Surgical Approaches to Pontine Tumors

Surgical management of pontine tumors requires a high-level skill and knowledge set to achieve maximally safe surgery in a deeply eloquent region. Thorough anatomical knowledge of the trajectory towards and the neurovascular structures surrounding the pons as well as the intrapontine architecture allows the surgeon to anticipate encountering the next critical structure that should be cautiously preserved. The anterior pontine surface can be visualized directly through an endoscopic endonasal transclival approach, where the superior ventral pontine entry zone permits relatively safe access to intrapontine lesions, or through the orbito-fronto-zygomatic approach, which exposes the upper anterior pons. The transpetrosal and retrosigmoid approaches are utilized to visualize the anterolateral surface of the pons; safe entry zones through the anterolateral surface include the peritrigeminal, supratrigeminal, and lateral pontine (middle cerebellar peduncle). The dorsal pons is best targeted by a classical median suboccipital telovelar route; the floor of the fourth ventricle allows access to the posterior pontine surface through the suprafacial collicular (suprafacial triangle), infrafacial collicular (infrafacial triangle), superior foveal (lateral sulcus limitans) and medial sulcal (interfacial) safe entry zones. This chapter provides an overview of the anatomy, safe entry zones, and surgical approaches utilized to tackle pontine lesions.