Abstract 3225: Frequency and Impact of Stent Fractures after Stent Implantation of Superficial Femoral Artery
Background: It has recently been reported that stent fractures of nitinol stent were associated with poor outcomes after femoropopliteal stenting. But a little is known about the frequency and the clinical impact of stent fractures after stent implantation of superficial femoral artery .
Objectives: In this study, we investigated its period of occurrence and the impact of stent fractures after femoropopliteal stenting.
Method: From Jan. 2004 to Des. 2005, we prospectively enrolled 40 patients (32 male gender, aged 71 ±8 years) who were treated in our hospital by implantation of self-expandable nitinol stents. We evaluated clinical and angiographic follow-up information at 3, 6 and 12 months after stenting. Stent fracture was defined as more than single strut fracture by using a systematic X-ray screening and fractures were classified as mild fracture (single strut), moderate fracture (more than 2 strut) and severe fracture (complete separation of stent).
RESULTS: All procedures were considered to be technically successful and all patients were treated with antiplatelet drug after stenting. Of all patients, 7 patient dropped out of this study. A total of 33 patients (39 legs and 53 stents) constituted the study population for this trials. In a stent bases analysis, the rate of stent fractures was 1.9% (3 months), 3.8% (6 months), 18.9% (9 months) and 18.9% (12 months). The mean period up to fracture after stenting was 182 ± 24 days . The classification of fractures was mild in 4 stents, moderate in 4 stents (44%) and severe in 1 stent (12%). There was a total stent reocclusion in a severe fracture case. Overall, 14 of all stents (36%) showed restenosis of more than 50% diameter reduction. Resenosis at the stent fracture site was 6 in 9 stents (67%). Kaplan-Meyer survival curve showed that the restenosis rate at 12 months was significant higher for patients with stent fractures (18% vs. 67%, p = 0.0034). Using univariate analysis of various factors that may have affected in-stent restenosis, stent fracture (Hazard ratio 4.6, 95% confidence interval 1.5 to 16, p=0.003) was identified as only predictors.
Conclusions: Stent fractures after femoropopliteal stenting were considered to be associated with in-stent renstenosis. Most of the occurrence was between 3 months and 9 months.