​Objective

To assess immediate and long-term safety and effectiveness of CAS using the dual-layer micromesh Roadsaver^TM stent in the treatment of symptomatic or high-risk extracranial carotid artery stenosis.

Study Group

• Retrospective, Single-arm, Single-center 
  

• CAS procedures performed between 2014 and 2019 in a high-volume Polish centre
  
• 298 non-consecutive procedures (287 pts) (mean age: 70.5 ± 8.6; 203 men)
• 89 symptomatic cases (30%): 50% stenosis (by quantitative angiography) and with ipsilateral stoke and/or transient ischemic attack (TIA) within <6 months
• 209 high-risk stenosis (70%): by morphology: echolucent, highly lipidic, thrombus-containing, ulcerated, and “stringsign”
• 11 patients underwent a bilateral procedure
  

Methods

• In each patient computed tomography (CT) cranial scan was performed as part of an independent pre-procedural evaluation

• The severity of stenosis were evaluated by duplex ultrasonography (DUS: (peak systolic velocity (PSV) and end diastolic velocity (EDV)) and/or CT.
• All patients were on high-dose statins and dual antiplatelet therapy (DAPT; aspirin 75 mg and clopidogrel 75 mg daily for at least 3 days before the procedure or loading doses of 300 mg of aspirin and clopidogrel on the day before the procedure). 
• During CAS unfractionated heparin (100 IU/kg) was administred
• Atropine (1–2 mg i.v.) was administered just before stent implantation to avoid a  severe baroreceptor response. 
• Access: 
• Femoral (93.6%)
• Radial (right) (5.7% )
• Brachial (right) (0.7%) 
  
• Embolic protection device (EPD) use:  100%: 
• Proximal (Mo.Ma): 40.2% 
• Distal: 59.7% 
  
• Direct stenting was performed in 132 (44.2%) vs. 166 (55.7%) pre-dilatation
• Post-dilation: 100%
• Patients were discharged 1–2 days after procedure completion with the recommendation of continuation of aspirin, statin (indefinitely) and clopidogrel (for 3 months). 
• In 35 patients with atrial fibrillation vitamin K antagonists or novel oral anticoagulants (NOAC) were restarted after CAS. 

Results

• Successful implantation: 100%
  
• Carotid stenosis was reduced from 84.9 ± 9.9% (50–99%) to 11.0 ± 9.4% (0–33%) (p < 000.1). 
• DUS at 24-48h post-procedure:
• Mean PSV: 1.30 ± 0.35 vs 3.77 ± 1.70 m/s pre-procedure (p < 0.0001)
• Mean EDV: 0.31 ± 0.11 vs 1.32 ± 0.56 pre-procedure (p < 0.0001)
• DUS at 30 days post-procedure 
  
• Mean PSV: 1.20 ± 0.58 
• Mean EDV: 0.34 ± 0.16 
• 30-day complications (death & stroke) incidence
•  9 (3.0%)
  
• 1 in-hospital ipsilateral major stroke (0.34%) 
• 3 in-hospital ipsilateral minor (NIHSS<5) ischemic strokes (1,01%)
• 2 deaths due to hemorhagic strokes (on day 9 in hospital (due to hyperperfusion syndrome) & on day 21 (post-discharge; due to an unknown cause) (0.67%)
• 3 ipsilateral minor strokes after discharge, within 30 days post-procedure (1.01%)
• 2 cases (0.67%) associated with in-stent thrombosis on day 5 and 14 post-procedure, 1 of which occuring in patient later diagnosed as clopidogrel resistant
  
• DUS at 6 months post-procedure 
• Mean PSV:  1.2 ± 0.4  
• Mean EDV:  0.4 ± 0.10  
• DUS at 24 months post-procedure 
• Mean PSV: 1.30 ± 0.4 
• Mean EDV: 0.40 ± 0.10  
• DUS at 48 months post-procedure 
  
• Mean PSV: 1.35 ± 0.35 
• Mean EDV: 0.40 ± 0.10 
  

• 4-year Kaplan Meier event-free survival curve estimates
• Overall survival 82%
  
• 77% in Ax and 97% Sx (p = 0.076)
• 2 patients died due to an ischemic stroke (at 33 and 37 months)
  
• Stroke-free survival was 89% 
• Ax 84%  vs. Sx 98% (p = 0.187)
• 7 patients (2.3%)  developed > 50% In-Stent Restenosis (ISR) between 5 and 12 months post-porecedure
• 4 underwent successful angioplasty using drug-eluting balloon
• 2 cases required self-expandable drug-eluting stent implantation
• 1 patient was left on best medical treatment after a failed revascularization attempt due to a problem with vascular access (Leriche syndrome and unsuccessful radial/brachial access attempt)

Conclusion

Carotid artery stenting using the dual-layer micromesh Roadsaver^TM stent for symptomatic and high risk carotid artery lesions showed to be safe and effective, with a low complication rate and acceptable In-Stent Restenosis risk in 4-year follow-up.