A Treatment Option for Nontraumatic Adult-Type Dural Arteriovenous Fistulas: Transarterial Venous Coil Embolization

Objective

Transvenous coil embolization of the affected venous outlet is the most effective treatment method for the management of nontraumatic adult dural arteriovenous fistulas (DAVFs). However, such an approach is not always feasible. We discuss nontraumatic adult DAVFs that were treated with transarterial coil embolization of the proximal venous outlet at our facility, as well as cases previously reported in the literature.

Methods

This study included 8 patients who had undergone transarterial coil embolization of the proximal venous outlet for the treatment of nontraumatic adult DAVFs (4 cases in our series and 4 cases in the literature). All clinical, angiographic, and procedural data were retrospectively collected from medical charts or the literature and recorded on standardized forms by a physician. The DAVFs were classified according to the venous drainage pattern.

Results

In all 8 patients, occlusion of the proximal venous site of the fistula was possible by using coils through the arterial feeders; this resulted in complete recovery in all patients. The access route for 7 of the 8 cases was the middle meningeal artery, and in 1 case was the meningohypophyseal artery. In all 8 patients the access artery was relatively smooth, with distal enlargement in the fistula region.

Conclusions

If a distally enlarged feeding artery is observed among the multiple feeding arteries, it suggests the existence of a large fistula and may serve as an access route for transarterial venous coil embolization. This procedure may offer a more effective and safer treatment than other endovascular approaches.

Introduction

Intracranial nontraumatic adult dural arteriovenous fistulas (DAVFs) (spontaneous DAVFs) may cause a variety of neurological symptoms. Both the symptoms and the venous drainage patterns should factor into the choice of treatment 11, 21, 22. Several therapeutic approaches for endovascular treatment have been proposed, including surgery, radiosurgery, and embolization, the latter being most often considered as the first-line treatment. Endovascular treatment can be done via the transarterial or transvenous approach 2, 4, 23.

In endovascular treatment of nontraumatic adult DAVFs, obliteration of the venous outlet, when made feasible by the available access route, is safe and highly effective for achieving a complete recovery. Where possible, retrograde, transvenous occlusion of the most proximal venous outlet represents the ideal endovascular option for curative treatment of DAVFs; however, such an approach is not always feasible, as in the case of an isolated sinus or a dural venous sinus occlusion 13, 21. In these cases, transarterial embolization is the next best endovascular treatment option. In this procedure, the usual approach is from the arterial side, and a liquid embolic agent is used to occlude the artery, fistula, and proximal part of the cortical vein. Liquid agents, e.g., glue or Onyx (ev3, Irvine, CA), are less controllable than coils and thus may present a higher risk 1, 13, 15, 19. However, the transarterial approach in which coils are passed through the fistulous site into the sinus has been rarely performed for the treatment of DAVFs because it is thought to be difficult to navigate the microcatheter through the fine vascular network of the fistula area. To our knowledge, this method has only been used in 4 cases of DAVF 3, 9, 10, 13, 21.

Here we report 4 cases of nontraumatic adult DAVFs that were obliterated using transarterial coil embolization of the proximal venous outlet. We reviewed 8 cases (4 cases in our series and 4 cases in the literature) and propose another angioarchitectural classification and treatment option for nontraumatic adult DAVFs.