Investigating TAAD in Pregnant Women
CT aortography, MRI and transoesophageal echocardiography (TOE) have all proven useful in the diagnosis of TAAD in pregnancy. The historical gold standard for the diagnosis of TAAD is CT aortography16. In pregnancy, there is often concern raised about potential fetal harm linked with radiation exposure. This fear could potentially lead to delayed or missed diagnosis.
Varying recommendations regarding the optimum investigation strategy for these women exists across different governing bodies. The American College of Obstetricians and Gynecologists recommend that ionizing radiation through the use of radiography, CT or nuclear imaging should not be withheld from a pregnant woman if it is more readily available or thought to be necessary in addition to ultrasonography or MRI14. This is because, with few exceptions, the radiation dose is much lower than the exposure associated with fetal harm17,18. In a similar sentiment, the European Society of Cardiology recommend for haemodynamically unstable patients, the quickest form of imaging should be utilised, whether MRI, CT or TOE19. If stable, they recommend the use of MRI. Advantages of TOE as a diagnostic tool also extend to its versatility, and can be used throughout the hospital, from intensive care, emergency department and theatres to assess real time information regarding location and extent of dissection, which is ideal for patients who are haemodynamically unstable20. Dissection complications such as pericardial effusion and aortic insufficiency can be assessed12. The disadvantages of TOE are of a practical nature; availability across hospital trusts, and it is an invasive procedure requiring an experienced technician due to operator-dependent results; sensitivity can vary, reported between 59 and 83%, and specificity 63 – 93%12. With this knowledge, a high clinical suspicion should not deter from an additional investigation such as CT or MRI12.