First-in-human, real-time artificial intelligence assisted cerebral aneurysm coiling: a preliminary experience.

BACKGROUND: Neuroendovascular procedures require careful and simultaneous attention to multiple devices on multiple screens. Overlooking unintended device movements can result in complications. Advancements in artificial intelligence (AI) have enabled real-time notifications of device movements during procedures. We report our preliminary experience with real-time AI-assisted cerebral aneurysm coiling in humans. METHODS: A real-time AI-assistance software (Neuro-Vascular Assist, iMed technologies, Tokyo, Japan) was used during coil embolization procedures in nine patients with an unruptured aneurysm. The AI system provided real-time notifications for 'coil marker approaching', 'guidewire movement', and 'device entry' on biplane fluoroscopic images. The efficacy, accuracy, and safety of the notifications were evaluated using video recordings. RESULTS: The AI system functioned properly in all cases. The mean number of notifications for coil marker approaching, guidewire movement, and device entry per procedure was 20.0, 3.0, and 18.3, respectively. The overall precision and recall were 92.7% and 97.2%, respectively. Five of 26 true positive guidewire notifications (19%) resulted in adjustment of the guidewire back toward its original position, indicating the potential effectiveness of the AI system. No adverse events occurred. CONCLUSIONS: The software was sufficiently accurate and safe in this preliminary study, suggesting its potential usefulness. To the best of our knowledge, this is the first reported use of a real-time AI system for assisting cerebral aneurysm coiling in humans. Large scale studies are warranted to validate its effectiveness. Real-time AI assistance has significant potential for future neuroendovascular therapy.

[Comparison of Bayesian Estimation and SVD Methods for CT Perfusion in Patients with Acute Stroke].

PURPOSE: There are various analysis methods for CT perfusion (CTP). Although the advantages of Bayesian estimation algorithms have been newly suggested, comparisons with other analysis methods on clinical data are still limited. In this study, we compared the Bayesian estimation method with the singular value decomposition (SVD) method in the evaluation of patients with acute cerebral infarction and examined its usefulness. METHODS: CTP data from 13 patients with acute stroke were analyzed using the SVD and Bayesian estimation methods implemented in Vitrea. Evaluation of visual clarity of the ischemic area and quantitative values of the healthy side-affected side ratio using the mean values of the left and right region of interest (ROI) on the images were compared using the SVD and Bayesian estimation methods. RESULTS: In visual evaluation, there were significant differences in CBV in four cases, and in CBF, MTT, and TTP in many cases. The healthy side-affected side ratio of the SVD and Bayesian estimation methods were as follows: CBF 1.19, 1.84; CBV 1.09, 1.02; MTT 1.12, 1.79; and TTP 1.48, 1.19. For CBF and MTT, the Bayesian estimation method had a larger ratio of the healthy side to the affected side, and for TTP, the SVD method had a larger ratio of the test side to the affected side. CONCLUSION: We suggest that the Bayesian estimation method is more useful than the SVD method for assessing CBF and MTT in CTP analysis of patients with acute stroke.

Primary results of mechanical thrombectomy for acute ischemic stroke: The K-NET registry in the Japanese metropolitan area.

BACKGROUND: Endovascular treatment (EVT) for acute large vessel occlusion has proven to be effective in randomized controlled trials. We conducted a prospective cohort study to evaluate the real-world efficacy of EVT in a metropolitan area with a large number of comprehensive stroke centers and to compare it with the results of other registries and randomized controlled trials (RCTs). METHODS: We analyzed the Kanagawa Intravenous and Endovascular Treatment of Acute Ischemic Stroke registry, a prospective, multicenter observational study of patients treated by EVT and/or intravenous tissue-type plasminogen activator (tPA). Of the 2488 patients enrolled from January 2018 to June 2020, 1764 patients treated with EVT were included. The primary outcome was a good outcome, which was defined as a modified Rankin Scale (mRS) of 0-2 at 90 days. Secondary analysis included predicting a good outcome using multivariate logistic regression analysis. RESULTS: The median age was 77 years, and the median National Institute of Health Stroke Scale (NIHSS) score was 18. Pretreatment mRS score 0-2 was 87%, and direct transport was 92%. The rate of occlusion in anterior circulation was 90.3%. Successful recanalization was observed in 88.7%. The median time from onset to recanalization was 193 min. Good outcomes at 90 days were 43.3% in anterior circulation and 41.9% in posterior circulation. Overall mortality was 12.6%. Significant predictors for a good outcome were as follows: age, male, direct transfer, NIHSS score, Alberta Stroke Program Early Computed Tomography Score, intravenous tPA, and successful recanalization. CONCLUSION: EVT in routine clinical use in a metropolitan area showed comparable good outcomes and lower mortality compared to previous studies, despite the high proportion of patients with older age, pretreatment mRS score of >2, posterior circulation occlusion, and higher NIHSS. Those results may have been associated with more direct transport and faster onset-to-recanalization times.

Safety, Pharmacokinetics and Pharmacodynamics of DS-1040, in Combination with Thrombectomy, in Japanese Patients with Acute Ischemic Stroke.

BACKGROUND AND OBJECTIVES: DS-1040 is a novel inhibitor of the activated form of thrombin-activatable fibrinolysis inhibitor that may have therapeutic potential in thromboembolic diseases, such as acute ischemic stroke (AIS) or pulmonary embolism. We undertook a Phase I clinical trial to investigate the safety, pharmacokinetics, and pharmacodynamics of DS-1040 in Japanese patients who were eligible for thrombectomy following AIS. METHODS: The trial enrolled patients with AIS due to large vessel occlusion, who were planned for thrombectomy within 8 h of symptom onset. Subjects were randomized to receive a single intravenous infusion of placebo or DS-1040 (0.6, 1.2, 2.4 or 4.8 mg) in a sequential-cohort design. The primary endpoints were the incidence of intracranial hemorrhage (ICH) and major extracranial bleeding within 36 and 96 h, respectively, of treatment initiation. Treatment-emergent adverse events (TEAEs) and pharmacokinetic/pharmacodynamic parameters were also assessed. RESULTS: Nine patients received placebo and 32 patients received DS-1040. There were no cases of symptomatic ICH or major extracranial bleeding with either placebo or DS-1040 after 36 and 96 h. One patient, who received DS-1040 0.6 mg, experienced a subarachnoid hemorrhage that was considered to be drug-related. Three patients died (2 placebo, 1 DS-1040), but no deaths were adjudicated as study drug-related. In vivo exposure to DS-1040 increased in proportion to dosage, but no clear dose-response relationship was seen for D-dimer levels and thrombin-activatable fibrinolysis inhibitor activity. CONCLUSIONS: Single doses of DS-1040 0.6-4.8 mg were well tolerated in Japanese patients with AIS undergoing thrombectomy. CLINICAL TRIAL REGISTRATION NUMBER: NCT03198715; JapicCTI-163164.

A Case of De Novo Basilar Artery Aneurysm Associated with Proximal Stenosis Treated by Coil Embolization.

Objective: This report highlights a case of a de novo aneurysm assumed to be caused by hemodynamic stress resulting from proximal basilar artery stenosis. Case Presentation: A 76-year-old woman presented at our hospital with tinnitus. Although MRI did not reveal the cause of her tinnitus, it did uncover an incidental finding of basilar artery stenosis. The patient reported a history of cerebral infarction, diabetes, and hypertension. Six years following the initial discovery of basilar artery stenosis, a saccular aneurysm was detected at the bifurcation of the basilar artery and the right anterior inferior cerebellar artery, corresponding to the distal portion of the basilar artery stenosis. Upon revelation of an enlarged aneurysm on the subsequent two-year follow-up MRI, the patient received coil embolization treatment. No signs of recurrence were observed on the next two-year follow-up MRI. Conclusion: It was assumed that proximal basilar artery arteriosclerotic stenosis had caused hemodynamic stress on the distal vessel wall, and that this was responsible for the formation and growth of a de novo aneurysm. This case suggests that cerebrovascular arteriosclerotic changes may be associated with de novo aneurysm formation and therefore requires careful follow-up.

Stenting Combined with Coil Embolization of a Dissecting Aneurysm after Traumatic Vertebral Artery Injury.

Objective: We report a case of dissecting aneurysm developed after traumatic vertebral artery dissection (VAD) treated by stenting combined with coil embolization. Case Presentation: A 47-year-old man was injured in a fall and presented with left VAD associated with central spinal injury due to C2 fracture. One week after admission, magnetic resonance imaging (MRI) demonstrated contralateral VAD with a dissecting aneurysm. Due to bilateral VAD, we employed coil embolization and stenting for the dissecting aneurysm to prevent rupture and embolic events, and to maintain the patency of the dominant right VA. There were no complications during the perioperative period. The follow-up angiogram 6 months after embolization confirmed obliteration of the dissecting aneurysm and patency of the parent artery. Conclusion: Stenting combined with coil embolization is an effective treatment for traumatic VAD with a dissecting aneurysm.

[Tentorial Dural Arteriovenous Fistula Presenting with Ocular Symptoms:A Case Report].

Tentorial dural arteriovenous fistula(dAVF)is classified as Cognard 4 with a high risk of aggressive feature, such as intracranial hemorrhage, venous infarction, and intracranial hypertension. We report a rare case presenting with ocular symptoms caused by tentorial dAVF. A 59-year-old man presented with progressive chemosis and exophthalmos of his left eye. Angiography showed a tentorial dAVF that was primarily fed by the middle meningeal artery and the meningohypophyseal artery. The AVF drained into the superior ophthalmic vein and the cerebellar cortical vein via an enlarged petrosal vein. Because transarterial Onyx embolization resulted in incomplete obliteration of the fistula, he underwent microsurgery via a suboccipital approach to obliterate the shunt. Postoperative angiography showed complete obliteration of the shunt. His ocular symptoms rapidly cured. We present this rare case and discuss the pathomechanism associated with the development of ocular symptoms secondary to a tentorial dAVF from the viewpoint of microvascular anatomy.

Observation of Neointimal Coverage Around the Aneurysm Neck After Stent-Assisted Coil Embolization by Optical Frequency Domain Imaging: Technical Case Report.

BACKGROUND AND IMPORTANCE: Stent-assisted coil embolization has been established as a treatment option for wide-necked or complex aneurysms. However, concerns have been raised about the incidence of thromboembolic complications, which is higher for coil embolization without stent assistance. Long-term antiplatelet therapy is necessary to prevent acute or delayed ischemic events potentially associated with incomplete stent apposition after treatment with stent-assisted coil embolization. Optical frequency domain imaging (OFDI) provides excellent-resolution images of intraluminal structures, allowing evaluation of the outcomes of stent-assisted procedures in terms of stent apposition and neointimal coverage. We here describe the novel use of OFDI for the observation of intravascular tissue formation after stent-assisted coil embolization. CLINICAL PRESENTATION: Two patients were treated with stent-assisted coil embolization for unruptured vertebral artery aneurysm. At the 1- or 2-yr follow-up visit, routine angiography followed by OFDI were performed to evaluate neointimal coverage of the stent strut and stent apposition to the vascular wall. OFDI enabled clear visualization of the vessel wall structures and demonstrated complete coverage of the stent struts as well as full stent wall apposition in 1 patient and incomplete coverage near the aneurism neck as well as mallaposition of some struts in the other patient. CONCLUSION: OFDI represents a feasible modality for the evaluation of intracranial vasculature and the outcomes of stent-assisted coil embolization in terms of intimal healing of aneurysms, stent-vessel interactions, and neointimal coverage of the stent. Such information is helpful in determining the duration of antiplatelet therapy after stent-assisted coil embolization.

Angiographic Characteristics of Pseudo-occlusion of the Internal Carotid Artery Before and After Stenting.

BACKGROUND: Various definitions of pseudo-occlusion and clinical outcomes after various treatments have been reported, but reports discussing the stenotic characteristics of pseudo-occlusion are rare. OBJECTIVE: To analyze the angiographic characteristics of pseudo-occlusion of the internal carotid artery (ICA) before and after carotid artery stenting (CAS). METHODS: We retrospectively reviewed the angiographic characteristics of 56 patients with pseudo-occlusion of the ICA treated with CAS. Angiographic changes were evaluated from digital subtraction angiography in terms of lesion characteristics of the stenosis and the diameter changes in the distal ICA before and after CAS. RESULTS: Fifty-six patients were successfully treated. Based on angiographic findings of ICA stenosis, 33 and 23 patients were classified into the single-channel and multiple-channel group, respectively. Regarding the diameter changes in the distal ICA after CAS, 31 cases were classified as immediate dilatation and the other 25 as restricted dilatation. Immediate dilatation of the distal ICA beyond the stent and that at a follow-up examination were observed significantly less frequently in the multiple-channel group than in the single-channel group. The use of multiple stents and stent occlusion at a follow-up examination were significantly more prevalent in the multiple-channel group than in the single-channel group. CONCLUSION: Stenotic lesions of pseudo-occlusion of the ICA were classified as single channel and multiple channel. Restricted dilatation of the distal ICA after CAS was more prevalent in the multiple-channel group. Because adverse events tended to be more frequent in the multiple-channel group than in the single-channel group, the indications for CAS should be determined carefully in multiple-channel patients. ABBREVIATIONS: CAS, carotid artery stentingICA, internal carotid artery.

A case of dural arteriovenous fistula draining to the diploic vein presenting with intracerebral hemorrhage.

The authors report an unusual case of a dural arteriovenous fistula (dAVF) draining only to the diploic vein and causing intracerebral hemorrhage. A 62-year-old woman presented with disturbance of consciousness and left hemiparesis. Brain CT scanning on admission showed a right frontal subcortical hemorrhage. Digital subtraction angiography revealed an arteriovenous shunt located in the region around the pterion, which connected the frontal branch of the right middle meningeal artery with the anterior temporal diploic vein and drained into cortical veins in a retrograde manner through the falcine vein. The dAVF was successfully obliterated by percutaneous transarterial embolization with N-butyl-2-cyanoacrylate. The mechanism of retrograde cortical venous reflux causing intracerebral hemorrhage is discussed.

Ruptured internal carotid artery aneurysm presenting with catastrophic epistaxis after repeated stereotactic radiotherapies for anterior skull base tumor: case reports and review of the literature.

Objectives Radiation-induced aneurysm is a rare complication for head and neck tumors. Only seven cases of an aneurysm after stereotactic radiosurgery and/or stereotactic radiotherapy (SRT) have been described. We report two patients with a ruptured internal carotid artery (ICA) aneurysm presenting with catastrophic epistaxis after repeated SRT for an anterior skull base tumor. Results Two male patients received repeated SRT in various combinations following surgery for an anterior skull base tumor. They presented with significant epistaxis due to rupture of the aneurysm of the ICA 6 and 77 months after the final SRT, respectively. The aneurysms were located within the radiation field. Preoperative angiography had revealed no aneurysms. Thus the aneurysms in these cases were most likely induced by the repeated SRT. Conclusions This is a proven report of aneurysm formation following repeated SRT without conventional radiotherapy. SRT may be very effective to control malignant skull base tumors. However, the possible development of radiation-induced aneurysm of the ICA should be considered in the case of repeated SRT. The surviving patients who have received SRT should undergo sequential follow-up for possible vascular involvement.

Effect of pitavastatin on preventing ischemic complications with carotid artery stenting: a multicenter prospective study--EPOCH-CAS study.

PURPOSE: Periprocedural ischemic stroke is one problem associated with carotid artery stenting (CAS). This study was designed to assess whether preoperative statin therapy reduces the risk of periprocedural ischemic complications with CAS. METHODS: In this prospective study at 11 centers, patients with carotid artery stenosis (symptomatic ≥50%, asymptomatic ≥80%) and a high risk of carotid endarterectomy but without previous statin treatments were divided into two groups by low-density lipoprotein cholesterol (LDL-C) levels. With LDL-C ≥120 mg/dl, the pitavastatin-treated (PS) group received pitavastatin at 4 mg/day. With LDL-C <120 mg/dl, the non-PS group received no statin therapy. After 4 weeks, both groups underwent CAS. Frequencies of new ipsilateral ischemic lesions on diffusion-weighted imaging within 72 h after CAS and cerebrovascular events (transient ischemic attack, stroke, or death) within 30 days were assessed. RESULTS: Among the 80 patients enrolled, 61 patients (PS group, n = 31; non-PS group, n = 30) fulfilled the inclusion criteria. New ipsilateral ischemic lesions were identified in 8 of 31 patients (25.8%) in the PS group and 16 of 30 patients (53.3%) in the non-PS group (P = 0.028). Cerebrovascular events occurred in 0 patients in the PS group and in 3 of 30 patients (10.0%) in the non-PS group (P = 0.071). Multivariate analyses demonstrated the pitavastatin treatment (ß = 0.74, 95% confidence interval 0.070-1.48, P = 0.042) to be an independent factor for decreasing post-CAS ischemic lesions. CONCLUSION: Pretreatment with pitavastatin significantly reduced the frequency of periprocedural ischemic complications with CAS.

A case of in-stent neoatherosclerosis 10 years after carotid artery stent implantation: observation with optical coherence tomography and plaque histological findings.

We report a patient's case of slow progressive in-stent restenosis 10 years after bare-metal stent implantation to his carotid artery. We treated the patient with an additional stent placement under a distal filter protection device. Optical coherence tomographic assessment and plaque histology during the carotid artery stenting (CAS) revealed atheromatous change at in-stent neointima, which contained lipid-rich plaque and calcification deposits. These findings suggest that in-stent neoatherosclerosis may play an important role in the pathogenesis of very late stent restenosis after CAS.

Formation and Rupture of the Internal Carotid Artery Aneurysm after Multiple Courses of Intensity-Modulated Radiation Therapy for Management of the Skull Base Ewing Sarcoma/PNET: Case Report.

Background Aneurysm formation after stereotactic irradiation of skull base tumors is rare. The formation and rupture of an internal carotid artery (ICA) aneurysm in a patient with skull base Ewing sarcoma/primitive neuroectodermal tumor (PNET), who underwent surgery followed by multiple courses of intensity-modulated radiation therapy (IMRT) and chemotherapy, is described. Case Description A 25-year-old man presented with a sinonasal tumor with intraorbital and intracranial growth. At that time cerebral angiography did not reveal any vascular abnormalities. The lesion was resected subtotally. Histopathologic diagnosis was Ewing sarcoma/PNET. The patient underwent multiple courses of chemotherapy and three courses of IMRT at 3, 28, and 42 months after initial surgery. The total biologically effective dose delivered to the right ICA was 220.2 Gy. Seven months after the third IMRT, the patient experienced profound nasal bleeding that resulted in hypovolemic shock. Angiography revealed a ruptured right C4-C5 aneurysm and irregular stenotic changes of the ICA. Lifesaving endovascular trapping of the right ICA was done. The patient recovered well after surgery but died due to tumor recurrence 6 months later. Conclusion Excessive irradiation of the ICA may occasionally result in aneurysm formation, which should be borne in mind during stereotactic irradiation of malignant skull base tumors.

De novo cerebral aneurysm formation associated with proximal stenosis.

BACKGROUND: Hemodynamic insults--high wall shear stress (WSS) combined with high positive WSS gradient (WSSG)--have been proposed to link to cerebral aneurysm initiation. We report 4 cases of aneurysms with proximal stenosis, including 1 de novo aneurysm, that might be associated with hemodynamic insults caused by the proximal stenosis. CLINICAL PRESENTATION: In 4 clinical cases, the diameter stenosis was 37% to 49% (mean, 42%) located 2.7 to 4.7 mm (mean, 3.7 mm) from the apex. We performed computational fluid dynamics simulations for 2 cases: a ruptured basilar terminus aneurysm with proximal stenosis (which had an angiogram taken 15 years previously that showed no aneurysm and no stenosis) and a cavernous carotid artery aneurysm with proximal stenosis. In both cases, the stenosis caused unphysiologically high WSS (> 7 Pa) at the apex, nearly doubling the WSS and WSSG values. To investigate the relationship between stenosis and distal hemodynamic elevation, we created a series of T-shaped vascular models by varying the degree and location of stenosis. We found that stenosis > 40% by diameter located within 10 mm from the apex caused unphysiologically high WSS and WSSG. All 4 clinical cases satisfied these conditions. CONCLUSION: Proximal stenosis could produce high WSS and high positive WSSG at the apex, thus potentially inducing de novo aneurysm formation. ABBREVIATIONS: BT, basilar terminusCFD, computational fluid dynamicsICA, internal carotid arteryWSS, wall shear stressWSS, wall shear stress gradient.

The clinical results of transcervical carotid artery stenting and frequency chosen as the approach route of carotid artery stenting in 1,067 consecutive cases.

BACKGROUND: Carotid artery stenting (CAS) is generally performed via a transfemoral approach. A transbrachial approach is usually chosen as an alternative when CAS via a transfemoral approach is difficult. At our institutions, a transcervical approach is chosen when the previous two approach routes are not available. We reviewed CAS cases treated via the transcervical route in our 1,067 CAS series to investigate the safety, feasibility, and frequency of this procedure as an approach route of CAS. METHODS: We performed 1,067 CAS procedures in 1,067 consecutive cases between December 2002 and June 2011. Initially, a transfemoral route was chosen, and secondarily a transbrachial route, the last choice was a transcervical route. A transbrachial approach was chosen in 96 (9.0%) cases and a transcervical approach in ten (0.9%). We reviewed the characteristics and outcomes of CAS performed via a transcervical approach. RESULTS: CAS was successfully performed on all ten transcervical-approach patients. Eight procedures were performed under local anesthesia and two under general anesthesia. Perioperative morbidity and mortality were both 0%. The modified Rankin scale (mRS) showed no deterioration at 3 months except for one case whose mRS became five because of an embolic stroke after aortic valve replacement. CONCLUSIONS: CAS via a transcervical approach was safe and feasible, and its frequency chosen as an approach route was 0.9%. This procedure can be an alternative to transfemoral or transbrachial approaches when CAS via either of these approaches is too difficult.

Optimal contrast material concentration for distinguishing among carotid artery lumen, carotid stent, and neck in cone-beam computed tomography during carotid angiography: basic and clinical studies.

PURPOSE: To explore the optimal contrast material (CM) concentration for distinguishing CM, carotid stent (CS), and neck components in cone-beam computed tomography (CBCT) during carotid angiography (CBCT-CA). MATERIALS AND METHODS: A neck phantom containing CS and contrast-filled imitation vessels of 9 mm diameter was scanned using CBCT. CM (300 mgI/ml) was used in concentrations of 100, 50, 33, 10, 5, and 1%. In a clinical study, 30 patients with a CS (Precise or Wallstent) underwent CBCT-CA with CM injected at a rate of 3 ml/s and a concentration of 10 or 20%. RESULTS: In the basic study, CBCTA using 5% CM enabled clear distinction among the three components under windowing at 1500 width and 300 center, and showed the exact diameter of the imitation vessel. Pixel values of CM inside the Precise and the Wallstent were 622.2 ± 32.9 (mean ± SD) and 746.0 ± 27.9, respectively. In the clinical study using CM at concentrations of 10 and 20%, pixel values of CM inside the Wallstent were 632.3 ± 69.2 and 1024.5 ± 99.0, respectively. CONCLUSION: Optimal CM concentration for distinguishing among the three components was 5% in the basic study; the optimal concentration was 10% in the clinical study.

Cilostazol activates function of bone marrow-derived endothelial progenitor cell for re-endothelialization in a carotid balloon injury model.

BACKGROUND: Cilostazol(CLZ) has been used as a vasodilating anti-platelet drug clinically and demonstrated to inhibit proliferation of smooth muscle cells and effect on endothelial cells. However, the effect of CLZ on re-endothelialization including bone marrow (BM)-derived endothelial progenitor cell (EPC) contribution is unclear. We have investigated the hypothesis that CLZ might accelerate re-endothelialization with EPCs. METHODOLOGY/PRINCIPAL FINDINGS: Balloon carotid denudation was performed in male Sprague-Dawley rats. CLZ group was given CLZ mixed feed from 2 weeks before carotid injury. Control group was fed normal diet. CLZ accelerated re-endothelialization at 2 weeks after surgery and resulted in a significant reduction of neointima formation 4 weeks after surgery compared with that in control group. CLZ also increased the number of circulating EPCs throughout the time course. We examined the contribution of BM-derived EPCs to re-endothelialization by BM transplantation from Tie2/lacZ mice to nude rats. The number of Tie2-regulated X-gal positive cells on injured arterial luminal surface was increased at 2 weeks after surgery in CLZ group compared with that in control group. In vitro, CLZ enhanced proliferation, adhesion and migration activity, and differentiation with mRNA upregulation of adhesion molecule integrin αvß3, chemokine receptor CXCR4 and growth factor VEGF assessed by real-time RT-PCR in rat BM-derived cultured EPCs. In addition, CLZ markedly increased the expression of SDF-1α that is a ligand of CXCR4 receptor in EPCs, in the media following vascular injury. CONCLUSIONS/SIGNIFICANCE: CLZ promotes EPC mobilization from BM and EPC recruitment to sites of arterial injury, and thereby inhibited neointima formation with acceleration of re-endothelialization with EPCs as well as pre-existing endothelial cells in a rat carotid balloon injury model. CLZ could be not only an anti-platelet agent but also a promising tool for endothelial regeneration, which is a key event for preventing atherosclerosis or restenosis after vascular intervention.

Endovascular recanalization of the completely occluded internal carotid artery using a flow reversal system at the subacute to chronic stage.

OBJECT: The efficacy and pitfalls of endovascular recanalization were evaluated in cases of internal carotid artery (ICA) occlusion in the subacute to chronic stage. METHODS: Fourteen cases (15 lesions) of symptomatic ICA occlusion with hemodynamic compromise or recurrent symptoms were treated at the subacute to chronic stage using an endovascular technique. The Parodi embolic protection system was used during the recanalization procedure to prevent embolic stroke by reversing the flow from the distal ICA to the common carotid artery. RESULTS: Recanalization of the occluded ICA was possible in 14 of 15 lesions. The occlusion points were 10 cervical ICAs and 4 petrous/cavernous ICAs in successfully recanalized cases. Ischemic symptoms disappeared completely after the treatment, and new ischemic symptoms did not appear related to the treated lesion. Single photon emission computed tomography findings demonstrated the improvement of hemodynamic compromise in all cases. One case showed right middle cerebral artery branch occlusion during the procedure, but this patient's neurological symptoms were stable due to preexisting hemiparesis. Endovascular recanalization was possible and effective in improving hemodynamic compromise. However, there are still several problems with this technique, such as hyperperfusion syndrome after recanalization, cerebral embolism during treatment, durability after treatment, and identification of the occlusion point before treatment. CONCLUSIONS: Endovascular recanalization using an embolic protection device can be considered as an alternative treatment for symptomatic ICA occlusion with hemodynamic compromise or refractoriness to antiplatelet therapy, even in the subacute to chronic stage of the illness.

Successful recanalization by in-stent percutaneous transluminal angioplasty with distal protection for acute carotid stent thrombosis.

A 71-year-old male presented with severe left cervical internal carotid artery stenosis manifesting as repeated transient ischemic attacks consisting of right hemiparesis and motor aphasia. Carotid artery stenting (CAS) under distal protection was performed to prevent further ischemic events. This procedure was uneventful. However, the patient exhibited progressive right hemiparesis and motor aphasia 3 days after CAS. Emergent angiography revealed carotid artery occlusion due to in-stent thrombosis. In-stent percutaneous transluminal angioplasty (PTA) was performed under distal protection. The carotid artery was recanalized with small residual thrombus. The neurological deficits almost completely disappeared after PTA. Follow-up angiography 9 months after stenting showed restenosis but no in-stent thrombosis. Carotid thrombosis after CAS can be resolved by in-stent PTA under distal protection and subsequent treatment with antithrombotic agents.