Evaluation of petrosal sinus patency with 3-dimensional contrast-enhanced magnetic resonance venography in petroclival meningiomas for surgical strategy.

BACKGROUND: The aim of this study was to perform a detailed anatomical analysis of petroclival venous structures as well as their patencies with 3D contrast-enhanced (CE) magnetic resonance venography (MRV) and to identify the potential contribution of these data to the therapeutic approach.

METHODS: Ten patients (8 women and 2 men) with unilateral petroclival meningioma were examined using 3D CE MRV in addition to conventional brain protocol. Both coronal source and multiplanar reconstructed images were evaluated for the anatomical orientation. Patency of the cavernous sinus, superior petrosal sinus (SPS), and inferior petrosal sinus (IPS) was assessed.

RESULTS: All the patients had a unilateral meningioma (7 on the right and 3 on the left) at the petroclival region. Both SPS and IPS were visualized with adequate intraluminal contrast enhancement in 6 patients, but IPS was absent in 3 on the lesion side, with a patent superior petrosal sinus as the drainage route. One patient had a partially occluded SPS, with IPS being the main course of cavernous sinus drainage.

CONCLUSIONS: Cerebral venous anatomy is a challenge to display with noninvasive methods because of flow dynamics, and CE 3D imaging seems to be the modality of choice to evaluate the variational anatomy and patency, which is essential in petroclival meningiomas. Because the cavernous sinus drains into either IPS or SPS, the patent sinus should be protected in surgery if there is tumoral occlusion of the others.