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.
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 was published by Robert
Otto Gsell, a Swiss physician in 1928, while the Austrian pathologist Jakob Erdheim
contributed the pathoanatomical findings in 1929.
King George II of England died of this condition while straining on
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 (EDS) (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.
echocardiography (visualization of aortic valve and degree of dilatation of
aorta, estimation of ventricular function); arterial angiogram if any doubt
about involvement of distal aorta and its major branches. Inquire about
Prophylactic administration of
beta-blockers to patients with documented aortic dilatation decreases
myocardial contractility and the rate of rise of aortic pressure. Because
left ventricular ejection velocity may be increased with vasodilators alone,
the concomitant use of beta-blockers is recommended. ...