• Journal of Veterinary Science
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• v.25 no.3
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• pp.37.1-37.10
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• 2024

Importance: The portal vein to aorta (PV/Ao) ratio is used to assess the clinical significance of extrahepatic portosystemic shunt (EHPSS). Previous studies using computed tomography (CT) were conducted in dogs but not in cats. Objective: This study aimed to establish normal reference values for PV indices (PV/Ao ratio and PV diameter) in cats and determine the usefulness of these for predicting symptomatic EHPSS. Methods: This study included 95 dogs and 114 cats that underwent abdominal CT. The canine normal (CN) group included dogs without EHPSS. The cats were classified into feline normal (FN, 88/114), feline asymptomatic (FA, 16/114), and feline symptomatic (FS, 10/114) groups. The PV and Ao diameters were measured in axial cross-sections. Results: The group FN had a higher PV/Ao ratio than the group CN (p < 0.001). Within the feline groups, the PV indices were in the order FN > FA > FS (both p < 0.001). The mean PV diameter and PV/Ao ratio for group FN were 5.23±0.77 mm and 1.46±0.19, respectively. The cutoff values between groups FN and FS were 4.115 mm for PV diameter (sensitivity, 100%; specificity, 97.7%) and 1.170 for PV/Ao ratio (90%, 92.1%). The cutoff values between group FA and FS were 3.835 mm (90%, 93.8%) and 1.010 (70%, 100%), respectively. Conclusions and Relevance: The results demonstrated significant differences in PV indices between dogs and cats. In cats, the PV/Ao ratio demonstrated high diagnostic performance for symptomatic EHPSS. The PV diameter also performed well, in contrast to dogs.

• Journal of Veterinary Clinics
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• v.30 no.4
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• pp.273-277
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• 2013

This study was performed to compare clinical and diagnostic imaging features between asymptomatic and symptomatic extrahepatic portosystemic shunts in dogs. The data of thirty patients diagnosed with extrahepatic PSS by multi-detector CT were reviewed, and the dogs were divided into asymptomatic (9/30) and symptomatic (21/30) groups. Signalments, hematologic results, liver size, morphologic classifications and main portal vein to abdominal aortic ratio (PV/AO) at the porta hepatis level from CT images were evaluated in two groups. Shih-tzu (5/9) was the most frequent breed in asymptomatic group, and various breeds were presented in symptomatic group. Mean age of asymptomatic group ($9.2{\pm}3.2$ years) was significantly higher than that of symptomatic group ($4.5{\pm}3.2$ years). The most morphologic form of shunt vessel was the splenophrenic shunt (16/30). PV/AO of asymptomatic group ($1.1{\pm}0.19$) was significantly higher than the values of symptomatic group ($0.55{\pm}0.19$). Clinical signs, hematologic results and diagnostic imaging findings of asymptomatic PSS are too nonspecific to suspect PSS. Therefore, considering of patient's age and CT examination with application of PV/AO ratio could be useful for the diagnosis of asymptomatic PSS.