Stent Retriever Deployment Tracing Susceptibility Vessel Sign in the M2 Branch Predicts the Effective First-Pass Reperfusion in Thrombectomy for M1 Occlusion.

BACKGROUND AND PURPOSE: Successful first-pass reperfusion is associated with better functional outcomes after mechanical thrombectomy (MT) for acute ischemic stroke, but its treatment strategies remain unclear. MATERIALS AND METHODS: We retrospectively recruited patients who underwent MT for M1 occlusion between December 2020 and May 2023 at our institution. The locations of susceptibility vessel sign (SVS) on magnetic resonance imaging were classified into M1 only, M1 to single M2 branch, or M1 to both M2 branches. Patients were included in the SVS tracing group when the stent retriever of the first pass covered the entire SVS length. Successful reperfusion was defined as a modified Thrombolysis in Cerebral Infarction scale 2b-3. Any intracranial hemorrhage detected at 24-hour postoperatively was included as a hemorrhagic complication. RESULTS: The SVS was detected in M1 only, M1 to single M2 branch, and M1 to both M2 branches in 8, 22, and 4 patients, respectively. Among the 34 patients, 27 were included in the SVS-tracing group. Successful first-pass reperfusion was significantly more frequent in the SVS-tracing group compared with the non-SVS tracing group (odds ratio, 14.4; 95% confidence interval, 2.0 - 101; P = 0.007). The procedural time was significantly reduced in the SVS tracing group (median, 29 [interquartile range, 22 - 49] minute vs. 63 [43 - 106] minute; P = 0.043). There was a trend toward less frequent hemorrhagic complications in the SVS tracing group (odds ratio, 0.17; 95% confidence interval, 0.029 - 1.0; P = 0.052). CONCLUSIONS: This study provides a thrombus imaging-based MT strategy to efficiently achieve first-pass reperfusion in M1 occlusion.

Preoperative Ocular Symptoms Predict Acute Glaucoma After Carotid Revascularization: An Analysis of Combined Single-Center Data and a Systematic Review.

BACKGROUND: Acute glaucoma is a potential complication of carotid revascularization procedures such as endarterectomy or stenting. Although preoperative ocular hypoperfusion may predispose patients to postoperative glaucoma, the details of this complication have not been clarified. METHODS: We retrospectively reviewed the medical records of consecutive patients who underwent carotid revascularization at our institution from January 2019 to December 2022. These patients were divided into glaucoma and nonglaucoma groups. Given the rarity of the event, a systematic literature review was performed to additionally include data from patients who developed acute glaucoma after carotid revascularization. Multivariate logistic regression was performed to identify the risk factors for acute glaucoma. RESULTS: Thirty-five cases, including 2 from our institution, were included in the glaucoma group, and 130 were included in the nonglaucoma group. Most cases (79%) occurred within five days postoperatively. Multivariate analysis revealed that preoperative ocular symptoms were significantly associated with the development of postoperative glaucoma (odds ratio, 361.06; 95% confidence interval, 34.09-3824.27; P < 0.001). Preoperative neovascularization at the iris or anterior chamber angle, indicating severe ocular hypoperfusion, was found in 84% of patients with glaucoma. Permanent visual loss occurred in 41% of patients. The incidence of postoperative glaucoma at our institution was 1.5% (2/132). The positive predictive value of preoperative ocular symptoms for postoperative glaucoma was 0.25 (95% confidence interval, 0.18-0.32). CONCLUSIONS: This study was the first to clarify the risk factors and characteristics of acute glaucoma after carotid revascularization.

Effective Mechanical Thrombectomy for Posterior Circulation Ischemia Using Magnetic Resonance Imaging-based Arterial Structures.

To improve the success of mechanical thrombectomy, three-dimensional turbo spin-echo (3D-TSE) sequences on T2WI can be employed to estimate the vascular structure of the posterior circulation. In addition to the short imaging time of 3D-TSE T2WI (33 sec), it can visualize the outer diameter of the main cerebral artery, including the occluded vessels. However, to date, the efficacy of mechanical thrombectomy in the posterior circulation remains unclear, and safer and more efficient mechanical thrombectomy procedures are required. Assessment of the anatomical variations in the posterior circulation using 3D-TSE T2WI is valuable for access decisions, device selection, and safe device guidance and retrieval techniques to the target vessel. Herein, we present representative cases of basilar artery and posterior cerebral artery occlusions in our institute and describe the utility of preoperative 3D-TSE T2WI in these patients.

Symptomatic atherosclerotic plaque accompanied by carotid web.

Here, we describe a case of a 67-year-old man who was transferred to our hospital with complaints of sudden upper right limb weakness and ataxia. Scattered acute cerebral infarction was found in the watershed zone between the left anterior cerebral artery and the middle cerebral artery territories. A shelf-like structure at the origin of the left carotid artery and a vulnerable plaque distal to the lesion was found. Symptomatic atherosclerotic plaque with concomitant carotid web was diagnosed. Carotid endarterectomy resulted in good revascularization. Hemodynamic changes associated with vascular stenosis are involved in atherosclerosis. The current case is valuable and shows that carotid web can cause not only embolic infarction but also cerebral thrombosis due to atheroma formation in the carotid artery.

Intramural Hematoma in Vertebrobasilar Dolichoectasia-Related Stroke: A Retrospective Analysis of Six Consecutive Patients.

BACKGROUND: The pathophysiology underlying vertebrobasilar dolichoectasia (VBD) is largely unknown. However, a few reports have demonstrated that acute intramural hematoma (IMH) in VBD is associated with stroke. We aimed to investigate the clinical and radiological features of IMH in VBD and the role of IMH in predicting rupture and patient outcomes. METHODS: We retrospectively reviewed the medical records of patients treated in 2 stroke centers between January 2012 and December 2021. Patients presenting with VBD and stroke were eligible for study inclusion. We excluded patients with stroke caused by arterial dissection or artery-to-artery embolism. IMH was defined as a crescent-shaped area of high signal density in the vessel wall on axial computed tomography in the absence of an intimal flap, double lumen, and pearl-and-string sign. RESULTS: Six patients were analyzed. All presented with symptoms of brainstem/cerebellar infarction without headache. Interobserver agreement for the presence or absence of IMH was excellent (100%). IMH was detected in 5 patients. The positive predictive value of IMH for rupture was 80% (95% confidence interval, 28%-99.5%). The median time from symptom onset to rupture was 2.5 days (range, 1.5-4). Median computed tomography values were significantly higher within the IMH than those in the lumen of the basilar artery (70 vs. 44.5 Hounsfield units; P = 0.008). The modified Rankin scale score on day 30 after onset was 5 in 1 patient and 6 in the remaining 5. CONCLUSIONS: IMH in patients with VBD presenting with brainstem/cerebellar infarction should be regarded as a sign associated with a high risk of rupture.

3D Turbo Spin-echo MRI-based Mechanical Thrombectomy at Middle Cerebral Artery Bifurcations.

We describe three cases with acute middle cerebral artery (MCA) occlusion. From the pre-operative MRI, including three-dimensional turbo spin-echo sequences using T1WI and T2WI, we assessed both thrombus configuration and arterial anatomy at the MCA bifurcations. For efficient endovascular thrombectomy, we identified the applied MCA segment 2 (M2) branch, in which the main thrombus was buried. Sufficient recanalization after a single pass was achieved and the patients made a marked recovery. Although mechanical thrombectomy for M2 occlusion has not been of proven benefit, the endovascular procedure based on three-dimensional turbo spin-echo imaging is useful for more complete thrombus removal at MCA bifurcations.

True superficial temporal artery aneurysm: A case after extracranial-intracranial bypass surgery and a systematic review.

Background: Nontraumatic true superficial temporal artery aneurysm (STAA) is rare, and its characteristics and pathogenesis are unclear. Methods: We report a case of STAA and performed a systematic review of PubMed, Scopus, and Web of Science using the keyword "superficial temporal artery aneurysm" to include studies on STAA reported through July 2022. We excluded studies on STAA associated with trauma, arterial dissection, infection, or vasculitis. Results: A 63-year-old woman who underwent left superficial temporal artery (STA)-middle cerebral artery bypass surgery 8 years previously was diagnosed with an aneurysm located at the left STA. The blood flow volume estimated by ultrasonography was higher in the left STA than in the contralateral counterpart (114 mL/min vs. 32 mL/min). She underwent clipping surgery to prevent aneurysmal rupture without sequela. The lesion was diagnosed as a true aneurysm by histology. The systematic review identified 63 cases (including the present case) of nontraumatic true STAA. The median age of the patients was 57 (interquartile range [IQR]: 41-70) years. Most (90.5%) cases were detected as a palpable mass. Aneurysmal rupture occurred in only 1 (1.6%) case, despite the large size of aneurysms (median size: 13 [IQR: 8-20] mm) and the high frequency (33.3%) of aneurysmal growth during observation. Most (93.7%) patients underwent surgical resection of STAA without sequela. Conclusion: Our findings suggest that the pathogenesis of true STAA is promoted by hemodynamic stress. The systematic review clarified patients' and aneurysmal characteristics and treatment outcomes, providing further insight into the pathogenesis of nontraumatic true STAA.

A Case of Spinal Ependymoma Developed in the Extramedullary Location: A Case Report and Literature Review.

Intradural extramedullary (IDEM) ependymoma except for tumors originated from the filum terminale or conus medullaris is rare. The present study showed a case of IDEM ependymoma. A 16-year-old boy was referred to our hospital with a complaint of right hypochondriac pain and motor weakness in his right leg. MRI revealed a solitary intradural tumor at Th5-8 level with syringomyelia at Th2-4 level. Microscopic total tumor resection was performed with right hemi-laminectomy of Th4-9. Histological diagnosis was ependymoma (WHO grade 2). Although his leg weakness was worsened transiently, he showed improvement in leg weakness being able to go up and down the stairs 1 month after the surgery. There was no tumor recurrence until now, 7 years after the surgery, without any adjunctive therapies. A total of 44 cases of IDEM ependymoma had been reported in the past literatures. They are thought to arise from ependymal cells which remained during the process of neural tube closure. Like intramedullary ependymomas, most of the IDEM ependymomas have clear border to surrounding tissue and often removed completely. However, a small number of recurrences and malignant transformations had been reported after complete resections despite benign histological features tumors. In the case of totally resected low grade IDEM ependymoma, it is thought to be reasonable to perform long-term periodical radiographic follow-up without postoperative adjunctive therapy.

Cerebral Amyloidoma Accompanied by Sjögren's Syndrome: A Case Report and Literature Review.

We present a 69-year-old woman with colorectal cancer and a left frontal lobe tumor that was diagnosed as a cerebral amyloidoma after surgical resection. Further postoperative systemic evaluation revealed another amyloidoma in her hip as well as Sjögren's syndrome. Systemic amyloidosis was not present. To the best of our knowledge, this is the first case of cerebral amyloidoma presenting as one of the multiple localized amyloidomas accompanied by Sjögren's syndrome. We also present a systematic review of 65 cerebral amyloidoma cases reported in the literature over the past 40 years and discuss patient characteristics and pathological and imaging findings associated with prognosis.

Cervical Open-Door Laminoplasty by Hydroxyapatite Implant Insertion Without Suturing.

OBJECTIVE: To assess the efficacy of cervical open-door laminoplasty by hydroxyapatite implant insertion between the lamina and the lateral mass without suturing. METHODS: All patients who underwent cervical open-door laminoplasty with C2/C7 undermining and insertion of hydroxyapatite implants from C3 to C6 were retrospectively evaluated for surgical time and neurological outcomes according to the Japanese Orthopaedic Association (JOA) score. To assess the alignment of the cervical spine and postoperative cervical pain, the C2-7 angle and a visual analogue scale score were used, respectively. RESULTS: The population consisted of 102 women and 222 men ranging in age from 32 to 90 years. The average surgical time was 86 minutes. Fourteen of 1,296 hydroxyapatite implants were kept in place with sutures due to a weak restoration force of the hinge during surgery. No hydroxyapatite implant dislocation was detected on cervical computed tomography at 1 year after surgery. The average JOA score was 10.2±2.5 before surgery and 14.6±2.8 at 1 year after surgery. The average recovery rate was 61.8%. The average C2-7 angle at the neutral position was 7.1°±6.2° before surgery and 6.5°±6.3° at 1 year after surgery. CONCLUSION: This method enabled us to achieve minimal exposure of the lateral mass, prevention of lateral mass injury and dural injury, and a shorter surgical time while maintaining acceptable surgical outcomes. The idea that firm suture fixation is needed to prevent spacer deviation during cervical open-door laminoplasty may need to be revisited.

Immunohistochemical analysis of a ruptured basilar top aneurysm autopsied 22†years after embolization with Guglielmi detachable coils.

The authors report on the histologic and immunohistochemical analyses of a cerebral aneurysm embolized with platinum coils and with the longest observation period. A 58-year-old woman presenting with subarachnoid hemorrhage due to ruptured basilar top aneurysm was treated with Guglielmi detachable coils (GDC) 22 years ago. She was the 15th case since the GDC was introduced. After she died of unrelated causes, an autopsy and thorough histologic examination were performed. Gross examination revealed no adhesion between the aneurysm wall and the surrounding brain tissue. Histologic and immunohistochemical analyses demonstrated that the cavity of the aneurysm was filled with homogeneous collagenous fibrous tissue, while the neck was completely covered by a dense collagenous neointima and a smooth muscle cell layer. The unique histologic results of this case may contribute to a better understanding of the long-term evolution of the healing process in intracranial aneurysms successfully treated with the GDC.

Correlation of clot imaging with endovascular recanalization in internal carotid artery terminus occlusion.

BACKGROUND AND PURPOSE: In a swine stroke model we have previously demonstrated a high-intensity fluid attenuated inversion recovery (FLAIR) signal representing the erythrocyte component of the clot. We hypothesized that the intensity of the FLAIR clot signal in patients with acute stroke may predict the efficacy of recanalization by thrombectomy devices. In this study we compared the pretreatment FLAIR signal intensity of the clots in the distal internal carotid artery (ICA) and the degree of angiographic recanalization rate after mechanical thrombectomy. METHODS: 25 consecutive acute stroke patients with ICA terminus (ICA-T) occlusion diagnosed with MRI at the UCLA Medical Center between 2002 and 2013 were retrospectively reviewed. The intensity of the FLAIR clot signal at the distal ICA was blindly compared with the angiographic recanalization status (successful recanalization defined as Thrombolysis In Cerebral Infarction (TICI) score of 2b-3) and non-successful recanalization as TICI score 0-2a) after endovascular treatment. Multivariate logistic regression analysis for successful recanalization was performed. RESULTS: Successful recanalization was achieved in 40% of patients (10/25) and showed a significantly higher FLAIR intensity (p=0.014). The cut-off value for clot intensity on the FLAIR sequence to predict recanalization was 0.7952, with 70% sensitivity and 80% specificity (95% CI 0.59 to 0.96) using a receiver operating characteristic curve. In multivariate logistic regression analysis, only a high FLAIR clot intensity (>0.7952) was associated with successful recanalization (OR 16.79; 95% CI 1.29 to 218.92; p=0.031). CONCLUSIONS: High signal intensity on FLAIR clot imaging may predict successful recanalization after endovascular therapy for ICA-T occlusion.

Immunohistochemical analysis of a ruptured basilar top aneurysm autopsied 22†years after embolization with Guglielmi detachable coils.

The authors report on the histologic and immunohistochemical analyses of a cerebral aneurysm embolized with platinum coils and with the longest observation period. A 58-year-old woman presenting with subarachnoid hemorrhage due to ruptured basilar top aneurysm was treated with Guglielmi detachable coils (GDC) 22 years ago. She was the 15th case since the GDC was introduced. After she died of unrelated causes, an autopsy and thorough histologic examination were performed. Gross examination revealed no adhesion between the aneurysm wall and the surrounding brain tissue. Histologic and immunohistochemical analyses demonstrated that the cavity of the aneurysm was filled with homogeneous collagenous fibrous tissue, while the neck was completely covered by a dense collagenous neointima and a smooth muscle cell layer. The unique histologic results of this case may contribute to a better understanding of the long-term evolution of the healing process in intracranial aneurysms successfully treated with the GDC.

Comparison of simulated structural deformation with experimental results after Wingspan stenting.

OBJECTIVES: Biomechanical stress distribution correlates with the biological responses after stenting. Computational analyses have contributed to the optimization of stent geometry. In particular, structural analysis based on pre-operative angiography can be used to predict the stent-artery interaction before endovascular treatments. However, the simulated results need to be validated. In this report, we compared the simulated arterial structure with post-operative images after an intracranial Wingspan stent. METHODS: A Wingspan stent was deployed at a slightly curved ascending pharyngeal artery (APA) in the swine. Using a finite element method (FEM), the configuration after stenting was simulated and quantitatively compared with post-procedural 3D angiography. RESULTS: The finite element analysis demonstrated arterial straightening after stenting. The simulated images were similar to the experimental results with respect to the curvature index of the center line and the cross-sectional areas. CONCLUSION: We assessed the simulated structural deformation after Wingspan stenting, by comparison with experimental results.

Structural analysis for Wingspan stent in a perforator model.

Perforator infarction represents a critical problem after intracranial Wingspan stent. To explore the mechanism of perforator infarction, we simulated the stent-artery interaction at an atheromatous plaque with perforator. Structural deformation and biomechanical stress distribution after stenting were analyzed. High radial stress values were located along the stent struts, which surrounded the area with high circumferential stress. Stretched perforator orifice in a circumferential direction after stenting was simulated. These results show that structural deformation could play a role in the mechanism of perforator occlusion after Wingspan stenting.

Simulated biomechanical responses at a curved arterial segment after Wingspan Stent deployment in swine.

OBJECTIVES: Endovascular treatment with the Wingspan Stent is frequently associated with in-stent restenosis at the curved portion, leading to late-phase stroke. To explore the cause of stroke complications after treatment with the Wingspan Stent, we simulated the biomechanical responses at a curved arterial segment using the finite element method. METHODS: A Wingspan stent was deployed at a slightly curved ascending pharyngeal artery (APA) in swine. Several stress distributions modeling solid mechanics were analyzed with structural deformation. Histopathological analysis of the selected APA was assessed at 28 days after stenting. RESULTS: Arterial straightening was simulated in this study. Both radial stress (RS) and circumferential stress (CS) concentrations increased at both stent ends. Marked lower axial stress (AS) concentration was observed at the outer wall of an arterial curvature. The proximal stent segment, ending in the curved portion, significantly impacted the solid mechanical environment. Eccentric neointimal hyperplasia was observed at the curved segment. DISCUSSION: These results show that the Wingspan stent exaggerated the non-uniform stress distributions in a curved artery. The understanding of stent-arterial wall interactions is of value to identify the current limitations of intracranial stenting, and will help to improve this treatment methodology and future devices.

Characterization of arterial thrombus composition by magnetic resonance imaging in a swine stroke model.

BACKGROUND AND PURPOSE: The aim of this study is to analyze the histological composition of acute arterial thrombi and their MRI signals. METHODS: Two different types of experimental thrombi, erythrocyte- and fibrin-rich thrombus, were created and injected into an experimentally formed stenotic common carotid artery in swine. MRI of the in vivo and in vitro samples was obtained immediately after the thrombus application. RESULTS: Erythrocyte component showed high on fluid-attenuated inversion recovery, and iso on T2-weighted signal in both in vitro and in vivo. Fibrin-rich thrombus was composed of fibrin/platelet and nucleated cell layers, which demonstrated iso- and low intensities, respectively, in both fluid-attenuated inversion recovery and T2-weighted images in vitro. Mixed signal was obtained in vivo. CONCLUSIONS: We successfully characterized the only erythrocyte component of acute thrombus by MRI.

Biomechanical responses after Wingspan Stent deployment in swine ascending pharyngeal artery.

OBJECTIVES: Symptomatic intracranial atherosclerotic stenosis is associated with a high rate of recurrent stroke. Endovascular angioplasty and stenting using the Wingspan(TM) Stent (Stryker) has been used for treatment of this disorder. However, a recent randomized trial (SAMMPRIS Clinical Trial) reported that it was inferior to aggressive medical management. To explore the cause of stroke complications after treatment with the Wingspan Stent, we simulated the biomechanical responses in a swine ascending pharyngeal artery (APA) using the finite element method. METHODS: A Wingspan Stent was deployed in a swine APA, and simulated stress distributions including radial, circumferential, and wall shear stress were evaluated. Histopathological analysis of the selected APA was made 28 days post-stenting. RESULTS: We detected increased radial stress concentration at distal stent markers with a stent edge and a graded augmentation of radial stress from proximal to distal. There was an impaired wall shear stress near the stent struts and stent markers. Intense neointimal hyperplasia was observed from the middle to distal segment of the stent 28 days after the procedure. DISCUSSION: This preliminary data suggest that the Wingspan Stent produces increased radial stress distribution with distal segment in a tapering artery. It is possible that the radial stress concentration plays a role in the development of neointimal hyperplasia.

Direct thrombus aspiration using the Penumbra system for the treatment of pediatric intracranial dissection.

We describe a case of a 15-year-old girl who developed a spontaneous intracranial arterial dissection with distal middle cerebral artery (MCA) occlusions. From the digital subtraction angiography provided, the dissection flap appeared to originate at the internal carotid artery terminus with extension into the right M1 segment and occluding the right anterior cerebral artery, A1 segment. CT perfusion study showed salvageable tissue in the posterior MCA territory, including the motor cortex. In order to avoid further injury to the dissection, clot retrieval systems were not a treatment option. We therefore performed selective thrombus aspiration with the Penumbra system for the occluded central and precentral arteries distal to the non-occlusive dissecting lesion. Sufficient recanalization was achieved and the patient made a marked recovery. Although mechanical thrombectomy with the use of retrieval intracranial stent systems has demonstrated satisfactory recanalization rates, the aspiration methodology remains useful for patients with an accompanying proximal vascular lesion.

Direct thrombus aspiration using the Penumbra system for the treatment of pediatric intracranial dissection.

We describe a case of a 15-year-old girl who developed a spontaneous intracranial arterial dissection with distal middle cerebral artery (MCA) occlusions. From the digital subtraction angiography provided, the dissection flap appeared to originate at the internal carotid artery terminus with extension into the right M1 segment and occluding the right anterior cerebral artery, A1 segment. CT perfusion study showed salvageable tissue in the posterior MCA territory, including the motor cortex. In order to avoid further injury to the dissection, clot retrieval systems were not a treatment option. We therefore performed selective thrombus aspiration with the Penumbra system for the occluded central and precentral arteries distal to the non-occlusive dissecting lesion. Sufficient recanalization was achieved and the patient made a marked recovery. Although mechanical thrombectomy with the use of retrieval intracranial stent systems has demonstrated satisfactory recanalization rates, the aspiration methodology remains useful for patients with an accompanying proximal vascular lesion.