Endoluminal flow diversion as a primary treatment strategy for pediatric traumatic intracranial aneurysms: a case-based review of literature.

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.

Endovascular occlusion of a persistent stapedial artery prior to stapedotomy: a novel approach.

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.

Combined cone-beam CT imaging and microsurgical dissection of cadaver specimens to study cerebral venous anatomy: a technical note.

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.

Hemorrhage due to a pseudoaneurysm on a dural-pial anastomosis after decompression for Chiari malformation type I: case report.

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.

Mortality among patients treated for aneurysmal subarachnoid hemorrhage in Eastern Denmark 2017-2019.

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.

Subdural contrast effusion during endovascular therapy: case report.

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.

Rapidly evolving large extracranial vertebral artery pseudoaneurysm in Behçet's disease: Case report and review of the literature.

Behçet's disease is a multisystem chronic autoimmune disease of unknown etiology with a wide spectrum of symptoms and organ system involvement. Arterial manifestations, particularly of the extracranial vertebral arteries, are rare. We report an unusual case of an African American patient with Behçet's disease, who presented with bilateral spontaneous vertebral artery pseudoaneurysms. The patient underwent successful endovascular parent vessel occlusion with detachable coils and on follow-up had complete clinical and angiographic signs of recovery.

The impact of stent design on the structural mechanics of the crossing Y-stent: an in vitro study.

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.

Endovascular Management of a Ruptured Aneurysm on a Posterior Inferior Cerebellar Artery with Extradural C2-Origin: Case Report and Literature Review.

Extracranial vascular pathology uncommonly causes intracranial subarachnoid hemorrhage (SAH). Among possible lesions are aneurysms at the craniocervical junction arising from a posterior inferior cerebellar artery (PICA) with an extradural origin. We describe a case of a 55-year-old female presenting with a sudden and severe headache. A computed tomography scan revealed a SAH within the fourth ventricle and cervical spinal canal, and a ruptured saccular aneurysm on a PICA with extradural C2-origin. Despite difficult access anatomy, endovascular treatment was feasible and resulted in subtotal initial occlusion and preservation of distal PICA flow. Upon 3-month follow-up, the aneurysm was completely occluded with a patent PICA. The patient's clinical status remained stable at the 1.5-year follow-up. In conclusion, we present a rare case of an aneurysm originating from a PICA with extradural C2-origin that was treated endovascularly with preservation of the PICA.

Dissecting pseudoaneurysm in a spinal cord AVM treated by flow diversion: Technical note.

We report the case of a 29-year-old woman presenting with severe back pain and S1-radiculopathy. Digital subtraction angiography revealed a spinal cord arteriovenous malformation complicated by acute feeder dissection and pseudoaneurysm (PA) formation causing mass effect. After conservative management with limited angiographic and clinical improvement, selective treatment of the PA by flow diversion (FD) led to occlusion and shrinkage with the resolution of clinical symptoms. FD may be a feasible treatment option for spinal artery aneurysms in selected patients with favorable anatomy. The need for antiplatelet therapy is a limitation of its use with currently available devices.

Fragmentation of Hydrophilic Guidewire Coatings During Neuroendovascular Therapy.

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.

Acute triage of childhood stroke in Denmark.

OBJECTIVE: This 2-year observational study aimed to test the feasibility of implementing a pediatric stroke triage-setup that connected frontline providers with vascular neurologists and to examine final diagnoses in children triaged for suspected stroke. METHODS: Prospective, consecutive registration of children with suspected stroke triaged by a team of vascular neurologists from Jan 1st, 2020 and through Dec 2021, Eastern Denmark (census 530,000 children). Based on the provided clinical information, the children were triaged to either assessment at the Comprehensive Stroke Center (CSC) in Copenhagen or to a pediatric department. All included children were retrospectively followed-up for clinical presentations and final diagnosis. RESULTS: A total of 163 children with 166 suspected stroke events were triaged by the vascular neurologists. Cerebrovascular disease was present in 15 (9.0%) suspected stroke events; one child had intracerebral hemorrhage, one had subarachnoid hemorrhage, two children presented with three TIA events and nine children presented with 10 ischemic stroke events. Two children with ischemic stroke were eligible for acute revascularization treatment of which both were triaged to the CSC. The sensitivity of the triage by acute revascularization indication was 1.00 (95% confidence interval (95% CI): 0.15-1.00) and specificity 0.65 (95% CI: 0.57-0.73). Non-stroke neurological emergencies were present in 34 (20.5%) children, including seizures in 18 (10.8%) and acute demyelinating disorders in 7 (4.2%). CONCLUSION: Implementing regional triage-setup that connected frontline providers to vascular neurologists was feasible; this system was activated for the majority of children with ischemic stroke according to an expected incidence and led to identification of children eligible for revascularization treatments.

Vertebro-Vertebral Fistula Occlusion Using a Woven EndoBridgeTM-Device.

Vertebro-vertebral fistulas (VVFs) are vascular lesions that may develop after trauma or spontaneously in association with connective tissue disorders. We present a rare case of a post-traumatic VVF in a young patient presenting with a painless swelling and a bruit in her left upper neck. Digital subtraction angiography showed an arteriovenous fistula between the left vertebral artery (VA) and the vertebral venous plexus with significant steal phenomenon. Endovascular therapy was performed using a Woven EndoBridgeTM (WEB)-device combined with coils that allowed preservation of the VA. The patient fully recovered from her symptoms and follow-up imaging showed stable occlusion. In conclusion, VVFs can be effectively treated using intrasaccular flow diverters such as the WEB-device, allowing for complete and stable occlusion while preserving the parent artery.

Polytetrafluoroethylene coating fragments during neuroendovascular therapy: An analysis of two damaged microguidewires.

Cerebral polymer coating embolism from intravascular devices represents a potentially serious complication to endovascular therapy (EVT). We report two cases of neuroendovascular treatment where filamentous polymer fragments were noted possibly due to damage of the surface coating during manipulation and backloading of microguidewires. As the exact origin of the debris was initially not known, microguidewires and fragments were examined with light microscopy, stereomicroscopy, scanning electron microscopy and attenuated-total-reflection Fourier transform infrared spectroscopy. Fragments consisted of polytetrafluoroethylene and silicone oil stemming from the proximal shaft of a standard microguidewire. To our knowledge, this is the first report of polytetrafluoroethylene coating fragments created during EVT. Future studies should assess the mechanism of polymer coating delamination and its potential consequences during EVT including inadvertent fragment migration into the cerebral circulation.

Alternative route to a hypoglossal canal dural arteriovenous fistula in case of failed jugular vein approach.

Hypoglossal canal dural arteriovenous fistulas (HC-DAVF) involve the anterior condylar vein (ACV) and anterior condylar confluence (ACC). They often present with tinnitus, bruit, and hypoglossal nerve palsy. The most common treatment in HC-DAVFs is transvenous embolization using coils and the most direct transvenous route is the trans-internal jugular vein access. When this approach is not feasible, a treatment attempt is possible through alternative routes. We report 2 patients with DAVFs involving the anterior condylar confluence. The first patient presented with pulsatile tinnitus and hypoglossal nerve palsy, and was treated by a standard transjugular approach. The second patient presented with pulse-synchronous bruit. Following an unsuccessful attempt of the transjugular approach, the fistulous point was reached via the deep cervical vein and complete occlusion was achieved by coil deployment. Both patients had complete regression of symptoms. Endovascular therapy is the elective treatment for HC-DAVFs and the transjugular approach is the most commonly used. The deep cervical vein (DCV) can be an alternative transvenous route when the transjugular approach fails.

eCLIPs bifurcation remodeling system for treatment of wide neck bifurcation aneurysms with extremely low dome-to-neck and aspect ratios: a multicenter experience.

BACKGROUND: Wide necked bifurcation aneurysms (WNBA) are among the most difficult aneurysms to treat. Very low dome-to-neck (DTN) and aspect ratios provide an even greater challenge in the management of WNBAs. We present the safety and efficacy profile for endovascular clip system (eCLIPs) device in the treatment of this subset of WNBAs with very unfavorable morphologies. METHODS: In our case series, 24 patients treated at 12 international centers were taken from a larger prospective voluntary post-marketing registry of 65 patients treated with the eCLIPs device and coiling. Those who had WNBAs at either the carotid or basilar terminus with a DTN ratio <1.6 and aspect ratio <1.2 were included. Radiologic and clinical outcomes were assessed immediately after the procedure and at the latest follow-up. RESULTS: The eCLIPs device was successfully deployed in 23 cases (96%). One patient (4.2%) died due to guidewire perforation distal to the implant site. No other complications were documented. After a mean follow-up of 15.8 months (range 3-40 months), good radiologic outcomes (modified Raymond-Roy classification (MRRC) scores of 1 or 2) were documented in 20 of 21 patients (95%) with follow-up data. The lone patient with an MRRC score of 3 showed coiled compaction after incomplete neck coverage with the device. CONCLUSION: Our series of patients with aneurysms having adverse DTN and aspect ratios demonstrated that the eCLIPs device has a safety and efficacy profile comparable with currently available devices in the treatment of WNBAs.

Temporal variations of wall shear stress parameters in intracranial aneurysms--importance of patient-specific inflow waveforms for CFD calculations.

PURPOSE: To assess reliability of wall shear stress (WSS)calculations using computational fluid dynamics (CFD) dependent on inflow in internal carotid artery aneurysms (ICA). MATERIALS AND METHODS: 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 (Delta WSS), and oscillatory shear index(OSI, a measure of variation in the WSS direction) on the aneurysmal wall for both conditions. RESULTS: For all cases, mean relative difference (PS-ID) of WSS () was -15% (range -32% to 11%). Mean Delta WSS 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. CONCLUSION: 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.

Dural Arteriovenous Fistula of the Vein of Trolard Mimicking a Cavernous Sinus Fistula.

BACKGROUND: Arteriovenous fistulas (AVFs) involving the cavernous sinus usually become clinically apparent due to eye symptoms. Although rare, the same symptoms can be associated with AVFs located remote from the cavernous sinus when the shunt drains into its tributaries. We report the unusual case of a dural AVF in which such communication was not immediately obvious from the diagnostic angiogram. CASE DESCRIPTION: A 61-year-old male presented with increasing lid swelling, proptosis, and redness of the right eye for 1 month. Digital subtraction angiography showed no evidence of a cavernous sinus fistula but revealed a dural AVF between the right middle meningeal artery and the vein of Trolard. The fistula had a minor drainage through a small superficial middle cerebral vein toward the middle cranial fossa. Late venous-phase images eventually revealed faint opacification of the right cavernous sinus and superior ophthalmic vein. Endovascular treatment was performed by transarterial embolization with complete occlusion of the AVF obtained after 2 sessions. CONCLUSIONS: Dural AVFs involving cortical veins may cause atypical symptoms suggesting a cavernous sinus fistula due to remote venous drainage. Understanding venous anatomy helps to correlate vascular pathology and clinical symptoms and thus allows efficient and safe treatment.