K-Wire-Assisted Intra-axial Intradural Approach for Cavernous Sinus Biopsy: A Case Report.

Petroclival approaches remain challenging given abundant cranial nerves and vessels. Common trajectories include transsphenoidal, transoral, middle fossa-extradural, and posterior through the cerebellar peduncle. We report a unique intra-axial, intradural approach to the petroclival and cavernous sinus. A 53-year-old female presented to our clinic with diplopia and a minor headache for 3 months. Imaging showed a lytic, contrast-enhancing petroclival and cavernous sinus lesion, encasing the cavernous internal carotid artery (ICA). A trajectory was planned through the superior temporal gyrus to the lateral cavernous sinus targeting the tumor margin at the cavernous sinus dural interface. A blunt attempt with the biopsy needle failed and thus a K-wire was used first to penetrate the dura followed by an exchange to the biopsy needle along the same trajectory for lesion sampling. The patient tolerated the procedure well, without any postoperative complications. Final pathology showed grade II chondrosarcoma. To our knowledge, this case represents the first K-wire-assisted intra-axial intradural biopsy of the lateral cavernous sinus. For lesions that either do not require or are not amenable to resection due to the involvement of critical skull base structures of the cavernous region, this represents a technically straightforward cost-effective approach in tumor biopsy.