Objectives: We investigated the time course of stent patency in the femoro-popliteal artery for as long as 4 years.
Background: Stent fracture has been related to poor 2-year patency in the femoro-popliteal artery.
Methods: We studied 239 consecutive patients who underwent provisional de novo stenting with nitinol stents for 333 limbs (Luminexx stent [C. R. Bard, Inc., Murray Hill, New Jersey] in 91 limbs; Smart stent [Cordis Corp., Miami Lakes, Florida] in 242 limbs) from April 2004 to December 2007. Stent fracture was determined by X-ray with multiple projections. Patency was assessed by duplex ultrasonography as peak systolic velocity ratio <2.4 or by angiography (% diameter stenosis <50%). Primary patency in those with and without stent fracture at follow-up was assessed along with factors influencing stent fracture.
Results: Primary patency was 81%, 74%, 68%, and 65% at 1, 2, 3, and 4 years, respectively. Stent fracture occurred in 14% (78 of 544) per stent and 17% (55 of 333) per limbs. Stent fracture was significantly associated with multiple stent deployments (with fracture = 2.3 +/- 0.9 stents vs. without fracture = 1.5 +/- 0.7 stents, p < 0.001) and long lesions (with fracture = 208 +/- 84 mm vs. without fracture = 121 +/- 79 mm, p < 0.001). Primary patency was 68% with fracture versus 83% without fracture at 1 year, p = 0.03; 65% versus 75% at 2 years, p = 0.05; 61% versus 69% at 3 years, p = 0.06; and 61% versus 65% at 4 years, p = 0.07. Neither type 1 nor type 3 fracture affected patency, although type 2 showed the worst patency.
Conclusions: Stent fracture worsened the patency during the first 2 years, but it did not apparently affect patency beyond 2 years. In particular, complete stent separation did not affect patency.