Observation Versus Intervention for Low-Grade Intracranial Dural Arteriovenous Fistulas

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

CLINICAL IMPACT

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

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.

A rare case of multiple high-grade dural arteriovenous fistulas manifesting as progressive confusion and abnormal behavior

INTRODUCTION AND IMPORTANCE

Multiple dural arteriovenous fistulas (AVFs) are rare intracranial vascular malformations with fatal consequences. Patients usually manifest with variable clinical presentations, which depend on the fistula's size, location, and the development of complication. Digital subtraction angiography continues to be the gold standard neuroimaging modality for diagnosis.

CASE PRESENTATION

A 47-year-old female patient was transferred from Gaza Hospital intubated under complete sedation after she had progressive confusion and abnormal behaviors. She was immediately admitted to our surgical ICU. Brain computed tomography angiography was done and showed middle and posterior cranial fossae high flow dural AVFs with grad IV Cognard classification. Also, right petrosal venous sinuses thrombosis, secondary brain edema and herniation were found. Cerebral catheterization revealed multiple dural AVFs with all branches of external carotid arteries and other branches from vertebral arteries fistulized into the transverse dural sinus, superior sagittal sinus, and sigmoid sinus.

CLINICAL DISCUSSION

Even though they are rare multiple dural AVFs do exist, and it is importance to consider while assessing patients who have symptoms that could point to arteriovenous fistulas. Early diagnosis and prompt intervention is a crucial step in such cases.

CONCLUSION

Multiple dural AVFs are rare conditions that are challenging, especially in low-middle-income countries where expertise and clinical resources are limited. A delay in the diagnosis may result in considerable morbidity and mortality.

Efficacy and safety of stereotactic radiosurgery versus endovascular treatment for symptomatic cavernous sinus dural arteriovenous fistula without ophthalmological emergency: a single-center 10-year experience

OBJECTIVE

Stereotactic radiosurgery (SRS) is emerging as a treatment option for cavernous sinus dural arteriovenous fistula (CS dAVF); it is less invasive and has a lower complication rate than conventional surgeries. However, little is known regarding the advantages and limitations of SRS compared to those of endovascular treatment (EVT). The aim of this study was to compare the efficacy and safety between EVT and SRS for treatment of CS dAVF.

METHODS

Between January 2011 and April 2021, a total of 86 consecutive patients diagnosed with CS dAVF were treated with EVT or SRS. Among them, 8 patients with ophthalmological emergency and 8 without follow-up data at ≥ 12 months were excluded. During the same period, no neurological deficit due to intracranial hemorrhage or seizure was noted in any of the patients. Ultimately, 70 patients (EVT 33, SRS 37) were included in this study. Demographic characteristics, initial clinical presentations, clinical outcomes, and radiological findings were retrospectively reviewed and compared. Procedure-related complications were also assessed after the treatments.

RESULTS

The patients’ baseline characteristics (except conjunctival symptoms) and angiographic features of CS dAVF were not significantly different between the EVT and SRS groups. Conjunctival symptoms were more frequently noted in the EVT than in the SRS group (69.7% vs 40.5%, p = 0.015). After EVT, initial complete obliteration was achieved in 20 cases (60.6%). Complete obliteration was achieved at 6 months in 86.4% of cases with EVT and in 77.8% of those treated with SRS (p = 0.507), and at 12 months in 86.4% cases with EVT and in 94.4% of those treated with SRS (p = 0.357). Worsening of symptoms developed at 1 month in 24.2% of cases with EVT and in 5.4% of those treated with SRS (p = 0.038); at 6 months in 22.6% of cases with EVT and in 10.8% of those treated with SRS; and at 12 months in 30.0% of cases with EVT and in 13.5% of those treated with SRS (p = 0.099). The angioarchitecture of CS dAVF did not affect angiographic obliteration after SRS. Procedure-related morbidity and mortality occurred more frequently in the EVT than in the SRS group (27.3% vs 8.1%, p = 0.034).

CONCLUSIONS

Both EVT and SRS were effective for the treatment of CS dAVF without ophthalmological emergency. However, procedure-related morbidity and mortality was less frequent in SRS than in EVT, and consequently SRS may be more advantageous in terms of safety.

Stereotactic Radiosurgery for Dural Arteriovenous Fistulas: A Systematic Review and Meta-Analysis and International Stereotactic Radiosurgery Society Practice Guidelines

BACKGROUND

Dural arteriovenous fistulas (dAVFs) are often treated with stereotactic radiosurgery (SRS) to achieve complete obliteration (CO), prevent future hemorrhages, and ameliorate neurological symptoms.

OBJECTIVE

To summarize outcomes after SRS for dAVFs and propose relevant practice recommendations.

METHODS

Using a PICOS/PRISMA/MOOSE protocol, we included patients with dAVFs treated with SRS and data for at least one of the outcomes of the study. Relevant outcomes were CO, symptom improvement and cure, and post-SRS hemorrhage or permanent neurological deficits (PNDs). Estimated outcome effect sizes were determined using weighted random-effects meta-analyses using DerSimonian and Laird methods. To assess potential relationships between patient and lesion characteristics and clinical outcomes, mixed-effects weighted regression models were used.

RESULTS

Across 21 published studies, we identified 705 patients with 721 dAVFs treated with SRS. The CO rate was 68.6% (95% CI 60.7%-76.5%) with symptom improvement and cure rates of 97.2% (95% CI 93.2%-100%) and 78.8% (95% CI 69.3%-88.2%), respectively. Estimated incidences of post-SRS hemorrhage and PNDs were 1.1% (95% CI 0.6%-1.6%) and 1.3% (95% CI 0.8%-1.8%), respectively. Noncavernous sinus (NCS) dAVFs were associated with lower CO (P = .03) and symptom cure rates (P = .001). Higher grade was also associated with lower symptom cure rates (P = .04), whereas previous embolization was associated with higher symptom cure rates (P = .01).

CONCLUSION

SRS for dAVFs results in CO in the majority of patients with excellent symptom improvement rates with minimal toxicity. Patients with NCS and/or higher-grade dAVFs have poorer symptom cure rates. Combined therapy with embolization and SRS is recommended when feasible for clinically aggressive dAVFs or those refractory to embolization to maximize the likelihood of symptom cure.

Microsurgical Management of a Marginal Sinus Dural Arteriovenous Fistula: 2-Dimensional Operative Video

Dural arteriovenous fistulas (DAVFs) are benign but may present with life-threatening hemorrhage or symptoms of venous hypertension (eg, progressive myelopathy).1-3 DAVFs follow well-described anatomic patterns.4 The marginal sinus is located between the layers of the dura, circumferentially around the foramen magnum. It communicates with the basal venous plexus of the clivus anteriorly and the occipital sinus posteriorly.5,6 Arterial supply to the dura in this region that fistulizes into the sinus arises from meningeal branches from the V3 or V4 segments.  A man in his early 70s presented with chronic neck pain and new onset of left arm and face paresthesias. He had brisk patellar reflexes bilaterally and a marginal sinus DAVF, with numerous dilated veins around the cisterna magna, causing dorsal cervicomedullary compression. Angiography confirmed the diagnosis of DAVF rather than arteriovenous malformation. Endovascular embolization was considered, but surgery was preferable because of poor transarterial access.  The patient underwent left far lateral craniotomy and C1 laminectomy with exposure of the condylar fossa. The dura was carefully elevated laterally, revealing a network of dilated tortuous veins, with multiple points of fistulous connection within the dura emanating in a large venous varix. Indocyanine green videoangiography showed the aberrant flow dynamics. The fistulous point was occluded with aneurysm clips on the venous side, then cauterized and interrupted. The patient was discharged within 3 d of surgery and had full resolution of symptoms at 6 wk. Angiography confirmed complete obliteration of the DAVF. The patient provided written informed consent for treatment. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.