The superior petrosal vein, also known as Dandy’s vein or simply the petrosal vein, is the largest vein in the posterior cranial fossa, draining the anterior aspect of the cerebellum and brainstem into the superior petrosal sinus. 

Gross anatomy

Each superior petrosal vein is usually formed by the convergence of multiple tributaries to form a single large vein that then empties into the superior petrosal sinus. On occasion (23%), there are 2 or 3 superior petrosal veins on a side ⁴. The largest tributary is the vein of the cerebellopontine fissure, which is located in the suprafloccular cistern (just above the flocculus along the surface of the middle cerebellar peduncle) ⁴. In general, the tributaries can be divided into 4 groups, each of which includes a large named vein ⁴:

1. petrosal group: vein of the cerebellopontine fissure

2. posterior mesencephalic group: pontotrigeminal vein

3. anterior pontomesencephalic group: transverse pontine vein

4. tentorial group: anterior lateral margin vein

History and etymology

The anatomical course of the superior petrosal vein was first described by Walter E Dandy (1886–1946) ³, the American neurosurgeon after whom the Dandy-Walker malformation is also named. He highlighted the relation of the vein to the trigeminal nerve and cerebellum, and its significance during surgery for trigeminal neuralgia.

Clinical importance

The superior petrosal vein can be a hindrance for the retrosigmoid approach to the posterior fossa, limiting the extent of cerebellar retraction and blocking access to the upper cerebellopontine angle during surgery for trigeminal neuralgia, vestibular schwannomas, and meningiomas. 

Preservation of this vein is a neurosurgical dilemma. A review has concluded that although the incidence of complications due to superior petrosal vein obliteration is low, preservation should be attempted since the sequelae might be worse than the natural history of the existing pathology ².

The superior petrosal vein has also been implicated in trigeminal neuralgia due to compression of the trigeminal nerve ¹.