Recent treatment strategies for arteriovenous malformations in children and adolescents. Long-term results of gamma knife radiosurgery and recent noninvasive radiosurgery

Although pediatric intracranial arteriovenous malformations (AVMs) presenting as intracerebral hematomas are usually treated with microsurgery, radiosurgery is indicated for AVMs in eloquent areas. Long-term results of gamma knife radiosurgery (GKRS) and recent noninvasive treatment are reported. Twenty-four patients aged 10 to 19 years (14 male and 10 female) were treated from 1991 through 1997. The mean follow-up period was 10 years and 3 months. Most patients presented with bleeding and had AVMs in functional areas or deep within the brain. Before GKRS, embolization was performed in 7 patients and microsurgical extirpation was performed in 2 patients. The AVM volume was 0.07 to 22.4 ml at the time of radiosurgery. Complete angiographic obliteration of the AVM was achieved in 88.8% of patients. Two patients underwent GKRS a second time to treat residual nidi. One of 6 patients who did not undergo imaging examinations had bleeding; however, the others patients were healthy and working or attending college. Paralysis due to damage of the internal capsule developed after the first treatment of a grade 5 AVM and after the second treatment of a grade 6 AVM. Late or delayed complications, such as necrosis, cyst formation, bleeding after obliteration, and radiation-induced tumors, did not occur. These results suggest that GKRS is a safe and effective treatment for children with AVMs in eloquent areas. Frameless radiosurgery (CyberKnife) and recent imaging techniques enabled noninvasive treatment of pediatric AVMs. (author)