Multi-detector row computed tomography angiography: an alternative imaging method for surgical strategy in lower extremity arterial occlusive disease.

Abstract : In order to show the value of CT angiography in the pretherapeutic assessment of lower leg ischemia, we studied 93 CT angiographies in 85 patients. Two groups were defined according to the level of revascularization: 52 angioscanner were made prior to suprainguinal revascularization and 41 prior to infrainguinal reconstruction. Two decision attitudes were chosen by two different physicians, a radiologist and vascular surgeon, members of the same team. The attitudes where then compared in order to evaluate the value of CT angiography. The first attitude was a pragmatic strategy based on the images as interpreted by the first physician and on the intraoperative information including surgical treatment and, if necessary, angiography. This indicates that the results of this attitude cover the performed revascularizations. The second attitude determined a virtual strategy and was chosen by the second physician a posteriori, based solely on the medical file with the same CT angiography images. These two strategies were compared in order to assess the agreement on the level of the lesion and the choice of revascularization. In 84 CT angiographies (90.3%), the analysis of the lesions and the choice of lesions to be treated were identical. In 9.6% of scans the strategies were not comparable because the lesions were interpreted differently or the scans were difficult to read. The sensitivity of CT angiography in detecting lesions and guiding the therapeutic strategy was 96% and its positive predictive value was 93%. Follow-up was reported according to the life-table method to assess the overall outcome and the results in both groups. The overall survival rate at 12 months for 85 patients was 90%. Secondary patency rates at 12 months in the group of patients who underwent a suprainguinal and infrainguinal revascularization were 98% and 71% respectively. Overall limb salvage at 12 months was 94%. In this setting, CT angiography allowed us to select adequate treatment in the majority of cases. These results obtained after a strategy based on CT angiography images are comparable with the results as published in the literature after the strategy based on conventional angiography.