Hepatobiliary surgery Flashcards
Describe the anatomy/blood supply of the liver
- 6 lobes
- Blood suppy
- Hepatic artery–20% blood volume
- Portal vein–80%
- Cystic artery supplies gallbladder
- Hepatic veins enter the caudal vena cava
What are the various techniques for obtaining a liver biopsy? Which techniques are best for generalized vs. multifocal vs. focal disease?
- Guillitine (most common)
- Lesions at the periphery of lobes
- Diffuse liver disease
- Punch
- Superficial lesions that are centrally located
- Generalized disease–multiple biopsies easily obtained
- Laparoscopy
- Samples relatively small and at periphery of lobes
What are the advantages/disadvantages of performing a percutaneous tru-cut biopsy?
- Advantages
- Minimally invasive
- Core tissue samples for histo evaluation
- U/S or CT guidance
- Disadvantage: increased risk of bleeding
What are the advantages/disadvantages of obtaining a FNA and cytology of the liver?
- Advantages
- Safe, minimally invasive
- U/S guidance
- Disadvantages
- Poor diagnostic yield
- 30% agreement between cytology and histo
What are the most common indications for complete or partial liver lobectomy?
- Neoplasia
- Trauma
- Abscess
- Cysts
What are the most common hepatic neoplasias? What is the most common form of neoplasia of the liver?
- Hepatocellular
- Cholangiocellular
- Mesenchymal
- Neuroendocrine
- Most common form = metastatic
- Hematopoietic or lymphoid
T/F: Liver tumors are more common in cats than dogs
FALSE
More common in dogs
What is the most common type of benign tumor in the dog?
Adenoma (hepatocellular tumor)
What is the prognosis for a hepatocellular tumor?
- Adenoma
- Benign–good prognosis
- Adenocarcinoma
- Massive form = good prognosis w/ complete surgical excision
- MST = ~1460days
- Nodular form = poor prognosis
- Complete excision unlikely
- Diffuse form = poor prognosis
- Mets to LN, peritoneum, lungs
- Massive form = good prognosis w/ complete surgical excision
What is the most common type of benign tumor in the cat?
Cholangiocellular tumors: adenomas
What is the prognosis for cholangiocellular tumors?
- Dogs
- High metastatic rate (88% at time of necropsy)
- Cats
- > 50% are adenomas = excellent prognosis following sx
- Carcinoma
- Metastasis 67-80% at time of diagnosis
What is the most common malignant tumor in cats?
Cholangiocellular carcinoma
What is the complete ligature technique for a complete liver lobectomy?
When should it be used?
- Ligature placed at base of liver lobe
- Glorified “Guillotine” technique
- Should only be used for left lateral and left medial lobectomies in small dogs and cats
What are the advantages of the TA stapler technique for complete or partial liver lobectomies?
- Technique used most commonly by surgeons
- Fast
- Provides excellent hemostasis
- Can supplement with gelfoam
- Must use appropriate sized staples
- Can be positioned by the hilus to achieve near complete resection of the lobe
- Can be utilized across a lobe for partial lobectomies
Explain the parenchymal fracture and ligation technique for partial liver lobectomies
- Cut through capsule at level of proposed excision
- Crush or aspirate parenchyma gently
- Can use inner portion of a Poole suction tip to aspirate soft parenchyma from underlying vessels
- Ligate or cauterize individual vessels
What is a disadvantage of the parenchymal frature and ligature technique for partial liver lobectomies?
Technique results in great blood loss
What is the overlapping sutures technique for a partial liver lobectomy?
- Series of overlapping guillotine sutures
- Must tie sutures tight enough to crush through tissues
What are the risks/complications of liver lobectomies?
- Hemorrhage
- Accidental ligation or occlusion of portal veins and cystic ducts to remaining liver lobes
- Incomplete tumor resection
- Tumor recurrence
What is a cholecystotomy?
Incision into the gallbladder
What is a cholecystectomy?
Removal of the gallbladder
What is a cholodocotomy?
Incision into the common bile duct
What is a cholodocoenterostomy?
Surgical anastomosis of the common bile duct to the intestine
What is a cholocystoduodenostomy?
Surgical anastomosis of the duodenum and the gallbladder
What is a cholocystojejunostomy?
Surgical anastomosis of the jejunum and the gallbladder
What is the most common cause of bile duct obstruction?
What surgical treatment is most recommended?
Cholecystitis is the most common cause
Cholocystectomy is the most reasonable surgical treatment
What are the breed and disease associations with gallbladder mucoceles?
- Breed (primarily seen in dogs)
- Small and medium breeds over-represented
- Shetland sheepdogs
- Cocker spaniels
- Mini Schnauzers
- Small and medium breeds over-represented
- Diseases
- Hypothyroidism
- Hyperadrenocorticism
What are the steps for performing a cholecystectomy?
-
Ensure patency of common bile duct prior to removal of gallbladder
- Normograde or retrograde catheterization of duodenal papilla
- Dissect gallbladder from hepatic capsule of quadrate lobe
- Ligate/clip cystic duct and the cystic artery together
- Must know anatomy to ensure common bile duct is not injured or ligated
- Collect bile for culture and save gallbladder for histo
What are the possible complications associated with a cholecystectomy?
- Bile peritonitis
- Failure to adequately ligate cystic duct
- Failure to recognize and ligate smaller hepatic ducts entering cystic duct
- Bleeding
- From hepatic parenchyma
- From cystic artery
What is the prognosis for dogs undergoing cholocystoduodenostomy?
What is it for cats?
- Dogs
- ?
- Cats
- ?
What are the complications associated with cholecystoduodenostomies?
- Leakage
- From gallbladder, duodenum, or both
- Bile peritonitis
- Septic peritonitis
- Ascending infection
- Stoma stricture
- Cats experience higher mobility and mortality than dogs
- Typically related to underlying disease vs. procedure
- Ascending infection and stricture
What diagnostic samples should be obtained when performing biliary surgery?
Bile for culture
Save gallbladder for histo
