Hepatobilliary Surgery Flashcards
Where is the gallbladder located? What artery supplies it?
between RM and quadrate lobes of the liver
cystic artery
What are the 2 major blood supplies to the liver? Efferent vessel?
- PORTAL VEIN (80%) - low pressure
- HEPATIC ARTERY (20%) - high pressure
hepatic vein enters the caudal vena cava
How do partial and complete lobectomies compare?
PARTIAL - only taking off a portion, very dangerous since there is no strong capsule to the liver
COMPLETE - removal of the entire lobe at the level of the hilus, safer because the vessel can be easily ligated
What is the ideal sample taken from liver biopsies?
multiple samples from multiple lobes
What 3 aspects of liver anatomy makes it difficult to perform surgery on?
- very friable tissue lacking a strong capsule
- difficult hemostasis
- biliary leaks possible
What are 6 major functions of the liver?
- synthesis of plasma proteins
- bile acid production
- produces coagulation factors
- maintains carbohydrate and lipid metabolism —> glucose concentration
- clearance organ (drugs and toxins)
- storage of vitamins, fat, glycogen, and minerals
What 3 things can ultrasonography be used for with the liver?
- rules out biliary obstruction and assesses the organ
- FNA/biopsy
- doppler enhanced = assess blood flow
How does hematocrit affect preoperative considerations?
if it is below 20%, patient should receive preoperative blood transfusions
When does clinical hypoalbuminemia occur? What is its significance?
70-80% of hepatic mass lost
- delayed healing
- decreased bound drugs = more free in plasma and more profound affects with normal dosages
What 6 drugs should be avoided with severe liver disease?
- Acepromazine
- alpha-2 agonists - Xylazine, Dexmedetomidine
- neuromuscular blocker - Pancuronium/Vecuronium
- Telazol
- Diazepam
- NSAIDs
How does liver disease affect coagulation?
causes coagulopathies due to decreased production of clotting factors or consumption
What 2 important aspects of a biochemistry panel are affected by liver disease?
- hypokalemia
- hypoglycemia
What important effect does biliary obstruction have?
alters enteric absorption of vitamin K and other fat-soluble vitamins (D, E, A)
- decreased synthesisi of plasma clotting proteins, factors II, VII, IX, and X
What 3 factors can reduce hepatic oxygenation? How can venous return be improved?
- hypotension
- excessive sympathetic stimulation (inadequate pain control)
- high airway pressures
remove ascites (sudden removal intra-operatively can cause hypotension)
How is hypotension treated to improve hepatic oxygenation?
vasopressors/inotropes
- Dobutamine
- Dopamine
- Ephedrine
- Epinephrine
- Norepinephrine
- Phenylephrine
What 3 antibiotics are recommended to improve hepatic oxygenation? What 3 should be avoided?
- Penicillin derivatives
- Metronidazole (high doses can cause severe neurological signs)
- Clindamycin
- Doxycycline
- Chlortetracycline
- Erythromycin
What 5 procedures are used for liver biopsies?
- percutaneous core biopsies with ultrasound-guided Trucut (12-18 g needle with a notch for tissue)
- FNA
- laparoscopic - double spoon forceps, guillotine with pre-formed loop suture
- surgical biopsy or lobectomies
- punch biopsy
How is liver trauma initially treated? How does the location of trauma affect this?
conservative - transfusions, fluids
closer to hilus = greater likelihood surgery is necessart (ligation, hepatectomy)
What are the 2 major types of hepatic neoplasia? Where are they more likely to metastasize?
- epithelial - hepatocellular carcinoma/adenoma, cholangiocellular carcinoma/adenoma, carcinoids; regional LNs and lungs
- mesenchymal - HSA (poor prognosis), fibrosarcoma, extraskeletal osteosarcoma, leiomyosarcoma; spleen
1% are primary
What primary hepatic neoplasms are most common in dogs and cats?
DOGS = hepatocellular* and cholangiocellular carcinomas
CATS = cholangiocellular
What are hepatic carcinoids? Biliary cystadenomas?
rare tumors arising from neuroectodermal cells in the liver
benign liver tumors in older cats
What are the 3 types of hepatocellular carcinomas? What are their prognoses like?
- diffuse - on all lobes, poor prognosis
- nodular - poor prognosis
- massive - 1 lobe, better prognosis
Where are most massive adenocarcinomas found?
left lobes
(massive = better prognosis; diffuse = poor)
What are the most common types of cholangiocellular tumors in cats?
adenomas - cystadenoma —> cholecystadenoma
(carcinomas —> carcinomatosis)
Why is metastatic neoplasia common in the liver? What are the most common ones seen?
acts as a filter between abdominal organs and systemic circulation
- lymphosarcoma*
- pancreatic adenocarcinomas
- HSA
- insulinomas
- alimentary and urinary tract tumors