Abstract 1788: Clinical Impact of the Diameter of a Self-expandable Stent in the Superficial Femoral Artery
Background Factors associated with patency of self-expandable stents placed in the superficial femoral artery (SFA) have not been clarified. In this study, we investigated the impact of stent diameter in patients who implanted self-expandable stents in the SFA.
Methods Self-expandable stents were placed in SFA lesions in 80 patients (84 limbs) at our hospital between January 2003 and December 2005 and we investigated prospectively for 18 months. A total of 144 stents were used: The mean vascular diameter at sites proximal and distal to the stent-placement region on angiography was defined as the vessel diameter, and the stent diameter/vessel diameter (S/V) ratio was calculated.
Results The age of the patients ranged from 44 to 88 years old (mean: 70.3 ± 6.8 years old), and 68 patients were male (85%). The mean diameter of the treated vessels was 5.1 ± 0.7 mm, the mean lesion length was 93.8 ± 43.8 mm, and 1.7 ± 0.6 stents were used per lesion. Chronic total occlusion was noted in 24 cases (30%). The primary (secondary) patency rates at 6, 12, and 18 months were 91.2% (97.5%), 74.5% (87.2%), and 63.6% (79.1%), respectively as estimated by the Kaplan-Meier method. An S/V ratio >1.3 was noted in 16 of the 80 patients (20%). There was a high percentage of patients with renal dysfunction and a smoking habit in this group, and the length of the treated lesion was long. In contrast, there were fewer patients with a high cholesterol level in this group. Other baseline parameters were similar between the two groups. A Kaplan-Meier estimate showed that the restenosis rate after 18 months was significantly higher in the S/V >1.3 group (87.5% vs. 35.5%, p<0.0001), whereas the primary patency was lower (31.3% vs. 73.4%, p<0.0001). Multivariate analysis indicated that lesion length >100 mm (Hazard ratio (HR) 6.6, p=0.015), chronic total occlusion (HR 6.0, p=0.035), stent fracture(HR 17.5, p=0.022), and S/V >1.3(HR 29.0, p=0.0014) were independent predictors of primary patency at 18 months.
conclusion The stent diameter of self-expandable stent was strongest predictor in primary patency at 18 months. The stent diameter of self-expandable stent can affect patency in the chronic phase.