lthough the initial success rate of endovascular therapy (EVT) for femoro-popliteal artery (FPA) had been reported as 95% for stenotic and more than 85% for occlusive lesions, 1 mid-and long-term patency has remained an unsolved clinical issue. [1][2][3] Balloon angioplasty, which is the conventional and traditional treatment for FPA lesions, is extremely limited because of its low primary patency rate of 40-60% after 6-12 months. 4,5 Early experience with stainless-steel stents showed no beneficial superiority of primary patency to angioplasty alone for FPA lesions, 6,7 so deployment of these stents was limited to cases of failed angioplasty in the TASC 2000 document. 2 Interestingly, in a retrospective study nitinol stents were associated with a significantly improved primary patency rate in FPA lesions compared with stainless steel stents, 8 and recently, treatment of superficial femoral artery (SFA) disease by primary implantation of a nitinol stent yielded results that were superior to those with the currently recommended approach of balloon angioplasty with optional secondary stenting at 12 months. 9 These improvements in primary patency contributed to a revision of the TASC II document. 1Although EVT with a nitinol stent is widely used in clinical practice for TASC II A/B lesions, the primary patency beyond 2 years remains unclear. Also, there are no clinical data regarding the predictors influencing the primary patency in the nitinol stent era. Therefore, in the present study we investigated the primary patency for as long as 4 years and sought the factors associated with patency after EVT with a nitinol stent in TASC II A/B FPA lesions.
Methods
Study SubjectsFrom April 2004 to December 2007, we retrospectively analyzed a prospectively maintained database that included 126 patients (189 limbs) who were successfully and consecutively treated with a nitinol stent for de novo TASC II A/B FPA lesions and who gave consent to undergo followup ultrasound and X-ray in the Cardiovascular Division of Kansai Rosai Hospital, Japan. All patients had symptoms of the FPA lesions (Rutherford 2-6) that affected their quality of life despite exercise and medication. We developed the study protocol in accordance with the Declaration