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Role of Transesophageal Echocardiography in Patients With Suspected Aortic Dissection

2005; Elsevier BV; Volume: 18; Issue: 11 Linguagem: Inglês

10.1016/j.echo.2004.12.006

1097-6795

Holger K. Eltzschig, Peter Rosenberger, R LEKOWSKIJR, J. E. Scott, Andrew H. Locke, Prem Shekar, Stanton K. Shernan, J. Fox,

Cardiac Structural Anomalies and Repair

Patients with acute aortic dissection of the ascending aorta benefit from rapid surgical intervention. We report a patient with suspected acute aortic dissection based on history and transthoracic echocardiography findings. This patient was taken to the operating room without further workup, where transesophageal echocardiography (TEE) revealed acute myocardial infarction and mitral regurgitation due to papillary muscle rupture. The patient underwent coronary bypass grafting and mitral valve replacement. This case demonstrates that intraoperative TEE can be used as a primary diagnostic modality to rule out aortic dissection, and can provide a definitive etiology for cardiogenic shock before a planned surgical intervention. Patients with acute aortic dissection of the ascending aorta benefit from rapid surgical intervention. We report a patient with suspected acute aortic dissection based on history and transthoracic echocardiography findings. This patient was taken to the operating room without further workup, where transesophageal echocardiography (TEE) revealed acute myocardial infarction and mitral regurgitation due to papillary muscle rupture. The patient underwent coronary bypass grafting and mitral valve replacement. This case demonstrates that intraoperative TEE can be used as a primary diagnostic modality to rule out aortic dissection, and can provide a definitive etiology for cardiogenic shock before a planned surgical intervention. Acute aortic dissection is a highly lethal disorder, with a mortality rate of 1% per hour during the first 24 hours after the onset of chest pain.1O'Gara P.T. Greenfield A.J. Afridi N.A. Houser S.L. Case 12-2004 a 38-year-old woman with acute onset of pain in the chest.N Engl J Med. 2004; 350: 1666-1674Crossref PubMed Scopus (11) Google Scholar, 2Hirst Jr, A.E. Johns Jr, V.J. Kime Jr, S.W. Dissecting aneurysm of the aorta a review of 505 cases.Medicine (Baltimore). 1958; 37: 217-279Crossref PubMed Scopus (1046) Google Scholar Early surgical intervention currently remains the mainstay therapy, particularly when the ascending aorta is involved (type A dissection).3Nienaber C.A. Eagle K.A. Aortic dissection: new frontiers in diagnosis and management. Part II, therapeutic management and follow-up.Circulation. 2003; 108: 772-778Crossref PubMed Scopus (205) Google Scholar, 4Nienaber C.A. Eagle K.A. Aortic dissection: new frontiers in diagnosis and management. Part I, from etiology to diagnostic strategies.Circulation. 2003; 108: 628-635Crossref PubMed Scopus (446) Google Scholar Surgical therapy is directed toward preventing aortic rupture or pericardial effusion, which may lead to cardiac tamponade and death. In addition, surgical intervention can address acute aortic regurgitation, coronary flow obstruction, or further extension of the dissection within the aorta or adjacent vessels.3Nienaber C.A. Eagle K.A. Aortic dissection: new frontiers in diagnosis and management. Part II, therapeutic management and follow-up.Circulation. 2003; 108: 772-778Crossref PubMed Scopus (205) Google Scholar Despite advanced surgical techniques, such as profound hypothermic circulatory arrest5Lai D.T. Robbins R.C. Mitchell R.S. Moore K.A. Oyer P.E. Shumway N.E. et al.Does profound hypothermic circulatory arrest improve survival in patients with acute type A aortic dissection?.Circulation. 2002; 106: 218-228Google Scholar and selective retrograde perfusion of head vessels,6Kazui T. Washiyama N. Muhammad B.A. Terada H. Yamashita K. Takinami M. et al.Extended total arch replacement for acute type A aortic dissection experience with seventy patients.J Thorac Cardiovasc Surg. 2000; 119: 558-565Abstract Full Text Full Text PDF PubMed Scopus (165) Google Scholar perioperative mortality rates remain between 15% and 35% in centers of excellence.3Nienaber C.A. Eagle K.A. Aortic dissection: new frontiers in diagnosis and management. Part II, therapeutic management and follow-up.Circulation. 2003; 108: 772-778Crossref PubMed Scopus (205) Google Scholar Nevertheless, the key to optimizing outcomes in patients with acute dissection of the ascending aorta remains urgent surgical intervention before the development of acute hemodynamic deterioration or nonreversible ischemic damage of vital organs.7Rizzo R. Aranki S. Aklog L. Couper G.S. Adams D.H. Collins Jr, J.J. et al.Rapid noninvasive diagnosis and surgical repair of acute ascending aortic dissection improved survival with less angiography.J Thorac Cardiovasc Surg. 1994; 108: 567-575Abstract Full Text PDF PubMed Scopus (110) Google Scholar The decision to initiate surgical intervention to treat acute aortic dissection depends on an efficiently acquired and reliable diagnosis to provide a detailed anatomic description of the aortic defect. However, clinical signs at the time of presentation, such as the acute onset of chest and/or back pain, are nonspecific; a pulse deficit is present only in < 20% of affected patients, and the initial chest x-ray films are frequently normal in patients who are later found to have acute aortic dissection.8Hagan P.G. Nienaber C.A. Isselbacher E.M. Bruckman D. Karavite D.J. Russman P.L. et al.The International Registry of Acute Aortic Dissection (IRAD) new insights into an old disease.JAMA. 2000; 28: 897-903Crossref Scopus (2376) Google Scholar Thus, detection of acute aortic dissection often relies on further formal diagnostic testing. Although such diagnostic interventions as angiography or magnetic resonance may be ideal, these time-consuming imaging modalities are not always easy to obtain, and doing so may delay definitive surgical intervention, thereby significantly increasing perioperative morbidity and mortality.7Rizzo R. Aranki S. Aklog L. Couper G.S. Adams D.H. Collins Jr, J.J. et al.Rapid noninvasive diagnosis and surgical repair of acute ascending aortic dissection improved survival with less angiography.J Thorac Cardiovasc Surg. 1994; 108: 567-575Abstract Full Text PDF PubMed Scopus (110) Google Scholar Transesophageal echocardiography (TEE) is considered a relatively noninvasive and efficient imaging modality for diagnosing acute dissection of the aorta, because it allows direct visualization of intimal tears and flaps, sites of entry and reentry, false lumen thrombosis, coronary involvement, intramural hematoma, pericardial effusion, and aortic insufficiency with high sensitivity and specificity.9Penco M. Paparoni S. Dagianti A. Fusilli C. Vitarelli A. De Remigis F. et al.Usefulness of transesophageal echocardiography in the assessment of aortic dissection.Am J Cardiol. 2000; 86: 53G-56GAbstract Full Text Full Text PDF PubMed Scopus (51) Google Scholar, 10Nienaber C. Spielmann R. von Kodolitsch Y. Siglow V. Piepho A. Jaup T. et al.Diagnosis of thoracic aortic dissection magnetic resonance imaging versus transesophageal echocardiography.Circulation. 1992; 85: 434-447Crossref PubMed Scopus (230) Google Scholar Although diagnostic interventions in patients with suspected acute dissection of the ascending aorta are most commonly performed in medical emergency rooms, radiology intervention rooms, and intensive care units, the practicality and utility of TEE has contributed to its popularity in the operative room setting. Thus, patients with high clinical suspicion of acute aortic dissection may be sent directly to the operating room without previous establishment of a definitive diagnosis or detailed anatomic description of the defect. This approach can be advantageous with regard to limiting the time before a surgical intervention and thereby decreasing morbidity and mortality. We report a patient in whom intraoperative TEE was used as a primary diagnostic modality to rule out aortic dissection, and provide a definitive etiology for acute cardiogenic shock before a planned surgical intervention. A 74-year-old woman with a past medical history of hypertension was brought to the hospital's emergency room complaining of sudden searing chest pain radiating to her back. In the emergency room, she progressed to cardiogenic shock with a blood pressure of 70/30 mm Hg. An electrocardiogram showed posterior and lateral ST elevations, and TTE revealed only a echolucent band anterior to the left ventricular wall consistent with pericardial fluid. She was immediately taken to the operating room with suspected acute aortic dissection and pericardial tamponade. A TEE examination performed in the operating room after induction of anesthesia and tracheal intubation showed an intact aorta without signs of dissection or intramural hematoma or any evidence of cardiac tamponade. But TEE revealed severe mitral regurgitation, a ruptured posterior papillary muscle, and hypokinesis of the lateral and posterior walls of the left ventricle, suggesting acute myocardial infarction and papillary muscle rupture. Consequently, the patient underwent mitral valve replacement and coronary artery bypass grafting (CABG) with vein grafts to the anterior descending and obtuse marginal coronary arteries, based on manual palpation of a large calcification within the left main coronary artery. The patient was then weaned from cardiopulmonary bypass and subsequently transferred to the intensive care unit. On the second postoperative day, the patient experienced sudden massive hemorrhage. Immediate surgical exploration at the bedside revealed rupture of the left ventricular free wall. Despite several attempts to repair the defect, the patient could not be resuscitated, and she died. Intraoperative TEE is frequently used to monitor cardiac performance or as a secondary diagnostic tool to obtain additional diagnostic information in patients undergoing cardiac surgery.11Click R.L. Abel M.D. Schaff H.V. Intraoperative transesophageal echocardiography 5-year prospective review of impact on surgical management.Mayo Clin Proc. 2000; 75: 241-247PubMed Google Scholar During repair of an acute aortic dissection, intraoperative TEE is useful for evaluating the extent of the dissection, identifying the involvement of adjacent vessels (eg, carotid or subclavian artery), or determining the degree and mechanism of aortic regurgiation.12Movsowitz H.D. Levine R.A. Hilgenberg A.D. Isselbacher E.M. Transesophageal echocardiographic description of the mechanisms of aortic regurgitation in acute type A aortic dissection implications for aortic valve repair.J Am Coll Cardiol. 2000; 36: 884-890Abstract Full Text Full Text PDF PubMed Scopus (111) Google Scholar However, the decision to perform surgery is usually determined preoperatively after a definitive diagnosis is made using angiography, computed tomography (CT), or magnetic resonance imaging (MRI). The present case demonstrates that TEE can be performed within the operating room to demonstrate the presence or absence of acute aortic dissection and rapidly determine the etiology of acute cardiogenic shock requiring surgical intervention. In fact, patients with a strong clinical suspicion of acute aortic dissection based on history (eg, typical back pain), physical examination (eg, pulse deficit) or simple noninvasive procedures (eg, TTE or chest x-ray) may be taken directly to the operating room, where a TEE examination can be performed after the induction of anesthesia and tracheal intubation. If the examination confirms acute dissection of the ascending aorta and surgery is indicated, then the operation can be performed without loosing precious time. In contrast, if TEE fails to demonstrate acute dissection, then the patient can be taken to an intensive care unit to recover and await further therapeutic intervention or diagnostic testing. Although the patient described in this case report eventually died, the presence of acute heart failure associated with postinfarction papillary muscle rupture and severe mitral regurgitation was rapidly diagnosed by TEE in the security of the operating room, where mitral valve replacement and CABG were ultimately performed. Some limitation of using TEE as a primary diagnostic tool in patients with acute dissection should be kept in mind. Due to its position relative to the left main bronchus, TEE views of the proximal ascending aorta can sometimes be limited.13Konstadt S.N. Reich D.L. Quintana C. Levy M. The ascending aorta how much does transesophageal echocardiography see?.Anesth Analg. 1994; 78: 240-244Crossref PubMed Scopus (115) Google Scholar Epicardial echocardiography may be used in such cases to further investigate details of the dissection of the ascending aorta and adjacent vessels after sternotomy.14Eltzschig H.K. Kallmeyer I.J. Mihaljevic T. Alapati S. Shernan S.K. et al.A practical approach to a comprehensive epicardial and epiaortic echocardiographic examination.J Cardiothorac Vasc Anesth. 2003; 17: 422-429Abstract Full Text Full Text PDF PubMed Scopus (55) Google Scholar In addition, TEE requires sedation and in some cases tracheal intubation before the examination, in contrast to CT or MRI. Finally, in some patients TEE may be contraindicated or can lead to such complications as aspiration, dysphagia, and, in extremely rare circumstances, esophageal rupture.15Kallmeyer I.J. Collard C.D. Fox J.A. Body S.C. Shernan S.K. The safety of intraoperative transesophageal echocardiography a case series of 7200 cardiac surgical patients.Anesth Analg. 2001; 92: 1126-1130Crossref PubMed Scopus (324) Google Scholar In summary, the present report suggests that patients with a high clinical suspicion of acute aortic dissection may be sent directly to the operating room for further diagnostic workup with TEE and preparation for surgery, thereby decreasing the time period before possible surgical intervention.7Rizzo R. Aranki S. Aklog L. Couper G.S. Adams D.H. Collins Jr, J.J. et al.Rapid noninvasive diagnosis and surgical repair of acute ascending aortic dissection improved survival with less angiography.J Thorac Cardiovasc Surg. 1994; 108: 567-575Abstract Full Text PDF PubMed Scopus (110) Google Scholar(Figure 1)