CardioVascular and Interventional Radiology

, Volume 39, Issue 11, pp 1541–1549 | Cite as

Incidence of New Ischaemic Brain Lesions After Carotid Artery Stenting with the Micromesh Roadsaver Carotid Artery Stent: A Prospective Single-Centre Study

  • Maria Antonella Ruffino
  • Riccardo Faletti
  • Laura Bergamasco
  • Paolo Fonio
  • Dorico Righi
Clinical Investigation

Abstract

Aims

Several randomized trials of patients with carotid stenosis show increased adverse neurological events with stenting versus endarterectomy in the 30-day post-procedure. This study examines the incidence of new ischaemic lesions in patients treated in our centre using the new Roadsaver stent.

Methods and results

Between September 2015 and January 2016, 23 consecutive patients (age 74.3 ± 7.3 years, 17.4 % female) underwent carotid artery stenting with the Roadsaver stent, a nitinol double-layer micromesh device. A distal protection device was used in all cases. Diffusion-weighted magnetic resonance imaging was performed 24 h before, and 24 h and 30 days after the procedure. The 24-h post-procedure imaging showed 15 new ipsilateral ischaemic lesions in 7 (30.4 %) patients: median volume 0.076 cm3 (interquartile range 0.065–0.146 cm3). All lesions were asymptomatic. The 30-day imaging showed complete resolution of all lesions and no new ischaemic lesions. Follow-up clinical and ultrasound examinations at 30 days and 6 months recorded no adverse cardiac or cerebrovascular events.

Conclusions

Protected stenting with micromesh Roadsaver stent showed good safety and efficacy in the treatment of carotid stenosis, with a low incidence of delayed embolic events and new ipsilateral ischaemic brain lesions. These preliminary results are encouraging, but need to be confirmed with larger populations.

Keywords

Internal carotid artery stenosis Carotid stenting Micromesh stent Embolic protection Diffusion-weighted magnetic resonance Ischaemic brain lesions 

Introduction

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are equally good at preventing strokes in the long term (>30 days) [1, 2, 3, 4]. In the short term, however, CAS is associated with a higher procedure-related and short-term (<30 days) risk of non-disabling stroke than CEA [5, 6, 7]. Diffusion-weighted magnetic resonance imaging (DW-MRI) demonstrated that about three times more patients have new ischaemic lesions in post-treatment scans after CAS than after CEA [4].

Plaque retention by the stent in the post-procedure period is an important and debated issue. Recently, Doig et al. reported a doubling of the risk of stroke for symptomatic patients receiving an open-cell design stent rather than a closed-cell design one [8].

The need for sustained embolic protection has led to the design of new dual-layer stents aimed at increasing plaque coverage and decreasing the risk of dislodging through the stent strut. Preliminary results with CGuard, a novel mesh-covered carotid stent, have been published [9]. The safety and the efficacy of Roadsaver, a nitinol dual-layer micromesh stent designed to contain plaque against the vessel wall preventing its protrusion and release of emboli after deployment, were satisfactorily tested by Hopf-Jensen et al. [10].

The aim of this paper is assess the performance of Roadsaver stent in regard to (i) post-procedure cerebral embolization, in particular number and volume of new ipsilateral ischaemic lesions observed by DW-MRI at 24-h and 30-day post-stenting, (ii) general procedure success, and (iii) incidence of adverse events at 30 days and 6 months, in particular lack of patency of the stent and external carotid artery, worsened clinical and neurological conditions, and rate of major cardiac cerebrovascular events (MACCE).

Methods

Study Design and Patient Population

The study is a prospective, single-centre, single-arm trial including 23 CAS procedures performed between September 2015 and January 2016 on 23 consecutive patients. During the study period, the total amount of CAS performed was 34.

Principal inclusion criteria were ≥18 years of age and carotid artery stenosis. Symptomatic patients had to have a stenosis ≥50 % evaluated by duplex ultrasound (DUS) according to the NASCET criteria [11]; for asymptomatic patients, the stenosis had to be ≥80 % and suitable for treatment according to the vascular and neurological specialists. Principal exclusion criteria were carotid obstruction or presence of endoluminal thrombus, previous stenting at the same site, acute stroke within the last 30 days, myocardial infarction within 72 h, and intracranial haemorrhage in the previous 12 months.

Patients were scheduled to undergo DW-MRI evaluations at baseline, 24 h and 30 days after stenting; clinical evaluation and DUS at baseline, 24 h, 30 days, and 6 months after stenting. The clinical evaluation included a neurological examination performed by an independent neurologist using the National Institute of Health Stroke Scale (NIHSS) and cognitive tests as the Mini-Mental State Examination and the Frontal Assessment Battery.

Plaque morphological characteristics were determined by DUS and defined as echolucent (lipidic plaque), echogenic (fibrotic plaque), and heterogeneous texture (heterogeneous plaque). Surface irregularity and plaque ulceration were also assessed. Presence, site, and volume of ischaemic lesions were assessed by DW-MRI.

Procedural success was defined as residual stenosis after stenting ≤30 % and no complications (serious device-related and procedure-related adverse events as defined per ISO 14155-1:2011).

The trial conformed to the guiding principles of the Declaration of Helsinki and was approved by our local Ethical Committee (Prot. N 0089315, Document N CS/642). All patients gave written informed consent.

Device Description

The Roadsaver carotid artery stent (Terumo, Japan) is a nickel titanium (nitinol) double-layer micromesh stent: the inner nitinol micromesh is woven into an external closed-cell stent achieving the smallest cell size currently available (375–500 μm) (Fig. 1). This structure has the flexibility of an open-cell stent with the benefits of a closed-cell stent. Like a closed-cell stent, it provides excellent coverage of plaque with optimal wall apposition to contain the plaque against the vessel wall, thus preventing plaque protrusion and release of emboli after stent implantation. Similarly to an open-cell device, it has a good trackability through tortuous arch and carotid anatomies. The braided mesh double-layer design without settled parts is very flexible allowing the device to conform to the carotid anatomy without need of tapered stent.
Fig. 1

Roadsaver carotid artery stent. A View of the self-expandable nitinol double-layer device. B Particular of the double layer

This device (5 Fr, 0.014-inch guidewire-compatible, rapid-exchange delivery system) is re-sheathable and repositionable (up to 50 % deployment). Its low profile gives the stent high crossability of stenotic lesions allowing primary stenting without pre-dilation. The presence of the proximal and distal flares makes the stent very stable during the deployment. The radiopaque markers located at the extremities of the double-layer mesh enhance the precision of the deployment over the target plaque. The final implanted stent length depends on the vessel diameter: for example, a device 7 × 30 mm2 has a micromesh layer stent length of 30 mm and an overall stent length of 40 mm. If deployed in a vessel with a calibre 1 mm smaller (6 mm), the micromesh layer length will be 40 and the overall length 53 mm.

Carotid Artery Stenting Procedure

The CAS procedure was performed according to standard practice except for using the Roadsaver carotid stent instead of a conventional one. A Roadsaver stent was implanted in presence of an echolucent or heterogeneous plaque (“soft plaque”) at DUS and/or a high-risk coronary plaque.

The intracranial circulation was visualized before and after the procedure. All patients received 100 mg acetylsalicylic acid (ASA) and a loading dose of 375 mg clopidogrel if they were not on dual antiplatelet therapy for other reasons. After the procedure, patients received a daily dose of 100 mg ASA and 75 mg clopidogrel for 1 month, and just ASA thereafter. During the procedure, ACT-based heparinization was administered using weight-adjusted initial dosing, advice description, and atropine (1 mg) was given before post-dilation of the stent.

All CAS were performed with the same distal embolic protection device (Emboshield NAV [3], Embolic Protection System, Abbott Vascular, Temecula, CA).

The same two operators with extensive experience (>50 CAS/year as first operators in the last 10 years) performed all procedures.

DW-MRI Analysis

MRI was performed with a 1.5 T scanner (Achieva, Philips, Best, The Nederland), including high-resolution DW sequences, with 0–1000 b values, gradient echo T2-weighted sagittal, and axial sequences. Fluid attenuation inversion recovery (FLAIR) 3D sequences on the axial plane were performed to measure cerebral white matter change and to investigate whether acute ischaemic brain lesions led to persistent lesion change.

For each scan, DW-MRI sequences were used to detect acute ischaemic brain lesions, defined as a focal hyperintense area on the FLAIR sequences, characterized by a restricted diffusion signal on the DW-MRI sequences, and confirmed by apparent diffusion coefficient mapping. A radiologist experienced in brain DW-MRI evaluated the images. Ischaemic lesion location (ipsilateral, contralateral, and bilateral hemisphere) and size were recorded. Volume analysis of acute ischaemic lesions was performed on a separate workstation (Volume Calculator, Osirix, Pixmeo).

Before the procedure, a magnetic resonance angiography with spoiled gradient echocardiographic 3D sagittal views oriented through the aortic arch was acquired after intravenous injection of paramagnetic contrast medium (gadobenate-dimeglumine 0.1 mmol/kg, flow rate 2.5 ml/s) to evaluate and classify arch morphology in order to adequately plan the procedure.

Data Analysis

Continuous variables were tested for normality with the Kolmogorov–Smirnov/Lilliefors test and the Shapiro–Wilks-W test. Normal data are presented as mean ± SD: otherwise they are presented with their median value, interquartile range (IQR), and total range (TR). Comparisons employed the non-parametric Mann–Whitney test. Statistical significance was set at p < 0.05.

The statistical procedures were run on StatPlus:macPro (Analyst Soft Inc. Walnut, CA).

Results

Patient and Stenosis Characteristics

Patient and lesion characteristics before the stenting procedure are reported in Tables 1 and 2 (second column).
Table 1

Patients characteristics

 

Total (N = 23)

Post-CAS embolization (N = 7)

No post-CAS embolization (N = 16)

Age (years)

74.3 ± 7.3

  

Male

82.6 % (19)

85.7 % (6)

81.3 % (13)

Symptomatic

60.9 % (14)

71.4 % (5)

56.3 % (9)

Smokers

26.1 % (6)

28.6 % (2)

25 % (4)

Former smokers

30.4 % (7)

14.3 % (1)

37.5 % (6)

Diabetes

47.8 % (11)

57.1 % (4)

43.8 % (7)

Hypertension

96.6 % (22)

100 % (7)

93.8 % (15)

Hyperlipidaemia

69.6 % (16)

85.7 % (6)

62.5 % (10)

Atrial fibrillation

8.7 % (2)

0 % (0)

12.5 % (2)

Previous TIA

30.4 % (7)

57.1 % (4)

18.8 % (3)

Previous myocardial infarction

56.5 % (13)

57.1 % (4)

56.3 % (9)

CHA2DS2-VAScore ≥3

78.2 % (18)

100 % (7)

68.7 % (11)

NIHSS = 0

39.15 % (9)

28.6 % (2)

43.8 % (7)

1

39.15 % (9)

42.9 % (3)

37.5 % (6)

2

21.7 % (5)

28.6 % (2)

18.8 % (3)

CHA2DS2-VAScore cardiac failure, hypertension, age ≥75, diabetes, stroke-vascular disease, age 65–74 and sex category

NIHSS National Institute of Health Stroke Score, TIA transient ischaemic attack

Table 2

Lesions characteristics

 

Total (N = 23)

Post-CAS embolization (N = 7)

No post-CAS embolization (N = 16)

Location

 Right ICA

47.8 % (11)

42.9 % (3)

50.0 % (8)

 Left ICA

52.2 % (12

57.1 % (4)

50.0 % (8)

Restenosis

30.4 % (7)

28.6 % (2)

31.2 % (5)

Plaque morphology

 Echolucent

43.5 % (10)

57.1 % (4)

37.5 % (6)

 Echogenic

22.7 % (5)

14.3 % (1)

25.0 % (4)

 Heterogeneous

34.8 % (8)

28.6 % (2)

37.5 % (6)

Plaque surface irregularity

34.8 % (8)

28.6 % (2)

37.5 % (6)

Plaque ulceration

17.4 % (4)

14.3 % (1)

18.8 % (3)

Length (mm)

15.3 ± 5.2

  

Percentage of stenosis

82.5 ± 4.8

79.3 ± 5.3

83.2 ± 5.7

ECA patency

100 % (23)

100 % (7)

100 % (7)

Controlateral ICA

 Stenosis

34.8 % (8)

42.9 % (3)

31.3 % (5)

  %

71 ± 21

62 ± 13

78 ± 24

 Occlusion

13 % (3)

0

18.8 % (3)

Anatomic variable

 Bovine arch

17.4 % (4)

28.6 % (2)

12.5 % (2)

 Aortic arch type I

30.4 % (7)

28.6 % (2)

31.3 % (5)

 Aortic arch type II

21.7 (5)

14.3 (1)

25.0 (4)

 Aortic arch type III

30.4 (7)

28.6 (2)

31.3 (5)

28.62 ICA tortuosity (vessel kinking >60°)

30.4 (7)

28.6 (2)

31.3 (5)

ECA external carotid artery, ICA internal carotid artery

Procedural data are reported in Table 3. Procedural success was achieved in all cases without complications during or after the procedure.
Table 3

Procedural data

 

Total (N = 23)

Post-CAS embolization (N = 7)

No post-CAS embolization (N = 16)

Access

 Femoral

95.7 % (22)

  

 Brachial

4.3 % (1)

  

Distal embolic protection

100 % (23)

100 % (23)

100 % (23)

Pre-dilation

17.4 % (4)

  

Post-dilation

100 % (23)

  

Pre and post-dilation pressure (atm)

6 (balloon nominal pressure)

  

Procedure success

100 % (23)

100 % (7)

100 % (16)

Stent diameter (mm)

8.7 ± 1.0

  

Stent length (mm)

26.9 ± 5.1

  

Post-CAS DW-MRI and DUS Results

The pre-treatment DW-MRI did not evidence acute ischaemic lesions in any patient. The DW-MRI at 24 h after CAS showed that 7 of the 23 patients (30.4 %) had developed 15 acute ipsilateral ischaemic lesions and 6 contralateral lesions (Fig. 2A). The third and fourth columns of Tables 1, 2, and 3 compare the characteristics of these 7 patients with those of the 16 patients who did not suffer post-CAS embolization: the two groups have no statistically significant differences in their baseline (presence of risk factors) nor in the procedure management.
Fig. 2

New acute ischaemic lesions. A Number of lesions in each patient. B Volumes of lesions. The box identifies the IQR: the blue line inside is the median, whereas the red line the mean volume; the green dots evidence the maximum and the minimum values (outliers)

As shown in Table 4, among the 7 patients, 3 had a total of 4 ipsilateral lesions (median volume 0.071 cm3, IQR 0.064–0.096, TR 0.064–0.157) accompanied by 6 contralateral ischaemic lesions (median volume 0.044 cm3, IQR 0.039–0.156, TR 0.011–0.284). Four had a total of 11 standalone ipsilateral lesions (median volume 0.110 cm3, IQR 0.052–0.137, TR 0.027–0.389). Comparisons between the volumes of not accompanied versus accompanied ipsilateral lesions yielded p = 0.52. None of the patients showed standalone contralateral lesions. The median volume of all 15 ipsilateral lesions was 0.076 cm3 (IQR 0.065–0.146; TR 0.027–0.389). All lesions were asymptomatic. The volumes of the different kinds of lesions are illustrated in Fig. 2B.
Table 4

24-h DWI-MR analysis data

Patient

Symptomatic

Plaque characteristics

Lesion sites and volume

Ipsilateral

Controlateral

1

No

Echolucent

0.076

0.284

0.045

2

Yes

Echogenic

0.157

0.065

0.194

0.043

0.038

3

Yes

Echolucent

0.064

0.011

Pooled volume (bilateral)

  

0.071 (0.064–0.096)*

0.044 (0.039–0.156)*

4

No

Heterogeneous/irregular surface

0.075

0.038

0.027

none

5

Yes

Echolucent/irregular surface

0.139

0.110

0.215

0.029

none

6

Yes

Echolucent

0.067

0.135

0.389

none

7

Yes

Heterogeneous

0.112

none

Pooled volume (unilateral)

  

0.110 (0.052–0.137)*

 

Pooled ipsilateral (uni & bilateral)

  

0.076 (0.065–0.146)*

 

* Median (IQR)

The number of ipsilateral lesions in a single patient ranged from 1 to 4. Overall, the 7 patients had a median rate of 3 lesions/patient (IQR 2.5–3.5; TR 1–5). Considering all the 23 patients who underwent stenting, the median number of lesions per patient was 0 (IQR 0–1.5; TR 0–5).

Among the 7 patients with ipsilateral lesions 5 (71 %) were symptomatic. Each of these patients had between 1 and 4 lesions, accounting for 11/15 (73 %) of all ipsilateral lesions; the highest number was found in the patient with an ICA fibrolipidic plaque and bovine arch. The two not symptomatic patients had 1 and 3 lesions. The median volume of the 11 lesions of symptomatic patients was 0.112 cm3 (IQR 0.066–0.148, TR 0.029–0.389), larger than the corresponding volume for the 4 lesions of asymptomatic patients 0.056 cm3 (IQR 0.035–0.075, TR 0.027–0.076); the difference does not reach statistical significance (p = 0.14), most probably because of small size of the asymptomatic sample.

Most new ischaemic lesions were found in the 6 patients with echolucent or heterogenous plaques (13/15, 87 %). The median volume of the 13 lesions was 0.076 cm3 (IQR 0.064–0.135, TR 0.027–0.389), consistent (p = 0.73) with the corresponding volume for the 2 lesions of the patient with an echogenic plaque (median volume 0.111 cm3, IQR 0.088–0.134, TR 0.065–0.157); the difference does not reach statistical significance most probably because of small size of the asymptomatic sample.

At the 24-h duplex US check, the external carotid artery (ECA) was patent in all subjects. All stents were patent without restenosis with a peak of systolic velocity (PSV) <100 cm/s and ICA/CCA ratio <2 [12].

30-Day and 6-Month Controls

The 30-day DWI-MR showed complete resolution of all post-CAS lesions (no focal hyperintense Flair signal at the site of post-treatment DWI) and no evidence of new acute ischaemic lesions (Fig. 3).
Fig. 3

Imaging evaluation of a patient with left ICA stenosis. A SSFP sagittal oblique sequences show a bovine arch. B Selective CCA angiogram: high-grade stenosis of left ICA. C Roadsaver carotid artery stent after the deployment. D Selective CCA angiogram post-CAS: absence of residual stenosis. E Baseline DWI-MR without recent ischaemic lesions. F 24-h DWI-MR: ipsilateral focal subcortical parietal recent ischaemic lesion (white arrow). G 30-day DWI-MR: complete recovery of the lesion without new ischaemic lesions

The DUS performed at 1 and 6 months after the procedure showed that all ECA and stents were patent without any in-stent restenosis (PSV <100 cm/s and ICA/CCA ratio <2).

Clinical and neurological evaluations excluded any major cerebrovascular event or a worsening of the neurological and cognitive conditions. No MACCE was observed.

Discussion and Limitations

To the best of our knowledge this is the first study analysing incidence, location, number, and volume of new ischaemic lesions after CAS using the double-layer Roadsaver carotid stent.

Its main results are the following:
  1. (1)

    Seven out of 23 patients (30.4 %) presented ipsilateral lesions on DW-MRI at 24-h post-CAS: the total number of lesions was 15, with a maximum of 4 per patient and median volume 0.076 cm3 (IQR 0.065–0.146; TR 0.027–0.389). Most lesions were found in symptomatic patients (73 %) and in patients with not stable plaques.

     
  2. (2)

    The 30-day DWI-MR showed resolution of all post-CAS lesions and no evidence of new ischaemic lesions.

     
  3. (3)

    At 30 days and 6 months, the MACCE rate was 0 %, and the ECA was patent in all cases.

     

In the following, we shall discuss these results using as reference frame three recent studies with CAS performed with filter protection. The first is the CARENET study [9], which tested the non-conventional CGuard stent on 26 procedures with distal protection (plus one with proximal protection). The other two studies made use of conventional stents: the PROFI study [13] involved 31 subjects with distal filter (plus 31 using proximal balloon occlusion) and the MRI substudy of the International Carotid Stenting Study (ICSS) [4] involved 56 subjects with distal filter (out of 124 stentings). The comparisons are not always homogeneous because of the different presentation of the data by the different authors.

Incidence of New DW-MRI Lesions on the Post-treatment Scan

Our 30.4 % rate of patients with new acute ischaemic brain lesions at 24-h post-CAS is consistent with the 34.6 % rate reported by the CARENET study. The studies with conventional stents report higher rates: 38/56 (68 %) for the MRI ICSS subgroup and 27/31 (87.1 %) for PROFI.

We hypothesize that the high plaque coverage of the dual-layer stents (C-Guard and Roadsaver) may reduce cerebral embolization of plaque debris through the stent struts into the ipsilateral hemisphere soon after the procedure. Contralateral lesions most probably originate from the aortic arch, as well as from various stages of the procedure, and are independent of the stent design.

Number of New DW-MRI Lesions Per Patient

We observed 21 new DW-MRI ischaemic lesions in 23 patients, yielding a median of 0 lesions per patient (IQR 0–1.5; TR 0–5), consistent with the report of the CARENET study about 29 lesions in 27 patients. The PROFI study reports a median of 2 lesions/procedure (TR 0–13).

Considering only patients with DWI lesions on the post-treatment scan, our median number of lesions per patient, 3(IQR 2.5–3.5; TR 1–5), is consistent with the value of 3(IQR 1–9) reported in the MRI ICSS subgroup for the whole stenting group (124 patients, of which only 56 with filter protection; there is no specific information on the 56-patients subgroup).

Ipsilateral Lesion Volume

Our median volume of the 15 ipsilateral ischaemic lesions, 0.076 cm3 (IQR 0.065–0.146; TR 0.027–0.389), which can be compared directly with the value of 0.17 ml (IQR 0.06–0.58) reported by the MRI ICSS substudy. The volumes of ipsilateral ischaemic lesions were similar for symptomatic and asymptomatic patients and stable/not stable plaques. The CARENET study reports volumes as normal variables, i.e., 0.04 ± 0.08 cm3, and does not indicate the median and the range: however, it quotes as upper limit 0.445 cm3, which is comparable to our upper limit of 0.389 cm3. The PROFI study reports a median volume of 0.47 cm3 (TR 0–2.4) including also the procedures with no lesions: if we carried out the same analysis, our median volume would drop to 0.03 cm3 (TR 0–0.389).

The comparatively smaller volumes of ischaemic lesions observed in dual-layer stents could be due to the struts of the micromesh stent that detach debris of smaller size than those prolapsed through the conventional stent net.

30-Day DW-MRI

DW-MRI at the 30-day examination showed 0 % incidence for both post-CAS lesions and new lesions. In the CARENET study, the incidence of new lesions at follow-up was 4 %, corresponding to 1 lesion with volume 0.08 cm3. The MRI ICSS substudy reports results only for the general stenting group: 28/124 (33 %) post-treatment lesions still evident and 6 (4.8 %) new ischaemic lesions.

The total recovery and the absence of new ischaemic lesions in our patients could be explained by the high plaque scaffolding operated by the Roadsaver stent during the first 30 days after the procedure.

Follow-Up (1-month and 6-month)

At the FU examinations carried out at 1 month and 6 months, our rate of MACCE was 0 %. The PROFI study reports a 2 % rate (1/31) and the MRI ICSS substudy reports a 8.9 % (11/124) rate at one month for the overall stenting group.

The low lesion incidence rate, the limited number of ischaemic lesions, and their small volume are favourable results of our trial, particularly at the light of recent studies reporting that silent lesions discovered on DW-MRI after CAS seem to be a marker of increased risk for recurrent cerebrovascular events [14] and could be associated with cognitive changes after CAS [15]. Even if few data are available about the actual relationship between number and volume of ischaemic lesions and their effects on cognitive function, it is obvious that a stenting procedure that involves a low number of lesions per procedure, with small volumes and complete recovery at 30 days, would be a valuable asset for patients with carotid artery stenosis not suitable for endarterectomy. Our data, as the CARENET data, agree in proving the good outcome of double-layer non-conventional stents; if larger registries and trials with longer follow-up times will confirm these results, using non-conventional stent for CAS could translate into a safer procedure than using conventional devices.

Study Limitations

This is a single-centre study; if, on one hand, this feature limited the number of patients and, on the other, allowed homogeneity of protocols, patient management and, most of all, the same two operators carrying out all 23 procedures.

Since a transcranial Doppler was not used during the procedure, it was impossible to identify how many ischaemic lesions were related to procedural steps or early post-procedural embolization of the plaque through the stent struts.

Finally, it is a one-arm study, without control groups with proximal protection or no protection.

Conclusion

The results of the first single-centre study of the incidence of new ischaemic brain lesions after CAS with the Roadsaver stent indicate that this new double-layer micromesh stent may exert intrinsic embolic protection and impact positively on CAS outcomes. CAS with Roadsaver seems to be a safe procedure with a lower incidence of new ischaemic cerebral lesions than those reported in studies with conventional carotid stents.

The small population of the study limited the analysis of ipsilateral lesion volume according to presence/absence of symptoms and plaque characteristics (stable/not stable).

If these data will be eventually confirmed by larger studies and longer follow-ups, they could lead to a revision of carotid artery stenting.

Notes

Author Contribution

MAR and RF designed the protocol of the study, MAR submitted it to ethical committee for approval. LB analysed the data and performed the statistical analysis, and PF and DR gave the final approval of the manuscript submitted. All the authors give their written consent to be named in the manuscript.

Compliance with Ethical Standards

Conflict of Interest

There is no financial arrangement or other relationship that could be construed as a conflict of interest for each and every one of listed authors.

Ethical Approval

All procedures performed in this study were in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This study does not contain any studies with animals performed by any of the authors.

Informed Consent

Informed consent was obtained from all individual participants included in the study. Additional informed consent was obtained from all individual participants for whom identifying information is included in this article: does not apply.

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Copyright information

© Springer Science+Business Media New York and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) 2016

Authors and Affiliations

  1. 1.Vascular Radiology Unit, Department of Diagnostic Imaging and RadiotherapyAzienda Ospedaliera Universitaria- Città della Salute e della Scienza di Torino, San Giovanni Battista HospitalTurinItaly
  2. 2.Radiology Unit, Department of Surgical SciencesUniversity of Torino, Azienda Ospedaliera Universitaria- Città della Salute e della Scienza di Torino, San Giovanni Battista HospitalTurinItaly
  3. 3.Department of Surgical SciencesUniversity of Torino, Azienda Ospedaliera Universitaria- Città della Salute e della Scienza di Torino, San Giovanni Battista HospitalTurinItaly

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