The Aortic Bifurcation Angle as a Factor in Application of the Outback for Femoropopliteal Lesions in Ipsilateral Versus Contralateral Approaches. 
To assess the technical success of the Outback reentry device in contralateral versus ipsilateral approaches for femoropopliteal arterial occlusion.  A retrospective review of patients treated for critical limb ischemia (CLI) using the Outback between January 2013 and July 2016 was performed.  Age, gender, length and site of the occlusion, approach site, aortic bifurcation angle, and reentry site were recorded.  Calcification score was assigned at both aortic bifurcation and reentry site.  Technical success was assessed.  During the study period, a total of 1300 endovascular procedures were performed on 489 patients for CLI.  The Outback was applied on 50 femoropopliteal chronic total occlusions.  Thirty-nine contralateral and 11 ipsilateral antegrade femoral were accessed.  The device was used successfully in 41 patients (82%).  There were nine failures, all in the contralateral approach group.  Six due to inability to deliver the device due to acute aortic bifurcation angle and three due to failure to achieve luminal reentry.  Procedural success was significantly affected by the aortic bifurcation angle (p = 0.013).  The Outback has high technical success rates in treatment of femoropopliteal occlusion, when applied from either an ipsi- or contralateral approach.  When applied in contralateral access, acute aortic bifurcation angle predicts procedural failure.