[Current management of arteriovenous malformations. Retrospective study of 31 cases and literature review]

To establish some therapeutic criteria about the treatment of AVMs of III, IV and V grade of Spetzler and Martin and to analyse the results in the subgroup of preoperative embolization plus surgery.

We perform a retrospective analysis of a group of 31 patients with arteriovenous malformations (AVMs) treated in our center between 1999 and 2004. There were 19 women and 12 men, with a mean age of 31.6 years old (range, 1-62a). Their symptoms upon admission were intracranial hemorrhage in 77.4%, seizures in 12.9%, headache, ischemic event and incidental finding in 3.2% each group. Diagnostic angiography was performed in 29 cases and anatomopathologic diagnostic in 2 cases. The malformations were classified with Spetzler and Martin Grading Scale, in 10.3% grade I, 24.1% grade II, 37.9% grade III, 24.1% grade IV and 3.4% grade V. Patients were classified in 6 subgroups of treatment (surgery, embolization, radiosurgery, embolization plus surgery, embolization plus radiosurgery and conservative treatment).

AVMs grade III, IV and V (19 patients) were treated with surgery (6 cases), embolization plus surgery (5 cases), but also other kind of treatments (embolization alone, radiosurgery and conservative) were used. Functional results in these groups of patients were 36.8% (7 cases) with no symptoms or slights symptoms (modified Rankin 0-1), 52.6% (10 cases) minor disability (mRankin 2), 5.3% (1 case) moderate disability and 5.3% (1 case) mortality. We observe a high rate of postembolization hemorrhage in the group of patients in which the combination of preoperative embolization plus surgery was used. In these cases, early surgery was performed with a good functional recovery. There was one case of postoperative mortality.

We should consider some factors like the natural history, clinical presentation (hemorrhage), angiographic features (deep arterial supply, aneurisms), Spetzler and Martin Grading and the clinical condition of the patient before treating a cerebral AVM. In the subgroup of treatment with embolization plus surgery, we recommend to achieve a subtotal preoperative embolization > 50%, not to obliterate more than 50% in one session, to perform staged embolization waiting from 4 to 6 weeks between procedures, and from 1 to 3 weeks between the last embolization and surgery.