With the increasing use of preoperative imaging of the abdominal vasculature prior to free flaps based on the abdominal wall, the identification of a previously undescribed anatomic structure has, that of large-vessel (macroscopic) arteriovenous communications, has emerged. These macrovascular arteriovenous shunts are observed in most patients, and provide a communication between the arterial perforators of the deep inferior epigastric artery and the superficial inferior epigastric vein. These communications provide vascular shunting occurring prior to capillary filling and have potentially profound clinical implications and therapeutic possibilities in a range of medical and surgical conditions. Although these have been demonstrated previously on computed tomographic angiography imaging, their macroscopic and microscopic anatomy has not been described. We present images in vivo, ex vivo, and histologically to highlight their anatomic features.