Global Sonographic Parameters
In Portosystemic Shunts
In 38 Dogs & Cats
E Lindquist, D Casey, J Frank
Eric Lindquist DMV , DABVP (Canine & Feline Practice)
Director: Sound-Eklin New Jersey Mobile Associates
Founder: SonoPath.com
To Shunt Or Not To
Shunt?
That Is The Question.
To Shunt
Not To Shunt
PV/CVC ≥0.75 and PV/AO ≥ 0.8.
D‘Anjou et. al. Vet rad and US Vol 45, No 5 2004 102
pqtients
Study Premise:
 Attempt to stabilize a
reliable global and
precise sonographic
criteria to diagnose or
rule out the presence
of portosystemic
shunting
Study Design: Retrospective
5 Sonographers, Trained By 1 Single Evaluator Experienced in
Dx Of PSS
 33 Dogs & Cats with
EHPSS
 5 Dogs With Intrahepatic




Shunts
Age Range: 2 mo- 12 yr
19/38 Sx Confirmed
Bile Acids: 93-473 umol/L
US Evaluation of Bladder,
Kidneys, Liver Size,
PV:CVC and PV:AO Ratios
Parameter 1: The Bladder
Normal:
No Calculi Or Sediment
Calculi Or Sediment 24/33
(73%) EHPSS Cases. 2/5
IHPSS(40%). 68% overall.
Parameter 2: The Kidneys
Normal:
No Renal Calculi
Renal Calculi 32/33 (97%) Of
EHPSS Cases. 3/5 for
IHPSS(60%). 92% overall
Parameter 3: Renomegaly
EHPSS 29/33.
88%
IHPSS 2/5.
40%
82 % Overall
Parameter 3: Liver Size
Normal:
Subjectively Normal Liver Size
Microhepatica 33/33 EHPSS.
5/5 IHPSS. 100% Of Cases
Overall
Parameters 4 & 5:
Normal Portal Hilus; PV:CVC, PV:AO Ratios
Normals: PV/CVC ≥0.75 and PV/AO ≥ 0.8.
D‘Anjou et. al. Vet Rad US Vol. 45, No 5, 2004. 102 Patients
Intrahepatic Shunt Parameters
 Bladder Sand/Stones:
2/5
 Renal Calculi: 3/5
 Renomegaly: 2/5
 Microhepatica: 5/5
 PV:CVC Ratio: 1:1
 PV:AO Ratio: 1:1
 CVC:AO Ratio: 1:1
Types Of Extrahepatic Shunts:
9 Gastrocaval (Looping), 18 Splenocaval (Short),
6 Splenoazygos (Long minimally curved)
Caval Shunts:
Increased Vena Cava Volume
Gastrocaval
Splenocaval
Scanning Target: Excessive Vena Caval
Volume For Gastrocaval & Splenocaval
Shunts
Caval EHPSS: 9 Gastrocaval & 18 Splenocaval Shunt
Ratios
(Normals PV/CVC ≥0.75 and PV/AO ≥ 0.8.)
Gastrocaval: PV/CVC: 0.4-0.67
PV/AO: 0.4-0.71
Splenocaval: PV/CVC: 0.280.75
PV/AO: 0.4-0.78
Azygos EHPSS Shunt Parameters
Azygos Shunt Bypasses The
Cava
Normal CVC:AO Ratio
6 Azygos Shunts:
Normal Vena Cava Volume:
Ratios: PV/CVC:0.4-0.63
PV/AO: 0.4-0.68
PV Pre/Post Shunt Differential
Double Aorta
PV/CVC Ratio 38 cases
1.2
1
0.8
0.6
0.4
0.2
0
1
2
3
4
5
6
7
8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38
PV/AO Ratio 38 Cases
1.2
1
0.8
0.6
0.4
0.2
0
1
2
3
4
5
6
7
8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38
Study Flaws
 Published Controls
 Non blinded
 Urolithiasis is a non
specific finding
 Microhepatica &
renomegaly are
subjective parameters
 Caval probe pressure
creates a variable
 Small number of cases
(38)
Conclusions
In this population of 38 dogs and
cats, the presence of :
 Urinary bladder sand/calculi,
 Renal mineralization
 Renomegaly
 Microhepatica
were reliable, non exclusive,
positive predictive factors for
the presence of PSS , but do
not distinguish IHPSS from
EHPSS.
 Subnormal PV/CVC and
PV/AO ratios (0.7 8 or less)
are highly reliable indicators
of the presence of EHPSS.
Questions?
Any
Questions?
Eric.Lindquist@
SonoPath.com