Radiofrequency ablation of retained placenta accreta after conservative management: preliminary evaluation in the pregnant ewe and in normal human placenta in vitro.

Objective  To evaluate radiofrequency (RF) efficiency and safety for the ablation of retained placenta in humans, using a pregnant sheep model. Design  Experimental study. Setting  Laboratory of Surgery School, Nancy, France. Population/sample  Three pregnant ewes/ten human placentas. Methods  Various RF procedures were tested in pregnant ewes on 50 placentomes (individual placental units). Reproducibility of the best procedure was then evaluated in a further 20 placentomes and on ten human term placentas in vitro after delivery. Main outcome measures  Placental tissues destruction, lesions’ size, myometrial lesions. Results  Low power (100 W) and low target temperatures (60°C) lead to homogenous tissue destruction, without myometrial lesion. No significant difference was observed in terms of lesion size and procedure duration for in the placentomes of pregnant ewe in vivo and in human placentas in vitro. The diameter of the ablation could be correlated with the tines deployment. Conclusion  The placental tissue structure is very permissive to RF energy, which suggests that RF could be used for the ablation of retained placenta, providing optimal control of tissue destruction. These results call for further experimental evaluations.