Does the order of ablation of vein-to-vein placental connections during fetoscopic laser photocoagulation affect outcomes in twin-twin transfusion syndrome?

OBJECTIVE

To assess whether the sequence of laser occlusion of vein-to-vein placental anastomoses is associated with fetal survival after laser photocoagulation for twin-twin transfusion syndrome.

STUDY

DESIGN

This post hoc analysis used data from the Sequential Trial, a randomized controlled trial comparing sequential vs selective laser photocoagulation techniques. Within this trial, a nested randomization assigned patients with superficial anastomoses (ie, artery-to-artery or vein-to-vein) to ablation of these anastomoses either at the beginning or at the end of surgery. For this analysis, we compared survival in patients with vein-to-vein anastomoses with a reference group lacking superficial anastomoses. Variables associated with survival were included in multiple logistic regression models, including the nested assignment to "Ablated First" vs "Ablated Last."

RESULTS

Of 642 trial patients, 64 (10%) had at least one vein-to-vein anastomosis (range, 1-3). Donor live birth was 421/466 (90.3%) in the No Superficial Anastomoses group and 48/64 (75.0%) in the vein-to-vein group (P=.001). Among the 64 patients with vein-to-vein anastomoses, 28 (43.8%) were randomized to Ablated First and 36 (56.3%) to Ablated Last. Donor survival in the No Superficial Anastomoses, Ablated First, and Ablated Last groups was 90.3%, 82.1%, and 69.4%, respectively (P<.001). Recipient survival was 94.2%, 96.4%, and 86.1% (P=.128). In adjusted models, the Ablated Last group had lower odds of donor survival (adjusted odds ratio, 0.24 [0.10-0.58]; P=.002) and recipient survival (adjusted odds ratio, 0.30 [0.10-0.92]; P=.035) compared with the No Superficial Anastomoses group.

CONCLUSION

In this post hoc exploratory analysis, end-of-procedure treatment of vein-to-vein anastomoses for twin-twin transfusion syndrome was associated with lower donor and recipient survival.