CONTRIBUTION OF SURGERY TO THE MANAGEMENT OF BRAIN-STEM TUMORS IN PEDIATRIC-PATIENTS

A pediatric series of 103 brainstem tumors managed surgically between 1970 and 1992 was reviewed. All but three tumors were both well-limite d and superficial, reaching or extending beyond the brainstem pia mate r or ependymal lining. In every case, the goal of surgery was to remov e as much of the tumor as possible. Starting in 1985, this was done us ing an ultrasonic aspirator (CUSA(R)). The extent of removal was asses sed based on findings from a postoperative computed tomography or magn etic resonance imaging study and was considered partial when only a sm all part of the tumor was removed, subtotal when the tumor remnant mea sured no more than a few cubic millimeters, and ''total'', when no tum or was visible on postoperative imaging studies. Excisions done withou t the CUSA(R) device were partial in 75% of cases and subtotal in 25%, whereas those done with the CUSA device were partial in 41% of cases, subtotal in 34%, and ''total'' in 25%. Most tumors were glial (87.2%) and benign (58.2%). Postoperative radiation therapy was given to all but 18 patients, who had subtotal or ''total'' excision of a benign tu mor. Results showed that 1) operative mortality fell from 25% before 1 985 to 5.2% after 1985, when the CUSA(R) device was introduced; 2) sur gery has not improved the outcome of malignant tumors; 3) the actuaria l survival rate in benign tumors was considerably higher after subtota l or ''total'', excision than after partial excision (96% and 56% afte r ten years, respectively; p<0.01); 4) none of the patients who did no t receive radiation therapy after subtotal or ''total'' excision of a benign tumor experienced recurrences; 5) younger age, an area of decre ased density surrounding the tumor, and rapid progression of symptoms before surgery were significantly correlated with malignancy.