Investigation of the surgically treated and untreated XXXX of the anterior circulation.

@entity1 @entity510 @entity999 @entity439 @entity911 @entity397 @entity438
BACKGROUND: The natural history of @entity438 and the surgical risks are modified by several factors including size, location, and presence of @entity510 ( @entity510 ). The main @entity911 arises because the backgrounds of the past reports describing the natural history or the surgical complication of @entity438 were different. The present study aimed to adjust the backgrounds and investigate the surgical indication with close monitoring of both surgically treated and untreated @entity438 . METHODS: In the past 9 years, 201 @entity1 who had unruptured anterior circulation @entity439 were monitored. The decision of the operation was not randomized. The @entity1 were divided into three subgroups by the size of the @entity439 (small group: below 5 mm, medium group: between 5 and 15 mm, large group: over 15 mm). In both surgically untreated and treated @entity1 , overall mortality and morbidity corresponding to Rankin score II or worse was counted as @entity439 related event. The ratio of event free was compared between surgically treated and untreated @entity1 using Log-rank test. RESULTS: In untreated @entity1 , @entity510 was noted in 1 in the small group and 4 in the medium group. The annual @entity397 rate of the medium group was 12 times higher than that of the small group. In surgically treated @entity1 , overall mortality and morbidity of the surgery was 2.3% in the small group, 3.6% in the medium group, and 20% in the large group. One surgically treated @entity1 had @entity510 because of regrowth of @entity439 . When ratio of event free was compared, no significant advantage of surgery was noted in the small group and in all of the @entity1 . However, the benefit of surgery was significant in the medium group (Log-rank p = 0.0189). CONCLUSIONS: The present results indicated that prophylactic surgery has a benefit for the medium-size @entity439 (5-15 mm) of the anterior circulation. For large @entity439 , individual investigation is necessary because of the variety of surgical difficulties, and the complex symptoms because of @entity397 and the mass effect as well as @entity999 . In small @entity439 , careful observation may be a reasonable choice unless the @entity439 is at a specially high risk of @entity397 .
