Radiosurgery Following Embolisation and/or Surgery of Brain AVM's

A series of 45 patients who have undergone combined treatment for cerebral arteriovenous malformations (AVM's) is presented. All patients underwent additional radiosurgery after endovascular and/or surgical treatment. Stereotactic radiosurgical treatment using the Gamma knife has been available in our institution since 1992. The treatment strategy for brain AVM's has changed since that time. The possibility for total cure of partially embolised AVM's, where other treatment options had been exhausted, increased with adjunctive radiosurgery. Complex or giant AVM's in eloquent areas can now be treated using radiosurgery after embolisation and/or microsurgery, with minor risk of neurological deficit. In all 45 patients treated since September 1992 at the University of Vienna, embolisation was performed to reduce the size of the nidus in order to facilitate surgical resection or radiosurgical treatment. In 37 patients radiosurgery was performed after endovascular treatment only, and in 8 patients radiosurgery was performed after embolisation and surgery. All AVM's were classified according to Spetzler's Grading System(1). 31 patients (68.9%) were classified as Grade 3 or 4. Two patients (4.5%) were classified as. Grade 5. In a mean follow up time of 16 months (range 2-40), there were 15 complete obliterations and 2 patients with unexpected residual AV M after two years. Of patients who required staged radiosurgical therapy, 12 have been followed for less than two years after their final procedure. In an additional 12 patients the follow-up period is less than 12 months. 4 patients were lost to follow up. There is a morbidity of 8.8% and no mortality in this patient group.