2-STAGE SKULL BASE SURGERY FOR TUMORS EXTENDING TO THE SUB-DURAL AND EPIDURAL SPACES

The surgical management of extensive skull base neoplasms, which often extend to both the sub- and epidural spaces, is still a great challen ge with considerable risk. The authors report 12 cases in which a two- stage operation was performed for such nonmalignant tumours. The serie s consisted of four cavernous sinus meningiomas, one sphenoid-ridge me ningioma, one cerebello-pontine angle meningioma, three pituitary aden omas, two chordomas, and one fibroma. Our operative strategy involved removal of the epidural part of the tumour and extensive skull base re forming during the first stage. After approximately one month, the sec ond stage operation was performed by removing the residual subdural pa rts and the affected dura, which were less vascular, with dural plasty and subsequent spinal drainage. No complications such as cerebrospina l fluid (CSF) leakage or infection were observed. During the long-term follow-up (1.4 to 4.6 years, with a mean of 2.7 years), tumour recurr ence was observed in a single case. In conclusion, the major advantage s of this procedure were as follows: [1] improvement of the total remo val rate, [2] prevention of postoperative CSF leak and infection, [3] residual tumours were avascular, necrotic, and dwindling, and also shi fted outwards resulting in less adhesions to the brain. Although it ma y counter the trend toward less invasive procedures, the two-staged sk ull base surgery warrants serious consideration as an option for the m anagement of patients with such extensive cranial base tumours.