MANAGEMENT OF PATIENTS WITH INTRAMURAL HEMATOMA OF THE THORACIC AORTA

Background. Intramural hematoma of the thoracic aorta (IMH) is a diagn osis of exclusion and represents spontaneous, localized hemorrhage int o the wall of the thoracic aorta in the absence of bona fide aortic di ssection, intimal tear, or penetrating atherosclerotic ulcer. This pro cess may arise from primary vasa vasorum hemorrhage within the aortic media or rupture of an atherosclerotic plaque. The clinical presentati on of patients with IMH mimics that of acute aortic dissection; moreov er, considerable diagnostic confusion exists despite the use of many d ifferent imaging modalities. The optimal mode of management of patient s with IMH (medical versus medical plus surgical) remains problematic because of the paucity of information available. Methods and Results. Thirteen patients with IMH were managed at two medical centers between 1983 and 1992. Patients with IMH caused by giant penetrating atherosc lerotic ulcers were specifically excluded. There were 8 women and 5 me n (mean age, 70 years [range, 54 to 82 years]). The admitting clinical diagnosis was acute aortic dissection, and all patients had a history of hypertension. There was no evidence of aortic dissection or intima l disruption as assessed by computed tomographic (CT) scan (n=11), aor tography (n=10), magnetic resonance imaging (MRI) scan (n=9), transeso phageal echocardiography (TEE) (n=6), or intravascular ultrasound (n=1 ). The diagnosis of IMH was established by exclusion. The descending t horacic aorta was involved in 10 cases and the ascending/arch in 3. Co nservative medical management was attempted initially. All 3 patients with IMH involving the ascending aorta ultimately required operative i ntervention, and 2 individuals died; 2 of 10 patients with descending aortic involvement eventually underwent surgery. Average hospital stay was 11 days; the mean follow-up interval for discharged patients was 29 months. Conclusions. IMH is a distinct pathological entity, should not be confused with aortic dissection, and probably will be identifie d more frequently in the future. All patients with IMH should be monit ored carefully and treated with aggressive antihypertensive therapy. F requent serial assessment is necessary using TEE or MRI/CT scans. Base d on this small experience, patients with ascending/arch IMH, ongoing pain, or IMH expansion should probably undergo early graft replacement . Patients with IMH involving the descending thoracic aorta who have n o evidence of progression and become pain free can probably be treated conservatively but require antihypertensive therapy and serial aortic imaging surveillance indefinitely.