Portal Vein/Aorta Ratio in Dogs with Acquired Portosystemic Collaterals

Area of Science:

• Veterinary Radiology
• Comparative Pathology
• Canine Medicine

Background:

• Portal hypertension (PH) in humans is associated with increased portal vein (PV) diameter.
• Unlike humans, evidence for PV enlargement in dogs with PH is lacking.
• This study investigates PV diameter in dogs with various forms of PH.

Purpose of the Study:

• To measure the portal vein-to-aorta (PV/Ao) ratio in dogs with PH (chronic hepatitis [CH], primary hypoplasia of the PV [PHPV]), extrahepatic congenital portosystemic shunt (EH-CPSS), and healthy controls.
• To evaluate the relationship between the PV/Ao ratio and splenic pulp pressure (SPP).

Main Methods:

• Retrospective analysis of computed tomography (CT) images from 25 dogs with acquired portosystemic collaterals (APSCs), 32 dogs with EH-CPSS, and 20 healthy dogs.
• PV/Ao ratio calculated from CT scans.
• Splenic pulp pressure (SPP) measured in 45 dogs during liver biopsy.

Main Results:

• Median PV/Ao ratio was similar in dogs with CH and healthy dogs.
• PV/Ao ratio was significantly lower in dogs with PHPV and EH-CPSS compared to CH and healthy dogs (P < .001).
• PV/Ao ratio positively correlated with SPP (r_s = 0.71; P < .001), but no intragroup correlation was found.

Conclusions:

• The PV/Ao ratio is a measurable parameter on CT in dogs with APSCs.
• Further research is needed to explore the SPP-PV/Ao relationship in larger canine PH populations.
• The clinical relevance of the PV/Ao ratio in canine PH requires further investigation.