Internal carotid-inferior petrosal sinus fistula complicating foramen ovale telemetry: successful treatment with detachable coils: case report and review.

OBJECTIVE AND IMPORTANCE: Iatrogenic internal carotid artery-cavernous sinus fistula complicating percutaneous foramen ovale (FO) instrumentation (e.g., retrogasserian rhizotomy for trigeminal neuralgia) has been reported in only four patients to date. To our knowledge, no case of fistula has previously been reported either to complicate FO telemetry or to involve the inferior petrosal sinus (IPS); moreover, most patients have presented within 48 hours. We present a case of internal carotid artery-IPS fistula that complicated FO telemetry in which the clinical syndrome was delayed by 4 weeks.

CLINICAL PRESENTATION: Four weeks after undergoing bilateral FO telemetry during Phase 2 investigations for surgery for epilepsy, a 37-year-old man suddenly developed a painful bilateral pupil-sparing oculomotor palsy, poor visual acuity, proptosis, conjunctival suffusion, and an audible bruit over the right frontotemporal region.

INTERVENTION: Cerebral angiography demonstrated a high-flow arteriovenous fistula between the junction of the petrous and laceral portions of the right internal carotid artery and right IPS, with rapid filling of both cavernous sinuses. Successful obliteration was obtained with Guglielmi detachable coils, followed by complete resolution of the bilateral ocular abnormality.

CONCLUSION: This is the first reported case of iatrogenic fistula formation to either involve the IPS or to complicate FO telemetry. In addition, symptomatology was anomalously delayed. This case highlights the importance of noting FO anatomic asymmetries before FO instrumentation and of routinely inquiring for "swooshing" noises after electrode withdrawal.