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

Resuscitative transesophageal echocardiography during the acute resuscitation of trauma: A retrospective observational study

BACKGROUND

Resuscitative transesophageal echocardiography (TEE) is an emerging POCUS modality that can be used to guide trauma resuscitation.

METHODS

Trauma patients who underwent TEE within 24 h of admission from 2013 to 2022 were prospectively identified. We retrospectively analyzed resuscitative TEE reports and patient charts in duplicate.

RESULTS

29 providers performed TEE for 54 acute trauma patients. 28 (52%) died in hospital; 33 (61%) required operative intervention (<24 h). Median injury severity score was 29 [IQR 22-43]. The most common indications for TEE were hemodynamic instability (34, 63%), inadequate windows for transthoracic echocardiography (14, 26%) and cardiac arrest (11, 20%). There were no identified complications. A new diagnosis was made in 31 (57%) cases: most commonly right ventricular dysfunction (10, 19%), pericardial effusion (9, 17%), and hypovolemia (6, 11%). TEE ruled out major cardiac injury in 83% of cases. TEE changed resuscitative strategy, in 17 (32%) patients, diagnostic imaging approach in 6 (11%) patients, procedural or operative approach in 5 (9%) patients and disposition from the trauma bay in 4 (7%) patients.

CONCLUSION

Resuscitative TEE during acute trauma care has an additional diagnostic yield to existing diagnostic pathways and may impact definitive management for some patients in the trauma bay.

Indications, Clinical Impact, and Complications of Critical Care Transesophageal Echocardiography: A Scoping Review

BACKGROUND

Critical care transesophageal echocardiography (ccTEE) is an increasingly popular tool used by intensivists to characterize and manage hemodynamics at the bedside. Its usage appears to be driven by expanded diagnostic scope as well as the limitations of transthoracic echocardiography (TTE) - lack of acoustic windows, patient positioning, and competing clinical interests (eg, the need to perform chest compressions). The objectives of this scoping review were to determine the indications, clinical impact, and complications of ccTEE.

METHODS

MEDLINE, EMBASE, Cochrane, and six major conferences were searched without a time or language restriction on March 31^st, 2021. Studies were included if they assessed TEE performed for adult critically ill patients by intensivists, emergency physicians, or anesthesiologists. Intraoperative or post-cardiac surgical TEE studies were excluded. Study demographics, indication for TEE, main results, and complications were extracted in duplicate.

RESULTS

Of the 4403 abstracts screened, 289 studies underwent full-text review, with 108 studies (6739 patients) included. Most studies were retrospective (66%), performed in academic centers (84%), in the intensive care unit (73%), and were observational (55%). The most common indications for ccTEE were hemodynamic instability, trauma, cardiac arrest, respiratory failure, and procedural guidance. Across multiple indications, ccTEE was reported to change the diagnosis in 52% to 78% of patients and change management in 32% to79% patients. During cardiac arrest, ccTEE identified the cause of arrest in 25% to 35% of cases. Complications of ccTEE included two cases of significant gastrointestinal bleeding requiring intervention, but no other major complications (death or esophageal perforation) reported.

CONCLUSIONS

The use of ccTEE has been described for the diagnosis and management of a broad range of clinical problems. Overall, ccTEE was commonly reported to offer additional diagnostic yield beyond TTE with a low observed complication rate. Additional high quality ccTEE studies will permit stronger conclusions and a more precise understanding of the trends observed in this scoping review.

Die traumatische Aortenruptur

Verkehrsunfälle sind für den größten Teil der traumatischen Aortenrupturen verantwortlich, meist zusammen mit weiteren schweren Begleitverletzungen. Die prähospitale Sterblichkeit ist hoch. Bei Verdacht auf eine beteiligte Aortenverletzung, aufgrund eines hohen traumatic aortic injury scores, ist eine Computertomographie durchzuführen. Es erfolgt eine Triage der Verletzungen, und die Versorgungspriorität der Aorta richtet sich nach dem Schweregrad der Aorten- und Begleitverletzungen sowie dem Zustand des Patienten. Bis zur definitiven Versorgung der aortalen Läsion muss der Blutdruck konsequent gesenkt werden. Grad I und II können in Einzelfällen unter enger Kontrolle inital konservativ gemanagt werden. Grad III (gedeckte Ruptur) und Grad IV (freie Ruptur) benötigen eine raschestmögliche Versorgung (interventionell, chirurgisch). In ausgesuchten Fällen kann auch eine verzögerte Versorgung günstig sein.

Als bevorzugte Versorgungsform hat sich die interventionelle Stentgrafttherapie etabliert.

[Acute post-trauma dissection of the descending thoracic aorta]

BACKGROUND

Traumatic injury to the descending thoracic aorta other than the isthmus is rare, and little known. Acute post-trauma rupture may occur in a context of multiple or rarely unique localizations.

CASE REPORT

We report the case of a young man who was the victim of multiple injuries with an isolated rupture of the descending thoracic aorta. Early diagnosis and adapted endovascular treatment led to favorable outcome.

CONCLUSION

In 90% of cases, acute post-trauma rupture of the aorta in a single localization involve the isthmus. Rupture of the descending aorta is more exceptional but must not be missed. The pathophysiological mechanism and appropriate management are discussed in light of a review of the literature.

Misdiagnosed coronary artery disease-acute aortic syndrome: A case report

It is estimated that 15% of traffic accidents cause trauma to large vessels. In about 70%-95% of cases, aortic rupture took place in the distal ligament of the left subclavian artery, whereas in the remaining cases rupture occurred in the ascending aorta above the aortic valve. Trauma to the aortic sinus and coronary arteries is rarely found in traffic accident victims. Therefore, coronary artery trauma is often misdiagnosed as coronary atherosclerotic heart disease. The present case is a 42 years old male who survived from a traffic accident. He presented with aortic sinus and left coronary artery trauma. He was misdiagnosed as having coronary atherosclerotic heart disease, and therefore wrongly given antiplatelet medicine, such as aspirin, in another hospital. Definite diagnosis was achieved in our hospital, and the patient underwent Bentall and mitral valve replacement, as well as tricuspid valvuloplasty. The aortic occlusion time during surgery was 47 min, and the total cardiopulmonary bypass time was 63 min. After surgery, transthoracic echocardiography confirmed that all the artificial valves worked sufficiently. The patient felt good and symptoms such as asthma and decreased exercise tolerance disappeared. This case taught us that acute aortic syndrome cannot be ignored when patients present with pectoralgia; antiplatelet medication should not be given before definite diagnosis.

Traumatic transection of descending thoracic aorta: A rare cause of pulmonary vein obstruction

Pulmonary vein obstruction is rare condition characterized by challenging diagnosis and unfavorable prognosis at advanced stage. Computerized tomography, magnetic resonance imaging, and transesophageal echocardiography (TEE) are often essential to reach a final diagnosis. External compression of pulmonary vein resulting from the mass effect of pseudoaneurysm and perianeurysmal hematoma due to aortic transection is extremely rare. We describe a case of traumatic transection of descending thoracic aorta where TEE was instrumental in the diagnosis of left upper pulmonary vein obstruction and help in the modification of the surgical plan.

Blunt chest trauma: a clinical chameleon

The incidence of blunt chest trauma (BCT) is greater than 15% of all trauma admissions to the emergency departments worldwide and is the second leading cause of death after head injury in motor vehicle accidents. The mortality due to BCT is inhomogeneously described ranging from 9% to 60%. BCT is commonly caused by a sudden high-speed deceleration trauma to the anterior chest, leading to a compression of the thorax. All thoracic structures might be injured as a result of the trauma. Complex cardiac arrhythmia, heart murmurs, hypotension, angina-like chest pain, respiratory insufficiency or distention of the jugular veins may indicate potential cardiac injury. However, on admission to emergency departments symptoms might be missing or may not be clearly associated with the injury. Accurate diagnostics and early management in order to prevent serious complications and death are essential for patients suffering a BCT. Optimal initial diagnostics includes echocardiography or CT, Holter-monitor recordings, serial 12-lead electrocardiography and measurements of cardiac enzymes. Immediate diagnostics leading to the appropriate therapy is essential for saving a patient’s life. The key aspect of the entire management, including diagnostics and treatment of patients with BCT, remains an interdisciplinary team involving cardiologists, cardiothoracic surgeons, imaging radiologists and trauma specialists working in tandem.

Role of speckle tracking imaging in the assessment of myocardial regional ventricular function in experimental blunt cardiac injury

PURPOSE

To evaluate the usefulness and information collecting ability of speckle tracking imaging techniques in the assessment of myocardial regional ventricular contractility in a rabbit model with blunt cardiac injury.

METHODS

Fifteen healthy New Zealand rabbits weighing (2.70 ±0.28) kg were anesthetized (3% pentobarbital sodium/i.v) and impacted using the BIM-II biological impact machine to induce myocardial contusion (MC). Hemodynamic parameters, such as heart rate, systolic pressure, mean arterial pressure, diastolic pressure and central venous pressure, were determined before and after MC. Further, parameters reflecting left ventricular functions, such as left ventricular end systolic pressure, left ventricular end diastolic pressure, isovolumic pressure (IP) and the maximal increasing/decreasing rate of left intraventricular pressure (±dp/dtmax), were also determined before and after MC. Left ventricular functions were determined either by two dimensional transthoracic echocardiography or by speckle tracking imaging for segmental abnormal ventricular wall motions.

RESULTS

Heart rate, systolic pressure, diastolic pressure and mean arterial pressure decreased significantly but transiently, while central venous pressure markedly increased after MC. In contrast to significant changes in diastolic functions, there was no significant change in cardiac systolic functions after MC. The speckle tracking imaging demonstrated that strain values of different myocardial segment significantly decreased post impact, and that of the ventricular segment decreased from segment to segment.

CONCLUSION

Speckle tracking imaging is useful and informative to assess myocardial regional dysfunctions post MC.

Atypical echocardiographic findings in traumatic aortic transection

Aortic rupture and transection are constituents of the acute aortic syndrome. Injury to the thoracic aorta during motor vehicle crashes is associated with blunt chest trauma and rapid deceleration mechanisms. Type A dissections and/or rupture of the aorta at the level of the aortic isthmus are the more common presentations of aortic injuries associated with motor vehicle crashes. We present the case of atypical echocardiographic findings of a nearly complete circumferential transection of the proximal ascending aorta injury after a motorcycle crash.

Role of Transesophageal Echocardiography in Blunt Chest Trauma

Patients who suffer blunt chest trauma are at risk for injury to the heart, and the thoracic aorta and its branch vessels. Unrecognized injury to the heart or aorta may lead to life threatening complications. Therefore, the physician caring for the trauma patient must be able to accurately and rapidly diagnose cardiac and thoracic aortic injury. Transesophageal echocardiography is an ideal tool to diagnose cardiac and aortic injury in the patient with blunt chest trauma because it provides high quality images of the heart and thoracic aorta and can safely and rapidly be performed in the emergency department, operating suite or intensive care unit. To utilize transesophageal echocardiography most effectively, the echocardiographer must be familiar with the indications, limitations, and piffalls of transesophageal echocardiography in patients with blunt chesttrauma. This review describes the role of transesophageal echocardiography in evaluating the patient with blunt chest trauma for cardiac, thoracic aortic, and mediastinal injury.

Echocardiography in the Emergency Department

In the busy emergency department, time-effective and accurate diagnostic and prognostic evaluation is essential Although clinical examination remains the mainstay of appropriate evaluation, remaining diagnostic uncertainty may need to be resolved by use of additional techniques. Echocardiography appears very well suited to the unique environment in the emergency department. It is portable to the patient's bedside, can be performed in minimal time, and results are immediately available. This facilitates correct triage and disposition of complicated cases. Small, hand-carried echocardiography systems have been developed with full imaging and Doppler capabilities. Thus, availability of echocardiography is increasing. Because both image acquisition and interpretation are operator-dependent, realization of full diagnostic potential requires extensive training and post-training experience to maintain proficiency.

Endovascular Repair for Acute Rupture of the Descending Thoracic Aorta

Purpose:

To report the endovascular treatment of acute descending thoracic aortic rupture as an alternative to open surgery in high-risk patients.

Methods:

Between November 1999 and April 2001, 10 patients (7 men; median age 75 years) underwent endovascular stent-grafting of the descending thoracic aorta for acute rupture from an aneurysm (n = 7) or blunt trauma (n = 3). All patients were evaluated as high operative risk. The aortic rupture was associated with isolated mediastinal hematomas (n = 7), left hemothorax (n = 2), or aortobronchial fistula (n = 1). The Excluder Thoracic Endoprosthesis was used predominantly.

Results:

The mean interval to the endovascular repair was 45.3 ± 28.4 hours. All stent-grafts were successfully deployed. Two patients required common iliac artery access, and 2 needed covered stents for iatrogenic iliac artery rupture. There was 1 postoperative death (myocardial infarction) and no renal failure, neurological complications, embolization, stent-graft migration, or perigraft leak. One patient died 4 months later from an unrelated cause. At a mean follow-up of 7.9 ± 5.1 months, all aneurysms and rupture sites were excluded with no evidence of endoleak or hematoma.

Conclusions:

Endoluminal treatment is a feasible technique for the management of acute rupture of the descending thoracic aorta. Long-term studies are required to assess the effectiveness and durability of this technique in comparison to open repair.

[Traumatic injuries of the descending thoracic aorta apart from the isthmus: diagnosis and therapeutic approach]

Lesions involving the descending thoracic aorta apart from isthmus are rare and less known by anesthetists. We report the clinical course of two severely injured patients who sustained a thoracic aortic rupture in whom favorable outcome was achieved with endovascular treatment. Mechanisms, diagnosis and therapeutics aspects of these rare lesions are discussed according to literature.

[Management of traumatic aortic rupture. About 37 cases]

OBJECTIVES

The aim of this study was to review our experience in the management of traumatic rupture of the aortic isthmus, to evaluate the results of surgery and endovascular exclusion and to develop an adequate therapeutic strategy based on the existence and severity of associated injuries.

MATERIAL

A series of 37 patients presenting posttraumatic aortic rupture associated with other severe lesions was collected from 2000 to 2012. There were 33 males and four females, mean age 38 years. In this series, 25 patients underwent surgical treatment and 12 endovascular exclusion.

RESULTS

Six patients died during or after surgery. Overall mortality was 16% (24% in the surgery group). The postoperative period was uneventful in all patients treated with the endovascular procedure. Postoperative computed tomography controls at one week, 1 month and 12 months showed good positioning of the stent without endoleakage.

CONCLUSION

Traumatic aortic rupture is often the result of a severe high-energy chest trauma. Other serious injuries are often associated. Results of immediate surgical repair are associated with high morbidity and mortality. The advent of endovascular treatment has revolutionized the treatment of traumatic aortic rupture, especially in patients with a high surgical risk.

Doppler tissue energy and stress echocardiography in the diagnosis of myocardial contusion in canines

We sought to evaluate the significance of Doppler tissue energy (DTE) and stressed echocardiography for diagnosing myocardial contusion (MC) in canines. Ten adult healthy dogs were anesthetized (3% pentobarbital sodium/i.v.) and impacted by BIM-II biological impact machine to induce MC. Conventional and stressed echocardiographies were used for segmental abnormal ventricular wall motions; DTE was also used to detect the abnormal ventricular wall motions and areas of injured myocardial fibers after MC, and the results were compared with those of triphenyl tetrazolium chloride (TTC) staining. The data show that both conventional and stressed echocardiographies identified ventricular wall segmental abnormal motions or even aneurysms. These segments were mainly distributed over the front and middle interventricular walls and anterolateral ventricular wall. The ventricular wall motion scoring and wall motion segment index (WMSI) increased remarkably after MC induction. Compared with TTC staining, the conventional echocardiography showed 100% sensitivity and 66.67% specificity, whereas the stressed echocardiography displayed 100% sensitivity and 88.89% specificity. DTE showed both the sensitivity and specificity of 100% for MC diagnosis. Thus, DTE has higher specificity than conventional and stressed echocardiographies. In conclusion, both DTE and stress echocardiography have higher clinical value for MC diagnosis in canines.

The role of echocardiography in the early diagnosis of the complications of endovascular repair of blunt aortic injury

PURPOSE

Endovascular repair of traumatic aortic injury has been associated with severe procedural complications, including endoleaks, coverage of the left subclavian artery, stent collapse, access complications, and questionable durability. Echocardiography has proven to be a valuable tool in the intraoperative detection of these complications. In the current study, we report on the use of echocardiography as an early postoperative diagnostic technique for the evaluation of endovascular stent graft positioning in the intensive care setting.

METHODS

From January 2005 to January 2009, 14 patients who underwent endovascular repair of a blunt aortic injury were admitted in our intensive care unit. Transesophageal and/or transthoracic echocardiography were used as first-line diagnostic tools in the assessment of the endovascular graft position.

RESULTS

Twenty-eight percent of patients (4 of 14) developed a pressure gradient between upper and lower limbs (greater than 50 mm Hg), which presented with persistent hypertension, requiring antihypertensive therapy in high doses and difficult weaning. In all 4 patients, stent graft malposition was identified using echocardiography. The diagnosis was verified by computed tomography and aortography.

CONCLUSION

Noninvasive echocardiographic monitoring proved to be a valuable tool in the early diagnosis of postoperative stent graft malalignment. To our knowledge, this is the first time that echocardiography is described in the relevant literature as an early diagnostic technique in this setting.

Aortic dissection in childhood and adolescence: an analysis of occurrences over a 10-year interval in New York State

BACKGROUND

Rarely occurring in the pediatric and adolescent population, aortic dissection is a condition with many predisposing factors. Previous studies have suggested that congenital cardiovascular disorders are the most common predisposing conditions. Trauma-associated aortic dissection is considered a rare occurrence.

METHODS

The Statewide Planning and Research Cooperative System database of New York State was used to retrieve cases of aortic dissection in persons < or = 21 years old over a 10-year period. A retrospective analysis for risk or associated conditions was undertaken.

RESULTS

Forty-five of a total of 12,142 cases of aortic dissection (0.37%) occurred in persons < or = 21 years old. No patient was younger than 15 years of age. Six of the 45 died (13%). Most patients were male (37 of 45, or 82%). Contrary to previous reports, the most common associated condition was trauma (19 of 45, or 42%), with Marfan syndrome the second most common (11 of 45, or 24%). Ten of 45 adolescent and young adult patients (22%) had no apparent risk factors.

CONCLUSIONS

Traumatic aortic disruptions must be considered in children and adolescents who survive serious chest trauma. Family members of pediatric and young adult patients with trauma-associated aortic dissection may need to be evaluated for possible risk of aortic dissection.

Endovascular treatment of blunt traumatic thoracic aortic injury

Blunt traumatic thoracic aortic injury (BTTAI) is a lethal injury associated with a prehospital mortality of 80% to 90%. Patients arriving in the emergency room and considered appropriate to undergo emergency open surgical repair still have a mortality rate of 15% to 30% because of severe associated injuries. Conventional open surgical repair requires a left thoracotomy, single lung ventilation, aortic-cross clamping and unclamping, with or without the adjunct use of partial or full cardiopulmonary bypass and systemic heparinization. All this leads to significant physiological stress and surgical trauma resulting in perioperative complications such as major blood loss, coagulopathy, myocardial infarction, stroke, respiratory failure, renal failure, bowel infarction, and paraplegia. Despite advances in anesthesia, critical care medicine, and surgical techniques, a recent meta-analysis showed no definite improvement in operative mortality over the past decade, following open surgical repair in patients with BTTAI. Endovascular repair of BTTAI does not require a thoracotomy, single lung ventilation, aorticcross clamping and unclamping, or systemic heparinization. As a result, endovascular repair of BTTAI has emerged as an effective, minimally invasive treatment alternative, especially in patients with severe concomitant injuries, which may be prohibitive to open surgical repair. Recent published studies have shown that endovascular repair of BTTAI is associated with lower morbidity, mortality, stroke, and paraplegia/paraparesis rates, when compared with open surgical repair of BTTAI.

Transesophageal echocardiography and noncardiac surgery

The use of transesophageal echocardiography (TEE) for monitoring during cardiac and noncardiac surgery has increased exponentially over the past few decades. TEE has evolved from a diagnostic tool to a monitoring device and a procedural adjunct. The close proximity of the TEE transducer to the heart generates high-quality images of the intracardiac structures and their spatial orientation. The use of TEE in noncardiac and critical care settings is not well studied, and the evidence of the benefits of its use in these settings is lacking. Despite the widespread availability of TEE equipment in US hospitals, less than 30% of anesthesiologists are formally trained in the use of perioperative TEE. In this review, the safety and indications of TEE are reviewed and detailed analysis of the best available evidence in this regard is presented. Landmark trials evaluating the use of TEE and its therapeutic impact in noncardiac surgical setting are critically reviewed. This article details recommendations to familiarize anesthesiologists with TEE technology to exploit it to its fullest potential to achieve better patient monitoring standards and eventually improve outcome. Training of greater numbers of anesthesiologists in TEE is needed to increase awareness of the indications and contraindications. Until relatively inexpensive TEE equipment is available, the initial cost of equipment acquisition remains a significant prohibitive factor limiting its widespread use.

Perioperative echocardiography: two-dimensional and three-dimensional applications

Perioperative echocardiography is an essential skill for today's cardiac anesthesiologist and a driving force for innovation and accomplishment for the future of the subspecialty. Real-time three-dimensional transesophageal echocardiography (RT3-D TEE) will dominate the future practice of perioperative echocardiography, but transthoracic echocardiography (TTE) will grow in application, as will contrast echocardiography. Hand-held ultrasonongraphs will rival current machines in capabilities and make it possible for TTE to become the stethoscope of the future for cardiac anesthesiologists.

[Blunt traumatic aortic injury: importance of transesophageal echocardiography]

Traumatic injury of the aorta can be a fatal complication of blunt thoracic trauma and if it is survived and diagnosed, surgery will be necessary. A prerequisite is a prompt imaging diagnosis of the injury in order to plan an optimal therapeutic procedure for the patient, depending on the severity of the injury. Digital angiography has now been replaced by non-invasive methods, such as computer tomography (CT) or transesophageal echocardiography (TEE). Using TEE it is possible to carry out a staging of the injury and this classification together with the corresponding clinical symptoms determines the therapeutic treatment regime. In many cases a staged treatment is standard procedure. In addition to the establishment of an adequate blood pressure (for prophylaxis of the open rupture), monitoring during the course of treatment may be necessary. The main advantage of TEE is that the examination of these mostly multiple traumatised patients can be carried out at the bedside. This review describes the use of TEE as a diagnostic tool in the early phase and for continuous monitoring of an initially conservative treatment regime.

Aortic aneurysm, dissection, or rupture: which one?

A 16-year-old boy was brought to the clinic because of persistence of vomiting. The only positive point was a history of an uneventful car accident 3 months earlier. Chest computed tomography scan showed aneurysmal structure obliterating the esophagus. Further delineation of the aortic anatomy with transesophageal echocardiography disclosed it as pseudoaneurysm of aorta. He was taken to the operating department where the rupture of aortic isthmus with a large pseudoaneurysm was discovered. The torn segment was excised and was replaced with a prosthetic graft.

Perioperative echocardiographic examination for ventricular assist device implantation

Ventricular assist devices (VADs) are systems for mechanical circulatory support of the patient with severe heart failure. Perioperative transesophageal echocardiography is a major component of patient management, and important for surgical and anesthetic decision making. In this review we present the rationale and available data for a comprehensive echocardiographic assessment of patients receiving a VAD. In addition to the standard examination, device-specific pre-, intra-, and postoperative considerations are essential to the echocardiographic evaluation. These include: (a) the pre-VAD insertion examination of the heart and large vessels to exclude significant aortic regurgitation, tricuspid regurgitation, mitral stenosis, patent foramen ovale, or other cardiac abnormality that could lead to right-to-left shunt after left VAD placement, intracardiac thrombi, ventricular scars, pulmonic regurgitation, pulmonary hypertension, pulmonary embolism, and atherosclerotic disease in the ascending aorta; and to assess right ventricular function; and (b) the post-VAD insertion examination of the device and reassessment of the heart and large vessels. The examination of the device aims to confirm completeness of device and heart deairing, cannulas alignment and patency, and competency of device valves using two-dimensional, and color, continuous and pulsed wave Doppler modalities. The goal for the heart examination after implantation should be to exclude aortic regurgitation, or an uncovered right-to-left shunt; and to assess right ventricular function, left ventricular unloading, and the effect of device settings on global heart function. The variety of VAD models with different basic and operation principles requires specific echocardiographic assessment targeted to the characteristics of the implanted device.

Aortic pathology: aortic trauma, debris, dissection, and aneurysm

The aorta is a conduit from the left ventricle that delivers pulsatile blood distally in either a compliant or stiffened vessel to organs and tissue beds. Only recently, since the advent of transesophageal echocardiographic imaging, did its presence and associated pathologies become more profound and more prominent for the intensivist. Angiography, the "gold standard" for diagnostic imaging, now seems to be in question since the advent of ultrasound (transesophageal echocardiography), improvements in magnetic resonance imaging, and particularly the advancement to 64-slice computed tomography. It is now a revelation of how revealing these newer imaging tools have expanded our knowledge potential of pathologies that involve the aorta. The latter three imaging modalities are continuing to improve, with established efficacy, particularly in the critically ill and injured patient. This article will enlighten the intensivist and others of their potential and contrast each imaging device in several prominent pathologies common to the critical care physician. The disadvantages of all will be brought forth. Evidence will be presented revealing the dynamic nature of imaging technologies that will continue to affect the outcome of our patients. The most common indications for interrogation of the aorta are in traumatic events in which there might be a catastrophic transection, intimal tear or flap, or subadventitial tear. The identification of hematomas (by these imaging devices) in the mediastinum might be associated with significant physical forces, and this article will show the relevance. The significance of atherosclerotic plaques, ulcers, and debris will also be debated. Finally, imaging of a patient with aortic dissection or aneurysm will be discussed, as its pathology and pathogenic process are well known, and the changing nature or paradigm shift in the imaging of this life-threatening disease will be addressed.

Multiple subfailures characterize blunt aortic injury

BACKGROUND

Blunt aortic injuries result from rapid deceleration of the thorax as may occur during automotive impacts and falls from extreme heights. Pathological findings can range from failure of specific vessel layers to immediate vessel wall rupture. The purpose of this investigation was to determine the sequence of local structural events that may lead to aortic wall disruption.

METHODS

Fourteen porcine aorta specimens were opened to expose the intima and longitudinally distracted until rupture. Longitudinal mechanics were quantified and subfailures were identified. Histology was used to examine internal layer subfailure.

RESULTS

Videography demonstrated that subfailures propagated into complete vessel wall rupture. Subfailures occurred before complete vessel rupture in 93% of specimens. Intimal and medial subfailures were present at 74% of the stress and 82% of the strain to rupture. Multiple subfailures were evident in 79% of specimens.

CONCLUSION

Present results supported the clinical theory that nonimmediate death as a result of blunt aortic injury is commonly caused by propagation of lesser lesions, initiating on the intimal layer, into complete vessel rupture including the adventitial layer. This finding, along with histologic evidence of subfailure pathological findings, confirms the presence of an acute window during which recognition and initiation of permissive hypotension may be lifesaving.

Identifying Chest Pain Emergencies in the Primary Care Setting

The majority of patients presenting to a primary care physician with acute chest pain will have non-life-threatening etiologies. Nevertheless, catastrophic cause of chest pain such as ACS, AD, PE, esophageal perforation, and pericarditis must be considered in the differential diagnosis. Often, these deadly conditions have atypical clinical presentations that must be recognized. Furthermore, the physical examination can be deceptively benign in patients harboring a catastrophic etiology of chest pain. By identifying these atypical presentations, recognizing the utility of the physical examination, and understanding of the limitations of traditional diagnostic imaging, primary care physicians can effectively diagnose patients who have life-threatening cause of acute chest pain.

Transesophageal echocardiography for diagnosis of traumatic aortic injury: an appraisal of the evidence

BACKGROUND

An overview of the validity of transesophageal echocardiography (TEE) in patients suspected to have traumatic aortic injury (TAI).

METHODS

Computerized bibliographic search of trials from 1994 to 2002 evaluating the use of TEE to confirm the diagnosis of TAI. Seven relevant studies out of 204 were identified, involving 758 patients. The accuracy of TEE was analyzed by constructing summary receiver-operating characteristic (sROC) curves and computing areas under the sROC curve.

RESULTS

No prospective randomized trial was found. Although accuracy varied greatly, summary ROC curve found that TEE enjoyed a high diagnostic performance. Some study characteristics can affect accuracy.

CONCLUSIONS

Our findings seems to indicate that TEE is a valuable tool for diagnosing TAI, and its use as first-line evaluation of such patients can be supported; however, given the lack of randomized trials, no standard of care can be drawn from the present overview: future studies should look at this problem more carefully, and should be methodologically rigorous.

Back pain emergencies

Most adults in the United States will experience an episode of back pain at some point during their lifetime. Most will present to their primary care physician for evaluation and treatment. Many patients have non-life-threatening etiologies and recover within 4 to 6 weeks. A small percentage, however, have back pain due to a potentially life-threatening emergency. AD,rupturing AAA, SEM, cauda equina syndrome, vertebral osteomyelitis,and SEA are just some of the medical emergencies that can present with back pain. Clinical suspicion for these diagnoses begins with a thorough history and physical examination. It is imperative that the office-based physician search for and accurately identify any red flag within the history or physical examination. Appropriate laboratory studies and diagnostic imaging are obtained based on the suspected etiology.