Clinical Implications of Focal Intimal Disruption in Patients With Type B Intramural Hematoma.

BACKGROUND: Focal intimal disruption (FID) has been described in >20% of type B intramural hematomas (IMH), with unclear prognosis and management.

OBJECTIVES: This study aimed to evaluate the short- and long-term evolution of medically treated patients with type B IMH with and without FID.

METHODS: There were 107 consecutive patients with acute type B IMH were included prospectively in a multicenter protocol of clinical and imaging follow-up. FID was defined as an intimal disruption with contrast material-filled outpouching from the aorta lumen with a communicating orifice of >3 mm.

RESULTS: There were 43 patients (40%) who developed an FID with larger basal maximum aortic diameter and hematoma thickness. Patients with acute FID had a higher risk of aorta-related events than those without FID (hazard ratio: 24.43; 95% confidence interval: 7.65 to 78.04; p < 0.001). Of the 94 discharged patients, 33 (35%) developed an FID within the first 6 months of follow-up: 19 evolved with mild (<1 mm/year), 8 with moderate (1 to 2 mm/year), and 6 with severe (>2 mm/year) aortic enlargement. Chronic FID was not associated with aorta-related events (hazard ratio: 0.98; 95% confidence interval: 0.22 to 4.34; p = 0.987).

CONCLUSIONS: The development of FID in the acute phase of type B IMH has a poor prognosis owing to the high risk of aortic rupture. In the chronic phase, most FIDs evolve with slow aortic dilation and without complications. Although acute FIDs should be treated early and invasively, lesions developing in the subacute-chronic phase can be managed with medical treatment and close imaging surveillance.