Below-the-ankle Angioplasty and Stenting for Limb Salvage: Anatomical Considerations and Long-term Outcomes

Abstract

To report the long-term angiographic and clinical results in a series of below-the-ankle (BTA) angioplasty procedures and to present some biomechanical issues related to the unique anatomical geometry of the ankle. We performed a retrospective analysis of BTA angioplasty procedures. Clinical end points included technical success, patient mortality, salvage of the treated foot, and repeat target lesion revascularization. Imaging end points included primary patency, binary restenosis of the target lesion at the 50% threshold, and stent integrity (stent fracture, deformation, or collapse). Univariate subgroup analysis was performed. In total, 40 limbs in 37 patients (age 73.5 ± 8.2 years) with critical limb ischemia were included and 42 inframalleolar lesions (4.2 ± 1.4 cm) were analyzed. Technical success was achieved in 95.2% (40 of 42). Provisional stent placement was performed in 45.2% (19 of 42). Two patients died, and two major amputations occurred up to 3 years. At 1 year, overall primary vessel patency was 50.4 ± 9.1%, lesion binary restenosis rate was 64.1 ± 8.3%, and repeat intervention-free survival was 93.6 ± 4.3% according to life table analysis of all treated lesions. Pairwise subgroup analysis showed that BTA self-expanding stents were associated with significantly higher restenosis and poorer primary patency compared to plain balloon angioplasty or sirolimus-eluting balloon-expandable stents. Significant deformation and/or fracture of balloon-expandable stents placed BTA were identified in five of 11. Dynamic imaging showed that the dorsalis pedis artery is kinked during foot dorsiflexion, whereas the distal posterior tibial artery is kinked during plantar flexion of the foot. BTA angioplasty for critical limb ischemia treatment is safe and feasible with satisfactory long-term results. BTA stent placement must be reserved for bailout indications.