Portosystemic Shunts

Question 1

Kraun, JAVMA, 2014:
EHPSS

1. Neuro signs were more common in dogs with shunts inserting where in relation to the liver?
2. Shunts originating from which vessel were more likely to be associated with urinary signs?
3. What % of dogs had urinary calculi or mineralization?
4. Albumin concentrations were lower in dogs with which type of shunts?
5. What breed of dog was 36 times as likely to develop an EHPSS than any other breed?

Answer 1

Kraun, JAVMA, 2014:

1. Neuro signs were more common in dogs with shunts inserting caudal to the liver
2. Shunts originating from the right gastric vein were more likely to be associated with urinary signs than shunts originating from the splenic vein
3. 60% had urinary calculi or mineralization
4. Albumin concentrations were lower in dogs with portocaval shunts than those with portoazygos shunts
5. Yorkies were 36 times as likely to develop an EHPSS than any other breed

Question 2

Caporali, JAVMA, 2015:
EHPSS

1. What % of dogs had crystalluria, and what were the most common type(s) of crystals?
2. 94% of the uroliths analyzed were composed of what?
3. Risk factors for urolithiasis?

Answer 2

Caporali, JAVMA, 2015:

1. 37% had crystalluria, mainly ammonium urate and struvite crystals
2. 94% of the uroliths analyzed were composed of ammonium urate
3. Risk factors for urolithiasis: male dogs, older dogs, dogs that received previous medical treatment

Question 3

Tamura, VRU, 2019:
Contrast-enhanced ultrasonography in EHPSS:

What finding could be used as an additional diagnostic test to distinguish EHPSS dogs from healthy dogs?

Answer 3

Tamura, VRU, 2019:

Rapid hepatic artery and hepatic parenchyma enhancements may reflect a compensatory increase in hepatic artery blood flow (arterialization) caused by a decrease in portal vein blood flow, and may be used as an additional diagnostic test to distinguish EHPSS dogs from healthy dogs

Question 4

Joffe, Vet Surg, 2019:
Methods of securing cellophane bands for EHPSS

1. Cellophane bands with how many layers were more likely to fail and failed at lower pressures?
2. Difference in failure rates between bands applied to create 25% vs 50% attenuation?
3. What sized clips failed less often?
4. Difference in failure rates between polymer locking ligation clips vs titanium ligation clips?

Answer 4

Joffe, Vet Surg, 2019:

1. 3-layer cellophane bands were 4 times more likely to fail than 4-layer cellophane bands and failed at lower pressures
2. No difference in failure rates between bands applied to create 25% vs 50% attenuation
3. Medium clips failed less often than medium-large clips
4. Failure rates did not differ between polymer locking ligation clips and titanium ligation clips

Question 5

Weisse, JAVMA, 2018:
IHPSS

1. Major intra-op complication rate?
2. Minor intra-op complication rate?
3. Early post-op complication rate?
4. What % of dogs had post-op GI hemorrhage?
5. Outcomes?
6. MST?
7. Dogs with shunts in which division of the liver had better outcomes?

Answer 5

Weisse, JAVMA, 2018:

1. Major intra-op complication rate: 3%
2. Minor intra-op complication rate: 12%
3. Early post-op complication rate: 16%
4. 21% had post-op GI hemorrhage
5. 66% excellent outcomes, 15% fair outcomes, 19% poor outcomes
6. MST: >6 years
7. Dogs with central divisional shunts had better outcomes (80% excellent outcome)

Question 6

Culp, Vet Surg, 2018:
Percutaneous transvenous coil embolization (PTCE) for IHPSS

1. Intra-op complication rate?
2. Short-term post-op complication rate?
3. Long-term post-op complication rate?
4. What % of dogs had a decrease in shunt fraction post-op?
5. What % of dogs had resolution of clinical signs at 3 months post-op?

Answer 6

Culp, Vet Surg, 2018:

1. Intra-op complication rate: 8%
2. Short-term post-op complication rate: 8%
3. Long-term post-op complication rate: 8%
4. 70% of dogs had a decrease in shunt fraction post-op, but none of the dogs had shunt fractions within the normal range
5. 92% of dogs had resolution of clinical signs at 3 months post-op

Question 7

Case, Vet Surg, 2018:
Cellophane banding vs percutaneous transvenous coil embolization (PTCE) for IHPSS

1. Any differences in resolution of clinical signs and improvements in hepatic biochemical markers post-op for cellophane banding vs PTCE?
2. Which technique had fewer post-op complications?

Answer 7

Case, Vet Surg, 2018:

1. No difference in resolution of clinical signs and improvements in hepatic biochemical markers post-op for cellophane banding vs PTCE
2. PTCE had fewer post-op complications

Question 8

Smith, Vet Surg, 2013:
Cellophane bands

1. Saline immersion reduced the strength of cellophane bands by how much?
2. Effects of various methods of sterilization on the strength of cellophane bands?

Answer 8

Smith, Vet Surg, 2013:

1. Saline immersion reduced the strength of cellophane bands by 48%
2. All sterilization methods except autoclaving significantly weakened wet cellophane

Question 9

Hunt, Vet Surg, 2014:
Ameroid ring constrictor (ARC) for EHPSS

What % of dogs had residual flow through the shunt?

Answer 9

Hunt, Vet Surg, 2014:

18% had residual flow through the shunt

Question 10

Nelson and Nelson, Vet Surg, 2016:
Cellophane banding for EHPSS:

1. Of the dogs that underwent complete attenuation, what were their shunt fractions post-op?
2. Cellophane banding resulted in improvement in biochemical and imaging parameters despite partial attenuation or cellophane band placement in a suboptimal location - true or false?

Answer 10

Nelson and Nelson, Vet Surg, 2016:

1. Of the dogs that underwent complete attenuation, their post-op shunt fractions were <10%
2. True

Question 11

Traverson, Vet Surg, 2018:
Ameroid ring constrictor (ARC) vs cellophane banding for EHPSS

1. What % of shunts were correctly localized by ultrasound?
2. What % of dogs had concurrent urinary calculi?
3. Post-op complication rate for ARC vs cellophane banding?
4. Most severe complication?
5. Post-op mortality rate for ARC vs cellophane banding?
6. Parameters of hepatic function returned to normal in what % of dogs following ARC vs cellophane banding?
7. Complete shunt occlusion was achieved at a median of 5 months post-op in what % of dogs following ARC vs cellophane banding?
8. What was a risk factor for post-op complications?

Answer 11

Traverson, Vet Surg, 2018:

1. Shunt location was consistent with ultrasonographic localization in 82% of the dogs
2. 41% had concurrent urinary calculi
3. Post-op complication rate: 26% for ARC vs 23% for cellophane banding
4. Coagulopathy was the most severe complication
5. Post-op mortality rate: 4% for ARC vs 0% for cellophane banding
6. Parameters of hepatic function returned to normal in 18% of ARC dogs vs 12% of cellophane banding dogs
7. Complete shunt occlusion was achieved at a median of 5 months post-op in 100% of ARC dogs vs 53% of cellophane banding dogs
8. Lower body weight was a risk factor for post-op complications - for every 1kg increase in body weight, the odds of developing post-op complications decreased by 30%

Question 12

Wallace, Vet Surg, 2018:
Self-retaining polyacrylic acid-silicone device for attenuation of an EHPSS

1. What % of shunts had complete attenuation by 4 weeks post-op and what % had complete attenuation by 8 weeks post-op?
2. Bile acids concentration normalized in what % of dogs?

Answer 12

Wallace, Vet Surg, 2018:

1. 33% had complete attenuation by 4 weeks post-op and 33% had complete attenuation by 8 weeks post-op; the remaining 34% had continued mild residual flow at 8 weeks post-op
2. Bile acids concentrations normalized in 83% of the dogs

Question 13

Strickland, Vet Surg, 2018:
Post-attenuation neurological signs (PANS)

1. What % of dogs developed PANS?
2. Risk factors for developing PANS?
3. What factor(s) were not associated with the development of PANS?
4. Effect(s) of prophylactic administration of levetiracetam?

Answer 13

Strickland, Vet Surg, 2018:

1. 11% developed PANS
2. Risk factors for PANS: pre-op hepatic encephalopathy (increased odds of PANS by 2.7-fold), increasing age (each year increase in age increased the odds of PANS 1.5-fold)
3. Pre-op ammonia levels and shunt location (extrahepatic vs intrahepatic) were not associated with development of PANS
4. Prophylactic administration of levetiracetam did not reduce the development of PANS or seizures

Question 14

Mullins, Vet Surg, 2019:
Post-attenuation neurological signs (PANS)

1. Overall incidence of PANS?
2. Effect of prophylactic treatment with levetiracetam on incidence of PANS?

Answer 14

Mullins, Vet Surg, 2019:

1. Overall incidence of PANS: 8%
2. Prophylactic treatment with levetiracetam was not associated with a reduced incidence of PANS

Question 15

Greenhalgh, JAVMA, 2014:

1. Overall mortality rate?
2. Did the surgical treatment group or the medical treatment group have a higher survival rate?
3. Did the surgical treatment group or the medical treatment group have fewer or less frequent clinical signs in the long-term follow-up period?

Answer 15

Greenhalgh, JAVMA, 2014:

1. Overall mortality rate: 36%
2. The surgical treatment group had a higher survival rate
3. The surgical treatment group had fewer or less frequent clinical signs in the long-term follow-up period