Author + information
Maintenance of long-term patency after implantation of Nitinol stent in the superficial femoral artery (SFA) remains to be one of the most challenging aspects of endovascular therapy. Studies have made conflicting observations regarding a possible association between Nitinol stent fractures (SF) in the SFA and development of in-stent restenosis (ISR).
We studied 63 consecutive patients (66 limbs) with angiographically confirmed obstructive Nitinol self-expandable stent ISR in the SFA. Mean age of the group was 72.4 ±7.5 years, 42.4% females, 25.8% smokers, 56% with diabetes. We excluded patients with Viabhan stents. Stents where evaluated by fluoroscopy/CINE using at least 2 orthogonal views for SF presence. We analyzed SF rates, severity, and angiographic relationship to ISR pattern and location. Procedural and demographic characteristics such as: time to ISR, number of stents, stented length, stent diameter and type, run off score, smoking, age, sex, and presence of comorbidities were analyzed as well.
Mean time from stent implantation to presentation with ISR was 14.5 ± 7.2 months. Out of the 66 limbs with ISR, SF was present in 25 (37.8%) and among those only 3 (12%) limbs had SF angiographically associated with ISR. SF occurred more frequently in males (p<0.018). Mean stented length was numerically but not statistically longer in patients with SF than in those without, 221 ± 112 mm vs. 176 ± 98.6 mm (p=0.09) respectively. There were no differences in other procedural and demographic characteristics between groups with and without SF.
Stent fractures in the SFA play a modest role in the development of ISR. In our study the association was seen in only 12% of patients with SF. Majority of the patients with ISR did not have SF. SF occured more frequently in males.
|Characteristic||All ISR limbs (n=66)||Stent fracture present (n=25)||Stent fracture absent (n=41)||p Value|
|Mean age (years)||72.42±7.5||72.6±6.1||72.3±8.3||0.884|
|Men||38 (57.6%)||19 (76%)||19 (46.3%)||0.018|
|Diabetes||37 (56.1%)||15 (60%)||22 (53.7%)||0.615|
|Smoking||17 (25.8%)||9 (36%)||8 (19.5%)||0.317|
|Mean stented length (mm)||193.1±105||220.8±112.2||176.24±98.6||0.096|
|Mean time to ISR (months)||14.5±7.2||15.2±7.3||14.1±7.1||0.548|
|Mean stent width||6.2±0.6||6.4±0.5||6.2±0.7||0.089|
|Mean number of stents implanted||1.9±0.9||2.1±1.2||1.8±0.8||0.256|
|Median run-off score||5||3||5.5||0.678|
- 2013 American College of Cardiology Foundation