Chronic dissection of the ascending aorta - a diagnostic challenge

A 61-year-old man was referred for elective coronary angiography suffering from atypical retrosternal chest pain. Out-patient electrocardiography under exertion had revealed no ischemia and transthoracal echocardiography no pathological findings, but coronary angiography four years ago had disclosed an asymptomatic 50 %-stenosis of the right coronary artery. The interventionist - who, having performed some 7,000 coronary angiographies and 3,000 coronary interventions in his career - for the first time was not able to intube the left ventricle of a patient, whom he had angiographied without any problems a couple of years ago. Intubation of the left coronary artery succeeded, intubation of the right coronary artery (RCA), however, failed. Aortography (Fig. [1] a) disclosed a sharp gap in contour at the lateral aortic wall and a line running along the lumen of the ascending aorta, highly suspicious of a dissection membrane. ECG-gated 16-slice computed tomography (Sensation 16, Siemens Medical Solutions, Forchheim, Germany; Fig. [1] b) confirmed a dissection membrane of the ascending aorta (arrowheads; AoV = aortic valve) and disclosed a significant lesion of the RCA, which apparently originated just beneath the dissection membrane: the bottom of that membrane had impaired the access to the RCA’s orifice (arrow). Surgery demonstrated a serous pericardial effusion, older signs of adventitial bleeding as well as scars in the right atrial region. The dissection extended up to the brachiocephalic trunk. Histopathology revealed a chronic myxoid degeneration and necrosis of the aortic media. The patient was successfully treated by aortic replacement through an aortic conduit prosthesis with reimplantation of the coronary arteries and a single bypass graft to the RCA..

Fig. 1 Aortography (a) and ECG-gated 16-slice computed tomography (b) of a dissection membrane of the ascending aorta (arrowheads; AoV = aortic valve): origin of the right coronary artery just beneath the dissection membrane (arrow).

Conclusion: If intubation of the left ventricle, in absence of an aortic stenosis, is challenging, any interventionist should bear in mind the possibility of an acute [1] [3] or - as presented above - a chronic aortic dissection, perform aortography and initiate multislice computed tomography [2]. For in the invasive diagnostic state an iatrogenic aortic dissection cannot be ruled out, interventionists should ensure a correct position of the diagnostic catheter by aortic pressure monitoring and careful preinjection of contrast medium.

References

• 1 Pethig K, Figulla H R. Akute Aortendissektion - Welche Therapiestrategien sind gesichert?.  Dtsch Med Wochenschr. 2004;  129 811-813
• 2 Quint L E, Platt J F, Sonnad S S, Deeb G M, Williams D M. Aortic intimal tears: detection with spiral computed tomography.  J Endovasc Ther. 2003;  10 505-510
• 3 Sakka S G, Hüttemann E. Paraparese der unteren Extremität bei akuter Aortendissektion und thorakalem Meningeom.  Dtsch Med Wochenschr. 2004;  129 1622-1624