| OCR Text |
Show Journal of Neuro- Ophthalmology 20( 4): 264- 265, 2000. © 2000 Lippincott Williams & Wilkins, Inc., Philadelphia Carotid Cavernous Fistula Associated With Persistent Primitive Trigeminal Artery Briggs E. Cook, Jr., MD, Jacqueline A. Leavitt, MD, Joseph W. Dolan, MD, and Douglas A. Nichols, MD A patient with diplopia had a carotid cavernous fistula associated with a persistent primitive trigeminal artery that was seen with angiography. Balloon occlusion of the carotid cavernous fistula resulted in flow stasis of the persistent primitive trigeminal artery and resolution of the symptoms. Persistent primitive trigeminal artery may be associated with a carotid cavernous fistula. Key Words: Carotid- Fistula- Primitive vessels. We present a case of persistent primitive trigeminal artery ( PPTA) associated with a carotid cavernous fistula ( CCF). Persistent primitive trigeminal artery is the most common remnant of the embryologic cerebral vascular system. The trigeminal artery is usually present for 7 days of fetal development and serves as an anastomosis between the carotid and vertebral systems. A PPTA was first described in 1844 by Quain ( 1). The first PPTA was diagnosed radiographically in 1950 by Sutton ( 2). Only 0.1% to 0.6% of cerebral angiograms show a PPTA. There is a 25% incidence of other associated cerebral vascular abnormalities with a PPTA ( 3,4,5). The presence of this congenital anomaly may predispose development of a traumatic cavernous sinus fistula despite trivial trauma. CASE REPORT An 83- year- old woman presented after a high- speed motor vehicle accident. She was confused but hemody-namically stable. Results of computed tomography of the head were negative. Twenty- four hours later, the patient experienced diplopia. Supported in part by an unrestricted grant from Research to Prevent Blindness, Inc., New York, New York. Manuscript received September 10, 1998; accepted March 23, 1999. From the Department of Ophthalmology ( BEC, JAL, JWD) and the Department of Radiology ( DAN), Mayo Clinic, Rochester, Minnesota. Dr. Dolan is currently at the Midelfort Clinic, Mayo Health System, Eau Claire, WI. Presented as a poster at the North American Neuro- Ophthalmology Society meeting, February 11- 15, 1996, Snowbird, Utah. Address correspondence and reprint requests to Jacqueline A. Leavitt, MD, 200 First Street, SW, Mayo Clinic, Rochester, MN 55905. Results of ophthalmologic evaluation showed cranial nerve deficits of nerves III ( partial), IV, V, and VI, and it showed Horner syndrome OD. Corneal sensation was decreased OD. Initially, there was minimal proptosis and injection of the eye; however, these signs increased over the ensuing days. Visual acuity and intraocular pressures remained normal and equal bilaterally. There was no evidence of facial trauma. Results of a repeated computed tomography scan of the head showed subtle soft- tissue fullness in the right cavernous sinus that extended posteriorly to the Meckel cave with enlargement of the right superior ophthalmic vein and mild proptosis. This supported the clinical diagnosis of a posttraumatic CCF. A cerebral angiogram delineated not only the expected direct CCF, but also a PPTA ( Figs. 1A and IB). Neuroradiologic intervention with balloon occlusion of the PPTA resulted in occlusion of the direct CCF with preservation of flow in the right internal carotid artery ( Figs. 2A and 2B). Symptoms began to resolve by 10 days after intervention. One month after intervention, the abduction deficits and Horner syndrome remained, but after 3 months, the patient had no residual symptoms and minimal findings. DISCUSSION The primitive trigeminal artery develops at the 4- mm embryonic stage and disappears at the 7- to 12- mm stage. It is the most common of the carotid- basilar anastomoses to persist into adult life. In utero, the trigeminal artery supplies the basilar artery before the development of the posterior communicating arteries and the vertebral arteries. When these vessels develop, the trigeminal artery usually disappears. The trigeminal artery arises from the proximal cavernous internal carotid artery with two distinct origins. If the artery runs lateral to the dorsum sella, its origin is from the posterolateral aspect of the cavernous internal carotid artery. If it has a midline course through or over the dorsum sella, the origin is from the posteromedial aspect of the cavernous internal carotid artery. 264 CAROTID CAVERNOUS FISTULA ASSOCIATED WITH PPTA 265 FIG. 1. Lateral ( A) and anteroposterior ( B) right internal carotid digital subtraction angiograms show the persistent primitive trigeminal artery and direct carotid cavernous fistula with venous drainage into the superior and inferior ophthalmic veins, the deep venous cerebral system, the inferior petrosal sinus, and the pterygoid venous plexus. Persistent primitive trigenimal artery, open arrow; distal basilar artery and posterior cerebral artery, small arrowheads; superior and inferior ophthalmic veins, long arrows; basal vein of Rosenthal, vein of Galen, and straight sinus, short arrows; inferior petrosal sinus, large arrowhead. Two forms of PPTA exist: 1) fetal, in which the posterior circulation is dependent on the anastomosis; and 2) adalt, where the posterior circulation is independent of the anastomosis. Our patient had the adult form of PPTA. The distal basilar artery opacified well on the vertebral injection ( Figs. 2A and 2B), and the patient did not experience any adverse sequelae after occlusion of the PPTA. Presentation may be with acute subarachnoid hemorrhage, oculomotor pareses, trigeminal neuralgia, or internal carotid artery emboli transmitted to the basilar artery. Other entities that can be associated with a PPTA include aneurysm, arteriovenous malformation, and CCF ( 3,4,5). The diagnosis of PPTA usually is made after an incidental finding. Before the introduction of magnetic resonance imaging techniques, PPTA could only be diagnosed with cerebral angiography. The presence of a PPTA does not affect blood flow direction if there is an associated fistula. Therapeutic options of PPTA and CCF include balloon occlusion, direct surgical clipping, or prophylactic external- internal carotid bypass, in addition to proximal occlusion. Balloon occlusion is the preferred method of treatment; however, microcoils can be used if the lesion is not amenable to balloon occlusion. In our patient, balloon occlusion alleviated the symptoms. Before balloon occlusion, it must be determined that the fistula is not filling via the PPTA from the vertebral- basilar circulation; if the fistula fills via the vertebral- basilar circulation, the balloon must be repositioned. The risk of posterior circulation infarction is dependent on the direction of the flow in the PPTA and the size of the native basilar artery; with a small native basilar artery, the risk of infarction is increased, whereas with a large native basilar artery, the risk of infarction is small. Although PPTA is a rare radiologic finding, this case shows that a PPTA can be considered when one encounters the neuro- ophthalmologic findings of a CCF occurring despite trivial trauma. REFERENCES 1. Quain R. The Anatomy of the Arteries of the Human Body and Its Applications to Pathology and Operative Surgery, With a Series of Lithographic Drawings. London: Taylor and Walton, 1844. 2. Sutton D. Anomalous carotid basilar anastomosis. Br J Radiol 1950; 23: 617- 9. 3. Agnoli AL. Vascular anomalies and subarachnoid haemorrhage associated with persisting embryonic vessels. Acta Neurochir Wien 1982; 60: 183- 99. 4. Debrun GM, Davis KR, Nauta HJ, et al. Treatment of carotid cavernous fistulae or cavernous aneurysms associated with a persistent trigeminal artery: report of three cases. AJNR 1988; 9: 749- 55. 5. Enomoto T, Sato A, Maki Y. Carotid- cavernous sinus fistula caused by rupture of a primitive trigeminal artery aneurysm: case report. J Neurosurg 1977; 46: 373- 6. FIG. 2. Lateral ( A) and oblique ( B) anteroposterior right internal carotid digital subtraction angiograms obtained with a balloon ( arrowheads) inflated in the persistent primitive trigenimal artery before detachment. The direct carotid cavernous fistula is occluded, and the distal basilar artery and its branches no longer opacify. J Neuro- Ophthalmol, Vol. 20, No. 4, 2000 |
