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Repair of an acute type A aortic dissection combined with an emergency cesarean section in a pregnant woman

Division of Cardiac Surgery, University of Alberta, 3H2.17 Walter Mackenzie Center, 8440-112 Street, Edmonton, Alberta, T6G 2B7, Canada

Received 30 April 2008; received in revised form 4 June 2008; accepted 5 June 2008

*Corresponding author. Tel.: +1 (780) 407-2186; fax: +1 (780) 407-2184.

E-mail address: RoderickMacarthur{at}cha.ab.ca (R. MacArthur).

	Abstract

Top Abstract 1. Introduction 2. Case 3. Discussion References

 
This case report describes a 35-week pregnant woman presenting with an acute type A aortic dissection. She underwent a successful emergency surgical repair and a concomitant cesarean section with a favorable outcome for the mother and the child.

Key Words: Aortic dissection; Pregnancy; Hypothermic circulatory arrest

	1. Introduction

Top Abstract 1. Introduction 2. Case 3. Discussion References

 
The association between pregnancy and type A aortic dissection is an uncommon presentation. Risk factors include a bicuspid aortic valve or a connective tissue disorder (e.g. Marfan's syndrome) [1]. In addition to being a life threatening surgical emergency, management could be complicated due to the hemodynamic changes that occur late in pregnancy, and the implications of the management strategy on fetal survival.

	2. Case

Top Abstract 1. Introduction 2. Case 3. Discussion References

 
The patient is a 36-year-old lady with a history of panhypopituitarism following a resection of a pituitary adenoma on hormonal replacement therapy. She was 35 weeks pregnant as a product of in vitro fertilization. She was referred to a tertiary care center for shortness of breath and chest pain. She was also known to have gestational hypertension. A chest computed tomography (CT) scan was performed to rule out a pulmonary embolism. The CT-scan revealed the presence of a type A aortic dissection involving the aortic arch (Fig. 1). It also showed the presence of a large pericardial effusion (Fig. 2). The patient was urgently referred to cardiac surgery and was transferred to the cardiac surgical intensive care unit. A transthoracic echocardiogram was preformed and showed early tamponade features as well as moderate aortic valve insufficiency. The patient was hemodynamically stable at that point, but due to the suspicion of a contained aortic rupture the decision was to arrange for an emergency combined cesarean section and repair of the aortic dissection. Care was taken to communicate the management plan with all the involved teams including the Anesthesia, Obstetrics, and Neonatal Intensive care unit (NICU) teams. The axillary artery was exposed and prepared for cannulation. After that, a median sternotomy was performed and the pericardial effusion was evacuated. Surprisingly, it was serous in nature with no evidence of active extravasation. At this point the cesarean section was performed prior to systemic heparinization. The neonate was intubated and transferred to the NICU. The uterus was closed and the incision was packed open for re-assessment of hemostasis at the end of the procedure once the systemic heparinization was reversed. Following that, the aortic repair was performed. The aortic root was found to be dilated and thin. The dissection flap was involving the left coronary ostium and the aortic valve annulus. After thorough assessment of the aortic valve and root dimensions, we decided it was not suitable for repair. The aortic repair consisted of replacement of the ascending aorta and the aortic arch in a bevelled hemiarch fashion with a Dacron graft (Gelweave^TM Graft, Vascutek USA Inc., Ann Arbor, MI) and replacement of the aortic root with a stentless aortic valve prosthesis (Freestyle^® Aortic Root Bioprosthesis, Medtronic Inc., Minneapolis, MN). The origin of the brachiocephalic artery was involved in the dissection and it was reimplanted separately to a preformed 8 mm side branch on the Dacron graft. The aortic arch replacement and the re-implantation of the brachiocephalic artery were performed under a period of hypothermic circulatory arrest and selective antegrade cerebral perfusion through the right axillary artery. The total cardiopulmonary bypass time was 260 min. The aortic cross-clamp and selective antegrade cerebral perfusion times were 200 and 49 min, respectively.

View larger version (115K): [in this window] [in a new window]   Fig. 1. Type A aortic dissection involving the aortic arch.

View larger version (97K): [in this window] [in a new window]   Fig. 2. Computed tomography showing a significant pericardial effusion.

	3. Discussion

Top Abstract 1. Introduction 2. Case 3. Discussion References

 
The association between pregnancy and aortic dissection has been well described in previous reports in the literature. Acute aortic dissection during pregnancy, particularly during the third trimester, accounts for half the cases in women under the age of 40 years [2]. The presence of a pre-existing aortopathy secondary to a connective tissue disorder increases the risk for dissection.

Several hemodynamic alterations take place during late pregnancy, including an increase in the total circulatory volume and systemic blood pressure. This may give a sensible explanation for the increased incidence of dissections during the third trimester. Adding to that risk is the ultra structural changes that occur in the aortic wall in a very similar pattern to the medial degeneration found in other cases of aortic dissection [3, 4]. The hormonal effects of naturally occurring increments in the levels of estrogen and progesterone during pregnancy on the aortic tissue include, fragmentation of the reticulin fibers, diminished amounts of acid mucopolysaccharides, loss of the normal corrugation of elastic fibers, and hypertrophy and hyperplasia of smooth muscle cells [5, 6]. Since the first report describing a successful post-partum surgical repair of an aortic dissection diagnosed in a pregnant woman in 1963 [7], several reports and small reviews have addressed the management of this rather challenging group of patients. The main challenge remains choosing the best strategy to timely manage the maternal surgical emergency but at the same time preserve the viability of the term or near-term fetus. Although a high flow, high pressure, normothermic flow on cardiopulmonary bypass is probably the safest for fetal preservation [8], a hypothermic circulatory arrest will almost invariably result in fetal loss [9]. Factors that will dictate the ideal management include, hemodynamic stability of the mother, gestational age and viability of the fetus. The extent of the aortic dissection and the presence of any directly related complications are also key factors in planning for the best surgical approach. A timely management plan aiming to optimize the care for both the mother and the fetus should be pursued whenever feasible, and especially after 28 weeks of gestation. A cesarean section followed shortly by aortic repair or performed concomitantly in the same operative session has been recommended for an acute type A aortic dissection presenting in a term or near-term pregnancy [1]. In this case, the patient had a large pericardial effusion with echocardiographic features of early tamponade. This raised concerns of serious hemodynamic compromise during the induction of anesthesia secondary to the loss of negative intrathoracic pressure and further reduction in the venous return to the heart. In addition, the rapid increase in circulatory volume as a result of uterine contraction imposed the theoretical risk of rupture of the ascending aorta. For these reasons we elected to expose the axillary artery and evacuate the pericardial effusion through a sternotomy prior to proceeding with the cesarean section. This way, hemodynamic improvement and immediate access for cannulation were assured. The successful outcome of this case represented in the complete surgical repair of the mother's dissection with an uneventful recovery and the salvage of the 35-week fetus, has led us to the following conclusions:

First, the necessity of a multidisciplinary approach in dealing with similar cases. Secondly, the safety of the hemodynamically compromised mother takes priority in the management plan. Finally, it is safe to conduct a combined approach aiming to save both the mother and the fetus with careful planning and the availability of immediate back up measures.

	References

Top Abstract 1. Introduction 2. Case 3. Discussion References

 

1. Immer FF, Bansi AG, Immer-Bansi AS, McDougall J, Zehr KJ, Schaff HV, Carrel TP. Aortic dissection in pregnancy: analysis of risk factors and outcome. Ann Thorac Surg 2003;76:309–314.[Abstract/Free Full Text]
2. Zeebregts CJ, Schepens MA, Hameeteman TM, Morshuis WJ, de la Riviere AB. Acute aortic dissection complicating pregnancy. Ann Thorac Surg 1997;64:1345–1348.[Abstract/Free Full Text]
3. Anderson RA, Fineron PW. Aortic dissection in pregnancy: importance of pregnancy-induced changes in the vessel wall and bicuspid aortic valve in pathogenesis. Br J Obstet Gynaecol 1994;101:1085–1088.[Medline]
4. Rutherford RB, Nolte JE. Aortic and other arterial dissections associated with pregnancy. Semin Vasc Surg 1995;8:299–305.[Medline]
5. Manalo-Estrella P, Barker AE. Histopathologic findings in human aortic media associated with pregnancy. Arch Pathol 1967;83:336–341.[Medline]
6. Campisi D, Bivona A, Paterna S, Valenza M, Albiero R. Oestrogen binding sites in fresh human aortic tissue. Int J Tissue React 1987;9:393–398.[Medline]
7. Hume M, Krosnick G. Dissecting aneurysm in pregnancy associated with aortic insufficiency. Report of a case with successful surgical repair. N Engl J Med 1963;268:174–178.[Medline]
8. Becker RM. Intracardiac surgery in pregnant women. Ann Thorac Surg 1983;36:453–458.[Abstract]
9. Mul TF, van Herwerden LA, Cohen-Overbeek TE, Catsman-Berrevoets CE, Lotgering FK. Hypoxic-ischemic fetal insult resulting from maternal aortic root replacement, with normal fetal heart rate at term. Am J Obstet Gynecol 1998;179:825–827.[CrossRef][Medline]

This article has been cited by other articles:

				M. F. Ibrahim and A. A. Refaat eComment: Acute type A aortic dissection at seven weeks of gestation in a Marfan patient Interactive CardioVascular and Thoracic Surgery, October 1, 2008; 7(5): 940 - 940. [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Mohammad Shihata Victor Pretorius Roderick MacArthur Permission Requests Citing Articles Citing Articles via HighWire Google Scholar Articles by Shihata, M. Articles by MacArthur, R. PubMed PubMed Citation Articles by Shihata, M. Articles by MacArthur, R. Related Collections Related Article