460: Highly realistic simulator for teaching and training fetoscopic laser surgery in twin-to-twin transfusion syndrome

Abstract

training fetoscopic laser surgery in twin-to-twin transfusion syndrome Suzanne Peeters, Lu-Ming Sun, Frans Klumper, Johanna Middeldorp, Rory Windrim, Enrico Lopriore, Dick Oepkes Leiden University Medical Center, Obstetrics, Leiden, Netherlands, Shanghai First Maternity and Infant Hospital, Obstetrics, Shanghai, China, Mt.Sinai Hospital, University of Toronto, Obstetrics, Toronto, ON, Canada, Leiden University Medical Center, Neonatology, Leiden, Netherlands OBJECTIVE: Fetoscopic laser surgery is the best treatment for TTTS. Success rate and safety depend on skills and experience of the fetal surgeons. Even large fetal treatment centers have limited numbers of cases, and animal models are lacking, therefore teaching and training this procedure is challenging. Aim of our project was to develop a simulator model with the highest possible level of realism. STUDY DESIGN: We injected fresh placentas from untreated monochorionic twins born between 16 and 26 weeks’ gestation with colored dye, realistic light red for veins and dark red for arteries. We inserted the injected placentas in a silicon high fidelity simulator originally developed to train ultrasound-guided obstetric procedures. Preparation, team setting and equipment were identical to real-life surgery. RESULTS: The training sessions included complete set-up and performance of the fetoscopic laser surgery, including identification of anastomoses, selective sequential laser coagulation and drawing of a ‘Solomon’ line. On video, the procedure was virtually identical to imaging in real patients. Using an internet-connection, telementoring of the simulator training sessions performed in centers on two other continents enabled off-site teaching. CONCLUSION: The training sessions included complete set-up and performance of the fetoscopic laser surgery, including identification of anastomoses, selective sequential laser coagulation and drawing of a ‘Solomon’ line. On video, the procedure was virtually identical to imaging in real patients. Using an internet-connection, telementoring of the simulator training sessions performed in centers on two other continents enabled off-site teaching, increasing training opportunities for start-up centers. 461 Fetal cardiac function in recipient fetuses of stage 4 twin-to-twin transfusion syndrome undergoing fetoscopic laser coagulation of placental anastomoses Tim Van Mieghem, Edgar Jaeggi, Rory Windrim, Lisa Hornberger, Greg Ryan Mount Sinai Hospital, Fetal Medicine Unit Obstetrics & Gynecology, Toronto, ON, Canada, Hospital for Sick Children, Fetal Cardiac Program Pediatric Cardiology, Toronto, ON, Canada, Stollery Children’s Hospital, Pediatric Cardiology, Edmonton, ON, Canada OBJECTIVE: Cardiac dysfunction is common in the recipient fetus of twin-to-twin transfusion syndrome (TTTS). Information on fetal cardiac dysfunction in stage 4 TTTS (fetal hydrops) is lacking. In this study, we document severity of fetal cardiac dysfunction in stage 4 TTTS and assess evolution of cardiac function longitudinally after fetoscopic laser. STUDY DESIGN: We retrospectively retrieved obstetric ultrasounds, preand postoperative echocardiograms and neonatal outcomes of 22 cases of stage 4 TTTS undergoing fetoscopic laser. The following echocardiographic parameters were assessed: myocardial performance index, atrio-ventricular valve flow patterns, ventricular shortening fraction, ventricular hypertrophy, outflow tract obstruction and venous Dopplers. RESULTS: Nineteen recipient fetuses (86%) had ascites, 8(36%) had pleural effusions, 9(41%) had a pericardial effusion and 12(55%) had subcutaneous edema at intial presentation. Preoperatively, fetal cardiac function was grossly abnormal in all cases. Eight fetuses (36%) had findings compatible with functional pulmonary atresia and 1 (4.5%) had functional aortic atresia. Postoperative survival of the recipient fetus was 77%. Echocardiographic follow-up at a mean of 26 days (range 1-82 days) postoperatively showed that indices of fetal cardiac function improved considerably, yet that cardiac function did not completely normalise. Six of eight fetuses with functional pulmonary atresia (75%), as well as the fetus with functional aortic atresia survived until birth. In all cases, the functional atresia resolved, often already within the first 48 hours after surgery and these fetuses did not have structural valve anomalies at birth. All fetal effusions resolved after the laser procedure. CONCLUSION: Fetoscopic laser coagulation of placental anastomoses reverses cardiac dysfunction and valvulopathy, even in the more severe cases of TTTS. Recovery however takes longer than in the early disease stages. Clinical characteristics and pregnancy outcomes