An arterial cannula which includes a diverting side hole which simultaneously perfuses blood to the body and the lower extremity. Two barbs on the cannula exterior position the diverting hole just inside the blood vessel and prevent the back wall of the blood vessel from blocking the diverting hole. A transparent flash chamber on the proximal end of the cannula provides a visual indication of the entrance of the diverting side hole into the blood vessel. When the diverting hole enters the blood vessel, blood immediately fills the flash chamber.