COMPLICATIONS AFTER MULTIDISCIPLINARY TREATMENT OF CEREBRAL ARTERIOVENOUS-MALFORMATIONS

Patients and techniques. A series of 67 patients treated for cerebral AVMs with a multidisciplinary approach is reported, with special atten tion for the complications due to treatment. The malformations were cl assified after the Spetzler Grading Scale, with 67% low-grade and 33% highgrade AVMs. Three modes of treatment were used: surgical resection , endovascular embolization, and radiosurgery (linear accelerator tech nique). The actual treatment was: resection alone (25% of cases), embo lization plus resection (24%), embolization alone (21%), and radiosurg ery (30%), either alone or after embolization or surgery. The followin g eradication rates were obtained: overall 80%, after resection (with or without embolization) 91%, after embolization alone 13%, after radi osurgery 87%. Clinical outcome. The outcome was evaluated in terms of deterioration due to treatment. A deterioration after treatment occurr ed in 19 patients (28%), and was a minor deterioration (19%), a neurol ogical deficit (4%), or death (4%). As far as the mode of treat ment i s concerned, surgical resection was responsible for deterioration (min or) in 17% of all cases operated upon. Radiosurgery was followed by a minor deterioration in 10% of irradiated cases. Embolization gave a co mplication in 25% of all embolized cases (minor or neurological defici t, or death). The mechanism of the complications was: resection or man ipulation of an eloquent area during surgery, radionecrosis after radi osurgery, ischaemia and haemorrhage (50% each) following embolization. In most cases of haemorrhage due to embolization, occlusion of the ma in venous drainage could be demonstrated. Discussion. The haemodynamic disturbances td AVMs and to their treatment are reviewed in the liter ature. The main haemodynamic mechanisms admitted at the beginning of a complication after treatment of cerebral AVMs are the normal perfusio n pressure breakthrough syndrome, the disturbances of the venous drain age (venous overload or occlusive hyperaemia), and the retrograde thro mbosis of the feeding arteries. Conclusions. According the authors' ex perience, the emphasis of treatment for cerebral AVMs has now shifted from surgical resection to endovascular embolization. One of the expla nations is that endovascular techniques are now employed in the most d ifficult cases (high grade AVMs). As severe complications of endovascu lar embolization may also occur for low-grade malformations, the quest ion arises whether surgery or radiosurgery should not be used first fo r this low-grade group even if embolization is feasible.