Abstract 095: Pulsatile Tinnitus from An Enlarged Mastoid Emissary Vein: Successful Management with Endovascular Embolization
Authors: Clark David C. , Reyes Cleo Zarina , Nasser Hussein H. 
Published: March 2024

Introduction
Tinnitus is a prevalent condition, affecting approximately 10% of the population. It can be categorized into vascular (pulsatile) and nonvascular (non‐pulsatile) based on its rhythmic quality in sync with the heartbeat (1). Recent literature identifies venous etiologies as the most common cause of pulsatile tinnitus, including venous sinus stenosis, venous diverticula, and the less common enlarged mastoid emissary vein (MEV). Emissary veins are residual connections between the extracranial venous system of the head and the intracranial venous system. Although rare, pathologically enlarged MEVs have been recognized as a cause of pulsatile tinnitus. Endovascular treatment is a novel approach for these patients, offering a safe and quicker recovery compared to traditional open surgical options (2). Here, we present a case of a young woman with debilitating pulsatile tinnitus due to an enlarged MEV, with technically successful treatment via endovascular embolization.

Methods
A 42‐year‐old female presented with left pulsatile tinnitus, imbalance, and headaches following a motor vehicle collision two years prior. Her symptoms included a persistent “whooshing” sound at rest, exacerbated by strenuous physical activity. A tinnitus handicap inventory score of Grade 4‐5 (severe to catastrophic) confirmed the severity of her condition. After ruling out other malignant causes through extensive imaging, a CT scan revealed an enlarged 4.4mm left mastoid emissary vein. Diagnostic suspicions were confirmed by physical examination with superficial compression of the vein along the mastoid region, effectively eliminating the tinnitus. A cerebral angiogram subsequently confirmed an enlarged 5.2mm left MEV, while excluding other malignant arterial or arteriovenous etiologies. After discussing surgical options with neurosurgery and ENT specialists, the patient chose to pursue endovascular intervention. Using a transvenous approach, a coaxial construct of a guide catheter with microcatheter was navigated into the emissary vein, with technically successful coil embolization/sacrifice of the MEV. Post embolization angiogram demonstrated complete occlusion of the MEV with preserved arterial, parenchymal, and venous phases on cerebral angiogram. No procedural complications were reported.

Results
Following the procedure, the patient reported complete resolution of her symptoms. At one‐month follow‐up, she experienced an occasional pulsatile sensation in the left ear, lasting less than one hour per day. The post‐procedural tinnitus handicap inventory scoring was 1, indicating significant improvement in her quality of life, and she resumed an essentially normal daily routine.

Conclusion
This case highlights the successful management of pulsatile tinnitus caused by an enlarged MEV through endovascular intervention, offering a new and safe alternative to traditional surgical treatments. Although emissary veins have been implicated as a venous cause of pulsatile tinnitus, reports of this specific etiology (mastoid emissary vein) and endovascular treatment remain limited (3),(4). The considerable improvement in the patient’s quality of life, rapid post‐procedural recovery, and minimally invasive nature of the procedure makes this approach a promising alternative for the management of pathologically enlarged MEVs as a cause of pulsatile tinnitus.