J Trauma Acute Care Surg. 2019 Jul;87(1S Suppl 1):S172-S177

# Predictors and timing of amputations in military lower extremity trauma with arterial injury.

Kauvar D, Thomas S, Schechtman D, Walters T

INTRODUCTION: Military lower extremity arterial injuries present threats to life and limb. These injuries are common and limb salvage is a trauma system priority. Understanding the timing and predictors of amputation through the phases of casualty evacuation can help inform future limb salvage efforts. This study characterizes limbs undergoing amputation at different operationally relevant time points.

METHODS: A retrospective cohort study of casualties with lower extremity arterial injuries undergoing initial vascular limb salvage in Iraq and Afghanistan was undertaken. Amputations were grouped as having been performed early (in theater at Role 2 or 3) or late (after evacuation to Role 4 or 5). Further distinction was made between late and delayed (after discharge from initial hospitalization) amputations.

RESULTS: 455 casualties met inclusion criteria with 103 (23%) amputations. 21 (20%) were performed in theater and 82 (80%) were performed following overseas evacuation. 21 (26% of late amputations) were delayed, a median of 359 days from injury (IQR 176-582). Most amputations were performed in the first 4 days following injury. Amputation incidence was highest in popliteal injuries (28%). Overall amputation was predicted by higher incidence of blast mechanism and fracture and greater limb and casualty injury severity. Early amputations had higher limb injury severity than late amputations. Delayed amputations had greater incidence of motor and sensory loss and contracture than early amputations.

CONCLUSION: Casualty and limb injury severity predict predictors and timing of amputation in military lower extremity arterial injury. Amputation following overseas evacuation was more common than in-theater amputation and functional loss is associated with delayed amputation. Future limb salvage efforts should focus on post-evacuation and rehabilitative care.

EVIDENCE LEVEL: Level III, epidemiologic.