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25-year mortality was five per cent, - higher than predicted.
It is possible that in early years (< a g e 40 years), the best-risk subjects can be considered for
unrestricted certification but our present inability to identify later risk indicates that the tetralogy of
Fallot is incompatible with unrestricted certification in the long term. Initial unrestricted certification
should be confined to applicants operated on before the age of 12 years who have no evidence of residual
right ventricular hypertrophy, significant pulmonary regurgitation or complex ventricular rhythm
disturbance, subject to regular monitoring by a cardiologist.
Patent ductus arteriosus
Patent ductus arteriosus is usually recognized early in life and closed surgically. In one review, the 25-
year mortality was less than one per cent, with no late deaths.
There is an association with bicuspid aortic valve, subaortic stenosis, pulmonary stenosis and aortic root
disease. In the absence of such complications, an applicant may be considered for unrestricted
certification. Complicating pathology requires further consideration and review.
Many congenital heart conditions are now consistent with long-term survival. Only those with the most
favourable outcomes will be acceptable for medical certification but as new data become available the
certificatory position will require further updating.
DISEASE OF THE GREAT VESSELS
Aortic aneurysm involves dilation of the aorta and in one-sixth of cases this will involve more than one
segment. Most commonly involving the abdomen, one-quarter of subjects with a thoracic aneurysm will
also have involvement of the ascending thoracic segment.
The condition is four times more common in men > age 55 years than in women, the prevalence in this
age group being three per cent. Increasing age, atheromatous degeneration of the wall, hypertension and
familial factors are all involved in the pathogenesis of abdominal aortic aneurysm. Aneurysms < 4.0 cm in
diameter have a two-year risk of rupture of less than two per cent, but aneurysms > 5 . 0 cm the risk is 22
per cent. One, five- and ten-year survival rates following surgical repair in one large series were 93 per
cent, 63 per cent and 40 per cent respectively in an older mean age group than the pilot population,
attrition being due to concomitant vascular complications. In another study, five-, ten- and 15-year
survival was 71 per cent, 38 per cent and 16 per cent respectively in the absence of coronary artery
disease in a population with a mean age of 69.8 years. Coexistent coronary artery disease reduced
survival further. Hypertension significantly impairs outcome both before and after treatment.
Thoracic aneurysms show less age-related increase in incidence, the descending, ascending and arch
portions being involved in that order. Aneurysm of the ascending aorta most frequently shows cystic
median degeneration with increasing prevalence of atheromatous disease distally. Occasional causes are
giant-cell arteritis and syphilis. In younger patients, the inherited disorders of collagen will be more
important. As with abdominal aneurysms, a luminal diameter > 5.0 cm is associated with a significantly
increased risk of rupture. Surgery carries a five to ten per cent mortality and significant morbidity.
ICAO Preliminary Unedited Version — October 2008 III-1-43
Marfan’s syndrome1
Marfan’s syndrome is transmitted as a dominant gene with variable expression. It is one of several
conditions marked by an inherited abnormality of the extra-cellular matrix, including the Ehlers-Danlos
syndrome2. It is a mutant form in about one-sixth of cases. Its prevalence in the population may be as high
as one per 10 000.
At times its variability makes it difficult to diagnose with confidence although the causative gene has now
been identified. In a report from the Cleveland Clinic, males outnumbered females by a ratio of two to
one. Three-fifths and two-fifths, respectively had a diastolic murmur and/or cardiomegaly on
presentation; follow-up was a mean of 99 months. Thirty-one of the 81 patients died at a mean age of 35
(range 3 to 63) years, 87 per cent from cardiovascular cause. Even after surgery the survival is not good
— 75 per cent at five years and 56 per cent at ten years. Survival following surgery for non-Marfan cystic
median necrosis of the aorta is equally bleak, at 57 per cent at five years. Increased ascending aortic
diameter predicts the onset of aortic regurgitation but less reliably of dissection.
Pilots in whom the diagnosis of aortic aneurysm has been queried require evaluation with transthoracic
echocardiography, MRI or magnetic resonance angiography (MRA) and, if indicated, aortography. A
　
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