Qian Zhuang, Christy R. Buckman and Mark R. Harrigan
Gyanendra Kumar, Reza Bavarsad Shahripour and Mark R. Harrigan
The impact of transcranial Doppler (TCD) ultrasonography evidence of vasospasm on patient-centered clinical outcomes following aneurysmal subarachnoid hemorrhage (aSAH) is unknown. Vasospasm is known to lead to delayed cerebral ischemia (DCI) and poor outcomes. This systematic review and meta-analysis evaluates the predictive value of vasospasm on DCI, as diagnosed on TCD.
MEDLINE, Scopus, the Cochrane trial register, and clinicaltrials.gov were searched through September 2014 using key words and the terms “subarachnoid hemorrhage,” “aneurysm,” “aneurysmal,” “cerebral vasospasm,” “vasospasm,” “transcranial Doppler,” and “TCD.” Sensitivities, specificities, and positive and negative predictive values were pooled by a DerSimonian and Laird random-effects model.
Seventeen studies (n = 2870 patients) met inclusion criteria. The amount of variance attributable to heterogeneity was significant (I2 > 50%) for all syntheses. No studies reported the impact of TCD evidence of vasospasm on functional outcome or mortality. TCD evidence of vasospasm was found to be highly predictive of DCI. Pooled estimates for TCD diagnosis of vasospasm (for DCI) were sensitivity 90% (95% confidence interval [CI] 77%–96%), specificity 71% (95% CI 51%–84%), positive predictive value 57% (95% CI 38%–71%), and negative predictive value 92% (95% CI 83%–96%).
TCD evidence of vasospasm is predictive of DCI with high accuracy. Although high sensitivity and negative predictive value make TCD an ideal monitoring device, it is not a mandated standard of care in aSAH due to the paucity of evidence on clinically relevant outcomes, despite recommendation by national guidelines. High-quality randomized trials evaluating the impact of TCD monitoring on patient-centered and physician-relevant outcomes are needed.
Paul M. Foreman, Christoph J. Griessenauer, Michelle Chua, Mark N. Hadley and Mark R. Harrigan
Approximately 10% of patients with blunt traumatic extracranial cerebrovascular injury have a complete occlusion of the vertebral artery (VA). Ischemic stroke due to embolization of thrombus from an occluded VA following cervical spine surgery has been observed. The risk of ischemic stroke with cervical spine surgery in the presence of an occluded VA, however, has never been determined.
A retrospective chart review of 52 patients with a VA occlusion following a blunt trauma was performed. Clinical and radiographic characteristics were collected and analyzed.
Ten patients (19.2%) suffered an ischemic stroke attributable to a traumatic VA occlusion. Univariate analysis demonstrated that patients with ischemic stroke were significantly older (p = 0.042) and had a lower rate of cervical spine surgery (p < 0.005). Multivariate analysis found cervical spine surgery to be protective against ischemic stroke (OR 0.049 [95% CI 0.014–0.167], p = 0.014); increasing age and bilateral VA injury (bilateral occlusion or unilateral occlusion with contralateral dissection) were risk factors for ischemic stroke (OR 1.05 [95% CI1.02–1.07], p = 0.065 and OR 13.2 [95% CI 2.98–58.9], p = 0.084, respectively).
Traumatic VA occlusion is associated with a risk of ischemic stroke and mortality. Corrective cervical spine surgery potentially decreases the risk of ischemic stroke by stabilizing the spine and thereby reducing motion across the occluded segment of the VA and preventing embolization of thrombus. While a high stoke risk may be inherent to the disease, novel therapies should be investigated.
Russell L. Griffin, Stephanie R. Falatko, Stella Aslibekyan, Virginia Strickland and Mark R. Harrigan
Blunt traumatic extracranial carotid or vertebral artery injury (i.e., traumatic cerebrovascular injury [TCVI]) occurs in 1%–2% of all blunt trauma admissions, carries a 10% risk of thromboembolic ischemic stroke, and accounts for up to 9600 strokes annually in the US. Screening CT angiograms (CTAs) of patients with trauma has become ubiquitous in recent years, and patients with initially asymptomatic TCVI are commonly treated with antiplatelet agents to prevent stroke. Prophylaxis with antiplatelets is thought to be safer than anticoagulation, which carries a significant risk of hemorrhage in patients with trauma. However, the risk of hemorrhagic complications due to antiplatelets has not been assessed in this population.
This is a retrospective cohort study of patients in whom a screening CTA was obtained after admission for blunt trauma at a Level 1 trauma center. Patients with CTAs indicating TCVI were treated routinely with 325 mg aspirin daily. The risk of transfusion > 24 hours after admission was compared according to CTA findings (CTA+ or CTA− for positive or negative findings, respectively) and aspirin treatment (ASA+ or ASA− for treatment or no treatment, respectively).
The mean overall transfusion amount (number of units of packed red blood cells [PRBCs]) was 0.9 ± 2.1 for CTA+/ASA+ patients (n = 196) and 0.3 ± 1.60 for CTA−/ASA− patients (n = 2290) (p < 0.0001). In adjusted models, the overall relative risk (RR) of PRBC transfusion was 1.70 (1.32–2.20) for CTA+/ASA+ patients compared with CTA−/ASA− patients. Among age groups, participants whose ages were 50–69 years had the greatest significantly elevated RR (1.71, 95% CI 1.08–2.72) for CTA+/ASA+ patients compared with CTA−/ASA− patients.
Treatment with aspirin for the prevention of stroke in patients with initially asymptomatic TCVI carries a significantly increased risk of PRBC transfusion. Future studies are needed to determine if this risk is offset by a reduced risk of ischemic stroke.
Andrew S. Ferrell, R. Shane Tubbs, Leslie Acakpo-Satchivi, John P. Deveikis and Mark R. Harrigan
Foix-Alajouanine syndrome has become a well-known entity since its initial report in 1926. The traditional understanding of this clinical syndrome is as a progressive spinal cord venous thrombosis related to a spinal vascular lesion, resulting in necrotic myelopathy. However, spinal venous thrombosis is extremely rare and not a feature of any common spinal vascular syndrome. A translation and review of the original 42-page French report revealed 2 young men who had presented with progressive and unrelenting myelopathy ultimately leading to their deaths. Pathological analysis demonstrated endomesovasculitis of unknown origin, including vessel wall thickening without evidence of luminal narrowing, obliteration of cord vessels, or thrombosis. Foix and Alajouanine also excluded the presence of intramedullary arteriovenous malformations. At the time, dural arteriovenous fistulas (dAVFs) had not been described, and therefore this type of lesion was not specifically sought. In retrospect, it seems possible that both patients had progressive myelopathy due to Type I dAVFs. In the decades since that original report, numerous authors have included spinal cord venous thrombosis as a central feature of Foix-Alajouanine syndrome. The inclusion of thrombosis in the clinical picture of this syndrome is not only incorrect but may leave one with the impression of therapeutic futility, thus possibly preventing successful surgical or endovascular therapy.
Xiao Wu and Ajay Malhotra
Christoph J. Griessenauer, Paul M. Foreman, John P. Deveikis and Mark R. Harrigan
The pathophysiology of extracranial traumatic aneurysm formation has not been fully elucidated. Intraarterial optical coherence tomography (OCT), an imaging modality capable of micrometer cross-sectional resolution, was used to evaluate patients presenting with saccular traumatic aneurysms of the internal carotid artery (ICA). Two consecutive trauma patients diagnosed with saccular traumatic aneurysms of the cervical ICA, per the institutional screening protocol for traumatic cerebrovascular injury, underwent digital subtraction angiography (DSA) with OCT. Optical coherence tomography demonstrated disruption of the intima with preservation and stretching of the more peripheral layers. In 1 patient the traumatic aneurysm was associated with thrombus formation and a separate, more proximal dissection not visible on CT angiography (CTA) or DSA. Imaging with OCT indicates that saccular traumatic aneurysms may develop from disruption of the intima with at least partial preservation of the media and adventitia. This provides in vivo evidence that saccular traumatic aneurysms result from a partial arterial wall tear rather than complete disruption. Interestingly, OCT was also able to detect arterial injury and thrombi not visible on CTA or DSA.
Paul M. Foreman, Christoph J. Griessenauer, Michael Falola and Mark R. Harrigan
Traumatic aneurysms occur in 10% of extracranial blunt traumatic cerebrovascular injuries (TCVI). The clinical consequences and optimal management of traumatic aneurysms are poorly understood.
A prospective study of TCVI at a Level I trauma center identified 7 patients with 19 extracranial traumatic carotid artery or vertebral artery aneurysms. An additional 6 patients with 7 traumatic aneurysms were followed outside of the prospective study, giving a total of 13 patients with 26 traumatic aneurysms. All patients were treated with 325 mg aspirin daily and underwent clinical and imaging follow-up beyond the initial hospitalization. Endovascular treatment was reserved for aneurysms demonstrating significant enlargement on follow-up imaging. Clinical and radiographic features were assessed.
The 7 patients with traumatic aneurysms identified in the prospective cohort comprised 10.3% of all patients with TCVI. Two (15.4%) of the 13 total patients suffered an ischemic stroke in the setting of TCVI with traumatic aneurysm formation. No patient experienced an ischemic stroke or new symptoms after the initiation of antiplatelet therapy. Clinical and radiographic follow-up averaged 15.8 months (range 0.4–41.7 months) and 22.0 months (range 6.6–55.7 months), respectively. Ten (38.5%) of 26 aneurysms were not visualized on last follow-up, 10 (38.5%) were smaller, 1 (3.8%) was unchanged, and 5 (19.2%) were larger. Saccular aneurysms were more likely to enlarge than fusiform aneurysms (33.3% vs 11.8%). Results of a Fisher exact test tend to support the assertion that the 2 different aneurysm morphologies behave differently (p = 0.07). Two saccular aneurysms were treated with stenting.
The majority of traumatic aneurysms can be managed with an antiplatelet regimen of 325 mg aspirin daily and serial imaging. Saccular aneurysms have a greater tendency to enlarge when compared with fusiform aneurysms.
Roberto C. Heros
Joseph H. Miller, Holly A. Zywicke, James B. Fleming, Christoph J. Griessenauer, Thomas R. Whisenhunt, Mamerhi O. Okor, Mark R. Harrigan, Patrick R. Pritchard and Mark N. Hadley
The April 27, 2011, tornados that affected the southeastern US resulted in 248 deaths in the state of Alabama. The University of Alabama at Birmingham (UAB) Medical Center, the largest Level I trauma center in the state, triaged and treated a large number of individuals who suffered traumatic injuries during these events, including those requiring neurosurgical assessment and treatment.
A retrospective review of all adult patients triaged at UAB Medical Center during the April 27, 2011, tornados was conducted. Those patients who were diagnosed with and treated for neurosurgical injuries were included in this cohort.
The Division of Neurosurgery at UAB Medical Center received 37 consultations in the 36 hours following the tornado disaster. An additional patient presented 6 days later, having suffered a lumbar spine fracture that ultimately required operative intervention. Twenty-seven patients (73%) suffered injuries as a direct result of the tornados. Twenty-three (85%) of these 27 patients experienced spine and spinal cord injuries. Four patients (15%) suffered intracranial injuries and 2 patients (7%) suffered combined intracranial and spinal injuries. The spinal fractures that were evaluated and treated were predominantly thoracic (43.5%) and lumbar (43.5%). The neurosurgery service performed 14 spinal fusions, 1 ventriculostomy, 2 halo placements, 1 diagnostic angiogram, 1 endovascular embolectomy, and 1 wound debridement and lavage. Twenty-two patients (81.5%) were neurologically intact at discharge and all but 4 had 1 year of follow-up. Three patients had persistent deficits from spinal cord injuries and there was 1 death in a patient with multisystem injuries in whom no procedures were performed. Two patients experienced postoperative complications in the form of 1 wound infection and 1 stroke.
The April 27, 2011, tornados in Alabama produced significant neurosurgical injuries that primarily involved the spine. There were a disproportionate number of patients with thoracolumbar fractures, a finding possibly due to the county medical examiner's postmortem findings that demonstrated a high prevalence of fatal cervical spine and traumatic brain injuries. The UAB experience can be used to aid other institutions in preparing for the appropriate allotment of resources in the event of a similar natural disaster.