Use of computed tomography angiography has potential in planning surgical treatment of an extrahepatic portosystemic shunt in dogs.

Abstract

Objective: To evaluate the impact of intrahepatic portal vein branching (IHPB)-grade assessment using preoperative CT angiography (CTA) on the surgical procedure and prognosis prediction for dogs with an extrahepatic portosystemic shunt (EHPSS).

Methods: This study involved 146 client-owned dogs with EHPSS. The shunt morphology of EHPSS and IHPB grades was determined using CTA. All dogs underwent surgical attenuation of the shunt with intraoperative portal vein pressure (PVP) measurement, followed by a liver biopsy of the left lateral lobe. The preoperative CTA findings were analyzed according to surgical procedures, intraoperative PVP, hepatic histopathology, and postoperative complications.

Results: The grade of IHPB did not correlate with baseline PVP while it significantly correlated with PVP during temporary occlusion and the difference in PVP between before and during the temporary occlusion. The grade of IHPB and PVP had significant differences between the dogs with partial ligation compared with those with complete ligation. The portal vein hypoplasia score on histopathology was generally higher in the dogs with low-grade IHPB than in those with high-grade IHPB. The IHPB grade had no significant influence on postoperative complications and prognosis.

Conclusions: This study demonstrated that although the grade assessment system of IHPB using preoperative CTA was unable to predict the prognosis of dogs with a single EHPSS, it may be useful for determining surgical procedure selection.

Clinical relevance: Preoperative CTA is suggested to not only be useful for the diagnosis and classification of EHPSS but also for surgical planning of EHPSS in dogs.