Liver and Biliary Surgery

Question 1

what are the liver lobes

Answer 1

left lateral
left medial
quadrate
right medial
right lateral
caudate (caudate process + papillary process)

Question 2

where is the gallbladder located

Answer 2

between the quadrate and right medial liver lobes

Question 3

cystic duct

Answer 3

connects the gallbladder to the first hepatic duct

Question 4

hepatic ducts

Answer 4

connects the liver to the cystic and common bile ducts

dogs: 2-7 hepatic ducts
cats: 1-5 hepatic ducts

Question 5

common bile duct

Answer 5

connects the cystic duct to the major duodenal papilla in the duodenum

Question 6

hepatic blood supply

Answer 6

dual blood supply
- hepatic artery
- portal vein

Question 7

hepatic artery

Answer 7

supplies 20% of blood supply and 50% of oxygen

cystic artery branches off to supply the gallbladder

Question 8

portal vein

Answer 8

provides 80% of blood supply and 50% of oxygen to the liver

Question 9

hepatic veins

Answer 9

drains deoxygenated blood from the liver into the caudal vena cava

Question 10

major duodenal papilla

Answer 10

exit point for the common bile duct and pancreatic duct into the duodenum

• dogs: CBD and PD enter separately
• cats: CBD and PD fuse prior to exiting

Question 11

minor duodenal papilla

Answer 11

exit point for the accessory pancreatic duct

• dogs: majority of pancreatic secretions into duodenum
• cats: only 20% of cats have accessory pancreatic duct

Question 12

what are preop considerations for liver surgery

Answer 12

1. hemorrhage - always run coag panels b/c liver is highly perfused
2. anesthesia & drug metabolism - avoid drugs that rely on the liver
3. antimicrobials - clavamox, clindamycin, or 3rd gen cephalosporins

Question 13

is it better to sample bile or liver parenchyma for cultures

Answer 13

bile
many animals have resident hepatic flora of enteric origin - sampling is likely to not be diagnostic

Question 14

what are the 4 techniques for liver biopsy

Answer 14

1. suture fracture
2. overlapping suture
3. skin punch biopsy
4. laparoscopic

Question 15

suture fracture biopsy

Answer 15

used for DIFFUSE hepatopathies

use 3-0 or 4-0 PDS to ligate and cut through parenchyma on the tip of a liver lobe

Question 16

overlapping suture biopsy

Answer 16

used for areas that are not easily looped around with suture

take overlapping suture bites then cut around the area of interest

Question 17

skin punch biopsy

Answer 17

used to sample areas away from the margin of the lobe

can fill the hole with gelatin sponge for homeostasis

Question 18

laparoscopic biopsy

Answer 18

less invasive
best for diffuse hepatopathies

Question 19

what are 4 surgical hepatobiliary diseases

Answer 19

• hepatic neoplasia
• extra hepatic biliary duct obstruction
• bile peritonitis
• gallbladder mucoceles

Question 20

how is hepatic neoplasia diagnosed

Answer 20

abdominal ultrasound

FNA/core biopsies are NOT always diagnostic and high risk of hemorrhage

Question 21

surgery for hepatic neoplasia

Answer 21

liver resection

can resect up to 75% of liver mass

Question 22

common causes of EHBDO in dogs

Answer 22

extraluminal:
- pancreatitis
- pancreatic abscess
- neoplasia

intraluminal:
- cholelithiasis
- foreign body
- neoplasia

intramural:
- neoplasia

Question 23

common causes of EHBDO in cats

Answer 23

inflammatory:
- cholangiohepatitis, cystitis, or lithiasis
- pancreatitis
- hepatic lipidosis

neoplasia
- pancreatic adenocarcinoma
- biliary adenocarcinoma

Question 24

diagnostics for EHBDO

Answer 24

• hyperbilirubinemia
• hypercholesterolemia
• cholestatic hepatopathy

abdominal US: CBD and GB distention, choleliths, masses, mucoceles

Question 25

bile peritonitis

Answer 25

bile leakage into the abdominal cavity due to gallbladder or biliary tree rupture

caused by trauma, necrotizing cholecystitis, ruptured mucoceles, EHBDO

can cause septic peritonitis if bile is infected

Question 26

how is bile peritonitis diagnosed

Answer 26

abdominocentesis
- fluid bilirubin >2x serum

abdominal fluid cytology
- bile pigments present

Question 27

surgery for bile peritonitis

Answer 27

repair the cause of the leakage (rupture site) and lavage

Question 28

gallbladder mucoceles

Answer 28

gel-like, congealed bile filling the gallbladder

caused by cystic mucinous hyperplasia

Question 29

diagnosis of gallbladder mucoceles

Answer 29

abdominal ultrasound

early: bile sludge accumulation
late: stellate/”kiwi” appearance of gallbladder

thickened gallbladder wall with hyperechoic surroundings

Question 30

surgery for gallbladder mucoceles

Answer 30

cholecystectomy - removal of the gallbladder

other options:
- rerouting - connecting GB directly to the duodenum (requires a healthy GB)
- biliary stent - used to repair bile duct trauma
- cholecystostomy - draining the gallbladder (risk of bile peritonitis)

Question 31

what surgery should be performed if you cannot determine the patency of the CBD

Answer 31

biliary rerouting

Question 32

what surgery should be performed if you’re unable to catheterize a functional EHBDO

Answer 32

biliary stent
OR
cholecystostomy

Question 33

what surgery should be performed for biliary mucoceles, choleliths, GB neoplasia, or trauma

Answer 33

cholecystectomy

Question 34

what surgery should be performed if there is trauma or rupture of the CBD

Answer 34

primary closure +/- stent or biliary rerouting

Question 35

what is the mortality rate for hepatobiliary surgery

Answer 35

HIGH - requires intensive postoperative management

complications:
- bile leakage/peritonitis
- hemorrhage
- pancreatitis
- re-obstruction
- sepsis