Supplementary Material for: Twin-Twin Transfusion Syndrome Complicated by Proximate Placental Cord Insertion Sites: Endoscopic Clip-Assisted Laser Occlusion

<b><i>Introduction:</i></b> Severe twin-twin transfusion syndrome (TTTS) with a large vascular communication between proximate placental cord insertion sites is a therapeutic dilemma because laser ablation may cause thermal injury to the cord roots and subsequent fetal demise. <b><i>Case Presentation:</i></b> Stage IV TTTS with placental cord insertion sites 1.3 cm apart and with an intervening large arterio-arterial (AA) anastomosis presented for treatment. The application of endoclips onto the large AA anastomosis between the cord roots allowed for successful laser occlusion using minimal energy. Both the donor and recipient twins were alive and well at 6 months of age. <b><i>Conclusion:</i></b> Endoscopic clip-assisted laser occlusion of a placental vessel is technically feasible and may be a useful therapeutic option in select cases.