Mediastinal evaluation utilizing the reverse Trendelenburg radiograph

When thoracic aortic rupture is suspected, a 45-degree reverse Trendelenburg (RT) anteroposterior (AP) chest radiograph should place the mediastinal structures in a more appropriate position and allow a more accurate evaluation than a supine AP radiograph. One hundred ninety-one consecutive hemodynamically stable adult patients with major blunt thoracic trauma were initially evaluated for mediastinal abnormalities associated with aortic disruption by both supine AP chest radiograph and an AP chest radiograph with the patient in 45-degree RT position. One hundred four patients underwent contrast aortography based on mediastinal abnormalities detected on the supine AP chest radiograph. Twenty of these patients had abnormal aortograms demonstrating traumatic aortic disruption confirmed at surgery. Supine and RT chest radiographs were retrospectively compared in a blinded fashion to evaluate their specificity and positive predictive value for detection of traumatic thoracic aortic rupture. If RT chest radiographic findings had been used to determine the need for further assessment, 29 angiograms (26%) would have been eliminated, specificity would have increased from 52 per cent to 69 per cent, and positive predictive value would have increased from 19 per cent to 27 per cent. Both supine and RT chest radiographs demonstrated mediastinal widening in all 20 patients with abnormal aortograms, with no missed thoracic aortic disruptions (100% sensitivity). This study indicated that the RT chest radiograph may be used instead of the standard supine radiograph as the initial screen for mediastinal evaluation, maintaining a high sensitivity and eliminating the cost and morbidity of many unnecessary aortograms.     

Dissection post-traumatique de l’isthme de l’aorte d’évolution favorable sans traitement chirurgical. Intérêt de l’échocardiographie transœsophagienne

We report a case of intimal rupture of aortic isthmus in a severe polytrauma patient diagnosed with transoesophageal echocardiography (TEE). TEE findings were as follows: localized intimai tear without increased aortic diameter or pseudoaneurysm, absence of mediastinal haematoma or false lumen. CT scan and MRI confirmed the diagnosls. Because of the assoclated Injuries, surgery was delayed. Conservative management was successful and the patient was discharged without aortic surgery. A follow up TEE, 3 and 6 months later showed a thrombosls of the intimai tear without false aneurysm. This case underlines the value of TEE in patients with thoracic trauma, for surgical or nonsurgical management of aortic rupture and for the follow up of the patients.     

The use of transesophageal echocardiography in the evaluation of chest trauma.

Transesophageal echocardiography (TEE) has been used over the last 10 years (1982-1992) to study the heart and thoracic aorta. We set out to evaluate the diagnostic applications of TEE in patients with thoracic trauma. Specifically, TEE was performed on patients suspected of having either a cardiac contusion or an injury of the thoracic aorta. Fifty-eight patients admitted with thoracic trauma underwent TEE. Fifty of those patients suspected of having a cardiac contusion also underwent transthoracic echocardiography (TTE). The two diagnostic modalities were compared. In 21 of these patients a wide mediastinum was apparent on admission chest x-ray films. Nineteen of this latter group underwent thoracic angiography in addition to TEE. Two patients underwent post-mortem examination. Of the 50 patients undergoing both TEE and TTE, a cardiac contusion was detected by TEE in 26 patients. Transthoracic echocardiography detected only six contusions in this group. Of the 21 patients with a wide mediastinum, TEE detected three obvious aortic disruptions. These findings were confirmed in each case by angiography. In 16 cases TEE showed the aorta to be normal. This was confirmed on the angiogram in 14 cases and by autopsy in two cases. Transesophageal echocardiography revealed an aortic intimal irregularity distal to the left subclavian artery in two cases. The results of aortography were normal in these last two cases. As a diagnostic modality, TEE more accurately detected cardiac contusions than TTE (p less than 0.001) and was a very sensitive screening tool in the early evaluation of patients with a wide mediastinum.     

Imaging of thoracic aortic injury

Isthmic aortic rupture or disruption should be systematically sought when there is high kinetic energy trauma to the thorax. This condition is extremely serious and life threatening. It needs to be diagnosed rapidly but diagnostic pitfalls must be avoided. CT angiography is the standard examination. The main CT signs of rupture or disruption of the thoracic aorta are periaortic hematoma, intimal flap, pseudo-aneurysm and contrast agent extravasation. There are three types of lesion: intimal, subadventitial or pseudo-aneurysmal, and complete rupture with lesion of the three tunicae, and it is important to grade them for better therapeutic management. The main diagnostic pitfalls of the CT scan are the presence of a ductus diverticulum and post-isthmic fusiform dilatation. Associated lesions must not be overlooked. The most common are ruptures of the aortic root and the thoracic aorta in the diaphragmatic hiatus.     

Aortic regurgitation causd by the proximal dissecting flap invagintion to the left ventricle

A 68-year-old male with sudden back pain and cardiogenic shock status transferred to our ward. Transthoracic echocardiography revealed that the abnormal rond shape string was in the left ventricular outflow tract. The continuity from the string to the aortic valve was unclear. Intimal flap could not be detected at the level of the ascending aorta. Color Doppler flow imaging showed that the severe AR jet extended into the round string. TEE showed that the intimal tear and flap was seen just above the left subclavian artery. Preoperative diagnosis was acute Stanford type A dissection and acute severe AR due to the inversion of the proximal intimal flap to the left ventricular outflow tract through the aortic valve. At operation, the proximal intimal flap was dissected circumferentially and was cut all the way around 8 cm above the aortic valve ring and was inverted to the left ventricular outflow tract. The aortic valve was preserved because of its normal character after exclusion of the proximal intimal flap. Ascending and arch replacement was carried out. Postoperative TEE and TTE showed no findings of AR. The patient’s postoperative course was uneventful. To our knowledge, this is the first reported case that severe AR caused by the proximal intimal invagination to the left ventricle.     

Acute aortic regurgitation due to aortic dissection confined to the sinus of Valsalva

A 34-year-old man with severe heart failure was diagnosed with acute aortic regurgitation (AR) by transthoracic echocardiography (TTE). However, this differential diagnosis was incomplete. Only transesophageal echocardiography (TEE) revealed an intimal flap, leading to a diagnosis of Stanford type A aortic dissection. No abnormal findings were observed in the ascending aorta by contrast-enhanced computed tomography (CT). Aortic dissection confined to the sinus of Valsalva has rarely been reported; however, TEE should still be considered for the differential diagnosis of acute AR, even if there is no evidence of dissection by TTE or contrast-enhanced CT.     

Evaluation of Transesophageal Echocardiography for Diagnosis of Traumatic Aortic Injury

Background: Traumatic aortic injury is a frequent cause of death after blunt trauma, but few patients survive to reach a trauma center. The role of transesophageal echocardiography (TEE) in the diagnosis of traumatic aortic injury remains debated.

Methods: Over a 9-yr period, 209 blunt trauma patients (mean age, 34 +/- 13 yr) were suspected of having traumatic aortic injury because of enlarged mediastinum and/or sudden deceleration, and underwent TEE and angiography (aortography and/or contrast-enhanced computed tomography.

Results: Traumatic aortic injury was diagnosed in 42 patients (20%). Angiography (aortography and/or contrast-enhanced computed tomography) was less accurate (sensitivity, 83%; specificity, 100%) than TEE (sensitivity, 98%; specificity, 100%) for the diagnosis of aortic injury because it failed to diagnose most minor injuries (intramural hematoma or limited intimal flap, n = 7). However, when considering only patients with major aortic injury (n = 33;i.e., those who might need surgery), angiography (sensitivity, 97%; specificity, 100%) and TEE (sensitivity, 97%; specificity, 100%) were equivalent.     

Traumatic rupture of the aorta. Indications for aortography

The indications for thoracic aortography in the blunt chest trauma patient remain controversial. Clinical and radiographic findings in 102 patients seen at a Level I Trauma Center over a five-year period were reviewed to evaluate criteria predictive of major thoracic vascular injury. Five patients had positive aortograms. There was no significant correlation with Revised Trauma Score, symptoms, or associated thoracic injuries, although patients with aortic rupture did have a higher incidence of extrathoracic injuries (P less than 0.001). A blinded review of admitting chest radiographs for five major findings (widened mediastinum, aortic arch abnormalities, aortopulmonary window opacification, left apical capping, and right apical capping) revealed a significant difference between patients with and without aortic injury (0.98 +/- 1.24 findings in the negative aortogram group and 3.00 +/- 0.71 findings in the positive aortogram group) (P less than 0.001). All patients with aortic rupture had at least two major positive findings on admitting chest radiographs. Admission chest x-ray evidence of at least one major abnormality is a safe method of screening blunt chest trauma patients for thoracic aortography.     

Obstacles in the diagnosis of acute aortic dissection

Acute aortic dissection (AAD) is a life-threatening condition for which prompt diagnosis is essential for successful management. The imaging modalities for demonstrating the dissecting membrane include retrograde aortography, contrast-enhanced computed tomography (CT), transesophageal echocardiography (TEE), and magnetic resonance imaging. Of these, aortography had long been considered the gold standard in diagnosing aortic dissection. We present a case of AAD in which contrast-enhanced CT and retrograde aortography failed to demonstrate an aortic membranous flap, whereas TEE swiftly provided clear-cut evidence of the pathology. TEE should be considered when AAD is suspected despite negative findings on other imaging modalities.     

Evaluation of transesophageal echocardiography for diagnosis of traumatic aortic injury

BACKGROUND: Traumatic aortic injury is a frequent cause of death after blunt trauma, but few patients survive to reach a trauma center. The role of transesophageal echocardiography (TEE) in the diagnosis of traumatic aortic injury remains debated. METHODS: Over a 9-yr period, 209 blunt trauma patients (mean age, 34 +/- 13 yr) were suspected of having traumatic aortic injury because of enlarged mediastinum and/or sudden deceleration, and underwent TEE and angiography (aortography and/or contrast-enhanced computed tomography. RESULTS: Traumatic aortic injury was diagnosed in 42 patients (20%). Angiography (aortography and/or contrast-enhanced computed tomography) was less accurate (sensitivity, 83%; specificity, 100%) than TEE (sensitivity, 98%; specificity, 100%) for the diagnosis of aortic injury because it failed to diagnose most minor injuries (intramural hematoma or limited intimal flap, n = 7). However, when considering only patients with major aortic injury (n = 33; i.e., those who might need surgery), angiography (sensitivity, 97%; specificity, 100%) and TEE (sensitivity, 97%; specificity, 100%) were equivalent. CONCLUSION: Transesophageal echocardiography is an accurate method for diagnosis of traumatic aortic injury. Nevertheless, the clinical implications of limited aortic injuries diagnosed by the technique have yet to be determined.     

The significance of chest wall injury in the diagnosis of traumatic aneurysms of the thoracic aorta

It has been suggested that patients sustaining blunt chest injury severe enough to result insignificant bony injury to the thorax may have traumatic aneurysms of the thoracic aorta in the absence of th widened mediastinum on plain film. To test the validity of this hypothesis, we performed aortograms on 14 patients with severe blunt chest injury but an otherwise normal chese X-ray. None of these patients was found to have an aortic injury. By contrast, of 21 patients with severe chest injury and a widened mediastinum who underwent thoracic aortography eight were found to have traumatic aneurysms of the thoracic aorta. These results suggest that in the absence of a widened mediastinum, severe chest wall injury is not an indication for aortography.     

The place of abdominal aortography in abdominal aortic aneurysm resection

We analyzed 110 patients who underwent abdominal aortography as a routine preliminary to abdominal aortic aneurysm resection. In 11 of the 15 patients for whom the procedures were useful in planning the operative tactics, the aortograms would have been performed anyway on clinical indications. In two patients, the changes in surgical maneuvers would not have been made through anatomic inspection at the time of the operations, but the lesions were asymptomatic. Biplane views and views of the femoropopliteal systems were rarely influential. Morbidity from the angiography was minimal and mortality was zero, but about seven aortograms were performed for each one that effected a change in procedure. We concluded that abdominal aortography as a preliminary to aneurysmectomy could be reasonably limited to patients in whom it was indicated by clinical features, including important hypertension, impaired renal function, diminished or absent femoral pulses, suspected mesenteric ischemia, suspected suprarenal extension of the aneurysm, or suspected (from the chest roentgenograms) thoracic aneurysm.     

Comparison of multiplane transesophageal echocardiography and contrast-enhanced helical CT in the diagnosis of blunt traumatic cardiovascular injuries

BACKGROUND: Multiplane transesophageal echocardiography (TEE) and helical computed tomography (CT) of the chest have been validated separately against aortography for the diagnosis of acute traumatic aortic injuries (ATAI). However, their respective diagnostic accuracy in identifying blunt traumatic cardiovascular lesions has not been compared. METHODS: During a 3-yr period, 110 consecutive patients with severe blunt chest trauma (age: 41 +/- 17 yr; injury severity score: 34 +/- 14) prospectively underwent TEE and chest CT as part of their initial evaluation. Results of both imaging methods were interpreted independently by experienced investigators and subsequently compared. All cases of subadventitial acute traumatic aortic injury were surgically confirmed. RESULTS: Seventeen patients had vascular injury and 11 had cardiac lesions. TEE and CT identified all subadventitial disruptions involving the aortic isthmus (n = 10) or the ascending aorta (n = 1) that necessitated surgical repair. In contrast, CT only depicted one disruption of the innominate artery. TEE detected injuries involving the intimal or medial layer, or both, of the aortic isthmus in four patients with apparently normal CT results who underwent successful conservative treatment. All cardiac injuries but two were identified only by TEE. CONCLUSIONS: In patients with severe blunt chest trauma, TEE and CT have similar diagnostic accuracy for the identification of surgical acute traumatic aortic injuy. TEE also allows the diagnosis of associated cardiac injuries and is more sensitive than CT for the identification of intimal or medial lesions of the thoracic aorta.     

The trend of using computed tomography in the detection of acute thoracic aortic and branch vessel injury after blunt thoracic trauma: single-center experience over 13 years

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.     

Acute type-A dissection of the aorta: which diagnostic modes remain for surgical indication?

The natural course of acute type-A dissection of the aorta (AADA) implies a mortality of 50% within the initial 2 days. Preoperative diagnostic tests have to be expeditious while avoiding hypertension and direct manipulation of the aneurysm to prevent aortic rupture. Since 1979, 51 patients have been operated upon for AADA. The diagnosis was established by one or more of the following methods: transthoracic echocardiography (TTE); transesophageal echocardiography (TEE); conventional angiography (CA); intravenous digital subtraction angiography (DSA); and computed tomography with bolus injection of contrast medium (CT). TTE (n = 26) showed a dissection in 72%, suggested an intimal flap in 25%, and missed the diagnosis in 1 case. CT (n = 15) and DSA (n = 10) failed to indicate dissection in 1 case each. CA (n = 27) demonstrated dissection in every case but was the most time-consuming and stressful method. Since the introduction of combined transthoracic and transesophageal echocardiography, no other diagnostic methods have been used. On the basis of this experience, we propose the following diagnostic plan: 1. in AADA, the demonstration of an intimal flap in the ascending aorta by TTE/TEE is an indication for immediate surgery without further diagnostic measures (10 patients: no false-positive findings); 2. if a dissection is suggested by TTE/TEE, then DSA is performed if the supra-aortic branches are suspected to be compromised; CT is preferred if an extrapericardial aortic rupture is suspected; 3. the time-consuming and stressful diagnostic approach of conventional angiography is no longer indicated.     

Spontaneous rupture of the ascending thoracic aorta resulting in a mimicking pseudoaneurysm.

We report on the rare and successful surgical treatment of a case of spontaneous rupture of the ascending thoracic aorta resulting in a mimicking pseudoaneurysm. A 72-year-old male who had complained of sudden onset of severe chest pain was admitted to our hospital. Initially, acute type A closing aortic dissection was suspected because computed tomography (CT) showed a small ulcer-like projection (ULP) in the posterior aspect of the ascending aortic wall, but it also revealed no intimal flap, false lumen or aortic aneurysm. CT and magnetic resonance imaging (MRI) indicated a change in the radiographic aspect of the ULP and revealed a mimicking saccular-type pseudoaneurysm and gradual increasing size of the pseudoaneurysm. Surgery was performed after considering the risk of pseudoaneurysmal rupture. We replaced the ascending aorta and diagnosed it as a spontaneous aortic rupture by histological examination of the rupture site after failing to observe an aneurysm or dissection. We discuss these results with reference to the literature, including our pathological and radiographical findings.     

Repeated true lumen collapse after repair of descending thoracic aneurysm in chronic type B dissection

The patient was 69-year-old man. Dilatation of the descending thoracic aorta in chronic type B dissection was revealed on computed tomography. During replacement of the descending thoracic aorta, distal anastomosis was performed in a double-barreled manner. On postoperative day (POD) 3, the patient complained of paralysis and dysesthesia of both legs, and he developed acute renal dysfunction. Based on the results of emergent aortography, we suspected true lumen collapse resulting from an expanded false lumen; therefore, we stabilized the intimal flap to the aortic wall. However, on POD 7 he complained of coldness in both legs. Emergent aortography revealed that occlusion of the abdominal aorta had recurred, and so right axillobifemoral bypass was performed. Preoperative conventional angiography may be mandatory to confirm reentry. There have been several reports of transcatheter fenestration in acute or chronic aortic dissection. The technique would also be effective for postoperative malperfusion.     

Two-dimensional echocardiography for diagnosing acute ascending aortic dissection

The diagnosis of type A aortic dissection (involving the ascending aorta) can be made with two-dimensional echocardiography, but surgeons usually demand angiographic confirmation. Between January 1983 and February 1984, 10 patients presented at St. Michael's Hospital in Toronto with type A aortic dissection. Six patients underwent two-dimensional echocardiography early in their evaluation. A positive diagnosis was made in four, based upon visualization of an intimal flap or a false lumen. In the other two patients, the findings of an enlarged ascending aorta and pericardial effusion were suggestive but not diagnostic. Three patients survived operation and are alive and well (follow-up ranging from 3 to 5 months). One patient died while awaiting surgery, one died during aortography and one died during operation. All echocardiographic and angiographic findings were confirmed at surgery or at autopsy. It is concluded that two-dimensional echocardiography can diagnose ascending aortic dissection quickly, accurately, easily and without risk to the patient. In selected cases the presence of a false lumen or of an intimal flap makes it possible to proceed with operation without delay or the potential hazards of aortography.     

Typical presentation of intramural aortic haemorrhage (IAH) with evidence of intimal tear at MRI and angiography

A typical appearance of IAH was evidenced by CT and TEE in a 56-year-old hypertensive female suspected of developping classical acute aortic dissection (AAD). Further examination with MRI and aortography showed unequivocally the presence of an intimal tear in the aortic arch. This coexistence of intimal tear has never been evidenced preoperatively in patients with IAH. This observation demonstrates at the outset that IAH is part of the spectrum of AAD.     

One stage operation for aneurysm of the diverticulum of the ductus arteriosus and coronary artery bypass grafting

Aneurysm of the diverticulum of the ductus arteriosus in the adult is rare. One stage operation for aneurysm of the diverticulum of the ductus arteriosis and coronary artery bypass grafting (CABG) is reported. A 61-year-old man was admitted for diagnosis of thoracic aneurysm on chest X-ray and CT. Chest CT scan showed an aneurysm above the left main pulmonary artery. An aortography showed the left vertebral artery originated directly from the aortic arch and a saccular aneurysm arising from the aortic isthmus and lesser curvature of the aortic arch. Coronary arteriography showed 75% stenosis at the right coronary artery (seg. #1) and 75% stenosis at the left anterior descending artery. Operation was performed through a median sternotomy. The aneurysm of 6 to 3 cm was located between the aortic isthmus and left pulmonary artery. Ascending aorta and right atrium were used to institute cardiopulmonary bypass (CPB). CABG (LITA to #7, SVG to #4 PD) was performed. Arterial cannulation was then switched to the left femoral artery. The proximal aorta was cross-clamped between the left vertebral artery and the left subclavian artery under the partial CPB, and the distal aorta was occluded with a occulusive balloon catheter via the right femoral artery. The selective left axillar artery cannulation was performed to perfuse LITA. The aneurysm was resected and closed with a patch. His post-operative course was uneventful.