Incidence, Anatomical Location, and Clinical Significance of Compressions and Fractures in Infrapopliteal Balloon-Expandable Metal Stents

Purpose: To investigate the incidence, anatomical location, and clinical impact of fractures and/or compression of infrapopliteal balloon-expandable metal stents implanted for critical limb ischemia (CLI) treatment. Methods: This prospective study included 63 CLI patients (45 men; mean age 71.3±9.5 years) who had been treated with infrapopliteal angioplasty and stent placement for 191 lesions in 84 limbs. In all, 369 stents (296 stainless steel and 73 cobalt-chromium alloy) were implanted; 239 were placed overlapping in tandem lesions. Mean length of the overall stented segment was 4.4±6.3 cm (range 1.6–14.0). Stents were located in the tibioperoneal (n=34), anterior tibial (n=195), posterior tibial (n=63), and peroneal (n=77) arteries. Follow-up consisted of digital subtraction angiography and infrapopliteal radiography imaging at 2 different angles. Evaluation of stents for the presence of fracture and/or compression was done after digital processing at the highest possible magnification. Stent fractures were defined according to published standards, whereas compression was classified as severe shape alteration and/or collapse of the stent mesh. Angiographic restenosis was based on a 50% threshold. Results: Mean follow-up was 15±11 months (range 6–60). Image analysis detected 1 (0.3%) severe stent fracture (complete separation and misalignment of stent struts) and 11 (3.0%) stent compressions. Infrapopliteal stent fracture and compressions were associated with increased artery restenosis [100% (12/12) versus 47.3% (169/357), p