Hepatic Surgery Flashcards
How many lobes are there in the liver and what are they?
4
- left which is the largest
- right
- caudate
- quadrate
Where does the liver sit in the abdomen?
within the cranial abdomen, 2/3 of its mass on the right hand side of midline
What is the liver attached to?
the diaphragm, right kidney, lesser curvature of the stomach and the proximal duodenum
What is attached to and runs through the liver?
vena cava
Where does the liver recieve its blood from?
hepatic portal vein from the digestive tract and spleen
Wahat percentage blood volume is supplied by the portal vein?
70-80%
How is the liver supplied with blood?
the hepatic artery and portal vein
What percentage volume of blood does the hepatic artery provide?
20%
Where does portal blood and arterial blood mix?
the sinusoids in the liver
Where does the portal blood drain into?
hepatic veins which exit the dorsal border of the liver into the caudal vena cava
What is the functionof the liver?
synthesis and clearance of proteins
- metabolism of nutrients (carbohydrates, lipids, amino acids)
= production/activation of clotting factors
- clearance of toxins (amonia, drugs etc)
- immunoregulation
- gastrointestinal function
- storage - vitamins, fats, glycogen, copper
What cells are involved in immunoregulation in the liver?
Kupffer cells
When will you see clinical signs of impairment if liver function is lost?
70-80%
What is synthesised in the liver?
bile acids
Where are bile acids excreted?
into hepatic ducts which drains the bile acid out of the liver
What do the multiple hepatic ducts converge to form?
common bile duct
What happens when the body is not digesting?
bile drains from the liver and passes via the cystic duct to the gall bladder where it is stored and concentrated
What happens to bile during digestion?
it flows out from the gall bladder via the cystic duct to the common bile duct and into the duodenum
What is the main functions of bile acids?
- help with digestion and absorption of fat
- neutralises gastric acid and inhbitis gastric acid secretion to prevent intestinal ulceration
What diagnostic testing can be done to test liver function?
- haematology, biochemistry, blood gas/electrolytes, urinalysis, dynamic bile acid testing
What abdominal diagnostic testing can be done to test liver function?
radiography (plain and contrast), ultrasound, CT, MRI, scintigraphy
What medical management can you doto stabilise the patient prior to liver surgery?
- prescription diet
- oral antibiotics
- oral lactulose
What drugs should you avoid if a patientis undergoing hepatic surgery?
those that undergo hepatic metabolism
What are some examples of drugs that should be avoided in hepatic surgery?
aspirin chloramphenicol, diazepam, fluorouracil, clindamycin,azathioprine , oxytetracycline
What could you consider giving as a pre-treatment if they have co-agulation abnormalities?
vitamin K or fresh frozen plasma
What should you do as soon as the patient has been admitted for hepatic surgery?
- complete coagulation profile
- minimum platelet count
- activated thromboplastin time
- prothrombin time
Why would you give antibiotics to these patients?
bacteria in the liver and risk of endotoxaemia/sepsis
What condition might occur due to significant liver resecton?
hypoglycaemia
Why might you blood type for a liver lobectomy?
risk of haemorrhage
What general nursing care should you provide to hepatic surgery patients?
- water replenishment and regular toilet trips due to PUPD
- tempting to eat if anorexic
Why might you peform a liver biopsy?
establish diagnosis/prognosis where hepatic disease is suspected
What might indcate a partial or complete hepatic lobectomy?
benign or malignant mass, abscess or liver lobe torsion
What might indicate surgical correction of portosystemic shunt?
portosystemic shunt
What might inidcate a cholecystectomy or cholecysoenterostomy?
- extrahepatic biliary tract obstruction
- cholelithiasis
- gall bladder mucocele
- pancreatitis
- neoplasia
- biliary tract rutpure and bile peritonitis
What is a cholecystectomy?
removal of the gall bladder
What is a cholecystoenterostomy?
rorouting the gall bladder to the duodenum
What are the peri-operative considerations?
- hypotension
- hypothermia
- haemorrhage and coagulation abnormalities
- IV fluid therapy
- pre-medication and induction agents - avoid drugs that undergo hepatic metabolism
- ventilation
- antibiotics
What post-operative care should be provided?
- intensive nursing for critical animals
- analgesia
- minimum database/haematology and biochemistry
- antibiotics if infection present
- nutrition
- monitor for sepsis or systemic inflammatory response syndrome (SIRS)
What post-op monitoring should you do?
- physical parameters
- bood pressure, ideally through arterial line
- signs of haemorrhage
- leakage of bile
What surgical complications can occur?
hypotension, hypothermia, hypoglycaemia, haemorrhage, leakage of bile, sepsis
What perentage of portosystemic shunts are congenital?
80%
What percentage of portosystemic shunts are acquired?
20%
What percentage of congenital portosystemic shunts are extrahepatic?
65-75%
What percentage of congenital portosystemic shunts are intrahepatic?
25-35%
What breeds are affected by extrahepatic portosystemic shunts?
small breeds, torkshire terriers, cairn terriers, west highland white terriers
What breeds are affected by intrahepatic portosystemic shunts?
large dog breeds, irish wolfhounds, australian cattle dogs, labradors
What is a portosystemic shunt?
anamolous blood vessel which connects the hepatic portal vein within the stsemic venous circulation e.g caudal vena cava, thereby bypassing the liver and diverting some of the portal blood supply away from the liver
