Role of transesophageal echocardiography in the diagnosis and management of traumatic aortic disruption

Management of Blunt Thoracic Aortic Injury

Blunt traumatic aortic transection (TAT) is an uncommon injury in clinical practice that is associated with a high morbidity and mortality. The approach to patients with such an injury is controversial with specific regard to the most effective diagnostic tools, timing of surgical intervention and mechanisms of spinal cord protection. Chest X-ray with widening of the mediastinum is unreliable as a diagnostic tool. Contrast enhanced helical CT Scan has replaced the traditional angiography as the screening diagnostic tool of choice Emergency thoracotomy and repair should be reserved for the few patients with isolated TAT without any major concomitant injuries. Delayed management approach with aggressive blood pressure control and serial radiological monitoring is a safe and recommended option for those with severe concomitant injuries or other medical co-morbidity that puts surgery at high risk. Active augmentation of the distal perfusion pressure during cross clamp offers the best protection against development of paraplegia during open surgical repair. Endovascular stenting offers a minimally invasive method of treatment but the long-term durability of the endovascular stent is still unknown. We feel that the greater feasibility of the endovascular repair in the acute phase of the thoracic injury is an advantage over the open surgery and should be the treatment of choice in patients with severe concomitant injuries.

Transesophageal echocardiography and therapeutic management of patients sustaining blunt aortic injuries

BACKGROUND

No objective criteria have been described to help selecting patients with major blunt aortic injury (BAI) for postponed surgical repair. The efficacy of conservative management of minor BAI needs further evaluation.

METHODS

We studied 31 patients (Injury Severity Score, 48 +/- 15) who sustained a BAI diagnosed using transesophageal echocardiography (TEE). In patients with major BAI, the timing of surgery was made on the basis of clinical findings (grade 2) or TEE results (grade 3). We retrospectively separated patients into group I (rapid surgery, < or = 12 hours; n = 13) and group II (late or no surgery; n = 11). All major BAIs were confirmed by alternative imaging modalities or surgery. Patients with minor BAI (grade 1; n = 7) prospectively underwent conservative management with serial TEE follow-up.

RESULTS

All patients with grade 3 BAI (n = 4) were promptly operated on. No group II patient died as a result of aortic rupture, and all of them exhibited a small false aneurysm formation (ratio between the maximal diameter of the injured aortic isthmus and the diameter of the normal descending aorta < 1.4) and hemomediastinum (< 7.2 mm). TEE follow-up of group II patients (mean, 5 months) showed stable BAI, whereas follow-up of patients with minor BAI (mean, 15 months) disclosed total healing (n = 3) or stable lesions (n = 4).

CONCLUSION

Conservative management of minor BAI with serial follow-up appears to be appropriate. In patients with a grade 2 BAI and small false aneurysm formation and hemomediastinum, postponed surgical repair appears to be safe. However, these TEE criteria remain to be tested prospectively.

Review of branch aortic injuries in blunt chest trauma

OBJECTIVES

To review the incidence, mechanisms of injury, diagnosis and treatment of injuries to the major branches of the thoracic aorta within the thoracic cavity following blunt trauma.

METHODS

Medline, Embase and Cochrane were searched using appropriate key word and MeSH headings. Full text articles were retrieved where there was any information relating to the mechanism of injury, incidence of injury, diagnosis, treatment or outcome in patients with injuries to the brachiocephalic, subclavian or carotid arteries within the thoracic cavity following blunt chest trauma.

RESULTS

The reported incidence of these injuries varied widely, most injuries were related to rapid deceleration injuries or falls. Diagnosis depends on a high level of clinic suspicion and appropriate investigations include helical CT scanning and arteriography. Treatment options have expanded in recent years with the use of endovascular stents; however, the optimal treatment remains uncertain.

CONCLUSIONS

Aortic branch injuries must be actively excluded in patients with suspicious mechanisms of injury. Guidelines determining appropriate investigative pathways and methods of treatment should be developed at all trauma centres.

Unsuspected vascular trauma: blunt arterial injuries

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

Bedside echocardiography in chest trauma

Bedside US has an established role in the evaluation of chest trauma patients. Transthoracic echocardiography and TEE can be used to obtain critical information at the bedside for many emergent conditions, including the immediate detection of hemopericardium and acute aortic injury. More recent work has demonstrated that US also can be used to detect hemothoraces and pneumothoraces with accuracy. These diagnostic techniques can improve patient outcome and are within the scope of practice of emergency physicians and trauma surgeons. Physicians caring for trauma patients should be familiar with these techniques.

Traumatic type B aortic dissection causing near total occlusion of aortic lumen and diagnosed by transthoracic echocardiography: A case report

A true dissection of the descending thoracic aorta resulting from blunt chest trauma is a relatively rare injury compared with aortic transsection and occurs mostly in the region of the aortic isthmus. It is a life-threatening condition that requires rapid and accurate diagnosis. In this case, we report a patient with Stanford type B aortic dissection caused by decelerating trauma of the chest in a motor vehicle accident causing near total occlusion of the aortic lumen. The diagnosis was made by transthoracic echocardiography and confirmed by aortography.

Aortic emergencies

Prompt recognition of actual or impending aortic emergencies is essential to the effective practice of emergency medicine. Understanding the pathophysiologic principles and awareness of the potential subtleties in the clinical presentations of aortic dissection, aneurysm, and occlusive disease are prerequisites to this task. Knowledge of current diagnostic modalities is also important if these entities are to be identified rapidly and managed efficiently to maximize the potential for a good patient outcome. Awareness of the potential complications of these conditions and the necessary interventional and resuscitative measures that might be called for in the appropriate clinical setting are likewise essential requirements for the EP. Appropriate surgical consultation and mobilization of operative resources form the backbone of appropriate management in the patient who has an aortic emergency.

Role of computed tomography and magnetic resonance imaging in assessment of acute aortic syndromes

Acute aortic syndromes refer to the spectrum of aortic emergencies that include nontraumatic diseases of the aorta, such as aortic dissection, intramural hematoma, penetrating atherosclerotic ulcer, aortic aneurysm leak, as well as traumatic aortic transection. Patients presenting with nontraumatic acute aortic syndromes usually have a similar clinical profile; hence, clinical diagnosis is difficult. Computed tomography (CT) and magnetic resonance imaging (MRI) allow for specific diagnosis of the underlying condition. Traumatic rupture of the aorta is one of the most dreaded complications of blunt chest trauma; therefore, in patients with high-risk deceleration injuries, radiographic assessment of the aorta is crucial. Imaging methods should detect even subtle aortic wall disruption and should provide a mechanism for communicating the findings to the surgical team. Noninvasive, cross-sectional imaging techniques have proven efficacy in the diagnosis of aortic pathology and have largely replaced aortography. Both CT and MR imaging provide aortogram-like reconstruction of the original data sets, and in addition to assessing the aortic lumen, permit detailed evaluation of the aortic wall, as well as comprehensive assessment of thoracic and abdominal viscera. This article addresses the role of different imaging modalities in assessment of acute aortic syndromes, with focus on CT and MRI, and with discussion of the key imaging findings that allow distinction among the various aortic pathologies.

Clinical, diagnostic, and management perspectives of aortic dissection

The incidence of aortic dissection ranges from 5 to 30 cases per million people per year, depending on the prevalence of risk factors in the study population. Although the disease is uncommon, its outcome is frequently fatal, and many patients with aortic dissection die before presentation to the hospital or prior to diagnosis. While pain is the most common symptom of aortic dissection, more than one-third of patients may develop a myriad of symptoms secondary to the involvement of the organ systems. Physical findings may be absent or, if present, could be suggestive of a diverse range of other conditions. Keeping a high clinical index of suspicion is mandatory for the accurate and rapid diagnosis of aortic dissection. CT scanning, MRI, and transesophageal echocardiography are all fairly accurate modalities that are used to diagnose aortic dissection, but each is fraught with certain limitations. The choice of the diagnostic modality depends, to a great extent, on the availability and expertise at the given institution. The management of aortic dissection has consisted of aggressive antihypertensive treatment, when associated with systemic hypertension, and surgery. Recently, endovascular stent placement has been used for the treatment of aortic dissection in select patient populations, but the experience is limited. The technique could be an option for patients who are poor surgical candidates, or in whom the risk of complications is gravely high, especially so in the patients with distal dissections. The clinical, diagnostic, and management perspectives on aortic dissection and its variants, aortic intramural hematoma and atherosclerotic aortic ulcer, are reviewed.

[Strategies diagnosis of polytraumatized adult patients with coma]

OBJECTIVE

To review the diagnostic strategy of management of multiple trauma patient during the first hours.

DATA SOURCES

Extraction from Pubmed database of French and English articles on the management of multiple trauma patient published for ten years.

DATA SELECTION

The collected articles were reviewed and selected according to their quality and originality. The more recent data were selected.

DATA SYNTHESIS

The first hours of management of multiple trauma patients are a particular challenge. The first dilemma is to drive the patient toward an adequate structure. In case of poor haemodynamic tolerance, the patient will be drive in the nearest hospital. When haemodynamic parameters are restored, multiple trauma patient has to be receive in a high level hospital by a trained medical team with an anesthesiologist, intensivist, neurosurgeon, general surgeon and radiologist. The initial assessment may have two priorities: quality and speed. The total body CT scan is actually the answer to these priorities.

[Traumatic rupture of the aortic isthmus revealed by a mesenteric infarct]

The traumatic rupture of the aortic isthmus is one of the worst complication due to high speed motor vehicle accidents. When death is not the immediate consequence of this lesion, the initial clinical signs are not very clear. The present article demonstrates the case of a 23-year-old patient, victim of a car accident. A traumatic aortic rupture was actually diagnosed after the unusual discovery of a mesenteric infarct. In this case report, the mesenteric infarct mechanism can be controversed, and an emphasis should be put on an early aortic lesion diagnosis and repair in order to avoid any ischaemic complications.

Minimal aortic injury: a lesion associated with advancing diagnostic techniques

BACKGROUND

With the increasing use of high-resolution diagnostic techniques, minimal aortic injuries (MAI) are being recognized more frequently. Recently, we have used nonoperative therapy as definitive treatment for patients with MAI. The current study examines our institutional experience with these patients from July 1994 to June 2000.

METHODS

All patients suspected of blunt aortic injury (BAI) by screening helical CT (HCT) underwent confirmatory aortography with or without intravascular ultrasound (IVUS). MAI was defined as a small (<1 cm) intimal flap with minimal to no periaortic hematoma.

RESULTS

Of the 15,000 patients evaluated by screening HCT, 198 (1.3%) were suspected of having BAI. BAI was confirmed in 87 (44%), and 9 (10%) of these had MAI. The initial aortogram was considered normal in five of the MAI patients. The correct diagnosis was made by IVUS (four patients), and video angiography (one patient). One MAI patient had surgery, and two (22%) died of causes not related to the aortic injury. Follow-up studies were done on the six MAI patients that were discharged. In two, the flap had completely resolved, and in one it remained stable. The remaining three patients formed small pseudoaneurysms.

CONCLUSION

Ten percent of BAI diagnosed with high resolution techniques have MAI. These intimal injuries heal spontaneously and hence may be managed nonoperatively. However, the long-term natural history of these injuries is not known, and hence caution should be exercised in using this form of treatment.

Differential transesophageal echocardiographic diagnosis between linear artifacts and intraluminal flap of aortic dissection or disruption

BACKGROUND

The relatively low specificity of transesophageal echocardiography (TEE) for the diagnosis of aortic dissection (AD) or traumatic disruption of the aorta (TDA) has been attributed to linear artifacts. We sought to determine the incidence of intra-aortic linear artifacts in a cohort of patients with suspected AD or TDA, to establish the differential TEE diagnostic criteria between these artifacts and true aortic flaps, and to evaluate their impact on TEE diagnostic accuracy.

METHODS AND RESULTS

During an 8-year period, patients at high risk of AD (n = 261) or TDA (n = 90) who underwent a TEE study and had confirmed final diagnoses were studied. In an initial retrospective series, linear artifacts were observed within the ascending and descending aorta in 59 of 230 patients (26%) and 17 of 230 patients (7%), respectively. TEE findings associated with linear artifacts in the ascending aorta were as follows: displacement parallel to aortic walls; similar blood flow velocities on both sides; angle with the aortic wall > 85 degrees; and thickness > 2.5 mm. Diagnostic criteria of reverberant images in the descending aorta were as follows: displacement parallel to aortic walls, overimposition of blood flow, and similar blood flow velocities on both sides of the image. In a subsequent prospective series (n = 121), systematic use of these diagnostic criteria resulted in improved TEE specificity for the identification of true intra-aortic flaps.

CONCLUSIONS

Misleading intra-aortic linear artifacts are frequently observed in patients undergoing a TEE study for suspected AD or TDA. Routine use of the herein-proposed diagnostic criteria promises to further improve TEE diagnostic accuracy in the setting of severely ill patients with potential need for prompt surgery.

Transesophageal echocardiography in the diagnosis of diseases of the thoracic aorta: part II-atherosclerotic and traumatic diseases of the aorta

Transesophageal echocardiography (TEE) has provided an accurate new window for the evaluation of diseases of the thoracic aorta. Experience with TEE has led to an increased recognition of atherosclerosis of the thoracic aorta as a source of cerebral and systemic embolism. Certain features of aortic plaque morphology detected by TEE may prove to have prognostic and therapeutic significance. The intraoperative assessment of thoracic aortic atherosclerosis by TEE may guide modifications in surgical techniques and aortic manipulations that reduce the incidence of perioperative neurologic complications. TEE has also become a valuable tool for the diagnostic evaluation of patients with blunt chest trauma. The precise role of TEE in the management of these disorders is currently under investigation.

[Aortic diverticulum: differential diagnosis of traumatic lesions of the thoracic aorta]

We report the case of a 31-year-old patient with a chest trauma after a mountaineering accident. Contrast enhanced spiral computed tomography of the thorax showed a lesion of the aortic isthmus, suspected of being an aortic disruption. As the diagnosis of aortic rupture could not be formally established with computed tomography, a transoesophageal echocardiography and an aortic angiography were performed which showed a ductus diverticulum, representing one of the differential diagnoses of traumatic aortic disruption. A knowledge of this entity and its diagnostic criteria may avoid an unnecessary thoracotomy.

Imaging of thoracic aortic disease

Computed tomography, magnetic resonance imaging, and transesophageal echocardiography represent the relatively noninvasive techniques available for imaging thoracic aortic disease, especially in the evaluation of aneurysms and dissections. The article discusses the technique and application of these modalities in the evaluation of thoracic aorta. Imaging appearances of the commonly encountered pathologies of the thoracic aorta are presented and discussed, and potential pitfalls of technique and diagnosis are addressed.

Evaluation of the patient with blunt chest trauma: an evidence based approach

The patient who has sustained blunt trauma to the chest can present a diagnostic challenge to the emergency physician. There are several diagnostic modalities available for treating life-threatening injuries to these patients. The authors review published studies to support the use of these tests in diagnosing injuries from blunt thoracic trauma. The article focuses chiefly on two current areas of controversy, the diagnosis of blunt aortic and blunt myocardial injury. Finally, the authors make recommendations for the use of various tests based on the available evidence.

Use of Transesophageal Echocardiography for the Assessment of Traumatic Aortic Injuries

Acute traumatic lesions of the thoracic aorta or its branches (TLA) constitute highly lethal yet treatable injuries that are increasingly diagnosed in surviving patients. Traumatic disruptions are limited to the region of the aortic isthmus in approximately 90% of cases. Unlike aortography, usually referred as the gold standard diagnostic technique, transesophageal echocardiography (TEE) is a noninvasive imaging modality that can be rapidly performed at the patient bedside. Accordingly, TEE is being increasingly used as a first-line screening test for the evaluation of patients with suspected TLA. The TEE signs associated with TLA depend on the anatomic type of aortic disruption. After a period of validation, multiplane TEE allows accurate diagnosis of traumatic disruptions of the aortic isthmus, with a sensitivity of 88% (range, 57%-100%) and a specificity of 96% (range, 84%-100%). False-negative TEE results have been mainly attributed to lacerations of aortic branches. Accordingly, aortography must be routinely performed when a traumatic injury to brachiocephalic arteries is suspected. False-positive TEE findings have been associated with the presence of ultrasound artifacts or atherosclerotic changes that mimic TLA. Accurate determination of the depth of aortic wall tears and diagnosis of blunt cardiac injuries during the TEE study are crucial to guide patient management. The presence of TEE signs associated with imminent risk of adventitial rupture should lead to prompt surgery. The use of TEE as a first-line imaging modality simplifies the initial assessment of patients at high risk for TLA and helps guide acute management.

[Transesophageal echocardiography for diagnosis of traumatic injuries to the major intrathoracic vessels in 150 patients: the effect of the learning curve]

OBJECTIVES

To evaluate the role of transoesophageal echocardiography (TOE) in the management of patients with suspected traumatic lesions of the thoracic aorta (TLA) and its branches; to assess the influence of the learning curve on the diagnostic accuracy of TOE for the identification of TLA.

STUDY DESIGN

Retrospective study.

PATIENTS

The study included 150 patients (age: 41 +/- 17; Injury Severity Scale score: 31 +/- 17) who were admitted during a 4-year period for severe blunt chest trauma and who underwent a TOE study.

METHODS

TOE were performed with either a monoplane (n = 54) or a multiplane probe (n = 96). In all cases, TLA were confirmed by angiography, computed tomography, surgery, or necropsy. Initially performed routinely, angiography was subsequently indicated when the TOE study was inconclusive or when a disruption of supraaortic arteries was suspected. Echocardiographic studies were reviewed by an experienced reader who was unaware of the medical history and initial conclusions. To evaluate the influence of the learning curve on the diagnostic accuracy of TOE, these conclusions were compared with the initial interpretations.

RESULTS

A TLA was recognized in 25 patients out of 150 (17%), and evidenced using TOE in 22 of them. Three false negative and two false positive TOE results (needless thoracotomy) were recorded. After a learning period, the rate of inconclusive TOE studies decreased (18/150 vs 7/150: P < 0.05) and no false positive finding was recorded. The sensitivity and specificity of TOE for the diagnosis of TLA were 88 and 100%, and positive and negative predictive values were 100 and 97%, respectively.

CONCLUSIONS

TOE is an accurate imaging technique for the diagnosis of TLA located at the aortic isthmus. However aortography becomes essential when injuries of the aorta branches are suspected. A learning period is required to improve the specificity of TOE for this indication.

Transesophageal echocardiography for ascending aortic dissection: is it enough for surgical intervention?

BACKGROUND

Acute ascending aortic dissection is a surgical emergency that requires expeditious diagnosis and prompt surgical intervention. In many centers, transesophageal echocardiography (TEE) is the test of choice on which surgical decisions are based. Echocardiographic false-positive diagnoses are rare but can occur with potentially severe consequences.

CASE REPORT

Two clinical cases where ascending aortic dissections were falsely diagnosed by TEE are presented.

DISCUSSION

Recent literature comparing the diagnostic accuracy of TEE and other imaging techniques are reviewed. Anatomical limitations of TEE and potential causes of false-positive results are discussed. Multiplane probe reduces, but does not eliminate, the occurrence of false-positive findings. To improve diagnostic specificity without undue delays in the course of clinical decision making, we recommend dividing positive TEE findings into "definite" and "probable" categories. Such subclassification is helpful in identifying cases where additional confirmatory tests are desirable in situations of uncertain diagnosis.

Quantification of traumatic hemomediastinum using transesophageal echocardiography: impact on patient management

STUDY OBJECTIVES

To determine whether the quantitative evaluation of hemomediastinum using transesophageal echocardiography (TEE) is predictive of the presence of a traumatic disruption of the thoracic aorta (TDA) or its branches in patients who have sustained severe blunt chest trauma.

DESIGN

Retrospective study.

SETTING

ICU of a tertiary referral teaching hospital.

PATIENTS

Forty-one patients sustaining severe blunt chest trauma (32 men, nine women; mean age, 43+/-16 years; mean Injury Severity Score, 39+/-22) who underwent a TEE study were divided into two groups, patients with (group TDA+, n=15) or without (group TDA-, n=26) major vascular injury diagnosed using an alternative method such as aortography, surgery, or necropsy. The control group included 41 age- and sex-matched patients with an unremarkable TEE study performed to rule out an intracardiac source of emboli.

INTERVENTIONS

The presence of hemomediastinum was quantitatively assessed by measuring the distances between the esophageal scope and anteromedial aortic wall (distance 1), and between the posterolateral aortic wall and left visceral pleura (distance 2) at the level of the aortic isthmus. An observer who was unaware of both medical history and final diagnosis measured the distances.

MEASUREMENTS AND RESULTS

In group TDA+, TEE demonstrated aortic injuries in 13 patients, revealed an isolated hemomediastinum in one patient (ruptured intercostal arteries), and was unremarkable in the remaining patient, who sustained a disrupted right subclavian artery. No associated major vessel injuries were diagnosed in the group TDA- (normal aortograms). When compared to the control group, mean distances were greater in patients with chest trauma (distance 1=5.5+/-4.4 mm vs 2.7+/-0.8 mm, p=0.001; distance 2=3.8+/-5.0 mm vs 1.2+/-0.3 mm, p=0.02). The corresponding distances were even greater in group TDA+ when compared with group TDA- (distance 1=8.6+/-5.9 mm vs 3.7+/-1.5 mm, and distance 2=7.1+/-7.0 mm vs 2.0+/-1.7; for both differences, p<0.01). A threshold value of 5.5 mm for distance 1 or 6.6 mm for distance 2 had a sensitivity of 80%, a specificity of 92%, a positive and negative predictive value of 86% and 89%, respectively, for the diagnosis of underlying major vascular injury.

CONCLUSIONS

TEE allows quantitative assessment of traumatic hemomediastinum. The presence of a large hemomediastinum requires further evaluation by aortography, even if the thoracic aorta appears normal during the TEE examination, in order to rule out an underlying major vascular injury which may be outside the field of view of the echocardiographer.

Aortic pain

With the exception of the pain of acute aortic dissection, the thoracic aorta is not usually considered as a pain-producing organ. However, nineteenth century clinicians considered the aorta as a source of cardiovascular pain in the presence of autopsy-documented inflammatory aortitis, aortic aneurysms, and arterial hypertension, whereas early in the twentieth century, aortic pain reactions were elicited in experimental studies involving distension of the ascending aorta or the application of stimulating substances to the outer surface of the aorta. More recently, increased attention to aortic elastic properties, and to aortic vascular biology at the molecular level refocused interest on the many facets of aortic function beyond that of a simple conduit. The recognition of pain of thoracic aortic origin now extends to patients with progressive aortic syndromes such as aortic intramural hematoma, aortic intimal tears, aortic penetrating ulcers, aortic root dilatation without dissection in connective tissue disorders, inflammatory aortopathies, and abnormalities of aortic distensibility. The occurrence of pain during balloon inflation at balloon angioplasty of aortic coarctation, which disappears immediately after deflation, is the modern equivalent of the early experimental studies. The authors present a consideration of thoracic aortic pain in light of contemporary concepts in cardiovascular medicine with roots in the rich historical reservoir of information about aortic function and disease.

A retrospective review of the role of transesophageal echocardiography in aortic and cardiac trauma in a level I Pediatric Trauma Center

This study examined the role of transesophageal echocardiography in blunt aortic and cardiac trauma in a Pediatric Level I Trauma Center. In a > 5-year retrospective review, we identified 10 children with blunt cardiac (n = 4; tricuspid valve in two; mitral valve in one; aortic valve in one) and aortic (n = 6; aortic rupture in five, subintimal flap in one) trauma. Diagnosis of the cardiac injuries was made with transthoracic echocardiography, with transesophageal echocardiography providing additional anatomic detail and postoperative assessment in three of four children who required surgical intervention. Diagnosis of the aortic injuries was made with transesophageal echocardiography in five of six patients; one patient underwent aortography before transfer. Transesophageal echocardiography also identified depressed myocardial function in one child and aided in surgical management of the five aortic ruptures. In blunt chest trauma, transesophageal echocardiography provides accurate evaluation of cardiovascular structure and function and guides operative repair.

Outcome of blunt thoracic aortic injury in a level I trauma center: an 8-year review

BACKGROUND

The purpose of this study was to evaluate our experience with blunt thoracic aortic injury and identify factors predictive of outcome.

METHODS

Hospital charts, trauma registry data, and autopsies of 64 patients with blunt thoracic aortic injury from 1988 to 1995 were reviewed.

RESULTS

Patients were identified and segregated based on admission physiology. Group 1 patients (n = 19) arrived in arrest. Group 2 patients (n = 10) arrived in shock with systolic BP 90. Group 3 patients (n = 35) arrived with systolic BP>90. All patients in groups 1 and 2 expired. Injury Severity Scores for nonsurvivors in group 3 (n = 12) were significantly higher than survivors. There were no significant differences when comparing time of injury to repair or arrival between groups, or in mortality or paralysis comparing repair techniques or clamp/bypass times. Double lumen endotracheal tubes caused significant operative delays compared to single lumen tubes.

CONCLUSIONS

Predictors of survivability were hemodynamic stability on arrival and lower Injury Severity Scores. In thoracic aortic injury patients arriving hemodynamically stable, Injury Severity Score correlated with mortality but not paralysis.

Transnasal transesophageal echocardiography

Transesophageal echocardiography has been used as a diagnostic tool in the critical care unit. However, long-term serial evaluation of ventricular function with transesophageal echocardiography is difficult because of the current probe sizes and intolerance to prolonged oral intubation. We performed 139 intubations (64 oral and 75 transnasal) with a new prototype probe in 128 patients referred for transesophageal echocardiography. Transnasal intubation with the prototype probe was possible in 63/75 attempts. Oral intubation was successful in all 64 attempts. Patients tolerated transnasal intubation well when mildly sedated or awake. Two-dimensional echocardiographic views obtained with the nasal probe were similar to those obtained with a standard monoplane probe. Image quality was rated as good or acceptable in nearly all cases. Transgastric short-axis imaging of the left ventricle combined with acoustic quantification provided stable left ventricular area waveforms. Using custom developed software we showed the feasibility of monitoring left ventricular performance with minimal probe adjustment while graphically displaying and updating left ventricular area and fractional area change. Thus, transesophageal echocardiography with a prototype miniaturized monoplane probe passed transnasally is feasible, safe, and well tolerated by patients. This probe provides excellent two-dimensional echocardiographic images and may allow long-term echocardiographic monitoring of ventricular performance.

Identification of the Aortic Arch Branches Using Transesophageal Echocardiography

In this report we describe the technique used for identification of the individual aortic arch vessels using transesophageal echocardiography.

Natural history and serial morphology of aortic intramural hematoma: a novel variant of aortic dissection

BACKGROUND

Acute aortic dissection is a cardiovascular emergency that requires prompt diagnosis and treatment. Transesophageal echocardiography is the current standard diagnostic imaging modality in many medical centers. Aortic intramural hematoma is a variant of aortic dissection whose natural history and prognosis have not been well studied. We performed transesophageal echocardiography in patients with aortic intramural hematoma to determine the echocardiographic characteristics and echocardiographic evolution of this lesion, impact on patient management, and patient outcome.

METHODS AND RESULTS

Twenty-one consecutive patients with aortic intramural hematoma confirmed anatomically (four patients) or with an additional diagnostic imaging technique (17 patients) underwent a transesophageal echocardiographic examination. Fifteen patients with longstanding hypertension had chest or back pain, and the intramural hematoma was visualized in the ascending aorta (n = 4), along the whole aorta (n = 4), in the descending aorta (n = 6), or in the aortic arch (n = 1). The thickening of the aortic wall was crescentic. Patients with ascending aortic intramural hematoma had the following results: two patients died suddenly, three patients underwent surgery because of increased aortic wall thickening (one patient) or secondary intimal tear (two patients), and the remaining three patients had regression of the hematoma. Patients with hematoma confined to the descending aorta and the patient with aortic arch involvement (n = 7) had a different result: one patient died from aortic rupture and the remaining six patients did well. Six patients had a traumatic aortic injury, and the intramural hematoma was located along the descending thoracic aorta. The thickening of the aortic wall was circular in five patients and crescentic in one. Three of these patients had normalized thickness of the aortic wall on follow-up transesophageal echocardiographic studies. The other three patients died from multiorgan system failure. Aortography showed a reduction of the diameter of the aortic lumen in four patients; diameter in the remaining 17 patients was normal.

CONCLUSIONS

Aortic intramural hematoma can be detected and monitored by transesophageal echocardiography but not by aortography. Two types of aortic intramural hematoma can be distinguished: (1) traumatic of good prognosis and (2) nontraumatic, which can be an early stage of the classic aortic dissection, with bad prognosis in cases involving the ascending aorta.

Use of transesophageal echocardiography for diagnosis of traumatic aortic injury

This prospective study was conducted to describe the signs on transesophageal echocardiography (TEE) associated with traumatic aortic injury (TAI). Twenty-eight patients with TAI underwent TEE, and they were compared with a control group of 30 thoracic trauma patients without aortic injury. The TEE signs were classified as direct or indirect signs, and the quality of imaging was assessed. Patients' TEE images were compared with their anatomic lesions. The direct signs were thick stripes (n=19), false aneurysm (n=7), aortic dissection (n=6), free-edge intimal flap (n=15), aortic wall hematoma (n=2), fusiform aneurysm (n=13), and complete aortic obstruction (n=2). The indirect signs included minor increases in aortic diameter (n=7), impairment of the aortic Doppler color flow (n= 18), and an increase of aorta-probe distance, indicating hemomediastinum (n=23). TEE allowed diagnosis of recently described limited intimal lesions frequently missed by other conventional methods, and permitted rapid diagnosis of complete rupture in which fast degeneration means that more time-consuming methods are not practicable. Significant blurring of the aortic outline was noted in 20% of cases and intraluminal artifacts were observed in 36% of cases, but neither sign impaired accurate diagnosis of TAI. The echocardiographic signs of aortic injury are complex and may be confined to a short section of the aorta. Therefore, examination by a physician highly trained in echocardiography is necessary in such cases.

Torn ascending aorta missed by transesophageal echocardiography

Transesophageal echocardiography has become a commonly used screening tool for traumatic tears of the descending aorta. The role of transesophageal echocardiography for ascending aortic tears is not yet well-defined. We report an ascending aortic tear imaged by aortography but missed on transesophageal echocardiography.

A case of nonpenetrating traumatic aortic regurgitation detected by transesophageal echocardiography

A 67-year-old man, who had fell 5 meters, landing on his back, one month before, was referred because of heart failure due to aortic regurgitation (AR). Transesophageal echocardiogram (TEE) confirmed injuries in the aortic valve and the Valsalva sinus of the aorta before the surgery: the intimal flap in the Valsalva sinus of right coronary cusp (RCC), the prolapse of the RCC, and the dissection by longitudinal length of 3 cm in the Valsalva sinus of noncoronary cusp (NCC), ending as a blind pouch. Postoperative TEE confirmed the dissection was not repaired in the Valsalva sinus of the NCC. In this instance, TEE was extremely useful, compared with transthoracic echocardiography, computed tomography and magnetic resonance imaging, to assess the mechanism of AR following a nonpenetrating trauma, and to know to what degree the aortic valve and the Valsalva sinus of the aorta were destroyed.

Transesophageal echocardiography

This article presents an overview of the benefits and efficacy of transesophageal echocardiography (TEE) in the critically ill patient. The echocardiographic evaluation of ventricular function both regional and global, is discussed with special emphasis on ischemic heart disease; assessment of preload, interrogation of valvular heart disease (prosthetic and native) and its complications; endocarditis and its complications; intracardiac and extracardiac masses, including pulmonary embolism; aortic diseases (e.g., aneurysan, dissection, and traumatic tears); evaluation of patent foramen ovale and its association with central and peripheral embolic events; advancements in computer technology; and finally, the effect of TEE on critical care.

Traumatic thoracic aortic rupture in the pediatric patient

BACKGROUND

Traumatic thoracic aortic rupture is a rare injury in the pediatric patient. Experiences with thoracic aortic rupture in patients less than 17 years of age are needed to help identify factors that can influence injury occurrence, diagnosis, management, and outcome.

METHODS

Between July 1989 and December 1995, 6 children were treated operatively for thoracic aortic rupture from blunt trauma at a level I pediatric trauma center. The average age was 13.2 years (range, 8 to 16 years). There were 4 females and 2 males. There were 5 motor vehicle accidents and 1 bicycle accident. Aortic injury was suspected based on the mechanism of injury and abnormal chest roentgenogram results, and was confirmed by aortography (3 cases) or chest computed tomography (2) and transesophageal echocardiography (3). Life-threatening central nervous system or gastrointestinal injuries were evaluated or treated first. Operative repair of the thoracic aorta was performed by cardiopulmonary bypass (2 patients) and clamp and sew technique (4).

RESULTS

Aortic ruptures were complete transections at the ligamentum arteriosum in 5 of 6 (83%); the other case was a cervical arch pseudoaneurysm. Associated injuries included pulmonary contusion (100%), pelvic/long bone fractures (50%), visceral laceration/perforation (50%), central nervous system (33%), paraplegia (17%), and myocardial contusion (17%). There were no rib fractures. Four of 5 patients (80%) were not wearing seat belts, and 2 of these were ejected. The average time from injury to the operating room was 17.6 hours (range, 5 to 48 hours); the time from diagnosis to the operating room exceeded 5 hours with aortography and was less than 3 hours with chest computed tomography and transesophageal echocardiography. Each diagnostic modality accurately identified an aortic injury. The average time for cardiopulmonary bypass and for clamp and sew was 52 minutes (range, 49 to 55 minutes) and 34 minutes (range, 16 to 45 minutes), respectively. One patient with preoperative paraplegia regained partial function; there were no other patients with paraplegia. There were no deaths. All patients are alive 2 months to 7 years after repair.

CONCLUSIONS

The multiply injured child with severe blunt trauma and an abnormal chest roentgenogram requires a search for aortic injury. We believe the most effective algorithm to follow for the diagnosis of traumatic thoracic aortic rupture in the child involves selective performance of chest computed tomography and transesophageal echocardiography. Our experience suggests that the mechanism of injury, the duration to diagnosis of an aortic injury, and failure to use seat belts may contribute to morbidity. A high index of suspicion and a systematic approach to the diagnosis and to the management strategy for injuries to the thoracic aorta can contribute to a good outcome in those few children who survive the injury.

Routine transesophageal echocardiography for the diagnosis of aortic disruption in trauma patients without enlarged mediastinum

OBJECTIVE

To assess the value of routine transesophageal echocardiography (TEE) in diagnosing traumatic disruption of the aorta (TDA) in trauma patients presenting without enlarged mediastinum on chest x-ray films.

DESIGN

Prospective study.

MATERIALS AND METHODS

TEE was routinely performed to exclude the presence of TDA in patients who sustained severe trauma secondary to abrupt deceleration collisions and presented with an upper mediastinum of fewer than 8 cm on supine chest x-ray films. Patients were divided into two groups according to the presence (group I) or absence (group II) of mediastinal hematoma diagnosed during TEE examination. Radiographic signs regarded as indicators of the presence of TDA were evaluated in both groups.

RESULTS

Among the 40 consecutive patients studied, TEE demonstrated two cases of TDA associated with a mediastinal hematoma that were confirmed by both aortography and surgery. One of the patients had a normal mediastinum on presentation chest x-ray films, and the other only exhibited a blurred aortic knob. Radiographic mediastinal abnormalities suggestive of TDA were observed in 13 patients, but chest x-ray films were unremarkable in 12 patients. Twenty patients had multiple rib fractures. The frequency of chest radiographic abnormalities was not significantly higher in group I (n = 6) when compared with group II patients (n = 34). TEE examination demonstrated a normal thoracic aorta in 35 patients and was nondiagnostic in 3 patients (normal aortography).

CONCLUSION

TEE should be routinely performed in victims of violent deceleration collisions, even in patients presenting apparently normal mediastinum on supine chest radiography.