Torcular herophili

The confluence of sinuses, torcular herophili, or torcula is the connecting point of the superior sagittal sinus, straight sinus, and occipital sinus. It is found deep to the occipital protuberance of the skull. Blood arriving at this point then proceeds to drain into the left and right transverse sinuses. The superior sagittal sinus often drains into (either exclusively or predominantly) one transverse sinus, and the straight sinus drains into the other.

Confluence of sinuses

An older term often used for the confluence of sinuses “torcular herophili”, describes the veins as a gutter, or canal, and honors Herophilos, the Greek anatomist who was the first to use cadavers for the systematic study of anatomy. This term more precisely refers to the concavity in the bone which is the location of the confluence of sinuses.

A common approach to lesions of the pineal region is along the midline below the torcula.

Variability in the location of the torcular can be observed in congenital cranial malformations. This study explores the feasibility of conducting posterior fossa surgery in cases of an extremely low-positioned torcular. A suboccipital craniotomy was performed on a patient with an extremely low torcular, without any associated cranial malformations. A left cerebellar hemisphere tumor was accessed through the narrow space (20 mm) between the low torcular and foramen magnum. The left cerebellar hemisphere tumor was resected. The patient experienced a favorable postoperative course with no complications. Significant variability in the location of the torcular can appear in patients without cranial malformation. This is the first report demonstrating the applicability of suboccipital craniotomy in patients with an extremely low torcular ¹⁾