Vascular ultrasound is a reliable non-invasive tool used for the routine assessment of vascular flow and patency in human recipients. We describe the use at three different time points (immediately, 1 week and 4 weeks postsurgery) of ultrasound studies and its validation by angiographic studies in 37 swine undergoing carotid graft replacement. We calculated predictive values (>92%), sensitivity (>85%) and specificity (>92%) with high results at all time points. Ultrasound appeared as an accessible non-invasive technique, providing rapid, safe, repeatable and reliable results. It is an excellent alternative to angiography, avoiding risks inherent to invasive methods and therefore contributing to animal welfare.