Surgery: General Principles
Surgery is the treatment of choice for most patients with meningiomas. In patients with benign meningiomas (WHO Grade I, comprising 92% of all meningiomas), the tumor location largely dictates the extent of removal, which, in turn determines the tumor recurrence and, ultimately, the patient’s long-term progression-free survival.
Primary goals of surgery include, as alluded to in the prior section (“Surgery: Indication and Goals”): (1) total removal of the tumor and the involved surrounding bone and dura (the brain covering from which meningiomas arise) when feasible, thereby possibly providing cure or significantly altering the natural history of the disease process, and (2) reversal or improvement in neurologic deficits/symptoms caused by the tumor.
In meningiomas of certain locations that are associated with very high operative morbidity, such as the cavernous sinus or petroclival regions where complete resection is not always possible, additional surgical goals may include confirmation of the tissue diagnosis and tumor reduction to less than 3 cm in maximum diameter in preparation for postoperative radiosurgery.
Given the benign nature of meningiomas and the established efficacy of adjuvant radiation, the goal of total removal must be balanced by the physician’s basic credo to “do no harm”. When total removal carries a significant risk of morbidity, a small piece of tumor may be left, with further plans of observation followed by reoperation or radiation when the tumor is noted to be growing or causing new symptoms.
Operative Goals (Summary):
- When possible, total removal including the surrounding/involved dura (the brain covering from which meningiomas arise) and the bone (skull), to provide “surgical cure”. This type of extensive surgery insures significantly altered natural history of the meningioma, and thereby prolonging one’s life (Benefit 1 as discussed in the “Management: Basic Principles” Section, #4.)
- Improvement and preservation of neurological function, thereby providing patients with optimal life quality. (Benefit 2)
- Planned subtotal removal for patients in whom total resection carries significant risks of morbidity.
- In short, it is critically important to remove “as much as possible and, at the same time, as safely as possible.” Knowing when to stop during meningioma surgery comes from the surgeon’s wisdom, gained through years of experience.