Selective transvenous coil embolization of dural arteriovenous fistula. A report of three cases

Endovascular treatment of dural arteriovenous fistulas involving the vein of Galen: a single-center cohort and meta-analysis

BACKGROUND

Dural arteriovenous fistulas (dAVFs) draining into the vein of Galen (VoG) are complex lesions that often necessitate treatment to minimize the risk of rupture and relieve symptoms. These lesions can be treated with open surgical resection, radiosurgery, or endovascular embolization. Unfortunately, endovascular treatment of dAVFs involving the VoG has not been robustly assessed across large patient cohorts. To meet this need, we performed a retrospective review of dAVFs involving the VoG at our center, and included these in a meta-analysis to identify the safety and efficacy of endovascular embolization, as well as describing current treatment trends for this disease.

METHODS

Consecutive patients with dAVFs involving the VoG treated at a single center were identified from a prospective database and retrospectively reviewed. A literature search was conducted with defined search criteria, and eligible studies were included alongside our cohort in a meta-analysis. Rates of complete dAVF treatment and clinical complications were pooled across studies with a random effects model and reported with a 95% CI.

RESULTS

Five dAVFs involving the VoG were treated endovascularly at our center during the study period. In this series, 80% of treatments led to complete occlusion of the fistula while no patients had clinical complications. Onyx was used for all treatments. In our meta-analysis, the overall rate of complete occlusion was 72.0% (95% CI 59.8% to 84.1%) and the overall rate of clinical complications was 10.0% (95% CI 4.7% to 15.3%).

CONCLUSIONS

Endovascular approaches for dAVFs involving the VoG are technically feasible, but carry a risk of clinical complications. Future work should identify optimal endovascular embolic agents.

Dural Arteriovenous Fistula within Superior Sagittal Sinus Wall with Direct Cortical Venous Drainage: A Systematic Literature Review

Dural arteriovenous fistulas (DAVFs) located within superior sagittal sinus (SSS) wall with direct cortical venous drainage are rare. They are also known as variant DAVF (vDAVF) and form a special subgroup of DAVFs. Their chance of presenting with aggressive features is high compared with transverse sigmoid sinus fistula. They drain directly into cortical veins (Borden type 3, Cognard type III and IV). A systematic English literature review of SSS vDAVF was made. Systematic literature review revealed a total of 31 published cases. These were commonly seen in male population, (24 males, 77.41%, 24/31). Average age of patients was 54 years. A total of 24 patients (77.41%, 24/31) had aggressive clinical presentations with 13 patients (41.93%, 13/31) having intracranial hemorrhages (ICH). Two patients had rebleeding (15.38%, 2/13). Middle portion of SSS was commonly involved (15 cases, 75%). A total of 25 (96.15%, 25/26) cases had patent SSS. Most of the fistulas were idiopathic (65.38%, 17/26), with trauma being a frequent etiological factor (26.92%, 7/26). Venous ectasia was seen in 19 patients (59.37%, 19/32). Middle meningeal arterial (MMA) supply was seen in all patients (100%, 26/26), with bilateral MMA supply in 21 cases (80.76%), and unilateral in 5 cases (19.23%). Twenty patients (62.50%, 20/32) received only endovascular treatment (EVT), while four patients had EVT followed by surgery (12.5%, 4/32). Transarterial route via MMA was the preferred treatment option (79.16%). Complete obliteration of fistulas was noted in all cases (100%, 30/30). No immediate complication was noted after EVT. As much as 92.30% patients showed good recovery. Thus, SSS vDAVF forms a special subgroup of DAVF, with aggressive presentation, and warrants urgent treatment. EVT is effective treatment option and can produce complete obliteration.

A Comprehensive Analysis of Dural Arteriovenous Fistula Involving the Superior Sagittal Sinus: A Systematic Review

Objective

To evaluate published papers concerning dural arteriovenous fistula involving the superior sagittal sinus (SSS dAVF) treated with endovascular intervention.

Methods

A literature review was performed to identify studies reporting the clinical characteristics, vascular anatomy, endovascular techniques, embolic materials, angiographical result, and outcomes of SSS dAVF.

Results

The analysis consisted of 40 case reports or series, comprising a total of 51 cases of SSS dAVF treated with endovascular intervention. Clinical symptoms included hemorrhage (29.4%), infarction (17.6%), and seizure (7.8%). The arterial supply included the middle meningeal artery (MMA) (100%), superficial temporal artery (STA) (62.7%), and occipital artery (OA) (49.0%). Bilateral MMAs supplied in 78.4% of the cases. A pial arterial supply was observed in 21.6% of the cases. Stenosis or occlusion of the sinus was seen in 37.3% of the cases. The distribution of the Borden classification was as follows: I (7.8%), II (37.3%), and III (54.9%). The endovascular techniques were transvenous embolization (TVE) alone (11.8%), transarterial embolization (TAE) alone (74.5%), and a combination thereof (13.7%). The types of embolic materials for TAE were a coil (25.5%), n-butyl-2-cyanoacrylate (NBCA) (33.3%), and Onyx (45.1%). The arterial pedicles for TAE included MMA (86.3%), STA (17.6%), and OA (9.8%). Direct surgical exposure for the alternative endovascular access was performed to the SSS (5.9%), MMA (3.9%), STA (5.9%), and OA (3.9%). Sinus angioplasty with or without stenting was done in 9.8% of the cases. Balloon-assisted Onyx TAE was done with proximal flow control (7.8%), collateral devascularization (5.9%), and sinus protection (3.9%). Complete occlusion was achieved in 86.3% of the cases while the number of endovascular sessions varied among patients: single (74.5%), double (15.7%), and triple (9.8%). The rate of a postoperative modified Rankin Scale (mRS) score of 0-2 was 89.3%, with morbidity and mortality rates of 7.8% and 3.9%, respectively. Two patients died, possibly due to postoperative acute SSS occlusion.

Conclusion

The current systematic review disclosed several specific results, namely, the angioarchitectures of the SSS dAVF, the relationship between classification and hemorrhagic presentation, the diversity of treatment techniques, the association between the complete occlusion rate and the SSS condition, and the difficulty of achieving curable occlusion in a single session. These findings underscore the need for the development of endovascular techniques and devices to treat this challenging lesion. Improvements in adjunctive endovascular procedures, such as balloon-assisted techniques for Onyx TAE, may help support to the safe and effective obliteration of SSS dAVF.

Spontaneous Resolution of Venous Aneurysms After Transarterial Embolization of a Variant Superior Sagittal Sinus Dural Arteriovenous Fistula: Case Report and Literature Review

We present a rare case of dural arteriovenous fistula (DAVF) with subarachnoid hemorrhage and intraventricular hemorrhage due to its venous aneurysms. A 63-year-old woman was admitted for a sudden loss of consciousness. Computed tomography angiograph, magnetic resonance imaging angiography, and digital subtraction angiography revealed a superior sagittal sinus DAVF. The fistula was fed by the left middle meningeal artery and left internal carotid artery, and was drained by a right vein of Trolard, the superficial Sylvian vein, deep Sylvian vein, and basal vein to the vein of Galen. The drainage veins were enlarged obviously with 3 aneurysmal venous malformations. There was a stenosis segment on the right basal vein. All the anatomic factors of direct cortical vein drainage, normal deep vein drainage, long tortuous drainage vein, outflow restriction, and multiple venous aneurysms, were contributed to the aggressive presentation of our case. Transarterial complete embolization of the fistula with balloon protection was successfully performed. Nine months later, a follow-up magnetic resonance imaging showed a complete disappearance of the 2 venous aneurysms located in the deep Sylvian vein and basal vein, and an obvious decrease in size of the venous aneurysm of the superficial Sylvian vein. This is the first report of a DAVF with 3 ballooned venous aneurysms and a spontaneous anatomy resolution of the venous aneurysms after the embolization of the fistula. At the same time, the clinical and radiologic characteristics of variant superior sagittal sinus DAVFs were summarized by review of the literatures reported previously.

Onyx removal after embolization of a superior sagittal sinus dural arteriovenous fistula involving scalp artery

BACKGROUND

Most dural arteriovenous fistula (DAVF) in superior sagittal sinus (SSS) requires multimodal treatment. Onyx embolization is useful for DAVF; however, scalp artery embolization has cast extrusion risk.

CASE DESCRIPTION

A 59-year-old male presented with involuntary movements of both legs and progressive dementia. Cerebral angiography demonstrated the DAVF in the SSS fed by bilateral superficial temporal, occipital, and middle meningeal arteries. The posterior SSS was thrombosed, and the main drainers were cortical veins. Combined treatment with transarterial embolization using Onyx and transvenous embolization using coils was performed. Although symptoms were improved, a small DAVF remained. Two months later, Onyx cast extrusion through the scalp was observed, requiring removal and debridement because of infection at the extrusion sites. Surgery for the residual DAVF would be difficult because of scalp condition; therefore, an additional endovascular treatment was conducted, completely occluding DAVF.

CONCLUSION

Onyx embolization is useful for DAVF; however, scalp artery embolization has cast extrusion risk. Therefore, scalp infection should be considered because it may preclude additional surgical procedures.