Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

RUSVM Small Animal Surgery 1 > Portosystemic Shunts > Flashcards

Portosystemic Shunts Flashcards

1
Q

What are the types of congenital PSS?

A

Macrovascular

  • intrahepatic
  • extrahepatic

Microvascular
- intrahepatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Single shunts arise from?

A

Trauma or iatrogenic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Multiple shunts arise from??

A

Diseases that cause portal hypertension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Extrahepatic PSS are associated with what signalment ?

A

Small dog and cat

  • YORKIES, Shih Tzu, Maltese, poodle, schauzers, dashunds, pug
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What anatomy is altered in an extrahepatic portosystemic shunt?

A

Veins that should join the portal vein enter the caudal vena cava or azygous vein instead

Usually the left gastric vein and splenic (gastrosplenic) vein — most commonly involved

Less commonly: portocaval, gastroduodenal, mesenteric (jejunal and colic veins)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Normally, the last vessel that should enter the caudal vena cava is the ____________, any vessels entering crainal to this are abnormal shunts

A

Phrenicoabdominal vein (drains the adrenals)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Signalment associated with intrahepatic PSS?

A

Large breed

  • labs
  • goldens
  • Australian shepherd
  • Old English sheepdog (OES)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the abnormal anatomy occurring in an intrahepatic shunt?

A

Patent ductus venosus

Intrahepatic branches of portal vein enter vena cava or hepatic vein bypassing the hepatic parenchyma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What affects the major pre-haptic vessels and causes ascities more commonly than other types of congenital shunts?

A

Portal vein atresia

Also results in hypoproteinemia (lack of blood flow to liver)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens when you occlude the shunt when there is portal vein atresia?

A

Portal hypertension —> blood cannot flow into liver this way so blood backs up int the gastric system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do you treat portal vein atresia??

A

Medically

You cannot close the shunt !!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the consequence of portal vein hypoplasia?

A

Hepatic microvascular dysplasia

—microshunting within the liver, may occur as a single entity or in conjunction with macrovascular shunts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What diagnostics can you do for portal vein hypoplasia?

A

Bile acids — only mildly elevated
Protein C activity >70% = microvascular shunt
—> plasma anticoagulant synthesized in liver, reflect hepatic synthetic activity and portal bloodflow

Nuclear scintigraphy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the treatment for portal vein hypoplasia?

A

Stable form— none OR medical management (diet often enough)

Progressive form - diet and medical management

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Multiple extrahepatic PSS are secondary to ??

A 
Diseases causing portal hypertension 
Microvascular shunt ligation 
Cirrhosis 
Non-cirrhosis portal hypertension (isopathic/ hepatic veno-occlusive disease)
Hepatic A-V malformation (fistula)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How do multiple extrahepatic shunts develop from portal hypertension?

A

Vestigial embryonic communications “open up”

17
Q

What are the general signs of microvascular shunts?

A

Poor growth rate, weight loss, anesthetic or tranquilizer intolerance

Lethargy, depression, weakness, behavioral changes, pacing, aggression, ataxia, stupor, head pressing, coma, seizures, blindness

Anorexia, vomiting, diarrhea, ptyalism, pica, ascities

Pu/PD, cystitis, urolithiasis, urethral obstruction

Ascities

18
Q

What PE finding in cats can indicate macrovascular shunts?

A

Copper coloured irises

Hypersalivation
Aggressive behaviour

19
Q

What do you see on CBC and biochem associated with macrovascular shunts?

A

Anemia, microcytosis, hhypochromasia, poikilocytosis, target cells, neutrophilia

Decreased BUN, albumin, and cholesterol
Hypoproteinemia
increased ALT and ALP

20
Q

What might be present on UA that could indicate macrovascular shunts?

A

Low specific gravity
Ammonium biurate crystals
Uterine sed suggestive of cystitis —> hematuria, pyuria, and proteinuria

21
Q

What liver fxn tests would you want to do and what would you see with a macrovascular shut?

A

Elevated serum bile acids — pre and post prandial

Hyperammonemia — fasting or after ammonia tolerance test

Protein C activity <70%

22
Q

What is a non invasive method of diagnosis of PSS and can distinguish it from microvascular dysplasia ?

A

Nuclear scintigraphy

Technetium 99
—> transcolonic (higher dose needed)
—> trans-spenic (smaller dose but can often identify shunt type)

23
Q

What is the most accurate non-invasive diagnostic method of PSS?

A

CT angiography

24
Q

What is the most commonly injected vein for portography?

A

Mesenteric vein

25
Q

How are PSS managed medically?

A

Diet (u/d, k/d, i/d)
Lactulose
Antimicrobial
Seizure control/ prevention

Control intestinal parasites

26
Q

An albumin level of _________ makes PSS ligation much more riskier

A

<1.5mg/dl

27
Q

What is the goal of surgery for PSS?

A

Divert blood flow back through portal system without creating portal hypertension (can be life threatening or can cause acquired shunts to open)

Improve liver fxn

28
Q

What are the surgical management options for portosystemic shunts?

A

Compete ligation

Partial attenuation with suture +/- reoperation

Gradual occlusion

  • ameroid constrictor
  • cellophane band
  • thrombogenic coils
  • hydraulic occluders
29
Q

How dos partial attenuation of the PSS function?

A

Vessel is partly occluded

Vessel may occlude spontaneously due to inflammation or altered blood flow mechanics

If it doesnt flow - reportage

30
Q

How are portal pressures measured? What is the maximum acceptable change with PSS?

A

Catheterize and measure mesenteric vessels

Maximum change 9-10cmH2O

31
Q

How does an ameroid constrictor work?

A

Gradual occlude

Casin ring - inflammatory thing that sweeps in contact with vessel

32
Q

Complications to to closure of PSS?

A

Acute occlusion

  • rapid closure
  • kinking

Chronic

  • incomplete occlusion
  • acquired shunts
  • implant migration
33
Q

How does cellophane banding function in ligation of PSS?

A

Occlusion by inflammatory reaction

Typically completely occludes within 812days

34
Q

What are the advantage and disadvantages to hydraulic occluders?

A

Advantages: single surgery w/o portal pressures, gradual and total vascular occlusion, reversible

Disadvantages: implant leakage or diffusion

35
Q

How are intrahepatic shunts occluded?

A

Intracaval
Transportal
Thrombogenic coils

36
Q

What are the acute postoperative complications with PSS ligation?

A 
Portal hypertension 
Portal vein thrombosis 
Hypoglycemia 
Seizure 
Hemorrhage
Electrolyte disturbances (hyponatremia)

RUSVM Small Animal Surgery 1 (39 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions