Supplementary Material for: Prenatal Percutaneous Fetoscopic Laser Photocoagulation of Chorioangioma: Report of Two Cases and Review of the Literature

<b><i>Introduction:</i></b> In Doppler flow diagnosis of a large placental chorioangioma with vascularization, there may be fetal consequences as cardiac output failure and polyhydramnios. Prenatal percutaneous fetoscopic laser photocoagulation of chorioangioma is a therapeutic option. First, we present 2 cases of chorioangioma treated by fetoscopic laser photocoagulation. Second, we conducted a narrative review to identify all reported cases of chorioangioma treated by fetoscopic laser photocoagulation. <b><i>Case Presentation:</i></b> Case 1 presented a chorioangioma measuring 48 × 36 × 42 mm, and the Doppler flow study showed vascularization with a high flow rate. The fetus showed dilatation of the right cardiac chambers, moderate tricuspid insufficiency, normal Doppler indices, and polyhydramnios. Case 2 presented a chorioangioma measuring 58 × 36 × 31 mm associated with polyhydramnios and elevated peak systolic velocity of the middle cerebral artery at 49 cm/s, that is, 1.65 MoM. The procedure was performed at 22⁺² and 23⁺⁵ WG for both cases. Photocoagulation of the chorioangioma vessels was performed first on the small superficial vessels (capillaries) and then on the feeding vessels (artery first and then vein), until complete cessation of blood flow on ultrasound. Successful devascularization was achieved when flow within the chorioangioma’s feeding vessels was no longer visualized on intraoperative ultrasound examination using Doppler flow. The ultrasound follow-up showed complete cessation of blood flow in the chorioangioma, normalization of fetal signs, and normal fetal growth in both cases. In case 1, a 2,350-g boy was delivered vaginally after spontaneous labor at 33⁺⁶ WG. In case 2, a 2,700-g boy was delivered vaginally after spontaneous labor at 39⁺² WG. Neonatal findings were normal, and the outcome at 1 year was normal for both children. <b><i>Conclusion:</i></b> Prenatal percutaneous fetoscopic laser photocoagulation improves survival in large chorioangioma, despite a risk of fetal death in utero.