Focal Intimal Disruption Size at Multidetector CT and Disease Progression in Type B Aortic Intramural Hematoma

Background: Recent imaging techniques show that patients with aortic intramural hematoma (IMH) have various sizes of focal intimal disruptions (FIDs) that may affect clinical outcomes. Purpose: To evaluate the relationship between size of FIDs detected at multidetector CT and disease progression in patients with type B IMH. Materials and Methods: This retrospective study analyzed consecutive patients with type B IMH who underwent multidetector CT at admission within 24 hours after symptom onset from January 2011 to March 2017. FID was defined as a focal contrast material-filled pouch projecting outside of the aorta lumen with a communicating orifice greater than 3 mm. Large FID was defined as an FID of at least 10 mm in length and width and at least 5 mm in depth. Aorta-related events were defined as a composite of aortic rupture, surgical or endovascular aortic repair, progressive aortic enlargement, and development of aortic dissection. Results: Seventy-six patients (mean age, 72 years +/- 11 [standard deviation]; 54 men) were evaluated. Fifty patients (66%; 50 of 76) had 91 FIDs. Twenty-eight patients had large FIDs and 22 patients had small FIDs. Aorta-related events occurred in 15 of 28 patients with large FIDs, two of 22 patients with small FIDs, and four of 26 patients with no FID. Patients with large FIDs showed lower aorta-related event-free survival rates than did patients with small FIDs or no FID (small FIDS, 63% +/- 10 vs 90% +/- 7 at 3 years, respectively [P =.001]; and no FIDS, 63% +/- 10 vs 84% +/- 7 at 3 years, respectively [P =.005]). Multivariable analysis showed that a maximum aortic diameter of at least 40 mm (hazard ratio, 4.8; 95% CI: 1.8, 12.6; P =.001) and large FID (hazard ratio, 3.2; 95% CI: 1.1, 8.9; P =.03) were the independent predictors of aorta-related events. Conclusion: A large portion of patients with B-intramural hematoma (IMH) had focal intimal disruption (FID) detected at CT at admission. Large FIDs were associated with disease progression of IMH. (C) RSNA, 2021