Incidence and Predictors of In-stent Re-Stenosis in the Superficial Femoral Artery: Evaluation of Long-Term Outcomes by Color Duplex Ultrasound

Peripheral Arterial Disease: A Narrative Review

Peripheral arterial disease (PAD) describes the partial or complete occlusion of blood flow in the distal arteries of the body. A decreased arterial patency may occur due to a reduction in the elasticity or diameter of the vessel. The goal of interventions is to decrease incidence and reduce complications by identifying and minimizing the primary causes. This paper discusses PAD affecting the aortoiliac, common femoral, and femoropopliteal arteries. In a significant portion of the population, PAD may lack usual symptoms such as limb pain, claudication, and diminished pulses. Imaging techniques become crucial to ensuring timely diagnosis, monitoring treatment effectiveness, and preventing recurrence. Duplex ultrasound (DUS) is a cheap and non-invasive preliminary technique to detect atherosclerotic plaques and grade arterial stenosis. Magnetic resonance angiography (MRA) provides the added advantage of minimizing artifacts. Digital subtraction angiography (DSA) remains the gold standard for grading the degree of stenosis but is only employed second-line to DUS or MRA due to the high dose of nephrotoxic contrast. Computed tomography angiography (CTA) is able to overcome the anatomical limitations of DUS and MRA and proves to be a suitable alternative to DSA in patients with renal disease. Preventative measures involve monitoring blood pressure, cholesterol levels, and tobacco usage. First-line treatment options include endovascular procedures as well as surgical interventions in cases of significant arterial involvement. Endovascular treatments involve the use of balloon angioplasty, drug-coated balloons, and drug-coated stents, to name a few, that serve as minimally invasive techniques to manage PAD. Surgical procedures, although more complex, are considered gold-standard treatment options for long and intricate lesions. Endovascular methods are generally preferred over surgical options as the complication risk is severely reduced and the rates of reintervention are comparable to surgical options.

Bailout stenting in femoropopliteal arterial segment

Background: Disabling peripheral arterial disease (PAD) of femoropopliteal segment is usually treated with percutaneous balloon dilatation, and when this is not successful, stent is placed. Long-term patency of stent is often compromised due to in-stent restenosis (ISR). We aimed to identify factors associated with bailout stenting, and to recognise risk factors for ISR in procedures without paclitaxel application. Patients and methods: We analysed 592 consecutive successful femoropopliteal interventions performed in patients with either disabling intermittent claudication or chronic critical limb ischemia (CLI). In patients with stent implantation, clinical and ultrasound (US) examination were performed one year after the intervention to establish the presence of ISR, defined as >50% stenosis on US imaging. Results: Bailout stenting was required in 133 (22.5%) procedures. Patients with stent placement were younger (70±10 vs 72±11 years, p=0.007) and less often presented with CLI (29.3% vs 40.5%, p=0.019). They more often reported smoking (63.2% vs 49.2%, p=0.005), less often had diabetes mellitus (35.3% vs 47.5%, p=0.013) and arterial hypertension (82.0% vs 90.8%; p=0.004). Stenting was also dependent on lesion complexity (TASC II C>B>A; p<0.001). Subgroup analysis of 110 procedures with bare metal stent (BMS) placement performed in 107 patients revealed ISR in 46.4% of stents, in half of cases it was symptomatic. Neither clinical nor lesion characteristics proved to differ between the group of procedures with ISR and group of procedures without ISR. Conclusions: Factors associated with bailout stenting were age, diabetes mellitus, arterial hypertension, smoking, clinical picture of PAD and complexity of treated lesions. We did not find any risk factors influencing development of ISR in BMS.

Pre-procedural color duplex ultrasound evaluation predicts restenosis after long-segment superficial femoral artery stenting

OBJECTIVES

Restenosis after stenting for superficial femoral artery atherosclerotic disease remains a significant clinical problem, especially for long-segment lesions. We assessed predictors of in-stent restenosis in patients with long-segment superficial femoral artery disease and hypothesized that pre-procedural ultrasound assessment would predict in-stent restenosis.

METHODS

This single-center study retrospectively analyzed 283 limbs in 243 patients who treated with superficial femoral artery nitinol stent placement for long-segment (≥15 cm) lesions between 2015 and 2018. Color duplex ultrasound was performed pre-procedure and post-procedure at 3, 6, 12, 24, and 36 months. The endpoint was ≥50% in-stent restenosis in the superficial femoral artery. Primary patency rates were analyzed with Kaplan-Meier survival analysis and compared using the log-rank test. A multivariable Cox proportional hazards model was used to evaluate the risk factors for in-stent restenosis.

RESULTS

The median length of lesions was 25.8 ± 8.1 cm. The cumulative freedom from ≥50% in-stent restenosis at 3, 6, 12, 24, and 36 months was 95.3%, 78.3%, 56.0%, 30.6%, and 15.9%, respectively. Univariate and multivariate Cox regression analysis showed that cumulative lesion length ≥ 25 cm (hazard ratio 1.681; p = 0.003), calcified plaque (hazard ratio 1.549, p = 0.006), poor runoff scores >10 (hazard ratio 1.870, p = 0.003), and chronic renal failure (hazard ratio 2.075, p = 0.009) were independent risk factors for in-stent restenosis. The agreement rate between ultrasound and angiography was 92.6% for cumulative lesion length (κ 0.851) and 91.9% for runoff score (κ 0.872).

CONCLUSIONS

The results indicate that pre-procedural color duplex ultrasound evaluation is helpful for the selection of appropriate candidates for superficial femoral artery stent placement. Cumulative lesion length ≥25 cm, plaque calcification, poor distal runoff, and chronic renal failure independently predicted in-stent restenosis.

Assessment of Mortality and Factors Affecting Outcome of Use of Paclitaxel-Coated Stents and Bare Metal Stents in Femoropopliteal PAD

The use of drug-coated devices in intravascular therapy is aimed at preventing neointimal hyperplasia caused by excessive proliferation of vascular smooth muscle and thereby restenosis. Although its use seemed initially promising, a recent publication has shown an increased risk of mortality with paclitaxel-coated devices, and there is an urgent need to reaffirm assessments of drug-eluting stents (DES). Objective: The aim of the study was to compare mortality and effectiveness of paclitaxel-coated stents and bare-metal stents (BMS) in the treatment of peripheral arterial disease (PAD) with long-term follow-up. Materials and methods: In a single center randomized study, 256 patients with PAD were treated intravascularly with stent implantation. Patients were randomized into two groups: the first (n = 126) were treated with DES, and the second (n = 130) were treated with BMS. The study included evaluation after the procedure, after about 6 months and 36 months. Co-morbidities, with risks for atherosclerosis, were analyzed in all patients. Patients were evaluated for clinical outcome, restenosis frequency, and safety (complications and total mortality). Results: Clinical benefit at the end of the investigation was statistically significantly better in the DES group compared with the BMS group: 85.7% versus 66.2% (p = 0.0003), respectively. Restenosis occurred significantly less frequently in patients with DES: 16.0% versus BMS: 35.0%, p = 0.012. There was no significant effect of comorbidities on the frequency of restenoses. There were no differences in all-cause mortality over the three years with paclitaxel and no-paclitaxel stents cohorts (8.7% versus 7.1%; long-rank p = 0.575). No association was found with mortality and treatment with DES or BMS. Conclusions: The use of paclitaxel-coated stents gave good clinical benefit and caused a significantly lower frequency of restenosis compared to bare-metal stents. The use of paclitaxel-coated stents did not increase mortality.

Outcome benefit of arterial duplex stent imaging after superficial femoral artery stent implantation

OBJECTIVE

In-stent stenosis is a frequent complication of superficial femoral artery (SFA) endovascular intervention and can lead to stent occlusion or symptom recurrence. Arterial duplex stent imaging (ADSI) can be used in the surveillance for recurrent stenosis; however, its uniform application is controversial. In this study, we aimed to determine, in patients undergoing SFA stent implantation, whether surveillance with ADSI yielded a better outcome than in those with only ankle-brachial index (ABI) follow-up.

METHODS

We performed a retrospective analysis of all patients undergoing SFA stent implantation for occlusive disease at a tertiary care referral center between 2009 and 2016. The patients were divided into those with ADSI and those with ABI follow-up only. Life-table analysis comparing stent patency, major adverse limb events (MALEs), limb salvage, and mortality between groups was performed.

RESULTS

There were 248 patients with SFA stent implantation included, 160 in the ADSI group and 88 in the ABI group. Groups were homogeneous in clinical indications of claudication and critical limb-threatening ischemia (for ADSI, 39% and 61%; for ABI, 38% and 62%; P = .982) and TransAtlantic Inter-Society Consensus class A, B, C, and D lesions (for ADSI, 17%, 45%, 16%, and 22%; for ABI, 21%, 43%, 16%, and 20%; P = .874). Primary patency was similar between groups at 12, 36, and 56 months (ADSI, 65%, 43%, and 32%; ABI, 69%, 34%, and 34%; P = .770), whereas ADSI patients showed an improved assisted primary patency (84%, 68%, and 54%) vs ABI patients (76%, 38%, and 38%; P = .008) and secondary patency. There was greater freedom from MALEs in the ADSI group (91%, 76%, and 64%) vs the ABI group (79%, 46%, and 46%; P < .001) at 12, 36, and 56 months of follow-up. ADSI patients were more likely to undergo an endovascular procedure as their initial post-SFA stent implantation intervention (P = .001), whereas ABI patients were more likely to undergo an amputation (P < .001).

CONCLUSIONS

In SFA stent implantation, patients with ADSI follow-up demonstrate an advantage in assisted primary patency and secondary patency and are more likely to undergo an endovascular reintervention. These factors are likely to have effected a decrease in MALEs, indicating the benefit of a more universal adoption of post-SFA stent implantation follow-up ADSI.

Optimal Ultrasound Criteria for Grading Stenosis of the Superficial Femoral Artery

This retrospective study determined the duplex ultrasound scanning criteria for detecting 50%-69% and 70%-99% stenosis of the superficial femoral artery (SFA). Examinations of 278 limbs in 185 patients with peripheral arterial disease were performed. Duplex ultrasound scanning was used to measure the diameter of the vascular lumen, the peak systolic velocity (PSV) at the stenotic segment of the SFA (PSV_st), the segment proximal to the stenosis (PSV_pro) and the popliteal artery (PSV_pop, distal to the stenosis). The ratios PSV_st/PSV_pro and PSV_st/PSV_pop were calculated. Receiver operator characteristic curves were plotted, with digital subtraction angiography as the reference. PSV_st and PSV_st/PSV_pop had the highest diagnostic value for stenosis. Cut-off thresholds were: for 50%-69% stenosis, PSV_st ≥ 210 cm/s, PSV_st/PSV_pop ≥ 2.5, with PSV_st the better parameter; for 70%-99% stenosis, PSV_st ≥ 275 cm/s, PSV_st/PSV_pop ≥ 4.0, with PSV_st/PSV_pop superior. PSV_st/PSV_pop may be a better parameter than PSV_st/PSV_pro for diagnosing SFA stenosis.