Traumatic Carotid-Cavernous Fistula with Pontomesencephalic and Cervical Cord Venous Drainage Presenting as Tetraparesis Diego A. Herrera, MD, Sergio A. Vargas, MD, Arthur B. Dublin, MD, MBA, FACR From the Department of Radiology, Neuroradiology Section, Universidad de Antioquia, Medellin, Colombia (DAH); Department of Radiology, Neuroradiology Section, Universidad de Antioquia, Medellin, Colombia (SAV); and Department of Radiology, Neuroradiology Section, UC Davis Medical Center, Sacramento, CA (ABD).
ABSTRACT A 27-year-old male presented with progressive ascending myelopathy leading to tetraparesis. Magnetic resonance imaging of the cervical spine showed dilated perimedullary veins and spinal cord edema. Catheter angiography demonstrated a direct carotid-cavernous fistula (CCF) with prominent pontomesencephalic and perimedullary venous drainage. Successful coil embolization of the fistula was performed with improvement of the patient’s symptoms. To our knowledge, no case of a direct CCF with perimedullary drainage has been previously reported.
Keywords: Carotid-cavernous fistula, endovascular therapy, coil embolization. Acceptance: Received January 6, 2009, and in revised form April 20, 2009. Accepted for publication May 9, 2009. Correspondence: Address correspondence to Diego A. Herrera, MD, Neuroradiologist, Department of Radiology, Neuroradiology Section, Universidad de Antioquia, Calle 32D 80B 34, Medellin, Colombia. E-mail:
[email protected]. Funding sources: None. Commercial associations: None. Conflict of interest to disclose: None. J Neuroimaging 2011;21:73-75. DOI: 10.1111/j.1552-6569.2009.00400.x
Introduction Carotid-cavernous fistulas (CCFs) can be spontaneous, secondary to trauma, or associated cavernous sinus pathology. Most direct CCFs are caused by trauma to the skull base.1 The symptoms are caused by arterialization of the venous outflow of the cavernous sinus and include proptosis, ophthalmoplegia, impaired visual acuity, and intracranial hemorrhage.2 The absence of proptosis is very unusual in this type of lesion. We describe the case of a 27-year-old male patient with preceding history of skull base trauma presenting with myelopathic symptoms secondary to spinal venous hypertension caused by a direct CCF.
Case Report A 27-year-old male was admitted to our hospital with 5 days of progressive tetraparesis and respiratory insufficiency that required intubation. Antecedent pertinent clinical history includes skull base fractures 2 years ago with right-eye blindness. No proptosis or chemosis were observed. An urgent magnetic resonance (MR) imaging of the cervical spine was performed (Fig 1) that revealed signal changes and edema involving the cervical cord with extension into the brainstem. There were multiple prominent perimedullary vascular structures suggesting an arteriovenous fistula. Cerebral angiography demonstrated a high-flow right CCF with the presence of an aneurysm and retrograde filling of the posterior portion of the cavernous sinus with reflux into the peripontomesencephalic and perimedullary veins (Fig 2). There was no filling of the ophthalmic vein. The injection of contrast in the external carotid
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artery did not show any dural component of the fistula. These findings are consistent with a direct CCF (Barrow type A) with posterior drainage and reflux into the perimedullary plexus causing venous hypertension and explaining the progressive myelopathic symptoms of the patient. The fistula was treated with an arterial approach, using conscious sedation (aliquots of 50 micrograms of Fentanyl and 1 milligram of Midazolam). A 6-French Envoy guiding catheter (Cordis Corp., Miami, FL) was placed into the distal cervical segment of the right internal carotid artery. Through this, a 2.3-French Prowler Plus microcatheter (Cordis Corp.) was advanced over a 0.014-inch Agility guidewire (Cordis Corp.) across the injured segment of the cavernous internal carotid artery. After gaining access to the fistula, both the aneurysm and cavernous sinus were packed with 19 hydrocoils. The immediate postinterventional angiogram showed occlusion of the fistula with preservation of the carotid artery (Fig 2). Over the following 4 months, the patient demonstrated progressively improved strength of his extremities, with the ability to walk with assistance.
Discussion CCFs are abnormal communications between the carotid artery and the cavernous sinus. The most frequent cause of CCF is trauma, which accounts for 70% to 90% of CCF cases. They are classified as direct (generally secondary to trauma of aneurysm rupture) or indirect. According to the Barrow classification,3 there are four types of CCF: type A, a direct shunt between the intracavernous internal carotid artery (ICA) and the cavernous
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Fig 1. Sagital MR short tau inversion recovery image of the cervical spine showing hyperintense signal (black arrows) of the cervical spinal cord and dorsal brainstem. There are perimedullary flow voids corresponding to enlarged veins (white arrows).
sinus; type B, a dural arteriovenous fistula supplied by the ICA; type C, a dural arteriovenous fistula supplied (DAVF) by the external carotid artery (ECA); and type D, a DAVF supplied by both the ICA and ECA. Types B, D, and C are often grouped under the common definition of dural or indirect CCFs. Direct CCFs often demonstrate high flow, whereas indirect fistulas are often present as low-flow lesions. The most frequent clinical manifestations are pulsating exophthalmos, eyelid swelling, chemosis, secondary glaucoma, and compromised retinal perfusion, with visual impairment.4 To the best of our knowledge, the clinical presentation of progressive myelopathy and the pontomesencephalic/perimedullary/cervical pattern of drainage have never been reported in direct CCFs. The perimedullary pattern of drainage is a known angiographic manifestation of dural CCFs well described elsewhere.5-7 When extrapolating data from reports of DAVF with cervical cord venous drainage, only 2.3% of the patients with that condition had an ascending myelopathy.7 We propose that the spontaneous thrombosis of the anterior/ophthalmic venous drainage component of the CCF, with subsequent development of a posterior/pontomesencephalic pattern of drainage could explain the unusual clinical and angiographic presentation in our patient. The most plausible mechanism for the myelopathy in patients with arteriovenous intracranial fistulas with perimedullary drainage is venous congestion secondary to venous hypertension.6 Disappearance of clinical and imaging changes related to edema following occlusion of DAVF with this drainage pattern has been previously reported.8 Brainstem dysfunction manifesting as respiratory insufficiency seems to be related to the involvement of the anterior pontomesencephalic vein, which is connected to the petrosal vein superiorly and to the anterior spinal vein inferiorly.6
Fig 2. Right internal carotid angiography, arterial phase (A), shows abnormal filling of the cavernous sinus (arrowheads) with an associated aneurysm consistent with direct CCF. No filling of the ophthalmic vein or anterior drainage was noted (B), but prominent reflux into the peripontomesencephalic and perimedullary veins was present (arrows). After transarterial coil embolization of the cavernous sinus the fistula was completely occluded (C).
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Direct CCFs rarely undergo spontaneous resolution. Today, endovascular treatment is considered the treatment of choice. Multiple techniques have been described including detachable balloon occlusion, coiling, and liquid agent embolization, obtaining complete obliteration in 80% to 90% of cases.4 The goal of treatment of intracranial DAVF with perimedullary drainage is to occlude the draining vein proximally as it exits the arteriovenous shunt. Improvement following embolization occurred in 3 out of 5 patients with this condition in one series.8 Our patient had only partial recovery of motor function following treatment. Chronic ischemic insult of the cord from venous hypertension before the patient noticed clinical symptoms of myelopathy could have precluded complete recovery despite prompt treatment. This reflects the high severity of the condition, requiring urgent treatment after diagnosis.
References 1. Coley SC, Pandya H, Hodgson TJ, et al. Endovascular trapping of traumatic carotid-cavernous fistulae. AJNR Am J Neuroradiol 2003;24:1785-1788.
2. Lasjaunias P, Ming C, Brugge KT, et al. Neurological manifestations of intracranial dural arteriovenous malformations. J Neurosurg 1986;64:724-730. 3. Barrow DL, Spector RH, Braun IF, et al. Classification and treatment of spontaneous carotid cavernous sinus fistulas. J Neurosurg 1985;62:248-256. 4. Shownkeen H, Bova D, Origitano TC, et al. Carotid-cavernous fistulas: pathogenesis and routes of approach to endovascular treatment. Skull Base 2001;11:207-218. 5. Cognard C, Gobin YP, Pierot L, et al. Cerebral dural arteriovenous fistulas: clinical and angiographic correlation with a revised classification of venous drainage. Radiology 1995;194:671680. 6. Lagares A, Perez-Nunez A, Alday R, et al. Dural arteriovenous fistula presenting as brainstem ischaemia. Acta Neurochir (Wien) 2007;149:965-967. 7. Brunereau L, Gobin YP, Meder JF, et al. Intracranial dural arteriovenous fistulas with spinal venous drainage: relation between clinical presentation and angiographic findings. AJNR Am J Neuroradiol 1996;17:1549-1554. 8. Ricolfi F, Manelfe C, Meder JF, et al. Intracranial dural arteriovenous fistulae with perimedullary venous drainage. Anatomical, clinical and therapeutic considerations. Neuroradiology 1999;41:803812.
Herrera et al: Carotid-Cavernous Fistula with Pontomesencephalic Venous Drainage
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