Incidence and Outcome of Aneurysmal Subarachnoid Hemorrhage: The Swiss Study on Subarachnoid Hemorrhage (Swiss SOS).

BACKGROUND AND PURPOSE: The purpose of this study was to assess nationwide incidence and outcomes of aneurysmal subarachnoid hemorrhage (aSAH). The Swiss SOS (Swiss Study on Subarachnoid Hemorrhage) was established in 2008 and offers the unique opportunity to provide this data from the point of care on a nationwide level. METHODS: All patients with confirmed aneurysmal subarachnoid hemorrhage admitted between January 1, 2009 and December 31, 2014, within Switzerland were recorded in a prospective registry. Incidence rates were calculated based on time-matched population data. Admission parameters and outcomes at discharge and at 1 year were recorded. RESULTS: We recorded data of 1787 consecutive patients. The incidence of aneurysmal subarachnoid hemorrhage in Switzerland was 3.7 per 100 000 persons/y. The number of female patients was 1170 (65.5%). With a follow-up rate of 91.3% at 1 year, 1042 patients (58.8%) led an independent life according to the modified Rankin Scale (0-2). About 1 in 10 patients survived in a dependent state (modified Rankin Scale, 3-5; n=185; 10.4%). Case fatality was 20.1% (n=356) at discharge and 22.1% (n=391) after 1 year. CONCLUSIONS: The current incidence of aneurysmal subarachnoid hemorrhage in Switzerland is lower than expected and an indication of a global trend toward decreasing admissions for ruptured intracranial aneurysms. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03245866.

Proximal arterial diameters on CT angiography and digital subtraction angiography correlate both at admission and in the vasospasm period after aneurysmal subarachnoid hemorrhage.

BACKGROUND: Comparison of artery diameters between CT angiography (CTA) and subtraction arteriography (DSA) has the limitation that measurements on DSA are provided as relative units, making a quantitative comparison difficult. On CTA, artery diameters may depend on windowing settings and may lead to false measurements. This study assesses the correlation between CTA and DSA based on measurements in a basic imaging viewer using normalized DSA values, and assesses whether the validity is time dependent. METHODS: Patients with aneurysmal subarachnoid hemorrhage (aSAH) were included if they underwent both CTA and DSA within 24 h. The analysis was performed using the basic imaging application Centricity Enterprise PACS viewer (GE Healthcare). A total of 15 arterial locations were assessed on CTA and DSA and a specific measurement protocol with normalization of all artery diameters to the cavernous segment of the internal carotid artery was used. Pearson correlation analysis was calculated to access the correlation of normalized arterial diameters measured with both methods at admission and at clinical onset of CVS. RESULTS: A total of 627 arteries in 38 patients were analyzed in both CTA and DSA. There was a significant correlation coefficient (R = 0.706) of artery diameters between CTA and DSA measures (p < 0.0001). This correlation remained high when comparing CTA and DSA at admission (correlation coefficient: 0.641; p < 0.0001) vs. in the vasospasm period (0.835; p < 0.0001). The correlation was good in all proximal artery segments and lost significance only when distal vessel segments were considered. CONCLUSION: Using basic imaging viewers, mostly accessible for clinicians, CTA is a noninvasive and reliable method to assess proximal arterial diameters of the brain in the management of cerebral vasospasm in the acute phase after aSAH. Significance is reached, independent of whether CTA is obtained in the acute phase or during the period of vasospasm, by normalization of basal cerebral artery diameters to a non-variable anatomic landmark, i.e., the petrous or cavernous internal carotid artery diameter.

Craniotomy without flap replacement for ruptured intracranial aneurysms to reduce ischemic brain injury: a preliminary safety and feasibility analysis.

BACKGROUND: Cortical and subcortical brain ischemia following aneurysmal subarachnoid hemorrhage (aSAH) remains a central challenge in improving patient outcome. Generally the bone flap is replaced after surgical clipping and no decompression is practiced in endovascularly treated patients. The aim of this preliminary safety and feasibility study is to clarify whether a first-line decompression would improve brain perfusion and salvage more tissue at risk in patients who developed delayed vasospasm. In addition, we assessed whether the risks involved with a second surgery to replace the bone flap would affect patient outcome. METHODS: We retrospectively analyzed patients with aSAH who underwent surgical clipping and developed cerebral vasospasm from 2009 to 2012 at our institution. We selected cases where the bone flap was not replaced at initial surgery and needed a second procedure for bone flap replacement. Primary end points were new delayed ischemic neurological deficits (DINDs), the extent of brain infarctions, and patient functional outcome. Secondary end points were hazards of the second procedure for bone replacement. RESULTS: We identified six patients in whom the surgeon chose not to replace the bone flap. In four patients, this was a pterional bone flap (standard), and in two patients it was a larger frontotemporoparietal flap. Despite the limited extent of the craniotomy, only one patient (16 %) required additional decompression. Two patients (33%) developed DINDs and five patients (83 %) showed delayed cerebral infarctions on computed tomography. Of those, three patients showed good outcome (Glasgow Outcome Scale score >4 and modified Rankin Scale score <3). No complications or new neurological deficits occurred during the second surgery for bone replacement. CONCLUSIONS: To date, no standardized criteria exist to decide whether the bone flap should be removed or replaced at initial surgery. Our single-center experience in a limited number of patients reveals a pattern with respect to initial clinical parameters and imaging findings that might be a first step in developing standardized decision parameters. This may prevent secondary surgery for decompression in deleterious conditions during the vasospasm phase. Based on these findings, we have developed a protocol for a prospective study that will further investigate the benefits of this management.