Usefulness of the echocardiographic paravertebral approach for the diagnosis of descending thoracic aortic dissection

Transthoracic echocardiography (TTE) is not recommended as the first-line diagnostic modality for Stanford type B aortic dissection (type-B AD).

The aims of this study were to evaluate the usefulness and factors influencing for the diagnosis of type-B AD using the transthoracic echocardiographic paravertebral approach (PVA).

We compared the image acquisition rate of descending thoracic aorta (DTA) and the diagnostic rate of type-B AD using TTE versus PVA. Both tests were compared with type-B AD, which was diagnosed by enhanced computed tomography (CT), as the reference standard. We also analyzed the factors influencing adequate image acquisition and the diagnosis of type-B AD using the PVA. The length between the dorsal thoracic surface and the DTA (TDAL) and thickness of lung on the TDAL line (LTh) were measured on the CT images.

No significant difference was found between the image acquisition rate of the DTA between the PVA and the TTE (70.1 vs. 64.2%, p = 0.56), while the diagnostic rate of type-B AD using the PVA was significantly greater than when using the TTE (56.7 vs. 26.9%, p < 0.001). Furthermore, when adequate images of DTA were obtained using the PVA, 80.9% of the patients were diagnosed with type-B AD. A multivariate analysis demonstrated that a lower LTh (p = 0.001) and the existence of a pleural effusion (p = 0.03) significantly influenced the diagnosis of type-B AD using the PVA.

The PVA might be a useful method for diagnosis of type-B AD, when adequate images of the DTA are obtained.