Limited vertical dural opening for lesions of the vermis, 4(th) ventricle, and distal PICA segments

BACKGROUND: Lesions of the vermis and 4(th) ventricle are commonly addressed through a midline suboccipital approach. Most neurosurgeons use either a Y-shaped or a curvilinear dural opening in this setting. Although these approaches offer a wide intraoperative surgical exposure, in occasion, the dural opening is difficult to repair primarily, often necessitating the use of a patch, which may increase the risk for development of CSF fistula. We are describing our experience with a limited, vertical, midline, dural opening for approaches to the vermis, tentorium, 4(th) ventricle, and distal posterior-inferior cerebellar artery (PICA) segments as an alternative to the classic Y-shaped or curvilinear incision. METHODS: We report our experience with a limited vertical midline durotomy in five patients with posterior fossa lesions. The lesions treated included a PICA dissecting aneurysm, three metastatic lesions (located in the vermian, floor of the 4(th) ventricle, and undersurface of the tentorium cerebelli), and one intra-axial tumor (ependymoma). All patients were positioned prone, and the lesions were accessed without difficulty through a limited, vertical, midline durotomy. RESULTS: Mass lesions and vascular abnormalities located from the midline as far lateral as the outlet foramina of the 4(th) ventricle can be accessed comfortably via a limited midline dural opening when combined with microsurgical techniques, and the use of a frameless Stealth Station Neuronavigation System (SSNS) [Medtronic Sofamor Danek, Inc., Memphis, TN]. By doing this, simple primary dural closure was achieved with a single running absorbable suture without tension in each case. CONCLUSION: In our experience, a suboccipital linear dural opening appears to be as effective as the more traditional Y-shaped incision, yet allows for quicker and easier primary dural repair.