Investigations
1st investigations to order
echocardiography
Test
If aortic dissection is found, there may potentially be rupture or leak.
Mitral valve regurgitation and/or calcification may occur.
Result
aortic regurgitation; aortic root dilation or ascending aortic dissection; mitral valve prolapse
slit-lamp eye examination with intra-ocular pressure measurement
Test
As part of a thorough ophthalmic assessment with full pupil dilation.[3]
Result
visualisation of subluxed/dislocated lens or other lens abnormalities (e.g., microspherakia, lens coloboma, or lens opacities); elevated intra-ocular pressure; other anterior segment findings (e.g., megalocornea or cornea plana, corneal endothelial guttata, iris coloboma, eccentric and poorly pharmacologically dilated pupils)
CT scan, thorax
Test
May be used if aortic root not clearly visible on echocardiography.
If aortic dissection is found, there may potentially be rupture or leak.
Mitral valve regurgitation and/or calcification may occur.
Result
aortic root dilation or ascending aortic dissection; aortic regurgitation; mitral valve prolapse
MRI, thorax
Test
May be used if aortic root not clearly visible on echocardiography.
Result
aortic root dilation or ascending aortic dissection, potentially with rupture or leak; aortic regurgitation; mitral valve prolapse/regurgitation/calcification
Investigations to consider
blood screening for fibrillin-1 (FBN-1) gene mutation
Test
Positive for mutation in 99% of classical Marfan syndrome patients.[11] In the absence of lens dislocation, genetic testing should be considered to exclude the possibility of Loeys-Dietz syndrome.[19]
Interpretation of results must be done in correlation with information gathered from accurate clinical examination.
Result
mutations in FBN-1 gene
CXR
Test
Helpful to exclude spontaneous pneumothorax and reveal pulmonary changes.
Result
pneumothorax, apical blebs; enlargement of the aortic and cardiac silhouette in thoracic dissection
CT scan, abdomen
Test
Used to examine the descending and abdominal aorta.[19]
Result
aortic dissection of descending aorta or abdominal aneurysm
MRI, abdomen
Test
Used to examine the descending and abdominal aorta.[19]
Result
aortic dissection of descending aorta or abdominal aneurysm
ultrasound, abdomen
Test
Useful for visualisation of the descending aorta.
Result
aortic dissection of descending aorta or abdominal aneurysm
CT scan, lower spine
Test
May be used to exclude dural ectasia.
Result
dural ectasia: widening or ballooning of dural sac
MRI, lower spine
Test
Patient should stand upright during investigation.
Result
dural ectasia: widening or ballooning of dural sac
plasma homocysteine
Test
Indicated if diagnosis is not clear and homocystinuria is suspected, especially in a child with dislocated lenses and suspected mental disability.
Result
levels not elevated
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