The Operation for Supratentorial Meningiomas in Children

Patient Positioning

• Head fixation: In general, the skull is rigidly fixed if the child is old enough for the skull to tolerate such fixation.
• Avoid air embolism risk: The region of the tumor is slightly elevated, although air embolism is a greater potential problem in children due to a tendency toward hypovolemia, so avoidance of excessive elevation and use of Doppler is advised.
• Position to use gravity for retraction: Depending on location, a position should be considered where the brain can fall away from the tumor with as little retraction as possible.

Surgical Approach

• Tumor-dependent: The approach varies greatly depending on the location of the tumor.

Intervention

• Dura and tumor involvement: Because dura is often involved, resecting the involved dura and dural tail is an important consideration. If a dural tail exists for the dural-based lesion, it is best to excise as much of it as is safely possible without compromising venous sinuses.
• Central coring for space: The tumors are often firm and have nice cleavage planes, but they are frequently spherical and need to be cored out internally and then collapsed in on themselves to avoid excessive retraction on the brain. Devices such as the ultrasonic aspirator and laser can play significant roles in debulking these tumors.
• Devascularization: It is useful to start by trying to take away the vascular supply if it is accessible, as many of these lesions have a single predominant feeder vessel (which can often also be accessed by embolization, if preferred).
• Working in plane between tumor and brain: For meningiomas that can be excised, a nice plane of separation generally exists around the tumor. Malignant and some atypical tumors will be invasive of brain, and careful consideration of eloquent cortex is needed.
• Leaving tumor adherent to nerves and vessels:  Tumor closely adherent to important nerves or vessels is generally left in place to avoid significant morbidity.

Closure

• Dural closure crucial: Dural reconstruction is important, particularly for those rare cases in children that require a skull base approach. If the optimal approach is transnasal, this surgery has a high degree of difficulty and should not be attempted by most surgeons who don’t have significant experience in this approach.
• Bone reconstruction sometimes required: Rarely, skull reconstruction is needed when there has been invasion of the skull by the tumor.