In-vivo studies

In-vivo studies

The description of placental vascular anastomoses from fetoscopies during laser photocoagulation of the chorionic plate may be used to study the placental architecture. This method is sensitive because of the endoscopic magnification of the image and is controlled because the placental surface remains with a white scar at the coagulation point. 

The problem is that technically difficult fetoscopies as anterior placentas or turbid amniotic fluid may give false negative for anastomoses detection. De Lia et al14 described ablating 8–10 communicating vessels per placenta in TTTS. 

In a recent study from Hamburg15 of 126 fetoscopies for laser photocoagulation of the chorionic plate vessels, the median number of anastomoses found was 5 (range 1–14), with 74% cases showing a higher number of AV anastomoses from donor to recipient. They always found at least one AV donor to recipient anastomoses. The postnatal correlation of the placenta was not possible in this study; 31% of the placentas had AA anastomoses and this was concordant with ex-vivo studies. Doppler diagnosis of arteriovenous anastomoses has been reported with a sensitivity of 33%.16 The only TTTS case presented in this paper was found to have one AV anastomosis at Doppler but five at placental dye injection.