The effectiveness of intraoperative mesenteric portography for preventing misdiagnosis of congenital absence of the portal vein in dog with extrahepatic portosystemic shunt: a case report

A 5-month-old mixed-breed dog and a 10-month-old Welsh corgi dog were presented for evaluation with signs of congenital portosystemic shunt. In both dogs, computed tomography angiography revealed a single extrahepatic portosystemic shunt with the absence of the portal vein cranial to the shunt origin. Intraoperative mesenteric portography (IOMP) was performed after temporary complete occlusion of the shunt, revealing the portal branches faintly opacified with contrast medium. A cellophane band was applied around the shunt vessel without intraoperative attenuation. Postoperatively, both the dogs showed significant clinical improvement and the portal veins, not observed on preoperative ultrasonography, were visualized on postoperative ultrasonography. This study suggests the efficacy of IOMP, enabling the appropriate surgical procedure to be determined.