The devastating potential of blunt vertebral arterial injuries

Unsuspected vascular trauma: blunt arterial injuries

Blunt arterial injury provides a tremendous challenge to the emergency physician and traumatologist. The overall incidence of these injuries, even with more modern and aggressive screening, is low. Often, they are clinically occult on initial presentation, and untreated, they frequently result in devastating consequences. Great potential exists, however, for averting these deadly consequences by recognizing patterns of injury, prompting expedient diagnosis by rapidly obtaining the appropriate diagnostic study and providing opportunity for specific therapy under the direction of the trauma surgeon.

Helical computed tomographic angiography: an excellent screening test for blunt cerebrovascular injury

BACKGROUND

Blunt cerebrovascular injury (BCVI) carries a high morbidity and mortality, especially when diagnosis is delayed. Recent studies have shown that increased recognition of these injuries is achieved with prompt screening, allowing for early treatment and better outcome. Controversy still exists, however, on the best screening test. This study was used to evaluate the role of helical computed tomographic angiography (CTA) of the carotid and vertebral arteries in the early screening of BCVI.

METHODS

All patients deemed at risk for BCVI underwent CTA within 24 hours of admission. Patients with a negative CTA test underwent no further radiologic evaluation of the cerebral vasculature. Those patients with positive or equivocal CTA results underwent four-vessel cerebral arteriography as a confirmatory test. Data were collected on the radiologic interpretation of all studies and patient clinical course.

RESULTS

Four hundred eighty-six patients fulfilled the criteria for screening and underwent CTA. Nineteen patients were diagnosed with 25 BCVIs during the period of study. There were 7 carotid injuries and 18 vertebral injuries. Eighteen of 19 patients with BCVI were screened with CTA. Seventeen patients were asymptomatic at the time of screening. Results of CTA for BCVI were as follows: sensitivity, 100%; specificity, 94.0%; prevalence (screened patients), 3.7%; positive predictive value, 37.5%; and negative predictive value, 100%. Except for one patient in whom the CTA was clearly misinterpreted by the radiologist, no patient with a negative CTA examination was subsequently found to have a missed injury.

CONCLUSION

CTA is an excellent test with which to screen for BCVI.

Vascular Injuries of the Neck and Thoracic Inlet: Helical CT–Angiographic Correlation

Imaging evaluation of patients suspected to have arterial injuries of the neck has traditionally been performed by using conventional angiography as an alternative to surgical exploration. However, there has been recent interest in and growing experience with use of noninvasive imaging techniques for the assessment of vascular injuries. Contrast material-enhanced helical computed tomographic (CT) angiography is increasingly being used to evaluate trauma patients in stable condition who are at risk for vascular injuries. It allows characterization of traumatic vascular lesions in the neck such as partial or complete occlusion, pseudoaneurysm, intimal flap, dissection, and arteriovenous fistula. In the same setting, CT angiography provides valuable additional information about the cervical soft tissues, aerodigestive tract, spinal canal, and spinal cord. In cases of penetrating gunshot injuries, the trajectory of the bullet and the locations of fragments can be assessed. CT angiography may be limited by artifacts from metallic fragments and occasionally by abundant soft-tissue air or streak artifacts in the shoulders. In such cases, conventional angiography is necessary for optimal assessment of vascular injuries. CT angiography can be used as a noninvasive alternative to conventional angiography in patients suspected to have vascular injuries but without initial indications for surgical treatment.

MR angiography of the extracranial circulation

In this article, the authors present a brief history of MR angiography (MRA) of the neck with emphasis on the techniques developed, particularly recent ones, to improve image quality. The goal of MRA is to eventually replace catheter angiography. The use of MRA, particularly contrast enhanced MRA with regards to pathology (atherosclerotic disease/plaque formation, dissection and post-traumatic aneurysm) involving the extra-cranial carotid and vertebral arteries is addressed. The authors also comment on computed tomographic angiography and sonography and how they compare with contrast enhanced MRA when pertinent.

Isolated contralateral vertebral artery injury in a stab wound to the neck

Ipsilateral vertebral artery injuries are a rare entity following trauma to the neck. We discuss the first case of an isolated right vertebral artery injury in a patient with a left stab wound. The patient required bilateral neck explorations and, due to massive bleeding, a median sternotomy in order to obtain control of the proximal segment of the right vertebral artery. We emphasize the importance for trauma surgeons to be familiar with basic but important vascular exposures. The anatomy, surgical exposure, and management of these rare injuries are discussed.

Specific Occupant and Collision Characteristics Are Associated with Motor Vehicle Collision-Related Blunt Cerebrovascular Artery Injury

BACKGROUND

Blunt cerebrovascular artery injury (BCI) remains difficult to diagnose but is recognized with increasing frequency after motor vehicle collisions (MVCs). Failure to detect this injury in a timely fashion can be devastating. Criteria that can be used to heighten the suspicion of this injury have been suggested; however, more encompassing screening has been recommended. To address this need, we sought to describe occupant, vehicle, and collision characteristics among MVC occupants who sustained a BCI.

METHODS

All cases of BCI identified in the National Automotive Sampling System Crashworthiness Data System, a national probability sample of passenger vehicles involved in police-reported tow-away MVCs, between 1993 and 2001 were selected. Information on occupant (e.g., demographics, seating position, and restraint use), collision (e.g., collision type and severity), and vehicle characteristics were obtained and summarized using descriptive statistics.

RESULTS

Nine-hundred forty individuals with BCI were identified in the Crashworthiness Data System data files. Over half were belted (57.4%) and 82.3% had airbag deployment; 16.2% were partially or completely ejected from the vehicle. Head and thoracic injuries were common (44.4% and 40.8%, respectively); 27.8% sustained a cervical spine fracture and 21.0% sustained a soft-tissue injury to the neck. The mean Injury Severity Score was 33.6. The case fatality rate was 44.5%. The majority of BCI occupants were drivers (76.0%). Among belted occupants, the lap/shoulder was the most commonly attributed as the injury source (61.4%). Among unbelted occupants, frequent injury sources included air bags (15.0%), windshield (13.7%), and other interior objects. With respect to collision characteristics, the average change in velocity (Delta V) was 43.3 km/h. The majority of collisions were frontal (76.2%).

CONCLUSION

This study indicates that BCI is both a rare and lethal injury typified by specific occupant and collision characteristics. These characteristics provide insight as to the cause of this injury that may aid in the evaluation and management of the blunt trauma patient at risk for BCI.

Cervical Spine Fracture Patterns Predictive of Blunt Vertebral Artery Injury

BACKGROUND

Aggressive screening for blunt cerebrovascular injury (BCVI) has uncovered an astonishing incidence of vertebral artery injuries (VAIs) and associated stroke rate. Stroke incidence is reduced with early recognition and prompt anticoagulation. Because of the proximity of the cervical spine and vertebral arteries, we queried whether all patients with cervical spine fractures required arteriography to rule out VAI.

METHODS

Four-vessel cerebrovascular angiography remains the standard screening test for patients at risk for BCVI. Patients undergoing angiographic screening for blunt cerebrovascular injuries have been prospectively followed at our regional trauma center since January 1990; however, in January 1996, we began aggressive screening based on injury patterns.

RESULTS

Ninety-two patients with vertebral artery injuries were identified during the study period from January 1996 to June 2002. Two patients with vertebral injuries had minor cervical fractures, a C6 body fracture and a C7 spinous process/laminar fracture; both underwent diagnostic angiography for injury mechanism. Of the 21 patients without cervical spine fracture, angiographic screening for BCVI was performed for neurologic symptoms (11 patients), basilar skull fracture (6 patients), or severe facial fractures (4 patients). Cervical spine fracture was the sole indication for VAI in 69 patients. The fracture patterns were subluxations in 38 patients (55%) or extension of the fracture through the foramen transversarium in 18 patients (26%). The remaining injuries (18%) were located in the upper cervical spine: isolated C1 arch in eight patients and C2/3 body fractures in five patients.

CONCLUSION

Blunt vertebral artery injury is associated with complex cervical spine fractures involving subluxation, extension into the foramen transversarium, or upper C1 to C3 fractures. Routine screening should incorporate these findings to maximize yield while limiting the use of invasive procedures.

Head and neck injuries in fatal motorcycle collisions as determined by detailed autopsy

Detailed layer-by-layer autopsy of the head and neck was performed on a prospective series of 73 fatally injured motorcyclists in order to identify occult injuries, particularly soft tissue neck injuries such as hemorrhage of vertebral and carotid arteries. The fatal cases were gathered as part of a larger study of 1,082 on-scene in-depth motorcycle crash investigations in Thailand. Detailed neck dissection was done on nearly all fatal cases. Injuries were coded using the 1990 revision of the Abbreviated Injury Scale (AIS 90) and an Injury Severity Score (ISS) was determined for each case. Additional AIS codes are proposed for neck injuries that were often identified during the detailed autopsy procedures, but which are not listed explicitly among existing AIS codes. Helmet use was determined based on analysis of injury patterns and helmet damage with consideration also given to witness statements. Both helmeted and unhelmeted motorcyclists showed a high frequency of occult neck injuries such as hemorrhages in the carotid sheath or surrounding the vertebral arteries, phrenic nerve, or brachial plexus. These soft tissue neck injuries sometimes accompanied more obvious injuries to cervical vertebrae or spinal cord, but about one-third of riders had no obvious injury to suggest the presence of occult neck injury. Twenty-eight motorcyclists had been wearing a helmet at the start of the collision sequence, but only nine helmets remained in place through the entire collision event. Helmeted riders showed more severe somatic (below-the-neck) injuries than unhelmeted riders, suggesting helmeted riders are less likely to die in low-threat accidents with somatic injuries below AIS-3. The most significant finding of this study was the identification of serious internal neck injuries despite the absence of external physical evidence of trauma to the neck. Virtually all riders with significant head injuries showed some of these soft tissue neck injuries. Approximately one-third of the critically injured riders who survived at least a few hours before death showed serious occult soft tissue neck injuries.

Neurotrauma: the role of CT angiogram

Cerebrovascular injuries can occur in blunt or penetrating head and neck trauma. A high index of suspicion based on mechanism of injury and clinical assessment warrants screening for intracranial and extracranial vascular lesions. Conventional angiogram has been and remains the gold standard for diagnosis of these injuries, but computerized tomography angiography offers a fast, noninvasive method of imaging for neurotrauma patients. Advantages and disadvantages of each modality are discussed.

Blunt carotid artery injury

Blunt carotid artery injury is an uncommon injury with a potentially devastating outcome. Although treatment is often unhelpful for an established neurologic deficit, there is frequently a delay between the episode of trauma and the onset of neurology. This delay provides a window of opportunity where early detection and intervention may significantly improve outcome and prevent lifelong morbidity in a generally young trauma patient population. This paper will review the literature regarding incidence, outcome, treatment options and optimal methods of diagnosis for this lesion. The following synopsis of a case seen at Royal Perth Hospital Emergency Department illustrates several of the classical features of blunt carotid injury, including delayed presentation and pattern of associated injuries. The patient, a 19-year-old female, presented following a single vehicle motor crash. On arrival she had a Glasgow Coma Scale (GCS) of 14 with no focal neurologic deficit. Multiple injuries were identified, including a large scalp laceration, a compound fracture of the mandible, pneumothorax, sternal fracture, subcapsular haematoma of the liver, and a knee laceration. Initial computed tomography (CT) scan of the head was normal. Twenty hours after the motor vehicle accident the patient's conscious state deteriorated to GCS 9. Repeat CT head demonstrated changes consistent with a left middle cerebral artery infarct. Cerebral angiography revealed traumatic dissection of the left internal carotid artery with complete occlusion of the lumen just distal to its origin. After 13 days in the intensive care unit and 2.5 months in the rehabilitation unit, she was discharged with a persistent severe receptive and expressive aphasia, as well as a dense right hemiparesis. She is now living at home with community supports.

Noninvasive diagnosis of blunt cerebrovascular injuries: a preliminary report

BACKGROUND

In light of their potential for devastating consequences, a liberalized screening approach for blunt cerebrovascular injuries (BCVI) is becoming increasingly accepted. The "gold standard" for diagnosis of BCVI is arteriography; however, noninvasive diagnostic alternatives offer clear advantages. Recent series have demonstrated the ability of computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) to identify BCVI, but have not compared their accuracy with arteriography. We hypothesized that CTA or MRA could reliably identify BCVI, obviating the need for arteriography. The purpose of this study was to determine the accuracy of CTA and MRA in identifying BCVI in asymptomatic patients.

METHODS

Asymptomatic patients meeting criteria for BCVI screening underwent arteriography, according to our institutional standard. A subset of patients requiring computed tomographic scanning underwent CTA; a subset of patients requiring magnetic resonance imaging underwent MRA. All of the studies were interpreted by radiologists in a blinded manner. Data were analyzed for sensitivity and specificity.

RESULTS

Forty-six patients underwent both CTA and arteriography. Of 23 with a normal CTA examination, 7 (30%) had BCVI on arteriography. Of 23 with an abnormal CTA examination, 8 (35%) had a normal arteriogram. The sensitivity, specificity, positive predictive value, and negative predictive value of CTA were 68%, 67%, 65%, and 70%, respectively. CTA missed 55% of grade I injuries, 14% of grade II injuries, and 13% of grade III injuries. Sixteen patients underwent both MRA and arteriography. One (11%) had a false-negative MRA result, and four (57%) had false-positive MRA results (75% sensitivity, 67% specificity, 43% positive predictive value, 89% negative predictive value).

CONCLUSION

CTA and MRA can identify BCVI, but they miss grade I, II, and III injuries. Future technical modifications may improve their accuracy. A prospective multicenter trial is warranted to define the capabilities and limitations of these noninvasive modalities. In the interim, arteriography remains the gold standard for diagnosis, but if arteriography is not available, CTA or MRA should be used to screen for BCVI in patients at risk.

Subclavian artery injury, vertebral artery dissection, and arteriovenous fistulae following attempt at central line placement

Vertebral artery dissection and arteriovenous fistulas are uncommon complications of vascular access and angiographic procedures. There are several cases of iatrogenic vertebral artery dissection secondary to central line placement reported in the literature. Only a few iatrogenic arteriovenous fistulae have been reported, but none also involving the dissection of the vertebral artery. In each of these cases, the fistulae were treated by direct ligation of the fistulous communication. We present an unusual case of an iatrogenic arteriovenous fistula and vertebral artery dissection as a result of left subclavian central line placement. The left subclavian artery and associated fistula were successfully repaired using a self-expanding endovascular graft.

Prospective screening for blunt cerebrovascular injuries: analysis of diagnostic modalities and outcomes

OBJECTIVE

To prospectively examine outcomes associated with an aggressive screening protocol for blunt cerebrovascular injury (BCVI), and to compare the accuracy of computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) versus conventional angiography with respect to BCVI diagnosis.

SUMMARY BACKGROUND DATA

In the past 5 years, BCVI (carotid and vertebral arteries) has been recognized with increasing frequency. Initial studies described blunt carotid injuries and their associated morbidity, while more recent reports have established the devastating potential of blunt vertebral injuries. It has been suggested that early diagnosis and anticoagulation will improve outcomes and that less-invasive diagnostic techniques than conventional angiography are desirable for screening. However, there are neither established screening criteria nor studies comparing optimal diagnostic modalities.

METHODS

The screened population included all patients with cervical spine fractures, LeFort II or III facial fractures, Horner's syndrome, skull base fractures involving the foramen lacerum, neck soft tissue injury, or neurological abnormalities unexplained by intracranial injuries. Patients underwent screening with four-vessel cerebral angiography. During the first half of the study, patients also underwent helical CTA. Selected patients during this same period underwent MRA. At the time of diagnosis, anticoagulant or antiplatelet therapy was instituted unless clinically contraindicated. Results of this screening protocol were compared to a previously published cohort with cerebrovascular injuries (1995-1999) from the authors' institution.

RESULTS

Two hundred sixteen patients were screened over a 2-year period (3.5% of all blunt trauma admissions). Angiography identified 24 patients with carotid artery injuries (CAI) and 43 patients with vertebral artery injuries (VAI) for an overall screening yield of 29%. While the incidence of CAI remained similar between the current study and the previous study group, the incidence of VAI diagnosis increased. Stroke rates in those with CAI were also similar between the two periods. The stroke rate in VAI, however, was markedly lower at 0% as compared to 14% in the previous group. Comparison of CTA and MRA with cerebral angiography in 143 patients demonstrated sensitivities of 47% and 50%, respectively, for CAI; sensitivities were 53% (CTA) and 47% (MRA) for VAI.

CONCLUSIONS

Aggressive screening of patients with blunt head and neck trauma identified an incidence of BCVI in 1.03% of blunt admissions. Early identification, which led to early treatment, significantly reduced stroke rates in patients with VAI, but provided no outcome improvement with CAI. More encompassing screening may be required to improve outcomes for patients with CAI. However, less-invasive diagnostic techniques (CTA and MRA) are inadequate for screening. Technological advances are necessary before abandonment of conventional angiography, which remains the standard for diagnosis.

Prospective screening for blunt cerebrovascular injuries: analysis of diagnostic modalities and outcomes

OBJECTIVE

To prospectively examine outcomes associated with an aggressive screening protocol for blunt cerebrovascular injury (BCVI), and to compare the accuracy of computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) versus conventional angiography with respect to BCVI diagnosis.

SUMMARY BACKGROUND DATA

In the past 5 years, BCVI (carotid and vertebral arteries) has been recognized with increasing frequency. Initial studies described blunt carotid injuries and their associated morbidity, while more recent reports have established the devastating potential of blunt vertebral injuries. It has been suggested that early diagnosis and anticoagulation will improve outcomes and that less-invasive diagnostic techniques than conventional angiography are desirable for screening. However, there are neither established screening criteria nor studies comparing optimal diagnostic modalities.

METHODS

The screened population included all patients with cervical spine fractures, LeFort II or III facial fractures, Horner's syndrome, skull base fractures involving the foramen lacerum, neck soft tissue injury, or neurological abnormalities unexplained by intracranial injuries. Patients underwent screening with four-vessel cerebral angiography. During the first half of the study, patients also underwent helical CTA. Selected patients during this same period underwent MRA. At the time of diagnosis, anticoagulant or antiplatelet therapy was instituted unless clinically contraindicated. Results of this screening protocol were compared to a previously published cohort with cerebrovascular injuries (1995-1999) from the authors' institution.

RESULTS

Two hundred sixteen patients were screened over a 2-year period (3.5% of all blunt trauma admissions). Angiography identified 24 patients with carotid artery injuries (CAI) and 43 patients with vertebral artery injuries (VAI) for an overall screening yield of 29%. While the incidence of CAI remained similar between the current study and the previous study group, the incidence of VAI diagnosis increased. Stroke rates in those with CAI were also similar between the two periods. The stroke rate in VAI, however, was markedly lower at 0% as compared to 14% in the previous group. Comparison of CTA and MRA with cerebral angiography in 143 patients demonstrated sensitivities of 47% and 50%, respectively, for CAI; sensitivities were 53% (CTA) and 47% (MRA) for VAI.

CONCLUSIONS

Aggressive screening of patients with blunt head and neck trauma identified an incidence of BCVI in 1.03% of blunt admissions. Early identification, which led to early treatment, significantly reduced stroke rates in patients with VAI, but provided no outcome improvement with CAI. More encompassing screening may be required to improve outcomes for patients with CAI. However, less-invasive diagnostic techniques (CTA and MRA) are inadequate for screening. Technological advances are necessary before abandonment of conventional angiography, which remains the standard for diagnosis.

Blunt vascular neck injuries: diagnosis and outcomes of extracranial vessel injury

BACKGROUND

Blunt vascular neck injuries (BVNIs) are rare, often occult, and potentially devastating injuries. The purpose of this study was to identify a high-risk group, which would benefit from screening.

METHODS

Patients with BVNIs were identified from our trauma registry and charts were reviewed. Potential risk factors for BVNI were evaluated by univariate and multivariate logistic regression.

RESULTS

Thirty-one BVNIs were identified in 22 patients. The stroke rate was 60% and the mortality rate was 25%. Univariate analysis showed Glasgow Coma Scale score < or = 8, head injury (Abbreviated Injury Scale [AIS] score > or = 3), basal skull fracture, facial injury, other neck injury, thorax injury (AIS score > or = 3), abdominal injury, and cervical spine injury to be significant (p < 0.05). The multivariate predictive model had two predictors remaining significant: thorax injury (AIS [thorax] score > or = 3) and Glasgow Coma Scale score < or = 8.

CONCLUSION

Screening should be undertaken for patients at increased risk for BVNI: those with risk factors identified in our regression analysis and factors previously reported.

Traumatic vascular injuries and their management

Traumatic vascular injury to the intracranial and extracranial circulation can be sequelae of blunt, penetrating, or iatrogenic insults to the head, face, or neck. Treatment options include conservative medical management, or more invasive surgical or endovascular therapy. The appropriate treatment depends on the risk-benefit ratio of each option considering the natural history of each. Injuries include mild intimal irregularities, intimal flaps, pseudoaneurysms, fistulas, and occlusions. Need for treatment is partly determined by the collateral circulation to the brain, and the degree to which the lesion is thrombogenic. Advances in endovascular devices and techniques provide us with less invasive alternatives to surgery intervention or allow the interventionalist to treat lesions not treatable by any other modality.

Treatment-related outcomes from blunt cerebrovascular injuries: importance of routine follow-up arteriography

OBJECTIVE

To assess the impact of routine follow-up arteriography on the management and outcome of patients with acute blunt cerebrovascular injuries (BCVI).

SUMMARY BACKGROUND DATA

During the past 5 years there has been increasing recognition of BCVI, but the management of these lesions remains controversial. The authors previously proposed a grading system for BCVI, with grade-specific management guidelines. The authors have noted that a significant number of injuries evolve within 7 to 10 days, warranting alterations in therapy.

METHODS

A prospective database of a regional trauma center's experience with BCVI has been maintained since 1990. A policy of arteriographic screening for BCVI based on injury mechanism (e.g., cervical hyperextension) and injury patterns (e.g., cervical and facial fractures) was instituted in 1996. A grading system was devised to develop management protocols: I = intimal irregularity; II = dissection/flap/thrombus; III = pseudoaneurysm; IV = occlusion; V = transection.

RESULTS

From June 1990 to October 2001, 171 patients (115 male, age 36 +/- 1 years) were diagnosed with BCVI. Mean injury severity score was 28 +/- 1; associated injuries included brain (57%), spine (44%), chest (43%), and face (34%). Mechanism was motor vehicle crash in 50%, fall in 11%, pedestrian struck in 11%, and other in 29%. One hundred fourteen patients had 157 carotid artery injuries (43 bilateral), and 79 patients had 97 vertebral artery injuries (18 bilateral). The breakdown of injury grades was 137 grade I, 52 grade II, 32 grade III, 25 grade IV, and 8 grade V. One hundred fourteen (73%) carotid and 65 (67%) vertebral arteries were restudied with arteriography 7 to 10 days after the injury. Eight-two percent of grade IV and 93% of grade III injuries were unchanged. However, grade I and II lesions changed frequently. Fifty-seven percent of grade I and 8% of grade II injuries healed, allowing cessation of therapy, whereas 8% of grade I and 43% of grade II lesions progressed to pseudoaneurysm formation, prompting interventional treatment. There was no significant difference in healing or in progression of injuries whether treated with heparin or antiplatelet therapy or untreated. However, heparin may improve the neurologic outcome in patients with ischemic deficits and may prevent stroke in asymptomatic patients.

CONCLUSIONS

Routine follow-up arteriography is warranted in patients with grade I and II BCVIs because most of these patients (61% in this series) will require a change in management. A prospective randomized trial will be necessary to identify the optimal treatment of BCVI.

Internal carotid artery pseudoaneurysm masquerading as a peritonsillar abscess

Blunt carotid arterial injuries are uncommon. Motor vehicle crashes are the most frequent cause, but this type of vascular injury can be secondary to any direct blow to the neck, intraoral trauma, or strangulation. Types of vascular injuries include dissection, pseudoaneurysm, thrombosis, rupture, and arteriovenous fistula formation. Patients with pseudoaneurysm of the internal carotid artery will usually present with neurologic complaints, ranging from the minor to complete stroke. On physical examination, neck hematoma, bruits, pulsatile neck mass, or a palpable thrill may be found. However, in 50% of cases, no external signs of neck trauma are observed. Onset of symptoms may occur within a few hours to several months after the initial injury. Angiography is considered the gold standard for diagnosis, but carotid Doppler ultrasound recently has been shown to be very sensitive in detecting these types of injuries. Treatment of pseudoaneurysm is often surgical, with endovascular stenting.

Management of vertebral artery injuries after nonpenetrating cervical trauma

DIAGNOSTIC

STANDARDS

There is insufficient evidence to support diagnostic standards.

GUIDELINES

There is insufficient evidence to support diagnostic guidelines.

OPTIONS

Conventional angiography or magnetic resonance angiography is recommended for the diagnosis of vertebral artery injury after nonpenetrating cervical trauma in patients who have complete cervical spinal cord injuries, fracture through the foramen transversarium, facet dislocation, and/or vertebral subluxation.

TREATMENT

STANDARDS

There is insufficient evidence to support treatment standards.

GUIDELINES

There is insufficient evidence to support treatment guidelines.

OPTIONS

Anticoagulation with intravenous heparin is recommended for patients with vertebral artery injury who have evidence of posterior circulation stroke. Either observation or treatment with anticoagulation in patients with vertebral artery injuries and evidence of posterior circulation ischemia is recommended. Observation in patients with vertebral artery injuries and no evidence of posterior circulation ischemia is recommended.

Vertebral artery injuries

Vertebral artery injuries are identified more frequently now than in the past for both penetrating and blunt trauma. This is as a result of increased suspicion and awareness, liberal use of color flow Doppler, CT angiography, and traditional four-vessel angiography. The vast majority of patients who are not exsanguinating at the time of presentation can be managed nonoperatively or by angiographic embolization. Operative management should be reserved only for patients with severe active bleeding or when interventional radiology fails. The surgical exposure is complex and demands excellent knowledge of the local anatomy.

Liberalized screening for blunt carotid and vertebral artery injuries is justified

BACKGROUND

Current literature suggests that blunt carotid injuries (BCIs) and vertebral artery injuries (BVIs) are more common than once appreciated. Screening criteria have been suggested, but only one previous study has attempted to identify factors that predict the presence of BCI/BVI. This current study was conducted for two reasons. First, we wanted to determine the incidence of BCI/BVI in our institution. Second, we wanted to determine the incidence of abnormal four-vessel cerebral angiograms ordered for injuries and signs believed to be associated with BCI/BVI and thus to determine whether the screening protocol developed was appropriate.

METHODS

From August 1998, we used liberalized screening criteria for patients who were prospectively identified and suspected to be at high risk for BCI/BVI if any of the following were present: anisocoria, unexplained mono-/hemiparesis, unexplained neurologic exam, basilar skull fracture through or near the carotid canal, fracture through the foramen transversarium, cerebrovascular accident or transient ischemic attack, massive epistaxis, severe flexion or extension cervical spine fracture, massive facial fractures, or neck hematoma. Four-vessel cerebral angiograms were used for screening for BCI/BVI.

RESULTS

Over the 18-month study period, 48 patients were angiographically screened, with 21 patients (44%) being identified as having a total of 19 BCIs and 10 BVIs. Nine patients had unilateral carotid artery injuries and three patients had bilateral carotid artery injuries. Vertebral artery injuries were unilateral in six patients. One patient had bilateral carotid artery injuries and a unilateral vertebral artery injury. One patient had a unilateral carotid artery injury and a unilateral vertebral artery injury, and one patient had a unilateral carotid artery injury and bilateral vertebral artery injuries. During the same study period, 2,331 trauma patients were admitted, with 1,941 (83%) secondary to blunt trauma. The overall incidence of BCI/BVI was 1.1%. The frequency of abnormal angiograms ordered for cerebrovascular accident or transient ischemic attack, massive epistaxis, or severe cervical spine fractures was 100%. The frequency of abnormal angiograms ordered for the other indications was as follows: fracture through foramen transversarium, 60%; unexplained mono- or hemiparesis, 44%; basilar skull fracture, 42%; unexplained neurologic examination, 38%; anisocoria, 33%; and severe facial fractures, 0%.

CONCLUSION

The liberalized screening criteria used in this study were appropriate to identify patients with BCI/BVI. This study suggests BCI/BVI to be more common than previously believed and justifies that screening should be liberalized.

Blunt cerebrovascular injuries: diagnosis and treatment

BACKGROUND

Blunt cerebrovascular injuries (BCVIs), once thought to be rare, have been recognized with increasing frequency in recent years. An incidence of 0.33% for carotid artery injury (CAI) was noted from our institution, with 24% stroke-related mortality. Vertebral artery injury (VAI) has been thought both rare and of questionable significance. Incidence, associated injury patterns, and outcomes were examined during a period of aggressive screening (four-vessel angiography).

METHODS

Patients with BCVI were identified from the registry of a Level I trauma center over a 5-year period (1995-1999).

RESULTS

One hundred thirty-nine BCVIs were identified in 96 patients: 75 were CAIs (14 bilateral), 64 were VAIs (14 bilateral), and 15 patients had both CAI and VAI. The incidence of CAI was 0.5% of all blunt trauma admissions, significantly higher than our earlier experience (p < 0.0002), whereas that for VAI was 0.4%. Thirty-four percent of CAIs were diagnosed because of ischemic changes and 38% because of injury pattern (neck, Horner syndrome, basilar skull fracture); only 12% of VAIs were diagnosed because of posterior circulation ischemia, with 64% because of injury pattern (cervical spine, soft tissue, facial fracture). Stroke-related mortality for CAI was 13%, and that for VAI was 4%. Forty-three of the 75 CAIs were treated (anticoagulation/antiplatelet) before development of ischemia. Thirty-nine of the 50 VAI patients were treated before development of ischemia. Stroke rate for CAI was 31% (hemiplegia/hemiparesis) and for VAI was 14% (brain stem dysfunction). Stroke rate for treated vessels (heparin, antiplatelet therapy) with CAI was 6.8% compared with 64% in untreated vessels (p < 0.001). Treated patients with VAI had a stroke rate of 2.6%, whereas untreated patients developed stroke 54% of the time.

CONCLUSION

Increased awareness and aggressive screening have resulted in significantly increased incidence of diagnosis of CAI, with associated lower stroke-related mortality. VAIs have been noted with similar incidence, and though the stroke rate is lower with VAI, stroke outcomes are generally catastrophic. Anticoagulation therapy is effective for both varieties of BCVI.

Cerebrovascular trauma

Cerebrovascular trauma includes a wide variety of injuries, including dissections, traumatic aneurysms, arteriovenous fistulas, and vascular occlusions. These entities, which are often underdiagnosed, can produce devastating neurologic complications. This article reviews the clinical and radiographic presentations of vascular trauma to increase awareness of these injuries and improve our ability to detect and treat them.

The high morbidity of blunt cerebrovascular injury in an unscreened population: more evidence of the need for mandatory screening protocols

BACKGROUND

Blunt cerebrovascular injuries are rare injuries causing substantial morbidity and mortality. The appropriate screening methods and treatment options for these injuries are controversial. We examined our experience with these injuries at a community Level I Trauma center over a 51 month period.

STUDY DESIGN

A retrospective review and analysis was done of all patients with the diagnosis of a blunt cerebrovascular injury during this period.

RESULTS

Fourteen patients had blunt carotid injury (0.40%) and three had blunt vertebral injury (0.09%) out of 3,480 total blunt admissions. The overall incidence of blunt cerebrovascular injury was 0.49%. The most common associated injuries were to the head (59%) and chest (47%) regions. The overall mortality rate was 59% (10 of 17), with death occurring in 8 of 14 (57%) blunt carotid injury patients and 2 of 3 (67%) blunt vertebral injury patients. Eight of ten (80%) deaths were directly attributable to the blunt cerebrovascular injury. Median time until diagnosis was 12.5 h (range 1-336 h) for the entire group and 19.5 h for nonsurvivors. Diagnosis was delayed > 24h in 7 patients and > 48h in 5 patients. All five patients whose diagnoses were delayed > 48 h developed complications, and four (80%) of these patients died.

CONCLUSIONS

Blunt cerebrovascular injury is uncommon, but lethal; particularly when the diagnosis is delayed. Aggressive screening protocols based on mechanism of injury, associated injuries, and physical findings are justified to minimize morbidity and mortality. Head and chest injuries may serve as markers for blunt cerebrovascular injury. Most deaths are directly attributable to the blunt cerebrovascular injury and not to associated injuries.