Onyx embolization for dural arteriovenous fistulas: a multi-institutional study

Long-term risk of hemorrhage and mortality after treatment of high-grade intracranial dural arteriovenous fistulas

BACKGROUND

Despite recent multi-institutional efforts, long-term data on clinical and radiological outcomes after treatment of high-grade dural arteriovenous fistulas (dAVFs) remain scarce. This study aimed to evaluate the long-term risk of hemorrhage and fistula-related mortality after treatment.

METHODS

Retrospective analysis of all consecutive patients primarily diagnosed with a high-grade dAVF (Cognard grade 2b, 2a+b, 3, 4) between January 2012 and September 2022 at a large neurovascular center. Primary endpoints were intracranial hemorrhage (ICH) and all-cause mortality after treatment; secondary endpoints were angiographic occlusion, complication rate and neurological deficits.

RESULTS

A total of 121 patients underwent 141 treatments (122 endovascular therapy (EVT), 5 radiotherapy, 14 surgery) of which 12 patients (10%) underwent retreatment. Follow-up was available in all patients for a median of 4.2 (IQR 2.5 to 6.6) years. Eleven patients (9%) died during the follow-up period, of which three deaths (2%) occurred after hemorrhagic presentation, one of them attributable to treatment. One death (0.8%) was due to delayed hemorrhage after partial occlusion from EVT. No other post-treatment bleedings occurred. Angiographic follow-up after multimodality treatment was available in 93% of patients after a median of 6 months; the overall occlusion rate was 90%. The overall rate of complications was 25% after EVT and 14% after surgery. The rates of new transient and permanent neurological deficits after EVT were 9% and 3%, respectively.

CONCLUSIONS

The long-term rate of re-bleeding or dAVF-related mortality was low when high rates of angiographic occlusion were achieved. The risk for treatment-related complications leading to neurological sequela was low.

Endovascular treatment strategy and clinical outcome of tentorial dural arteriovenous fistula

Introduction

To evaluate treatment strategies and clinical outcomes following endovascular embolization of tentorial dural arteriovenous fistulas.

Methods

We retrospectively analyzed 19 patients with tentorial dural arteriovenous fistulas admitted to the Department of Neurosurgery at Jiangsu Provincial People's Hospital between October 2015 and May 2022, all treated with endovascular therapy. To collect and analyze patients' clinical presentation, imaging data, postoperative complications, and prognosis and to analyze the safety and clinical outcomes of endovascular treatment of tentorial dural arteriovenous fistulas.

Results

Imaging cure was achieved in 18 patients, with the arterial route chosen for embolization in 17 patients and the venous route in one patient; one patient received partial embolization. Staged embolization was performed in four patients. At postoperative follow-up of 9-83 months (37.8 ± 21.2), all 19 patients had recovered well (mRS score ≤ 2). Three patients experienced perioperative complications: intraoperative Onyx reflux into the middle cerebral artery in one patient; postoperative permanent limited left visual field loss and deafness in the left ear in one patient; and transient diplopia, vertigo, and decreased pain and temperature sensation of the left limb in one patient, with no abnormalities on post-procedure magnetic resonance examinations. A total of 17 patients completed a postoperative digital subtraction angiography review during follow-up, and one patient had a recurrence of an arteriovenous fistula.

Conclusion

Endovascular treatment of tentorial dural arteriovenous fistulas is safe and effective. Reduction of the Borden or Cognard classification via eliminating cortical venous reflux through multi-staged embolization or combined open surgery is a reasonable goal of treatment where complete obliteration of the fistula is not achievable.

Case report: Onyx embolization of tentorial dural arteriovenous fistula via the meningohypophyseal trunk and medial tentorial artery of Bernasconi-Cassinari

For tentorial dural arteriovenous fistula (TDAVF), the meningohypophyseal trunk (MHT), and medial tentorial artery (MTA) of Bernasconi-Cassinari are rarely used as transarterial paths to perform the successful endovascular treatment (EVT). We reported a TDAVF mainly fed by the MHT. Onyx-18 casting in the MTA of Bernasconi-Cassinari under the assistance of coil embolization in proximal MHT was performed. The technique was reported in case 1. At the same time, case 2 with a similar TDAVF was chosen as a control. In case 1, a 52-year-old man suffered a cerebellar hemorrhage. A TDAVF was confirmed by computed tomography angiography and digital subtraction angiography. The feeding arteries included the MHT, middle meningeal artery (MMA), and the artery of Wollschlaeger and Wollschlaeger of the superior cerebellar artery. The MHT and MTA of Bernasconi-Cassinari were hypertrophied. First, a Marathon microcatheter was placed in the MTA to wait for Onyx casting, and then an Echelon-10 microcatheter was placed in the proximal MHT trunk with an aneurysmal dilation to perform coiling to prevent Onyx reflux. Then, Onyx casting obliterated the TDAVF. Case 2 was a 75-year-old woman with TDAVF, and the MTA of Bernasconi-Cassinari was the main feeder. First, the TDAVF experienced incomplete EVT with Onyx casting via the MTA under no assistance of coil embolization in the proximal MTA. The second EVT had to be performed via MMA. Then, Onyx casting obliterated the TDAVF. Therefore, for selected TDAVFs with hypertrophied MHT, under the assistance of coil embolization in proximal MHT, Onyx casting via MHT can finish the complete EVT.

Tentorial venous anatomy of mice and humans

We recently described a transtentorial venous system (TTVS), which to our knowledge was previously unknown, connecting venous drainage throughout the brain in humans. Prior to this finding, it was believed that the embryologic tentorial plexus regresses, resulting in a largely avascular tentorium. Our finding contradicted this understanding and necessitated further investigation into the development of the TTVS. Herein, we sought to investigate mice as a model to study the development of this system. First, using vascular casting and ex vivo micro-CT, we demonstrated that this TTVS is conserved in adult mice. Next, using high-resolution MRI, we identified the primitive tentorial venous plexus in the murine embryo at day 14.5. We also found that, at this embryologic stage, the tentorial plexus drains the choroid plexus. Finally, using vascular casting and micro-CT, we found that the TTVS is the dominant venous drainage in the early postnatal period (P8). Herein, we demonstrated that the TTVS is conserved between mice and humans, and we present a longitudinal study of its development. In addition, our findings establish mice as a translational model for further study of this system and its relationship to intracranial physiology.

Endovascular embolization of high-grade cerebral dural arteriovenous fistulas - assessment of long-term recurrences

INTRODUCTION

Endovascular therapy has shown to be safe and effective for the treatment of cerebral dural arteriovenous fistulas; however, recurrence after complete occlusion is not uncommon, and the timing of recurrence remains unknown.

METHODS

A retrospective single-center cohort study was conducted from January 2005 to December 2020. Patients with high-grade (≥Borden II-Cognard IIB) dural arteriovenous fistulas treated with endovascular therapy were included in this study. Clinical and angiographic characteristics were collected for hospitalization and at follow-up.

RESULTS

A total of 51 patients with a median age of 61 years were studied; 57% were female. High-flow symptoms related to the high-flow fistula were the most common presentation (67%), and 24% presented with intracranial hemorrhage. Transverse-sigmoid (26%) and cavernous (26%) sinuses were the most common dural arteriovenous fistula locations. A total of 40 patients (70%) had middle meningeal arterial feeders and 4 (7%) had deep cerebral venous drainage. The mean number of embolization procedures per patient was 1.4. Transarterial access was the most frequent approach (61%). Onyx alone was the most common embolic agent (26%). Complete occlusion rate was achieved in 46 patients (80.1%). Last mean radiographic follow-up time was 26.7 months for all 57 dural arteriovenous fistulas. Dural arteriovenous fistula recurrence after radiographic resolution at last treatment was seen in six cases (6/46, 13.1%). Mean time for recurrence was 15.8 months. Mean time of last clinical follow-up was 46.1 months for the 51 patients (100%). A total of 10 (20%) experienced any procedural complications, among which two (4%) became major thromboembolic events.

CONCLUSION

Endovascular therapy is safe and effective for the treatment of high-grade dural arteriovenous fistulas. Given the significant recurrence rate of embolized dural arteriovenous fistulas even after 2 years, long-term angiographic follow-up might be needed.

Is the Middle Meningeal Artery the Optimal Path for Dural Arteriovenous Fistula Embolization?

Background: The middle meningeal artery (MMA) is the optimal arterial path for endovascular treatment (EVT) of dural arteriovenous fistulas (DAVFs). However, the details are not completely understood.

Materials and Methods: We performed a retrospective study of patients who were admitted to the First Hospital of Jilin University with a diagnosis of cranial DAVF with involvement of the MMA as a feeding artery. On the basis of the arterial path chosen and the role of the MMA in the first EVT procedure, EVT was divided into three types (I–III), each of which was further divided into two subclasses (a and b). The degree of embolization was analyzed.

Result: The 104 included patients ranged in age from 13 to 80 years (mean, 53.6 ± 11.8 years). There were 48 cases of hemorrhage (46.2%, 48/104). Complete embolization was achieved in the first procedure in 64.4% of cases, and success was eventually achieved using EVT (the first attempt or a subsequent attempt) in 74.1% of cases. EVT caused complications in 6.7% of cases. A modified Rankin scale score of 0 or 1 was achieved in 78.8% of patients. Statistical analyses revealed that type Ia and IIb EVTs had the lowest complete embolization rates, but no difference was found between type Ia and IIb EVTs. Types IIa and III EVT had the highest complete embolization rates. Most cases had a good prognosis.

Conclusion: These findings elucidate the features of the different EVT classes defined by the first EVT procedure and the role of the MMA. The delivery of treatment via slim and tortuous MMA branches increased the failure rate of EVT. A thick, straight MMA branch is the optimal path for treatment.