No abstract

Intracranial or brain arteriovenous malformations (BAVMs) are some of the most interesting and challenging lesions treated by the cerebrovascular neurosurgeon. It is generally believed that the combination of BAVMs and intracranial aneurysms (IAs) is associated with higher hemorrhage rates at presentation and higher rehemorrhage rates and thus with a more aggressive course and natural history. There is wide variation in the literature on the prevalence of BAVM-associated aneurysms (range 2.7%–58%), with 10%–20% being most often cited in the largest case series. The risk of intracranial hemorrhage in patients with unruptured BAVMs and coexisting IAs has been reported to be 7% annually, compared with 2%–4% annually for those with BAVM alone. Several different classification systems have been applied in an attempt to better understand the natural history of this combination of lesions and implications for treatment. Independent of the classification used, it is clear that a few subtypes of aneurysms have a direct hemodynamic correlation with the BAVM itself. This is exemplified by the fact that the presence of a distal flow-related or an intranidal aneurysm appears to be associated with an increased hemorrhage risk, when compared with an aneurysm located on a vessel with no direct supply to the BAVM nidus. Debate still exists regarding the etiology of the association between those two vascular lesions, the subsequent implications for patients’ risk of hemorrhagic stroke, and finally the determination of which patients warrant treatment and when. The ultimate goals of the treatment of a BAVM associated with an IA are to prevent hemorrhage, avoid stepwise neurological deterioration, and eliminate the mortality risk associated with recurrent hemorrhagic events. The treatment is only justifiable if the risks associated with an intervention are lower than or equivalent to the long-term risks of disability or mortality caused by the lesion itself. When faced with this difficult decision, a few questions need to be answered by the treating neu-rosurgeon: What is the mode of presentation? What is the symptomatic lesion? Which one of the lesions bled? What is the relationship between the BAVM and IA? Is it possible to safely treat both BAVM and IA? The objective of this review is to discuss the demographics, natural history, classification, and strategies for management of BAVMs associated with IAs.

Diagnostic study, level II.

Object Screening of blunt vertebral artery (VA) injuries has increased since research has shown that they occur at a higher incidence than originally reported. Grade 1 and 2 injuries are the most common form of blunt VA injury. Proper screening, management, and follow-up of these injuries remain controversial. In this report, imaging, progression, treatment, and outcomes of Grade 1 and 2 blunt VA injuries were analyzed to better define their natural history and to establish a rational management plan based upon their risk of progression and cerebral infarct. Methods A retrospective review of all blunt traumatic carotid artery and VA injuries from December 2003 to April 2013 was performed. For the purposes of this report, focus was given to Grade 1 and 2 VA injuries. Grade 1 injuries were defined as a vessel lumen stenosis of less than 25%, and Grade 2 injuries were defined as vessel lumen stenosis between 25% and 50%. Demographic information, radiological imaging, number of images performed per individual, length of radiological follow-up, radiological outcome at the end of follow-up, treatment provided, and documentation of stroke or transient ischemic attack were recorded. Results One hundred eighty-seven Grade 1 and 2 VA injuries in 143 patients were identified. Of these 143 patients, 120 with 152 Grade 1 or 2 blunt VA injuries were available for follow-up. The mean duration of follow-up was 40 days. Repeat imaging showed that 148 (97.4%) Grade 1 or 2 blunt VA injuries were stable, improved, or resolved on final follow-up imaging. Seventy-nine patients (66%) were treated with aspirin, whereas 35 patients (29%) received no treatment. The remaining patients were treated with other antiplatelet agents or anticoagulant medication. Neuroimaging demonstrated 2 cases (1.7%) with posterior circulation infarcts that were believed to be related to their blunt VA injuries, both of which occurred during the initial hospitalization and within the first 4 days after injury. Conclusions Although follow-up imaging showed progressive worsening without radiological improvement in only a small number of patients with low-grade blunt VA injuries, these findings did not correlate with adverse clinical outcome. The posttraumatic cerebral infarction rate of 1.7% may be overestimated, and the use of acetylsalicylic acid or other antiplatelet or anticoagulant medication did not correlate with radiological changes or rate of cerebral infarction. While these data suggest the possibility that these low-grade VA injuries may not require treatment or follow-up, future prospective studies are needed to make conclusive changes related to management.

Evidence is emerging that isolated traumatic subarachnoid hemorrhage (ITSAH) may be a milder form of traumatic brain injury (TBI). If true, ITSAH may not benefit from intensive care unit (ICU) admission, which would, in turn, decrease resource utilization. We conducted a retrospective review of all TBI admissions to our institution between February 2010 and November 2012 to compare the presentation and clinical course of subjects with ITSAH to all other TBI. We then performed descriptive statistics on the subset of ITSAH subjects presenting with a Glasgow Coma Score (GCS) of 13-15. Of 698 subjects, 102 had ITSAH and 596 had any other intracranial hemorrhage pattern. Compared to all other TBI, ITSAH had significantly lower injury severity scores ( p < 0.0001), lower head abbreviated injury scores ( p < 0.0001), higher emergency department GCS ( p < 0.0001), shorter ICU stays ( p = 0.007), higher discharge GCS ( p = 0.005), lower mortality ( p = 0.003), and significantly fewer head computed tomography scans ( p < 0.0001). Of those ITSAH subjects presenting with a GCS of 13-15 (n = 77), none underwent placement of an intracranial monitor or craniotomy. One subject (1.3%) demonstrated a change in exam (worsened headache and dizziness) concomitant with a progression of his intracranial injury. His symptoms resolved with readmission to the ICU and continued observation. Our results suggest that ITSAH are less-severe brain injuries than other TBI. ITSAH patients with GCS scores of 13-15 demonstrate low rates of clinical progression, and when progression occurs, it resolves without further intervention. This subset of TBI patients does not appear to benefit from ICU admission.

As a basis for venous thromboembolism (VTE) prophylaxis after traumatic brain injury (TBI), we have previously published an algorithm known as the Parkland Protocol. Patients are classified by risk for spontaneous progression of hemorrhage with chemoprophylaxis regimens tailored to each tier. We sought to validate this schema. In our algorithm, patients with any of the following are classified ''low risk'' for spontaneous progression: subdural hemorrhage £ 8 mm thick; epidural hemorrhage £ 8 mm thick; contusions £ 20 mm in diameter; a single contusion per lobe; any amount of subarachnoid hemorrhage; or any amount of intraventricular hemorrhage. Patients with any injury exceeding these are ''moderate risk'' for progression, and any patient receiving a monitor or craniotomy is ''high risk.'' From February 2010 to November 2012, TBI patients were entered into a dedicated database tracking injury types and sizes, risk category at presentation, and progression on subsequent computed tomgraphies (CTs). The cohort (n = 414) was classified as low risk (n = 200), moderate risk (n = 75), or high risk (n = 139) after first CT. After repeat CT scan, radiographic progression was noted in 27% of low-risk, 53% of moderate-risk, and 58% of high-risk subjects. Omnibus analysis of variance test for differences in progression rates was highly significant ( p < 0.0001). Tukey's post-hoc test showed the low-risk progression rate to be significantly different than both the moderate-and high-risk arms; no difference was noted between the moderate-and high-risk arms themselves. These criteria are a valid tool for classifying TBI patients into two categories of risk for spontaneous progression. This supports tailored chemoprophylaxis regimens for each arm.

T he management of blunt cerebrovascular injuries (BCVIs), including low-grade blunt carotid artery injuries (BCIs), remains controversial; however, antiplatelet agents or anticoagulation continue to be firstline treatments, with endovascular stenting typically reserved for symptomatic or higher-grade injuries. 5,7,8,16,19,26 Whereas our earlier reports explored blunt vertebral artery injuries (BVIs), this current report presents our evaluation of Grade 1 and 2 BCIs. Imaging, progression of injury, and outcomes of these lower-grade BCIs were analyzed to abbreviatioNs ASA = acetylsalicylic acid; BCI = blunt carotid artery injury; BCVI = blunt cerebrovascular injury; BVI = blunt vertebral artery injury; CTA = CT angiography; DSA = digital subtraction angiography; MVC = motor vehicle collision. obJect Proper screening, management, and follow-up of Grade 1 and 2 blunt carotid artery injuries (BCIs) remains controversial. These low-grade BCIs were analyzed to define their natural history and establish a rational management plan based on lesion progression and cerebral infarction. methods A retrospective review of a prospectively maintained database of all blunt traumatic carotid and vertebral artery injuries treated between August 2003 and April 2013 was performed and Grade 1 and 2 BCIs were identified. Grade 1 injuries are defined as a vessel lumen stenosis of less than 25%, and Grade 2 injuries are defined as a stenosis of the vessel lumen between 25% and 50%. Demographic information, radiographic imaging, number of imaging sessions performed per individual, length of radiographic follow-up, radiographic outcome at end of follow-up, treatment(s) provided, and documentation of ischemic stroke or transient ischemic attack were recorded. results One hundred seventeen Grade 1 and 2 BCIs in 100 patients were identified and available for follow-up. The mean follow-up duration was 60 days. Final imaging of Grade 1 and 2 BCIs demonstrated that 64% of cases had resolved, 13% of cases were radiographically stable, and 9% were improved, whereas 14% radiographically worsened. Of the treatments received, 54% of cases were treated with acetylsalicylic acid (ASA), 31% received no treatment, and 15% received various medications and treatments, including endovascular stenting. There was 1 cerebral infarction that was thought to be related to bilateral Grade 2 BCI, which developed soon after hospital admission. coNclusioNs The majority of Grade 1 and 2 BCIs remained stable or improved at final follow-up. Despite a 14% rate of radiographic worsening in the Grade 1 and 2 BCIs cohort, there were no adverse clinical outcomes associated with these radiographic changes. The stroke rate was 1% in this low-grade BCIs cohort, which may be an overestimate. The use of ASA or other antiplatelet or anticoagulant medications in these low-grade BCIs did not appear to correlate with radiographic injury stability, nor with a decreased rate of cerebral infarction. Although these data suggest that these Grade 1 and 2 BCIs may require less intensive r...

ObJect Grade 3 and 4 blunt vertebral artery (VA) injuries may carry a different natural course from that of lower-grade blunt VA injuries. Proper screening, management, and follow-up of these injuries remain controversial. Grade 3 and 4 blunt VA injuries were analyzed to define their natural history and establish a rational management plan based on lesion progression and cerebral infarction. MetHODS A retrospective review of a prospectively maintained database of all blunt traumatic carotid and vertebral artery injuries from August 2003 to April 2013 was performed, and Grade 3 and 4 blunt VA injuries were identified. Grade 3 injuries were defined as stenosis of the vessel greater than 50% or the development of a pseudoaneurysm, and Grade 4 injuries were defined as complete vessel occlusion. Demographic information, radiographic imaging findings, number of imaging sessions performed per individual, length of radiographic follow-up, radiographic outcome at end of follow-up, treatment(s) provided, and documentation of ischemic stroke or transient ischemic attack were recorded. reSultS A total of 79 high-grade (Grade 3 and 4) blunt VA injuries in 67 patients were identified. Fifty-nine patients with 66 high-grade blunt VA injuries were available for follow-up. There were 17 patients with 23 Grade 3 injuries and 42 patients with 43 Grade 4 injuries. The mean follow-up duration was 58 days for Grade 3 and 67 days for Grade 4 blunt VA injuries. Repeat imaging of Grade 3 blunt VA injuries showed that 39% of injuries were radiographically stable, 43% resolved, and 13% improved, while 1 injury radiographically worsened. Repeat imaging of the Grade 4 blunt VA injuries showed that 65% of injuries were radiographically stable (persistent occlusion), 30% improved (recanalization of the vessel), and in 2 cases (5%) the injury resolved. All Grade 3 injuries that were treated were managed with aspirin or clopidogrel alone, as were the majority of Grade 4 injuries. There were 3 cerebral infarctions thought to be related to Grade 4 blunt VA injuries, which were likely present on admission. All 3 of these patients died at a mean of 13.7 days after hospital admission. No cerebral infarctions directly related to Grade 3 blunt VA injuries were identified. cONcluSiONS The majority of high-grade blunt VA injuries remain stable or are improved at final follow-up. Despite a 4% rate of radiographic worsening in the Grade 3 blunt VA injury group and a 35% recanalization rate in the Grade 4 blunt VA injury group, there were no adverse clinical outcomes associated with these radiographic changes. No cerebral infarctions were noted in the Grade 3 group. A 7% stroke rate was identified in the Grade 4 blunt VA injury group; however, this was confined to the immediate postinjury period and was associated with 100% mortality. While these data suggest that these high-grade vertebral artery injuries may require less intensive radiographic follow-up, future prospective studies are needed to make conclusive changes related to treatment and management....