Purpose: For patients with Stanford type B aortic intramural hematoma (IMH), medical treatment is usually selected. However, the outcomes of patients with type B IMH are not completely understood, and some cases can have fatal complications develop or surgical treatment necessitated. The purpose of this study was to investigate predictors of progression of the affected aorta in patients with type B IMH with initial computed tomography (CT) images.
Methods: Thirty-five patients with type B IMH were studied with serial CT images. Initially, medical therapy was selected for all patients. CT findings of the affected aorta were evaluated on admission and at follow-up. We divided the patients into two groups (progression group or regression group) on the basis of CT findings and investigated predictors of progression of the affected aorta with initial CT images.
Results: We defined 15 patients who showed increased maximum aortic diameter (n = 14), increased maximum aortic wall thickness (n = 3), progression to overt dissection (n = 4), or rupture of the aortic wall (n = 2) during the follow-up period as the progression group. The other 20 patients, who all showed decreased maximum aortic wall and aortic wall thickness, were defined as the regression group. In the maximum aortic diameter, an optimal cutoff value of 40 mm resulted in positive predictive and negative predictive values of 86.7% and 90.0%, respectively. Both a maximum aortic diameter of 40 mm or more (P =.0011) and a maximum aortic wall thickness of 10 mm or more (P =.0009) were shown to be significantly predictive of the progression with Cox regression analysis.
Conclusion: Maximum aortic diameter and maximum aortic wall thickness on initial CT images are predictive for progression of the affected aorta in patients with type B IMH. For type B IMH with a maximum aortic diameter of 40 mm or more or a maximum aortic wall thickness of 10 mm or more, careful follow-up studies must be required.