To view and record the blood flow immediately during a surgical bypass procedure (repairing diseased arteries in the neck, kidneys or lower legs with healthy veins from the leg) the doctor may order an ultrasound. Ultrasound is a procedure that uses sound waves to see inside the body. An interoperative duplex ultrasound shows the surgeon the path and volume of blood flow before the surgery is completed. This exam is performed along with the surgical procedure.

The vascular surgeon performs the ultrasound procedure following surgery but before the skin is closed. The transducer (small, microphone-like device) is placed in a sterile sleeve. The surgeon holds the transducer next to the blood vessel being evaluated. Sound waves bounce off the blood moving in the arteries and the tissue in the body. This creates echoes that are reflected back to the transducer. A television monitor shows images as the transducer converts the echoes to electronic signals. These images will be viewed immediately and photographed for further study.