Acute Orbital Compartment Syndrome After Coil Embolization of a Contralateral Carotid Cavernous Fistula

Carotid cavernous fistula (CCF) is an abnormal communication between the cavernous sinus and the carotid arterial system that results in high-pressure arterial blood entering the low-pressure venous system. CCFs may be classified as high-flow/direct or low-flow/indirect.

Clinical Correspondence Section Editors: Robert Avery, DO Karl C. Golnik, MD Caroline Froment, MD, PhD An-Guor Wang, MD Acute Orbital Compartment Syndrome After Coil Embolization of a Contralateral Carotid Cavernous Fistula Christiana L. Gandy, MD, Andrea A. Tooley, MD, Andrew Y. J. Lee, BS, Ann Q. Tran, MD, Cristiano Oliveira, MD, Athos Patsalides, MD, Kyle J. Godfrey, MD C arotid cavernous fistula (CCF) is an abnormal communication between the cavernous sinus and the carotid arterial system that results in high-pressure arterial blood entering the low-pressure venous system. CCFs may be classified as high-flow/direct or low-flow/indirect. Although high-flow direct fistulas require emergent intervention, lowflow indirect fistulas may self-resolve and treatment is required only when high risk features are present, including uncontrollable intraocular pressure, persisting diplopia, proptosis leading to exposure keratopathy, optic neuropathy, retinal ischemia, severe bruit, and cortical venous drainage from the fistula (1). The gold standard treatment for both types of CCFs involves embolization to achieve occlusion of the arteriovenous shunt (1). Ipsilateral orbital compartment syndrome (OCS) has been reported as a rare complication after embolization (2), but to the best of the authors’ knowledge, no cases of contralateral OCS have been published. We describe a patient with bilateral low-flow indirect CCFs who acutely developed a contralateral OCS after unilateral coil embolization of the higher risk fistula that was successfully treated through a transorbital approach. A 70-year-old woman with systemic hypertension presented with 3-month history of left-sided pulsatile tinnitus. Her neuro-ophthalmological examination was significant for normal afferent and efferent visual function, with no proptosis, conjunctival injection, or chemosis. The patient underwent contrast enhanced magnetic resonance angiography of the head which showed arterialized flow and early venous filling of both cavernous sinuses (Fig. 1A) with a prominent left superior ophthalmic vein (SOV) (Fig. 1B, C) consistent with bilateral left greater than right low-flow indirect CCFs. Subsequent diagnostic cerebral catheter angiogram demonstrated high-risk cortical venous drainage from the left fistula (Fig. 1D) which prompted the decision to proceed with embolization on Department of Ophthalmology (CLG, AAT, AQT, CO, KJG), Weill Cornell Medical College, New York, New York; Weill Cornell Medical College (AYJL), New York, New York; and Departments of Neurological Surgery (AP) and Radiology (AP), Weill Cornell Medical College, New York, New York. Supported by an unrestricted grant from the Research to Prevent Blindness Foundation. The authors report no conflicts of interest. Address correspondence to Kyle J. Godfrey, MD, Department of Ophthalmology, Weill Cornell Medicine, 1305 York Avenue, 11th Floor, New York, NY 10065; E-mail: [e-mail] e398 the left side by a transvenous approach to decrease the risk of intracerebral hemorrhage, despite her reassuring neuroophthalmological examination. From a neurointerventional perspective, crossing over to the right cavernous sinus was not feasible because of bony septa between the right and left cavernous sinuses. After successful coil embolization of the left fistula, the patient developed rapidly progressive proptosis of the right eye. Urgent inpatient ophthalmologic examination of the right eye demonstrated count fingers visual acuity, a relative afferent pupillary defect, eyelid edema and chemosis, complete ophthalmoplegia, and an intraocular pressure of 62 mm Hg, overall consistent with acute OCS. Physical examination of the left eye and orbit was unchanged. The patient underwent emergent right-sided lateral canthotomy and cantholysis, which rapidly decreased the intraocular pressure to 31 mm Hg (Fig. 2A). Repeat angiography demonstrated increased flow of the right CCF with an engorged SOV (Fig. 2B). The previously noted drainage of the CCF through the inferior petrosal sinus was absent, indicating interval thrombosis. The patient was immediately returned to the interventional neuroradiology suite where embolization of the right CCF was performed. Several attempts to access the fistula through the right inferior petrosal sinus were not successful because of thrombosis. Embolization through external carotid artery feeders was not curative, and the decision was made to use an orbital approach. Through a medial eyelid crease incision, the SOV was exposed in the orbit and directly cannulated (Fig. 2C). This enabled successful coil embolization of the fistula with a corresponding rapid decrease in intraocular pressure to 15 mm Hg and durable resolution of the OCS. The patient did well postoperatively, and at 3 months follow-up, the visual acuity was at baseline, visual fields were full, and ocular motility was full with no subjective diplopia (Fig. 2D). OCS is a rare, vision threatening complication that may occur following embolization of a CCF. Cases of OCS ipsilateral to the embolized fistula have been described (2); however, to the best of the authors’ knowledge, a compartment syndrome contralateral to the side of CCF embolization has not been reported. Patients with bilateral fistulas do not always present with bilateral or symmetric signs and symptoms. It has been postulated that this asymmetry in presentation is a result of differences in size and intrinsic hemodynamic properties of Gandy et al: J Neuro-Ophthalmol 2022; 42: e398-e400 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Clinical Correspondence FIG. 1. Pre-embolization contrast enhanced magnetic resonance angiography showing arterialized flow and early venous filling of bilateral cavernous sinuses (A) and prominent early filling of the left superior ophthalmic vein (B and C). Preembolization catheter angiogram (D) demonstrates bilateral carotid cavernous fistulas (white arrowheads) with high risk cortical venous drainage on the left side (white arrow). the fistulas (3). Bilateral fistulas may communicate with each other through the intercavernous sinus and may ultimately share the same venous drainage pathway. In those cases, cerebral angiography usually shows more prominent venous engorgement on one side. In our patient with bilateral fistulas, angiography demonstrated greater venous engorgement FIG. 2. Postembolization of the left carotid cavernous fistula. Photograph shows persisting right-sided proptosis, chemosis, and eyelid edema status after right-sided lateral canthotomy and cantholysis (A). Catheter angiogram (B) demonstrates occluded left cavernous sinus post coil embolization (white arrow) and increased flow through the right carotid cavernous fistula (black arrow) with interval development of right-sided cortical venous drainage, a high risk feature. Catheter angiogram (C) showing cannulated superior ophthalmic vein (black arrows). At 3-month postoperative follow-up (D), the patient demonstrated baseline visual acuity, full visual fields, and full extraocular motility without subjective diplopia. Gandy et al: J Neuro-Ophthalmol 2022; 42: e398-e400 e399 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Clinical Correspondence tension on the right side, which manifested clinically as a contralateral compartment syndrome. In our patient, attempts to access the right cavernous sinus through conventional endovascular approaches were unsuccessful because of thrombosis of the inferior petrosal sinus and alternative vascular routes. In this setting, a transorbital approach for direct cannulation of the arterialized SOV allowed for successful embolization of the cavernous sinus. The orbital approach to the SOV is typically reserved for use in the setting of failed traditional endovascular embolization. Despite concerns of the vein’s fragility and proximity to the optic nerve, the SOV approach has been shown to be a safe and effective alternative (4). The surgical technique involves a medial upper eyelid incision, followed by dissection through the orbicularis oculi and orbital septum, and between the nasal and central fat pads toward the trochlea in search of arterialized venous feeders of the SOV (Fig. 3A). Using delicate, blunt dissection the feeder vessels are traced to the main trunk of the SOV (Fig. 3B), which is then cannulated providing access to the cavernous sinus. Unilateral embolization of a CCF may result in acutely altered hemodynamics and worsening venous hypertension on the contralateral side, particularly in the setting of thrombosis of collateral outflow pathways. We recommend close postoperative surveillance in these cases and expedited treatment if OCS develops. Simultaneous bilateral treatment is also an option. In cases where femoral approach to coil embolization of CCF is unsuccessful, direct cannulation of the SOV through an orbital approach can be used. STATEMENT OF AUTHORSHIP Category 1: a. Conception and design: C. L. Gandy, A. A. Tooley, A. Y. J. Lee, A. Q. Tran, C. Oliveira, A. Patsalides, and K. J. Godfrey; b. Acquisition of data: C. L. Gandy, A. A. Tooley, A. Q. Tran, C. Oliveira, A. Patsalides, and K. J. Godfrey; c. Analysis and interpretation of data: C. L. Gandy, A. A. Tooley, A. Y. J. Lee, A. Q. Tran, C. Oliveira, A. Patsalides, and K. J. Godfrey. Category 2: a. Drafting the manuscript: C. L. Gandy and A. Y. J. Lee; b. Revising it for intellectual content: C. L. Gandy, A. A. Tooley, A. Y. J. Lee, A. Q. Tran, C. Oliveira, A. Patsalides, and K. J. Godfrey. Category 3: a. Final approval of the completed manuscript: C. L. Gandy, A. A. Tooley, A. Y. J. Lee, A. Q. Tran, C. Oliveira, A. Patsalides, and K. J. Godfrey. FIG. 3. Intraoperative photographs showing the dissected arterialized feeder vessel of the superior ophthalmic vein (A) and the main trunk of the superior ophthalmic vein (B) before cannulation. on the left side. The intercavernous communication may have allowed the smaller, right-sided fistula to primarily drain into the left cavernous sinus and then through the same outflow pathway as the left-sided fistula. In addition, a right inferior petrosal vein thrombosis is believed to have developed in the short interim between the initial angiography and the treatment. Occlusion of the left cavernous sinus during coil embolization therefore resulted in acute venous hypere400 REFERENCES 1. Henderson AD, Miller NR. Carotid-cavernous fistula: current concepts in aetiology, investigation, and management. Eye (Lond). 2018;32:164–172. 2. Sia PI, Sia DI, Scroop R, Selva D. Orbital compartment syndrome following transvenous embolization of carotid-cavernous fistula. Orbit. 2014;33:52–54. 3. Ng SH, Wan YL, Ko SF, Lee ST, Wong HF, Chen YL, Cheung YC. Bilateral traumatic carotid-cavernous fistulas successfully treated by detachable balloon technique. J Trauma. 1999;47:1156–1159. 4. Wolfe SQ, Cumberbatch NM, Aziz-Sultan MA, Tummala R, Morcos JJ. Operative approach via the superior ophthalmic vein for the endovascular treatment of carotid cavernous fistulas that fail traditional endovascular access. Oper Neurosurg (Hagerstown). 2010;66:293–299. Gandy et al: J Neuro-Ophthalmol 2022; 42: e398-e400 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.