A critical appraisal of impact of compounding factors in limb salvage decision making in combat extremity vascular trauma

Objective For more than half a century, surgeons who managed vascular injuries were guided by a 6-hour maximum ischaemic time dogma in their decision to proceed with vascular reconstruction or not. Contemporary large animal survival model experiments aimed at redefining the critical ischaemic time threshold concluded this to be less than 5 hours. Our clinical experience from recent combat vascular trauma contradicts this dogma with limb salvage following vascular reconstruction with an average ischaemic time of 6 hours. Methods During an 8-month period of the Sri Lankan Civil War, all patients with penetrating extremity vascular injuries were prospectively recorded by a single surgeon and retrospectively analysed. A total of 76 arterial injuries was analysed for demography, injury anatomy and physiology, treatment and outcomes. Subsequent statistical analysis was performed to evaluate the impact of independent variables to include; injury anatomy, concomitant venous, skeletal trauma, shock at presentation and time delay from injury to reconstruction. Results In this study, the 76 extremity arterial injuries had a median ischaemic time of 290 (IQR 225-375) min. Segmental arterial injury (p=0.02), skeletal trauma (p=0.05) and fasciotomy (p=0.03) were found to have a stronger correlation to subsequent amputation than ischaemic time. Conclusions Multiple factors affect limb viability following compromised distal circulation and our data show a trend towards various subsets of limbs that are more vulnerable due to inherent or acquired paucity of collateral circulation. Early identification and prioritisation of these limbs could achieve functional limb salvage if recognised. Further prospective research should look into the clinical, biochemical and morphological markers to facilitate selection and prioritisation of limb revascularisation.