Combined open microsurgical and endoscopic resection of hypothalamic hamartomas.

Hypothalamic hamartomas (HHs) are typically located within the vicinity of the third ventricle. They can be attached to the walls of the third ventricle, within the interpeduncular cistern (third ventricle floor), and/or attached to the mammillary bodies and hypothalamus. Depending on their location, resection is performed either through the third ventricle, approaching from above, or via a frontotemporal craniotomy (pterional or frontoorbital), approaching from below. "Above" approaches typically include the transcallosal-anterior interforniceal approach, and recently, purely endoscopic approaches performed transforaminally. The authors present a combined open and endoscopic approach for resection of HHs located within the third ventricle. They used this approach in 2 young girls with relatively small lateral and third ventricles. Following an interhemispheric, transcallosal approach and exposure of the right foramen of Monro, an endoscope was inserted through the foramen, which enabled safe resection of the HH. The main advantage of the combined approach is when the lateral and third ventricles are relatively small, making a purely endoscopic approach more challenging and possibly riskier.