Thoracic aortic aneurysm in pregnancy: morphological analysis of 6 cases

Aortic dissection is rare but life-threatening complication in pregnancy, causing significant maternal and perinatal losses. Pregnancy may influence the integrity of the vessel wall and is a risk factor for dissection. There are very few data in the literature on structural changes in the aortic walls during pregnancy complicated by aortic dissection. Aim. Study of pathological features in the wall of ascending aorta (AA) during or immediately after pregnancy is presented in the article. Materials and methods. Material after surgical correction of AA in patients during pregnancy and in the early postpartum period was studied. Frozen sections were made from one part of the sample, followed by hematoxylin and eosin (H&E) staining, as well as Sudan III–IV staining to detect lipids. Paraffin sections were stained with H&E and picrofuchsin (van Gieson’s stain) for differentiation of collagen and muscle fibers, as well as fuchselin (Weigert’s elastic stain). Results. Six cases of aortic surgery during pregnancy (n = 1) and postpartum period (n = 5) were included: severe aortopathy caused by Marfan syndrome (MS) (n = 3), aortic coarctation with bicuspid aortic valve (n = 1), renal hypertension (n = 1), and pregnancy-induced hypertension (n = 1). Pathohistological studies showed that in all patients who underwent aortic surgery at the end of the third trimester in the early postpartum period changes in aortic wall collagen structure were observed. In contrast, in a pregnant woman with MS and severe aortopathy, who underwent preventive aortic surgery at 19 weeks of gestation, there were no such changes, the morphologic samples showed areas of scarring. In all 6 cases signs of lipoidosis in the AA wall were observed. All these data require further theoretical study, but clinicians are already faced with the question of the feasibility of preventive surgery in women with severe aortopathy on the preconception stage or during pregnancy. Conclusions. The specific effect of pregnancy on the AA wall leads to collagen disruption and the appearance of lipoidosis in late pregnancy, which is an important pathomorphological substrate for the occurrence of acute aortic pathology.