Aortic sac enlargement after endovascular aneurysm repair: volume-related changes and the impact of intraluminal thrombus

Abstract

Purpose: Abdominal aortic aneurysm (AAA) growth after endovascular aneurysm repair (EVAR) is still unpredictable. The issue of optimal frequency of computed tomography angiography for surveillance and its measurement method accuracy remain unclear. We aimed to assess the value of abdominal aneurysm sac volume measurement for detecting expansions and the association of preprocedural intraluminal thrombus (ILT) volume with aneurysm sac growth following EVAR. Material and methods:A total of 107 patients underwent elective EVAR. Inclusion criteria provided a cohort of 39 patients. Changes of postoperative maximum aneurysm sac diameter and AAA volume were calculated. Volumetric AAA changes and demographic data of the cases with clinically irrelevant AAA diameter enlargement were evaluated. Preoperative ILT volumes were collected. ILT and AAA sac volume ratio was calculated. Statistical data analysis was performed using standard methods. Results:The mean changes of maximum AAA diameter and volume in percentage after EVAR were -5.08 ± 8.20 mm and -13.39 ± 23.32%, respectively. A moderate positive linear correlation between those changes was found (R 2 = 0.731; p < 0.0001). The mean relative AAA volume increase in cases without clinically relevant diameter enlargement was 11.50 ± 8.27%. The means of ILT and AAA sac ratios were 0.59 ± 0.17 and 0.52 ± 1.8 in growing AAA sac and in stable or shrinking AAA sac groups, respectively (p = 0.308). Conclusions:Volumetric AAA measurement may be useful as an additional method to diameter measurement after EVAR to identify clinically relevant sac growth. Preoperative volume of ILT may not significantly affect the growth rate of AAA after EVAR.

The Value of Aortic Volume and Intraluminal Thrombus Quantification for Predicting Aortic Events after Endovascular Thoracic Aneurysm Repair

“…However, to our knowledge, there is no literature on how thrombus volume changes after TEVAR and why, according to our results, a greater ATV impedes sac regression. Concerning EVAR, conflicting results [15,33,34] have been reported regarding different aspects of thrombus burden (size and volume) and localization. The biomechanical characteristics of the thrombus may therefore be important in relation to sac changes after TEVAR.…”

“…On the other hand, the use of aortic diameter as a surrogate marker has several limitations, and aortic volume is better than aortic diameter because it reflects the three-dimensional (3D) morphological changes in the aneurysm [12,13]. Aortic volume measurement is now used widely in the follow-up of EVAR to evaluate the behavior of the aneurysm; many authors consider this parameter much more reliable than the simple maximum diameter measurement [14,15].…”

Abdominal Aortic Aneurysm Diameter versus Volume: A Systematic Review

“…These findings might be partially influenced by the methodologies used to calculate diameter and volume. A number of different methods to calculate aortic diameter were used, for example, orthogonal and axial planes, antero–posterior, leading edge to leading edge, inner to inner, and outer to outer measurements [ 5 , 9 , 17 , 18 , 19 , 24 , 30 ]. It is important to highlight the lack of a standardized way to measure AAA volume.…”

“…Most authors measure volume from below the lowest renal artery to the aortic bifurcation [ 5 , 6 , 16 , 19 , 20 , 22 , 24 , 25 , 28 , 30 , 31 ]. Others measure volume in the portion that includes the abdominal aorta, aneurysm, and iliac arteries covered by stent graft [ 17 ]. However, a significant portion of AAA volume measurement also involves iliac arteries, which could be measured likewise [ 21 ].…”

The Role of Aortic Volume in the Natural History of Abdominal Aortic Aneurysms and Post-Endovascular Aortic Aneurysm Repair Surveillance

“…Diameter evaluation failed to identify an aneurysm volume increase in 61–72% of patients with a persistent type II endoleak. Skrebunas et al [ 24 ] discovered a moderate positive linear correlation between diameter and volume (R 2 = 0.731) in 39 patients. In 28.2% of the patients, the diameter increased, while in 31% of the cohort, the volume increased.…”