Selective Fetoscopic Laser Photocoagulation of Placental Anastomoses Leads to Early Reduction of Cardiovascular Burden in the Twin-Twin Transfusion Syndrome

Objective: Cardiovascular disturbances are common in twin-twin transfusion syndrome (TTTS). However, the rate of improvement in cardiovascular burden in response to selective fetoscopic laser photocoagulation (SFLP) is not well known. Method: Fetal echocardiograms were performed prior to and 1 week following SFLP. Cardiovascular burden was characterized using the Children's Hospital of Philadelphia (CHOP) TTTS Cardiovascular (CV) Score. Pulsatility indices (PI) of the umbilical artery (UA) and middle cerebral artery (MCA), cerebroplacental ratio (CPR) and elements of CHOP CV Score were analyzed pre and post SFLP. Results: SFLP was performed in 198 subjects; 17 were excluded due demise post SFLP. Following SFLP, recipient (R) demonstrated an increase in MCA PI and a decrease in UA PI, with an increase in CPR. Donor (D) demonstrated a similar magnitude decrease in MCA PI and UA PI, yielding no change in CPR. Following SFLP, the mean CHOP CV Score decreased. The magnitude of change was greater in the subgroup with greater pre-SFLP cardiovascular burden (CHOP CV Score ≥ 6). Conclusion: Improvement in CV burden is seen as early as 1-week post-SFLP, supporting acute alteration of loading conditions as a significant contributor. Further study of the trajectory of CV alterations may provide insight into the complex mechanisms underlying TTTS.