未破裂脳動静脈奇形に対する臨床判断分析に基づく治療法の選択 : 経過観察か,ガンマナイフか,手術か?(<特集>未破裂脳動静脈奇形)  [in Japanese] Treatment Selection for Unruptured Small Cerebral Arteriovenous Malformations with Clinical Decision Analysis : Observation, Gamma Knife or Microsurgery?(<Topics>Unruptured Arteriovenous Malformations)  [in Japanese]

We present an optimal treatment for unruptured small (3cm or less) cerebral arteriovenous malformations (AVM) among conservative treatment, gamma knife surgery (GKS) and microsurgery using clinical decision analysis according to patients' age. All cases for this study were small AVMs. We analyzed 973 cases with conservative treatment, 176 with GKS and 110 with microsurgery. The expected utility indexes were calculated from the results of each group. We hypothesized the standardized expected utility indexes as 100 in healthy, 75 in disabled and 0 in dead. Microsurgery was the first choice for patients younger than 55 years with AVM located in a surgically accessible region. GKS is recommended for patients aged between 55 and 70, and the best treatment is observation for patients older than 70 years. The proposed clinical decision analysis is very useful in obtaining informed consent for choosing the treatment modality for unruptured small AVM.