Association between time to revascularization and limb loss in military femoropopliteal arterial injuries.

OBJECTIVE

Expeditious revascularization is key to limb salvage after arterial injuries, but the relationship between time to revascularization and amputation risk is not well-defined. We aimed to explore amputation risk based on time to revascularization in a cohort of military femoropopliteal arterial injuries.

METHODS

A database of vascular injuries from Iraq and Afghanistan casualties (2004-2012) was queried for femoral (common, superficial, or deep) and/or popliteal arterial injuries that underwent revascularization. Time from injury to initial revascularization (via shunt or reconstruction) was divided into groups of <3 hours, 3 to 6 hours, 6 to 9 hours, and >9 hours, and bivariate comparisons were performed.

RESULTS

Revascularization times were available for 120 cases. Injury and treatment characteristics by time group were generally similar between time groups. Shunting and vein injuries were more common in limbs revascularized earlier, whereas blast mechanism and fasciotomy were more common with later revascularization. Ten cases (8%) underwent revascularization in less than 3 hours, 63 (53%) were revascularized in 3 to 6 hours, 33 (28%) in 6 to 9 hours, and 14 (12%) after 9 hours. Amputation rates within the cohorts were 10%, 21%, 24%, and 50%, respectively (P = .085, χ of amputation rates across time groups). The mean ± standard deviation revascularization time for amputated limbs was 442 ± 348 minutes vs 347 ± 183 minutes for salvaged limbs (P = .057). Amputation was performed in 19% of limbs revascularized in <6 hours and in 32% revascularized >6 hours from injury (P = .112). The >9-hour group, however, had a 50% amputation rate vs 21% for those with revascularization in <9 hours (P = .016). Fractures were more common in >9-hour limbs than <9-hour limbs (79% vs 44%; P = .016), but other limb injury characteristics were similar, with no difference in limb injury severity scores. Among 91 salvaged limbs, neither vascular nor other complications were predicted by time to revascularization. All seven >9-hour limbs had a limb complication, most commonly infection (71%), and three (42%) required a skin graft to close their fasciotomies.

CONCLUSIONS

Increasing time from injury to initial revascularization was associated with increasing rates of limb loss. Revascularization within 3 hours of injury resulted in a low amputation rate, whereas one-half of limbs treated after 9 hours were amputated. Arterial shunting was associated with earlier revascularization and should be considered a mainstay of combat casualty vascular care. Forward-deployed surgical assets play a pivotal role in providing early revascularization and reducing rates of limb loss in modern combat casualty care.