Aneurismal subarachnoid hemorrhage: who remains for surgical treatment in the post-ISAT era?

INTRODUCTION: Although there have been a number of studies on changes and trends in the management of aneurismal subarachnoid hemorrhage (aSAH) since publication of the International Subarachnoid Aneurysm Trial (ISAT), no data exist on what category of patients still remains for surgical treatment. Our goal was to investigate the changes that occurred in the characteristics of a population of aSAH patients treated surgically in the post-ISAT period in a single neurosurgical center, with limited availability of endovascular service. MATERIAL AND METHODS: The study included 402 aSAH patients treated surgically in our unit between January 2004 and December 2011. Each year, data regarding number of admissions, age, aneurysm location and size, clinical and radiological presentation, outcome and mortality rates were collected and analyzed. RESULTS: The annual number of admissions more than halved in the study period (from 69 in 2004 to 32 in 2011). There were no linear trends regarding patients’ mean age, clinical presentation and outcomes, but the number of patients in Fisher grade 4 increased and mortality slightly decreased. An unexpected, statistically significant increase occurred in the incidence of anterior communicating artery aneurysms (from 36.2% to 50%) and medium size aneurysms (from 34.7% to 56.2%) treated surgically, with a corresponding decrease in the incidence of middle cerebral artery aneurysms (from 40.5% to 34.3%) and large aneurysms (from 21.7% to 12.5%). CONCLUSIONS: Unexpected trends in characteristics of aSAH patients treated surgically could be related to treatment decision modality. Trend patterns could be properly expressed in the constant availability of endovascular services.