Stereotactic radiosurgery for noncavernous sinus dural arteriovenous fistulas: treatment outcomes and their predictors

OBJECTIVE

Stereotactic radiosurgery (SRS) has emerged as a safe and effective treatment modality for dural arteriovenous fistulas (dAVFs), particularly cavernous sinus (CS) dAVFs. However, the long-term outcomes of non-CS dAVFs are not well known. This study aimed to evaluate the efficacy and safety of SRS for non-CS dAVFs and to investigate the risk factors for incomplete obliteration.

METHODS

Between 2007 and 2020, 65 non-CS dAVFs in 63 patients were treated using SRS at a single institution. Demographic characteristics, initial clinical presentations, clinical outcomes, and radiological findings were retrospectively reviewed. The procedure-related complications were assessed. Radiological outcomes were evaluated as complete obliteration, incomplete obliteration, and angiographic worsening, whereas clinical outcomes were evaluated for symptom recovery.

RESULTS

At a median follow-up of 17 months, the overall complete obliteration rate was 63.1%, and the cumulative obliteration rates were 24.6%, 60.0%, 70.0%, and 74.3% at 12, 24, 36, and 48 months, respectively. Six patients underwent retreatment due to angiographic worsening; in 5 of these patients, recruitment of arterial feeders was newly observed in the adjacent sinus, which was not treated in the initial SRS. In the multivariate analysis, high-flow shunt and venous ectasia were associated with incomplete obliteration. No adverse events occurred after SRS.

CONCLUSIONS

SRS for non-CS dAVFs is safe, and its efficacy is highly variable according to location. High-flow shunts may indicate greater radioresistance. In the retreated cases, new fistulas tended to be accompanied by sinus steno-occlusion and formed in the adjacent sinus segments.

A Case of Extremely Rapid Progression in Foix-Alajouanine Syndrome

Foix-Alajouanine syndrome is a rare cause of spinal dural arteriovenous fistula that can cause irreversible myelopathy and paraplegia if not treated promptly. The complex nature of this pathology often leads to missed or delayed diagnosis regardless of broad workups executed. We present a symptomatically classic Foix-Alajouanine 68-year-old patient with an accelerated progression reaching stages of severe myelopathy in less than a year. Even with endovascular intervention, our patient was unable to recover neurologically. Including appropriate spinal imaging early in the workup for Foix-Alajouanine syndrome is necessary to halt or treat this disease process.

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.

Sinus reconstruction therapy for superior sagittal sinus dural arteriovenous fistula caused by parasagittal meningioma invasion: a case report

A dural arteriovenous fistula (dAVF) involving the superior sagittal sinus (SSS) is relatively rare, and its clinical course is usually aggressive. Its concomitance with a tumor has rarely been reported. Here, we present a case of SSS dAVF due to meningioma invasion, which was treated with sinus reconstruction and endovascular embolization. A 75-year-old man who had undergone tumor resection for parasagittal meningioma 4 years prior presented with intra-ventricular hemorrhage. Computed tomography angiography and magnetic resonance imaging revealed recurrent tumor invasion into the SSS causing occlusion. Cerebral angiography revealed multiple shunts along the occluded segment of the SSS, diffuse deep venous congestion, and cortical reflux. Borden type 3 SSS dAVF was diagnosed. We first performed direct tumor resection, followed by stenting for the occluded SSS and partial embolization of the shunts. After a 6-month interval, transvenous occlusion of the SSS was performed along the stent, resulting in complete obliteration of the dAVF. Sinus reconstruction therapy was effective in the immediate improvement of venous hypertension, obtaining the access route to the fistulas, and eradicating the shunts.

Trans-radial spinal angiography: A single-center experience

INTRODUCTION

Spinal angiography (SpAn) is the gold standard for diagnosis of spinal dural fistulas and arteriovenous malformations. A complete spinal angiogram necessitates the interrogation of the segmental arteries arising from the aorta at every level as well, the internal iliac; and median sacral arteries at the caudal end; and the cervical vasculature at the cranial end. SpAn has traditionally been performed with transfemoral arterial access and could be challenging. Of late, transradial arterial access has emerged as a popular alternative for endovascular surgical Neuroradiology (ESN) procedures including SpAn. However, there is paucity of the literature regarding transradial access for spinal angiography.

METHODS

After IRB approval, records and imaging were reviewed in a series of patients who underwent SpAn at our institution.

RESULTS

A total of nine spinal angiograms were performed via transradial access in a consecutive series of eight patients between July 2019 and December 2020 at our institution. Eight of these were diagnostic SpAn's, and one patient underwent SpAn with transradial approach for the treatment of a type I spinal dural arteriovenous fistula. No complications occurred during or subsequent to the procedures.

CONCLUSION

SpAn can be successfully and safely accomplished via transradial access. This approach appears to provide a stable method for interventions, as well.

Dural arteriovenous fistula presenting with recurrent focal status epilepticus and lateralised periodic epileptiform discharges

BACKGROUND

Dural arteriovenous fistulae (dAVF) are relatively infrequently encountered, and status epilepticus (SE) and lateralised periodic discharges (LPDs) on electroencephalography (EEG) have only rarely been associated with these arteriovenous malformations.

METHODS

We present a patient with recurrent presentations with focal SE, aphasia and other focal deficits of cortical function and ictal and peri-ictal LPDs on serial EEG, who was shown to have a left hemispheric dAVF associated with left transverse and sigmoid sinus thrombosis. Seizures proved refractory to four anti-seizure medications but became more amenable to control after successful embolisation of the dAVF, with subsequent resolution of the focal cortical deficits. We discuss the co-occurrence of SE and LPDs with dAVF and review previously reported cases with this rare association.

CONCLUSIONS

Our report supports a causative relationship between dAVF and focal SE, manifesting as ictal LPDs on EEG, and highlights the importance of active dAVF management in achieving seizure control. The relatively good patient outcome contrasts to the few similar case reports. Whilst rare, it is important to consider dAVF as a potentially treatable condition underlying new-onset seizures, including SE.

An isolated Sinus Intracranial Dural Arteriovenous Fistula with Unusual Drainage Pattern

Isolated sinus dural arteriovenous fistulas (DAVFs) involve a dural sinus with occlusion on both sides of the diseased sinus segment. Because of venous drainage refluxing from the isolated sinus into the cortical veins, all isolated sinus DAVFs are Borden type III or Cognard type Ⅲ/Ⅳ. Venous drainage typically involves temporo-occipital cortical veins or the superior petrosal sinus and tributaries of the petrosal vein. However, drainage veins involving the perimedullary venous system are extremely rare. Here, we present a case of Cognard type V isolated sinus DAVF successfully treated with balloon catheter and Onyx.

Observation versus intervention for Borden type I intracranial dural arteriovenous fistula: A pooled analysis of 469 patients

BACKGROUND

While it is thought that Borden Type I intracranial dural arteriovenous fistula (dAVF) have a benign clinical course, their management remains controversial.

METHODS

A comparative meta-analysis was completed to evaluate the outcomes of intervention verses observation of Borden Type I intracranial dAVF. Outcome measures included: grade progression, worsening symptoms, death due to dAVF, permanent complications other than death, functional independence (mRS 0-2), and rate of death combined with permanent complication, were evaluated. Risk differences (RD) were determined using a random effects model.

RESULTS

Three comparative studies combined with the authors' institutional experience resulted in a total of 469 patients, with 279 patients who underwent intervention and 190 who were observed. There was no significant difference in dAVF grade progression between the intervention and observation arms, 1.8% vs. 0.7%, respectively (RD: 0.01, 95% CI: -0.02 to 0.04, P = 0.49), or in symptom progression occurring in 31/279 (11.1%) intervention patients and 11/190 (5.8%) observation patients (RD: 0.03, CI: -0.02 to 0.09, P = 0.28). There was also no significant difference in functional independence on follow up. However, there was a significantly higher risk of dAVF related death, permanent complication from either intervention or dAVF related ICH or stroke in the intervention group (11/279, 3.9%) compared to the observation group (0/190, 0%) (RD: 0.04, CI: 0.1 to 0.06, P = 0.007).

CONCLUSION

Intervention of Borden Type I dAVF results in a higher risk of death or permanent complication, which should be strongly considered when deciding on management of these lesions.

Dural arteriovenous fistula of the craniocervical junction

Dural arteriovenous (AV) fistulas of the craniocervical junction can be challenging to diagnose. We describe a 70-year-old man with subacute progressive myelopathy whose MR scan of cervical spine showed serpiginous dorsal vessels, suggesting a dural AV fistula. However, a detailed diagnostic angiogram was normal, prompting additional work-up and a wider differential, which was non-revealing. His symptoms progressed over months, but the evolution of the lesion characteristics on repeat spinal imaging still suggested a dural AV fistula. Repeat angiogram identified an infratentorial dural AV fistula arising from the meningohypophyseal artery. He improved following retrosigmoid craniotomy and clipping. Initial angiography does not always demonstrate a dural AV fistula; if there is clinical and radiographic evolution, repeat angiography might identify a fistula with a rare arterial feeder.

Direct superior sagittal sinus puncture via a surgical burr hole for curative embolization of the complex transverse-sigmoid sinus dural arteriovenous fistula: How I do it

BACKGROUND

Transvenous embolization of high-grade dural arteriovenous fistulas (dAVFs) is challenging particularly when the direct sinus access is favorable due to the complex venous anatomy which prohibits endovascular access via the transfemoral approach.

METHOD

The procedure was conducted in the hybrid operating suite, where a burr hole was performed, followed by direct catheterization of the superior sagittal sinus. Coil embolization was then executed to achieve complete obliteration of the fistula.

CONCLUSION

The direct puncture of the superior sagittal sinus is a safe and effective method for treating complex dAVFs. This approach grants access to the fistula channel which facilitates curative embolization.

Comparative study of non-contrast silent and time-of-flight magnetic resonance angiographic sequences in the evaluation of intracranial dural arteriovenous fistula

AIM

To compare the performance of two non-contrast magnetic resonance angiography (MRA) sequences, silent MRA and time of flight (TOF) MRA, in the evaluation of intracranial dural arteriovenous fistula (DAVF).

MATERIALS AND METHODS

Forty consecutive patients with DAVF were enrolled and evaluated prospectively using silent MRA, TOF MRA, and digital subtraction angiography (DSA). The location, Cognard classification, arterial feeders, and venous drainage were evaluated. The therapeutic strategy and possible route were predicted on both silent and TOF MRA and these were compared with DSA during subsequent endovascular treatment.

RESULTS

Sensitivity and accuracy of silent and TOF MRA for localisation (96.4% versus 96% and 96% versus 95%, respectively) and classification (96% versus 94% and 96% versus 93.5%, respectively) were high. Silent MRA showed higher sensitivity than TOF MRA for arterial feeders and draining veins (87% versus 79% and 81.6% versus 67%). This improved to a sensitivity of 96.4% and 89% when prominent feeders were considered. The sensitivity and accuracy were 92.6% and 85.8% for immediate draining veins. Both silent and TOF MRA were accurate for therapeutic planning (96% versus 85%), although silent MRA was more accurate.

CONCLUSION

Silent MRA can more reliably evaluate the various angioarchtectural components of DAVF compared to TOF MRA.

Intracranial dural arteriovenous fistulas: association with cerebral venous thrombosis, baseline aggressiveness, and clinical outcomes. A retrospective multicenter study on 263 consecutive patients and literature review

OBJECTIVE

The pathogenesis of intracranial dural arteriovenous fistulas (icDAVFs) is controversial. Cerebral vein thrombosis (CVT) and venous hypertension are recognized predisposing factors. This study aimed to evaluate the incidence of association between icDAVF and CVT and describe baseline aggressiveness and clinical outcomes for icDAVFs associated with CVT. The authors also performed a literature review of studies reporting icDAVF associated with CVT.

METHODS

Two hundred sixty-three consecutive patients in two university hospitals with confirmed icDAVFs were included. A double-blind imaging review was performed to determine the presence or absence of CVT close or distant to the icDAVF. Location, type (using the Cognard classification), aggressiveness of the icDAVF, clinical presentation, treatment modality, and clinical and/or angiographic outcomes at 6 months were also collected. All prior brain imaging was analyzed to determine the natural history of onset of the icDAVF.

RESULTS

Among the 263 included patients, 75 (28.5%) presented with a CVT concomitant to their icDAVF. For 18 (78.3%) of 23 patients with previous brain imaging available, CVT preceding the icDAVF was proven (6.8% of the overall population). Former/active smoking (OR 2.0, 95% CI 1.079-3.682, p = 0.022) and prothrombogenic status (active inflammation or cancer/coagulation trouble) were risk factors for CVT associated with icDAVF (OR 3.135, 95% CI 1.391-7.108, p = 0.003). One hundred eighty-seven patients (71.1%) had a baseline aggressive icDAVF, not linked to the presence of a CVT (p = 0.546). Of the overall population, 11 patients (4.2%) presented with spontaneous occlusion of their icDAVF at follow-up. Seven patients (2.7%) died during the follow-up period. Intracranial DAVF + CVT was not associated with a worse prognosis (modified Rankin Scale score at 3-6 months: 0 [interquartile range {IQR} 0-1] for icDAVF + CVT vs 0 [IQR 0-0] for icDAVF alone; p = 0.055).

CONCLUSIONS

This was one of the largest studies focused on the incidence of CVT associated with icDAVF. For 6.8% of the patients, a natural history of CVT leading to icDAVF was proven, corresponding to 78.3% of patients with previous imaging available. This work offers further insights into icDAVF pathophysiology, aiding in identifying high-risk CVT patients for long-term follow-up imaging. Annual imaging follow-up using noninvasive vascular imaging (CT or MR angiography) for a minimum of 3 years after the diagnosis of CVT should be considered in high-risk patients, i.e., smokers and those with prothrombogenic status.

Dural arteriovenous fistula in the setting of cerebral venous sinus thrombosis and COVID-19 infection

OBJECTIVE

The aim of this study was to examine the presence of concurrent venous thrombosis and COVID-19 infections in patients with dural arteriovenous fistulas (dAVFs).

METHODS

An analysis of all patients diagnosed with dAVF via cerebral angiography by the senior author was conducted, with special attention given to the presence of cerebral venous sinus thrombosis (CVST) and COVID-19 infection. General demographics, clinical presentation, presence of CVST, and COVID-19 infection status were reported.

RESULTS

A total of 30 patients with dAVFs were included in this study. Three patients were diagnosed with COVID-19 (10%), with one of these patients developing CVST (33%) at 6 months postinfection. Of the 27 patients not infected with COVID-19, one was diagnosed with a likely chronic CVST at the time of presentation of dAVF (4%). A total of 11 case reports and 3 retrospective studies describing patients diagnosed with CVST at or after diagnosis of dAVFs have been reported in the literature. The incidence of dAVFs in patients with CVST has been reported as 2.4%, and the incidence of dAVF has reportedly increased five- to tenfold since the COVID-19 pandemic.

CONCLUSIONS

COVID-19 infections may pose as an emerging risk factor for the development of CVST and subsequent dAVF development. To the authors' knowledge, this study presents the first cases in the literature describing a temporal relationship between COVID-19 and development of a dAVF with CVST. The effect of both COVID-19 and associated vaccines should be further assessed in future studies to examine its impact as an effect modifier on the association of dAVF and CVST.

Safety evaluation of sinus patency after stereotactic radiosurgery for transverse-sigmoid sinus dural arteriovenous fistulas: implications of treatment options for patients with Borden type I fistulas

OBJECTIVE

This study aimed to assess the efficacy and safety of stereotactic radiosurgery (SRS) in treating transverse-sigmoid sinus dural arteriovenous fistulas (TSS DAVFs), and to investigate post-SRS sinus patency, focusing on the risk factors associated with treated sinus occlusion.

METHODS

Data from 34 patients treated with SRS between January 2006 and April 2023 were analyzed. Detailed angioarchitecture was confirmed using digital subtraction angiography before SRS. Angiography of the ipsilateral internal carotid artery and vertebral artery was performed to evaluate whether the involved side of the TSS was used for normal venous drainage. TSS stenosis was defined as sinus diameter < 50% of the normal proximal diameter. DAVF shunt obliteration, TSS occlusion, neurological status, and adverse events were also evaluated.

RESULTS

Of the 34 patients, 21 had Borden type I and 14 had Borden type II DAVFs. The median age at SRS was 64 years (interquartile range 54-71 years), and the follow-up period was 31 months (interquartile range 15-94 months). Complete shunt obliteration was achieved in 24 (70.6%) patients. The cumulative 2-, 3-, and 5-year shunt obliteration rates were 49.6%, 71.2%, and 86.0%, respectively. Borden type I had higher obliteration rates (60.5%, 83.1%, and 94.4%, respectively) than Borden type II (41.7%, 51.4%, and 75.7%, respectively; p = 0.034). TSS occlusion occurred in 5 patients (14.7%). The cumulative 1-, 5-, and 10-year TSS occlusion rates were 2.9%, 8.3%, and 23.6%, respectively, across the entire cohort. All occlusions occurred exclusively in the sinuses that were not used for normal venous drainage. Cox proportional analyses revealed that TSS stenosis and the sinus not being used for normal venous drainage were significantly associated with a greater risk of TSS occlusion after SRS (HR 9.44, 95% CI 1.01-77.13; p = 0.049).

CONCLUSIONS

SRS is effective and safe for TSS DAVF and results in favorable shunt obliteration, symptom improvement, and low complication rates. TSS occlusion after SRS is asymptomatic and is limited to sinuses that are not used for normal venous drainage.

Clinical and radiological features of parasagittal dural arteriovenous fistulas: a report of 8 cases from a single institution

OBJECTIVE

Dural arteriovenous fistulas (dAVFs) of the superior sagittal sinus (SSS) are uncommon and represent 5%-12% of all intracranial dAVFs. SSS dAVFs can be divided into two main subtypes. The first type involves direct arterialization of the SSS, whereas the second type consists of a parasagittal arteriovenous shunt draining into a cortical vein directly lateral to the SSS and has retrograde cortical venous drainage with only secondary involvement of the SSS. Descriptions of the latter type of SSS dAVF are limited. As such, the authors present a consecutive case series of parasagittal SSS dAVFs from their institution. They detail clinical presentation, treatment strategies, and clinical and radiographic outcomes.

METHODS

The authors retrospectively reviewed a prospectively collected database of dAVFs that were treated between 2017 and 2023. All dAVFs characterized by an arterialized parasagittal vein directly lateral to the SSS were included in this study. Baseline demographic, clinical, radiological, treatment, and outcome-specific variables of interest were abstracted.

RESULTS

One hundred fifty-four dAVFs were seen at the authors' institution over the 6-year period of interest. Eight (5.2%) were parasagittal dAVFs. At initial diagnostic imaging, 7 were Cognard grade III and 1 was grade IV. All patients initially underwent embolization of their dAVF. Three patients did not have complete obliteration of their dAVF after the first embolization. One patient underwent further treatment with repeat embolization, and 1 underwent microsurgical disconnection-both resulted in complete occlusion of the dAVF. Seven dAVFs were obliterated at final follow-up and 1 remained patent as the patient refused further treatment despite angiographic progression of dAVF. All symptomatic patients had resolution of their symptoms, and the average length of follow-up was 16.8 months.

CONCLUSIONS

Treatment of parasagittal dAVFs consists of occluding the proximal portion of the parasagittal arterialized draining vein. Endovascular therapy with liquid embolic agents is usually the first line of treatment. Surgical ligation is a valid option if the fistula cannot be successfully obliterated with embolization. Symptoms related to the SSS dAVF resolve after their obliteration.

Cavernous venous malformations in and around the central nervous system. Part 1: Dural and extradural

Cavernous-type malformations are venous lesions that occur in multiple locations throughout the body, and when present in the CNS, they have canonically been referred to as cavernomas, cavernous angiomas, and cerebral cavernous malformations. Herein all these lesions are referred to as "cavernous venous malformations" (CavVMs), which is congruent with the current International Society for the Study of Vascular Anomalies classification system. Even though histologically similar, depending on their location relative to the dura mater, these malformations can have different features. In Part 1 of this review, the authors discuss and review pertinent clinical knowledge with regard to CavVMs as influenced by anatomical location, starting with the dural and extradural malformations. They particularly emphasize dural CavVMs (including those in the cavernous sinus), orbital CavVMs, and spinal CavVMs. The genetic and histopathological features of CavVMs in these locations are reviewed, and commonalities in their presumed mechanisms of pathogenesis support the authors' conceptualization of a spectrum of a single disease entity. Illustrative cases for each subtype are presented, and the pathophysiological and genetic features linking dural and extradural to intradural CavVMs are examined. A new classification is proposed to segregate CavVMs based on the location from which they arise, which guides their natural history and treatment.

Localization of spinal dural arteriovenous fistulas from the spatial relationships of perimedullary vessels on standard MRI

OBJECTIVE

The goal in this study was to explore the spatial relationship of perimedullary vessels visualized on MRI to localize the side and the site of spinal dural arteriovenous fistula (SDAVF).

METHODS

A retrospective analysis of 30 consecutive patients diagnosed with SDAVF on MRI was undertaken. Two experienced reviewers blinded to all reports and angiographic images analyzed T2-weighted as well as postcontrast T1-weighted sequences. A focal prominent zone of perimedullary vessels with lateralization to one side in the thecal space was evaluated to locate the side and the site of the fistula. Spinal digital subtraction angiography served as the gold standard technique.

RESULTS

Good interrater agreement (κ = 0.77) was shown for the diagnosis of SDAVF with perimedullary vessels on T2-weighted MRI. Flow voids on T2-weighted MRI demonstrated a sensitivity of 1.0 (95% CI 1.0-1.0) and an accuracy of 0.87 (95% CI 0.79-0.95) to identify the presence of fistula. The flow voids on T2-weighted MRI also demonstrated 0.88 (95% CI 0.71-1.03) sensitivity and 0.81 (95% CI 0.70-0.92) accuracy to identify the side of SDAVF. Furthermore, flow voids on T2-weighted MRI showed 0.87 (95% CI 0.71-1.03) sensitivity and 0.87 (95% CI 0.79-0.95) accuracy to identify the site of SDAVF within 3 vertebral levels above or below the actual site. Area under the receiver operating characteristic curve demonstrated significant results (0.87 [95% CI 0.73-1.0]; p < 0.001) for flow voids on T2-weighted MRI to identify the site of shunts within 3 vertebral levels in the cranial or caudal direction.

CONCLUSIONS

Spatial distribution of perimedullary vessels observed on standard MRI show promise to locate the side and the site of fistula in patients with SDAVF.

Dural arteriovenous fistulas are not observed to convert to a higher grade after partial embolization

OBJECTIVE

Borden-Shucart type I dural arteriovenous fistulas (dAVFs) lack cortical venous drainage and occasionally necessitate intervention depending on patient symptoms. Conversion is the rare transformation of a low-grade dAVF to a higher grade. Factors associated with increased risk of dAVF conversion to a higher grade are poorly understood. The authors hypothesized that partial treatment of type I dAVFs is an independent risk factor for conversion.

METHODS

The multicenter Consortium for Dural Arteriovenous Fistula Outcomes Research database was used to perform a retrospective analysis of all patients with type I dAVFs.

RESULTS

Three hundred fifty-eight (33.2%) of 1077 patients had type I dAVFs. Of those 358 patients, 206 received endovascular treatment and 131 were not treated. Two (2.2%) of 91 patients receiving partial endovascular treatment for a low-grade dAVF experienced conversion to a higher grade, 2 (1.5%) of 131 who were not treated experienced conversion, and none (0%) of 115 patients who received complete endovascular treatment experienced dAVF conversion. The majority of converted dAVFs localized to the transverse-sigmoid sinus and all received embolization as part of their treatment.

CONCLUSIONS

Partial treatment of type I dAVFs does not appear to be significantly associated with conversion to a higher grade.

Digital exoscope versus surgical microscope in spinal dural arteriovenous fistula surgery: a comparative series

OBJECTIVE

Surgical treatment of spinal dural arteriovenous fistulas (DAVFs) has been reported to be superior to endovascular treatment in terms of occlusion of the fistula. Despite the increased availability of digital 3D exoscopes, the potential benefits of using an exoscope in spinal DAVF surgery have not been studied. The purpose of this study was to report and compare the results of exoscope- and microscope-assisted surgery for spinal DAVFs.

METHODS

All consecutive adult patients (≥ 18 years of age) treated surgically for spinal DAVFs from January 2016 to January 2023 in a tertiary neurosurgical referral center were included. All patients were operated on by one neurosurgeon. Their pre- and postoperative clinical findings, imaging studies, and intra- and postoperative events were evaluated and surgical videos from the operations were analyzed.

RESULTS

Altogether, 14 patients received an operation for spinal DAVF during the study period, 10 (71%) with an exoscope and 4 (29%) with a microscope. The DAVFs were most commonly located in the lower parts of the thoracic spine in both groups. The duration of exoscopic surgeries was shorter (141 vs 151 minutes) and there was less blood loss (60 vs 100 ml) than with microscopic surgeries. No major surgical complications were observed in either group. Of the 14 patients, 10 had gait improvement postoperatively: 7 (78%) patients in the exoscope group and 3 (75%) in the microscope group. None of the patients experienced deterioration following surgery.

CONCLUSIONS

Exoscope-assisted surgery for spinal DAVFs is comparable in safety and effectiveness to traditional microscopic surgery. With practice, experienced neurosurgeons can adapt to using the exoscope without major additional risks to the patient.

Microsurgical versus endovascular treatment of ethmoidal dural arteriovenous fistulas: systematic review and meta-analysis with a single-center case series

OBJECTIVE

Ethmoidal dural arteriovenous fistulas (DAVFs) are often associated with cortical venous drainage (CVD) and a higher incidence of hemorrhage compared with DAVFs in other locations. They may be treated with open surgical disconnection or with endovascular treatment (EVT). In this systematic review and meta-analysis, the authors compare the outcomes of ethmoidal DAVFs treated with open microsurgery versus EVT and report four additional cases of ethmoidal DAVFs treated with open microsurgery in their institution.

METHODS

A literature search of the PubMed and Scopus databases was conducted between December 2021 and May 2022 to identify relevant articles published between 1990 and 2021 using the PRISMA guidelines. References were reviewed and screened by two authors independently, and disagreements were resolved through consensus. Exclusion criteria included non-English-language studies, those with an incorrect study design, those reporting DAVFs in a nonethmoidal location, and studies whose outcomes were not stratified based on DAVF location. Inclusion criteria were any studies reporting on ethmoidal DAVFs treated by either microsurgery or EVT. A risk of bias assessment was performed using the Newcastle-Ottawa Scale. The authors performed a pooled proportional meta-analysis to compare patient outcomes.

RESULTS

Twenty studies were included for analysis. Of 224 patients, 142 were treated with surgery, while 103 were treated with EVT. Seventy percent (148/210) of the patients were symptomatic at presentation, with hemorrhage being the most common presentation (48%). CVD was present in 98% of patients and venous ectasia in 61%. The rates of complete DAVF obliteration with surgery and EVT were 89% and 70%, respectively (95% CI -30% to -10%, p < 0.03). Twenty percent (21/103) of endovascularly treated fistulas required subsequent surgery. Procedure-related complications occurred in 10% of the surgical cases, compared with 13% of the EVT cases. The authors' case series included 4 patients with ethmoidal DAVFs treated surgically with complete obliteration, without any postoperative complications.

CONCLUSIONS

The complete obliteration rates of ethmoidal DAVF appear to be higher and more definitive with microsurgical intervention than with EVT. While complication rates between the two procedures seem similar, patients treated with EVT may require further interventions for definitive treatment. The limitations of this study include its retrospective nature, the quality of studies included, and the continued evolving technologies of EVT. Future studies should focus on the association between venous drainage pattern and the proclivity toward venous ectasia or rate of hemorrhage at presentation.

Comparison between endovascular and surgical treatment of spinal dural arteriovenous fistulas: a single-center cohort and systematic review

OBJECTIVE

With recent advancements in minimally invasive techniques, endovascular embolization has gained popularity as a first-line treatment option for spinal dural arteriovenous fistulas (sDAVFs). The authors present their institution's case series of sDAVFs treated endovascularly and surgically, and they performed a systemic review to assess the outcomes of both modalities of treatment.

METHODS

The authors conducted a retrospective observational study of 24 consecutive patients with sDAVFs treated between 2013 and 2023. The primary outcome was the rate of occlusion, which was compared between the surgically and endovascularly treated sDAVFs. They also conducted a systemic review of all the literature comparing outcomes of endovascular and surgical treatment of sDAVFs.

RESULTS

A total of 24 patients with 24 sDAVFs were studied. The mean patient age was 63.8 ± 15.5 years, and the majority of patients were male (n = 19, 79.2%). Of the 24 patients, 8 (33.3%) received endovascular treatment, 15 (62.5%) received surgical treatment, and 1 (4.2%) patient received both. Complete occlusion at first follow-up was higher in the surgical cohort but did not achieve statistical significance (66.7% vs 25%, p = 0.52). Recurrence was higher in the endovascular cohort (37.5% vs 13.3%, p = 0.3), while the rate of postprocedural complications was higher in the surgical cohort (13.3% vs 0%, p = 0.52); however, neither of these differences was statistically significant.

CONCLUSIONS

Endovascular embolization in the management of sDAVFs is an alternative treatment to surgery, whose long-term efficacy is still under investigation. These findings suggest overall comparable outcomes between endovascular and open surgical treatment of sDAVFs. Future studies are needed to determine the role of endovascular embolization in the overall management of sDAVFs.

Evaluating the diagnostic accuracy of 3D contrast-enhanced magnetic resonance angiography versus digital subtraction angiography in spinal dural arteriovenous fistulas

OBJECTIVE

Spinal dural arteriovenous fistulas (SDAVFs) often go undiagnosed, leading to irreversible spinal cord dysfunction. Although digital subtraction angiography (DSA) is the gold standard for diagnosing SDAVF, DSA is invasive and operator dependent, with associated risks. MR angiography (MRA) is a promising alternative. This study aimed to evaluate the performance of MRA as an equal alternative to DSA in investigating, diagnosing, and localizing SDAVF.

METHODS

Prospectively collected data from a single neurosurgeon at a large tertiary academic center were searched for SDAVFs. Eligibility criteria included any patient with a surgically proven SDAVF in whom preoperative DSA, MRA, or both had been obtained. The eligible patients formed a consecutive series, in which they were divided into DSA and MRA groups. DSA and MRA were the index tests that were compared to the surgical SDAVF outcome, which was the reference standard. Accurate diagnosis was considered to have occurred when the imaging report matched the operative diagnosis to the correct spinal level. Comparisons used a two-sample t-test for continuous variables and Fisher-Freeman-Halton's exact test for categorical variables, with p < 0.05 specifying significance. Univariate, bivariate, and multivariate analyses were conducted to investigate group associations with DSA and MRA accuracy. Positive predictive value, sensitivity, and accuracy were calculated.

RESULTS

A total of 27 patients with a mean age of 63 years underwent surgery for SDAVF. There were 19 male (70.4%) and 8 female (29.6%) patients, and the mean duration of symptoms at the time of surgery was 14 months (range 2-48 months). Seventeen patients (63%) presented with bowel or bladder incontinence. Bivariate analysis of the DSA and MRA groups further revealed no significant relationships between the characteristics and accuracy of SDAVF diagnosis. MRA was found to be more sensitive and accurate (100% and 73.3%) than DSA (85.7% and 69.2%), with a subanalysis of the patients with both preoperative MRA and DSA showing that MRA had a greater positive predictive value (78.6 vs 72.7), sensitivity (100 vs 72.7), and accuracy (78.6 vs 57.1) than DSA.

CONCLUSIONS

In surgically proven cases of SDAVFs, the authors determined that MRA was more accurate than DSA for SDAVF diagnosis and localization to the corresponding vertebral level. Incomplete catheterization at each vertebral level may result in the failure of DSA to detect SDAVF.

Long-term treatment outcomes and natural course of low-grade intracranial dural arteriovenous fistulas

OBJECTIVE

In contrast to high-grade dural arteriovenous fistula (dAVF), low-grade dAVF is mainly associated with tinnitus and carries a low risk of morbidity and mortality. It remains unclear whether the benefits of active interventions outweigh the associated risk of complications in low-grade dAVF.

METHODS

The authors conducted a retrospective single-center study that included all consecutive patients diagnosed with an intracranial low-grade dAVF (Cognard type I and IIa) during 2012-2022 with DSA. The authors analyzed symptom relief, symptomatic angiographic cure, treatment-related complications, risk for intracerebral hemorrhage (ICH), and mortality. All patients were followed up until the end of 2022.

RESULTS

A total of 81 patients were diagnosed with a low-grade dAVF. Of these, 48 patients (59%) underwent treatment (all primary endovascular treatments), and 33 patients (41%) did not undergo treatment. Nine patients (19%) underwent retreatments. Angiographic follow-up was performed after median (IQR) 7.7 (6.1-24.1) months by means of DSA (mean 15.0, median 6.4 months, range 4.5-83.4 months) or MRA (mean 29.3, median 24.7 months, range 5.9-62.1 months). Symptom control was achieved in 98% of treated patients after final treatment. On final angiographic follow-up, 73% of patients had a completely occluded dAVF. There were 2 treatment-related complications resulting in 1 transient (2%) and 1 permanent (2%) neurological complication. One patient showed recurrence and progression of a completely occluded low-grade dAVF to an asymptomatic high-grade dAVF. No cases of ICH- or dAVF-related mortality were found in either treated patients (median [IQR] follow-up 5.1 [2.0-6.8] years) or untreated patients (median [IQR] follow-up 5.7 [3.2-9.0] years).

CONCLUSIONS

Treatment of low-grade dAVF provides a high rate of symptom relief with small risks for complications with neurological sequela. The risks of ICH and mortality in patients with untreated low-grade dAVF are minimal. Symptoms may not reveal high-grade recurrence, and radiological follow-up may be warranted in selected patients with treated low-grade dAVF. An optimal radiographic follow-up regimen should be developed by a future prospective multicenter registry.

Treatment outcomes and the role of the DES scheme in the appropriate treatment selection for high-grade dural arteriovenous fistulas

OBJECTIVE

Endovascular and microsurgical treatment are viable options for the majority of Borden type III dural arteriovenous fistulas (dAVFs). The aim of this study was to examine treatment outcomes in a comparative analysis of endovascular and surgical treatment modalities for Borden type III fistulas and explore clinical implications of the DES scheme in selecting ideal candidates for surgical therapy.

METHODS

Patients diagnosed with dAVFs with leptomeningeal venous drainage admitted to the Departments of Neurosurgery or Neuroradiology of the University Hospital Zurich between January 2014 and October 2021 were included in this study. Comprehensive patient data including demographics, clinical presentation, and dAVF characteristics, including established classifications, were collected. Treatment outcomes were assessed based on postinterventional angiography findings. In addition, treatment-related complications were assessed based on the Clavien-Dindo classification.

RESULTS

Among all Borden type III dAVFs, 15 were initially treated endovascularly (60% complete occlusion rate) and 10 with microsurgical disconnection (90% complete occlusion rate) (p = 0.18). Subgroup analysis of dAVFs meeting the criteria for directness and exclusivity based on the DES scheme showed a 100% complete occlusion rate after microsurgical disconnection, whereas embolization achieved a complete occlusion rate of 60% (p = 0.06). There was no significant difference in the rate or severity of treatment-related complications between treatment modalities.

CONCLUSIONS

This study suggests that microsurgical disconnection is a viable primary treatment modality for Borden type III dAVFs, particularly for dAVFs that meet the criteria of directness and exclusivity according to the DES scheme. The DES scheme demonstrates its relevance in selecting the most appropriate treatment strategy for affected patients.

How I do it: angiography-assisted full endoscopic treatment of spinal dural arteriovenous fistula

BACKGROUND

Spinal dural arteriovenous fistula (sDAVF) is a rare vascular malformation that leads to serious neurological symptoms. We treat a 52-year-old man with sDAVF in the thoracic segment exhibiting uncoordinated gait.

METHOD

Thoracic MRI of the lesion indicated myelomalacia and dilated blood vessels, while DSA revealed the right T6 radicular artery as the feeding arteriole. A full endoscopic obliteration of the lesion was performed under angiography guidance in a hybrid operation room.

CONCLUSION

The case underscores the importance of a multidisciplinary and individualized approach to successfully manage sDAVF using a fully endoscopic approach.

Isolated sinus dural arteriovenous fistulas: a single-center experience in 44 patients

BACKGROUND

Isolated sinus dural arteriovenous fistulas (DAVFs) constitute a rare and distinctive subtype of DAVF, typically found in small case numbers or case reports. The optimal treatment for this DAVF type remains unclear.

OBJECTIVE

This study aims to further detail the treatment outcomes of isolated sinus DAVFs in a sizable cohort from a single center.

METHODS

A retrospective study was undertaken on a consecutive series of patients with isolated sinus DAVFs treated at a single institution from 2002 to 2022. The article delineates the clinical presentation, angiographic features, treatment strategy, clinical and angiographic outcomes, and complications.

RESULTS

The cohort consisted of 31 males and 13 females, with an average age of 52.0 ± 15.5 years (range, 16-83). The success rate for trans-arterial embolization (TAE) was 97.3% (36/37). Transvenous embolization (TVE) with the reopening technique was successful in 3 of 4 patients (75.0%). Two open burr-hole TVE cases (66.7%, 2/3) and one surgery (100%) resulted in immediate complete closure of the fistula. Immediate complete occlusion was achieved in 93.2% (41/44) of cases. There was one major complication (2.3%, 1/44) and two fistulas recurred (9.5%, 2/21).

CONCLUSIONS

The majority of isolated sinus DAVFs can be effectively treated with TAE using Onyx. TVE and surgery serve as alternative techniques when arterial access is deemed inappropriate or when complete occlusion cannot be attained with TAE. Complete embolization of isolated sinus DAVFs by TAE can typically be achieved without delay.

Endovascular embolisation of posterior condylar canal dural arteriovenous fistula

We describe a rare case of dural arteriovenous fistula (dAVF) of the posterior condylar canal in a man in his 30s who presented with recent onset headache and neck pain and subsequently acute intracranial haemorrhage. Radiological workup showed a medulla bridging vein draining dAVF of the right posterior condylar canal supplied by a meningeal branch of the right occipital artery. A dilated venous sac was seen compressing over cerebellar tonsil on the right side. There was acute haemorrhage in the posterior fossa and fourth ventricle. He was successfully managed with transarterial endovascular embolisation via a supercompliant balloon microcatheter without any complication. The balloon microcatheter effectively prevented reflux of the liquid embolic agent into the parent artery and vasa nervosa of lower cranial nerves.

The VEBAS score: a practical scoring system for intracranial dural arteriovenous fistula obliteration

BACKGROUND

Tools predicting intracranial dural arteriovenous fistulas (dAVFs) treatment outcomes remain scarce. This study aimed to use a multicenter database comprising more than 1000 dAVFs to develop a practical scoring system that predicts treatment outcomes.

METHODS

Patients with angiographically confirmed dAVFs who underwent treatment within the Consortium for Dural Arteriovenous Fistula Outcomes Research-participating institutions were retrospectively reviewed. A subset comprising 80% of patients was randomly selected as training dataset, and the remaining 20% was used for validation. Univariable predictors of complete dAVF obliteration were entered into a stepwise multivariable regression model. The components of the proposed score (VEBAS) were weighted based on their ORs. Model performance was assessed using receiver operating curves (ROC) and areas under the ROC.

RESULTS

A total of 880 dAVF patients were included. Venous stenosis (presence vs absence), elderly age (<75 vs ≥75 years), Borden classification (I vs II-III), arterial feeders (single vs multiple), and past cranial surgery (presence vs absence) were independent predictors of obliteration and used to derive the VEBAS score. A significant increase in the likelihood of complete obliteration (OR=1.37 (1.27-1.48)) with each additional point in the overall patient score (range 0-12) was demonstrated. Within the validation dataset, the predicted probability of complete dAVF obliteration increased from 0% with a 0-3 score to 72-89% for patients scoring ≥8.

CONCLUSION

The VEBAS score is a practical grading system that can guide patient counseling when considering dAVF intervention by predicting the likelihood of treatment success, with higher scores portending a greater likelihood of complete obliteration.

Transarterial Embolization of Anterior Cranial Fossa Dural AVFs as a First-Line Approach: A Single-Center Study

BACKGROUND AND PURPOSE

Endovascular treatment has been increasingly used for anterior cranial fossa dural AVFs. Evidence on the safety and efficacy of different endovascular treatment strategies is limited. We report clinical and angiographic outcomes of patients with anterior cranial fossa dural AVFs who underwent treatment using transarterial embolization with n-BCA as a first-line approach.

MATERIALS AND METHODS

Consecutive patients undergoing treatment for anterior cranial fossa dural AVFs at the Amsterdam University Medical Centers between 2010 and 2023 were retrospectively included. Transarterial embolization was used as a first-line approach, while transvenous treatment and surgery were used in cases of unsuccessful transarterial embolization. Treatment was evaluated on the basis of the angiographic cure rate, procedural complications, and clinical outcome.

RESULTS

Fourteen patients were included with 15 anterior cranial fossa dural AVFs. All patients underwent primary endovascular treatment (12 transarterial, 1 transvenous, and 1 combined). Complete occlusion using only transarterial embolization was reached in 69% of patients (9/13), while the overall complete occlusion by endovascular treatment was reached in 79% of patients (11/14). Navigation and embolization were performed through the ophthalmic artery in 13 patients, with no procedural complications. Visual acuity was preserved in all patients. Three patients underwent an operation after failed endovascular treatment. All patients had complete anterior cranial fossa dural AVF occlusion at follow-up.

CONCLUSIONS

Treatment of anterior cranial fossa dural AVFs using transarterial embolization with n-BCA as a first-line approach is a safe and feasible first-line treatment strategy. No visual complications due to embolization through the ophthalmic artery occurred in this study.

Enhanced Treatment Options for Dural Arteriovenous Fistulas at the Craniocervical Junction: Endovascular Embolization Versus Microsurgery? A Single-Center 23-Year Experience

OBJECTIVE

The occurrence of dural arteriovenous fistulas (DAVFs) at the craniocervical junction (CCJ) is an uncommon vascular malformation. The diagnosis and treatment of CCJ DAVFs present a formidable challenge. This study aims to investigate the effect of endovascular embolization and microsurgery on improving patient prognosis.

METHODS

This retrospective study included patients diagnosed with CCJ DAVFs who received treatment at the First Affiliated Hospital of Fujian Medical University between January 2000 and January 2023. The clinical records, imaging data, and treatment methods were obtained from the hospital's medical record system. The patients were classified into microsurgery and embolization groups based on the surgical technique employed for treatment. The primary outcome measures were surgical-associated neurological dysfunction (SAND) and long-term neurological outcomes. The Cox proportional hazard regression was utilized to determine hazard ratios and 95% confidence intervals (CI) to assess the relationship between treatment methods and prognosis. Kaplan-Meier survival analysis was employed to evaluate the incidence of SAND in both cohorts.

RESULTS

This study recruited 46 patients with an average age of 53.72 ± 13.83 years. In the microsurgery group, there were 12 cases (26.1%) observed. While in the embolization group, there were 34 cases (73.9%). Of these patients, 16 (34.8%) experienced SAND after treatment. In the microsurgery group, there were 8 cases (75.0%), while in the embolization group, only 8 cases (23.5%) were reported. Specifically, the embolization group exhibited a significantly lower risk of SAND [adjusted hazard ratio = 0.259, 95% CI = 0.096-0.700; P = 0.008)] compared to the microsurgery group. Additionally, the combined Borden grade 2-3 was found to be significantly associated with SAND (adjusted hazard ratio = 3.150, 95% CI = 1.132-8.766; P = 0.028). The results of the Kaplan-Meier survival analysis indicated a statistically significant difference in the occurrence of favorable functional outcomes between the 2 groups (log-rank P = 0.0081).

CONCLUSIONS

CCJ DAVFs are uncommon disorders characterized by a diverse range of clinical manifestations. The functional prognosis of endovascular treatment may be superior to microsurgery.

An Intraosseous Pterygopalatine Fossa Dural Arteriovenous Fistula

Intraosseous dural arteriovenous fistulas (DAVFs) are distinct in that the fistula is located within the bone rather than the dura through which the dural vessels pass. It has been stated that only fistulas within marrow should be considered as intraosseous DAVFs rather than DAVFs with traditional angioarchitecture that erode into bone or are located within a bony foramen. The ambiguity in the definition may have contributed to the oversight and scarcity of relevant cases reported in the literature. Three- or four-dimensional digital subtraction angiography is useful for determining the location of the fistula and developing treatment plans. We present an intraosseous DAVF around the pterygopalatine fossa using a transvenous approach.

An infratentorial dural arteriovenous fistula mimicking cervical myelopathy: A case report

Dural arteriovenous fistulas may have insidious clinical presentations and are often challenging to diagnose. A small number of cases have been associated with perimedullary venous congestion and cord oedema, mimicking common pathologies, such as cervical myelopathy. We describe a case report of a patient presenting with a constellation of symptoms and radiological signs mimicking C5/6 cervical myelopathy secondary to disc herniation. The patient was managed with anterior cervical discectomy and fusion, with postoperative neurological deterioration unresponsive to steroid therapy. This prompted further investigation of other pathologies. An infratentorial Cognard 5 and Borden type 3 dural arteriovenous fistula was diagnosed on 6-vessel DSA and managed with onyx embolization. Marked improvement of neurological symptoms, notably bilateral lower limb weakness, was achieved postoperatively. In summary, this case demonstrates the importance of considering alternative, less common pathologies that involve the cervical spinal cord when neurological improvement is not achieved following decompressive surgery for cervical myelopathy.

Dural Arteriovenous Fistula Mimicking Acute Encephalitis

We herein report a case of acute neurological symptoms and a fever initially suspected of being encephalitis but later revealed to be dural arteriovenous fistula (dAVF). An 84-year-old woman had a fever and cerebral edema and was initially treated for encephalitis. A review of her magnetic resonance imaging findings revealed abnormal blood flow signals. After cerebral angiography, the patient was finally diagnosed with left transverse-sigmoid sinus dAVF. The present case showed that dAVF can also present with an acute onset and a fever, mimicking acute encephalitis. Because the treatments for encephalitis and dAVF differ greatly, the possibility of dAVF should also be considered when diagnosing encephalitis.

Severe papilledema and multiple hypercoagulability abnormalities in patient with dural arterio-venous fistulas

A 54-year-old man noticed right-sided pulsatile tinnitus for the past six months and recently started experiencing transient visual obscurations when standing up. MRI demonstrated two separate brain dural arteriovenous fistulas (bdAVF) in sagittal and right sigmoid dural sinuses. Neuro-ophthalmological exam demonstrated severe bilateral optic disc edema with preserved visual acuity but early nerve fiber bundle defects on visual field testing. Hypercoagulable profile testing revealed very elevated D-dimer, significantly decreased protein S level and elevated homocysteine levels. This case highlights importance of referring all patients with bdAVFs for neuro-ophthalmological consultation as venous hypertension can cause increased intracranial pressure and resultant papilledema. Papilledema does not affect central vision until late stages when visual loss is irreversible thus screening for its presence and pre-treatment extent of peripheral visual loss is paramount. It also demonstrates that hypercoagulable workup should be initiated in all patients with bdAVF in order to prevent future thromboembolic events.

Angiographic challenges of spinal dural and epidural arteriovenous fistulas: report on 45 cases

PURPOSE

The localization of the fistula level in spinal dural arteriovenous fistulas (dAVFs) and epidural arteriovenous fistulas (edAVFs) remains a diagnostic challenge.

METHODS

Consecutive patients with spinal dAVFs and edAVFs in the thoracic, lumbar, and sacral regions were included. The primary endpoint was to describe the characteristics of patients who required angiography with multiple catheterizations of segmental arteries (10 or more).

RESULTS

Forty-five patients (median age 69 years; male 89%; dAVFs, n = 31; edAVFs, n = 14) were included. Spinal dAVFs commonly developed in the thoracic region and edAVFs in the lumbosacral region. Fistulas were predicted at the correct level or plus/minus 2 level in less invasive examinations using multi-detector CT angiography (n = 28/36, 78%) and/or contrast-enhanced MR angiography (n = 9/14, 64%). We encountered diagnostic challenges in the localization of fistulas in 6 patients. They underwent angiography a median of 2 times. In each patient, spinal levels were examined at a median of 25 levels with a median radiation exposure of 3971 mGy and 257 ml of contrast. Fistulas were finally localized at the high thoracic region (T4-6) in 3 patients, the sacral region (S1-2) in 2, and the lumbar region (L3) in 1. Four patients were diagnosed with edAVFs and 2 with dAVFs. The correlation coefficient between the fistula level and the rostral end of the intramedullary T2 high-signal intensity on MRI was interpreted as none.

CONCLUSION

In patients in whom less invasive examinations failed for fistula localization, high thoracic or sacral AVFs need to be considered.

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.

Anticoagulation helps shrink giant venous lakes and arteriovenous fistulas in dural sinus malformation

BACKGROUND

Dural sinus malformations (DSMs) associated with high flow arteriovenous shunts are a challenging disease in babies that can lead to severe neurological damage or death. We report our treatment strategy in seven consecutive DSMs.

METHODS

We performed a retrospective analysis of seven consecutive patients from four centres, treated with transarterial embolization and anticoagulants.

RESULTS

Mean clinical and imaging follow-up was 2.8 years (IQR1-3 1.8-5.3). At baseline, the median size of the dilated venous pouch (giant lake) was 35 mm (IQR1-3 24-41) that decreased to a normal or near normal venous collector diameter of median size 11.5 mm (IQR1-3 8.5-13.8). This was achieved after a median of two embolization sessions targeted on dural feeders (IQR1-3 1.5-2.5), leaving associated pial feeders untreated. There were no cerebral hemorrhagic complications during the anticoagulation treatment. Median percentage of shunt remaining after embolization was 30% (IQR1-3 12-30), which spontaneously decreased with anticoagulation and even after discontinuation of anticoagulation, in parallel with the reduction in diameter of the dilated sinus, up to healing (or near healing). At the last clinical assessment, the modified Rankin Scale score was 0 in four patients, 1 in one patient, and 3 in two patients.

CONCLUSIONS

Anticoagulants may help to potentiate transarterial embolization in DSMs in babies by decreasing venous dilatation and reducing the remaining arteriovenous shunt, particularly the pial feeders. We did not observe recurrence of arteriovenous shunts after treatment, especially during anticoagulation treatment. Further studies are needed to support our findings.

Dural arteriovenous fistula embolisation with venous remodelling following venous sinus stenting

We report a case of the formation of a dural arteriovenous fistula (dAVF) of the transverse-sigmoid sinus following venous sinus stenting (VSS), treated with trans-arterial embolisation and venous remodelling. An obese woman in her 30s presented with persistent daily headaches after undergoing endoscopic repair of a skull base cerebrospinal fluid leak. Angiography demonstrated a focal right transverse-sigmoid sinus stenosis, and she underwent VSS of the right transverse sinus. She developed progressive pulsatile tinnitus within 3 months, and angiography demonstrated the formation of a Borden type 1 dAVF along the stent. Trans-arterial embolisation of the dAVF was performed with venous remodelling using a Copernic RC balloon. While VSS has become a promising treatment for venous sinus stenosis and idiopathic intracranial hypertension, dAVF formation is a rare but significant potential complication. Embolisation with venous remodelling can be performed to treat these lesions.