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Intraoperative Diagnosis of Aortic Dissection in Pregnancy
Intraoperative Diagnosis of Aortic Dissection in Pregnancy Ryan Crowley, MD, Jennifer Corniea, MA, David Chavez, MD, Jonathan K. Ho, MD, and Aman Mahajan, MD, PhD
A
ORTIC DISSECTION in young patients is primarily associated with trauma, cocaine use, chronic hypertension, bicuspid aortic valve, congenital coarctation of the aorta, or connective tissue disorders such as Marfan, Turner, and EhrlosDanlos syndromes.1-4 Aortic dissection during pregnancy is rare, and reported cases are associated with underlying risk factors.3 However, because of the low incidence of aortic dissection in pregnant women, clinical suspicion may remain low, leading to a delayed or missed diagnosis. Furthermore, the management of acute aortic dissection in the presence of fetal distress during late pregnancy is not well described. The authors report a unique case of a pregnant patient mistakenly diagnosed with myocardial infarction (MI) secondary to acute coronary syndrome who presented to the operating room (OR) for emergent Cesarean section with heart failure and fetal distress. Although the patient had no underlying risk factors for aortic pathology, intraoperative echocardiography identified an acute ascending aortic dissection, leading to successful simultaneous repair of the dissection and operative delivery of the baby. CASE REPORT A 34-year-old, G4P2, 158-cm tall, 82-kg woman at 37 weeks gestation presented with complaints of acute chest pain and mild shortness of breath. She had no significant past medical history and had 2 previous uneventful pregnancies. At an outside facility, she was diagnosed with acute MI based on an electrocardiogram (ECG) showing anterior and anterior-septal myocardial ischemia and a serum troponin of 0.79 ng/mL (normal ⬍0.1). She was transferred to the authors’ institution for tertiary care. On arrival, her blood pressure was 135/80 mmHg, heart rate was 130 beats/min, respiration was 20 breaths/min, and arterial oxygen saturation was 95% on 10 L by facemask. A repeat ECG showed an evolving MI, and serum troponins were further elevated to 17.2 ng/mL. A transthoracic echocardiogram (TTE) performed in the emergency department (ED) showed decreased left ventricular ejection fraction; no valvular pathology; and moderate anterior, anterior-septal, and lateral wall hypokinesis consistent with the ECG changes suggestive of acute MI. A chest radiograph performed showed mild pulmonary venous congestion but no widening of the mediastinum. With the presumptive diagnosis of an acute MI, the patient was prepared for transfer to the interventional cardiac catheterization laboratory. However, at this time, the fetus started to have late decelera-
From the Department of Anesthesiology, David Geffen School of Medicine at UCLA, Los Angeles, CA. A.M. was supported by intramural departmental funds and by grants from NIH/NHLBI P01 HL078931 and NIH RO1-HL084261. Address reprint requests to Aman Mahajan, MD, PhD, Department of Cardiothoracic Anesthesiology, David Geffen School of Medicine at UCLA, 757 Westwood Plaza, Suite 3325, Los Angeles, CA 90095. E-mail: [email protected] © 2010 Elsevier Inc. All rights reserved. 1053-0770/10/2401-0022$36.00/0 doi:10.1053/j.jvca.2009.03.013 Key words: aortic dissection, pregnancy, cardiac surgery, ischemia, aortic regurgitation, transesophageal echocardiogram, echocardiography, diagnosis, treatment 116
tions, prompting the obstetrics team to bring the patient to the OR for an emergent Cesarean section. On arrival to the OR, the fetal heart rate and variation temporarily returned to normal; however, the patient’s dyspnea increased significantly. A repeat TTE during this time by a cardiac anesthesiologist showed severe biventricular dysfunction and aortic regurgitation (AR), whereas the ascending aorta could not be well visualized (Fig 1). The TTE findings of acute AR and ischemia were believed to be consistent with aortic dissection rather than primary acute coronary syndrome. Shortly after the TTE examination, the patient required endotracheal intubation because of worsening tachypnea and hypoxemia. Given the acuity of the patient’s clinical deterioration and poor oxygenation, intubation followed a rapid-sequence induction with cricoid pressure using etomidate and succinylcholine. The hemodynamic effects of laryngoscopy were minimized with the use of esmolol and nitroglycerin. To confirm the diagnosis of aortic dissection, a transesophageal echocardiogram (TEE) was performed, clearly showing an ascending aortic dissection, severe biventricular dysfunction, and moderate AR (Fig 2). After consultation among the cardiothoracic surgery, obstetrics, and anesthesiology teams, it was decided to simultaneously perform a Cesarean section before the administration of heparin while femoral cannulation and median sternotomy were performed to repair the aortic dissection. The abdomen was left open during the cardiopulmonary bypass (CPB) portion of the case to monitor for bleeding until after the reversal of heparin and to perform a hysterectomy if bleeding could not be controlled. Fortunately, uterine atony and hemorrhage were readily prevented with the use of oxytocic drugs after delivery of the baby. The baby was resuscitated, intubated, and transported to the neonatal intensive care unit. The baby was eventually discharged on postoperative day 4 and continues to do well with no medical problems. On surgical inspection, the dissection was limited to the sinus of Valsalva and extended into both coronary ostia. Therefore, a Bentall procedure and 3-vessel coronary artery bypass grafting using saphenous vein grafts were performed. The patient was successfully weaned from CPB, transferred to the intensive care unit with inotropes, and discharged home on postoperative day 8. A postoperative pathology examination of the aortic specimen did not reveal underlying connective tissue disease. Six months after discharge, the patient’s TTE showed an ejection fraction of 40%. She is currently active with no reported functional limitations. DISCUSSION
A highly unusual presentation of an acute aortic dissection in a young pregnant patient without any predisposing risk factors is reported. Although the patient was initially diagnosed with primary acute coronary syndrome, intraoperative echocardiography was critical in correctly defining the etiology of MI as a type-A dissection, prompting a change in the management of the patient. Fetal distress likely occurred because of the hypotension and low cardiac output from worsening acute heart failure. To the authors’ knowledge, this is the first reported case of aortic dissection diagnosed in the OR at the time of presentation for an emergent Cesarean section. Coordinated efforts between the obstetric, surgical, and anesthesiology teams allowed successful management of a difficult medical emergency.
Journal of Cardiothoracic and Vascular Anesthesia, Vol 24, No 1 (February), 2010: pp 116-118
AORTIC DISSECTION IN PREGNANCY
Fig 1. line.)
117
A transthoracic parasternal view showing aortic regurgitation and a dilated left ventricle. (Color version of figure is available on-
Fig 2. (A) A TEE midesophageal short-axis view of the aorta showing the aortic dissection flap. (B) A TEE midesophageal long-axis view of the aorta showing the aortic dissection flap.
The most critical period in managing a patient with aortic dissection begins with a timely diagnosis and requires a high level of clinical suspicion. Unfortunately, the initial misdiagnosis of aortic dissection continues to be high (38%-44%), leading to increased morbidity.4,5 Untreated, mortality is estimated to be as high as 1% per hour for the first 24 to 48 hours.4,6 Although it is unclear if pregnancy is itself an independent risk factor, aortic dissection should be considered early in the differential diagnosis in any pregnant female presenting with chest pain.6,7 Studies suggest that hemodynamic or hormonal changes in pregnancy can worsen the shearing stress in the aorta.2,3 Hypertension and Marfan syndrome are the 2 main risk factors linked with aortic dissections during pregnancy.3,4,7,8 Marfan syndrome typically worsens during pregnancy, accounting for the increased incidence of aortic dissections noted in young pregnant females.1-4,6,7 The absence of underlying risk factors in the present patient delayed the consideration of a diagnosis of aortic dissection in the ED. Although TTE offers the advantage of being noninvasive, suboptimal imaging windows because of the patient’s body habitus delayed the diagnosis. Additionally, the sensitivity and specificity of TEE for type-A dissection in experienced hands are as high as 98% and 99%, respectively.2,4,9 TEE allows the diagnosis of the entry site of the dissection, involvement of the coronary vessels, severity of aortic valve regurgitation, and presence of pericardial effusions, all of which were valuable in the present patient.4,9 For an unstable patient who might not be able to undergo a computed tomography scan or magnetic resonance imaging, TEE offers a rapid and accurate assessment for aortic dissection in the ED or OR. In summary, a highly unusual case of acute aortic dissection and MI in a pregnant female without predisposing risk factors, which was diagnosed intraoperatively on presentation for an emergent Cesarean section, is reported. This case underscores the need to maintain a high level of clinical
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suspicion for aortic dissection in pregnant patients presenting with chest pain. The authors believe the prompt diagnosis with TEE in the OR and subsequent timely coordination
of multiple procedures with obstetrics and cardiothoracic surgery were instrumental in a positive outcome for both this patient and her child.
REFERENCES 1. Immer FF, Bansi AG, Immer-Bansi AS, et al: Aortic dissection in pregnancy: Analysis of risk factors and outcome. Ann Thorac Surg 76:309-314, 2003 2. Weissmann-Brenner A, Schoen R, Divon MY: Aortic dissection in pregnancy. Obstet Gynecol 103:1110-1113, 2004 3. Zeebregts CJ, Schepens MA, Hameeteman TM, et al: Acute aortic dissection complicating pregnancy. Ann Thorac Surg 64:1345-1348, 1997 4. Khan IA, Nair CK: Clinical, diagnostic, and management perspectives of aortic dissection. Chest 122:311-328, 2002 5. Alsous F, Islam A, Ezeldin A, et al: Potential pitfalls in the diagnosis of aortic dissection. Conn Med 67:131-134, 2003
6. Schnitker MA, Bayer CA: Dissection aneurysm of the aorta in young individuals, particularly in association with pregnancy. Ann Intern Med 29:486-511, 1944 7. Oskoui R, Lindsay J Jr: Aortic dissection in women ⬍40 years of age and the unimportance of pregnancy. Am J Cardiol 73:821-823, 1994 8. Lewis S, Ryder I, Lovell AT: Peripartum presentation of an acute aortic dissection. Br J Anaesth 94:496-499, 2005 9. Green RG, Kron IL: Aortic Dissection, Advanced Therapy in Cardiac Surgery (ed 2). Hamilton, BC Decker Inc, 2003, pp 347-363
A
ORTIC DISSECTION in young patients is primarily associated with trauma, cocaine use, chronic hypertension, bicuspid aortic valve, congenital coarctation of the aorta, or connective tissue disorders such as Marfan, Turner, and EhrlosDanlos syndromes.1-4 Aortic dissection during pregnancy is rare, and reported cases are associated with underlying risk factors.3 However, because of the low incidence of aortic dissection in pregnant women, clinical suspicion may remain low, leading to a delayed or missed diagnosis. Furthermore, the management of acute aortic dissection in the presence of fetal distress during late pregnancy is not well described. The authors report a unique case of a pregnant patient mistakenly diagnosed with myocardial infarction (MI) secondary to acute coronary syndrome who presented to the operating room (OR) for emergent Cesarean section with heart failure and fetal distress. Although the patient had no underlying risk factors for aortic pathology, intraoperative echocardiography identified an acute ascending aortic dissection, leading to successful simultaneous repair of the dissection and operative delivery of the baby. CASE REPORT A 34-year-old, G4P2, 158-cm tall, 82-kg woman at 37 weeks gestation presented with complaints of acute chest pain and mild shortness of breath. She had no significant past medical history and had 2 previous uneventful pregnancies. At an outside facility, she was diagnosed with acute MI based on an electrocardiogram (ECG) showing anterior and anterior-septal myocardial ischemia and a serum troponin of 0.79 ng/mL (normal ⬍0.1). She was transferred to the authors’ institution for tertiary care. On arrival, her blood pressure was 135/80 mmHg, heart rate was 130 beats/min, respiration was 20 breaths/min, and arterial oxygen saturation was 95% on 10 L by facemask. A repeat ECG showed an evolving MI, and serum troponins were further elevated to 17.2 ng/mL. A transthoracic echocardiogram (TTE) performed in the emergency department (ED) showed decreased left ventricular ejection fraction; no valvular pathology; and moderate anterior, anterior-septal, and lateral wall hypokinesis consistent with the ECG changes suggestive of acute MI. A chest radiograph performed showed mild pulmonary venous congestion but no widening of the mediastinum. With the presumptive diagnosis of an acute MI, the patient was prepared for transfer to the interventional cardiac catheterization laboratory. However, at this time, the fetus started to have late decelera-
From the Department of Anesthesiology, David Geffen School of Medicine at UCLA, Los Angeles, CA. A.M. was supported by intramural departmental funds and by grants from NIH/NHLBI P01 HL078931 and NIH RO1-HL084261. Address reprint requests to Aman Mahajan, MD, PhD, Department of Cardiothoracic Anesthesiology, David Geffen School of Medicine at UCLA, 757 Westwood Plaza, Suite 3325, Los Angeles, CA 90095. E-mail: [email protected] © 2010 Elsevier Inc. All rights reserved. 1053-0770/10/2401-0022$36.00/0 doi:10.1053/j.jvca.2009.03.013 Key words: aortic dissection, pregnancy, cardiac surgery, ischemia, aortic regurgitation, transesophageal echocardiogram, echocardiography, diagnosis, treatment 116
tions, prompting the obstetrics team to bring the patient to the OR for an emergent Cesarean section. On arrival to the OR, the fetal heart rate and variation temporarily returned to normal; however, the patient’s dyspnea increased significantly. A repeat TTE during this time by a cardiac anesthesiologist showed severe biventricular dysfunction and aortic regurgitation (AR), whereas the ascending aorta could not be well visualized (Fig 1). The TTE findings of acute AR and ischemia were believed to be consistent with aortic dissection rather than primary acute coronary syndrome. Shortly after the TTE examination, the patient required endotracheal intubation because of worsening tachypnea and hypoxemia. Given the acuity of the patient’s clinical deterioration and poor oxygenation, intubation followed a rapid-sequence induction with cricoid pressure using etomidate and succinylcholine. The hemodynamic effects of laryngoscopy were minimized with the use of esmolol and nitroglycerin. To confirm the diagnosis of aortic dissection, a transesophageal echocardiogram (TEE) was performed, clearly showing an ascending aortic dissection, severe biventricular dysfunction, and moderate AR (Fig 2). After consultation among the cardiothoracic surgery, obstetrics, and anesthesiology teams, it was decided to simultaneously perform a Cesarean section before the administration of heparin while femoral cannulation and median sternotomy were performed to repair the aortic dissection. The abdomen was left open during the cardiopulmonary bypass (CPB) portion of the case to monitor for bleeding until after the reversal of heparin and to perform a hysterectomy if bleeding could not be controlled. Fortunately, uterine atony and hemorrhage were readily prevented with the use of oxytocic drugs after delivery of the baby. The baby was resuscitated, intubated, and transported to the neonatal intensive care unit. The baby was eventually discharged on postoperative day 4 and continues to do well with no medical problems. On surgical inspection, the dissection was limited to the sinus of Valsalva and extended into both coronary ostia. Therefore, a Bentall procedure and 3-vessel coronary artery bypass grafting using saphenous vein grafts were performed. The patient was successfully weaned from CPB, transferred to the intensive care unit with inotropes, and discharged home on postoperative day 8. A postoperative pathology examination of the aortic specimen did not reveal underlying connective tissue disease. Six months after discharge, the patient’s TTE showed an ejection fraction of 40%. She is currently active with no reported functional limitations. DISCUSSION
A highly unusual presentation of an acute aortic dissection in a young pregnant patient without any predisposing risk factors is reported. Although the patient was initially diagnosed with primary acute coronary syndrome, intraoperative echocardiography was critical in correctly defining the etiology of MI as a type-A dissection, prompting a change in the management of the patient. Fetal distress likely occurred because of the hypotension and low cardiac output from worsening acute heart failure. To the authors’ knowledge, this is the first reported case of aortic dissection diagnosed in the OR at the time of presentation for an emergent Cesarean section. Coordinated efforts between the obstetric, surgical, and anesthesiology teams allowed successful management of a difficult medical emergency.
Journal of Cardiothoracic and Vascular Anesthesia, Vol 24, No 1 (February), 2010: pp 116-118
AORTIC DISSECTION IN PREGNANCY
Fig 1. line.)
117
A transthoracic parasternal view showing aortic regurgitation and a dilated left ventricle. (Color version of figure is available on-
Fig 2. (A) A TEE midesophageal short-axis view of the aorta showing the aortic dissection flap. (B) A TEE midesophageal long-axis view of the aorta showing the aortic dissection flap.
The most critical period in managing a patient with aortic dissection begins with a timely diagnosis and requires a high level of clinical suspicion. Unfortunately, the initial misdiagnosis of aortic dissection continues to be high (38%-44%), leading to increased morbidity.4,5 Untreated, mortality is estimated to be as high as 1% per hour for the first 24 to 48 hours.4,6 Although it is unclear if pregnancy is itself an independent risk factor, aortic dissection should be considered early in the differential diagnosis in any pregnant female presenting with chest pain.6,7 Studies suggest that hemodynamic or hormonal changes in pregnancy can worsen the shearing stress in the aorta.2,3 Hypertension and Marfan syndrome are the 2 main risk factors linked with aortic dissections during pregnancy.3,4,7,8 Marfan syndrome typically worsens during pregnancy, accounting for the increased incidence of aortic dissections noted in young pregnant females.1-4,6,7 The absence of underlying risk factors in the present patient delayed the consideration of a diagnosis of aortic dissection in the ED. Although TTE offers the advantage of being noninvasive, suboptimal imaging windows because of the patient’s body habitus delayed the diagnosis. Additionally, the sensitivity and specificity of TEE for type-A dissection in experienced hands are as high as 98% and 99%, respectively.2,4,9 TEE allows the diagnosis of the entry site of the dissection, involvement of the coronary vessels, severity of aortic valve regurgitation, and presence of pericardial effusions, all of which were valuable in the present patient.4,9 For an unstable patient who might not be able to undergo a computed tomography scan or magnetic resonance imaging, TEE offers a rapid and accurate assessment for aortic dissection in the ED or OR. In summary, a highly unusual case of acute aortic dissection and MI in a pregnant female without predisposing risk factors, which was diagnosed intraoperatively on presentation for an emergent Cesarean section, is reported. This case underscores the need to maintain a high level of clinical
118
CROWLEY ET AL
suspicion for aortic dissection in pregnant patients presenting with chest pain. The authors believe the prompt diagnosis with TEE in the OR and subsequent timely coordination
of multiple procedures with obstetrics and cardiothoracic surgery were instrumental in a positive outcome for both this patient and her child.
REFERENCES 1. Immer FF, Bansi AG, Immer-Bansi AS, et al: Aortic dissection in pregnancy: Analysis of risk factors and outcome. Ann Thorac Surg 76:309-314, 2003 2. Weissmann-Brenner A, Schoen R, Divon MY: Aortic dissection in pregnancy. Obstet Gynecol 103:1110-1113, 2004 3. Zeebregts CJ, Schepens MA, Hameeteman TM, et al: Acute aortic dissection complicating pregnancy. Ann Thorac Surg 64:1345-1348, 1997 4. Khan IA, Nair CK: Clinical, diagnostic, and management perspectives of aortic dissection. Chest 122:311-328, 2002 5. Alsous F, Islam A, Ezeldin A, et al: Potential pitfalls in the diagnosis of aortic dissection. Conn Med 67:131-134, 2003
6. Schnitker MA, Bayer CA: Dissection aneurysm of the aorta in young individuals, particularly in association with pregnancy. Ann Intern Med 29:486-511, 1944 7. Oskoui R, Lindsay J Jr: Aortic dissection in women ⬍40 years of age and the unimportance of pregnancy. Am J Cardiol 73:821-823, 1994 8. Lewis S, Ryder I, Lovell AT: Peripartum presentation of an acute aortic dissection. Br J Anaesth 94:496-499, 2005 9. Green RG, Kron IL: Aortic Dissection, Advanced Therapy in Cardiac Surgery (ed 2). Hamilton, BC Decker Inc, 2003, pp 347-363