Type B Dissection in a Pregnant Woman Managed With Peripartum Thoracic Endovascular Aortic Repair
A 39-year-old woman (gravida 2, para 1-0-0-1) with no medical history developed acute, tearing chest pain radiating to her back, which reached maximal intensity within minutes of onset. She was then 31 weeks into an uncomplicated pregnancy with no evidence of pre-eclampsia or systemic hypertension. Routine prenatal care was pursued throughout the pregnancy, and testing for HIV infection and syphilis was negative. Vital signs on presentation to her local emergency department were notable for a blood pressure of 129/55 mm Hg and troponin I levels that were undetectable (<0.04 ng/mL) on serial evaluations. A computed tomography pulmonary angiogram revealed a type B aortic dissection (Figure 1) that extended to the aortic bifurcation (Figure 2). She was subsequently transferred to our institution where transthoracic echocardiography showed the dissection flap in the descending aorta (Figure 3 and Movie I in the online-only Data Supplement), an aortic sinus and ascending aorta within normal limits of size (3.7 and 2.9 cm, respectively), no evidence of aortic coarctation, and a trileaflet aortic valve. Color-flow Doppler revealed more prominent flow in the true lumen than in the false lumen (Figure 4 and Movie II in the online-only Data Supplement). Medical management of the dissection proceeded with an intravenous infusion of labetalol, which led to intolerable bradycardia at a maximal dose of 2 mg/min and prompted the addition of a low-dose nicardipine infusion (2.5 mg/h). Despite adequate control of blood pressure and heart rate with medical management, fetal distress developed, and repeat imaging 48 hours into admission demonstrated interval aortic dilatation. As a result, the fetus was delivered via cesarean section, followed immediately by thoracic endovascular aortic repair in which a 28 mm×10 cm endoprosthesis was successfully deployed immediately distal to the takeoff of the left subclavian artery (Figure 5). Serial computed tomography angiograms of the aorta at scheduled 3- and 9-month follow-up confirmed stable positioning and patency of the graft, as well as no endoleak (Figures 6 and 7).
The patient was also noted to have translucent skin and an exaggerated ratio of arm span to height. Examination revealed no pectus excavatum or carinatum, scoliosis, or palatal abnormalities. Nonetheless, the aforementioned findings were concerning for an underlying connective tissue disorder. Although there was no family history of aortopathy, stillbirth, or sudden cardiac death, multiple siblings and the patient’s eldest daughter had significant myopia. The patient was seen by a genetic specialist but refused further testing.
Aortic dissection is an infrequent but potentially fatal complication of pregnancy for both the mother and fetus. Findings from the Nationwide Inpatient Sample revealed that aortic dissection complicated 0.0004% of all pregnancies, and only 0.01% of all aortic dissections occurred in the setting of pregnancy between 1998 and 2008.1 Two fundamental mechanisms, increased wall stress and degeneration of the medial layer of the arterial wall, underlie the pathogenesis of the condition, and both may be influenced by the gravid state. Women with uncontrolled hypertension from pre-eclampsia, compounded by the stress and hemodynamic changes accompanying labor, are predisposed to dissection as the aorta experiences increased shearing forces.2 Alternatively, connective tissue disorders, including syndromic (ie, Marfan syndrome, Ehlers-Danlos syndrome–vascular type, and Loeys-Dietz syndrome) and nonsyndromic variants (ie, familial thoracic aortic aneurysm and dissection), lead to degeneration of the medial arterial layer, which may occur with greater frequency during pregnancy as hormonal fluctuations influence elastic fibril organization and vascular integrity. Most type B dissections are managed medically during pregnancy, although indications for operative intervention include fetal distress, expanding dissection, and evidence of compromised end-organ perfusion. A case series of 4 patients demonstrated the safety of thoracic endovascular aortic repair in women diagnosed with type B aortic dissections late in the third trimester of pregnancy (ie, beyond 36 weeks’ gestation).3 To the best of our knowledge, this case represents the earliest gestational age (32 weeks) at which thoracic endovascular aortic repair was performed for the management of a type B dissection.
The online-only Data Supplement is available with this article at http://circ.ahajournals.org/lookup/suppl/doi:10.1161/CIRCULATIONAHA.115.019735/-/DC1.
- © 2016 American Heart Association, Inc.