Aneurysms and dissections of the aorta usually result from degenerative changes in the aortic wall. Thoracic aortic aneurysms and dissections are primarily associated with a characteristic histologic appearance known as “medial necrosis” or “Erdheim cystic medial necrosis” which is characterized by degeneration and fragmentation of elastic fibers, loss of smooth muscle cells, and accumulation of basophilic ground substance. The association between congenital bicuspid aortic valve and medial necrosis of the aorta has been suggested. Ectopia of the pigment layer of the iris onto the anterior surface of the iris has been associated with this medical condition.
Medionecrosis of the Aorta; Annuloaortic Ectasia; Cystic Medial Necrosis of Aorta; Erdheim Disease; Erdheim-Gsell Cystic Medial Necrosis; Familial Aortic Dissection; Erdheim Cystic Medial Necrosis of Aorta; Medionecrosis Cystica Erdheim-Gsell.
The first comprehensive description of this medical condition was published by Robert Otto Gsell, a Swiss physician in 1928. The Austrian pathologist Jakob Erdheim contributed the pathoanatomical findings in 1929. King George II of England died of this condition while straining on a commode.
The true incidence is difficult to estimate. However, based on autopsy results, the prevalence is approximately six new aneurysms per 100,000 persons per year. Evidence of aortic dissection is found in 1 to 3% of all autopsies.
Loss of elastic fibers, deposits of mucopolysaccharide-like substances, and cystic medial changes in the aortic wall predispose to dilatation and dissection/rupture.
Familial history (aortic dissecting aneurysms over generations), clinical features, chest radiographs revealing prominent ascending aorta, confirmed by echocardiography, and on arteriogram demonstrating dilatation of aortic root and sinuses of Valsalva. Left ventricular hypertrophy and bicuspid aortic valve may be present, as well as dilatation of the aorta more distally and dilatation of some of the major aortic branches. Histologic examination reveals the cystic medial necrosis of the aorta and deposits of mucopolysaccharide-like material (mucoid degeneration). Differential diagnosis includes ☞Marfan Syndrome or ☞Ehlers-Danlos Syndrome (patients with Gsell-Erdheim Syndrome are usually not tall and do not have hyperextensible joints and skin, or lens subluxation, or collagen and skin fibroblast anomalies).
A majority of affected patients are normotensive throughout life. A systolic ejection click is often heard on the left parasternal border. If not followed up and treated early, patients may die from ruptured or dissecting aortic aneurysm at a young age (teen years and early adulthood). Occasionally, coloboma and/or ectopia of the iris pigment layer on the anterior surface of the iris are observed.
Precautions before anesthesia
Cardiovascular evaluation: echocardiography (visualization of aortic valve and degree of dilatation of aorta, estimation of ventricular function); arterial angiogram if any ...