EPIDEMIOLOGY OF VASCULAR INJURY

The rate of vascular injury in modern combat is five times that reported in previous wars. One in five (20%) battle injuries (non-return to duty) are classified as hemorrhage control not otherwise specified, suggesting the presence of significant bleeding.1 Using codes for specific blood vessel injuries or repairs, the rate of vascular injury is 12% in Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF), which is higher than the 1-3% reported in WWII, Korea, and Vietnam.1 Contemporary data utilizing the Department of Defense Trauma Registry reported 17.5% of combat related injuries had a vascular component.2 Extremity vessels account for 70-80% of vascular injuries while 10-15% are in the cervical region and 5-10% in the torso.1-4 Potential reasons for this increase in vascular injuries are the number of extremity amputees that have vascular trauma and also likely secondary to the widespread training and use of tourniquets on the modern battlefield, allowing casualties that would have died from extremity hemorrhage in the field to now reach medical care.5 The “golden hour” policy and the rapid medical evacuation (MEDEVAC) capability, particularly by rotary wing, that characterized OIF and OEF is also a contributing factor to patients with severe vascular injury surviving to surgical care.5

Outcome research on wartime vascular injuries show that over half of vascular injuries sustained in combat can now have an attempt at repair.1-2 This is a major shift in practice that has now been documented in more recent studies (since the last CPG update). This data confirms a complete transition away from the WWII doctrine which included a mandate against vascular injury repair and carried the recommendation to ligate all blood vessel injuries. The opportunity for military surgeons to address and repair 60% of vascular injuries in combat is a result of improved prehospital care, rapid MEDEVAC, forward positioning surgical capabilities and the use of temporary vascular shunts.2

Combat casualty data has demonstrated that the ischemic threshold for the injured extremity is half of the previously touted 6 hours.6 Preclinical data from military labs shed light on this change in dogma, and more recently published clinical studies performed in conjunction with the United Kingdom and the Joint Trauma System (JTS) have confirmed that in order to achieve functional or quality limb salvage, arterial flow must be restored in the injured limb within 3 hours, and in 1 hour or less in patients who are in hemorrhagic shock.7 To this point, the effectiveness of temporary vascular shunts in meeting the rapid restoration of perfusion goal has been confirmed in the civilian setting.9-12 These findings have substantial implications for the military in terms of training, equipping, and positioning of its surgical assets.

In order to achieve functional or quality limb salvage, arterial flow must be restored in the injured limb within 3 hours, and in 1 hour or less in patients who are in hemorrhagic shock.