Three-dimensional fusion imaging to assess apposition of low-profile visualized intraluminal support stent for intracranial aneurysm coiling

Objective

To investigate on three-dimensional (3D) fusion images the apposition of low-profile visualized intraluminal support (LVIS) stents in intracranial aneurysms after treatment and assess inter-rater reliability.

Materials and methods

Records of all patients with unruptured intracranial aneurysms who were treated with the LVIS stent were retrospectively accessed and included in this study. Two neurosurgeons evaluated the presence of malapposition between the vessel walls and the stent trunk (crescent sign) and the vessel wall and the stent edges (edge malappostion) on 3D fusion images. These images were high-resolution cone-beam computed tomography images of the LVIS stent fused with 3D-digital subtraction angiography images of the vessels. Associations between malapposition and aneurysm location were assessed by Fisher's exact test, and inter-rater agreement was estimated using Cohen's kappa statistic.

Results

Forty consecutive patients were included. In all patients, 3D fusion imaging successfully visualized the tantalum helical strands and the closed-cell structure of the nitinol material of the low-profile visualized intraluminal support. A crescent sign was observed in 27.5 % and edge malapposition in 47.5 % of the patients. Malapposition was not significantly associated with location (p = 0.23 crescent sign, p = 0.07 edge malapposition). Almost perfect (κ = 0.88) and substantial (κ = 0.76) agreements between the two raters were found for the detection of crescent signs and edge appositions, respectively.

Conclusions

3D fusion imaging provided clear visualization of the LVIS stent and parent arteries, and could detect malapposition with excellent inter-rater reliability. This technique may provide valuable guidance for surgeons in determining postoperative management.

Status of alternative angiogenic pathways in glioblastoma resected under and after bevacizumab treatment

Glioblastoma multiforme (GBM) acquires resistance to bevacizumab (Bev) treatment. Bev affects angiogenic factors other than vascular endothelial growth factor (VEGF), which are poorly understood. We investigated changes in angiogenic factors under and after Bev therapy, including angiopoietin-1 (ANGPT1), angiopoietin-2 (ANGPT2), placental growth factor (PLGF), fibroblast growth factor 2, and ephrin A2 (EphA2). Fifty-four GBM tissues, including 28 specimens from 14 cases as paired specimens from the same patient obtained in three settings: initial tumor resection (naïve Bev), tumors resected following Bev therapy (effective Bev), and recurrent tumors after Bev therapy (refractory Bev). Immunohistochemistry assessed their expressions in tumor vessels and its correlation with recurrent MRI patterns. PLGF expression was higher in the effective Bev group than in the naïve Bev group (p = 0.024) and remained high in the refractory Bev group. ANGPT2 and EphA2 expressions were higher in the refractory Bev group than in the naïve Bev group (p = 0.047 and 0.028, respectively). PLGF expression was higher in the refractory Bev group compared with the naïve Bev group for paired specimens (p = 0.036). PLGF was more abundant in T2 diffuse/circumscribe patterns (p = 0.046). This is the first study to evaluate angiogenic factors other than VEGF during effective and refractory Bev therapy in patient-derived specimens.

Hemodynamic and morphological differences in cerebral aneurysms between before and after rupture

OBJECTIVE

Although it has been proposed that aneurysm morphology is different after rupture, detailed research of the morphological changes using 3D imaging acquired before and after rupture has not been conducted because of the difficulty of data collection. Similarly, hemodynamic changes due to morphological alterations after rupture have not been analyzed. The aim of this study was to investigate the changes in morphology and hemodynamics observed after aneurysm rupture.

METHODS

For 21 cerebral aneurysms (21 patients) that ruptured during observation, 3D geometry of the aneurysms and parent arteries were reconstructed based on the angiographic images before and after their rupture. In addition, using the reconstructed geometry, blood flow was simulated by computational fluid dynamics (CFD) analysis. Morphological and hemodynamic parameters were calculated both before and after rupture, and their changes from before to after were compared.

RESULTS

In the morphological parameters, statistically significantly higher values were observed after rupture in height (before: 5.5 ± 2.1 mm, after: 6.1 ± 2.0 mm; p < 0.0001), aspect ratio (p = 0.002), aneurysm volume (p = 0.04), and undulation index (p = 0.005). In terms of hemodynamic changes, the mean normalized wall shear stress (NWSS) decreased significantly (before: 5.4 × 10-1 ± 2.9 × 10-1, after: 4.4 × 10-1 ± 2.8 × 10-1; p < 0.001) as well as the other NWSS parameters, including maximum and minimum NWSS, which were associated with stagnant flow due to the morphological changes after rupture.

CONCLUSIONS

Aneurysm morphology was found to change after rupture into an elongated and irregular geometry, accompanied by an increase in aneurysm volume. These morphological changes were also associated with statistically significant hemodynamic alterations that produced low wall sheer stress by stagnant flow. The authors' results also provide the opportunity to explore and develop a risk evaluation method for aneurysm rupture based on prerupture morphology and hemodynamics by further exploration in this direction.

[Simulation for Endovascular Treatment]

With the advent of high-resolution imaging and advancements in computational fluid dynamics(CFD)and computational structural mechanics(CSM)analyses, clinical simulation of endovascular intervention has gradually become feasible. Virtual stents have become indispensable for coil embolization. For braided stents, such as those with low-profile visualized intraluminal support and flow diverters, predicting postplacement elongation and contraction is challenging; however, software development has enabled more precise treatment planning. Additionally, simulations utilizing three-dimensional(3D)printer models can enable realistic simulations of procedures such as intracranial stents and Woven EndoBridge placement. This approach is beneficial for shunt disorders such as arteriovenous malformations and dural arteriovenous fistulas, offering 3D visualization of shunt access routes and intuitive treatment strategy planning, even for beginners. Furthermore, it can be applied to procedures such as open surgical clipping and nidus resection, aiding in the selection of suitable clips and considerations for ideal resection based on nidus curvature. Simulations using CFD, CSM, and 3D printers are crucial for training surgeons and handling new devices. Harnessing medicine-engineering synergy is essential, and regulatory approval(insurance coverage)and appropriate commercialization of simulations are paramount for the future.

An exploratory prospective phase II study of preoperative neoadjuvant bevacizumab and temozolomide for newly diagnosed glioblastoma

PURPOSE

This multi-institutional phase I/II study was conducted to confirm the safety and explore the clinical utility of preoperative Bevacizumab (Bev) for newly diagnosed glioblastoma (GB).

METHODS

Patients were enrolled based on magnetic resonance imaging (MRI) findings typically suggestive of GB. Preoperative Bev and temozolomide (TMZ) were administered at doses of 10 mg/kg on day 0 and 150 mg/m2 on days 1-5, respectively. Surgical resection was performed between days 21 and 30, inclusive. The safety and efficacy were evaluated in a total of 15 cases by progression-free survival (PFS), changes in tumor volume, Karnofsky Performance Scale (KPS) and Mini-Mental State Examination (MMSE) scores after preoperative therapy.

RESULTS

Tumor resection was performed on a mean of day 23.7. Pathological diagnosis was GB, isocitrate dehydrogenase (IDH)-wildtype in 14 cases and GB, IDH-mutant in 1 case. Severe adverse events possibly related to preoperative Bev and TMZ were observed in 2 of the 15 patients, as wound infection and postoperative hematoma and thrombocytopenia. KPS and MMSE scores were significantly improved with preoperative therapy. Tumor volume was decreased in all but one case on T1-weighted imaging with contrast-enhancement (T1CE) and in all cases on fluid-attenuated inversion recovery, with mean volume decrease rates of 36.2% and 54.0%, respectively. Median PFS and overall survival were 9.5 months and 16.5 months, respectively.

CONCLUSION

Preoperative Bev and TMZ is safe as long as the instructions are followed. The strategy might be useful for GB in some patients, not only reducing tumor burden, but also improving patient KPS preoperatively.

TRIAL REGISTRATION NUMBER

UMIN000025579, jRCT1031180233 https://jrct.niph.go.jp/latest-detail/jRCT1031180233 . Registration Date: Jan. 16, 2017.

A Novel Braided Stent With Customized Simulation Software for Treatment of Intracranial Aneurysms: Multicenter Prospective Trial Before Unrestricted Clinical Application

BACKGROUND AND OBJECTIVES

Planning/guidance software became important tools for physicians' presurgical optimal decision-making. However, there are no intracranial stent products with specifically associated simulation software. We report the "premarket" clinical trial of a new braided stent with a customized simulation software.

METHODS

A stent system with 3 mesh density types (16, 24, and 32 wire mesh) was designed based on computational flow dynamics technology, and a simulation software (virtual stent planner [VSP]) was developed for the optimal stent deployment planning. Stents were selected after simulation on preoperative 3D-processed angioimages, and accuracy of the VSP was evaluated.

RESULTS

Thirty-three unruptured intracranial aneurysms were successfully treated with VSP guidance. Twenty aneurysms (61%) were anterior circulation aneurysms, and 13 (39%) were posterior circulation aneurysms. The average aneurysm size was 7.1 mm, and the mean follow-up period was 19.2 months (11-39.0). There was no major recurrence or retreatment during follow-up, 2 morbidity cases, and no mortality. VSP planning presented slightly smaller stent dimensions compared with postdeployment: 24.2 vs 25.5 mm average, error -1.3 mm, and difference rate-5.46%.

CONCLUSION

Based on this result, the new stents and software guidance system were approved by the Ministry of Health and Welfare as a combined medical device. VSP provided precise deployment with minimal error compared with actual stent and can contribute to better stent deployment even for less experienced physicians.

Intermediate catheter use is associated with complete occlusion and dense packing in coil embolization of unruptured cerebral aneurysms: a propensity score matched study

BACKGROUND

An intermediate catheter (IMC) can improve the maneuverability and stability of the microcatheter.

OBJECTIVE

To investigate the efficacy and safety of using an IMC in triaxial systems for coil embolization of unruptured cerebral aneurysms (UCAs).

METHODS

A total of 2430 consecutive saccular UCAs (2259 patients) that underwent initial coil embolization at three institutions between November 2003 and May 2023 were retrospectively reviewed. Patients were classified into two groups: with IMC (IMC(+)) and without IMC (IMC(-)). To investigate whether IMC use increased the rate of complete occlusion and the packing density, a propensity score-matched analysis was used to control for clinical, anatomical, and procedural features.

RESULTS

Ultimately, 595 (24.5%) coil embolization used an IMC. Propensity score matching was successful for 424 paired IMC(+) and IMC(-) aneurysms. Compared with the IMC(-) group, the IMC(+) group had significantly higher rate of Raymond-Roy Occlusion Classification class 1 immediately after treatment (30.0% vs 20.8%, P=0.003) and at 6 months (28.8% vs 20.0%, P=0.004) and a higher volume embolization ratio (27.2% (SD 6.5%) vs 25.9% (SD 6.2%), P=0.003). Re-treatment rates were not significantly different between the two groups (0.7% vs 0.2%, P=0.624). No significant differences in the incidences of ischemic and hemorrhagic complications and IMC-related parent artery dissection were found between the two groups.

CONCLUSION

Use of IMCs in triaxial systems can provide effective and safe support in coil embolization of UCAs because complete occlusion and dense coil packing can be achieved without increased complications.

Risk factors and management of intraprocedural rupture during coil embolization of unruptured intracranial aneurysms: role of balloon guiding catheter

Introduction

Intraprocedural rupture (IPR) is a serious complication of endovascular coil embolization of unruptured intracranial aneurysms (UIAs). Although outcomes after IPR are poor, methods to prevent subsequent neurological deterioration have not yet been investigated. We evaluated the risk factors and management strategies for IPR, particularly the role of balloon guiding catheters (BGCs) in rapid hemostasis.

Methods

We retrospectively reviewed all UIA cases treated with coil embolization at three institutions between 2003 and 2021, focusing on preoperative radiological data, operative details, and outcomes.

Results

In total, 2,172 aneurysms were treated in 2026 patients. Of these, 19 aneurysms in 19 patients (0.8%) ruptured during the procedure. Multivariate analysis revealed that aneurysms with a bleb (OR: 3.03, 95% CI: 1.21 to 7.57, p = 0.017), small neck size (OR: 0.56, 95% CI: 0.37 to 0.85, p = 0.007), and aneurysms in the posterior communicating artery (PcomA) (OR: 4.92, 95% CI: 1.19 to 20.18, p = 0.027) and anterior communicating artery (AcomA) (OR: 12.08, 95% CI: 2.99 to 48.79, p < 0.001) compared with the internal carotid artery without PcomA were significantly associated with IPR. The incidence of IPR was similar between the non-BGC and BGC groups (0.9% vs. 0.8%, p = 0.822); however, leveraging BGC was significantly associated with lower morbidity and mortality rates after IPR (0% vs. 44%, p = 0.033).

Discussion

The incidence of IPR was relatively low. A bleb, small aneurysm neck, and location on PcomA and AcomA are independent risk factors for IPR. The use of BGC may prevent fatal clinical deterioration and achieve better clinical outcomes in patients with IPR.

Superiority of Endovascular Coiling Over Surgical Clipping for Clinical Outcomes at Discharge in Patients With Poor-Grade Subarachnoid Hemorrhage: A Registry Study in Japan

BACKGROUND AND OBJECTIVES

The differences in clinical outcomes between endovascular coiling (EC) and surgical clipping (SC) in patients with poor-grade aneurysmal subarachnoid hemorrhage (aSAH) are controversial. Therefore, this study aimed to evaluate whether EC is superior to SC and identify risk factors in patients with poor-grade aSAH.

METHODS

We used data from the "Predict for Outcome Study of aneurysmal SubArachnoid Hemorrhage." World Federation of Neurological Societies (WFNS) grade III-V aSAH was defined as poor-grade aSAH, and unfavorable clinical outcomes (modified Rankin Scale scores 3-6) were compared between SC and EC after propensity score matching (PSM). In-hospital mortality was similarly evaluated. Predictors of unfavorable clinical outcomes were identified using multivariable analysis.

RESULTS

Ultimately, 1326 (SC: 847, EC: 479) and 632 (SC: 316, EC: 316) patients with poor-grade aSAH were included before and after PSM, respectively. Unfavorable clinical outcomes at discharge were significantly different between SC and EC before (72.0% vs 66.2%, P = .026) and after PSM (70.6% vs 63.3%, P = .025). In-hospital mortality was significantly different between groups before PSM (10.5% vs 16.1%, P = .003) but not after PSM (10.4% vs 12.7%, P = .384). Predictors of unfavorable clinical outcomes in both SC and EC were WFNS grade V, older than 70 years, and Fisher computed tomography (CT) grade 4. Predictors of unfavorable clinical outcomes only in SC were WFNS grade IV (odds ratio: 2.46, 95% CI: 1.22-4.97, P = .012) and Fisher CT grade 3 (4.90, 1.42-16.9, P = .012). Predictors of unfavorable clinical outcome only in EC were ages of 50s (3.35, 1.37-8.20, P = .008) and 60s (3.28, 1.43-7.52, P = .005).

CONCLUSION

EC resulted in significantly more favorable clinical outcomes than SC in patients with poor-grade aSAH, without clear differences in in-hospital mortality. The benefit of EC over SC might be particularly remarkable in patients with WFNS grade IV and Fisher CT grade 3.

Local thrombolytics via balloon-assisted intra-arterial infusion as rescue therapy for thromboembolism during endovascular coil embolisation

Thromboembolism is the most frequent complication of coil embolisation for intracranial aneurysm. Complications of thromboembolism can lead to stroke and have a serious impact on sequelae and mortality, necessitating appropriate rescue therapy. Here, we succeeded in recanalisation of an occluded stent by balloon-assisted local infusion of a thrombolytic agent following stent-assisted coil embolisation of an unruptured posterior communicating artery aneurysm. This method involves inflating a microballoon just distal to the occluded vessel and then administering a thrombolytic agent through a microcatheter. This technique may increase the rate of vessel reopening by maximising the local drug concentration. This method can be applied to any type of thrombolytic agent and helps reduce the dose of systemic drugs, which might decrease the incidence of haemorrhagic complications. Balloon-assisted intra-arterial thrombolytic infusion for an occluded vessel during endovascular coil embolisation could offer an alternative rescue therapy when conventional thrombolytic agent administration fails to improve thromboembolism.

Prognostic survival biomarkers of tumor-fused dendritic cell vaccine therapy in patients with newly diagnosed glioblastoma

Dendritic cell (DC)-based immunotherapy has been applied to glioblastoma (GBM); however, biomarkers informing response remain poorly understood. We conducted a phase I/IIa clinical trial investigating tumor-fused DC (TFDC) immunotherapy following temozolomide-based chemoradiotherapy in patients with newly diagnosed GBM and determined prognostic factors in patients receiving TFDC immunotherapy. Twenty-eight adult patients with GBM isocitrate dehydrogenase (IDH) wild-type (IDH-WT) were enrolled; 127 TFDC vaccine injections (4.5 ± 2.6 times/patient) were administered. Patients with GBM IDH-WT had a respectable 5-year survival rate (24%), verifying the clinical activity of TFDC immunotherapy, particularly against O6-methylguanine-DNA methyltransferase (MGMT) unmethylated GBM (5-year survival rate: 33%). To identify novel factors influencing overall survival (OS) in GBM IDH-WT treated with TFDC immunotherapy, clinical parameters were assessed and comprehensive molecular profiling involving transcriptome and exome analyses was performed. MGMT promoter methylation status, extent of tumor resection, and vaccine parameters (administration frequency, DC and tumor cell numbers, and fusion ratio) were not associated with survival following TFDC immunotherapy. Old age and pre- and post-operative Karnofsky performance status were significantly correlated with OS. Low HLA-A expression and lack of CCDC88A, KRT4, TACC2, and TONSL mutations in tumor cells were correlated with better prognosis. We validated the activity of TFDC immunotherapy against GBM IDH-WT, including chemoresistant, MGMT promoter unmethylated cases. The identification of molecular biomarkers predictive of TFDC immunotherapy efficacy in GBM IDH-WT will facilitate the design of and patient stratification in a phase-3 trial to maximize treatment benefits.

Virtual coil images can optimize the visualization of the neckline of intracranial aneurysms during coil embolization: A technical note

Background

During coil embolization of intracranial aneurysms, the aneurysmal neck needs to be evaluated because coil protrusion into the parent artery may lead to ischemic complications. However, the neck cannot always be clearly visualized due to the limitation of the angiography system and due to the structure of the aneurysm. As a visual aid, we propose a color-coded fusion imaging method that generates "virtual coil" images using preoperative three-dimensional digital subtraction angiography (3D-DSA) images.

Case Description

Coil embolization for intracranial aneurysms was performed using the working angles determined from the preoperative 3D-DSA. The aneurysms were located at the middle cerebral artery, anterior communicating artery (A-com), and posterior communicating artery (P-com). The A-com and P-com aneurysms were recurrent. During the later phase of the procedure, physicians could not judge whether coils protruded into the parent artery on two-dimensional digital subtraction angiography (2D-DSA) images because an optimal working angle could not be realized. Virtual coil images were displayed on the angiography system's monitor to show the expected completed embolization, which could be compared to the current 2D-DSA images as a visual aid.

Conclusion

Virtual coil images can provide visual aid to the treating physician during aneurysm coil embolization, which is useful when an accurate working angle cannot be reached.

Contrast Injection from an Intermediate Catheter Placed in an Intradural Artery is Associated with Contrast-Induced Encephalopathy following Neurointervention

BACKGROUND AND PURPOSE

Contrast-induced encephalopathy can result from neurotoxicity of contrast medium in the affected area. The development of intermediate catheters has allowed guidance of catheters to more distal arteries. This study focused on the association between contrast-induced encephalopathy and contrast injection from an intermediate catheter guided into a distal intradural artery during neurointervention for cerebral aneurysms.

MATERIALS AND METHODS

We retrospectively reviewed 420 consecutive aneurysms in 396 patients who underwent neurointervention for extracranial aneurysms and unruptured intracranial aneurysms at our institution from February 2012 to January 2023. Patients were divided into a group with contrast-induced encephalopathy and a group without. To identify risk factors for contrast-induced encephalopathy, we compared clinical, anatomic, and procedural factors between groups by multivariate logistic regression analysis and stepwise selection.

RESULTS

Among the 396 patients who underwent neurointervention for cerebral aneurysms, 14 (3.5%) developed contrast-induced encephalopathy. Compared with the group without contrast-induced encephalopathy, the group with contrast-induced encephalopathy showed significantly higher rates of patients on hemodialysis, previously treated aneurysms, intradural placement of a catheter for angiography, nonionic contrast medium, and flow-diversion procedures in univariate analyses. Stepwise multivariate logistic regression analysis revealed intradural placement of a catheter for angiography (OR = 40.4; 95% CI, 8.63-189) and previously treated aneurysms (OR = 8.20; 95% CI, 2.26-29.6) as independent predictors of contrast-induced encephalopathy.

CONCLUSIONS

Contrast injection from an intradural artery and retreatment of recurrent aneurysms were major risk factors for contrast-induced encephalopathy. Attention should be paid to the location of the intermediate catheter for angiography to avoid developing contrast-induced encephalopathy.

Therapeutic efficacy and complications of radial versus femoral access in endovascular treatment of unruptured intracranial aneurysms

PURPOSE

The transradial approach (TRA) in neuroendovascular treatment is known to have a lower risk of complications than the transfemoral approach (TFA). However, little research has focused on assessments of efficacy and risk of complications in the treatment of intracranial aneurysms. This study aimed to compare the efficacy and complications of TRA and TFA in coil embolization of unruptured intracranial aneurysms (UIAs) at our institution.

METHODS

Consecutive patients who underwent endovascular surgery via TRA or TFA at a single institution from 1 April 2019, to 28 February 2022, were retrospectively analyzed. Patients were classified into TRA and TFA groups and assessed using propensity-adjusted analysis for outcomes including fluoroscopy time, volume embolization ratio (VER), and complications.

RESULTS

A total of 163 consecutive UIAs were treated with coil embolization during the 35-months study period. The incidence of minor access site complications (ASCs) was significantly higher with TFA (20%, 25/126) than with TRA (2.7%, 1/37; p = 0.01). Propensity-adjusted analysis (matched for age, sex, aneurysm volume, embolization technique, and sheath size) revealed that TRA was associated with a lower risk of minor ASCs (odds ratio, 0.085; 95% confidence interval 0.0094-0.78; p = 0.029). However, TRA did not differ significantly from TFA with respect to fluoroscopy time, VER, major ASCs, and non-ASCs.

CONCLUSIONS

Coil embolization for UIAs via TRA can reduce risk of minor ASCs without increasing the risk of non-ASCs compared with conventional TFA, and can achieve comparable results in term of efficacy and fluoroscopy time.

Risk factors for radial artery occlusion after neurointervention for unruptured intracranial aneurysm via transradial access

PURPOSE

Neurointervention via transradial access (TRA) is less invasive than via transfemoral access. However, radial artery occlusion (RAO) may occur with TRA. The purpose of this study was to explore risk factors for RAO after coil embolization of unruptured intracranial aneurysms (UIAs) via TRA.

METHODS

Forty-two consecutive patients who underwent coil embolization for UIAs via TRA between March 2021 and March 2022 and were available for angiographic evaluation 1 year after treatment were retrospectively reviewed. Multivariate logistic regression analysis was conducted to identify potential risk factors for RAO.

RESULTS

Seventeen (40%) of the 42 patients showed RAO. Compared with the non-RAO group, radial artery size was significantly smaller (2.2 mm [interquartile range (IQR): 2.1, 2.4 mm] vs 2.6 mm [IQR: 2.5, 2.7 mm]; p = 0.001) and the incidence of radial artery spasm (RAS) was significantly higher in the RAO group. Multivariate analysis identified radial artery size (odds ratio [OR] 4.9 × 10^-3, 95% confidence interval [CI] 6.4 × 10^-5-0.38) and incidence of RAS (OR 14.8, 95%CI 2.1-105) as significant independent predictors of subsequent RAO. Based on receiver operating characteristic (ROC) curve analysis, the optimal cutoff for radial artery size was 2.5 mm (sensitivity, 82.4%; specificity, 76.0%; area under the ROC curve, 0.80 [95%CI 0.66-0.95]).

CONCLUSION

Radial artery size and RAS represent reliable parameters for predicting RAO 1 year after coil embolization for UIA via TRA. Prophylaxis against RAS and limiting neurointervention via TRA to patients with radial artery larger than 2.5 mm in diameter may reduce the risk of postoperative RAO.

Three-dimensional fusion images from digital subtraction angiography for the treatment of direct carotid-cavernous fistulas: illustrative case

BACKGROUND

Direct carotid-cavernous fistulas (dCCFs) are often treated endovascularly. However, because the dCCF is usually a high-flow shunt, it is often difficult to obtain an accurate vascular structure using conventional digital subtraction angiography (DSA). Here, the authors report a case of successfully treated dCCF using three-dimensional (3D) fused DSA images.

OBSERVATIONS

The patient presented with tinnitus, followed by oculomotor palsy, prompting magnetic resonance imaging that indicated a dural arteriovenous fistula of the cavernous sinus. DSA was performed before treatment, and a diagnosis of dCCF due to a ruptured aneurysm was made. In this case, the 3D fused simulation images enabled the authors to obtain an accurate vascular structure, resulting in successful coil embolization.

LESSONS

Three-dimensional fusion images from DSA provide detailed anatomical information and are useful for treating high-flow dCCFs.

Predicting difficult transradial approach guiding into left internal carotid artery on unruptured intracranial aneurysms

BACKGROUND

The transradial approach (TRA) is less invasive than the transfemoral approach (TFA), but the higher conversion rate represents a drawback. Among target vessels, the left internal carotid artery (ICA) is particularly difficult to deliver the guiding catheter to through TRA. The purpose of this study was thus to explore anatomical and clinical features objectively predictive of the difficulty of delivering a guiding catheter into the left ICA via TRA.

METHODS

Among 78 consecutive patients who underwent coil embolization for unruptured intracranial aneurysms through TRA in a single institution between March 1, 2021, and August 31, 2022, all 29 patients (37%) who underwent delivery of the guiding catheter into the left ICA were retrospectively analyzed. Clinical and anatomical features were analyzed to assess correlations with difficulty in guiding the catheter into the left ICA.

RESULTS

Of the 29 aneurysms requiring guidance of a catheter into the left ICA, 9 aneurysms (31%) required conversion from TRA to TFA. More acute innominate-left common carotid artery (CCA) angle (P < 0.001) and older age (P = 0.015) were associated with a higher conversion rate to TFA. Receiver operating characteristic analysis revealed that optimal cutoff values for the innominate-left CCA angle and age to distinguish between nonconversion and conversion to TFA were 16° (area under the curve [AUC], 0.93; 95% confidence interval [CI], 0.83-1.00) and 74 years (AUC, 0.79; 95% CI, 0.61-0.96), respectively.

CONCLUSION

A more acute innominate-left CCA angle and older age appear associated with difficulty delivering the guiding catheter into the left ICA for neurointervention through TRA.

Intraoperative Cone-Beam Computed Tomography Assessment of Spinal Pedicle Screws Placement Precision Is in Full Agreement with Postoperative Computed Tomography Assessment

OBJECTIVE

To assess agreement between pedicle screw placement evaluated on postoperative computed tomography (CT) and on intraoperative cone-beam CT (CBCT) and compare procedure characteristics when using first-generation and second-generation robotic C-arm systems in the hybrid operating room.

METHODS

All patients who received pedicle screws for spinal fusion at our institution between June 2009 and September 2019 and underwent intraoperative CBCT and postoperative CT were included. The CBCT and CT images were reviewed by 2 surgeons to assess the screw placement using the Gertzbein-Robbins and the Heary classifications. Intermethod agreement of screw placement classifications as well as interrater agreement were assessed using Brennan-Prediger and Gwet agreement coefficients. Procedure characteristics using first-generation and second-generation generation robotic C-arm systems were compared.

RESULTS

Fifty-seven patients were treated with 315 pedicle screws at thoracic, lumbar, and sacral levels. No screw had to be repositioned. On CBCT, accurate placement was found for 309 screws (98.1%) using the Gertzbein-Robbins classification and 289 (91.7%) using the Heary classification and on CT, these were 307 (97.4%) and 293 (93.0%), respectively. Intermethod between CBCT and CT and interrater agreements between the 2 raters were almost perfect (>0.90) for all assessment. There were no significant differences in mean radiation dose (P = 0.83) and fluoroscopy time (P = 0.82), but length of surgery using the second-generation system was estimated at 107.7 minutes (95% confidence interval, 31.9-183.5 minutes; P = 0.006) shorter.

CONCLUSIONS

Intraoperative CBCT provides accurate assessment of pedicle screw placement and enables intraoperative repositioning of misplaced screws.

Development of Machine Learning Model for Selecting the 1st Coil in the Treatment of Cerebral Aneurysms by Coil Embolization

To achieve good treatment outcomes in coil embolization for cerebral aneurysms, it is important to select an appropriate 1st coil for each aneurysm since it serves as a frame to support the subsequent coils to be deployed. However, its selection as appropriate size and length from a wide variety of lineups is not easy, especially for inexperienced neurosurgeons. We developed a machine learning model (MLM) to predict the optimal size and length of the 1st coil by learning information on patients and aneurysms that were previously treated with coil embolization successfully. The accuracy rates of the MLM for the test data were 86.3% and 83.4% in the prediction of size and length, respectively. In addition, the accuracy rates for the 30 cases showed good prediction by the MLM when compared with two different skilled neurosurgeons. Although the accuracy rate of the well-experienced neurosurgeon is similar to MLM, the inexperienced neurosurgeon showed a worse rate and can benefit from the method.Clinical Relevance- The developed MLM has the potential to assist in the selection of the 1st coil for aneurysms. A technically and cost efficient supply chain in the treatment of aneurysms may also be achieved by MLM application.

18F-Fluoromisonidazole-Positron Emission Tomography and Immunohistochemistry Verified Tumor Oxygenation, Stemness, and Immunosupportive Microenvironment After Preoperative Neoadjuvant Bevacizumab for Newly Diagnosed Glioblastoma

BACKGROUND

Cancer stemness and immunosuppressive tumor microenvironment (TME) in accordance with tumor oxygenation are variable during bevacizumab (Bev) therapy for glioblastoma (GBM). Positron emission tomography (PET) using 18F-fluoromisonidazole (FMISO) reflects hypoxic TME. The aim of this study was to compare FMISO-PET and immunohistochemical findings of tumor oxygenation in the TME of GBM during Bev treatment.

METHODS

Seven patients with newly diagnosed IDH-wildtype GBM underwent FMISO-PET during follow-up. Three patients received preoperative neoadjuvant Bev (neo-Bev) and subsequently underwent surgical resection. Reoperation was performed at the recurrence. FMISO-PET was performed before and after neo-Bev. Four patients who underwent tumor resection without neo-Bev were included as the control group. Expressions of hypoxic markers (carbonic anhydrase; CA9), stem cell markers (nestin, FOXM1), and immunoregulatory molecules (CD163, FOXP3, PD-L1) in tumor tissues were analyzed by immunohistochemistry (IHC).

RESULTS

All 3 patients treated with neo-Bev showed decrease in FMISO accumulation in accordance with expressions of CA9 and FOXM1 compared with the control group. Two of these 3 patients at the recurrence showed increase in FMISO accumulation. IHC showed increased CA9-and FOXM1-positive cells in recurrent tumors. Expression of PD-L1 tended to be lower after neo-Bev compared with the control group.

CONCLUSIONS

FMISO-PET effectively visualized TME oxygenation after neo-Bev. Increased FMISO accumulation at the time of recurrence, even under Bev treatment, suggests that FMISO-PET might be useful for monitoring the duration of Bev efficacy by reflecting tumor oxygenation.

Spontaneous shrinkage of vestibular schwannoma with the recovery of impaired hearing: A case report and literature review

Background

Sporadically occurring vestibular schwannomas (VSs) are the most frequent tumors in the cerebellopontine cistern and internal meatus and are commonly associated with hearing loss. These tumors have demonstrated spontaneous shrinkage rates of 0-22%; however, the relationship between tumor shrinkage and changes in hearing remains unclear.

Case Description

We report a case of a 51-year-old woman with a diagnosis of a left-sided VS and accompanying moderate hearing loss. The patient was treated with a conservative approach for 3 years, and the tumor showed a regression along with an improvement in her hearing ability during the yearly follow-ups.

Conclusion

The spontaneous shrinkage of a VS along with an associated improvement in hearing is a rare phenomenon. Our case study may support that the "wait and scan" approach is an alternative option for patients with VS and moderate hearing loss. Further investigations are needed to understand spontaneous VS regression and hearing changes.

Different Risk Factors Between Cerebral Infarction and Symptomatic Cerebral Vasospasm in Patients with Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE

Cerebral infarction due to cerebral vasospasm (IVS) after aneurysmal subarachnoid hemorrhage is associated with poor outcomes and symptomatic cerebral vasospasm (SVS). However, the difference of risk factors between SVS and IVS was unclear to date. In this study, we aimed to elucidate the risk factors for SVS and IVS based on the registry study.

METHODS

The modified World Federation of Neurosurgical Societies scale study comprises 1863 cases. Patients with aneurysmal subarachnoid hemorrhage who underwent radical treatment within 72 hours with a premorbid modified Rankin Scale score 0-2 as the inclusion criteria were retrospectively examined. The risk factors for SVS and IVS were analyzed using multivariable logistic regression analysis.

RESULTS

Among them, 1090 patients who met the inclusion criteria were divided into 2 groups according to SVS and IVS; 273 (25%) patients with SVS and 92 (8.4%) with IVS. Age was not a risk factor for SVS, but for IVS, and Fisher scale was a risk factor for SVS, but not for IVS.

CONCLUSIONS

The prevalence of IVS was not associated with the Fisher scale but with older age, suggesting possible factors other than SVS. Different associated factors between SVS and IVS were confirmed in this study.

The REMIT scale: A novel prediction scale for embolism in hyperacute stroke with large vessel occlusion

BACKGROUND AND PURPOSE

Large vessel occlusion (LVO) in hyperacute ischemic stroke occurs mainly by one of two mechanisms, embolism or atherosclerosis. However, the mechanism is difficult to identify prior to treatment. We aimed to investigate the factors associated with embolic LVO in hyperacute ischemic stroke, and to develop a preoperative predictive scale for the event.

MATERIALS AND METHODS

This retrospective multicenter study was conducted with consecutive ischemic stroke patients with LVO who underwent thrombectomy, thrombolysis, or both. The embolic LVO was defined as an occlusion that underwent recanalization with no residual stenosis. Multivariate logistic regression analysis for embolic LVO was performed to identity the independent risk factors. With this approach, a novel prediction scale (Rating of Embolic Occlusion for Mechanical Thrombectomy [REMIT] scale) was developed.

RESULTS

A total of 162 patients (104 men; median age 76 years; interquartile range 68-83) were included in this study. Embolic LVO was observed in 121 patients (75%). Multivariate logistic regression analysis showed that embolic LVO was independently associated with high brain natriuretic peptide (BNP), high National Institutes of Health Stroke Scale (NIHSS) on admission, and absence of non-culprit stenosis (NoCS). The REMIT scale comprises high BNP (>100 pg/dL), high NIHSS (>14) and absence of NoCS, with one point for each risk factor. The frequencies of embolic LVO for the REMIT scale scores were as follows: score 0, 25%; score 1, 60%; score 2, 87%; score 3, 97% (C-statistic 0.80, P < 0.001).

CONCLUSION

The novel REMIT scale has predictive value for embolic LVO.

Compartment syndrome associated with vascular avulsion caused by transradial access in neurointervention for unruptured intracranial aneurysm: illustrative case

BACKGROUND

Transradial access (TRA) has a lower risk of access-site complications than transfemoral access but can cause major puncture-site complications, including acute compartment syndrome (ACS).

OBSERVATIONS

The authors report a case of ACS associated with radial artery avulsion after coil embolization via TRA for an unruptured intracranial aneurysm. An 83-year-old woman underwent embolization via TRA for an unruptured basilar tip aneurysm. Following embolization, strong resistance was felt during removal of the guiding sheath due to vasospasm of the radial artery. One hour after neurointervention via TRA, the patient complained of severe pain in the right forearm, with motor and sensory disturbance of the first 3 fingers. The patient was diagnosed with ACS causing diffuse swelling and tenderness over the entire right forearm due to elevated intracompartmental pressure. The patient was successfully treated by decompressive fasciotomy of the forearm and carpal tunnel release for neurolysis of the median nerve.

LESSONS

TRA operators should be aware that radial artery spasm and the brachioradial artery pose a risk of vascular avulsion and resultant ACS and warrant precautionary measures. Prompt diagnosis and treatment are essential because ACS can be treated without the sequelae of motor or sensory disturbance if properly addressed.