Prevalence of Intimal Defect in the Patients with Surgically Treated Acute Type A Intramural Hematoma of the Aorta

Park, Kay Hyun

Abstract

BACKGROUND: There is a controversy regarding the pathogenesis and management principle of an acute intramural hematoma (IMH) of the aorta. Recent studies have reported intimal defects in many patients diagnosed with IMH, and suggested that intimal defects play important roles in the pathogenesis, progression of the pathology, and prognosis. MATERIAL AND METHOD: This study reviewed the preoperative and postoperative computed tomography (CT) scan images of 36 patients who underwent surgical treatment for Stanford type A acute IMH of the aorta. The surgical findings were also reviewed retrospectively from the medical records. RESULT: In 15 patients (41.7%), the findings suggestive of the intimal defects were found in the preoperative CT. During the operation, 26 patients (72.2%) were found to have small intimal defects in the ascending aorta or the arch, of which 13 patients (50.5%) did not have the CT findings suggestive of intimal defects. In 17 patients, the intimal defects were located in the aortic arch or distal ascending aorta, where a gross examination would have been impossible without total circulatory arrest. In all patients, the intimal defects identified were included in the resected aortic segment, or locally closed. Follow-up CT at 4 months or longer after surgery showed that the IMH in the descending aorta had disappeared or was markedly improved.
CONCLUSION
Most patients undergoing surgical treatment for acute type A IMH had intimal defects. This suggests that a large proportion of IMH might have a similar pathogenic mechanism as classic dissection. Consequently, it is believed that those two entities of acute aortic syndrome should be treated using the same principles.