Dangerous extracranial-intracranial anastomoses and supply to the cranial nerves: vessels the neurointerventionalist needs to know

Endovascular treatment of chronic subdural hematoma in a dual-trained neurosurgical unit: Results and proposal of a randomized controlled trial protocol

INTRODUCTION

Chronic subdural hematoma (cSDH) is a prevalent neurosurgical condition with an increasing incidence due to the rising life expectancy and the widespread use of anticoagulant and antiplatelet therapies. Insights into the inflammatory origins of cSDH led to the exploration of Middle Meningeal Artery (MMA) embolization as a therapeutic strategy. In recent years the endovascular treatment of MMA has gained momentum. Herein we present the initial experience of a dual trained neurovascular unit implementing this therapeutic technique.

METHODS

This single-center, prospective pilot study aimed to evaluate the feasibility, safety, and efficacy of MMA embolization in the treatment of cSDH. Following ethical approval and informed consent, demographic, clinical, and radiological data were collected. Patients requiring emergent surgical treatment were excluded. The study focused on assessing clinical outcomes, including the Modified Rankin Score (mRS) and volumetric analysis of cSDH, before and after embolization.

RESULTS

Fifteen patients underwent MMA embolization, with a predominance of males (80%) and a mean age of 72.4 years. The most common presenting symptom was headache (53.3%). The average hospital stay was 3.9 days. Various embolization techniques were employed, with DMSO-EVOH being the most frequent. All procedures were successfully conducted without complications. Although not statistically significant, trends suggested better outcomes in patients with homogeneous cSDH on the CT scan, displaying the cotton wool sign on angiography and treated with EVOH-DMSO.

CONCLUSION

MMA embolization for cSDH demonstrates promise as a safe and effective treatment, potentially reducing the need for surgical intervention and recurrence rates. This study lays the groundwork for a larger, randomized controlled trial which protocol is herein presented.

Microsurgical treatment for superior petrosal sinus dural arteriovenous fistulas

Superior petrosal sinus (SPS) dural arteriovenous fistulas (DAVFs) are a commonly encountered type of tentorial DAVF that occasionally requires microsurgical intervention. This study aims to analyze the tributaries of the superior petrosal vein (SPV) observed intraoperatively, their association with clinical symptoms, and venous drainage patterns. This retrospective study reviewed 34 consecutive patients with SPS DAVFs who underwent microsurgical treatment at a single institution between 2014 and 2022. The cohort had a mean age of 52.8 ± 11.8 years, with 85.3% (29/34) being male. Predominant symptoms included venous hypertensive myelopathy (VHM) (55.9%) and intraparenchymal or subarachnoid hemorrhage (23.5%). Standard retrosigmoid approach was used to ligate 94.1% (32/34) of the lesions, resulting in immediate complete fistula occlusion for all patients. Supratentorial venous drainage patterns were associated with a higher incidence of intracranial hemorrhage and venous varix (P = 0.047). Infratentorial drainage patterns were more frequently linked with VHM-related symptoms (P<0.001). Patients presenting VHM-related symptoms showed a higher prevalence of drainage through the vein of the cerebellopontine fissure (VCPF) (P = 0.01), while those with intracranial hemorrhage symptoms exhibited a higher prevalence of pontotrigeminal vein (PTV) drainage (P = 0.033) in their DAVFs. Endovascular management of SPS DAVFs carries inherent risks. Surgical treatment via standard retrosigmoid craniotomy offers favorable clinical outcomes with high rates of cure. In cases featuring infratentorial venous drainage, the predominant arterialized tributary of the SPV was the VCPF, commonly associated with VHM-related symptoms. Conversely, in cases with supratentorial venous drainage, the predominant arterialized SPV tributary was the PTV, often associated with intracranial hemorrhage symptoms.

Rare neurovascular variants that you probably have not seen before

BACKGROUND

Recognition of neurovascular variants is crucial for safe endovascular and neurosurgical interventions. We aim to review and highlight various uncommon neurovascular variants and anomalies with a discussion of their relevant embryology and pathology.

METHODS

A retrospective review of a prospectively maintained neurovascular database was performed to identify uncommon neurovascular variants and anomalies. A pictorial review of these neurovascular findings is provided along with relevant embryological development, clinical significance, and potential pathological associations.

RESULTS

A pictorial review of selected neurovascular variants and anomalies is presented. These entities, divided between intra- and extra-cranial findings, include infra-optic origin of the anterior cerebral artery, meningo-ophtalmic artery, duplicated posterior cerebral artery, duplicate middle cerebral artery (MCA), MCA fenestration, twig-like MCA, pure arterial malformation, corkscrew basilar artery, persistent hypoglossal artery, persistent trigeminal artery and its variants, direct branches from the common carotid and cervical internal carotid arteries (ICA) (ascending pharyngeal artery from the ICA, thyroidal arteries from the CCA/brachiocephalic, arteria thyroidea ima), and extra-cranial carotid fenestration. The angiographic findings of these entities are presented with relevant 3D reconstruction and multimodal cross-sectional imaging correlation when available.

CONCLUSIONS

This pictorial review highlights uncommon neurovascular variants and anomalies that neuroradiologists, interventionalists, and neurosurgeons should be aware of for accurate diagnosis and safe interventions.

Traumatic occipital artery pseudoaneurysm: Case report, anatomical considerations, and literature review

We describe a case of a 22-year-old man with a traumatic occipital artery pseudoaneurysm revealed by a painful expanding neck hematoma after a penetrating knife injury. A neuroendovascular consultation was requested after a computed tomography angiogram showed active pseudoaneurysm bleeding. Anatomical considerations of the upper cervical region including dangerous anastomosis between the vertebral and internal carotid artery are discussed, illustrating how this impacted our treatment strategy. We also discuss other treatment modalities after a thorough literature review of traumatic occipital artery pseudoaneurysms.

Carotid Cavernous Fistula

Carotid cavernous fistulae (CCFs) are arteriovenous shunts involving the cavernous sinus. CCFs are defined as direct or indirect. Direct CCFs are treated by deconstructive or reconstructive techniques depending on whether the affected internal carotid artery is required to perfuse the ipsilateral cerebral hemisphere, as determined by a balloon test occlusion. Indirect CCFs, or dural fistulae of the cavernous sinus wall, are most often treated with transvenous embolization. Stereotactic radiosurgery is reserved for cases of indirect CCFs that are not completely obliterated by embolization. Overall, cure rates are high with relatively low complication rates.

The Influence of Coagulopathy on Radiographic and Clinical Outcomes in Patients Undergoing Middle Meningeal Artery Embolization as Standalone Treatment for Non-acute Subdural Hematomas

Middle meningeal artery embolization (MMAE) is emerging as a safe and effective standalone intervention for non-acute subdural hematomas (NASHs); however, the risk of hematoma recurrence after MMAE in coagulopathic patients is unclear. To characterize the impact of coagulopathy on treatment outcomes, we analyzed a multi-institutional database of patients who underwent standalone MMAE as treatment for NASH. We classified 537 patients who underwent MMAE as a standalone intervention between 2019 and 2023 by coagulopathy status. Coagulopathy was defined as use of anticoagulation/antiplatelet agents or pre-operative thrombocytopenia (platelets <100,000/μL). Demographics, pre-procedural characteristics, in-hospital course, and patient outcomes were collected. Thrombocytopenia, aspirin use, antiplatelet agent use, and anticoagulant use were assessed using univariate and multivariate analyses to identify any characteristics associated with the need for rescue surgical intervention, mortality, adverse events, and modified Rankin Scale score at 90-day follow-up. Propensity score-matched cohorts by coagulopathy status with matching covariates adjusting for risk factors implicated in surgical recurrence were evaluated by univariate and multivariate analyses. Minimal differences in pre-operative characteristics between patients with and those without coagulopathy were observed. On unmatched and matched analyses, patients with coagulopathy had higher rates of requiring subsequent surgery than those without (unmatched: 9.9% vs. 4.3%; matched: 12.6% vs. 4.6%; both p < 0.05). On matched multivariable analysis, patients with coagulopathy had an increased odds ratio (OR) of requiring surgical rescue (OR 3.95; 95% confidence interval [CI] 1.68-9.30; p < 0.01). Antiplatelet agent use (ticagrelor, prasugrel, or clopidogrel) was also predictive of surgical rescue (OR 4.38; 95% CI 1.51-12.72; p = 0.01), and patients with thrombocytopenia had significantly increased odds of in-hospital mortality (OR 5.16; 95% CI 2.38-11.20; p < 0.01). There were no differences in follow-up radiographic and other clinical outcomes in patients with and those without coagulopathy. Patients with coagulopathy undergoing standalone MMAE for treatment of NASH may have greater risk of requiring surgical rescue (particularly in patients using antiplatelet agents), and in-hospital mortality (in thrombocytopenic patients).

A primer to vascular anatomy of the brain: an overview on anterior compartment

PURPOSE

Knowledge of neurovascular anatomy is vital for neurosurgeons, neurologists, neuro-radiologists and anatomy students, amongst others, to fully comprehend the brain's anatomy with utmost depth. This paper aims to enhance the foundational knowledge of novice physicians in this area.

METHOD

A comprehensive literature review was carried out by searching the PubMed and Google Scholar databases using primary keywords related to brain vasculature, without date restrictions. The identified literature was meticulously examined and scrutinized. In the process of screening pertinent papers, further articles and book chapters were obtained through analysis and additional assessing of the reference lists. Additionally, four formalin-fixed, color latex-injected cadaveric specimens preserved in 70% ethanol solution were dissected under surgical microscope (Leica Microsystems Inc, 1700 Leider Ln, Buffalo Grove, IL 60089 USA). Using microneurosurgical as well as standard instruments, and a high-speed surgical drill (Stryker Instruments 1941 Stryker Way Portage, MI 49002 USA). Ulterior anatomical dissection was documented in microscopic images.

RESULTS

Encephalic circulation functions as a complex network of intertwined vessels. The Internal Carotid Arteries (ICAs) and the Vertebral Arteries (VAs), form the anterior and posterior arterial circulations, respectively. This work provides a detailed exploration of the neurovascular anatomy of the anterior circulation and its key structures, such as the Anterior Cerebral Artery (ACA) and the Middle Cerebral Artery (MCA). Embryology is also briefly covered, offering insights into the early development of the vascular structures of the central nervous system. Cerebral venous system was detailed, highlighting the major veins and tributaries involved in the drainage of blood from the intracranial compartment, with a focus on the role of the Internal Jugular Veins (IJVs) as the primary, although not exclusive, deoxygenated blood outflow pathway.

CONCLUSION

This work serves as initial guide, providing essential knowledge on neurovascular anatomy, hoping to reduce the initial impact when tackling the subject, albeit the intricate vasculature of the brain will necessitate further efforts to be conquered, that being crucial for neurosurgical and neurology related practice and clinical decision-making.

Occult middle meningeal artery to middle cerebral artery anastomosis associated with prior trauma

The report describes a patient who presented with traumatic right temporoparietal calvarial fracture with chronic right subdural haematoma who underwent right middle meningeal artery embolisation with n-BCA during which direct filling of an anterior temporal branch of the middle cerebral artery was observed.

Middle Meningeal Artery Embolization for Management of Chronic Subdural Hematoma

Chronic subdural hematoma (CSDH) is a prevalent medical condition with potentially severe consequences if left untreated. While surgical removal has traditionally been the standard approach for treatment, middle meningeal artery (MMA) embolization has emerged as a promising minimally invasive alternative to reduce recurrences. This comprehensive review provides the general radiology community with an overview of MMA embolization as a therapeutic option for managing CSDH. The authors base their insights on existing evidence and their institutional experience. This overview encompasses the pathophysiology of CSDH as well as the potential advantages and limitations, safety profile, and potential complications of MMA embolization as compared with surgical treatment. The imaging findings seen before and after MMA, as well as insights into the procedural techniques used at the authors' institution, are described. On the basis of reports in the current literature, MMA embolization appears to be a safe and effective therapeutic option for managing CSDH, especially in patients who are unsuitable for surgery or at risk for recurrence. Nonetheless, further research is needed to validate these findings. Results from ongoing clinical trials hold promise for future validation and the establishment of scientific evidence. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material. See the invited commentary by Chatterjee in this issue.

Ruptured pial-pial collateral aneurysm associated with left internal carotid artery occlusion: nuances of surgical management. Illustrative case

BACKGROUND

Carotid occlusion often leads to the formation of a collateral network. On rare occasions, due to hemodynamic influence, aneurysms can occur. Here, the authors describe a 69-year-old male presenting with intracerebral hemorrhage secondary to a ruptured aneurysm within such a network.

OBSERVATIONS

The patient presented to the emergency department with an altered level of consciousness. Imaging showed a left temporal lobe hemorrhage extending into the ventricle, subdural hematoma, and evidence of contrast extravasation. Digital subtraction angiography revealed an occluded left internal carotid artery with the left middle cerebral artery territory reconstituted by flow through an external carotid artery-internal carotid artery anastomosis. The latter was formed by the superficial temporal artery-superior orbital artery, as well as pial-pial collaterals from the posterior temporal artery. Notably, a 4-mm aneurysm arising from the pial-pial collateral network was identified. Surgical intervention involved a left temporal craniectomy and aneurysm excision, with special attention paid to preserving the anastomotic flow through the superficial temporal artery.

LESSONS

This case underscores the importance of recognizing and preserving collateral vascular pathways in cases of carotid occlusion with an associated aneurysm. It emphasizes the necessary balance between managing aneurysm risk and maintaining cerebral perfusion, highlighting the need for careful preoperative planning and intraoperative caution.

Simple coiling of middle meningeal artery embolization for chronic subdural hematoma: An inverse probability of treatment weighting matched cohort study

BACKGROUND

Middle meningeal artery embolization (MMAE) for chronic subdural hematoma (CSDH) has gained much attention in recent years. However, unintended embolization may occur when employing liquid embolic agents or particles. We present our clinical experience in simple coiling of MMAE to manage CSDH.

METHODS

Patients underwent either surgical evacuation or MMAE with simple coiling for CSDH were reviewed. Clinical and radiographic outcomes were assessed at admission, 1-month, and 6-month intervals. Two treatment groups were matched with inverse probability of treatment weighting.

RESULTS

One hundred twelve patients were included, with 27 patients in MMAE group and 87 patients in surgery group. In MMAE group, significant reductions were observed in hematoma width (admission vs. 1-month, 2.04 [1.44-2.60] cm vs. 0.62 [0.37-0.95] cm, p < 0.001). The adjusted odds ratio (aOR) of surgical rescue rate (0.77 95%CI 0.13-4.47, p = 0.77), hematoma reduction (>50%) (0.21 95%CI 0.04-1.07, p = 0.06), and midline shift improvement rate (3.22, 95%CI 0.84-12.4, p = 0.09) had no substantial disparities between two groups at 1-month follow-up. In addition, no significant difference was noted between two groups in terms of hematoma reduction (>50%) at 6-month follow-up (aOR 1.09 95%CI 0.32-3.70, p = 0.89). No procedure-related complications were found in MMA embolization group.

CONCLUSION

Simple coiling for MMA had comparable outcomes with surgical evacuation for CSDH. Our findings suggest that simple coiling can be an alternative choice for liquid agents or particles in MMA embolization for CSDH with acceptable safety.

Endovascular treatment for sphenoidal region dural arteriovenous fistula

Sphenoidal region dural arteriovenous fistulas (DAVFs) are rare. Endovascular treatment (EVT) is an effective treatment approach. However, understanding and performing EVT for sphenoidal region DAVFs are difficult and challenging. Therefore, we performed a review to explore this issue further. In this review, we discuss the dural feeders and venous structures of the sphenoidal region, the angioarchitecture of sphenoidal region DAVFs, the role and principle of EVT, various EVT techniques, and the prognosis and complications associated with EVT. We found that various EVT techniques, including transarterial embolization (TAE), retrograde transvenous embolization (TVE), and direct puncture EVT, can be used to treat sphenoidal region DAVFs. TAE represents the most commonly utilized approach. TVE and direct puncture EVT should be limited to highly selective cases. EVT must penetrate the fistula and very proximal venous recipient pouch with a liquid embolic agent or coil the fistula point to have a complete curative effect. Successful EVT can lead to the obliteration of sphenoidal region DAVFs and a good clinical outcome. However, these complications cannot be neglected.

Middle cranial fossa non-cavernous sinus dural arteriovenous fistulas: 20 years of experience

Non-cavernous sinus (CS) dural arteriovenous fistulas (DAVFs) involving the sphenoid bone are rare entities that are easily confused with one another due to the complex structure and high variability of the venous system around the middle cranial fossa. We present a large retrospective study on middle cranial fossa non-CS DAVFs and review the literature on DAVF treatment in this location as well as relative anatomy. 15 patients had DAVFs involving the lesser sphenoid wing and 11 patients had DAVFs involving the greater sphenoid wing. Six patients presented with intracranial hemorrhage or subarachnoid hemorrhage (23.1%, 6/26). The most common symptoms were eye symptoms (38.5%, 10/26). Nineteen patients were treated with trans-arterial embolization (TAE) using liquid embolic agents and two patients were treated with transvenous embolization (TVE) using Onyx or in combination with coils. Surgical disconnection of the drainage veins was performed in five patients, with three cases experiencing unsuccessful TAE. Anatomic cure was achieved in 92.3% of the patients (24/26). Twelve patients had DSA and clinical follow-up from 3 to 27 months. There was one recurrence (8.3%) of the fistula in the patient two months after the initial complete occlusion. The majority of patients can be cured endovascularly. Laterocavernous sinus DAVFs may not be embolized by transvenous approach via the cavernous sinus because there is often no connection between them in most patients. A small percentage of patients may require surgical ligation to be cured.

Middle meningeal artery embolization without surgical evacuation for chronic subdural hematoma: a single-center experience of 209 cases

Background

Middle meningeal artery (MMA) embolization is a minimally invasive treatment option for new and recurrent chronic subdural hematomas (cSDH).

Objective

To examine the safety and efficacy profile of MMA embolization without surgical evacuation for cSDH patients.

Methods

A single-center retrospective study of patients with cSDHs treated by MMA embolization was undertaken. Patient demographics, hematoma characteristics, procedural details, and clinical and radiological outcomes were collected. The primary outcome was the need for retreatment, and the secondary outcomes were at least a 50% reduction in the maximum width of cSDH on the last CT imaging, complications, and an improvement in the modified Rankin scale (mRS) score. All results were presented as descriptive statistics.

Results

A total of 209 MMA embolizations were successfully performed on 144 patients. Polyvinyl alcohol particles were the primary embolization agent in all procedures. Of the total of 206 cSDH, the median maximum width at pre-intervention and last follow-up were 12 and 3 mm, respectively, and the median reduction percentage was 77.5%, with a >50% improvement observed in 72.8% at the last follow-up imaging. A total of 13.8% of patients needed retreatment for recurrent, refractory, or symptomatic hematomas after embolization. The mRS score improved in 71 (49.3%) patients. Of 144 patients, 4 (2.8%) experienced complications related to the procedure, and 12 (8.4%) died during follow-up due to causes unrelated to the MMA embolization procedures.

Conclusion

This study supports the fact that MMA embolization without surgical evacuation is a safe and effective minimally invasive option for the treatment of cSDHs.

Advances in Imaging Modalities for Pediatric Brain and Spinal Cord Tumors

BACKGROUND

Neuroimaging has evolved from anatomical imaging toward a multi-modality comprehensive anatomical and functional imaging in the past decades, important functional data like perfusion-weighted imaging, permeability imaging, diffusion-weighted imaging (DWI), and diffusion tensor imaging (DTI), tractography, metabolic imaging, connectomics, event-related functional imaging, resting state functional imaging, and much more is now being offered.

SUMMARY

Precision diagnostics has proven to be essential for precision treatment. Many minimal invasive techniques have been developed, taking advantage of digital subtraction angiography and interventional neuroradiology. Furthermore, intraoperative CT and/or MRI and more recently MR-guided focused ultrasound have complemented the diagnostic and therapeutic armamentarium.

KEY MESSAGES

In the current manuscript, we discuss standard imaging sequences including advanced techniques like DWI, DTI, susceptibility-weighted imaging, and 1H magnetic resonance spectroscopy, various perfusion weighted imaging approaches including arterial spin labeling, dynamic contrast enhanced imaging, and dynamic susceptibility contrast imaging. Pre-, intra, and postoperative surgical imaging including visualize imaging will be discussed. The value of connectomics will be presented for its value in neuro-oncology. Minimal invasive therapeutic possibilities of interventional neuroradiology and image-guided laser ablation and MR-guided high-intensity-focused ultrasound will be presented for treatment of pediatric brain and spinal cord tumors. Finally, a comprehensive review of spinal cord tumors and matching neuropathology has been included.

Head and Neck Arteriovenous Malformations: Clinical Manifestations and Endovascular Treatments

Arteriovenous malformations (AVMs) are vascular malformations that present high-flow direct communication between the arteries and veins, not involving the capillary beds. They can be progressive and lead to various manifestations, including abnormal skin or mucosal findings, ischemia, hemorrhage, and high-output heart failure in severe cases. AVMs often involve the head and neck region. Head and neck AVMs can present region-specific clinical manifestations, angioarchitecture, and complications, especially in cosmetic appearance and ingestion, respiratory, and neuronal functions. Therefore, when planning endovascular treatment of head and neck AVMs, physicians should consider not only the treatment strategy but also the preservation of the cosmetic appearance and critical functions. Knowledge of the functional vascular anatomy as well as treatment techniques should facilitate a successful management. This review summarizes AVMs' clinical manifestations, imaging findings, treatment strategy, and complications.

Endovascular Embolization of Intracranial Meningiomas

Although benign in histology, the hypervascularity and skull base location of meningiomas can make them surgically challenging lesions. Preoperative endovascular embolization with superselective microcatheterization of vascular pedicles may be efficacious in decreasing intraoperative transfusion requirements with equivocal postoperative functional benefit. The potential benefits of preoperative embolization should be weighed against the risks of ischemic complications. Appropriate patient selection is critical. All patients should be monitored closely postembolization, and a course of steroids can be considered to minimize neurologic symptoms.

[Endovascular Treatment for Head and Neck Trauma]

Trauma to the head and neck region can have serious consequences for vital organs such as the brain, and injuries to blood vessels can cause permanent neurological damage or even death. Thus, prompt treatment of head and neck vessels is crucial. Although the level of evidence is moderate, an increasing amount of research indicates that endovascular treatments can be a viable alternative to traditional surgery or medical management. Embolization or reconstructive endovascular procedures can significantly improve patient outcomes. This article provides an overview of various endovascular options available for specific clinical scenarios, along with examples of cases in which they were employed.

Hybrid treatment of large extracranial carotid artery aneurysm

An extracranial carotid artery aneurysm (ECAA) is a rare condition. The major complications are rupture and thromboembolism. Therefore, treatment is generally recommended. We report the case of a young woman affected by an ECAA, with a cervical pulsatile mass. A multidisciplinary evaluation was performed to ensure the best treatment in terms of safety and efficacy, and the patient underwent hybrid treatment. The 6-month computed tomography angiogram revealed patency of the carotid artery stents and the venous graft, in the absence of any relevant complications. An ECAA is a serious clinical condition. The treatment is challenging, and a multidisciplinary evaluation and precise planning are recommended.

Middle Meningeal Artery Embolization in the Management of Chronic Subdural Hematoma: a Comprehensive Review of Current Literature

PURPOSE OF REVIEW

Chronic subdural hematoma (cSDH) is a common intracranial hemorrhagic disorder with a high incidence rate among the elderly. While small, asymptomatic cSDH may resolve spontaneously, surgical intervention has been the treatment of choice for larger, symptomatic cases. Surgical evacuation of cSDH may be associated with high rates of recurrence, and even asymptomatic cSDH cases tend to progress. Over the last few years, middle meningeal artery (MMA) embolization has proven to be a safe non-invasive treatment of choice with favorable outcomes and a low recurrence rate. The ensuing paper discusses current treatment modalities for cSDH and reviews existing literature on the anatomy of MMA and its embolization as a treatment option for cSDH.

RECENT FINDINGS

Recent studies show that traumatic head injury leading to subdural hemorrhage can induce neovascularization that may initiate a cycle of recurrent subdural hematoma. Distal branches of MMA supply blood to the dural layers. Several studies have revealed that embolization of the MMA can stop the neovascularization process and blood flow. In addition, patients who underwent MMA embolization had a significantly quicker brain re-expansion and lower recurrence rate. Although the management of cSDH is still very much a dilemma, recent research findings bring MMA embolization to light as a promising treatment alternative and adjunctive therapy.

Transcatheter arterial embolization of the subclavian and axillary artery branches for hemorrhage control

OBJECTIVE

To evaluate the effectiveness and safety of transcatheter arterial embolization (TAE) of the branches of the subclavian and axillary arteries for hemorrhage control.

METHODS

Between January 2015 and June 2022, 35 TAE procedures were performed for hemorrhage from the branches of the subclavian and axillary arteries in 34 patients (22 men, 12 women; 1 male underwent TAE twice; mean age = 76 years). Pre-TAE CT showed hematomas in the chest (n = 25) and abdominal walls (n = 3), shoulder (n = 2), and lower neck (n = 2). CT showed hemothorax in eight cases. Angiographic findings, embolization technique, and technical and clinical success of TAE were retrospectively assessed in all cases.

RESULTS

TAE was performed by transfemoral (n = 16), transradial (n = 12), and transbrachial (n = 7) approaches. Angiography revealed contrast media extravasation or pseudoaneurysms in 32 cases (91.4%). The most commonly embolized arteries were the internal thoracic (n = 12), lateral thoracic (n = 6), and thoracoacromial (n = 6) arteries. Technical and clinical success rates were 100 and 85.7%, respectively. A complication (skin necrosis after injection of the liquid embolic agent) developed in only one patient (2.9%) and was conservatively managed.

CONCLUSION

TAE is an effective and safe treatment for hemorrhage from the branches of the subclavian and axillary arteries.

ADVANCES IN KNOWLEDGE

Transfemoral approach has been used for TAE of the branches of the subclavian and axillary artery. Transradial and transbrachial approaches can also be considered.

Successful Endovascular Treatment of a Traumatic Cervical Arteriovenous Fistula After a Carotid Paraganglioma Resection: A Case Report

Traumatic cervical arteriovenous fistulas are rare, accounting for only 4% of all arteriovenous fistulas. They can be caused by penetrating, or rarely, blunt trauma, resulting in high-pressure arterial blood draining directly into a vein, decreasing distal perfusion. They are seldom reported as a complication of a carotid paraganglioma surgical resection. Historically, arteriovenous fistulas were treated initially conservatively, after that, surgically; nowadays, endovascular treatment, when feasible, is the preferred method as it offers advantages over surgery. This case report describes a rare traumatic cervical arteriovenous fistula that developed after a carotid paraganglioma resection and was successfully treated using coils and Onyx embolic agent via endovascular embolization. After successful embolization, the patient had a smooth recovery and remained stable. In conclusion, vascular injury seems to be the only constant in all acquired cervical arteriovenous fistulas independent of the trauma mechanism; and endovascular treatment, when feasible, is preferred over surgery as it offers superior advantages.

Bilateral visual loss after selective artery embolization in the neck for hemorrhage of malignant tumor

INTRODUCTION AND IMPORTANCE

Currently, selective arterial embolization (SAE) has been widely applied for the treatment of many diseases due to its minimal invasiveness. But the complications caused by SAE can be serious.

CASE PRESENTATION

Here, we report a case of a patient who experienced bilateral blindness 4 h after selective arterial embolization (SAE). A 67-year-old man, with a 13-year history of nasopharyngeal carcinoma, was admitted to our hospital for nasopharyngeal carcinoma hemorrhage and was scheduled for SAE. The patient did not have any thromboembolic complications. His had a platelet count of 43 × 109/L (range 150-400 × 109/L) and a prothrombin time (PT) of 9.3 s. The surgery was completed under local anesthesia. However, 4 h after the surgery, the patient complained of visual loss. We performed a fundoscopy examination, which showed bilateral ophthalmic artery embolism.

CLINICAL DISCUSSION

Bilateral ophthalmic artery embolism is fatal to vision. When this occurs, it would be difficult to save the eyes. So, the relevant selection of the optimal properties of the used PVA and coil embolization materials is important during SAE.

CONCLUSION

It is important to improve the existing understanding of the involvement various vessels during embolization of head and neck tumors. Furthermore, special and paramount attention is to be paid to the specific pre-operative angio-architecture, particular patient condition, and the prudent choice of embolic material to prevent the occurrence of ectopic embolization.

Embolization in Juvenile Nasopharyngeal Angiofibroma Surgery: A Systematic Review and Meta-Analysis

OBJECTIVE

To compare outcomes of juvenile nasopharyngeal angiofibroma (JNA) resection between embolized and non-embolized cohorts, and between transarterial embolization (TAE) and direct puncture embolization (DPE).

DATA SOURCES

Per PRISMA guidelines, PubMed, Embase, Web of Science, Scopus, and Cochrane databases were searched for publications prior to or in 2021.

MATERIALS AND METHODS

Original English manuscripts investigating the resection of JNA with and without preoperative embolization were included. Embolization type, recurrence rate, complication rates, blood loss, and transfusions were extracted. Risk of bias was assessed by the Risk of Bias in Non-randomized Studies-of Interventions method.

RESULTS

There were 61 studies with 917 patients included. Preoperative embolization was performed in 79.3% of patients. Of those embolized, 75.8% (N = 551) underwent TAE and 15.8% (N = 115) underwent DPE. JNA recurrence in embolized patients was lower than in non-embolized patients (9.3% vs. 14.4%; odds ratio [OR]: 0.61, 95% confidence interval [CI]: 0.35, 1.06). DPE resulted in lower rates of disease recurrence (0% vs. 9.5%; OR: 0.066, 95% CI: 0.016, 0.272) and complications (1.8% vs. 21.9%; OR: 0.07, 95% CI: 0.02, 0.3) than TAE. A random effects Bayesian model was performed to analyze the difference in mean blood loss in 6 studies that included both embolized and non-embolized patients. This analysis showed a mean reduction in blood loss of 798 mL in the embolized group.

CONCLUSIONS

We found embolization decreases blood loss in JNA resection. DPE led to improved recurrence and complication rates when compared to TAE, but future prospective studies are needed to further evaluate which embolization technique can optimize outcomes in JNA.

LEVEL OF EVIDENCE

NA Laryngoscope, 2023.

Unilateral hard palate necrosis following gingival injections with hyaluronic acid

Hyaluronic acid (HA) injections into the oral mucosa have proven to be effective as a non-invasive method for the reconstruction of interproximal papillary defects in aesthetic areas. Despite being a minimally invasive and safe technique, certain side effects may occur after treatment.We report the first case of a patient with unilateral necrosis of the mucosa of the hard palate after HA filling in the maxillary anterior gingiva. Familiarity with these events and competent knowledge of the anatomy is essential to avoid complications, achieve and offer adequate treatment and good results to our patients.

Multimodal MRI diagnosis and transvenous embolization of a basicranial emissary vein dural arteriovenous fistula: A case report

A dural arteriovenous fistula (DAVF) is an abnormal linkage connecting the arterial and venous systems within the intracranial dura mater. A basicranial emissary vein DAVF drains into the cavernous sinus and the ophthalmic vein, similar to a cavernous sinus DAVF. Precise preoperative identification of the DAVF location is a prerequisite for appropriate treatment. Treatment options include microsurgical disconnection, endovascular transarterial embolization (TAE), transvenous embolization (TVE), or a combination thereof. TVE is an increasingly popular approach for the treatment of DAVFs and the preferred approach for skull base locations, due to the risk of cranial neuropathy caused by dangerous anastomosis from arterial approaches. Multimodal magnetic resonance imaging (MRI) can provide anatomical and hemodynamic information for TVE. The therapeutic target must be precisely embolized in the emissary vein, which requires guidance via multimodal MRI. Here, we report a rare case of successful TVE for a basicranial emissary vein DAVF, utilizing multimodal MRI assistance. The fistula had vanished, pterygoid plexus drainage had improved, and the inferior petrosal sinus had recanalized, as observed on 8-month follow-up angiography. Symptoms and signs of double vision, caused by abduction deficiency, disappeared. Detailed anatomic and hemodynamic assessment by multimodal MRI is the key to guiding successful diagnosis and treatment.

Preoperative Transarterial Embolization of Advanced Juvenile Nasopharyngeal Angiofibroma Using n-Butyl Cyanoacrylate: Case-Control Comparison with Microspheres

PURPOSE

To evaluate the efficacy and safety of transarterial embolization (TAE) with n-butyl cyanoacrylate (nBCA) for juvenile nasopharyngeal angiofibroma (JNA).

MATERIALS AND METHODS

A retrospective review was performed on patients with JNA who underwent TAE and endoscopic resection between 2020 and 2022. Patients embolized with nBCA were identified, and those embolized with microspheres were set as the control group. Data on demographics, symptoms, tumor characteristics, blood loss, adverse events, residual disease, and recurrence were collected, and case-control analysis was performed for the 2 groups. Differences in characteristics between the groups were tested using the Fisher exact and Wilcoxon tests. A generalized linear model (GLM) was used to analyze the univariate and multivariate influences on blood loss.

RESULTS

Twenty patients were included in this study: 13 in the microsphere group and 7 in the nBCA group. The median blood loss was 400 mL (interquartile range [IQR], 200-520 mL) in the nBCA group and 1,000 mL (IQR, 500-1,000 mL) in the microsphere group (P = .028). The GLM confirmed lower blood loss in the nBCA group (relative risk, 0.58 [0.41-0.83]; P = .01). A residual tumor was found in 1 patient in each group (7.7% vs 14.3%; P = 1.000). Recurrence was not observed in any patient. None of the patients experienced adverse events during embolization.

CONCLUSIONS

TAE of advanced JNA with nBCA glue is safe and effective and can significantly reduce intraoperative blood loss compared with microspheres.

Retrieval of N-Butyl-2-Cyanoacrylate Glue Migrated to the Vertebral Artery via Dangerous Anastomosis, Using the Stent-Retriever Aspiration Technique, during Dural Arteriovenous Fistula Embolization: A Case Report

Objective

We report a case of accidental N-butyl-2-cyanoacrylate (NBCA) glue migration into the vertebral artery (VA) via dangerous anastomosis during transarterial embolization (TAE) for transverse sinus (TS)-dural arteriovenous fistula (DAVF), which was rescued by mechanical retrieval using a stent retriever and aspiration devices.

Case Presentation

A 49-year-old right-handed female patient was admitted to our hospital with motor aphasia. MRI revealed congestion in the left temporal and occipital lobes, involving a small hemorrhage. DSA revealed a DAVF complicated by a sinus thrombus in the left TS. The DAVF was mostly fed by the left occipital artery (OA) and drained into the cortical veins of the temporal and occipital lobes through the patent part of the sinus. TAE was performed via the left OA with low-concentration NBCA. However, NBCA glue migrated into the left VA through a dangerous anastomosis, and a left VA angiogram revealed severe VA stenosis and floating NBCA glue. There was a fragile attachment of the NBCA glue to the arterial inner wall; therefore, we successfully retrieved the NBCA glue with a stent retriever and aspiration devices without complications. Finally, TAE was performed using another feeder, and the DAVF was completely obliterated.

Conclusion

TAE using NBCA is useful for the treatment of DAVF; however, it should be noted that there is a risk of migration via potential anastomotic routes. Low-concentration NBCA glue can be retrieved using these devices in limited cases.

Endovascular embolisation of external carotid artery system haemorrhage in radiated nasopharyngeal carcinoma

PURPOSE

To review the effectiveness and safety of embolisation in managing haemorrhage from the external carotid artery (ECA) system in radiated nasopharyngeal carcinoma (NPC) patients.

METHODS

Radiated NPC patients who presented with severe oronasal bleeding and underwent digital subtraction angiography that excluded blowouts from the internal carotid artery from 2011 to 2021 were reviewed. Those who subsequently underwent embolisation of the ECA system were analysed for technical success rate, post-embolisation re-bleeding rate and complications.

RESULTS

Seventeen embolisations were performed in fifteen patients during the 10-year period. The technical success rate was 100%, however the early haemostatic rate (no re-bleed within 7 days of embolisation) was 70.6% (12/17) and the overall long-term haemostatic rate was 58.8% (10/17). The re-bleed rates of targeted and empiric embolisations were 33.3% (3/9) and 50.0% (4/8), respectively. The re-bleed rates with liquid agents, coils and particles were 0% (0/7), 33.3% (1/3) and 85.7% (6/7), respectively. Amongst the embolisations utilising liquid agents, 71.4% (5/7) were targeted, distal embolisations. All re-bleeds underwent surgical ligation or repeat embolisation; half of them further experienced recurrent bleeding. There were no significant complications with embolisation.

CONCLUSION

Although embolisation of the ECA system in NPC has a high technical success rate and is safe, re-bleeding appears to be common. Targeted, distal embolisation with liquid embolics appear to have good haemostatic effect. Clinicians should be aware that patients may need repeated procedures to secure haemostasis.

Transcatheter arterial embolization for traumatic injury to the pharyngeal branch of the ascending pharyngeal artery: Two case reports

BACKGROUND

The ascending pharyngeal artery (APhA) comprises the pharyngeal trunk (PT) and neuromeningeal trunk. The PT feeds the nasopharynx and adjacent tissue, which potentially connects with the sphenopalatine artery (SPA), branched from the internal maxillary artery (IMA). Due to its location deep inside the body, the PT is rarely injured by trauma. Here, we present two cases that underwent transcatheter arterial embolization (TAE) of the PT of the APhA due to trauma and iatrogenic procedure.

CASE SUMMARY

Case 1 is a 49-year-old Japanese woman who underwent transoral endoscopy under sedation for a medical check-up. The nasal airway was inserted as glossoptosis occurred during sedation. Bleeding from the nasopharynx was observed during the endoscopic procedure. As the bleeding continued, the patient was referred to our hospital for further treatment. Contrast-enhanced computed tomography (CT) demonstrated extravasation in the nasopharynx originating from the right Rosenmuller fossa. TAE was performed and the extravasation disappeared after embolization. Case 2 is a 28-year-old Japanese woman who fell from the sixth floor of a building and was transported to our hospital. Contrast-enhanced CT demonstrated a complex facial fracture accompanying extravasation in the left pterygopalatine fossa to the nasopharynx. Angiography demonstrated an irregular third portion of the IMA. As angiography after TAE of the IMA demonstrated extravasation from the PT of the APhA, additional TAE to the artery was performed. The bleeding stopped after the procedure.

CONCLUSION

Radiologists should be aware that the PT of the APhA can be a bleeding source, which has a potential connection with the SPA.

The Vascular Architecture of Cavernous Sinus Dural Arteriovenous Fistula and Its Impact on Endovascular Treatment Approach Selection and Outcome

BACKGROUND

A cavernous sinus (CS) dural arteriovenous fistula (DAVF) is a form of abnormal arteriovenous communication that can be treated with endovascular embolization. Establishing an optimal access route should be based on vascular architecture. We reviewed 64 patients with CS-DAVF who underwent endovascular embolization and report the endovascular treatment approach selection and outcome.

METHODS

Clinical data were obtained from 64 patients with CS-DAVF who had been surgically treated at the authors' hospital between 2009 and 2022. Patients' medical records, imaging data, and follow-up outcomes were retrospectively analyzed.

RESULTS

All 64 patients (15 male, 49 female; mean age, 50 years) underwent CS-DAVF embolization. The most common symptoms were exophthalmos (39.1%), chemosis (35.9%), and headache (28.1%). On digital subtraction angiography images, 34.4% of the DAVFs were unilateral, and 82.8% were fed by both the external carotid artery and internal carotid artery. Of the patients' inferior petrosal sinuses (IPSs), 54.7% were nonopacified. The most common intravascular approaches included trans-IPS (37.5%) and trans-artery (28.1%) approaches. More than half of the CS-DAVFs were embolized by both coils and Onyx (62.5%). A total of 85.9% of the fistulas were completely embolized, and the follow-up rate was 76.6%. The modified Rankin Scale score was 0.9 ± 1.0.

CONCLUSIONS

The vascular architecture of CS-DAVF is closely related to endovascular treatment approach selection and outcome. Combined with the modified IPS recanalization technique, the trans-IPS approach is the safest and most effective approach. Dual microcatheter and balloon assistance techniques ensure the safety and completeness of embolization.

Vascular Safe Zones for Facial Soft Tissue Filler Injections

The number of soft tissue filler injections performed by aesthetic injectors has continued to increase over the last few years. To provide a high standard of safety and achieve individualized, reproducible, and long-lasting outcomes, aesthetic injectors must have a solid foundation in anatomy, facial biomechanics, rheology, and injection biomechanics. Adverse events associated with soft tissue filler injections can be severe, especially if the aesthetic injector unintentionally injects the soft tissue filler into the patient's arterial vascular circulation and the administered product reaches the arterial bloodstream. Although the face has a rich arterial vascular supply that may seem overwhelmingly complex, it can be broken down systematically according to its internal and external vascular territories. To provide guidance for aesthetic practitioners performing minimally invasive facial injections for aesthetic purposes, this narrative article will discuss the course, depth, and branching pattern of the facial arteries based on the most frequently injected anatomical regions. In this article, we focus on vascular safe zones rather than danger zones .

Bridging a Century-Old Problem: The Pathophysiology and Molecular Mechanisms of HA Filler-Induced Vascular Occlusion (FIVO)-Implications for Therapeutic Interventions

Biocompatible hyaluronic acid (HA, hyaluronan) gel implants have altered the therapeutic landscape of surgery and medicine, fostering an array of innovative products that include viscosurgical aids, synovial supplements, and drug-eluting nanomaterials. However, it is perhaps the explosive growth in the cosmetic applications of injectable dermal fillers that has captured the brightest spotlight, emerging as the dominant modality in plastic surgery and aesthetic medicine. The popularity surge with which injectable HA fillers have risen to in vogue status has also brought a concomitant increase in the incidence of once-rare iatrogenic vaso-occlusive injuries ranging from disfiguring facial skin necrosis to disabling neuro-ophthalmological sequelae. As our understanding of the pathophysiology of these injuries has evolved, supplemented by more than a century of astute observations, the formulation of novel therapeutic and preventative strategies has permitted the amelioration of this burdensome complication. In this special issue article, we review the relevant mechanisms underlying HA filler-induced vascular occlusion (FIVO), with particular emphasis on the rheo-mechanical aspects of vascular blockade; the thromboembolic potential of HA mixtures; and the tissue-specific ischemic susceptibility of microvascular networks, which leads to underperfusion, hypoxia, and ultimate injury. In addition, recent therapeutic advances and novel considerations on the prevention and management of muco-cutaneous and neuro-ophthalmological complications are examined.

Tumor Embolization through Meningohypophyseal and Inferolateral Trunks is Safe and Effective

BACKGROUND AND PURPOSE

Skull base tumors are commonly supplied by dural branches of the meningohypophyseal and inferolateral trunks. Embolization through these arteries is often avoided due to technical challenges and inherent risks; however, successful embolization can be a valuable surgical adjunct. We aimed to review the success and complications in our series of tumor embolizations through the meningohypophyseal and inferolateral trunks.

MATERIALS AND METHODS

We performed a retrospective review of patients with tumor treated with preoperative embolization at our institution between 2010 and 2020. We reviewed the following data: patients' demographics, tumor characteristics, endovascular embolization variables, and surgical results including estimated blood loss, the need for transfusion, and operative time.

RESULTS

Among 155 tumor embolization cases, we identified 14 patients in whom tumor embolization was performed using the meningohypophyseal (n = 13) or inferolateral (n = 4) trunk. In this group of patients, on average, 79% of tumors were embolized. No mortality or morbidity from the embolization procedure was observed in this subgroup of patients. The average estimated blood loss in the operation was 395 mL (range, 200-750 mL). None of the patients required a transfusion, and the average operative time was 7.3 hours.

CONCLUSIONS

Some skull base tumors necessitate embolization through ICA branches such as the meningohypophyseal and inferolateral trunks. Our series demonstrates that an effective and safe embolization may be performed through these routes.

Cerebral venous anatomy: implications for the neurointerventionalist

Meaningful contributions to neurointerventional practice may be possible by considering the dynamic aspects of angiography in addition to fixed morphologic information. The functional approach to venous anatomy requires integration of the traditional static anatomic features of the system-deep, superficial, posterior fossa, medullary veins, venous sinuses, and outflow routes into an overall appreciation of how a classic model of drainage is altered, embryologically, or pathologically, depending on patterns of flow-visualization made possible by angiography. In this review, emphasis is placed on balance between alternative venous networks and their redundancy, and the problems which arise when these systems are lacking. The role of veins in major neurovascular diseases, such as dural arteriovenous fistulae, arteriovenous malformations, pulsatile tinnitus, and intracranial hypertension, is highlighted, and deficiencies in knowledge emphasized.

Vascular Safe Zones for Facial Soft Tissue Filler Injections

The number of soft tissue filler injections performed by aesthetic injectors has continued to increase over the last few years. To provide a high standard of safety and achieve individualized, reproducible, and long-lasting outcomes, aesthetic injectors must have a solid foundation in anatomy, facial biomechanics, rheology, and injection biomechanics. Adverse events associated with soft tissue filler injections can be severe, especially if the aesthetic injector unintentionally injects the soft tissue filler into the patient's arterial vascular circulation and the administered product reaches the arterial bloodstream. Although the face has a rich arterial vascular supply that may seem overwhelmingly complex, it can be broken down systematically according to its internal and external vascular territories. To provide guidance for aesthetic practitioners performing minimally invasive facial injections for aesthetic purposes, this narrative article will discuss the course, depth, and branching pattern of the facial arteries based on the most frequently injected anatomical regions. In this article, we focus on vascular safe zones rather than danger zones.

Endovascular Management of Intracranial Dural AVFs: Transvenous Approach

In this third review article on the endovascular management of intracranial dural AVFs, we discuss transvenous embolization approaches. Transvenous embolization is increasingly popular and now the first-line approach for ventral dural AVFs involving the cavernous sinus and hypoglossal canal. In addition, transvenous embolization is increasingly used in lateral epidural dural AVFs in high-risk locations such as the petrous and ethmoid regions. The advantage of transvenous embolization in these locations is the ability to retrogradely embolize the draining vein and fistula while reducing the risk of ischemic cranial neuropathy or brain parenchymal infarction commonly feared from a transarterial approach. By means of coils ± ethylene-vinyl alcohol copolymer, transvenous embolization can achieve angiographic cure rates of 80%-90% in ventral locations. Potential complications include transient cranial neuropathy, neurologic deterioration due to venous outflow obstruction, and perforation while navigating pial veins. Transvenous embolization should be considered when dural AVFs arise in proximity to the vasa nervosum or extracranial-intracranial anastomoses.

Intracranial Flow Volume Estimation in Patients with Internal Carotid Artery Occlusion

(1) Background: Carotid artery occlusion (CAO) in population studies has a reported prevalence of about 6 per 100,000 people; however, the data may be underestimated. CAO carries a significant risk of stroke. Up to 15% of large artery infractions may be secondary to the CAO, and in 27−38% of patients, ischaemic stroke is a first presentation of the disease. The presence of sufficient and well-developed collateral circulation has a protective influence, being a good prognostic factor in patients with carotid artery disease, both chronic and acute. Understanding the mechanisms and role of collateral circulation may be very important in the risk stratification of such patients. (2) Materials and Methods: This study included 46 patients (mean age: 70.5 ± 6 years old; 15 female, mean age 68.5 ± 3.8 years old and 31 male, mean age 71.5 ± 6.7 years old) with unilateral or bilateral ICA occlusion. In all patients, a Doppler ultrasound (DUS) examination, measuring blood flow volume in the internal carotid artery (ICA), external carotid artery (ECA), and vertebral artery (VA), was performed. The cerebral blood flow (CBF) was compared to the previously reported CBF values in the healthy population >65 years old. (3) Results: In comparison with CBF values in the healthy population, three subgroups with CBF changes were identified among patients with ICA occlusion: patients with significant volumetric flow compensation (CBF higher than average + standard deviation for healthy population of the same age), patients with flow similar to the healthy population (average ± standard deviation), and patients without compensation (CBF lower than the average-standard deviation for healthy population). The percentage of patients with significant volumetric flow compensation tend to rise with increasing age, while a simultaneous decline was observed in the group without compensation. The percentage of patients with flow similar to the healthy population remained relatively unchanged. ICA played the most important role in volumetric flow compensation in patients with CAO; however, the relative increase in flow in the ICA was smaller than that in the ECA and VA. Compensatory increased flow was observed in about 50% of all patent extracranial arteries and was more frequently observed in ipsilateral vessels than in contralateral ones, in both the ECA and the VA. In patients with CAO, there was no decrease in CBF, ICA, ECA, and VA flow volume with increasing age. (4) Conclusions: Volumetric flow compensation may play an important predictive role in patients with CAO.

Embolization of Skull Base Meningiomas with Embosphere® Microspheres: Factors Predicting Treatment Response and Evaluation of Complications

OBJECTIVE

Preoperative embolization for intracranial meningiomas can cause tumor necrosis, reduce intraoperative blood loss, and facilitate surgery. This study aimed to evaluate the efficacy of tumor embolization using Embosphere® microspheres for skull base meningiomas and analyze post-embolization plain computed tomography (CT) and magnetic resonance imaging (MRI) scans to identify findings that could potentially predict treatment response.

METHODS

Between April 2014 and April 2020, 80 patients with skull base meningiomas presenting at our medical center underwent embolization with Embosphere® microspheres. The effects of tumor embolization were evaluated through a comparison of post-embolization plain CT and contrast-enhanced MRI.

RESULTS

A total of 143 vessels (102/108 external carotid artery branches; 41/65 internal carotid artery branches) from 80 skull base meningiomas were embolized with Embosphere® microspheres. Microspheres 100-300 μm in size were used in two cases, microspheres 300-500 μm in size were used in 12 cases, and microspheres 500-700 μm in size were used in 66 cases. Post-embolization contrast-enhanced MRI showed reductions in enhancing lesions within the tumor in 55/80 cases. Post-embolization plain CT scans showed high-density lesions within the tumor in 41/55 cases. Thus, reductions in enhancing lesions on post-embolization contrast-enhanced MRI were statistically significantly associated with the presence of high-density lesions on post-embolization plain CT (P<0.001). Embolization-related neurological complications occurred in three cases.

CONCLUSIONS

Embosphere® microspheres are user friendly and effective embolic materials for the embolization of skull base meningiomas. Post-embolization contrast-enhanced MRI and plain CT findings may be useful for evaluating the effects of tumor embolization.

Endovascular Management of Intracranial Dural Arteriovenous Fistulas: Transarterial Approach

In this second of 3 review articles on the endovascular management of intracranial dural AVFs, we discuss transarterial treatment approaches. The treatment goal is to occlude the fistulous point, including the most distal portion of the arterial supply together with the most proximal portion of the draining vein (ie, the "foot" of the vein), which can be accomplished with liquid embolic agents via transarterial access. Anatomic factors to consider when assessing the safety and efficacy of a transarterial approach using liquid embolic agents include location, angioarchitecture, and proximity of arterial feeders to both the vasa nervosum of adjacent cranial nerves and the external carotid-internal carotid/vertebral artery anastomoses. Anatomic locations typically favorable for transarterial approaches include but are not limited to the transverse/sigmoid sinus, cerebral convexity, and superior sagittal sinus. In this review article, we discuss the technical approaches, outcomes, potential complications, and complication avoidance strategies for transarterial embolization.

Morphometric study regarding ophthalmic and internal carotid arteries utilizing computed tomography angiography

The aim of the present study was to accurately measure the diameter of the ophthalmic artery (OA) and investigate whether bilateral variations in diameter can be recorded in relation to patient age and sex. A retrospective study including 80 computed tomography angiographic (CTA) examinations and a total of 160 arteries was conducted to demonstrate the morphometric aspects of the OAs analyzed bilaterally by CTA examinations, while considering the references of the internal carotid artery (ICA) caliber. Precise measurements performed on the OA and the ICA below and above the ophthalmic emergence revealed an OA diameter of 1.38±0.24 mm and a narrowing of the ICA between the origin of the OA of 1.5±0.25 mm. Variations in the OA and the ICA calibers were studied in subjects with normal cervical vasculature on CTA. After a thorough statistical study, variations in OA and ICA caliber on each side were identified, between both sex and age-related groups, revealing morphometric parameters of the OA in relation to the ICA.

Willis Covered Stent for Treating Intracranial Pseudoaneurysms of the Internal Carotid Artery: A Multi-Institutional Study

OBJECTIVE

This work aimed to retrospectively analyze Willis covered stent (WCS)'s therapeutic efficacy in intracranial pseudoaneurysms (PSAs) of the internal carotid artery (ICA).

METHODS

Between June 2018 and July 2021, 56 individuals with intracranial PSAs of the ICA treated with WCS in three centers were included to analyze information regarding medical records, operative parameters, imaging findings and follow-up data.

RESULTS

All WCSs were successfully targeted to the ICA lesions. Total exclusion of PSA was found in 53 cases (94.6%) right upon surgery, and mild endoleak into the aneurysm remained in 3 cases (5.4%). Intraoperative thrombosis occurred in 1 case (1.8%), and tirofiban was utilized for recanalization. Follow-up by angiography showed total aneurysm occlusion in the total number of individuals, including in the 3 above cases with residual endoleak. In-stent stenosis occurred in 7 (12.5%) patients. No stent-related ischemic event was encountered. Predictive factors of late in-stent stenosis following WCS implantation in this patient group were irregular post-operative antiplatelet treatment (p = 0.015) and C4-C5 segment of the ICA (p = 0.043).

CONCLUSION

WCSs are effective in treating intracranial PSAs of the ICA.

Endovascular Treatment of Medial Tentorial Dural Arteriovenous Fistula Through the Dural Branch of the Pial Artery

Background: Tentorial dural arteriovenous fistula is a rare subtype of intracranial dural arteriovenous fistula (DAVF) with a deteriorating natural course, which may be attributed to its pial angioarchitecture. TDAVF often harbors feeders arising from pial arteries (FPAs). Reports have revealed that, if these feeders are not obliterated early, the restricted venous outflow during the embolization process may cause upstream congestion in the fragile pial network, which increases the risk of hemorrhagic complications. Because most reported cases of TDAVF were embolized through feeders from non-pial arteries (FNPAs), little is known of the feasibility of direct embolization through FPAs.

Methods: We present three patients with medial TDAVFs that were embolized through the dural branches of the posterior cerebral and superior cerebellar arteries. Findings from brain magnetic resonance imaging, computed tomography, angiography, and clinical outcomes are described. Furthermore, we performed a review of the literature on TDAVFs with FPAs.

Results: The fistulas were completely obliterated in two patients; both recovered well with no procedure-related complications. The fistula was nearly obliterated in one patient, who developed left superior cerebellum and midbrain infarct due to the reflux of the embolizer into the left superior cerebellar artery. Including our cases, eight cases of TDAVFs with direct embolization through the FPAs have been reported, and ischemic complications occurred in three (37.5%).

Conclusions: Advancing microcatheter tips as close to the fistula point as possible and remaining highly aware of potential embolizer flow back into the pial artery are key factors in achieving successful embolization. Balloon-assisted embolization may be an option for treating TDAVFs with FPAs in the future.

Endovascular management of cavernous sinus dural arteriovenous fistulas: Overall review and considerations

Cavernous sinus dural arteriovenous fistulas (CSDAVFs) are arteriovenous shunts between small dural branches arising from the external and/or internal carotid arteries and the cavernous sinus (CS). And now a days, endovascular treatment is the treatment of choice in CSDAVF. We review the anatomy and classifications of CSDAVFs, discussing and detailing these considerations in the treatment of CSDAVFs, theoretically and in the light of recent literatures.