Sideway Aspiration Technique for Thrombus in a Sharply Bifurcated Branch of a Large Vessel.

Objective: Standard thrombectomy techniques, including stent retrieval and a direct aspiration first pass technique, are not effective when the occluded vessel is narrow and sharply bifurcated from the main trunk. Here, we present a new and alternative method for patients with such anatomical features and describe two cases treated by this method. Case Presentations: Case 1 was a 66-year-old woman who presented with consciousness disturbance and left hemiparesis. MRA suggested a right middle cerebral artery occlusion. Case 2 was an 86-year-old man who presented with sudden onset of consciousness disturbance; MRA indicated occlusion of the basilar artery. Both cases were successfully treated by our new method. First, we navigated a microcatheter, microguidewire, and aspiration catheter into the patent and visible branch adjacent to the occluded branch. The aspiration catheter was then carefully pulled back with continuous mechanical aspiration. When reverse blood flow from the aspiration catheter was suspended, we slightly advanced the catheter and caught the thrombus. Complete recanalization was attained in the two cases treated with this technique, which was named as sideway aspiration technique (SAT). Conclusion: Although it warrants further study, SAT may be a potentially safe and effective method for thrombectomy in cases with thrombus in a sharply bifurcated branch.

Efficacy of combined use of a stent retriever and aspiration catheter in mechanical thrombectomy for acute ischemic stroke.

BACKGROUND: The efficacy of combined stent retriever (SR) and aspiration catheter (AC; combined technique: CBT) use for acute ischemic stroke (AIS) is unclear. We investigated the safety and efficacy of single-unit CBT (SCBT)-retrieving the thrombus as a single unit with SR and AC into the guide catheter-compared with single use of either SR or contact aspiration (CA). METHODS: We analysed 763 consecutive patients who underwent mechanical thrombectomy for AIS between January 2013 and January 2020, at six comprehensive stroke centers. Patients were divided into SCBT and single device (SR/CA) groups. The successful recanalization with first pass (SRFP) and other procedural outcomes were compared between groups. RESULTS: Overall, 240 SCBT and 301 SR/CA (SR 128, CA 173) patients were analyzed. SRFP (modified Thrombolysis In Cerebral Infarction (mTICI) ≥2c, 43.3% vs 27.9%, p<0.001; mTICI 3, 35.8% vs 25.5%, p=0.009) and final mTICI ≥2b recanalization (89.1% vs 82.0%, p=0.020) rates were significantly higher, puncture-to-reperfusion time was shorter (median (IQR) 43 (31.5-69) vs 55 (38-82.2) min, p<0.001), and the number of passes were fewer (mean±SD 1.72±0.92 vs 1.99±1.01, p<0.001) in the SCBT group. Procedural complications were similar between the groups. In subgroup analysis, SCBT was more effective in women, cardioembolic stroke patients, and internal carotid artery and M2 occlusions. CONCLUSIONS: SCBT increases the SRFP rate and shortens the puncture-to-reperfusion time without increasing procedural complications.

Association between Pericytes in Intraplaque Neovessels and Magnetic Resonance Angiography Findings.

(1) Background: Pericytes are involved in intraplaque neovascularization of advanced and complicated atherosclerotic lesions. However, the role of pericytes in human carotid plaques is unclear. An unstable carotid plaque that shows high-intensity signals on time-of-flight (TOF) magnetic resonance angiography (MRA) is often a cause of ischemic stroke. The aim of the present study is to examine the relationship between the pericytes in intraplaque neovessels and MRA findings. (2) Methods: A total of 46 patients with 49 carotid artery stenoses who underwent carotid endarterectomy at our hospitals were enrolled. The patients with carotid plaques that were histopathologically evaluated were retrospectively analyzed. Intraplaque hemorrhage was evaluated using glycophorin A staining, and intraplaque neovessels were evaluated using CD34 (Cluster of differentiation) stain as an endothelial cell marker or NG2 (Neuron-glial antigen 2) and CD146 stains as pericyte markers. Additionally, the relationships between the TOF-MRA findings and the carotid plaque pathologies were evaluated. (3) Results: Of the 49 stenoses, 28 had high-intensity signals (TOF-HIS group) and 21 had iso-intensity signals (TOF-IIS group) on TOF-MRA. The density of the CD34-positive neovessels was equivalent in both groups. However, the NG2- and CD146-positive neovessels had significantly higher densities in the TOF-HIS group than in the TOF-IIS group. (4) Conclusion: The presence of a high-intensity signal on TOF-MRA in carotid plaques was associated with intraplaque hemorrhage and few pericytes in intraplaque neovessels. These findings may contribute to the development of new therapeutic strategies focusing on pericytes.

Use of Middle Cerebral Artery Visualization with Coronal Computed Tomography to Access Target Artery in Mechanical Thrombectomy.

BACKGROUND: When introducing a microguidewire into an occluded vessel during mechanical thrombectomy (MT), visual information on the vessel course distal to the occluded site could help to avoid perforation. We examined whether visualization of the middle cerebral artery (MCA) by coronal images of nonenhanced computed tomography (coronal CT) provides useful preoperative information on the vessel course in the setting of MT. METHODS AND RESULTS: We retrospectively studied 29 patients with ischemic stroke of the internal carotid artery and MCA occlusion who were admitted to our hospital within 4.5 hours from stroke onset and underwent MT. Coronal CT images were preoperatively created by a dedicated workstation and adjusted to visualize the M1 segment of the MCA (M1) and nearby areas. We referred to these images while performing MT. The shape and course of M1 on preoperative coronal CT images were compared with that in intraoperative angiography after recanalization. The median time from the start of imaging to arterial puncture was 40 minutes (interquartile range: 32.5-55.0 minutes). Successful recanalization of the thrombolysis in cerebral infarction 2b-3 was achieved in 89.7% of patients. The degree of matching was assessed as moderate to excellent, and was useful as preoperative information in 27 (93.1%) patients. CONCLUSIONS: Preoperative information on the vessel course by coronal CT well matched that in the intraoperative angiography. Only a little extra time and a small additional procedure are necessary for this technique. The addition of coronal CT images could contribute to a safe and successful MT.

Aspiration Catheter Reach to Thrombus (ART) Sign in Combined Technique for Mechanical Thrombectomy: Impact for First-Pass Complete Reperfusion.

OBJECTIVE: The important factor for successful first-pass complete reperfusion (FPR) after combined techniques for mechanical thrombectomy (MT) is unclear. We consider that for successful FPR, the aspiration catheter (AC) should reach to and hold the thrombus before the device is pulled out. Therefore, we defined an ART (AC reached thrombus) sign characterized by the cessation of reverse blood flow in aspiration pump and deformation of stent retriever (SR) at the tip of AC. The purpose of this study was to identify the impact of the ART sign on the outcomes of the combined techniques. METHODS: A retrospective analysis was conducted between January 2015 and September 2018 on the data of consecutive patients who underwent MT for anterior circulation stroke using both SR and AC at the first-pass procedure. We divided the patients into 2 groups based on whether the first-pass procedure achieved the ART sign (ARTs group) or not (Non-ARTs group). The primary endpoint was FPR defined as modified thrombolysis in cerebral infarction (mTICI) score of 3. RESULTS: Sixty-six patients were included in our study (n = 38, ARTs group; n = 28, Non-ARTs group). There were no differences at mTICI 2b/3 (97.3% versus 89.2%, P = .30), but the FPR and mTICI3 were more common in the ARTs group (81.5% versus 14.2%, P < .001; and 89.4% versus 32.1%, P < .001, respectively). CONCLUSIONS: ART sign in combined technique was found to be an important factor for successful FPR.

Reversible cerebral vasoconstriction complicated with brain infarction immediately after carotid artery stenting.

Reversible cerebral vasoconstriction is a very rare complication after carotid artery stenting (CAS). It has been reported to occur more than several hours after CAS and to have a good clinical course. A 73-year-old man underwent CAS for a high-grade symptomatic stenosis of his left carotid artery. Immediately after CAS, he had consciousness disturbance and right hemiparesis. We first suspected hyperperfusion syndrome, but antihypertensive therapy exacerbated his symptoms. On repeated postoperative angiography, the middle cerebral artery (MCA) appeared to become progressively narrower. Perfusion computed tomography indicated hypoperfusion in the left MCA territory, so we diagnosed the patient with ischemic symptoms due to hypoperfusion associated with MCA vasoconstriction. Although these findings were temporary, right weakness and cognitive dysfunction lingered and caused severe disability. As vasoconstriction after CAS may result in a poor outcome, it must be promptly distinguished and treated accordingly.

Possible involvement of pericytes in intraplaque hemorrhage of carotid artery stenosis.

OBJECTIVEIntraplaque hemorrhage (IPH) is most often caused by the rupture of neovessels; however, the factors of intraplaque neovessel vulnerability remain unclear. In this study, the authors focused on pericytes and aimed to investigate the relationship between IPH and pericytes.METHODSThe authors retrospectively analyzed the medical records of all patients with carotid artery stenoses who had undergone carotid endarterectomy at their hospitals between August 2008 and March 2016. Patients with carotid plaques that could be evaluated histopathologically were eligible for study inclusion. Intraplaque hemorrhage was analyzed using glycophorin A staining, and patients were divided into the following 2 groups based on the extent of granular staining: high IPH (positive staining area > 10%) and low IPH (positive staining area ≤ 10%). In addition, intraplaque neovessels were immunohistochemically evaluated using antibodies to CD34 as an endothelial cell marker or antibodies to NG2 and CD146 as pericyte markers. The relationship between IPH and pathology for intraplaque neovessels was investigated.RESULTSSeventy of 126 consecutive carotid stenoses were excluded due to the lack of a specimen for histopathological evaluation; therefore, 53 patients with 56 carotid artery stenoses were eligible for study inclusion. Among the 56 stenoses, 37 lesions had high IPH and 19 had low IPH. The number of CD34-positive neovessels was equivalent between the two groups. However, the densities of NG2- and CD146-positive neovessels were significantly lower in the high IPH group than in the low IPH group (5.7 ± 0.5 vs. 17.1 ± 2.4, p < 0.0001; 6.6 ± 0.8 vs. 18.4 ± 2.5, p < 0.0001, respectively).CONCLUSIONSPlaques with high IPH are associated with fewer pericytes in the intraplaque neovessels. This finding may help in the development of novel therapeutic strategies targeting pericytes.

Treatment outcomes of carotid artery stenting with two types of distal protection filter device.

PURPOSE: Preventing cerebral embolism from debris produced during carotid artery stenting (CAS) is important. This study compared the treatment outcomes of CAS using two types of filter-based embolic protection devices currently in use in Japan. MATERIALS AND METHODS: We assessed 121 consecutive cases of CAS performed with FilterWire EZ™ between July 2010 and November 2012 and 37 consecutive cases of CAS performed with the Spider FX™ between November 2012 and June 2013. A Carotid Wallstent™ was used in all cases. The incidence of positive lesions on diffusion-weighted magnetic resonance imaging (DWI) and stroke were compared between the groups. RESULTS: Postoperative DWI-positive lesions were observed in 38 (31.4%) and 14 (37.8%) patients in the FilterWire and Spider groups, respectively. In the FilterWire group, complications were transient ischemic attacks in 3 (2.5%) patients, cerebral infarction in 2 (1.7%) patients (1 patient each with minor and major stroke), and cerebral hemorrhage due to hyperperfusion syndrome in 1 (0.8%) patient. In the Spider group, except for cerebral infarction (minor stroke) in 1 (2.7%) patient, no complications were observed. No significant differences were observed in the incidence of complications between the groups. CONCLUSION: FilterWire EZ and Spider FX are comparable in terms of treatment outcome.