Water content for clot composition prediction in acute ischemic stroke.

BACKGROUND: Mechanical thrombectomy (MT) has become the gold standard care for treating acute ischemic stroke (AIS) due to large vessel occlusion. Emerging evidence suggests that understanding the composition of clots prior to intervention could be useful for the selection of neuroendovascular techniques, potentially improving the efficacy of treatments. However, current imaging modalities lack the ability to distinguish clot composition accurately and reliably. Since water content can influence signal intensity on CT and MRI scans, its assessment may provide indirect clues about clot composition. This study aimed to elucidate the correlation between water content and clot composition using human clots retrieved from stroke patients and experimentally generated ovine clots. MATERIALS AND METHODS: This study involved an analysis of ten clots retrieved from patients with AIS undergoing MT. Additionally, we created ten red blood cells (RBC)-rich and ten fibrin-rich ovine blood clots, which were placed in a human intracranial vascular model under realistic flow conditions. The water content and compositions of these clots were evaluated, and linear regression analyses were performed to determine the relationship between clot composition and water content. RESULTS: The regression analysis in human stroke clots revealed a significant negative association between RBC concentration and water content. We also observed a positive correlation between water content and both fibrin and platelets in ovine blood clots. Conclusion.

Erratum to "Crossing double stent retriever technique for refractory terminal internal carotid artery occlusion" [Radiology Case Reports 17 (2022) 1848-1852].

[This corrects the article DOI: 10.1016/j.radcr.2022.03.023.].

Devices and Techniques.

This extensive review explores the intricacies of the three principal mechanical thrombectomy techniques: the stent retriever technique, contact aspiration technique, and a combined approach, and their application in managing acute ischemic stroke. Each technique operates uniquely on the thrombus, leading to differences in their efficacy. Factors including clot size, clot stiffness, vessel tortuosity, and the angle of interaction between the aspiration catheter and the clot significantly influence these differences. Clinical trials and meta-analyses have shown the overall equivalency of these techniques for the treatments of large vessel occlusion and distal medium vessel occlusions. However, there are nuanced differences that emerge under specific clinical circumstances, highlighting the absence of a one-size-fits-all strategy in acute ischemic stroke management. We emphasize the need for future investigations to elucidate these nuances further, aiming to refine procedural strategies and individualize patient care for optimal outcomes.

In vitro comparison of manual and robotic endovascular thrombectomy for acute ischemic stroke.

BACKGROUND: Robotic endovascular systems have the potential to reduce radiation exposure to physicians and expand timely neurointerventional access to patients in remote areas. The goal of the study was to determine the feasibility of robotic endovascular thrombectomy (EVT) in an in vitro model. METHODS: In vitro procedures were conducted manually and robotically using the Corpath GRX robotic system in a human vascular simulator with an elastic ovine clot in the M1 segment of the left middle cerebral artery. Due to the limited device compatibility of the CorPath GRX, a simple technique with a stent retriever and guiding catheter without a balloon was used in the study. Seven robotic EVT and manual EVT were carried out in each group. Metrics including procedural time, success rate, and radiation dose were compared between the two groups. RESULTS: In robotic EVT, the mean total preparation and procedural time was 892 s, which was significantly longer than manual operation at 357 (p = 0.0001). There was no significant difference in the success rate between the two approaches (robotic: 28.6% vs. manual 42.9%, p = 0.577). The mean radiation exposure to operating physicians was significantly lower during robotic operation compared to manual operation (0.02 µSv vs. 0.22 µSv, p < 0.0001). CONCLUSIONS: Robotic EVT was feasible in our human vascular simulator with significantly reduced radiation exposure to the operating physicians, despite an increased length of procedure when compared to manual procedures. Future technological advancement is warranted for reducing procedural length using endovascular robotic techniques.

An aggressive dural arteriovenous fistula manifested by unilateral subcortical calcification and cerebral edema: A case report.

Unilateral subcortical calcifications are unique radiographic findings indicating specific focal pathologies. When the lesion is accompanied by edema, cerebral neoplasm usually leads to a differential diagnosis. This report presents a case of unilateral subcortical calcification and edema that resulted in cerebral hemorrhage and a subsequent diagnosis of an aggressive dural arteriovenous fistula. A man in his 60s presented with left hemianopsia and a progressive headache for over 6 months. Initial computed tomography revealed unilateral subcortical calcification and cerebral edema in the right occipital lobe, raising the suspicion of oligodendroglioma. However, 10 days later, a cerebral hemorrhage occurred in the lesion. Magnetic resonance imaging revealed flow void clusters and dilatation of the bilateral external carotid arteries and cortical veins, indicating a dural arteriovenous fistula. Cerebral angiography confirmed the presence of a parasagittal dural arteriovenous fistula (Borden type III). The patient was successfully treated with trans-arterial embolization using Onyx. Thus, calcifications with edema are more commonly associated with cerebral neoplasms; however, in this case, they indicated the presence of a dural arteriovenous fistula with severe corticovenous reflux. The presented case highlights the importance of recognizing these imaging features in dural arteriovenous fistulas and raises awareness of the potential danger of early hemorrhage after diagnosis. Therefore, timely evaluation of cranial vessels is essential in cases of unilateral subcortical calcification and edema to facilitate the early detection and management of aggressive dural arteriovenous fistulas.

Hemostatic patch with ultra-strengthened mechanical properties for efficient adhesion to wet surfaces.

Controlling traumatic bleeding from damaged internal organs while effectively sealing the wound is critical for saving the lives of patients. Existing bioadhesives suffer from blood incompatibility, insufficient adhesion to wet surfaces, weak mechanical properties, and complex application procedures. Here, we engineered a ready-to-use hemostatic bioadhesive with ultra-strengthened mechanical properties and fatigue resistance, robust adhesion to wet tissues within a few seconds of gentle pressing, deformability to accommodate physiological function and action, and the ability to stop bleeding efficiently. The engineered hydrogel, which demonstrated high elasticity (>900%) and toughness (>4600 kJ/m3), was formed by fine-tuning a series of molecular interactions and crosslinking mechanisms involving N-hydroxysuccinimide (NHS) conjugated alginate (Alg-NHS), poly (ethylene glycol) diacrylate (PEGDA), tannic acid (TA), and Fe3+ ions. Dual adhesive moieties including mussel-inspired pyrogallol/catechol and NHS synergistically enhanced wet tissue adhesion (>400 kPa in a wound closure test). In conjunction with physical sealing, the high affinity of TA/Fe3+ for blood could further augment hemostasis. The engineered bioadhesive demonstrated excellent in vitro and in vivo biocompatibility as well as improved hemostatic efficacy as compared to commercial Surgicel®. Overall, the hydrogel design strategy described herein holds great promise for overcoming existing obstacles impeding clinical translation of engineered hemostatic bioadhesives.

First-in-human trial of Center Wire for neuroendovascular therapy to avoid guidewire-related complications.

BACKGROUND: An exchange maneuver is useful for the delivery of devices to target vessels. However, hemorrhagic complications can occur due to vessel perforation during an exchange maneuver. In addition, the exchange is often challenging due to unfavorable anatomy. Center Wire is an exchange-length wire with a nondetachable stent that was developed to improve navigation and stability during exchange maneuvers. The aim of this study is to investigate the safety and efficacy of Center Wire of the anchor wire technique during neuroendovascular treatment. METHODS: Ten patients with intracranial aneurysms were treated after signing a Certified Review Board-approved consent. Anchor wire technique was used in all patients to navigate catheters to the target vessel for aneurysm treatment. RESULTS: Anchor wire technique was successfully applied in all 10 cases using Center Wire. One device-related incident of vasospasm occurred which was asymptomatic. No device-related dissection, perforation, or thromboembolic events occurred. One patient had intraoperative aneurysm rupture during coil placement which was treated immediately without clinical consequences. Two patients had postoperative ischemic strokes due to thrombotic occlusion of branches originating from the aneurysm which were unrelated to the device. CONCLUSIONS: This first-in-human trial of Center Wire demonstrated the safety and efficacy of the anchor wire technique for neuroendovascular treatment in a strictly regulated prospective registry trial.

First-in-human trial of Stabilizer device in neuroendovascular therapy.

Objectives: Flow diverter or stent implantation to intracranial target lesion requires large inner diameter microcatheter navigation. The exchange method using stiff long wire is often necessary if it is difficult to navigate over the regular guidewire. However, this method has an intrinsic risk of vessel damage and may cause severe complications. We investigated the safety and efficacy of a new device, the Stabilizer device for navigation in a first-in-human clinical trial under the Certified Review Board agreement. Materials and methods: The Stabilizer is a 320 cm length exchange wire with a stent for anchoring and is compatible with a 0.0165" microcatheter. The trial design is a prospective single-arm open-label registry. Inclusion criteria are elective flow diverter treatment or stent-assisted coiling, expected to be difficult to navigate a microcatheter with a regular micro guidewire, and obtained documented consent. The primary endpoint of the study was a hemorrhagic complication. Results: Five patients were enrolled in this trial. The median age is 52 years, ranges from 41 to 70, and all patients were female. Three aneurysms were located on the internal carotid artery, one on the vertebral artery, and one on the basilar artery. Basilar artery aneurysm was treated by stent-assisted coiling and others were treated by flow diverter deployment. All cases successfully navigate microcatheter for the treatment by the trial method using Stabilizer device without any adverse event. Conclusions: The results from this first-in-human consecutive five cases show the safety of the Stabilizer device in neuro-endovascular therapy for navigation of devices to the intracranial target lesion.

Acute internal carotid artery occlusion due to dissection of the paraclinoid segment: Diagnostic usefulness of angiographic findings during stent retriever deployment.

Intracranial artery dissection is an uncommon but possible cause of ischemic stroke, and is usually diagnosed based on imaging findings such as mural hematoma and dissection flap. However, it is challenging to recognize the underlying dissection in cases of acute large vessel occlusion. In this report, we present a case of acute internal carotid artery occlusion, in which the underlying dissection of the paraclinoid segment was found during the thrombectomy procedure. Two thrombectomy procedures failed to recanalize the acute internal carotid artery occlusion without removing any clot. Angiography performed during a Trevo stent retriever deployment in the first pass showed obscure contrast defects in the stent strut with temporary flow restoration. In the next pass, the appearance of the contrast defects changed and a parallel linear contrast appeared on the outside of the vessel wall. These angiographic findings were identified as mural hematoma and dissection flap, indicating dissection of the paraclinoid as the cause of the occlusion. During antiplatelet loading and preparation of a dedicated intracranial stent, the Trevo stent retriever was left deployed again at the occlusion site to maintain the blood flow. After permanent stenting with an Enterprise stent, angiography revealed complete recanalization. The patient recovered fully after the procedure. In the present case, stent retriever deployment revealed the hallmarks of dissection on angiography, such as mural hematoma, dissection flap, and temporal morphological changes, by restoring the blood flow temporarily. Such angiographic findings can provide useful information on the occlusion characteristics and real-time feedback for optimal treatment strategy.

Endovascular Treatment of Tandem Atherosclerotic Cervical Internal Carotid Artery Occlusion in the Setting of Acute Ischemic Stroke.

BACKGROUND: Among tandem occlusions, atherosclerotic cervical internal carotid artery occlusion (ACICAO) can be technically challenging and associated with its unique complications. We evaluated our experience with endovascular treatment (EVT) of ACICAO in the setting of acute ischemic stroke. METHODS: In total, 154 consecutive patients who underwent EVT for acute anterior circulation stroke at our institute were retrospectively reviewed. Patients with tandem ACICAO were analyzed in this study. Procedures, recanalization rates, complications, and prognoses were evaluated. RESULTS: Ten patients (6%) of all 154 patients had ACICAO. In nine (90%) of the 10 patients, cervical lesions were successfully crossed and intervened upon. Four patients underwent stenting and five underwent angioplasty alone, followed by intracranial procedure. Eight patients (80%) achieved successful recanalization following mechanical thrombectomy for intracranial occlusion. However, one patient had massive subarachnoid hemorrhage during the procedure and another patient developed massive intracranial hemorrhage after EVT, both after stenting. Four of the five patients who initially underwent angioplasty alone subsequently underwent staged endarterectomy or stenting for residual stenosis on or after the next day. The single patient in whom the cervical lesion could not be crossed and another with reocclusion after EVT underwent a rescue bypass procedure due to persistent ischemic symptoms. After 90 days, four patients (40%) were functionally independent (modified Rankin scale score 0-2). CONCLUSIONS: Our experience suggests that EVT for ACICAO is technically feasible; however, it involves the potential risk of several significant complications. To avoid serious hemorrhagic complications, cervical lesions may be better treated with angioplasty alone first.

Crossing double stent retriever technique for refractory terminal internal carotid artery occlusion.

Mechanical thrombectomy is highly effective for the recovery of acute ischemic stroke with large vessel occlusion. However, refractory occlusions are still encountered despite the use of currently available devices. In this article, we present a case of refractory terminal internal carotid artery occlusion treated with the "crossing double stent retriever technique." Two thrombectomy procedures with the combined technique using a stent retriever and aspiration catheter failed to recanalize the terminal internal carotid artery occlusion that involved the dominant anterior cerebral artery. We then applied the crossing double stent retriever technique as a rescue technique. Two microcatheters were advanced across the occlusion: one to the anterior cerebral artery and the other to the middle cerebral artery. First, a Trevo NXT 4 mm stent retriever was deployed from the anterior cerebral artery. Next, an additional Trevo NXT 4 mm stent retriever was deployed from the middle cerebral artery, and full immediate restoration of flow was achieved on angiography. Intraprocedural radiological images showed that the 2 microcatheters traversed different pathways, and the 2 stent retrievers completely covered the entire vessel with apparent in-stent clot sign. Both stent retrievers were then pulled back together, and a hard clot was retrieved. Subsequent angiography revealed complete recanalization. The crossing double stent retriever technique seems an effective rescue technique for treating refractory terminal internal carotid artery occlusion, especially with the anatomical feature of branching of the dominant anterior cerebral artery. This technique can facilitate the device-clot-vessel interaction by engaging the clot via 2 different device pathways.

Potential of machine learning to predict early ischemic events after carotid endarterectomy or stenting: a comparison with surgeon predictions.

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are recommended for high stroke-risk patients with carotid artery stenosis to reduce ischemic events. However, we often face difficulty in determining the best treatment strategy. We aimed to develop an accurate post-CEA/CAS outcome prediction model using machine learning that will serve as a basis for a new decision support tool for patient-specific treatment planning. Retrospectively collected data from 165 consecutive patients with carotid stenosis underwent CEA or CAS and were divided into training and test samples. The following five machine learning algorithms were tuned, and their predictive performance was evaluated by comparison with surgeon predictions: an artificial neural network, logistic regression, support vector machine, random forest, and extreme gradient boosting (XGBoost). Seventeen clinical factors were introduced into the models. Outcome was defined as any ischemic stroke within 30 days after treatment including asymptomatic diffusion-weighted imaging abnormalities. The XGBoost model performed the best in the evaluation; its sensitivity, specificity, positive predictive value, and accuracy were 31.9%, 94.6%, 47.2%, and 86.2%, respectively. These statistical measures were comparable to those of surgeons. Internal carotid artery peak systolic velocity, low-density lipoprotein cholesterol, and procedure (CEA or CAS) were the most contributing factors according to the XGBoost algorithm. We were able to develop a post-procedural outcome prediction model comparable to surgeons in performance. The accurate outcome prediction model will make it possible to make a more appropriate patient-specific selection of CEA or CAS for the treatment of carotid artery stenosis.

Contribution of Endoplasmic Reticulum Stress to the Clinical Instability of Carotid Plaques in Human Carotid Stenosis.

Endoplasmic reticulum (ER) stress is an important process during the progression of atherosclerosis. The aim of this study was to elucidate the association of ER stress and clinical instability of carotid plaque. One hundred ninety-three patients with carotid stenosis undergoing carotid endarterectomies (CEAs) were enrolled. We classified the patients into 3 groups: the asymptomatic, symptomatic, and cTIA (crescendo transient ischemic attack)/SIE (stroke in evolution) groups. Immunohistological staining was performed to assess ER stress and apoptosis. The correlation between ER stress marker expression and clinical instability was analyzed by Tukey-Kramer test and ordinal logistic regression. From the 193 CEAs, 24 asymptomatic plaques and 24 symptomatic plaques were randomly selected, and all 7 plaques in the cTIA/SIE group were selected. Glycophorin A staining demonstrated significant correlation between intraplaque hemorrhage and clinical instability (odds ratio [OR], 1.27; 95%CI, 1.14-1.41). The expression of ER stress markers (glucose-regulated protein 78 [GRP78] and C/EBP homologous protein [CHOP]) exhibited a significant correlation with clinical instability (GRP78: OR, 1.25; 95%CI, 1.14-1.38, CHOP: OR, 1.39; 95%CI, 1.16-1.66). Double-label immunofluorescence demonstrated ER stress markers were detected in CD68-positive cells and smooth muscle actin (SMA)-positive cells. The coexpression of the ER stress markers exhibited a significant correlation with clinical instability (CD68/GRP78: OR, 1.13; 95%CI, 1.05-1.20, CD68/CHOP: OR, 1.092; 95%CI, 1.04-1.14, SMA/CHOP: OR, 1.082; 95%CI, 1.04-1.13). However, the colocalization of CHOP and cleaved caspase-3 (apoptosis marker) did not correlate with clinical instability. These findings indicated that the ER stress pathway may be a potential therapeutic target in the prevention of stroke.

Geranylgeranylacetone attenuates cerebral ischemia-reperfusion injury in rats through the augmentation of HSP 27 phosphorylation: a preliminary study.

BACKGROUND: We previously reported that heat shock protein 27 (HSP27) phosphorylation plays an important role in the activation of glucose-6-phosphate dehydrogenase (G6PD), resulting in the upregulation of the pentose phosphate pathway and antioxidant effects against cerebral ischemia-reperfusion injury. The present study investigated the effect of geranylgeranylacetone, an inducer of HSP27, on ischemia-reperfusion injury in male rats as a preliminary study to see if further research of the effects of geranylgeranylacetone on the ischemic stroke was warranted. METHODS: In all experiments, male Wistar rats were used. First, we conducted pathway activity profiling based on a gas chromatography-mass spectrometry to identify ischemia-reperfusion-related metabolic pathways. Next, we investigated the effects of geranylgeranylacetone on the pentose phosphate pathway and ischemia-reperfusion injury by real-time polymerase chain reaction (RT-PCR), immunoblotting, and G6PD activity, protein carbonylation and infarct volume analysis. Geranylgeranylacetone or vehicle was injected intracerebroventricularly 3 h prior to middle cerebral artery occlusion or sham operation. RESULTS: Pathway activity profiling demonstrated that changes in the metabolic state depended on reperfusion time and that the pentose phosphate pathway and taurine-hypotaurine metabolism pathway were the most strongly related to reperfusion among 137 metabolic pathways. RT-PCR demonstrated that geranylgeranylacetone did not significantly affect the increase in HSP27 transcript levels after ischemia-reperfusion. Immunoblotting showed that geranylgeranylacetone did not significantly affect the elevation of HSP27 protein levels. However, geranylgeranylacetone significantly increase the elevation of phosphorylation of HSP27 after ischemia-reperfusion. In addition, geranylgeranylacetone significantly affected the increase in G6PD activity, and reduced the increase in protein carbonylation after ischemia-reperfusion. Accordingly, geranylgeranylacetone significantly reduced the infarct size (median 31.3% vs 19.9%, p = 0.0013). CONCLUSIONS: As a preliminary study, these findings suggest that geranylgeranylacetone may be a promising agent for the treatment of ischemic stroke and would be worthy of further study. Further studies are required to clearly delineate the mechanism of geranylgeranylacetone-induced HSP27 phosphorylation in antioxidant effects, which may guide the development of new approaches for minimizing the impact of cerebral ischemia-reperfusion injury.

Iatrogenic intracranial vessel dissection during mechanical thrombectomy rescued by emergent stenting: 2 case reports.

Intracranial vessel dissection is a procedural complication associated with endovascular treatment. However, there have been few reports on its potential causes and management during mechanical thrombectomy. In approximately 250 cases of mechanical thrombectomy over the past 5 years at our institution, iatrogenic intracranial dissection occurred in 2 patients (0.8%). In this report, we described these 2 cases that were rescued through emergent stenting. Mechanical thrombectomy, using both a stent retriever and an aspiration catheter, was performed for acute middle cerebral artery M2 occlusion in Patient 1 (a 69-year-old man) and for distal M1 occlusion in Patient 2 (an 83-year-old woman). In both cases, recanalization was achieved with the procedure, but irregular stenosis developed at the initially nonoccluded, but mildly arteriosclerotic, M1, after recanalization. During the thrombectomy procedure, the aspiration catheter sifted up to the arteriosclerotic M1. In both cases, the lesions were considered vessel dissection, due to a shift of the aspiration catheter tip into the arteriosclerotic vessel wall. Repeated percutaneous angiography with antithrombotic therapy failed to improve the lesions and to maintain the antegrade blood flow. Finally, lesions in each patient were successfully rescued through the use of emergent stenting. A drug-eluting stent for coronary use was deployed in Patient 1, and an Enterprise stent was applied in Patient 2. Inadvertent shift of the aspiration catheter into arteriosclerotic vessels can cause a serious intracranial vessel dissection. When performing mechanical thrombectomy, intracranial stents need to be available as rescue treatment devices to manage refractory iatrogenic intracranial vessel dissection.

An Aneurysm at the Origin of a Duplicated Middle Cerebral Artery Treated by Stent-Assisted Coiling Using the "Wrapped-Candy" Low-Profile Visualized Intraluminal Support (LVIS) Technique: A Technical Case Report and Review of the Literature.

BACKGROUND: Aneurysms at the origin of a duplicated middle cerebral artery (DMCA) are quite rare. Here, we report a patient with such an aneurysm successfully treated endovascularly using our novel "wrapped-candy" low-profile visualized intraluminal support (LVIS) technique. CASE DESCRIPTION: A 44-year-old woman underwent endovascular treatment for an unruptured wide-necked aneurysm at the origin of a DMCA that incorporated the origin of the DMCA into its neck. Stent-assisted coiling was performed using our newly developed "wrapped-candy" LVIS technique. To protect the origin of the DMCA and increase the stent metal density at the neck, an LVIS blue 3.5-mm × 22-mm stent was deployed by pushing the delivery wire aggressively to transform the visible wire components of the LVIS into a shape like "wrapped candy," maximizing the strut compaction at the neck of the aneurysm. Subsequently, the aneurysm component was coiled using a jailed microcatheter. The final procedural angiography demonstrated almost complete aneurysm occlusion with DMCA preservation. CONCLUSIONS: Stent-assisted coiling can be a feasible treatment for an unruptured, usually wide-necked, aneurysm at the origin of a DMCA. The wrapped-candy LVIS technique may be useful in more challenging morphologies such as wide-necked aneurysms that incorporate the branch origin into the aneurysm neck.

Double Stent Retriever (SR) Technique: A Novel Mechanical Thrombectomy Technique to Facilitate the Device-Clot Interaction for Refractory Acute Cerebral Large Vessel Occlusions.

BACKGROUND: Mechanical thrombectomy has become the standard treatment for acute ischemic stroke caused by large vessel occlusion; however, refractory occlusions still occur despite various thrombectomy procedures. The double stent retriever (SR) technique, which employs 2 SRs simultaneously at the occlusion, can be useful for such refractory occlusions. METHODS: We described 2 cases of refractory acute cerebral occlusion despite the use of conventional thrombectomy procedures that were both treated with the double SR technique. To discuss the technical aspects of how this easy-to-perform technique facilitates the device-clot interaction, we also evaluated radiographic findings of the SR strut during the procedure. RESULTS: In both cases, conventional thrombectomy procedures, including an SR alone, an aspiration catheter alone, and combined use of the SR and aspiration catheter, failed to recanalize the occlusion. The double SR technique was then performed with the stent-in-stent method in 1 patient and the parallel stent method in 1 patient. One pass of this technique retrieved hard clots and successfully recanalized the refractory occlusion in both cases. Intraprocedural radiographic images of these cases showed that the degree of stent expansion improved after deployment of the second SR compared with the first SR. CONCLUSIONS: Our radiographic findings suggested that adding a second SR facilitates the device-clot interaction at the occlusion site. The double SR technique may be an easy-to-perform thrombectomy technique to improve clot-capturing ability for the management of refractory acute cerebral artery occlusions.

Impact of introducing endovascular treatment on acute ischemic stroke outcomes: A shift from an era of medical management to thrombectomy in Japan.

BACKGROUND: Endovascular treatment (EVT) has increasingly become the standard treatment of acute cerebral large vessel occlusion (LVO). We evaluated the impact of introducing EVT on LVO therapy in a single center where intravenous thrombolysis (IVT) had been the only recanalization therapy. MATERIALS AND METHODS: Between April 2013 and March 2017, 354 consecutive patients with LVO admitted to our institution were analyzed. We compared outcomes between two chronological groups before (Pre-EVT group) and after (Post-EVT group) introducing EVT in April 2015. We assessed prognostic factors for favorable outcomes (modified Rankin scale score ≤2 at 90 days). RESULTS: In the Pre-EVT group, all 140 patients were treated medically, including 30 patients (21%) undergoing IVT. In the Post-EVT group, 118 patients (55%) underwent EVT, and the remaining 96 patients treated medically, including six patients (3%) undergoing IVT. The proportion undergoing recanalization therapy with IVT or EVT significantly increased after introducing EVT (21% versus 58%, p < 0.001). The rate of patients achieving favorable outcomes also significantly increased (14% versus 31%, p < 0.001). In multivariate regression analysis, introducing EVT was an independent predictive factor after adjusting for age, stroke severity and extent, and time (p = 0.005). The arrival time in patients with helicopter transport was significantly shorter than that with ground ambulance for a distance of more than 10 km (p < 0.001). CONCLUSIONS: This study demonstrated that the introduction of EVT improved outcomes of acute LVO patients, increasing the opportunity to receive recanalization therapy. Further efforts to establish medical systems to provide EVT are required throughout the country.

Surgical Thromboendarterectomy for Free-Floating Thrombus Associated with Cervical Carotid Artery Dissection: A Case Report.

BACKGROUND: Free-floating thrombus (FFT) of the cervical carotid artery is a rare but critical condition leading to stroke. The most common underlying pathology is atherosclerotic plaque; nonatherosclerotic pathologies are much rarer. Here we report a case of FFT associated with cervical carotid artery dissection that was successfully treated by surgical thromboendarterectomy. METHODS: A 51-year-old man presented with headache, pain in the left neck, and amaurosis fugax. Magnetic resonance angiography revealed mild stenosis in the bifurcation of the left carotid artery. The stenotic lesion was considered as a possible dissection because of the normal appearance of the vessel 2 years ago and its clinical presentation. Oral aspirin was initiated with the diagnosis of transient ischemic attack. Two weeks later, ultrasound was planned for further examination, which demonstrated a massive FFT with intramural hematoma in the lesion. Because FFT was present despite taking aspirin, surgical thromboendarterectomy was performed to prevent further ischemic events. RESULTS: Intraoperative findings revealed that FFT was the thrombus protruding from the intramural hematoma caused by arterial dissection. After the whole dissected layer was removed, the residual lumen was reinforced by multiple tacking sutures to prevent recurrence of dissection. No further ischemic events and recurrence occurred during the 1-year of follow-up after the surgery. CONCLUSIONS: When managing patients with carotid artery dissection, the formation of FFT should be considered as a possible critical feature. Surgical thromboendarterectomy with intimal tacking sutures might be an option for the treatment, ensuring immediate, preventive effects against the risk of cerebral embolism.