populationbased analysis of arteriovenous malformation treatment object the author sought to describe overall management data on cerebral arteriovenous malformations avms and to focus the actuarial need for different treatment modalities on a populationbased scale such data would seem important in the planning of regional or national multimodality strategies for the treatment of avms this analysis of a nonselected consecutive series of patients representing every diagnosed case of cerebral avm in a population of 1000000 over one decade may serve to shed some light on these treatment aspectsmethods during the 11year period from 1989 to 1999 data from every patient harboring a cerebral avm that was presented clinically or discovered incidentally in a strictly defined population of 986000 people were collected prospectively no patient was lost to follow up there were 124 de novo diagnosed avms per 1000000 population per year 135 avms large highgrade avms spetzlermartin classification were rare and grade 1 to 3 lesions represented 85 of the caseload hemorrhage was the initial manifestation of avm in 696 of the cases lntracerebral hematoma was the most common hemorrhagic manifestation occurring in 78 patients there were 44 cases per 1000000 population per year of hematomas needing expedient surgical evacuation in the remaining patients who did not require hematoma surgery small critically located grade 3 and grade 4 lesions amounted to 16 cases per 1000000 population per year there were 58 cases per 1000000 population per year of grade 1 to 2 and larger noncritically located grade 3 malformations there were 05 cases per 1000000 population per year of grade 5 avms the overall outcome in 135 patients was classified as good according to the glasgow outcome scale score 5 in 61 of the cases and the overall mortality rate was 9conclusions in centers with populationbased referral avm of the brain is predominantly a disease related to intracranial bleeding and parenchymal clots have a profound impact on overall management outcome the rupture of an avm is as devastating as that of an aneurysm aneurysm ruptures are more lethal whereas avm rupture tends to result in more neurological disability due to the high occurrence of lobar intracerebral hematoma in an attempt to quantify the need for different modalities of avm treatment based on a population of 1000000 people figures for surgeries performed range from six to 10 operations per year and embolization as well as gamma knife surgery procedures range from two to seven per year depending on the strategy at hand when using nonsurgical approaches to grade 1 to 3 lesions the number of patients requiring treatment with more than one method for obliteration increases drastically as does the potential risk for procedurerelated complications