THE COMBINED MANAGEMENT OF CEREBRAL ARTERIOVENOUS-MALFORMATIONS - EXPERIENCE WITH 100 CASES AND REVIEW OF THE LITERATURE

A series of 100 patients treated for a cerebral arteriovenous malforma tion (AVM) is presented. Patients were admitted between 1985 and April 1992. Two groups are considered: the first group including 52 patient s treated before the availability of radiosurgery (1985-1988), and the second group including 48 patients treated after the availability of radiosurgery (1989-1992). AVM's were classified in five grades accordi ng to the Spetzler's Grading System. Three techniques of treatment wer e used: surgical resection, intravascular embolization (with cyanoacry late), and radiosurgery (linear accelerator). These three techniques w ere used either alone or in association, giving four types of manageme nt: surgical resection alone, embolization and resection, embolization alone, and radiosurgery (alone, or after embolization, or after surgi cal resection). From 1989 on, the availability of radiosurgery was res ponsible for the decrease of the ''embolization and resection'' group, which until then was predominantly used as well for low-grade (I, II, III) as for high-grade AVM's (IV, V). Overall, for the low-grade AVM' s, the treatment of choice was surgical resection (79% of cases), with pre-operative embolization in one-half of these cases; the other low- grade AVM's were irradiated, with various combinations. For the high-g rade AVM's, the treatment of choice was intravascular embolization (95 % of cases), either alone, or followed by resection (45%) or radiosurg ery (9%). Results were evaluated in terms of deterioration following t reatment, in five groups: no deterioration (59%), minor deterioration (20%), long-lasting deficit (10%), major deterioration (5%), and death (6%). Overall, results improved after 1989: favourable outcome (no de terioration and minor deterioration) increased from 67% to 90%. Result s were not related to the patients' age. More favourable results were obtained for low-grade AVM's (93%) than for high-grade AVM's (60%). Fo r the low-grade AVM's the evolution from 1989 on (favourable outcomes increasing from 89% to 96%) occurred with the lowering of the mortalit y rate. For the high-grade AVM's, the evolution from 1989 onwards (fav ourable outcome increasing from 46% to 78%) occurred with the decrease of the with deficits. The angiographic results were strongly related to the management: 95% of complete eradication after surgical resectio n and 5% only after embolization alone. Concerning the results in irra diated cases, the follow-up is not long enough.The review of the neuro surgical literature since 1972 demonstrates progressive modifications in the therapeutic attitude as regards AVM's. The surgical management which was predominantly used at the beginning gave way progressively t o a combined management, with a combination of embolization, surgery, and lately radiosurgery. The authors' present attitude is in favour of combined treatment using the three techniques. Direct surgical resect ion is proposed for small and readily accessible AVM's. Direct radiosu rgery is proposed for small but deep AVM's or those located in highly functional areas. Intravascular embolization is proposed in every othe r situation. After embolization has been completed, totally eradicated AVM's are left in place; no further treatment is proposed for AVM's w hich are still large with high surgical risk. AVM's which are sufficie ntly reduced in size are either operated on (if accessible) or irradia ted (if deeply situated). When the results of radiosurgery are assesse d with long enough follow-up (in terms of eradication and clinical out come) the authors' attitude may either increase the role of radiosurge ry or return towards surgical resection, depending of the quality of t he results.