Mechanism of the formation of dural arteriovenous fistula: the role of the emissary vein

Microsurgical Management of Craniocervical Dural Arteriovenous Fistula: A Case Report and Literature Review

Dural arteriovenous fistula (DAVF) of the craniocervical junction is exceptionally rare. The anatomy of the craniocervical junction area is very complex and is composed of the medulla and spinal cord along with intricate neurovascular structures. A thorough assessment of the angioarchitecture of the fistula is obligatory for choosing the most appropriate treatment for the patient. In this report, we describe the nuance of microsurgical obliteration of craniocervical junction DAVF utilizing intraoperative angiography. A 38-year-old male in a normal state of health was referred to our hospital for an abnormality in his brain checkup. Workup diagnostics showed a DAVF on the craniocervical junction area with feeders from ascending pharyngeal, vertebral, and occipital arteries, with the draining vein mainly to the basal vein of Rosenthal. Microsurgical obliteration of the main draining vein was done with the help of intraoperative digital subtraction angiography with a good outcome. Craniocervical DAVF is a rare entity. Meticulous evaluation of arterial and venous fistula points is necessary to decide the best treatment option for this case. Microsurgical obliteration is a feasible and more straightforward procedure for treating craniocervical DAVF.

Systemic immune-inflammation index in dural arteriovenous fistula: a feasible biomarker reflecting its clinical characteristics

PURPOSE

The systemic immune-inflammation index (SII), a marker of systemic inflammation, can be calculated using peripheral blood tests. Although the SII has been reported as a feasible biomarker in various cerebrovascular diseases, no studies have explored in dural arteriovenous fistula (DAVF). A retrospective cohort study was performed to test whether the SII reflects the clinical characteristics of DAVF and whether this index could serve as a feasible biomarker.

METHODS

This study included 28 patients who underwent endovascular treatment (39 sessions) for DAVF between 2014 and 2023. The SII was calculated using the following formula: platelet count multiplied by neutrophil count divided by lymphocyte count. We investigated the correlation between the SII and various clinical characteristics of DAVF, including symptom manifestation, and digital subtraction angiography findings. Additionally, we compared pre- and post-endovascular treatment changes in the SII.

RESULTS

A significantly higher SII was observed in patients with multiple lesions, clinical symptoms (particularly aggressive symptoms), pseudophelebitic pattern (PPP), and sinus occlusion. Multivariate regression analysis revealed that the presence of symptoms (coefficient 270.9, P = 0.021) and PPP (coefficient 272.4, P = 0.017) were independent factors contributing to SII elevation. Notably, following endovascular treatment, there was a significant decrease in the elevated SII in patients whose symptoms resolved (P = 0.039) and where the DAVF was angiographically cured (P = 0.012).

CONCLUSION

Elevation of the SII in patients with advanced DAVF and its decrease following endovascular treatment suggests that the SII reflects the disease condition and indicates its potential as a promising biomarker.

Tigroid Enhancement: A Characteristic Enhancement Pattern of the Cerebellar Hemisphere on MRI With Intracranial Dural Arteriovenous Fistulas

PURPOSE

This study aims to investigate a characteristic cerebellar hemisphere enhancement pattern on magnetic resonance imaging (MRI) that could aid in early and specific diagnosis of intracranial dural arteriovenous fistulas (DAVFs).

MATERIALS AND METHODS

Pretreatment MR images of 57 patients with intracranial DAVFs between January 1, 2017, and February 28, 2023, were retrospectively analyzed. A total of 128 patients with confirmed alternative cerebellar lesions during the same period were included as a control group. All patients underwent enhanced MRI with a 3.0T scanner. The presence or absence of parallel enhanced linear striations on the surface of the cerebellar lesions was documented. Statistically significant differences were determined by the Fisher exact test.

RESULTS

Cerebellar lesions were identified in 4 intracranial DAVF patients (7.0%). All 4 patients were male, with an average age of 64 years (range: 58-76 years). The pretreatment MR images of all 4 DAVF patients with cerebellar lesions demonstrated the characteristic tigroid enhancement pattern. Tortuous flow voids were present in the MR images of 3 of the 4 patients. Tigroid enhancement pattern was not observed in the remaining 53 intracranial DAVF patients and all control patients. The differences in the incidence of the pattern were significant (p=0.01).

CONCLUSION

A characteristic tigroid enhancement pattern of the cerebellar hemisphere on MRI may aid in the early and specific diagnosis of intracranial DAVFs, allowing timely treatment and improving outcomes.

CLINICAL IMPACT

The identification of a characteristic tigroid enhancement pattern on MRI for cerebellar hemisphere lesions holds significant promise for clinical practice. This pattern serves as a distinctive marker aiding in the early and specific diagnosis of intracranial dural arteriovenous fistulas (DAVFs). Clinicians can now utilize this innovative finding to expedite diagnostic workflows, enabling timely intervention and management strategies. The incorporation of this novel imaging feature enhances diagnostic accuracy, potentially reducing misdiagnosis rates and preventing delays in treatment initiation. Ultimately, this advancement may lead to improved patient outcomes and quality of care in neurosurgical and neuroradiological practice.

De novo formation of remote dural arteriovenous fistula following treated cavernous sinus dural arteriovenous fistula

Background

The development of new dural arteriovenous fistulas (DAVFs) at another location following endovascular treatment of cavernous sinus DAVFs (CSDAVFs) are extremely rare. Our aim is to review cases of de Novo DAVFs that occurred after treatment of CSDAVFs at our institution and those reported in the literature.

Methods

We reviewed all cases of CSDAVFs evaluated by 2 experienced neuroradiologists. A literature search was performed using the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines focusing on De Novo DAVFs following the endovascular treatment of cerebrovascular malformations. Addition articles were searched through the reference lists of the included articles.

Results

From June 2004 and September 2019., we identified 3 (2.5%) cases of De Novo DAVFs occurred after endovascular treatment or spontaneous obliteration of CSDAVFs from 119 treated CSDAVFs at our institute. Our review yielded 9 articles involving 12 patients with 15 de novo DAVFs, including our 3 patients. The mean age was 55.08 ± 12.9 years (range 43-69), 83.3% were females (n = 10). The new remote DAVFs occurred after endovascular treatment of CSDAVFs in 10 (83.3%) patients. The de novo DAVFs occurred following spontaneous complete regression in 2 (16.7%) patients. All de novo DAVFs developed after complete obliteration of treated CSDAVFs.

Conclusion

Sinus thrombosis and elevated venous pressure may play an important role in the pathogenesis of a de novo DAVF formation. In addition, thrombophilic abnormalities and the use of contraceptives may contribute to sinus thrombosis, leading to the development of the second remote DAVF after treatment of CSDAVFs.

Endovascular treatment of trigeminal neuralgia with cranial autonomic symptoms due to a right-sided petrous ridge dAVF

Dural arteriovenous fistula represents a rare cause of secondary Trigeminal Neuralgia. To date, there have been 18 reported cases of successful treatment of trigeminal neuralgia with endovascular embolization. Here we describe a unique case of a 51-year-old man with right-sided petrous ridge dural arteriovenous fistula causing ipsilateral V1 pain and cranial autonomic dysfunction. Cerebral angiography confirmed a Cognard type 3 right-sided tentorial dAVF supplied by an enlarged meningo-hypophpyseal vessel from the extradural ICA and by the middle meningeal artery. The fistula drains towards the midline via deep cerebral veins, the internal cerebral vein and the straight sinus with likely variceal compression of the right trigeminal nerve root entry zone. Transarterial Onyx embolization resulted in complete obliteration of the dural arteriovenous fistula with immediate resolution of facial pain and autonomic symptoms. After 24 months, the patient remains symptom-free and has no radiographic or clinical evidence of fistula recurrence. To date, there have been no other cases reported of trigeminal neuralgia with cranial autonomic symptoms or SUNCT syndrome due to a dural arteriovenous fistula. The presence of cranial autonomic symptoms with trigeminal neuralgia or a diagnosis of SUNCT should not deter endovascular treatments of dural arteriovenous fistulas or treatment of other compressive vascular lesions.

Acute traumatic dural arteriovenous fistula of the superior sagittal sinus: illustrative case

BACKGROUND

Dural arteriovenous fistulas (dAVFs) are aberrant vascular communications between meningeal arteries and venous sinuses or cortical veins. dAVF pathogenesis is incompletely understood; however, formation likely occurs as a result of angioneogensis.

OBSERVATIONS

A 78-year-old man presented after trauma with basal and cortical subarachnoid hemorrhage (SAH). Computed tomography revealed a parietal bone fracture overlying the superior sagittal sinus (SSS). Catheter angiography performed within 24 hours of the injury demonstrated an SSS dAVF supplied by the middle meningeal artery, adjacent to the fracture.

LESSONS

The authors present the case of an acute traumatic dAVF adjacent to a calvarial fracture. In this case, the authors proprose that the underlying pathogenesis is suggestive of direct vessel injury rather than the pathway commonly associated with this pathology.

Use of a Rigid-Tipped Microguidewire for the Endovascular Treatment of Cavernous Sinus Dural Arteriovenous Fistulas with an Occluded Inferior Petrosal Sinus

OBJECTIVE

Transvenous embolization (TVE) via an occluded inferior petrosal sinus (IPS) in a cavernous sinus dural arteriovenous fistula (CSDAVF) is challenging, often requiring navigation of a microcatheter through resistive obstacles between the occluded IPS and shunted pouch (SP), although the reopening technique was successfully performed. We report five cases of successful access to the cavernous sinus (CS) or SP using the rigid-tipped microguidewire such as chronic total occlusion (CTO) wire aiming to share our initial experience with this wire.

METHODS

In this retrospective study, four patients with CSDAVF underwent five procedures using the CTO wire puncture during transfemoral transvenous coil embolization. Puncture success, shunt occlusion, and complications including any hemorrhage and cranial nerve palsy were evaluated.

RESULTS

Despite successful access through the occluded IPS, further entry into the target area using neurointerventional devices was impossible due to a short-segment stricture before the CS (three cases) and a membranous barrier within the CS (two cases). However, puncturing these structures using the rigid-tipped microguidewire was successful in all cases. We could advance the microcatheter over the rigid-tipped microguidewire for the navigation to the SP and achieved complete occlusion of the SP without complications.

CONCLUSION

The use of the rigid-tipped microguidewire in the TVE via the occluded IPS of the CSDAVF would be feasible and safe.

Anomalous Frontal Extra-Axial Midline Traversing Vein as the Potential Source of Subarachnoid Hemorrhage

Extra-axial developmental venous anomalies (DVAs) are important anatomic structures that contribute to supplemental venous drainage of intracranial contents into the extracranial veins. We present the case of a 35-year-old woman with a sudden-onset severe headache, nausea, and vomiting who was found to have an atraumatic subarachnoid hemorrhage of left frontal convexity. Workup revealed a large anomalous extra-axial vein originating in the right frontal area, traversing the left frontal region, penetrating the left frontal bone just above the supraorbital foramen with likely drainage into the left external jugular vein. This vein could not be classified as an emissary vein given the lack of direct communication with the superior sagittal sinus anterior portion, which was found to be hypoplastic. This case report adds to the literature a description of a previously unreported midline traversing frontal extra-axial vein directly draining frontal lobes with a potential implication in an atraumatic subarachnoid hemorrhage of frontal convexity.

Contralateral Transverse Sinus Occlusion After Treatment of Transverse-Sigmoid Sinus Dural Arteriovenous Fistula: A Case Report

A dural arteriovenous fistula (DAVF) is a pathologic arteriovenous shunt located within the dural wall of a venous sinus. In addition, DAVFs are associated with sinus thrombosis. Consequently, sinus occlusion may occur near DAVF lesions, making treatment challenging. However, there are few reports of sinus occlusion unrelated to lesions. In this study, we present a rare case of contralateral transverse sinus occlusion in a patient who underwent endovascular treatment and stereotactic radiosurgery for DAVF in the transverse-sigmoid sinus with ipsilateral sigmoid sinus occlusion.

Surgical Treatment of a Giant Popliteal Venous Aneurysm and Arteriovenous Fistula on the Adjacent Femoral Vein and Its Postoperative Findings

A case of a giant popliteal venous aneurysm that caused massive pulmonary thromboembolism with an arteriovenous fistula draining into the adjacent proximal femoral vein is reported herein. Deep veins in the lower leg were occluded by thrombi. The inlet and outlet orifice inside the aneurysm was closed and aneurysmorraphy was performed. The fistula was retained on the estimation that it would maintain the blood flow and prevent thrombus formation inside the femoral vein. The aneurysm was shrunk, the femoral vein was patent, and the fistula was not observed 1 year later, although it still existed 1 week after the operation.

Risk Factors of Aggressive Clinical Presentation in Patients with Angiographically Aggressive Cranial Dural Arteriovenous Fistulas

Compared to nonaggressive cranial dural arteriovenous fistulae (cDAVF), aggressive cDAVF carries leptomeningeal venous drainage (LVD) and has approximately 15% annual risk of hemorrhagic and non-hemorrhagic aggressive neurological presentations. In terms of aggressive clinical presentations, the previous classification does not adequately differentiate the higher risk group from the lower risk group. Herein, we retrospectively collected a series of patients with aggressive cDAVF and explored the risk factors for differentiating the higher-risk group from the lower-risk group with aggressive clinical presentations. We retrospectively collected patients with aggressive cDAVF from March 2011 to March 2019. The risk of aggressive clinical presentation was recorded. Risk factors were included in the analysis for aggressive clinical presentations. From March 2011 to March 2019, 37 patients had aggressive cDAVF. Among them, 24 presented with aggressive clinical presentation (20, hemorrhagic presentation; four, non-hemorrhagic presentation). In patients presenting with hemorrhage, four patients experienced early rebleeding after diagnosis. In the univariate analysis, risk location, directness of LVD, exclusiveness of LVD, and venous strain were significantly different in patients with aggressive clinical presentation. In the multivariate analysis, exclusiveness of LVD and venous strain were observed, with a significant difference between patients with aggressive clinical presentation and those with benign clinical presentation. Among patients with angiographically aggressive cDAVFs, approximately 65% presented with aggressive clinical presentations in our series. Among all potential risk factors, patients with exclusiveness of LVD and venous strain have even higher risk and should be treated aggressively and urgently.

Spinal epidural arteriovenous fistula with intradural venous reflux: The possibility of acquired origin caused by spinal stenosis and/or disc herniation

BACKGROUND

Spinal epidural arteriovenous fistulas (SEAVFs) are relative rare lesions. The pathogenesis of these fistulas remains unclear. Our aim is to review cases of SEAVFs at our institution.

METHODS

We reviewed a consecutive series of spinal vascular disease at our institution and collected all patients harboring SEAVFs. Medical charts were retrospectively reviewed regarding patient demographic data (i.e., gender and age), presenting symptoms and signs, previous history of spinal surgery or trauma, treatment methods, and neurological outcome after treatment. All image studies, including plain radiography, spinal MRI, MRA, and angiography were analyzed.

RESULTS

We identified 9 cases of lumbosacral SEAVFs with intradural venous reflux treated at our institution from June 2010 to August 2020. Their median age was 67 years, range 52-83 years. Only one patient had a history of trauma. Interestingly, our observations found that all fistulas are associated with spinal stenosis and/or disc herniation. An additional literature search about SEAVFs coexisting with spinal stenosis and/or disc herniation was performed and found another 19 cases with median age 69 years, range 39-83 years. Only 2 patients had a history of previous spinal surgery. The level of shunted pouch in all 28 patients was correlated with the level of spinal canal stenosis and/or disc herniation.

CONCLUSIONS

Our study may provide an additional evidence supporting an acquired etiology of SEAVFs, which mainly manifest in late adulthood. It is possible that spinal stenosis and/or disc herniation may result in thrombosis or impairment of venous drainage, causing increased venous pressure, leading to fistulous formation.

Filum Terminale Arteriovenous Fistula Coexisting with a Large L2-L3 Disc Sequestration and Associated Diffuse Lumbar Arachnoiditis

The authors describe a case of filum terminale arteriovenous fistula (FTAVF) in association with a large L2–L3 disc sequestration and diffuse lumbar arachnoiditis. A 64-year-old male manifested with chronic back pain and gait difficulty. Magnetic resonance imaging (MRI) of the thoracic and lumbosacral spine revealed spinal cord congestion extending from the conus medullaris to the level of T9. There was a large disc sequestration came from L2–L3 disc herniation. In addition, thickening, clumping, and enhancement of the entire cauda equina were noted, probably representing arachnoiditis. MR angiography (MRA) and spinal angiography confirmed FTAVF at the level of L5. The patient underwent laminectomy with lysis adhesions and obliteration of the fistula. His postoperative course was uneventful. MRI and MRA of the thoracolumbar spine obtained 4 months after surgery revealed complete obliteration of the fistula and significant resolution of spinal cord congestion. Enhancement of the cauda equina roots was no longer visible. Interestingly, the significant resorption of the sequestrated disc was documented on MRI. The formation of the FTAVF in the present study may result from severe spinal canal stenosis caused by a large disc sequestration blocking the rostral venous drainage of the fistula, or chronic inflammation, and adhesions of the caudal nerve roots from lumbar arachnoiditis. It seems that FTAVF may be of acquired origin by this evidence.

Endovascular Treatment of Intracranial Pial-Dural Arteriovenous Fistula: A Case Report

Intracranial pial arteriovenous fistula (PAVF) is a rare cerebrovascular pathology characterized by abnormal direct high-flow connection between the pial or cortical feeding artery and draining vein. Dural arteriovenous fistula (DAVF) is a pathological shunt between the meningeal arteries and dural sinuses or meningeal veins. In case of association between PAVF and DAVF, diagnosis and treatment are more challenging. The high-flow arteriovenous shunt and deep venous drainage make PAVF more preferable for endovascular treatment; however, their embolization during single-session procedures can lead to extensive thrombosis of the draining veins and unfavorable outcomes. We present a case report of endovascular embolization of an intracranial PAVF-DAVF in a 2.5-year-old child. At the time of admission, the patient had hydrocephalus, mental retardation, pyramidal insufficiency, and seizures. Occlusion of the fistula was performed during two stages of embolization to reduce the risk of severe venous stasis and venous thrombosis. Guglielmi detachable coils (GDCs) and a liquid embolic agent (Histoacryl with Lipiodol) were used for embolization. The patient recovered well after the procedure, with significant mental improvement. This suggests that the deployment of GDCs in the afferent artery near a fistula before embolization with a liquid embolic agent can minimize the risk of uncontrolled penetration of the embolization into the draining veins and dural sinus. A multisession procedure can be an effective and reasonable method of PAVF and DAVF occlusion among existing treatment options.

Filum Terminale Arteriovenous Fistula in Association with Degenerative Lumbosacral Spinal Canal Stenosis: Report of 3 Cases and Review of the Literature

BACKGROUND

Filum terminale arteriovenous fistulas (FTAVFs) are rare, and the pathogenesis of these fistulas remains unclear. They may be either congenital or acquired in origin. The authors report 3 cases of FTAVFs in association with severe spinal canal stenosis. The authors also review literature of FTAVFs associated with spinal canal stenosis.

CASE DESCRIPTION

All 3 cases harboring FTAVFs manifested with progressive myelopathy and bowel/bladder dysfunction following long history of back pain, sciatica, and/or intermittent claudication. The fistulas were located around or at the level of spinal canal stenosis and supplied by the anterior spinal and/or lateral sacral arteries with cranial drainage from the dilated vein of the filum terminale to the perimedullary veins. The first and third cases were treated concomitantly by performing instrumented fusion with decompressive laminectomy along with occlusion of the fistula with good results. The second case was unsuccessfully treated by endovascular treatment through the lateral sacral artery and denied further surgical treatment.

CONCLUSIONS

Our 3 case reports may provide additional evidence supporting an acquired etiology of FTAVFs, probably secondary to the severe central canal stenosis. From our review, the level of the fistulas in most patients is correlated with the level of spinal canal stenosis. The authors preferred the concomitant surgical treatment by performing decompressive laminectomy and obliteration of the fistula in the same surgical session.

Spinal Sparganosis Coexisting with Acquired Arteriovenous Fistula of the Filum Terminale

BACKGROUND

Spinal sparganosis associated with filum terminale arteriovenous fistula (FTAVF) has not been reported in the literature. In previous studies, these 2 rare diseases were usually reported separately. We report the first case of spinal sparganosis with concomitant FTAVF.

CASE DESCRIPTION

Spinal sparganosis associated with FTAVF manifested in a middle-aged man with progressive back pain and paraparesis. Magnetic resonance imaging of the lumbosacral spine revealed large intradural mass-like lesions involving the conus medullaris and entire cauda equina. Additionally, there was degenerative spinal stenosis at the level of L2-3 to L5-S1. Magnetic resonance imaging of the thoracic spine disclosed abnormal hypersignal intensity extending from the level of the conus medullaris to T7 with tortuous intradural flow voids along the ventral more than dorsal surfaces of the spinal cord. Magnetic resonance angiography and spinal angiography confirmed FTAVF at the level of L3-4. The patient underwent surgical removal of the granulation tissues with lysis adhesions and obliteration of the FTAVF simultaneously in the same surgical session. Histologic findings were consistent with sparganosis.

CONCLUSIONS

The formation of FTAVF in the present case may have resulted from severe spinal canal stenosis caused by lumbar spondylosis and spinal sparganosis, inducing chronic inflammation and severe adhesion of spinal nerve roots. This evidence indicates that FTAVF may have been acquired.

Sphenoid dural arteriovenous fistulas

Sphenoid wing dural AVFs represent a rare clinical entity. These lesions may be asymptomatic or present with focal neurologic deficits, intracranial venous hypertension, or intracranial hemorrhage. Diagnosis is based on clinical findings and diagnostic imaging. They are alternatively classified as lesions of either the greater or lesser wings of the sphenoid bone. We performed a search of the PubMed database of studies evaluating the clinical behavior and surgical and endovascular therapies of these lesions. Dural AVFs draining into the superficial middle cerebral vein and/or laterocavernous sinus, or rather, lesions of the greater wing of the sphenoid, exhibit a greater likelihood of developing an aggressive clinical course, with higher probability of cortical venous reflux and consequent intracranial venous hypertension, intracranial hemorrhage, and symptomatic presentation. Dural AVFs of the sphenoparietal sinus, that is, lesions of the lesser wing of the sphenoid, typically exhibit a more benign clinical course, as there is a prominent epidural venous drainage into the cavernous sinus, reducing the risk of cortical venous reflux, and consequently, the probability of intracranial venous hypertension, hemorrhage, and floridly symptomatic presentation. These lesions may be treated via surgical clipping of the fistulous point, transarterial or transvenous embolization, and/or stereotactic radiosurgery. Though surgical intervention was the principal therapy due to facility of craniotomy access to the fistulous point, embolization has become standard of care permitted by innovation in endovascular technology. The natural history, clinical presentation, angioarchitecture, diagnosis, and management of these lesions are reviewed and discussed.

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.

Straight sinus dural arteriovenous fistula presenting with reversible parkinsonism: A case report and literature review

RATIONALE

A dural arteriovenous fistula (DAVF) refers to an abnormal direct connection between an intracranial artery and a dural venous sinus. A DAVF presenting with parkinsonism is rare, and is therefore easily misdiagnosed. Therefore, early consideration of DAVF in the differential diagnosis of reversible parkinsonism is necessary.

PATIENT CONCERNS

We present the case of a 51-year-old male with progressive parkinsonism.

DIAGNOSES

He was diagnosed as straight sinus occlusion. Imaging studies revealed a DAVF associated with cerebral hypoperfusion of the lenticular nuclei and frontal lobe white matter.

INTERVENTIONS

Endovascular embolization was performed through his left occipital artery.

OUTCOMES

Treatment resulted in marked clinical improvement that a major improvement of parkinsonism was observed concomitant with no evidence of early venous drainage of this patient.

LESSONS

DAVF should always be considered as a potential cause of progressive parkinsonism on account of its potential reversibility. Our case suggests a concomitant role of basal ganglia degeneration and frontal white matter hypoperfusion in the pathology of parkinsonism due to DAVF. However, the precise pathophysiology remains to be investigated.

Mastoid Epidermoid Tumor and Associated Dural Arteriovenous Fistula with Venous Sinus Occlusion

BACKGROUND

Dural arteriovenous fistula (DAVF) is an abnormal vascular connection between arterial and venous channels within dura mater. Although DAVFs have been linked to other types of intracranial tumors, this is the first case reporting the association between DAVF and an epidermoid tumor.

CASE DESCRIPTION

A middle-aged patient with chronic headache presented with Borden type II DAVF draining into the right transverse sigmoid junction and was also found to have an epidermoid tumor over the right mastoid. The patient underwent staged embolization of the fistula through both transvenous and transarterial routes. Continuous intraoperative venous pressure monitoring confirmed marked reduction in intracranial venous pressure, and the patient's symptoms completely resolved. However, the fistula still remained. The residual DAVF was then surgically disconnected, and the epidermoid tumor was resected in the same procedure.

CONCLUSIONS

This case demonstrates a DAVF can be associated with an epidermoid tumor. Tumor can compromise the venous outflow, which can then lead to intracranial venous hypertension and development of the DAVF. Venous pressure monitoring offers an objective method to verify resolution of venous hypertension, which might correlate with resolution of clinical symptoms.

Staged Arterial and Venous Embolizations in Treatment of Type IV Intraosseous Dural Arteriovenous Fistula

OBJECTIVE

This is a case report of an adult male with complex type IV intraosseous DAVF causing severe venous hypertension and bony destruction, presenting with severe hemotympanum, and a novel way of staged arterial and venous embolizations to treat the emergent symptoms.

METHODS

First and second stages were direct selective arterial embolizations using Onyx liquid agent. Goal was to reduce flow into the fistula by embolizing the feeder branch and distal penetration of the nidus with Onyx. The third stage was performed through the venous route: the transverse sinus and the sigmoid sinus were embolized using Penumbra Ruby coils and Onyx, two microcatheters were used and two large coils were placed simultaneously to form a stable coil mass, and the entire sinus was embolized using Coils and Onyx.

RESULTS

Patient's venous hypertension and degree of hydrocephalus had significantly decreased after the procedure. He was able to return to work, but was instructed to avoid heavy lifting and placing anything in and around his right ear.

CONCLUSIONS

Multiple step arterial and venous embolization procedures were successful in decreasing the frequency of hemotympanum, degree of hydrocephalus, and improving quality of life of this patient.

Evolutionary History of Multiple Dural Fistula

Intracranial dural arteriovenous fistulas (DAVFs) are abnormal communications between arteries and veins or dural venous sinuses, which sit between the sheets of the dura. They represent 10% to 15% of intracranial vascular malformations. Clinical manifestations and prognosis depend on the pattern of venous drainage and location. The clinical presentation of DAVF may be mistaken for vascular or nonvascular brain pathologies. For that reason, within the differential diagnosis come a wide range of conditions, such as secondary headaches, encephalopathies, dementias including those with rapid progression, neurodegenerative diseases, inflammatory processes, or tumors typically at the orbital level or in the cavernous sinus. Diagnosis requires a high degree of suspicion because of the multiplicity of symptoms and presentations, making this pathology an entity that provides a major challenge for clinicians, yet early and multidisciplinary treatment of high-grade fistulas improve the possibility of avoiding poor or unfavorable outcomes for the patient.

Skull Base Osseous Arteriovenous Fistula-A Rare Clinical Entity: Case Report and Literature Review

PURPOSE

To describe a rare clinical entity of intraosseous skull base arteriovenous fistula managed with transvenous fistula embolization.

CASE PRESENTATION

A 57-year-old woman presented with complaints of headache and episodic tinnitus with progressive left-sided visual deterioration. Cross-sectional imaging of the head revealed multiple vascular channels in the sphenoid bone and in bilateral masticator spaces. Catheter angiography showed the presence of a large osseous arteriovenous fistula epicentered in the body of sphenoid and left pterygoid plates with arterial feeders from bilateral external carotid arteries and venous drainage into bilateral cavernous sinuses and the pterygoid venous plexus. She was managed by transvenous coil and liquid embolic agent (Squid 18) embolization of the venous sac with significant reduction of shunt. In the postprocedure period, the patient developed paradoxical worsening of symptoms due to central retinal vein occlusion.

CONCLUSIONS

Skull base osseous fistulae are uncommon clinical entities and fistulae centered within the sphenoid bone are very rare. The aim of this report was to highlight management issues associated with such a case and review the available literature on the subject.

Abnormal Large Central Occipital Emissary Vein: A Case Report and Review of Literature

A detailed description of the anatomy of the central occipital emissary vein, its embryology, anatomy, and abnormal variations is not available in the literature. This is the first known case report. A 48-year-old female underwent cerebral angiography to rule out dural arterio-venous fistula. Her angiography revealed an abnormally large central occipital emissary vein originating from the torcula, penetrating the cranium and draining into the suboccipital venous plexus. We provide discussion of the case with a review of the related literature. This case and its attached radiological images introduce a new type of entity to the existing data about the cranial emissary veins.

Cranial dural arteriovenous shunts. Part 1. Anatomy and embryology of the bridging and emissary veins

We reviewed the anatomy and embryology of the bridging and emissary veins aiming to elucidate aspects related to the cranial dural arteriovenous fistulae. Data from relevant articles on the anatomy and embryology of the bridging and emissary veins were identified using one electronic database, supplemented by data from selected reference texts. Persisting fetal pial-arachnoidal veins correspond to the adult bridging veins. Relevant embryologic descriptions are based on the classic scheme of five divisions of the brain (telencephalon, diencephalon, mesencephalon, metencephalon, myelencephalon). Variation in their exact position and the number of bridging veins is the rule and certain locations, particularly that of the anterior cranial fossa and lower posterior cranial fossa are often neglected in prior descriptions. The distal segment of a bridging vein is part of the dural system and can be primarily involved in cranial dural arteriovenous lesions by constituting the actual site of the shunt. The veins in the lamina cribriformis exhibit a bridging-emissary vein pattern similar to the spinal configuration. The emissary veins connect the dural venous system with the extracranial venous system and are often involved in dural arteriovenous lesions. Cranial dural shunts may develop in three distinct areas of the cranial venous system: the dural sinuses and their interfaces with bridging veins and emissary veins. The exact site of the lesion may dictate the arterial feeders and original venous drainage pattern.

Spinal dural arteriovenous fistula associated with L-4 isthmic spondylolisthesis

The authors describe a case of a 79-year-old man with a lumbar spinal dural arteriovenous fistula (DAVF) and isthmic spondylolisthesis at the same level. The patient's thoracic spine MRI study demonstrated swelling and increased T2 signal in the spinal cord and regional dilated perimedullary vessels. Lumbar spine MRI showed L-4 isthmic spondylolisthesis with severe bilateral L4–5 foraminal stenoses. Spinal angiography revealed a fistulous connection at the left L-4 nerve root sleeve between perimedullary veins and a dural branch of the L-4 radicular artery. Based on previous reports about secondary spinal DAVFs, the abnormal vascular communication likely developed secondary to the microtrauma and inflammation on the left L-4 nerve root sleeve, which was attributable to the isthmic spondylolisthesis. The authors performed disconnection of the arteriovenous shunt as well as an L4–5 decompression and posterior instrumented fusion with pedicle screws. The patient's postoperative course was uneventful, and he improved neurologically. It is important to bear in mind that a spinal DAVF may develop as a consequence of any sort of trauma or inflammation involving nerve roots. One should consider the concomitant treatment of both the spinal DAVF and the underlying pathology that may have given rise to the spinal DAVF.

Superselective shunt occlusion for the treatment of cavernous sinus dural arteriovenous fistulae

BACKGROUND

In treating cavernous sinus dural arteriovenous fistulae (CSdAVFs), transvenous embolization of the whole affected sinus is usually performed, which may result in the disturbance of normal venous drainage or permanent cranial nerve palsy.

OBJECTIVE

To describe superselective shunt occlusion of CSdAVFs.

METHODS

Between July 2005 and August 2011, we had 20 consecutive cases of CSdAVFs. In 14 cases (70%), we could detect the restricted locus of arteriovenous shunts by 3-dimensional rotational angiography and/or superselective arteriography. After navigating the microcatheter to the shunt segment, consecutive superselective arteriovenography was performed to confirm the location of the microcatheter at the proper position.

RESULTS

In 12 of 14 cases (85.7%) in which the shunt was restricted, coiling only in the small venous pouch or compartment, which was just downstream of the shunt point, led to complete disappearance of the shunt without obliterating the entire sinus. No recurrence or permanent cranial nerve palsy was observed during the follow-up period with a mean of 46 months (range, 3-69 months) in 12 cases treated by superselective shunt occlusion.

CONCLUSION

This technique, which enables complete extirpation of shunts by small amounts of coils, is a feasible way to treat CSdAVFs with excellent mid- to long-term results. Understanding of the angioarchitecture by 3-dimensional rotational angiography and consecutive superselective arteriovenography was useful. This method should be considered before sinus packing or mere obliteration of dangerous venous outlets.

Cranial dural arteriovenous fistula as a rare cause of tinnitus - case report

Background

Tinnitus, occurring at least once in a lifetime in about 10–20% of the population, is an important clinical problem with complex etiology. Rare causes of tinnitus include cranial dural arteriovenous fistulas (DAVFs), which are usually small lesions consisting of abnormal connections between branches of dural arteries and venous sinuses or veins.

Case Report

Authors present a case of a 44-year-old woman with persistent, unilateral, treatment-resistant pulsatile tinnitus caused by a small dural arteriovenous fistula revealed in computed tomography angiography.

Conclusions

Computed tomography angiography is a useful diagnostic method that in some cases allows for establishing the cause of unilateral, pulsatile tinnitus.

Dural arteriovenous fistula discovered in patient presenting with recent head trauma

Patient

Male, 32

Final Diagnosis: Dural arterio-venous fistula

Symptoms: Eye redness • post-trauma headache • tinnitus

Medication: —

Clinical Procedure: Fistula embolization

Specialty: Neurology

Relationship between diabetes mellitus with dural arteriovenous fistula

INTRODUCTION

The aetiology of dural arteriovenous fistula (DAVF) is not well known, but it has been suggested that abnormality in angiogenesis plays a pathological role. Abnormality in angiogenesis is also involved in diabetes mellitus (DM). The purpose of this study was to quantify the relation between DAVF and DM in a Korean population.

METHODS

Medical records of 192 patients with DAVF between 2002 and 2011 were reviewed. Age, sex and the presence of DM, hypertension, hyperlipidaemia, stroke, coronary artery disease and cancers were compared between DAVF and control subjects. Data for control were obtained from the Korean National Health and Nutrition Examination Survey. The relationship of DM and DAVF location, presenting symptoms (benign vs. aggressive) and classification (Borden and Geibprasert) were assessed using the Pearson's chi-square test.

RESULTS

Prevalence of DM was higher in DAVF patients (19.8 %) than in controls (9.5 %; p = 0.004). Univariate analysis showed that DM (odds ratio (OR), 2.356; 95 % confidence interval (CI), 1.634-3.399; p < 0.001) and age (OR, 1.022; 95 % CI, 1.012-1.032; p < 0.001) increased the odds of DAVF. This was supported by multivariate analysis (DM: OR, 2.092; 95 % CI, 1.391-3.145; p = 0.0004 and Age: OR, 1.021; 95 % CI, 1.009-1.033; p = 0.001). When these analyses were repeated after stratification by sex, there was no relation between age and DAVF in men. Borden II and III (p = 0.038) and aggressive symptoms (p = 0.023) were related to DM.

CONCLUSION

There was a positive relation between DM and DAVF in a Korean population. DAVFs with aggressive symptoms and behaviour were more commonly related to DM.

[Intracranial dural arteriovenous fistulae. Experience after 81 cases and literature review]

OBJECTIVES

To analyse the clinical, radiological and therapeutic variables of intracranial dural arteriovenous fistulae (DAVF) treated at our institution, and to assess the validity of the Borden and Cognard classifications and their correlation with the presenting symptoms.

MATERIAL AND METHODS

The DAVF identified were retrospectively analysed. They were classified according to their location, drainage pattern and the Borden and Cognard classifications. We recorded the different treatments, their complications and efficacy.

RESULTS

There were 81DAVF identified between 1975 and 2012. The cavernous sinus (CS) location was the most frequent one. The Borden and Cognard classifications showed an interobserver Kappa index of 0.72 and 0.76 respectively. The odds ratio of aggressive presentation in the presence of cortical venous drainage (CVD) was 19.3 (2.8-132.4). No location, once adjusted by venous drainage pattern, showed significant association with an aggressive presentation. Endovascular transarterial treatment of cavernous sinus DAVF achieved symptomatic improvement of 78%, with a complication rate of 5%. The DAVF of non-CS locations, with CVD, treated surgically were angiographically shown cured in 100% of the cases, with no treatment-related complications.

CONCLUSIONS

The presence of CVD was significantly associated with aggressive presentations. The Borden and Cognard classifications showed little interobserver variability. Endovascular treatment for CS DAVF is safe and relatively effective. Surgical treatment of non-CS DAVF with CVD is safe, effective and the first choice treatment in our environment.

A unique type of dural arteriovenous fistula at confluence of sinuses treated with endovascular embolization: a case report

Dural arteriovenous fistula (DAVF) is classically defined as abnormal arteriovenous connections located within the dural leaflets. Though the exact etiology is still not clear, they are generally accepted as acquired lesions. However, some DAVFs formed as the congenital disorders are called dural arteriovenous malformations and these lesions with a marked cortical venous reflux are considered to be aggressive and warrant an early intervention. The authors describe a case of 35-year-old man presented with unique type of DAVF. The fistula was located adjacent to the confluence of venous sinuses with multiple feeders. The feeders drained into a large venous pouch just anterior to the confluence which had a bilateral venous drainage. This was associated with multiple cerebellar venous ectasia along the draining cortical vein. It was managed by staged endovascular procedures and complete cure could be achieved. The pathogenesis and technique of embolization of this complex fistula/malformation are also discussed.

Anatomy and pathology of the cranial emissary veins: a review with surgical implications

Emissary veins connect the extracranial venous system with the intracranial venous sinuses. These include, but are not limited to, the posterior condyloid, mastoid, occipital, and parietal emissary veins. A review of the literature for the anatomy, embryology, pathology, and surgery of the intracranial emissary veins was performed. Detailed descriptions of these venous structures are lacking in the literature, and, to the authors', knowledge, this is the first detailed review to discuss the anatomy, pathology, anomalies, and clinical effects of the cranial emissary veins. Our hope is that such data will be useful to the neurosurgeon during surgery in the vicinity of the emissary veins.

Recurrence of "cured" dural arteriovenous fistulas after Onyx embolization

Endovascular embolization with Onyx has been increasingly used to treat intracranial and spinal dural arteriovenous fistulas (DAVFs). Several case series have been published in recent years reporting high DAVF cure rates with this technique. Although it is seldom reported, DAVF recurrence may occur despite initial "cure." The authors present 3 separate cases of a recurrent DAVF after successful transarterial Onyx embolization. Despite adequate Onyx penetration into the fistula and draining vein, these cases demonstrate that DAVF recanalization may reappear with filling from previous or newly recruited arterial feeders. Other published reports of DAVF recurrence are examined, and potential contributory factors are discussed. These cases highlight the need for awareness of this possible phenomenon and suggest that follow-up angiography should be considered in patients treated with catheter embolization.