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Background and Objectives: The internal capsule is supplied by perforators originating from the internal carotid artery, middle cerebral artery, anterior choroidal artery and anterior cerebral artery. The aim of this study is to examine the vascular anatomy of the internal capsule, along with its related white matter anatomy, in order to prevent potential risks and complications during surgical interventions., Methods: Twenty injected hemispheres prepared according to the Klingler method were dissected. Dissections were photographed at each stage. The findings obtained from the dissections were illustrated to make them more understandable. Additionally, the origins of the arteries involved in the vascularization of the internal capsule, their distances to bifurcations, and variations in supplying territories have been thoroughly examined., Results: The insular cortex and the branches of the middle cerebral artery on the insula and operculum were observed. Following decortication of the insular cortex, the extreme capsule, claustrum, external capsule, putamen and globus pallidus structures were exposed. The internal capsule is shown together with the lenticulostriate arteries running on the anterior, genu and posterior limbs. Perforators supplying the internal capsule originated from the middle cerebral artery, anterior cerebral artery, internal carotid artery and anterior choroidal artery. The internal capsule's vascular supply varied, with the medial lenticulostriate arteries (MLA) and lateral lenticulostriate arteries (LLA) being the primary arteries. The anterior limb was most often supplied by the MLA, while the LLA and anterior choroidal artery dominated the genu and posterior limb. The recurrent artery of Heubner originated mostly from the A2 segment. The distance from the ICA bifurcation to the origin of the first LLA on M1 is 9.55 ± 2.32 mm, and to the first MLA on A1 is 5.35 ± 1.84 mm. MLA branching from A1 and proximal A2 ranged from 5 to 9, while LLA originating from the MCA ranged from 7 to 12., Conclusion: This study provides comprehensive understanding of the arterial supply to the internal capsule by combining white matter dissection. The insights gained from this study can help surgeons plan and execute procedures including oncological, psychosurgical, and vascular more accurately and safely. The illustrations derived from the dissections serve as valuable educational material for young neurosurgeons and other medical professionals., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: The M1 middle cerebral artery (MCA) commonly bifurcates into M2 superior and M2 inferior segments. However, MCA anatomy is highly variable rendering classification for mechanical thrombectomy trials difficult. This study explored safety and effectiveness of M2 MCA stroke thrombectomy stratified by M2 MCA anatomy., Methods: Cases of large vessel occlusion strokes treated by mechanical thrombectomy between February 2016 and August 2022 were reviewed (N = 784). M1 (n = 431) and M2 (n = 118) MCA occlusions were assessed. Among M2 MCA occlusions, only prototypical MCA bifurcation anatomy cases were included (n = 99). Dominance was assessed based on angiography. Procedural and outcome data were compared between M1, M2 superior, and M2 inferior MCA occlusions., Results: Baseline demographics and periprocedural criteria of M2 superior (n = 56) and M2 inferior (n = 43) occlusion mechanical thrombectomies were comparable. The occluded branch was dominant in 41/43 (95.3%) M2 inferior cases, but in only 37/56 (66.1%) M2 superior cases (P < 0.001). The 90-day favorable functional outcome (modified Rankin Scale score 0-2) and mortality (modified Rankin Scale score 6) rates were 60.0% and 8.9% in M2 superior, 42.9% and 32.6% in M2 inferior, and 44.1% and 26.0% in M1 (n = 431) cases. Compared with M2 superior cases, in M2 inferior cases, favorable outcome rates were lower (P = 0.094) and mortality rates were higher (P = 0.003) and resembled M1 rates (P = 0.750 and P = 0.355, respectively)., Conclusions: In the setting of prototypical MCA bifurcation anatomy, thrombectomy of dominant M2 inferior occlusions had outcome rates similar to M1 occlusions. In contrast, M2 superior occlusions had significantly lower mortality rates and a trend toward better favorable functional outcome rates., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background:  Gentian violet ink is used as a skin marker in various surgical procedures, including neurosurgery. The dye is also used to visualize the edges of blood vessels during bypass surgery. However, gentian violet ink carries the risks of carcinogenicity and venous injury, which causes microvascular thrombosis. In this study, we compare the gentian violet-free dye C.I. Basic Violet 4 (BV4) and gentian violet. The usefulness, in terms of color, and formation of microvascular thrombosis in anastomosis were compared., Methods:  We used the gentian violet-free dye in 20 cases involving 3 vascular anastomoses. The bone cutting lines on the bone surface, superior temporal artery, and middle cerebral artery were drawn using BV4 and gentian violet ink., Results:  The colors of BV4 and gentian violet ink were similar. No thrombus formation was observed at the vascular anastomosis when using BV4., Conclusion:  BV4 can be used similarly to gentian violet ink. No adverse effects such as thrombus formation in microvascular anastomosis were experienced when BV4 was used., Competing Interests: None declared., (Thieme. All rights reserved.)

Our study aimed to evaluate the postoperative outcome of patients with unruptured giant middle cerebral artery (MCA) aneurysm revealed by intracranial hypertension associated to midline brain shift. From 2012 to 2022, among the 954 patients treated by a microsurgical procedure for an intracranial aneurysm, our study included 9 consecutive patients with giant MCA aneurysm associated to intracranial hypertension with a midline brain shift. Deep hypothermic circulatory flow reduction (DHCFR) with vascular reconstruction was performed in 4 patients and cerebral revascularization with aneurysm trapping was the therapeutic strategy in 5 patients. Early (< 7 days) and long term clinical and radiological monitoring was done. Good functional outcome was considered as mRS score ≤ 2 at 3 months. The mean age at treatment was 44 yo (ranged from 17 to 70 yo). The mean maximal diameter of the aneurysm was 49 mm (ranged from 33 to 70 mm). The mean midline brain shift was 8.6 mm (ranged from 5 to 13 mm). Distal MCA territory hypoperfusion was noted in 6 patients. Diffuse postoperative cerebral edema occurred in the 9 patients with a mean delay of 59 h and conducted to a postoperative neurological deterioration in 7 of them. Postoperative death was noted in 3 patients. Among the 6 survivors, early postoperative decompressive hemicraniotomy was required in 4 patients. Good functional outcome was noted in 4 patients. Complete aneurysm occlusion was noted in each patient at last follow-up. We suggest to discuss a systematic decompressive hemicraniotomy at the end of the surgical procedure and/or a partial temporal lobe resection at its beginning to reduce the consequences of the edema reaction and to improve the postoperative outcome of this specific subgroup of patients. A better intraoperative assessment of the blood flow might also reduce the occurrence of the reperfusion syndrome., (© 2024. The Author(s).)

Background: The comparison of mechanical thrombectomy (MT) outcomes between patients with the hyperdense middle cerebral artery sign (HMCAS) and non-HMCAS is important to evaluate the impact of this radiological finding on treatment efficacy. This meta-analysis aimed to assess the association between HMCAS and clinical outcomes in patients undergoing thrombectomy, comparing the outcomes over non-HMCAS., Methods: A systematic literature search was conducted in PubMed, Ovid Embase, Google Scholar, and Cochrane Library to identify studies on MT outcomes for M1 occlusions of HMCAS over non-HMCAS. Inclusion criteria encompassed modified Rankin Scale (mRS) score, mortality, symptomatic intracranial hemorrhage (sICH), and successful recanalization. Using R software version 4.1.2, we calculated pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CI)., Results: The meta-analysis was performed for 5 studies with 724 patients. There was no association found between presence of HMCAS and achieving mRS 0-2 (OR = 0.65, 95% CI: 0.29-1.47; p = .544). Mortality analysis also showed no significant association with presence of HMCAS (OR = 0.78, 95% CI: 0.37-1.65; p = .520). No significant difference in sICH risk (OR = 1.54, 95% CI: 0.24-9.66; p = .646) was found between groups. Recanalization analysis showed a non-significant positive association (OR = 1.23, 95% CI: 0.67-2.28; p = .501). Heterogeneity was observed in all analyses., Conclusion: Our findings showed that there is no statistically significant difference in mRS scores, mortality, sICH, and recanalization success rates between the HMCAS and non-HMCAS groups., Competing Interests: Declaration of conflicting interestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: W.B. holds equity in Nested Knowledge, Superior Medical Editors, Piraeus Medical, Sonoris Medical, and MIVI Neurovascular. He receives royalties from Medtronic and Balloon Guide Catheter Technology. He receives consulting fees from Medtronic, Stryker, Imperative Care, MicroVention, MIVI Neurovascular, Cerenovus, Asahi, and Balt. He serves in a leadership or fiduciary role for MIVI Neurovascular, Marblehead Medical LLC, Interventional Neuroradiology (Editor in Chief), Piraeus Medical, and WFITN. D.F.K. holds equity in Nested Knowledge, Superior Medical Editors, and Conway Medical, Marblehead Medical, and Piraeus Medical. He receives grant support from MicroVention, Medtronic, Balt, and Insera Therapeutics; has served on the Data Safety Monitoring Board for Vesalio; and received royalties from Medtronic.

Background and Objectives: STA-MCA bypass surgery is mainly used for Moyamoya disease, giant intracranial aneurysms, and resection of intracranial tumors requiring sacrifice of blood vessels. The intraoperative patency of the reconstructive vessels is critical to the efficacy of the procedure. This study aimed to evaluate the efficacy of intra-arterially infused tirofiban for the treatment of acute thrombosis during STA-MCA bypass surgery and countermeasures for acute thrombosis., Methods: This study involved 209 patients (272 hemispheres) who underwent STA-MCA surgery between November 2020 and December 2023. Intraoperative acute thrombosis occurred in eight patients (3.83%,8 hemispheres). We retrospectively reviewed the clinical and imaging data, surgical procedure, and follow-up outcomes of eight patients. We implemented the different thrombolytic methods to evaluate the optimal thrombosis management during the bypass surgery. After three months, we assessed neurological functions using the modified Rankin Scale (mRS) and conducted a literature review using PubMed., Results: Eight patients (four male patients and four female patients) developed acute thrombosis during the bypass surgery. Of the eight patients, two underwent re-anastomosis after thrombus removal, three received local injections of tirofiban into the anastomosis or the branches of the superficial temporal artery, and three underwent superselective intra-arterial tirofiban infusion using a microcatheter. Thrombosis were resolved, and arteries were recanalized in all patients. The mRS score was 0 in all patients. No major ischemic or hemorrhagic complications occurred., Conclusion: Our treatment methods were efficacious in the management of acute thrombosis. Intra-arterial tirofiban administration seems to be a simple and effective treatment option for acute thrombosis during STA-MCA bypass surgery., (© 2024. The Author(s).)

The pterional approach has traditionally been employed for managing middle cerebral artery (MCA) aneurysms. With potential benefits like reduced surgical morbidity and improved postoperative recovery, the lateral supraorbital approach (LSO) should be considered individually based on aneurysm morphology, location and patient-specific variations of the MCA anatomy, which requires considerable technical expertise traditionally acquired through years of experience. The goal of this study was the development and evaluation of a novel phantom simulator in the context of clinical decision-making in the managmement of MCA aneurysms. For this purpose, high-fidelity simulators inclusive of MCA models with identical M1- and bifurcation aneurysms were manufactured employing 3D reconstruction techniques, additive manufacturing and rheological testings. Medical students, neurosurgical residents, and seasoned neurosurgeons (n = 22) tested and evaluated both approaches. Participants' performances and progress over time were assessed based on objective metrics. The simulator received positive ratings in face and content validity, with mean scores of 4.9 out of 5, respectively. Objective evaluation demonstrated the model's efficacy as a practical training tool, particularly among inexperienced participants. While requiring more technical expertise, results of the comparative analysis suggest that the LSO approach can improve clipping precision and outcome particularly in patients with shorter than average M1-segments. In conclusion, the employed methodology allowed a direct comparison of the pterional and LSO approaches, revealing comparable success rates via the LSO approach while reducing operation time and complication rate. Future research should aim to establish simulators in the context of clinical decision making., (© 2024. The Author(s).)

Introduction: Conventionally, one branch of the superficial temporal artery (STA) is utilized to revascularize the middle cerebral artery (MCA). However, there is the possibility of utilizing both branches of the STA when performing the bypass, characterizing the double-barrel (DB) STA-MCA bypass. Notably, a lack of studies evaluating this technique led the authors to conduct a systematic review and single-arm meta-analysis., Methods: PubMed, Embase and Web of Science were searched systematically for publications of DB-STA-MCA bypass on November 1st, 2023. The findings were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Case reports were not included for statistical analysis purposes., Results: The review included 408 patients and 534 bypasses from 34 studies. The main etiology was Moyamoya disease (64.6%), followed by cerebral ischemia (22.2%) and aneurysms (12.5%). The median of the mean follow-ups of each study was 12.8 months (range 1.5-87.9). The postoperative patency was 100%. The follow-up patency was 98% (95% CI: 96%-100%; I 2  = 0%). The procedure-related mortality was 0% (95% CI: 0%-1%; I 2  = 0%). Aneurysms obtained 87% (95% CI: 72%-100%; I 2  = 4%) of good clinical outcomes, while Moyamoya disease yielded a rate of 70% (95% CI: 10%-100%; I 2  = 97%). Ischemic complications occurred at a rate of 6% (95% CI: 2%-11%; I 2  = 36%), while hemorrhagic occurred at 6% (95% CI: 1%-11%; I 2  = 56%). Hyperperfusion syndrome rate was calculated as 18% (7%-30%; I 2  = 55%) for Moyamoya disease., Conclusions: The procedure appears to be safe, with excellent patency rates. The clinical efficacy for ischemic and Moyamoya diseases warrants further standardized robust investigation with a broader number of patients, and aneurysm studies are required to enhance sample sizes. The main complication for the Moyamoya subgroup is hyperperfusion syndrome., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Studies comparing different treatment methods in patients with middle cerebral artery (MCA) aneurysms in different subgroups of onset symptoms are lacking. It is necessary to explore the safety and efficacy of open surgical treatment and endovascular therapy in patients with MCA aneurysms in a specific population. This study aimed to compare microsurgical clipping versus endovascular therapy regarding complication rates and outcomes in patients with MCA aneurysms presenting with neurological ischemic symptoms. This was a retrospective cohort study in which 9656 patients with intracranial aneurysms were screened between January 2014 and July 2022. Further, 130 eligible patients were enrolled. The primary outcome was the incidence of serious adverse events (SAEs) within 30 days of treatment, whereas secondary outcomes included postprocedural target vessel-related stroke, disabling stroke or death, mortality, and aneurysm occlusion rate. Among the 130 included patients, 45 were treated with endovascular therapy and 85 with microsurgical clipping. The primary outcome of the incidence of SAEs within 30 days of treatment was significantly higher in the clipping group [clipping: 23.5%(20/85) vs endovascular: 8.9%(4/45), adjusted OR:4.05, 95% CI:1.20-13.70; P = 0.024]. The incidence of any neurological complications related to the treatment was significantly higher in the clipping group [clipping:32.9%(28/85) vs endovascular:15.6%(7/45); adjusted OR:3.49, 95%CI:1.18-10.26; P = 0.023]. Postprocedural target vessel-related stroke, disabling stroke or death, mortality rate, and complete occlusion rate did not differ significantly between the two groups. Endovascular therapy seemed to be safer in treating patients with MCA aneurysms presenting with neurological ischemic symptoms compared with microsurgical clipping, with a significantly lower incidence of SAEs within 30 days of treatment and any neurological complications related to the treatment during follow-up., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Superficial temporal artery (STA) to middle cerebral artery (MCA) bypass surgery for internal carotid artery (ICA) occlusive disease necessarily requires sufficient external carotid artery (ECA) blood flow. Surgical bypass is therefore precluded if there is common carotid artery (CCA) occlusion. Here we present two such cases: one patient had a CCA occlusion and the other had an ICA occlusion and ECA stenosis. Both had failed medical management, and were therefore treated with angioplasty and stenting of the ECA, followed by STA-MCA bypass. We describe the clinical and radiologic outcomes of these cases, and remark on the potential pitfalls associated with this novel approach., Competing Interests: None declared., (Thieme. All rights reserved.)

Objective: This study was design to investigate the surgical and functional outcome based on the preaneurysmal M 1 length for unruptured MCA aneurysm., Methods: Among 250 consecutive patients with unruptured aneurysms operated in our institution between 2015 and 2017, 72 were MCA aneurysms. Risk factors for IR (i.e., intraoperative rupture) were investigated including age, sex, preaneurysmal M 1 length, maximal MCA aneurysm diameter, neck size, aneurysm shape, sphenoid ridge proximation sign. Outcome was measured at discharge, 1 yr and last follow-up. Outcome was compared according to the preaneurysmal M 1 length., Results: Among 68 patients included, five patients (7.3%) suffered IR. Mean maximal diameter of MCA aneurysm (7.9 mm ± 3.4 vs. 4.5 ± 1.8; p = 0.01) was significantly associated with IR risk. Mean M 1 length seemed to be shorter in the IR group although not statistically significant (16.2 mm ± 5.1 vs. 11.5 mm ± 4.8; p = 0.053). Mid-term outcome was favorable for all patients at last follow-up but was worsen in case of short preaneurysmal M 1 segment (10.7 mm ± 4.8 vs. 16.4 mm ± 5.3, p = 0.02). Complete aneurysm occlusion was achieved for sixty-nine patients (95.5%) with 6.9% of early postoperative complications., Conclusions: The microsurgical treatment of unruptured MCA aneurysm was associated with favorable mid-term outcome in all patients and high rates of complete occlusion. Aneurysm size was significantly associated with the intraoperative rupture risk for unruptured MCA aneurysm and patients with a short preaneurysmal M1 segment seemed to have a greater risk of intraoperative rupture although not statistically significant. Short preaneurysmal M1 patients had worsen mid-term outcome., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Background: Aneurysms located in the distal middle cerebral artery (DMCA) are relatively rare and lack an established treatment strategy. For DMCA aneurysms, we performed a one-stage combined procedure of endovascular parent artery occlusion (PAO) with coils and superficial temporal artery to middle cerebral artery (STA-MCA) bypass in a hybrid operating room (HOR). The aim of this study was to evaluate the safety and efficacy of this procedure., Methods: Cases of unruptured DMCA aneurysms treated with the one-stage combined PAO and STA-MCA bypass in HOR were retrospectively examined, and patients' and aneurysmal backgrounds, surgical procedures, and treatment outcomes were analyzed., Results: Six patients were included in the study. The average maximum diameter of the aneurysms was 14.4 mm. One aneurysm was located at M2 and five at M3. All aneurysms had a fusiform shape. No cases were associated with infection, trauma, or malignant tumors. In all 6 cases, the combined PAO and STA-MCA bypass was successfully completed. No postoperative hemorrhagic complications occurred. A symptomatic ischemic complication occurred in 1 case whose symptom disappeared in a week. Three months after surgery, complete obliteration of the aneurysm and patency of the bypass was confirmed in all cases., Conclusions: The one-stage combined PAO and STA-MCA bypass in the HOR is safe and effective for DMCA aneurysms, potentially serving as a treatment option for this complex aneurysm., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Cerebral hyperperfusion (CHP) occurred frequently after direct superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery for moyamoya disease (MMD). We analyzed cortical microvascular density (CMD) and the change of cerebral blood flow (LΔCBF) using intraoperative laser speckle contrast imaging (LSCI) on 130 hemispheres of 95 consecutive adult patients with MMD. The demographic characteristics, cortical hemodynamic sources, bypass methods, intraoperative blood flow data, and relative CBF changes on single-photon emission computed tomography (SPECT) examination (SΔrCBF) were compared between the groups with and without CHP. The median values for CMD, LΔCBF, and SΔrCBF were significantly higher in the CHP group than in the non-CHP group (CMD 0.240 vs 0.206, P  = 0.004; LΔCBF 2.285 vs 1.870, P <  0.001; SΔCBF 1.535 vs 1.260, P <  0.001). Multivariate analysis revealed that hemodynamic sources of recipient parasylvian cortical arteries from MCA (M-PSCAs), end-to-side (E-S) bypass method, CMD ≥ 0.217, and LΔCBF ≥ 1.985 were the risk factors for CHP. Intraoperative LSCI was useful for evaluating hemodynamics and predicting CHP in patients with MMD., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: At present, the most effective treatment for symptomatic moyamoya disease (MMD) is surgery. However, the high incidence of postoperative complications is a serious problem plaguing the surgical treatment of MMD, especially the acute cerebral infarction. Decreased cerebrovascular reserve is an independent risk factor for ischemic infarction, and the pulsatility index (PI) of transcranial Doppler (TCD) is a common intuitive index for evaluating intracranial vascular compliance. However, the relationship between PI and the occurrence of ischemic stroke after operation is unclear., Objective: To explore whether the PI in the middle cerebral artery (MCA) could serve as a potential predictor for the occurrence of ischemic infarction after bypass surgery in MMD., Methods: We performed a retrospective analysis of data from 71 patients who underwent combined revascularization surgery, including superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis and encephalo-duro-myo-synangiosis (EDMS). The patients were divided into two groups according to the median of ipsilateral MCA-PI before operation, low PI group (MCA-PI < 0.614) and high PI group (MCA-PI ≥ 0.614). Univariate and multivariate regression analysis were used to explore risk factors affecting the occurrence of postoperative cerebral infarction., Results: Among the 71 patients with moyamoya disease, 11 patients had cerebral infarction within one week after revascularization. Among them, 10 patients' ipsilateral MCA-PI were less than 0.614, and another one's MCA- PI is higher than 0.614. Univariate analysis showed that the lower ipsilateral MCA-PI (0.448 ± 0.109 vs. 0.637 ± 0.124; P = 0.001) and higher Suzuki stage (P = 0.025) were linked to postoperative cerebral infarction. Multivariate analysis revealed that lower ipsilateral MCA-PI was an independent risk factor for predicting postoperative cerebral infarction (adjusted OR = 14.063; 95% CI = 6.265 ~ 37.308; P = 0.009)., Conclusions: A lower PI in the ipsilateral MCA may predict the cerebral infarction after combined revascularization surgery with high specificity. And combined revascularization appears to be safer for the moyamoya patients in early stages., (© 2024. The Author(s).)

Purpose: Superficial temporal artery to middle cerebral artery (STA-MCA) direct bypass surgery is the most common surgical procedure to treat moyamoya disease (MMD). Here, we aim to compare the performance of the 3D exoscope in bypass surgery with the gold standard operative microscope., Methods: All direct STA-MCA bypass procedures performed at a single university hospital for MMD between 2015 and 2023 were considered for inclusion. Data were retrospectively collected from patient files and surgical video material. From 2020 onwards, bypass procedures were exclusively performed using a digital three-dimensional exoscope as visualization device. Results were compared with a microsurgical bypass control group (2015-2019). The primary endpoint was defined as total duration of surgery, duration of completing the vascular anastomosis (ischemia time), bypass patency, number of stiches to perform the anastomosis, added stiches after leakage testing of the anastomosis and the Glasgow outcome scale (GOS) at last follow-up as secondary outcome parameter., Results: A total of 16 consecutive moyamoya patients underwent 21 STA-MCA bypass procedures. Thereof, six patients were operated using a microscope and ten patients using an exoscope (ORBEYE® n = 1; AEOS® n = 9). Total duration of surgery was comparable between devices (microscope: 313 min. ± 116 vs. exoscope: 279 min. ± 42; p = 0.647). Ischemia time also proved similar between groups (microscope: 43 min. ± 19 vs. exoscope: 41 min. ± 7; p = 0.701). No differences were noted in bypass patency rates. The number of stiches per anastomosis was similar between visualization devices (microscope: 17 ± 4 vs. exoscope: 17 ± 2; p = 0.887). In contrast, more additional stiches were needed in microscopic anastomoses after leakage testing the bypass (p = 0.035)., Conclusion: Taking into account the small sample size, end-to-side bypass surgery for moyamoya disease using a foot switch-operated 3D exoscope was not associated with more complications and led to comparable clinical and radiological results as microscopic bypass surgery., (© 2024. The Author(s).)

Background: The safety and efficacy of mechanical thrombectomy (MT) for proximal large vessel occlusion after acute ischemic stroke (AIS) have been demonstrated. Clinical investigations of endovascular approaches for treating AIS due to M2 occlusions have been ongoing., Purpose: To assess the outcomes of M2 occlusions according to treatment modality and anatomical division., Methods: A total of 113 consecutive M2 occlusions treated with endovascular treatment (EVT) at our tertiary stroke center between January 2019 and December 2022 were retrospectively analyzed. Patients were divided into three groups: mechanical thrombectomy (MT); intravenous thrombolysis plus MT (IVT + MT); and IVT alone. The primary outcomes were good prognosis (mRS = 0-2) and mortality (mRS = 6) on day 90. The secondary outcome was to determine the differences in outcomes between lesions in the superior and inferior branches of M2., Results: In total, 55 (48.7%) patients underwent MT. In 42 (37.2%) patients, bridging IVT was performed with MT, and IVT alone was applied in 16 (14.2%) patients. Neither the prognosis at 90 days nor the mortality rate significantly differed among the groups. The outcomes did not significantly differ between occlusions in the superior and inferior branches of M2., Conclusion: MT was found to be safe and effective for treating M2 occlusions in this series., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Superficial temporal artery (STA)-middle cerebral artery (MCA) bypass surgery has been widely adopted in treating moyamoya disease (MMD). Geometric variations including high tortuosity and stenosis exist in many cases, but the hemodynamic effects have not been comprehensively evaluated. We aim to evaluate the hemodynamic effects of bypass geometry variations based on patient-specific data., Methods: In total, 17 patients with MMD who underwent STA-MCA bypass surgery with highly tortuous bypass geometry were included. For each patient, the original 3-dimensional structure of STA-MCA bypass was reconstructed from clinical imaging data. The bypass structure was virtually improved by removing the tortuosity and stenosis. Computational fluid dynamics simulation was performed on both bypass structures under identical patient-specific condition. The simulated hemodynamic parameters of the bypass and its distal branches were compared between the original and virtually improved bypass geometries in all cases using paired t-test or Wilcoxon signed-rank test. The changes of hemodynamic parameters were compared between the cases with and without mild-to-moderate stenosis (44.0-70.3% in diameter) in the bypass using t-test or Mann-Whitney U test., Results: The virtual improvement of bypass geometry significantly increased the flow rate of the bypass and its distal branches (P < 0.05) and decreased the transcranial flow resistance (P < 0.05). The hemodynamic changes in cases with stenosis removal were significantly greater than those without stenosis (P < 0.05)., Conclusions: High tortuosity and stenosis can significantly change the hemodynamics of STA-MCA bypass, and the optimization of bypass geometry deserves further consideration., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background:  Patients with severe steno-occlusive disease of a main cerebral artery without causative lesions on magnetic resonance imaging (MRI) often develop cognitive impairment. However, the effects of revascularization surgery and the source of the cognitive impairment remain unclear. Therefore, we investigated the early postoperative course of cognitive function and its association with cerebral blood flow (CBF), cerebrovascular reserve (CVR), white matter disease (WMD), lacunar infarction, and cerebrovascular risk factors., Methods:  Cognitive function was examined using neurobehavioral cognitive status examination (COGNISTAT) in 52 patients with steno-occlusive disease of a main cerebral artery before and at 6 months after superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis. We examined how cognition changed before and at 1, 3, and 6 months after STA-MCA anastomosis in 27 of 52 patients. CVR and CBF were calculated from 123 I-N-isopropyl-p-iodoamphetamine single photon emission computed tomography, in addition to other cerebrovascular risk factors in 34 of 52 patients. Cerebral infarction and WMD (periventricular hyperintensity [PVH] and deep subcortical white matter hyperintensity) were also evaluated preoperatively by MRI., Results:  COGNISTAT scores improved at 1 month after STA-MCA anastomosis in patients with severe steno-occlusive disease of a main cerebral artery. Multiple stepwise regression analysis revealed that CVR (regression coefficient = -2.237, p  = 0.0020) and PVH (regression coefficient = 2.364, p  = 0.0029) were the best predictors of postoperative improvement in COGNISTAT scores ( R 2  = 0.415; p  = 0.0017)., Conclusion:  Cognitive function improves in relation to preoperative CVR and PVH early after STA-MCA anastomosis in patients with steno-occlusive disease of a main cerebral artery., Competing Interests: None declared., (Thieme. All rights reserved.)

Decreased cerebral blood flow (CBF) leads to impaired cerebral hemodynamics, which causes an increased risk of stroke. Revascularization has been shown to improve CBF in patients with moyamoya disease. The study is devoted to the retrospective study of clinical features and cerebral hemodynamic characteristics of 17 patients with moyamoya disease before, during and after surgical treatment using extracranial-intracranial (EC-IC) bypass by STA-MCA type. Patients underwent superficial temporal artery-middle cerebral artery bypass surgeries. All patients were carried out by DSA, MSCT-angiography, and MSCT-perfusion imagine (MSCTPI) before and 6 months after surgery. The hemodynamic parameters during MSCTPI, changes in cerebral vascular pattern, and clinical outcomes were evaluated. Cerebral blood flow and mean transit time (MTT) were measured using MSCT-perfusion imaging to identify areas of hypoperfusion. Intraoperative indocyanine green (ICG) analysis was performed to assess local cerebral hemodynamics before and after the creation of the STA-MCA bypass. Results showed that hemodynamics improved significantly on the surgery side after revascularization. After STA-MCA bypass CBF increased and MTT reduced by almost 2 times compared to the level before the bypass. The modified Rankin Scale scores demonstrated an improvement in the neurological status of patients following surgical revascularization. Thus, STA-MCA-type surgical revascularization significantly improved cerebral perfusion parameters and reduced the risk of stroke in patients with moyamoya disease. MSCTPI can serve as an effective and noninvasive method for monitoring cerebral hemodynamics in these patients. Intraoperative ICG angiography is a safe method that can display hemodynamic characteristics in the surgical area.

Objective: Few studies have reported local hemodynamic changes after revascularization surgery. This study aimed to identify regional hemodynamic changes after combined revascularization surgery for moyamoya disease using single-photon emission computed tomography with N-isopropyl-p- 123 I-iodoamphetamine., Methods: A total of 46 adults with moyamoya disease who underwent combined revascularization surgery from August 2009 to July 2021 at our facility were enrolled. The combined bypass procedure comprised a single direct bypass to the motor area and encephalo-duro-arterio-myo-synangiosis. The preoperative and postoperative cerebral blood flow (CBF) and cerebral vascular reserve (CVR) in the genu; precentral, central, parietal, angular, temporal, and posterior regions; splenium; hippocampus; and cerebellum were measured. To modify the examination variability, the cerebral-to-cerebellar activity ratio (CCR) was calculated by dividing the counts in the region by those in the cerebellum (CBF-CCR and CVR-CCR)., Results: Postoperatively, asymptomatic cerebral infarction occurred in three (6.5%) patients. The CBF-CCR and CVR-CCR improved in the precentral, parietal, and temporal regions and in the overall middle cerebral artery (MCA) territory. Sub-analysis of anterior cerebral artery (ACA) and posterior cerebral artery (PCA) territory hemodynamics revealed that patients with normal preoperative hemodynamics showed no changes in the CBF-CCR and CVR-CCR postoperatively, whereas patients with preoperative perfusion impairment exhibited improved CVR-CCR in the ACA territory (0.13-0.3, p=0.019) and CBF-CCR in the PCA territory (0.93-0.96, p=0.0039)., Conclusion: Combined revascularization surgery with single bypass to the motor area improved hemodynamics in the primary targeted MCA territory and in the ACA and PCA territories among patients with preoperative hemodynamic impairment., Competing Interests: Declaration of Competing Interest The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Treating complex middle cerebral artery (MCA) trifurcation aneurysms requires a delicate balance between achieving aneurysm obliteration and preserving vascular integrity. Various cerebral revascularization techniques, including bypass, and clip reconstruction are considered individually or in combination., Methods: This case report outlines a successful repair of a ruptured neck and base of MCA trifurcation aneurysm using a suturing-clip reconstruction technique. Temporary aneurysm trapping was implemented, with maintained elevated blood pressure to ensure collateral perfusion during repair of ruptured base and neck of MCA aneurysm., Conclusion: The suturing-clip reconstruction exhibited long-term radiological stability, emerging as a valuable alternative for managing challenging MCA trifurcation aneurysms., (© 2024. The Author(s).)

In STA-MCA bypass surgery, it is important to select the optimal recipient using preoperative simulation to avoid complications. We report a preoperative simulation for STA-MCA bypass using the Brain LAB iPLAN platform ® BRAIN LAB)and the 3DCG simulation software GRID ® Kompath). Here, we introduce the basics and applications of preoperative simulation for occlusive atherosclerotic lesions and present a target bypass for periventricular anastomosis and peripheral vessels of aneurysms in Moyamoya disease. By creating and visualizing 3D fusion images, the optimal donor and recipient can be selected. Determining the skin incision and extent of craniotomy according to the case is also applicable to the minimally invasive STA-MCA bypass. Preoperative simulations enable accurate pinpoint bypass surgery and prevent complications.

Background:  Aneurysmal subarachnoid hemorrhage remains one of the most prevalent causes of strokes in the young causing a high socioeconomic damage. Both emergent and elective treatments of intracranial aneurysms remain essential challenges for neurovascular centers. We aim to present conceptual education on clip ligation of middle cerebral artery bifurcation aneurysms in an accessible and structured way to maximize the educational takeaway of residents from aneurysm cases., Methods:  After 30 years of experience of the senior author in cerebrovascular surgery in three centers, we closely reviewed an exemplary case of elective right middle cerebral artery bifurcation aneurysm clipping and contrasted it to an alternative microneurosurgical approach to illustrate key principles of microneurosurgical clip ligation for neurosurgical trainees., Results:  Dissection of the sylvian fissure, subfrontal approach to the optic-carotid complex, proximal control, aneurysm dissection, dissection of kissing branches, dissection of aneurysm fundus, temporary and permanent clipping, as well as aneurysm inspection and resection are highlighted as key steps of clip ligation. This proximal-to-distal approach is contrasted to the distal-to-proximal approach. Additionally, general principles of intracranial surgery such as use of retraction, arachnoid dissection, and draining of cerebrospinal fluid are addressed., Conclusion:  Due to a constantly decreasing case load in the era of neurointerventionalism, the paradox of facing increased complexity with decreased experience must be met with a sophisticated practical and theoretical education of neurosurgical trainees early on and with a low threshold., Competing Interests: None declared., (Thieme. All rights reserved.)

This case report details the pathological findings of a vessel wall identified as the bleeding point for intracranial hemorrhage associated with Moyamoya disease. A 29-year-old woman experienced intracranial hemorrhage unrelated to hyperperfusion following superficial temporal artery-middle cerebral artery bypass surgery. A pseudoaneurysm on the lenticulostriate artery (LSA) was identified as the causative vessel and subsequently excised. Examination of the excised pseudoaneurysm revealed a fragment of the LSA, with a disrupted internal elastic lamina and media degeneration. These pathological findings in a perforating artery, akin to the circle of Willis, provide insights into the underlying mechanisms of hemorrhage in Moyamoya disease., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Background: We report a patient with extensive subarachnoid hemorrhage caused by the rupture of a middle cerebral artery pseudoaneurysm from a foreign body that had been left for two decades., Case Presentation: A 74-year-old male patient from Han nationality was admitted to the emergency department of our hospital with impaired consciousness for 1 hour. Cranial computed tomography examination indicated a massive subarachnoid hemorrhage with intraventricular blood accumulation, and a high-density short strip dense shadow was seen in the M1 segment of the right middle cerebral artery, considering the possibility of a foreign body. Subsequently, a cerebral angiography was suggested; the foreign body was seen through the right middle cerebral artery, and the aneurysm was seen in the lower wall, so a pseudoaneurysm was considered. The emergent surgical intervention involved the clipping of the pseudoaneurysm and intracranial extraction of the foreign body. Unfortunately,the patient ultimately expired due to severe pulmonary infection., Conclusion: Intracranial pseudoaneurysm caused by foreign body has been rarely reported previously, and microsurgical treatment of an intracranial pseudoaneurysm caused by a foreign body is a good choice., (© 2024. The Author(s).)

Background and Objectives: The treatment of complex intracranial aneurysms with bypass surgery using 2 branches of the superficial temporal artery (STA) proves to be an effective surgical option. However, the harvest of these 2 STA branches, combined with a pterional craniotomy, carries the potential risk of delayed wound healing of the skin flap. This study undertook a retrospective analysis to examine and identify the factors associated with this delayed wound healing., Methods: A total of 56 consecutive cases, including both ruptured and unruptured complex intracranial aneurysms, that underwent bypass surgery with 2 branches of the STA, were analyzed retrospectively., Results: Major delayed wound healing was observed in 6 (10.7%) cases. Univariate analysis demonstrated significant associations with the following factors: rupture (P = 0.023), presence of diabetes mellitus (P = 0.028), large craniotomy size (P = 0.012), and the type of skin incision (P ≤ 0.001). Age (P = 0.283), sex (P = 0.558), body mass index (P = 0.221), and other blood test parameters did not demonstrate any statistical significance. Similarly, the presence of a dominant frontal branch (P = 0.515) or a low-positioned frontal branch (P = 0.622) did not reveal statistically significant results., Conclusions: In the treatment of complex intracranial aneurysms, where harvesting of the 2 STA branches is involved with a pterional craniotomy, producing a smaller skin flap (L- or T-shaped incision) is effective in minimizing the risk of delayed wound healing. The process of harvesting the STA and closing the wound demands meticulous care, taking into consideration the normal anatomical structures and the subdermal vascular plexus of the scalp., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: The aim of this study was to report the results of a subgroup analysis of the ASTER2 trial (Effect of Thrombectomy With Combined Contact Aspiration and Stent Retriever vs Stent Retriever Alone on Revascularization in Patients With Acute Ischemic Stroke and Large Vessel Occlusion) comparing the safety and efficacy of the combined technique (CoT) and stent retriever as a first-line approach in internal carotid artery (ICA) terminus±M1-middle cerebral artery (M1-MCA) and isolated M1-MCA occlusions., Methods: Patients enrolled in the ASTER2 trial with ICA terminus±M1-MCA and isolated M1-MCA occlusions were included in this subgroup analysis. The effect of first-line CoT versus stent retriever according to the occlusion site was assessed on angiographic (first-pass effect, expanded Treatment in Cerebral Infarction score ≥2b50, and expanded Treatment in Cerebral Infarction score ≥2c grades at the end of the first-line strategy and at the end of the procedure) and clinicoradiological outcomes (24-hour National Institutes of Health Stroke Scale, ECASS-III [European Cooperative Acute Stroke Study] grades, and 3-month modified Rankin Scale)., Results: Three hundred sixty-two patients were included in the postsubgroup analysis according to the occlusion site: 299 were treated for isolated M1-MCA occlusion (150 with first-line CoT) and 63 were treated for ICA terminus±M1-MCA occlusion (30 with first-line CoT). Expanded Treatment in Cerebral Infarction score ≥2b50 (odds ratio, 11.83 [95% CI, 2.32-60.12]) and expanded Treatment in Cerebral Infarction score ≥2c (odds ratio, 4.09 [95% CI, 1.39-11.94]) were significantly higher in first-line CoT compared with first-line stent retriever in patients with ICA terminus±M1-MCA occlusion but not in patients with isolated M1-MCA., Conclusions: First-line CoT was associated with higher reperfusion grades in patients with ICA terminus±M1-MCA at the end of the procedure., Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03290885., Competing Interests: Disclosures Dr Clarençon is a consultant for Artedrone, Balt USA, Medtronic, Penumbra, and Stryker. Dr Caroff is a consultant for Balt USA, Medtronic, and Stryker. Dr Marnat is a consultant for Balt USA, Bracco Imaging, Johnson & Johnson Medical Devices & Diagnostics Group, Medtronic, MicroVention, phenox, and Stryker. Dr Barreau is a consultant for MicroVention. Dr Spelle is a consultant for Balt USA, Medtronic, MicroVention, phenox, and Stryker. The other authors report no conflicts.

Background: Experience using flow diverter devices (FDDs) to treat proximal (M1) middle cerebral artery aneurysms associated with the lenticulostriate artery (M1A-LA) remains limited. This study aimed to examine the efficacy and safety of an FDD to manage M1A-LA., Method: Patients with M1A-LA who received FDD treatment at a single center were included in the analysis. Data on the baseline characteristics, postoperative conditions, and follow-up results of the participants were recorded and analyzed. The aneurysms were categorized into three subtypes based on morphology and location. Aneurysms confined to the M1 segment were categorized as subtype A. Those extending to the M2 segment were classified as subtype B. Aneurysms designated as subtype C were confined to the M1 segment but with another independent aneurysm in the distal artery and the presence of healthy vessels between the two. Subgroup analyses were conducted on these subtypes and aneurysm sizes. To assess the consistency of follow-up results, Cronbach's kappa/alpha was used to calculate inter-rater variability. Somers's D coefficient was used to assess the correlation between each subgroup and the imaging outcomes; Fisher's exact test was used to compare the variability among the subgroups., Result: The cohort comprised 11 patients. Their Modified Rankin Scale scores between the perioperative and follow-up periods did not differ. During the follow-up period, four patients had completely occluded aneurysms, and five patients had partial occlusions. The remaining patients did not present with changes in their aneurysms. The kappa coefficient was 0.864 (p < 0.001). M1A-LA was divided into subtypes A, B, and C. Subtype A (defined as an aneurysm completely located in the M1 segment) had a higher complete occlusion rate than that of subtypes B and C, Somers's D R/C correlation coefficient was 0.553, with a 95% confidence interval of 0.1229-0.9823 (p = 0.009). The radiographic follow-up findings were not significantly correlated with the size of the aneurysm (p = 0.121) or the use of coiling (p = 0.903). No significant differences in subtypes (p = 0.264), aneurysm size (p = 0.657), or coiling use (p > 0.999) were observed., Conclusion: FDDs were safe and possibly effective against M1A-LA. However, they were not as effective as for intracranial aneurysms in other locations. FDDs are a satisfactory treatment option for M1A-LA, particularly for subtype A aneurysms., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background and Importance: Extracranial-intracranial bypass remains an enduring procedure for a select group of patients suffering from steno-occlusive cerebrovascular disease. Although the superficial temporal artery (STA) to middle cerebral artery (MCA) bypass is most familiar among neurosurgeons, particular circumstances preclude the use of an STA donor. In such cases, alternative revascularization strategies must be pursued., Clinical Presentation: A 63-year-old female presented with symptoms of hemodynamic insufficiency and was found to have left common carotid artery occlusion at the origin. She experienced progressive watershed ischemia and pressure-dependent fluctuations in her neurological examination despite maximum medical therapy. The ipsilateral STA was unsuitable for use as a donor vessel. We performed an extracranial vertebral artery (VA) to MCA bypass with a radial artery interposition graft., Conclusion: This technical case description and accompanying surgical video review the relevant anatomy and surgical technique for a VA-MCA bypass. The patient was ultimately discharged home at her preoperative neurological baseline with patency of the bypass. The VA can serve as a useful donor vessel for cerebral revascularization procedures in pathologies ranging from malignancies of the head and neck to cerebral aneurysms and cerebrovascular steno-occlusive disease., (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)

Objective: The effectiveness of revascularization for complex aneurysms is well-established. This study aimed to describe the technical characteristics and clinical efficacy of intracranial-to-intracranial (IC-IC) bypass for the treatment of complex intracranial aneurysms., Methods: We retrospectively reviewed all patients with aneurysms who underwent a preplanned combination of surgical or endovascular treatment and IC-IC bypass at our institution between January 2006 and September 2023. IC-IC bypass techniques included four strategies: type A (end-to-end reanastomosis), type B (end-to-side reimplantation), type C (in situ side-to-side anastomosis), and type D (IC-IC bypass with a graft vessel)., Results: During the study period, ten patients with aneurysms each underwent IC-IC bypass surgery. Aneurysms were located in the middle cerebral artery (60.0%), anterior temporal artery (10.0%), anterior cerebral artery (20.0%), and vertebral artery (10.0%). There were three saccular aneurysms (30.0%), two fusiform aneurysms (20.0%), one dissecting aneurysm (10.0%), and four pseudoaneurysms (40.0%). We performed the type A strategy on five patients (50.0%), type B on one (10.0%), type C on one (10.0%), and type D on three (30.0%). During a mean period of 68.3 months, good clinical outcomes (modified Rankin Scale score, 0-2) were observed in all patients. Follow-up angiography demonstrated complete aneurysmal obliteration in all patients and good bypass patency in nine of ten patients (90.0%)., Conclusion: The treatment of complex aneurysms remains a challenge with conventional surgical or endovascular treatments. IC-IC bypass surgery is a useful technique, associated with favorable clinical outcomes, for treating complex aneurysms., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Objective: To modify the method for establishing mouse models of middle cerebral artery occlusion (MCAO)-induced focal cerebral ischemia using electrocoagulation., Methods: Forty-six C57/BL6J male mice were divided into MCAO model group ( n =34) and sham-operated group ( n =12). In the model group, MCAO was induced by permanent coagulation of the right middle cerebral artery (MCA) using a coagulator, and cerebral blood flow perfusion was monitored before and at 20 min and 1 day after modeling. Neurological deficits of the mice at 1, 7, and 14 days after modeling were evaluated using Longa score, mNSS score, beam walking test, cylinder test and corner test. TTC staining was used to measure the cerebral infarct size, and Western blotting was performed to detect the expressions of BDNF, GFAP and DCX proteins in the ischemic cortex., Results: The mice in the model group showed significantly reduced cerebral blood flow in the MCA on the ischemic side and obvious neurological deficits with increased forelimb use asymmetry on days 1, 7 and 14 after modeling ( P < 0.05). In the cerebral cortex on the ischemic side of the model mice, the expressions of GFAP and DCX increased significantly at 1, 7, and 14 days ( P < 0.05) and the expression of BDNF increased at 1 day after modeling ischemia ( P < 0.05)., Conclusion: We successfully prepared mouse models of MCAO using a modified method by changing the electrocoagulation location from the distal location of the junction between the MCA and the inferior cerebral vein to a 2 mm segment medial to the junction between the MCA and the olfactory bundle.

STA bypass assessment by ultrasonography after bypass surgery in patients with moyamoya disease is minimally invasive and can be performed repeatedly. With STA bypass assessment by ultrasonography, it was shown that in the short term, blood flow that passes through the STA peaks approximately 5 days after the bypass surgery and then gradually decreases over 7 days. In the medium and long terms, it has been shown that the blood flow through the bypass decreases, compared with that during the first postoperative week, and continues for approximately half a year. The ultrasonographic STA parameters can also clearly indicate bypass patency, but there remains some discussion regarding bypass function. Although some reports have tried to show that these parameters are also useful for predicting acute-phase TNEs and predicting the future of bypass function, no studies have yet examined these parameters in detail in relation to the state of cerebral circulation or degree of residual antegrade flow, and additional studies are needed in the future., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The role of superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass in acute ischemic stroke (AIS) is contentious, with no evidence in patients with AIS and large vessel occlusion (AIS-LVO). We conducted a cohort study to assess emergency STA-MCA outcomes in AIS-LVO and a meta-analysis to evaluate STA-MCA outcomes in early AIS treatment. From January 2018 to March 2021, we consecutively recruited newly diagnosed AIS-LVO patients, dividing them into STA-MCA and non-STA-MCA groups. To evaluate the neurological status and outcomes, we employed the National Institutes of Health Stroke Scale (NIHSS) during the acute phase and the modified Rankin Scale (mRS) during the follow-up period. Additionally, we conducted a meta-analysis encompassing all available clinical studies to assess the impact of STA-MCA on patients with AIS. In the cohort study (56 patients), we observed more significant neurological improvement in the STA-MCA group at two weeks (p = 0.030). However, there was no difference in the clinical outcomes between the two groups. Multivariable logistic regression identified the NIHSS at two weeks (OR: 0.840; 95% CI: 0.754-0.936, p = 0.002) as the most critical predictor of a good outcome. Our meta-analysis of seven studies indicated a 67% rate for achieving a good outcome (mRS < 3) at follow-up points (95% CI: 57%-77%, I 2  = 44.1%). In summary, while the meta-analysis suggested the potential role of STA-MCA bypass in mild to moderate AIS, our single-center cohort study indicated that STA-MCA bypass does not seem to improve the prognosis of patients who suffer from AIS-LVO., (© 2024. The Author(s).)

Microsurgeries are common for complex aneurysms of the middle cerebral artery (MCA)., Objective: To evaluate the incidence and types of venous cerebral disorders after microsurgeries for complex MCA aneurysms., Material and Methods: A retrospective study included 285 patients with complex MCA aneurysms between 2009 and 2020. Pterional craniotomy and transsylvian approach were used in all cases. Aneurysm clipping was performed in 230 cases, revascularization - 27, trapping without bypass - 17, reinforcement - in 11 cases. Computed tomography within 1-3 days after surgery recognized venous cerebral disorders as heterogeneous foci of abnormal brain density with unclear boundaries. These foci were crescent-shaped as a rule and located in deep and basal parts of the frontal lobes., Results: Venous abnormalities occurred in 76 (26.7%) patients. Thirty-five (12.3%) patients had mild venous edema of the frontal lobe alone. In 35 (12.3%) patients, we found moderate disorders with focus in the frontal lobe and compression of anterior horn of the left lateral ventricle with or without hemorrhagic imbibition. Severe disorders occurred in 6 (2.1%) patients with lesion extending to the frontal, insular and temporal lobes. These lesions were accompanied by hemorrhagic imbibition, and lateral dislocation exceeded 5 mm., Conclusion: Careful dissection of veins in Sylvian fissure with preservation of bridging veins is likely to reduce the risk of this complication. Cauterization of a large vein in Sylvian fissure should be followed by careful hemostasis within frontal or temporal cortex. Bleeding and cortical tension can indicate intracerebral hematoma whose likelihood is higher in patients with venous cerebral disorders.

Aim: To gain a better understanding of ischemia risk related to in-stent stenosis (ISS) or in-stent thrombosis (IST) of the middle cerebral artery (MCA) and lenticulostriate arteries after flow-diverting devices (FDD) deployment from the internal carotid artery (ICA) to proximal middle cerebral artery (M1)., Material and Methods: Using data from a prospectively maintained database, we retrospectively evaluated patients who were treated with FDD between January 2015 and 2020 at a single academic center. Only patients with unruptured ICA aneurysms where the FDD was extended into M1 were included., Results: In total, 89 patients with 94 ICA aneurysms were treated with FDD. A total of 34 patients with 36 aneurysms had FDD extending into M1. Of the 34 patients, four experienced MCA, and lenticulostriate territory ischemia. Three patients had in-stent thrombosis (IST), and one patient had severe in-stent stenosis (ISS). The overall ischemic complication rate was 17.6%, which resulted in a permanent neurological deficit in 11.7% of the patients., Conclusion: If the distance of the distal neck of the aneurysm to the ICA terminus (ICAT) is ≤5 mm, or if the aneurysm is located directly at the ICAT, FDD should be considered only as a last option when other treatment modalities are not suitable. In addition, in the treatment of distal ICA aneurysms, extra effort should be exerted during the procedure to deploy the FDD without extending into M1. However, when traditional microsurgical clipping and other endovascular procedures are not suitable, the use of FDD is effective in terms of high aneurysm occlusion rates and preventing aneurysm rupture.

Objective: To investigate the application of high-resolution magnetic resonance vessel wall image (HRMR-VWI) in treating middle cerebral artery (MCA) M1 segment stenosis., Methods: We retrospectively analyzed preoperative clinical data, imaging data, preoperative evaluation, stent procedure, and postoperative complications in 35 patients with atherosclerotic stenosis of the MCA M1 segment. And the 30-day postoperative mortality and disability and the 12-month restenosis were followed up., Results: There were 21 males and 14 females, with a median age of 55 and a median duration of 1 month from onset to stenting. DSA confirmed that the stenosis locates in the M1 segment, with a stenosis degree of (75.00 ± 17.15) %, a stenosis length of (4.34 ± 1.51) mm, and a blood vessel diameter of (2.25 ± 0.42) mm. After the operation, there was 1 case of death after a craniotomy to remove hematoma + decompression due to reperfusion hemorrhage. There were two technical complications during the procedure (1 case of asymptomatic occlusion of the A1 segment due to the covering of stent at the initial part of A1, 1 case of intraparenchymal hematoma in the temporal lobe due to penetrating distal small blood vessel with guide wire)., Conclusion: HRMR-VWI is of great value in observing plaques' location, morphology, and stability. It can improve the safety and effectiveness of stenting treatment of MCA M1 segment stenosis., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests to report., (Copyright © 2023 Asian Surgical Association and Taiwan Robotic Surgery Association. Published by Elsevier B.V. All rights reserved.)

Objective: Treating scalp defects after revascularization surgery is difficult because the scalp microcirculation is severely compromised. We aimed to review the clinical effects of using rotational flaps in scalp defect reconstruction and explore risk factors for wound-related complications (WRC) after reconstruction surgery., Methods: We retrospectively identified patients with scalp defects after combined revascularization surgery who were surgically treated with rotational flap reconstruction at our institution between January 2018 and December 2022. We analyzed treatment results in different surgical technique and revascularization strategy cohorts, including direct bypass superficial temporal artery branch selection, indirect bypass types, and skin incisions., Results: Eleven patients were included. The superficial temporal artery parietal branch was selected for direct bypass surgery in 10 (90.9%) patients, 4 (40%) of whom had WRC after flap reconstruction. Five types of indirect bypass surgeries were performed; three patients treated by encephalo-duro-myo-arterio-perio-synangiosis and 1 patient treated by encephalo-duro-myo-perio-synangiosis had WRC after flap reconstruction. Question mark (n = 6, 54.5%), curved (n = 4, 36.65%), and Y-shaped (n = 1, 9.1%) incisions were used; in the first three incision cohorts, 2 patients in each cohort had WRC after flap reconstruction., Conclusions: Patients had the following commonalities that may be risk factors for WRC after flap reconstruction: 1) wounds with nonviable bone exposure after revascularization surgery; 2) three or more tissues used as donor tissues and donor tissues containing the periosteum; and 3) thin scalp around the defect., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: Complex middle cerebral artery (MCA) aneurysms incorporating parent or branching vessels are often not amenable to standard microsurgical clipping or endovascular embolization treatments. We aim to discuss the treatment of such aneurysms via a combination of surgical revascularization and aneurysm exclusion based on our institutional experience., Methods: Thirty-four patients with complex MCA aneurysms were treated with bypass and aneurysm occlusion, 5 with surgical clipping or wrapping only, and 1 with aneurysm excision and primary reanastomosis. Bypasses included superficial temporal artery (STA)-MCA, double-barrel STA-MCA, occipital artery-MCA, and external carotid artery-MCA. After bypass, aneurysms were treated by surgical clipping, Hunterian ligation, trapping, or coil embolization., Results: The average age at diagnosis was 46 years. Of the aneurysms, 67% were large and most involved the MCA bifurcation. Most bypasses performed were STA-MCA bypasses, 12 of which were double-barrel. There were 2 wound-healing complications. All but 2 of the aneurysms treated showed complete occlusion at the last follow-up. There were 3 hemorrhagic complications, 3 graft thromboses, and 4 ischemic insults. The mean follow-up was 73 months. Of patients, 83% reported stable or improved symptoms from presentation and 73% reported a functional status (Glasgow Outcome Scale score 4 or 5) at the latest available follow-up., Conclusions: Cerebral revascularization by bypass followed by aneurysm or parent artery occlusion is an effective treatment option for complex MCA aneurysms that cannot be safely treated by standard microsurgical or endovascular techniques. Double-barrel bypass consisting of 2 STA branches to 2 MCA branches yields adequate flow replacement in most cases., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Competing Interests: Disclosures None.

Background:  Human immunodeficiency virus (HIV) associated vasculopathy can cause ischemic cerebral stroke; however, there is limited evidence on optimal management. Herein, we report a case of acute ischemic stroke due to progressive internal carotid artery (ICA) stenosis in an HIV-positive patient. Superficial temporal artery to middle cerebral artery (STA-MCA) bypass, in addition to the best medical treatments, prevented stroke progression., Clinical Description:  A 39-year-old man with HIV infection presented with a sudden onset of aphasia and right hemiparesis. Magnetic resonance imaging revealed an ischemic lesion in the left basal ganglia and concentric thickening of the vessel wall in the terminal portion of the bilateral ICAs. Despite maximal medical treatments for HIV-associated vasculopathy and possible opportunistic infections, bilateral ICA stenoses progressed, leading to a second hemodynamic stroke event. Because tissue plasminogen activator treatment failed, we performed STA-MCA bypass. A significant improvement in neurologic symptoms and cerebral blood flow was observed after surgery. No further stroke events occurred during the continuation of medical treatments., Conclusion:  This is the first case of STA-MCA bypass performed in a patient with recurrent ischemic stroke caused by HIV-associated vasculopathy. Although further evidence is needed, such treatment options can shed new light on the management of progressive HIV-associated vasculopathy, which is refractory to maximal medical treatment., Competing Interests: None declared., (Thieme. All rights reserved.)

Objective: Giant aneurysms in pediatric patients are vascular lesions that can cause significant neurological morbidity and mortality. Their rarity has precluded large cohort studies to inform their management. The objective of this study was to understand the clinical course and outcomes of giant aneurysms in pediatric patients., Methods: The authors performed a multi-institutional cohort study of cases from Boston Children's Hospital and Barrow Neurological Institute, as well as a systematic review and pooled cohort analysis of previously reported cases using descriptive statistics and multivariate regression modeling., Results: Fifteen patients were included in the multi-institutional cohort, and an additional 88 patients were included from 14 series, yielding 103 patients within the pooled cohort. Among the pooled cohort, the most common aneurysm locations were in the middle cerebral artery (36%), internal carotid artery (27%), vertebral artery (11%), and vertebrobasilar junction (8%). Within 69 cases containing radiographic data in the analysis, 38% of aneurysms were saccular. Twenty-eight cases presented with aneurysm rupture (28%), including 0% of cavernous carotid aneurysms, 26% of other anterior circulation aneurysms, and 44% of posterior circulation aneurysms (p = 0.003). In multivariate analysis, posterior circulation location (OR 2.66, 95% CI 1.03-6.86) and younger age (OR 0.90 per year, 95% CI 0.81-1.00) were associated with aneurysm rupture presentation. Most cases were treated (97%) rather than observed (3%). The mortality rate was 3% for unruptured aneurysms and 18% for ruptured aneurysms. A favorable neurological outcome occurred in 80% of unruptured aneurysm cases and 54% of ruptured cases. In multivariate analysis, unruptured aneurysm presentation (OR 3.74, 95% CI 1.24-11.29) and endovascular treatment modality (OR 5.05, 95% CI 1.56-16.29) were associated with a favorable outcome., Conclusions: Giant aneurysms are rare entities in pediatric patients that are unlikely to be discovered incidentally and usually merit treatment. Most patients survive with good neurological outcome, even in ruptured aneurysm cases. These data reveal that posterior circulation location and younger age are risk factors that correlate with an increased risk of aneurysm rupture.

Background: Flow diverter (FD) devices provide a safe and effective treatment option especially for wide-necked intracranial aneurysms. One of the main concerns in patients treated with FD devices is patency of arterial branches jailed by the stent. However, there are no long-term data from magnetic resonance perfusion (MRP) studies regarding jailed branches. In this study we aimed to reveal the MRP findings in patients with jailed middle cerebral artery (MCA) cortical branches during long-term follow-up after flow diversion., Methods: Patients who underwent FD stent treatment for MCA aneurysms with a resulting jailed cortical branch were included. Follow-up clinical, angiographic, and MRP examination findings were recorded. Different MRP parameters were measured in the MCA territory regarding the jailed branches., Results: Eighteen patients treated endovascularly with flow diversion for a total of 20 MCA aneurysms were included. At angiographic follow-up (median 35 months, range 7-95 months) complete occlusion was observed in 13 (65%) aneurysms and partial occlusion was observed in 6 (30%). The mean transit time (MTT) prolongation, MTT ratio, time-to peak (TTP) prolongation, and TTP ratio were 1.34, 1.20, 1.18, and 1.06 s, respectively, when compared with the contralateral side in the MCA territory. MTT, TTP, and cerebral blood volume values of the patients showed statistically significant differences compared with the contralateral side (P<0.05)., Conclusions: Flow diversion treatment of complex bifurcation aneurysms can be effective and safe. MRP examination may reveal perfusion changes in the territory vascularized via a jailed branch, and these changes are rarely accompanied by clinical findings., Competing Interests: Competing interests: CI has a consulting and proctoring agreement with Medtronic, Inc., outside of this work. NK has a consulting and proctoring agreement with MicroVention, Inc. and Medtronic, Inc., outside of this work. OK has a consulting and proctoring agreement with Acandis GmbH and Stryker, Inc., outside of this work. The other authors have no conflicts of interest to declare., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)