Effect of Femoropopliteal Stent Fracture on Patency Studied
July 20, 2009—In the Journal of the American College of Cardiology: Cardiovascular Interventions, Osamu Iida, MD, et al published findings from their investigation of the time course of stent patency in the femoropopliteal artery for as long as 4 years (2009;2:665–671). The investigators noted that stent fracture has been related to poor 2-year patency in the femoropopliteal artery.
According to the investigators, they studied 239 consecutive patients who underwent provisional de novo stenting with nitinol stents for 333 limbs (Luminexx stent [Bard Peripheral Vascular, Inc., Tempe, AZ] in 91 limbs; Smart stent [Cordis Corporation, Bridgewater, NJ] 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 patients with and without stent fracture at follow-up was assessed along with factors influencing stent fracture.
The investigators reported that primary patency was 81%, 74%, 68%, and 65% at 1, 2, 3, and 4 years, respectively. Stent fracture occurred in 14% (78 of 544) of stents and 17% (55 of 333) of 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 < .001) and long lesions (with fracture, 208 ± 84 mm vs without fracture, 121 ± 79 mm; P < .001). Primary patency was 68% with fracture versus 83% without fracture at 1 year (P = .03); 65% versus 75% at 2 years (P = .05); 61% versus 69% at 3 years (P = .06); and 61% versus 65% at 4 years (P = .07). Neither type 1 nor type 3 fracture affected patency, although type 2 showed the worst patency.
The investigators concluded that stent fracture worsened the patency during the first 2 years, but it apparently did not affect patency beyond 2 years. In particular, complete stent separation did not affect patency.