Management of aortic aneurysm presenting during pregnancy: A case report

Short abstract

Aortic aneurysm in pregnancy is associated with higher risk of complications due to the stress induced by the physiologic changes in pregnancy. Many of the reports are concentrated on those with catastrophic outcomes or who underwent surgical repair during pregnancy/puerperium. We report a case of aortic aneurysm, who presented during the second trimester and had a successful pregnancy outcome, and discuss the various issues concerning the management during pregnancy.

Introduction

Aortic aneurysm is an uncommon pathology in women of child-bearing age, often associated with catastrophic outcomes.^1,2 Hemodynamic and hormonal changes in pregnancy, especially those occurring during labor increases the stress to aorta. As a result, the risk of dissection and rupture increases with gestational age.¹ Nearly 50% of the dissections in young females are reported with pregnancy.² We report a case of aortic aneurysm diagnosed during the second trimester, who had a successful pregnancy outcome.

Case report

A 28-year-old primigravida was referred to emergency department at 20 weeks with a diagnosis of aortic aneurysm and chronic kidney disease diagnosed during the anomaly scan. At admission, her pulse rate was 86 beats per minute and all peripheral pulses were palpable. Blood pressure was 140/90 mmHg, while on amlodipine (5 mg daily) and metoprolol (25 mg twice daily) for hypertension which was diagnosed the preceding year. She did not have a marfanoid habitus and obstetric examination showed a uterine fundal height of 20 weeks.

Abdominal Doppler sonography showed a fusiform abdominal aortic aneurysm (11 cm × 3.4 cm) with thrombus noted in the infrarenal segment (Figure 1). Doppler showed that the right kidney was shrunken (7.7 cm × 4.5 cm) suggesting renal artery stenosis, whereas the left kidney measured 9.5 × 4.5 cm with renal artery showing delayed systolic peak with mild increase in acceleration time (0.08 s). Doppler examination of all extremities and carotid artery was normal. Echocardiogram showed mild concentric left ventricular hypertrophy and the calibers of thoracic aorta were normal (aortic annulus was 19 mm (normal (N): 20–31 mm), aortic root at sino-tubular junction 30 mm (N: 22–36 mm) and aortic arch 25 mm (N: 22–36)). Anti-nuclear antibody and work up for antiphospholipid syndrome (lupus anticoagulant, anti-beta2 glycoprotein and anti-cardiolipin antibodies (IgG and IgM)) were negative. CT aortogram was deferred in view of pregnancy and MRI could not be offered due to logistic difficulties.

Figure 1.

Ultrasound image (a) and Doppler sonographic image (b) of the dilated abdominal aorta (34 mm) with a shadow in the lower portion marked with two arrows.

Multidisciplinary team involving obstetrician, cardiologist and cardiothoracic surgeon monitored her management throughout pregnancy. Her renal function remained stable throughout pregnancy (serum creatinine 1.4–1.2 mg/dl). In view of a clinical suspicion of Takayasu arteritis, prednisolone was started. After discussion with the multidisciplinary team, enoxaparin was started in view of a thrombus in infrarenal segment of aorta and pregnancy being a pro-coagulant state. In view of an increase in TSH levels (5.73 IU/l), thyroxine (25 µg) was started. Her hemoglobin was 8.4 g/dl and she received therapeutic doses of oral iron therapy for iron deficiency anemia.

She was kept under regular follow-up with monitoring of blood pressure and imaging using Doppler ultrasonography and echocardiography. The pregnancy proceeded uneventfully. On follow-up, aortic diameter was noted to be 47 mm. She was readmitted at 36 weeks and cesarean section was planned, after discussion with multidisciplinary team, in view of aortic aneurysm and breech presentation. Cesarean section was performed at 37 weeks under general anesthesia, delivering a female child with 2270 g and an Apgar score of 9 at 5 min. Immediate post-op period was uneventful. She developed a headache on the third post-operative day and MRI brain showed tortuous course of bilateral internal carotid arteries in cervical segments. Bilateral cavernous and supraclinoid internal carotid artery was normal. Anterior, middle, and posterior cerebral arteries, vertebral, and basilar arteries appeared to be normal with no stenosis or intraluminal abnormalities. Multiple hyper-intense foci were noted in subcortical and periventricular white matter in bilateral cerebral hemispheres, suggestive of small vessel ischemic changes.

CT aortogram postpartum revealed dilatation of whole thoracic aorta and the lower portion of the descending abdominal aorta up to the bifurcation. Both renal arteries were small in caliber, and there was a hematoma noted in the arterial wall which was earlier mistaken for a thrombus (Figure 2). Risk of complete renal shutdown (the renal artery supplying the only functional kidney (left side) was small in caliber) was perceived to be high during an extensive procedure, which could also add to increased risk of morbidity/mortality. Therefore, after discussing the benefits vs. risk involved in surgical intervention and risk of rupture/dissection with well-controlled blood pressure, by the team of cardiologists and cardiothoracic surgeon with patient and family, it was decided to repeat and review the disease status with CT aortogram at six months. She was discharged with a healthy baby, on anti-hypertensives. On her postnatal follow-up at six weeks, she was doing well and the blood pressure was controlled (on amlodipine 5 mg and metoprolol 25 mg daily). She was asymptomatic and her imaging showed the maximum aortic diameter to be 45 mm at her visit six months following delivery.

Figure 2.

Images from the CT aortogram. (a) Coronal section with arrows pointing towards the dilated thoracic and abdominal aorta. (B) Sagittal section showing dilated arch and thoracic aorta (one white arrow), the coeliac trunk and superior mesentric artery (two white arrows) and the dilated abdominal aorta with hematoma (three white arrows) noted in the wall. (c) The inferior mesentric artery (one arrow) and the hematoma in the wall (three arrows).

Discussion

Aortic disease during pregnancy and postpartum increases the risk of fetal and maternal morbidity and mortality. The exact prevalence of aortic aneurysm complicating pregnancy is unknown, as cases reported in the literature are the one with either catastrophic complications and/or the ones where repair was attempted in pregnancy.^3–6 Predisposing conditions can be categorized into those associated with genetic factors such as Marfan’s syndrome, Loeys–Dietz syndrome, Turner syndrome, Ehler Danlos syndrome or congenital bicuspid aortic valve, and non-genetic risk factors like hypertension and smoking.^1,7 Multi-parity and pregnancy itself, especially third trimester or the peripartum period, is identified as a risk factor for complications such as dissection or rupture.^1,8 In this case, hypertension, which was diagnosed a year before conception, was controlled and in the absence of any clinical features of any genetic syndromes, the cause of aneurysm was yet to be identified.

Counseling and management by a multidisciplinary team involving a cardiologist, a cardiothoracic surgeon, an anesthetist along with an experienced obstetrician will help to tackle the cardiovascular-related events and risks associated with pregnancy. Concern of dissection or rupture should be discussed with the patient and family on an individual basis and the decision to discourage pregnancy should be taken after considering the (i) caliber of the aneurysm/dilatation, (ii) rate of growth, and (iii) any history of dissection in the family.^7,8 Prenatal diagnosis may be offered in those women with a known mutation for any of the genetic syndromes.

Pregnant women with suspected aortic aneurysm need to be evaluated further with echocardiography and when needed, with cardiac magnetic resonance (CMR) imaging according to the recent ESC guidelines.⁷ Strict and frequent follow-up remains the cornerstone for prevention/early diagnosis of aortic dissection or rupture. It should include four to eight weekly echocardiography/MRI (preferably without gadolinium) during pregnancy.^7,9 Ultrasonography and echocardiography aided the initial diagnosis in our case and the same was used for follow-up monitoring. Due to the logistical difficulties, an MRI could not be offered to this woman.

Strict blood pressure control is advised for these women; alpha methyl dopa or beta-blockers to be used as the first-line therapy when needed. In our case, blood pressure was controlled with a beta-blocker and calcium channel blocker which was continued during pregnancy. Lifestyle modification such as cessation of smoking should be encouraged. Angiotensin converting enzyme inhibitors, angiotensin receptor blockers, and use of statins are better avoided during pregnancy due to the teratogenic and/or fetotoxic effects on fetus.^1,7,9

Since surgical treatment during pregnancy increases the risk of fetal loss or long-term neurological sequelae in children, it is reserved for those cases with life-threatening complications for the mother. Mortality rates reported with abdominal aneurysmal ruptures range from 65 to 85%.¹⁰ Surgery is best performed between 13 and 28 weeks’ gestation, under full maternal/fetal monitoring.^1,7 Steps to reduce associated surgical risk include more attention to the cardiopulmonary bypass, pulsatile perfusion, near-normothermia, and avoidance of vasoconstrictors. If the fetus is viable, cesarean section should be performed prior to the repair.⁹ Due to the risk of complications in future, surgery or follow-up is advisable in the presence of aortic dilatation of 45 mm in Marfan syndrome or Loeys–Dietz syndrome, and 50 mm in the association of bicuspid aortic valve or other predisposing conditions.⁷ Fusiform abdominal aortic aneurysm compared to saccular or eccentric type of aneurysm is at lesser risk of rupture. Early repair is recommended for those with rapid aneurysmal growth with more than 10 mm per year and those who are symptomatic (abdominal, chest, or back pain), due to increased risk of rupture.¹⁰ As the risk of surgery-related mortality and morbidity was higher in our case than the risk of rupture of aneurysm (fusiform aneurysm with dilatation less than 50 mm), after counseling, six-monthly follow-up with imaging was arranged. On her follow-up visit, imaging showed the aneurysmal diameter to be the same as at the time of discharge and further review after six months was arranged.

As the risk of complications is higher during labor and delivery, cesarean section is recommended when the aortic diameter was above 45 mm, as in the index case.^7,9 In high-risk cases or in those with dissection, it is better performed in cardiothoracic operating room with Cardio-Thoracic and Vascular Surgery (CTVS) team as standby to complete the aortic repair after cesarean section. Vaginal delivery can be considered in low-risk patients with dilatation less than 40 mm, especially under epidural analgesia which will reduce the hemodynamic stress and provide adequate pain relief.⁷

Conclusion

Changes in the aorta during pregnancy along with other risk factors such as hypertension will lead to an increased risk of complications in these women. Therefore, timely identification, counseling, and risk reduction strategies such as strict blood pressure control, in centers with experience in managing pregnant women with such complications may be helpful in optimizing the outcomes.

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

Ethical approval

The patient provided written informed consent for publication.

Guarantor

AK.

Contributorship

NT, GD, MS and AK conceived the idea and performed the search. AK and NT wrote the first draft. AK, MS, AAP, SC and reviewed and revised the final draft. AK and GD reviewed and commented on the final draft.