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Background: Traumatic intracranial aneurysms (TICAs) constitute a notable portion of pediatric intracranial aneurysms. Their unstable structure dictates a high incidence of rupture or mass effect from enlarging unruptured aneurysms, necessitating prompt diagnosis and treatment. TICAs often lack a true neck or are wide-necked, making them unsuitable for coil embolization and surgical clipping, and their fragile nature poses a risk of rupture during surgical and intrasaccular interventions. Endoluminal flow diverters (FD), deployed without requiring direct access to the aneurysmal sac, have emerged as an appealing sole treatment modality for TICAs. However, the clinical experience with this technique remains limited in the pediatric population. Method: We describe the successful treatment of a paraclinoid TICA in a 4-year-old female using an endoluminal FD alone. Additionally, we conducted a literature review to assess the safety and effectiveness of this treatment modality in pediatric TICAs. Results: Endoluminal flow diversion led to complete aneurysm obliteration in our case, with no observed complication, at the 9-month follow-up. Our review of the previously reported pediatric TICAs managed by standalone flow diversion highlights this technique as safe, efficient, and promising as a sole treatment modality, particularly in the anterior circulation, with a high rate of persistent total obliteration and a low rate of complications. However, the requirement for long-term antiplatelet therapy with the possibility of frequent dose monitoring and adjustments warrants special attention when using endoluminal FDs. Until guidelines specifically addressing optimal antiplatelet therapy in children with intracranial FDs are formulated, adherence to existing protocols is imperative to avoid in-stent thrombosis. Conclusion: Our literature review and personal experience indicate that endoluminal flow diversion can be a viable treatment approach for pediatric TICAs. However, prospective studies with extensive follow-ups are required to assess the durability of endoluminal FDs in treating pediatric TICAs, considering the long life expectancy of this demographic. [ABSTRACT FROM AUTHOR]

Background: The stapedial artery is an embryonic artery that transiently supplies the cranial vasculature of the human embryo. Postnatal persistence of the stapedial artery may cause conductive hearing loss and pulsatile tinnitus due to its course through the middle ear. We describe a patient with a persistent stapedial artery (PSA) managed by endovascular coil occlusion prior to stapedotomy. Methods: A 48-year-old woman presented with left-sided conductive hearing loss and pulsatile tinnitus. Ten years earlier the patient had undergone explorative tympanoplasty, which was aborted due to a large PSA. Digital subtraction angiography was performed to confirm the anatomy and endovascular occlusion of the proximal PSA was achieved by deployment of coils. Results: The pulsatile tinnitus improved immediately after the procedure. The size of the artery subsequently decreased and surgery could be performed with only a minor intraoperative bleeding. Successful stapedotomy resulted in postoperative normalization of her hearing with some minor residual tinnitus. Conclusion: Endovascular coil occlusion of a PSA is feasible and safe in patients with favorable anatomy and facilitates middle ear surgery. It decreases the size of the artery and minimizes the risk of intraoperative bleeding in patients with a large PSA. The future role of this novel technique in the management of patients with PSA-related conductive hearing loss and pulsatile tinnitus remains to be determined. [ABSTRACT FROM AUTHOR]

Purpose: Cadaver dissections and X-ray based 3D angiography are considered gold standards for studying neurovascular anatomy. We sought to develop a model that utilize the combination of both these techniques to improve current tools for anatomical research, teaching and preoperative surgical planning, particularly addressing the venous system of the brain. Materials and methods: Seven ethanol-fixed human cadaveric heads and one arm were injected with a latex-barium mixture into the internal jugular veins and the brachial artery. After the ethanol-based fixation, specimens were scanned by high-resolution cone-beam CT and images were post-processed on a 3D-workstation. Subsequent, microsurgical dissections were performed by an experienced neurosurgeon and venous anatomy was compared with relevant 3D venograms. Results: Latex-barium mixtures resulted in a homogenous cast with filling of the cerebral venous structures down to 150 μm in diameter. The ethanol-based preparation of the cadaveric brains allowed for near-realistic microsurgical maneuverability during dissection. The model improves assessment of the venous system for anatomical education and hands-on surgical training. Conclusion: To our knowledge we describe the first preparation method which combines near-realistic microsurgical dissection of human heads with high-resolution 3D imaging of the cerebral venous system in the same specimens. [ABSTRACT FROM AUTHOR]

Purpose: Cerebral polymer coating embolism from intravascular devices may cause serious complications after endovascular therapy (EVT) for neurovascular diseases. Although polymer fragments are often created during endovascular procedures, exact mechanisms of their formation, especially if of small size, are largely unknown. Methods: In this study eight microguidewires (Asahi Chikai 200 cm (Asahi Intecc, Aichi, Japan), Asahi Chikai Black (Asahi Intecc), Fathom™ (Boston Scientific, Marlborough, MA, USA), Hybrid (Balt Extrusion, Montmorency, France), Radifocus® Guide Wire GT (Terumo, Leuven, Belgium), Synchro2® (Stryker, Kalamazoo, MI, USA), Transend™ EX (Boston Scientific), and Traxcess™ (MicroVention®, Tustin, CA, USA)) frequently used during EVT were investigated ex vivo using their dedicated metal or plastic insertion tools to assess for coating delamination after backloading of the microguidewires. Results: Backloading caused damage to the coating of all microguidewires especially when the main body of the guidewires was bent in front of the insertion tool. All studied microguidewires produced microscopic filamentous and/or band-like coating fragments. Few larger irregular fragments were observed, but also very small fragments measuring 1–3 µm in diameter were found. Spectroscopic measurements of polymer fragments and microguidewires identified various polymers. Conclusion: Backloading of polymer-coated microguidewires during EVT should be minimized if possible. More stable hydrophilic coatings on microguidewires and less traumatic insertion tools are desirable. [ABSTRACT FROM AUTHOR]

While intracranial aneurysms rarely develop after neurosurgical procedures, delayed pseudoaneurysm formation after foramen magnum decompression (FMD) has never been reported. A 52-year-old woman presented with an atypical subarachnoid hemorrhage in the posterior fossa 12 years after a FMD for symptomatic Chiari malformation type I was performed. A pseudoaneurysm on a dural-pial anastomosis was identified as the bleeding source and successfully occluded by endovascular means with full clinical recovery of the patient. Injury to the distal posterior inferior cerebellar artery related to surgery and postoperative infection likely caused formation of a dural-pial anastomosis. Additionally, hemodynamic stress or dissection may have contributed to delayed pseudoaneurysm formation and rupture. [ABSTRACT FROM AUTHOR]

These lesions are not visualized simultaneously but in the order: 1) DVA, 2) VM, 3) DVA-varix, 4) VM/varix-vein of Labbé. Venous 3D-DSA-based volume rendering technique (VRT) and maximum intensity projection (MIP) images confirmed that both the varix-like structure as well as the superficial VM consisted of multiple various-sized channels rather than a single-lumen varix or venous ectasia (Figs. Large asterisk Varix, small asterisk VM, curved arrows flow directions from the larger collector vein towards deep venous drainage and varix Graph: Fig. Developmental venous anomalies (DVA) are the most frequently encountered asymptomatic cerebral vascular malformations and are often found incidentally on routine computed tomography angiography (CTA) and magnetic resonance imaging (MRI) studies. [Extracted from the article]

Objective: The aim of the study was to investigate (1) the 30-day, 3-month, and 12-month cumulative mortalities for patients who underwent aneurysm occlusion, and (2) the causes of death, and (3) the potential risk factors for death. Methods: All patients who underwent surgical clipping or endovascular treatment of a ruptured aneurysm at Copenhagen University Hospital, during the period of January 1, 2017–December 31, 2019, were included and followed up for 12 months. Data regarding vital status, causes of death, comorbidities, treatment, and clinical presentations on admission was collected. The absolute mortality risk was estimated as a function of time with a 95% confidence interval. The associations between potential risk factors and death were estimated as odds ratios with 95% confidence intervals using logistic regression models. Results: A total of 317 patients were included. The overall cumulative mortalities after 30 days, 3 months, and 12 months were 10.7%, 12.9%, and 16.1%, respectively. The most common cause of death was severe primary hemorrhage (52.9%), followed by infections (15.7%) and rebleeding (11.8%). WFNS score > 3 and Fisher score > 3 on admission, preprocedural hydrocephalus, and preprocedural rebleeding were found significantly associated with higher risk of death. Conclusions: Considerable mortality was seen. Possible preventable causes accounted for approximately 22% of the deaths. The occurrence of both pre- and postprocedural rebleeding's indicates an opportunity of further improvement of the mortality by (1) further reduction of time from aSAH to aneurysm occlusion and (2) continuous efforts in improving methods of aneurysm occlusion. [ABSTRACT FROM AUTHOR]

In conclusion, EVT using standard transarterial catheterization techniques is feasible and appears safer in patients with milder LDS forms when compared to patients with other connective tissue disorders, e.g. EDS type IV. Patients with LDS have a prevalence of intracranial aneurysms of 19-32% [[4], [11]], and EDS type IV patients may present with carotid-cavernous fistulas associated with major endovascular procedure-related complications and possible fatal outcome [[5]]. Typical LDS patients have hypertelorism, bifid uvula or cleft palate but the phenotypic spectrum of LDS is broad and overlaps with Marfan syndrome (MFS) and Ehlers-Danlos syndrome (EDS) [[1]-[3]]. [Extracted from the article]

Vessel wall imaging (VWI) using MRI sequences has emerged as a promising tool for understanding the pathology and natural history of intracranial aneurysms. Traditionally, imaging focused on luminal abnormalities, but recent studies have highlighted the importance of VWI in visualizing the aneurysm wall and identifying inflammation. VWI can aid in risk stratification, guide treatment decisions, and improve patient outcomes. However, there are challenges to overcome, such as limited spatial resolution and the need for standardization and software development. Advancements in imaging technology and collaboration among clinicians, radiologists, and MRI physicists are necessary to fully realize the potential of VWI in aneurysm management. [Extracted from the article]

Traumatic MMA fistulas near the foramen spinosum may clinically mimic CCFs due to arterialization of the cavernous sinus (CS) [[10]]. 2 Left external carotid artery injection in frontal (a) and lateral (b) views revealed a high-flow arteriovenous fistula supplied by the middle meningeal artery shunting directly into an irregular and enlarged venous channel (arrow) that drained via the cavernous sinus (asterisks) into the enlarged left superior ophthalmic vein (arrowhead). In the adult population, MMA fistulas develop in 1.8% of patients with head trauma [[2]] and skull fractures may be a causative factor in 97% of fistulas [[1]]. Conclusion Traumatic MMA fistulas are exceedingly rare in the pediatric population but should be taken into consideration when a bruit develops even after a minor head trauma as it is highly suspicious for an extracranial or intracranial AVF. [Extracted from the article]

Accumulation of contrast medium in the subdural space after diagnostic intraarterial contrast administration is a rare observation. The authors report the case of a subdural contrast effusion (SCE) presenting during endovascular treatment of an intracranial dural arteriovenous fistula (DAVF) mimicking an acute subdural hematoma. Differentiation between the two by computed tomography (CT) or intraprocedural Dyna CT and early neurological examination can be crucial for patient management. We believe that repeated large-volume contrast injections via large-bore intermediate catheters into the territory of an (even partly) occluded DAVF may induce leakage of contrast medium into the extravascular subdural space thereby causing a SCE. [ABSTRACT FROM AUTHOR]

Introduction: Crossing Y-stent technique is a valid option for coiling wide-necked bifurcation aneurysms. Two main designs of stents, the closed- (CCS) and open-cell (OCS), are used in combination for a crossing Y-construct. This in vitro study was conducted to assess the mechanical characteristics of each stent-combination and to suggest an optimal combination for clinical practice. Methods: The Enterprise and the Neuroform3 stents were used as closed-cell and open-cell stents, respectively. Four different Y-stent combinations; double CCSs (CCS-CCS; Enterprise-Enterprise), OCS followed by CCS (OCS-CCS; Neuroform-Enterprise), CCS followed by OCS (CCS-OCS; Enterprise-Neuroform), and double OCSs (OCS-OCS; Neuroform-Neuroform) were tested in a bifurcation aneurysm model. Images of the model were obtained by digital subtraction angiography (DSA), and morphological changes of Y-constructs caused by interaction between stents were compared. Results: Double OCSs showed the best stent apposition to model branches and no collapse of the second stent at the intersection, whereas Y-stent combinations using a CCS as the second stent showed tubular collapse of the second stent at the crossing point. These combinations revealed unsatisfactory apposition to the model branch in which the second stent was deployed. Most narrowing of the second stent was noted in the double CCSs construct, which resulted in poorest stent apposition. Conclusion: Based on a simple in vitro experiment, we suggest that double OCSs Y-construct is optimal for achieving best stent-wall apposition. Furthermore, our findings suggest that Y-stent combinations utilizing a CCS as the second stent may increase the risk of thromboembolic complications due to poor stent-wall apposition. [ABSTRACT FROM AUTHOR]

To assess reliability of wall shear stress (WSS) calculations using computational fluid dynamics (CFD) dependent on inflow in internal carotid artery aneurysms (ICA). Six unruptured ICA aneurysms were studied. 3D computational meshes were created from 3D digital subtraction angiographic images (Axiom Artis dBA, Siemens Medical Solutions). Transient CFD simulations (Fluent, ANSYS Inc.) were performed for two inflow conditions: (1) idealized averaged waveform from normal subjects (ID) and (2) patient-specific waveform (PS) measured with 2D phase contrast magnetic resonance imaging. Stability of calculation was assessed by comparing mean WSS (), temporal wall shear stress magnitude variation (ΔWSS), and oscillatory shear index (OSI, a measure of variation in the WSS direction) on the aneurysmal wall for both conditions. For all cases, mean relative difference (PS−ID) of WSS () was −15% (range −32% to 11%). Mean ΔWSS difference was −29.3% ( −100% to 67%). Mean OSI difference was 7.5% (−12% to 40%). Large variations in histograms of these parameters were noted. For accurate calculations of WSS parameters, patient-specific information on physiological flow may be necessary. Results obtained with averaged or idealized flow waveforms may have to be interpreted with caution. [ABSTRACT FROM AUTHOR]

To evaluate if knowledge of patient-specific inflow data in computational fluid dynamics simulations is required for the accurate calculation of intra-aneurysmal flow patterns and wall shear stress in an aneurysm of the anterior communicating artery (AcomA). 3D digital subtraction angiography (3D-DSA) and phase contrast magnetic resonance (pcMRI) images were obtained in a 71-year old patient with an unruptured aneurysm of the anterior communicating artery (AcomA). A baseline computational flow dynamics simulation was performed using inflow boundary conditions measured with pcMRI. Intra-aneurysmal flow patterns, maximum, minimum and average values of wall shear stress and wall shear stress histograms were calculated. Five additional computational flow dynamics simulations were performed, in which simulated inflow from the right and left A1 segment was varied, while keeping the total inflow constant. Intra-aneurysmal flow patterns measured with pcMRI were qualitatively compared to intra-aneurysmal flow patterns derived from the simulations. Intra-aneurysmal flow patterns calculated in the baseline simulation were in good qualitative agreement with pcMRI measurements. Intra-aneurysmal flow patterns and wall shear stress changed considerably when inflow conditions were altered. Changes in the flow distribution between right and left A1 segments caused variations of the averaged wall shear stress as high as 43%. Intra-aneurysmal flow patterns and wall shear stress in an AcomA aneurysm calculated with computational flow dynamics depended strongly on the flow distribution between A1 segments. Patient-specific flow data measured with pcMRI obtained prior to computational flow dynamics are necessary for an accurate simulation of intra-aneurysmal flow patterns and calculation of wall shear stress in AcomA aneurysms. Further studies may indicate if wall shear stress calculated with computational flow dynamics can predict aneurysm growth and/or rupture. [ABSTRACT FROM AUTHOR]

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