Different Clinical Features of Aortic Intramural Hematoma Versus Dissection Involving the Descending Thoracic Aorta

Abstract

The objective of this study is to test the hypothesis that the absence of flow communication in aortic intramural hematoma (IMH) involving the descending aorta may have a different clinical course compared with aortic dissection (AD). We prospectively evaluated clinical and echocardiographic data in AD (76 patients) and IMH (27 patients) of the descending thoracic aorta. Patients did not differ with regard to age, gender, or clinical presentation. IMH and AD had the same predictors of complications at follow-up: aortic diameter (>5 cm) at diagnosis and persistent back pain. Surgical treatment was more frequently selected in AD (39% vs. 22%, P < 0.01) and AD patients who underwent surgical treatment had higher mortality than those with IMH (36% vs. 17%, P < 0.01). There was no difference in mortality with medical treatment (14% in AD vs. 19% in IMH, P = 0.7). During follow-up, of 23 patients with IMH, 11 (47%) showed complete resolution or regression, 6 (26%) increased the diameter of the descending aorta, and typical AD developed in 3 patients (13%). No changes occurred in 14% of the group. Three-year survival rate did not show significant differences between both groups (82 +/- 6% in IMH vs. 75 +/- 7% in AD, P = 0.37). IMH of the descending thoracic aorta has a relatively frequent rate of complications at follow-up, including dissection and aneurysm formation. Medical treatment with very frequent imaging and timed elective surgery in cases with complications allows a better patient management.