Aortic Ductus Diverticulum Mimicking Aortic Dissection: A Case of Diagnostic Ambiguity in Transthoracic Echocardiography.

Background: Aortic dissection is a critical condition often presenting with acute, severe chest pain and haemodynamic instability. Early diagnosis is essential to mitigate the high mortality risk. Imaging modalities play a pivotal role in diagnosing aortic conditions, but determining the appropriate method can be challenging.

Case Description: We report an asymptomatic 55-year-old female undergoing transthoracic echocardiography (TTE) for mitral and aortic valve regurgitation surveillance. Incidentally, a suspicious flow jet at the distal aortic arch was discovered, raising concerns of aortic dissection. A subsequent CT angiogram (CTA) identified this as an aortic ductus diverticulum at the aortic isthmus, not a dissection.

Discussion: Aortic dissection has a high initial 48-hour mortality, with even surgically managed cases exhibiting a 26% risk. Imaging tools such as a transoesophageal echocardiogram (TEE), CT and MRI scans are instrumental for diagnosis, with their applicability depending on the patient's clinical situation. The aortic ductus diverticulum, a developmental outpouching, often mimics other aortic pathologies, emphasising the importance of accurate imaging interpretation.

Conclusion: Aortic ductus diverticulum presents diagnostic challenges due to its resemblance to other aortic conditions. Advancements in imaging modalities improve diagnostic accuracy, but awareness and careful interpretation are paramount to ensure timely and appropriate patient care.

Learning Points: Distinguishing aortic anomalies: recognise the differences between aortic dissection and aortic ductus diverticulum using imaging findings.Evaluating imaging modalities: understand the pros and cons of transthoracic echocardiography (TTE), transoesophageal echocardiogram (TEE), CT and MRI scans for diagnosing aortic conditions.Addressing diagnostic pitfalls: identify potential ambiguities in imaging results, especially concerning the aortic isthmus, and ensure accurate diagnosis before treatment.