Surgical management of congenital extrahepatic portosystemic shunts in dogs and cats

A portosystemic shunt is an erroneous venous communication between the portal vein and the systemic circulation. Surgery is the treatment of choice. Progressive attenuation of the shunt is indicated in most cases to prevent portal hypertension. Gauged attenuation using silk was the first method used. Different methods are used to estimate the degree of closure that can be tolerated by the patient and will not cause portal hypertension, but they are time-consuming and not always equally reliable. If only partial closure is possible, a second surgery may be needed. Gradual attenuation can be achieved using an ameroid constrictor (AC), cellophane banding (CB), a hydraulic occluder or thrombogenic coils. There is great interpatient variability between the rate and degree of shunt closure when using an ameroid constrictor or cellophane banding. Thrombogenic coils and hydraulic occluders appear to give a more controlled shunt closure, but further investigation is needed.