Microsurgical Management of Complex Meningiomas Involving Dural Venous Sinuses: Operative Techniques, Case Illustrations and Long-Term Outcomes in a Series of 70 Cases.

BACKGROUND: Meningiomas involving the dural venous sinuses present unique therapeutic challenges. While gross total resection remains the mainstay of treatment for meningiomas, involvement of critical vascular structures may limit extent of resection and increase the risk of recurrence. Optimal management of meningiomas with venous sinus involvement has been discussed in the literature, with some advocating for subtotal resection with postoperative surveillance and radiation, if necessary, while others recommend total resection with reconstruction of resection of the involved sinus. METHODS: We performed a review of our series of 70 patients at a single institution who underwent resection of a meningioma involving the dural venous sinuses with reconstruction as needed, evaluating demographics, preoperative assessment of venous anatomy, surgical technique, and outcomes. RESULTS: In our series, we found successful maximal safe resection was achievable in patients with dural venous sinus involvement. We identified no venous infarctions and a low rate of recurrence. CONCLUSIONS: Maximal safe resection, including resection and reconstruction of involved sinuses, may be a safe and effective treatment for many patients. Careful preoperative assessment of venous anatomy and planning extent of resection and reconstruction are essential for safe and successful surgery in these patients.

Unruptured giant lateral thoracic meningocele: extremely rare cause of cerebrospinal fluid (CSF) hypotension in neurofibromatosis type 1.

Neurofibromatosis type 1 (NF1) is a multisystem neurocutaneous disorder. Scoliosis and dural ectasia are features of the associated mesodermal dysplasia. Lateral thoracic meningoceles can develop in NF1 and progressively enlarge due to cerebrospinal fluid (CSF) pulsations. Large meningoceles can cause compressive symptoms in the thorax. We are reporting a case of a NF1 presenting with acute onset respiratory distress, who also had chronic orthostatic headaches. CT chest showed unruptured enlarging bilateral lateral thoracic meningoceles causing lung compression. MRI of the brain and spine showed features of CSF hypotension, explaining the headaches. CSF hypotension with unruptured meningoceles is extremely rare. Management of the condition is challenging since surgical removal is prone to complications due to underlying mesodermal abnormalities. Cystoperitoneal shunting to relieve lung compression may worsen CSF hypotension. A shunt with a programmable valve allowed controlled drainage and successfully relieved lung compression without worsening of orthostatic headaches in our case.

Duplication and Fenestration of the Inferior Petrosal Sinus: Cadaveric Study with Application to Imaging, Skull Base Surgery, and Neurointerventional Procedures.

BACKGROUND: Reports of a duplicated or fenestrated inferior petrosal sinus (IPS) are scarce or not found in the literature, respectively. To our knowledge, there are no cadaveric reports of the latter. METHODS: This study used 20 adult cadaveric heads (40 sides). After removal of the brain, the IPS was dissected using a surgical microscope. Specimens with duplication or fenestration of the IPS anywhere along its course were photographed and measured. RESULTS: On 2 (5%) left sides, a fenestration was identified in the IPS. One of these was found to have 2 fenestrations. The mean length and width of the 3 fenestrations were 2.3 mm and 0.95 mm, respectively. The 3 fenestrations were located at the middle to terminal parts of the IPS. On 2 (5%) left sides and 1 (2.5%) right side, the IPS was duplicated over a part of its course. The mean length and width of the duplicated parts of the IPS were 25.9 mm and 3.1 mm, respectively. No statistical significance was found for fenestrations or duplications comparing males versus females, but fenestrations were statistically significant (P < 0.05) for occurring on left sides. CONCLUSIONS: Unfamiliarity with a duplicated or fenestrated IPS could increase risk of iatrogenic injury and misinterpretation of imaging. Further radiological imaging studies are required to substantiate more accurately the mechanisms by which a duplicated or fenestrated IPS affects clinical outcomes. Nonetheless, anatomical awareness of such lesser known variations of the IPS is crucial for promoting safe and effective interventional approaches at the skull base.

Torcular Herophili: A Review of the History of the Term and Synonyms.

The eponymous term torcular Herophili has been used for the confluence of sinuses. Although no original writings of Herophilus are extant, his accomplishments and descriptions live on in the writings of such authors as Galen. However, in regard to the torcular Herophili, there are some inconsistencies in the secondary sources and their translations regarding what was actually originally described by Herophilus. Herein, we review the history of the term torcular Herophili, which is so often used in clinical medicine.

Navigability of a long sheath in the lateral dural sinuses facilitated by the pilot balloon technique: technical note.

Dural sinus stenting is an increasingly recognized intervention for the treatment of lateral sinus stenosis. This procedure can be challenging in tortuous anatomy and in the presence of intraluminal septa because of poor trackability and crossability of long sheath commonly used for stenting. We report a technique using a pilot angioplasty balloon positioned at the distal end of the long sheath that improves its navigability in dural sinuses and facilitated the intervention.

Craniovascular traits and braincase morphology in craniosynostotic human skulls.

Middle meningeal vessels, dural venous sinuses, and emissary veins leave imprints and canals in the endocranium, and thus provide evidence of vascular patterns in osteological samples. This paper investigates whether craniovascular morphology undergoes changes in craniosynostotic human skulls, and if specific alterations may reflect structural and functional relationships in the cranium. The analyzed osteological sample consists of adult individuals with craniosynostoses generally associated with dolichocephalic or brachycephalic proportions, and a control sample of anatomically normal adult skulls. The pattern and dominance of the middle meningeal artery, the morphology of the confluence of the sinuses, and the size and number of the emissary foramina were evaluated. Craniovascular morphology was more diverse in craniosynostotic skulls than in anatomically normal skulls. The craniosynostotic skulls often displayed enlarged occipito-marginal sinuses and more numerous emissary foramina. The craniosynostotic skulls associated with more brachycephalic morphology often presented enlarged emissary foramina, while the craniosynostotic skulls associated with dolichocephalic effects frequently displayed more developed posterior branches of the middle meningeal artery. The course and morphology of the middle meningeal vessels, dural venous sinuses, and emissary veins in craniosynostotic skulls can be related to the redistribution of growth forces, higher intracranial pressure, venous hypertension, or thermal constraints. These functional and structural changes are of interest in both anthropology and medicine, involving epigenetic traits that concern the functional and ontogenetic balance between soft and hard tissues.

[Thrombosis and anatomic variants of intracranial dural venous sinuses]. / Tromboz i varianty stroeniya sinusov tverdoi mozgovoi obolochki.

A rather large number of different anatomic variants of intracranial dural venous sinuses are known, and they are found so often that interpreting them only as anomalies is unlikely, except for variations such as sinus aplasia or doubling, which can be attributed to anomalies of the venous system. Diameter reduction (hypoplasia) of the transverse and sigmoid sinuses is observed relatively often. In cases of dural sinuses anomalies, sinuses on the contralateral side are necessarily evaluated as the main source of compensation. When diagnosing dural sinus thrombosis, it is necessary to have a clear idea of the structure of the cerebral venous system, so as not to mistakenly accept hypoplasia or sinus aplasia for thrombosis. Our own experience is based on the results of a neuroimaging study of cerebral veins and venous sinuses in 103 patients (average age 35±10 years) with a tension-type headache. Hypoplasia of the transverse and sigmoid sinuses was detected in 21 (22.4%) cases. In 10 cases (6 men, 4 women), a connection was established between hypoplasia of the dural sinuses and thrombosis. Four patients, presented with hypoplasia of the right transverse and sigmoid sinuses and 6 patients with hypoplasia of the left transverse and sigmoid sinuses. Thrombosis developed on the side of sinus hypoplasia (9 patients) or on the contralateral side (1 patient). Early diagnosis of cerebral venous thrombosis is crucial because the use of anticoagulants reduces the risk of a poor prognosis, severe disability without an additional increase in the risk of brain hematomas progression.

Long-term survival in patients with long-segment complex meningiomas occluding the dural venous sinuses: illustrative cases.

BACKGROUND: Invasive sagittal sinus meningiomas are difficult tumors to cure by resection alone. Stereotactic radiosurgery (SRS) can be used as an adjuvant management strategy to improve tumor control after incomplete resection. OBSERVATIONS: The authors reported the long-term retrospective follow-up of two patients whose recurrent parasagittal meningiomas eventually occluded their superior sagittal sinus. Both patients underwent staged radiosurgery and fractionated radiation therapy to achieve tumor control that extended to 20 years after their initial surgery. After initial subtotal resection of meningiomas that had invaded major cerebral venous sinuses, adjuvant radiosurgery was performed to enhance local tumor control. Over time, adjacent tumor progression required repeat SRS and fractionated radiation therapy to boost long-term tumor response. Staged multimodality intervention led to extended survival in these patients with otherwise unresectable meningiomas. LESSONS: Multimodality management with radiosurgery and fractionated radiation therapy was associated with long-term survival of two patients with otherwise surgically incurable and invasive meningiomas of the dural venous sinuses.

Venous anatomy of the supratentorial compartment.

The cerebral venous drainage system in humans has several unique characteristics that set it apart from its arterial counterpart. The intracranial drainage system can be broadly divided into supra- and infratentorial components. The supratentorial venous drainage is further subclassified into superficial and deep systems, each with a unique set of features. A thorough knowledge of the normal and variant venous drainage pathways is important to understand the different pathologic processes involving the venous vasculature, to identify and anticipate the different venous channels encountered during surgery and also to predict the possible sequelae of intentional or inadvertent venous sacrifice during surgery. This chapter summarizes the anatomic and radiologic characteristics of the venous supply of the supratentorial compartment of the brain, reviews its general characteristics, sheds light on the different classifications and nomenclature used for its descriptions, and briefly discusses its embryologic development.

Dural Venous Sinuses: What We Need to Know.

BACKGROUND: The dural venous sinuses (DVS), in general, are frequently asymmetrical and display far more anatomical variations than arterial systems. A comprehensive study of the anatomy and variants of the DVS can help surgeons in the preoperative evaluation and management as well as minimizing possible complications in the following treatment. METHODS: The current review was designed to provide a general overview of the normal anatomy and notable variants of the cerebral venous system as surveyed from the available literature. The pros and cons of different multimodal imaging methods for investigating DVS are also outlined. Finally, cases of various pathological entities are illustrated from our clinical practice. CONCLUSION: There are many anatomical variations and lesions involving the DVS. MRI examination can provide essential information both on anatomical variation and morphological or functional change of the offending DVS in most circumstances. Multimodal non-invasive venography protocols may become a feasible alternative to the classical digital subtraction angiography and would improve the diagnostic accuracy in future studies.

Anatomical implications of posterior cephaloceles in the dural venous sinuses.

OBJECTIVE: To analyze the venous anatomy of the dural sinuses of patients with posterior encephaloceles, in order to formulate anatomical patterns which can ensure safer surgery. METHODS: This is a retrospective study, analyzing eight patients diagnosed with posterior encephalocele throughout 1 year. RESULTS: Eight patients with cephaloceles were evaluated in our study from January 2017 to January 2018. The most common alteration was dysgenesis of the straight sinus (n = 7), followed by venous anomalies in the encephalocele and alterations in the SSS (superior sagittal sinus) (n = 4), and the occurrence of a falcine sinus (FC) in 3 patients. CONCLUSION: Anatomical variations are frequent in patients with cephaloceles. Therefore, an understanding of them is necessary for safe and effective treatment.

Variations of the CNS Venous System Mimicking Pathology: Spectrum of Imaging Findings.

Variations in the venous drainage of the central nervous system can have imaging and clinical findings that mimic pathology, presenting a challenge for neuroimagers and clinicians. Patients with these variants may undergo unnecessary testing, and patients with pathology may receive delayed diagnoses because of overlap with benign findings. Consequently, the accurate identification of venous variations on cross-sectional imaging and angiography and their potential causes are critical for differentiating benign imaging variants from potential pathologic processes requiring further evaluation. For example, in the epidural space, benign dilation of the epidural venous plexus may be mistaken for evidence of a fistula, abscess, or metastasis. Hypoplasia of a dural venous sinus or an arachnoid granulation may mimic venous sinus thrombosis. The superior ophthalmic vein may demonstrate benign dilation in intubated patients, mimicking thrombosis, increased intracranial pressure, orbital varix, inflammatory pseudotumor, or other conditions. Furthermore, certain venous variations, such as the occipital sinus or emissary veins, may complicate surgery or herald pathology and should be reported. In addition, some supposedly benign variations, such as the developmental venous anomaly, can be complicated by pathology. The objective of this review article is to provide a descriptive and pictorial review of common anatomic and physiologic variations in the venous drainage system of the brain, spine, and orbits that can mimic pathology. Neuroimaging findings of related pathologies and differences in clinical presentations will also be discussed to assist in the approach to differential diagnosis.

Cerebral Sinus Venous Thrombosis in the Setting of Acute Mastoiditis.

Cerebral sinus venous thrombosis (CSVT) is a rare complication of acute mastoiditis with a declining incidence in the post-antibiotic era. In the adult population its incidence ranges from three to four cases per million. Here we present a case of a 47-year-old female with triple negative breast cancer on chemotherapy who underwent a molar tooth extraction, which was followed two weeks later by the sudden onset of left-sided frontotemporal headache radiating down the face, left ear fullness with associated hearing loss, toothache, and left orbital pain. Imaging studies performed included magnetic resonance imaging (MRI) as well as magnetic resonance venography (MRV), both of which showed thrombosis of the left transverse sinus, sigmoid sinus as well as the internal jugular vein, which was consistent with a diagnosis of cerebral sinus venous thrombosis. Following the diagnosis, the patient was managed with anti-coagulation and antibiotics, which resulted in improvement of her symptoms. This case highlights the need to be vigilant in patients with acute mastoiditis for the above clinical syndrome in order to promptly diagnose this rare complication and avoid life-threatening consequences.

3D Brain Imaging in Vascular Segmentation of Cerebral Venous Sinuses.

The three-dimensional (3D) visualization of dural venous sinuses (DVS) networks is desired by surgical trainers to create a clear mental picture of the neuroanatomical orientation of the complex cerebral anatomy. Our purpose is to document those identified during routine 3D venography created through 3D models using two-dimensional axial images for teaching and learning neuroanatomy. Anatomical data were segmented and extracted from imaging of the DVS of healthy people. The digital data of the extracted anatomical surfaces was then edited and smoothed, resulting in a set of digital 3D models of the superior sagittal, inferior sagittal, transverse, and sigmoid, rectus sinuses, and internal jugular veins. A combination of 3D printing technology and casting processes led to the creation of realistic neuroanatomical models that include high-fidelity reproductions of the neuroanatomical features of DVS. The life-size DVS training models were provided good detail and representation of the spatial distances. Geometrical details between the neighboring of DVS could be easily manipulated and explored from different angles. A graspable, patient-specific, 3D-printed model of DVS geometry could provide an improved understanding of the complex brain anatomy. These models have various benefits such as the ability to adjust properties, to convert two-dimension images of the patient into three-dimension images, to have different color options, and to be economical. Neuroanatomy experts can model such as the reliability and validity of the designed models, enhance patient satisfaction with improved clinical examination, and demonstrate clinical interventions by simulation; thus, they teach neuroanatomy training with effective teaching styles.

Variations of the Transverse Sinus: Review with an Unusual Case Report.

The dural venous sinuses are venous channels in the cranium that drain blood and cerebrospinal fluid circulating from the brain into the vascular system via the internal jugular veins. The transverse sinus is a dural venous sinus present in the posterior aspect of the cranium. We report an unusual variant of this sinus with the presence of a fenestration at its proximal segment. We will review and discuss the background and the potential clinical relevance of this anatomical variation.

Assessment of the Inferior Petrosal Sinus on T1-Weighted Contrast-Enhanced Magnetic Resonance Imaging.

CONTEXT: Skull base venous anatomy. AIMS: While prior studies have focused on the efficacy of conventional fluoroscopic venography and multidetector computed tomography venography to evaluate the inferior petrosal sinus (IPS) before image-guided intervention (such as dural venous sinus sampling), we believe that routine magnetic resonance imaging (MRI) may provide reliable structural information helpful for planning without the need for further imaging. SETTINGS AND DESIGN: Retrospective review of brain MRI. MATERIALS AND METHODS: Retrospective analysis was carried out on IPSs on contrast-enhanced T1-weighted MR images. Qualitative measurements were made regarding the grade of patency of the IPS, variation in IPS drainage pattern, and grading of the ipsilateral transverse and sigmoid sinuses (TS and SS). STATISTICAL ANALYSIS USED: Pearson's product-moment correlation. RESULTS: Evaluation of a total of 148 IPSs revealed that 91% of cases were grade 3 or grade 2 (either fully or mostly visualized), with 65% of cases demonstrating "typical" (type A) drainage directly into the internal jugular vein and no statistically significant correlation between the patency of the IPS and the dominance of the ipsilateral TS/SS. A bilateral concordance rate of 77% was also observed. CONCLUSIONS: Our analysis indicates that routine thin-slice contrast-enhanced T1-weighted MRI can provide sufficient anatomic detail to identify typical drainage pattern of the IPS in a majority of cases. In cases where routine drainage was not identified, spatial resolution was not sufficient to further delineate complex drainage anatomy. No correlation was observed between the TS/SS dominance and patency of the ipsilateral IPS.

A review of extraaxial developmental venous anomalies of the brain involving dural venous flow or sinuses: persistent embryonic sinuses, sinus pericranii, venous varices or aneurysmal malformations, and enlarged emissary veins.

This paper is a narrative review of extraaxial developmental venous anomalies (eDVAs) of the brain involving dural venous flow or sinuses: persistent embryonic sinuses, sinus pericranii, enlarged emissary veins, and venous varices or aneurysmal malformations. The article highlights the natural history, anatomy, embryology, imaging, clinical implications, and neurosurgical significance of these lesions, which the authors believe represent a continuum, with different entities characterized by distinct embryopathologic features. The indications and surgical management options are discussed for these individual intracranial pathologies with relevant illustrations, and a novel classification is proposed for persistent falcine sinus (PFS). The role of neurointervention and/or microsurgery in specific cases such as sinus pericranii and enlarged emissary veins of the skull is highlighted. A better understanding of the pathophysiology and developmental anatomy of these lesions can reduce treatment morbidity and mortality. Some patients, including those with vein of Galen malformations (VOGMs), can present with the added systemic morbidity of a high-output cardiac failure. Although VOGM is the most studied and classified of the above-mentioned eDVAs, the authors believe that grouping the former with the other venous anomalies/abnormalities listed above would enable the clinician to convey the exact morphophysiological configuration of these lesions, predict their natural history with respect to evolving venous hypertension or stroke, and extrapolate invaluable insights from VOGM treatment to the treatment of other eDVAs. In recent years, many of these symptomatic venous malformations have been treated with endovascular interventions, although these techniques are still being refined. The authors highlight the broad concept of eDVAs and hope that this work will serve as a basis for future studies investigating the role of evolving focal venous hypertension/global intracranial hypertension and possibilities of fetal surgical intervention in these cases.

Development of Life-Size Patient-Specific 3D-Printed Dural Venous Models for Preoperative Planning.

BACKGROUND: Despite significant improvement in clinical care, operative strategies, and technology, neurosurgery is still risky, and optimal preoperative planning and anatomical assessment are necessary to minimize the risks of serious complications. Our purpose was to document the dural venous sinuses (DVS) and their variations identified during routine 3-dimensional (3D) venography created through 3D models for the teaching of complex cerebral anatomy. METHODS: 3D models of the DVS networks were printed. Compared with the controls, cases with cortical venous thrombosis have altered venous anatomy, which has not been previously compared. RESULTS: Geometrical changes between the neighboring DVS could be easily manipulated and explored from different angles. Modeling helped to conduct the examination in detail with reference to geometrical features of DVS, degree of asymmetry, its extension, location, and presence of hypoplasia/atresia channels. Challenging DVS anatomy was exposed with models of adverse anatomical variations of the DVS network, including highly angulated, asymmetrical view, narrowed lumens, and hypoplasia and atresia structures. It assisted us in comprehending spatial anatomy configuration of life-like models. CONCLUSIONS: Patient-specific models of DVS geometry could provide an improved understanding of the complex brain anatomy and better navigation in difficult areas and allow surgeons to anticipate anatomical issues that might arise during the operation. Such models offer opportunities to accelerate the development of expertise with respect to new and novel procedures as well as new surgical approaches and innovations, thus allowing novice neurosurgeons to gain valuable experience in surgical techniques without exposing patients to risk of harm.

Occipital Sinus Thrombosis: An Exceptional Case Report.

BACKGROUND: Variations of the dural venous sinuses may result in inaccurate imaging interpretation or complications during surgical approaches. One variation of the dural venous sinuses reported infrequently in the literature is the occipital sinus. We report an exceptional case of occipital sinus thrombosis. CASE REPORT: A 48-year-old right-handed man with a 5-month history of hypertension and chronic renal failure presented with cephalalgia, vomiting, and blurred vision evolving over 48 hours. Neurological examination revealed papillary edema stage 1 with no others abnormalities. An initial brain computed tomography (CT) scan performed was normal. The opening pressure of cerebrospinal fluid (CSF) was 35 cmH2O with normal level of protein and no hypercellularity in CSF analysis. The evolution was marked by the occurrence of generalized tonic-clonic seizure. A second CT scan performed showed a hyperdensity of the occipital sinus. Magnetic resonance imaging and magnetic resonance venography studies confirmed the diagnosis with highlighting the thrombosis of the occipital sinus in association to an ectasia of the torcular. The patient received adequate anticoagulation for 6 months in association to antiepileptic drugs with a good evolution. DISCUSSION: According to our review, such a thrombosis must be a rare condition, because our literature search has shown a lack of any report describing this condition. Herein, we review the anatomy of the occipital sinus and we illustrate the characteristics of this unusual thrombosis with multiple imaging modalities. CONCLUSION: Understanding of the cerebral venous anatomy and recognition of venous variations essentially help when dealing with a pathology, which presents along with a particular venous variation, no matter how rare this combination is.

Trombosis del seno sagital en un neonato / Sagittal sinus thrombosis in a newborn

La trombosis de los senos venosos durales es una rara y devastadora enfermedad. Se presenta generalmente en mujeres y ancianos, y no es frecuente en niños, aunque se reconoce ya como una causa de morbilidad y mortalidad en la población pediátrica. Se han reportado pocos casos en el mundo de neonatos afectados por esta entidad, en su mayoría fatales e insuficientemente investigados. A continuación se presenta el caso de un recién nacido con una trombosis del seno sagital que sobrevivió. Los factores predisponentes para la aparición de la enfermedad en este caso fueron la asfixia neonatal, la deshidratación severa unida al uso de una línea venosa central, y la inmovilización prolongada. Aunque la TAC contrastada no es el estudio ideal para su diagnóstico, permitió realizarlo oportunamente en este caso. El tratamiento temprano con anticoagulantes permitió una rápida recuperación y favoreció la recanalización venosa del seno involucrado. Hasta el momento no se han detectado secuelas neurológicas y el paciente tiene buen desarrollo psicomotor.

Dural venous sinus thrombosis is a rare devastating disease. It is generally found in females and old people, but is infrequent in children; however, it is already recognized as a morbidity and mortality cause in the pediatric population. Few cases of newborns with this disease have been reported worldwide; most of them were poorly studied and had fatal outcomes. Here is the presentation of a newborn with sagittal sinus thrombosis, who managed to survive. The predisposing factors for the disease were neonatal asphyxia, severe dehydration together with the use of central venous line and extended immobilization. Although contrast CAT is not the ideal study, it helped to promptly arrive at the right diagnosis in this case. The early treatment based on anticoagulants allowed rapid recovery and facilitated venous retaking of the involved venous sinus. No neurological sequels have been so far detected and the psychomotor development of the child is good.