Role of CT in excluding major arterial injury after blunt thoracic trauma

Multidetector CT of blunt traumatic venous injuries in the chest, abdomen, and pelvis

Venous injuries as a result of blunt trauma are rare. Even though current protocols for multidetector computed tomography (CT) of patients with trauma are designed to evaluate primarily the solid organs and arteries, blunt venous injuries may nevertheless be identified, or at least suspected, on the basis of the multidetector CT findings. Venous injuries are associated with high morbidity and mortality rates. Diagnosis of a possible venous injury is crucial because the physical findings of a venous injury are nonspecific and may be absent. This article aims to make the radiologist aware of various venous injuries caused by blunt trauma and to provide helpful hints to aid in the identification of venous injuries. Multidetector CT technology, in combination with interactive manipulation of the raw dataset, can be useful in the creation of multiplanar reconstructed images and in the identification of a venous injury caused by blunt trauma. Familiarity with direct and indirect signs of venous injuries, as well as with examples of blunt traumatic venous injuries in the chest, abdomen, and pelvis, will help in the diagnosis of these injuries.

Diagnosis of blunt traumatic aortic injury 2007: still a nemesis

In recent years, the use of multidetector computed tomography (MDCT) for the diagnosis of acute thoracic injury in blunt trauma has expanded. MDCT has shown high accuracy for the diagnosis or exclusion of injury to the aorta and its primary branches, decreasing the need for thoracic angiography and allowing earlier treatment of this often rapidly fatal lesion. With increasing use of MDCT, more subtle injuries and variants of vascular anatomy are being recognized that create pitfalls in the diagnosis. Of perhaps more concern is the recognition that aortic injury can occur with little or no associated mediastinal hematoma, the principle chest radiographic finding indicating a need for further imaging. The importance of recognizing unusual sites of aortic injury, congenital variants of mediastinal anatomy, the precise extent of injury, and the anatomic pathology present as key factors in deciding among treatment options is emphasized.

Arch vessel injury: geometrical considerations. Implications for the mechanism of traumatic myocardial infarction II

Background

Various types of vascular injury have been reported in the medical literature; the isthmic part of the aorta is at particularly high risk of traumatic rupture. Early diagnosis results in better survival, justifying the search for potential risk factors and diagnostic tests. The aim of this research was to investigate the complex mechanism of blunt injury to the vascular wall with particular focus on the branching region of the vessels. Geometric peculiarities were investigated.

Methods

Multi-phase equations have been used. The system of equations with certain boundary conditions was solved numerically by applying the finite-difference method with order of approximation equal to 0.0001.

Results

The degree of curvature (the Dean number) is highly informative about the shear stress on the external surface of the vessel. An important function of the blood flow on the external wall is to destroy rouleaux. The viscosity of phase 2 (f₂) exceeds, by many times, the viscosity of phase 1 (f₁). The major stress created by blood flow is expressed as the shear stress of f₂. The volume fraction of rouleaux depends to a greater degree on the concentration of erythrocytes (expressed as the viscosity of the mixture) than on the shear stress. The peculiarities of rouleaux formation were assessed and their impact on the local shear stress and, therefore, on the internal wall was determined in relation to the erythrocyte concentration.

Conclusion

The results of this research take into account certain geometrical peculiarities of the branching part of the vessel. The mathematical model created in this study will improve our understanding of the complex mechanism of blunt injury to the vascular wall and, therefore, conditions such as aortic rupture and traumatic acute myocardial infarction.

Critical Evaluation of Chest Computed Tomography Scans for Blunt Descending Thoracic Aortic Injury

BACKGROUND

Although aortography has been the long-held "gold standard" for diagnosis of traumatic blunt aortic injury, advances in imaging technology offer less-invasive, more-rapid, and potentially more cost-effective evaluation. The purpose of this study was to review this hospital's experience with the screening and diagnosis of blunt aortic injury with emphasis on the critical evaluation of computed tomography (CT) scans for defining descending thoracic aortic injury.

METHODS

A retrospective single-center analysis of all patients undergoing aortography to evaluate for blunt aortic injury between January 1, 1997, and August 31, 2004, was performed. A policy of relying on CT scans to definitively diagnose blunt aortic injury was not in force, and all patients with positive, equivocal, and negative screening CT scans with significant injury mechanism underwent subsequent aortography; this contributed to an unbiased analysis. A subgroup of patients imaged with the latest generation multislice CT scanners (July 1, 2003, to August 31, 2004) was separately analyzed with rapid three-dimensional reconstruction.

RESULTS

Of 856 aortograms, 206 (24.1%) were preceded by chest CT scan. Of 31 patients with confirmed aortic injury, 20 had undergone CT scan with 16 positive for definite injury, 3 positive for possible injury, and 1 false-negative study. Of the 206 patients scanned, 114 (55.3%) showed possible injury, 76 (36.9%) were negative, and 16 (7.8%) were positive. Only 3 of the 114 with possible injury (2.6%) were true positives whereas 1 of the 76 negative scans (1.3%) was a false negative and all 16 positive scans were true positives. These data for CT scan imaging result in a sensitivity of 95%, a specificity of 40%, a positive predictive value of 15%, and a negative predictive value of 99%.

CONCLUSIONS

Chest CT is an acceptable screening tool based on prerequisite high sensitivity and ease of performance in the trauma patient suspected of having a descending thoracic aortic injury. Although the excellent negative predictive value resulted in an algorithm change at this institution, there were a significant number of equivocal scans that required subsequent aortography. Three-dimensional software reconstruction of the aorta can aid in diagnosing blunt aortic injury when findings are equivocal, but there will continue to be artifacts and limitations that require aortography for clarification.

Periaortic Hematoma at Diaphragmatic Crura at Helical CT: Sign of Blunt Aortic Injury in Patients with Mediastinal Hematoma

PURPOSE

To evaluate periaortic hematoma (PH) near the level of the diaphragm at abdominal computed tomography (CT) as an indirect sign of acute traumatic aortic injury after blunt trauma in patients with mediastinal hematoma.

MATERIALS AND METHODS

From 1998 to 2001, 97 patients with CT evidence of mediastinal hematoma after blunt thoracic trauma were retrospectively identified at two level 1 trauma centers. The presence or absence of PH near the level of the diaphragmatic crura was retrospectively established by a blinded reviewer at each institution. Aortic injury status was determined by reviewing angiographic, surgical, and clinical records. Sensitivity, specificity, positive and negative productive values, and positive and negative likelihood ratios were calculated.

RESULTS

Among the 97 patients with mediastinal hematoma, 14 had both PH near the level of the diaphragm and aortic injury; six had aortic injuries without PH, five had PH near the level of the diaphragm without aortic injury, and 72 had no evidence of PH near the diaphragm and no aortic injury. Sensitivity for PH near the level of the diaphragm as a sign of aortic injury was 70%; specificity, 94%; positive predictive value, 74%; and negative predictive value, 92%. The positive likelihood ratio for the presence of aortic injury was 10.8, and the negative likelihood ratio was 0.3.

CONCLUSION

PH near the level of the diaphragmatic crura is an insensitive but relatively specific sign for aortic injury after blunt trauma. The presence of this sign at abdominal CT should prompt imaging of the thoracic aorta to evaluate potential thoracic aortic injury.

Do we really need routine computed tomographic scanning in the primary evaluation of blunt chest trauma in patients with "normal" chest radiograph?

BACKGROUND

A major cause of morbidity and mortality after blunt chest trauma remains undetected injuries. This study evaluates the role of routine computed tomographic (CT) scan.

METHODS

We studied 93 consecutive patients from January 1999 to July 2000: 73 (76.3%) after motor vehicle crash with crash speed > 10 mph, and 22 (23.7%) after fall from height > 5 ft. Simultaneous with initial clinical evaluation, anteroposterior chest radiograph and helical chest CT scan were obtained for all patients.

RESULTS

Sixty-eight patients (73.1%) showed at least one pathologic sign on chest radiograph, and 25 patients (26.9%) had normal chest radiograph. In 13 (52.0%) of these 25 patients, the CT scan showed multiple injuries; among these were two aortic lacerations, three pleural effusions, and one pericardial effusion.

CONCLUSION

Over 50% of patients with normal initial chest radiograph showed multiple injuries on the CT scan, among which were also two (8%) potentially fatal aortic lesions. We therefore recommend primary routine chest CT scan in all patients with major chest trauma.

Newer diagnostic modalities for vascular injuries: the way we were, the way we are

The article discusses the role of modalities in diagnosing vascular injuries starting with angiography and tracing the evolution of the use of color flow Doppler, CT, and CT angiography. It also addresses the controversy of minimal vascular injury and outlines vascular injuries that may be safely observed and followed-up. Finally, the evolution from angiography to the use of helical CT for the diagnosis of thoracic aortic injuries is reviewed in detail.

Making the transition: the role of helical CT in the evaluation of potentially acute thoracic aortic injuries

OBJECTIVE

The purpose of this study was to show that helical CT could be used at our center in lieu of routine aortography to examine patients who have had serious blunt chest trauma. We also wanted to assess the potential savings of using CT to avoid unnecessary aortography.

MATERIALS AND METHODS

The institutional review board approved the parallel imaging-CT immediately followed by aortography-of patients presenting with blunt chest trauma between August 1997 and August 1998. To screen patients for potential aortic injuries, we performed parallel imaging on 142 patients, and these patients comprised our patient population. CT examinations of the patients were reviewed for signs of injury by radiologists who were unaware of each other's interpretations and the aortographic results. Findings of CT examinations were classified as negative, positive, or inconclusive for injury. Aortography was performed immediately after CT. The technical and professional fees for both transcatheter aortography and helical CT were also compared.

RESULTS

Our combined kappa value for all CT interpretations was 0.714. The aortographic sensitivity and negative predictive value were both 100%. Likewise, the sensitivity and negative predictive value of CT were 100%. The total costs of performing aortography were estimated at approximately $402,900, whereas those for performing helical CT were estimated at $202,800.

CONCLUSION

Helical CT has a sensitivity and negative predictive value equivalent to that of aortography. Using CT to eliminate the possibility of mediastinal hematoma and to evaluate the cause of an abnormal aortic contour in a trauma patient allows us to use aortography more selectively. Avoiding the performance of unnecessary aortography will expedite patient care and reduce costs. We report the results of our experience with CT and how our center successfully made this transition in the initial examination of patients with serious thoracic trauma.

Imaging of blunt aortic and great vessel trauma

The thoracic aorta and great vessels are at risk of injury by both blunt and penetrating trauma. High-speed deceleration injury, predominately caused by motor vehicle accidents, is the primary cause of blunt traumatic aortic injury (TAI). Though largely fatal if untreated, these injuries are amenable to surgical repair if appropriately diagnosed. Algorithms for both diagnosis and treatment of TAI have undergone changes in recent years. Radiologic imaging plays a key role in the evaluation of TAI, and this review focuses on the relative roles of chest radiography, computed tomography (CT) (particularly helical CT), and aortography in the diagnostic algorithm for TAI. Other aortic imaging methods have been used in the setting of TAI, such as transesophageal echocardiography, magnetic resonance imaging, and intravascular ultrasound; although these techniques may play a complementary role in TAI evaluation, they are unlikely to have as significant an impact on routine radiologic practice as will CT.

Can chest CT be used to exclude aortic injury?

PURPOSE

To determine whether chest computed tomography (CT) can be used to exclude aortic injury.

MATERIALS AND METHODS

Patients in whom there was very high suspicion of traumatic aortic injury were examined with aortography only. Other patients were examined with contrast material-enhanced CT. Follow-up aortography was performed in all patients with moderate to high suspicion of traumatic aortic injury and in all patients with CT scans that were positive for traumatic aortic injury. CT scans were regarded as positive when they showed mediastinal hematoma or direct findings of aortic injury. During a 4 1/2-year period, 1,009 patients (263 female, 746 male; age range, 3-90 years) were evaluated for possible traumatic aortic injury.

RESULTS

Of the 207 patients who underwent aortography directly without CT, 10 had traumatic aortic injury. Of the 802 patients who were examined with CT, 382 underwent follow-up aortography. In this group, there were 10 true-positive and no false-negative CT scans. CT had 100% sensitivity and a 100% negative predictive value for the detection of traumatic aortic injury.

Helical (spiral) CT in the evaluation of emergent thoracic aortic syndromes. Traumatic aortic rupture, aortic aneurysm, aortic dissection, intramural hematoma, and penetrating atherosclerotic ulcer

For the near future, CT will play the critical and dominant role in the evaluation of patients presenting with emergent aortic syndromes. Its convenience, accuracy, and utility in the rapid evaluation of not just the aorta, but the entire thorax, make it ideally suited for use in emergency settings. Further benefits are likely to be realized in speed and resolution with multislice CT, although it is as yet not widely available.

Helical CT grading of traumatic aortic injuries. Impact on clinical guidelines for medical and surgical management

Helical CT is a reliable method for screening patients with blunt chest trauma for vascular and visceral injuries. Thoracic aortic injuries detected by CT examination affect the immediate clinical management and patient triage. This article describes the clinical indications and imaging protocols for helical CT of the chest used to detect aortic injuries, provides a grading system of the range of aortic injuries demonstrated by CT, and discusses the clinical management decisions that should be considered based on the CT grade of the aortic injury.

Use of spiral computed tomography for the assessment of blunt trauma patients with potential aortic injury

PURPOSE

The purpose of this study was to prospectively examine the accuracy of contrast-enhanced spiral thoracic computed tomography (CEST-CT) for direct detection of traumatic aortic injury resulting from blunt thoracic trauma.

METHODS

During a 25-month period, all blunt trauma patients who had abnormal mediastinal contours on admission chest radiographs underwent CEST-CT. The presence and location of mediastinal blood and any direct signs of aortic injury, such as pseudoaneurysm, were recorded. Computed tomographic results were compared with results of aortography, when performed, surgery, or clinical status at discharge.

RESULTS

There were 7,826 patients classified as having blunt trauma admitted during the study. Of these, 1,104 (14.3%) had CEST-CT performed. Mediastinal hemorrhage was detected on 118 (10.7%) of all thoracic computed tomographic scans. Direct evidence of aortic injury was detected in 24 patients (20.3%) with mediastinal hemorrhage and 2.2% of all patients undergoing CEST-CT. In this prospective series, CEST-CT was 100% sensitive based on clinical follow-up; it was 99.7% specific, with 89% positive and 100% negative predictive values and an overall diagnostic accuracy of 99.7%.

CONCLUSION

CEST-CT is a valuable ancillary study for the detection of traumatic aortic injury. Spiral computed tomography is accurate for the detection and localization of both hemomediastinum and direct signs of aortic injury.

Prospective study of blunt aortic injury: helical CT is diagnostic and antihypertensive therapy reduces rupture

OBJECTIVE

There were two aims of this study. The first was to evaluate the application of helical computed tomography of the thorax (HCTT) for the diagnosis of blunt aortic injury (BAI). The second was to evaluate the efficacy of beta-blockers with or without nitroprusside in preventing aortic rupture.

SUMMARY BACKGROUND DATA

Aortography has been the standard for diagnosing BAI for the past 4 decades. Conventional chest CT has not proven to be of significant value. Helical CT scanning is faster and has higher resolution than conventional CT. Retrospective studies have suggested the efficacy of antihypertensives in preventing aortic rupture.

METHODS

A prospective study comparing HCTT to aortography in the diagnosis of BAI was performed. A protocol of beta-blockers with or without nitroprusside was also examined for efficacy in preventing rupture before aortic repair and in allowing delayed repair in patients with significant associated injuries.

RESULTS

Over a period of 4 years, 494 patients were studied. BAI was diagnosed in 71 patients. Sensitivity was 100% for HCTT versus 92% for aortography. Specificity was 83% for HCTT versus 99% for aortography. Accuracy was 86% for HCTT versus 97% for aortography. Positive predictive value was 50% for HCTT versus 97% for aortography. Negative predictive value was 100% for HCTT versus 97% for aortography. No patient had spontaneous rupture in this study.

CONCLUSIONS

HCTT is sensitive for diagnosing intimal injuries and pseudoaneurysms. Patients without direct HCTT evidence of BAI require no further evaluation. Aortography can be reserved for indeterminate HCTT scans. Early diagnosis with HCTT and presumptive treatment with the antihypertensive regimen eliminated in-hospital aortic rupture.

Chest trauma

Trauma is a major cause of morbidity and mortality worldwide. Despite the advent of specialised trauma centres the outcome of patients who sustain major trauma remains disappointing. Plain radiography and more advanced imaging techniques such as ultrasound, computerised tomography (CT) and angiography, have a major role to play in the early decision making and subsequent management of patients who sustain polytrauma. This article discusses the choice of emergency imaging techniques available in chest trauma for clinicians and radiologists; their evaluation and some of the common pitfalls that may lead to errors of interpretation.

Traumatic rupture of the descending thoracic aorta

Traumatic rupture of the descending thoracic aorta is a highly lethal injury caused by sudden, rapid deceleration in high-speed motor vehicular collisions and falls from heights. Deceleration causes the mobile ascending aorta and aortic arch to move forward while the descending thoracic aorta remains fixed by the mediastinal pleura. This opposing movement creates a tear at the aortic isthmus just distal to the origin of the left subclavian artery. Patients with traumatic ruptured descending thoracic aortas often have serious multisystem injuries, and approximately 85% of these patients die at accident scenes or during emergency department resuscitation. The most frequent cause of death is free rupture of periaortic tissues that temporarily have provided tamponade to the sites of aortic ruptures. Surgical mortality rates for patients who survive initial resuscitation are between 10% and 25%. Advances in field triage and emergency medical transportation systems and new preoperative evaluation modalities have improved the survival of patients with traumatic descending thoracic aorta ruptures.

Selected topics in chest trauma

Trauma is the leading cause of death of young adults in the United States, and chest trauma is one of the leading causes of trauma-related fatalities. This article presents an approach to the radiological evaluation and diagnosis of pneumothorax, pneumomediastinum, traumatic aortic rupture, and thoracic spine injuries. Also discussed is the radiological assessment of vascular catheters, endotracheal tubes, and thoracostomy tubes.

Computed tomography of thoracic aortic trauma

During a 63-month period, 28 consecutive patients suspicious for injury of the thoracic aorta were examined by computed tomography (CT). Twelve aortic ruptures were evidenced; pseudoaneurysm and mediastinal haematoma in close contact with the aorta were present in 12 patients, marginal lucency in 9, marginal irregularity in 8 and intimal flap in 6. CT was falsely negative in 1 patient with injury of the left subclavian artery. Angiography and surgery confirmed the diagnosis in 7 patients, and surgery alone in 5 patients. CT had a sensitivity of 92% and a specificity of 100%. The need for angiography was obviated in 67% of patients. A radiologist with experience in trauma management, CT and angiography should perform both examinations.

Transesophageal echocardiography for the initial evaluation of the widened mediastinum in trauma patients

Traumatic disruption of the thoracic aorta is an injury that is rapidly fatal if not recognized and treated early. Increasingly, transesophageal echocardiography (TEE) is being used to evaluate the thoracic aorta after trauma with reported sensitivity and specificity rates of up to 100%. To confirm these results, we instituted a protocol using TEE as the initial diagnostic study for excluding a ruptured thoracic aorta in patients with widened mediastinum. All TEE studies were done by experienced cardiologists; 96% were done in the trauma receiving area. TEE studies were classified as positive, negative, or indeterminant. Indeterminant studies were those in which the diagnosis of aortic injury could not be excluded based solely on TEE findings. Because we were interested in using TEE as a "definitive" diagnostic modality, indeterminant studies were regarded as positive for our analysis. This protocol was used in 114 trauma patients over a 3-year period. TEE identified five thoracic aortic disruptions--three confirmed by aortography and two by thoracotomy. TEE was read as indeterminant in 17 patients and further investigation with aortography showed no aortic injury in these patients. TEE was negative in 89 patients who had no further evaluation and were subsequently discharged or who died from other injuries. TEE failed to reveal significant lesions in three patients who had aortograms that revealed disruptions requiring thoracotomy. The use of TEE for the definitive diagnosis of ruptured aorta in this series yields a sensitivity of 63% and a specificity of 84%.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Posttraumatic Rupture of the Thoracic Aorta: An Eleven-Year Experience

An 11-year experience with 17 acute traumatic ruptures of the thoracic aorta is reviewed. Superior mediastinal widening on initial chest X-ray (CXR) was present in 15 patients. In 2 patients the mediastinum on CXR was initially normal but became wider with regular subsequent films. The diagnosis was made by aortography in 16 patients. All ruptures involved the aortic isthmus although one extended into the distal aortic arch. Emergency aortic repair was performed in all cases. Two had direct suture repair, 1 had a Dacron® patch, and the others required interposition tube grafts. Techniques used to enhance repair varied from a simple cross-clamp without heparinization to total cardiopulmonary bypass, deep hypothermia, and circulatory arrest. Four patients underwent surgery for other conditions prior to aortic repair (2 craniotomies, 2 laparotomies). There was 1 postoperative death and 2 cases of permanent paraparesis, both of which had been documented preoperatively. Aortography is a reliable diagnostic investigation in this condition. Repair should be performed in a center equipped with cardiopulmonary bypass. Surgical priority over the aortic repair should be given only to intracranial hemorrhage or selected cases of intraabdominal bleeding. Paraplegia can result from the injury as well as being associated with the aortic repair.

Pictorial review: imaging of traumatic aortic injury

Traumatic aortic injury is a leading cause of death in patients with blunt trauma of the thorax. More than 120 patients with traumatic aortic injury have been admitted to our institution. This institutional experience is the source of the material that is presented in this pictorial review. The appearance of traumatic aortic injury on chest radiography, thoracic aortography and CT scan is demonstrated.

Associated injuries in patients with blunt chest trauma: detection by abdominal roentgenograms after aortography

To determine the value of abdominal roentgenograms after aortography for detecting additional organ injuries, we retrospectively evaluated the abdominal and pelvic roentgenograms after aortography of 170 trauma patients who underwent arch aortography to detect aortic rupture. In 160 (94%) of 170 patients, the results of arch studies were normal. Ten (6%) of 170 patients had aortic rupture (8 patients) or rupture of a major vessel (2 patients). Thirty-one (18%) of 170 patients had associated injuries demonstrated by the roentgenograms taken after aortography, including pelvic or femoral fractures (13%), pelvic hematomas (5.8%), renal injuries (1.1%), and bladder ruptures (2.9%). We conclude that abdominal and pelvic pain roentgenograms should be part of a routine arch aortography performed for blunt chest trauma to detect additional organ injuries that frequently accompany injuries from motor vehicle crashes.

Computed tomography as a screening exam in patients with suspected blunt aortic injury

BACKGROUND

Chest computed tomography (CT) screening of patients with blunt trauma for thoracic aortic injury is controversial. This study was undertaken to determine whether CT could exclude aortic injury and be used to select patients for aortography.

METHODS

Computed tomography and aortography were used to evaluate 155 patients with blunt trauma. Computed tomography scans were reviewed separately by four attending radiologists who were unaware of the patients' clinical course and angiographic findings.

RESULTS

Eight of 155 patients had aortic injuries requiring operation. Computed tomography scans in five patients were read as positive by all reviewers. One scan was read as positive by three reviewers and as negative by one. Two scans were read as positive by two radiologists and as negative by two. After poor scans were excluded, the combined sensitivity of CT for detecting aortic injury was 88%, specificity was 54%, positive predictive value was 9%, and negative predictive value 99%.

CONCLUSIONS

The sensitivity of CT scan for indicating the need for aortography is observer dependent. As CT manifestations of aortic injury are often subtle, CT does not reliably exclude aortic injury.

Trauma radiology: part II. Diagnostic imaging of thoracic trauma: review and update

Frontal chest radiographs are the principal diagnostic imaging study to detect, verify, or exclude acute thoracic injury after trauma, and they should be obtained as quickly as possible without compromising clinical assessment and resuscitation. Chest radiographs provide important information about potentially life-threatening conditions, such as tension pneumothorax, major hemothorax, and major arterial injury. In many patients, chest radiographs also provide helpful clues to the presence of such conditions as diaphragmatic rupture, pulmonary contusion/laceration, and tracheobronchial injury. In selected patients, computed tomography scans can supplement information provided by radiography, particularly for detection of mediastinal hemorrhage, aortic pseudoaneurysm, subtle pneumothorax, and delineation of complex pleuroparenchymal processes. On occasion, magnetic resonance imaging can be used to assess integrity of the hemidiaphragms and visceral herniation when other diagnostic studies are equivocal. We consider typical imaging findings associated with a variety of acute thoracic injuries, as well as the most appropriate use of available imaging techniques in different clinical scenarios.

The successful surgical repair of a traumatic transection of the descending thoracic aorta: report of a case

An 18-year-old man involved in a traffic accident presented with a left-sided hemothorax. After undergoing left chest tube drainage, he showed temporary stable hemodynamics for 7 h. Later, an emergency left thoracotomy was performed because of abrupt hemorrhagic shock. The intima and media of the descending thoracic aorta was completely transected, and a tube graft was successfully interposed with a simple aortic clamp in 47 min. The patient was eventually discharged from the hospital with no sequelae, such as paraplegia.

Detection of aortic tear in the acute trauma patient using MRI

Traumatic aortic tears are life threatening and, therefore, need to be evaluated urgently. Typically, a thoracic aortogram is conducted; however, aortography occasionally demonstrates nonspecific abnormalities. These equivocal examinations can lead to unnecessary thoracotomies, or repeated angiography and catastrophic delays in aortic repair. We report a case in which magnetic resonance (MR) imaging was very useful in the diagnosis of aortic tear.

Fractured rib with penetrating cardiopulmonary injury

Described is an unusual injury, arising from a motorized vehicle accident, in which a detached fractured rib from a flail chest caused lung perforation and hemopericardium. The full diagnosis was only appreciated on computed tomography. Therefore, thoracotomy averted potential disaster.

Traumatic aortic injuries: current concepts

This article summarizes current concepts of traumatic injuries of the aorta. The "osseous pinch" mechanism of injury is presented and discussed. The role of each imaging modality in patient evaluation is considered and a rational approach to their use suggested based on current technology and practices.

Use of CT for diagnosis of traumatic rupture of the thoracic aorta

CT imaging of traumatic aortic rupture has been both advocated and disparaged in the current literature as a reliable diagnostic modality. In a retrospective review of blunt chest trauma patients at our institution evaluated by both thoracic CT and arteriography, we found a 17% false negative rate and a 39% false positive rate. Although we feel CT is not sufficiently sensitive at present to evaluate traumatic rupture of the aorta directly, it is an invaluable adjunctive imaging modality for stable blunt chest trauma patients with equivocal chest radiographs or arteriograms.

Right atrial rupture due to blunt trauma: CT evaluation

Controversy currently exists over the use of CT versus aortography in initial evaluation of blunt chest trauma. A case is described in which CT expeditiously diagnosed cardiac rupture and ruled out aortic trauma.

Acute posttraumatic rupture of the thoracic aorta: the role of angiography in a 7-year review

Between 1983 and 1989, 15 patients with acute rupture of the thoracic aorta by blunt trauma were seen. Superior mediastinal widening and obscuration of the aortic arch were the most important findings on chest radiograph. Computed tomography examinations in 7 patients showed mediastinal hematomas but did not reveal aortic lesions. Definitive diagnosis of traumatic aortic rupture was established by aortography in all 15 patients. Intraarterial digital subtraction angiography proved to be as accurate as conventional film aortography and saved time.

Traumatic aortic rupture in the pediatric population. Role of plain film, CT and angiography in the diagnosis

A retrospective review was undertaken to determine the incidence of, and radiologic findings associated with aortic rupture resulting from blunt chest trauma in children. Records and imaging data of 54 consecutive pediatric patients admitted over a 2 year period to a pediatric trauma center after sustaining blunt chest trauma were reviewed. Four of 54 (7.4%) had a documented aortic tear. Plain films were evaluated for 7 radiographic signs described in the adult literature as sensitive indicators of aortic rupture, including abnormal aortic contour and mediastinal widening. Two groups of patients were defined: Group 1 (n = 4) had aortic rupture confirmed by angiography or operation and Group 2 (n = 50) with no angiographic investigation. All patients in Group 1 demonstrated mediastinal widening and abnormal aortic contour; however, 50 percent of patients in Group 2 had similar findings. Computed tomograms of the thorax where obtained were reviewed, including 1 patient from Group 1 and 6 patients from Group 2. The aortic tear was well demonstrated in the one patient from Group 1; however, the remaining computed tomograms were deemed inadequate for reliable exclusion of significant aortic injury. Plain chest radiographic findings in 5 consecutive children who underwent aortography in the two years subsequent to this series, including 2 additional patients with aortic rupture, were also reviewed, with similar results. In conclusion, traumatic aortic rupture in the pediatric population may be more common than previously reported. Plain film findings of aortic rupture in children are similar to those in adults, and are sensitive but non-specific. Currently, at least in our institution, this injury may be underinvestigated. Angiography remains the modality of choice in the diagnosis of aortic tears in children.(ABSTRACT TRUNCATED AT 400 WORDS)

The normal mediastinum in blunt traumatic rupture of the thoracic aorta and brachiocephalic arteries

In a review of 52 articles, published between 1953 and 1989, 656 patients with blunt traumatic rupture of the thoracic aorta or brachiocephalic arteries were identified. Of these, 608 (92.7%) had an abnormal mediastinum on initial chest radiographs obtained in the emergency department, thus allowing early detection of the vascular injury. Unfortunately, 48 (7.3%) of these patients had a normal mediastinum on their initial chest radiographs. This appears to occur when the traumatic pseudoaneurysm is not accompanied by associated mediastinal hemorrhage or hematoma formation, and the pseudoaneurysm is either small or is situated in such a way that it does not alter the mediastinal contour. The use of accessory clinical and radiographic signs to indicate the need for aortography has been shown to be of very low yield, but would have allowed the early detection of an additional 5.6% of the reported cases. Performing aortography solely on the basis of a history of major decelerating blunt trauma to the thorax remains the only way, in the acute emergency department setting, to detect the 1.7% of patients with aortic or brachiocephalic arterial rupture who have no mediastinal abnormality or accessory clinical or radiographic signs of vascular injury. There is evidence from the literature, however, to suggest that the evaluation of serial chest radiographs obtained at close intervals for the first month following trauma for the development of mediastinal abnormality or large hemothorax is an acceptable alternative to the routine performance of aortography in those blunt chest trauma victims with no clinical or radiographic suspicion of vascular injury.

Rapid diagnosis of thoracic aortic transection using intravenous digital subtraction angiography

Rupture of the thoracic aorta associated with blunt trauma remains a frequently lethal injury. Although increasing numbers of patients with ruptured aortas are surviving to reach the hospital, the in-hospital mortality attending this injury remains high. Death due to transected aorta has been related to a delay in diagnosis. In an attempt to decrease the time necessary for diagnosis of this injury, we studied 50 patients using intravenous digital subtraction angiography (IVDSA) and conventional biplane angiography. We found that IVDSA was significantly faster than conventional biplane angiography, and that when IVDSA films are of diagnostic quality, they are sufficient to reliably demonstrate the presence of traumatic aortic transection. Our study was too small to establish whether IVDSA is a sufficiently sensitive test to exclude aortic injury. Further studies in this area need to be performed.

Computed tomography in the diagnosis of traumatic rupture of the thoracic aorta

Over a 26-month period, 25 patients admitted to the Trauma Unit at UCSD Medical Center following blunt trauma were investigated for suspected traumatic rupture of the thoracic aorta by computed tomography (CT) of the chest. A retrospective review of these patients was performed. Twenty-one (84%) also had CT of other body areas, most commonly the head or abdomen. Nine of the 25 patients subsequently had aortography; in 15 patients the CT findings were felt at the time to exclude rupture, and one patient was not investigated further because of severe head injuries. In general, if CT failed to show a mediastinal haematoma, aortography was not performed. However, five patients with CT evidence of a haematoma, including two with vertebral fractures, were not investigated by aortography. Two of the 25 patients (8%) had angiographically proven aortic ruptures; in both CT had shown not only a haematoma but also an abnormal outline of the aorta on contrast-enhanced scans. The haematoma was large in one patient and small in the other. Although 10 of the 25 patients had unenhanced scans, no case of aortic rupture is known to have been missed. During the same study period, 47 patients were investigated for suspected aortic rupture solely by aortography. Four patients (8% of this group) had aortic rupture, and two had subclavian or innominate artery ruptures. Only a minority (approximately one-quarter) also had CT of the head or abdomen. The role of CT in the diagnosis of traumatic rupture of the aorta is critically assessed in the light of our experience and a review of the literature.