Treatment of caudal cavoatrial junction obstruction in a dog with a balloon-expandable biliary stent.

A 2-year-old intact female mixed breed dog was presented for ascites. Echocardiography demonstrated severe obstruction at the level of the caudal right atrium. Initially, a variant of cor triatriatum dexter was diagnosed, and balloon catheter dilation was performed. However, ascites recurred within a week. Further imaging revealed an obstruction at the entrance of the caudal vena cava into the right atrium rather than a dividing membrane in the right atrium. The diagnosis was revised to suprahepatic obstruction of the caudal vena cava because of remnant Eustachian valve tissue. Deployment of a balloon-expandable biliary stent was performed relieving the obstruction. Fifteen months after stent deployment, the patient is doing well without reaccumulation of ascitic fluid.