Clint W. Sliker

Blunt cerebrovascular injuries: does treatment always matter?

BACKGROUND Blunt cerebrovascular injuries (BCVI) have become an increasingly recognized entity. Stroke as a result of these injuries can have devastating consequences. Optimal screening criteria, diagnostic imaging, and therapy for BCVIs have not been elucidated. Our institution began to apply liberal screening criteria using a whole-body scanning protocol with multidetector computed tomographic (WB-MDCT) scans to diagnose these injuries. The purpose of this study is to describe a single institutions large experience in patients with BCVI in an effort to provide insight into the diagnosis and management of these injuries. METHODS All patients with a BCVI admitted to the R Adams Cowley Shock Trauma Center during a 30-month period were included in this study. Choice of diagnostic evaluation and treatment regimens were at the discretion of the treating attending physician. Review of medical records and all relevant radiographic studies were retrospectively performed for the purposes of this study. RESULTS During the study period, there were 12,667 patients admitted to the R Adams Cowley Shock Trauma Center. There were 147 patients identified with 200 carotid or vertebral artery injuries. The incidence of BVCI was 1.2%. Mortality was 13%. Anatomic injury risk factors for BCVI (major facial fractures, skull base fractures, cervical spine fractures or spinal cord injury, or traumatic brain injury) were found in only 78%. Major thoracic injury was found in 63% of patients with carotid artery injuries and cervical spine fractures or spinal cord injury was found in 74% of patients with vertebral artery injuries. The initial screening test employed was a WB-MDCT in 96% of patients of which 84% detected a BCVI. Treatments included endovascular therapy (22%), antiplatelet medications (36%), anticoagulation (10%), and combination therapy with antiplatelet agents and anticoagulation (18%). Thirty percent received no therapy, primarily due to contraindications from concomitant injuries. There were 18 (12%) patients who had a stroke. Of these patients, 8 (44%) had evidence of infarction at admission, 6 were diagnosed within 72 hours, and 4 were diagnosed after 1 week. Stroke-related mortality was 50%, whereas clinical follow-up after hospital discharge demonstrated only one patient with disability as a result of infarction. Of 10 patients who did not have stroke at admission, 3 were fully treated, 5 had specific contraindications to therapy, and 2 had no or false-negative imaging before infarction. Stroke rates for untreated patients were 25.8% and patients treated with any therapy had a stroke rate of 3.9% (p = 0.0003). Radiographic follow-up >1 month after injury demonstrated improvement in over 50% of patients. CONCLUSIONS BCVIs are not infrequent after blunt trauma. These injuries occur even in the absence of classically described risk factors. Liberal screening with WB-MDCT incorporates detection of these injuries into the initial diagnostic evaluation. Stroke occurs in a substantial number of patients and carries a very high mortality. However, nearly one third of patients with BCVI are not candidates for therapy. Treatment does reduce the risk of infarction in patients with BCVI, but strokes, when they occur, are not preventable.

Diagnosis of Blunt Cerebrovascular Injuries with 16-MDCT: Accuracy of Whole-Body MDCT Compared with Neck MDCT Angiography

OBJECTIVE The objective of our study was to determine whether whole-body 16-MDCT and neck MDCT angiography (MDCTA) can be used to diagnose blunt cerebrovascular injuries with comparable accuracy using angiography as the reference standard. MATERIALS AND METHODS Retrospective review of radiology reports and prospective clinical observation identified 108 blunt trauma patients examined with either whole-body MDCT or neck MDCTA followed by angiography over a 23-month period. From this group, results from the retrospective interpretations of 77 whole-body MDCT and 48 neck MDCTA examinations were compared with the results extracted from angiography reports to estimate the accuracy of each protocol for detecting blunt cerebrovascular injuries. Fishers exact test was used to determine any significant difference in the results of those patients scanned with both protocols. RESULTS Angiography confirmed blunt cerebrovascular injury in 83 patients, with 25 (30%) showing multiple sites of injury. Most injuries were detected in cervical arterial segments. The respective sensitivities of whole-body MDCT and neck MDCTA were 69% (36/52) and 64% (16/25) for cervical internal carotid artery injuries, and specificities were 82% (58/71) and 94% (49/52). Respective sensitivities for cervical vertebral artery injuries were 74% (17/23) and 68% (13/19), and specificities were 91% (60/66) and 100% (40/40). In 17 patients scanned with both protocols, the results were not significantly different (carotid arteries, p = 1.00; vertebral arteries, p = 0.68). CONCLUSION Whole-body 16-MDCT and neck MDCTA can be used to diagnose blunt cerebrovascular injuries with comparable accuracy. Both show high specificities for cervical arterial injury. The sensitivity of whole-body 16-MDCT is sufficiently high to serve as an initial screening examination for blunt cerebrovascular injuries.

Correlation of Multidetector CT Findings with Splenic Arteriography and Surgery: Prospective Study in 392 Patients

BACKGROUND To determine the accuracy of contrast-enhanced multidetector CT (MDCT) in demonstrating splenic vascular injury based on results of splenic angiography and operation. STUDY DESIGN This institutional review board-approved study included 392 hemodynamically stable blunt trauma patients whose admission MDCTs demonstrated splenic injury. Images were assessed for parenchymal injury grade, hemoperitoneum volume, and evidence of bleeding and nonbleeding splenic vascular injury. Splenic arteriography was performed for high splenic injury grade and splenic vascular injury. Medical records were reviewed to determine arteriographic interpretation, surgery indications and findings, outcomes, and demographics. Sensitivity, specificity, predictive values, and accuracy of MDCT in detecting vascular injury were calculated based on results of arteriography and operation. RESULTS Splenic vascular injury was seen in 22% of patients (86 of 392) on MDCT. Presence of a vascular injury correlated with the CT-based parenchymal splenic injury grade (p < 0.0001). Active splenic bleeding was associated with subsequent clinical deterioration (p < 0.0001). Overall, MDCT had a sensitivity of 76% (76 of 100); specificity of 90% (95 of 106); negative and positive predictive values of 80% (95 of 119) and 87% (76 of 87), respectively; and accuracy of 83% (171 of 206) in detecting vascular injury compared with reference standards. The success rate of nonoperative management was 96%. CONCLUSIONS MDCT provides valuable information to direct initial clinical management of patients with blunt splenic trauma by demonstrating both active bleeding and nonbleeding vascular injuries. Not all vascular injuries are detected on MDCT, and splenic angiography is still indicated for high-grade parenchymal injury.

Blunt cerebrovascular injury screening guidelines: what are we willing to miss?

BACKGROUND Blunt cerebrovascular injury (BCVI) is reported to occur in approximately 2% of blunt trauma patients, with a stroke rate of up to 20%. Guidelines for BCVI screening are based on clinical and radiographic findings. We hypothesized that liberal screening of the neck vasculature, as part of initial computed tomographic (CT) imaging in blunt trauma patients with significant mechanisms of injury, identifies BCVI that may go undetected. METHODS As per protocol, patients at risk for significant injuries undergo a noncontrast head CT scan followed by a multislice CT scan (40-slice or 64-slice) incorporating an intravenous contrast-enhanced pass from the circle of Willis through the pelvis (whole-body CT [WBCT] scan). The trauma registry was retrospectively reviewed, and all patients with BCVI from 2009 to 2012 were analyzed. Patients undergoing WBCT scan were then identified, and records were reviewed for BCVI indicators (skull base fracture, cervical spine injury, displaced facial fracture, mandible fracture, Glasgow Coma Scale score ⩽ 8, flexion mechanism, hard signs of neck vascular injury, or focal neurologic deficit). RESULTS Of 16,026 patients evaluated during the study period, 256 (1.6%) were diagnosed with BCVI. The population consisted of 185 patients with suspected BCVI after WBCT scan. One hundred twenty-nine patients (70%) had at least one indicator for BCVI screening, while 56 (30%) had no radiographic or clinical risk factors; 48 of the 56 patients underwent confirmatory CT angiography of the neck within 71 hours of initial WBCT scan, with 35 patients having 45 injuries. CONCLUSION More liberalized screening for BCVI during initial CT imaging in trauma patients clinically judged to have sufficient mechanism is warranted. Using current BCVI screening guidelines leads to missed BCVI and risk of stroke. LEVEL OF EVIDENCE Diagnostic study, level III.

After-Hours Radiology: Challenges and Strategies for the Radiologist.

OBJECTIVE Because of the increase in the use of 24-hour-a-day 7-day-a-week real-time radiologic interpretation, radiologists more frequently perform after-hours work. The purpose of this article was to examine the challenges arising from after-hours work and describe evidence-based strategies meant to limit the adverse physical and psychologic stresses of after-hours work. CONCLUSION Working nontraditional hours affects a radiologists health, social life, professional productivity, and possibly interpretive accuracy. Appropriate attention to these factors and targeted countermeasures can optimize the professional development and personal well-being of radiologists working after hours.

Long-term follow-up of blunt cerebrovascular injuries: Does time heal all wounds?

BACKGROUND The short-term natural history of blunt cerebrovascular injuries (BCVIs) has been previously described in the literature, but the purpose of this study was to analyze long-term serial follow-up and lesion progression of BCVI. METHODS This is a single institutions retrospective review of a prospectively collected database over four years (2009–2013). All patients with a diagnosis of BCVI by computed tomographic (CT) scan were identified, and injuries were graded based on modified Denver scale. Management followed institutional algorithm: initial whole-body contrast-enhanced CT scan, followed by CT angiography at 24 to 72 hours, 5 to 7 days, 4 to 6 weeks, and 3 months after injury. All follow-up imaging, medication management, and clinical outcomes through 6 months following injury were recorded. RESULTS There were 379 patients with 509 injuries identified. Three hundred eighty-one injuries were diagnosed as BCVI on first CT (Grade 1 injuries, 126; Grade 2 injuries, 116; Grade 3 injuries, 69; and Grade 4 injuries, 70); 100 “indeterminate” on whole-body CT; 28 injuries were found in patients reimaged only for lesions detected in other vessels. Sixty percent were male, mean (SD) age was 46.5 (19.9) years, 65% were white, and 62% were victims of a motor vehicle crash. Most frequently, Grade 1 injuries were resolved at all subsequent time points. Up to 30% of Grade 2 injuries worsened, but nearly 50% improved or resolved. Forty-six percent of injuries originally not detected were subsequently diagnosed as Grade 3 injuries. Greater than 70% of all imaged Grade 3 and Grade 4 injuries remained unchanged at all subsequent time points. CONCLUSIONS This study revealed that there are many changes in grade throughout the six-month time period, especially the lesions that start out undetectable or indeterminate, which become various grade injuries. Low-grade injuries (Grades 1 and 2) are likely to remain stable and eventually resolve. Higher-grade injuries (Grades 3 and 4) persist, many up to six months. Inpatient treatment with antiplatelet or anticoagulation did not affect BCVI progression. LEVEL OF EVIDENCE Prognostic study, level III; therapeutic study, level IV.

Vascular Injuries to the Neck After Penetrating Trauma: Diagnostic Performance of 40- and 64-MDCT Angiography

OBJECTIVE The purposes of this study were to assess the diagnostic performance of 40- and 64-MDCT angiography with digital subtraction angiography as the reference standard in the detection of arterial injuries in patients at high risk after penetrating neck trauma and to perform a separate analysis of injuries to the external carotid artery. MATERIALS AND METHODS In a retrospective evaluation of 53 sets of angiograms from 51 patients with penetrating neck injury, three reviewers unaware of the digital subtraction angiographic findings reviewed the CT angiographic (CTA) images to discern the presence or absence of arterial injuries. Sensitivity and specificity of CTA were calculated per injury, and a separate analysis of external carotid artery injuries was performed. RESULTS Sensitivity of CTA for detecting arterial injuries ranged from 75.7% (95% CI, 62.3-86.9%) to 82.2% (95% CI, 69.5-92.1%). Specificity ranged from 96.4% (95% CI, 94.0-98.4%) to 98.4% (95% CI, 96.0-100%). CTA was highly sensitive for detection of the subgroup of injuries involving the large-caliber vessels that contribute to cerebral circulation. These sensitivities ranged from 92.8% (95% CI, 66-98.8%) to 100% (95% CI, 76.6-100%) for internal carotid artery injuries and from 88.9% (95% CI, 65.2-98.3%) to 94.4% (95% CI, 72.6-99.0%) for vertebral artery injuries. In contrast, sensitivity of CTA was limited for external carotid artery injuries, ranging from 63.4% (95% CI, 45.5-79.5%) to 70.0% (95% CI, 52.0-85.0%). CONCLUSION CTA can be used for initial evaluation and may help guide management decisions if an external carotid artery injury is detected. Negative findings should not preclude close clinical follow-up, repeat CTA evaluation, or, in the presence of high suspicion of arterial injury due to clinical findings or wound trajectory, evaluation with digital subtraction angiography.

Lethal now or lethal later: The natural history of Grade 4 blunt cerebrovascular injury.

BACKGROUND Grade 4 blunt cerebrovascular injury (BCVI4) has a known, significant rate of stroke. However, little is known about the natural history of BCVI4 and the pathophysiology of subsequent stroke formation. METHODS A 4-year review of patients with BCVI4 at the R Adams Cowley Shock Trauma Center was performed. Rates of BCVI4-related stroke, stroke-related mortality, and overall mortality were calculated. The relationship of change in vessel characteristics and BCVI4-related stroke was examined, as was the mechanism of stroke formation. RESULTS There were 82 BCVI4s identified, with 13 carotid artery (ICA) and 69 vertebral artery BCVI4s. BCVI4-related stroke rate was 2.9% in vertebral artery BCVI4 and 70% in ICA BCVI4 patients surviving to reimaging. Stroke mechanisms included embolic strokes, thrombotic strokes, and combined embolic and thrombotic strokes. Peristroke vessel recanalization and an embolic stroke mechanism were seen in 100% of ICA BCVI4-related strokes developing after admission. BCVI4-related stroke occurred within 10 hours of hospital admission in 67% of the patients with strokes. Contraindications to anticoagulation were present in most patients with BCVI4-related stroke developing after admission. CONCLUSION Multiple etiologies of stroke formation exist in BCVI4. Early risk-benefit analysis for initiation of anticoagulation or antiplatelet agents should be performed in all patients with BCVI4, and the use of endovascular vessel occlusion should be considered in those with true contraindications to anticoagulation. However, more aggressive medical therapy may be needed to lessen BCVI4-related stroke development. LEVEL OF EVIDENCE Prognostic study, level IV; therapeutic study, level V.

Renal artery mycotic pseudoaneurysm: diagnosis with multi-detector computed tomographic angiography

Renal artery mycotic pseudoaneurysms are uncommon complications of bacterial endocarditis and bacteremia. Complications include hemorrhage and refractory bacteremia, and prompt diagnosis can lead to appropriate treatment. Reported is a case where multi-detector computed tomography angiography led to the correct diagnosis.

Predicting Arterial Injuries after Penetrating Brain Trauma Based on Scoring Signs from Emergency CT Studies

The objective of this study was to determine the accuracy of individual radiologists in detection of vascular injury in patients after penetrating brain injury (PBI) based on head CT findings at admission. We retrospectively evaluated 54 PBI patients who underwent admission head CT and digital subtraction angiography (DSA), used here as a reference standard. Two readers reviewed the CT images to determine the presence or absence of the 29 CT variables of injury profile and quantified selected variables. Four experienced trauma radiologists and one neuroradiologist assigned their own specific scores for each CT variable, a high score indicative of a high probability of artery injury. A sixth set consisted of the average score obtained from the five sets, generated by five experts. Receiver operating characteristic (ROC) curves were constructed for each set to assess the diagnostic performance of an individual radiologist in predicting an underlying vascular injury. The area under ROC curve (AUC) was higher for CT scores obtained from the sixth set (average of five sets of scores) of variable rank score 0.75 (95% CI 0.62–0.88) and for the rest of the data sets, the value ranged from 0.70 (95% CI 0.56–0.84) to 0.74 (95% CI 0.6–0.88). In conclusion, radiologists may be able to recommend DSA with a fair accuracy rate in selected patients, deemed ‘high-risk’ for developing intracranial vascular injuries after PBI based on admission CT studies. A better approach needs to be developed to reduce the false positive rate to avoid unnecessary emergency DSA.