Surgical Clipping of a Petrosal Tentorial Dural Arteriovenous Fistula (Lawton's Type 5)

Abstract

Objectives To demonstrate the surgical clipping of a lateral petrosal tentorial dural arteriovenous fistula (DAVF), located in the cerebellopontine angle (CPA), through a retrosigmoid approach.

Method A previously healthy 49-year-old man presented a sudden episode of headache, photophobia, and dizziness. Due to the persistence of his symptoms despite proper analgesic treatment, he sought medical attention. The initial computed tomography (CT) scan showed a hyperdense lesion in the left CPA. Magnetic resonance imaging (MRI) demonstrated the vascular nature of the lesion, corresponding to an engorged superior petrosal vein (SPV) and Rosenthal's vein. The preoperative angiography showed a lateral tentorial DAVF (Lawton's type 5), fed by multiple transpetrous branches coming off the external carotid artery, and draining into the SPV. A standard retrosigmoid approach was planned for clipping and exclusion of the DAVF.

Results Through a left retrosigmoid craniotomy the DAVF was approached, along with the different neurovascular structures of the CPA. The DAVF originated at the tentorial petrosal junction. The fistulous vein was closely attached to the trigeminal nerve and the anterior inferior cerebellar artery (AICA). The fistulous vein was dissected and clipped close to its base at the lateral tentorium, achieving complete occlusion of the DAVF. The patient fully recovered after surgery with neither relapse of his symptoms nor postoperative complications.

Conclusion The retrosigmoid craniotomy is the best surgical approach for lateral tentorial DAVFs, as it provides a direct way to the fistula origin and permits a successful clipping of the draining vein.

The link to the video can be found at: https://youtu.be/Fj3uqrTPX5c.

Keywords

cerebellopontine angle - dural arteriovenous fistula - superior petrosal vein - Lawton's type 5 tentorial fistula - retrosigmoid craniotomy - superior petrosal sinus