INTRAMURAL HEMORRHAGE AS A PRECURSOR OF A ORTIC DISSECTION

Aortic dissection without entry and blood-flow in a false lumen was re cently identified at necropsy and in vivo as intramural hemorrhage in the aortic wall (IMH). It was the purpose of the study to elucidate cl inical signs and prognosis in this rare and poorly understood conditio n. Among 360 prospectively evaluated patients with clinical suspicion of aortic dissection, 195 patients presented with evidence of aortic d isease. Of these, 25 patients (13,2 %) had IMH of the thoracic aorta w ith no primary intimal tear, flap or overt dissection as shown by MRI (n = 12), contrastenhanced CT (n = 14) and TEE (n = 3). IMH was confir med intraoperatively or at necropsy. There were 16 men and 9 women of ages 56 +/- 13 years; arterial hypertension was associated in 84 % and Marfan's syndrome in 12 %. IMH involved the ascending aorta in 12 (48 %), the arch in 2 (8 %), and the descending aorta in 11 cases (44 %). IMH occupied 8.5 +/- 5 cm in length and 2.0 +/- 1.2 cm in aortic wall thickness. Both aortic regurgitation and pericardial/mediastinal effu sion was present in 42 % of type A and in 18 % of type B IMH. IMH prog ression to overt dissection, rupture and/or acute tamponade occurred i n 8/25 cases (32 %) within 24 to 72 h, indicating the need for urgent surgical repair. The 30-day mortality of IMH inflicting the ascending aorta was 80 % (4 of 5) with medical treatment in contrast to none (of 7) with early surgical treatment (p < 0.01). One-year survival was 71 % in surgically treated patients and 20 % with medical treatment (p < 0.05). Thirty-day survival in IMH confined to the descending aorta wa s 83 % (5/6) with medical treatment and 100 % (5/5) with surgical ther apy (n.s.). At 1-year follow-up both strategies revealed survival rate s of 80 % and 83 %, respectively (n.s.). Thus, undelayed surgical repa ir should be carried out in patients with IMH inflicting the ascending aorta, whereas with IMH confined to the descending aortic segment, an tihypertensive medication should primarily be considered.