Identifying patients at risk for intracranial and extracranial blunt carotid injuries

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.

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.

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 rupture of deep neck structures in hanging: two case reports

Injuries to the neck structures are various in case of hanging. Soft tissue lesions generally consist in sternocleidomastoid and subhyoid muscle hemorrhages. Traumatic ruptures of deep neck structures are rare. We report 2 cases of partial and complete ruptures of sternocleidomastoid muscles after suicidal hanging. Both were typical and complete hanging. In 1 case, muscle laceration was associated with common carotid rupture on the same side. Hemorrhage at the rupture site was only found at the microscopic level. Such injuries may result from the ligature's compression and depend on duration of suspension. Heavy body weight, rigid rope material, and fall after a jump may promote their occurrence.

Incidence and trends in the diagnosis of traumatic extracranial cerebrovascular injury in the nationwide inpatient sample database, 2003-2010

Patients with traumatic extracranial cerebrovascular injury (TCVI) comprise about 1% of all blunt trauma admissions according to numerous single-center studies. However, previous studies have used aggressive screening protocols; these studies may not reflect common practice and the overall incidence of TCVI. The annual incidence of the diagnosis of TCVI from 2003 to 2010 was estimated using the Nationwide Inpatient Sample (NIS). For comparison, a systematic review of previous studies of the incidence of the diagnosis of TCVI was conducted. The estimated total number of admissions with TCVI ranged from 1283 to 2652; these admissions represented 0.46-0.95% of all blunt trauma admissions. There was a significant increase in the incidence of TCVI during the study period. A total of 49 studies of TCVI reported incidences of diagnosis ranging from 0.03% to 4.8%. In conclusion, the annual nationwide incidence of the diagnosis of TCVI is increasing. Although NIS incidences of the diagnosis of TCVI are at the low end of the range of previous reports, the increasing incidence in the NIS data likely reflects increasing use of aggressive screening protocols.

Imaging of blunt vascular neck injuries: a clinical perspective

OBJECTIVE

We will review the common injuries and anatomic distributions of blunt cerebrovascular injuries (BCVIs) of the neck, explain the grading criteria, and discuss the corresponding management. Artifacts associated with BCVI on CT will also be examined.

CONCLUSION

Identifying common injury patterns and anatomic distributions associated with BCVI can help decide the grade and management earlier and reduce the risk for potential complications. Recognizing the common artifacts associated with BCVI helps the reader successfully recognize a true BCVI.

Diagnostic accuracy of computed tomographic angiography for blunt cerebrovascular injury detection in trauma patients: a systematic review and meta-analysis

OBJECTIVE

To compare the diagnostic accuracy of computed tomographic angiography (CTA) with digital subtraction angiography (DSA) for blunt cerebrovascular injury (BCVI) detection in trauma patients.

BACKGROUND

Controversy exists as to whether the diagnostic performance of CTA compares favorably with the reference-standard, DSA.

METHODS

We searched electronic databases (1950 to May 22, 2012), article bibliographies, conference proceedings (2008-2011), and clinical trial registries for studies comparing the accuracy of CTA with DSA for BCVI detection in trauma patients. Pooled estimates of sensitivity, specificity, and positive and negative likelihood ratios were calculated using bivariate random effects models.

RESULTS

Eight studies that examined 5704 carotid or vertebral arteries in 1426 trauma patients met inclusion criteria. The pooled sensitivity and specificity for BCVI detection with CTA versus DSA was 66% (95% CI, 49%-79%; I = 80.4%) and 97% (95% CI, 91%-99%; I = 94.6%), respectively. Corresponding pooled positive and negative likelihood ratios were 20.0 (95% CI, 6.9-58.4; I = 87.7%) and 0.35 (95% CI, 0.22-0.56; I = 74.9%), respectively. Although pooled sensitivity varied with the number of available CT slices, the training of interpreting radiologists, and in a pattern suggestive of differences in diagnostic threshold for judging CTA positivity, it remained 80% or less among studies that used scanners with 16 or more slices per rotation and where the CTA was read by neuroradiologists.

CONCLUSIONS

Existing evidence suggests that the diagnostic performance of CTA varies considerably across studies, likely due to an implicit variation in diagnostic threshold across trauma centers. Moreover, although CTA appears to lack sensitivity to adequately rule out BCVI, it may be useful to rule in BCVI among trauma patients with a high pretest probability of injury.

Cerebrovascular dissections: a review. Part II: blunt cerebrovascular injury

Traumatic cerebrovascular injury (TCVI) is present in approximately 1% of all blunt force trauma patients and is associated with injuries such as head and cervical spine injuries and thoracic trauma. Increased recognition of patients with TCVI in the past quarter century has been because of aggressive screening protocols and noninvasive imaging with computed tomography angiography. Extracranial carotid and vertebral artery injuries demonstrate a spectrum of severity, from intimal disruption to traumatic aneurysm formation or vessel occlusion. The most common intracranial arterial injuries are carotid-cavernous fistulae and traumatic aneurysms. Data on the long-term natural history of TCVI are limited, and management of patients with TCVI is controversial. Although antithrombotic medical therapy is associated with improved neurological outcomes, the optimal medication regimen is not yet established. Endovascular techniques have become more popular than surgery for the treatment of TCVI; endovascular options include stenting of dissections, intra-arterial thrombolysis for acute ischemic stroke caused by trauma, and embolization of traumatic aneurysms.

Improving the screening criteria for blunt cerebrovascular injury: the appropriate role for computed tomography angiography

BACKGROUND

Screening criteria and diagnostic methods for blunt cerebrovascular injury (BCVI) are evolving. Using current screening guidelines, up to 20% of injuries are not recognized until symptoms occur, and thus missing the therapeutic window. All patients who meet screening criteria at our institution undergo angiography due to conflicting sensitivity data reported for computed tomographic angiography (CTA). We sought to refine screening criteria for BCVI to optimize patient care.

METHODS

All trauma admissions screened for BCVI over a 29-month period ending May 2009 were analyzed. Thirty-two channel CTA was obtained during initial radiologic evaluation. Patients underwent angiography for conventional screening criteria or abnormal CTA. Demographics, criteria for BCVI screening, fracture patterns, associated injuries, and results of CTA and angiography were analyzed.

RESULTS

A total of 748 patients were screened, 143 injuries (78 carotid and 65 vertebral) were diagnosed in 117 patients (16%). Nineteen of the 117 patients (16%) with BCVI had no conventional criteria and were only screened for CTA abnormalities. One patient developed neurologic symptoms subsequent to initial evaluation with no conventional screening criteria or CTA findings.

CONCLUSIONS

The conventional screening criteria identify most patients with BCVI (84%). CTA as a screening criterion captures nearly all remaining patients before symptoms developing. This allows for detection and treatment of injuries in patients that otherwise would be missed until symptomatic. CTA should be part of the radiologic evaluation for potential head, neck, and facial injuries. Unfortunately, CTA is not sensitive enough to reliably detect injuries, but should be added as a screening criterion. Angiography remains the gold standard for BCVI diagnosis.

Blunt traumatic carotid artery dissection still a pitfall? The rationale for aggressive screening

Introduction

The optimal diagnostic strategy for carotid dissection following blunt trauma is yet unclear. The rationale for aggressive screening will be discussed based on a consecutive case series of blunt traumatic carotid artery dissection (CAD).

Materials and methods

Five patients admitted to our level I trauma center developed severe complications as a consequence of blunt traumatic CAD. The diagnosis of CAD was delayed in all five patients until serious cerebral ischemia occurred. Despite the current awareness that CAD can result from blunt trauma, this type of injury is often overlooked. Clinical and radiological advances have considerably increased the knowledge of incidence and underlying mechanisms of traumatic CAD. This could have implications for case identification and the evaluation of treatment strategies in clinical trials in the future.

Conclusion

Screening may increase the rate of early CAD diagnosis, but it is unclear if screening will also result in early detection of a treatable lesion. Trials have to provide the answer to whether initiating therapy will lead to improvements in the outcome in traumatic CAD. We therefore believe that screening is a basic condition for initiation of future clinical trials.

An update of the role of endovascular repair in blunt carotid artery trauma

Blunt carotid injury (BCAI) is an increasingly recognised entity in trauma patients. Without a prompt diagnosis and a proper treatment, they can result in devastating consequences with cerebral ischaemia rate of 40-80% and mortality rate of 25-60%. Several applied screening protocols and continuously improving diagnostic modalities have been developed to identify patients with BCAI. The appropriate treatment of BCAI still remains controversial and strictly individualised. Besides anti-thrombotic/anticoagulation therapy and surgical intervention, continuously evolving endovascular techniques emerge as an additional treatment option for patients with BCAI. We provide an update on blunt carotid trauma, emphasising the role of endovascular approaches.

Comparison of conservative and operative treatment for blunt carotid injuries: analysis of the National Trauma Data Bank

OBJECTIVES

Blunt carotid injury (BCI) is uncommon but potentially devastating. The best treatment modality for this injury remains undetermined. We conducted this study to better understand the hospital course and treatment outcomes for patients with BCI who received different interventions.

METHODS

BCI and related vascular procedures were identified by ICD-9-CM codes from the National Trauma Data Bank(1) using data gathered from 2002 to 2006. Conservative and operative treatment groups were compared by variables of patient demographics, initial assessment in the emergency department (ED), hospital course, and treatment outcomes. Open surgical and endovascular interventions were further compared.

RESULTS

A total of 842 BCI were identified from 1,633,126 discharged blunt trauma patients (0.05%). Of these, 762 (90.5%) were treated conservatively and 80 (9.5%) received operative intervention. No differences in demographics were observed between these treatment groups. On initial assessment, no differences between conservative and operative treatment groups were noted with regard to vital signs, Glasgow coma scale, presence of drugs or alcohol in blood, or Trauma Related Injury Severity Score survival probability. Significant differences were seen in terms of the presence of a base deficit (-3.1 +/- 6.8 vs -7.6 +/- 8.3; P = .01), likelihood of a positive head computed tomography (CT) scan (58.6% vs 26.1%; P = .003), and total Injury Severity Score (29.8 +/- 13.3 vs 26.1 +/- 14.1; P = .02). Hospital course and treatment outcomes were comparable, with no differences in hospital length of stay (13.4 +/- 15.3 days vs 13.7 +/- 13.6 days; P = .86), total Functional Independence Measure (8.8 +/- 3.3 vs 9.3 +/- 3.1; P = .38), progression of original neurologic insult (7.5% vs 4.6%; P = .61) or mortality (28.1% vs 19%; P = .08). When comparing open surgical to endovascular interventions (46 open, 34 endovascular, including 3 combined), the only significant differences were in the total Injury Severity Score (22.4 +/- 12.2 vs 31.4 +/- 15.4; P = .01) and length of intensive care unit (ICU) and hospital stay (5.0 +/- 6.0 days vs 10.7 +/- 10.4 days; P = .01, and 10.3 +/- 9.2 days vs 19.3 +/- 17.7 days; P = .01). Multivariate regression analysis confirmed that neither Functional Independence Measure (FIM) nor mortality was associated with conservative or operative treatment.

CONCLUSION

BCI is rare and carries a poor prognosis. Operative intervention is not associated with functional improvement or a survival advantage. This study was unable to support that less invasive endovascular treatment improves treatment outcome when compared to open surgery.

Blunt cerebrovascular injury: an evaluation from a major trauma centre

BACKGROUND

Blunt cerebrovascular injury (BCVI), although uncommon, is associated with substantial morbidity and mortality and remains poorly understood. This study was conducted to determine the pattern and outcome of BCVI at a major trauma centre.

METHODS

A retrospective review of all trauma admissions between 1996 and 2004 at Liverpool Hospital, the major trauma service for south-west Sydney, was undertaken using the hospital's computerized trauma registry.

RESULTS

Fourteen of the 7788 (0.18%) admitted blunt trauma patients sustained BCVI. Blunt carotid injury occurred in 10 of 14 and blunt vertebral injury occurred in 4 of 14 patients. Road trauma accounted for 9 of 14 cases. The median time to diagnosis was 2 days (range 1-45 days). The stroke rate was 36%, and the overall mortality was 29%.

CONCLUSION

This study identified BCVI as a relatively infrequent occurrence but with significant mortality and morbidity rates. Practice guidelines for both the screening and management of this patient group need to be developed and introduced in this major trauma centre.

Incidence and pattern of direct blunt neurovascular injury associated with trauma to the skull base

Object

Skull base fractures are often associated with potentially devastating injuries to major neural arteries in the head and neck, but the incidence and pattern of this association are unknown.

Methods

Between April and September 2002, 1738 Level 1 trauma patients were admitted to St. Joseph's Hospital and Medical Center in Phoenix, Arizona. Among them, a skull base fracture was diagnosed in 78 patients following computed tomography (CT) scans. Seven patients had no neurovascular imaging performed and were excluded. Altogether, 71 patients who received a diagnosis of skull base fractures after CT and who also underwent a neurovascular imaging study were included (54 men and 17 women, mean age 29 years, range 1–83 years). Patients underwent CT angiography, magnetic resonance angiography, or digital subtraction angiography of the head and craniovertebral junction, or combinations thereof.

Results

Nine neurovascular injuries were identified in six (8.5%) of the 71 patients. Fractures of the clivus were very likely to be associated with neurovascular injury (p < 0.001). A high risk of neurovascular injury showed a strong tendency to be associated with fractures of the sella turcica–sphenoid sinus complex (p = 0.07).

Conclusions

The risk of associated blunt neurovascular injury appears to be significant in Level 1 trauma patients in whom a diagnosis of skull base fracture has been made using CT. The incidence of neurovascular trauma is particularly high in patients with clival fractures. The authors recommend neurovascular imaging for Level 1 trauma patients with a high-risk fracture pattern of the central skull base to rule out cerebrovascular injuries.

Functional outcome after blunt and penetrating carotid artery injuries: analysis of the National Trauma Data Bank

BACKGROUND

We analyzed the functional outcome at discharge among a cohort of patients suffering traumatic carotid arterial injury (CAI) and compared them with matched controls.

METHODS

CAI were identified by International Classification of Diseases-9 codes from the National Trauma Data Bank. Control groups were matched by age, mechanism, head Abbreviated Injury Scale score, Injury Severity Score, base deficit, and admission Glasgow Coma Scale score. Outcome was assessed using the functional independence measure (FIM) score for feeding, locomotion, and expression. FIM scores for each category ranged from 1 (full assistance required) to 4 (fully independent), with a maximum total FIM score of 12 representing full independence.

RESULTS

There were 967 CAI identified among 474,024 patients for an overall incidence of 0.2%. The mechanism of injury was blunt in 570 (59%) and penetrating in 397 (41%) patients. Seventy-eight percent of penetrating CAI patients were fully independent for locomotion at discharge (FIM = 4) compared with only 37% of blunt patients (p < 0.01). Compared with the control group of similarly injured patients without carotid injury (n = 14,119), the blunt CAI group demonstrated more severe functional disability (FIM < or = 2) at discharge for feeding, expression, and locomotion. Fifty-five percent of blunt control patients were discharged fully independent (FIM total = 12) compared with only 33% of blunt CAI (odds ratio= 2.5; p < 0.01). The penetrating CAI group showed no significant difference in severe disability for feeding, expression, or locomotion compared with controls. However, 80% of penetrating control patients were discharged fully independent (FIM total = 12) compared with only 67% of patients with penetrating CAI (odds ratio = 2.0; p = 0.01).

CONCLUSION

Blunt CAI is associated with more severe functional disability at discharge than penetrating CAI. Even when compared with a similarly injured control group, blunt CAI results in significant additional severe functional disabilities in feeding, expression, and locomotion.

Utility of Screening for Blunt Vascular Neck Injuries with Computed Tomographic Angiography

PURPOSE

To prospectively study the impact of implementing a computed tomographic angiography (CTA)-based screening protocol on the detected incidence and associated morbidity and mortality of blunt vascular neck injury (BVNI).

METHODS

Consecutive blunt trauma patients admitted to a single tertiary trauma center and identified as at risk for BVNI underwent admission CTA using an eight-slice multi-detector computed tomography scanner. The detected incidence, morbidity, and mortality rates of BVNI were compared with those measured before CTA screening. A logistic regression model was also applied to further evaluate potential risk factors for BVNI.

RESULTS

A total of 1,313 blunt trauma patients were evaluated. One hundred seventy screening CTAs were performed, of which 33 disclosed abnormalities. Twenty-three were evaluated angiographically, of which 15 were considered to have significant BVNIs, as were 4 of the 10 patients with abnormal CTAs and no angiogram. The incidence of angiographically proven BVNIs in our series was 1.1%. If four patients who were treated for BVNIs based on CTA alone are included, the incidence rises to 1.4%. This is significantly higher than the 0.17% incidence before screening (p < 0.001). In addition, the delayed stroke rate and injury-specific mortality fell significantly from 67% to 0% (p < 0.001) and 38% to 0% (p = 0.002), respectively. Overall mortality also fell significantly, from 38% to 10.5% (p = 0.049). Univariate logistic regression identified the presence of cervical spine injury as a significant predictor of BVNI (p < 0.001).

CONCLUSION

CTA screening increases the detected incidence of BVNI 8-fold, with rates similar to angiographically based screening protocols. CTA screening significantly decreases BVNI-related morbidity and mortality in an efficient manner, underlying its utility in the early diagnosis of this injury.

Current Diagnosis and Management of Blunt Internal Carotid Artery Injury

BACKGROUND

Blunt carotid artery injury (BCI) is a rare but potentially devastating injury. When undiagnosed it can result in severe disability or death.

METHODS

A Medline-based literature search was performed using key words 'blunt carotid injury' and cross-referenced with further original papers obtained from the references from this search.

RESULTS AND CONCLUSIONS

The incidence of BCI is very low. However, given the serious consequences of a missed injury, recent efforts have focussed on targeted screening for this injury in trauma patients. Conventional angiography remains the investigation of choice but may be superceded in the future by non-invasive methods such as magnetic resonance angiography or CT angiography. Operative intervention is rarely required and anti-coagulation remains the treatment of choice where dissection or pseudoaneurysm is diagnosed. The role of anti-platelet therapy is currently being investigated. Endovascular management using stents has been described but medium to long term results are not yet available.

Diagnosis of blunt cerebrovascular injuries

PURPOSE OF REVIEW

Blunt cerebrovascular injuries (BCVI) are being increasingly recognized. The optimal criteria for screening, and the best diagnostic test, remain a matter of controversy. This review analyzes the available literature to propose management guidelines for the diagnosis of BCVI.

RELEVANT FINDINGS

A number of centers are screening asymptomatic patients for BCVI. The criteria vary from center to center. The incidence of injuries diagnosed is proportional to the breadth of screening criteria. Noninvasive diagnostic modalities such as duplex ultrasonography, computed tomographic angiography, and magnetic resonance angiography have been proposed as screening tools. Although they are all capable of identifying many injuries, prospective comparisons reveal inaccuracies.

SUMMARY

Screening for BCVI is appropriate. Institutions should adopt formal criteria, recognizing that more restrictive criteria are likely to miss injuries. Noninvasive modalities must be used with caution, because they have been found to be inferior to arteriography.