Dural Arteriovenous Fistula of the Transverse Sinus following Internal Jugular Vein Ligation: A Case Report with a Focus on Anatomic Venous Variants.

Eight years after resection of hypopharyngeal carcinoma with neck dissection and ligation of the left internal jugular vein, a man in his 50s presented with an incidentally discovered isolated left transverse sinus dural arteriovenous fistula. Transvenous embolization was performed to achieve complete obliteration. The patient likely developed venous hypertension due to stenosis of the left transverse sinus, limiting contralateral drainage and the absence of collateral communication between the internal jugular vein and the suboccipital cavernous sinus. A retrospective review of serial imaging revealed progression of venous drainage from the initial development of transverse sinus dural arteriovenous fistula to an eventual isolated sinus configuration. Although dural arteriovenous fistula formation is associated with venous hypertension, this case suggests that anatomic venous variants may predispose individuals to delayed dural arteriovenous fistula formation, with abrupt alterations in venous flow serving as triggers. The serial imaging demonstrates the progressive nature of this pathology. Assessment of venous anatomy in patients undergoing planned occlusion of major venous pathways may help predict long-term complications.