Transvenous treatment of a complex cavernous sinus dural arteriovenous fistula secondary to balloon embolization of a traumatic carotid-cavernous fistula

Although recurrent traumatic carotid-cavernous fistula (CCF) and its treatment have been reported sporadically,1 a complex cavernous sinus dural arteriovenous fistula (DAVF) secondary to balloon embolization of a direct traumatic CCF is rare. In 2005, we treated such a case via transvenous approach using coils and N-buty-2-cyanoacrylate (NBCA). The causes of recurrent cavernous sinus DAVF and its endovascular approach are discussed. CASE REPORT A 24-year-old man with severe head injury was admitted to our hospital on March 8, 2005. CT scan on admission showed a basal skull fracture on the right side and subarachnoid hemorrhage. The patient returned to a normal life after conservative treatment. Three months after the head trauma, the patient exhibited visual loss, proptosis, chemosis and ocular bruit in the right side associated with retro-orbital pain. MRI revealed a flow void corresponding to a large vascular compartment in the sellar region. Cerebral angiography was performed to evaluate the causes of these symptoms and signs. The right internal carotid artery (ICA) angiogram revealed a direct right-sided CCF (Fig. 1A), draining from the cavernous sinus into the right ophthalmic vein, and the superior and inferior petrosal sinuses.Fig. 1.: Anteroposterior angiography showing a direct CCF (arrow) in the right ICA before operation (A). The fistula was occluded completely after the operation and the collateral circulation was adequate (B).Balloon embolization was performed via the femoral arterial approach under local anesthesia. Owing to the large volume (about 3–4 cm in diameter) of the right cavernous sinus, detachable inflated balloon entered into the cavernous sinus easily and migrated in the cavernous sinus. The second balloon had to be detached into the cavernous sinus, but even this failed to occlude the fistula completely. Then, the other two balloons were introduced to occlude the parent ICA. Postembolization angiogram confirmed complete occlusion of the fistula and adequate cross-filling of the right anterior cerebral artery (ACA) and middle cerebral artery (MCA) territory from the left ICA following the right ICA occlusion (Fig. 1B). However, two months after the first operation, the symptoms and signs reoccurred. Cerebral angiography revealed a complex cavernous sinus DAVF fed by multiple branches of the right external carotid artery (ECA), left ICA and ECA, and right posterior cerebral artery (PCA) from the vertebrobasilar system (Fig. 2). The cavernous sinus DAVF drained into the right ophthalmic vein and the right inferior petrosal sinus. Because there are multiple feeders arising from the right ECA, left ICA, ECA, and PCA associated with complete occlusion of the right ICA, the transvenous approach via the right inferior petrosal sinus-right cavernous sinus was chosen. Coiling of the cavernous sinus with 56 coils did not occlude the fistula but decreased flow through the fistula. Therefore, 33% diluted NBCA was injected into the right cavernous sinus with permeation of the perifistulous collateral network. Postembolization angiograms confirmed that the fistula was occluded completely (Fig. 3). One-year follow-up showed no recurrence of the related symptoms or signs.Fig. 2.: Two months after the first operation, lateral angiogram of the right CCA in early arterial phase showing a cavernous sinus DAVF fed by the branches of the ECA (A, arrow); lateral angiogram of the left ICA revealing that the DAVF was also fed by the dural branches of the ICA (B, arrow), draining into the ophthalmic vein (arrowhead) and inferior petrosal sinus (open arrow). In addition, anteroposterior angiogram of the left ECA in the early arterial phase demonstrating that the DAVF was fed by the branches of the left ECA (C, arrow); and anteroposterior angiogram of the left VA showing that the DAVF was also fed by the right PCA from the vertebrobasilar system (D, arrow).Fig. 2.: ContinuedFig. 3.: At the end of the second operation, lateral angiograms of the right CCA (A), left CCA (B), and VA (C) showing a completely occluded cavernous sinus DAVF.DISCUSSION CCFs are classified into direct and indirect fistulae.2 Embolization of the direct CCF using detachable balloons has been widely accepted. The size of the cavernous sinus and the fistula may affect the success of the detachable balloon embolization of a CCF.3 When the cavernous sinus is large as in the current case, the detachable balloon may migrate easily into the large cavernous sinus. Under this circumstance, multiple balloons are needed to fill the cavernous sinus and occlude the fistula even if the parent ICA is sacrificed. Usually, cavernous sinus DAVFs are well tolerated and resolve spontaneously. In our case, the recurrent symptoms including visual disturbance, bruit, chemosis and proptosis prompted us to treat this lesion as soon as possible. To cure a DAVF, its pathological arteriovenous connection must be eliminated. Using an exclusively arterial approach often results in frustration and poor outcomes in treating complicated DAVFs with multiple feeding vessels. A transvenous approach should be considered when the arterial route is blocked or the fistula has multiple feeding arteries. There are various venous routes, depending on the types of venous drainage (anteriorly, the ophthalmic and facial veins; and posteriorly, the inferior and superior petrosal sinuses) and anatomy.4–8 The venous route usually goes through the internal jugular vein and the inferior petrosal sinus up to the pathologic shunts of the cavernous sinus.9 However, it is often difficult to advance a balloon into the cavernous sinus via the inferior petrosal sinus, against the direction of flow. Coiling of the cavernous sinus may be an alternate approach, since it is easier to reach the desired location using the microcatheter and wire combination. NBCA has been widely used for embolization of indirect CCFs because of its good penetration and rapid induction of thrombosis after polymerization. However, the drug has potential risks of cerebral infarction from the uncontrolled escape of the polymers during injection and deposition.10 Therefore, preoperative angiograms have to be carefully reviewed to exclude the presence of veins from cortical territories draining into the compartment to be embolized. To our knowledge, use of NBCA in combination with coils via the inferior petrosal sinus-cavernous sinus has not been previously described in the treatment of complex cavernous sinus DAVFs. The causes of secondary cavernous sinus DAVF is unclear. In this case, the development of cavernous sinus DAVF may be due to: (1) Therapeutic cavernous sinus occlusion with balloons activated the expression of the related angiogenic factors and then elicited angiogenesis within the cavernous sinus dural wall. (2) Increased pressure within the cavernous sinus after balloon embolization resulted in the opening of the intrinsic arteriovenous communications in the dural mater of the cavernous sinus. (3) Head trauma led to both the direct CCF and potential DAVFs in the cavernous sinus. The hemodynamic alteration could mask the observation of the potential DAVFs on the first angiographic assessment. Then, the venous outflow obstruction and collateral circulation resulted from complete occlusion of the direct CCF and the right ICA expanded the potential arteriovenous shunts. In conclusion, by using coils and NBCA endovascularly, we successfully treated a complex cavernous sinus DAVF secondary to balloon embolization of a direct CCF. A primary transvenous approach is useful, safe, and effective in treating cavernous sinus DAVFs with complex arterial supplies.