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Background: An increasing number of minimal aortic injuries (MAIs) are being identified with modern computed tomography (CT) imaging techniques. The optimal management and natural history of these injuries are unknown. We have adopted a policy of selective multidisciplinary nonoperative management of MAI. This study examines our experience with these patients from July 2004 to June 2009., Methods: Retrospective chart review of all blunt trauma patients who underwent chest CT angiography to evaluate for blunt aortic injury (BAI) was undertaken. All patients deemed to have a MAI were managed nonoperatively, and those with a severe aortic injury underwent repair. Data collected included age, mechanism of injury, Injury Severity Score, type and location of aortic injury, intensive care unit length of stay (LOS), overall LOS, ventilator days, disposition, and mortality. In addition, all BAIs were graded according to the Presley Trauma Center CT Grading System of Aortic Injury., Results: Forty-seven patients with BAI were identified. Thirty-two were classified as severe injuries, and 15 were considered MAI (32%). Nineteen underwent operative repair, 13 underwent endovascular stent graft repair, and 15 were managed nonoperatively. The average Injury Severity Score was 31 ± 10, and the average age was 44 ± 20 with no significant difference across treatment groups. There was no difference in overall or intensive care unit LOS. The nonoperative group had a shorter duration of ventilator days (1.1 vs. 4.28, p = 0.02). There were five deaths, none in the nonoperative group. None of these patients required subsequent intervention. All nonoperative patients had follow-up imaging at median of 4 days; on CT chest angiography, five injuries had resolved, eight had stable intimal flaps or pseudoaneurysm, and two had no detectable injury on subsequent aortogram., Conclusion: Almost one-third of our BAI were safely managed nonoperatively. Patients with MAI should be considered for selective nonoperative management in a multidisciplinary approach with close radiographic follow-up. We recommend that patients with MAIs should be considered for selective nonoperative management.

Background: The optimal method of vascular control and resuscitation in patients with life-threatening, extrathoracic torso hemorrhage remains debated. Guidelines recommend emergency department thoracotomy (EDT) with aortic clamping, although transabdominal aortic clamping followed by vascular control and direct vascular control (DVC) without aortic clamping are alternatives. The objective of this study is to compare the effectiveness of three approaches to extrathoracic torso hemorrhage in a large animal model., Methods: Adolescent swine (Sus Scrofa) (mean weight = 80.9 kg) were randomized into three groups all of which had class IV shock established by hemorrhage from an iliac artery injury. Group 1: EDT with thoracic aortic clamping (N = 6); group 2: transabdominal supraceliac aortic clamping (SCC; N = 6); and group 3: DVC of bleeding site without aortic clamping (N = 6). After hemorrhage, EDT or SCC was performed in groups 1 and 2, respectively, with subsequent exploration of the bleeding site and placement of a temporary vascular shunt (TVS). Group 3 (DVC) underwent direct exploration of the injury and placement of a TVS. All groups were resuscitated to predefined physiologic endpoints over 6 hours with repeated measures of central and cerebral perfusion and end-organ function at standardized time points. Postmortem tissue analysis was performed to quantify injury to critical tissue beds., Results: There was no difference in mortality among the groups and no TVS failures. Central aortic pressure, carotid flow, and partial pressure brain tissue oximetry, all demonstrated increases in EDT and SCC after application of the aortic clamp relative to DVC (p < 0.05). During resuscitation, serum lactate levels were higher in EDT compared with SCC and DVC (6.85 vs. 3.08 and 2.15, respectively; p < 0.05) and serum pH in EDT reflected greater acidosis than SCC and DVC (7.24 vs. 7.36 and 7.39, respectively; p < 0.05). EDT and SCC required more intravenous fluid than DVC (2,166 mL and 2,166 mL vs. 667 mL, respectively; p < 0.05) and more vasopressors were used in EDT and SCC compared with DVC (52.1 μg and 43.5 μg vs. 12.4 μg, respectively; p < 0.05). Brain and myocardial tissue stains demonstrated the same degree of acute ischemic changes in all groups., Conclusion: Although aortic clamping increases central and cerebral perfusion, DVC results in less physiologic derangement. The optimal method of aortic control would incorporate the benefits of maintained central pressure with less associated morbidity. Clinical studies evaluating DVC are warranted.

Background: Thoracic endovascular aortic repair (TEVAR) has become the preferred intervention for managing traumatic thoracic aortic injury. The literature suggests that TEVAR is associated with reduced mortality and paraplegia compared with open repair (OR). The lack of guidelines for reporting results and the paucity of patient follow-up make interpretation of the literature difficult., Methods: A literature review of English language papers on thoracic aortic trauma published between 2005 and 2010 was performed. Papers were analyzed to determine how many commented on injury data known to affect outcome (age, hemodynamic stability, injury severity, degree of aortic injury, etc.)., Results: Sixty-two retrospective reviews and six meta-analysis papers were identified. Of the review papers, only 6.4% described aortic anatomy using standard criteria, only 25.8% reported the degree of aortic injury, only 19.4% defined early or emergent intervention, only 32.3% provided details regarding hemodynamic stability, and only 56.5% described injury severity by Injury Severity Score. In a subset analysis of papers containing trauma relevant data, comparing TEVAR with OR, the TEVAR population was older, whereas the OR group was more often unstable. TEVAR had a significantly lower mortality, a trend to reduction in paralysis, but a significantly increased stroke rate. Follow-up was minimal in both groups., Conclusion: The lack of reporting guidelines coupled with a paucity of follow-up data weakens any recommendation regarding the optimal choice of intervention. To address these deficiencies, we recommend reporting guidelines specific to the trauma population that will allow better risk adjustment and improve the quality of the evidence base.

Background: The epidemiology of vascular injuries in the geriatric patient population has not been described. The purpose of this study was to examine nationwide data on vascular injuries in the geriatric patients and to compare this with the nongeriatric adult patients with respect to the incidence, injury mechanisms, and outcomes., Methods: Geriatric patients aged 65 or older with at least one traumatic vascular injury were compared with an adult cohort aged 16 years to 64 years with a vascular injury using the National Trauma Databank version 7.0., Results: During the study period, 29,736 (1.6%) patients with a vascular injury were identified. Of those, geriatric patients accounted for 7.6% (2,268) and the nongeriatric adult patients accounted for 83.1% (n=24,703). Compared with the nongeriatric adult patients, the geriatric vascular patients had a significantly higher Injury Severity Score (26.6±17.0 vs. 21.3±16.7; p<0.001) and less frequently sustained penetrating injuries (16.1% vs. 54.1%; p<0.001). The most commonly injured vessels in the elderly were vessels of the chest (n=637, 40.2%), including the thoracic aorta and innominate and subclavian vessels. The overall incidence of thoracic aorta injuries was significantly higher in geriatric patients (33.0% vs. 13.9%; p<0.001) and increased linearly with progressing age. After adjusting for confounding factors, geriatric patients demonstrated a fourfold increase in mortality following vascular injuries (adjusted odds ratio, 3.9; 95% confidence interval, 3.32-4.58; p<0.001)., Conclusion: Vascular trauma is rare in the geriatric patient population. These injuries are predominantly blunt, with the thoracic aorta being the most commonly injured vessel. Although vascular injuries occur less frequently than in the nongeriatric cohort, in the geriatric patient, vascular injury is associated with a fourfold increase in adjusted mortality.

Background: Noncompressible hemorrhage from central vascular injuries remains the leading cause of preventable death in modern combat. This report introduces a large animal model of noncompressible torso hemorrhage, which permits assessment of the various approaches to this problem., Methods: Yorkshire swine were anesthetized and monitoring devices for central aortic pressure, carotid flow, and intracerebral and transcutaneous brain oximetry were applied. Class IV hemorrhagic shock was induced through an iliac arterial injury and animals were subjected to different vascular control methods including thoracic aortic clamping, supraceliac aortic clamping, direct vascular control, and proximal endovascular balloon occlusion. After vascular control, the injury was shunted, and damage control resuscitation was continued. Serum markers, intravenous fluid volumes, and vasopressor requirements were tracked over a subsequent resuscitation period. Postmortem tissue analysis was performed to compare levels of acute ischemic injury between groups., Results: The protocol for animal preparation, hemorrhage volume, open surgical technique, and posthemorrhage resuscitation was developed using four animals. The endovascular approach was developed using two additional animals. After model development, treatment animals subsequently underwent noncompressible hemorrhage with thoracic aortic clamping, supraceliac aortic clamping, direct vascular control, and endovascular aortic occlusion. Premature death occurred in one animal in the direct vascular control group., Conclusion: This study presents a large animal model of class IV hemorrhagic shock from noncompressible hemorrhage, which permits comparison of various vascular control methods to address this challenging problem. Future studies using this model as the standard will allow further development of strategies for the management of noncompressible hemorrhage.

Objective: The objective of this study was to identify the incidence and patterns of thoracic aortic injuries in a series of blunt traumatic deaths and describe their associated injuries., Methods: All autopsies performed by the Los Angeles County Department of Coroner for blunt traumatic deaths in 2005 were retrospectively reviewed. Patients who had a traumatic thoracic aortic (TTA) injury were compared with the victims who did not have this injury for differences in baseline characteristics and patterns of associated injuries., Results: During the study period, 304 (35%) of 881 fatal victims of blunt trauma received by the Los Angeles County Department of Coroner underwent a full autopsy and were included in the analysis. The patients were on average aged 43 years±21 years, 71% were men, and 39% had a positive blood alcohol screen. Motor vehicle collision was the most common mechanism of injury (50%), followed by pedestrian struck by auto (37%). A TTA injury was identified in 102 (34%) of the victims. The most common site of TTA injury was the isthmus and descending thoracic aorta, occurring in 67 fatalities (66% of the patients with TTA injuries). Patients with TTA injuries were significantly more likely to have other associated injuries: cardiac injury (44% vs. 25%, p=0.001), hemothorax (86% vs. 56%, p<0.001), rib fractures (86% vs. 72%, p=0.006), and intra-abdominal injury (74% vs. 49%, p<0.001) compared with patients without TTA injury. Patients with a TTA injury were significantly more likely to die at the scene (80% vs. 63%, p=0.002)., Conclusion: Thoracic aortic injuries occurred in fully one third of blunt traumatic fatalities, with the majority of deaths occurring at the scene. The risk for associated thoracic and intra-abdominal injuries is significantly increased in patients with thoracic aortic injuries.

Purpose: To report our experience with the diagnosis and treatment of aortoiliac vascular injuries caused by misplaced orthopedic fixation screws., Materials: Six patients (age range, 35-60 years; mean, 52 years) were diagnosed with seven arterial injuries related to misplacement of fixation screws. The location of the injuries were thoracic aorta (n = 4) and common iliac arteries (n = 3). There was vessel wall penetration in five injuries resulting in active bleeding in two patients, contained penetrations in two patients, and vessel occlusion in one patient. One patient had associated inferior vena cava injury and pulmonary embolism. Two patients had asymptomatic impingement of the aortic wall by the screws., Results: Vascular injuries resulted in death in one patient and limb amputation in another patient. Three patients were treated with placement of stent grafts and screw removal. Screw replacement was performed in one patient. Conservative observation was done in one patient., Conclusions: Vascular injuries related to misplacement of fixation screws are relatively infrequent but potential life and limb-threatening complications that require early recognition with prompt repair of vascular lesions and screw reposition.

Introduction: Despite advances in the surgical therapy of aortic injury (AI) using endovascular prostheses, more than 60% of motor vehicle crash (MVC) induced AIs die at the scene. In 80 cases of MVC AI, both change in velocity on impact (Delta V) and impact energy (IE) were correlated with autopsy or surgical findings. Of the 34 AIs due to lateral impact MVCs (LMVC), 91% had an aortic isthmus laceration. Computer simulation is used to study the cause of LMVC AI., Methods: To delineate AI mechanism, 10 real life LMVCs (8 left, 2 right) were simulated using a computer-based finite element numerical model. Each began with the initial vehicle impact with another vehicle or fixed object, followed by the vehicle's compartment structures' impact with the patient's chest wall, causing a rise in intra-aortic pressure and the resulting location and pattern of aortic wall stresses and strains. In the real LMVCs, the Delta V ranged from 27.5 to 62 kph with impact energies of from 46,051 to 313,502 joules. In both real-life and the model, the main cause of the chest wall impact was intrusion of the car's B-pillar. Dynamic simulations delineate increased stress and strains at the aortic Isthmus. In some LMVCs, the B-pillar intrusion was also seen to impact the head in the AI cases., Results: In the simulations, aortic pressure rose from 100 mm Hg precrash to as high as 1,322 mm Hg. Both the maximum aortic longitudinal tensile strain and the von Mises Stress were proportional to the maximum force impacted on the chest wall. Aortic isthmus maximum stresses ranged from 1.1 Mega Pascal (MPa) to 3.2 MPa, with longitudinal tensile strains ranging from 8.2% to 48.5%. The simulation dynamics demonstrated that the proximal pressurized turgid aorta initially moves toward the LMVC impact. As a result, the ascending aorta and aortic arch (proximal ascending aorta) rotate about the fulcrum of the great vessels, so that this aortic unit, acting as the long-arm of an Archimedes lever system, exerts the maximum stress and strain at the aortic isthmus or short-arm, where the real-life aortic rupture occurs., Conclusion: Simulation supports the lever hypothesis that the force on the short-arm aortic isthmus is proportionally greater than at the long-arm proximal aorta. Simulation also suggests improved vehicle construction techniques, which increase the strength and resistance to deformation of the B-pillar and vehicle side structure plus a B-pillar airbag will limit the intrusion forces causing LMVC AIs and reduce the incidence of associated head injuries.

Background: Treatment of traumatic vascular injury using endovascular techniques has evolved as endovascular capabilities have advanced over the past several decades. Several endovascular techniques have been employed to address the challenges of traumatic arterial injury, including coil embolization and the use of stents, which may be either bare metal or covered with graft material. Compared with traditional surgical repair, endovascular stent grafting for the repair of traumatic arterial injury offers the advantage of decreased morbidity because a remote access site may be used, avoiding surgical dissection and lengthy operating times., Methods: A Medline (1995-2007) search was performed to find all studies discussing the use of endovascular means to treat supradiaphragmatic arterial trauma., Results: In this review of 195 studies published between January 1995 and December 2007, the overall technical success rate of endovascular treatment of supradiaphragmatic arterial injury was 96.7%, and the complication rate was 6.4%., Conclusion: The results of this review suggest a potential morbidity and mortality benefit over traditional open repair; however, long-term data are lacking. Long-term follow-up for stent durability is of particular concern in the trauma population, which tends to comprise younger patients with minimal atherosclerotic disease. The success of endovascular techniques is also limited by the availability of skilled interventionalists, properly outfitted angiography suites, and suitable stent graft devices. Despite these challenges, the potential advantages of endovascular stenting make it a welcome addition to the armamentarium of the vascular interventionalist who treats arterial traumatic injuries.

Background: The traditional approach to stable blunt thoracic aortic injuries (TAI) is immediate repair, with delayed repair reserved for patients with major associated injuries. In recent years, there has been a trend toward delayed repair, even in low-risk patients. This study evaluates the current practices in the surgical community regarding the timing of aortic repair and its effects on outcomes., Methods: This was a prospective, observational multicenter study sponsored by the American Association for the Surgery of Trauma. The study included patients with blunt TAI scheduled for aortic repair by open or endovascular procedure. Patients in extremis and those managed without aortic repair were excluded. The data collection included demographics, initial clinical presentation, Injury Severity Scores, type and site of aortic injury, type of aortic repair (open or endovascular repair), and time from injury to aortic repair. The study patients were divided into an early repair (< or = 24 hours) and delayed repair groups (> 24 hours). The outcome variables included survival, ventilator days, intensive care unit (ICU) and hospital lengths of stay, blood transfusions, and complications. The outcomes in the two groups were compared with multivariate analysis after adjusting for age, Glasgow Coma Scale, hypotension, major associated injuries, and type of aortic repair. A second multivariate analysis compared outcomes between early and delayed repair, in patients with and patients without major associated injuries., Results: There were 178 patients with TAI eligible for inclusion and analysis, 109 (61.2%) of which underwent early repair and 69 (38.8%) delayed repair. The two groups had similar epidemiologic, injury severity, and type of repair characteristics. The adjusted mortality was significantly higher in the early repair group (adjusted OR [95% CI] 7.78 [1.69-35.70], adjusted p value = 0.008). The adjusted complication rate was similar in the two groups. However, delayed repair was associated with significantly longer ICU and hospital lengths of stay. Analysis of the 108 patients without major associated injuries, adjusting for age, Glasgow Coma Scale, hypotension, and type of aortic repair, showed that in early repair there was a trend toward higher mortality rate (adjusted OR 9.08 [0.88-93.78], adjusted p value = 0.064) but a significantly lower complication rate (adjusted OR 0.4 [0.18-0.96], adjusted p value 0.040) and shorter ICU stay (adjusted p value = 0.021) than the delayed repair group. A similar analysis of the 68 patients with major associated injuries, showed a strong trend toward higher mortality in the early repair group (adjusted OR 9.39 [0.93-95.18], adjusted p value = 0.058). The complication rate was similar in both groups (adjusted p value = 0.239)., Conclusions: Delayed repair of stable blunt TAI is associated with improved survival, irrespective of the presence or not of major associated injuries. However, delayed repair is associated with a longer length of ICU stay and in the group of patients with no major associated injuries a significantly higher complication rate.

Background: Blunt thoracic aortic injuries (BTAI) have a high mortality rate. For survivors, chest X-ray (CXR) findings are used to determine the need for further diagnostic testing with chest computerized tomography with angiography (CTA) or conventional angiography. We set to determine the adequacy of utilizing CXR alone as a screening tool for BTAI., Methods: All patients diagnosed with BTAI at a level I trauma-center during a 7-year-period were identified. CXRs of these patients and those of a control group of blunt trauma patients with an injury severity score >15 were reviewed by four trauma surgeons blinded to the diagnosis. Based on each CXR viewed, the surgeons decided if they would have proceeded to chest CTA, angiography, or required no further studies to rule out BTAI., Results: In the 7-year-period, 83 patients had BTAI. CXRs were available in 45 patients. The four surgeons viewed 96 CXRs including those of 51 controls. Based on the CXR appearance in patients with BTAI, the surgeons chose to proceed to chest CTA in 38 patients (84.4%), conventional aortography in two patients (4.4%), and no further testing in five patients (11.2%). A widened mediastinum (75%) and loss of the aorto-pulmonary window (40%) were the most frequent CXR abnormalities. Patients with BTAI were more likely to have an abnormal CXR-40 of 45 (88.8%) patients when compared with the controls-25 of 51 (49%)patients-p < 0.001., Conclusions: Although CXR is a sensitive screening modality, it failed to identify the possibility of BTAI in 11% of patients. The liberal use of chest CTA after high speed motor vehicle crashes is recommended to minimize the incidence of missed BTAI.

Background: The diagnosis and management of blunt thoracic aortic injuries has undergone many significant changes over the last decade. The present study compares clinical practices and results between an earlier prospective multicenter study by the American Association for the Surgery of Trauma completed in 1997 (AAST1) and a new similar study completed in 2007 (AAST2)., Methods: The AAST1 study included 274 patients from 50 participating centers over a period of 30 months. The AAST2 study included 193 patients from 18 centers, over a period of 26 months. The comparisons between the two studies included the method of definitive diagnosis of the aortic injury [computed tomography (CT) scan, aortography, transesophageal echocardiogram (TEE) or magnetic resonance imaging], the method of definitive aortic repair (open repair vs. endovascular repair, clamp and sew vs. bypass techniques), the time from injury to procedure (early vs. delayed repair), and outcomes (survival, procedure-related paraplegia, other complications)., Results: There was a major shift of the method of definitive diagnosis of the aortic injury, from aortography in the AAST1 to CT scan in AAST2, and a nearly complete elimination of aortography and TEE in the AAST2 study. In the AAST2 study the diagnosis was made by CT scan in 93.3%, aortography in 8.3%, and TEE in 1.0% of patients when compared with 34.8%, 87.0%, and 11.9%, respectively, in the AAST1 study (p < 0.001). The mean time from injury to aortic repair increased from 16.5 hours in the AAST1 study to 54.6 hours in the AAST2 study (p < 0.001). In the AAST1 study, all patients were managed with open repair, whereas in the AAST2 study only 35.2% were managed with open repair and the remaining 64.8% were managed with endovascular stent-grafts. In the patients managed with open repair, the use of bypass techniques increased from 64.7% to 83.8%. The overall mortality, excluding patients in extremis, decreased significantly from 22.0% to 13.0% (p = 0.02). Also, the incidence of procedure-related paraplegia in patients with planned operation, decreased from 8.7% to 1.6% (p = 0.001). However, the incidence of early graft-related complications increased from 0.5% in the AAST1 to 18.4% in the AAST2 study., Conclusions: Comparison between the two AAST studies in 1997 and 2007 showed a major shift in the diagnosis of the aortic injury, with the widespread use of CT scan and the almost complete elimination of aortography and TEE. The concept of delayed definitive repair has gained wide acceptance. Endovascular repair has replaced open repair to a great extent. These changes have resulted in a major reduction of mortality and procedure-related paraplegia but also a significant increase of early graft-related complications.

Background: There is no consensus on the mechanism of traumatic injury to the thoracic aorta and no reproducible animal model. Advances in injury scene analysis suggest that lateral and oblique force vectors cause aortic injury. We hypothesized that the spectrum of aortic injury could be reproduced in an animal model by application of an obliquely directed load to the pressurized aorta., Methods: Graded air impulses of 80, 100, 110, and 120 pounds per square inch (PSI) were delivered to the descending thoracic aorta of 19 swine with a novel pneumatic device. Aortic isthmus strain was recorded with microminiature probes. Gross and microscopic injury was recorded with digital photography., Results: The spectrum of human aortic injury was reproduced in this model. Deep injuries to the aortic media were common. The majority of injuries occurred within the region of the isthmus. Impulse pressure of 120 PSI caused transections, whereas lower impulse pressure resulted in less severe injuries. Aortic isthmus strain was greater in the animals exposed to 120 PSI than those receiving lower PSI (19.6 +/- 4.9% vs. 8.7 +/- 2.5%, p = 0.067)., Conclusions: Direct loading of the pressurized descending thoracic aorta causes isthmus injury secondary to aortic wall strain. Deep medial lesions are common and could propagate soon after injury to form pseudoaneurysms. A critical load is required to cause complete uncontained transection with exsanguination, which may have relevance to injury scene death.

Introduction: The purpose of this American Association for the Surgery of Trauma multicenter study is to assess the early efficacy and safety of endovascular stent grafts (SGs) in traumatic thoracic aortic injuries and compare outcomes with the standard operative repair (OR)., Patients: Prospective, multicenter study. Data for the following were collected: age, blood pressure, and Glasgow Coma Scale (GCS) at admission, type of aortic injury, injury severity score, abbreviate injury scale (AIS), transfusions, survival, ventilator days, complications, and intensive care unit and hospital days. The outcomes between the two groups (open repair or SG) were compared, adjusting for presence of critical extrathoracic trauma (head, abdomen, or extremity AIS >3), GCS score 55 years. Separate multivariable analysis was performed, one for patients without and one for patients with associated critical extrathoracic injuries (head, abdomen, or extremity AIS >3), to compare the outcomes of the two therapeutic modalities adjusting for hypotension, GCS score 55 years., Results: One hundred ninety-three patients met the criteria for inclusion. Overall, 125 patients (64.9%) were selected for SG and 68 (35.2%) for OR. SG was selected in 71.6% of the 74 patients with major extrathoracic injuries and in 60.0% of the 115 patients with no major extrathoracic injuries. SG patients were significantly older than OR patients. Overall, 25 patients in the SG group (20.0%) developed 32 device-related complications. There were 18 endoleaks (14.4%), 6 of which needed open repair. Procedure-related paraplegia developed in 2.9% in the OR and 0.8% in the SG groups (p = 0.28). Multivariable analysis adjusting for severe extrathoracic injuries, hypotension, GCS, and age, showed that the SG group had a significantly lower mortality (adjusted odds ratio: 8.42; 95% CI: [2.76-25.69]; adjusted p value <0.001), and fewer blood transfusions (adjusted mean difference: 4.98; 95% CI: [0.14-9.82]; adjusted p value = 0.046) than the OR group. Among the 115 patients without major extrathoracic injuries, higher mortality and higher transfusion requirements were also found in the OR group (adjusted odds ratio for mortality: 13.08; 95% CI [2.53-67.53], adjusted p value = 0.002 and adjusted mean difference in transfusion units: 4.45; 95% CI [1.39-7.51]; adjusted p value = 0.004). Among the 74 patients with major extrathoracic injuries, significantly higher mortality and pneumonia rate were found in the OR group (adjusted p values 0.04 and 0.03, respectively). Multivariate analysis showed that centers with high volume of endovascular procedures had significantly fewer systemic complications (adjusted p value 0.001), fewer local complications (adjusted p value p = 0.033), and shorter hospital lengths of stay (adjusted p value 0.005) than low-volume centers., Conclusions: Most surgeons select SG for traumatic thoracic aortic ruptures, irrespective of associated injuries, injury severity, and age. SG is associated with significantly lower mortality and fewer blood transfusions, but there is a considerable risk of serious device-related complications. There is a major and urgent need for improvement of the available endovascular devices.

Objectives: Traumatic thoracic aorta injuries account for nearly 8,000 deaths annually in the United States. Clamp-and-sew techniques can lead to high rates of paraplegia. Use of distal aortic perfusion can lead to heparin-related complications, particularly with associated head trauma. Our objective was to evaluate whether or not an individualized approach to operative management provides acceptable neurologic outcomes., Methods: A retrospective review (1991-2004) of patients with a traumatic thoracic aortic injury at a Level I trauma center was performed., Results: A total of 67 patients fit the study criteria. Ninety-one percent of patients had concomitant injuries. Median time from injury to evaluation was 38.0 minutes and from evaluation to operating room (OR) 111.0 minutes. Fifty-three percent of patients died before definitive repair could be undertaken; 29% were in the emergency department and 24% were in the OR. When definitive repair occurred, distal aortic perfusion was used in 81% of cases (75% left heart bypass, 6% cardiopulmonary bypass). The remaining 19% underwent clamp-and-sew technique without heparinization. There were no spinal cord deficits or adverse cerebral events related to repair. If definitive repair was completed, the mortality was 16%. Male sex and increasing time, both to evaluation and to OR, were the only risk factors associated with increased mortality., Conclusions: Judicious use of clamp-and-sew techniques can achieve excellent neurologic outcomes, equivalent to distal aortic perfusion. Prompt evaluation leads to improved survival. Factors such as age, mechanism of injury, site of aortic injury, or operative technique did not affect mortality.

Background: To use motor vehicle crash (MVC) characteristics to determine risk of thoracic aortic injury (TAI) and provide updated mortality data., Methods: Vehicle crash variables and patient medical data from 64,245 MVC occupants (1988-2002) were obtained from the National Automotive Sampling System. Descriptive and logistic regression analyses were used to determine the relationship of crash and occupant characteristics to TAI., Results: Seven hundred ninety occupants (1.2%) had TAI. Overall mortality with TAI was 92%. Prehospital mortality was 63%. Patients taken to a trauma center had significantly lower mortality (75%) than did patients taken to a non-trauma center (90%) (p = 0.006). Risk of TAI was highest with a near-side crash impact. Risk of TAI increased with increasing change in velocity and increasing mass of the striking vehicle. Seat belts were protective not only for all occupants in frontal crashes, but also for drivers and front passengers in a near side lateral impact, whereas airbags were protective only in frontal crashes. No specific injuries reliably predicted TAI with sufficient sensitivity and specificity to be clinically useful., Conclusions: TAI remains a highly lethal injury. Prehospital mortality in this series is lower than in most previous reports, and survival is higher at trauma centers versus non-trauma centers. Associated injuries are poor predictors of TAI. Screening for TAI should include increased emphasis on crash and vehicle occupant characteristics, especially high-velocity MVC, near-side impact, and lack of seat belt use.

Background: Thoracic aortic injury (TAI) is associated with high mortality. It is not practical to evaluate all patients with blunt chest trauma with dedicated aortic imaging. The purpose of this study was to define a group of patients with blunt chest trauma after motor vehicle collision (MVC) that do not require aortic imaging based on information available in the emergency department., Methods: This was a secondary analysis of a prospectively-collected database. Consecutive patients with blunt chest trauma after MVC were included. Characteristics of mechanism, examination, and chest radiographic findings were collected for each patient. All patients underwent chest computed tomography (CT), aortography, or both for TAI evaluation. Binary recursive partitioning was used to derive and validate a clinical decision rule to predict exclusion of TAI., Results: During the study period, 1,096 patients were included, and 22 (2.0%) were diagnosed with TAI. The decision rule for exclusion of TAI included findings from the chest radiograph, incorporating left paraspinous line displacement, obscured aortic knob, and mediastinal widening. The rule resulted in a sensitivity of 86% (95% confidence interval [CI]: 65% to 97%), a specificity of 77% (95% CI: 75% to 80%), a positive predictive value of 7% (95% CI: 4% to 11%), a negative predictive value (NPV) of 99.6% (95% CI: 99.0% to 99.9%), a positive likelihood ratio of 3.8 (95% CI: 1.1-12.9), and a negative likelihood ratio of 0.18 (95% CI: 0.05-0.61). This would potentially reduce aortic imaging by 76% (95% CI: 74% to 79%)., Conclusion: We report a clinical decision rule with a high NPV for exclusion of TAI. This may standardize the approach to such patients and may reduce the need for CT.

Objectives: Can aortic isthmus disruption occurring in a lateral motor vehicle crash (LMVC) be explained by the Archimedes Lever Hypothesis, where the intrathoracic aorta, super-pressurized by the thoracic impact force, functions as a rigid lever system? The long arm of this lever system is the proximal aorta-aortic arch, the short arm is the aortic isthmus fixed distally at the descending aorta, and the fulcrum is at the great vessels, especially the left subclavian artery., Methods: The theory was tested by a simulation technique using a computer-based finite element numerical model system. This simulation model included the dynamics of the crashed vehicles, the direction of force impact, and the structure of the thorax and intrathoracic viscera, including the entire intrathoracic aorta. The specific patient whose data were entered into the model was chosen from a study of 34 LMCV aortic injuries (AIs). The model was constrained by patient and vehicle data from this surviving case., Results: Three sequential lateral thoracic levels impacted by the vehicle side structures were selected. At each level, the maximum mean intra-aortic pressure was 50 to 100 ms after impact, the structure dynamics of the actual crash and the resultant vehicle deformation were simulated; only when the lateral impact was induced in a transverse plane including the first 4 ribs at the level of the aortic arch/isthmus system, with intra-aortic pressures from 200 to 500 mm Hg, were AI-compatible stresses and deformations in the aortic wall achieved at the isthmus., Conclusions: In LMVC AI, the simulation suggests that the aorta functions as an Archimedes Lever System in which the magnified force mediated by the long lever arm produces sufficient strain on the short lever arm to rupture the aorta at the isthmus.

Background: Traumatic injuries of the thoracic aorta have a high morbidity and mortality. Treatment options include either open surgery or endovascular stent graft implantation., Methods: We have reviewed retrospectively all our patients treated for acute and chronic traumatic injury of the thoracic aorta and compared the outcome of the endovascular versus open therapy. Age, gender, severity of injuries, interventional delay, perioperative morbidity, 30-day mortality, length of intensive care, and overall hospital stay were evaluated., Results: In all, 46 patients were treated over the past 14 years. Overall 30-day mortality was 16% in patients treated for acute or contained aortic ruptures (n = 31) and not significantly different after endovascular versus open repair (13.3% versus 18.8%). There was no mortality in the patients receiving elective stent grafting or open surgery for chronic posttraumatic aortic aneurysms (n = 15). Conversion and/or operative revision following stent graft implantation occurred in three patients (12.5%). Neurologic complications were absent in the stent graft group (0 of 24), whereas paraplegia (n = 2) or minor neurologic (n = 3) deficits developed following open surgery (5 of 22; 22.7%; p = 0.013). Length of intensive care and overall hospital stay were significantly shorter for patients after elective stent graft treatment compared with open surgery (p = 0.045)., Conclusions: According to our midterm results, minimally invasive endovascular repair for patients with acute traumatic ruptures and chronic posttraumatic aneurysms is an equally effective treatment option compared with open surgery, with advantages regarding perioperative neurologic complications and duration of hospital stay under elective circumstances.

Background: The standard management for patients with blunt aortic injury is surgery; however, a small number of patients have been medically managed. The outcome of these nonoperatively managed patients is unknown., Methods: Seven patients diagnosed as blunt aortic injury were managed without aortic surgery between January 1993 and April 2002, and their outcomes were retrospectively investigated., Results: There were three men and four women, with a mean age of 48.7+/-22.7 years and Injury Severity Score of 37.7+/-16.9. The reason for nonoperative management was refusal of surgery (2), do-not-resuscitate order (1), diffuse brain injury (2), small intimal tear (1), and technical difficulty (1). Two patients died resulting from associated injuries. Five patients are alive, and in three patients complete resolution of aortic injury was observed., Conclusions: In selected patients with multiple associated injuries or severe comorbidity, nonoperative management after blunt aortic injury can be a treatment of choice.

Background: Untreated traumatic aortic transection carries a mortality rate higher than 85%. Standard therapy has been open repair via a left thoracotomy with systemic heparin and is associated with a high risk of paralysis. We reviewed our experience of endoluminal stent-graft repair for treatment of acute traumatic thoracic aortic transection., Methods: Between February 2001 and February 2005, 11 patients sustaining severe blunt trauma with multiple injuries underwent acute endovascular repair for thoracic aortic transection with 'off-the-shelf' commercially available proximal aortic cuffs. No systemic heparin was used. Access to the aorta was obtained either through a femoral/iliac cutdown (n = 4) or percutaneously through the femoral artery (n = 7). Mean follow-up was 21 months (range, 3-49 months)., Results: Technically successful repair was achieved in 100% of patients, as determined by completion angiography demonstrating apposition of the stent-grafts to the aortic wall, normal perfusion of the aortic branches, and exclusion of the aortic transection without evidence of extravasation. None of the patients required secondary interventions, and there were no instances of death or paralysis. Patient follow-up, using computed tomography angiography, demonstrated durability of endovascular repair without evidence of endoleak, stent migration, or late pseudoaneurysm formation., Conclusion: Adaptation and use of commercially available abdominal devices in the thoracic aorta has proven to be technically feasible. Urgent repair of thoracic aortic transection in the setting of blunt trauma can be transformed into a well-tolerated surgical intervention using endovascular techniques. Long-term durability of endovascular repair of traumatic thoracic transections remains unknown, but early and midterm results are promising.

Background: Lethal injuries can be surgically repaired under asanguineous hypothermic condition (suspended animation) with excellent outcome. However, the optimal rate for the induction of hypothermic metabolic arrest following uncontrolled lethal hemorrhage (ULH) is unknown., Methods: ULH was induced in 32 female swine (80-120 lbs) by creating an iliac artery and vein injury, followed 30 minutes later by laceration of the descending thoracic aorta. Through a left thoracotomy approach, total body hypothermic hyperkalemic metabolic arrest was induced by infusing organ preservation fluids into the aorta. Experimental groups were: normothermic controls (no cooling, NC), or hypothermia induced at a rate of 0.5 degrees C/min (slow, SC), 1 degrees C/min (medium, MC), or 2 degrees C/min (fast, FC). Vascular injuries were repaired during the 60 minutes of profound (10 degrees C) hypothermic arrest. Hyperkalemia was reversed by hypokalemic fluid exchange, and blood was infused for resuscitation during the re-warming (0.5 degrees C/ minute) period. The survivors were monitored for 6 weeks., Results: The 6 week survival rates were 0% (NC), 37.5% (SC), 62.5% (MC), and 87.5% (FC) respectively (p < 0.05 MC&FC versus NC). All of the surviving hypothermic arrest animals were neurologically intact and displayed no long term organ dysfunction., Conclusion: Hypothermic metabolic arrest can be used to maintain viability of key organs during repair of lethal injuries. Survival is influenced by the rate of cooling with the best outcome following rapid induction of hypothermia.

Objective: To examine the effect of change in velocity (MV) and energy dissipation (IE) on impact, above and below the test levels for federal motor vehicle crash (MVC) safety standards, on the incidence of aortic injury (AI) and its mortality and associated injury patterns in frontal (F) and lateral (L) MVCs. Comparison of 80 AI and 796 non-AI patients of AIS=3., Methods: Eight hundred seventy-six MVC adult drivers or front-seat passengers (552 F and 324 L) evaluated by 10 Level I CIREN study Trauma Centers together with vehicle and crash scene engineering reconstruction. Patient seatbelt and/or airbag use correlated with clinical or autopsy findings., Results: In AI, 63% of cases were dead at the scene and only 16% survived to leave hospital. The relation between IE dissipated in the MVC and the DeltaV on impact was exponential as DeltaV increased, but the rise in IE for a given DeltaV was greater in LMVC than in FMVC (p <0.05). A more rapid rise in IE/DeltaV occurred above the mean DeltaV of 48 +/- 19.7 kph (30 mph) in FMVC and above the mean DeltaV of 36 +/- 16.2 kph (23 mph) in LMVC. As DeltaV increased above these means, 65% of 46 FMVC aortic injuries (AIs) and 64% of 34 LMVC AIs occurred. In AI patients there was evidence of focusing of the point of IE impact on the upper chest with a higher incidence of rib1-4 fractures than in non-AI (p <0.01) and more brain, heart, lung and spleen injuries (p <0.01) consequent to lower seatbelt use (p <0.01), but LMVC also had more pelvic fx (p <0.05). Airbags + seatbelts in FMVC and seatbelts in LMVC reduced mortality (p <0.05) Comparison of AI incidence in three successive 4-year vehicle model year periods showed a progressive decrease as new safety devices were introduced (p < 0.05)., Conclusions: The implications for AI of the focused IE at the upper chest suggest a probable mechanism for MVC AI with the pressurized aortic arch acting as the long arm of a lever system with the fulcrum at the subclavian artery, producing maximum torsional strain at the short arm of the isthmus where 75% of the AIs occurred. AI mortality is also influenced by the associated injuries. To develop more effective safety systems to prevent AI, MVC safety testing with airbags and seatbelts should be carried out at DeltaVs of 1 SD above means for FMVC and LMVC.

Background: General mediastinal width, left mediastinal width, and mediastinal width ratio were compared as radiographic predictors of aortic injury., Methods: A retrospective study investigated the chest radiographs of 51 patients admitted to a level 1 trauma center during a 6-year period for a thorough survey of aortic injury. Mediastinal width (MW >/= 8 cm), left mediastinal width (LMW >/= 6 cm), mediastinal width ratio (MWR >/= 0.60), and a combination of LMW and MWR were compared as predictors of aortic injury. The cutoff points were predetermined by receiver-operator-curve to accommodate 100% sensitivity for each criterion., Results: Of the 51 patients, 21 had aortic injuries and 30 had normal imaging studies. All criteria had 100% negative predictive value. The specificities and positive predictive values, respectively, were 13.3% and 44.7% (MW), 40.0% and 53.8% (LMW), 43.3% and 55.3% (MWR), and 66.7% and 67.7% (combined LMW and MWR). The positive likelihood ratio of aortic injury was 3.00 when LMW was 6 cm or more and MWR was 0.60 or more., Conclusions: Both an LMW of 6 cm or more and an MWR of 0.60 or more are better radiographic criteria than an MW of 8 cm or more for predicting blunt aortic injury. Trauma patients with positive test results based on the combined LMW and MWR criteria should proceed immediately to aortography or helical computed tomography.

Background: Endovascular stent grafting (EVSG) has emerged as a new treatment for aortic disease and has recently been applied to the treatment of acute blunt aortic injury (BAI). The purpose of this study was to determine the outcome of EVSG for patients with BAI at two tertiary (Level I) trauma centers., Methods: A retrospective review of patients treated between January 1, 1999, and February 1, 2003, at two centers, Calgary Health Region (Calgary, Alberta) and Harborview Medical Center (Seattle, WA), with EVSG for acute BAI is reported. Variables assessed included age, sex, Injury Severity Score, total length of stay (LOS), intensive care unit LOS, operative technique, complications, technical success, mortality, and follow-up data., Results: Twenty-eight patients treated with EVSG for BAI were identified during this period. Twelve patients were excluded because injuries occurred more than 30 days before grafting (n = 7) or under a different protocol (n = 4), or the procedure was performed in a different center (n = 1). Sixteen patients with acute BAI were reviewed. The mean Injury Severity Score was 36.9 (SD, 17.0), with a median intensive care unit LOS of 7.5 days (interquartile range, 1-17 days) and total LOS of 24.5 days (interquartile range, 7-41 days). Mean follow-up was 10.7 months (range, 3-30 months). Technical success was achieved in all patients, no graft-related complications have been detected during follow-up, and no patient developed postoperative paraplegia. One postoperative mortality occurred secondary to severe comorbid injury. A single patient with a preoperative traumatic carotid dissection demonstrated a postoperative stroke, and one patient required thoracentesis for a pleural effusion., Conclusion: Repair of BAI with EVSG can be performed safely in patients with BAI. Mortality, morbidity, and especially paraplegia are reduced. Further long-term studies are required to support the routine use of EVSG technology for BAI.

Background: The purpose of this study was to review the trend of using chest computed tomography (CT) and aortography in evaluating patients with blunt thoracic trauma., Methods: A total of 85 patients who had blunt aortic injury diagnosed by chest CT, aortography, or both were included in this study., Results: Aortography was the dominant modality before 1998, and the use of chest CT has increased to 50% of patients with aortic injuries as of 2001. Isolated aortic, branch vessel, or combined injuries were found in 71 (84%), 11 (13%), and 3 (4%) patients, respectively. All 14 patients with branch vessel injuries were diagnosed by aortography. Ninety-eight percent of patients with aortography were true-positives, and 20% of patients with chest CT had indirect signs of aortic injury., Conclusion: Our institution has increased the use of chest CT to evaluate blunt thoracic trauma. Patients with indirect signs of aortic injuries shown on chest CT require further evaluation. In our experience, angiography remains the optimal diagnostic modality for evaluating aortic branch vessel injuries.

Background: Endovascular stent graft (EV) technology has been successfully adapted to the repair of blunt traumatic aortic injuries. The purpose of this study was to compare the outcomes of patients treated with EV repair and open repair after blunt thoracic aortic trauma., Methods: A review of a tertiary trauma center's prospective trauma registry identified all patients who suffered a blunt traumatic thoracic aortic injury over an 11-year period (1991-2002). Operative interventions and outcomes were then compared., Results: Over an 11-year period, 18 patients underwent repair of a blunt thoracic aortic injury (EV, 6; open, 12). There were no significant differences in demographics, injury, or crash statistics between groups. The open group had a 17% early mortality rate (n = 2), a paraplegia rate of 16% (n = 2), and an 8.3% incidence of recurrent laryngeal nerve injury (n = 1). This is in contrast to a 0% rate of mortality, paraplegia, and recurrent laryngeal nerve injury in the EV group. A definite trend toward decreased morbidity, mortality, intensive care unit length of stay, and number of ventilator-dependent days was seen with EV repair., Conclusion: We observed a clear trend toward improved outcomes after EV repair of thoracic aortic injuries compared with standard open repair. EV repair is emerging as the preferred method of repairing blunt thoracic aortic injuries in trauma patients with multiple injuries.

Purpose: The objective of our study was to use transesophageal echocardiography (TEE) and intravascular ultrasonography (IVUS) to evaluate their role in interrogating abnormal or equivocal findings seen on thoracic aortography performed on blunt chest trauma patients., Methods: A prospective, nonblinded, observational, institutional review board-approved study of IVUS and TEE was conducted in acute blunt chest trauma victims with abnormal findings on thoracic aortograms. IVUS was performed with a 20-MHz catheter and TEE was performed with an omniplane probe., Results: Abnormal aortographic findings were present in 10 men and 4 women (mean age, 40.5 years). All 14 patients were evaluated with IVUS and 13 with TEE. TEE was not performed on one patient because of time constraints. By IVUS, there were 11 true-positives, 2 true-negatives, and 1 equivocal (considered as false-negative), resulting in 91.7% sensitivity and 100% specificity. In the equivocal case, an intimal flap was missed by IVUS and by TEE, but was present at surgery. By TEE, there were six true-positives, two true-negatives, one false-positive, and four false-negatives, resulting in 60% sensitivity and 66.7% specificity. In the false-positive case, an avulsed intercostal artery without an intimal flap was found at surgery. The remaining three false-negative cases were a missed intimal flap, a missed intramural hematoma, and a missed intimal flap obscured by a mural hematoma. In our study, both IVUS and TEE were found to be diagnostic in the four equivocal aortograms. Three of the equivocal results were cases read as a prominent ductus diverticulum versus a pseudoaneurysm. Two were confirmed to be false lumen/pseudoaneurysm by both IVUS and TEE, whereas the other was confirmed to be a prominent ductus diverticulum by both of these modalities. In the fourth equivocal case, thoracic aortography showed an abnormal contour but no intimal flap located along the lesser curvature of the aorta at the junction of the arch and isthmus. No abnormalities were found by IVUS or TEE. This patient was followed clinically. A follow-up thoracic aortogram obtained 1 year later showed no aortic injury., Conclusion: When thoracic aortography yields an abnormal and especially equivocal findings, both IVUS and TEE are helpful in further sorting this out rather than subjecting the patient to a potentially unnecessary thoracotomy. In cases of aortic injury suspected at the lesser curvature of the arch-isthmic junction, TEE allowed better delineation because of multiplane imaging capability.

Background: Blunt thoracic aortic injury (BAI) is a rare and highly lethal injury. We sought to identify occupant and collision characteristics associated with motor vehicle collision (MVC)-related BAI., Methods: The 1995 to 2000 National Automotive Sampling System data files were used. The National Automotive Sampling System is a national probability sample of passenger vehicles involved in police-reported tow-away MVCs. The risk of BAI was calculated according to specific occupant (e.g., age, seat belt use) and collision (e.g., delta-V [estimated change in velocity], vehicular intrusion) characteristics. The association between BAI and these characteristics was calculated using risk ratios (RRs) and associated 95% confidence intervals (CIs)., Results: Specific occupant and collision characteristics demonstrated independent association with BAI. Occupant characteristics included age >or= 60 (RR, 3.6; 95% CI, 2.5-5.2), seat belt use (RR, 0.3; 95% CI, 0.2-0.5), and being a front-seat occupant (RR, 3.1; 95% CI, 1.5-6.3). Frontal and near-side MVCs were associated with an increased risk (RR, 3.1; 95% CI, 1.9-5.1; and RR, 4.3; 95% CI, 2.6-7.2, respectively) relative to other collision types. Collisions with a delta-V >or= 40 km/h (RR, 3.8; 95% CI, 2.6-5.6) or that produce extensive vehicle crush (>or= 40 cm) (RR, 4.1; 95% CI, 2.7-6.3) or intrusion (>or= 15 cm) (RR, 5.0; 95% CI, 3.5-7.3) also increase the risk of BAI., Conclusion: The risk factors for BAI identified in this study support generally accepted etiologic mechanisms for this injury.