The ischemic threshold of the extremity

Military efforts to limit ischemic time and reperfusion injury are being investigated with a focus on functional limb salvage as opposed to the more historic statistical salvage, since a dysfunctional limb may be a worse outcome than amputation. Translatable animal research, supported by reports from forward deployed surgeons in the field, is needed to improve care. Current studies have determined the threshold for meaningful recovery is less than 6 hours. Attempts at modeling vascular injury and ischemia reperfusion can be divided into 2 categories: chronic ischemia that mimics human age related disease and acute vascular injury that represents traumatic injury. A swine model to evaluate battlefield injuries and scenarios encountered in traumatic extremity vascular injury with a focus on functional limb salvage has been developed. Future endeavors should focus on understanding the factors that affect ischemic threshold as well as testing therapeutic and physical maneuvers to prolong this threshold.