Clinical trial of carotid artery stenting using dual-layer CASPER stent for carotid endarterectomy in patients at high and normal risk in the Japanese population

A case of de novo extra-stent ulceration induced by persistent plaque protrusion after carotid artery stenting with a CASPER stent for a large-volume unstable plaque

Plaque protrusion (PP) has been identified as a perioperative complication of carotid artery stenosis treated with carotid artery stenting (CAS). The CASPER stent (CS), a dual-layer micromesh stent, may be able to prevent PP. Despite using CS, de novo extra-stent ulceration induced by persistent PP is rare. A 75-year-old male patient, whose superficial temporal artery-middle cerebral artery bypass tended to occlude, underwent CAS using a CS for symptomatic pseudo-occlusive internal carotid artery with a large-volume unstable plaque. This led to de novo extra-stent ulceration induced by persistent PP, resulting in ischemic stroke that necessitated the application of the stent-in-stent technique. There was no recurrence of cerebral infarction postoperatively at 12 months. Here, we present, to the best of our knowledge, the first case of a patient with de novo extra-stent ulceration induced by persistent PP after CAS that led to de novo extra-stent ulceration. The inhibition of intimal formation on the stent surface caused by persistent PP was considered to be the underlying mechanism. The stent-in-stent technique is beneficial even in cases of PP accompanied by de novo extra-stent ulceration.

Important Notes for Preventing Entrapment of Distal Filter-based Embolic Protection Device in Carotid Artery Stenting

Failure to retrieve a distal filter-based embolic protection device (EPD) is a potential complication of carotid artery stenting. This may be caused by trapping of the proximal marker of the EPD within the stent tip marker. Maintaining an adequate distance between the two can prevent this. We examined the behavior of several stent-filter-based EPD combinations, focusing on their propensity to become trapped or disengage in vitro. Four physicians subjectively rated the force required to result in trapping using a 5-point scale. Moreover, the force required to disengage trapped devices was evaluated. The Casper stent-Spider FX EPD combination was difficult to disengage when entrapment occurred, which suggested that this phenomenon tended to occur with this combination. The stent tip marker of the closed-cell stents advanced as they shortened, which may be a unique feature of closed-cell stents. Although trapping is uncommon, it can cause serious complications. To prevent these complications, device characteristics should be well understood before they are used in patients.

Free-Cell Area Impact on Stroke Prevention in Asymptomatic Patients Undergoing Carotid Artery Stenting: The "Carotid Artery sTenting And CeLl-area Impact on Stroke and Major Adverse events" (CATACLISMA) Multicenter Registry

PURPOSE

The study investigated the association between cell-stent area and cerebrovascular events incidence in asymptomatic patients undergoing carotid artery stenting (CAS).

MATERIALS AND METHODS

This is an observational, retrospective, multicenter, cohort study. Between 2012 and 2022, all patients undergoing primary CAS for severe asymptomatic carotid artery stenosis were evaluated. Three groups were defined on the basis of the cell area (open cell, OC; closed cell, CC; double layer, DL). Periprocedural primary outcomes were 30-day stroke, mortality, myocardial infarction (MI), and major adverse event (MAE, stroke/mortality composite outcome) rates. Follow-up primary outcomes included overall survival, stroke-free survival (SFS), freedom from ipsilateral stroke (FFiS), and freedom from stroke-related mortality (FF-SRM). Data were analyzed at short-term (1 year) and mid-term (2.5 years) period.

RESULTS

A total of 1096 CAS were considered (787 men, 71.8%, median age = 74 years). Technical success was achieved in 99.5% procedures. Periprocedural 30-day stroke rate was 1.5% (OC: 1.1%, CC: 2.3%, DL: 1%, p=0.27), mortality was 0.7% (OC: 1.1%, CC: 0.3%, DL: 0.5%, p=0.35), and no MI was recorded. The MAE rate was 2.1% (OC: 2%, CC: 2.6%, DL: 1.5%, p=0.66). Median follow-up was 46 months. At 1 and 2.5 years, estimated overall survival was 96.1% and 91% (p=0.41), SFS was 99.1% and 98.2% (p=0.007, CC stroke rates 2.9% and 4.2% at timepoints), FFiS was 99.4% and 99% (p=0.014, CC FFiS rates 1.7% and 2.6% at timepoints) and FF-SRM was 99.5% and 99% (p=0.28). During follow-up, no stroke events occurred in DL group. CC design showed higher rates of any (4.2%) and ipsilateral stroke (2.6%) within 2.5 years.

CONCLUSION

In asymptomatic patients undergoing CAS, the contemporary overall stroke incidence is 1.5%. No statistical differences were observed in terms of 30-day stroke incidence among groups. The closed free-cell area showed higher rates of any and ipsilateral stroke within 2.5 years. The DL stents may offer the best available performances in terms of mid-term stroke prevention.

CLINICAL IMPACT

The study analyzed the contemporary results of carotid artery stenting (CAS) focusing on the impact of cell-stent area on peri- and post-operative cerebrovascular events in a multicenter real-world experience. In asymptomatic patients undergoing CAS the contemporary overall stroke incidence is 1.5%. No statistical differences were observed in terms of 30-day stroke incidence among groups. The closed free-cell area showed higher rates of any and ipsilateral stroke within 2.5 years. DL stents may offer the best available performances in terms of mid-term stroke prevention.

Clinical results of 30 consecutive patients of carotid artery stenosis treated with CASPER stent placement: 1-year follow-up and in-stent findings on intravascular ultrasound examination immediately and 6 months after treatment

BACKGROUND

The CASPER stent is expected to reduce periprocedural ischemic complications, but there is concern about restenosis in the early period. One-year follow-up results of CASPER stenting and findings on intravascular ultrasound (IVUS) immediately and 6 months after treatment are evaluated.

METHODS

Thirty consecutive patients were treated with CASPER stents for carotid artery stenosis. IVUS was performed immediately after stenting, and MRI and carotid ultrasonography were performed the next day, at 1 week, at 2 weeks, and then every 3 months. One-year follow-up results were evaluated. Twenty-five patients underwent follow-up angiography and IVUS after 6 months and their findings were investigated.

RESULTS

All patients were treated without complications during the intraoperative and periprocedural periods. After 6 months, all 25 patients with follow-up angiography and IVUS showed various degrees of intimal formation on IVUS and 8 of them had ≥50% stenosis on angiography. Three of the 30 patients required retreatment within 6 months because of severe restenosis. In these patients, the inner layer of the stent was deformed toward the inside due to intimal hyperplasia on follow-up IVUS, and there was dissociation between the inner and outer layers. All but the 3 of 30 patients with 1-year follow-up did not lead to symptomatic cerebrovascular events or retreatment.

CONCLUSIONS

The CASPER stent appears to be effective for preventing periprocedural ischemic complications. IVUS showed various degrees of intimal formation within 6 months after treatment, and it is possible that the CASPER stent is structurally prone to intimal formation or hyperplasia.

Finite element analysis of braided dense-mesh stents for carotid artery stenosis

When braided dense-mesh stents are used to treat carotid stenosis, the structural mechanics of vascular stents, the contact mechanics with blood vessels, and the fluid mechanics in the blood environment need to be studied in depth to reduce the damage of stents to blood vessels and the incidence of in-stent restenosis. Three types of braided stents with 8, 16, and 24 strands and laser-cut stents with the corresponding size parameters were designed, and the bending behavior of each of these types of stent, deployment, and fluid dynamic analysis of the 24-strand braided stent were simulated. The results show that the bending stress of the 8-, 16-, and 24-strand braided stents is 46.33%, 50.24%, and 31.86% of that of their laser-cut counterparts. In addition, higher strand density of the braided stents was associated with greater bending stress; after the 24-strand braided stent was expanded within the stented carotid artery, the carotid stenosis rate was reduced from 81.52% to 46.33%. After stent implantation, the maximum stress on the vessel wall in a zero-pressure diastolic environment decreased from 0.34 to 0.20 MPa, the maximum pressure on the intravascular wall surface decreased from 4.89 to 3.98 kPa, the area of high-pressure region decreased, the wall shear force of the stenotic segment throat decreased, and blood flow increased in the stenosis segments. The braided stent had less bending stress and better flexibility than the laser-cut stent under the same stent size parameters; after the 24-strand braided stent was implanted into the stented vessel, it could effectively dilate the vessel, and the blood flow status was improved.

The case of treatment for carotid web - Double-layer micromesh stent implantation in our hospital

Background

A carotid web is a shelf-like structure on the posterior wall of the origin of the internal carotid artery, and it is believed to cause cerebral infarction due to thrombus formed by turbulent flow with stagnation of blood flow. Recently, it has been suggested that recurrent cerebral infarction cannot be prevented in patients with a symptomatic carotid web by conventional medical management alone. However, there is still no consensus on the treatment of carotid webs. Carotid artery stenting (CAS) with the CASPER stent (Microvention, Terumo, Tustin, CA, USA) was performed in six consecutive patients with symptomatic carotid webs, and the results are reported along with a review of the literature.

Methods

Six consecutive patients with a diagnosis of internal carotid artery stenosis due to a carotid web on magnetic resonance imaging and digital subtraction angiography (DSA) were included in this study. All patients underwent dual antiplatelet therapy approximately 10 days before surgery and after 6 months, and then, a CASPER stent was implanted under general anesthesia. All patients were evaluated postoperatively by DSA 6 months after treatment.

Results

In all patients, no in-stent stenosis was seen 6 months after the operation, and no symptomatic cerebral infarction occurred within 1 year after the procedure.

Conclusions

CASPER stent implantation may be effective for treating carotid webs.

Subacute In-Stent Occlusion 2 Weeks after CASPER Rx Stenting: A Case Report

Objective

CASPER Rx stent (Terumo, Tokyo, Japan) is one of the dual-layer micromesh stents for carotid artery stenosis. Although it is expected to be safe and efficacious even for vulnerable plaque, we report a case of in-stent occlusion 2 weeks after stenting with CASPER Rx stent.

Case Presentation

The patient was a 78-year-old man with a symptomatic, severely stenosed lesion of the cervical internal carotid artery (ICA). He had an unstable plaque and underwent carotid artery stenting with the CASPER Rx stent. There were no problems with the procedure or the patient's subsequent course, and he was discharged home 1 week after the procedure. However, on postoperative day 14, the patient had a transit ischemic attack and imaging showed acute occlusion due to thrombus in the stent and in the distal part of the ICA. Mechanical thrombectomy was performed and good recanalization was achieved, but postoperative cerebral infarction was observed and the patient was transferred to other hospital with modified Rankin Scale 2.

Conclusion

We experienced a case of in-stent occlusion 2 weeks after stenting with the CASPER Rx stent.

Carotid Artery Stenting Using Stent-in-Stent Technique with a Closed-Cell Stent and a Dual-Layer Micromesh Stent: A Case Report

Objective

Recent studies evaluating plaque protrusion at carotid artery stenting (CAS) using optical coherence tomography showed not a few cases of plaque protrusion when using double-layer micromesh stents. We report a case of symptomatic internal carotid artery (ICA) stenosis with at-risk unstable plaques in which CAS was successfully performed using a stent-in-stent technique by the combined use of a closed-cell stent and a dual-layer micromesh stent.

Case Presentation

An 87-year-old Japanese man with dysarthria and right hemiparesis was diagnosed with atheromatous cerebral embolism caused by severe left ICA stenosis on MRI and DSA. MRI with T1-weighted black blood methods showed high intensities in the plaques of the left ICA, suggesting unstable plaque characteristics with intraplaque hemorrhage components. On day 20, CAS was performed. After the pre-stent dilation under proximal and distal protection, a Carotid WALLSTENT was placed to cover the stenotic lesion. Then, a CASPER Rx was placed from the proximal left ICA to the common carotid artery to cover the Carotid WALLSTENT. Although visible plaque debris was recognized in the aspirated blood, the debris became invisible after aspiration of 1300 mL. Postoperative angiography showed enough dilation of the left ICA, with no plaque protrusion or acute stent thrombosis. The patient had an uneventful postoperative course and was discharged without any neurological sequelae.

Conclusion

The present case suggests that the combined stent-in-stent technique using a closed-cell stent and a micromesh stent can be considered as one of the treatment strategies for preventing plaque protrusion and procedural ischemic complications in patients with high-risk carotid plaques.

Intraprocedural Plaque Protrusion during Carotid Artery Stenting with a CASPER Stent: A Case Report

Objective

Plaque protrusion (PP) during carotid artery stenting (CAS) is considered to be associated with periprocedural ischemic stroke. A new double-layer micromesh stent, the CASPER stent (CS), was approved for use in Japan in 2020. The expectation is that this micromesh stent system will reduce the risk of PP, but we report a case of PP during CAS despite the use of a CS.

Case Presentation

An 87-year-old man presented with left hemiparesis. MRI showed right brain infarction and angiography showed right internal carotid artery stenosis with thrombus. Follow-up angiography after medical treatment showed that thrombus disappeared. We therefore performed CAS for right internal carotid artery stenosis with unstable plaque. CAS was performed under local anesthesia with Mo.Ma Ultra and FilterWire EZ protection using a CS placed to sufficiently cover the stenotic region. Conservative post-dilatation was then performed. Intravascular ultrasonography (IVUS) after post-dilatation showed the presence of PP. A second CS was then added using the stent-in-stent technique. No postoperative neurological abnormalities were found and the patient was discharged without postoperative complications. No stroke or restenosis has been observed as of 16 months after CAS.

Conclusion

PP can occur even when CAS is performed using the CS for carotid artery stenosis with unstable plaque. The importance of checking for PP using IVUS is suggested.

Characteristics of Calcification and Their Association with Carotid Plaque Vulnerability

BACKGROUND

Carotid plaque vulnerability is one of the important features for evaluating the risk of subsequent ischemic stroke. Although magnetic resonance imaging (MRI) is the gold standard modality for evaluating plaque vulnerability, some patients cannot undergo MRI because of physical or economic issues. Computed tomography (CT) is more readily available. The purpose of this study was to establish a new category of calcification on CT and to assess its usefulness for detecting vulnerable plaque.

MATERIALS AND METHODS

We retrospectively evaluated consecutive patients who underwent plaque imaging using CT and MRI before carotid revascularization at our institute. Calcifications were classified into 4 types according to the new calcium classification. The patients were divided into 2 groups, the double layer sign (DLS)-positive group and the DLS-negative group. Signal intensity ratio (SIR) of carotid plaque was measured on MRI for evaluating plaque vulnerability and compared between type of calcification and SIR.

RESULTS

Among the 132 patients evaluated, 50 patients (62.5%) in DLS positive group and 16 patients (30.8%) in DLS negative group had calcification with vulnerable plaque (SIR > 1.47) (P < 0.01). Substantial interobserver agreement of type of calcification was observed (kappa, 0.79; P < 0.01). Multivariate analysis showed that DLS (odds ratio 3.03; 95% confidence interval 1.35-6.8; P < 0.01) and male sex (odds ratio 3.15; 95% confidence interval 1.02-9.68; P = 0.04) were independent predictors of vulnerable plaque.

CONCLUSIONS

DLS in our new classification of calcification on CT reliably detects vulnerable plaque and could thus be used in patients who cannot undergo MRI.

The endothelialization on carotid web treated with dual layer stent placement: a case report

Carotid webs are known to cause acute ischemic stroke in younger adults and have a high recurrence rate. Herein, we report a case of a symptomatic carotid web in a 51-year-old man who was transferred to our hospital after developing consciousness disturbance and left hemiparesis. He was diagnosed with right middle cerebral artery occlusion and underwent mechanical thrombectomy. Because his carotid web was the likely embolic source, we performed carotid artery stenting using a dual-layer stent to crimp the vessel wall and secure closure of the web pocket. Follow-up angiography was performed at 3 weeks after stenting, and endothelialization on the web pocket was confirmed. The high scaffolding effect of the dual layer stent may promote the endothelialization on the carotid web.

Clinical Outcomes of Second- versus First-Generation Carotid Stents: A Systematic Review and Meta-Analysis

Background: Single-cohort studies suggest that second-generation stents (SGS; “mesh stents”) may improve carotid artery stenting (CAS) outcomes by limiting peri- and postprocedural cerebral embolism. SGS differ in the stent frame construction, mesh material, and design, as well as in mesh-to-frame position (inside/outside). Objectives: To compare clinical outcomes of SGS in relation to first-generation stents (FGSs; single-layer) in CAS. Methods: We performed a systematic review and meta-analysis of clinical studies with FGSs and SGS (PRISMA methodology, 3302 records). Endpoints were 30-day death, stroke, myocardial infarction (DSM), and 12-month ipsilateral stroke (IS) and restenosis (ISR). A random-effect model was applied. Results: Data of 68,422 patients from 112 eligible studies (68.2% men, 44.9% symptomatic) were meta-analyzed. Thirty-day DSM was 1.30% vs. 4.11% (p < 0.01, data for SGS vs. FGS). Among SGS, both Casper/Roadsaver and CGuard reduced 30-day DSM (by 2.78 and 3.03 absolute percent, p = 0.02 and p < 0.001), whereas the Gore stent was neutral. SGSs significantly improved outcomes compared with closed-cell FGS (30-day stroke 0.6% vs. 2.32%, p = 0.014; DSM 1.3% vs. 3.15%, p < 0.01). At 12 months, in relation to FGS, Casper/Roadsaver reduced IS (−3.25%, p < 0.05) but increased ISR (+3.19%, p = 0.04), CGuard showed a reduction in both IS and ISR (−3.13%, −3.63%; p = 0.01, p < 0.01), whereas the Gore stent was neutral. Conclusions: Pooled SGS use was associated with improved short- and long-term clinical results of CAS. Individual SGS types, however, differed significantly in their outcomes, indicating a lack of a “mesh stent” class effect. Findings from this meta-analysis may provide clinically relevant information in anticipation of large-scale randomized trials.

Comparison of Restenosis Risk in Single-Layer versus Dual-Layer Carotid Stents: A Duplex Ultrasound Evaluation

PURPOSE

The aim of this study was to report intermediate-term results of duplex ultrasound follow-up of carotid artery stenting performed with the dual-layer stent as compared to concurrent patients treated with other commercially available single-layer carotid stents.

MATERIALS AND METHODS

A single centre, retrospective, nonrandomized study including 162 non-consecutive patients with 199 implanted carotid stents treated over a 7-year period was conducted. Patients with at least one ultrasound examination after treatment were included. Procedural and follow-up data for patients treated with the dual-layer stent implantation (83 stents) vs first-generation carotid stents implantations (116 stents) were compared.

RESULTS

The median follow-up time was 24.0 months (IQR 10-32 months) for dual-layer stents and 27.5 months (IQR 10.3-59 months) for single-layer stents. The rate of severe restenosis was significantly higher in the dual-layer stent group than in the single-layer group (13.3% [11/83] vs 3.4% [4/116], p = 0.01). Seven reinterventions were performed in 5 patients with dual-layer stents. The rate of reintervention was significantly higher compared to no reinterventions in single-layer stents (6% [5/83] vs 0% [0/116], p = 0.012). Patients with restenosis had significantly higher presence of dyslipidaemia (100% [12/12] vs 63.3% [95/150], p = 0.009).

CONCLUSIONS

In this real-world cohort of patients undergoing carotid artery stenting, the patients treated with low-profile dual-layer micromesh stent showed higher rates of restenosis and reinterventions compared to first-generation single-layer stents.

Efficacy of Post-Dilatation during Carotid Artery Stenting for Unstable Plaque Using a Double-Layer Stent Evaluated by OFDI

Objective

This study aimed to use optical frequency domain imaging (OFDI) to evaluate the efficacy of post-dilatation (PD) after stent placement for unstable plaques during carotid artery stenting (CAS) using a double-layer stent.

Methods

Twelve unstable carotid plaque lesions diagnosed by MRI were evaluated using OFDI during CAS. The pre-procedural minimum lumen diameter was 1.6 ± 0.7 mm. Each lesion was pre-dilated with balloon catheters (diameter, 5.3 ± 0.5 mm), and a double-layer stent was deployed. PD was performed with balloon catheters of the same size as those used for pre-dilatation. Cross-sectional OFDI images within the stented segment were evaluated at 1-mm intervals for a 20-mm segment, including the most stenotic lesion. Slice rates for the presence of in-stent plaque protrusion (PP) and plaque between the double-layer lumen were calculated.

Results

No procedural complications occurred with the use of an embolic protection device. Compared to after stent placement, slice rates for any PP (44 ± 19% to 62 ± 22%, P <0.05) and plaque between the double-layer lumen (79 ± 16% to 91 ± 34%, P <0.05) were significantly increased after PD; slice rates for >500 μm PP (7.5 ± 14% to 0%, P <0.05) were significantly decreased. Visible debris were captured in 50% of lesions.

Conclusion

PD after double-layer carotid stent placement decreases in-stent large PP. Double-layer construction contributed to the prevention of large PP, as the PP may have been crushed into debris by PD.

Diabetes Mellitus and Clinical Outcomes in Carotid Artery Revascularization Using Second-Generation, MicroNet-Covered Stents: Analysis from the PARADIGM Study

INTRODUCTION

Carotid artery stenting (CAS) using conventional (single-layer) stents is associated with worse clinical outcomes in diabetes mellitus (DM) vs. non-DM patients: an effect driven largely by lesion-related adverse events. CAS outcomes with MicroNet-covered stents (MCS) in diabetic patients have not been evaluated.

AIM

To compare short- and long-term clinical outcomes and restenosis rate in DM vs. non-DM patients with carotid stenosis treated using MCS.

MATERIALS AND METHODS

In a prospective study in all-comer symptomatic and increased-stroke-risk asymptomatic carotid stenosis, 101 consecutive patients (age 51-86 years, 41% diabetics) underwent 106 MCS-CAS. Clinical outcomes and duplex ultrasound velocities were assessed periprocedurally and at 30 days/12 months.

RESULTS

Baseline characteristics of DM vs. non-DM patients were similar except for a higher prevalence of recent cerebral symptoms in DM. Type 1 and type 1+2 plaques were more prevalent in DM patients (26.7% vs. 9.8%, p = 0.02; 62.2% vs. 37.7%, p = 0.01). Proximal embolic protection was more prevalent in DM (60% vs. 36%; p = 0.015). 30-day clinical complications were limited to a single periprocedural minor stroke in DM (2.4% vs. 0%, p = 0.22). 12-month in-stent velocities and clinical outcomes were not different (death rate 4.8% vs. 3.3%; p = 0.69; no new strokes). Restenosis rate was not different (0% vs. 1.7%, p = 0.22).

CONCLUSIONS

MCS may offset the adverse impact of DM on periprocedural, 30-day, and 12-month clinical complications of CAS and minimize the risk of in-stent restenosis. In this increased-stroke-risk cohort, adverse event rate was low both in DM and non-DM. Further larger-scale clinical datasets including extended follow-ups are warranted.

Contemporary Results of Carotid Artery Stenting Using Low-Profile Dual-Metal Layer Nitinol Micromesh Stents in Relation to Single-Layer Carotid Stents

PURPOSE

To evaluate patients characteristics, procedural details, perioperative outcomes, and midterm results of carotid artery stenting (CAS) performed with the Roadsaver/Casper stent (Terumo Corp, Tokyo, Japan) as compared to concurrent patients treated with other commercially available carotid stents.

MATERIALS AND METHODS

This is a single-center, retrospective, nonrandomized study including 200 consecutive patients who underwent a total of 205 elective CAS procedures due to severe internal carotid artery stenosis between April 2015 and December 2018. Procedural data and outcomes for patients treated with the Roadsaver/Casper stent implantation (100 procedures, in 97 patients) vs first-generation carotid stents implantations (90 procedures, in 88 patients) were compared. Fifteen patients were treated with CGuard carotid stent (InspireMD, Tel Aviv, Israel), and outcomes were reported separately. Primary endpoints were the occurrence of major adverse cerebrovascular events (MACE), including death, ipsilateral stroke, and transitory ischemic attack (TIA). Secondary endpoints were the rate of intrastent stenosis, the need for reintervention, and the occurrence of adverse cardiovascular events, including myocardial infarction, arrhythmias, and need for inotropic support.

RESULTS

No difference in demographics and preoperative risk factors were observed between patients treated with and without the Roadsaver/Casper stent. The mean procedure time was shorter in the Roadsaver/Casper group (40.7±16.9 vs 49.4±27.3 minutes; p=0.008), while radial percutaneous access was more frequent (24% vs 5%; p<0.001). The rate of stroke/TIA/death at 30 days was 3% in the Roadsaver group vs 1% in the first-generation stent group (p=0.623). The primary patencyrate was 100% and 93.4% at 1- and 3-year of follow-up in the Roadsaver/Casper groupand 99% and 94.3% in the other stent group, respectively (p=0.95).

CONCLUSIONS

In this real-world cohort of patients undergoing CAS, the Roadsaver/Casper stent was used to treat more symptomatic and vulnerable carotid plaques as compared to other carotid stents. Nevertheless, patients treated with this low-profile dual-layer micromesh stent showed low events rates at both 30 days and follow-up, similar to that observed for other stents.

A Case of Intraprocedural Plaque Protrusion during Carotid Artery Stenting Using the Stent-in-Stent Technique for Carotid Artery Stenosis with Unstable Plaque

Objective

Carotid artery stenting (CAS) using the stent-in-stent technique was reported to prevent intraprocedural plaque protrusion (PP) in patients with carotid artery stenosis with unstable plaque. We report a case of intraoperative PP after CAS despite the use of stent-in-stent technique.

Case Presentation

A 63-year-old man presented with rapid progression of right carotid artery stenosis with unstable plaque during follow-up and was admitted to undergo CAS. Under local anesthesia with Mo.Ma Ultra and FilterWire EZ protection, CAS was performed using the stent-in-stent technique. The first 8 mm × 29 mm Carotid Wallstent (CWS) was placed. The second CWS (6 mm × 22 mm) was placed in a stent-in-stent manner to match the stenotic lesion, and conservative postdilation was performed. Then the third CWS (6 mm × 22 mm) was added due to the presence of PP on intravascular ultrasonography (IVUS). No postoperative neurological abnormalities were found, and no new high-signal areas were observed on diffusion-weighted MRI the day after surgery. The patient was discharged without postoperative complications. No stroke and restenosis were observed at 3 months after CAS.

Conclusion

PP can occur even with stent-in-stent technique, suggesting the importance of diagnosis by IVUS.