CLINICAL INVESTIGATION The Aortic Bifurcation Angle as a Factor in Application of the Outback for Femoropopliteal Lesions in Ipsilateral Versus Contralateral Approaches Daniel Raskin 1 • Boris Khaitovich 1 • Shmuel Balan 1 • Daniel Silverberg 2 • Moshe Halak 2 • Uri Rimon 1 Received: 4 June 2017 / Accepted: 25 July 2017 Ó Springer Science+Business Media, LLC and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) 2017 Abstract Purpose To assess the technical success of the Outback reentry device in contralateral versus ipsilateral approaches for femoropopliteal arterial occlusion. Materials and Methods 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. Results During the study period, a total of 1300 endovas- cular 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. Pro- cedural success was significantly affected by the aortic bifurcation angle (p = 0.013). Conclusion 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. Keywords Outback Á Recanalization Á Chronic total occlusion Á Angulation Á Catheter Á Reentry Catheter Á Crossing techniques Á Antegrade approach Á Retrograde approach Á True lumen Introduction Subintimal angioplasty of chronic total occlusions (CTOs) of the femoropopliteal segment is an accepted method to achieve recanalization in cases of failure of the endolu- minal approach. This method was first described by Bolia et al. [1]. It involves entering the subintimal space with a catheter proximal to or at the level of the occlusion, passing the wire and catheter into the subintimal plane, and by creating a wire loop, causing a dissection. Once the wire passes the occluded segment, true lumen is to be regained. Gaining access to the true lumen from the subintimal space at the distal end of the occlusion is challenging and not always successful with failure rates of up to 20% [2, 3]. This procedure holds risks for distal extension of the dis- section or compromise of important collaterals when the reentry point is distal to the vessel reconstitution point [3, 4]. Thus, precise reentry, whether intentional or unin- tentional, is a major factor in completing the procedure. To assist in this technical issue, fluoroscopy-guided reentering devices were created. One of these devices is the Outback LTD (Cordis, Miami lakes, Florida, USA). This device comprises a long hollow retractable curved nitinol needle Daniel Raskin and Boris Khaitovich have contributed equally to this work. & Daniel Raskin Daniel.Raskin@sheba.health.gov.il 1 Department of Diagnostic Imaging, Sheba Medical Center, Tel-Hashomer, Affiliated to ‘‘Sackler’’ School of Medicine, Tel-Aviv University, 52621 Tel-Aviv, Israel 2 Department of Vascular Surgery, Sheba Medical Center, Tel- Hashomer, Affiliated to ‘‘Sackler’’ School of Medicine, Tel- Aviv University, 52621 Tel-Aviv, Israel 123 Cardiovasc Intervent Radiol DOI 10.1007/s00270-017-1761-7