Impact of analysis interval size on the quality of optical frequency domain imaging assessments of stent implantation for lesions of the superficial femoral artery

Temporal Course of Vascular Response After Fluoropolymer Paclitaxel-Eluting Stent Implantation for Femoropopliteal Artery Lesions

BACKGROUND

Limited data are available regarding the vascular response after fluoropolymer paclitaxel-eluting stent (FP-PES) implantation. This study sought to assess the vascular response at 6 and 12 months after FP-PES implantation for femoropopliteal artery lesions using serial optical coherence tomography (OCT) examination.Methods and Results:From the IMPERIAL trial, this study evaluated 10 de novo femoropopliteal lesions treated with FP-PES. The primary study endpoint was neointimal tissue coverage at a 6- and 12-month follow up, as assessed by serial OCT examination. The incidence of peri-strut low-intensity area (PLIA) and extra-stent lumen (ESL) was also assessed. A total of 203 matched cross-sectional images were evaluated at 6 and 12 months (5,615 and 5,763 struts, respectively). From 6 to 12 months, the mean neointimal thickness tended to increase from 198 µm to 233 µm, with a significant reduction in the incidence of malapposed struts (0.59% vs. 0.28%, P=0.039). Conversely, uncovered struts and PLIA were more frequently observed at 12 months (4.4% vs. 7.8%, P=0.01; 12.7% vs. 21.0%, P<0.001, respectively). The ESL area significantly increased over time without any difference in its incidence (0.24±0.32 mm²vs. 0.38±0.36 mm², P=0.009).

CONCLUSIONS

Neointimal proliferation was markedly inhibited from 6 to 12 months after FP-PES implantation, whereas the incidence of uncovered struts and PLIA significantly increased over time with the enlargement of ESL.

Influence of Self-Expanding Paclitaxel-Eluting Stent Sizing on Neointimal Hyperplasia in Superficial Femoral Artery Lesions

BACKGROUND

Although self-expanding drug-eluting stents (DES) have recently shown superior outcomes for superficial femoral artery (SFA) lesions, optimal sizing of DES diameter in SFA intervention is unclear.Methods and Results:A total of 40 de novo SFA lesions were randomized 1:1 to receive self-expanding DES with either a 1-mm or 2-mm larger diameter than the reference vessel diameter. Follow-up optical coherence tomography (OCT) was scheduled 6 months after DES implantation to evaluate the vascular response to the stents. Volume index (VI) was defined as volume divided by stent length. The primary endpoint was neointimal VI at 6 months. Baseline reference vessel diameter was similar between the 1-mm larger diameter group and the 2-mm larger diameter group (5.0±0.8 mm vs. 4.7±0.9 mm, P=0.35). Stent diameter was 6.3±0.6 mm in the 1-mm larger group and 7.1±0.6 mm in the 2-mm larger group (P<0.0001), and stent to reference vessel diameter ratio (SV ratio) was 1.3±0.2 and 1.5±0.2 (P<0.0001), respectively. At 6-month, neointimal VI was greater in the 2-mm larger diameter group (5.5±1.5 mm²vs. 9.6±3.4 mm², P<0.001). The correlation analysis revealed that degree of neointimal VI was positively correlated with SV ratio (r=0.43, P<0.01).

CONCLUSIONS

Implantation of self-expanding DES with a considerably high SV ratio resulted in neointimal hyperplasia in SFA lesions.

FD-OCT and IVUS intravascular imaging modalities in peripheral vasculature

Intra-Vascular Ultra-Sound (IVUS) and Frequency Domain-Optical Coherence Tomography (FD-OCT), in vivo, intra-vascular, imaging modalities, widely used in the field of coronary disease, have been recently implemented in peripheral endovascular procedures, for procedural assessment, plaque characterization and determination of predictors of treatment outcomes. Their unique characteristics have also been used in order to provide additional features and improve the performance of re-entry devices and atherotomes. Areas covered: Present review focuses on available literature regarding these two promising imaging technologies in the peripheral vasculature, highlighting the added value produced by their use in endovascular therapy, their limitations and their utilization in new endovascular devices. Authors also provide their future perspective and the possible benefits in understanding vascular behavior and lesion characterization in peripheral endovascular interventions. Expert commentary: By providing both quantitative but also qualitative data on vessel and lesion morphology, intravascular imaging modalities offer a valid solution for endovascular treatment evaluation and outcome presentation homogeneity.