Sphenoparietal Sinus Transposition: Operative Technique for Optimizing Pretemporal Posterior Circulation Access While Preserving the Sylvian Venous Complex.

BACKGROUND: Transsylvian approaches are a cornerstone of complex cranial operations, with wide applicability across cerebrovascular, skull base, and neuro-oncology operations. Deep lesions, especially those involving the basilar apex, midbrain, or interpeduncular fossa, require wide exposures that may be inhibited by the presence of a large complex of superficial sylvian veins (SSV) draining into the sphenoparietal sinus. This report describes technical and clinical aspects of the sphenoparietal sinus transposition (SPST) technique. METHODS: Technical case report of the SPST technique, including a step-by-step neuroanatomic description, overview of common indications, clinical pearls and pitfalls, and illustrative case examples. RESULTS: Once the benefits of proceeding with SPST have been established, the maneuver is initiated with 2 stepwise dural incisions: an incision from lateral to medial along the lateral margin of the lesser sphenoid wing, followed by an orthogonal cut across the temporal pole down the middle fossa floor. The pretemporal dura is peeled off the lateral wall of the cavernous sinus, allowing mobilization of the SSV complex and temporal pole posteriorly without disrupting or straining the connection point at the sphenoparietal sinus. Illustrative case examples include a clip reconstruction of a basilar apex aneurysm for which earlier endovascular treatment had failed and microsurgical resection of a peduncular cavernous malformation. CONCLUSIONS: SPST is a simple but versatile technique with important applications in complex cranial surgery. By mobilizing the SSV complex together with its dural attachment, the transsylvian corridor can be markedly widened, allowing access to the basilar apex region and ventral midbrain.

Tentorial dural arteriovenous fistula with perimedullary venous drainage-associated cervical myelopathy: illustrative case.

BACKGROUND: Tentorial dural arteriovenous fistulas (DAVFs) with perimedullary venous drainage causing cervical myelopathy are very uncommon conditions with an extremely aggressive behavior. When the characteristic radiological clues are missing, the unspecific clinical picture may cause delay and make the diagnosis challenging. OBSERVATIONS: Here the authors report a case of a 58-year-old man who developed progressive spastic tetraparesis and dyspnea with an extensive mild enhancing cervical cord lesion initially oriented as a neurosyphilis-associated transverse myelitis. Acute worsening after steroid administration redirected the diagnosis, and a tentorial Cognard type V DAVF was elicited. The microsurgical disconnection process is described, and previously documented cases in the literature are reviewed. LESSONS: If a DAVF is highly suspected, it is important to consider the possibility of its intracranial origin, and spinal as well as cerebral arteriography must be performed.