Aortic wall thickness: an independent risk factor for aortic dissection?
OBJECTIVE
Aortic aneurysm size is known to portend a higher likelihood of aortic complications in patients with connective tissue disorders (CTD), but other objective tools are needed to determine which patients are at greatest risk of dissection, especially those which reflect the structural integrity and strength of the aortic wall.


METHODS
The aortic wall pathology was evaluated in CTD patients with and without acute aortic dissection to identify parameters that affect the risk of dissection. A retrospective review was performed of aneurysm pathology from patients with Marfan syndrome (MFS; n = 53) without dissection undergoing prophylactic aortic root surgery, and acute type A aortic dissection patients (AAAoD; n = 16). Patients without a cardiovascular cause of death (n = 19) served as controls. The minimal aortic medial wall thickness was measured, and medial myxoid degeneration (MMD) and the degree of elastin loss and fragmentation were graded.


RESULTS
The mean minimal aortic wall thickness was 1,625 +/- 364 microm in controls, and 703 +/- 256 microm and 438 +/- 322 microm for MFS and AAAoD patients, respectively. Aortic root diameters did not correlate with aortic wall thickness. A comparison of aortic medial thickness showed that the media was significantly thinner among acute dissection patients than either elective surgical patients (p = 0.02) or controls (p < 0.001). Aortic size, degree of MMD, and elastin loss did not vary significantly between CTD patients.


CONCLUSIONS
A diminished aortic wall medial thickness may be linked to aortic dissection. High-resolution imaging techniques in the future may lead to the morphological assessment of aortic medial wall thickness in vivo becoming a reality which, in theory, could provide a more refined risk prognostication for acute aortic dissection.
Hadas
H
Shiran
Justin
J
Odegaard
Gerald
G
Berry
D Craig
DC
Miller
Michael
M
Fischbein
David
D
Liang
D000328:Adult; D001011:Aorta / Q000293:injuries* / Q000473:pathology*; D001027:Aortography; D016022:Case-Control Studies; D054326:Coronary Sinus / Q000473:pathology; D004452:Echocardiography; D005260:Female; D006801:Humans; D008297:Male; D008382:Marfan Syndrome / Q000601:surgery; D008875:Middle Aged; D012307:Risk Factors; D013194:Staining and Labeling; D014057:Tomography, X-Ray Computed; D017540:Tunica Media / Q000473:pathology