The predictive value of multidetector CTA on outcomes in patients with below-the-knee vascular injury

Multidetector computed tomographic angiography (MDCTA) has become the gold standard for the early assessment of lower extremity vascular injury. The objective of this study was to evaluate the predictive value of MDCTA documented vessel run-off to the foot on limb salvage rates after lower extremity vascular injury.

All trauma patients undergoing lower extremity MDCTA for suspected vascular injury assessed at 2 high-volume Level I trauma centers between January 2009 and December 2012. Demographics, clinical data and outcomes (compartment syndrome requiring fasciotomy and limb salvage) were extracted. The predictive value of MDCTA vessel run-off was tested against an aggregate gold standard of operative intervention, clinical follow-up and all imaging obtained.

During the 4-year study period, 398 patients sustained lower extremity trauma and were screened for inclusion into this study. Of those, 166 (41.7%) patients (72.9% at MHH and 27.1% at LAC+USC Medical Center) underwent initial evaluation with MDCTA, 86 (51.8%) had vascular injury below the knee identified by MDCTA. Among these, the average age was 38.0±15.8 years, 80.2% were men and 83.7% sustained a blunt injury mechanism. On admission, 8.1% were hypotensive and the median ISS was 10 (range 1-57). There was a direct correlation between the number of patent vessels to the foot and the need for operative intervention (86.4% with no patent vessels, 56.0% with 1 patent vessel, 33.3% with 2 and 0.0% with 3, p<0.001). When outcomes were analysed, the rates of fasciotomy for compartment syndrome decreased in a stepwise fashion as the number of patent vessels to the foot increased (63.6% with no patent vessels; 44.0% with 1; 21.2% with 2; and 0.0% with 3; p=0.003). No amputations occurred in patients with 2 or more patent vessels to the foot (68.2% for no patent vessel; 16.0% for 1; 0.0% for 2; and 0.0% for 3; p<0.001).

In this multicenter evaluation of patients undergoing MDCTA for suspected below-the-knee vascular injury, there was a stepwise increase in the need for operative intervention, fasciotomy and amputation as the number of patent vessels to the foot decreased.