多平面经食管超声心动图技术对主动脉夹层的诊断价值

目的 探讨多平面经食管超声心动图(TEE)技术对主动脉夹层(AD)的诊断价值。方法 对19例疑诊AD患者进行了多平面TEE检查。结果 19例患者均由多平面TEE明确诊断，其中14例经CT或MRI证实，5例由手术证实，准确性和特异性均为100％。DeBakey分型Ⅰ型夹层患者4例，Ⅱ型3例，破口均位于升主动脉；Ⅲ型12例中，9例破口位于降主动脉近心端，3例未探及内膜破口。结论 多平面TEE技术为AD无创性诊断开辟了新途径。     

Diagnostic goals in aortic dissection. Value of transthoracic and transesophageal echocardiography]

The combination of different ultrasound techniques like transthoracic, suprasternal, subcostal and transesophageal echocardiography have a high sensitivity and specificity in the diagnosis of aortic dissection. The limitation of this combined ultrasound technique is related to the visualization of the ascending part of the aortic arch which, cause of the interposition of the trachea, can not be visualized completely. The beginning or the end of a dissection in this part of the aorta may be misinterpreted. False negative results are rare. False positive results due to artefacts resulting from reverberations in an ectatic ascending aorta have to be taken into account. The most important diagnostic aims in acute or chronic aortic dissection can be described: 1. confirmation of the diagnosis by visualization of the intima membrane, 2. the differentiation of the true and false lumen depending on visualization of spontaneous echocardiographic contrast thrombus formation, slow or reduced reversed flow, systolic diameter reduction and signs of entry jet into the false lumen, 3. detection of intimal tear, demonstrating communication by two-dimensional or color Doppler echocardiography, 4. determination of the extent of the dissection with classification according to DeBakey type I, II and III or Stanford A and B with differentiation to communicating or non-communicating dissection, antegrade or retrograde dissection limited to the descending aorta or expanding to the ascending aorta, 5. detection of wall motion abnormalities as a sign of preexisting coronary artery disease or myocardial ischemia due to ostium occlusion by an intimal flap, coronary artery rupture or collapse of the true lumen during diastole, 6. detection and grading of aortic insufficiency, 7. detection of side branch involvement by suprasternal, subcostal and abdominal sonography, which will gain the information which side can be chosen for cannulation or catheterization at the femoral artery, 8. detection of pericardial pleural effusion and mediastinal hematoma as a sign of emergency as rupture can occur within minutes. Without surgical intervention have be performed. Based on these informations, surgery can be performed in all acute situations in type A dissection without further investigations. This decision is particularly important in patients with signs of emergency like pericardial or pleural effusion or mediastinal hematoma.     

Usefulness of transesophageal echocardiography in the diagnosis of conditions mimicking aortic dissection

Between September 1987 and April 1989, forty patients suspected to have aortic dissection were evaluated by transesophageal echocardiography. Aortic dissection was identified in 18 patients. This study evaluated the ability of transesophageal echocardiography in the assessment of the 22 patients in whom aortic dissection was not found. A range of pathologic conditions was diagnosed in these patients. Five patients had ischemic heart disease when they were initially seen. Among the remaining 17 only one patient had a normal aorta. Aortic disease was present in the other 16 patients with aortic dilatation in 10. Atheromas were detected in seven patients with concomitant aortic dilatation in five of them. An extrinsic aortic mass was present in two patients. Transesophageal echocardiography correctly identified an anastomotic leak at the site of left coronary artery implantation in a patient with a recent Bentall procedure, and a large mobile clot within the proximal descending aorta in a patient with blunt chest trauma. These findings obviated the need for other tests in 15 patients and led to surgery in four with no ancillary tests performed in three of them. Thus transesophageal echocardiography has an important role in assessing patients with suspected dissection. Aortic disease is common even in patients in whom aortic dissection is excluded, and some of the conditions can be just as life-threatening as dissection. Transesophageal echocardiography not only reliably identifies dissection but can also detect luminal and extraluminal diseases not adequately visualized by other modalities.     

Accuracy of biplane and multiplane transesophageal echocardiography in diagnosis of typical acute aortic dissection and intramural hematoma

Objectives. The purpose of this study was to evaluate the diagnostic accuracy of biplane and multiplane transesophageal echocardiography in patients with suspected aortic dissection, including intramural hematoma.Background. Transesophageal echocardiography is a useful technique for rapid bedside evaluation of patients with suspected acute aortic dissection. The sensitivity of transesophageal echocardiography is high, but the diagnostic accuracy of biplane and multiplane transesophageal echocardiography for dissection and intramural hematoma is less well defined.Methods. We studied 112 consecutive patients at a major referral center who had undergone biplane or multiplane transesophageal echocardiography to identify aortic dissection. The presence, absence and type of aortic dissection (type A or B, typical dissection or intramural hematoma) were confirmed by operation or autopsy in 60 patients and by other imaging techniques in all. The accuracy of transesophageal echocardiography for ancillary findings of aortic dissection (intimal flap, fenestration and thrombosis) was assessed in the 60 patients with available surgical data.Results. Of the 112 patients, aortic dissection was present in 49 (44%); 10 of these had intramural hematom (5 with and 5 without involvement of the ascending aorta). Of the remaining 63 patients without dissection, 33 (29%) had aortic aneurysm and 30 (27%) had neither dissection nor aneurysm. The overall sensitivity and specificity of transesophageal echocardiography for the presence of dissection were 98% and 95%, respectively. The specificity for type A and type B dissection was 97% and 99%, respectively. The sensitivity and specificity for intramural hematoma was 90% and 99%, respectively. The accuracy of transesophageal echocardiography for diagnosis of acute significant aortic regurgitation and pericardial tamponade was 100%.Conclusions. Biplane and multiplane transesophageal echocardiography are highly accurate for prospective identification of the presence and site of aortic dissection, its ancillary findings and major complications in a large series of patients with varied aortic pathology, Intramural hematoma carries a high complication rate and should be treated identically with aortic dissection.     

Usefulness of transesophageal echocardiography in assessment of aortic dissection

BACKGROUND. The value of transesophageal echocardiography in the assessment of patients with aortic dissection was studied. METHODS AND RESULTS. Group 1 (34 patients) represented all patients studied at our institution with this technique in whom aortic dissection was proven by aortography, surgery, or autopsy. Group 2 (27 patients) represented all patients studied with this technique at our institution in whom aortic dissection was excluded by aortography. Transesophageal echocardiography made a correct diagnosis of aortic dissection in 33 of 34 patients (sensitivity, 97%; specificity, 100%). It also correctly demonstrated the type of dissection in all 29 patients with aortographic or surgical proof. On the other hand, computed tomography scanning, performed in 24 of 34 patients in group 1, made a correct diagnosis in only 67% of patients and misclassified the type of dissection in 33%. Transesophageal echocardiography correctly identified involvement of the coronary arteries by aortic dissection in six of seven patients as well as absence of both left and right coronary artery involvement in 10 patients with aortic dissection. This technique was also useful in detecting communications between the true and false lumens, presence of thrombi in the false lumen, and, in two patients, localized dissection rupture with formation of a false aneurysm. In both groups 1 and 2, transesophageal echocardiography correctly identified patients with moderate to severe aortic regurgitation. CONCLUSIONS. Transesophageal echocardiography is very useful in the assessment of aortic dissection.     

Clinical diagnosis of acute aortic dissection]

Despite the availability of modern imaging technology, 35% of aortic dissections remain undiagnosed in vivo because clinical criteria for aortic dissection are not available to date. The present study analyzed 250 patients with acute chest and/or back pain, absence of an established differential diagnosis of the pain syndrome and clinical suspicion of acute aortic dissection for presence of 26 clinical variables. Multivariate analysis identified an aortic pain syndrome with immediate onset and/or tearing or ripping character (P < 0.0001), mediastinal and/or aortic widening on chest radiography (P < 0.0002) and pulse- and/or blood pressure differentials (P < 0.0001) as predictors of acute aortic dissection. Probability of dissection was low (7%) with absence of all three variables, intermediate (31 and 39%, respectively) with isolated findings of "aortic pain" or "mediastinal widening", and high (> 83%) with either isolated "pulse- and/or blood pressure differentials" or any combination of the three variables. This model appears useful to improve selection of patients for emergency imaging of the thoracic aorta.     

Emergency surgical management of acute aortic dissection: role of transesophageal echocardiography.

The accuracy of transesophageal echocardiography in the diagnosis and surgical management of acute aortic dissection was determined in 54 patients who underwent surgery for acute aortic dissection. Results of the investigations were compared to the surgical assessment. From April 1993 to November 1997, we operated 54 patients (44 male and 10 female) for acute aortic dissection. Mean age was 60 +/- 9 years. At surgery, a De Bakey type I aortic dissection was diagnosed in 30 patients, type II in 23 and type III retrograde in 1. Operating procedures were: replacement of ascending aorta (24 cases), replacement of ascending aorta and aortic arch (17 cases), replacement of ascending aorta and aortic valve replacement (2 cases), Bentall procedure (6 cases) and end-to-end anastomosis of the ascending aorta (4 cases). Initial diagnosis, performed in emergency wards, was done on a clinical basis in 6 patients, on CT scan in 19, on transthoracic echocardiography in 14, and on TEE basis in 12. Three patients underwent angiography before our evaluation. As per our protocol, all patients underwent confirmation of the diagnosis by TEE. Seven patients needed additional instrumental investigations, 2 with CT scan and 5 with angiography. TEE confirmed the diagnosis of aortic dissection in all cases but one. Moreover, it described the site of the intimal tear, the extension of the dissecting process and accessory findings, such as pericardial effusion, aortic incompetence and left ventricular function. The interval between patient presentation and skin incision was a maximum of 70 minutes. At surgery, diagnosis of De Bakey classification was confirmed in 98% of cases; in 90.7% of cases exact location of the entry site was confirmed. In one case, an entry site in the arch diagnosed by TEE but not recognized at surgery, was observed at necropsy. Intraoperatively, we routinely used TEE to monitor retrograde systemic perfusion and correct implant of the vascular prosthesis. One case of malperfusion of the thoracic aorta through the false lumen was observed and managed. In one case we diagnosed acute obstruction of the prosthesis by bleeding in the wrapped aorta, which required reoperation. Assessment of ventricular function was obtained in all patients: in two cases, observation of low right ventricular function led us to perform aortocoronary by-pass to the right coronary artery. In conclusion, the high level of correspondence between TEE diagnosis and surgical anatomy prompted us to perform transesophageal echocardiography as the primary and often sole diagnostic procedure in acute aortic dissection. TEE, in experienced hands, has proven to be a highly reliable, safe and low-cost diagnostic tool. It can be performed at the patient's bedside within just a few minutes of the suspected diagnosis, thereby lowering the mortality rate of the natural history. Again, it can also be used in the operating theatre as an "on-line examination" as well as for assessment of correct surgical repair. Other diagnostic procedures do not yield more information and can cause dangerous delays in intervention.     

Intravascular ultrasound in patients with suspected aortic dissection: comparison with transesophageal echocardiography]

Thirteen patients with suspected aortic dissection (two women, 11 men, age 61 +/- 10.8 years) underwent transesophageal echocardiography (TEE), intravascular ultrasound (IVUS), angiography, and in part computed tomography (CT). TEE was performed using 3.5 or 3.75 MHz ultrasound transducers. IVUS examination was done using a 6F 20 MHz "rotational-tip" IVUS catheter (Boston Scientific) advanced over a guiding-wire positioned in the ascending aorta by the "side-saddle" technique. In two patients it was not possible to advance the catheter into the abdominal aorta. Of the remaining 11 patients, eight had aortic dissection (six Typ III, one Typ II, and one Typ I, de Bakey classification). Two patients had aortic aneurysms without dissection and one patient had a perforation of the ascending aorta. TEE, CT, and angiography led to the correct diagnosis in all patients, while IVUS failed to provide precise information within the ascending aorta and the aortic arch. Reasons were the limited scanfield of the 20 MHz transducer and the inability to steer and position the IVUS catheter. Contrary to the limited value in the ascending aorta, IVUS could successfully scan the entire descending aorta, including the dissection membrane and the originating vessels, if the max. diameter was less than 4 cm. No adverse effects occurred. Intravascular ultrasound allows to scan the entire aorta in patients with suspected aortic dissection. The current limitations can be solved only by the introduction of steerable and/or low frequency catheters.     

Follow-up of patients undergoing surgery for aortic dissection: evaluation with transesophageal echocardiography]

BACKGROUND. Transesophageal echocardiography (TEE) is a useful means in the diagnosis of acute aortic dissection (AD), owing to its very high sensibility and specificity. In this study, TEE was performed to assess post-surgical evolution. PATIENTS. Between 1982 and 1991, 119 pts. were operated on in our institution for AD (De Bakey I and II type): 87 pts. underwent replacement of the ascending aorta with a composite tubular graft bearing a mechanical valve; 26 had a simple tubular graft and 6 had aortic reconstruction. Sixty-eight of 72 discharged pts. were followed for up to 9.5 years (mean 4.5 +/- 2.6). Nine years after surgery actuarial survival of discharged pts. was 75%. Seven pts. died after a mean period of 3.4 years from surgery: only one died from postoperative complication (dehiscence of proximal anastomosis), none for aortic rupture distal to the graft. TEE was performed in 32 of these pts. and in other two operated on elsewhere, after 4.4 +/- 2.7 years from surgery; before the operation, type I AD was diagnosed in 23 pts. and type II in 11 pts. RESULTS. In 10/11 pts. with type II AD the aortic arch and the descending aorta looked normal; in one patient a localized intimal flap was found up to the arch. The descending aorta diameter was somewhat higher than in normal subjects (25.2 +/- 2.8 vs 21.9 +/- 3.7 mm), but in only one case was it beyond 2DS (32 mm). In all type I pts. an intimal flap persisted distal to the graft, along the whole thoracic aorta. Within the false lumen a flow was detected by color-Doppler in 14/23 pts. (61%), and spontaneous echo-contrast was noted in 14 pts. (61%). A thrombus was observed in 7 pts. (30%) and it was generally localized; in only one case it was extensive with total obliteration of the false lumen. In 16 pts. (70%) communications between the two lumina were found. The descending aorta diameter ranged from 25 to 53 mm, and mean value was higher than in normal subjects (34.2 +/- 6.2 vs 21.9 +/- 3.7 mm). CONCLUSIONS. In most pts. with type II AD, surgery can be a definitive treatment, as the remaining aorta keeps to normal size and appearance. In type I AD, operation is only palliative, as the dissection persists: the false lumen is often perfused through one or more communications with the true lumen and seldom its obliteration is noted. The persistence of dissection does not necessarily seem to be an ominous finding, as the survival of the study population was high and no patient died from aortic rupture. Nevertheless, long-term prognosis can be affected by aorta dilation that often (but not always) follows the persistence of wall dissection. For its high reliability, easy feasibility and low cost TEE is a very useful method for following up patients operated on for AD and for detecting those who are at higher risk of aortic rupture because of lumen dilation.     

Assessment of aortic atherosclerosis with transesophageal echocardiography]

OBJECTIVE: To image the thoracic aorta by transesophageal echocardiography (TEE) and study atherosis (morphology and extent of atheroma plaques) and sclerosis (stiffness) and secondarily correlate them with serum lipid levels (cholesterol, HDL, LDL and triglycerides). METHODS: We studied 29 patients (pts) who underwent TEE electively (male 18 pts, age 57.8 +/- 14.6 years). The parameters evaluated were: the stiffness coefficient = ln (PAsist/PAdiast)/(Dsyst/Dmin), and the morphology, location and extent of atheroma plaques. The systolic distension (Dsyst) was the difference between the maximal and the minimal dimensions (Dmin) of the aortic diameter measured by M mode. The lesions were classified in 4 degrees (0-3): 0--normal intima, 1--intimal thickening, 2--atheroma, 3--complicated lesion. Five aortic segments were studied: arch, D1-D4 (descending aorta at 5 cm intervals from the first 25 cm distal of the incisors line). We calculated the individual score = 1 x theta 1/180 + 2 x theta 2/180 + 3 x theta 3/180, theta n represents the angles occupied by the lesions and n (1-3) the severity of atherosis of each lesion. The total atherosis index (TAI) was sigma scores/(n. degree of visualized segments). RESULTS: The arch was not visualized in 3 pts, and the segment D4 was only visualized in 3 pts. TAI mean = 0.82 +/- 0.74, stiffness coefficient mean (SC) = 9.56 +/- 15.072. There were no significant correlations between the lipid levels and the TAI or SC. The only significant positive correlations were: TAI vs age (r = 0.62, p < 0.001) and SC and diastolic blood pressure (BP) (r = 0.42, p < 0.05). CONCLUSIONS: The best visualized segments belong to the descending aorta (25 to 40 cm from the incisors). In this group of patients the lipid levels did not seem to be a preponderant factor in aortic atherosclerosis. The most important factors were age for atherosis and BP for sclerosis.     

Anomalous inferior vena cava mimicking aortic dissection on transesophageal echocardiography

Transesophageal echocardiography (TEE) is considered an excellent method for the diagnosis of aortic dissection, especially that involving the descending aorta. It has also proved useful in the evaluation of conditions mimicking aortic dissection, usually disclosing in these situations other types of severe aortic disease. We are not aware of any report dealing with venous abnormalities which presented diagnostic problems in a patient evaluated with TEE because of a suspected aortic dissection. Left ventricular (LV) free wall rupture complicated with acute myocardial infarction (AMI) usually occurs in the early phase of AMI. True aneurysm of the LV is sometimes a complication of AMI but rarely ruptures. In our patient, a 72-year-old woman, the LV free wall ruptured on Day 49 after the onset of AMI and the ruptured site was the thinnest wall of large true aneurysm of the LV. The large aneurysmal formation probably was due to corticosteroids used for pericarditis. More attention should be paid to late cardiac rupture and the use of corticosteroids.     

Role of echocardiography in the diagnosis of aortic dissection

We evaluated sensitivity, specificity and predictive values of echocardiography in detecting aortic dissection. We studied in the same period of time two groups of consecutive patients with good quality echocardiographic examination. Group I, with high prevalence of the disease (76%), was composed of 25 patients; 19 patients with aortic dissection (11 of the type A and 8 of the type B) and 6 patients with clinical and echocardiographic suggestion of aortic dissection which was not confirmed by angiography. Group II, with lower prevalence of the disease (4%), was composed of 382 adult patients who underwent aortic angiography for different reasons. In this second group there were 16 out of the 19 patients of the first group, with aortic dissection, who underwent aortic angiography and the 6 patients with suspicion of aortic dissection which was not confirmed by angiography. Type A dissection: The finding of intimal flap on echocardiography was highly specific (98%) but relatively insensitive (45%); its positive predictive value was low (50% in the first and 34% in the second group). The specificity of increased thickness of aortic wall was lower (89%) and the sensitivity higher (81%); its positive predictive value was satisfactory in the first group (81%) and very low in the second (13%). Aortic root dilatation was fairly specific (76%); the sensitivity of this finding was high (87%) but its positive predictive value was still low (66% in the first and 7% in the second group). To conclude: the positive predictive value of the 3 echocardiographic signs of aortic dissection varied, in relation to the different prevalence of the disease, from 50, 81 and 66% in the first group to 34, 13 and 7% in the second group; the diagnostic utility of the echocardiographic examination appeared limited, in these patients, by the low values of sensitivity and positive predictive values; aortography is still the most valuable technique in the diagnosis of aortic dissection; echocardiography was useful in the early evaluation of some emergency cases (chest pain, shock, collapse...) suggesting sometimes the correct diagnostic hypothesis of aortic dissection; in the presence of a typical clinical picture, the contemporary presence of the 3 echocardiographic signs, though having the lowest sensitivity (36%), was highly predictive of the type A dissection. Type B dissection: In these patients the clinical picture, in contrast with type A dissection, Type A, was not indicating careful and complete echocardiographic aortic scan. Then the echocardiographic examination was even more disappointing: sensitivity 25%.     

Value of transesophageal echocardiography combined with computed tomography for assessing repaired type A aortic dissection.

Thirty-two patients with repaired type A aortic dissection were examined by transthoracic echocardiography (TTE) (n = 32), transesophageal echocardiography (TEE) (n = 30), computed tomography (CT) (n = 29), or a combination of all 3, to assess course and complications as a function of the surgical procedure. The mean follow-up period was 55.7 months (range 3 to 132). Surgery consisted of a replacement of the ascending aorta in 25 patients (group 1) with extension to the transverse aorta in 7 (group 2). The transverse diameter of the aorta, the persistence of the false lumen, thrombus formation and flow dynamics in the false lumen were evaluated by TEE. Ten patients (31%) had a dilation in the initial ascending aorta (sinus of Valsalva aneurysm in 6 patients, and a false aneurysm in the other 4). Three of 4 patients with a proximal pseudoaneurysm underwent operation after TEE and CT evaluation. In the descending thoracic aorta, there was good agreement between TEE and CT scan determinations of transverse vessel diameter. Persistence of flow within the false lumen was significantly more frequent in patients with a dilated aorta (p < 0.05), whereas thrombosis was seen more often and false lumen less often in patients with nondilated aorta. No significant differences in vessel status or outcome were observed between the 2 groups, although this may have been due to the small size of group 2. TEE is thus a well-tolerated method for postoperative follow-up of type A aortic dissection whatever the type of surgery. For the upper ascending aorta, CT provided sufficient data.     

Usefulness of transesophageal echocardiography in the diagnosis of aortic intramural hematoma

Aortic intramural hematoma or atypical aortic dissection is an aortic dissection without intimal tear nor flow communication and it may be the first step of a typical dissection. We describe five cases, in which transesophageal echocardiography detected intramural hematoma of the aorta. Transesophageal echocardiography is a safe, accurate and specific method that allows bedside diagnosis as well as follow-up of patients with hematoma of the aorta.     

Diagnosis of acute aortic dissection by echocardiography

Until recently, the diagnosis of aortic dissection rested on aortography. The purpose of this study was to evaluate the diagnostic value of echocardiography in that disease and its ability to inform on the extent of the dissection and on the presence of associated lesions. Twenty-six patients (mean age 64 +/- 10 years) admitted for suspected aortic dissection were explored by echocardiography and the results were compared with those of angiography and/or anatomical findings. Echocardiography provided the diagnosis in 14 of the 16 patients with aortic dissection and excluded it in the remaining 10 patients. The sensitivity and specificity of the method were 87.5 p. 100 and 100 p. 100 respectively. The type of dissection was correctly determined in 90 p. 100 of the patients whose aorta had been totally explored by echocardiography. Aortic regurgitation and pericardial effusion were detected in 81 p. 100 and 50 p. 100 respectively of patients with aortic dissection. These results confirm the diagnostic value of echocardiography in dissection of the aorta. The extent of the lesion can only be evaluated when the whole of the aorta is visualized. The echocardiographic diagnosis is easier when the ascending aorta is involved (type I), while in type III aortic dissection there is a risk of missing a retrograde lesion of the aorta and confusing this type with type I. In this study two kinds of intimal flap motion were observed: in the first one the motion was independent of that of the aorta, while the second one resembled a division of the aortic, wall the motion of which is parallel to that of the aorta.