A novel technique with cool-tip radiofrequency ablation for selective fetal reduction in complicated monochorionic twin

Objective

To invent a novel method for selective fetal reduction in monochorionic (MC) twin using cool-tip radiofrequency ablation (RFA) and analysis the perinatal outcome.

Material and methods

Complicated MC twins including twin-to twin transfusion syndrome (TTTS), selective fetal growth restriction (sFGR) and twin reverse arterial perfusion sequence (TRAP) were enrolled from 2020 to 2024. All cases were indicated for selective fetal reduction due to expected poor outcome. Equilateral triangle method using single puncture 4 times ablation with 17G cool-tip RFA to cord insertion site, umbilical vein and two umbilical arteries for complete stopping the blood flow. The power was starting from 60 W, 80 W, 80 W and 100 W 1 min each site. Outcome were analyzed.

Results

A total of 51 cases were collected and treated in a single medical center. We divided first 20 cases as tradition group using single point ablation and novel 4-point ablation group after 21st cases. The overall co-twin survival rate after RFA procedure was 88 % (45 out of 51) in whole series. However, the co-twin survival rate in the novel 4-point group was better than single point group (93.5 % vs 80 %) with statistically significance. The maternal age, procedure at gestational age, procedure time and preterm birth rate did not show statistically difference between two groups.

Conclusions

This novel equilateral triangle method to stop all the umbilical blood flow achieved the high successful rate without maternal complication. The 17 g cool-tip RFA worked at low temperature to avoid thermal damage. This might be the new choice of RFA in monochorionic pregnancies.