Intraluminal thrombus asymmetrical deposition in ruptured and symptomatic abdominal aortic aneurysm

The role of intraluminal thrombus (ILT) has special attention in these studies. One of the papers showed that asymmetrical intraluminal thrombus deposition (ATDI) has an important role in growth of the AAA. The aim of our study was to assess the asymmetrical thrombus deposition index in ruptured and symptomatic aneurysms. We collected data for 33 aneurysms, 21 (63.63%) asymptomatic and 12 (33.37%) ruptured or symptomatic. Asymmetrical thrombus deposition index (ATDI) was measured by Onis DICOM viewer software. Also, lumen's geometrical centre (LGC) was defined and ATDI was considered positive when the LGC was laid on the posterior section of the sac (meaning dominant anterior ILT distribution) and negative when it was laid on the anterior section (meaning dominant posterior ILT distribution). Maximum aneurysm diameter was 63.4mm in average (50-100mm, SD=12.89); 59.8mm in asymptomatic and 71.16mm in symptomatic or ruptured aneurysm (p=0.012). The absolute value of asymmetric thrombus deposition index was significantly higher in symptomatic/ruptured compared to asymptomatic aneurysm, 0.54 and 0.33, respectively (p=0.041), while there was no difference in frequency of positive or negative thrombus deposition (p=0.261). There was no significant correlation between maximal aneurysm size and absolute value of ATDI (p=0.505). Values of thrombus deposition index are correlating with the development of symptomatology or rupture of the AAA. This variable should be included in much wider mathematical rupture prediction model in order to have more accurate rupture risk assessment.