"TIPS" and Technical Nuances for Digital Illustration in Neurointerventional Surgery.

Medical illustrations represent a precious resource for learning surgical anatomy and surgical techniques, allowing pre- and postoperative reviews. As traditional hand-drawn illustrations are difficult to use and expressing the area of neurointerventional surgery is time-consuming, we proposed methods for neurointerventional surgeons to create digital illustrations (DIs) for neurointerventional surgery using the iPad-exclusive Procreate application (Savage Interactive, Hobart, Australia). Dedicated "digital pens" were created and used for each endovascular device, creating straightforward representations of neurointerventional procedures and changes over time. DIs in neurointervention easily depict changes to highlighted surgical scenes for various devices with complex configurations and structures. DIs are also versatile, allowing easy intra- and inter-institutional sharing and discussion of technical tips on the manipulation of medical devices (coils, catheters, stents, etc.) among neurointerventional surgeons worldwide. DIs can be applied as educational tools not only in neurointerventional surgery, but also in craniotomy surgery and for surgical records from other specialties.

First multicenter study evaluating the utility of the BENCHMARKTM BMXTM 81 large-bore access catheter in neurovascular interventions.

INTRODUCTION: This study is the first multicentric report on the safety, efficacy, and technical performance of utilizing a large bore (0.081″ inner diameter) access catheter in neurovascular interventions. METHODS: Data were retrospectively collected from seven sites in the United States for neurovascular procedures via large bore 0.081″ inner diameter access catheter (Benchmark BMX81, Penumbra, Inc.). The primary outcome was technical success, defined as the access catheter reaching its target vessel. Safety outcomes included periprocedural device-related and access site complications. RESULTS: There were 90 consecutive patients included. The median age of the patients was 63 years (IQR: 53, 68); 53% were female. The most common interventions were aneurysm embolization (33.3%), carotid stenting (12.2%), and arteriovenous malformation embolization (11.1%). The transradial approach was most used (56.7%), followed by transfemoral (41.1%). Challenging anatomic variations included severe vessel tortuosity (8/90, 8.9%), type 2 aortic arch (7/90, 7.8%), type 3 aortic arch (2/90, 2.2%), bovine arch (2/90, 2.2%), and severe angle (<30°) between the subclavian artery and target vessel (1/90, 1.1%). Technical success was achieved in 98.9% of the cases (89/90), with six cases requiring a switch from radial to femoral (6.7%) and one case from femoral to radial (1.1%). There were no access site complications or complications related to the 0.081″ catheter. Two postprocedural complications occurred (2.2%), unrelated to the access catheter. CONCLUSION: The BMX™ 81 large-bore access catheters was safe and effective in both radial and femoral access across a wide range of neurovascular procedures, achieving high technical success without any access site or device-related complications.

Multicenter comparison using two AI stroke CT perfusion software packages for determining thrombectomy eligibility.

BACKGROUND: Stroke AI platforms assess infarcted core and potentially salvageable tissue (penumbra) to identify patients suitable for mechanical thrombectomy. Few studies have compared outputs of these platforms, and none have been multicenter or considered NIHSS or scanner/protocol differences. Our objective was to compare volume estimates and thrombectomy eligibility from two widely used CT perfusion (CTP) packages, Viz.ai and RAPID.AI, in a large multicenter cohort. METHODS: We analyzed CTP data of acute stroke patients with large vessel occlusion (LVO) from four institutions. Core and penumbra volumes were estimated by each software and DEFUSE-3 thrombectomy eligibility assessed. Results between software packages were compared and categorized by NIHSS score, scanner manufacturer/model, and institution. RESULTS: Primary analysis of 362 cases found statistically significant differences in both software's volume estimations, with subgroup analysis showing these differences were driven by results from a single scanner model, the Canon Aquilion One. Viz.ai provided larger estimates with mean differences of 8cc and 18cc for core and penumbra, respectively (p<0.001). NIHSS subgroup analysis also showed systematically larger Viz.ai volumes (p<0.001). Despite volume differences, a significant difference in thrombectomy eligibility was not found. Additional subgroup analysis showed significant differences in penumbra volume for the Phillips Ingenuity scanner, and thrombectomy eligibility for the Canon Aquilion One scanner at one center (7 % increased eligibility with Viz.ai, p=0.03). CONCLUSIONS: Despite systematic differences in core and penumbra volume estimates between Viz.ai and RAPID.AI, DEFUSE-3 eligibility was not statistically different in primary or NIHSS subgroup analysis. A DEFUSE-3 eligibility difference, however, was seen on one scanner at one institution, suggesting scanner model and local CTP protocols can influence performance and cause discrepancies in thrombectomy eligibility. We thus recommend centers discuss optimal scanning protocols with software vendors and scanner manufacturers to maximize CTP accuracy.

Effective and organ doses in patient undergoing interventional neuroradiology procedures: A multicentre study.

PURPOSE: Radiation doses to adult patients submitted to cerebral angiography and intracranial aneurysms treatments were assessed by using DICOM Radiation Dose Structured Reports (RDSR) and Monte Carlo simulations. Conversion factors to estimate effective and organ doses from Kerma-Area Product (PKA) values were determined. METHODS: 77 cerebral procedures performed with five angiographic equipment installed in three Italian centres were analyzed. Local settings and acquisition protocols were considered. The geometrical, technical and dosimetric data of 16,244 irradiation events (13305 fluoroscopy, 2811 digital subtraction angiography, 128 cone-beam CT) were extracted from RDSRs by local dose monitoring systems and were input in MonteCarlo PCXMC software to calculate effective and organ doses. Finally, conversion factors to determine effective and organ doses from PKA were determined. Differences between centres were assessed through statistical analysis and accuracy of dose calculation method based on conversion factors was assessed through Bland-Altman analysis. RESULTS: Large variations in PKA (14-561 Gycm2) and effective dose (1.2-73.5 mSv) were observed due to different degrees of complexity in the procedures and angiographic system technology. The most exposed organs were brain, salivary glands, oral mucosa, thyroid and skeleton. The study highlights the importance of recent technology in reducing patient exposure (about fourfold, even more in DSA). No statistically significant difference was observed in conversion factors between centres, except for some organs. A conversion factor of 0.09 ± 0.02 mSv/Gycm2 was obtained for effective dose. CONCLUSIONS: Organ and effective doses were assessed for neuro-interventional procedures. Conversion factors for calculating effective and organ doses from PKA were provided.

Health budget implications of mechanical thrombectomy for acute ischaemic stroke in Australia.

INTRODUCTION: This research evaluates the budget impact of treating acute ischaemic stroke (AIS) using a combination of mechanical thrombectomy (MT) with stent retrievers (SR) and intravenous tissue-plasminogen activator (IV-tPA) in Australia. METHODS: This study examined the economic impact over five years for a patient cohort based on the number of patients treated with MT+ IV-tPA in Australia 2021, versus treatment with IV-tPA alone. A budget impact (BI) model was developed to project direct medical costs (economic impact) of IV-tPA+ MT with SR vs. Intravenous tissue-plasminogen activator alone over a five-year period (2021-2025 inclusive) from a healthcare perspective. The model is composed of a short-run decision tree model based on a 3-month post-treatment modified Rankin Scale (mRS) from the EXTEND-IA study and a published long-run Markov state transition model. Acute, mid-term and long-term care costs were projected based on anticipated mRS scores from the EXTEND-IA trial. Estimated yearly and cumulative budget impact were reported to indicate the economic impact of the two treatment strategies for AIS in the Australian healthcare system. RESULTS: MT+IV-tPA had a greater budgetary impact than IV-tPA alone, with annual savings starting at Year 1 and continuing through to Year 5. Cost savings of 21% or approximately $36 million can be achieved over five years for the patient cohort treated in Australia in 2021. Each MT procedure performed delivers approximately $3280 in annual health system savings per patient. CONCLUSION: Treatment of AIS with a combination of MT+IV-tPA generates significant savings in the Australian healthcare system compared with IV-tPA alone.

Endovascular Applications for the Management of High-Grade Gliomas in the Modern Era.

High-grade gliomas (HGGs) have a poor prognosis and are difficult to treat. This review examines the evolving landscape of endovascular therapies for HGGs. Recent advances in endovascular catheter technology and delivery methods allow for super-selective intra-arterial cerebral infusion (SSIACI) with increasing precision. This treatment modality may offer the ability to deliver anti-tumoral therapies directly to tumor regions while minimizing systemic toxicity. However, challenges persist, including blood-brain barrier (BBB) penetration, hemodynamic complexities, and drug-tumor residence time. Innovative adjunct techniques, such as focused ultrasound (FUS) and hyperosmotic disruption, may facilitate BBB disruption and enhance drug penetration. However, hemodynamic factors that limit drug residence time remain a limitation. Expanding therapeutic options beyond chemotherapy, including radiotherapy and immunobiologics, may motivate future investigations. While preclinical and clinical studies demonstrate moderate efficacy, larger randomized trials are needed to validate the clinical benefits. Additionally, future directions may involve endovascular sampling for peri-tumoral surveillance; changes in drug formulations to prolong residence time; and the exploration of non-pharmaceutical therapies, like radioembolization and photodynamic therapy. Endovascular strategies hold immense potential in reshaping HGG treatment paradigms, offering targeted and minimally invasive approaches. However, overcoming technical challenges and validating clinical efficacy remain paramount for translating these advancements into clinical care.

[Drug therapy for acute and elective stent angioplasty]. / Medikamentöse Therapieregimes bei akuter und elektiver Stentangioplastie.

CLINICAL ISSUE: Carotid artery stenoses are constrictions of the common carotid artery and the internal carotid artery. They cause around 15% of all cerebral ischemia, which is why their detection and correct treatment play an important role in clinical practice. PRACTICAL RECOMMENDATIONS: Depending on the severity and clinical symptoms, carotid artery stenosis is treated conservatively, surgically or endovascularly by means of stent angioplasty. In the case of stent angioplasty in particular, correct drug therapy plays an important role in avoiding/reducing thromboembolic complications.

A Simplified One-Size-Fits-All Approach to Carotid Stenting.

BACKGROUND: Carotid artery stenosis causes up to 20% of ischemic strokes. Stenting is used as an alternative to endarterectomy in symptomatic patients. Each commercially available stent offers numerous stent diameters/lengths. Most centers thus carefully match each individual stenosis to a specific stent length/diameter stent size. However, this process can be time-consuming and costly while the relative benefit of a custom stent sizing versus one-size-fits-all approach has not been well evaluated yet. We hypothesized that a 'one-size-fits-all' default approach to carotid stenting results in comparable results to a customized approach. METHODS: We conducted a descriptive retrospective cohort study on 154 patients who presented to our academic carotid revascularization clinic with symptomatic carotid artery stenosis who underwent carotid artery stenting for peri- and postprocedural carotid artery stenting complications. The primary outcomes were periprocedural (within 24 hours of the procedure) or postprocedural (within 30 days of the procedure) TIA, stroke, or death. The secondary outcome was the estimated degree of stenosis on follow-up ultrasound performed within 6 months of the procedure. RESULTS: The complication rate within the first 24 hours was 4.5% while that during the first 30 days postprocedure was 6.5%. Age over 80 and degree of stenosis on postprocedural cerebral angiogram were associated with an increased risk of complications. Severe restenosis was reported in 16.8% of patients within 6 months postprocedure. CONCLUSION: Our study suggests that using a simplified, one-size-fits-all, approach to carotid stenting results in safe and effective outcomes, suggesting an alternative to simplify a complex medical procedure.

Artificial intelligence applied in acute ischemic stroke: from child to elderly.

This review will summarize artificial intelligence developments in acute ischemic stroke in recent years and forecasts for the future. Stroke is a major healthcare concern due to its effects on the patient's quality of life and its dependence on the timing of the identification as well as the treatment. In recent years, attention increased on the use of artificial intelligence (AI) systems to help categorize, prognosis, and to channel these patients toward the right therapeutic procedure. Machine learning (ML) and in particular deep learning (DL) systems using convoluted neural networks (CNN) are becoming increasingly popular. Various studies over the years evaluated the use of these methods of analysis and prediction in the assessment of stroke patients, and at the same time, several applications and software have been developed to support the neuroradiologists and the stroke team to improve patient outcomes.

Treatment of a posterior cerebral artery aneurysm in the context of complex cardio-cerebrovascular variations using the Tubridge flow diverter.

We present a case of intracranial aneurysm located in the P1 segment of left posterior cerebral artery in the context of tetralogy of Fallot. Complex variations included right aortic arch with abnormal branching. Also, the bilateral vertebral arteries were absent, with a type I persistent proatlantal intersegmental artery of the left side. The aneurysm was treated with endovascular intervention with a Tubridge flow diverter and was noted to be completely cured on 6-month follow-up. We discuss the many considerations in this patient including developmental and modern-era treatment.

Efficacy and safety of percutaneous cement discoplasty in the management of degenerative spinal diseases: A systematic review and meta-analysis.

BACKGROUND: Percutaneous cement discoplasty (PCD) is a minimally invasive procedure. We aim to explore the efficacy and indication(s) of PCD in patients with degenerative disc disease (DDD). METHODS: The search was conducted across Ovid MEDLINE, Ovid Embase, and PubMed. Data on study design, patient demographics, pre- and post-procedure Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) scores, and complications were extracted. Inclusion criteria focused on adult patients with degenerative spinal diseases treated with cement discoplasty. The overall effect size was evaluated using a forest plot, and heterogeneity was assessed using the I2 statistic and chi-squared test. RESULTS: The search strategy yielded six studies, which included 336 patients (73.8% female, 26.2% male) with a mean average age of 74.6 years. VAS scores were reported in all studies, showing a significant difference between pre- and post-PCD pain scores (Weighted Mean Difference [WMD]: -3.45; 95% CI: -3.83, -3.08; I2 = 15%; P < .001). ODI scores were reported in 83% of studies, with a significant difference between pre- and post-PCD scores (WMD: -22.22; 95% CI: -25.54, -18.89; I2 = 61%; p < .001). Complications reported included infections, thrombophlebitis, vertebral fractures, disc extrusion, and the need for further operations. CONCLUSIONS: The analysis showed clinically significant improvements in pain and functional disability based on VAS and ODI scores. However, due to methodological limitations and a high risk of bias, the validity and generalizability of the findings are uncertain. Despite these issues, the results provide preliminary insights into PCD's potential efficacy and can guide future research to address current limitations.

Small volume blood-brain barrier opening in macaques with a 1 MHz ultrasound phased array.

The use of focused ultrasound to open the blood-brain barrier (BBB) has the potential to deliver drugs to specific regions of the brain. The size of the BBB opening and ability to localize the opening determines the spatial extent and is a limiting factor in many applications of BBB opening where targeting a small brain region is desired. Here we evaluate the performance of a system designed for small opening volumes and highlight the unique challenges associated with pushing the spatial precision of this technique. To achieve small volume openings in cortical regions of the macaque brain, we tested a custom 1 MHz array transducer integrated into a magnetic resonance image-guided focused ultrasound system. Using real-time cavitation monitoring, we demonstrated twelve instances of single sonication, small volume BBB opening with average volumes of 59 ± 37 mm3 and 184 ± 2 mm3 in cortical and subcortical targets, respectively. We found high correlation between subject-specific acoustic simulations and observed openings when incorporating grey matter segmentation (R2 = 0.8577), and the threshold for BBB opening based on simulations was 0.53 MPa. Analysis of MRI-based safety assessment and cavitation signals indicate a safe pressure range for 1 MHz BBB opening and suggest that our system can be used to deliver drugs and gene therapy to small brain regions.

Image Quality and Radiation Dose of Conventional and Wide-Field High-Resolution Cone-Beam Computed Tomography for Cerebral Angiography: A Phantom Study.

There has been an increase in the use of interventional neuroradiology procedures because of their non-invasiveness compared to surgeries and the improved image quality of fluoroscopy, digital subtraction angiography, and rotational angiography. Although cone-beam computed tomography (CBCT) images are inferior to multi-detector CT images in terms of low-contrast detectability and lower radiation doses, CBCT scans are frequently performed because of their accessibility. This study aimed to evaluate the image quality and radiation dose of two different high-resolution CBCTs (HR CBCT): conventional (C-HR CBCT) and wide-field HR CBCT (W-HR CBCT). The modulation transfer function (MTF), noise power spectrum (NPS), and contrast-to-noise ratio (CNR) were used to evaluate the image quality. On comparing the MTF of C-HR CBCT with a 256 × 256 matrix and that of W-HR CBCT with a 384 × 384 matrix, the MTF of W-HR CBCT with the 384 × 384 matrix was larger. A comparison of the NPS and CNR of C-HR CBCT with a 256 × 256 matrix and W-HR CBCT with a 384 × 384 matrix showed that both values were comparable. The reference air kerma values were equal for C-HR CBCT and W-HR CBCT; however, the value of the kerma area product was 1.44 times higher for W-HR CBCT compared to C-HR CBCT. The W-HR CBCT allowed for improved spatial resolution while maintaining the image noise and low-contrast detectability by changing the number of image matrices from 256 × 256 to 384 × 384. Our study revealed the image characteristics and radiation dose of W-HR CBCT. Given its advantages of low-contrast detectability and wide-area imaging with high spatial resolution, W-HR CBCT may be useful in interventional neuroradiology for acute ischemic stroke.

Salvageable Intra-stent Coil Embolization Treatment for Spinal Dural Arteriovenous Fistula in a Child.

Spinal dural arteriovenous fistulae (SDAVF) are rare diseases that exhibit abnormal connections between arteries and veins. They are even rarer in the pediatric population and pose diagnostic and treatment challenges for physicians. Its presentation varies depending on the site and size of the SDAVF. Multiple management options are available, which are usually tailored depending on the patient's condition. Here, we present a rare case of SDAF in a four-year-old girl who initially presented with bilateral lower limb weakness. The patient was then treated successfully using primary major fistula point stenting and intra-stent coiling, with complete closure achieved. Full recovery was achieved over the course of follow-ups. The deep analysis of SDAVF, its classification, and the utilization of the best available endovascular tools by a dedicated neurovascular team offer the best outcome in dealing with complex spinal neurovascular pathologies.

Basilar artery recanalization by proximal balloon occlusion and aspiration in a single vessel vertebrobasilar system: A case report.

The authors present a case of a patient with a hypoplastic right vertebral artery (VA) ending in the posterior inferior cerebellar artery who sustained an acute onset basilar artery occlusion. A balloon-guided catheter was used to proximally occlude the dominant left VA, and aspiration was applied until reversal of flow was achieved in the basilar artery. Thus, basilar artery reperfusion was achieved without the need for stent-retrieval thrombectomy. We believe this represents the first described case of successful thrombectomy in the vertebrobasilar system using only proximal artery occlusion and aspiration. This novel technique may decrease the time to recanalization and improve outcomes for patients with acute basilar artery occlusion in the setting of a hypoplastic contralateral VA.

Comparative verification of control methodology for robotic interventional neuroradiology procedures.

PURPOSE: The use of robotics is emerging for performing interventional radiology procedures. Robots in interventional radiology are typically controlled using button presses and joystick movements. This study identified how different human-robot interfaces affect endovascular surgical performance using interventional radiology simulations. METHODS: Nine participants performed a navigation task on an interventional radiology simulator with three different human-computer interfaces. Using Simulation Open Framework Architecture we developed a simulation profile of vessels, catheters and guidewires. We designed and manufactured a bespoke haptic interventional radiology controller for robotic systems to control the simulation. Metrics including time taken for navigation, number of incorrect catheterisations, number of catheter and guidewire prolapses and forces applied to vessel walls were measured and used to characterise the interfaces. Finally, participants responded to a questionnaire to evaluate the perception of the controllers. RESULTS: Time taken for navigation, number of incorrect catheterisations and the number of catheter and guidewire prolapses, showed that the device-mimicking controller is better suited for controlling interventional neuroradiology procedures over joystick control approaches. Qualitative metrics also showed that interventional radiologists prefer a device-mimicking controller approach over a joystick approach. CONCLUSION: Of the four metrics used to compare and contrast the human-robot interfaces, three conclusively showed that a device-mimicking controller was better suited for controlling interventional neuroradiology robotics.