Symptomatic atherosclerotic plaque progression in a first-generation carotid stent—case report: Management and 5-year clinical and imaging outcome

Background Restenosis in first-generation (single-layer, nitinol) carotid stents (FGS) is believed to represent an exaggerated healing response of (neo)intimal hyperplasia (NIH) formation. Rather than NIH, we describe symptomatic in-FGS unstable plaque (neo)atherosclerosis mandating re-revascularization. To halt continued plaque evolution, we propose a novel treatment strategy involving a micronet-covered stent to sequestrate the plaque from the vessel lumen. A durable long-term result is documented using multi-modal imaging. Case summary With a seemingly optimal result of FGS (Precise) symptomatic carotid lesion revascularization followed by optimal medical therapy, a late (≥3 years) progressive ISR arose. At year 11, crescendo ipsilateral transient ischaemic attacks occurred. Angiography showed an ulcerated tight lesion throughout stent length. Intravascular ultrasound (IVUS) revealed thin-cap fibroatheroma. Re-intervention was performed under distal protection. Undersized balloon predilatation caused symptomatic no-flow, and aspiration catheter was used to reduce the filter load. A micronet-covered stent (CGuard) was implanted and post-dilated to ensure full lumen gain; IVUS confirmed complete plaque sequestration. The optimal anatomic result remained unchanged throughout 5 years (ultrasound and computed tomography verification); this was accompanied by clinical cure. Discussion This is the first demonstration of in-FGS (neo)atherosclerosis resolution using a micronet-covered stent to sequestrate and insulate the atherosclerotic plaque. We show that ISR may be underlined by late atherosclerotic plaque progression via the FGS single-layer stent struts that may show vulnerable plaque phenotype and may be associated with cerebral ischaemia. The anatomically and clinically effective exclusion of the atherosclerotic plaque by a micronet-covered stent enabled lasting, optimal endovascular reconstruction and clinical cure.

Stenting of ultraembolic hazardous carotid stenotic lesions using the technique of triple antiembolic protection

Objective ‒ to develop a technique of triple antiembolic protection with the simultaneous use of proximal antiembolic protection systems, distal antiembolic filters and two-layer micromesh carotid stents for carotid stenting of ultraembolic hazardous carotid stenosis. Evaluate its effectiveness and safety.Materials and methods. Since 2016, 23 carotid stenting of ultraembolic hazardous carotid stenoses has been performed using the technique of triple antiembolic protection (proximal antiembolic protection systems, distal antiembolic filters and two-layer micromesh carotid stents). All patients had symptomic stenosis: transient ischemic attacks in a certain carotid pool (n = 7), ischemic strokes (n = 16). The age of patients was from 57 to 84 years. Men prevailed among patients (n = 15). Postoperative follow-up included magnetic resonance imaging (MRI) of the brain on the first or second day after surgery with T2*, FLAIR and DWI sequences to determine the presence of «fresh» embolic ischemic foci and to exclude hemorrhagic complications. After 6 months, a control clinical examination, computed tomography or MRI of the brain, ultrasound angioscanning of the main arteries of the head were performed.Results. In all patients the patency of the carotid arteries was completely restored, and in the early postoperative period, no clinical signs of recurrent ischemic brain damage were detected in any of the cases. No signs of plaque prolapse through the stent were detected in any case. A significant amount of atheromatous debris was in 11 cases when aspirated on an external filter. In 3 cases, emboli were also detected in the distal protection filter. This fact indicates that the joint use of distal and proximal antiembolic systems reliably protects against the risk of embolism in such cases. According to MRI on the 1st or 2nd day there were no signs of «fresh» subclinical embolic ischemic foci, as well as hemorrhage. In 20 patients who underwent a follow-up examination, no signs of restenosis in the stent were recorded in any case, as well as repeated ischemic strokes. In 7 cases where the plaque had an ulcer, the ulcer resolved under the stent. Three patients are expected for a follow-up examination. According to the remote survey, these patients do not have new ischemic brain lesions. The effectiveness of the technique of triple antiembolic protection for the treatment of patients with subtotal ultraembolic hazardous carotid stenosis is indicated by the absence of clinical and neuroradiological signs of recurrent ischemic lesions.Conclusions. The technique of triple antiembolic protection for the treatment of patients with subtotal ultraembolic hazardous carotid stenoses is safe and highly effective. It is the improvement of carotid stenting results in this most dangerous group that gives reason to think about revealing the advantages of carotid stenting over carotid endarterectomy in general.

Abstract 1122‐000174: Stroke Risk of Carotid Artery Stenting Using Balloon‐Guide Catheter Versus Distal Embolic Protection Devices

Introduction : Prevention of distal embolization during carotid artery stenting (CAS) is a key element of procedural technique and is standardly performed using distal protection devices (DPDs). Data in support of DPDs, however, are limited. Here, we present our experience of proximal occlusion using a balloon guide catheter (BGC) during CAS as the primary method of distal embolic protection. Methods : We conducted a retrospective review of patients undergoing CAS at our healthcare system between January of 2018 to March of 2021. Procedures were categorized by embolic protection strategy: DPD or BGC (with or without DPD). Emergent cases were defined as patients receiving CAS within <24 hours of presenting with an ischemic stroke or TIA ipsilateral to the carotid disease side. Severe stenosis was defined as 70–99% per NASCET criteria. The primary outcome was rate of procedural ischemic stroke between the DPD and BGC groups, and was defined as acute focal neurological deficit lasting for ≥ 24 hours following CAS related to an embolic event during the procedure. Results : A total of 126 CAS procedures were performed during the study period. 91 cases were performed under proximal BGC protection (of which 24 also included DPD usage) and 35 CAS cases via DPD as a primary mean for embolic protection. The median age for the cohort was 68 [IQR 62‐76], 37% females, 31% (n = 39) cases were treated emergently, and elective cases were 69% (n = 87). Baseline characteristics were similar in both groups except for hyperlipidemia (BGC vs DPD, 71.4% vs 42.9%; p = 0.003) and history of smoking (BGC vs DPD, 56% vs 34.4%; p = 0.029). Severe carotid stenosis was present in 80.2% BGC group and 77.1% in DPD (p = 0.573). Post‐stenting balloon angioplasty was more frequent in the BGC group as compared with DPD (54% vs. 26%, BGC vs. DPD, p = 0.005). Procedural embolic stroke rates were low in both groups, and not significantly different (1.1% vs. 2.9%, BGC vs. DPD, p = 0.48). Conclusions : CAS with BGC as the primary means of distal embolic protection showed comparable, low rates of procedural embolic ischemic events compared to those with DPD. These findings suggest BGC embolic strategies may be a viable alternative to DPD usage.

A novel treatment using a guide extension catheter and distal protection device for refractory coronary embolism: case report

Background A large thrombus burden in patients with acute myocardial infarction is associated with worse outcomes. Although various methods of thrombus aspiration have been described, there is a potential limitation in the mechanism of eliminating a thrombus with only the use of an aspiration device. In this report, we present a novel method of retrieving massive thrombus using a guide extension catheter and a filter device. Case summary An 80-year-old man was diagnosed with anterior ST-elevation myocardial infarction (STEMI). Emergency coronary angiography revealed that the left anterior descending artery (LAD) showed an acute thrombotic occlusion in the mid-section. The percutaneous coronary intervention was performed to recanalize an occluded LAD. Although thrombectomy using an aspiration catheter and a guide catheter extension system was performed repeatedly, only a small amount of the thrombus was retrieved, and the LAD was still occluded. Therefore, we planned to remove the large thrombus burden by capturing the entire thrombus between the tip of the guide extension catheter and distal protection device, followed by pulling them out of the guide catheter together. A large amount of red thrombus, which adhered to the axis of the filter device, was successfully retrieved. The occluded LAD was successfully recanalized without balloon dilatation or stent implantation. Discussion Although a variety of aspiration devices are available, removal of large coronary artery thrombi with the use of an aspiration catheter alone can at times prove difficult. To solve this problem, we developed a novel technique for retrieving large thrombi. This method is effective in removing refractory thrombi for the treatment of STEMI patients.

Use of distal protection filter device for rescue mechanical thrombectomy for symptomatic free-floating thrombus of the cervical internal carotid artery

Background Intraluminal free floating thrombus (FFT) of the cervical internal carotid artery (ICA) is a potentially high-risk lesion for recurrent ischemic strokes, with no single optimal treatment established. Objective To describe a novel interventional technique for mechanical thrombectomy of intraluminal free floating thrombus using a distal protection filter device and aspiration. Methods We identified two cases where anticoagulation was contraindicated in patients with intraluminal FFT and minimal underlying stenosis. In both cases, a distal protection device was used to extract the thrombus under proximal flow arrest and aspiration. Results Mechanical thrombectomy was successful in both cases, one with “en bloc” removal of the thrombus and one with piecemeal removal. Neither case showed any residual angiographic stenosis or atherosclerotic disease. Conclusion Mechanical thrombectomy using a distal protection device is a novel and technically feasible approach for select cases of cervical intraluminal thrombus. This may represent a therapeutic option in select cases with high risk of anticoagulation and in the unusual subset of younger patients with minimal atherosclerotidc disease.

The role of intracoronary thrombolysis in selected patients presenting with ST-elevation myocardial infarction: a case series

Background Primary percutaneous coronary intervention (PCI) is the cornerstone of management for ST-elevation myocardial infarction (STEMI). However, large intracoronary thrombus burden complicates up to 70% of STEMI cases. Adjunct therapies described to address intracoronary thrombus include manual and mechanical thrombectomy, use of distal protection device and intracoronary anti-thrombotic therapies. Case summary This series demonstrates the use of intracoronary thrombolysis in the setting of large coronary thrombus, bifurcation lesions with vessel size mismatch, diffuse thrombosis without underlying plaque rupture, and improving coronary flow to allow vessel wiring and proceeding to definitive revascularization. Discussion Larger intracoronary thrombus burden correlates with greater infarct size, distal embolization, and the associated no-reflow phenomena, and propagates stent thrombosis, with subsequent increase in mortality and major adverse cardiac events. Intracoronary thrombolysis may provide useful adjunct therapy in highly selected STEMI cases to reduce intracoronary thrombus and facilitate revascularization.