Dissecting Aortic Aneurism
This dissecting aneurism was found in a 76 year old man who died from cerebral haemorrhage.
The specimen includes aortic arch, thoracic and abdominal aorta. The probe passes down the true aortic lumen, overlying which is the false channel of an old dissecting aneurism. The false channel has been opened and is lined by an atheromatous intima. Intercostal arteries are seen to arise from it. The dissecting aneurism communicates with the aortic arch by a split seen at the top of the specimen, and in life, blood re-entered the vascular system proper by a further intimal split in one of the common iliac arteries.
This is an example of "double-barrelled aorta", i.e. self-cure of a dissecting aneurism leading to a double aortic lumen. Such self-cure of a dissecting aneurism is rare. The factors which pre-dispose to dissecting aneurism are systemic hypertension and patchy myxoid degeneration of the media of the aorta. The latter, (known as medial degeneration) is not uncommon after middle age. Similar changes also occur in the aorta of persons with Marfan's syndrome. These patients have an increased incidence of aortic rupture and dissecting aneurism. Dissecting aneurism usually presents with very severe chest pain. It is usually fatal within a few days unless there is successful surgical intervention. In this patient, there may have been underlying systemic hypertension, which lead to both the dissecting aneurism and to the cerebral haemorrhage.