Spontaneous aortic intramural haematoma

Spontaneous intramural haematoma (IMH) represents a distinct event which can proceed aortic dissection (dissn). Pathological examination reveals an intact intima and localised mural haemorrhage. Although IMH is increasingly recognisable using non-invasive imaging, optimal management and the long term prognosis is uncertain. We performed a prospective 3 year study of patients (pts) presenting to a Regional Centre with possible acute dissn. Following clinical assessment, pts underwent diagnostic transoesophageal echocardiography (TOE). Cases of IMH received aggressive blood pressure control, comparative MRI or CT scan and serial TOE &/or MRI follow up. 64 patients had acute aortic syndromes (34 type A dissn, 19 type B, 1 ascending aneurysm rupture and 10 IMH. All Pts with IMH (6 male mean age 67yrs) had a history of hypertension. Each presented with typical symptoms of chest/back pain, 2 had paralysis of the lower limbs. IMH affected the ascending (asc) aorta in 2 and the descending (desc) aorta in 8 pts. One pt had 2 discrete areas of IMH in the desc aorta. Both pts with asc involvement died (one perioperatively at presentation & the other 7 months later). IMH involving the desc aorta resolved completely in one pt during follow up. 2 pts with desc IMH subsequently required aortic surgery for either acute type A dissn (3 weeks later) or aneurysm formation (10 months later). Although TOE and MRI findings were concordant, CT scanning failed to delineate the extent and diagnosis of IMH in 2 pts. At follow up, 8/10 pts were alive, although one remained paraplegic (desc IMH). Despite medical treatment, pts with IMH are at risk of dissn, aneurysm formation and death. Vigilant follow up using either TOE and/or MRI is necessary even when the asc aorta appears normal.