Blunt Traumatic Vertebral Artery Injuries: Incidence, Therapeutic Management, and Outcomes.

BACKGROUND: Blunt cerebrovascular injury (BCVI) is a term for injuries to the carotid and vertebral arteries (blunt vertebral artery injury [BVAI]) caused by blunt trauma. Computed tomographic angiography is currently the best screening test for BCVI. The subsequent management of any identified vessel injury, however, is not clearly defined. OBJECTIVE: To describe one of the largest cohorts of isolated vertebral artery injuries and report the evolution of treated and untreated lesions and clinical outcomes of treatment regimens used to reduce the risk of injury-related stroke. METHODS: The list included patients who presented to or were transferred to a level 1 trauma center and found to have an isolated BVAI. Patients were included if imaging was performed within 24 hours of presentation. Data collected included location and grade of injury, timing and type of initial therapy, follow-up imaging, evolution of the disease, and associated strokes. RESULTS: A total of 156 patients were included in the analysis. Most patients (135/156) were treated with aspirin alone, 3 with anticoagulation therapy, and 18 did not receive treatment. Three strokes were detected within 24 hours of admission and before treatment initiation. No strokes were detected during the length of the hospitalization for any other patient. CONCLUSION: Our data demonstrate that the risk of stroke after cervical vertebral artery injury is low, and aspirin as a prophylactic is efficacious in grade I and IV injuries. There are limited data regarding grade II and grade III injuries. The benefit of early interval imaging follow-up is unclear and warrants investigation.

Noninvasive in vivo Assessment of the Re-endothelialization Process Using Ultrasound Biomicroscopy in the Rat Carotid Artery Balloon Injury Model.

OBJECTIVES: Ultrasound biomicroscopy (UBM), or ultra high-frequency ultrasound, is a technique used to assess the anatomy of small research animals. In this study, UBM was used to assess differences in intimal hyperplasia thickness as a surrogate measurement of the re-endothelialization process after carotid artery balloon injury in rats. METHODS: Ultrasound biomicroscopic data from 3 different experiments and rat strains (Sprague Dawley, Wistar, and diabetic Goto-Kakizaki) were analyzed. All animals were subjected to carotid artery balloon injury and examined with UBM (30-70 MHz) 2 and 4 weeks after injury. Re-endothelialization on UBM was defined as the length from the carotid bifurcation to the most distal visible edge of the intimal hyperplasia. En face staining with Evans blue dye was performed at euthanasia 4 weeks after injury, followed by tissue harvesting for histochemical and immunohistochemical evaluations. RESULTS: A significant correlation (Spearman r = 0.63; P < .0001) was identified when comparing all measurements of re-endothelialization obtained from UBM and en face staining. The findings revealed a similar pattern for all rat strains: Sprague Dawley (Spearman r = 0.70; P < .0001), Wistar (Spearman r = 0.36; P < .081), and Goto-Kakizaki (Spearman r = 0.70; P < .05). A Bland-Altman test showed agreement between en face staining and UBM. Immunohistochemical staining confirmed the presence of the endothelium in the areas detected as re-endothelialized by the UBM assessment. CONCLUSIONS: Ultrasound biomicroscopy can be used for repeated in vivo assessment of re-endothelialization after carotid artery balloon injury in rats.

Carotid and vertebral injury study (CAVIS) technique for characterization of blunt traumatic aneurysms with reliability assessment.

Traumatic aneurysms occur in up to 20% of blunt traumatic extracranial carotid artery injuries. Currently there is no standardized method for characterization of traumatic aneurysms. For the carotid and vertebral injury study (CAVIS), a prospective study of traumatic cerebrovascular injury, we established a method for aneurysm characterization and tested its reliability. Saccular aneurysm size was defined as the greatest linear distance between the expected location of the normal artery wall and the outer edge of the aneurysm lumen ("depth"). Fusiform aneurysm size was defined as the "depth" and longitudinal distance ("length") paralleling the normal artery. The size of the aneurysm relative to the normal artery was also assessed. Reliability measurements were made using four raters who independently reviewed 15 computed tomographic angiograms (CTAs) and 13 digital subtraction angiograms (DSAs) demonstrating a traumatic aneurysm of the internal carotid artery. Raters categorized the aneurysms as either "saccular" or "fusiform" and made measurements. Five scans of each imaging modality were repeated to evaluate intra-rater reliability. Fleiss's free-marginal multi-rater kappa (κ), Cohen's kappa (κ), and interclass correlation coefficient (ICC) determined inter- and intra-rater reliability. Inter-rater agreement as to the aneurysm "shape" was almost perfect for CTA (κ = 0.82) and DSA (κ = 0.897). Agreements on aneurysm "depth," "length," "aneurysm plus parent artery," and "parent artery" for CTA and DSA were excellent (ICC > 0.75). Intra-rater agreement as to aneurysm "shape" was substantial to almost perfect (κ > 0.60). The CAVIS method of traumatic aneurysm characterization has remarkable inter- and intra-rater reliability and will facilitate further studies of the natural history and management of extracranial cerebrovascular traumatic aneurysms.

Anthropometric assessment of cervical neurovascular structures using CTA to determine zone-specific vulnerability to penetrating fragmentation injuries.

AIM: To determine military-specific cervical neurovascular and external anthropometric data to scale future numerical injury models of the neck and improve body armour design with a view to prevention or mitigation of combat neck injury. MATERIALS AND METHODS: Contrast-enhanced computed tomography (CT) angiograms of 50 UK servicemen were analysed. Mean diameters and distances from the skin surface were determined for the carotid artery (CA), internal jugular vein (IJV), vertebral artery (VA) and spinal cord (SC) at the three surgical neck zones. Horizontal neck circumference at C6 and three potential vertical cervical anthropometric measurements were analysed to determine which had the least variability between subjects. RESULTS: The diameters of cervical vascular structures are greater and the vessels more superficial as the anatomical plane moves caudally. The SC and VA are better protected than the IJV and CA due to their greater depth and bony coverage, except for the VA in zone 1. CONCLUSION: Future cervical anthropometric assessments should use the vertical angle of mandible to mid-claviclular distance in combination with the horizontal neck circumference as these demonstrated the least variability. Cervical neurovascular structures are least vulnerable posterosuperiorly and therefore extending the posterior aspect of a ballistic helmet inferiorly or adding a nape protector would appear to be less justified. Cervical vessels are most vulnerable in zone 1 and a circumferential collar of ballistic material at least 75 mm high would cover this area in 95% of this population.

In vivo assessment of the effects of ginsenoside Rb1 on intimal hyperplasia in ApoE knockout mice.

OBJECTIVE: This study investigated the effects of ginsenoside Rb1 (Rb1) on injury-induced intimal hyperplasia in ApoE knock out (ApoE -/-) mice. We also examined the value of an ultrasound micro-image system in dynamic monitoring of lumen diameter and flow velocity. METHODS: After guide wire injury of the distal left common carotid artery (CCA), ApoE-/- mice were treated with intraperitoneal infusion of normal saline (NS), homocysteine (Hcy), ginsenoside Rb1 (Rb1), or Hcy+Rb1 for 4 wk. Bilateral CCA luminal diameters and flow velocities were measured with an ultrasound micro-image system before surgery and weekly afterwards. Following the final ultrasound, CCAs were harvested and analyzed for intima-medium thickness ratios. RESULTS: Progressive reduction in luminal diameters and increase in flow velocity of the injured left distal CCA segment were observed using ultrasound micro-imaging system in all groups compared with the relatively stable left proximal CCA and right CCA. The NS and Hcy groups had significantly higher degree of diameter reduction compared with the Rb1 and Rb1+Hcy groups. The ultrasound findings were consistent with histology analyses at 4 wk post-op. CONCLUSIONS: The study suggested that Rb1 attenuated the effects of Hcy on injured carotid arteries of ApoE -/- mice. The study also showed that ultrasound micro-image system was a reliable tool in monitoring luminal reduction after injury in a murine model. This study establishes a fundamental step of in vivo monitoring of the therapeutic effects of agents in a murine model without sacrificing the animals.

Screening for blunt cerebrovascular injuries is cost-effective.

BACKGROUND: Recent reports have argued that screening for blunt carotid injury is futile and have called for a cost analysis. Our data previously supported screening asymptomatic trauma patients for blunt cerebrovascular injury (BCVI) to prevent associated neurologic sequelae. Our hypothesis is that aggressive angiographic screening for BCVI based on a patient's injury pattern and symptoms allows for early diagnosis and treatment and is cost-effective because it prevents ischemic neurological events (INEs). METHODS: Beginning in January 1996, we began comprehensive screening using 4-vessel cerebrovascular angiography based on injury patterns; these patients have been followed-up prospectively. Patients without contraindications received antithrombotic therapy immediately for documented BCVI. RESULTS: From January 1996 through June 2004, there were 15,767 blunt-trauma patient admissions to our state-designated level I urban trauma center, of which 727 patients underwent screening angiography. Twenty-one patients presented with signs or symptoms of neurologic ischemia before diagnosis. BCVI was identified in 244 patients (34% screening yield); the majority were men (68%) with a mean age of 35 +/- 3.7 years and mean Injury Severity Score of 28 +/- 3.8. Asymptomatic patients (n = 187) were treated (heparin in 117, low molecular-weight heparin in 11, and antiplatelet in 59); 1 patient had a stroke (0.5%). Using estimated stroke rate by grade of injury, we averted neurologic events in 32 asymptomatic patients with antithrombotic treatment. Of the 48 asymptomatic patients who did not receive adequate anticoagulation, 10 (21%) had an INE. Patients with BCVI-related neurologic events had a statistically higher percentage requiring discharge to rehabilitation facilities (50% vs. 77% for carotid artery injury [CAI]), a higher percentage requiring rehabilitation for BCVI-related stroke (0% vs. 55% for CAI), and a higher stroke-related mortality rate (0% vs. 21% for CAI and 0% vs. 17% for vertebral artery injury) than those without neurologic events. CONCLUSIONS: The cost of long-term rehabilitation care and human life after BCVI-associated neurologic events is substantial. Surgeons caring for the multiply injured should screen for carotid and vertebral artery injuries in high-risk patients.

A comprehensive approach to visual and functional assessment of experimental vascular lesions in vivo.

The rat carotid injury model is the most widely used model to study the pathophysiology of neointimal hyperplasia as well as the value of novel therapeutic approaches to limit vasoproliferative diseases such as restenosis. For lesion assessment, the current gold standard of histomorphometry neither provides integral insight into the vascular lesion in vivo nor assesses of functional lesion-associated flow alterations and the time course of lesion development. To overcome these limitations, we applied and validated duplex sonography as a novel tool for comprehensive lesions assessment in vivo. Left rat common carotid arteries (CCA) were balloon injured. Duplex sonography was performed in both injured and noninjured CCAs before and up to 14 days postinjury. Sham-operated animals served as controls. The parameters determined were vessel lumen diameter as well as systolic and end-diastolic flow velocity, time-dependent lesion development, and intra- and interobserver variability. Subsequently, the model was applied to validate the therapeutic effect of gene transfer into the vessel wall and compared with histomorphometry. We show that duplex sonography in the experimental carotid injury model allows accurate follow-up of lesion development in vivo with low intra- and interobserver variability. It can be easily adopted to assess the efficacy of therapeutic approaches even with limited technical experience and adds valuable functional data to mere postmortem histomorphometric analysis, thereby closing the gap between experimental approaches and clinical importance of vascular lesions.

[Post-traumatic lesion of the carotid artery. Evaluation of the clinico-radiological diagnosis]. / Lesión postraumática de la arteria carótida. Valoración del diagnóstico clinicorradiológico.

INTRODUCTION: Posttraumatic vascular lesions of the carotid artery (PLCA) are infrequent but have a high morbid-mortality, so early diagnosis and treatment is important. OBJECTIVE: To review the clinical and radiological findings of the PLCA with the hypothesis that there are signs which permit early diagnosis. PATIENTS AND METHODS: A retrospective study of 9 patients (p) with PLCA. RESULTS: The cause was road traffic accident (4p), fall (1p) or a single abrupt cervical movement (4p). The initial clinical feature was cervical pain (1p), deafness (1p), Claude-Bernard-Horner syndrome (4p) or symptoms of a cerebral vascular accident (6p). Cranial CT showed a cerebral infarct in the territory of the middle cerebral artery (6p), subarachnoid hemorrhage (1p) or normal (3p). Diagnosis of the vascular lesion was made using magnetic resonance (9p), arteriography (5p) and echo-Doppler (4p). The vascular lesions were: severe stenosis due to a mural thrombosis (3p), complete obstruction due to thrombosis (4p) and pseudoaneurysm (2p). CONCLUSIONS: PLCA should be suspected following craniofacial-cervical trauma when there was an abrupt neck movement, a Claude-Bernard-Horner syndrome is present or a cerebral infarct in the territory of the middle cerebral artery is shown.