///2017 Abstract Details
2017 Abstract Details2019-08-02T15:54:53-06:00

Successful Delivery in a Parturient with Aortic Aneurysm and Chronic Stanford Type B Aortic Dissection

Abstract Number: SUN-26
Abstract Type: Case Report/Case Series

Amy W Willett M.D.1 ; Amy W Willett M.D. 2; Leon Freudzon M.D.3

We present an otherwise healthy 28-year-old who was diagnosed incidentally four years prior on CXR. It was surmised that the dissection occurred peripartum during her first pregnancy six years prior which was uncomplicated and ended with a normal vaginal delivery facilitated by epidural anesthesia. Pre-pregnancy MRA demonstrated an aortic dissection beginning distal to the left subclavian artery, causing descending aortic arch dilation to 46 mm; a separate abdominal aortic dissection identified at the level of the diaphragm continued caudally to the level of aortic bifurcation.

The patient presented after a positive home pregnancy test and underwent multidisciplinary evaluation by obstetrics, MFM, cardiac anesthesiology, and CT surgery. Maternal echocardiogram performed at 12 gestational weeks showed normal valvular and ventricular contractile function. No acute pathology or interval growth was demonstrated on MRA at 14 gestational weeks.

At 37 weeks and 0 days, the patient was admitted for a scheduled primary cesarean delivery to be conducted in the cardiac OR. A pre-spinal arterial line was placed with local anesthesia. A single-shot L3-L4 spinal anesthetic delivered 1.6mg bupivacaine, 0.1 mg preservative-free morphine, and 10 mg meperidine. General anesthesia would be induced for decompensated hemodynamics or if the patient demonstrated symptoms of aortic rupture or progressing aortic dissection. TEE was available in the OR. Cardiopulmonary bypass and the CT surgery team were immediately available on standby.

By titrating phenylephrine and nitroglycerin infusions, hemodynamic parameters were successfully kept within a range of SBP 90-110 mm Hg. A vigorous female infant was delivered. The remainder of the operative course was uneventful and the patient was transferred to the CTICU. On postpartum day 1, CT angiogram showed an interval increase in size of the aorta aneurysm from 46 to 50 mm in maximal diameter. The patient was monitored overnight and considered safe for transfer to the postpartum floor on POD 2.

Discussion: The absence of connective tissue disorders, vasculitis, familial aortic disease/premature death in this patient highlights the heterogeneity of aortic disease and the inherent risks associated with pregnancy. Providers should have a lower threshold for diagnostic testing in pregnant or postpartum patients than in non-pregnant women of similar age. The exact mechanisms by which pregnancy and the postpartum state increase the risk of aortic complications are unclear--increases in heart rate, stroke volume, cardiac output, and left ventricular dimensions occur in the presence of gravid uterus compression. This accumulation of forces may mediate the increased risk of aortic complications in pregnancy. Hemodynamic changes require 3-6 months to return to pre-pregnancy levels; as such, our patient will continue to be monitored closely as an outpatient, and is planned to undergo prompt multi-staged surgical aortic repair.

SOAP 2017