Dural Arteriovenous Fistula Research Articles

Dural arteriovenous fistula draining into the superior petrosal vein: a comparative analysis of two case reports for enhanced anatomical understanding and optimal treatment strategy

Dural arteriovenous fistula draining into the superior petrosal vein: a comparative analysis of two case reports for enhanced anatomical understanding and optimal treatment strategy

Surgical considerations and techniques using intraoperative indocyanine green angiography for ethmoidal dural arteriovenous fistula.

This study aims to investigate the efficacy of microsurgery with intraoperative indocyanine green (ICG) angiography as a treatment approach for ethmoidal dural arteriovenous fistula (DAVF). Between January 2010 and July 2021, our institution encountered a total of eight cases of ethmoidal DAVF. In each of these cases, microsurgical treatment was undertaken utilizing a bilateral sub-frontal interhemispheric approach, with the aid of intraoperative ICG angiography. ICG angiography identified bilateral venous drainage with single dominance in four cases (50%) of ethmoidal DAVF, a finding that eluded detection during preoperative transfemoral cerebral angiography (TFCA). The application of microsurgical treatment, in conjunction with intraoperative ICG angiography, resulted in consistently positive clinical outcomes for all patients, as evaluated using the Glasgow Outcome Scale (GOS) at the 6-month postoperative follow-up assessment; six patients showed GOS score of 5, while the remaining two patients attained a GOS score of 4. The use of intraoperative ICG angiography enabled accurate identification of both dominant and non-dominant venous drainage patterns, ensuring complete disconnection of the fistula and reducing the risk of recurrence.

Diagnosis of a Dural Arteriovenous Fistula Involving the Superior Sagittal Sinus: The MMA Sign on Routine 3D-TOF MR Angiography

The main feeding artery of a dural arteriovenous fistula (DAVF) involving the superior sagittal sinus (SSS) is the middle meningeal artery (MMA). MMA extends continuously from the proximal part to SSS in DAVF involving SSS. It is possible to diagnose DAVF involving SSS by evaluating the proximal part of MMA on routine three-dimensional time-of-flight MR angiography (MRA). We termed the finding in an anteroposterior maximum intensity projection (MIP) image of routine MRA in which MMA was continuously visualized at the top of the imaging slab (the upper corpus callosum level) without tapering as the MMA sign. The purpose of the present study was to examine the frequency of the MMA sign on routine MRA in patients with DAVF involving SSS and control patients. Subjects comprised 18 patients with DAVF involving SSS confirmed by angiography and 871 control subjects who underwent routine MRA. The presence of the MMA sign was retrospectively evaluated using an anteroposterior MIP image of routine MRA in patients with DAVF involving SSS and control patients. The MMA sign was observed in 17 of the 18 (94%) patients with DAVF involving SSS. In one patient with DAVF involving the posterior part of SSS without the MMA sign, the main feeding artery was the occipital artery, not MMA. The MMA sign was observed in 13 of the 871 (1.5%) control patients. The MMA sign on routine MRA is useful, suggesting DAVF involving SSS.

Aneurysm of the Artery of Wollschlaeger and Wollschlaeger.

The Artery of Wollschlaeger and Wollschlaeger (AWW) is a non-eloquent, tentorial branch of the superior cerebellar artery (SCA). Coursing posteriorly from an intradural origin, the AWW passes through the ambient cistern and supplies the medial tentorium. Due to its small diameter, the AWW is often only identified in the context of secondary dilation from pathologies such as dural arteriovenous fistulas (DAVF). Herein, we report the first case, to our knowledge, of an aneurysm of the AWW associated with a posterior fossa DAVF Swift identification and diagnosis followed by cautious treatment of both the aneurysm and fistula were critical to avert rupture and optimize outcomes, avoiding potential hemorrhagic complications.

Parasagittal and Superior Sagittal Sinus Dural Arteriovenous Fistulas: Clinical Presentations, Imaging Characteristics, and Treatment Strategies.

Parasagittal and superior sagittal sinus (SSS) dural arteriovenous fistulas (DAVFs) are often inappropriately classified. We explore the clinical presentations, imaging characteristics, and endovascular treatment strategies of these 2 DAVF subtypes. Clinical and imaging data of 19 patients with SSS or parasagittal sinus DAVFs who underwent endovascular treatment in our institution between 2017 and 2022 were retrospectively analyzed. The angiographic findings, endovascular treatment strategies, and angiographic outcomes were evaluated and recorded. Among these 19 patients, 14 had a parasagittal DAVF, 4 had a SSS DAVF, and 1 patient had both parasagittal and SSS DAVF. Only 1 (1/19, 5.26%) patient presented with intracranial hemorrhage. For the parasagittal DAVF group, most of the shunts were located along the middle third of the SSS (12/15, 80%), on the dura in proximity with the junctional zone between the bridging vein and SSS (15/15, 100%), with ipsilateral cortical venous reflux (CVR) (15/15, 100%). For the SSS DAVF group, all 5 patients had shunting zone along the middle third of the SSS, on the sinus or parasinus wall, with bilateral CVR. Transarterial embolization, via the middle meningeal artery as the primary route of access, was the primary treatment approach in 95% of cases (19/20). Reflux of embolization material into the SSS was observed in 1 case (1/5, 20%) of SSS DAVF in which balloon sinus protection was not used during embolization. Our study found that parasagittal DAVFs have shunting point(s) centered on the junctional zone of the bridging vein and the SSS with ipsilateral CVR, while SSS DAVFs have shunting point(s) centered on the sinus or parasinus wall with bilateral CVR. Transarterial embolization via the middle meningeal artery can be used as the primary treatment strategy in most cases. Balloon sinus protection during embolization is not necessary in cases of parasagittal DAVF with occluded or stenosed connection with the SSS but its use should be considered in cases of SSS DAVF with patent sinus.

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.

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. 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. 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.

The Impact of Magnetic Resonance Imaging Findings in Predicting Neurological Status Pre- and Post-Treatment of Spinal Dural Arteriovenous Fistulas: A 22-Year Experience in a Neurovascular and Spine Center.

Successful treatment of spinal dural arteriovenous fistulas (SDAVF) requires prompt diagnosis with definitive fistula localization and non-delayed treatment. Magnetic resonance imaging (MRI) is used for the screening and follow-up of SDAVF, although the value of MRI signs such as myelopathy and flow voids is controversial. Therefore, we investigated the predictive value of MRI signs pre- and post-treatment and their correlation with the neurological status of SDAVF patients. We retrospectively analyzed the clinical records of 81 patients who underwent surgical or endovascular treatment for SDAVF at our hospital between 2002 and 2023. A total of 41 SDAVF patients with follow-up MRI of 4.6 [2.9-6.5] months (median [interquartile range]) post-treatment and clinical follow-up of 3, 6, and 12 months were included. The extent of pretreatment myelopathy was seven [6-8] vertebral levels, with follow-up MRI showing no myelopathy in 70.7% of cases. The pretreatment flow voids extended over seven [4.5-10] vertebral levels and completely disappeared on follow-up MRI in 100% of cases. The modified Aminoff-Logue scale of disability (mALS) was four [2-7] pretreatment and two [0-4.5] at the third follow-up, with improvement in 65.9% of patients. The American Spinal Injury Association motor score (ASIA-MS) was 97 [88-100] pretreatment and 100 [95-100] at the third follow-up assessment, with 78% of patients improving. Pretreatment ASIA-MS correlated with the extent of myelopathy at admission (R2: 0.179; 95% CI: -0.185, -0.033; p = 0.006) but not with flow voids at admission, while pretreatment mALS showed no correlation with either MRI signs. The improvement in ASIA-MS and mALS between admission and the last follow-up showed no correlation with the extent of pretreatment myelopathy and flow voids or with pos-treatment MRI changes. The diagnostic sensitivity of magnetic resonance angiography (MRA) for localization of the fistula was 68.3% (28/41). The severity of the clinical condition in SDAVF patients has a multifactorial cause, whereby the ASIA-MS correlates with the extent of myelopathy pretreatment. MRI changes after treatment showed no correlation with the clinical outcome and cannot be used as a prognostic factor.

Diagnostic, clinical management, and outcomes in patients with spinal dural arteriovenous fistula.

Spinal dural arteriovenous fistulas (SDAVFs) are rare spinal vascular malformations, but account for 70 to 80% of all spinal arteriovenous malformations. SDAVFs can be treated either surgically or endovascularly, with surgical treatment appearing to lead to higher closure rates. Our aim was to analyze the demographic data, diagnostic history, treatment characteristics and clinical short- and long-term outcomes. The medical records of 81 patients who underwent surgical (n = 70, 86.4%) and endovascular (n = 11, 13.6%) treatment for SDAVF at a university hospital between 2002 and 2023 were retrospectively analyzed. SDAVF was observed more frequently in men than women (61, 75.3% vs. 20, 24.7%) with a mean age of 63.5 ± 12.7 years and a mean duration of symptoms to diagnosis of 12.0 ± 12.8 months. The most common first symptom was gait disturbance (36, 44.4%), followed by sensory disturbance (24, 29.6%). The location of the fistula point was most common in the lower thoracic region (36, 44.5%), followed by the lumbar region (23, 28.4%). Incomplete or failed occlusion of the fistula occurred in 8 patients (9.9%), with 6 patients (7.4%) undergoing further treatment either surgically or endovascularly. Treatment- or hospital-related complications were observed in 16 patients (19.8%). A single-level laminectomy was the most common approach (31, 44.3%), followed by single-level hemilaminectomy (28, 40.0%), and unilateral interlaminar fenestration (11, 15.7%). Back pain or radiculopathy was observed in 58% of patients (47/81) pre-treatment and had already decreased to 24.7% at hospital discharge (p < 0.001). No significant differences were observed in sensory disturbances (p = 0.681). The median of American Spinal Injury Association motor score (ASIA-MS) was 94 [82.5-100] at admission, 98 [86.5-100] at hospital discharge, 100 [90-100] at the first, second, and third follow-up (p = 0.019). The median modified Aminoff-Logue scale (mALS) was 5 [2-7] at admission, 3 [1-6] at hospital discharge, 2 [1-5] at the first follow-up, 2 [0.5-5] at the second follow-up and 2 [1-7] at the third follow-up (p = 0.006). SDAVF occurs predominantly in men in the 6th decade of life and can be safely and effectively treated surgically and endovascularly, improving symptoms such as pain and motor deficits, gait disturbances as well as bowel and bladder dysfunction, but not sensory disturbances.

Radiosurgery as a Stand-Alone Treatment Option for Cerebral Dural Arteriovenous Fistulas: the Vienna Series.

Gamma Knife radiosurgery (GKRS) has been demonstrated to be an effective and safe treatment method for dural arteriovenous fistulas (DAVFs). However, only few studies, mostly with limited patient numbers, have evaluated radiosurgery as a sole and upfront treatment option for DAVFs. Thirty-three DAVF patients treated with GKRS as a stand-alone management at our institution between January 1992 and January 2020 were included in this study. Obliteration rates, time to obliteration, neurologic outcome, and complications were evaluated retrospectively. Complete overall obliteration was achieved in 20/28 (71%) patients. The postradiosurgery actuarial rates of obliteration at 2, 5, and 10 years were 53, 71, and 85%, respectively. No difference in time to obliteration between carotid-cavernous fistulas (CCFs; 14/28, 50%, 17 months; 95% confidence interval [CI]: 7.4-27.2) and non-CCFs (NCCFs; 14/28, 50%, 37 months; 95% CI: 34.7-38.5; p = 0.111) were found. Overall, the neurologic outcome in our series was highly favorable at the time of the last follow-up. A complete resolution of symptoms was seen in two-thirds (20/30, 67%) of patients. One patient with multiple DAVFs suffered from an intracranial hemorrhage of the untreated lesion and died during the follow-up period, resulting in a yearly bleeding risk of 0.5%. No complications after radiosurgery were observed in our series. Our results show that GKRS is a safe and effective stand-alone management option for selected DAVF patients.

Histopathological analysis of the wall enhancement of the spinal dural arteriovenous fistulae's draining veins.

The mechanism behind SDAVF is still unclear. We discovered that the vessel wall of the SDAVF-DV occasionally showed enhancement in MRI, and this study assessed the relationship between the enhancement of the draining vein's wall and its histology. For histopathologic analysis, 16 draining vein samples from 16 patients with SDAVF were included, 3 normal arteries and 3 normal veins were chosen as comparison. We assessed the imaging and microscopic characteristics of the draining veins in SDAVF patients. The former included the presence of significant enhancement of the wall of the draining vein in MRI, and the latter included the adherence, aggregation, infiltration of pro-inflammatory factors and inflammatory cells. Immuno-histochemical staining was performed using IL-1β, IL-8, TGF-β as well as MPO and MMP-9, and positive results were counted. Multiple logistic regression analysis was used to determine whether the infiltration of inflammatory cells was connected to vessel wall enhancement in the SDAVF-DV. Infiltration of inflammatory cells was significantly higher in SDAVF-DV compared to normal vessels, 7 out of 16 patients significantly had enhancement of the vessel wall of SDAVF-DV, and logistic regression analysis showed that samples with more infiltration of inflammatory cells were more likely to show enhancement of the SDAVF-DV walls. There was considerable inflammatory cells infiltration in SDAVF-DV, and this may explain why their vessel wall had such a significant enhancement in MRI.

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

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. 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. 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. 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.

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

BackgroundThe 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. MethodsWe 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. ResultsFrom 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. ConclusionSinus 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.

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

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). 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. 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. 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.

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

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. 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. 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. 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.

The negative impact of treatment delays on the long-term neurological outcomes of spinal dural arteriovenous fistulas: a longitudinal cohort study.

Dural arteriovenous fistulas are rare vascular malformations that affect the brain and spinal cord. Spinal dural arteriovenous fistulas (sdAVFs) are the most frequently encountered vascular malformation affecting the spinal cord. The object of this study was to evaluate the impact of treatment delays on the long-term neurological outcomes of either open surgical or interventional treatment of sdAVFs. In this retrospective, population-based cohort study, the authors examined consecutive patients with diagnosed sdAVFs at a tertiary care center between 2005 and 2020. Patients were assessed using the Aminoff-Logue disability scale (ALS) at various time points including symptom onset, primary care visit, first specialist outpatient visit, as well as both short and long-term follow-ups. The postoperative long-term ALS gait and bladder grades constituted the primary outcomes of the study. Among the 34 patients included in the study, the median age was 65 years, and there was a male predominance (71%). Most lesions were in the lumbar region (47%). Significant worsening in ALS gait and bladder grades was observed preoperatively, followed by postoperative improvements (p < 0.05). There was no difference in outcomes between surgical and endovascular treatments. Older age (OR 1.10, 95% CI 1.03-1.17, p = 0.007), worse preoperative ALS gait grades (OR 5.12, 95% CI 2.18-12.4, p < 0.001), and longer time from first specialist outpatient visit to first treatment (OR 1.00, 95% CI 1.00-1.01, p = 0.040) were independently associated with worse long-term gait outcomes. Only the preoperative ALS bladder score was a predictor of worse long-term bladder function (OR 92.7, 95% CI 28.0-306.7, p < 0.001). Both surgical and endovascular treatments for sdAVFs led to significant neurological improvements. However, treatment delays were associated with less favorable long-term outcomes. Prompt diagnosis and early intervention prior to symptom progression may enhance recovery and help to preserve neurological function.

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

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. 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. 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). 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.

Stereotactic radiosurgery with versus without embolization for intracranial dural arteriovenous fistulas: a systematic review and meta-analysis.

Stereotactic radiosurgery (SRS) has been established as a safe and alternative treatment for dural arteriovenous fistulas (dAVFs). While embolization alone is the most commonly used modality for the treatment of dAVFs, the adjunctive use of embolization with SRS, with the growing use of SRS, has gained increasing interest in the past few years. However, the relative efficacy and safety of SRS combined with embolization versus SRS alone for dAVFs remains uncertain. Hence, this systematic review aimed to evaluate the efficacy of SRS with adjunctive embolization for intracranial dAVFs. A systematic review and meta-analysis was conducted by searching electronic databases, including PubMed, Embase, and the Cochrane Library, up to August 2023. All studies evaluating the utilization of adjunctive embolization and SRS for dAVFs were included. Risk of bias was assessed using the Newcastle-Ottawa Scale. A meta-analysis was conducted on the suitable outcomes. Eighteen studies involving 715 patients were included. The mean age of the participants in the study was 64.30 years in the adjunctive embolization group and 60.51 years in the SRS-alone group. In the adjunctive embolization group 41.3% of patients were female, compared with 47.1% in the SRS-only group. The dAVF obliteration rates were 64.7% and 65.7% in the adjunctive embolization and SRS-alone groups, respectively. These obliteration rates were comparable between the two groups (p = 0.96), as were the symptom improvement rates (p = 0.35). Adverse events were rare, and were more commonly associated with the adjunctive embolization procedure, although further causal analysis was not possible. This study provides evidence that adjunctive embolization plus SRS provides similar obliteration and symptom improvement rates compared with SRS alone, with both having very limited SRS-related adverse events. Considering the added burden and adverse events of additional endovascular treatment, the authors recommend embolization be reserved for more complex dAVFs or when embolization can potentially be curative alone or provide more rapid symptomatic relief or protection during the radiosurgical latency period.

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

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. 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. 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. 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.

Simulation for Endovascular Treatment

With the advent of high-resolution imaging and advancements in computational fluid dynamics(CFD)and computational structural mechanics(CSM)analyses, clinical simulation of endovascular intervention has gradually become feasible. Virtual stents have become indispensable for coil embolization. For braided stents, such as those with low-profile visualized intraluminal support and flow diverters, predicting postplacement elongation and contraction is challenging; however, software development has enabled more precise treatment planning. Additionally, simulations utilizing three-dimensional(3D)printer models can enable realistic simulations of procedures such as intracranial stents and Woven EndoBridge placement. This approach is beneficial for shunt disorders such as arteriovenous malformations and dural arteriovenous fistulas, offering 3D visualization of shunt access routes and intuitive treatment strategy planning, even for beginners. Furthermore, it can be applied to procedures such as open surgical clipping and nidus resection, aiding in the selection of suitable clips and considerations for ideal resection based on nidus curvature. Simulations using CFD, CSM, and 3D printers are crucial for training surgeons and handling new devices. Harnessing medicine-engineering synergy is essential, and regulatory approval(insurance coverage)and appropriate commercialization of simulations are paramount for the future.

A contemporary analysis of surgical ligation versus endovascular embolization in patients with intracranial dural arteriovenous fistulas: a propensity score-matched and mixed-effects model study.

Intracranial dural arteriovenous fistulas (dAVFs) are rare vascular lesions that can be asymptomatic or can lead to devastating hemorrhage based on the dAVF's aggressiveness. Several approaches can be taken to treat dAVFs, such as endovascular embolization and surgical ligation. However, very few studies have evaluated the influence of surgery compared to endovascular approaches on patient outcomes. This study was performed to analyze the clinical characteristics and outcomes of patients who underwent treatment for intracranial dAVF in which either endovascular embolization or microsurgical ligation was used. The Nationwide Readmissions Database was reviewed for all patients who underwent treatment for dAVFs (n = 18,152) between 2016 and 2019. Patients who received only surgical ligation or endovascular embolization (i.e., not both) were included. Variables regarding demographics, clinical outcomes, and healthcare utilization were queried. Primary outcome measures were nonroutine discharge, 1-year readmission, top quartile length of stay (LOS), and top quartile of inpatient all-payer cost. Propensity score matching was performed to evaluate the influence of either surgery or embolization on patient outcomes. Receiver operating characteristic (ROC) curves were created for each outcome measure. The area under the curve (AUC) of each ROC was used to estimate mixed-effects model performance. Following propensity score matching, 127 and 113 patients made up the surgical ligation and endovascular embolization cohort, respectively. There were no differences found in age (p = 0.16), sex (p = 0.57), or average Elixhauser Comorbidity Index (p = 0.32). Patients receiving surgical ligation had lower odds of readmission (OR 0.37, p = 0.028) and greater odds of nonroutine discharge (OR 2.21, p = 0.03) compared to patients who underwent endovascular embolization. The authors found no differences in the top quartile of LOS (p = 0.84), top quartile of cost (p = 0.38), or mortality (p > 0.99) between cohorts. ROC curves revealed that the mixed-effects models inclusive of approach outperformed models agnostic to approach with respect to nonroutine discharge (AUC with approach, 0.871; AUC without approach, 0.850; p = 0.018) and readmission (AUC with approach, 0.686; AUC without approach, 0.651; p = 0.019), but no differences were observed regarding top quartile of LOS (p = 0.17) and top quartile of cost (p = 0.40). Surgical approach may influence perioperative outcomes in patients treated for intracranial dAVF-most significantly discharge disposition and 1-year readmission. Future longitudinal prospective studies with more clinical detail will be required to fully capture the predictive utility of surgical approach in patients treated for intracranial dAVF, particularly for various dAVF subtypes.