Placental Angiodysplasia: A New Sign for Prediction of Fetal Outcome?

Abstract

The study of the placenta is of great importance, not only in the attempt to understand the etiopathogenesis of various maternal-fetal pathologies, but also in the attempt to understand whether it is possible to find the cause of pathological neonatal outcomes. On the other hand, abnormalities of blood vessel formation, such as angiodysplasias, have been poorly characterised in the literature, and there is a need for more studies investigating the potential impact on the fetus. In this paper, we retrospectively analysed 2063 placentas received at the Department of Pathology of the University of Bari 'Aldo Moro', among which we identified 70 placentas affected by angiodysplasia. On these placentas, we carried out histochemical staining with Masson's Trichrome, orcein-alcian blue, and, subsequently, immunostaining with anti-CD31, CD34, and desmin and actin muscle smoothness antibodies. Finally, we performed a morphometric analysis on the allantochorionic and truncal vessels and correlated the results with neonatal outcomes. We studied the characteristics of the angiodysplasias in detail, dividing the patients into two classes (A and B) according to the morphology and histochemical characteristics of the affected vessels; statistical analysis reported a statistically significant association (p < 0.05) between the ratio of maximum thickness to maximum diameter (Tmax/Dmax) and neonatal outcome, with only 30% physiological outcome in the cohort of the placentas affected by angiodysplasia. These results shed light on a rather neglected aspect in the 2015 Amsterdam Classification, as well as in the literature, and provided strong evidence that placental angiodysplasia is predictive of an increased likelihood of the pathological fetal outcome, while other factors remain in the field. Studies with larger case series and guidelines with more attention to these aspects are mandated to further investigate the predictive potential of this pathology.

Keywords: angiodysplasia; gynaecology; malformation; neonatal; obstetrics; outcome; placenta.

Figure 1

(A) Histological photomicrograph of serial sections showing arteries with fibro-intimal thickening and subsequent thrombosis in the organisation phase (black arrow), class A (Hematoxylin–Eosin, original magnification 10×). (B) Histochemical preparation showing the fibro-intimal thickening of the wall of the class A angiodysplasia and the reduction of lumen of the vessel (Masson’s trichrome, original magnification 10×). (C) Immunohistochemical preparation with anti-SMA antibody showing the presence of different orientations of the muscle fibres in class A angiodysplasia (Immunohistochemistry for SMA, original magnification 10×).

Figure 2

(A) Histological photomicrograph showing disarrangement of the muscle fibres of the middle tonaca of the arteries (black arrow), characteristic of class B (Hematoxylin–Eosin, original magnification 10×). (B) Histochemical preparation showing further disarrangement of the muscle fibres of the wall with aspects of initial arterial thrombosis (Masson’s trichrome, original magnification 10×). (C) Immunohistochemical preparation with anti-SMA antibody showing disarrangement of the muscle fibres of the wall and different types of orientation (black arrow) (Immunohistochemistry for SMA, original magnification 10×).

Figure 3

(A) CD-68 distribution in class A with positivity in the intimal/media tunica of the wall of the vessels. (B) Negativity for presence of macrophage in the wall of the vessels with presence of positivity in Hofbauer cells. (Immunohistochemistry for CD-68, original magnification 20×).

Figure 4

Neonatal outcomes in relation to classes A and B. The distribution of neonatal outcome resulted not associated with classes A and B (χ² = 4.97 p > 0.05).

Figure 5

Distribution according to the 2015 Amsterdam Consensus Conference.

Figure 6

Difference in maximum thickness/maximum diameter ratios (δ mm) between healthy and pathological vessels for each placenta under study.

Figure 7

Physiological and pathological outcomes related to classes A and B.

Figure 8

Physiological and pathological outcomes related to presence or absence of maternal pathologies.

Figure 8

Physiological and pathological outcomes related to presence or absence of maternal pathologies.

Figure 9

Neonatal outcomes in relation to the value of the T_max/D_max ratio.

Figure 10

T_max/D_max ratio in pathological vessels in relation to physiological/pathological outcome.