Impact of stent diameter on vascular response after self-expanding paclitaxel-eluting stent implantation in the superficial femoral artery.

BACKGROUND: The optimal sizing of self-expanding paclitaxel-eluting stents (PES) in the treatment for superficial femoral artery (SFA) lesions is unclear. This study sought to investigate the influence of PES diameter on stent patency in SFA lesions using optical frequency domain imaging (OFDI).

METHODS: A total of 20 de novo SFA lesions were randomized 1:1 to receive either self-expanding PES with a nominal diameter of 6mm or 8mm. Follow-up angiography and OFDI was scheduled six months after stent implantation, and volumetric OFDI analysis was performed to evaluate vascular response to the stents. Volume index (VI) was defined as the volume divided by the stent length. The primary end point was lumen VI at the 6-month follow-up. Secondary end point was minimum lumen diameter (MLD) by quantitative vascular angiography (QVA) at the follow-up.

RESULTS: Stent length was 78.0±23.9mm in the 6-mm group and 70.0±23.6mm in the 8-mm group (p=0.46). Baseline QVA data were also similar between the two groups. MLD immediately after stent implantation was similar between the two groups (4.2±0.5mm in the 6-mm group and 3.9±0.5mm in the 8-mm group, p=NS). At the 6-month follow-up, MLD was greater in the 8-mm group compared to the 6-mm group (4.0±1.0mm vs. 3.2±0.4mm, p<0.05). Stent VI was larger in the 8-mm group (28.4±6.7mm3 /mm vs. 22.2±1.2mm3 /mm, p=0.01). Neointimal VI was similar between the two groups (5.8±2.9mm3 /mm vs. 5.2±2.6mm3 /mm, p=0.68). Lumen VI was greater in the 8-mm group (23.2±7.6mm3 /mm vs. 17.3±2.6mm3 /mm, p=0.04).

CONCLUSIONS: Chronic stent enlargement resulted in greater lumen area after implantation of self-expanding PES with a large diameter at the mid-term follow-up. Stent diameter might be important for stent patency in procedure with PES for SFA lesions.