ASA Main Site  |  Past & Future Meetings
American Surgical Association

Back to 2022 Abstracts


Impact of ischemia duration on lower limb salvage in combat casualties
Alexander Kersey3, Zane Perkins1, Alexis Lauria3, David Burmeister2, Paul White3, Brandon Propper3, Todd Rasmussen4, Joseph White3
1Queen Mary University of London, London, United Kingdom, 2Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States, 3Walter Reed National Military Medical Center, Bethesda, Maryland, United States, 4Mayo Clinic, Rochester, Minnesota, United States

Introduction: The traditional six-hour threshold at which irreversible cellular damage and ischemia transpires following extremity arterial injury, lacks substantive clinical data to corroborate this time interval. This study aims to characterize the relationship between the duration of limb ischemia and successful limb salvage for military personnel sustaining lower-extremity arterial trauma. We hypothesize that earlier limb revascularization will potentiate limb salvage, and that shock will have a negative impact on ischemic tolerance.
Methods: This was a retrospective cohort study of United States (US) and United Kingdom (UK) military service members who sustained limb-threatening lower extremity arterial trauma while serving in Iraq or Afghanistan between 2003 and 2013. The outcomes of consecutive patients who sustained lower extremity injury involving the external iliac, common femoral, superficial femoral or popliteal artery, and underwent surgery to attempt limb revascularization, were evaluated. Duration of ischemia, shock, and the reason for failed limb salvage was recorded. Continuous data was compared with the log-rank (Mantel-Cox) test, and results presented as Kaplan-Meier curves. Outcome comparisons are reported as Hazard Ratios (HR) with corresponding 95% Confidence Intervals (CI). An exponential curve with 95% CI was fitted to the Kaplan-Meier curve using the least squares regression method.
Results: One hundred twenty-two military personnel (average age 24, 18-52) sustained proximal arterial injuries in 129 lower limbs (7 bilateral injuries) at the iliac (n=3, 2.3%), femoral (n=73, 56.6%), and popliteal (n=53, 41.1%) level. Overall, 87 limbs (67.4%) were successfully salvaged and only one casualty (0.8%) died from injuries. The probability of limb salvage was 86.0% (49/57) when the duration of ischemia was ? 1 hour; 68.3% (28/41) when between 1 and 3 hours; 56.3% (9/16) when between 3 and 6 hours; and 6.7% (1/15) when ischemia duration was greater than 6 hours (p < 0.0001). The probability of limb salvage decreased by 10% for every 60-minute delay to revascularization during the first six hours following injury. The presence of shock more than doubled the risk of failed limb salvage (HR 2.42;95% CI: 1.27 to 4.62) at any time point, and the window for successful limb revascularization was shorter in shocked casualties compared to non-shocked (p = 0.024, log-rank (Mantel-Cox) test).
Conclusion: Lower extremity limb salvage following wartime injury is dependent on the duration of ischemia with a 10% reduction in the probability for every hour delay to revascularization. The presence of shock worsens this relationship. Military trauma systems should aim to enable rapid hemorrhage control and prioritize early limb revascularization within one hour of injury.


Back to 2022 Abstracts