2025 Proffered Presentations
S207: STEP-BY-STEP ANATOMICAL DISSECTION OF THE PTERIONAL TRANSSYLVIAN APPROACH FOR ACCESSING VENTRAL SUPERIOR PONTINE LESIONS
Serdar Rahmanov, MD; Mohammadmahdi Sabahi, MD; Abdulrahman Albakr; Badih Adada; Hamid Borghei-Razavi; Cleveland Clinic Florida
Introduction: The brainstem, particularly the pons, remains one of the most challenging regions for surgical intervention due to its intricate internal anatomy, despite advancements in neurosurgical techniques. Lesions within the pons often necessitate microsurgical resection, particularly for cavernous malformations and tumors. Microsurgery offers a definitive treatment by eliminating the risks of hemorrhage and neurological decline, unlike stereotactic radiosurgery. The success of such interventions hinges on the precise selection of the surgical approach tailored to the lesion's anatomy. The ventral superior pons presents a notable challenge due to its deep location and proximity to vital neurovascular structures. The pterional transsylvian approach is one of the most viable methods for addressing such lesions.
Material and Methods: Microsurgical dissection was performed bilaterally on four freshly injected cadaveric specimens at the Skull Base Laboratory. The Pterional Transsylvian Approach was applied to all specimens. Specimens were preserved in 75% alcohol, and the dissection was conducted using microsurgical instruments and a Leica M320 microscope with magnification ranging from ×6 to ×40. Two-dimensional and three-dimensional images were captured with a Nikon D7000 camera. Additionally, 360° 3D models were created at each dissection stage to document the process.
Results: The step-by-step dissection using the pterional transsylvian approach effectively exposed the ventral superior pons. Key surgical steps included: pterional craniotomy, opening of the Sylvian fissure, dissection of the basal cisterns and identification of the neurovascular anatomy, tentorial edge incision to relax and mobilize the oculomotor nerve and access the oculomotor triangle, drilling of the posterior clinoid process, culminating in the exposure of the basilar artery and superior pons.
Conclusion: The pterional transsylvian approach offers a highly effective method for addressing both ventral superior pontine lesions and basilar artery aneurysms. This step-by-step anatomical dissection demonstrates the approach's versatility and technical precision in navigating these intricate neurovascular regions, providing an invaluable guide for neurosurgeons seeking to treat complex lesions in this challenging area with minimal morbidity.
