The association of body composition with abdominal aortic aneurysm growth after endovascular aneurysm repair

Background Body composition (BC) may be associated with abdominal aortic aneurysm (AAA) growth, but the results of previous research are contradictory. This study aimed to explore the relationship between BC and postoperative aneurysm progression. Methods Patients with regular postoperative follow-ups were retrospectively identified. The volume change of the aneurysm was measured to evaluate AAA progression. After segmenting different body components (subcutaneous fat, visceral fat, pure muscle, and intramuscular fat), the shape features and gray features of these tissues were extracted. Uni- and multivariable methods were used to analyze the relationship between imaging features of BC and AAA growth. Results A total of 94 patients (68 +/- 8 years) were eligible for feature analyses. Patients with expansive aneurysms (29/94; volume change > 2%) were classified into Group(+) and others with stable or shrunken aneurysms (65/94) were classified into Group(-). Compared with Group(+), Group(-) showed a higher volume percent of pure muscle (21.85% vs 19.51%; p = .042) and a lower value of intramuscular fat (1.23% vs 1.65%; p = .025). CT attenuation of muscle tissues of Group(-) got a higher mean value (31.16 HU vs 23.92 HU; p = .019) and a lower standard deviation (36.12 vs 38.82; p = .006) than Group(+). For adipose tissue, we found no evidence of a difference between the two groups. The logistic regression model containing muscle imaging features showed better discriminative accuracy than traditional factors (84% vs 73%). Conclusions Muscle imaging features are associated with the volume change of postoperative aneurysms and can make an early prediction. Adipose tissue is not specifically related to AAA growth.