Treating previable twin-twin transfusion syndrome with fetoscopic laser surgery: Outcomes following the learning curve

Aims: We have performed fetoscopic laser occlusion of chorioangiopagous vessels (FLOC) in previable pregnancies affected by twin-twin transfusion syndrome (TTTS) since 1988. Treatment outcomes obtained after the procedure's learning curve are presented and compared to those from other centers performing FLOC or other treatment methods. Methods: A total of 100 cases of FLOC have been performed at our centers. The later 67 TTTS patients had a mean gestational age of 21.1+/-1.7 weeks (range 18-24.5) with a mean fundal height of 33.1 +/- 4.9 cm (range 27-44) when treated. Eighteen (27 %) had failed another treatment method before FLOC. Results: All 67 cases have delivered with 82 % (55/67) having at least one surviving twin and 93/134 (69 %) of the twins surviving overall. Thirty-eight have surviving twins, 17 have one survivor (5 neonatal and 12 fetal deaths), and 12 have none. The mean duration of pregnancy following FLOC was 9.9 +/- 5.5 weeks (range 1.0-19). Only 4 of 93 (4.3 %) survivors have significant handicaps at a mean follow-up of 14.3 +/- 10.1 months (range 1.0-34). Conclusion: Fetoscopic laser occlusion of chorioangiopagous vessels within the vascular equator limits the duration of fetal pathophysiology in TTTS and results in neonatal outcomes superior to the modified procedure and other treatment methods.