Eur J Cardiothorac Surg 2007;32:541-543. doi:10.1016/j.ejcts.2007.05.030
Copyright © 2007, European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved
Metachronous type III and type II acute aortic dissections in puerperium
Marc A. Radermeckera,*,
Rodolphe Durieuxa,
Jean-Luc Canivetb,
Raymond Limeta
a Department of Cardiovascular and Thoracic Surgery, University Hospital of Liège, CHU du Sart-Tilman, 4000 Liège, Belgium
b Department of Anesthesiology and Intensive Care, University Hospital of Liège, CHU du Sart-Tilman, 4000 Liège, Belgium
Received 8 March 2007;
received in revised form 7 May 2007;
accepted 11 May 2007.
* Corresponding author. Address: Department of Cardiovascular and Thoracic Surgery, CHU du Sart-Tilman, 4000 Liège, Belgium. Tel.: +32 4 366 71 63; fax: +32 4 366 71 64. (Email: mradermecker{at}chu.ulg.ac.be).
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Abstract
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The case of a 30-year-old non-Marfan woman who developed a type III acute aortic dissection 5 days after delivery, followed within 16 h by an independent type II dissection, is reported. Preoperative CT scan imaging and TEE suggested metachronous type II and type III dissection. This was confirmed at surgery, where limited dissection of the aortic root without communication with the isthmic area via the aortic arch was evidenced. The patient underwent repair of the aortic root and adjacent ascending aorta and was medically treated for her type III dissection. This is the first report of metachronous acute aortic dissections in puerperium.
Key Words: Aortic dissection • Pregnancy • Great vessels
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1. Introduction
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Although rare, acute aortic dissection in young women is often associated with pregnancy. Most of the literature on this subject emphasizes the coexistence of pregnancy and discusses acute management of both mother and fetus. We present the case of an acute DeBakey type III aortic dissection followed within less than 24 h by an independent type II DeBakey dissection. This observation documents an unusual modality of transformation of a Stanford Type B dissection into a type A dissection. The factors that account for an increased risk of aortic dissection during pregnancy and puerperium are reviewed.
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2. Case report
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A 30-year-old G2P2 woman, whose mother had died from acute aortic dissection at the age of 50, and without sufficient diagnostic criteria for the Marfan syndrome or connective tissue disorder, history of drug abuse or hypertension, developed an acute type III aortic dissection 5 days after an uneventful pregnancy and delivery.
The patient experienced a sudden back and interscapular pain migrating towards the lower back, accompanied by shortness of breath. The diagnosis was obtained by contrast CT scan, which showed a typical aspect of type III dissection without involvement of the arch and ascending aorta (Fig. 1a and b). This was confirmed by transesophageal echography.
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Fig. 1. (a) CT scan of the thoracic descending aorta below the isthmic region. Evidence of an acute type III aortic dissection with significant pleural effusion. (b) Absence of involvement of the aortic arch. (c) TEE 0° of the infraisthmic descending aorta with an image of aortic dissection with false (FL) and true (VL) lumen. (d) Transversal view of the isthmic region of the descending aorta free from dissection. (e) Parasagittal 117° view of the aortic root, which shows the left ventricle (VG), the aortic valve (VAo) and the dissected area (arrows).
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The patient was treated with IV labetalol (Trandate® Celltech, Lancashire, UK) to maintain the systolic blood pressure between 90 and 120 mmHg. After 16 h of that treatment in ICU, the patient experienced a retrosternal chest pain and was transferred to our hospital. Repeated CT scans disclosed the type III dissection and mild pleural effusion on the left side. There was a strong suspicion of an intimal tear in the proximal ascending aorta. A transesophageal echography revealed an anomalous flap in the aortic root (non-coronary sinus of Valsalva and immediate adjacent ascending aorta) (Fig. 1c–e). The patient underwent median sternotomy and full cardiopulmonary bypass with left femoral reinjection was instituted. At the opening of the pericardium, there was a typical aspect of a limited acute dissection of the aortic root and of the first centimeter of the ascending aorta. The ascending aorta was fully dissected posteriorly and this showed no evidence of extension of the proximal dissection towards the arch.
The aorta was cross-clamped below the arterial brachiocephalic trunk and transected at that level without evidence of dissection. Careful inspection of the ascending aorta and aortic root revealed an intimal tear just above the non-coronary sinus of Valsalva, with the dissection involving that sinus, the right coronary sinus, and sparing the left one. Downstream, it extended anterolaterally on the first 3 cm of the ascending aorta. The aortic valve was found competent. Replacement of the non coronary sinus of Valsalva and the ascending aorta was performed with a 22 mm woven Dacron graft (Vascutec®, Renfrewshire, Scotland). The patient was easily weaned from bypass, and medical therapy for her distal dissection was continued in the postoperative period.
The postoperative course was uneventful without malperfusion or progression of the left pleural effusion. Routine pathological study of the resected aorta showed medial dystrophy (Erdheim's disease).
Six years after this surgery, the patient is alive and well. There is an I/IV aortic regurgitation on echo, a normal aspect of the repair of the ascending aorta, no dissection of the aortic arch, and a mild pseudoaneurysmal dilatation of the descending aorta (2.9 cm) (Fig. 2a and b).
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Fig. 2. (a) Parasagittal view of the aorta at 6 years. (b) 3 D reconstruction of the aorta showing the repaired ascending aorta, normal arch segment and healed proximal dissection of the descending thoracic aorta.
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3. Discussion
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Possibly overestimated, as suggested by Oskui and Lindsay [1], the link between pregnancy and acute aortic dissection is an epidemiologic fact. Half of the dissections seen in women less than 40 years of age occur during pregnancy. There are several reasons for this.- 1. Augmentation of cardiac output, stroke volume and systemic blood pressure are characteristics of the third trimester. Severe hypertension and eclampsia in late pregnancy have been associated with aortic dissection [2]. Recent studies by Duvekot [3] have shown that important hemodynamic stress was also present during the second trimester and during labor. These factors contribute to increase shear stress and have been reported to facilitate acute aortic dissection in patients with pre-existent aortic dystrophy of the media's extracellular matrix. This is obviously true in Marfan syndrome or in patients with coarctation of the aorta or bicuspid aortic valve, where the ascending aorta is known to be abnormal and who are intrinsically exposed to an increased risk of dissection. Patients with aortic root enlargement (
4 cm) or an increase of aortic root size during pregnancy are at considerable risk [4].
- 2. Alterations in the structure of the aortic wall during pregnancy have been reported to be very similar to the patterns of medial dystrophy, as found in patients with acute aortic dissection. The hormonal environment of pregnancy is undoubtedly involved [5]. Experimental data have shown that aortic sclerosis with progressive deterioration of the elastic tissue occurs in Sprague-Dawley breeder rats, with calcification and cartilaginous metaplasia appearing during the post-weaning phase. Arterial changes consist of copious subintimal and medial mucopolysaccharide pooling, and subintimal fibrosis, and intense elastolytic and calcific activities. (These arterial changes may be related to catecholamine secretion [2]). The gravidic factors responsible for these changes are not clearly understood. It is possible that the in vitro inhibition of vascular smooth muscle cell proliferation and migration by estrogen plays a role in these observations. This could be due to down-regulation of growth factor expression, including PDGF-A, IL-1 and IL-6, in smooth muscle cells [6].
The incidence of type B dissection in pregnant women was 33% in the longitudinal study conducted over 12 years by Zeebregts et al. [7]. This case appears therefore as an unusual type of dissection that occurs in the puerperium and represents a unique observation of a double, nearly simultaneous, type III and type II dissection. The time interval between the first symptoms of type III dissection and the symptomatology of the type II dissection was less than 24 h, making the adjective ‘acute’ suitable for both conditions.
The diagnosis of two metachronous dissections was highly suspected, based on the images of the CT scan taken after the patient experienced precordial chest pain in spite of medical treatment administered in ICU. Repeated CT-scans and TEE showed an unambiguous dissection of the aortic root, sparing the distal ascending aorta and an image of type III dissection below the aortic isthmus. The final confirmation was obtained during surgery, where the aorta was found to be circumferentially normal between the two sites of dissection. Femoral cannulation was routine at that period in time at our institution. A posteriori, especially in the context of an acute type III dissection, was probably not the optimal option. We would nowadays advocate for axillary-subclavian artery cannulation and open distal anastomosis during moderately hypothermic conditions and antegrade cerebral perfusion.
This observation therefore allows us to suggest that in special, and probably rare circumstances, transformation of a type III into a type I dissection may not proceed necessarily through a retrograde mechanism, but may result from the conjunction of two nearly simultaneous phenomena. This conjunction of events may be explained by intrinsic alterations of the whole aortic wall submitted to the hemodynamic stress resulting from the orthosympathetic response to the first dissection. In this particular patient, a hereditary factor was suspected. On clinical basis, this patient had two major criteria for Marfan disease but lacked other arguments to establish this diagnosis. Since the imaging of the lumbosacral dura and research for mutation of fibrillin were not performed, this diagnosis cannot be absolutely discarded. No evidence existed for Elhers-Danlos and Tuner syndrome was out of the question. Homocystinuria was excluded. The patient had neither bicuspid aortic valve nor coarctation. The morphological aspect of the ascending aorta was an aspecific medial dystrophy. In this case, histopathology may have associated in the additive way an intrinsic parietal abnormality further aggravated by the pregnancy-induced changes in the arterial vessel wall as reported by Anderson [4].
In conclusion, this case represents a rare case of metachronous type III and type II aortic dissections occurring in a young lady in the puerperium. This presentation illustrates a rare mode of transformation of a type III dissection into a type I by another mechanism than retrograde extension. As the two dissections were eventually type II and III, and accordingly type A in the Stanford classification, surgical correction was required.
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Footnotes
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\#9734; The authors wish to honor the memory of Dr Frederic Van Den Brule, MD, PhD (Department of Gynecology) who contributed to this paper.
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References
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- Oskoui R, Lindsay Jr. J. Aortic dissection in women <40 years of age and the unimportance of pregnancy. Am J Cardiol 1994;73:821-823.[CrossRef][Medline]
- Wexler BC. Histochemical demonstration of increased adrenomedullary catecholamine secretion in repeatedly bred arteriosclerotic rats. Paroi Arterielle 1981;7:121-131.[Medline]
- Duvekot JJ, Peeters LL. Maternal cardiovascular hemodynamic adaptation to pregnancy. Obstet Gynecol Surv 1994;49:S1-S14.[CrossRef][Medline]
- Immer FE, Bansi AG, Immer-Bansi AS, Mc Dougall 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]
- Anderson A, 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]
- Okubo T, Urabe M, Tsuchiya H, Iwasa K, Yokota K, Kikuchi N, Yamamoto T, Honjo H. Effect of estrogen and progesterone on gene expression of growth regulatory molecules and proto-oncogene in vascular smooth muscle cells. Endocr J 2000;47:205-214.[Medline]
- Zeebregts CJ, Schepens MA, Hameeteman TM, Moshuis WJ, de la Rivière AB. Acute aortic dissection complicating pregnancy. Ann Thorac Surg 1997;64:1345-1348.[Abstract/Free Full Text]
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Abstract
1. Introduction
