hepatobiliary pt 5: portosystemic shunt cont. & review Qs

Question 1

Portosystemic Shunt: less common clinical signs / findings - size? kidneys? eyes? testicles?

Answer 1

• Small for age and breed
• Can have prominent kidneys
• Copper coloured irises in cats
• Intact males can be cryptorchid

Question 2

Portosystemic Shunt: Diagnosis - CBC findings

Answer 2

• Microcytosis

Question 3

Portosystemic Shunt: Diagnosis - urinalysis findings

Answer 3

• Low USG
• Ammonium biurate crystals

Question 4

Portosystemic Shunt: Diagnosis - serum biochem findings

Answer 4

• Decreased albumin / total protein
• Decreased urea
• Decreased cholesterol
• Decreased glucose
• Mild elevation in ALP and/or ALT

Question 5

Portosystemic Shunt: Diagnosis - bile acids? ammonia?

Answer 5

• Elevated pre and post-prandial bile acids (often marked), majority
• Elevated NH3 (not widely available)

Question 6

Portosystemic Shunt: radiograph findings

Answer 6

• Small liver, enlarged kidneys
• Lack of portal perfusion, insulin, glucagon, and other trophic factors
• Urate calculi often radiolucent

Question 7

Portosystemic Shunt: abdominal ultrasound findings

Answer 7

• Identification of abnormal blood vessel
• Assessment for urate calculi
• Other ‘footprints’ can include small liver, renomegaly

Question 8

Portosystemic Shunt - when can we use CT angiography for Dx? what is its use?

Answer 8

• Helpful when ultrasound does not identify PSS despite clinical suspicion
• Outlines shunt anatomy which can increase surgical success

Question 9

Portosystemic Shunt: Treatment options overview

Answer 9

• Initial stabilization for dogs with hepatic encephalopathy
• Long-term treatment of PSS:
  > Surgical correction
  > Medical management

Question 10

Hepatic Encephalopathy: Treatment - 3 goals

Answer 10

• Alleviate neurologic signs
• Reduce incidence of predisposing factors
• Identify underlying hepatic condition for specific management

Question 11

hepatic encephalopathy diet therapy considerations, esp protein and fiber

Answer 11

• Most dogs can have normal protein levels
• Feeding smaller, more frequent meals helps decrease protein load at once,
  maintains appropriate calorie/protein nutrition
• Mild and temporary protein restriction might be required – only in severe cases
• Avoid protein malnutrition
  > Body protein breakdown will cause elevation in NH3
  > Monitor BCS and MCS carefully
• Fibre in diet helps trap ammonia, other toxins in feces for evacuation, decreases contact time of feces & bacteria
  > Decrease ammonia / other toxin production and absorption

Question 12

HE: Medical Therapy options

Answer 12

• Lactulose
• Antibiotic therapy
• Reduce triggers of HE
  > Inflammation, infection

Question 13

what is lactulose and what is its use in treating HE?

Answer 13

• Soluble fibre
• Acidifies colonic contents and traps ammonium ion in colon
• Promotes ammonia incorporation into bacteria
• Hastens colonic transit time (reduced time/ability for toxin absorption)
  ()
• 2.5 to 5ml (cat); 2.5 to 15 ml (dog) every 8 hours
• Titrate dose to produce 2-3 soft stools per day

Question 14

antibiotic therapy for HE? purpose?

Answer 14

• Amoxicillin, or metronidazole
• Decrease bacterial populations
• Decreases amount of toxin production in the intestinal tract

Question 15

preferred treatment option for HE due to shunt?

Answer 15

• Surgical attenuation of the shunt is the preferred treatment option (referral surgery)
• Medical management
  > Treatment for hepatic encephalopathy

Question 16

Portosystemic Shunt: post surgical treatment medical therapy should be continued for how long

Answer 16

Post-operatively continue medical therapy for HE as liver function restored
* Generally discontinued by 8-12 weeks

Question 17

Portosystemic Shunt: Surgical Outcomes: prognosis? what long term observations may we see?

Answer 17

• Good prognosis for normal life with attenuation of a single shunt
  > Most dogs able to discontinue medical therapy 8-12 weeks post-op
• Long-term, serum bile acids may remain abnormal
  > Some degree of vessel changes (portal vein hypoplasia) in liver

Question 18

Portosystemic Shunt: Surgical Outcomes - rate of surgical complications?

Answer 18

• Low rate of surgical complications

Question 19

Portosystemic Shunt: Surgical Outcomes - what neuro problem do we sometimes see and how serious is it? how can we prevent?

Answer 19

• Post-operative seizures – can be very severe
• Pre-operative levetiracetam might reduce frequency and severity but evidence conflicting

Question 20

what might preclude ligation for portosystemic shunt surgery?

Answer 20

Portal hypertension during shunt surgery might preclude ligation
* Uncommon

Question 21

why can clinical signs sometimes persist after surgical treatment for portosystemic shunt?

Answer 21

• Some PSS ligations are only partial and a degree of clinical signs can persist

Question 22

if a dog does not undergo surgery to correct portosystemic shunt, what other option should be continued?

Answer 22

• Continue treatment for HE if surgery not pursued

Question 23

what dogs are good candidates for medical treatment of portosystemic shunt?

Answer 23

• Mildly affected dogs & older dogs are the best candidates for good
  outcomes
  > Small shunt fraction

Question 24

PSS: Medical vs Surgical Treatment? which is better? are the others doomed?

Answer 24

• Overall, dogs undergoing surgery have better outcome
  > Longer survival times
  > Reduced long-term clinical signs
• Dogs responding to medical management can do very well
  > Mean survival times >2 years
  > 1/5 of dogs survived >6 years in one study
  > Recurrence of signs, uroliths

Question 25

* Which of the following liver enzymes are considered due to hepatocellular leakage, and which are due to induction / cholestasis? a) ALT b) GGT c) ALP d) AST

Answer 25

Hepatocellular injury: ALT, AST - Alanine transferase (ALT) - Aspartate aminotransferase (AST) Induced / Cholestasis: ALP, GGT - Alkaline phosphatase (ALP) - Gamma-glutamyl transferase (GGT) - Also note: Bilirubin (stasis - not induced)

Question 26

Which of the following is NOT a marker of decreased hepatic synthetic function (when decreased)? a) Albumin b) Creatinine c) Urea d) Cholesterol

Answer 26

b) Creatinine Markers of decreased synthetic function: * Decreased albumin * Decreased cholesterol * Decreased urea * Decreased glucose

Question 27

Identify the true statement: a) Patients with lymphocytic cholangitis often present acutely ill and febrile b) Ascites and elevated globulins is a common feature of neutrophilic cholangitis c) E. coli is most common bacteria cultured from bile of cats with neutrophilic cholangitis d) Hyperbilirubinemia is uncommon in cats with neutrophilic cholangitis

Answer 27

c) E. coli is most common bacteria cultured from bile of cats with neutrophilic cholangitis

Question 28

* In what situations is an elevated ALT/ALP in an otherwise healthy patient concerning? (list 3)

Answer 28

* Any elevation in a cat (short half-lives of enzymes) * Both ALT and ALP elevation * >2x upper limit in a dog * Persistence

Question 29

Which of the following medications decreases bile stasis and decreases toxicity of bile acids? a) S-adenosylmethionine b) D-penicillamine c) Ursodiol d) Prednisone

Answer 29

c) Ursodiol

Question 30

A 6 month old male Yorkshire Terrier presents with a 2-day history of dull mentation, and episodes of apparent blindness today. Your initial diagnostics identify mild decrease in urea, mild elevation in ALT, and marked elevation in pre-and post-prandial bile acids. Which of the following is the most likely differential diagnosis? a) Copper associated chronic hepatopathy b) Neutrophilic cholangitis c) Extrahepatic portosystemic shunt d) Acquired portosystemic shunt

Answer 30

c) Extrahepatic portosystemic shunt

Question 31

A 6 month old male Yorkshire Terrier presents with a 2-day history of dull mentation, and episodes of apparent blindness today. Your initial diagnostics identify mild decrease in urea, mild elevation in ALT, and marked elevation in pre-and post-prandial bile acids. Which of the following is the most likely differential diagnosis? Which of the following medications would be most effective in decreasing the signs of hepatic encephalopathy in the Yorkie puppy from the previous slide? a) Lactulose b) Ursodiol c) Vitamin E d) Omeprazole

Answer 31

a) Lactulose

Question 32

TRUE OR FALSE: Protein restriction should be considered in all dogs and cats with a suspected portosystemic shunt.

Answer 32

false * Most dogs can have normal protein levels * Feeding smaller, more frequent meals helps decrease protein load at once, maintains appropriate calorie/protein nutrition * Mild and temporary protein restriction might be required – only in severe cases