Case Report
Dural Arteriovenous Fistula with Shunt Restricted to the Superior Orbital Fissure: A Case Report
2025 Volume 19 Issue 1 Article ID: cr.2024-0113
Details
2025 Volume 19 Issue 1 Article ID: cr.2024-0113
Objective: Dural arteriovenous fistulas (DAVFs) in the superior orbital fissure (SOF) are extremely rare. We report a case of DAVF in the SOF and discuss the characteristics of angioarchitecture and the treatment strategies.
Case Presentation: A 72-year-old woman presented with chemosis, exophthalmos. Digital subtraction angiography revealed a right SOF DAVF mainly supplied from the accessory meningeal artery and the ophthalmic artery, which drained into the facial vein (FV) through the superior ophthalmic vein (SOV) without drainage into the cavernous sinus. A microcatheter was introduced into the shunt pouch via the FV and SOV, and coil embolization of the shunt pouch and SOV was performed, resulting in complete occlusion. However, 1 month later, DAVF recurred, with increased intraocular pressure and decreased vision. A semi-emergent transarterial glue embolization from the accessory meningeal artery was performed and complete occlusion was obtained.
Conclusion: SOF DAVFs often lack cavernous sinus drainage, and transvenous embolization via the FV is recommended if FV drainage is present, but transarterial embolization may be the next treatment of choice if transvenous embolization is unsuccessful.
accessory meningeal artery
CScavernous sinus
DAVFdural arteriovenous fistula
FVfacial vein
ICAinternal carotid artery
ILTinferolateral trunk
IOAVFintraorbital arteriovenous fistula
IOPintraocular pressure
IOVinferior ophthalmic vein
MHTmeningohypophyseal trunk
MMAmiddle meningeal artery
NBCAn-butyl-cyanoacrylate
OphAophthalmic artery
SOVsuperior ophthalmic vein
SOFsuperior orbital fissure
TAEtransarterial embolization
TVEtransvenous embolization
Dural arteriovenous fistulas (DAVFs) in the superior orbital fissure (SOF) are extremely rare.1) The SOF is a transitional region between the cavernous sinus (CS) and the orbit. Accordingly, there are 2 types of AVFs adjacent to the SOF: CS DAVF and intraorbital AVF (IOAVF).2,3) Which of these 2 types represents an SOF DAVF is sometimes difficult to determine. We report a case of DAVF in the SOF and discuss the characteristics of angioarchitecture and the treatment strategies.
A 72-year-old woman presented with chemosis, exophthalmos, and mild proptosis in her right eye. Intraocular pressure (IOP) was 21.1 mmHg in the right eye, and 15.7 mmHg in the left. Visual acuity in the right eye was 1.0, but no ocular movement disorder or diplopia was found. She had a history of hypertension and dyslipidemia, but no history of trauma.
T2-weighted MR imaging showed dilatation of the right superior ophthalmic vein (SOV) (Fig. 1A), and MR angiography showed increased signal intensity in the SOV, suggesting a DAVF.
Right external carotid angiography showed an AVF in the right SOF mainly supplied from the right accessory meningeal artery (AMA) with additional flow from the artery of the SOF and the middle meningeal artery (MMA), draining into the right SOV, then the angular, facial, and external jugular vein, with no drainage into the CS (Fig. 1B and 1C). A multiplanar image showed the shunt located in the SOF (Fig. 1D). Right internal carotid arteriography showed the right ophthalmic artery (OphA) was also the feeder (Fig. 1E), whereas the inferolateral trunk (ILT) and meningohypophyseal trunk (MHT) were not feeders. The anterior part of the CS was not opacified and the superficial middle cerebral vein mainly flowed into the pterygoid plexus in the venous phase (Fig. 1F). We diagnosed DAVF in the right SOF and planned transvenous embolization (TVE) via the facial vein (FV).
First embolizationUnder general anesthesia, a 6F FUBUKI guiding catheter (Asahi Intecc, Aichi, Japan) was introduced into the right external jugular vein, but failed. The approach was changed to direct puncture of the right external jugular vein in the neck. A 2-cm skin incision was made in the neck to expose the external jugular vein, and a 4F Super sheath (Medikit Corporation, Tokyo, Japan) was inserted. A 3.2F TACTICS (Technocrat Corporation, Aichi, Japan) was used as an intermediate catheter and Headway Duo (Terumo Corporation, Tokyo, Japan) was advanced to the shunt pouch in the SOF via the right FV, angular vein, and SOV using CHIKAI 14 (Asahi Intecc). The shunt pouch was multisegmented, not a single lumen, and tight packing was not possible, but complete occlusion of the shunt was achieved by packing the SOV using 6 coils (Fig. 2).
Postoperatively, the hyperemia in the right eye improved, but the IOP had increased to 26.5 mmHg and visual acuity had decreased from 1.0 to 0.5, 1 month later. Ophthalmologic examination revealed central retinal vein occlusion and neovascular glaucoma. Cerebral angiography showed the blood flow from the AMA had resumed, and blood flow in the SOV and inferior ophthalmic vein (IOV) slowly passed through the coil mass and stagnated distally (Fig. 3A), causing rapid IOP elevation and vision loss. Additional semi-emergent endovascular treatment was scheduled, but just prior to treatment, right IOP was elevated at 36 mmHg.
Transarterial glue embolization was performed from the AMA. Under general anesthesia, a 6F FUBUKI was placed in the right external carotid artery and a Guidepost (Tokai Medical Products, Aichi, Japan) was placed just below the foramen ovale as an intermediate catheter. After passing through the foramen ovale, the AMA divided into 2 branches toward the shunt point (Fig. 3B). A Magic 1.2 (Balt, Montmorency, France) was introduced into the upper branch (arrow in Fig. 3B) with CHIKAI 008 (Asahi Intecc) and 33% n-butyl-cyanoacrylate (NBCA) was injected. Some NBCA flowed into the shunt pouch, but the shunt persisted (Fig. 3C). Since the branch connecting to MHT (asterisk in Fig. 3B) was observed, the proximal portion of the upper branch was embolized with i-ED coils (Kaneka Medix, Osaka, Japan) to avoid migration of NBCA into the internal carotid artery (ICA) during the next embolization (Fig. 3D). Next, the lower branch (arrowhead in Fig. 3B) was embolized with 33% NBCA. Some NBCA flowed into the shunt pouch and was refluxed to the AMA (Fig. 3E). Fortunately, the shunt disappeared on internal and external carotid arteriography (Fig. 3F).
Immediately after embolization, sensory disturbance appeared in the region of the third division of the right trigeminal nerve, which was considered to be a complication of the treatment. The IOP in the right eye decreased to 17 mmHg and there was no worsening of vision in the right eye. Since then, the patient has been followed up in the outpatient clinic, and there has been no recurrence.
Consent for publication of the case report was obtained from the patient.
DAVFs with shunt restricted to SOF are extremely rare.1) The SOF is a transitional region between the CS and orbit. Accordingly, there are 2 types of AVFs adjacent to the SOF: CS DAVF and IOAVF. Some cases of SOF DAVFs may have been reported as CS DAVF or IOAVF.2,4) It is difficult to determine which of these 2 types the reported cases belong to.
The shunt point of CS DAVF in 19 cases was posteromedial in 16 cases and posterolateral in 13 cases,5) and most of the 40 shunt points identified in CS DAVF were located in the posterior compartment of the CS, and only 1 case with multiple shunt points had anterior shunt.6) Based on these reports, the shunt point of CS DAVF is mostly located posteriorly, and anteriorly is rare.
A case of SOF DAVF was supplied from the ILT and MMA and drained into the SOV/IOV without drainage to the CS.1) The first MR angiography indicated a connection between the SOV and the CS, but his connection disappeared in the DSA after 1 week. Based on these findings, this case was hypothesized to be originally a DAVF with a shunting point in the SOF located at the frontal tip of the CS. The SOV was separated from the CS by thrombosis and blood flow changed in the SOF. IOAVFs are primarily supplied by the OphA, followed by branches of the external carotid artery. A review of 26 IOAVFs found that they were characterized by outflow into the SOV or IOV and rare outflow into the CS.4) The present case is similar to an IOAVF in that the IOP elevation and visual impairment were more aggressive compared with CS DAVF, the OphA and AMA were the main inflow arteries, and there was no outflow to the CS. The CS is formed by the venous return to the primary head sinus from the superior and inferior orbital veins, merging with the veins of the surrounding bone and dura mater. Therefore, from an embryological perspective, it is hard to believe that the SOV is not connected to the CS. In the present case, the anterior part of the CS was not opacified by preoperative internal carotid angiography. Therefore, we speculate that there was a shunt from the anterior CS to the SOF and that these transitions were thrombosed, resulting in only SOV drainage.7)
In the present case, TVE of the shunt pouch and SOV was selected via the FV instead of the inferior petrosal sinus because CS drainage was absent, and complete obliteration of the fistula was obtained. Postoperatively, hyperemia in the right eye improved, but IOP increased and visual acuity decreased due to recurrence of the fistula 1 month later. Semiurgent complete closure of the shunt was required to improve the rapidly progressing visual impairment. Since the SOV was blocked by the coil after TVE, other possible routes to reach the shunt pouch from the occluded CS via the inferior petrosal sinus were considered, but were not always feasible. Transarterial coil embolization is difficult to achieve complete occlusion and requires glue. Therefore, embolization from the AMA was chosen because of the risk of central retinal artery occlusion with glue embolization from the OphA or MMA. The AMA connects to the ICA through the ILT or MHT and supplies the third division of the trigeminal nerve.
Thererfore, we used NBCA, which has less penetration into the neurotrophic vessels than Onyx, but caused trigeminal nerve palsy. TAE with Onyx from artery of SOF may have been an option.8)
An orbital apex DAVF (probably SOF DAVF) was treated with transarterial embolization (TAE) using NBCA.9) In this case, NBCA injection from the artery of SOF was performed and complete occlusion was achieved by preventing NBCA migration to the ICA and OphA using protective balloon inflation in the ICA at the origin of ILT or temporary placement of coil in the OphA. If the shunt point is difficult to access transvenously, as in this case, TAE is effective, but the procedure is complicated by the need to prevent reflux of NBCA into the ICA or OphA. In the TVE treatment of our case, if a detailed angioarchitecture of the shunt pouch was studied by superselective angiography and tight packing was performed, recurrence was likely to have been avoided. Therefore, we believe that TVE is the first choice if FV drainage is present, and TAE is the next treatment of choice if TVE is unsuccessful.
We reported a rare case of DAVF with the shunt restricted to the SOF. DAVFs in this region often lack CS drainage, and TVE via the FV is recommended if FV drainage is present, but TAE may be the next treatment of choice if TVE is unsuccessful.
All authors have no conflict of interest.
