Life-Threatening Aortic Dissection during Pregnancy: A Case Report of Undiagnosed FBN1-Related Marfan Syndrome at 39 Weeks Gestation

Abstract

BACKGROUND Inherited deficiencies in the FBN1 gene, which encodes fibrillin-1, result in Marfan syndrome, an autosomal dominant connective tissue disorder that is associated with aortic root dilatation and predisposes to aortic dissection. This report is of a 37-year-old woman presenting at 39 weeks of pregnancy with acute thoracic aortic dissection due to previously undiagnosed FBN1-related Marfan syndrome. This case report aims to illustrate the challenges in the diagnosis and in the peri-operative management of acute aortic dissection during pregnancy. CASE REPORT A healthy 37-year-old woman at 39 weeks of gestation presented to our hospital with dyspnea and chest pain. Initial evaluation for pulmonary embolism with chest computed tomography was unrevealing. The patient was admitted to the intensive care unit for further management. Overnight, her clinical conditions deteriorated, and a transthoracic echocardiography was obtained, demonstrating an acute ascending aortic dissection. She emergently underwent a successful combined cesarean section and ascending aortic dissection repair, with no immediate complications. On postoperative day 4 she developed cardiac tamponade, for which she underwent emergent mediastinal exploration. She was discharged home on postoperative day 10. A month later she completed genetic testing, which revealed a pathogenic mutation in the FBN1 gene, consistent with a molecular diagnosis of Marfan syndrome. CONCLUSIONS This report has shown that FBN1-related Marfan's syndrome has a variable clinical presentation that can include life-threatening aortic dissection during pregnancy. Successful diagnosis and management of these patients is challenging and requires multidisciplinary expertise, including confirmation of the diagnosis by a clinical geneticist.

Figure 1.

Chest computed tomography scan with contrast. (A) Sagittal chest computed tomography scan with contrast administration timed to evaluate the pulmonary arteries. No pulmonary embolic disease was detected. Higher density of blood along the aortic arch and descending aorta (arrows) was appreciated. The fetus was intentionally not imaged to minimize radiation exposure. (B) Axial chest computed tomography scan with contrast administration timed to evaluate the pulmonary arteries showing the true lumen of the descending aorta dissection (star).

Figure 2.

Transthoracic echocardiogram of the aortic valve, short axis view. Short axis view of the aortic valve demonstrating a dissection flap (arrows) in close proximity to, and prolapsing across, the aortic valve (triangles), with significant aortic valve regurgitation.

Figure 3.

Three-dimensional transesophageal echocardiogram of the aortic valve. Short axis view (A) and modified 3-chamber view (B) demonstrating a dissection flap in close proximity to, and prolapsing across, the aortic valve (arrows).

Figure 4.

Post-bypass gross photograph of the heart and ascending aorta. The aortic root was reconstructed using a valve-sparing technique. The right atrium (star) was used for central venous cannulation and later secured with a blue tourniquet. The arterial cannula has been removed and hemostasis achieved using a pledgeted purse string suture on the lateral side of the aortic graft (triangle). The right coronary artery demonstrates periarterial hematoma (arrow) from the proximal dissection, which was bypassed with a vein graft (circle). A blue vessel loop is retracting the innominate vein to better expose the innominate artery, which was reimplanted.

Figure 5.

Post-procedure three-dimensional computed tomography scan of chest, abdomen, and pelvis. Postprocedural changes of the aortic root and unchanged aortic dissection extending into the left subclavian artery (star), to the descending thoracic and abdominal aorta, as well as to both common iliac arteries, with a maximum diameter of 4.3 cm at the level of the proximal descending thoracic aorta (arrow).