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Ischemic Stroke
Original research
Safety and efficacy of an open-cell stent and double-balloon protection for unstable plaques: analysis of 184 consecutive carotid artery stentings
  1. Yusuke Funakoshi1,
  2. Hirotoshi Imamura1,
  3. Shoichi Tani1,
  4. Hidemitsu Adachi1,
  5. Ryu Fukumitsu1,
  6. Tadashi Sunohara1,
  7. Yoshihiro Omura1,
  8. Yuichi Matsui1,
  9. Natsuhi Sasaki1,
  10. Tatsumaru Fukuda1,
  11. Ryo Akiyama1,
  12. Kazufumi Horiuchi1,
  13. Shinji Kajiura1,
  14. Masashi Shigeyasu1,
  15. Koji Iihara2,
  16. Nobuyuki Sakai1
  1. 1 Department of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
  2. 2 Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
  1. Correspondence to Dr Yusuke Funakoshi, Neurosurgery, Kobe City Medical Center General Hospital, Kobe 650-0047, Japan; sf1wan0610{at}gmail.com

Abstract

Introduction In our institute, most cases of carotid artery stenosis are treated by carotid artery stenting (CAS) with an open-cell stent and double-balloon protection, even if plaques are unstable. This study was performed to examine the outcome of CAS with an open-cell stent and double-balloon protection for unstable plaques.

Methods A total of 184 CAS procedures in our institute between October 2010 and February 2018 were assessed. Ultrasonography findings of low-echo plaques, plaque ulceration, or both were defined as unstable plaques. A plaque-to-muscle ratio (PMR) of >1.8 on T1-weighted black blood imaging using spin-echo was also defined as an unstable plaque. Seventy-four unstable plaques on ultrasonography and 86 unstable plaques evaluated by PMR were included. Open-cell stents and double-balloon protection (proximal balloon protection during lesion crossing and distal balloon protection after lesion crossing) were used in all cases.

Results On ultrasonography, perioperative asymptomatic thromboembolization was significantly more frequent in the unstable plaque group (39/74, 52.7%) than in the stable plaque group (41/110, 37.3%, p=0.0384). Asymptomatic thromboembolization was also significantly more frequent in the PMR >1.8 group (44/86, 51.2%) than in the PMR <1.8 group (36/98, 36.7%, p=0.0489). However, symptomatic thromboembolization was rare (n=5, 2.7%), and all of these patients had minor stroke. During the 4-year follow-up, the risk of ipsilateral stroke was 0.28% and 0.27% per year in patients with symptomatic and asymptomatic lesions, respectively.

Conclusions The outcomes of CAS with an open-cell stent and double-balloon protection are acceptable. This method is effective and safe, even if carotid artery stenosis comprises unstable plaques.

  • plaque
  • stenosis
  • stent
  • stroke

https://doi.org/10.1136/neurintsurg-2019-015393

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    Introduction

    In 2004, the SAPPHIRE trial showed that carotid artery stenting (CAS) was not inferior to carotid endarterectomy (CEA) in patients with a high risk of CEA.1 In the CREST study, which investigated the normal risk of CEA, no significant difference in the risk of the composite primary outcome of stroke, myocardial infarction, or death was found between CEA and CAS in 2010.2 Symptomatic and asymptomatic carotid artery stenosis were assessed in the SAPPHIRE trial and CREST. However, in 2016, the ACT-1 study showed that CAS was non-inferior to CEA for asymptomatic carotid artery stenosis with regard to the primary composite end point (death, stroke, or myocardial infarction within 30 days after the procedure or ipsilateral stroke within 1 year).3 Evidence of using CAS has recently been accumulated from the results of these studies.

    Plaque characteristics are important for selecting CEA or CAS and determining what devices should be used when CAS is selected.4–8 Ultrasonography (US) or MRI is useful for preoperative diagnosis of unstable plaques. With regard to performing CAS for carotid artery stenosis with unstable plaques, the risk of thromboembolization has been reported but sufficient safety of CAS has not been established.4 5 CEA is recommended for the treatment of unstable plaques,6 7 and the safety of tailored CAS has recently been reported.8 However, in our institute, most cases of carotid artery stenosis are treated by CAS with an open-cell stent and double-balloon protection. This study was performed to examine the outcomes of CAS with an open-cell stent and double-balloon protection (proximal balloon protection during lesion crossing and distal balloon protection after lesion crossing) for unstable plaques.

    Methods

    Study population

    In our institute, CAS was performed for symptomatic carotid artery stenosis with >50% stenosis by the NASCET angiographic criteria, and for asymptomatic carotid artery stenosis with >80% stenosis or a peak systolic velocity of >300 cm/s. In total, 267 CAS procedures were performed between October 2010 and February 2018 in our institute. Of these, 184 consecutive CAS procedures with an open-cell stent (PRECISE; Cordis, Miami, Florida, USA) and double-balloon protection (distal balloon protection combined with proximal balloon protection) were retrospectively assessed. Twenty-eight patients who had acute symptomatic carotid artery stenosis treated within 1 week from onset and four patients who developed restenosis after CAS were excluded. One patient who was treated via the transbrachial approach because of difficult access via the transfemoral approach was also excluded. Additionally, we excluded 36 patients who were treated with a stent device other than the PRECISE (Carotid Wallstent, Boston Scientific, Natick, Massachusetts, USA (n=14); Protégé, ev3-Covidien, Irvine, California, USA (n=8), or an off-label stent (n=14)) and 14 patients treated under distal filter protection (FilterWire EZ, Boston Scientific (n=12) and Spider FX, ev3-Covidien (n=2)).

    Plaque imaging

    The plaques were evaluated by US (LOGIQ E9; GE Healthcare Japan, Tokyo, Japan) and MRI (MAGNETOM AVANTO 1.5 T scanner; Siemens, Erlangen, Germany). On US, unstable plaques showed an echolucent appearance and ulceration.9 10 In the present study, US findings of low-echo plaques, plaque ulceration, or both were defined as unstable plaques. The plaque-to-muscle ratio (PMR) measured using MRI is a reliable and convenient index for evaluating unstable plaques.11 A PMR of >1.8 on T1-weighted black blood imaging using spin-echo was also defined as an unstable plaque.

    Periprocedural antiplatelet management

    Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel was generally performed for CAS. The patients took 100 mg aspirin and 75 mg clopidogrel daily for at least 7 days before the procedure. For the patients who had previously taken cilostazol, aspirin was added. DAPT was discontinued after at least 3 months postoperatively, and single antiplatelet therapy was continued as a life-long treatment. When cardiovascular disease was diagnosed before the procedure, treatment for cardiovascular disease preceded the procedure.

    CAS procedure

    CAS was generally performed under local anesthesia during observation by transcranial Doppler US using the LOGIQ E9 and near infrared spectroscopy using a spectrophotometer (INVOS; Somanetics Corp, Troy, Michigan, USA). Two CAS procedures were performed under general anesthesia because of an extremely high risk of hyperperfusion. All patients received heparin after an arterial puncture to maintain an activated clotting time of >300 s during the procedure. CAS was performed via the transfemoral approach with a guiding system (Mo.Ma Ultra; Medtronic, Minneapolis, Minnesota, USA). When the Mo.Ma Ultra could not be induced, a 9 Fr balloon guiding catheter (Optimo; Tokai Medical Products, Aichi, Japan or Cello; ev3-Covidien) was used. In all cases, double-balloon protection was performed. Double-balloon protection was defined as proximal balloon protection during lesion crossing combined with distal balloon protection after lesion crossing. During lesion crossing, a proximal balloon with the Mo.Ma Ultra (which can interrupt the common carotid artery (CCA) and the external carotid artery (ECA)) or another balloon guiding catheter (which interrupted only the CCA) was inflated and flow to the lesion was reduced (proximal balloon protection) (figure 1A,D). After lesion crossing, a distal balloon with the PercuSurge GuardWire (Medtronic) was inflated and a proximal balloon at the CCA was deflated (transition from proximal balloon protection to distal balloon protection) (figure 1B,E). The distal balloon with the PercuSurge GuardWire was fitted at the distal aspect of the lesion in all cases. The angioplasty balloon diameter was determined by intravascular US measurement (Volcano Eagle Eye Platinum imaging catheter; Volcano Corporation, San Diego, California, USA). Pre-dilatation was generally performed with a 3.0–3.5 mm diameter angioplasty balloon and post-dilatation was performed with a 3.5–4.5 mm diameter angioplasty balloon. These diameters were approximately 80% undersized compared with the distal non-diseased vessel diameter. The PRECISE stent was deployed in all cases (figure 1C,F). After post-dilatation, intravascular US was repeated to evaluate in-stent plaque protrusion. Finally, the distal balloon was deflated after aspirating as much debris as possible.

    Figure 1
    Figure 1

    Double-balloon protection. (A) Proximal balloon protection was used during lesion crossing. The external carotid artery and the common carotid artery (CCA) were interrupted with the Mo.Ma ultra guiding system (Medtronic, Minneapolis, Minnesota, USA), which is shown in blue. (B) The PercuSurge GuardWire (Medtronic), which is shown in green, was used as distal balloon protection after lesion crossing and interruption of the CCA was discontinued. (C) The precise stent was deployed under distal balloon protection. (D–F) When the Mo.Ma ultra system could not be induced, a 9 Fr balloon guiding catheter was used to interrupt the CCA without interruption of the external carotid artery.

    Follow-up

    Neurological evaluation was performed at baseline, immediately after the procedure, 24 hours after the procedure, and once a day for 7 days. Intraprocedural and 30-day postprocedural complications were defined as periprocedural complications. MRI and single-photon emission CT were performed the day after the procedure. Follow-up studies were performed at 1, 6, and 12 months afterwards and annually thereafter. The modified Rankin scale (mRS) was used to evaluate the functional prognosis. Stroke was defined as an acute neurological event with focal symptoms and signs that lasted for ≥24 hours and were consistent with focal cerebral ischemia. Minor stroke was defined as a 1 or 2 point increase in the mRS score, and major stroke was defined as a ≥3 point increase in the mRS score. Carotid US was performed before the procedure; at 1, 6, and 12 months after the procedure; and every year thereafter.

    Statistical analysis

    Statistical analyses were performed using statistical software (JMP software, version 14; SAS Institute, Cary, North Carolina, USA). Periprocedural complications were evaluated using the χ2 test. A P value of<0.05 was considered statistically significant.

    Results

    Patient and lesion characteristics

    The characteristics of the patients and lesions are shown in table 1. The mean age of the included patients was 72.5±7.1 years and there were 156 (84.8%) men. A total of 98 (53.3%) asymptomatic lesions were included. With regard to risk factors for stroke, 146 (79.3%) patients had hypertension, 70 (38.0%) had diabetes, 124 (67.4%) had dyslipidemia, 117 (63.6%) were smokers, 66 (35.9%) had previous cardiovascular disease, 52 (28.3%) had undergone previous coronary artery bypass grafting or percutaneous coronary intervention, 42 (22.8%) had previous cerebrovascular disease, and 17 (9.2%) had previous peripheral artery disease. The median peak systolic velocity was 310.8 cm/s, and the median percentage of stenosis measured on digital subtraction angiography was 72.0%. In total, 74 (40.2%) unstable plaques were evaluated by US. The median PMR was 1.76 and 86 (46.7%) unstable plaques were evaluated by MRI. Proximal protection with the Mo.Ma Ultra combined with distal protection with the PercuSurge GuardWire was performed in 79 (42.9%) patients. Optimo or Cello catheters instead of the Mo.Ma Ultra guiding system were used in 105 (57.1%) patients. PRECISE stents were used in all 184 patients.

    View this table:
    Table 1

    Patient and lesion characteristics and devices used for carotid artery stenting

    Periprocedural complications

    Periprocedural complications are shown in table 2. Bradycardia/hypotension occurred in 50 (27.2%) and intolerance in 36 (19.6%) patients. In-stent plaque protrusion was found in 23 (12.5%) and asymptomatic thromboembolization in 80 (43.5%) patients. Symptomatic thromboembolization was rare (n=5, 2.7%), and all of these patients had minor stroke. Five (2.7%) patients had asymptomatic hyperperfusion and three (1.6%) had hyperperfusion syndrome. Although intracranial hemorrhage occurred in one patient, it was asymptomatic with a small amount of subarachnoid hemorrhage.

    View this table:
    Table 2

    Periprocedural complications in the stable and unstable plaque groups

    US showed 74 patients with unstable plaques and 110 with stable plaques. Asymptomatic thromboembolization was significantly more frequent in the unstable plaque group than in the stable plaque group (p=0.0384).

    MRI showed that 86 patients had a PMR of >1.8 (unstable plaque) and that 98 had a PMR of <1.8 (stable plaque). Asymptomatic thromboembolization was significantly more frequent in the unstable plaque group than in the stable plaque group (p=0.0489).

    Both US and MRI showed no significant difference in the occurrence of symptomatic thromboembolization between the stable and unstable plaque groups.

    Follow-up study

    The 4-year follow-up outcomes are shown in table 3. Six patients with symptomatic lesions died, and the annual risk of death was 1.7%. Minor ipsilateral stroke occurred in one patient, and the annual rate was 0.28%. Restenosis requiring retreatment occurred in three patients, and the annual rate was 0.84%. Two patients with asymptomatic lesions died, and the annual risk of death was 0.54%. Minor ipsilateral stroke occurred in one patient, and the annual rate was 0.27%. The patient stopped antiplatelet therapy without permission. Restenosis requiring retreatment did not occur in any patients.

    View this table:
    Table 3

    Outcomes at 4 years of follow-up

    Discussion

    Principle of CAS in our institute

    Evidence regarding the usefulness of CAS has recently accumulated.1–3 The safety of tailored CAS has been reported and the importance of device selection has been emphasized.8 We consider that CAS with a consistent method has fewer problems than different and unaccustomed methods. Most cases of carotid artery stenosis are treated by CAS with an open-cell stent (PRECISE stent) and double-balloon protection via the transfemoral approach in our institute. CAS with distal balloon protection via the transbrachial approach is performed only when the transfemoral approach is impossible. Additionally, CEA is selected when the curve of the lesion is too great for achieving good crimping of the stent, DAPT is impossible because of patient-related factors, or access to the lesion is impossible due to problems of the aortic arch.

    Periprocedural complications

    The SAPPHIRE trial showed the safety and efficacy of CAS in patients with a high risk of CEA, and the rate of stroke within 30 days after the procedure was 3.1%.1 The CREST study investigated the normal risk of CEA, and the rate of stroke within 30 days after the procedure was 4.1%.2 The ACT-1 study showed the safety and efficacy of CAS compared with CEA for only asymptomatic carotid artery stenosis, and the rate of stroke within 30 days after the procedure was 2.8%.3 In the present study, the rate of stroke within 30 days after the procedure was 3.3% (2.2% in symptomatic lesions and 4.3% in asymptomatic lesions). This included five cases of symptomatic thromboembolization and one case of asymptomatic minor subarachnoid hemorrhage. There was no major stroke or myocardial infarction, which occurred in previous studies.1–3 The outcomes in our study were not inferior to those of previous studies.

    Ogasawara et al reported that the rate of hyperperfusion syndrome after CAS was 1.1% and that 44% of cases of this syndrome caused intracranial hemorrhage.12 In the present study, three patients (1.6%) developed hyperperfusion syndrome. The hyperperfusion syndrome in one (33.3%) of these three patients caused intracranial hemorrhage. This frequency is almost equal to that in the study by Ogasawara et al 12

    Follow-up study

    In the CREST study the 4-year rate of ipsilateral stroke was 5.9%.2 The long-term outcomes of the International Carotid Stenting Study, including CAS and CEA only for symptomatic carotid artery stenosis, showed that the 5-year cumulative risk rate of ipsilateral stroke after CAS was 4.7%.13 In ACT-1, the 5-year rate of freedom from non-procedure-related ipsilateral stroke was 97.8%.3 The risk of stroke in patients with carotid artery stenosis may decline because medical treatment is improving. In the SMART study, in which asymptomatic carotid artery stenosis was evaluated, the annual risk of ischemic stroke in any territory was 0.43% in 50–99% of patients with asymptomatic stenosis, and the annual risk of ipsilateral ischemic stroke was 0.27%.14 In the present study, the annual risk of ischemic stroke in any territory was 0.56% in patients with symptomatic lesions and 0.54% in those with asymptomatic lesions, and the annual risk of ipsilateral ischemic stroke was 0.28% in patients with symptomatic lesions and 0.27% in those with asymptomatic lesions. No major ischemic stroke occurred in any patients. These outcomes are considered acceptable. Additionally, although eight patients died in the follow-up term, the causes of death were carcinoma in four, pneumonia in two, respiratory failure in one, and renal failure in one patient. None of the patients died of stroke.

    Plaque imaging

    Conventionally, US is a well-known method for evaluating carotid disease.15 Unstable plaques are associated with fatty and hemorrhagic content, with an echolucent appearance and ulceration.9 10 Unstable plaques are also associated with an increased risk of future stroke or transient ischemic attack and periprocedural complications of CAS.4 16 T1-weighted black blood imaging is widely used to evaluate the characterization and assessment of plaques. The PMR is a reliable and convenient index for evaluation of unstable plaques.11 In the present study the plaques were classified as stable or unstable depending on the MRI and US findings. MRI and US showed significantly more cases of asymptomatic thromboembolization in the unstable plaque group than in the stable plaque group, as expected. However, symptomatic complications, including symptomatic thromboembolization, were rare, and there were no significant differences between the groups. The functional prognosis may be at the same level in the two groups.

    Stent device

    Schillinger et al reported that the difference in stent cell design was not related to neurological complications, stroke, or mortality risk.17 The PRECISE is a nitinol self-expanding open-cell stent. This stent is used for most cases of CAS in our institute because we believe that there are fewer technical and device issues with the PRECISE than with other stents. The Carotid Wallstent, which is a nitinol self-expanding closed-cell stent with a small free-cell area, is recommended for CAS, particularly with unstable plaques.18 However, slipping down or shortening of this stent has been reported,19 and Harada et al stated that even closed-cell stents may not solve the problem of unstable plaque tissue prolapse between struts using optical coherence tomography.20 Additionally, the risk of restenosis in the PRECISE stent is lower than that in the Carotid Wallstent. The risk of restenosis in the SAPPHIRE trial, in which the PRECISE stent was used, was 0.6% at 1 year.1 The risk of restenosis in the BEACH trial, in which the Carotid Wallstent was used, was 5.2% at 1 year.21 In fact, technical and device issues with the PRECISE stent did not occur, and restenosis occurred in only three symptomatic lesions at the 4-year follow-up in the present study.

    Double-balloon protection

    Although embolization protection devices, such as distal balloon protection, proximal balloon protection, or distal filter protection, are selected depending on the cases, the risk of thromboembolization is probably not different among these devices.22 However, Lee et al emphasized the importance of proximal protection, including interruption of the ECA, and reported a novel balloon technique in which flow is arrested at the proximal internal carotid artery after distal CCA occlusion with an angioplasty balloon and balloon guiding catheter.23 In our institute, double-balloon protection (a combination of distal and proximal balloon protection) is performed because reliable protection should be achieved. In this method, proximal balloon protection is used during lesion crossing. Once distal balloon protection is completed after lesion crossing, proximal balloon protection is discontinued and the procedure proceeds under distal balloon protection. With this protection, high-intensity transient signals during monitoring by transcranial Doppler US are rarely experienced. Distal filter protection is rarely used in our institute because migration of small particulate debris (smaller than the filter pores) into the cerebral artery can occur, and advancement of the filter device across an unstable lesion is not always safe.24–26 Distal balloon protection combined with proximal protection has an advantage because the same procedure is possible regardless of plaque characteristics, and it is effective for unstable plaques or severe stenosis causing problems and difficulty in lesion crossing.27 28

    Study limitations

    The present study was a non-randomized, retrospective, observational study, although the patients were consecutively enrolled. The follow-up population was too small to assess the detailed long-term prognosis. Additionally, interpretation of the radiographic data was performed in a non-blinded manner. Although we compared periprocedural complications between the stable plaque and unstable plaque groups, the definition of unstable plaques should be established more strictly. Furthermore, outcomes are affected by other factors, including the skill level of the surgeons and the type of devices used. Therefore, future studies with more patients are required.

    Conclusion

    The outcomes of CAS with an open-cell stent and double-balloon protection in our institution were acceptable. This method is effective and safe even if carotid stenosis comprises unstable plaques.

    Acknowledgments

    We thank Angela Morben from Edanz Group (www.edanzediting.com/ac) for editing a draft of this manuscript.

    References

    1. ↵
      2. Yadav JS ,
      3. Wholey MH ,
      4. Kuntz RE , et al
      . Protected carotid-artery stenting versus endarterectomy in high-risk patients. N Engl J Med 2004;351:1493–501.doi:10.1056/NEJMoa040127
      OpenUrlCrossRefPubMedWeb of Science
    2. ↵
      2. Brott TG ,
      3. Hobson RW ,
      4. Howard G , et al
      . Stenting versus endarterectomy for treatment of carotid-artery stenosis. N Engl J Med 2010;363:11–23.doi:10.1056/NEJMoa0912321
      OpenUrlCrossRefPubMedWeb of Science
    3. ↵
      2. Rosenfield K ,
      3. Matsumura JS ,
      4. Chaturvedi S , et al
      . Randomized trial of stent versus surgery for asymptomatic carotid stenosis. N Engl J Med Overseas Ed 2016;374:1011–20.doi:10.1056/NEJMoa1515706
      OpenUrl
    4. ↵
      2. Yoshimura S ,
      3. Yamada K ,
      4. Kawasaki M , et al
      . High-Intensity signal on time-of-flight magnetic resonance angiography indicates carotid plaques at high risk for cerebral embolism during stenting. Stroke 2011;42:3132–7.doi:10.1161/STROKEAHA.111.615708
      OpenUrlAbstract/FREE Full Text
    5. ↵
      2. Sakamoto M ,
      3. Taoka T ,
      4. Nakagawa H , et al
      . Magnetic resonance plaque imaging to predict the occurrence of the slow-flow phenomenon in carotid artery stenting procedures. Neuroradiology 2010;52:275–83.doi:10.1007/s00234-009-0623-7
      OpenUrlCrossRefPubMed
    6. ↵
      2. Kashiwazaki D ,
      3. Shiraishi K ,
      4. Yamamoto S , et al
      . Efficacy of carotid endarterectomy for mild (<50%) symptomatic carotid stenosis with unstable plaque. World Neurosurg 2019;121:e60–9.
      OpenUrlCrossRefPubMed
    7. ↵
      2. Takai H ,
      3. Uemura J ,
      4. Yagita Y , et al
      . Plaque characteristics of patients with symptomatic mild carotid artery stenosis. J Stroke Cerebrovasc Dis 2018;27:1930–6.doi:10.1016/j.jstrokecerebrovasdis.2018.02.032
      OpenUrlCrossRefPubMed
    8. ↵
      2. Miyachi S ,
      3. Taki W ,
      4. Sakai N , et al
      . Historical perspective of carotid artery stenting in Japan: analysis of 8,092 cases in the Japanese CAS survey. Acta Neurochir 2012;154:2127–37.doi:10.1007/s00701-012-1508-9
      OpenUrlCrossRefPubMed
    9. ↵
      2. Mathiesen EB ,
      3. Bønaa KH ,
      4. Joakimsen O
      . Echolucent plaques are associated with high risk of ischemic cerebrovascular events in carotid stenosis: the Tromsø study. Circulation 2001;103:2171–5.doi:10.1161/01.CIR.103.17.2171
      OpenUrlAbstract/FREE Full Text
    10. ↵
      2. Prabhakaran S ,
      3. Rundek T ,
      4. Ramas R , et al
      . Carotid plaque surface irregularity predicts ischemic stroke: the Northern Manhattan study. Stroke 2006;37:2696–701.
      OpenUrlAbstract/FREE Full Text
    11. ↵
      2. Eto A ,
      3. Kinoshita Y ,
      4. Matsumoto Y , et al
      . Relationship between the carotid plaque T1 relaxation time and the plaque-to-muscle signal intensity ratio on black-blood magnetic resonance imaging scans. J Stroke Cerebrovasc Dis 2016;25:2580–4.doi:10.1016/j.jstrokecerebrovasdis.2016.06.041
      OpenUrlCrossRefPubMed
    12. ↵
      2. Ogasawara K ,
      3. Sakai N ,
      4. Kuroiwa T , et al
      . Intracranial hemorrhage associated with cerebral hyperperfusion syndrome following carotid endarterectomy and carotid artery stenting: retrospective review of 4494 patients. J Neurosurg 2007;107:1130–6.doi:10.3171/JNS-07/12/1130
      OpenUrlCrossRefPubMedWeb of Science
    13. ↵
      2. Bonati LH ,
      3. Dobson J ,
      4. Featherstone RL , et al
      . Long-term outcomes after stenting versus endarterectomy for treatment of symptomatic carotid stenosis: the International Carotid Stenting Study (ICSS) randomised trial. Lancet 2015;385:529–38.doi:10.1016/S0140-6736(14)61184-3
      OpenUrlCrossRefPubMed
    14. ↵
      2. den Hartog AG ,
      3. Achterberg S ,
      4. Moll FL , et al
      . Asymptomatic carotid artery stenosis and the risk of ischemic stroke according to subtype in patients with clinical manifest arterial disease. Stroke 2013;44:1002–7.doi:10.1161/STROKEAHA.111.669267
      OpenUrlAbstract/FREE Full Text
    15. ↵
      2. Naim C ,
      3. Douziech M ,
      4. É T , et al
      . Vulnerable atherosclerotic carotid plaque evaluation by ultrasound, computed tomography angiography, and magnetic resonance imaging: an overview. Can Assoc Radiol J 2014;65:275–86.
      OpenUrl
    16. ↵
      2. Gupta A ,
      3. Baradaran H ,
      4. Schweitzer AD , et al
      . Carotid plaque MRI and stroke risk: a systematic review and meta-analysis. Stroke 2013;44:3071–7.doi:10.1161/STROKEAHA.113.002551
      OpenUrlAbstract/FREE Full Text
    17. ↵
      2. Schillinger M ,
      3. Gschwendtner M ,
      4. Reimers B , et al
      . Does carotid stent cell design matter? Stroke 2008;39:905–9.doi:10.1161/STROKEAHA.107.499145
      OpenUrlAbstract/FREE Full Text
    18. ↵
      2. Bosiers M ,
      3. de Donato G ,
      4. Deloose K , et al
      . Does free cell area influence the outcome in carotid artery stenting? Eur J Vasc Endovasc Surg 2007;33:135–41.doi:10.1016/j.ejvs.2006.09.019
      OpenUrlCrossRefPubMedWeb of Science
    19. ↵
      2. Yoon S-M ,
      3. Jo KW ,
      4. Baik MW , et al
      . Delayed carotid Wallstent shortening resulting in restenosis following successful carotid artery angioplasty and stenting. J Korean Neurosurg Soc 2009;46:495–7.doi:10.3340/jkns.2009.46.5.495
      OpenUrlCrossRefPubMed
    20. ↵
      2. Harada K ,
      3. Oshikata S ,
      4. Kajihara M
      . Optical coherence tomography evaluation of tissue prolapse after carotid artery stenting using closed cell design stents for unstable plaque. J Neurointerv Surg 2018;10:229–34.doi:10.1136/neurintsurg-2017-013004
      OpenUrlAbstract/FREE Full Text
    21. ↵
      2. White CJ ,
      3. Iyer SS ,
      4. Hopkins LN , et al
      . Carotid stenting with distal protection in high surgical risk patients: the BEACH trial 30 day results. Catheter Cardiovasc Interv 2006;67:503–12.doi:10.1002/ccd.20689
      OpenUrlCrossRefPubMedWeb of Science
    22. ↵
      2. Omran J ,
      3. Mahmud E ,
      4. White CJ , et al
      . Proximal balloon occlusion versus distal filter protection in carotid artery stenting: a meta-analysis and review of the literature. Catheter Cardiovasc Interv 2017;89:923–31.doi:10.1002/ccd.26842
      OpenUrl
    23. ↵
      2. Lee SH ,
      3. Lee DG ,
      4. Kwon SU , et al
      . Relay-balloon technique for recanalization of acute symptomatic proximal internal carotid artery occlusion with short balloon-tipped guiding catheter landing zone. J Neurointerv Surg 2018;10:39–43.doi:10.1136/neurintsurg-2016-012900
      OpenUrlAbstract/FREE Full Text
    24. ↵
      2. Siewiorek GM ,
      3. Wholey MH ,
      4. Finol EA
      . In vitro performance assessment of distal protection devices for carotid artery stenting: effect of physiological anatomy on vascular resistance. J Endovasc Ther 2007;14:712–24.doi:10.1177/152660280701400517
      OpenUrlCrossRefPubMedWeb of Science
    25. ↵
      2. Finol EA ,
      3. Siewiorek GM ,
      4. Scotti CM , et al
      . Wall apposition assessment and performance comparison of distal protection filters. J Endovasc Ther 2008;15:177–85.doi:10.1583/07-2272.1
      OpenUrlCrossRefPubMed
    26. ↵
      2. Dargazanli C ,
      3. Mahmoudi M ,
      4. Cappucci M , et al
      . Angiographic patterns and outcomes achieved by proximal balloon occlusion in symptomatic carotid artery stenosis stenting. Clin Neuroradiol 2019. doi:doi:10.1007/s00062-019-00770-8. [Epub ahead of print: 07 Mar 2019].
    27. ↵
      2. Parodi JC ,
      3. Schönholz C ,
      4. Ferreira LM , et al
      . "Seat belt and air bag" technique for cerebral protection during carotid stenting. J Endovasc Ther 2002;9:20–4.doi:10.1177/152660280200900104
      OpenUrlCrossRefPubMedWeb of Science
    28. ↵
      2. Tsumoto T ,
      3. Terada T ,
      4. Tsuura M , et al
      . Carotid artery stenting for stenosis with intraluminal thrombus. Neuroradiology 2006;48:54–9.doi:10.1007/s00234-005-0015-6
      OpenUrlCrossRefPubMedWeb of Science

    Footnotes

    • Contributors All authors meet the ICMJE authorship criteria. YF designed this study and wrote the initial draft of the manuscript. All other authors critically reviewed the manuscript and assisted in the preparation of the manuscript. All authors approved the final version of the manuscript, and agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

    • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

    • Competing interests None declared.

    • Patient consent for publication Not required.

    • Provenance and peer review Not commissioned; externally peer reviewed.

    • Data availability statement Data are available upon reasonable request.