Free tissue transfer for lower extremity reconstruction: A study of the role of computed angiography in the planning of free tissue transfer in the posttraumatic setting

BACKGROUND: Computed tomographic angiography can be used as a means of assessing lower leg vasculature before performing free tissue transfer, but its reliability within a trauma setting has not been evaluated. The aim of this study was to examine the findings of preoperative computed tomographic angiography and correlate these findings to flap survival and limb salvage. METHODS: Seventy-six consecutive lower extremity trauma patients underwent preoperative computed tomographic angiography before free flap reconstruction. Arterial inflow, venous outflow, and the incidence of traumatic occlusion were recorded. Flap survival rates, limb salvage, and postoperative complications were noted. RESULTS: There were no complications associated with the computed tomographic angiography procedure. Computed tomographic angiography demonstrated normal vascular anatomy in 40 patients (52.6 percent), anatomical variants in seven patients, and atherosclerotic occlusive disease in six patients. Traumatic arterial occlusion was identified in 22 patients (28.9 percent). Flap failure was seen in five patients and the limb salvage rate was 94.7 percent. All four of the limbs amputated had at least a single artery occluded on preoperative computed tomographic angiography; preoperative arterial occlusion was found to be a significant predictor of limb loss (p < 0.05). CONCLUSIONS: The incidence of single-vessel traumatic arterial occlusion within traumatized lower limbs undergoing free tissue transfer may be as high as 29 percent. Computed tomographic angiography provided excellent visualization of lower extremity vasculature, and its routine use for trauma patients is safe. Flap failure rates were low when using this technique for preoperative planning. Flap failure occurred only in patients with evidence of arterial injury. Evidence of arterial occlusion on computed tomographic angiography may be a risk factor for limb loss.