Visceral segment aortic thrombus is associated with proximal aortic degeneration after infrarenal abdominal aortic aneurysm repair

Abstract

Objective: To identify predictors of aortic aneurysm formation at or above an infrarenal abdominal aortic aneurysm repair.

Methods: A total of 881 infrarenal abdominal aortic aneurysm repairs were identified at a single institution from 2004 to 2008; 187 of the repairs were identified that had pre-operative and post-operative computed tomography imaging at least one year or greater to evaluate for aortic degeneration following repair. Aortic diameters at the celiac, superior mesenteric, and renal arteries were measured on all available computed tomographic scans. Aortic thrombus and calcification volumes in the visceral and infrarenal abdominal aortic segments were calculated. Multivariable modeling was used with log transformed variables to determine potential predictors of future aortic aneurysm development after infrarenal abdominal aortic aneurysm repair.

Results: Of the 187 patients in the cohort, 100 had an open abdominal aortic aneurysm repair while 87 were treated with endovascular repair. Proximal aortic aneurysms developed in 26% (n = 49) of the cohort during an average of 72 ± 34.2 months of follow-up. After multivariable modeling, visceral segment aortic thrombus on pre-operative computed tomography imaging increased the risk of aortic aneurysm development above the infrarenal abdominal aortic aneurysm repair within both the open abdominal aortic aneurysm (hazard ratio 2.04, p = 0.033) and endovascular repair (hazard ratio 3.31, p = 0.004) cohorts. Endovascular repair was independently associated with a higher risk of future aortic aneurysm development after infrarenal abdominal aortic aneurysm repair when compared to open abdominal aortic aneurysm (hazard ratio 2.19, p = 0.025).

Conclusions: Visceral aortic thrombus present prior to abdominal aortic aneurysm repair and endovascular repair are both associated with an increased risk of future proximal aortic degeneration after infrarenal abdominal aortic aneurysm repair. These factors may predict patients at higher risk of developing proximal aortic aneurysms that may require complex aortic repairs.

Keywords: Infrarenal aortic aneurysm; aortic thrombus; visceral aortic aneurysm.