Comparison of diagnostic and therapeutic value of transesophageal echocardiography, intravascular ultrasonic imaging, and intraluminal phased-array imaging in aortic dissection with tear in the descending thoracic aorta (type B)

Transesophageal echocardiography (TEE) and conventional intravascular ultrasound (IVUS) have limited capabilities in type B aortic dissection. To evaluate its diagnostic value, intraluminal phased-array imaging (IPAI) was compared with IVUS and TEE. In 23 patients with type B aortic dissection, IPAI was tested with respect to its ability to depict true lumen (TL) and false lumen (FL), to localize which abdominal arteries originate from the TL and FL, and to identify all entries and reentries. After the completion of TEE, 2 additional examiners performed angiography and positioned an AcuNav catheter inside the TL. An IVUS catheter was then introduced into the TL by a fourth examiner. All examiners were blinded to one another. Four additional patients with type B aortic dissection developed peripheral malperfusion due to TL collapse. Transvenous IPAI was used to guide emergency fenestration of the intimal flap. TL and FL could be equally well identified by all diagnostic methods. IPAI detected more entries than IVUS (3.0 +/- 1.2 vs 0.8 +/- 0.5, p <0.001), and thoracic IPAI depicted more entries than TEE (1.8 +/- 1.0 vs 1.2 +/- 0.5, p <0.001). IPAI and IVUS showed >90% of the abdominal side branches. In all patients with peripheral malperfusion, successful emergency intimal flap fenestration was safely guided by IPAI. In conclusion, in the detailed diagnostic evaluation of type B aortic dissection, IPAI is superior to IVUS and TEE in detecting communications between the TL and FL. IPAI is also highly useful as a guiding tool for emergency intimal flap fenestration.     

Outcomes of medically treated patients with aortic intramural hematoma

PURPOSE: Aortic intramural hematoma has been considered a precursor of aortic dissection, and the same treatment strategy, usually involving surgery, has been applied to both conditions. However, the outcomes of patients with aortic intramural hematoma who are treated medically, including the remodeling process that occurs after an acute event, are not known. SUBJECT AND METHODS: A total of 124 patients with acute aortic intramural hematoma (41 in the proximal aorta and 83 in the distal aorta) was enrolled from five institutions in South Korea. Patients received medical treatment without surgery. A follow-up imaging study was performed in 105 patients. RESULTS: Pericardial (59% [n = 24] vs. 11% [n = 9], P <0.004) and pleural effusions (63% [n = 26] vs. 45% [n = 37], P = 0.05) were more common in patients with the proximal type than in those with the distal type. In-hospital mortality was somewhat higher with proximal hematomas (7% [n = 3 deaths] vs. 1% [n = 1 death], P = 0.11). A follow-up imaging study in 36 patients with proximal hematomas confirmed resorption of the hematoma in 24 patients (67%) and development of aortic dissection in 9 (25%). Resorption was confirmed in 54 (78%) of the 69 patients with distal hematomas who underwent follow-up imaging; localized aortic dissection developed in 11 (16%) of these patients. The 3-year survival rate was 78% in the proximal type and 87% in the distal type (P = 0.10). CONCLUSION: Patients with aortic intramural hematoma had a high rate of resorption with medical treatment regardless of the affected site. Further investigation is necessary to determine the optimal treatment strategy and timing of surgical intervention, especially for patients with proximal hematomas.     

Comparison of conventional and transesophageal echocardiography with magnetic resonance imaging for anatomical mapping of thoracic aortic dissection

Thirty-five consecutive patients with clinically suspected aortic dissection were subjected to a dual noninvasive imaging protocol using comprehensive echocardiography and ECG-triggered MRI with multi-slice spin echo and cine sequences in random order. The purpose of this dual imaging study was to compare the diagnostic accuracy of two-dimensional and color-coded Doppler echocardiography using the conventional transthoracic (TTE) and the transesophageal approach (TEE) with magnetic resonance imaging (MRI) for the exact morphologic evaluation and anatomical mapping of the thoracic aorta. The results of each diagnostic method were validated independently against the gold standard of intraoperative findings (n=17), necropsy (n=4) or contrast angiography (n=22).Compared to conventional transthoracic echocardiography both TEE and MRI were more reliable in detecting aortic dissections (TTE vs TEE: p<0.02; TTE vs MRI: p<0.01) and associated epiphenomena. Moreover, the reliability of TTE decreased significantly from proximal to distal segments of the aorta, e.g. from the ascending segment to the arch (p<0.05) and to the descending aorta (p<0.005), whereas the sensitivities of both TEE and MRI were excellent irrespective of the site of dissection. With regard to epiphenomena such as thrombus formation and entry location, MRI emerged as the optimal method for detailed morphologic information in all segments of the aorta. No serious side effects were encountered with either method.Thus, in patients with suspected acute or subacute aortic dissections the echocardiographic assessment should include the transesophageal approach for significant improvement of the moderate sensitivity and specificity of TTE. Both TEE and MRI are non-traumatic, safe and diagnostically accurate to identify and classify acute and subacute dissections of the thoracic aorta irrespective of their location. MRI provides superb anatomical mapping of all type A and B dissections and more detailed information on the site of entry and thrombus formation than TEE. These features of TEE and MRI may render retrograde contrast angiography obsolete in the setting of thoracic aortic dissection and may encourage surgical interventions exclusively on the basis of noninvasive imaging.     

Association between chronic kidney disease and thoracic aortic atherosclerosis detected using transesophageal echocardiography

Objective: Accelerated atherosclerosis occurs with a high frequency in patients with chronic kidney disease (CKD). We evaluated the association between CKD and thoracic aortic plaques using transesophageal echocardiography (TEE). Methods: This study population consisted of 297 patients who underwent TEE. Aortic plaques were evaluated in the proximal thoracic aorta (PTA) (from the ascending aorta to the aortic arch) and the distal thoracic aorta (DTA) (the descending aorta) using TEE. Aortic plaques were defined as complex plaques of ≥4 mm thickness and with ulceration or mobile components. CKD was defined as the estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m². The association between CKD and aortic plaques was evaluated using multivariate analysis after adjusting for traditional atherosclerotic risk factors. Results: Patients with CKD (n = 144) had a higher incidence of any plaques and complex plaques compared with those without CKD (n = 153) (85% vs. 47% and 42% vs. 17%, respectively, both P < 0.001). Univariate analysis indicated that the presence of CKD was significantly associated with complex plaques both in the DTA and the PTA (both, P < 0.001); however, multivariate analysis indicated that the presence of CKD was associated with only complex plaques in the DTA (P < 0.05), but not with those in the PTA. Conclusion: The presence of CKD was associated with complex aortic plaques, with this association being stronger for complex plaques in the DTA than those in the PTA.     

Penetrating atherosclerotic aortic ulcer: documentation by transesophageal echocardiography

Objectives. This study sought to describe the ability of transesophageal echocardiography (TEE) to document the presence of penetrating atherosclerotic aortic ulcers and their complications.Background. TEE has greatly enhanced our ability to assess patients with suspected aortic disease. However, the utility of this technique in the diagnosis of penetrating atherosclerotic aortic ulcers is still undefined.Methods. TEE was performed prospectively in 194 patients to evaluate aortic disease. Twelve patients with the diagnosis of aortic ulcers or their complications were specifically studied. The diagnosis was confirmed by pathologic studies in six patients and by an additional diagnostic technique (angiography, computed tomography or magnetic resonance imaging) in the other six. All 12 patients were hypertensive and presented with chest or back pain; the mean age was 65 years (range 56 to 79). The initial working diagnosis was acute aortic dissection in nine patients. Aortic ulcers were located in the descending thoracic aorta in eight patients, the aortic arch in two and the ascending aorta in two.Results. TEE could detect aortic ulcers or their complications in 10 patients but failed to detect these lesions in the remaining 2 (1 with aortic ulcers in the distal ascending aorta and 1 with aortic ulcers in the aortic arch). In four patients, aortic ulcers were detected as a calcified focal outpouching of the aortic wall and were associated with concomitant aneurysmal dilation of the aorta in two patients and with a small localized intramural hematoma in one. TEE visualized a partially thrombosed pseudoaneurysm complicating an aortic ulcer in the descending thoracic aorta of two patients. Four patients had an aortic ulcer complicated by a “limited aortic dissection” in the descending aorta that could be detected by TEE. Five patients underwent operation, two because of aneurysmal dilation of the aorta and three because of aortic dissection; two patients died of aortic rupture; the remaining five did well (11-month follow-up) without operation.Conclusions. Aortic ulcers should be included in the differential diagnosis of chest or back pain, especially in elderly hypertensive patients. These ulcers and their complications may be recognized by TEE.     

Diagnosis of thoracic aortic dissection. Magnetic resonance imaging versus transesophageal echocardiography.

BACKGROUND. Aortic dissection requires prompt and reliable diagnosis to reduce the high mortality. The purpose of this study was to assess the reliability of both ECG-triggered magnetic resonance imaging (MRI) and transesophageal two-dimensional echocardiography combined with color-coded Doppler flow imaging (TEE) for the diagnosis of thoracic aortic dissection and associated epiphenomena. METHODS AND RESULTS. Fifty-three consecutive patients with clinically suspected aortic dissection were subjected to a dual noninvasive imaging protocol in random order; imaging results were compared and validated against the independent morphological "gold standard" of intraoperative findings (n = 27), necropsy (n = 7), and/or contrast angiography (n = 53). No serious side effects were encountered with either imaging method. In contrast to a precursory screening transthoracic echogram, the sensitivities of both MRI and TEE were 100% for detecting a dissection of the thoracic aorta irrespective of its location. The specificity of TEE, however, was lower than the specificity of MRI for a dissection (TEE, 68.2% versus MRI, 100%; p less than 0.005), which resulted mainly from false-positive TEE findings confined to the ascending segment of the aorta (TEE, 78.8% versus MRI, 100%; p less than 0.01). In addition, MRI proved to be more sensitive than TEE in detecting the formation of thrombus in the false lumen of both the aortic arch (p less than 0.01) and the descending segment of the aorta (p less than 0.05). There were no discrepancies between the two imaging techniques in detecting the site of entry to a dissection, aortic regurgitation, or pericardial effusion. CONCLUSIONS. Both MRI and TEE are atraumatic, safe, and highly sensitive methods to identify and classify acute and subacute dissections of the entire thoracic aorta. TEE, however, is associated with lower specificity for lesions in the ascending aorta. These results may still favor TEE as a semi-invasive diagnostic procedure after a precursory screening transthoracic echogram in suspected aortic dissection, but they establish MRI as an excellent method to avoid false-positive findings. Anatomic mapping by MRI may emerge as the most comprehensive approach and morphological standard to guide surgical interventions.     

Diagnostic accuracy of transesophageal echocardiography, helical computed tomography, and magnetic resonance imaging for suspected thoracic aortic dissection: systematic review and meta-analysis

BACKGROUND: Patients with suspected thoracic aortic dissection require early and accurate diagnosis. Aortography has been replaced by less invasive imaging techniques including transesophageal echocardiography (TEE), helical computed tomography (CT), and magnetic resonance imaging (MRI); however, accuracies have varied from trial to trial, and which imaging technique should be applied to which risk population remains unclear. We systematically reviewed the diagnostic accuracy of these imaging techniques in patients with suspected thoracic aortic dissection. METHODS: Published English-language reports on the diagnosis of thoracic aortic dissection by TEE, helical CT, or MRI were identified from electronic databases. Sensitivity, specificity, and positive and negative likelihood ratios were pooled in a random-effects model. RESULTS: Sixteen studies involving a total of 1139 patients were selected. Pooled sensitivity (98%-100%) and specificity (95%-98%) were comparable between imaging techniques. The pooled positive likelihood ratio appeared to be higher for MRI (positive likelihood ratio, 25.3; 95% confidence interval, 11.1-57.1) than for TEE (14.1; 6.0-33.2) or helical CT (13.9; 4.2-46.0). If a patient had shown a 50% pretest probability of thoracic aortic dissection (high risk), he or she had a 93% to 96% posttest probability of thoracic aortic dissection following a positive result of each imaging test. If a patient had a 5% pretest probability of thoracic aortic dissection (low risk), he or she had a 0.1% to 0.3% posttest probability of thoracic aortic dissection following a negative result of each imaging test. CONCLUSION: All 3 imaging techniques, ie, TEE, helical CT, and MRI, yield clinically equally reliable diagnostic values for confirming or ruling out thoracic aortic dissection.     

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.     

The clinical recognition of dissecting aortic aneurysm.

The clinical, roentgenologic and laboratory findings in 124 patients with dissecting aneurysm of the aorta are reported. In 53 patients the dissection occurred in the ascending aorta ("proximal" dissection), and in 71 patients the site of origin was the descending thoracic aorta ("distal" dissection). Certain distinct clinical differences between the groups were apparent. Although hypertension was an important predisposing factor, it was significantly more common in distal dissection, as was atherosclerosis. Back pain and hypertension on hospital presentation characterized patients with distal dissection. Conversely patients with proximal dissection were younger and had a significantly higher incidence of Marfan's syndrome, cystic medial necrosis, anterior chest pain, pulse deficits, neurologic compromise, aortic insufficiency and congestive heart failure. In both groups, syncope appeared to correlate well with the occurrence of cardiac tamponade. Chest roentgenograms almost always showed an abnormal aortic contour. Aortic angiography, when performed, was usually confirmatory of the diagnosis.     

A transesophageal echocardiographic study on risk factors for stroke in elderly patients with atrial fibrillation: a comparison with younger patients

STUDY OBJECTIVES: Atrial fibrillation (AF) becomes an increasingly important cause of stroke as patients get older. The aim of the study was to determine whether risk factors of cerebral embolism among elderly patients with AF differed from those of younger patients by using transesophageal echocardiography (TEE). Design and setting: Cross-sectional study at a university hospital. METHODS: Cardiovascular lesions with the potential for thromboembolism in patients with AF were investigated using TEE. Left atrial spontaneous echocardiographic contrast (SEC), peak flow velocity in the left atrial appendage (LAA-flow), and aortic atherosclerosis of the thoracic aorta were assessed in 67 elderly (> or = 70 years old) and 135 younger (< 70 years old) patients. All patients underwent either brain CT (n = 54) or MRI (n = 148) to assess presence of cerebral infarction. RESULTS: Cerebral infarction due to embolism was noted in 113 patients with AF. There was a higher prevalence of cerebral embolism in elderly patients when compared with younger patients (78% vs 45%; p < 0.001). Cerebral embolism found in younger patients was associated with high grade of SEC and lower LAA-flow (p < 0.05). In addition to these TEE findings, aortic atherosclerosis was more severe in elderly patients with cerebral embolism than in those without cerebral embolism (p < 0.0001). By multivariate logistic analysis, LAA-flow was an independent predictor of cortical infarction in younger patients, but not in elderly patients, whereas aortic atherosclerosis was a useful marker in predicting embolic risk in elderly patients. CONCLUSIONS: TEE findings indicative of left atrial blood stasis were useful to identify the embolic risk of younger patients with AF, while atherosclerosis of the thoracic aorta appears to be an important marker for cerebral embolism in elderly patients.     

Relationship between plasma total antioxidant capacity and thoracic aortic intima-media thickness

It is known that antioxidants have an important role in the prevention of coronary artery disease (CAD). Low total antioxidant capacity (TAC) is a risk factor for ischemic heart disease. However, no data are available concerning the relationship between TAC and severity of thoracic aortic atherosclerosis. This study using multiplane transesophageal echocardiography (TEE) examined the relationship between atherosclerotic thoracic aortic intima-media thickness (TAIMT) and TAC. Twenty-nine patients (17 male, 12 female; mean age 36 +/- 8 years) without a history of atherosclerotic cardiovascular disease referred for TEE were included. The patients with obesity, hypertension, diabetes, and CAD were excluded. The TAC was measured for each patient using a more recently developed method. TAIMT and grade of thoracic aortic atherosclerosis were evaluated in each patient by using TEE. Mean TAC level was 1.91 +/- 0.53 mmol Trolox equiv/l. There was a negative and significant correlation between the TAC levels and TAIMT and grade of thoracic aortic atherosclerosis (r = -0.799, P < 0.001 versus r = -0.827, P < 0.001, respectively). Multiple linear regression analysis showed that TAIMT was independently associated with TAC (beta = -0.734, P < 0.001). The mean values of TAC in grade I, II, and III were 2.23 +/- 0.31, 1.58 +/- 0.31, and 1.04 +/- 0.27 mmol Trolox equiv/l, respectively (ANOVA P < 0.001). This study indicates that the TAC is an independent variable for TAIMT and it has a potential for an independent variable for atherosclerotic lesions in the major arterial locations.     

Two-Year Single-Center Experience With Thoracic Endovascular Aortic Repair Using the EndoFit Thoracic Stent-Graft

Purpose: To analyze our single-center experience of thoracic endovascular aortic aneurysm repair (TEVAR) using the EndoFit Thoracic Aortic Endograft. Methods: A retrospective review was conducted of 87 consecutive patients (64 men; median age 67.8+/-8.7 years, range 24-88) undergoing TEVAR using the EndoFit thoracic stent-graft from December 2005 to December 2007. Slightly more than half (n = 46) of the patients had thoracic aortic aneurysm, while 41 had thoracic aortic dissection. Seventeen cases were performed emergently. All patients had imaging follow-up before discharge; at 1, 3, and 6 months; and annually thereafter. Results: The technical success rate was 100%. Fifty-five (63.2%) patients had different debranching procedures to extend the proximal or distal landing zone. The in-hospital and 30-day mortality rate was 9.2% (8/87). Neurological complications occurred in 8 (9.3%) patients, including 5 strokes (2 fatal) and 3 cases of paraplegia. One intraoperative massive bleeding from an ascending aortic debranching anastomosis was rescued with the aid of a pump. Five patients had immediate proximal type I endoleak; 3 were remedied with a proximal cuff, 1 was rescued with tri-lobe balloon, and 1 was left untreated. One type II endoleak remains under observation. The average follow-up was 15.2 months (range 5-29), during which 10 (11.5%) patients died of causes unrelated to the aneurysm or stent-graft. All the extra-anatomical bypasses and stent-grafts were patent; no stent-graft kinking, collapse, or dislocation was detected. Two post-TEVAR proximal endoleaks were remedied with a proximal cuff after debranching. There was no post-TEVAR rupture or conversion to open surgery. Conclusion: Our 2-year single-center experience using the EndoFit system for TEVAR showed a high technical success rate and a low incidence of device- or aneurysm-related complications. The flexible, hydrophilic introducer was easy to insert and track through the vasculature. The debranching techniques to extend the landing zones not only broaden the applicability of TEVAR but also reduce post-TEVAR complications.     

Value of echocardiography in patient follow-up after surgically corrected type A aortic dissection.

BACKGROUND: To identify patients (pts) at risk of late complications, follow-up after surgery for type A aortic dissection is essential. We assessed the value of echocardiography to monitor patients after surgery for type A aortic dissection. METHODS: 80 out of 108 pts operated between 1989 and 1999 for type A aortic dissection survived surgery. 62 pts with at least one TEE, CT or MRI examinations during follow-up were included in this study. All pts had transthoracic echocardiography (TTE), 53 transesophageal echocardiography (TEE), 51 had CT, and 39 had MRI. RESULTS: At the first follow-up, 12 of 48 pts with aortic valve sparing surgery presented with aortic insufficiency >I degrees detected using echocardiography. 16 pts evolved a distal aortic aneurysm of over 5 cm, all seen in TEE, CT and MRI. A distal intimal flap was present in 39 pts and could be seen in TEE, CT and MRI in all patients. A new proximal aortic root dissection took place in 5 pts. Progressive aortic pathology led to reoperation in 9 pts. TEE was especially useful in 2 pts to confirm redissection, in 1 pt to rule out redissection assumed by CT, and in 1 with paraprosthetic blood flow after ascending aortic replacement. MRI led to additional information in 1 patient with false aneurysm of the distal anastomosis and 1 with redissection not seen in TEE 6 month before. CT and MRI were superior to TEE in demonstrating aortic arch pathology, whereas TEE was more effective in showing the flow pattern and residual entry sites. CONCLUSIONS: Echocardiography is an effective and cost-saving diagnostic tool to monitor pts after surgery for type A aortic dissection, and should be the method of choice to ascertain aortic pathology initially after surgery. Follow-up intervals and need for additional CT or MRI should be determined afterwards according to specific pathologies.     

Ascending thoracic aneurysms are associated with decreased systemic atherosclerosis

STUDY OBJECTIVES: We noted clinically that patients with aortic root aneurysms and dissections seemed to have little systemic atherosclerosis. It is our objective to determine whether there is a negative association between ascending thoracic aneurysms and systemic atherosclerosis. DESIGN: Atherosclerosis was quantified by evaluating non-contrast CT images of the chest and scoring the degree of calcifications as a marker for atherosclerosis in the coronary arteries and aorta. PATIENTS: The degree of calcification was compared in 64 patients with aortic root aneurysm (annuloaortic ectasia, 31 patients; type A dissection, 33 patients) vs 86 control subjects. Multivariable analysis was applied to test for an association between aortic root aneurysms and systemic calcification independent of risk factors for atherosclerosis. RESULTS: Multivariable analysis revealed that patients with ascending aortic aneurysms of the annuloaortic ectasia type and patients with type A dissections had significantly lower overall calcification scores in their arterial vessels compared to patients in the control group (p = 0.03 and p < 0.0001, respectively). These results were independent of all other risk factors for atherosclerosis. Smoking, dyslipidemia, diabetes, and age were all found to increase the degree of atherosclerosis (p < 0.01 to 0.05). CONCLUSIONS: Aortic root pathology (annuloaortic ectasia or type A dissection) is associated with decreased systemic atherosclerosis. It is possible that a mechanism exists whereby the same genetic mutations predisposing patients to ascending aortic aneurysms also exert a protective effect against systemic atherosclerosis.     

Comparative evaluation of TEE, conventional MRI and contrast-enhanced 3D breath-hold MRA in the post-operative follow-up of dissecting aneurysms

Purpose: To verify the diagnostic potentialities of conventional magnetic resonance imaging (MRI), breath-hold 3D contrast enhanced MR angiography (C3D MRA) and transesophageal echocardiography (TEE) in patients surgically treated for type A aortic dissection. Materials and methods: Twenty-nine patients (21 males and 8 females), surgically treated for type A aortic dissection, were evaluated with MRI using a 1.5 T (GE Horizon Echospeed 8.2) with standard gated SE sequences and breath-hold 3D fast SPGR after intravenous Gd injection (0.2 mmol/kg). 3D MIP reconstruction was obtained. TEE evaluation was performed with a HP 2000 system and a biplane 5 MHz probe. The sizes of aortic root, distal anastomosis, descending aorta and periprosthetic thickening were measured. Regional false lumen and aortic branch involvement were also evaluated. Results: Concordance among TEE, conventional MRI and C3D MRA was observed in the evaluation of aortic root (MRI vs. C3D MRA r = 0.93; MRI vs. TEE r = 0.84; C3D MRA vs. TEE r = 0.84) and descending aorta (r = 0.94, 0.91 and 0.92, respectively). The interobserver variability was also very low. Inadequate agreement was observed for distal anastomosis. C3D MRA was inadequate in the evaluation of periprosthetic thickening; r = 0.73 was obtained between MRI and TEE. For qualitative data: TEE was inadequate in the evaluation of the abdominal aorta and branches. C3D MRA depicted supra-aortic vessel involvement in more cases than the other techniques. Conclusion: C3D MRA is a fast and accurate technique in the evaluation of the endoluminal alterations and involvement of the aortic branches. Conventional MRI allows a direct evaluation of the aortic wall and periaortic tissue. TEE is less accurate in the evaluation of aortic branches and abdominal aorta.     

Assessment of atherosclerotic lesions and distensibility of the thoracic aorta in familial hypercholesterolemia by biplane transesophageal echocardiography]

Atherosclerosis involving the thoracic aorta frequently occurs in patients with familial hypercholesterolemia (FH). In this study, we employed two-dimensional (2-D) transesophageal echocardiography (TEE: 5 MHz) to assess atherosclerotic lesions of the thoracic aorta in 9 patients with FH (47.8 +/- 10.3 yrs) and 11 age-matched normal control subjects. Biplane TEE probe (i.e., transverse or sagittal scan transducer) was used to permit direct imaging of the distal half of the ascending aorta. The atherosclerotic lesions were classified based on the severity of the aortic wall sclerosis as intimal thickening (I.), atheromatous plaque, (II.) and calcification (III.). In all of the patients with FH, atherosclerotic lesions of grade I. or greater were observed particularly in the aortic arch and descending aorta, while, lesions more severe than grade I. in the thoracic aorta were not observed in any of the control subjects. In 6 FH patients (67%), atherosclerotic lesions more severe than grade II. were frequently observed, which were more frequent in the aortic arch and descending aorta than in the ascending aorta.     

Aortic Distensibility and Aortic Intima‐Media Thickness in Patients without Clinical Manifestation of Atherosclerotic Cardiovascular Disease

Background: There is growing evidence that aortic distensibility (AD) is a subclinical marker of early atherosclerosis. Aortic intima‐media thickness (IMT) was an earlier marker than carotid IMT of preclinical atherosclerosis. In this study, we aimed to assess the relationship between thoracic aortic IMT and AD. Methods: We studied 192 patients (mean age: 45.5 ± 8.4 years) who underwent transesophageal echocardiography (TEE) for various indications. Four different grades were determined according to IMT of thoracic aorta (Grade 1 < 1 mm; 1 mm ≤ Grade 2 < 3 mm; 3 mm ≤ Grade 3 < 5 mm; 5 mm ≤ Grade 4). AD was calculated from the echocardiographically derived ascending aorta diameters and hemodynamic pressure measurements in all patients. High sensitive C‐reactive protein (hsCRP) and other biochemical markers were measured using an automated chemistry analyzer. Results: TEE evaluation characterized thoracic aortic intimal morphology as grade 1 in 71 patients (37%), grade 2 in 57 patients (29.7%), grade 3 in 34 patients (17.7%), and grade 4 in 30 (15.6%) patients. The lowest AD level was observed in grade 4 group compared with grade 1 and grade 2 groups (P < 0.001, P = 0.009, respectively). AD level of grade 3 group was lower than grade 1 and grade 2 group (P < 0.001, P = 0.021, respectively). In multiple linear regression analysis, AD was independently associated with age (β = ?0.138, P = 0.029), hsCRP (β = ?0.209, P = 0.001), and aortic IMT (β = ?0.432, P < 0.001). Conclusion: AD is independently associated with age, thoracic aortic IMT, and hsCRP. Impaired elasticity index of the aorta might be an independent predictor for the severity of thoracic atherosclerosis.     

Rapid progression of discrete type A intramural hematoma: prevention of a "procedure-related" complication by intraoperative transesophageal echocardiography.

PURPOSE: To report a case illustrating the utility of transesophageal echocardiography (TEE) before planned stent-graft placement for chronic type B aortic dissection. CASE REPORT: A 64-year-old man with acute aortic syndrome and an 8-year-old interposition graft in the distal aortic arch for acute type B dissection was referred for dissection of the descending thoracic aorta down to the aortic bifurcation; the false lumen was dilated to 65 mm and was partially thrombosed. The ascending aorta showed discrete, eccentric, 4-mm wall thickening that was not considered clinically significant. Stent-graft closure of the entry tear in the proximal descending thoracic aorta was elected. However, as the endovascular procedure was about to commence, TEE showed striking eccentric thickening of the aortic wall of up to 18 mm. The endovascular procedure was stopped, as it was decided to urgently replace the ascending aorta. The next day, the patient underwent successful ascending aortic replacement and simultaneous antegrade stent-graft implantation over the descending thoracic aortic entry tear via the open aortic arch. The postoperative course was uncomplicated, and the patient was discharged 19 days after surgery. He remains well at 6 months after the procedure. CONCLUSIONS: Our case demonstrates that dissection of the ascending aorta may occur not only due to endograft-induced intimal injury, but may also occur due to underlying but undiagnosed or underestimated disease of the ascending aorta or arch. Besides procedural guidance, intraoperative TEE is a useful tool to detect such disease to avoid subsequent "procedure-related" complications.     

Ascending thoracic aorta dimension and outcomes in acute type B dissection (from the International Registry of Acute Aortic Dissection [IRAD])

It is not well known if the size of the ascending thoracic aorta at presentation predicts features of presentation, management, and outcomes in patients with acute type B aortic dissection. The International Registry of Acute Aortic Dissection (IRAD) database was queried for all patients with acute type B dissection who had documentation of ascending thoracic aortic size at time of presentation. Patients were categorized according to ascending thoracic aortic diameters ≤4.0, 4.1 to 4.5, and ≥4.6 cm. Four hundred eighteen patients met inclusion criteria; 291 patients (69.6%) were men with a mean age of 63.2 ± 13.5 years. Ascending thoracic aortic diameter ≤4.0 cm was noted in 250 patients (59.8%), 4.1 to 4.5 cm in 105 patients (25.1%), and ≥4.6 cm in 63 patients (15.1%). Patients with an ascending thoracic aortic diameter ≥4.6 cm were more likely to be men (p = 0.01) and have Marfan syndrome (p <0.001) and known bicuspid aortic valve disease (p = 0.003). In patients with an ascending thoracic aorta ≥4.1 cm, there was an increased incidence of surgical intervention (p = 0.013). In those with an ascending thoracic aorta ≥4.6 cm, the root, ascending aorta, arch, and aortic valve were more often involved in surgical repair. Patients with an ascending thoracic aorta ≤4.0 were more likely to have endovascular therapy than those with larger ascending thoracic aortas (p = 0.009). There was no difference in overall mortality or cause of death. In conclusion, ascending thoracic aortic enlargement in patients with acute type B aortic dissection is common. Although its presence does not appear to predict an increased risk of mortality, it is associated with more frequent open surgical intervention that often involves replacement of the proximal aorta. Those with smaller proximal aortas are more likely to receive endovascular therapy.     

Transthoracic echocardiography using second harmonic imaging: diagnostic alternative to transesophageal echocardiography for the detection of atrial right to left shunt in patients with cerebral embolic events

OBJECTIVES: We sought to evaluate whether transthoracic contrast echocardiography using second harmonic imaging (SHI) is a diagnostic alternative to transesophageal contrast echocardiography (TEE) for the detection of atrial right to left shunt. BACKGROUND: Paradoxic embolism is considered to be the major cause of cerebral ischemic events in young patients. Contrast echocardiography using TEE has proven to be superior to transthoracic echocardiography (TTE) for the detection of atrial shunting, SHI is a new imaging modality that enhances the visualization of echocardiographic contrast agents. METHODS: We evaluated 111 patients with an ischemic cerebral embolic event for the presence of atrial right to left shunt using an intravenous (IV) contrast agent in combination with three different echocardiographic imaging modalities: 1) TTE using fundamental imaging (FI); 2) TTE using SHI; and 3) TEE. The severity of atrial shunting and the duration of contrast visibility within the left heart chambers were evaluated for each imaging modality. Image quality was assessed separately for each modality by semiquantitative scoring (0 = poor to 3 = excellent). Presence of atrial right to left shunt was defined as detection of contrast bubbles in the left atrium within the first three cardiac cycles after contrast appearance in the right atrium either spontaneously or after the Valsalva maneuver. RESULTS: A total of 57 patients showed evidence of atrial right to left shunt with either imaging modality. Fifty-one studies were positive with TEE, 52 studies were positive with SHI, and 32 were positive with FI (p<0.001 for FI vs. SHI and TEE). The severity of contrast passage was significantly larger using SHI (61.6+/-80.2 bubbles) compared to FI (53.7+/-69.6 bubbles; p<0.005 vs. SHI) but was not different compared to TEE (43.9+/-54.3 bubbles; p = NS vs. SHI). The duration of contrast visibility was significantly longer for SHI (17.4+/-12.4 s) compared to FI (13.1+/-9.7 s; p<0.001) and TEE (11.9+/-9.6 s; p<0.02). Mean image quality improved significantly from FI (1.5+/-0.8) to SHI (2.0+/-0.8; p<0.001 vs. FI) and TEE (2.5+/-0.7; p<0.001 vs. SHI). CONCLUSIONS: In combination with IV contrast injections, TEE and SHI have a comparable yield for the detection of atrial right to left shunt. Both modalities may miss patients with atrial shunting. In young patients with an unexplained cerebrovascular event and no clinical evidence of cardiac disease, a positive SHI study may obviate the need to perform a TEE study to search for cardiac sources of emboli.