GRADE ZERO REMOVAL OF SUPRATENTORIAL CONVEXITY MENINGIOMAS

ALTHOUGH MENINGIOMAS ARE benign intracranial tumors, their frequency o f recurrence after surgery has not been as low as expected. The recurr ence rate of meningiomas is clearly related to the degree of tumor rem oval. Simpson Grade I removal, which entails excising the tumor and it s dural and sinus attachments, is associated with the lowest rate of r ecurrence. To further minimize the recurrence of convexity meningiomas , we removed an additional dural margin of about 2 cm around the tumor (Grade 0 removal). For tumors involving bone, we removed the hyperost otic bone with a healthy margin and pericranium in en bloc resection. Between 1982 and 1992, 37 patients (15 men, 22 women) with an average age of 52.1 years were operated on by the above technique. Nineteen ha d a follow-up period of more than 5 years. To date, no tumors have rec urred and no morbid incidences have occurred with this maneuver. We be lieve that the recurrence rate of convexity meningiomas can be diminis hed by including in the resection a margin of dura that might harbor a foci of tumor cells.