Funding: Companion Animal Funds, Michigan State University.
ANATOMY OF EXTRAHEPATIC PORTOSYSTEMIC SHUNTS IN DOGS AS DETERMINED BY COMPUTED TOMOGRAPHY ANGIOGRAPHY
Article first published online: 20 MAY 2011
© 2011 Veterinary Radiology & Ultrasound
Veterinary Radiology & Ultrasound
Volume 52, Issue 5, pages 498–506, September/October 2011
How to Cite
NELSON, N. C. and NELSON, L. L. (2011), ANATOMY OF EXTRAHEPATIC PORTOSYSTEMIC SHUNTS IN DOGS AS DETERMINED BY COMPUTED TOMOGRAPHY ANGIOGRAPHY. Veterinary Radiology & Ultrasound, 52: 498–506. doi: 10.1111/j.1740-8261.2011.01827.x
- Issue published online: 16 SEP 2011
- Article first published online: 20 MAY 2011
- Received January 3, 2011; accepted for publication April 19, 2011.
- computed tomography;
- portosystemic shunt
Congenital extrahepatic portosystemic shunts are anomalous vessels joining portal and systemic venous circulation. These shunts are often diagnosed sonographically, but computed tomography (CT) angiography produces high-resolution images that give a more comprehensive overview of the abnormal portal anatomy. CT angiography was performed on 25 dogs subsequently proven to have an extrahepatic portosystemic shunt. The anatomy of each shunt and portal tributary vessels was assessed. Three-dimensional images of each shunt type were created to aid understanding of shunt morphology. Maximal diameter of the extrahepatic portosystemic shunt and portal vein cranial and caudal to shunt origin was measured. Six general shunt types were identified: splenocaval, splenoazygos, splenophrenic, right gastric-caval, right gastric-caval with a caudal shunt loop, and right gastric-azygos with a caudal shunt loop. Slight variations of tributary vessels were seen within some shunt classes, but were likely clinically insignificant. Two shunt types had large anastomosing loops whose identification would be important if surgical correction were attempted. A portal vein could not be identified cranial to the shunt origin in two dogs. In conclusion, CT angiography provides an excellent overview of extrahepatic portosystemic shunt anatomy, including small tributary vessels and loops. With minor variations, most canine extrahepatic portosystemic shunts will likely be one of six general morphologies.