Cesarean Delivery in a Patient with Uncorrected Aortic Coarctation
Abstract Number: F-40
Abstract Type: Case Report/Case Series
Introduction: Uncorrected aortic coarctation (AC) is associated with 90% mortality by the age of 50 years.1 Most patients are diagnosed and treated at birth. This case demonstrates the successful use of neuroaxial anesthesia for Cesarean section (CS) in a parturient with an unrepaired severe AC.
Case: A 30 y.o. G2P1 at 38 3/7 weeks gestation presented for elective repeat CS and bilateral tubal ligation. She had a long-standing history of hypertension but was not diagnosed with AC until further work-up was done during this pregnancy. An echocardiogram revealed a Type A severe aortic arch coarctation or interruption distal to the left subclavian artery with no antegrade flow. There was borderline concentric LVH and a normal aortic valve. A multidisciplinary meeting with obstetricians, cardiologists, neonatologists and anesthesiologists was held, and she was maintained on labetolol 300mg BID during the pregnancy to keep her upper arm BP in the 140-160/80-90 range without drastically reducing placental perfusion.
In the OR, a right femoral arterial catheter was placed under ultrasound guidance, after several failed attempts at the right and left dorsalis pedis arteries. Average femoral mean arterial pressure was 95mmHg; a gradient of more than 20mmHg compared to the non–invasive BP in the right brachial artery. A combined spinal-epidural was performed at L3-L4 with an intrathecal injection of 15mcg of fentanyl and 300mcg of morphine. A total of 20cc 2% lidocaine was administered epidurally over 40 minutes with continuous fetal heart rate monitoring. A phenylephrine infusion was titrated to keep the femoral systolic BP greater than 100mmHg. A male infant with Apgars of 8 and 9 was delivered via a Pfannensteil incision. Postoperatively, the patient required aggressive diuresis and addition of an ACE inhibitor for BP control. She was discharged on POD #4 with referral to the cardiology clinic for future surgical repair.
Discussion: AC represents a localized deformity of the media, which concentrically narrows the aortic lumen, resulting in arterial stiffness and hypertension proximal to the lesion. Pregnancy is associated with increased heart rate and stroke volume, so pregnant women with AC are at increased risk of cardiovascular complications including aortic rupture and dissection, cerebral aneurysm rupture, and LV failure.2,3 Despite collaterals, perfusion of abdominal and pelvic organs is usually compromised, and neonatal morbidity including IUGR and preterm labor is common.2 The anesthetic challenge is to control maternal systolic BP without reducing uterine blood flow.
1. Walker E and Malins AF. IJOA 2004;13:266-70.
2. Krieger, E., et al. Am J Cardiol 2011;107: 529-34.
3. Zwiers, W.J., et al. J Clin Anesth 2006;18:300-03.