Different clinical features of aortic intramural hematoma versus dissection involving the descending thoracic aorta

OBJECTIVE: 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). METHODS: We prospectively evaluated clinical and echocardiographic data in AD (76 patients) and IMH (27 patients) of the descending thoracic aorta. RESULTS: 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). CONCLUSION: 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.