Abernethy
malformation

congenital anomaly of the splanchnic vasculature, arises from defects in vitelline vein formation; in type 1, portal vein completely
diverted into IVC and complete absence of formation of intrahepatic portal vein; in type 2, portal venous system is formed, but there
is an abnormal communication with systemic veins, usually IVC; associated with hepatic encephalopathy and hepatopulmonary
syndrome; more common in dogs, particularly Yorkshire terriers
Adamkiewicz, artery
of

artery responsible for anterior spinal syndrome; can be severed in AAA repair