K. J. Balinger1, A. Elmously1, B. A. Hoey1, C. D. Stehly1,2, S. P. Stawicki1,2, M. E. Portner1 1St Luke’s University Health Network,Level I Regional Trauma Center,Bethlehem, PA, USA 2St. Luke’s University Health Network,Department Of Research & Innovation,Bethlehem, PA, USA
Introduction: Computed tomographic angiography (CTA) tends to be over utilized in patients with traumatic subarachnoid hemorrhage (tSAH) to rule out occult aneurysmal rupture and arteriovenous malformations (AVM). We hypothesized that there are two specific categories of patients with tSAH that are at increased risk for aneurysm/AVM and warrant targeted CTA use: (a) patients "found down" with an unknown mechanism of injury and (b) those with central subarachnoid hemorrhage (CSH) or blood in the subarachnoid cisterns and Sylvian fissures.
Methods: A retrospective analysis was performed on trauma patients with blunt head injury and tSAH who underwent CTA of the brain between January 2008 and December 2012 at a Level I Regional Trauma Center. Variables utilized in the current analysis included patient demographics, injury mechanism and severity (ISS), Glasgow Coma Scale (GCS), CTA and related radiographic studies, as well as operative interventions. The principal outcome measure was "confirmed diagnosis" of a ruptured aneurysm/AVM. Independent sample t-test and chi square test were used for univariate analyses. Logistic regression was utilized in multivariate analyses. Statistical significance was set at alpha = 0.05.
Results: Out of 617 patients with tSAH, 186 underwent CTA. Mean age of the study group was 57 years, with 64% of patients being male. The mean GCS on presentation was 11±5.0, with mean ISS of 20±11.5. CTA scans were positive in 23/186 cases (12.3%) with an aneurysm found in 21 patients and an AVM in 2 patients. Findings were felt to be incidental in 15/23 patients with "positive" CTA. Among 14/186 patients (7.5%) who were "found down" none had an aneurysm or an AVM. A total of 8 patients had a ruptured aneurysm, with 5/8 (62.5%) presenting after a fall and 3 (37.5%) presenting after an MVC. All 8 patients with aneurysmal rupture (100%) had CSH. None of the 81 patients with only peripheral SAH had a ruptured aneurysm/AVM. Multivariate regression analysis demonstrated that suprasellar cistern hemorrhage on CT is independently associated with aneurysm rupture (OR, 6.39; CI 1.32-30.8). Patients with a ruptured aneurysm had a significantly higher mean arterial pressure (MAP) on presentation (mean, 116±7 mmHg) than those without an aneurysm/AVM (mean, 104±18 mmHg, p<0.005). Of the 8 patients with a ruptured aneurysm, 6 patients underwent neurosurgical clipping or coiling, 1 underwent a ventriculostomy, and 1 underwent a craniotomy for evacuation of hemorrhage.
Conclusion: These preliminary data support a more selective approach to screening CTAs in patients with tSAH. CTA should be utilized in those patients with CSH regardless of mechanism of injury. A more selective approach should be considered in those patients with only peripheral SAH. Overall cost savings would be significant.