describe the 3 phases of pancreatic exocrine secretion
- Cephalic - under vagal control
- Gastric - under vagal control
- Intestinal - CCK and secretin
Where is somatostatin secreted from
Delta-cell of the pancreas
Where is pancreatic polypeptide secreted from
F-cells of the pancreas
What is the half-life of insulin
5-10 minutes
Inhibitors of insulin secretion
- Sympathetic stimulation
- Dopamine
- Serotonin
- Somatostatin
Role of insulin in carbohydrate metabolism
- Promotes glucose uptake
- Promotes glycogenesis
- Stimulates glycolysis
Role of glucagon in lipid metabolism
Stimulates lipase activity to increase plasma FFAs and glycerol
Effects of somatostatin
- Inhibits release of insulin and glucagon
- Reduces GI motility, secretion, absorption
Causes of pancreatitis
- Gallstone
- Ethanol
- Toxins
- Surgery or trauma
- Metaboolic
- Autoimmune
- Snake bite
- Hypothermia
- ERCP
- Duodenal obstruction
Indication for pancreatic necrosectomy (what test must be performed)
Necrosis must be confirmed on FNA first
Test on pancreatic exocrine function
Lundh meal
Two scoring systems for pancreatitis
- Glasgow
2. Ranson’s criteria
Glasgow score indicating severe disease
> 3
Management of pancreatitis secondary to gallstones
- Urgent ERCP with mandatory sphincterotomy
- Cholecystectomy on same admission or within 2 weeks
- Necrosectomy if proven
Risk factors for pancreatic carcinoma
- Age
- Smoking
- Diabetes
- Chronic pancreatitis
Microscopic and macroscopic appearance of pancreatic tumour
- Mostly adenocarcinoma
- Large, white diffuse tumour
Trousseau’s sign
- Thrombophlebitis migrans
- Associated with visceral cancer including the pancreas
Management of periampullary cancers
Whipple’s resection
Management of cancer of the pancreatic body and tail
- Resection rate <7%
- Adjuvant therapy has no proven role
- Prognosis is poor
CA-19-9
Elevated in 75-90% of pancreatic cancers
Metabolic picture in the presence of a pancreatic fistula
Hypokalaemic metabolic acidosis due to loss of HCO3
When is a pancreatic pseudocyst likely to develop
3-6 weeks post pancreatitis
Most common type of GB cancer
Adenocarcinoma
Describe Mirizzi syndrome
Compression of the common hepatic duct causing obstructive jaundice secondary to a stone in the cystic duct or neck of the GB
What are the three grades of pancreatic trauma
- Minor = injury does not involve the main ducts
- Intermediate = distal injury +/- duct disruption
- Major = injury to the head of the pancreas or pancreaticoduodenal artery
AXR features of pancreatic trauma
Air bubbles:
- Along the right psoas margin
- Upper pole of right kidney
- Lower mediastinum
- Obliteration of psoas shadow - Ground glass appearance of lesser sac
Most common bacteria associated with cholangitis
E.coli
Cause of Hydatid cyst
Echinococcus granuosus which initiates a type 1 hypersensitivity reaction
Appearance of Hydatid cyst on imaging
Calcified liver lesion
Biliary disease associated with HIV
Sclerosing cholangitis
In whom is acalculous cholecystitis common
T2DM
Why is Callot’s triangle obliterated in Mirizzi syndrome
Repeated inflammation caused by the stone in the cystic duct
In whom is hepatocellular adenoma most common
30-50 year old women on the COCP
How should hepatocellular adenomas be managed in males
Superficial resection due to higher risk of malignant transformation
Lap chole wound infection rate
3-5%
How is biliary atresia treated
Roux-en-Y
What must be performed if ERCP fails in pancreatic cancer
Percutaneous transhepatic cholangiogram and drain
Describe a Klatskin tumour
Hilar cholangiocarcinoma
What must be done if a gallstone cannot be removed during surgery
Construct choledocoduodenostomy
What skin condition is associated with Glucagonoma
Necrolytic migratory erythema
What is the most sensitive test for pancreatitis
Serum lipase
How is insulinoma managed
Enucleation (mostly benign)
