Diagnosis Of Aortic Dissection Research Articles

Multidimensional imaging of the thorax: practical applications.

Over the past decade, faster CT scan times, thinner collimation, and the development of multirow detectors, coupled with the increasing capability of computers to process large amounts of data in short periods of time, have lead to an expansion in the ability to create diagnostically useful two-dimensional (2D) and three-dimensional (3D) images within the thorax. Applications within the thorax include, but are not limited to, evaluation of pulmonary and systemic vasculature, evaluation of the tracheobronchial tree, and delineation of diffuse lung disease. Pulmonary nodule volume and growth can be more accurately predicted, and represents an improvement in the evaluation of the solitary pulmonary nodule. Multiplanar images increase our understanding of thoracic anatomy and can help to guide bronchoscopic procedures. Because there are strengths and weaknesses to all the reconstruction algorithms, the utility of any given technique is dependent on the clinical question to be answered. For instance, although maximum intensity projection imaging (MIP) is helpful in the evaluation of micronodular lung disease, it is of little value in the diagnosis of aortic dissection. As the ability to generate faster and more precise multidimensional images grow, the demand for such imaging is likely to increase. In this review, the authors discuss the various reconstruction techniques available, followed by a discussion of the clinical applications.

Differential Transesophageal Echocardiographic Diagnosis Between Linear Artifacts and Intraluminal Flap of Aortic Dissection or Disruption

The relatively low specificity of transesophageal echocardiography (TEE) for the diagnosis of aortic dissection (AD) or traumatic disruption of the aorta (TDA) has been attributed to linear artifacts. We sought to determine the incidence of intra-aortic linear artifacts in a cohort of patients with suspected AD or TDA, to establish the differential TEE diagnostic criteria between these artifacts and true aortic flaps, and to evaluate their impact on TEE diagnostic accuracy. During an 8-year period, patients at high risk of AD (n = 261) or TDA (n = 90) who underwent a TEE study and had confirmed final diagnoses were studied. In an initial retrospective series, linear artifacts were observed within the ascending and descending aorta in 59 of 230 patients (26%) and 17 of 230 patients (7%), respectively. TEE findings associated with linear artifacts in the ascending aorta were as follows: displacement parallel to aortic walls; similar blood flow velocities on both sides; angle with the aortic wall > 85 degrees; and thickness > 2.5 mm. Diagnostic criteria of reverberant images in the descending aorta were as follows: displacement parallel to aortic walls, overimposition of blood flow, and similar blood flow velocities on both sides of the image. In a subsequent prospective series (n = 121), systematic use of these diagnostic criteria resulted in improved TEE specificity for the identification of true intra-aortic flaps. Misleading intra-aortic linear artifacts are frequently observed in patients undergoing a TEE study for suspected AD or TDA. Routine use of the herein-proposed diagnostic criteria promises to further improve TEE diagnostic accuracy in the setting of severely ill patients with potential need for prompt surgery.

Should ascending aortic intramural hematoma be treated surgically?

Should ascending aortic intramural hematoma be treated surgically?

La dissection aortique chez les Noirs. À propos de six cas congolais

Introduction – The authors report on six cases of aortic dissection (AD). The work intended to bring out AD characteristics and attempt to define a profile of African patients who manifested this disease. The diagnosis of AD was determined on the basis of: clinical and radiological criteria (six cases); echocardiographic data (five cases); aortographic and surgical informations (two cases). Patients and methods – There were three males and three females with an average age of 40.2 years, with a variation of ±10.6 years (from 17 to 49). The frequency of AD was estimated at 1.8/10 000 admissions considering all causes and 5.4/10 000 for cardiovascular disease. Strain was the only triggering factor – noted in two cases (Observations 2 and 3). All patients suffered from severe arterial hypertension (AHT) of which there was one case of renovascular AHT based on the Takayasu arteritis. All symptoms and physical findings were the same described in litterature. Operations were successful on two patients. The four unoperated patients died (tamponade: two cases, undetermined cause: two cases). Conclusion – The authors conclude as to the similarity of the AD charts described in the literature. However they stress the almost exclusive role of AHT in African studies series as well as that, in rare cases, of Takayasu's disease. They recommend preventing AD through the sustained and effective treatment of AHT.

Localized Aortic Dissection: Unusual Features by Transesophageal Echocardiography

Transesophageal echocardiography relies on the presence of an undulating intimal flap for the diagnosis of aortic dissection. Furthermore, to distinguish true dissection from echo artifacts, the flap has to be identified in more than one view, and it must have a motion independent of the aortic wall. We describe the transesophageal echocardiography appearance of a localized aortic dissection with atypical features for an intimal flap. Awareness of this unusual echocardiographic appearance of an intimal flap will avoid misdiagnosis of the poten-tially serious acute aortic dissection. (J Am Soc Echo-cardiogr 2000;13:1130-4.)

Verschiedene Spiral-CT-Untersuchungsprotokolle und ihre Wertigkeit bei Aortendissektionen: eine prospektive Vergleichsstudie

Development of an optimized Spiral CT protocol type for the diagnosis of aortic dissections. 121 consecutive CT examinations applying 5 different protocol types were blindly read by two experienced radiologists and then compared with: (a) 45 biplane transesophageal echocardiographies (TEE), (b) 52 transthoracic echocardiographies (TTE), (c) 52 operative findings and, furthermore, related to the clinical course over at least six months in 79 patients. The sensitivity of the spiral computed tomography for detection of dissection was 97% (biplane TEE: 88%), the specificity 100% (biplane TEE: 91%). In 15% dissections with atypical origin and entries (mid-portion of the aortic arch, distal thoracic aorta, etc.) were found. The optimal CT-protocol was the one with a combination of two separate but adjacent spiral scans achieving high spatial resolution for the aortic arch and enough spatial resection for the residual aorta (1. helical scan 3 mm collimation, pitch 2. 2. helical scan 5 mm collimation and pitch 2, 130 ml contrast medium at 5 ml/s) with a classification accuracy of 100%, visualization of entries of 100%, reentries of 100% (40% direct, 60% indirect). The identification of the ostia of the aortic branches were: supraaortic 93%, visceral 100%, left renal artery 100%, right renal artery 93%, iliac 64%. The CT angiography, designed as aortic arch angiography, showed a good contrast in the aortic arch vessels (79-86%) and the visceral vessels too (91%). Thoracic CT angiography can be used as gold standard in the primary evaluation of aortic dissections.

Rapid diagnosis and management of thoracic aortic dissection and intramural haematoma: a prospective study of advantages of multiplane vs. biplane transoesophageal echocardiography.

The purposes of this study were to compare the accuracy of multiplane vs. biplane transoesophageal echocardiography (TEE) in the diagnosis of aortic dissection and aortic intramural haematoma, and to test whether these techniques provide all the diagnostic information required to make management decisions. Fifty-eight consecutive patients with clinically suspected aortic dissection were studied with multiplane TEE; all cases who required surgery underwent intraoperative monitoring with multiplane TEE. The following multiplane TEE data were analysed: the angle between current and 0 degrees plane at which each view was obtained; the success rate in the evaluation of true and false lumen, entry tear, coronary artery involvement, aortic regurgitation, pericardial effusion. Advantages of multiplane over biplane TEE have been evaluated by the demonstration of usefulness of views obtained in planes other than 0 degrees-20 degrees or 70 degrees-110 degrees, assuming that with manipulation of a biplane probe a 20 degrees arc could be added to the conventional horizontal and vertical planes. On the basis of TEE findings, aortic dissection was confirmed in 36 cases (18 type A, 12 type B, six intramural haematoma). The specificity and sensitivity of TEE in terms of the presence or absence of aortic dissection or intramural haematoma were 100%. An additional clinical value of multiplane over biplane TEE in the evaluation of ascending aorta, aortic arch, entry tears and coronary artery involvement was demonstrated. All cases with type A aortic dissection or intramural haematoma involving the ascending aorta had an operation that was performed immediately after the diagnosis (hospital mortality, 13%). Patients with type B aortic dissection were treated medically; 25% of these cases were operated later (hospital mortality, 0%). Multiplane and biplane TEE have excellent and similar accuracies in the evaluation of aortic dissection and intramural haematoma. Multiplane TEE improves the visualization of coronary arteries, aortic arch and entry tears; it appears to be an ideal method as the sole diagnostic approach before surgery in type A aortic dissection.

Clinical Comparison of Aortic Intramural Hemorrhage with Aortic Dissection Involving the Ascending Aorta

Background and Objectives:Although aortic intramural hemorrhage (AIH) is different from classic aortic dissection (AD) in terms of absence of continuous direct flow communication through intimal tear, the same treatment strategy, emergent surgical repair, has been applied for patients with AIH involving the ascending aorta. The impact of different false lumen hemodynamic has not been seriously investigated and clinical features of AIH and AD have not been directly compared. Methods:From 1990 to December 1998, clinical evaluation with various imaging modalities confirmed the diagnosis of proximal AD and AIH in 73 and 18 patients, respectively. Direct comparison of clinical data including clinical features, hospital course, and follow-up data was performed retrospectively. Results:Patients with AIH were older (69±10 years-old 49± 14, p 0.05). Conclusions:Patients with proximal AIH shows different clinical features and much better prognosis with medical treatment compared to those with AD. These results 논문접수일:1999년 11월 23일 심사완료일:2000년 2월 17일 교신저자:송재관, 138-736 서울 송파구 풍납동 388-1 울산대학교 의과대학 서울중앙병원 심장내과학교실 전화:(02) 2224-3149, 3150·전송:(02) 486-5918 E-mail:jksong@www.amc.seoul.kr

Intracoronary serum smooth muscle myosin heavy chain levels following PTCA may predict restenosis.

Recently a novel biochemical method that uses an immunoassay to quantitate serum smooth muscle myosin heavy chain (SMMHC) levels was developed for diagnosis of aortic dissection.) The purpose of this study was to determine whether SMMHC released from the coronary arterial wall can be used to predict restenosis after percutaneous transluminal coronary angioplasty (PTCA). Fifty-two consecutive patients undergoing successful PTCA for single vessel disease were examined (40 men, 12 women, 63 +/- 8 years). Intracoronary blood samples were obtained distal to the lesion, and from the femoral artery after PTCA. In 10 patients, blood samples were taken immediately after the final balloon inflation, and 10 and 20 minutes after PTCA. SMMHC levels were measured by ELISA using SMMHC-specific monoclonal antibodies. Follow-up coronary angiography was performed 3 months after PTCA. Intracoronary serum SMMHC levels were significantly higher than those obtained from the femoral artery (10.6 +/- 1.5 vs 2.1 +/- 0.1 ng / ml, p < or = 0.001). Of 40 patients without apparent dissection, the 23 patients who did not develop restenosis in the follow-up study were found to have had higher levels of intracoronary SMMHC levels immediately after PTCA compared to the 17 patients with restenosis (15.2 +/- 2.9 vs 7.1 +/- 1.2 ng /ml, p < or = 0.05). We suggest that elevated intracoronary SMMHC levels after PTCA may reflect the extent of injury to the arterial wall. Intracoronary SMMHC may be a possible biochemical marker for the prediction of restenosis.

Acute Aortic Dissection Presenting as Left Upper Limb Ischemia

Acute upper limb ischemia is most frequently the result of an embolus that originates in the heart. Ascending aortic dissection is a life-threatening vascular emergency that must be treated immediately. Isolated upper limb ischemia secondary to acute aortic dissection has not been previously reported. Two cases of DeBakey type I aortic dissection presenting as unilateral upper limb ischemia are reported. This presentation may result in delayed diagnosis of aortic dissection and, consequently, in high mortality. The possibility should be borne in mind when dealing with all cases of acute arm ischemia because embarking on a brachial embolectomy which may delay the diagnosis of a more serious and fatal condition. The etiology of this unusual presentation and possible therapeutic interventions are discussed.

Aortic Dissection: A “Humerus” Case

Aortic dissection usually presents with acute onset of severe chest pain. Classically there is a pressure differential between the 2 arms and widening of the mediastinum. Echocardiography is considered the investigation of choice in many institutions. A case is presented in which the presentation and clinical signs are classical for dissection. Transthoracic echocardiography demonstrated “enlargement” of the descending aorta and a “flap.” A surprise diagnosis was made by transesophageal echocardiography. Other vascular structures in the para-aortic regions should be considered when the diagnosis of aortic dissection is entertained. (J Am Soc Echocardiogr 1999;12:864-5.)

Spiral CT angiography of aortic dissection

Spiral CT angiography (CTA) is one of the newest imaging techniques used for the evaluation of aortic dissection. Current spiral CT scanners with high-performance tubes and subsecond scanning allow increased regions of coverage. Large volumes of data are rapidly acquired through the aorta during maximum contrast enhancement. Multiplanar reformat (MPR), curved planar reformat (CPR), and 3-D rendering techniques including shaded surface display (SSD) and maximum intensity projection (MIP) are then applied to the data to generate CT angiographic images of the aorta. Emergent spiral CTA may be performed in patients with suspected aortic dissection who are hemodynamically stable. Postprocessing is performed immediately following data acquisition and can provide additional information for aortic dissection diagnosis and clinical management. The technique, applications, and limitations of spiral CTA for the evaluation of aortic dissection will be discussed relative to the role of other imaging modalities.

Utility of Contrast Echocardiography in the Diagnosis of Aortic Dissection

Determination of ascending aortic involvement in aortic dissection has significant implications in prognosis, immediate surgical referral, and surgical approach. We report 2 cases of the use of an echo contrast agent in enhancing the diagnostic capability of transesophageal echocardiography in suspected ascending aortic dissection. Contrast echocardiography eliminated the linear artifacts often confused with true dissection flaps and allowed easy identification of the presence of true and false lumina. (J Am Soc Echocardiogr 1999;12:155-9.)

Evaluation of acute aortic dissection by cine-MRI.

We investigated operative indication of acute aortic dissection by analyzing the movement of the intimal flap using cine-MRI. Ten consecutive cases of acute aortic dissection diagnosed between December 1997 and September 1998 participated in this study. Six of these patients had in Stanford type A and four Stanford type B aortic dissection. The diagnosis of aortic dissection was based on demonstration of two aortic channels with each cardiac cycle. After obtaining SE(spin-echo) images, gradient echo sequences (FFE) were obtained such that the false lumen was maximally imaged and the intimal flap was depicted perpendicularly. During one RR-interval of ECG, 12 to 16 measurements were recorded and combined in a cineloop mode. We defined the intimal flap, the site of the entry and thrombosis in the false lumen, and evaluated the movement of the intimal flap as the flap movement index (FMI). Maximum and minimum aortic diameters (ADmax, ADmin), as well as maximum and minimum false lumen diameters (FDmax, FDmin) were measured. FMI was defined as[(FDmax/ADmax) - (FDmin/ADmin)]/(FDmin/ADmin) x 100(%). Total thrombosis was noted in four cases, partial thrombosis in 3, and in the remaining 3 no thrombosis of the false lumen was noted. The FMI ranged between 4% and 87% (mean 26.3 +/- 8.6%). Among the 4 cases with the large FMI of greater than 30%, 3 underwent emergency surgery and were confirmed to have no thrombosis in the false lumen. The fourth case, who had partial thrombosis, underwent medical therapy, but since complete thrombosis in the false lumen never did occur in this case, surgery became absolutely necessary. The other 6 cases with a FMI of less than 30% showed a tendency toward gradual reduction of the false lumen. FMI is a potentially useful parameter in cases with acute aortic dissection to determine whether or not emergency surgery is indicated.

Biochemical diagnosis of aortic dissection: from bench to bedside.

Aortic dissection is an acute cardiovascular disease associated with high mortality and morbidity. Although uncommon, recent studies have shown that the incidence of this catastrophic disease is steadily increasing. Unfortunately, the disease is still not well recognized on clinical presentation due to lack of specific signs and symptoms. As early diagnosis and initial management are critical for survival, we focused on developing a biochemical diagnostic approach for this disease given its meritorious properties in use in the acute clinical situation and additional projected combined use with established imaging modalities. Studies using an assay developed against smooth muscle myosin heavy chain, a protein which is released from the aortic medial smooth muscle cells on insult to the aortic wall, showed promising results for use of this assay in the diagnosis of aortic dissection. The background of this pioneering assay in addition to its clinical use are discussed in this review.

Quality of History Taking in Patients With Aortic Dissection

Aortic dissection generally is an acute catastrophe. Rapid diagnosis is critical. We hypothesized that the quality of history taking contributes to the accuracy of diagnosis in patients with dissection. Retrospective chart review of 83 patients, whose diagnosis of aortic dissection was confirmed by autopsy, surgery, CT scan, echocardiogram, or angiogram. The quality of the initial history was reviewed using predetermined criteria. The physicians' initial clinical impressions were recorded. The examining physician correctly suspected aortic dissection after the initial clinical evaluation in 54 of 83 patients (65%). Only 33 of 78 patients with symptoms (42%) were asked about the quality, location, and onset of their pain, the three descriptors identified a priori as important. In 19 patients (24%), only zero or one descriptor was recorded. When all three questions were asked, dissection was suspected in 30 of 33 patients (91%); when zero, one, or two questions were asked, dissection was suspected in 22 of 45 patients (49%). Despite important advances in diagnostic imaging, accurate diagnosis of aortic dissection requires an accurate history. In our series, the quality of initial history was associated with the accuracy of the initial clinical impression in patients with aortic dissection.

Biochemical diagnosis of aortic dissection by raised concentrations of creatine kinase BB-isozyme

Aortic dissection is associated with a high mortality and morbidity. Despite advancements in surgical and medical treatment, aortic dissection is often diagnosed too late or is overlooked. There have been improvements in diagnostic imaging, such as transesophageal echocardiography and magnetic resonance imaging, but biochemical diagnosis have not been explored. We have reported raised serum smooth-muscle-myosin heavy chain concentrations in aortic dissection;1–3 we now show creatine kinase BB-isozyme concentrations to be raised in acute aortic dissection.

Novel biochemical diagnostic method for aortic dissection. Results of a prospective study using an immunoassay of smooth muscle myosin heavy chain.

Aortic dissection is one of the most common aortic catastrophes. Although newer diagnostic methods as exemplified by image diagnostic techniques have greatly improved the diagnosis of aortic dissection, the diagnosis is still frequently missed today because the signs and symptoms of the disease are at times obscure. A reliable biochemical diagnostic method for aortic dissection would be beneficial. A novel biochemical diagnostic method for diagnosis of aortic dissection was developed that uses an immunoassay of monoclonal antibodies to smooth muscle myosin heavy chain. A prospective study was conducted to ascertain the usefulness of the method in the diagnosis of aortic dissection. Twenty-seven patients with aortic dissection admitted within the first 24 hours after onset were enrolled. Serial assay of serum smooth muscle myosin heavy chain showed significant elevations within the first 24 hours after onset of aortic dissection, with levels exceeding 10 ng/mL, with subsequent rapid reductions. The sensitivity of the assay within the first 12 hours was 90% with a specificity of 97%. Analysis of 65 patients with acute myocardial infarction showed that the method could accurately differentiate myocardial infarction from aortic dissection. The immunoassay of serum smooth muscle myosin heavy chain is a rapid and reliable biochemical method in the diagnosis of aortic dissection. The potential use of the method in clinical medicine is promising.

Diagnosis of ascending aortic dissection by transesophageal echocardiography: Utility of M-mode in recognizing artifacts

This study sought to assess the reliability of biplanar transesophageal echocardiography in the diagnosis of ascending aortic dissection and to test the utility of M-mode information in the differential diagnosis of ascending aortic ultrasound artifacts and intimal flap images. Transesophageal echocardiography is a useful technique in the diagnosis of aortic dissection. However, ultrasound artifacts in the ascending aorta are an important limitation. Transesophageal echocardiography was performed in 132 consecutive patients with clinically suspected aortic dissection. Two-dimensional and M-mode echocardiography and color Doppler were used to diagnose intimal flap and artifact images. Diagnoses were validated either anatomically or with reference techniques. The sensitivity and specificity of transesophageal echocardiography in the diagnosis of ascending aortic dissection were 96.8% and 100%, respectively. Ninety-three artifacts were observed in 56 (55%) of 101 patients without ascending aortic dissection. Two-dimensional echocardiography easily identified 74 artifacts (80%). Color Doppler showed no ascending flow abnormalities in 71% of artifact images. M-mode echocardiography showed three location and mobility artifact patterns related to the posterior wall of the aorta or the right pulmonary artery. In contrast, intimal flap movement showed no relation to the aortic wall movement in 25 cases (83%). Blind analysis of transesophageal echocardiographic study tapes underlined the utility of M-mode in the differential diagnosis. Ranges of sensitivity, specificity and positive predictive value (established by including doubtful results as either positive or negative) improved from 87.1-93.5% to 93.5-96.8%, from 85.1-94.1% to 99-100% and from 65.9-81.8% to 96.8-100%, respectively, with the inclusion of M-mode data. Biplanar transesophageal echocardiography permits reliable diagnosis of ascending aortic dissection. Ultrasound artifacts are common, but assessment of the location and mobility of intraluminal images by M-mode echocardiography definitely improves diagnostic accuracy.

64-Year-Old Woman With Chest Pain and Presyncope

64-Year-Old Woman With Chest Pain and Presyncope