Small Animal Surgery Exam 1

hepatobilliary sx,

what are the goals of hepatobilliary surgery?

• confirm underlying disease process (i.e. getting a biopsy)

• establish a patent biliary system

• minimizing perioperative complication

What are some of the complications following heptobilliary surgery to be aware of?

• potential bleeding

• hypoglycemia

• sepsis

Name the 6 lobes of the liver

1. left lateral

2. left medial

3. quadrate

4. right medial

5. right lateral

6. caudate lobe (2 processes: caudate and papillary)

what are afferent blood supplies for the liver?

• portal

• arterial

describe the portal system in the liver (pressure, % BV)

• low pressure

• 80% of blood volume

describe the arterial system in the liver (pressure, %BV)

• high pressure

• 20% of blood volume

• branches from hepatic artery

what artery supplies the gall bladder?

cystic artery

where do the hepatic veins enter into the systemic circulation?

caudal vena cava

where is the gallbladder located in respect to the liver?

between the right medial and quadrate lobes

what are some of the important liver functions?

• synthesis of plasma proteins

• bile acid production

• coagulation factor production

• maintenance of carbohydrates and lipid metabolism → maintains glucose concentration

• clearance organ (drugs, toxins)

• storage (vitamin, fat, glycogen, minerals)

what are some liver characteristics?

• difficult to palpate due to rib cage

• no clinical signs until advanced stage due to reserve capacity

• hepatic failure may affect other systems: CNS, kidney, intestines, heart, coagulation, wound healing

what are the gold standard diagnostic tools to diagnose liver issues?

• ultrasound

• CT scan

what are some important pre-surgical considerations prior to hepatic surgery?

• HCT: want above 20%, if not then needs a transfusion

• Albumin: levels below 2 g/dL can delay healing

  • albumin is made only in the liver

• drug choice

• coagulopathy (b/c liver is responsible for synthesis of many)

• low potassium levels

• biliary obstruction

• hypoglycemia

• preservation of hepatic oxygenation (poor oxygenation = sepsis)

what is a consequence of hypoalbuminemia in respect to drugs?

drugs bind albumin and if there is low albumin, there will be unbound/ free drugs = more profound effects with normal drug doses

what is a consequence of biliary obstruction in respect to coagulopathy?

biliary obstruction will cause less bile to be released = enteric absorption of vitamin K and other fat soluble vitamins will decrease

• vitamin K is important in the formation of clotting factors 2,7,9,10

what are some of the factors that can reduce hepatic oxygenation?

• hypotension

• excessive sympathetic stimulation (from poor pain management)

• high airway pressures

list the drugs that should be avoided with severe liver disease

• acepromazine

• alpha-2 agonists (xylazine & dexmedetomidine)

• pancuronium/ vecuronium

• telazol

• diazepam

• NSAIDs

what types of antibiotics should be used in the case of hepatobilliary surgery?

broad spectrum

• penicillin

• metronidazole

• clindamycin

what antibiotics should be avoided in the case of liver disease?

• doxycycline

• chlortetracycline

• erythromycin

what is the best surgical approach for adequate exposure of the liver?

ventral midline incision

list the ways that one can collect a liver biopsy?

• percutaneous core biopsy

• FNA

• laparoscopic wedge biopsy

• surgical liver biopsy (partial or complete lobectomy)

list hepatic diseases that may require surgery

• obstruction

• trauma

• neoplasia

• liver lobe torsion

• cysts

• abscesses

list vascular malformations of the liver

• portosystemic shunts

• hepatic microvascular dysplasia

• non-cirrhotic portal hypertension

  • idiopathic portal hypertension

• A-V fistula

list biliary diseases that may require surgery

• cholecystitis

• biliary mucocele

• obstruction

• trauma

• neoplasia

• cholelithiasis

what type of liver neoplasia is more common? epithelial vs. mesenchymal

epithelial

what is the most common hepatic epithelial neoplasia?

hepatocellular carcinoma

epithelial tumors most often metastasize to the __________

• regional lymph node

• lungs

mesenchymal tumors most often metastasize to the ___________

• spleen

what type of primary hepatic neoplasm is most common in dogs?

hepatocellular and cholangiocellular carcinomas

what type of primary hepatic neoplasm is most common in cats?

cholangiocellular adenomas

what are the basic forms of hepatocellular carcinomas?

• diffuse

• nodular

• massive

what form of hepatocellular carcinoma has the best prognosis?

massive form

what is the most common secondary hepatic tumor?

lymphosarcoma

what are the types of biliary diversion surgeries?

• cholecystoduodenostomy

• cholecystojejunostomy

• cholecystoenterostomy

list the complications following a total lobectomy

• HEMORRHAGE

• biliary peritonitis

• bacterial proliferation

• sepsis

• coagulopathy

• portal hypertension

• ascites

clinical signs of liver abscess

• anorexia

• lethargy

• weight loss

• intermittent abdominal pain

clinical signs of hepatic cysts

• asymptomatic

• abdominal distension

• if there is a secondary infection = behaves like an abscess

list the treatments for cavitary lesions

• drainage & omentalization

• lobectomy or partial hepatectomy

• antibiotics for 7-10 days

list the indications for partial lobectomy

• biopsy

• trauma

• abscess

• cysts