Pulsatile Changes of the Aortic Diameter May Be Irrelevant Regarding Endograft Sizing in Patients With Aortic Disease

Abstract

Purpose:

Endovascular aortic repair has become the preferred elective treatment of infrarenal aortic aneurysms. Aortic pulsatility may pose problems regarding endograft sizing. The aims of this study are to determine the aortic pulsatility in patients with aortic disease and to evaluate the effect of pulsatility on the growth of aneurysms.

Materials and Methods:

In this retrospective study, analyses of computed tomography angiography (CTA) images of 31 patients under conservative treatment for small abdominal aortic aneurysms were performed. Reconstructions of the raw electrocardiography (ECG) gated dataset at 30% and 90% of the R-R cycle were used. After lumen segmentation, total aortic cross-sectional area was measured in diastole and systole in the following zones: Z0, Z3, Z5, Z6, Z8, and Z9. Effective diameters (EDs) were calculated from the systolic (ED_sys) and diastolic (ED_dia) cross-sectional areas to determine absolute (ED_sys – ED_dia, mm) and relative pulsatility [(ED_sys – ED_dia) / ED_dia, %]. Diameter of the aneurysms was measured on baseline images and the last preoperative follow-up study of each patient.

Results:

A total of 806 measurements were completed, 24 pulsatility and 2 growth measurements per patient. The mean pulsatility values at each point were as follows: Z0: 0.7±0.8 mm, Z3: 1.0±0.6 mm, Z5: 1.0±0.6 mm, Z6: 0.8±0.7 mm, Z8: 0.7±1.0 mm, Z9: 0.9±0.9 mm. Follow-up time was 5.5±2.2 years during which a growth of 13.42±9.09 mm (2.54±1.55 mm yearly) was observed. No correlation was found between pulsatility values and growth rate of the aneurysms.

Conclusion:

The pulsatility of the aorta is in a submillimetric range for the vast majority of patients with aortic disease, thus probably not relevant regarding endograft sizing. Pulsatility of the ascending aorta is smaller than that of the descending segment, making an additional oversize of a Z0 implantation questionable.

Clinical Impact

Endovascular aortic repair reqiures precise preoperative planning. Pulsatile changes of the aortic diameter may pose issues regarding endograft sizing. In our retrospective single-centre study, aortic pulsatility of patients with AAA was measured on ECG gated CTA images. Pulsatility values reached a maximum at the descending aorta, however absolute pulsatility values did not exceed 1 mm at any point along the aorta. Therefore, significance of aortic pulsatility regarding the sizing of EVAR prostheses is questionable. Correlation between pulsatility and AAA growth was not found.