Purpose: To determine and compare the rates of in-stent restenosis, late clinical deterioration, and stent fractures in nitinol stents versus Wallstents implanted for suboptimal angioplasty in the superficial femoral artery (SFA).
Methods: Interrogation of an angioplasty database identified 286 consecutive patients (178 men; mean age 67+/-10 years, range 44-87) with severe claudication (n=254) or critical limb ischemia (n=32) who had stents implanted after suboptimal angioplasty over a 5-year period. Wallstents with a mean stented lesion length of 107+/-71 mm were implanted in 116 patients, while nitinol stents were used in 170 patients: 45 SMART stents (mean stented lesion length 139+/-88 mm) and 125 Dynalink/Absolute stents (mean stented lesion length 125+/-84 mm). Patients were followed for in-stent restenosis (>50%) by duplex ultrasound, clinical deterioration by at least 1 Fontaine stage compared to baseline, and stent fractures by biplanar radiography.
Results: In-stent restenosis rates at 1, 2, and 3 years were 46%, 66%, and 72% for Wallstents compared to 20%, 36%, and 53% for nitinol stents (p<0.001), respectively, without significant difference between the 2 nitinol stent groups (p=0.59). Clinical deterioration at 1, 2, and 3 years was found in 10%, 15%, and 18% with Wallstents versus 4%, 5%, and 5% with nitinol stents (p=0.014), respectively, without difference between the 2 nitinol stent groups (p=0.47). Fracture rates were 19% for Wallstents after a mean 43+/-24 months, 28% for SMART stents after mean 32+/-16 months, and 2% for Dynalink/Absolute stents after a mean 15+/-9 months.
Conclusions: Intermediate-term in-stent restenosis remains a major problem even with current nitinol stent technology; however, clinical deterioration seems no matter of serious concern with SMART and Dynalink/Absolute stents. Stent fractures may be lower with Dynalink/Absolute stents, but randomized head-to-head comparisons are needed to validate these data.