Carotid Stent: Systematic Review with ☸️SAIMSARA.

• Generated: 2026-02-04 10:18:28 CET
• Plan: Pro (expanded craft tokens; source: Semantic Scholar)
• Source: Semantic Scholar
• Scope: All fields
• Keyword Gate: Fuzzy (≥60% of required terms, minimum 2 terms matched in title/abstract)
• Total Abstracts/Papers: 443352
• Downloaded Abstracts/Papers: 1000
• Included original Abstracts/Papers: 265
• Total study participants (naïve ΣN): 120140

• Bias: Qualitatively inferred from study design fields, with a notable presence of mixed-design, cohort, and retrospective studies alongside randomized controlled trials (RCTs). Sample sizes vary widely, from single case reports to large registries, introducing potential for selection bias and varying levels of evidence.

• Stent Design and Hemodynamics: Closed-cell stents are associated with larger areas of low Wall Shear Stress (WSS), elevated Oscillatory Shear Index (OSI), and high Relative Residence Time (RRT) compared to open-cell stents, which may influence restenosis [2, 18]. Open-cell stents demonstrated less moderate or higher restenosis (35.5%) compared to closed-cell stents (46.0%) over 4.0 years [3]. Computational fluid dynamics (CFD) and in-vitro studies analyze stent cell design and vessel scaffolding [8, 28, 65, 262].
• In-Stent Restenosis (ISR) and its Predictors: ISR is a significant complication, with reported rates ranging from 2.0% (≥70% ISR) to 46.0% [3, 4, 21]. Predictors include initial Carotid Wallstent implantation [4], contralateral carotid occlusion, carotid endarterectomy (CEA) restenosis, and postprocedural carotid duplex ultrasound with a peak systolic velocity (PSV) ≥120 cm/s [21]. Radiation-induced stenosis is also a strong predictor of ISR (25.7%) [161]. Inflammation and specific serum markers are implicated in ISR development [20, 47, 50, 249].
• Cerebral Protection and Embolic Events: Distal embolic protection devices reduce periprocedural diffusion-weighted imaging (DWI) lesion burden [6, 9]. Studies have evaluated various protection systems, including filter devices and balloon occlusion-aspiration, demonstrating their efficacy in preventing cerebral embolic events and collecting embolized debris [46, 54, 97, 98, 102, 110, 121, 127, 131, 172, 191, 192, 199, 201, 209, 210, 216, 230, 234, 240, 241, 255]. However, intraplaque hemorrhage was not a significant risk factor for cerebral embolism during CAS [86].
• Comparison with Carotid Endarterectomy (CEA): Transcarotid artery revascularization (TCAR) was associated with a lower risk of in-hospital stroke or death (1.6% vs 3.1%) compared to transfemoral carotid artery stenting (TF-CAS) [17]. Randomized trials comparing CAS and CEA show varied outcomes; for instance, CAS had a higher risk of stroke, death, or procedural myocardial infarction within 120 days (8.5% vs 5.2%) but similar long-term fatal or disabling stroke rates compared to CEA [157]. Overall, CAS is often associated with higher periprocedural stroke rates, while CEA may have a survival advantage [155, 158, 160, 165].
• Procedural Complications and Management: Complications include in-stent thrombosis (20.8%) and stent occlusion (7.5%) in emergent extracranial internal carotid artery (ICA) stenting for tandem occlusions [83]. Stent occlusions (5 cases) were noted in novel double-layer mesh stents used for acute stroke [5]. Periprocedural hypotension and bradycardia are common, with carotid sinus reactions influencing clinical outcomes [12, 31, 48, 79, 141, 193, 197, 259]. Symptomatic intracranial hemorrhage (sICH) rates ranged from 9% to 16.6% in emergency stenting with mechanical thrombectomy [87, 89], with higher intraprocedural heparin dosage increasing risk in specific subgroups [39].
• Specialized Applications and Novel Techniques: Intravascular lithotripsy has been used as an adjunct for stent expansion in heavily calcified lesions [1]. Robotic-assisted CAS demonstrates technical feasibility and safety, with 100% technical success and no neurological complications in small series [25, 150, 151]. Covered stents (e.g., Willis stent) are used for complex traumatic direct carotid-cavernous fistulas, pseudoaneurysms, and coil herniation during aneurysm embolization [7, 42, 45, 106, 107, 207]. Flow-diverter stents (FDSs) are used for aneurysms, though covering the ophthalmic artery may lead to complications (40%) despite patency (86%) [88, 146].
• Imaging and Monitoring: Duplex ultrasound is crucial for diagnosing and following up ISR, with specific velocity criteria established [24, 52, 58, 59, 74, 75, 117, 126, 130, 145]. Advanced imaging techniques like contrast-enhanced magnetic resonance angiography (CE-MRA), 3D time-of-flight (TOF), computed tomography angiography (CTA), and optical coherence tomography (OCT) are used for pre- and post-stent evaluation, though artificial lumen narrowing can be a challenge [22, 29, 32, 33, 115]. Near-infrared spectroscopy (NIRS) can predict cerebral hyperperfusion syndrome [174].

• Stent Selection: Open-cell stents may be preferred over closed-cell designs to reduce the risk of moderate or higher restenosis [3].
• Risk Stratification: Patients with radiation-induced carotid stenosis, a history of CEA restenosis, or younger age may be at higher risk for ISR and require closer monitoring [21, 161, 183].
• Cerebral Protection: Embolic protection devices are critical for reducing periprocedural cerebral embolic events and should be routinely employed in carotid stenting procedures [6, 9, 172, 191].
• Antiplatelet Therapy: Dual antiplatelet therapy is associated with better functional outcomes in acute stroke patients with tandem occlusions [39], and resistance to antiplatelet agents, particularly clopidogrel (51.9%), is a concern [147].
• Emergency Settings: While emergency stenting for acute stroke and tandem occlusions appears safe and effective for recanalization, careful management of antiplatelet agents and heparin is crucial to mitigate hemorrhage risk [39, 87, 89, 152].

• Long-term Outcomes of Novel Techniques: Further long-term follow-up studies are needed to fully establish the durability and safety of newer techniques like robotic-assisted stenting, intravascular lithotripsy, and specific covered/flow-diverter stents [1, 25, 88, 146, 151].
• Optimal Antiplatelet Regimens: Research is warranted to determine optimal antiplatelet strategies, particularly in patients with detected resistance or those undergoing emergency procedures, to balance thrombosis and hemorrhage risks [36, 39, 147, 194, 205, 231].
• Stent Design and Hemodynamics: More prospective studies are needed to correlate computational fluid dynamics (CFD) predictions of Wall Shear Stress (WSS) and Oscillatory Shear Index (OSI) with long-term clinical outcomes, especially ISR rates, across different stent designs [2, 18, 30].
• Cognitive Function Impact: The long-term impact of carotid stenting on various cognitive domains requires more comprehensive and standardized assessment beyond short-term improvements in specific scores [116, 129, 175].
• Imaging Modality Standardization: Development of standardized, stent-specific imaging protocols (e.g., CTA, CE-MRA, duplex ultrasound) is needed to accurately assess in-stent lumen and restenosis, accounting for artificial lumen narrowing [29, 32, 52, 58, 59, 74, 75].

• Heterogeneity of Study Designs — The diverse range of study designs (mixed, cohort, RCTs, case reports) limits direct comparability and meta-analysis of outcomes.
• Variability in Reporting — Inconsistent reporting of restenosis definitions (e.g., >50% vs ≥70%), follow-up durations, and specific patient populations complicates the synthesis of robust numerical results.
• Limited Long-term Data — While some studies offer long-term follow-up, many newer techniques or specific stent designs lack extensive long-term outcome data.
• Small Sample Sizes — Many studies, particularly those on novel techniques or specific complications, involve small sample sizes, which restricts the generalizability of their findings.
• Lack of Standardized Metrics — Different studies use varying metrics for success, complications, and imaging criteria, making it challenging to draw definitive comparative conclusions.

• Standardized Outcome Reporting — Implement uniform definitions and reporting standards for restenosis, stroke, and other complications across studies.
• Comparative Effectiveness Trials — Conduct large-scale, long-term randomized controlled trials comparing newer CAS techniques (e.g., TCAR, robotic-assisted) against established methods like transfemoral CAS and CEA.
• Advanced Imaging Biomarkers — Develop and validate advanced imaging techniques (e.g., AI-enhanced CTA/MRA, NIRS) for early detection of ISR, hyperperfusion syndrome, and plaque vulnerability.
• Robotic System Integration — Explore the integration of robotic systems for carotid stenting in diverse clinical settings, including remote locations, to improve precision and access.
• Personalized Antiplatelet Regimens — Investigate genotype-guided or platelet function-guided antiplatelet therapy to optimize outcomes and minimize complications in CAS patients.