A Case of Cavernous Sinus Dural Arteriovenous Fistula with Persistent Left Superior Vena Cava.

Objective: Persistent left superior vena cava (PLSVC) is rare, occurring in approximately 0.3%-0.5% of the population. In endovascular treatment (EVT), the left internal jugular vein (IJV) is approached via the left innominate vein from the superior vena cava; however, the left innominate vein is occasionally absent in patients with PLSVC. Careful consideration is required when performing EVT, particularly transvenous embolization (TVE). Case Presentation: A 70-year-old female presented with a left cavernous sinus dural arteriovenous fistula. Left external carotid angiography findings showed that multiple feeders from the ascending pharyngeal artery, accessory meningeal artery, middle meningeal artery, and the artery of the foramen rotundum had formed a shunted pouch posterolateral to the left cavernous sinus. We initially planned to perform a TVE via the right femoral vein. However, PLSVC was detected on common carotid artery angiography. Consequently, a TVE via the left IJV and coil embolization were performed, resulting in the disappearance of the shunt. The patient was discharged without neurological deficits. PLSVC is a rarely observed thoracic venous malformation, with few reports concerning its management in cerebrovascular EVT. Contrast-enhanced computed tomography is useful for diagnosis; however, most patients with PLSVC are clinically asymptomatic and this abnormality is typically an incidental finding, remaining challenging to detect during a preoperative examination. Conclusion: It is essential to consider the possibility of PLSVC and to verify the appropriate access route, including the right atrial level and the venous phase, during preoperative cerebral angiography.