PSS

Question 1

What is a portosystemic shunt?

Answer 1

Abnormality in blood flow that results in deviation of blood from the liver into systemic circulation

Question 2

What type of shunts make up the majority of PSS?

Answer 2

Singe. congenital, extrahepatic

Question 3

How much of its blood flow does the liver receive from portal circulation for detoxification?

Answer 3

2/3 of its blood flow

Question 4

What vessels are shunts usually associated with?

Answer 4

Portal, left gastric, or splenic vein

Question 5

If shunted blood doesn’t drain into portal circulation, which other vessels do they drain into?

Answer 5

Caudal vena cava or azygous vein

Question 6

What is the typical signalment for a congenital extrahepatic PSS?

Answer 6

Small breed usually <1yo

Question 7

What is the poster child for congenital extrahepatic PSS?

Answer 7

Yorkies

Question 8

What size breeds have a higher likelihood of an intrahepatic shunt?

Answer 8

Large breeds

Question 9

What is a classic PSS clinical sign in cats?

Answer 9

Copper colored iris

Question 10

Why do neuro signs accompany PSS?

Answer 10

Hepatic encephalopathy d/t high ammonia levels

Question 11

What are neuro signs assoc. w/PSS and when do they typically occur?

Answer 11

Head pressing or star gazing, esp after eating

Question 12

How are bile acids affected by a PSS?

Answer 12

Dramatically high post-prandial bile acids should make you highly suspicious of a PSS

Question 13

Are ammonia or bile acid tests more sensitive for dx PSS?

Answer 13

Ammonia, but must measure immediately after blood draw (and analyzers are not widely available)

Question 14

What might you see on a PSS urinalysis?

Answer 14

Ammonium biurate crystals

Question 15

How will the liver appear on radiographs?

Answer 15

Microhepatia

Question 16

Can you usually see aberrant vessels on ultrasound of a PSS?

Answer 16

Only 60% of the time

Question 17

What type of bladder stones are assoc. w/PSS?

Answer 17

Urate

Question 18

How can you medically manage a PSS?

Answer 18

Metronidazole, lactulose, low-protein diet

Question 19

Decreases urease-producing bacteria in the colon

Answer 19

Metronidazole

Question 20

Decreases colonic pH, which results in decreased ammonia absorption

Answer 20

Lactulose

Question 21

What can you give for a PSS that is seizuring?

Answer 21

KBr

Question 22

What are surgical options for a PSS?

Answer 22

Ameroid constrictor, cellophane band, or partial/complete ligation

Question 23

What is the most commonly used PSS closure technique?

Answer 23

Ameroid constrictor

Question 24

Which surgical technique causes higher portal hypertension and higher complication rates than the others?

Answer 24

Partial/complete ligation

Question 25

What does post-op pain indicate in a PSS patient?

Answer 25

Complete vessel occlusion and life-threatening portal hypertension

Question 26

Shunting at the level of the hepatocyte

Answer 26

Microvascular dysplasia

Question 27

Why must you always take a liver biopsy when surgically correcting a PSS?

Answer 27

Rule in or out microvascular dysplasia

Question 28

How will presence of microvascular dysplasia influence your treatment post-op?

Answer 28

Presence will indicate long-term medical therapy is also needed

Question 29

What are clinical signs of a PSS in cats?

Answer 29

Pytalism, copper iris (pathognomonic)

Question 30

What are the only veins that should enter the vena cava between the hepatic and renal veins?

Answer 30

Phrenicoabdominal veins

Question 31

How much protein should you feed a PSS?

Answer 31

The maximum amount they will tolerate w/o showing encephalopathy signs