LIVER, PANCREAS: 95, 96, 97 Flashcards
Liver anatomy
442
4 lobes (right, left, quadrate, caudate) 4 sublobes (right, left lateral and medial) 2 processes (caudate, papillary)
is it more difficult to access surgically the left or right lobe? why?
easier the LEFT (sustantial cleft separating the medial and lateral portions
the right medial lobe has a substantial attachment to the quadrate lobe
the right lateral lobe is fused at it’s base with the caudate lobe
blood supply and O2 supply to the liver
HEPATIC ARTERY: 20% volume, 50% O2
PORTAL VEIN: 80% volume, 50% O2
possible conformation of the Heparic artery
1- common trunk
2- right lateral + left
3- right lateral + right medial + left
left always the larger
where the cystic artery of the gallbladder originates from?
from the left branch of the hepatic artery
DOG vs CAT: difference in anatomy beetween intrahepatic portal vein
CANINE: usually divide in right and left main branch
FELINE: usually divide in 3 branches ( right, central, left)
how it is called the manouvre to stop the the blood inflow to the liver?
pringle manouvre
number of hepatic ducts in dog
2-8
DOG vs CAT: major and minor papilla differences
DOG:
major papilla: CBD. Adjacent to CBD enters the pancreatic duct
minor papilla: accessory pancreatic duct (larger)
CAT:
major papilla: CBD + pancreatic duct (conjoined with the CBD)
minor papilla: 20% cats have accessory pancreatic duct (smaller)
compensatory hypertrophy and hyperplasia of liver after 70% resection
usually reached after 6 days. may take up to 6-10 weeks
factors that impede liver regeneration
diabetes mellitus: insulin is one of the most potent hepatotrophic factors in protal blood
most common cause of extrahepatic biliary tract injury
blunt abdominal trauma
most common causes of extrahepatic biliary obstruction
pancreatitis, neoplasia, mucoceles, cholangitis, cholelitiasis
possible consequences of extrahepatic biliary tract obstruction
hypotension decreased myocardial contractility AKI coagulopaties gastrointestinal hemorrage delayed wound healing
absence of bile salts lead to bacterial overgrowth?
mortality rates beetween sterile-septic bile peritonitis
higher mortality rates with septic bile peritonitis
RX visualization of coleliths
50% radiopaque in dogs
80% radiopaque in cats
first US sign of extrahepatic biliary tract obstruction
CBD dilation (normal: 3-4 mm) begins to dilate as soon as 48 h after obstruction
prevalence of coagulation abnormality in dogs with liver desease
up to 57% of dog with at least one abnormality
is there a concrete risk of hemorrage with liver desease?
in human no increased bleeding tendencies have been seen in patients with coagulation abnormalities due to liver desease
degree of liver resection at wich we can observe hypoglicemia
when up to 70% of liver is resected
most common bacteria isolated in liver culture
clostridium perfringens
staphylococcus spp
oxidized regenerated cellulose VS gelatin sponge
ORC seem to have antibacterial properties
name the 3 technique to control extensive hemorrage from hepatic surgery
1- control of central venous pressure
2- occlusion of liver inflow
3- occlusion of liver inflow and outflow
time of liver inflow occlusion tolerated
20 min: dogs are less tolerant than humans because they have reduced intrinsic portosystemic collateral circulation
difference beetween stapling technique and dissection and ligation technique
both safe and effective
dissection and ligation tough associated with more microscopic hemorrage, necrosis and inflammation
serum bilirubin concentration to see icterus
> 1.5- 2 mg/dl
is there aboundant fluid associated with bile peritonitis? how it is diagnosed?
usually yes, because of hyperosmolar nature of bile
diagnosed when bilirubin concentration of peritoneal fluid is 2- > then bil in the serum
DOG vs CAT: prevalence of positive culture of bile
17-39% of dogs
30-50% cats
best antibiotic choice for septic bile peritonitis
2 gen cephalosporin, it lack efficacy against enterococci
-> add ampicillin for enterococcus spp.
critical point to decide when medical treatement alone or when perform surgery?
if patency of the CBD can not be demostrated via normograde or retrograde catheterization of the duct, consider a sirgical approach with cholecistoenterostomy.
choledochal catheterization approach in order:
1- small antimesenteric duodenotomy to cateterize major papilla
2- establish patency
3- colecistectomy
4- thorough flushing of the duct
cholecistectomy tip
always flushing the CBD to ensure that all gelatinous bile is removed from the common bile duct
port placement for laparoscopic cholecystectomy
4 PORT:
subumbilical camera
LEFT: 5-8 lateral, 3-5 cranial umbilicus
RIGHT: 3-5 lateral umbilicus
RIGHT: 5-8 lateral umbilicus
1 PORT: umbilicus
tip to remove the gallbladder laparoscopically from the abdomen
when in the retrival bag, puncture and aspirate it’s content to facilitate exteriorization
when to perform a cholecystoenterostomy
- when the CBD is too small or fragile to permit choledochoduodenostomy
- can’t reestablish patency of CBD
-not do when suspect pf necrotic gallbladder
how to reduce stroma narrowing with cholecystoenterostomy
appose mucosa on mucosa
size of stenting fot choledocal stenting
CAT: 3.5-5 Fr
DOG: 8-12 Fr
choledocal stenting outcome in cats
probably due to reduced diameter it can lead to reobstruction after a few days-weeks from the stenting
surgical options for a colecystostomy tube
traditional “open” technique
laparoscopic assisted
percoutaneous drainage ad alcoholization of hepatic abscesses (Zatelli et al.)
ultrasound guidance place 20 G needle aspirate 95% ethanol 1/2 volume removed left in situ for 3 minutes
signalment of dogs with liver lobe torsion
middle-old large breed dogs
no gender or underlying desease predisposition
endocrinopaties associated with gallbladder mucocele
hypotiroidism, hyperadrenocorticism
can you perform a cholecistoduodenostomy in a dog with gallbladder mucocele?
usually no, because gallbladder wall is not healthy enough
choleliths composition ad difference with humans
in dogs less saturated with colesterol
usually composed of calcium carbonate or calcium bilirubinate, cholesterol in varying quantities
what are the 4 possible general type hepatic tumors
hepatocellular
cholangiocellular
neuroendocrine
mesenchymal
metastatic
what’s the most common liver neoplasm? DOG VS CAT
DOG: hepatocellular carcinoma (50-70%) of non hematopoietic
CAT: bile duct tumors most common primary hepatic tumor (biliary duct adenomas 2 more common than biliary duct carcinomas). hepatocellular adenomas more common than carcinomas
possible forms of diffusion of liver tumors
massive (61%)
nodular (29%)
diffuse (10%)
left lobe in 67% cases
tributaries of the portal vein from caudal to cranial
CRANIAL MESENTERIC : jejunal+caudal pancreaticoduodenal
CAUDAL MESENTERIC: ileocolic+left colic+right colic+middle colic
SPLENIC: splenic+left gastroepiploic+left gastric+branch from pancreas
GASTRODUODENAL: pancreas+duodenum +stomach (right gastric and right gastroepiploic)
portal vein anatomy
RIGHT BRANCH
caudate process+right lateral lobe
LEFT BRANCH
RIGHT VENTROLATERAL BRANCH right medial lobe
PAPILLARY BRANCH to papillary process
DIVIDE IN quadrate, left medial, left lateral
how many hepatic veins usually a dog have?
5 to 8
how many pairs of cardinal veins develop in the embryonic trunk?
3
caudal cardinal
subcardinal
sopracardinal
a congenital portocaval or portoazygos shunt is an abnormal connection beetween the ……………….. and ……………………….system
cardinal vitelline
left sided IHPSS usually result from patency of
the ductus venosus
name the 3 categories of liver vascular desease
1- congenital PSS
2- primary hypoplasia of the portal vein (PVH)
PVH with portal hypertension (idiopatic noncirrhotic portal hypertension)
PVH without PH (microvascular dysplasia MVD)
3- disturbances in portal outflow
prevalence of PSS in dogs with PVH-MVD
58% dogs and 87% cats with PVH-MVD have a congenital PSS
what is a hepatic arteriovenous malformation?
multiple high pressure vessel connecting hepatic artery with portal vein through multiple (tens to hundreds) shunting vessels
name some of the toxins implicated with hepatic encephalopathy
14:
ammonia
aromatic amino acids
bile acids
decrease alpha ketoglutarate
endogenous benzodiazepines
GABA
false neurotransmitters
tyrosine phenylalanine methionine glutamine tryptophan phenol SCFAs
coagulopaties in patients with PSS
43% found coagulation abnormalities
40 times more lijely when hepatic encephalophaty present
breed associated with increase in PSS prevalence
EHPSS
35.9% yorkshire terrier maltese pugs miniature schnauzer norwegian terriers havanese
IHPSS
large breed dogs: irish wolfhounds, retrievers, australian cattle dog, australian sheperd. left divisional considered heritable in irish wolfhounds
potential causes of PU-PD in dogs with PSS
poor medullary gradient due to low urea
increased GFR
increase in ACTH associated with hypercortisolism
psycogenic polididpsia
hypoalbuminemia in dogs with PSS
most common in dogs with a concurrent
PLE
GI ulceration or IBD or lymphangectasia
heavy intestinal parasite loads
liver function tests
bile acids: after 12 h fasting and 2 hour postprandial (up to 100% sensitive with both measurements or only post-prandial)
ammonia: abnormal in 62% to 88% of animals
ammonia tolerance test? (amonium cloride orally or rectally)
common findings in histopatology of PSS liver
bile duct proliferation hypoplasia of intrahepatic portal tributaries hepatocellular atrophy arteriolar proliferation or duplication lipidosis cytoplasmatic vacuolar changes smooth muscle hypertrophy increased lymphatics around central veins Ito and Kupffer cell hypertrophy
is it possible to differentiate PSS from PVH-MVD (without hypertension) from PVH (with hypertension) based on hustopatologhic changes?
usally no
dogs with non cirrothic PH often have more significant fibrosis extending in the parenchima
Portal vein to Aorta ratio to detect PSS
PV/Ao
1-2 normal
0,14-‘,6 suggestive of PSS
medical management of PSS
lactulose: entrapment of luminal ammonia in form of ammonium (acidificate colon content) + osmothic effect
plasma for coagulopathies
antiacids for GI ulcerations
seizure control. benzo-amtagonist to reverse hepatic encephalopaty? seizures not caused by hypoglicemia or hyperammoniemia treated with benzodiazepines
mannitol to decrease cerebral edema
hepatoprotector
diuretics for ascites. spironolactome is a potassium sparing drugs, furosemide may potentiate hypokaliemia
prognosis IHPSS vs EHPSS
IHPSS: on medical management persistent neuro and urinary signs, nut GI gets better
EHPSS: neuro, urinary, GI, same or better with medical therapy
for how long should preoperative therapy be used?
at least 2 weeks
possible location of EHPSS
phrenic: esophageal hiatus
azygos: aortic hiatus
epiploic foramen: CVC dorsal, HA PV ventral, celiac artery caudally
caudal abdomen: colon caval shunts, falciform ligament, hilus liver to internal thoracic vein
determining the degree of shunt attenuation
up to 86% of dogs undergoing acute occlusion require partial attenuation
MAX 17-24 mmHg post ligation, or 2x the previous measured pressure
closure limited to a degree where the flow become epatopetal
how can you classify IHPSS
shunt of the left division
shunt of the central division
shunt of the right division
name the 4 main concearn-complications associated with PSS surgical attenuation
- significant postoperative hypoglicemia: reported in up to 44% of dogs within 4 hours of surgery
- hemorrage anemia
- portal hypertension: 2-14% with acute ligation, less common in partial. clinical signs can be hypovolemic shock, hypotermia, abdominal pain, abdominal distention, dhiarrea, vomiting.
pancreas vascular suppy
CELIAC ARTERY:
splenic artery (left limb)
hepatic artery: terminates as cranial PD artery (body+proximal right limb)
CRANIAL MESENTERIC
caudal PD artery
name the 2 pancreatic ducts
accessory PD: duct of Santorini (dog bigger, exit at minor papilla)
second duct: duct of Wirsung (dog smaller, exit major papilla)
80% cats have only one duct thet fuses with CBD and exit at major papilla
what are the 3 mechanism to prevent autodigestion of pancreas
1: stored as inactive zymogens
2: storage of inactuve zymogen inside the rough endoplasmic reticulum of pancreas
3: pancreatic secretory trypsin inhibitor
what are the 2 molecules that activate the exocrine pancreas secretion?
secretin (bicarbonates)
cholacystokinin (digestive enzymes)
released from duodenal cells whan ingesta passes or smell, or food in the stom
what anesthetic shouldn’t be used in dogs with insulinoma or diabetes mellitus?
a2 agonist: in normal animals produce hypoinsulinemia and hyperglicemia. in diseased animals the impact is unknown
based on hystopatologic result, wtah technique beetween blunt dissection and suture fracture technique is the best for pancreatic biopsy?
blunt dissection revealed less severe inflammatory reaction.
however, no differences detected on clinical signs beetween two groups
bacterial culture in pancreatic abscesses in dog and cats
in humans majority of pancreatic abscesses have positive cultures.
dogs majority seems to be sterile.
serum lipase correlation with pancreatic carcinoma
when 25 times upper normal limit highly suggestive of malignant carinoma rather tha simply pancreatitis
insulinomas: benign or malign?
60% are carcinomas, 40% are adenomas.
50 % metastasis at time of diagnosis
MST: no met (18 months) met (7-9 months)
insulinomas on TC
insulinomas appear uniformly hypervascular and can be differentiated from usually hypovascular exocrine carcinomas.
common false positive results for detection of metastases
gastrinoma: what are the cells involved in malignant transformation?
somatostatin-secreting delta cells
condition usually associated with glucagonoma
rather than the expected hyperglicemia, usually associated with hepatocoutaneous syndrome (superficial necrolytic dermatitis).
