Computed Tomographic Angiography for the Diagnosis of Blunt Carotid/Vertebral Artery Injury

Traumatic Cervical Cerebrovascular Injury and the Role of CTA: AJR Expert Panel Narrative Review

Traumatic cerebrovascular injury (CVI) involving the cervical carotid and vertebral arteries is rare but can lead to stroke, hemodynamic compromise, and mortality in the absence of early diagnosis and treatment. The diagnosis of both blunt cerebrovascular injury (BCVI) and penetrating CVI is based on cerebrovascular imaging. The most commonly used screening criteria for BCVI include the expanded Denver criteria and the Memphis criteria, each providing varying thresholds for subsequent imaging. Neck CTA has supplanted catheter-based digital subtraction angiography as the preferred screening modality for CVI in patients with trauma. This AJR Expert Panel Narrative Review describes the current state of CTA-based cervical imaging in trauma. We review the most common screening criteria for BCVI, discuss BCVI grading scales that are based on neck CTA, describe the diagnostic performance of CTA in the context of other imaging modalities and evolving treatment strategies, and provide a practical guide for neck CTA implementation.

Antiplatelets versus anticoagulants in the treatment of blunt cerebrovascular injury (BCVI) - A systematic review and meta-analysis

INTRODUCTION

Blunt cerebrovascular injury (BCVI) occurs in 1-3% of blunt traumas and is associated with stroke, disability, and mortality if unrecognized and untreated. Early detection and treatment are imperative to reduce the risk of stroke, however, there is significant variation amongst centers and trauma care providers in the specific medical management strategy used. This study compares antiplatelets vs. anticoagulants to determine BCVI-related stroke risk and bleeding complications to better understand the efficacy and safety of various treatment strategies.

METHODS

A systematic review of MEDLINE, Embase, and Cochrane CENTRAL databases was conducted with the assistance of a medical librarian. The search was supplemented with manual review of the literature. Included studies reported treatment-stratified risk of stroke following BCVI. All studies were screened independently by two reviewers, and data was extracted in duplicate. Meta-analysis was conducted using pooled estimates of odds ratios (OR) with a random-effects model using Mantel-Haenszel methods.

RESULTS

A total of 3315 studies screened yielded 39 studies for inclusion, evaluating 6552 patients (range 8 - 920 per study) with a total of 7643 BCVI. Stroke rates ranged from 0% to 32.8%. Amongst studies included in the meta-analysis, there were a total of 405 strokes, with 144 (35.5%) occurring on therapy, for a total stroke rate of 4.5 %. Meta-analysis showed that stroke rate after BCVI was lower for patients treated with antiplatelets vs. anticoagulants (OR 0.57; 95% CI 0.33-0.96, p = 0.04); when evaluating only the 9 studies specifically comparing ASA to heparin, the stroke rate was similar between groups (OR 0.43; 95% CI 0.15-1.20, p = 0.11). Eleven studies evaluated bleeding complications and demonstrated lower risk of bleeding with antiplatelets vs. anticoagulants (OR 0.29; 95% CI 0.13-0.63, p = 0.002); 5 studies evaluating risk of bleeding complications with ASA vs. heparin showed lower rates of bleeding complications with ASA (OR 0.16; 95% CI 0.04-0.58, p = 0.005).

CONCLUSIONS

Treatment of patients with BCVI with antiplatelets is associated with lower risks of stroke and bleeding complications compared to treatment with anticoagulants. Use of ASA vs. heparin specifically was not associated with differences in stroke risk, however, patients treated with ASA had fewer bleeding complications. Based on this evidence, antiplatelets should be the preferred treatment strategy for patients with BCVI.

Blunt Cerebrovascular Injury: Are We Overscreening Low-Mechanism Trauma?

BACKGROUND AND PURPOSE

Screening patients with trauma for blunt cerebrovascular injury with neck CTA is a common practice, but there remains disagreement regarding which patients should be screened. We reviewed adult blunt cerebrovascular injury data from a level 1 trauma center to investigate whether screening is warranted in low-mechanism trauma.

MATERIALS AND METHODS

We reviewed all neck CTAs performed on adult trauma patients in the emergency department during the 2019 calendar year. Clinical and imaging risk factors for blunt cerebrovascular injury, trauma mechanism, initial neck CTA interpretations, results from subsequent CTA and DSA studies, antiplatelet and anticoagulant treatments, and outcome data were recorded.

RESULTS

One thousand one hundred thirty-six neck CTAs met the inclusion criteria, of which 965 (85%) were interpreted as having negative findings; 125, as having indeterminate findings (11%); and 46, as having positive findings (4%). Review of subsequent imaging and clinical documentation led to classification of 40 indeterminate studies (32%) as true-positives and 85 (68%) as false-positives. Blunt cerebrovascular injury was identified in 77 (12.6%) cases meeting and in 9 (1.7%) cases not meeting the expanded Denver criteria. The subset of 204 low-mechanism trauma cases (ground-level falls, blunt assaults, and low-impact motor vehicle collisions) not meeting the expanded Denver criteria (18% of the entire data set) could have been excluded from screening with 1 questionable injury and 0 ischemic strokes missed and 12 false-positive cases prevented.

CONCLUSIONS

We advocate reservation of blunt cerebrovascular injury screening in low-mechanism trauma for patients meeting the expanded Denver criteria. Further research is needed to determine the behavior of indeterminate cases and to establish criteria for separating true-positive from false-positive findings.

Photon Counting CT: Technical Principles, Clinical Applications, and Future Prospects

Photon-counting computed tomography (PCCT) is a new technique that utilizes photon-counting detectors to convert individual X-ray photons directly into an electrical signal, which can achieve higher spatial resolution, improved iodine signal, radiation dose reduction, artifact reduction, and multienergy imaging. This review introduces the technical principles of PCCT, and summarizes its first-in-human experience and current applications in clinical settings, and discusses the future prospects of PCCT.

The Utility of CTA in Pediatric Oropharyngeal Trauma: A Systematic Review and Meta-Analysis

OBJECTIVE(S)

To analyze the utility of computed tomography angiography (CTA) in identifying internal carotid artery (ICA) injury and reducing cerebrovascular accident (CVA) incidence in children presenting with normal neurologic exams after oropharyngeal trauma (OT).

DATA SOURCES

PubMed, Scopus, CINAHL, and Cochrane.

REVIEW METHODS

A systematic review and meta-analysis were performed following PRISMA guidelines. Of 1,185 studies screened, 95 studies of pediatric OT met inclusion criteria. Meta-analysis of proportions was performed.

RESULTS

A total of 1224 children with OT were analyzed. Excluding case reports, the weighted proportion of a CVA after OT was 0.31% (95% CI 0.06-0.93). If a child presented without neurologic deficits, 0.30% (95% CI 0.05-0.95) returned with new neurologic deficits. An ICA injury was identified in 0.89% (95% CI 0.16-2.74) of screening CTAs. No difference in CVA incidence was seen in children with screening CTA (0.52% [95% CI 0.02-2.15]) compared to children without screening CTA (0.42% [95% CI 0.06-1.37]). Patients who developed CVA had a higher proportion of injuries >2 cm, injuries at the posterior pillar or tonsil, and injuries with a writing utensil or popsicle stick compared to patients without CVA.

CONCLUSION

The proportion of children experiencing an ICA injury leading to CVA after sustaining OT is low. CTAs infrequently show ICA changes in children with normal neurological exams. Children who receive CTAs do not have a significantly lower incidence of CVAs than children who do not receive CTAs. Clinicians should weigh the risks and benefits of a CTA based on an individual child's presentation and discuss this with caregivers for shared decision-making. Laryngoscope, 133:25-37, 2023.

Cervical fracture patterns associated with blunt cerebrovascular injures when utilizing computed tomographic angiography: a systematic review and meta-analysis

BACKGROUND CONTEXT

Prior studies have demonstrated an association between cervical spine fractures and blunt cerebrovascular injuries (BCVI) due to the intimate anatomic relationship between the cervical spine and the vertebral arteries. Digital subtraction angiography (DSA) has historically been the gold standard, but computed tomography angiography (CTA) is commonly used to screen for BCVI in the trauma setting. However, there is no consensus regarding which fracture patterns mandate screening. Over aggressive screening may lead to increased radiation, increased false positives, and overtreatment of patients which can cause unnecessary patient harm, and increased healthcare costs.

PURPOSE

The aim of this meta-analysis is to analyze which cervical spine fracture patterns are most predictive of BCVI when utilizing CTA.

STUDY DESIGN/SETTING

Systematic review and meta-analysis.

OUTCOME MEASURES

Odds ratios for specific cervical fracture patterns and risk of developing a BCVI.

METHODS

A systematic literature review of all English language studies from 2000-2020 was conducted. The year 2000 was chosen as the cut-off because use of CTA prior to 2000 was rare. Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Scopus, Global Index Medicus, and ClinicalTrials.gov were queried. Studies were included if they met the following criteria: (1) the diagnostic imaging modality was CTA; (2) investigated blunt cervical trauma; (3) noted specific cervical spine fracture patterns associated with BCVI; (4) odds ratios for specific cervical spine fracture patterns or the odds ratio could be calculated; (5) subjects were 18 years old or older. Studies were excluded if they: (1) included DSA or magnetic resonance imaging; (2) included penetrating cervical trauma; (3) included pediatric patients less than 18 years of age; (4) were not written in English. All statistical analysis was performed using R Studio (RStudio, Boston, MA, USA).

RESULTS

The initial search, after duplicates were removed, resulted in 10,940 articles for independent review. Six studies met the criteria for inclusion in the meta-analysis. Specific fracture patterns mentioned are isolated C1, C2, C3 fractures, any C1-C3 fracture, any C4-C7 fracture, two-level fractures, subluxation/dislocations, and transverse foramen (TF) fractures. Three studies were included in the meta-analysis for C1, C2, C1-C3, subluxations/dislocations, and TF fractures. Two studies were included in the meta-analysis for C3, C4-C7, and two-level fractures. The pooled odds ratio with 95% confidence interval for: C1 fractures and BCVI is 1.3 (0.8-2.1); C2: 1.6 (0.9-2.8); C3: 1.8 (0.9-3.6); C1-C3: 2.2 (1.1-4.2); C4-C7: 0.7 (0.3-1.7); Two-level: 2.5 (1.4-4.6); Subluxation/Dislocation: 2.9 (1.8-4.5); TF: 3.6 (1.4-8.9).

DISCUSSION/CONCLUSION

This study found that when utilizing CTA for screening of BCVI only fractures in the C1-C3 region, two-level fractures, subluxations/dislocations, and transverse foramen fractures were associated with increased incidence of a BCVI. Further refinement of protocols for CTA in the setting of blunt cervical trauma may help limit unnecessary patient harm from overtreatment and reduce healthcare costs.

Emergent neurovascular imaging in patients with blunt traumatic injuries

Blunt cerebrovascular injuries (BCVIs) are commonly encountered after blunt trauma. Given the increased risk of stroke incurred after BCVI, it is crucial that they are promptly identified, characterized, and treated appropriately. Current screening practices generally consist of computed tomography angiography (CTA), with escalation to digital subtraction angiography for higher-grade injuries. Although it is quick, cost-effective, and readily available, CTA suffers from poor sensitivity and positive predictive value. A review of the current literature was conducted to examine the current state of emergent imaging for BCVI. After excluding reviews, irrelevant articles, and articles exclusively available in non-English languages, 36 articles were reviewed and included in the analysis. In general, as CTA technology has advanced, so too has detection of BCVI. Magnetic resonance imaging (MRI) with sequences such as vessel wall imaging, double-inversion recovery with black blood imaging, and magnetization prepared rapid acquisition echo have notably improved the utility for MRI in characterizing BCVIs. Finally, transcranial Doppler with emboli detection has proven to be associated with strokes in anterior circulation injuries, further allowing for the identification of high-risk lesions. Overall, imaging for BCVI has benefited from a tremendous amount of innovation, resulting in better detection and characterization of this pathology.

Diagnostic accuracy of computed tomography angiography (CTA) for diagnosing blunt cerebrovascular injury in trauma patients: a systematic review and meta-analysis

Objectives

Previous literature showed that the diagnostic accuracy of computed tomographic angiography (CTA) is not equally comparable with that of the rarely used golden standard of digital subtraction angiography (DSA) for detecting blunt cerebrovascular injuries (BCVI) in trauma patients. However, advances in CTA technology may prove CTA to become equally accurate. This study investigated the diagnostic accuracy of CTA in detecting BCVI in comparison with DSA in trauma patients.

Methods

An electronic database search was performed in PubMed, EMBASE, and Cochrane Library. Summary estimates of sensitivity, specificity, positive and negative likelihood, diagnostic odds ratio, and 95% confidence intervals were determined using a bivariate random-effects model.

Results

Of the 3293 studies identified, 9 met the inclusion criteria. Pooled sensitivity was 64% (95% CI, 53–74%) and specificity 95% (95% CI, 87–99%) The estimated positive likelihood ratio was 11.8 (95%, 5.6–24.9), with a negative likelihood ratio of 0.38 (95%, 0.30–0.49) and a diagnostic odds ratio of 31 (95%, 17–56).

Conclusion

CTA has reasonable specificity but low sensitivity when compared to DSA in diagnosing any BCVI. An increase in channels to 64 slices did not yield better sensitivity. There is a risk for underdiagnosis of BCVI when only using DSA to confirm CTA-positive cases, especially in those patients with low-grade injuries.

Key Points

• Low sensitivity and high specificity were seen in identifying BCVI with CTA as compared to DSA.

• Increased CTA detector channels (≤ 64) did not lead to higher sensitivity when detecting BCVI.

• The use of CTA instead of DSA may lead to underdiagnosis and, consequently, undertreatment of BCVI.

The Relationship Between Cerebrovascular Injuries and Craniomaxillofacial Fractures: Findings From a Tertiary Hospital in Saudi Arabia

Background and objective

Blunt cerebrovascular injuries (BCVIs) can lead to serious outcomes, particularly because they are difficult to detect in the acute phase. There are studies that have described the association between cerebrovascular injuries and craniomaxillofacial (CMF) fractures; however, no such study has been conducted among a Saudi population. In light of this, we conducted this study to evaluate the correlation between BCVI and CMF fractures among the local population in Saudi Arabia. In addition, the most common types of fractures associated with BCVI were identified.

Methods

This retrospective cohort study was conducted at the King Abdulaziz Medical City, a tertiary hospital in Riyadh, Saudi Arabia. All eligible patients with CMF fractures who were hospitalized at the King Abdulaziz Medical City were included. Consecutive patients were screened; no sampling or randomization was required. Patients with penetrating or avulsive mechanisms of injury were excluded.

Results

Out of a total of 1,560 patients included in the study, 1,537 (98.5%) had CMF fractures, while 23 (1.5%) had BCVIs. None of the patients with CMF fractures had BCVIs. Among the patients with BCVIs, 12 (52.2%) were men and 11 (47.8%) were women. The mean age of these patients was 46.91 ± 17.04 years. Among patients with CMF fractures, 1,071 (69.7%) were men and 466 (30.3%) were women. Their mean age was 23.93 ± 17.36 years.

Conclusion

The study did not identify any correlation between BCVI and CMF fractures; however, further studies with larger samples across multiple centers are needed to validate our findings and gain deeper insight into the relationship between BCVI and CMF fractures.

Characterizing Comorbid Cerebrovascular Insults Among Patients With TBI at a TBI Model Systems Rehabilitation Center

OBJECTIVE

Determine incidence and predictors of comorbid cerebrovascular injuries in patients with moderate to severe traumatic brain injury (TBI) and whether it influences rehabilitation outcomes.

SETTING

Inpatient Rehabilitation Facility (IRF) brain injury unit participating in NIDILRR TBI Model Systems (TBIMS).

PARTICIPANTS

A total of 663 patients with moderate to severe TBI.

DESIGN

Observational study with prospective and retrospective data collection.

MAIN MEASURES

New traumatic cerebral artery injury (TCAI) lesions of head/neck and new cerebral infarcts (CIs) abstracted from neuroimaging reports and clinical notes.

RESULTS

The incidence of comorbid CI was 8%, among whom 19% also had TCAI identified. The incidence of TCAI increased over time from 2% before 2008 to 10% after, probably from greater screening. Both CI and TCAI were associated with longer acute care stay. Cerebral infarct was also associated with longer posttraumatic amnesia and lower rate of functional gains.

CONCLUSIONS

Using in-depth abstraction of imaging findings, the incidence of traumatic head/neck artery injuries, and CIs in patients with moderate to severe TBI were both higher than a recent TBIMS-wide study utilizing ICD coding. Cerebral infarct was associated with longer posttraumatic amnesia duration and slower functional gains. Further research is recommended on the outcome implications of concomitant cerebrovascular injury in patients with TBI.

Treatment of asymptomatic blunt cerebrovascular injury (BCVI): a systematic review

Background

The management of asymptomatic blunt cerebrovascular injury (BCVI) with respect to stroke prevention and vessel healing is challenging.

Objectives

The aim of this systematic review was to determine if a specific treatment results in lower stroke rates and/or improved vessel healing in asymptomatic BCVI.

Data sources

An electronic literature search of MEDLINE, EMBASE, Cochrane Library, CINAHL, SCOPUS, Web of Science, and ClinicalTrials.gov performed from inception to March 2020.

Study eligibility criteria

Studies were included if they reported on a comparison of any treatment for BCVI and stroke and/or vessel healing rates.

Participants and interventions

Adult patients diagnosed with asymptomatic BCVI(s) who were treated with any preventive medication or procedure.

Study appraisal and synthesis methods

All studies were systematically reviewed and bias was evaluated by the Newcastle-Ottawa Scale. No meta-analysis was performed secondary to significant heterogeneity across studies in patient population, screening protocols, and treatment selection. The main outcomes were stroke and healing rate.

Results

Of 8781 studies reviewed, 19 reported on treatment effects for asymptomatic BCVI and were included for review. Any choice of medical management was better than no treatment, but no specific differences between choice of medical management and stroke outcomes were found. Vessel healing was rare and the majority of healed vessels were following low-grade injuries.

Limitations

Majority of the included studies were retrospective and at high risk of bias.

Conclusions or implications of key findings

Asymptomatic BCVI should be treated medically using a consistent, local protocol. High-quality studies on the effect of individual antithrombotic agents on stroke rates and vessel healing for asymptomatic BCVI are required.

Risk Factors for Transverse Ligament Disruption and Vertebral Artery Injury Following an Atlas Fracture

BACKGROUND

Atlas fracture occurs in 3%-13% of all cervical spinal injuries and is often associated with other injuries. The factors associated with concomitant transverse ligament disruption and vertebral artery injury remain underexamined.

METHODS

We retrospectively reviewed 97 consecutive cases of atlas fractures. We analyzed demographic and clinic characteristics, including mechanism of injury, fracture type, and associated injuries. We identified factors independently associated with vertebral artery injury and/or transverse ligament disruption.

RESULTS

On multivariable analysis, vertebral artery injury was independently, positively associated with injury to the transverse ligament (odds ratio [OR], 8.51 [1.17, 61.72], P = 0.034), associated facial injury (OR, 7.78 [1.05, 57.50]; P = 0.045), intoxication at presentation (OR, 51.42 [1.10, 2408.82]; P = 0.045), and negatively associated with type 3 fractures (OR, 0.081 [0.0081, 0.814]; P = 0.033). There was a trend toward a positive association with a violence mechanism of injury (OR, 33.47 [0.75, 1487.89]; P = 0.070). Transverse ligament injury was independently associated with other injuries to the spine (OR, 13.07362 [2.43, 70.28]; P = 0.003), atlantodental interval (OR, 2.63 [1.02, 6.75]; P = 0.045), lateral mass displacement (OR, 1.78 [1.32, 2.39]; P < 0.001), and male sex (OR, 7.07 [1.47, 34.06]; P = 0.015). There was a trend toward a positive association with injury to the vertebral artery (OR, 5.13 [0.96, 27.35]; P = 0.056).

CONCLUSIONS

Among patients with atlas fractures, vertebral artery injury and transverse ligament disruption are associated with each other. Mechanism of injury, fracture type, and intoxication at the time of injury were associated with vertebral artery injury, and atlantodental interval and lateral mass displacement are associated with magnetic resonance imaging-confirmed injury to the transverse ligament.

Vertebral Artery Injury with Coinciding Unstable Cervical Spine Trauma: Mechanisms, Evidence-based Management, and Treatment Options

Unstable traumatic cervical spine fracture is a commonly encountered neurosurgical issue. Concomitant vertebral artery injuries present a challenge in surgical decision-making regarding the timing and order of surgical intervention with respect to endovascular intervention and internal fixation of the unstable fracture. Currently, there are no studies that have specifically examined stroke rate or outcomes for patients who have vertebral artery injuries and unstable cervical spine fractures with respect to temporal treatment course. The purpose of this paper is to review the current evidence for the standards of diagnosis and management of vertebral artery injuries with coinciding unstable cervical spine injuries and propose an evidence-based algorithm for workup and treatment.

Imaging of Brain Trauma

Conventional imaging in the acute setting of brain trauma, relevant pathophysiology of injury, and advanced imaging techniques that may provide value in understanding the immediate management and long-term sequela of traumatic brain injury are reviewed. Key imaging findings that can guide clinical management related to such injuries as concussions, hematomas, dissections, dural atrioventricular fistula, and diffuse axonal injury are discussed. The role and accuracy of computed tomography, dual-energy computed tomography, computed tomography angiography, and magnetic resonance angiography in the acute setting are evaluated. In addition, caveats related to imaging the elderly and pediatric population are addressed.

Augmenting Denver criteria yields increased BCVI detection, with screening showing markedly increased risk for subsequent ischemic stroke

Purpose

BCVI may lead to ischemic stroke, disability, and death, while being often initially clinically silent. Screening criteria for BCVI based on clinical findings and trauma mechanism have improved detection, with Denver criteria being most common. Up to 30% of patients do not meet BCVI screening criteria. The aim of this study was to analyze the effect of augmented Denver criteria on detection, and to determine the relative risk for ischemic stroke.

Methods

Denver screening criteria were augmented by any high-energy trauma of the cervical spine, thorax, abdomen, or pelvis. All acute blunt trauma WBCT including CT angiography (CTA) over a period of 38 months were reviewed retrospectively by two Fellowship-trained radiologists, as well as any cerebral imaging after the initial trauma.

Results

1544 WBCT studies included 374 CTA (m/f = 271/103; mean age 41.5 years). Most common mechanisms of injury were MVA (51.5%) and fall from a height (22.3%). We found 72 BCVI in 56 patients (15.0%), with 13 (23.2%) multiple lesions. The ICA was affected in 49 (68.1%) and the vertebral artery in 23 (31.9%) of cases. The most common injury level was C2, with Biffl grades I and II most common in ICA, and II and IV in VA. Interobserver agreement was substantial (Kappa = 0.674). Of 215 patients imaged, 16.1% with BCVI and 1.9% of the remaining cases had cerebral ischemic stroke (p < .0001; OR = 9.77; 95% CI 3.3–28.7). Eleven percent of patients with BCVI would not have met standard screening criteria.

Conclusions

The increase in detection rate for BCVI justifies more liberal screening protocols.

Photon-Counting Computed Tomography for Vascular Imaging of the Head and Neck: First In Vivo Human Results

PURPOSE

The purpose of this study was to evaluate image quality of a spectral photon-counting detector (PCD) computed tomography (CT) system for evaluation of major arteries of the head and neck compared with conventional single-energy CT scans using energy-integrating detectors (EIDs).

METHODS

In this institutional review board-approved study, 16 asymptomatic subjects (7 men) provided informed consent and received both PCD and EID contrast-enhanced CT scans of the head and neck (mean age, 58 years; range, 46-75 years). Tube settings were (EID: 120 kVp/160 mA vs PCD: 140 kVp/108 mA) for all volunteers. Quantitative analysis included measurements of mean attenuation, image noise, and contrast-to-noise ratio (CNR). Spectral PCD data were used to reconstruct virtual monoenergetic images and iodine maps. A head phantom was used to validate iodine concentration measurements in PCD images only. Two radiologists blinded to detector type independently scored the image quality of different segments of the arteries, as well as diagnostic acceptability, image noise, and severity of artifacts of the PCD and EID images. Reproducibility was assessed with intraclass correlation coefficient. Linear mixed models that account for within-subject correlation of analyzed arterial segments were used. Linear regression and Bland-Altman analysis with 95% limits of agreement were used to calculate the accuracy of material decomposition.

RESULTS

Photon-counting detector image quality scores were significantly higher compared with EID image quality scores with lower image noise (P < 0.01) and less image artifacts (P < 0.001). Photon-counting detector image noise was 9.1% lower than EID image noise (8.0 ± 1.3 HU vs 8.8 ± 1.5 HU, respectively, P < 0.001). Arterial segments showed artifacts on EID images due to beam hardening that were not present on PCD images. On PCD images of the head phantom, there was excellent correlation (R = 0.998) between actual and calculated iodine concentrations without significant bias (bias: -0.4 mg/mL [95% limits of agreements: -1.1 to 0.4 mg/mL]). Iodine maps had 20.7% higher CNR compared with nonspectral PCD (65.2 ± 9.0 vs 54.0 ± 4.5, P = 0.01), and virtual monoenergetic image at 70 keV showed similar CNR to nonspectral images (52.6 ± 4.2 vs 54.0 ± 4.5, P = 0.39).

CONCLUSIONS

Photon-counting CT has the potential to improve the image quality of carotid and intracranial CT angiography compared with single-energy EID CT.

Influence of luminal stenosis in aneurysmal and non-aneurysmal blunt cerebrovascular injury

BACKGROUND

Current blunt cerebrovascular injury (BCVI) grading grossly differentiates injury characteristics such as luminal stenosis (LS) and aneurysmal disease. The effect of increasing degree of LS beyond the current BCVI grading scale on stroke formation is unknown.

STUDY DESIGN

BCVI over a 3-year period were retrospectively reviewed. To investigate influence of LS beyond the BCVI grading scale within aneurysmal and non-aneurysmal BCVI, grade 2 BCVI were subdivided into BCVI with ≥ 25% and ≤ 50% LS and BCVI with > 50% and ≤ 99% LS. Grade 3 BCVI were subdivided into BCVI with pseudoaneurysm (PSA) without LS and BCVI with PSA and LS. We hypothesized increased LS beyond the current BCVI grade distinctions would be associated with higher rates of stroke formation.

RESULTS

312 BCVI were included, of which 140 were carotid BCVI and 172 vertebral BCVI. Sixteen carotid BCVI underwent endovascular intervention (EI) and 19 suffered a stroke. In carotid BCVI stroke rates increased sequentially with BCVI grade except in grade 3. There was a stroke rate of 12% in grade 1 carotid BCVI, 18% in grade 2, 6% in grade 3, and 31% in grade 4. In subgroup analysis for grade 2 carotid BCVI, BCVI with > 50% and ≤ 99% LS had higher rates of stroke (22% vs. 15%, p = 0.44) than BCVI with ≥ 25% and ≤ 50% LS. In subgroup analysis of grade 3 carotid BCVI, BCVI with PSA and LS had higher rates of stroke (9% vs. 4%, p = 0.48) than BCVI with PSA without LS. Higher rates of EI in grade 2 carotid BCVI with > 50% and ≤ 99% LS (22% vs. 5%, p = 0.14) and grade 3 carotid BCVI with PSA and LS (35% vs. 4%, p = 0.01) were noted in subgroup analysis.

CONCLUSION

Higher percentage LS beyond the currently used BCVI grading scale has a non-significantly increased rate of stroke in both aneurysmal and non-aneurysmal BCVI. Grade 3 BCVI with PSA and LS seems to be a high-risk subgroup. Use of EI confounds modern measurement of stroke risk in higher LS BCVI.

Best practice guidelines for blunt cerebrovascular injury (BCVI)

Blunt cerebrovascular injury (BCVI) is a non-penetrating injury to the carotid and/or vertebral artery that may cause stroke in trauma patients. Historically BCVI has been considered rare but more recent publications indicate an overall incidence of 1-2% in the in-hospital trauma population and as high as 9% in patients with severe head injury. The indications for screening, treatment and follow-up of these patients have been controversial for years with few clear recommendations. In an attempt to provide a clinically oriented guideline for the handling of BCVI patients a working committee was created. The current guideline is the end result of this committees work. It is based on a systematic literature search and critical review of all available publications in addition to a standardized consensus process. We recommend using the expanded Denver screening criteria and CT angiography (CTA) for the detection of BCVI. Early antithrombotic treatment should be commenced as soon as considered safe and continued for at least 3 months. A CTA at 7 days to confirm or discard the diagnosis as well as a final imaging control at 3 months should be performed.

Management of blunt cerebrovascular injury (BCVI) in the multisystem injury patient with contraindications to immediate anti-thrombotic therapy

INTRODUCTION

Practice management guidelines for screening and treatment of patients with blunt cerebrovascular injury (BCVI) have been associated with a decreased risk of ischemic stroke.

TREATMENT

of patients with BCVI and multisystem injuries that delays immediate antithrombotic therapy remains controversial. The purpose of this study was to determine the timing of BCVI treatment initiation, the incidence of stroke, and bleeding complications as a result of antithrombotic therapy in patients with isolated BCVI in comparison to those with BCVI complicated by multisystem injuries.

MATERIALS AND METHODS

This study was a retrospective review of all adult blunt trauma patients admitted to a level 1 trauma center from 2009 to 2014 with a diagnosis of BCVI.

RESULTS

A total of 28,305 blunt trauma patients were admitted during the study period. Of these, 323 (1.1%) had 481 BCEVIs and were separated into two groups. Isolated BCVI was reported in 111 (34.4%) patients and 212 (65.6%) patients had accompanying multisystem injuries (traumatic brain injury (TBI), solid organ injury, or spinal cord injury) that contraindicated immediate antithrombotic therapy.

TREATMENT

started in patients with isolated BCVI at a median time of 30.3 (15, 52) hours after injury in contrast to 62.4 (38, 97) hours for those with multisystem injuries (p<0.001). The incidence of stroke was identical (9.9%) between groups and no bleeding complications related to antithrombotic therapy were identified.

CONCLUSION

The lack of bleeding complications and equivalent stroke rates between groups suggests that the presence of TBI, solid organ injury, and spinal cord injury are not contraindications to anti-thrombotic therapy for stroke prevention in patients with BCVI.

Overutilization of Cross-Sectional Imaging in the Lower Extremity Trauma Setting

Objective  In an era of managed care and cost savings, we are faced with the question of whether another test is necessary to confirm our clinical suspicion. We hypothesized that a few computed tomography angiographies (CTAs) are necessary to identify lower extremity vascular injuries (LEVIs). We reviewed our trauma center's experience in the management of LEVI. Methods  A retrospective review of all trauma patients between 2012 and 2016 was performed. Four-thousand nine-hundred fourteen trauma patients were evaluated with 46 suspected LEVIs (either with cross-sectional imaging and/or operative exploration). Our primary end point was the utility of CTA in the setting of LEVI. Receiver operating characteristic curves were performed to evaluate sensitivity and specificity for hard signs and CTA identification of LEVI. Results  Out of the initial 46 patients with suspected LEVI, 41 (89%) had a CTA as part of their initial evaluation. Sixteen patients (35%) with LEVI were due to penetrating injuries. Seventeen patients (41%) had a CTA with LEVI. Fourteen of the 17 patients (82%) with injury on CTA also had hard signs of LEVI. Twenty-two patients (48%) underwent operative exploration: three had no LEVI that was previously believed to be on CTA; operative exploration identified two missed injuries not observed on CTA. Seven of forty-one (17%) CTA studies provided a false assumption of the presence/absence of LEVI. One patient (2%) underwent operative exploration and was found to have LEVI in the absence of hard signs, but with a CTA identifying LEVI. Conclusion  The recognition of hard signs through physical examination is paramount to assessing need for operative intervention with suspicion of LEVI. CTA should be reserved as an adjunct for identification of LEVI in patients with high clinical suspicion and absence of hard signs, rather than utilizing CTA as an initial screening tool for the identification of LEVI.

Contemporary Strategies in the Management of Civilian Neck Zone II Vascular Trauma

Neck trauma is the leading cause of death mainly in younger persons posing to surgeons the dilemma whether to proceed with reconstruction of vascular injuries either in the presence of coma or in severe neurological deficit. Vascular injuries in zone II predominate over the other injuries located in zones I/III of the neck. Conventional open repair of carotid injuries with primary closure or interposition grafting is always recommended due to the effective long-term results for penetrating injuries or for patients unfit for endovascular intervention. In cases of blunt trauma, anticoagulation or antiplatelet therapy should be administered first in neurologically stable patients. In case of worsening of the neurological status of the patient despite adequate anticoagulation endovascular means should be considered in cases of appropriate anatomy of the arterial trauma. We provide an update on penetrating/blunt trauma in zone II of the neck, giving emphasis on the anticoagulant and endovascular treatment.

Pediatric Intracranial Aneurysms: Considerations and Recommendations for Follow-Up Imaging

BACKGROUND

Pediatric intracranial aneurysms (IAs) are rare. Compared with adult IAs, they are more commonly giant, fusiform, or dissecting. Treatment often proves more complex, and recurrence rate and de novo aneurysmogenesis incidence are higher. A consensus regarding the most appropriate algorithm for following pediatric IAs is lacking.

METHODS

We sought to generate recommendations based on the reported experience in the literature with pediatric IAs through a thorough review of the PubMed database, discussion with experienced neurointerventionalists, and our own experience.

RESULTS

Digital subtraction angiography (DSA) was utilized immediately post-operatively for microsurgically-clipped and endovascularly-treated IAs, at 6-12 months postoperatively for endovascularly-treated IAs, and in cases of aneurysmal recurrence or de novo aneurysmogenesis discovered by non-invasive imaging modalities. Computed tomographic angiography was the preferred imaging modality for long-term follow-up of microsurgically clipped IAs. Magnetic resonance angiography (MRA) was the preferred modality for following IAs that were untreated, endovascularly-treated, or microsurgically-treated in a manner other than clipping.

CONCLUSIONS

We propose incidental untreated IAs to be followed by magnetic resonance angiography without contrast enhancement. Follow-up modality and interval for treated pediatric IAs is determined by initial aneurysmal complexity, treatment modality, and degree of posttreatment obliteration. Recurrence or de novo aneurysmogenesis requiring treatment should be followed by digital subtraction angiography and appropriate retreatment. Computed tomography angiography is preferred for clipped IAs, whereas contrast-enhanced magnetic resonance angiography is preferred for lesions treated endovascularly with coil embolization and lesions treated microsurgically in a manner other than clipping.

Current opinion in otolaryngology: update on vascular injuries in craniomaxillofacial fractures

PURPOSE OF REVIEW

The primary purpose of this chapter is to define current recommendations for vascular work-up of patients with craniomaxillofacial (CMF) trauma with emphasis on imaging to include intraoperative fluorescence, angiography, and surgical exploration. The second goal is to review current management recommendations for observation versus surgical exploration based on the neck zones of injury.

RECENT FINDINGS

Over the past two decades, endovascular techniques are increasingly utilized, particularly in zones I and III of the neck. Additionally, modern advances in radiographic technology have allowed for selective exploration of penetrating zone II injuries. A high suspicion for blunt cerebrovascular injury should be maintained for patients with high-speed deceleration mechanisms of injury, with a majority of patients managed with medical therapy or conservative monitoring over surgical intervention.

SUMMARY

CMF fractures are associated with vascular injuries to the intracranial carotid system, extracranial carotid system, or vertebral artery system. A thorough understanding of at risk patients, optimal work-up, and timely treatment algorithms is imperative given the devastating sequellae of stroke and death.

Extracranial Cervical Artery Dissections

Cervical artery dissections (CeAD) include both internal carotid and vertebral artery dissections. They are rare but important causes of stroke, especially in younger patients. CeAD should be considered in patients with strokelike symptoms, a new-onset headache and/or neck pain, and/or other risk factors. Early imaging with computed tomography (CT) or magnetic resonance imaging (MRI) is key to making the diagnosis. Treatment may vary depending on the extent of the dissection, timing of the dissection, and other comorbidities. The overall prognosis is good, but does depend on the initial severity of symptoms.

Blunt vertebral vascular injury in trauma patients: ATLS® recommendations and review of current evidence

Blunt cerebrovascular injury (BCVI) encompasses two distinct clinical entities: traumatic carotid artery injury (TCAI) and traumatic vertebral artery injury (TVAI). The latter is the focus of our review. These are potentially devastating injuries which pose a diagnostic challenge in the acute trauma setting. There is still debate regarding the optimal screening criteria, diagnostic imaging modality and treatment methods. In 2012 the American College of Surgeons proposed criteria for investigating patients with suspected TVAI and subsequent treatment methods, caveated with the statement that evidence is limited and still evolving. Here we review the historical evidence and recent literature relating to these recommendations.

Blunt Traumatic Extracranial Cerebrovascular Injury and Ischemic Stroke

Background

Ischemic stroke occurs in a significant subset of patients with blunt traumatic cerebrovascular injury (TCVI). The patients are victims of motor vehicle crashes, assaults or other high-energy collisions, and suffer ischemic stroke due to injury to the extracranial carotid or vertebral arteries.

Summary

An increasing number of patients with TCVI are being identified, largely because of the expanding use of computed tomography angiography for screening patients with blunt trauma. Patients with TCVI are particularly challenging to manage because they often suffer polytrauma, that is, numerous additional injuries including orthopedic, chest, abdominal, and head injuries. Presently, there is no consensus about optimal management.

Key Messages

Most literature about TCVI and stroke has been published in trauma, general surgery, and neurosurgery journals; because of this, and because these patients are managed primarily by trauma surgeons, patients with stroke due to TCVI have been essentially hidden from view of neurologists. This review is intended to bring this clinical entity to the attention of clinicians and investigators with specific expertise in neurology and stroke.

The Use of High-Risk Criteria in Screening Patients for Blunt Cerebrovascular Injury: A Survey

RATIONALE AND OBJECTIVES

Blunt cerebrovascular injury (BCVI) is uncommon, but delayed detection can have disastrous consequences. The Denver criteria are the most commonly used screening criteria. We aim to examine the utilization of screening criteria in the emergency department (ED) of our institution and assess whether patients with risk factors were imaged.

MATERIALS AND METHODS

A survey questionnaire was sent out to radiologists in a large academic institution. A search was performed in the database on the use of CT angiography (CTA) and MR angiography (MRA) among patients with risk factors in the last 11 years.

RESULTS

The survey was sent to 173 radiologists, with 41 responses (35 complete). Most of the physicians (30 out of 35) surveyed selected CTA as their preferred modality to screen for BCVI, whereas the remaining physicians selected MRA. None of the respondents reported routine use of Denver screening criteria or grading scale in their readouts. Only five respondents selected risk factors in the Denver criteria correctly. In the institution search, among the 1331 patients with blunt trauma and risk factors for BCVI, 537 underwent at least one angiographic study (40.3%). There was an increase in the screening rate after February 2010 in all risk factors, but only statistically significant among patients with foramen transversarium fractures and C1-C3 fractures.

CONCLUSIONS

Both the Denver screening criteria and grading scale of vascular injury have been underutilized in the ED for patients with risk factors. Greater awareness and utilization of imaging can potentially result in decreased incidence of subsequent stroke in patients with blunt injury.

Clinical utility of a screening protocol for blunt cerebrovascular injury using computed tomography angiography

OBJECTIVE

Blunt cerebrovascular injury (BCVI) occurs in approximately 1% of the blunt trauma population and may lead to stroke and death. Early vascular imaging in asymptomatic patients at high risk of having BCVI may lead to earlier diagnosis and possible stroke prevention. The objective of this study was to determine if the implementation of a formalized asymptomatic BCVI screening protocol with CT angiography (CTA) would lead to improved BCVI detection and stroke prevention.

METHODS

Patients with vascular imaging studies were identified from a prospective trauma registry at a single Level 1 trauma center between 2002 and 2008. Detection of BCVI and stroke rates were compared during the 3-year periods before and after implementation of a consensus-based asymptomatic BCVI screening protocol using CTA in 2005.

RESULTS

A total of 5480 patients with trauma were identified. The overall BCVI detection rate remained unchanged postprotocol compared with preprotocol (0.8% [24 of 3049 patients] vs 0.9% [23 of 2431 patients]; p = 0.53). However, postprotocol there was a trend toward a decreased risk of stroke secondary to BCVI on a trauma population basis (0.23% [7 of 3049 patients] vs 0.53% [13 of 2431 patients]; p = 0.06). Overall, 75% (35 of 47) of patients with BCVI were treated with antiplatelet agents, but no patient developed new or progressive intracranial hemorrhage despite 70% of these patients having concomitant traumatic brain injury.

CONCLUSIONS

The results of this study suggest that a CTA screening protocol for BCVI may be of clinical benefit with possible reduction in ischemic complications. The treatment of BCVI with antiplatelet agents appears to be safe.

Neurologic complications of polytrauma

Neurologic complications in polytrauma can be classified by etiology and clinical manifestations: neurovascular, delirium, and spinal or neuromuscular problems. Neurovascular complications include ischemic strokes, intracranial hemorrhage, or the development of traumatic arteriovenous fistulae. Delirium and encephalopathy have a reported incidence of 67-92% in mechanically ventilated polytrauma patients. Causes include sedation, analgesia/pain, medications, sleep deprivation, postoperative state, toxic ingestions, withdrawal syndromes, organ system dysfunction, electrolyte/metabolic abnormalities, and infections. Rapid identification and treatment of the underlying cause are imperative. Benzodiazepines increase the risk of delirium, and alternative agents are preferred sedatives. Pharmacologic treatment of agitated delirium can be achieved with antipsychotics. Nonconvulsive seizures and status epilepticus are not uncommon in surgical/trauma intensive care unit (ICU) patients, require electroencephalography for diagnosis, and need timely management. Spinal cord ischemia is a known complication in patients with traumatic aortic dissections or blunt aortic injury requiring surgery. Thoracic endovascular aortic repair has reduced the paralysis rate. Neuromuscular complications include nerve and plexus injuries, and ICU-acquired weakness. In polytrauma, the neurologic examination is often confounded by pain, sedation, mechanical ventilation, and distracting injuries. Regular sedation pauses for examination and maintaining a high index of suspicion for neurologic complications are warranted, particularly because early diagnosis and management can improve outcomes.

Impact of Continuous Evaluation of Technology and Therapy: 30 Years of Research Reduces Stroke and Mortality from Blunt Cerebrovascular Injury

BACKGROUND

Blunt cerebrovascular injury (BCVI) was underdiagnosed until the 1990s when blunt carotid injuries were found to be more common than historically described. Technological advancements and regionalization of trauma care have resulted in increased screening and improved diagnosis of BCVI. The aim of this study was to demonstrate that systematic evaluation of the screening and diagnosis of BCVI, combined with early and aggressive treatment, have led to reductions in BCVI-related stroke and mortality.

STUDY DESIGN

Patients with BCVI from 1985 to 2015 were identified and stratified by age, sex, and Injury Severity Score. BCVI-related stroke and mortality rates were then calculated and compared. Patients were divided into 5 eras based on changes in technology, screening, or treatment algorithms at our institution.

RESULTS

Five hundred and sixty-four patients were diagnosed with BCVI: 508 carotid artery and 267 vertebral artery injuries. Sixty-five percent of patients were male, mean age was 41 years, and mean Injury Severity Score was 27. Incidence of BCVI diagnosis increased from 0.33% to approximately 2% of all blunt trauma (p < 0.001) during the study period. Ninety (14%) patients suffered BCVI-related stroke, with the incidence of stroke significantly decreasing over time from 37% to 5% (p < 0.001). Twenty-eight (5%) patients died as a direct result of BCVI, and BCVI-related mortality also decreased significantly over time from 24% to 0% (p < 0.001).

CONCLUSIONS

Although increased screening has resulted in a higher incidence of injuries over time, BCVI-related stroke and mortality have decreased significantly. Continuous critical evaluation of evolving technology and diagnostic and treatment algorithms has contributed substantially to those improved outcomes. Appraisals of technological advances, preferably through prospective multi-institutional studies, should advance our understanding of these injuries and lead to even lower stroke rates.

Aetiologies of internal carotid artery pseudo-occlusions in acute stroke patients: what neurointerventionalists can expect

In cases of acute stroke, differentiation between an occluded and a patent internal carotid artery (ICA) is crucial for diagnosis and management. Although CT angiography (CTA) can be highly accurate in defining high-grade stenosis and ICA occlusions, misleading ICA occlusion patterns are not rare in patients with acute stroke. We investigated the underlying causes of ICA pseudo-occlusions with CTA with respect to digital subtraction angiography. 11 out of 72 patients had pseudo-occlusion on CTA. Of these, there were three cases of tandem occlusions accompanying high-grade ICA stenosis, five cases of Distal ICA bifurcation occlusion as a result of atrial fibrillation, two cases of cervical ICA dissection and one acute thrombosis of the stent. Consideration of the aforementioned aetiologies by interventionists is warranted, as it may change the planning of endovascular intervention and treatment of acute stroke.

Blunt Cerebrovascular Injury in Cervical Spine Fractures: Are More-Liberal Screening Criteria Warranted?

Study Design Retrospective comparative study. Objective To compare strict Biffl criteria to more-liberal criteria for computed tomography angiography (CTA) when screening for blunt cerebrovascular injury (BCVI). Methods All CTAs performed for blunt injury between 2009 and 2011 at our institution were reviewed. All patients with cervical spine fractures who were evaluated with CTA were included; patients with penetrating trauma and atraumatic reasons for imaging were excluded. We then categorized the patients' fractures based on the indications for CTA as either within or outside Biffl criteria. For included subjects, the percentage of studies ordered for loose versus strict Biffl criteria and the resulting incidences of BCVI were determined. Results During our study period, 1,000 CTAs were performed, of which 251 met inclusion criteria. Of the injuries, 192 met Biffl criteria (76%). Forty-nine were found to have BCVIs (19.5%). Forty-one injuries were related to fractures meeting Biffl criteria (21.4%), and 8 were related to fractures not meeting those criteria (13.6%). The relative risk of a patient with a Biffl criteria cervical spine injury having a vascular injury compared with those imaged outside of Biffl criteria was 1.57 (p = 0.19). Conclusions Our data demonstrates that although cervical spine injuries identified by the Biffl criteria trend toward a higher likelihood of concomitant BCVI (21.4%), a significant incidence of 13.6% also exists within the non-Biffl fracture cohort. As a result, a more-liberal screening than proposed by Biffl may be warranted.

Reliability assessment of the Biffl Scale for blunt traumatic cerebrovascular injury as detected on computer tomography angiography

OBJECTIVE Blunt traumatic cerebrovascular injury (TCVI) represents structural injury to a vessel due to high-energy trauma. The Biffl Scale is a widely accepted grading scheme for these injuries that was developed using digital subtraction angiography. In recent years, screening CT angiography (CTA) has been used to identify patients with TCVI. The reliability of this scale, with injuries assessed using CTA, has not yet been determined. METHODS Seven independent raters, including 2 neurosurgeons, 2 neuroradiologists, 2 neurosurgical residents, and 1 neurosurgical vascular fellow, independently reviewed each presenting CTA of the neck performed in 40 patients with confirmed TCVI and assigned a Biffl grade. Ten images were repeated to assess intrarater reliability, for a total of 50 CTAs. Fleiss' multirater kappa (κ) and interclass correlation were calculated as a measure of interrater reliability. Weighted Cohen's κ was used to assess intrarater reliability. RESULTS Fleiss' multirater κ was 0.65 (95% CI 0.61-0.69), indicating substantial agreement as to the Biffl grade assignment among the 7 raters. Interclass correlation was 0.82, demonstrating excellent agreement among the raters. Intrarater reliability was perfect (weighted Cohen's κ = 1) in 2 raters, and near perfect (weighted Cohen's κ > 0.8) in the remaining 5 raters. CONCLUSIONS Grading of TCVI with CTA using the Biffl Scale is reliable.

Evaluation for Blunt Cerebrovascular Injury: Review of the Literature and a Cost-Effectiveness Analysis

BACKGROUND AND PURPOSE

Evaluation for blunt cerebrovascular injury has generated immense controversy with wide variations in recommendations regarding the need for evaluation and the optimal imaging technique. We review the literature and determine the most cost-effective strategy for evaluating blunt cerebrovascular injury in trauma patients.

MATERIALS AND METHODS

A comprehensive literature review was performed with data extracted to create a decision-tree analysis for 5 different strategies: anticoagulation for high-risk (based on the Denver screening criteria) patients, selective DSA or CTA (only high-risk patients), and DSA or CTA for all trauma patients. The economic evaluation was based on a health care payer perspective during a 1-year horizon. Statistical analyses were performed. The cost-effectiveness was compared through 2 main indicators: the incremental cost-effectiveness ratio and net monetary benefit.

RESULTS

Selective anticoagulation in high-risk patients was shown to be the most cost-effective strategy, with the lowest cost and greatest effectiveness (an average cost of $21.08 and average quality-adjusted life year of 0.7231). Selective CTA has comparable utility and only a slightly higher cost (an average cost of $48.84 and average quality-adjusted life year of 0.7229). DSA, whether performed selectively or for all patients, was not optimal from both the cost and utility perspectives. Sensitivity analyses demonstrated these results to be robust for a wide range of parameter values.

CONCLUSIONS

Selective CTA in high-risk patients is the optimal and cost-effective imaging strategy. It remains the dominant strategy over DSA, even assuming a low CTA sensitivity and irrespective of the proportion of patients at high-risk and the incidence of blunt cerebrovascular injury in high-risk patients.

The limitations of using risk factors to screen for blunt cerebrovascular injuries: the harder you look, the more you find

Introduction

Blunt cerebrovascular injury (BCVI) is reported to occur in 1–2 % of blunt trauma patients. Clinical and radiologic risk factors for BCVI have been described to help identify patients that require screening for these injuries. However, recent studies have suggested that BCVI frequently occurs even in the absence of these risk factors. The purpose of this study was to determine the incidence of BCVI in blunt trauma patients without risk factors and whether these patients could be identified by a more liberal CTA screening protocol.

Methods

We conducted a retrospective cohort study of all blunt trauma patients seen between November 2010 and May 2014. In May 2012, a clinical practice guideline for CTA screening for BCVI was implemented. The records of all patients with BCVI were reviewed for the presence of risk factors for BCVI previously described in the literature.

Results

During the 43 month study period, 6,602 blunt trauma patients were evaluated, 2,374 prior to, and 4,228 after implementation of the clinical practice guideline. Nineteen percent of all blunt trauma patients underwent CTA of the neck after protocol implementation compared to only 1.5 % prior to protocol implementation (p = 0.001). As a result, a 5-fold increase in the identification of BCVI was observed (p = 0.00003). Thirty-seven percent of patients with BCVI identified with the enhanced CT screening protocol had none of the signs, symptoms, or risk factors usually associated with these injuries.

Conclusions

Our findings demonstrate that reliance on clinical or radiologic risk factors alone as indications for screening for BCVI is inadequate. We recommend routine CTA screening for BCVI in all patients who have sustained a mechanism of injury sufficient to warrant either a CT of the cervical spine or a CTA of the chest.

Initial screening test for blunt cerebrovascular injury: Validity assessment of whole-body computed tomography

INTRODUCTION

Our whole-body computed tomography protocol (WBCT), used to image patients with polytrauma, consists of a noncontrast head computed tomography (CT) followed by a multidetector computed tomography (40- or 64- slice) that includes an intravenous, contrast-enhanced scan from the face through the pelvis. WBCT is used to screen for blunt cerebrovascular injury (BCVI) during initial CT imaging of the patient with polytrauma and allows for early initiation of therapy with the goal of avoiding stroke. WBCT has not been directly compared with CT angiography (CTA) of the neck as a screening tool for BCVI. We hypothesize that WBCT is a valid modality to diagnose BCVI compared with neck CTA, thus screening patients with polytrauma for BCVI and limiting the need for subsequent CTA.

METHODS

A retrospective review of the trauma registry was conducted for all patients diagnosed with BCVI from June 2009 to June 2013 at our institution. All injuries, identified and graded on initial WBCT, were compared with neck CTA imaging performed within the first 72 hours. Sensitivity was calculated for WBCT by the use of CTA as the reference standard. Proportions of agreement also were calculated between the grades of injury for both imaging modalities.

RESULTS

A total of 319 injured vessels were identified in 227 patients. On initial WBCT 80 (25%) of the injuries were grade I, 75 (24%) grade II, 45 (14%) grade III, 41 (13%) grade IV, and 58 (18%) were classified as indeterminate: 27 vertebral and 31 carotid lesions. Twenty (6%) of the 319 injuries were not detected on WBCT but identified on subsequent CTA (9 grade I, 7 grade II, 4 grade III); 6 vertebral and 14 carotid. For each vessel type and for all vessels combined, WBCT demonstrated sensitivity rates of over 90% to detect BCVI among the population of patients with at least one vessel injured. There was concordant grading of injuries between WBCT and initial diagnostic CTA in 154 (48% of all injuries). Lower grade injures were more discordant than higher grades (55% vs 13%, respectively; P < .001). Grading was upgraded 8% of the time and downgraded 25%.

CONCLUSION

WBCT holds promise as a rapid screening test for BCVI in the patient with polytrauma to identify injuries in the early stage of the trauma evaluation, thus allowing more rapid initiation of treatment. In addition, in those patients with high risk for BCVI but whose WBCT results are negative for BCVI, neck CTA should be considered to more confidently exclude low-grade injuries.

Treatment of a high large extracranial carotid artery pseudoaneurysm from trauma using a Viabahn graft

Blunt cerebrovascular injury has received much attention over the recent years; however, there is still considerable variability in terms of adequate criteria and treatment strategies. A case report was conducted to discuss the available literature in this disease process relative to the current practices at a level 1 urban trauma center. Screening and treatment methods were discussed. A patient with a high cervical extracranial pseudoaneurysm of the internal carotid artery was treated successfully with endovascular techniques without future neurologic sequalae.

Management of carotid artery trauma

With increased awareness and liberal screening of trauma patients with identified risk factors, recent case series demonstrate improved early diagnosis of carotid artery trauma before they become problematio. There remains a need for unified screening criteria for both intracranial and extracranial carotid trauma. In the absence of contraindications, antithrombotic agents should be considered in blunt carotid artery injuries, as there is a significant risk of progression of vessel injury with observation alone. Despite CTA being used as a common screening modality, it appears to lack sufficient sensitivity. DSA remains to be the gold standard in screening. Endovascular techniques are becoming more widely accepted as the primary surgical modality in the treatment of blunt extracranial carotid injuries and penetrating/blunt intracranial carotid lessions. Nonetheless, open surgical approaches are still needed for the treatment of penetrating extracranial carotid injuries and in patients with unfavorable lesions for endovascular intervention.

Traumatic cerebrovascular injury following severe head injury: proper diagnostic timetable and examination methods

Traumatic cerebrovascular injury (TCVI) is a serious complication of severe head injury, with a high mortality rate. To establish a proper treatment strategy for TCVI, we investigated patients with a high risk of TCVI according to the Guidelines for the Management of Severe Head Injury (hereafter "the Guidelines") to elucidate the validity of the criteria for TCVI in the Guidelines and the appropriate screening timing and methods. Of those transported to our facility between December 2008 and June 2012, 67 individuals with a high risk of TCVI were evaluated to reveal the proper timing and methods of vascular evaluation. Of the 67 patients, 21 had a diagnosis of TCVI based on cerebral angiography, three-dimensional computed tomography angiography (3DCTA), or magnetic resonance imaging (MRI), accounting for 6.4% of all patients with severe head injury and as high as 31.3% of patients with a high risk of TCVI according to the Guidelines. In addition, according to the Glasgow Outcome Scale (GOS), outcomes were three deaths due to primary brain injury, six cases of persistent vegetative state, five cases of severe disability, three cases of moderate disability, and four cases of good recovery. Although 3DCTA is a simple and convenient diagnostic method, cerebral angiography is necessary to evaluate dissecting lesions. If patients have any signs or symptoms of TCVI, as described in the Guidelines, cerebral angiography or 3DCTA should be performed as an initial screening method within 72 hours of admission, followed by cerebral angiography on postadmission Day 14 ± 2 to prevent failed diagnosis.