Anatomical Variations of the Transverse-Sigmoid Sinus Junction: Implications for Endovascular Treatment of Idiopathic Intracranial Hypertension.

Venous sinus pathology can result in multiple pathological diseases, including idiopathic intracranial hypertension (IIH). There remains a paucity of information on anatomical luminal variations of the major venous sinuses which may contribute to the etiology of certain disease states. Thirty-six transverse and sigmoid sinuses were removed following dissection of 19 unfixed cadaveric heads. Sinuses were opened longitudinally to study luminal variations. A semiquantitative classification system was developed to assess septations and blind pouches. Seventy-nine percent of cadavers had a luminal anatomical variation. Forty-four percent and 42% of sinuses dissected had occurrence of a septations or blind pouches, respectively. Thirty percent of septations and 25% of pouches were classified as large. Incidence of anatomical variations was not statistically significant between cadaver gender or sinus laterality. Luminal variations are present in the transverse and sigmoid sinuses at rates higher than expected. This study is the first to report the presence of blind pouches in the luminal wall of transverse and sigmoid sinuses. These variations can have clinical importance to the endovascular surgeon and may also contribute to the pathophysiological etiology of venous sinus diseases. Anat Rec, 299:1037-1042, 2016.