Introduction: To determine management strategy of unruptured cerebral aneurysms (UCA), management risks and natural course need to be determined. In this paper, we report management outcome of UCA in Japan according to UCAS Japan.
Methods: From January through April 2004, we enrolled newly identified cases with UCA form 276 institutions. The management outcome from cases who had originally modified Rankin scale (mRS) 0 or 1 were analyzed. We defined the morbidity as outcome mRS 2 or more one month after surgery. Cognitive function was not recorded in this study. Outer reviewer confirmed the validity of records in one tenth of the cases.
Results: This study enrolled 2,558 cases. Open surgeries were performed in 2,270 cases, endovascular intervention in 314, and both in 4 cases. Morbidity was noted in 75 cases (2.9%, 95% confidence interval, 2.2~3.6%). Multivariate logistic regression model showed significant factors (p<0.05) related with morbidity were size 10~24mm(odds: 2.87) and 25mm or more (odds: 13.42), location (basilar aneurysms: odds 3.80), high blood pressure at the time of registration (odds: 2.59) Diabetes Mellitus (odds; 2.51) and surgery done for multiple aneurysms at one session (odds: 2.47). Type of treatment (endovascular versus open surgery), volume of surgery at each institution (more or less than 60 aneurysm surgeries in 2year before this study) did not affect the outcome.
Conclusions: UCA can be managed with relatively low morbidity. However, in cases with large or basilar located, and/or complicated with physical comorbidity, careful indication is mandatory and further improvement of management should be entertained.
Patient Care: To know the high risk cases for manageing unruptued cerebral aneurysms.And to know the appropriate indication for management of unruputured aneurysms.
Learning Objectives: Understand the risks of intervention for unrputred cererbal aneurysms
References: The UCAS Japan Investigators: The Natural Course of Unruptured Cerebral Aneurysms in a Japanese Cohort. New Engl J Med 366: 2474-82, 2012