Aortic dissection is a dynamic and evolving pathology but once the acute phase is over the intimal flap does not always resolve, even if the proximal entry tear has been stented or surgically repaired. I have seen a mobile flap persist eight years after the original episode. In this case, the false lumen initially showed extensive thrombus. Surgery was declined. A four week follow up showed a mobile flap and the false lumen was free of clot. At eight weeks it had clotted up again! You may suspect that I may have contrived this sequence, I blame you not. I could hardly believe it either, so just before retirement I reviewed the images and clinical record again and it is as presented. There was no use of anticoagulants at any time.
The CT on presentation. An acute ascending aortic intramural haematoma and a clotted descending dissection.
TOE at three days shows no flap in the ascending aorta but in the descending aorta (right) there is a classic tear with no clot in the false lumen at this level.
At four weeks, the ascending aorta now shows a free dissection flap and the false lumen was unclotted throughout.
At eight weeks the ascending aorta has mostly healed and the false lumen below has clotted again.
I suspect that the initial tear was the one in the descending aorta and the ascnding IMH was a retrograde haematoma. Nevertheless it progressed to look like a typical type A dissection at four weeks. If the patient had agreed to surgery, what would you have done? Treat it as a type A and concentrate on the ascending aortic element or stent over the wound in the descending? Not easy: a careful perioperative TOE would of course have been done and might well have resolved the issue.