Abstract
Case A 51-year-old female presented to ophthalmology for left lid swelling with painful extraocular movement after a cat scratch injury. She was treated for pre-septal cellulitis, however CT/CT angiogram showed dilatation of the left superior ophthalmic vein, and cavernous sinus, raising concerns for carotico-cavernous fistula. Her care was transferred to interventional neuroradiology. The cerebral catheter angiogram excluded an arteriovenous shunt, but demonstrated near complete anterior cavernous venous capture bilaterally and absent bilateral sigmoid sinuses, without morphological clues to aetiology. This venous outflow appeared chronic and cerebral drainage was adequately compensated, hence no neuro-interventional treatment was necessary. She was on-referred to neurology clinic to exclude secondary causes of occult venous occlusion.
Further history reveals a possible lifelong history of facial and orbital varix. Perinatal history is unclear, however she has a normal development. Medical history is notable for gestational hypertension and one miscarriage, without prior venous thromboembolism or prothrombotic state. She has prominent facial and eyelid varix and an otherwise normal neurological and ocular exam. Thrombophilia and vasculitis screen is negative.
Discussion We describe an unusual case of variceal dilatation of normal orbital veins as a compensatory dominant drainage pathway of the brain, due to bilateral absent sigmoid venous sinuses and internal jugular veins of indeterminate but likely longstanding cause. These abnormal appearing structures provide critical cerebral drainage pathways. Further unnecessary treatment will risk cerebral venous congestion. Our case demonstrates the highly variable intracranial venous anatomy, and the importance of further evaluation by appropriate experts to avoid potential fatal intervention.
