Ann Thorac Surg 1996;61:1541-1543
© 1996 The Society of Thoracic Surgeons
Case Report
Traumatic Rupture of the Thoracic Aorta During the Second Trimester of Pregnancy
Gillian Lemermeyer, BScN,
Manoj K. Talwar, MD,
John C. Mullen, MD,
Neil Klassen, MD
Division of Cardiothoracic Surgery and Department of Anaesthesia, University of Alberta, Edmonton, Alberta, Canada
Accepted for publication November 27, 1995.
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Abstract
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A 36-year-old woman in the second trimester of pregnancy underwent emergent operative repair of a traumatic aortic disruption caused by a motor vehicle accident. Left atrial-to-femoral artery bypass was used to maintain fetal circulation during the cross-clamp period. Her healthy, full-term child was subsequently delivered 3 months later by normal vaginal delivery.
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Introduction
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Autopsy studies reveal that 90% of patients with traumatic rupture of the thoracic aorta die at the accident scene and 25% reaching the hospital do not survive [1]. When traumatic aortic rupture occurs in a pregnant woman, determining the best course of treatment becomes a difficult challenge [2]. We describe the successful management of a woman in the second trimester of pregnancy who required emergent repair of an aortic rupture caused by a motor vehicle accident.
A 36-year-old woman in the 25th week of her first pregnancy presented to the Emergency Department after a high-speed motor vehicle accident. Her blood pressure remained stable after volume resuscitation. She was found to have a dislocation of her right hip and a widened mediastinum on chest roentgenogram. The fetal heart rate was normal. Arch aortography showed an aortic disruption distal to the left subclavian artery (Fig 1
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Fig 1. . Thoracic aortograms: (A) Oblique view demonstrating an indentation distal to the left subclavian artery. (B) Anteroposterior view showing disruption in the descending aorta just distal to the left subclavian artery.
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In the operating theater under general anesthesia, the right hip dislocation was reduced first. Blood pressure was monitored via right radial and femoral arterial cannulas. The left femoral artery was exposed and the chest was entered through a left posterolateral thoracotomy. A hemothorax (1 L) was evacuated. A large hematoma involved the descending aorta from the level of the left subclavian artery. Left atrial-to-left femoral artery bypass was employed to provide perfusion to the lower body (and thereby fetal perfusion) during the cross-clamp period. A Bio-Medicus centrifugal pump (Medtronic Inc. Minneapolis, MN) was used and a low dose of heparin (5000 IU intravenously) was given. The aorta was clamped proximal to the left subclavian artery and distal to the hematoma. The mean arterial pressure in the distal aorta was monitored and maintained greater than 50 mm Hg. There was complete disruption of the aorta for a 5-cm length, not amenable to primary repair, which was replaced with a 22-mm Hemashield collagen-impregnated woven double-velour Dacron graft (Meadox Medicals Inc, Oakland, NJ) using 4-0 polypropylene sutures. The cross-clamp time was 40 minutes and the bypass time was 45 minutes.
Premature labor occurred 8 hours postoperatively and was arrested with intravenous magnesium sulfate. Her remaining postoperative course was uneventful. At 41 weeks of gestation spontaneous labor was augmented with oxytocin, and epidural anesthesia was employed for pain control. Blood pressure was monitored frequently noninvasively and remained well controlled. A healthy baby boy weighing 3.2 kg was delivered. Both mother and child were discharged in excellent condition 2 days later.
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Comment
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Immediate treatment of traumatic aortic rupture is critically important. A pregnant patient with this condition imposes the additional challenge to save the fetus. Becker's [3] survey of nonemergent cardiac operations using cardiopulmonary bypass in pregnant women showed high maternal and fetal survival. He recommended high-flow, high-pressure normothermic perfusion during cardiopulmonary bypass to optimize fetal safety. Zitnik and colleagues [4] also found open heart operations during pregnancy to be safe.
Williams and associates [5] reported a similar patient (32 weeks pregnant) with traumatic aortic rupture who was managed by performing a cesarean section and then proceeding with aortic repair with partial cardiopulmonary bypass (femoral vein to femoral artery). Another case report in the literature involved a 27-year-old woman who was 6 months pregnant [6]. Partial cardiopulmonary bypass was employed for fetal perfusion, and 2 months later the child was delivered by planned cesarean section.
The initial decision as to the course of managing this patient was a difficult one. Immediate cesarean section would have led to a greatly increased risk for the 25-week premature infant as well as for the mother, as blood loss associated with a cesarean section may have led to dramatic hemodynamic changes. Left atrial-to-left femoral artery bypass provides consistent, controllable flow to the lower body, decreasing the risk of paraplegia and kidney damage, and ensuring perfusion of the placenta. Distal perfusion pressure was carefully maintained to preserve uterine blood flow as the placental vasculature is maximally dilated [2]. Left atrial cannulation eliminates the need for an oxygenator and can reduce or eliminate the need for heparin to prevent clot formation. High-dose heparin was avoided to decrease the risk of bleeding at the site of the aortic replacement. Heparin is safe during pregnancy [2] as it does not cross the placental barrier.
In Merin and associates' [6] patient, who was similar to our patient, a cesarean section was performed electively at term based on the concern that the acute rise in systemic blood pressure during labor and delivery might lead to re-rupture due to reported changes [7] in the aortic wall during pregnancy (accumulation of mucoid material, decrease in acid mucopolysaccharides in the reticulum fibers, and hypertrophy of smooth muscle). Other reports suggest that vaginal delivery after cardiac repairs is possible and safe [4, 8]. Blood pressure was carefully monitored and controlled during vaginal delivery of this child, and the child was born without incident.
We recommend left atrial-to-femoral bypass as the most important adjunct in surgical treatment of traumatic aortic disruption during pregnancy, to optimize the chance for a successful outcome for both mother and child.
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Footnotes
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Address reprint requests to Dr Mullen, Departments of Surgery and Pediatrics, University of Alberta, 2D3.78 WC Mackenzie Health Sciences Centre, 8440-112 St, Edmonton, Alberta T6G 2B7, Canada.
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References
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- Lee RB, Stahlman GC, Sharp KW. Treatment priorities in patients with traumatic rupture of the thoracic aorta. Am Surg 1992;58:37–43.[Medline]
- Strickland RA, Oliver WC, Chantigian RC, Ney JA, Danielson GK. Anaesthesia, cardiopulmonary bypass, and the pregnant patient. Mayo Clin Proc 1991;66:411–29.[Medline]
- Becker RM. Intracardiac surgery in pregnant women. Ann Thorac Surg 1983;36:453–8.[Abstract]
- Zitnik RS, Brandenburg RO, Sheldon R, Wallace RB. Pregnancy and open-heart surgery. Circ 1969;39(Suppl 1):257–62.
- Williams GM, Gott VL, Brawley RK, Schauble JF, Labs JD. Aortic disease associated with pregnancy. J Vasc Surg 1988;8:470–5.[Medline]
- Merin G, Bitran D, Donchin Y, Weinshtein D, Borman JB. Traumatic rupture of the thoracic aorta during pregnancy. Chest 1981;79:99–100.[Abstract/Free Full Text]
- Manalo-Estrella P, Barker AE. Histopathologic findings in human aortic media associated with pregnancy. Arch Pathol 1967;83:336–41.[Medline]
- Pamulapati M, Teague S, Stelzer P, Thadani U. Successful surgical repair of a ruptured aneurysm of the sinus of Valsalva in early pregnancy. Ann Intern Med 1991;115:880–2.
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Abstract
Introduction
