case report J Neurosurg 122:933-938, 2015 P aracavernous venous plexus fistulas are rare types of dural arteriovenous fistulas (DAVFs) that can mimic indirect carotid-cavernous fistulas (CCFs) in both imaging characteristics and clinical presentation. While similar to CCFs, their anatomical differences lead to differences in management. Key differences include the distinct patterns of venous drainage, which affect the options for endovascular access, and the actual location of the abnormal shunt. Both types of fistula may have drainage through the superior ophthalmic vein, the plexus of the foramen ovale to the pterygoid plexus, and/or the deep middle cerebral vein. However, unlike a CCF, the paracavernous venous plexus fistula does not drain directly through the inferior petrosal sinus, but rather it drains through the cavernous sinus. Because the fistulous connection resides in the paracavernous venous plexus and not in the cavernous sinus, embolization of the cavernous sinus does not treat the fistula and can endanger the patient by altering the drainage toward cerebral veins (Fig. 1). This anatomical difference in location and venous drainage can make these types of DAVFs very difficult to treat by endovascular interventions alone.In this report the authors describe the presentation, imaging findings, and integrated open surgery and endovascular embolization of a rare type of DAVF, a paracavernous venous plexus fistula.
case report
History and ExaminationA 66-year-old right-handed Asian man presented with a 2-year history of persistent right eye chemosis. He was initially evaluated by an ophthalmologist who prescribed steroid eye drops, resulting in mild temporary improvement. However, the symptoms recurred and persisted. He reported right-sided occipital region headaches occurring approximately 3 times per week and mild right orbital proptosis. At presentation, he denied eye pain, recent change in his visual acuity, double vision, photophobia, nausea, and neck stiffness. On examination, he was found to have right eye chemosis, proptosis, and an orbital bruit. His right eye intraocular pressure was measured at 19 mm Hg. His visual fields were full to confrontation. Brain MRI/ MR angiography revealed mild right proptosis without obvious prominence of the right cavernous sinus or enlargement of the right superior ophthalmic vein. Cerebral angiography demonstrated an arteriovenous shunt of the right paracavernous venous plexus (Fig. 2). The fistula was fed by meningeal branches of a dilated inferolateral trunk, the right accessory meningeal artery, and the artery of the foramen rotundum. There was early filling of the left cavernous sinus across the intercavernous sinus. The venous drainage of the fistula was predominantly through the abbreviatioNs CCF = carotid-cavernous fistula; CTA = CT angiography; DAVF = dural arteriovenous fistula; ICA = internal carotid artery; LCS = laterocavernous sinus; LWSS = lesser wing of the sphenoid sinus; SMCV = superficial middle cerebral vein. The authors report the treatment ...