2025 Volume 19 Issue 1 Article ID: cr.2025-0034
Objective: A tentorial dural arteriovenous fistula (DAVF) draining into the superior petrosal vein, also referred to as a petrous DAVF, is a Borden type 3 lesion with an aggressive natural history. Standard treatment options include surgical disconnection of the drainer or transarterial embolization (TAE). While the former requires an invasive craniotomy, the latter is associated with incomplete occlusion and a high complication rate. Transvenous embolization (TVE) has traditionally been considered challenging. We report a case of TVE performed through a tortuous pial vein using the retrograde pressure cooker technique (RPCT).
Case Presentation: A 38-year-old woman presented with right pulsatile tinnitus. Angiography revealed a petrous DAVF supplied by the petrous branch of the middle meningeal artery, the ophthalmic artery, and the inferolateral trunk. A TAE attempt failed due to the narrow and tortuous access of the eloquent feeder. Consequently, TVE was performed via right jugular access, with retrograde navigation of 2 microcatheters through the vein of Galen, basal vein of Rosenthal, and lateral mesencephalic vein. After coils were placed as a plug scaffold in the draining vein, Onyx 34 (Medtronic, Irvine, CA, USA) was injected under intentional systemic hypotension. This resulted in the occlusion of the foot of the drainer, the fistulous point, and the feeders adjacent to the fistula. Due to the significant resistance encountered and the associated risk of venous injury, the microcatheter used for Onyx injection was left in place. The patient’s symptoms resolved completely without any neurological deficit.
Conclusion: TVE using the RPCT achieved complete obliteration of a petrous DAVF. Further cases are needed to validate the feasibility and safety of this technique.
A tentorial dural arteriovenous fistula (DAVF) is associated with an aggressive natural history, often leading to intracerebral hemorrhage or venous infarction.1,2) A tentorial DAVF directly draining into the superior petrosal vein (SPV) is its subtype, the fistulous site of which is located in the anterior part of the cerebellar tentorium near the petrous apex. This condition has also been described as petrous DAVF,3) petrous apex DAVF,4,5) SPV DAVF,6) or superior petrosal sinus (SPS) DAVF with SPS occlusion.7–9)
Historically, surgical disconnection of the SPV or transarterial embolization (TAE) has been the main treatment option to treat a DVAF involving the SPV.4–6,9,10) Retrosigmoid approach can provide an ideal exposure around the SPV, and an open surgical outcome is excellent.8,11) By contrast, TAE alone is often insufficient for complete occlusion because the feeders are usually fine and tortuous and coming from highly eloquent arteries.3,10) The complete occlusion rate with TAE alone is unsatisfactory and is associated with a high complication rate.5,12) In some cases, the role of TAE may be limited to flow reduction before open surgery.4,10)
Transvenous embolization (TVE) of DAVF with SPV drainage has been technically challenging, particularly in Borden type 3 cases with an occluded or hypoplastic SPS. Catheterization through a tortuous draining vein is difficult and carries a high risk of venous perforation.4,6,9,10) However, due to the increasingly sophisticated performance of neuroendovascular devices combined with high-resolution imaging enabling precise assessment of the lesion’s angioarchitecture, complete obliteration by TVE can now be safely achieved by experienced hands.
Recently, a transvenous retrograde pressure cooker technique (RPCT) for curative embolization of arteriovenous malformation (AVM) has been reported.13) Application of this technique to non-sinus type DAVFs is limited. Herein, we report a transvenous RPCT for a case of Borden type 3 tentorial DAVF draining directly into the SPV.
A 38-year-old woman with an unremarkable medical history presented with right pulsatile tinnitus and dizziness. MRA revealed an aggregation of small vessels near the petrous apex. DSA demonstrated a tentorial DAVF supplied by the petrosal branch of the right middle meningeal artery (MMA), the recurrent meningeal artery from the right ophthalmic artery (OphA), and the marginal tentorial artery from the inferolateral trunk (ILT) of the internal carotid artery (Fig. 1A and 1B). No pial feeders were evident. Slab maximum intensity projection images from the fusion of 3D rotational angiography and heavily T2-weighted volumetric MRI clearly visualized the shunt point, which was located in the anterior part of the cerebellar tentorium near the petrous apex (Fig. 1C). High-resolution cone-beam CT (Vaso-CT; Philips Medical Systems, Best, The Netherlands) identified the SPV as the single drainer, which divided into the lateral mesencephalic vein (LMCV), the superior hemispheric vein, the vein of the great horizontal fissure, and the transverse pontine vein. The main drainage route was supratentorial, through the LMCV to the basal vein of Rosenthal, the vein of Galen, and the straight sinus. The absence of right SPS visualization suggested its occlusion or hypoplasia. Curative treatment was indicated because the lesion was symptomatic and considered to have a high hemorrhagic risk as a Borden type 3 DAVF. However, the patient had a strong preference to avoid craniotomy. Thus, an endovascular approach was pursued to achieve complete obliteration.
The 1st attempt was TAE via the petrosal branch of the MMA. However, due to the tortuous and narrow access, the 1.3 Fr microcatheter (DeFrictor Nano; Medico’s Hirata, Osaka, Japan) could not be advanced close enough to the shunt. Given the risk of facial nerve palsy, TAE was abandoned. Other arterial routes via the OphA and ILT were also deemed unfeasible and unsafe (Fig. 1D–1G).
As a result, a 2nd endovascular approach was planned: TVE using the RPCT via the LMCV, the primary but tortuous draining vein (Fig. 2). Based on computed tomography venography findings regarding access to the straight sinus, the right jugular vein was chosen for access. A 6 Fr sheath was placed in the right internal jugular vein, and a manually shaped 6 Fr guiding catheter (FUBUKI; Asahi Intecc, Aichi, Japan) was advanced, using a 4 Fr coaxial catheter, to accommodate the course from the right transverse sinus to the straight sinus and its angle with the vein of Galen. Two microcatheters, a 1.5 Fr Marathon (Medtronic, Irvine, CA, USA) and a 1.5 Fr DeFrictor Bull (Medico’s Hirata) were carefully navigated through the basal vein and LMCV using soft microguidewires (TENROU S10; Kaneka Medix, Osaka, Japan; and Chikai X10; Asahi Intecc). Two iED coils (Kaneka Medix) were deployed through the Marathon microcatheter, which was then removed. Subsequently, under intentional systemic hypotension (systolic blood pressure maintained below 70 mmHg), Onyx 34 (Medtronic) was injected via the DeFrictor Bull microcatheter, positioned closer to the shunt than the coils. Initially, Onyx 34 diffused into tributaries of draining veins and injection was stopped several times to minimize unnecessary occlusion of the veins. Then, Onyx refluxed to the tip of the microcatheter and coils that were placed as a scaffold of plug formation. After several pauses, Onyx advanced to the shunt point through the SPV, and further to the feeders. Care was taken to avoid excessive reflux to the eloquent feeders. After Onyx had refluxed sufficiently to the LMCV, angiography confirmed complete shunt occlusion. An attempt was made to remove the microcatheter, but strong resistance was encountered. As forcibly pulling it was considered hazardous, the decision was made to leave the microcatheter in the vein. After cutting the microcatheter close to the hub, the proximal end of a 0.014-inch, 200-cm wire was inserted into the microcatheter in reverse to supplement its length. The distal access catheter, guiding catheter, and sheath were subsequently removed. The microcatheter was then slightly withdrawn and cut at the puncture site, leaving the distal portion. Hemostasis was easily achieved with brief manual compression. Informed consent regarding the potential intravenous retention of the microcatheter, along with associated risks such as thrombosis and infection, had been obtained preprocedurally. The patient’s symptoms resolved completely without complications. Follow-up MRA at 3 and 9 months confirmed no recurrence of the lesion.
In this report, we have presented a transvenous RPCT for curative embolization of a Borden type 3 tentorial DAVF directly draining into the SPV. Given its natural history, hemorrhagic risk, and symptomatic nature, treatment was indicated. However, the patient strongly preferred to avoid undergoing craniotomy. So, after a failed attempt of TAE through the eloquent thin feeder, complete occlusion of the lesion was achieved by TVE.
TAE is often not suitable for DAVFs involving the SPV, which is usually supplied from the feeders from the eloquent arteries such as the petrosal branch of the MMA, the meningohypophyseal trunk (MHT), the OphA, the ascending pharyngeal artery, the occipital artery, and the pial arteries from cerebellar arteries.3,5,6,14) Unless the microcatheter reached close to the fistula with enough safety margin, TAE have a risk of facial nerve palsy or ischemic complications.3) In our case, because the feeders were thin, tortuous, and originated from eloquent arteries, the TAE attempt resulted in microcatheterization that did not reach close enough to the fistula.
TVE is also often challenging in DAVFs draining into the SPV because the SPS downstream from the fistula is frequently occluded, requiring microcatheter navigation through tortuous pial veins.7,14) According to previous literature, TVE for Borden type 3 DAVFs draining into the SPV has been reported since the early days, with coils being used to occlude the engorged drainers.7,15) Using coils alone does not appear to be a safe option, as incomplete occlusion or intraoperative restriction of the outflow may lead to hazardous hemorrhagic complications. Ideally, embolization should target the foot of the drainer, the shunt point, and the fine network of feeders while preserving normal venous flow to ensure complete occlusion safely. The technique presented here, which combines the liquid embolic material with coils as a plug scaffold, effectively meets these requirements. It is crucial to avoid occluding the normal venous system, as excessive occlusion of veins around the brainstem can result in fatal hemorrhage.16) Additionally, excessive Onyx (Medtronic) infiltration into the feeders should be prevented to protect the cranial nerve supply.3) Onyx 34 is well-suited for creating a plug and achieving occlusion over a short segment. When deep penetration into fine feeders is essential to prevent hemorrhage—such as in brain AVMs or DAVFs with evident pial arterial supply—adding Onyx 18 may be preferred due to its lower viscosity and improved distal penetration.
Pial transvenous navigation requires the use of soft devices, carefully manipulated by experienced hands, due to the fragile and mobile nature of the venous route. Jugular venous access using a manually shaped guiding catheter is recommended to ensure sufficient stability and maneuverability during microcatheterization. The transvenous RPCT for DAVF may carry a lower risk of hemorrhage compared with that for AVM, as the feeders are primarily dural arteries. Therefore, induced systemic hypotension may not be necessary in all cases. However, frequent involvement of pial arterial supply and its associated risk of embolization-related hemorrhagic complication have been reported in tentorial DAVFs.2,17,18) While pial arterial supply was not evident in our case, it would be prudent to inject Onyx under systemic hypotension in tentorial DAVFs with pial supply. TVE using Onyx can also embolize the pial feeder in a retrograde manner, which may help reduce hemorrhagic complications.
Until recently, navigating a microcatheter through the deep venous system or cortical veins was generally considered unfeasible. Only enlarged, non-tortuous vessels were deemed suitable candidates for pial venous catheterization. However, with the advent of microcatheters featuring flexible tips harboring excellent trackability combined with soft microguidewires, an increasing number of non-sinus type DAVFs can now be completely occluded by endovascular treatment through previously inaccessible narrow routes.19) When venous access tortuosity hinders the placement of 2 microcatheters, advancing a single microcatheter, such as Marathon (Medtronic) or DeFrictor Bull (Medico’s Hirata), in combination with a low-profile intermediate catheter, is sufficient for both coiling and Onyx injection. This approach has been reported as a modification of the RPCT.20)
A potential disadvantage of this technique is the risk of venous injury. To minimize the risk of perforation, extremely soft microcatheters and microwires should be used by an experienced operator. When strong resistance is encountered, withdrawal of a non-detachable catheter after Onyx injection is generally not recommended due to the risk of hemorrhage caused by stretching of the venous route. From our experience, as well as reports from other experts,20) no complications have been associated with leaving a microcatheter in the venous system. However, a long-term follow-up is necessary to assess potential risks, such as thrombosis or infection. In settings where the detachable tip microcatheters are unavailable, this approach should be limited to carefully selected cases involving patients with contraindications to craniotomy or a strong preference to avoid it. The possibility of microcatheter retention and its associated risks must be thoroughly explained, and informed consent should be obtained in advance.
The transvenous RPCT proved effective for treating a tentorial DAVF draining into the superior petrosal vein. Further cases with long-term follow-up are necessary to confirm its feasibility and safety.
The authors declare that they have no conflicts of interest.
