Factors Predicting Spontaneous Thrombosis of Aggressive Cranial Dural Arteriovenous Fistulas

Spontaneous closure of a superior sagittal sinus dural arteriovenous fistula with an extensive angioarchitectural network: A case report and systematic review of the literature

BACKGROUND

Intracranial dural arteriovenous fistulas (DAVFs) have been documented to occasionally spontaneously regress. However, the mechanism responsible for this occurrence remains speculative.

METHODS

We present a case of a Borden II - Cognard IIa+b DAVF involving the superior sagittal sinus (SSS) with bilateral external carotid artery supply that regressed spontaneously. A systematic literature review was conducted to explore the current theories explaining the spontaneous regression of DAVFs according to Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines.

RESULTS

A total of 26 studies and 54 cases were included in our results. Of the included cases, 57.14% of cases were Borden I, 16.33% were Borden II, and 26.53% were Borden III. Ruptured status or intracranial hemorrhage was documented in 24.1% of all cases, the majority of which (69.2%) were in cases with aggressive lesions (Borden II or greater). The most commonly involved location was the transverse sinus (38.89% of cases, n = 21), and the SSS was only involved in 12.96% of all cases. 50% of included cases proposed a mechanism responsible for spontaneous regression. The most frequently proposed mechanisms were thrombosis of the involved sinus/chronic inflammatory changes or direct endothelial injury, endoluminal stasis, and thrombogenic effects of contrast medium during angiography. We present the case of a 54-year-old woman with an aggressive ruptured DAVF that likely developed following a pediatric traumatic brain injury that was left untreated before she presented to our institution after significant delay. Her DAVF regressed on repeat angiography before neurovascular intervention without a clear identifying mechanism as proposed by the current literature.

CONCLUSION

Our results suggest that spontaneous regression is not necessarily associated with lower risk DAVFs. The present case offers a unique long-term insight into the natural history of an aggressive ruptured DAVF of the SSS that regressed without intervention. Further research into the natural history of DAVFs will be helpful in deducing key factors leading to spontaneous regression.

Clinical characteristics and outcome of dural arteriovenous fistulas secondary to cerebral venous sinus thrombosis: a primary or secondary event?

BACKGROUND

The Dural Arteriovenous Fistulas (DAVFs) secondary to cerebral venous sinus thrombosis (CVST) are rather rare. The aim of present study is to investigate the clinical and radiological features, and treatment outcome of DAVFS in patients following CVST.

METHODS

Data about demographic information, clinical presentations, radiological findings, as well as treatment and outcome of DAVFs sequence to CVST were collected to analysis from January 2013 to September 2020 in this retrospective study.

RESULTS

Fifteen patients with DAVFs after CVST were included in the study. The median age was 41 years (range17-76 years). Ten patients (66.67%) were male and 6 patients (33.33%) were female. The median duration of presenting CVST was 182 days (Range 20-365). Mean time from diagnosis of CVST to confirmation of DAVFs was 97 days (range 36-370 days). The most common manifestations of DAVFs following CVST were headache and visual disturbance seen in 7 patients respectively. Five patients had pulsatile tinnitus (%) and 2 had nausea/vomiting. The DAVFs are most frequently located at the transverse/sigmoid sinus (7/15, 46.67%), followed by the superior sagittal the sinus and confluence sinus (6/15, 40.00%) respectively. Angiography of DAVFs revealed Board type I in seven (46.7%) patients, Board type II and III in 4(26.7%) patients, respectively. The Cognard I was noted in seven (46.7%), Cognard IIa and IV in 3 patients, IIb and III in one patient, respectively. The main feeding arteries of DAVFs most commonly originate from the branches of the external carotid artery in 6 (40.0%) patients. The other DAVFs are conjointly supplied by multiple feeders from internal and external carotid artery and vertebral arteries. Fourteen (93.33%) patients were treated with endovascular embolization and none of the patients had permanent deficits during follow-up.

CONCLUSION

Intracranial DAVFs following CVST are rare presentations. Most patients have a good outcome after timely interventional therapy. Continued observation and follow-up of (DSA) are important to find DAVFs secondary to CVST.

Dural Arteriovenous Fistula Formation Secondary to Cerebral Venous Thrombosis: Longitudinal Magnetic Resonance Imaging Assessment Using 4D-Combo-MR-Venography

BACKGROUND AND PURPOSE

 Dural arteriovenous fistulae (DAVFs) can develop secondary to cerebral venous thrombosis (CVT). The incidence of DAVF has not yet been investigated prospectively.

METHODS

 Between July 2012 and January 2018, combined static and dynamic 4D MR venography (4D-combo-MRV) was performed in 24 consecutive patients at diagnosis of CVT and after 6 months. 3 Tesla magnetic resonance imaging with time of flight and contrast-enhanced magnetization-prepared rapid acquisition with gradient echo were performed at baseline to evaluate the extent of thrombosis and affected vessel segments. Baseline and follow-up 4D-combo-MRV were assessed for signs of DAVF. Interrater reliability of DAVF detection and the extent of recanalization were analyzed with kappa statistics.

RESULTS

 DAVFs were detected in 4/30 CVT patients (13.3%, 95% confidence interval [CI] 3.3-26.7). Two of 24 patients (8.3%, 95% CI: 0-20.8) had coincidental DAVF with CVT on admission. At follow-up, de novo formation of DAVF following CVT was seen in 2/24 patients (8.3%, 95% CI: 0-20.8). Both de novo DAVFs were low grade and benign fistulae (Cognard type 1, 2a), which had developed at previously thrombosed segments. Endovascular treatment was required in two high degree lesions (Cognard 2a + b) detected at baseline and in one de novo DAVF (Cognard 1) because of debilitating headache and tinnitus. Thrombus load, vessel recanalization, and frequency of cerebral lesions (hemorrhage, ischemia) were not associated with DAVF occurrence.

CONCLUSION

 This exploratory study showed that de novo DAVF formation occurs more frequently than previously described. Although de novo DAVFs were benign, 75% of all detected DAVFs required endovascular treatment. Therefore, screening for DAVF by dynamic MRV, such as 4D-combo-MRV, seems worthwhile in CVT patients.

Spontaneous closure of non-cavernous sinus dural arteriovenous fistulas: A case series and systematic review of the literature

BACKGROUND AND PURPOSE

To report 9 new cases of non-cavernous sinus dural arteriovenous fistulas (NCS-DAVFs) that closed spontaneously and systematically review reports of other cases in the literature.

MATERIAL AND METHODS

We performed a retrospective analysis of 9 cases from 2 institutions of NCS-DAVFs that closed spontaneously. Using PubMed and Scopus in accordance with the PRISMA guidelines, we systematically reviewed English language articles about NCS-DAVFs showing spontaneous closure.

RESULTS

Review of the cases from 2 institutions identified 9 cases of NCS-DAVFs showing spontaneous closure in follow-up magnetic resonance angiography (MRA), and the systematic review of the literature yielded an additional 38 cases, which had been diagnosed by repeated arteriography. Collectively, the patients included 23 men and 24 women with a mean age of 54 years. The shunts were located in the transverse-sigmoid sinus in 24 cases (51%), anterior condylar confluence in 11, and other locations in 12. Based on the venous drainage pattern on arteriography, 27 cases (57%) were classified as low-risk NCS-DAVF (without cortical venous reflux) and 17 were classified as high-risk NCS-DAVF (with cortical venous reflux). Shunt closure was observed within 3 months in 17 cases (36%). Extrinsic predisposing factors for shunt closure were detected in 14 cases (30%). These included angiography in 7 cases, sinus recanalization in 4, development of sinus occlusion in 2, and sinus compression by a newly developed hematoma in 1.

CONCLUSION

Spontaneous closures of NCS-DAVFs can occur for both high- and low-risk types. One-third of these closures occur within 3 months.

Multiple Cranial Dural and Pial Arteriovenous Fistulas with Occlusion of All After Embolization of Primary Superior Sagittal Sinus Dural Fistula

BACKGROUND

We present a rare case of multiple intracranial arteriovenous fistulas (AVFs). A young female presented with headache and a left eyelid pulsatile swelling.

CASE DESCRIPTION

Magnetic resonance imaging demonstrated numerous dilated cortical veins, along with a prominent left superior ophthalmic vein. A diagnostic cerebral angiogram revealed 5 distinct AVFs including 4 dural AVFs (dAVFs) and a pial AVF (pAVF). The largest dAVF was at the superior sagittal sinus. The others included bilateral ethmoidal, torcular, and a pAVF arising of the right pericallosal artery. She was treated by endovascular transarterial Onyx embolization. Only the superior sagittal sinus fistula was treated via middle meningeal artery feeders with complete occlusion. Immediate follow-up angiogram also showed complete spontaneous occlusion of the untreated dAVFs and pial AVF.

CONCLUSIONS

This case is exceedingly unique considering the multiplicity of AVFs, concurrent presence of pial and dural AVF, and spontaneous occlusion of all untreated AVFs after embolizing the largest shunting fistula.