Potential mechanisms of in-stent occlusion in the femoropopliteal artery: an angioscopic assessment.

Although stent implantation has become widespread for the treatment of patients with peripheral artery disease with femoropopliteal (FP) lesions, in-stent restenosis, especially in-stent occlusion (ISO), remains as a major concern for refractory recurrence. Furthermore, the mechanisms of ISO in FP lesions have not been well elucidated. We performed angioscopy for 6 lesions (bare-metal stent: 3, drug-eluting stent: 3) from 5 patients (mean age 74 ± 10 years, male 40 %) with ISO in the FP artery immediately after wire-passing or thrombus aspiration. The presence of thrombus as well as the presence and location of organic stenosis were evaluated. Median duration from stent implantation to angioscopic evaluation was 1099.5 (514.5-2272.5) days, while the duration from recurrence of symptoms to angioscopic evaluation was 45 (5.75-60) days. Mixed thrombi were observed in all stents. Organic stenosis was detected at the proximal edge of the stents in 5 lesions. Organic stenosis was observed at the overlapping segment of the stent in one lesion. The distal edge of the stents could be evaluated in 3 lesions, and all of them showed organic stenosis at the site. Mixed thrombi and organic stenosis were observed in all stents. Partial development of organic stenosis in a stent followed by thrombus formation may be the potential mechanism of the development of ISO in the FP artery though the sample size of this study was small and it had no serial angioscopic data so that we should consider it as preliminary one at best.

Impact of Calcification on Clinical Outcomes After Endovascular Therapy for Superficial Femoral Artery Disease: Assessment Using the Peripheral Artery Calcification Scoring System.

PURPOSE: To investigate whether the severity of lesion calcification assessed by the novel peripheral artery calcification scoring system (PACSS) was associated with clinical outcomes after endovascular therapy (EVT) for superficial femoral artery (SFA) lesions. METHODS: A retrospective analysis was conducted of 394 consecutive patients (mean age 72±8 years; 290 men) with intermittent claudication [223 (57%) with diabetes, 81 (21%) on hemodialysis] who underwent successful EVT for de novo SFA lesions [length 152.1±95.7 mm; 199 (50%) TransAtlantic Inter-Society Consensus II class C/D] between January 2010 and December 2013. The patients were retrospectively categorized using the PACSS classification (grades 0-4: no visible calcification of the target lesion, unilateral wall calcification <5 cm, unilateral calcification ≥5 cm, bilateral wall calcification <5 cm, and bilateral calcification ≥5 cm, respectively). The main outcome was primary patency, while the secondary outcome measures were mortality and major adverse limb events [MALE: any intervention (repeat EVT or surgical revision) or major (above ankle) amputation]. Cox proportional hazards analysis was used to explore whether the PACSS classification was an independent predictor of clinical outcomes. Results are presented as the hazard ratio (HR) and 95% confidence interval (CI). RESULTS: The distribution of PACSS grades was 0 in 54%, grade 1 in 16%, grade 2 in 12%, grade 3 in 9%, and grade 4 in 9%. The 2-year primary patency rates in these grades, respectively, were 70.0%, 66.6%, 72.1%, 55.6%, and 36.3% (p<0.001). After multivariate analysis, PACSS grade 4 (HR 2.74, 95% CI 1.56 to 4.83, p<0.001), diabetes (HR 1.52, 95% CI 1.06 to 2.20, p=0.022), lesion length (HR 1.04, 95% CI 1.01 to 1.07, p=0.006), and vessel diameter (HR 0.80, 85% CI 0.65 to 0.98, p=0.038) were associated with loss of primary patency. PACSS grade 4 was also associated with MALE and mortality (p=0.048 and 0.011, respectively). Bare metal stent use (HR 0.47, 95% CI 0.30 to 0.73, p<0.001) was positively associated with primary patency. CONCLUSION: PACSS grade 4 calcification was independently associated with clinical outcomes after EVT for de novo SFA lesions.

Angioscopic assessment of peri-stent contrast staining following drug-eluting stent implantation.

BACKGROUND: Peri-stent contrast staining (PSS) has been recognized as a predictor of late stent thrombosis following drug-eluting stent (DES) implantation. However, the intravascular conditions at PSS sites remain unclear. METHODS AND RESULTS: We evaluated 10 patients (median age 72 years, 80% male) with stable angina pectoris by coronary angioscopy. The patients had a total of 11 DES implantations (5 sirolimus-eluting stents; 4 paclitaxel-eluting stents; 2 everolimus-eluting stents) that showed PSS. Neointimal coverage (NIC), presence of thrombus, and yellow plaques underneath the stent were compared between PSS and non-PSS sites for each stent. NIC was graded as: grade 0, struts exposed; grade 1, struts bulging into the lumen, although covered; grade 2, struts embedded by neointima, but translucent; grade 3, struts fully embedded and invisible. Mean follow-up was 394±206 days (median: 289). NIC grade was lower at PSS sites (P=0.021) with 8 out of 11 stents (73%) having grade 0. Angioscopy detected a thrombus more frequently at PSS sites than at non-PSS sites (64% vs. 9%, P=0.012). Yellow plaques tended to be more significant at PSS sites than at non-PSS sites (82% vs. 45%, P=0.091). CONCLUSIONS: The angioscopic findings suggest high thrombogenicity at PSS sites.

Angioscopic assessment of arterial repair following biodegradable polymer-coated biolimus A9-eluting stent implantation. - Comparison with durable polymer-coated sirolimus-eluting stent-.

BACKGROUND: Second-generation drug-eluting stents (DES) are expected to show better arterial repair than older DES. We angioscopically compared the biodegradable polymer-coated biolimus A9-eluting stent (BES) and durable polymer-coated sirolimus-eluting stent (SES) to explore differences in arterial repair. METHODS AND RESULTS: Angioscopy was performed 9 ± 1 months after 15 BES and 16 SES were implanted initially in the native coronary artery. Heterogeneity of neointimal coverage (NIC) as well as the dominant NIC grade was examined. NIC was defined as: grade 0 = fully visible struts; grade 1 = struts bulging into the lumen, but covered; grade 2 = embedded, but translucent struts; grade 3 = invisible struts. Heterogeneity was judged when the NIC grade varied ≥ 1. In-stent late loss (0.06 ± 0.23 vs. 0.07 ± 0.18 mm, P = 0.80), and dominant NIC grade (1.5 ± 0.8 vs. 1.3 ± 0.7, P = 0.45) were similar for BES and SES. Within the stents, NIC was more heterogeneous in SES than in BES (P = 0.035). 80% of BES showed homogeneous NIC, while 56% of SES had heterogeneous NIC. CONCLUSIONS: BES showed limited late loss similar to that for SES. Nonetheless, the NIC with BES was more homogeneous than that with SES. Biodegradable polymer-coated BES may have an advantage in homogeneous NIC.