Clinical Characteristics and Microsurgery Treatment of Anterior Cranial Fossa Dural Arteriovenous Fistula

Transarterial embolization for anterior cranial fossa dural arteriovenous fistula based on multi-modal three-dimensional imaging

Background

Dural arteriovenous fistula (DAVF) in the anterior cranial fossa (ACF) is known to show a high risk of intracranial hemorrhage. Recently, multi-modal fusion imaging with computed tomography angiography, computed tomography venography, and three-dimensional (3D) rotation angiography have been used preoperatively to ensure anatomical safety. We report on endovascular treatment as a first-line approach for ACFDAVF based on the understanding of vascular anatomy obtained from multi-modal fusion imaging.

Methods

All patients with ACF-DAVF treated endovascularly as a first-line approach were included in this study. Analyses took into account complications (particularly visual function), immediate angiographic outcomes, and follow-up findings in consecutive patients with ACF-DAVF treated with interventional treatment based on multi-modal fusion imaging.

Results

Five patients with ACF-DAVF underwent six sessions of transarterial embolization (TAE) in our institution. The five male patients (mean age, 74.5 years; range, 60-84 years) were treated with liquid embolic agents (Onyx, four procedures; n-butyl 2-cyanoacrylate, two procedures). No difference was seen between preoperative image evaluation and image evaluation during the endovascular procedure, and in all cases, a microcatheter was navigated into a target artery assumed from preoperative multi-modal imaging, allowing treatment completion in a single procedure. In all cases, the shunt disappeared completely and visual function after procedure was maintained. At the last follow-up, all patients showed a modified Rankin scale score of 0 or 1 with no recurrences.

Conclusion

Multi-modal fusion imaging facilitates a 3D understanding of the vascular anatomy, allowing TAE as the first-line treatment for ACF-DAVF.

Dural arteriovenous fistulas at the craniocervical junction: a systematic review and meta-analysis

BACKGROUND

The management for craniocervical junction dural arteriovenous fistulas (CCJ-DAVFs) remains controversial and clinically challenging. We systemically summarized the clinical and angiographic outcomes of microsurgery, embolization, and conservative management.

METHODS

Relevant articles were retrieved from PubMed, Scopus, Web of Science, and Cochrane, following PRISMA guidelines. A systematic review and meta-analysis were conducted on the clinical characteristics, management approaches, and clinical and angiographic outcomes.

RESULTS

We included 13 articles (166 patients). The weighted mean age was 58.9 years (95%CI: 53.2-64.5), 58.8 years (95%CI: 48.4-69.2), and 63.8 years (95%CI: 60.1-67.5), in microsurgery, embolization, and conservative groups respectively, with an overall male sex predominance (microsurgery [n = 51/77, 66.2%], embolization [n = 44/56, 78.6%], and conservative management [n = 6/8, 75.0%]). Patients were managed with microsurgery (n = 80/172, 46.5%), embolization (n = 79/172, 45.9%), and conservative treatment (n = 13/172, 7.6%). Foramen magnum was the most common location (microsurgery [n = 34/77, 44.2%], embolization [n = 31/56, 55.4%], and conservative treatment [n = 3/8, 37.5%]). Vertebral artery was the primary feeder (microsurgery [n = 58/84, 69.1%], embolization [n = 41/86, 47.6%], and conservative treatment [n = 4/7, 57.1%]). Complete fistula obliteration rates were 74.1% (95%CI:52.3-88.2%) in the microsurgery group and 54.9% (95%CI:30.7-77.0%) in the embolization group. Complications rates were 16.2% (95%CI:6.7-34.5%) in the embolization group, 11.6% (95%CI:3.8-30.4%) in the microsurgery group, and 7.7% (95%CI:1.1-39.1%) in the conservative group. Different rates of good clinical outcomes were observed [microsurgery: 66.4% (95%CI:48.1-80.8%), embolization: 51.9% (95%CI:30.8-72.4%), and conservative: 11.6% (95%CI:4.4-27.4%)].

CONCLUSIONS

In patients with CCJ-DAVFs, each management approach has its own merits based on the fistula and patient characteristics.

Endovascular Treatment of Anterior Cranial Fossa Dural Arteriovenous Fistula

Anterior cranial fossa (ACF) dural arteriovenous fistula (DAVF) is a rare lesion among cerebral DAVFs. This lesion shows significant bleeding risk because of the angioarchitecture, involving direct leptomeningeal retrograde venous drainage, as a nonsinus-type DAVF. Over the years, direct surgery has been considered the primary treatment for ACF DAVF, offering favorable clinical outcomes compared to a low complete obliteration rate with endovascular treatment and the relatively high risk of blindness due to central retinal artery occlusion with transophthalmic artery embolization. In recent years, however, significant improvements in DSA and 3D reconstruction imaging quality have allowed a much more precise understanding of the angioarchitecture of the shunt and vascular access route. In addition, advances in endovascular devices, including catheters and embolic materials, have facilitated microcatheter navigation into more distal vessels and more reliable closure of the fistulous point. Supported by such technological innovations, endovascular approaches to the treatment of ACF DAVF have been becoming successful first-line treatments. This article reviews the evolution of treatment strategies and the current status of endovascular treatment for ACF DAVF, with a particular focus on transarterial embolization.

Complication rate, cure rate, and long-term outcomes of microsurgery for intracranial dural arteriovenous fistulae: a multicenter series and systematic review

Although microsurgery is an established treatment modality for intracranial dural arteriovenous fistula (dAVF), data regarding the perioperative complication rate, cure rate, and long-term outcomes remain scarce. The aims of this study were to describe our original experience with microsurgery, including the surgical complications and pitfalls, and conduct a systematic review of the relevant literature. A multicenter cohort of patients with dAVF treated by microsurgery was retrospectively assessed. In addition, the PubMed database was searched for published studies involving microsurgery for dAVF, and the complication rate, cure rate, and long-term outcomes were estimated. The total number of patients in our multicenter series and published articles was 553 (593 surgeries). The overall rates of transient complications, permanent complications, death, and incomplete treatment were 11.4, 4.0, 1.2, and 6.5%, respectively. A favorable outcome was achieved for 90.1% patients, even though almost half of the patients presented with intracranial hemorrhage. Of note, the incidence of recurrence was only one per 8241 patient-months of postoperative follow-up. Surgeries for anterior cranial fossa dAVF were associated with a lower complication rate, whereas those for tentorial dAVF were associated with higher complication and incomplete treatment rates. The complication and incomplete treatment rates were lower with simple disconnection of cortical venous drainage than with radical occlusion/resection of dural shunts. Our findings suggest that the cure rate, complication rates, and outcomes of microsurgery for dAVF are acceptable; thus, it could be a feasible second-line treatment option for dAVF. However, surgeons should be aware of the specific adverse events of microsurgery.

Sphenoid dural arteriovenous fistulas

Sphenoid wing dural AVFs represent a rare clinical entity. These lesions may be asymptomatic or present with focal neurologic deficits, intracranial venous hypertension, or intracranial hemorrhage. Diagnosis is based on clinical findings and diagnostic imaging. They are alternatively classified as lesions of either the greater or lesser wings of the sphenoid bone. We performed a search of the PubMed database of studies evaluating the clinical behavior and surgical and endovascular therapies of these lesions. Dural AVFs draining into the superficial middle cerebral vein and/or laterocavernous sinus, or rather, lesions of the greater wing of the sphenoid, exhibit a greater likelihood of developing an aggressive clinical course, with higher probability of cortical venous reflux and consequent intracranial venous hypertension, intracranial hemorrhage, and symptomatic presentation. Dural AVFs of the sphenoparietal sinus, that is, lesions of the lesser wing of the sphenoid, typically exhibit a more benign clinical course, as there is a prominent epidural venous drainage into the cavernous sinus, reducing the risk of cortical venous reflux, and consequently, the probability of intracranial venous hypertension, hemorrhage, and floridly symptomatic presentation. These lesions may be treated via surgical clipping of the fistulous point, transarterial or transvenous embolization, and/or stereotactic radiosurgery. Though surgical intervention was the principal therapy due to facility of craniotomy access to the fistulous point, embolization has become standard of care permitted by innovation in endovascular technology. The natural history, clinical presentation, angioarchitecture, diagnosis, and management of these lesions are reviewed and discussed.