[Fibrous obliterations of chorionic plate- and villous stem vessels of the placenta following intrauterine fetal death]

[The so-called recanalisation of cotyledonary vessels with endangitis obliterans of placenta vessels (author's transl)]

With a graphic reconstruction on serial sections, performed with placentas which altogether showed so-called recanalisation, it is possible to work out the fact, that the recanalisation is an effect of the paravascular capillary network and with it to clarify the problem of the so-called recanalisation. It is proved, that the paravascular capillaries undertake compensatory hemodynamic functions and this undertaking of function prevents a complete occlusion of the cotyledonary vessels, so that you have to speak of restlumen and restflow but not of recanalisation. The endangitis obliterans of cotyledonary vessels is again unequivocally pointed out by this phenomenon as a intravital process.

[Obliterative angiopathy of placental stem villi (author's transl)]

Out of 136 placentas with vascular obliterations, 25 cases were placentas of children born alive, in 92 cases the placentas belonged to children born dead. In 19 cases we had no data on the baby. In placentas of babies born alive, the same vascular changes (subtotal and total obliterations, septal partitions of vascular lumina) were found as in those of dead-born children, although considerably less severe. Vascular obliterations should not be considered as post-mortal alterations of the placenta blood vessels, since only quantitative differences could be proved. Septum-like partitions are hardly ever found in placentas of babies born alive, in dead-born babies they are more frequent. They seem to present recanalizations, and are understood as a compensation mechanism for a placental insufficiency caused by vascular obliterations. The accentuated collagenization of the placental periphery, noticed in placentas of babies born alive, is being interpreted as the consequence of an impaired blood circulation, caused by partial and total vascular obliterations. The high collagen rate in the placental periphery in placentas of the dead-born is probably a reaction to the diminished fetal circulation. Endangitis obliterations in 73 placentas out of 4600 pregnancies of cases with late abortions, premature deliveries, perinatal death, underweigh and small for gestational age babies, impaired adaptation in newborns of mothers with proteinuria and hypertension speak strongly for assuming that endangitis obliterans presents a form of placental insufficiency. Endangitis obliterans of the placental blood-vessels has, however, been discovered frequently after Rubella infection in early pregnancy. The etiological factors of the endovascular process can be multiple, the morphological and the pathophysiological reactions are the same.